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Graduate Study in - Chemistry - Johns Hopkins University

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<strong>Chemistry</strong><br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

www.jhu.edu/~chem


Contents<br />

2 Welcome<br />

3 Baltimore<br />

4 <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

5 Department of <strong>Chemistry</strong><br />

7 Faculty<br />

7 Kit H. Bowen<br />

8 Paul J. Dagdigian<br />

9 David E. Draper<br />

10 D. Howard Fairbrother<br />

11 David P. Goldberg<br />

12 Marc M. Greenberg<br />

13 Tamara L Hendrickson<br />

14 Kenneth D. Karl<strong>in</strong><br />

15 Thomas Lectka<br />

16 Gerald J. Meyer<br />

17 Douglas Poland<br />

18 Gary H. Posner<br />

19 Harris J. Silverstone<br />

20 Joel R. Tolman<br />

21 John P. Toscano<br />

22 Craig A. Townsend<br />

23 David R. Yarkony<br />

24 Instrumentation<br />

26 Useful Information<br />

28 Baltimore Map & Directions to Campus<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

1


Welcome<br />

Rendition of new chemistry<br />

build<strong>in</strong>g currently under<br />

construction<br />

Greet<strong>in</strong>gs and welcome to the Department of <strong>Chemistry</strong> at <strong>Johns</strong><br />

Hopk<strong>in</strong>s <strong>University</strong>. As you will see throughout this brochure,<br />

we offer an excit<strong>in</strong>g environment for graduate studies <strong>in</strong> all areas<br />

of the chemical sciences. Our department has a unique<br />

advantage <strong>in</strong> its ability to ma<strong>in</strong>ta<strong>in</strong> <strong>in</strong>ternationally recognized<br />

research programs <strong>in</strong> a wide variety of chemical discipl<strong>in</strong>es, while<br />

rema<strong>in</strong><strong>in</strong>g small enough for close student-faculty <strong>in</strong>teractions. This<br />

tradition of excellence has been carried forward from the department’s<br />

<strong>in</strong>ception as the first Ph. D. program <strong>in</strong> chemistry <strong>in</strong> America, and as you<br />

will see, is now cont<strong>in</strong>ued by an outstand<strong>in</strong>g group of scientific leaders<br />

that make up the <strong>Chemistry</strong> Department faculty. It is an excit<strong>in</strong>g time to<br />

enter our department. The <strong>Chemistry</strong> department resides <strong>in</strong> Remsen Hall,<br />

which underwent a complete renovation <strong>in</strong> the 1990’s, Dunn<strong>in</strong>g Hall, and<br />

the new state-of-the-art <strong>Chemistry</strong> build<strong>in</strong>g that is be<strong>in</strong>g constructed to<br />

accommodate department growth. The build<strong>in</strong>g will follow a Georgian<br />

style (see sketch) to blend with the Hopk<strong>in</strong>s campus. Students choos<strong>in</strong>g to<br />

do their graduate work here will benefit from cutt<strong>in</strong>g-edge research<br />

programs and facilities, while work<strong>in</strong>g <strong>in</strong> a friendly environment <strong>in</strong> which<br />

access to faculty is unrestricted.<br />

Students can work on many projects that cross the traditional<br />

l<strong>in</strong>es of chemistry, rang<strong>in</strong>g from materials chemistry and surface<br />

science to bioorganic and bio<strong>in</strong>organic chemistry. There is an<br />

extraord<strong>in</strong>ary commitment here by the faculty towards the<br />

development and growth of the graduate students; one only has to<br />

look at the many students who have graduated from the <strong>Chemistry</strong><br />

Department and gone on to successful careers <strong>in</strong> both <strong>in</strong>dustry and<br />

academia as concrete evidence of this commitment.<br />

The Department is located on the Homewood campus of <strong>Johns</strong><br />

Hopk<strong>in</strong>s <strong>University</strong>, approximately 3 miles from the Inner Harbor<br />

of downtown Baltimore. The city of Baltimore offers all of the<br />

advantages and recreational activities of a major metropolitan area,<br />

and has seen a fantastic revitalization <strong>in</strong> the downtown section and<br />

Inner Harbor <strong>in</strong> the past few years. Many other outstand<strong>in</strong>g<br />

research <strong>in</strong>stitutions are located <strong>in</strong> the Baltimore/Wash<strong>in</strong>gton D.C.<br />

area, <strong>in</strong>clud<strong>in</strong>g the National Institutes of Health (NIH) <strong>in</strong> Bethesda,<br />

Maryland, the National Institute of Standards and Technology (NIST) <strong>in</strong><br />

Gaithersburg, Maryland, the Food and Drug Adm<strong>in</strong>istration (FDA), the<br />

National Aeronautics and Space Adm<strong>in</strong>istration (NASA), the Naval<br />

Research Laboratory (NRL), the Army Research Laboratory (ARL), and<br />

the <strong>University</strong> of Maryland’s Baltimore County campus, as well as its<br />

Biotechnology Institute at College Park. This concentration of scientific<br />

research centers and programs is one of the highest <strong>in</strong> the country and<br />

gives students <strong>in</strong> the <strong>Chemistry</strong> Department the opportunity for<br />

collaborations and other <strong>in</strong>teractions, <strong>in</strong>clud<strong>in</strong>g sem<strong>in</strong>ars and meet<strong>in</strong>gs<br />

with different scientists from private <strong>in</strong>dustry, government laboratories<br />

and other academic <strong>in</strong>stitutions. If you are <strong>in</strong>terested <strong>in</strong> this type of<br />

stimulat<strong>in</strong>g environment and are committed to push<strong>in</strong>g the boundaries of<br />

the scientific frontier, we <strong>in</strong>vite you to jo<strong>in</strong> one of the country’s<br />

outstand<strong>in</strong>g chemistry departments.<br />

2 <strong>Graduate</strong> <strong>Study</strong> <strong>in</strong> <strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


Baltimore<br />

<strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong> is located with<strong>in</strong> the city<br />

of Baltimore, a very livable and affordable East<br />

Coast city situated between Philadelphia and<br />

Wash<strong>in</strong>gton. The <strong>Chemistry</strong> Department is housed<br />

on the Homewood campus, which lies with<strong>in</strong> a<br />

residential neighborhood about 2 miles north of the<br />

central bus<strong>in</strong>ess area.<br />

Baltimore has undergone an urban renaissance <strong>in</strong><br />

recent years. Many long established neighborhoods have<br />

experienced a significant <strong>in</strong>flux of new residents. The<br />

area around the Homewood Campus cont<strong>in</strong>ues to be an<br />

attractive neighborhood <strong>in</strong> which to live, and is<br />

typified by artistic brownstones, row houses, and newer<br />

apartment build<strong>in</strong>gs.<br />

The city offers ample recreational and cultural activities.<br />

Harborplace, located along the scenic Inner Harbor just south of the<br />

central bus<strong>in</strong>ess district, is a strik<strong>in</strong>g collection of pavilions and<br />

promenades set at the water’s edge. The National Aquarium adjo<strong>in</strong>s<br />

Harborplace on the east and has undergone a major recent expansion. To<br />

the south of Harborplace is the Maryland Science Center, which features a<br />

variety of scientific exhibits and houses a planetarium and Imax theater.<br />

To the west is the Camden Yards baseball stadium, home of the Baltimore<br />

Orioles, and Raven’s Stadium, home of the Baltimore Ravens.<br />

There are a number of major museums located with<strong>in</strong> the city.<br />

These <strong>in</strong>clude the Walters Art Museum, which possesses a large collection<br />

of antiquities, and the Baltimore Museum of Art, which houses an<br />

excellent collection of French Impressionist pa<strong>in</strong>t<strong>in</strong>g and is adjacent to the<br />

Hopk<strong>in</strong>s Homewood campus. Also located <strong>in</strong> the city is the Baltimore and<br />

Ohio Railroad Museum, which has an extensive collection of historic<br />

railway equipment, the Babe Ruth Museum, and a museum dedicated to<br />

Edgar Allen Poe (a former Baltimore resident). Baltimore is also home to<br />

several f<strong>in</strong>e musical organizations. The Baltimore Symphony Orchestra is<br />

world-renowned and offers a range of symphonic and “pop” music at the<br />

modern Joseph A. Meyerhoff concert hall. The Baltimore Opera Company<br />

performs at the renovated Lyric Theatre.<br />

Throughout the year, a variety of festivals and special events occur<br />

<strong>in</strong> Baltimore. These <strong>in</strong>clude the Preakness, which is held at Pimlico Race<br />

course and is the second leg of thoroughbred rac<strong>in</strong>g’s Triple Crown, the<br />

Baltimore Marathon, and Artscape, a citywide arts festival.<br />

Baltimore is conveniently located to other<br />

attractions <strong>in</strong> the mid-Atlantic region. Wash<strong>in</strong>gton, D.C.<br />

is less than an hour to the south by car or tra<strong>in</strong> and offers<br />

some of the best museums and cultural offer<strong>in</strong>gs <strong>in</strong> the<br />

country. Philadelphia is less than two hours north of<br />

Baltimore. With<strong>in</strong> Maryland, the Chesapeake Bay and<br />

the Atlantic shore offer water and beach<br />

activities, while the mounta<strong>in</strong>s lie two hours west of<br />

Baltimore, for ski<strong>in</strong>g <strong>in</strong> the w<strong>in</strong>ter and year-round hik<strong>in</strong>g<br />

and camp<strong>in</strong>g.<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

3


<strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

Establishment<br />

<strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong> was the first American <strong>in</strong>stitution to offer and<br />

emphasize graduate education. Its history began <strong>in</strong> 1867, when at the<br />

request of <strong>Johns</strong> Hopk<strong>in</strong>s, a successful Baltimore bus<strong>in</strong>essman, two<br />

corporations were formed: <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong> and <strong>Johns</strong> Hopk<strong>in</strong>s<br />

Hospital.<br />

With this unique vision and generous private endowment, Daniel<br />

Coit Gilman opened the doors to <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong> <strong>in</strong> 1876.<br />

Throughout the years, the name <strong>Johns</strong> Hopk<strong>in</strong>s has become world<br />

renowned and synonymous with scholarly excellence, cutt<strong>in</strong>g edge<br />

scientific research, the advancement of medic<strong>in</strong>e and care of humanity.<br />

<strong>Johns</strong> Hopk<strong>in</strong>s has consistently ranked among the top universities by U.S.<br />

News and World Report.<br />

Organization<br />

<strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong> is a privately endowed, coeducational<br />

<strong>in</strong>stitution consist<strong>in</strong>g of several academic divisions. The Zanvyl Krieger<br />

School of Arts and Sciences (which <strong>in</strong>cludes the <strong>Chemistry</strong> department)<br />

and the G.W.C. Whit<strong>in</strong>g School of Eng<strong>in</strong>eer<strong>in</strong>g occupy the Homewood<br />

campus, a 200 year old estate located <strong>in</strong> a pleasant residential<br />

neighborhood <strong>in</strong> northern Baltimore. The School of Medic<strong>in</strong>e<br />

and the School of Public Health and Hygiene are located <strong>in</strong> east<br />

Baltimore adjacent to the <strong>Johns</strong> Hopk<strong>in</strong>s Hospital. A regular 20<br />

m<strong>in</strong>ute shuttle bus service connects the two campuses. The<br />

Peabody Conservatory of Music is located <strong>in</strong> the elegant Mt.<br />

Vernon neighborhood of Baltimore, between the two ma<strong>in</strong><br />

campuses and is also served by shuttle bus.<br />

Also on the Homewood campus are the Space Telescope<br />

Science Institute, which is the ground base for NASA’s Hubble<br />

Space Telescope, and the Carnegie Institution of Wash<strong>in</strong>gton, a<br />

well known molecular biology research <strong>in</strong>stitute. The Applied<br />

Physics Laboratory is located midway between Baltimore and<br />

Wash<strong>in</strong>gton, and the School of Advanced International Studies is<br />

<strong>in</strong> Wash<strong>in</strong>gton, D.C.<br />

<strong>Johns</strong> Hopk<strong>in</strong>s now has an<br />

<strong>in</strong>ternational identity with learn<strong>in</strong>g<br />

centers <strong>in</strong> Italy and Ch<strong>in</strong>a, but<br />

the city of Baltimore, and the<br />

Homewood campus, rema<strong>in</strong>s its<br />

home. No matter the season, this<br />

<strong>in</strong>comparable campus consist<strong>in</strong>g<br />

of impeccable landscap<strong>in</strong>g, marble<br />

and iron balustrades, and red<br />

brick halls, creates an air of<br />

Victorian decorum. Whatever the<br />

scholarly spirit, this campus<br />

<strong>in</strong>spires!<br />

4<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


The Department of <strong>Chemistry</strong><br />

The <strong>Graduate</strong> Program<br />

F<strong>in</strong>ancial Support<br />

Each graduate student is provided with f<strong>in</strong>ancial<br />

support <strong>in</strong> the form of full tuition and a stipend,<br />

assum<strong>in</strong>g that normal progress toward the degree is<br />

ma<strong>in</strong>ta<strong>in</strong>ed. F<strong>in</strong>ancial support is provided from a<br />

comb<strong>in</strong>ation of teach<strong>in</strong>g and research<br />

assistantships. In addition to the regular stipend,<br />

the department awards a number of fellowships<br />

(Marks Awards) to students of exemplary promise.<br />

Students are also encouraged to apply for the many<br />

national fellowships that are available.<br />

Course Requirements<br />

Eight graduate-level courses are required, and a<br />

program is tailored to the <strong>in</strong>dividual <strong>in</strong>terests and<br />

needs of each student dur<strong>in</strong>g an advis<strong>in</strong>g session<br />

with a faculty committee. Course requirements are<br />

typically completed <strong>in</strong> the first year of graduate<br />

study. <strong>Graduate</strong> courses can be taken with<strong>in</strong> the<br />

<strong>Chemistry</strong> Department or <strong>in</strong> other departments,<br />

and a current list of possible courses can be found<br />

on the <strong>Chemistry</strong> department’s web page<br />

(www.jhu.edu/~chem). Many students take<br />

selected courses <strong>in</strong> the Departments of Biology,<br />

Biophysics, Earth and Planetary Sciences, Electrical<br />

and Computer Eng<strong>in</strong>eer<strong>in</strong>g, Geography and<br />

Environmental Eng<strong>in</strong>eer<strong>in</strong>g, Materials Science and<br />

Eng<strong>in</strong>eer<strong>in</strong>g, Physics and Astronomy, as well as<br />

Pharmacology and Molecular Sciences on the<br />

Medical School campus.<br />

Select<strong>in</strong>g a Faculty Advisor<br />

The choice of a research advisor and dissertation<br />

topic occurs dur<strong>in</strong>g the first semester. To aid <strong>in</strong> this<br />

process, new graduate students at <strong>Johns</strong> Hopk<strong>in</strong>s<br />

attend a series of research sem<strong>in</strong>ars given by<br />

<strong>in</strong>dividual faculty members detail<strong>in</strong>g their<br />

current research activities. New graduate students<br />

also meet <strong>in</strong>dividually with potential faculty<br />

mentors. Most students jo<strong>in</strong> a research group and<br />

beg<strong>in</strong> their <strong>in</strong>dependent graduate work by the end<br />

of the fall semester.<br />

Oral Exam<strong>in</strong>ation<br />

To be recommended for candidacy for the Ph. D.<br />

degree <strong>in</strong> <strong>Chemistry</strong>, each student must prepare and<br />

defend a research proposal that describes his or her<br />

objectives <strong>in</strong> the planned dissertation research. This<br />

proposal should describe progress and accomplishments<br />

to date and plans for future research. The<br />

proposal is presented <strong>in</strong> writ<strong>in</strong>g to a faculty<br />

committee two weeks before the scheduled oral<br />

exam<strong>in</strong>ation. The faculty committee consists of<br />

three members of the <strong>Chemistry</strong> faculty; these faculty<br />

should also be considered as a resource for the<br />

student dur<strong>in</strong>g the rema<strong>in</strong>der of his/her studies.<br />

Students are also required to pass a universityrequired<br />

<strong>Graduate</strong> Board oral exam<strong>in</strong>ation, for<br />

which a committee of five <strong>Chemistry</strong> and outside<br />

faculty members are assembled.<br />

Research<br />

Research is at the heart of the Ph.D. program at<br />

<strong>Johns</strong> Hopk<strong>in</strong>s, and descriptions of faculty member’s<br />

research <strong>in</strong>terests are conta<strong>in</strong>ed <strong>in</strong> this<br />

brochure. Throughout the graduate program,<br />

coursework, sem<strong>in</strong>ars and presentations are<br />

designed to help students with their research<br />

activities and to prepare them for describ<strong>in</strong>g their<br />

work to a scientific audience. For each graduate<br />

student, the successful completion, publication and<br />

dissem<strong>in</strong>ation of results from one or more research<br />

projects forms the basis of the Ph. D. degree.<br />

Dissertation and Defense<br />

The f<strong>in</strong>al step towards a Ph.D. degree is the writ<strong>in</strong>g<br />

of a thesis that describes a student’s <strong>in</strong>dependent<br />

and orig<strong>in</strong>al research accomplishments. This<br />

dissertation is written <strong>in</strong> close consultation with<br />

your faculty advisor. F<strong>in</strong>ally, each student presents<br />

his or her graduate research <strong>in</strong> a departmental<br />

sem<strong>in</strong>ar and private defense before their<br />

dissertation committee.<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

5


The Department of <strong>Chemistry</strong><br />

Faculty Research<br />

The Department of<br />

<strong>Chemistry</strong> at <strong>Johns</strong><br />

Hopk<strong>in</strong>s <strong>University</strong> is<br />

made up of a diverse<br />

group of faculty. In addition<br />

to the traditional<br />

areas of chemical<br />

research, many <strong>in</strong>terdiscipl<strong>in</strong>ary<br />

research <strong>in</strong>terests<br />

are present with<strong>in</strong><br />

the department, at the<br />

<strong>in</strong>terface of chemistry and fields <strong>in</strong>clud<strong>in</strong>g biology,<br />

medic<strong>in</strong>e, physics, and environmental and material<br />

sciences. Each faculty member has <strong>in</strong>cluded a brief<br />

description of their research <strong>in</strong>terests <strong>in</strong> this<br />

brochure.<br />

Several faculty members have jo<strong>in</strong>t<br />

appo<strong>in</strong>tments with other departments <strong>in</strong>clud<strong>in</strong>g<br />

Biology, Biophysics, Materials Science and<br />

Eng<strong>in</strong>eer<strong>in</strong>g, and Pharmacology and Molecular<br />

Sciences. A number of <strong>in</strong>terdiscipl<strong>in</strong>ary programs<br />

and research centers based at <strong>Johns</strong> Hopk<strong>in</strong>s<br />

<strong>in</strong>clude members of the <strong>Chemistry</strong> department.<br />

These <strong>in</strong>clude the Materials Research Science and<br />

Eng<strong>in</strong>eer<strong>in</strong>g Center on nanostructures with<br />

enhanced magneto-electronic properties, the NSFsupported<br />

environmental research program <strong>in</strong><br />

Redox-Mediated Dehalogenation <strong>Chemistry</strong>, and<br />

the Program <strong>in</strong> Molecular Biophysics.<br />

Remsen Lecture<br />

Each year, the Department of <strong>Chemistry</strong>, <strong>in</strong><br />

collaboration with the Maryland Section of the<br />

American Chemical Society, bestows a Remsen<br />

Award to a noteworthy Chemist of <strong>in</strong>ternational<br />

acclaim. The award ceremony is accompanied by a<br />

lecture given by the award recipient. The annual<br />

Remsen Award Lectures were <strong>in</strong>augurated <strong>in</strong> May,<br />

1946 by the Maryland Section of the American<br />

Chemical Society to honor Ira Remsen, Professor of<br />

<strong>Chemistry</strong> and President of the <strong>Johns</strong> Hopk<strong>in</strong>s<br />

<strong>University</strong>. The Remsen Memorial Lecturers are<br />

chemists of outstand<strong>in</strong>g achievement, <strong>in</strong> keep<strong>in</strong>g<br />

with Ira Remsen’s long and devoted career as an<br />

exponent of the highest standards <strong>in</strong><br />

teach<strong>in</strong>g and research <strong>in</strong> chemistry.<br />

Past Remsen Award Recipients <strong>in</strong>clude:<br />

2001 Dr. Ad Bax NIH<br />

2000 Dr. Alexander P<strong>in</strong>es UC-Berkeley<br />

1999 Dr. Thomas J. Meyer UNC-Chapel Hill<br />

1998 Dr. Peter B. Dervan Cal Tech<br />

1997 Dr. William H. Miller UC-Berkeley<br />

1996 Dr. David A. Evans Harvard <strong>University</strong><br />

1995 Dr. Alfred G. Redfield Brandeis <strong>University</strong><br />

1994 Dr. Edward I. Solomon Stanford <strong>University</strong><br />

1993 Dr. Christopher T. Walsh Harvard Medical School<br />

1992 Dr. William Klemperer Harvard <strong>University</strong><br />

1991 Dr. Rudolph A. Marcus Cal Tech<br />

Application and Admission<br />

No formal degree is required for admission, although enter<strong>in</strong>g students usually hold a<br />

bachelor’s or master’s degree <strong>in</strong> chemistry or a related science. All applicants for admission are required to<br />

furnish academic transcripts, three letters of recommendation, and scores of <strong>Graduate</strong> Record<br />

Exam<strong>in</strong>ations, <strong>in</strong>clud<strong>in</strong>g the Advanced <strong>Chemistry</strong> Exam<strong>in</strong>ation. An application to our graduate program is<br />

<strong>in</strong>cluded at the end of this brochure and on our web page (www.jhu.edu/~chem).<br />

For further <strong>in</strong>formation, or if you have any questions, please contact:<br />

Academic Program Coord<strong>in</strong>ator<br />

Phone: 410-516-7427<br />

Fax: 410-516-8420<br />

E-mail chem.grad.adm@jhu.edu<br />

Faculty members are also happy to answer questions about their <strong>in</strong>dividual research <strong>in</strong>terests; their e-mail<br />

addresses are <strong>in</strong>cluded <strong>in</strong> the faculty research section of this brochure.<br />

6<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


Kit H. Bowen<br />

Experimental Physical <strong>Chemistry</strong>: Clusters and Nanoparticles<br />

kitbowen@jhu.edu<br />

Clusters are aggregates of atoms and/or molecules held together by the same<br />

<strong>in</strong>teratomic or <strong>in</strong>termolecular forces which are responsible for cohesion <strong>in</strong><br />

solids and liquids. Clusters are thus f<strong>in</strong>ite-size microcosms of the condensed<br />

phase, the realm <strong>in</strong> which most chemistry occurs. A major objective of Dr.<br />

Bowen’s research is to provide a molecule’s eye view of many-body, condensed<br />

phase <strong>in</strong>teractions. The study of size-specific and composition-specific clusters<br />

provides an <strong>in</strong>cisive means of address<strong>in</strong>g this fundamental and longstand<strong>in</strong>g problem<br />

<strong>in</strong> phyical chemistry.<br />

For technical reasons, clusters are best studied as negatively-charged species.<br />

Experimental methods utilized <strong>in</strong> Dr. Bowen’s group to study clusters <strong>in</strong>clude both<br />

cont<strong>in</strong>uous and pulsed negative ion photoelectron spectroscopy, mass spectrometry,<br />

and photodissociation spectroscopy. This work is <strong>in</strong>strumentally oriented, with major<br />

components of his several ion beam apparatus <strong>in</strong>clud<strong>in</strong>g both cont<strong>in</strong>uous and pulsed<br />

lasers, high vacuum systems, ion and electron optics, electronics and computers, as<br />

well as time-of-flight, quadrupole, magnetic sector, and Wien filter mass<br />

spectrometers. The tra<strong>in</strong><strong>in</strong>g <strong>in</strong> advanced <strong>in</strong>strumentation, afforded students <strong>in</strong> Dr.<br />

Bowen’s group, lays a firm foundation for careers <strong>in</strong> either physical or analytical<br />

chemistry. Experimental emphasis is also placed on design<strong>in</strong>g unique sources of<br />

cluster ions and on the preparation and characterization of nanoparticles for a variety<br />

of technological applications, such as catalysis.<br />

A particularly attractive aspect of cluster studies concerns the very wide<br />

variety of scientific problems that can be addressed, stretch<strong>in</strong>g from the edge of<br />

biology, through chemistry and condensed matter physics, to the edge of<br />

astrophysics. Us<strong>in</strong>g the versatile techniques described above, Dr. Bowen’s group is<br />

study<strong>in</strong>g the number of water molecules necessary to <strong>in</strong>duce the formation<br />

of zwitterions <strong>in</strong> am<strong>in</strong>o acids, the energetics of electron capture <strong>in</strong><br />

hydrated nucleic acid bases, the solvent-<strong>in</strong>duced stabilization of otherwise unstable<br />

organic anions, the solvation of anions by aqueous and non-aqueous solvents, the<br />

energetics and growth paths of charged atmospheric aerosols, the microscopic<br />

conditions necessary for form<strong>in</strong>g solvated electrons, the stability of color centers <strong>in</strong><br />

nanocrystals of metal compounds, the <strong>in</strong>sulator-to-metal transition <strong>in</strong> clusters of<br />

divalent metals, the electronic structure of alkali metal clusters, the prospects for<br />

magic clusters as build<strong>in</strong>g blocks of futuristic cluster-assembled materials, the nature<br />

of exotic species such as dipole bound and double Rydberg anions, the magnetism<br />

exhibited by silicon-encapsulated transition metals, and the role of nanoclusters <strong>in</strong><br />

<strong>in</strong>terstellar dust. The opportunity to be <strong>in</strong>volved <strong>in</strong> such a diversity of fields is an<br />

excit<strong>in</strong>g aspect of this work for Dr. Bowen and his research group.<br />

Ph.D., Harvard <strong>University</strong><br />

Postdoctoral, Harvard<br />

<strong>University</strong><br />

Fellow, American Physical<br />

Society<br />

Humboldt Research Awardee<br />

K + K + K + K +<br />

Selected Publications <strong>in</strong>clude:<br />

“In search of theoretically-predicted magic clusters: lithium-doped alum<strong>in</strong>um cluster anions,” O.C. Thomas, W.-J. Zheng, T.P. Lippa,<br />

S.-J. Xu, S.A. Lyapust<strong>in</strong>a, and K.H. Bowen, J. Chem. Phys. 114, 9895 (2001).<br />

“Solvent-<strong>in</strong>duced stabilization of the naphthalene anion by water molecules: A negative cluster ion photoelectron spectroscopic<br />

study”, S.A. Lyapust<strong>in</strong>a, S.-J. Xu, J.M. Nilles, and K.H. Bowen, J. Chem. Phys. 112, 6643 (2000).<br />

“Vibrationally-resolved photoelectron spectroscopy of MgO - , and ZnO - , and the low-ly<strong>in</strong>g electronic states of MgO, MgO - , and<br />

ZnO”, J.H. Kim, X. Li, L.-S. Wang, H.L. deClercq, C.A. Fancher, O.C. Thomas, and K.H. Bowen, J. Phys. Chem. A. 105, 5709<br />

(2001).<br />

K +<br />

Al - 13<br />

K + K +<br />

K + 7<br />

“Magic numbers <strong>in</strong> copper-doped alum<strong>in</strong>um cluster anions”, O.C. Thomas, W.–J. Zheng, and K.H. Bowen, J. Chem. Phys. 114,<br />

5514 (2001).<br />

The cluster-assembled ionic<br />

“molecule”, KAl 13 , the kernel of<br />

a new material<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


Paul J. Dagdigian<br />

Experimental Physical <strong>Chemistry</strong><br />

Gas-Phase Collision Dynamics and Spectroscopy<br />

pjdagdigian@jhu.edu<br />

Ph. D., <strong>University</strong> of<br />

Chicago<br />

Postdoctoral, Columbia<br />

<strong>University</strong><br />

Fellow, American Physical<br />

Society<br />

We are employ<strong>in</strong>g laser fluorescence excitation and resonance-enhanced<br />

multiphoton ionization of atoms and small molecules <strong>in</strong> studies of<br />

gas-phase collisional processes, <strong>in</strong>volv<strong>in</strong>g chemical reactions,<br />

photodissociation, and nonreactive energy transfer processes. Recent<br />

work has <strong>in</strong>cluded the study of collision-<strong>in</strong>duced rotational and<br />

electronic transitions <strong>in</strong> the CN radical and the photodissociation of vibrationally<br />

excited methyl chloride.<br />

We are also <strong>in</strong>terested <strong>in</strong> understand<strong>in</strong>g the non-bond<strong>in</strong>g <strong>in</strong>teractions<br />

between light atoms, such as boron, carbon, alum<strong>in</strong>um, and silicon, with rare gases<br />

and small molecules such as H 2 . We <strong>in</strong>terrogate these <strong>in</strong>teractions through the<br />

measurement of the electronic spectra of weakly bound complexes of these species,<br />

prepared <strong>in</strong> a free-jet supersonic expansion. Such studies allow us to <strong>in</strong>fer the<br />

evolution of the chromophore of an atomic transition from that <strong>in</strong> the free atom,<br />

b<strong>in</strong>ary and higher complexes through to the atom-doped solid.<br />

There is a cont<strong>in</strong>u<strong>in</strong>g need for the development of laser diagnostics for the<br />

detection of transient species <strong>in</strong> reactive environments, as well as the detection of<br />

explosives <strong>in</strong> trace quantities. Our group is participat<strong>in</strong>g <strong>in</strong> a recently funded DoD<br />

multi-university <strong>in</strong>itiative, “Spectroscopic and Time Doma<strong>in</strong> Detection of Trace<br />

Explosives <strong>in</strong> Condensed and Vapor Phases.” We will be implement<strong>in</strong>g cavity<br />

r<strong>in</strong>g-down spectroscopy (CRDS) as one of a suite of ultrasensitive laser analytical<br />

techniques to be applied to the detection of land m<strong>in</strong>es. In our laboratory, we are also<br />

employ<strong>in</strong>g CRDS to study the spectroscopy and k<strong>in</strong>etics of transient <strong>in</strong>termediates,<br />

for example the H 2 CN radical.<br />

Selected Publications <strong>in</strong>clude:<br />

Tan, X.; Dagdigian, P. J.; and Alexander, M. H., “Electronic Spectroscopy and Excited State Dynamics of the Al–H 2 /D 2 Complex,”<br />

Faraday Discuss. 2001, 118, 387.<br />

Lei, J.; and Dagdigian, P. J., “Laser Fluorescence Excitation Spectroscopy of the CAr van der Waals Complex,” J. Chem. Phys.<br />

2000, 113, 602.<br />

Lei, J.; Teslja, A.; Nizamov, B.; and Dagdigian, P. J., “Free-Jet Electronic Spectroscopy of the PO 2 Radical,” J. Phys. Chem. A 2001,<br />

105, 7828.<br />

Nizamov, B.; Dagdigian, P. J.; and Alexander, M. H., “State-Resolved Rotationally Inelastic Collisions of Highly Rotationally Excited<br />

CN(A 2 ∏) with Helium: Influence of the Interaction Potential,” J. Chem. Phys. 2001, 115, 8393.<br />

8 <strong>Graduate</strong> <strong>Study</strong> <strong>in</strong> <strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


David E. Draper<br />

Physical Biochemistry<br />

draper@jhu.edu<br />

“<br />

RNA fold<strong>in</strong>g” has become a vigorous area of research as many unexpected and<br />

important functional roles have been discovered for RNA molecules. Research<br />

<strong>in</strong> my lab is concerned with two related questions about RNA: What are the<br />

energetics of fold<strong>in</strong>g compact RNA tertiary structures How do prote<strong>in</strong>s<br />

recognize specific RNA sites and carry out specific tasks A variety of<br />

physical, biochemical, and genetic techniques are be<strong>in</strong>g used to explore several RNA<br />

systems.<br />

For a number of years, we have used ribosomal prote<strong>in</strong> - RNA complexes as<br />

systems to explore different aspects of prote<strong>in</strong> - RNA recognition and RNA fold<strong>in</strong>g.<br />

Most of our current efforts <strong>in</strong> this area concern two highly conserved regions of the<br />

ribosome that b<strong>in</strong>d elongation factor G (EF-G), which catalyzes GTP hydrolysis and<br />

translocation of the ribosome along the messenger RNA. Each region consists of a<br />

ribosomal RNA fragment and several ribosomal prote<strong>in</strong>s; assembly of these<br />

complexes and their <strong>in</strong>teractions with EF-G are be<strong>in</strong>g studied by physical methods.<br />

Mutations whose properties are known from the <strong>in</strong> vitro studies are be<strong>in</strong>g <strong>in</strong>troduced<br />

<strong>in</strong>to ribosomes <strong>in</strong> vivo, to probe the functional significance of the complexes that are<br />

be<strong>in</strong>g prepared. Initial work <strong>in</strong> this area resulted <strong>in</strong> the first crystal structure of a<br />

ribosomal prote<strong>in</strong> - RNA complex (Conn et al., 1999), which, <strong>in</strong> conjunction with<br />

solution thermodynamic studies, has yielded considerable <strong>in</strong>sight <strong>in</strong>to prote<strong>in</strong> - RNA<br />

recognition mechanisms and unexpected features of RNA tertiary fold<strong>in</strong>g. Our<br />

crystallographic efforts are be<strong>in</strong>g carried out <strong>in</strong> collaboration with Prof. Ed Lattman’s<br />

laboratory <strong>in</strong> the Biophysics Department.<br />

In the last few years we have been particularly concerned with electrostatic<br />

aspects of RNA. Fold<strong>in</strong>g of an RNA tertiary structure is opposed by the unfavorable<br />

free energy needed to br<strong>in</strong>g negatively charged phosphates <strong>in</strong>to proximity, and it has<br />

long been known that Mg 2+ is much more effective than monovalent ions at<br />

reduc<strong>in</strong>g the electrostatic free energy of RNA tertiary folds. We have recently<br />

developed a theoretical framework for describ<strong>in</strong>g cation <strong>in</strong>teractions with RNA. The<br />

model successfully accounts for the special properties of Mg 2+ , and we are mak<strong>in</strong>g<br />

direct experimental measurements of Mg 2+ - RNA <strong>in</strong>teractions to further test our<br />

predictions. In other work, we are exam<strong>in</strong><strong>in</strong>g the electrostatic component of prote<strong>in</strong> -<br />

RNA b<strong>in</strong>d<strong>in</strong>g, and aga<strong>in</strong> are mak<strong>in</strong>g measurements <strong>in</strong> simple peptide - RNA<br />

complexes to test our theoretical predictions quantitatively.<br />

Ph.D., <strong>University</strong> of<br />

Oregon<br />

Postdoctoral, <strong>University</strong><br />

of Colorado<br />

NIH Career Development<br />

Award<br />

NIH MERIT Award<br />

Selected publications <strong>in</strong>clude:<br />

Conn, G. L., Gittis, A. G., M<strong>in</strong>od, V., Lattman, E. E. & Draper, D. E. (2002). A compact RNA tertiary structure conta<strong>in</strong>s a buried<br />

backbone - K + complex. J. Mol. Biol., 318, 963-973.<br />

Misra, V. K. & Draper, D. E. (2001). A thermodynamic framework for Mg 2+ b<strong>in</strong>d<strong>in</strong>g to RNA. Proc. Natl. Acad. Sci. U S A 98, 12456-<br />

12461.<br />

Misra, V. K. & Draper, D. E. (2002). The l<strong>in</strong>kage between magnesium b<strong>in</strong>d<strong>in</strong>g and RNA fold<strong>in</strong>g. J. Mol. Biol., 317, 507-521.<br />

Gerstner, R. B., Pak, Y. & Draper, D. E. (2002). Recognition of 16S rRna by ribosomal prote<strong>in</strong> S4 from Baccillus stearothermophilus.<br />

Biochemistry 40, 7165-7133.<br />

Shiman, R. & Draper, D. E. (2000). Stabilization of RNA tertiary structure by monovalent cations. J. Mol. Biol., 302, 79-91.<br />

Draper, D. E. (1999). Themes <strong>in</strong> RNA-prote<strong>in</strong> recognition. J. Mol. Biol., 293, 255-270.<br />

Conn, G. L., Draper, D. E., Lattman, E. E. & Gittis, A. G. (1999). Crystal structure of a conserved ribosomal prote<strong>in</strong> - RNA complex.<br />

Science, 284, 1171-1174.<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

9


D. Howard Fairbrother<br />

Ph.D., Northwestern<br />

<strong>University</strong><br />

Postdoctoral, <strong>University</strong><br />

of California, Berkeley<br />

NSF CAREER Award<br />

Experimental Surface <strong>Chemistry</strong><br />

Reactions at Polymer and Environmental Interfaces<br />

Materials Process<strong>in</strong>g<br />

howardf@jhu.edu<br />

Dr. Fairbrother’s research program is focused on elucidat<strong>in</strong>g the mechanisms of<br />

chemical reactions that occur on surfaces and <strong>in</strong> th<strong>in</strong> films as well as their<br />

impact on material properties. This <strong>in</strong>terest is motivated by the wide range of<br />

technologically significant processes that are mediated by surface reactions<br />

<strong>in</strong>clud<strong>in</strong>g catalysis, materials process<strong>in</strong>g as well as adhesion and friction.<br />

The modification of polymer surfaces <strong>in</strong> vacuum environments is important<br />

<strong>in</strong> a number of different situations <strong>in</strong>clud<strong>in</strong>g plasma process<strong>in</strong>g, polymer<br />

metallization and for vehicles <strong>in</strong> low earth orbits. We are explor<strong>in</strong>g the microscopic<br />

surface events that accompany polymer surface process<strong>in</strong>g (Figure 1) and their impact<br />

on <strong>in</strong>terfacial properties. For example, we have explored the modification of<br />

fluor<strong>in</strong>ated organic films dur<strong>in</strong>g X-ray irradiation and metallization as well as the<br />

reactions of oxygen free radicals with self assembled monolayers.<br />

Surface reactions are also responsible for a wide range of environmental<br />

processes <strong>in</strong>clud<strong>in</strong>g atmospheric chemistry on ice and aerosol particles and the<br />

elementary reaction steps <strong>in</strong> Fe-based organohalide remediation <strong>in</strong> groundwater.<br />

Us<strong>in</strong>g an electrochemical cell coupled to a surface analysis chamber we are study<strong>in</strong>g<br />

the liquid/solid <strong>in</strong>terface, specifically the effect of surface composition on the rate and<br />

product partition<strong>in</strong>g associated with Fe-based organohalide remediation. In related<br />

studies we are also study<strong>in</strong>g the mechanisms associated with electron beam and<br />

plasma remediation of chlorocarbons <strong>in</strong> aqueous solutions (Figure 2).<br />

Our studies utilize a wide variety of modern surface analytical tools<br />

<strong>in</strong>clud<strong>in</strong>g X-ray Photoelectron Spectroscopy (XPS), Infrared Spectroscopy, Mass<br />

Spectrometry and Atomic Force Microscopy (AFM). A number of our projects are<br />

highly collaborative <strong>in</strong> nature, <strong>in</strong>volv<strong>in</strong>g <strong>in</strong>teractions with the Department of<br />

Geography and Environmental Eng<strong>in</strong>eer<strong>in</strong>g and the Department of Materials Science<br />

and Eng<strong>in</strong>eer<strong>in</strong>g.<br />

Selected Publications:<br />

“Electron-Stimulated Chemical Reactions <strong>in</strong> Carbon Tetrachloride/Water (Ice) Films” A. J. Wagner, C. Vecitis, D. H. Fairbrother,<br />

J. Phys. Chem. B. 102 (2002) 4432.<br />

“Effect of X-ray Irradiation on the Chemical and Physical Properties of Semifluor<strong>in</strong>ated Self- Assembled Monolayer”, A. J. Wagner,<br />

S. R. Carlo, C. Vecitis, D. H. Fairbrother, Langmuir 18 (2002) 1542.<br />

“Self-Assembled Monolayers as Models for Polymeric Interfaces,” C. C. Perry, S. R. Carlo, A.<br />

J. Wagner, C. Vecitis, J. Torres, K. Kolegraf, D. H. Fairbrother (ACS Symposium Series on “Solid Surfaces and Th<strong>in</strong> Films”)<br />

“Radical Reactions with Organic Th<strong>in</strong> Films: Chemical Interaction of Atomic Oxygen with an X-ray Modified Self-Assembled<br />

Monolayer” J. Torres, C.C. Perry, S.J. Bransfield, D.H. Fairbrother, J. Phys. Chem. B., 106 (2002) 6265.<br />

Figure 1: AFM image of a PTFE<br />

(Teflon) surface dur<strong>in</strong>g Ti<br />

Deposition<br />

Figure 2: Mass Spectrum of Volatile Species Produced<br />

dur<strong>in</strong>g Electron Beam Irradiation of Ice (bottom)<br />

and a 13 CCl 4 /Ice Film (top)<br />

10 <strong>Graduate</strong> <strong>Study</strong> <strong>in</strong> <strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


David P. Goldberg<br />

Inorganic <strong>Chemistry</strong><br />

Bio<strong>in</strong>organic <strong>Chemistry</strong><br />

Environmental <strong>Chemistry</strong><br />

dpg@jhu.edu<br />

Our research addresses a number of <strong>in</strong>terest<strong>in</strong>g challenges <strong>in</strong><br />

<strong>in</strong>organic/bio<strong>in</strong>organic chemistry. Currently, our group is divided <strong>in</strong>to two<br />

ma<strong>in</strong> areas. Part of our research group is <strong>in</strong>terested <strong>in</strong> the synthesis, physical<br />

properties and reactivity of new porphyr<strong>in</strong>oid compounds. We have<br />

recently discovered a method for synthesiz<strong>in</strong>g corrolaz<strong>in</strong>es, a new class of<br />

porphyr<strong>in</strong>-like compounds that are related to r<strong>in</strong>g-contracted compounds called<br />

corroles. Corroles, known for over 30 years, have a remarkable advantage over<br />

porphyr<strong>in</strong>s <strong>in</strong> stabiliz<strong>in</strong>g high-valent oxidation states (e.g. Mn V , Fe IV , Co IV , Ni III ), yet<br />

little is known about their ability to function as catalysts and/or mimics for<br />

biological systems because of the difficulties encountered <strong>in</strong> their preparation. We<br />

have synthesized Co, Ni, Cu, Mn, and Fe corrolaz<strong>in</strong>es, and are now mapp<strong>in</strong>g out a<br />

new area of metallocorrolaz<strong>in</strong>e reactivity and catalysis. Applications immediately<br />

envisioned for these complexes <strong>in</strong>clude their reactivity toward O 2 and H 2 O 2 for<br />

oxygen activation, the oxygenation/functionalization of substrates such as<br />

hydrocarbons, and their use <strong>in</strong> mediat<strong>in</strong>g the dehalogenation of environmentally<br />

significant organohalides.<br />

In another area, we are design<strong>in</strong>g and synthesiz<strong>in</strong>g small-molecule analogues<br />

of the active sites of certa<strong>in</strong> metalloprote<strong>in</strong>s. Many biological processes rely on<br />

transition metals to effect catalytic reactions. For example, peptide deformylase (PDF)<br />

relies on an unusual (His) 2 (Cys)Fe II (OH 2 ) active site for deformylation dur<strong>in</strong>g<br />

bacterial prote<strong>in</strong> synthesis. We have synthesized new N 2 S thiolate ligands to mimic the<br />

His 2 Cys coord<strong>in</strong>ation sphere found <strong>in</strong> PDF, and have prepared a family of new<br />

transition metal complexes with these ligands. Some of these complexes represent<br />

stabilized forms of <strong>in</strong>termediates postulated to exist dur<strong>in</strong>g catalysis, such as<br />

[(PATH)Zn(formate)], which was prepared from the useful synthon [(PATH)Zn(Me)].<br />

Other complexes exhibit the functional capacity to effect the hydrolysis of certa<strong>in</strong><br />

substrates (e.g. esters), and these reactions are be<strong>in</strong>g exam<strong>in</strong>ed through k<strong>in</strong>etic<br />

studies. We have recently prepared new, more elaborate ligands with imidazole<br />

donors and are explor<strong>in</strong>g their transition metal chemistry, <strong>in</strong>clud<strong>in</strong>g d<strong>in</strong>uclear,<br />

hydroxo-bridged z<strong>in</strong>c complexes that are relevant to enzymes that cleave DNA and<br />

RNA. The study of these complexes will shed light on the fundamental role of metal<br />

ions <strong>in</strong> the related biological systems, and may lead to the development of<br />

<strong>in</strong>dustrially important catalysts and novel pharmaceutical agents.<br />

Ph.D. Massachusetts<br />

Institute of Technology<br />

NIH Postdoctoral Fellow,<br />

Northwestern <strong>University</strong><br />

NSF CAREER Award<br />

Alfred P. Sloan Research<br />

Fellowship<br />

Recent publications <strong>in</strong>clude:<br />

Chang, S.; Karambelkar, V. V.; di Targiani, R. C.; Goldberg D. P. “Model Complexes of the Active Site of Peptide Deformylase: A<br />

New Family of Mononuclear N 2 S-M II Complexes,” Inorg. Chem., 2001, 40, 194-195.<br />

Ramdhanie, B.; Stern, C. L.; Goldberg. D. P. “Synthesis of the First Corrolaz<strong>in</strong>e: A New Member of the Porphyr<strong>in</strong>oid Family” J. Am.<br />

Chem. Soc., 2001, 123, 9447-9448.<br />

Chang, S.; Sommer, R.; Rhe<strong>in</strong>gold, A.; Goldberg, D. P. “A Model Complex of a Possible Intermediate <strong>in</strong> the Mechanism of Action of<br />

Peptide Deformylase: First Example of an N 2 SZn-formate Complex,” J. Chem. Soc., Chem. Commun., 2001, 2396-2397.<br />

Chang, S.; Karambelkar, V. V.; Sommer, R.; Rhe<strong>in</strong>gold, A.; Goldberg, D. P. “New Monomeric Cobalt(II) and Z<strong>in</strong>c(II) Complexes of a<br />

Mixed N,S(alkylthiolate) Ligand: Model Complexes of (His)(His)(Cys) Metalloprote<strong>in</strong> Active Sites,”Inorg. Chem. 2001, 41, 239-<br />

248.<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

11


Marc M. Greenberg<br />

Organic and Bioorganic <strong>Chemistry</strong><br />

mgreenberg@jhu.edu<br />

Ph.D., Yale <strong>University</strong><br />

American Cancer Society<br />

Postdoctoral Fellow,<br />

California Institute of<br />

Technology<br />

Alfred P. Sloan Research<br />

Fellowship<br />

As the carrier of genetic <strong>in</strong>formation, it is no surprise that DNA damage and<br />

repair is important <strong>in</strong> ag<strong>in</strong>g and a variety of genetically based diseases, such<br />

as cancer. However, modified nucleic acids are becom<strong>in</strong>g <strong>in</strong>creas<strong>in</strong>gly<br />

important as diagnostic tools and therapeutic agents. The pivotal roles of<br />

DNA <strong>in</strong> chemistry and biology are <strong>in</strong>terwoven. For <strong>in</strong>stance, the reactivity of<br />

DNA with reactive oxygen species determ<strong>in</strong>es the types of structural modifications<br />

(lesions) formed. The <strong>in</strong>teraction of lesions with repair and polymerase enzymes <strong>in</strong><br />

turn determ<strong>in</strong>es their biological effects. Identify<strong>in</strong>g the location and level of DNA<br />

lesions <strong>in</strong> the genome may assist the diagnosis and treatment approach of disease.<br />

Our research group uses organic chemistry to address questions concern<strong>in</strong>g<br />

the reactivity, function, structure, and uses of nucleic acids. Examples of current<br />

projects <strong>in</strong> our group are:<br />

• determ<strong>in</strong><strong>in</strong>g how nucleic acids are oxidatively damaged by synthesiz<strong>in</strong>g molecules<br />

(e.g 1) that enable us to <strong>in</strong>dependently generate reactive <strong>in</strong>termediates at def<strong>in</strong>ed<br />

sites <strong>in</strong> DNA.<br />

• elucidat<strong>in</strong>g the effects of specific DNA lesions (e.g. 2, 3) on the function of nucleic<br />

acids, and their structural basis.<br />

• the development of methods and applications for modified oligonucleotide<br />

synthesis.<br />

To br<strong>in</strong>g these projects to fruition we synthesize novel molecules and study<br />

their behavior us<strong>in</strong>g a variety of physicochemical, biochemical, and biological<br />

techniques. Recent accomplishments by our research group <strong>in</strong> these areas <strong>in</strong>clude:<br />

• the discovery of novel pathways for DNA damage that produce tandem lesions<br />

(Scheme 1).<br />

• the discovery of the first example of irreversible <strong>in</strong>hibition of DNA repair by a DNA<br />

lesion (Scheme 2).<br />

• the first synthesis of oligonucleotides conta<strong>in</strong><strong>in</strong>g formamidopyrimid<strong>in</strong>e lesions (e.g.<br />

Fapy•dG) and determ<strong>in</strong>ation of their effects on DNA repair and polymerase<br />

enzymes.<br />

• the development of highly efficient, convergent methods for oligonucleotide<br />

conjugate synthesis.<br />

In addition to cont<strong>in</strong>u<strong>in</strong>g these research projects, the above discoveries have<br />

given rise to new projects <strong>in</strong> our group that <strong>in</strong>clude the development of novel<br />

radiosensitiz<strong>in</strong>g agents and mechanism based <strong>in</strong>hibitors of DNA repair enzymes.<br />

Selected publications <strong>in</strong>clude:<br />

Fapy•dA Induces Nucleotide Mis<strong>in</strong>corporation Translesionally by a DNA Polymerase. Delaney, M. O.; Wiederholt, C. J.; Greenberg,<br />

M. M. Angew. Chem. Int. Ed. 2002, 41, 771.<br />

Oxygen Dependent DNA Damage Amplification Involv<strong>in</strong>g 5,6-Dihydrothymid<strong>in</strong>-5-yl <strong>in</strong> a Structurally M<strong>in</strong>imal System. Tallman, K.<br />

A.; Greenberg, M. M. J. Am. Chem. Soc. 2001, 123, 5181.<br />

(3)<br />

The 2-Deoxyribonolactone Lesion Produced <strong>in</strong> DNA by Neocarz<strong>in</strong>ostat<strong>in</strong> and Other DNA Damag<strong>in</strong>g Agents Forms Cross-L<strong>in</strong>ks with<br />

the Base-Excision Repair Enzyme Endonuclease III. Hashimoto, M.; Greenberg, M. M.; Kow, Y. W.; Hwang, J.-T.; Cunn<strong>in</strong>gham, R. P.<br />

J. Am. Chem. Soc. 2001, 123, 3161.<br />

Introduc<strong>in</strong>g Structural Diversity <strong>in</strong> Oligonucleotides Via Photolabile, Convertible C5-Substituted Nucleotides. Kahl, J. D.; Greenberg,<br />

M. M. J. Am. Chem. Soc. 1999, 121, 597.<br />

Scheme 1 Scheme 2<br />

1<br />

2<br />

12<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


Bioorganic <strong>Chemistry</strong> and Enzymology<br />

hendrick@jhu.edu<br />

Tamara L. Hendrickson<br />

Our research group is <strong>in</strong>terested <strong>in</strong> evaluat<strong>in</strong>g the mechanisms and<br />

consequences of complex enzymatic systems, with<strong>in</strong> the broad field of<br />

prote<strong>in</strong> translation. We use a multidiscipl<strong>in</strong>ary approach, <strong>in</strong>tegrat<strong>in</strong>g tools<br />

from biochemistry, molecular biology, enzymology and synthetic organic<br />

chemistry.<br />

Several projects focus on an <strong>in</strong>direct pathway for tRNA am<strong>in</strong>oacylation.<br />

Traditionally, it was believed that all organisms use 20 am<strong>in</strong>oacyl-tRNA synthetases<br />

(one for each encoded am<strong>in</strong>o acid) to biosynthesize a complement of<br />

am<strong>in</strong>oacyl-tRNAs. The wealth of genomic data that has become available over the<br />

past few years, however, has revealed that many bacteria and archaea thrive <strong>in</strong> the<br />

absence of glutam<strong>in</strong>yl- and/or asparag<strong>in</strong>yl-tRNA synthetase. In these cases,<br />

tRNA Gln and tRNA Asn are misacylated respectively by either glutamyl- or<br />

aspartyl-tRNA synthetase. Next, a glutam<strong>in</strong>e-dependent amidotransferase<br />

(Glu-AdT) converts the misacylated tRNA to the correct species. (Fig. 1 depicts this<br />

process for the generation of glutam<strong>in</strong>ylated-tRNA Gln .) Very little is known about<br />

Glu-Adt, its mechanism of action or the methods by which it recognizes two different<br />

tRNA substrates (tRNA Gln and tRNA Asn ). Several projects <strong>in</strong> our lab seek to address<br />

some of these issues, by evaluat<strong>in</strong>g Glu-Adt from the stomach ulcer-<strong>in</strong>duc<strong>in</strong>g<br />

pathogenic bacterium H. pylori, from human mitochondria and from the<br />

hyperthermophilic archaeon P. furiousus.<br />

The second area of <strong>in</strong>terest <strong>in</strong> the lab is the biosynthesis of glycosyl<br />

phosphatidyl<strong>in</strong>ositol (GPI) membrane anchored prote<strong>in</strong>s (Fig. 2). GPI anchor<br />

attachment converts a soluble prote<strong>in</strong> <strong>in</strong>to a membrane-associated prote<strong>in</strong>. The<br />

complexity of this system is due to the specificity with which a putative transamidase<br />

(GPI-T) aligns two large substrates, target<strong>in</strong>g the carbohydrate anchor to a particular<br />

amide bond with<strong>in</strong> the prote<strong>in</strong> substrate. GPI prote<strong>in</strong>s are found throughout<br />

eukaryotes, and are particularly abundant <strong>in</strong> some forms of parasitic protozoa,<br />

mak<strong>in</strong>g this modification a potential target for drug design. We are currently<br />

develop<strong>in</strong>g the first soluble k<strong>in</strong>etic assay for GPI-T by synthetically <strong>in</strong>corporat<strong>in</strong>g<br />

chromophoric groups <strong>in</strong>to a typical peptide substrate. The development of such an<br />

assay will enable the first detailed exam<strong>in</strong>ation of the mechanism of action of this<br />

complex enzyme.<br />

Selected publications<br />

Hendrickson, T. L., Nomanbhoy, T. K., de Crecy-Lagard, V., Schimmel, P. “Mutational Separation of Two Pathways for Edit<strong>in</strong>g by a<br />

Class I tRNA Synthetase,” Mol. Cell, 2002, 9, 353-362.<br />

Ph.D., California Institute<br />

of Technology<br />

NIH Postdoctoral Fellow,<br />

Massachusetts Institute of<br />

Technology and The<br />

Scripps Research Institute<br />

Research Corporation<br />

Innovation Award<br />

Hendrickson, T. L. “Recogniz<strong>in</strong>g the D-Loop of Transfer RNAs,” Proc. Natl. Acad. Sci., 2001, 98, 13473-13475.<br />

Dör<strong>in</strong>g, V.; Mootz, H. D.; Nangle, L. A.; Hendrickson,T. L.; de Crécy-Lagard, V.; Schimmel, P.; and Marliére, P. “Enlarg<strong>in</strong>g the Am<strong>in</strong>o<br />

Acid Set of Escherichia coli by Infiltration of the Val<strong>in</strong>e Cod<strong>in</strong>g Pathway,” 2001, 292, 501-504.<br />

Hendrickson, T. L.; Spencer, J. R.; Kato, M.; Imperiali, B. “Design and Evaluation of Potent Inhibitors of Asparag<strong>in</strong>e-L<strong>in</strong>ked Prote<strong>in</strong><br />

Glycosylation,” J. Am. Chem. Soc., 1996, 118, 7636-7637.<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

13


Kenneth D. Karl<strong>in</strong><br />

Ph. D., Columbia<br />

<strong>University</strong><br />

Postdoctoral, Cambridge<br />

<strong>University</strong>, England<br />

Editor, Progress <strong>in</strong><br />

Inorganic <strong>Chemistry</strong><br />

(Wiley)<br />

Buck-Whitney Award<br />

Biological and Environmental Inorganic <strong>Chemistry</strong><br />

Synthetic Models for Heme and/or Copper Prote<strong>in</strong>s<br />

Reactions with O 2 , NOx & R-Cl; Cu-DNA & peptide <strong>in</strong>teractions<br />

karl<strong>in</strong>@jhu.edu<br />

Dr. Karl<strong>in</strong>’s bio<strong>in</strong>organic research focuses on coord<strong>in</strong>ation chemistry relevant to<br />

biological and environmental processes. Essential prote<strong>in</strong>s with active-site<br />

copper aggregates or heme (porphyr<strong>in</strong>-iron) centers react with O 2 or nitrogen<br />

oxides. Thus, we study reactions <strong>in</strong>volv<strong>in</strong>g O 2 , NO – 2 (nitrite), NO (nitric<br />

oxide), N 2 O (nitrous oxide) as well as organohalides. Metal/O 2 chemistries<br />

with organic substrates, DNA and prote<strong>in</strong>s are also under <strong>in</strong>vestigation.<br />

Our laboratory approaches <strong>in</strong>clude (a) the rational design and syntheses of<br />

ligands allow<strong>in</strong>g formation of appropriate Cu or Fe complexes, b) elucidation of<br />

structure and physical properties us<strong>in</strong>g X-ray crystallography and a variety of<br />

physical methods, and c) reactivity and k<strong>in</strong>etic-mechanistic <strong>in</strong>vestigations. The<br />

studies should provide <strong>in</strong>sights to questions of biological concern, and also may<br />

provide a rationale for the chemist to design practical reagents for O 2 -mediated<br />

oxidations, NOx-reduction catalysts, or agents which can dehalogenate R-Cl<br />

pollutants.<br />

Recent notable achievements (also see diagrams below) <strong>in</strong>clude: (a) the<br />

detailed characterization of several types of copper-dioxygen adducts, <strong>in</strong>clud<strong>in</strong>g the<br />

trans -1,2-peroxodicopper(II) complex shown below, (b) the generation of<br />

cytochrome c oxidase (heme-copper) O 2- reactivity models, with -peroxo Fe III -(O 2<br />

2–)<br />

-Cu II and -oxo Fe III -(O 2– )-Cu II species, and (c) the demonstration that <strong>in</strong> a highly specific<br />

manner, certa<strong>in</strong> ligand-Cu 2 (or Cu 3 ) complexes oxidatively cleave DNA at the<br />

junction of double and s<strong>in</strong>gle-stranded regions.<br />

Recent publications <strong>in</strong>clude:<br />

Zhang, C. X.; Liang, H.-C.; Kim, E.-i.; Gan, Q.-F.; Tyeklár, Z.; Lam, M.; Rhe<strong>in</strong>gold, A. L.; Kaderli, S.; Zuberbühler, A. D.; Karl<strong>in</strong>, K. D.,<br />

“Dioxygen Mediated oxo-transfer to an am<strong>in</strong>e and oxidative N-dealkylation chemistry with a d<strong>in</strong>uclear copper complex”, Chem.<br />

Commun., 2001, 631-632.<br />

Ghiladi, R. A.; Hatwell, K. R.; Karl<strong>in</strong>, K. D.; Huang, H.-w.; Moënne-Loccoz, P.; Krebs, C.; Marzilli, L. A.; Cotter, R. J.; Kaderli, S.;<br />

Zuberbühler, A. D. “Dioxygen Reactivity of Mononuclear Heme and Copper Components Yield<strong>in</strong>g a High-Sp<strong>in</strong> Heme-Peroxo-Cu<br />

Complex”, J. Am. Chem. Soc., 2001, 123, 6183-6184.<br />

Humphreys, K. J.; Karl<strong>in</strong>, K. D.; Rokita, S. E. “Recognition and Strand Scission at Junctions between S<strong>in</strong>gle- and Double-Stranded<br />

DNA by a Tr<strong>in</strong>uclear Copper Complex”, J. Am. Chem. Soc., 2001, 123, 5588-5589.<br />

Fellow, American<br />

Association for the<br />

Advancement of Science<br />

(AAAS)<br />

Ira Remsen Chair<br />

<strong>in</strong> <strong>Chemistry</strong><br />

14<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


Thomas Lectka<br />

Organic <strong>Chemistry</strong><br />

lectka@jhu.edu<br />

The thrust of our research is towards the development of new catalytic<br />

asymmetric reactions. In particular we are <strong>in</strong>terested <strong>in</strong> chiral, all-organic<br />

molecules, and Lewis acids as catalysts, as illustrated <strong>in</strong> three projects:<br />

Project I. Catalytic, Asymmetric -Lactam and -Am<strong>in</strong>o Acid Synthesis.<br />

We have developed practical methodology for the catalytic, asymmetric synthesis<br />

of lactams <strong>in</strong> high diastereo- and enantioselectivity employ<strong>in</strong>g chiral nucleophiles<br />

as catalysts. Our reactions should provide access to a large number of ser<strong>in</strong>e protease<br />

<strong>in</strong>hibitors of prostate specific antigen, cytomegalovirus protease, elastase, thromb<strong>in</strong>,<br />

and cell metathesis. We have also recently developed a new synthesis of am<strong>in</strong>o acid<br />

derivatives through a catalytic, asymmetric process <strong>in</strong> which the chiral nucleophile<br />

benzoylqu<strong>in</strong><strong>in</strong>e (BQ) plays no less than five discrete roles. The reaction is a<br />

multistage, multicomponent reaction <strong>in</strong> which the start<strong>in</strong>g materials are <strong>in</strong>expensive.<br />

Project II. Asymmetric Catalysis on Sequentially-L<strong>in</strong>ked Columns.<br />

The all-organic nature of our catalyst systems renders them attractive to attach to a<br />

solid phase. Along those l<strong>in</strong>es, we have developed a catalytic, asymmetric process <strong>in</strong><br />

which reactions are conducted on a series of sequentially-l<strong>in</strong>ked columns packed with<br />

solid-phase based catalysts and reagents. Our goal is ultimately to produce a<br />

“synthesis mach<strong>in</strong>e” <strong>in</strong> which a complex series of transformations is conducted on the<br />

column assemblies.<br />

Project III. Catalytic, Asymmetric Halogenation.<br />

The third project we have underway concerns the development of catalytic,<br />

asymmetric halogenation reactions. Asymmetric halogenation represents a<br />

challeng<strong>in</strong>g new frontier <strong>in</strong> asymmetric synthesis.<br />

Representative Publications:<br />

“Catalytic, Enantioselective Alkylation of Im<strong>in</strong>o Esters: The Synthesis of Nonnatural Am<strong>in</strong>o Acid Derivatives” J. Am. Chem.<br />

Soc. 2002, 124, 67-77.<br />

“Asymmetric Catalysis on Sequentially-L<strong>in</strong>ked Columns” J. Am. Chem Soc. 2001, 123, 10853-10859.<br />

“Reactive Ketenes through a Carbonate/Am<strong>in</strong>e Shuttle Deprotonation Strategy: Catalytic, Enantioselective<br />

Halides” Org. Lett. 2001, 3, 2049-2051.<br />

“Catalytic, Asymmetric Halogenation” J. Am. Chem. Soc. 2001, 123, 1531-1532.<br />

“Catalytic, Asymmetric Synthesis of Lactams” J. Am. Chem. Soc. 2000, 122, 7831-7832.<br />

Brom<strong>in</strong>ation of Acid<br />

Ph.D. Cornell <strong>University</strong><br />

Postdoctoral, Universität<br />

Heidelberg<br />

NIH Postdoctoral Fellow,<br />

Harvard <strong>University</strong><br />

Alfred P. Sloan Research<br />

Fellowship<br />

Camille Dreyfus Teacher-<br />

Scholar Award<br />

DuPont ATE Award<br />

NSF CAREER Award<br />

Eli Lilly Young Investigator<br />

Grantee<br />

NIH First Award<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

15


Gerald J. Meyer<br />

Inorganic Materials <strong>Chemistry</strong><br />

Environmental <strong>Chemistry</strong><br />

meyer@jhu.edu<br />

(a)<br />

Ph.D., <strong>University</strong> of<br />

Wiscons<strong>in</strong> at Madison<br />

Postdoctoral, <strong>University</strong><br />

of North Carol<strong>in</strong>a at<br />

Chapel Hill<br />

The Meyer group research focuses on <strong>in</strong>organic chemistry with a particular<br />

emphasis on the <strong>in</strong>terface between molecules and solid-state materials. A<br />

theme of our research has been to design materials at the molecular level that<br />

have desired optical, electrical, environmental, biological, magnetic, and/or<br />

catalytic functions. Summarized below are three key research areas:<br />

We prepare solar cells, based on<br />

Nanocrystall<strong>in</strong>e Semiconductor Interfaces.<br />

nanocrystall<strong>in</strong>e semiconductors sensitized to light with <strong>in</strong>organic coord<strong>in</strong>ation<br />

compounds that efficiently convert sunlight <strong>in</strong>to electrical power. These materials<br />

also allow <strong>in</strong>terfacial electron transfer processes to be quantified <strong>in</strong> unprecedented<br />

molecular detail. Shown below, is a schematic representation of an <strong>in</strong>terface designed<br />

for fundamental photo-<strong>in</strong>duced electron transfer studies. Other ongo<strong>in</strong>g research<br />

projects with these <strong>in</strong>terfaces <strong>in</strong>clude the study of bimetallic compounds, charge<br />

transport, energy transfer, and catalysis.<br />

Magnetic Nanowire Interfaces. Nanowires with segments of different magnetic and<br />

non-magnetic materials are prepared <strong>in</strong> our labs. An example is shown below where<br />

a magnetic nickel segment has been functionalized with a fluorescent dye while a<br />

non-magnetic gold segment has not. In the visible image (a) the two wire segments<br />

appear similar while the fluorescent image (b) clearly reveals the nickel segment. The<br />

magnetic properties of the nanowire materials are under active study as part of the<br />

Hopk<strong>in</strong>s’ NSF-funded MRSEC and can be used for applications <strong>in</strong> separations, sens<strong>in</strong>g,<br />

magnetic record<strong>in</strong>g and biotechnology.<br />

Environmental Interfaces. We prepare materials that convert sunlight <strong>in</strong>to electrical<br />

power and materials that can decontam<strong>in</strong>ate water of halocarbon pollutants. This<br />

latter project is the subject of a NSF-funded ‘CRAEMS’ program that <strong>in</strong>volves<br />

<strong>in</strong>terdiscipl<strong>in</strong>ary research with five Hopk<strong>in</strong>s groups. Our approach has been to study<br />

mechanistic aspects of organohalide reaction with natural and synthetic iron<br />

porphyr<strong>in</strong>s. These studies provide <strong>in</strong>sights <strong>in</strong>to how liv<strong>in</strong>g organisms can both<br />

dehalogenate organic halocarbons and die from exposure to them.<br />

Recent Publications:<br />

Pseudo-halogens for Dye-Sensitized TiO 2 Photoelectrochemical Cells. Oskam, G.; Bergeron, B.V; Meyer, G.J.; Searson,<br />

P.C. J. Phys. Chem. B 2001, 105, 6867.<br />

Long Distance Electron Transfer Across Molecular-Nanocrystall<strong>in</strong>e Semiconductor Interfaces. Galopp<strong>in</strong>i, E.; Guo, W.;<br />

Qu, P.; Meyer, G.J. J. Am. Chem. Soc. 2001, 123, 4342.<br />

Magnetic Alignment of Fluorescent Nanowires. Tanase, M.; Bauer, L.A.; Hultgren, A.; Silevitch, D.M.; Sun, L.; Reich, D.H.;<br />

Searson, P.C.; Meyer, G.J. NanoLett. 2001, 1, 155.<br />

Proton Controlled Electron Injection from Molecular Excited States to the Empty States <strong>in</strong> Nanocrystall<strong>in</strong>e TiO 2 .<br />

Qu, P.; Meyer, G.J. Langmuir 2001, 17, 6720.<br />

(b)<br />

Crowded Cu(I) Complexes Involv<strong>in</strong>g Benzohqu<strong>in</strong>ol<strong>in</strong>e: π-Stack<strong>in</strong>g Effects and Long Lived Excited States. Riesgo,<br />

E.C.; Hu, Y.-Z.; Bouvier, F.; Thummel, R.P.; Scaltrito, D.V.; Meyer, G.J. Inorg. Chem. 2001, 40, 3413-3422.<br />

16<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


Douglas Poland<br />

Theoretical <strong>Chemistry</strong><br />

Statistical Mechanics, K<strong>in</strong>etics of Cooperative Processes,<br />

Distribution Functions <strong>in</strong> Prote<strong>in</strong>s and Nucleic Acids<br />

poland@jhu.edu<br />

Early <strong>in</strong> my career I was <strong>in</strong>terested <strong>in</strong> the application of the methods of<br />

equilibrium statistical mechanics to the problem of conformational transitions<br />

(helix-coil) transitions <strong>in</strong> prote<strong>in</strong>s and nucleic acids. This work is reviewed <strong>in</strong><br />

two books: (with H.A. Scheraga) Theory of Helix-Coil Transitions <strong>in</strong> Biopolymers<br />

(Academic Press, New York, 1970) and Cooperative Equilibria <strong>in</strong> Physical<br />

Biochemistry (Oxford <strong>University</strong> Press, London, 1978). My <strong>in</strong>terests then turned to<br />

simple lattice-gas models for phase transitions. This work <strong>in</strong>volved extensive<br />

calculation of exact series expansions for thermodynamic functions for various latticegas<br />

models and the analysis of the series (search for phase-transition s<strong>in</strong>gularities). I<br />

also became <strong>in</strong>terested <strong>in</strong> the use of statistical mechanics to treat the k<strong>in</strong>etics of<br />

cooperative phenomena such as cooperative adsorption and enzyme reaction<br />

networks. The general problem <strong>in</strong> this area of study is to understand the nonl<strong>in</strong>ear<br />

equations that arise <strong>in</strong> such systems. When a system is far from equilibrium<br />

<strong>in</strong>stabilities can arise, often giv<strong>in</strong>g rise to limit cycles (oscillations <strong>in</strong> the density) or<br />

chaotic behavior.<br />

Recently my <strong>in</strong>terests have returned to biological macromolecules. In<br />

particular I have been explor<strong>in</strong>g ways to determ<strong>in</strong>e distributions functions for various<br />

molecular properties. For example, given the temperature dependence of the heat<br />

capacity one can convert this data <strong>in</strong>to a f<strong>in</strong>ite set of moments of the distribution<br />

funtion for molecular enthalpies (analog of the Maxwell-Boltzmann distribution of<br />

k<strong>in</strong>etic energies). Given a set of moments one can then use the maximum-entropy<br />

method to construct an approximate distribution function, the quality of the<br />

approximation <strong>in</strong>creas<strong>in</strong>g with the number of moments used. For many prote<strong>in</strong>s this<br />

distribution function is bimodal, <strong>in</strong>dicat<strong>in</strong>g the presence of two major species, the<br />

native and denatured form of the prote<strong>in</strong>. This same technique can be used to<br />

determ<strong>in</strong>e distribution functions for the number of ligands bound to prote<strong>in</strong>s and<br />

nucleic acid us<strong>in</strong>g data from an appropriate b<strong>in</strong>d<strong>in</strong>g isotherm.<br />

Ph.D., Cornell <strong>University</strong><br />

Postdoctoral, Cornell<br />

<strong>University</strong><br />

Selected Publications Include:<br />

Poland, D. "Maximum-Entropy Calculation of Energy Distributions", Journal of Chemical Physics, 2000, 112, 4774-4784.<br />

Poland, D. "Enthalpy Distributions <strong>in</strong> Prote<strong>in</strong>s", Biopolymers, 2001, 58, 89-105.<br />

Poland, D. "Prote<strong>in</strong>-B<strong>in</strong>d<strong>in</strong>g Polynomials", Journal of Prote<strong>in</strong> <strong>Chemistry</strong>, 2001, 20, 91-97.<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

17


Gary H. Posner<br />

Organic <strong>Chemistry</strong>; Medic<strong>in</strong>al <strong>Chemistry</strong><br />

ghp@jhu.edu<br />

Professor Posner’s research deals generally with development of new synthetic<br />

methods and asymmetric synthesis of natural products, with special emphasis<br />

on design and synthesis of new compounds hav<strong>in</strong>g beneficial effects on the<br />

quality of human life (i.e., new medic<strong>in</strong>al agents). Recently, the Posner<br />

research team has prepared a promis<strong>in</strong>g analog of vitam<strong>in</strong> D 3 for treatment of<br />

the sk<strong>in</strong> disease psoriasis, a promis<strong>in</strong>g analog of the Ch<strong>in</strong>ese medic<strong>in</strong>e q<strong>in</strong>ghaosu for<br />

treatment of malaria, and some new isothiocyanates as promis<strong>in</strong>g lead compounds<br />

for prevention of cancer.<br />

Professor Posner is well known for his <strong>in</strong>volvement with organocopper<br />

chemistry as a researcher and writer. His orig<strong>in</strong>al research publications and his two<br />

review articles and one book on organocopper chemistry have helped to make this<br />

area one of the fastest develop<strong>in</strong>g ones <strong>in</strong> modern synthetic organometallic chemistry.<br />

Recent publications <strong>in</strong>clude:<br />

Posner, G.H.; Northrop, J.; Paik, I.-K.; Borstnik, K.; Dolan, P.; Kensler, T.W.; Xie, S.; Shapiro, T. A., “New Chemical and Biological<br />

Aspects of Artemis<strong>in</strong><strong>in</strong>-Derived Trioxane Dimers,” Bioorg. Med. Chem. 2002, 10, 227-232.<br />

Ph.D., Harvard <strong>University</strong><br />

Postdoctoral, <strong>University</strong><br />

of California, Berkeley<br />

<strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

Dist<strong>in</strong>guished Teach<strong>in</strong>g<br />

Award<br />

Executive Editor,<br />

Tetrahedron Reports<br />

Gardezi, S.A.; Nguyen, C.; Malloy, P.J.; Feldman, D.; Posner, G. H.; Peleg, S., “A Rationale for Treatment of Hereditary Vitam<strong>in</strong> D<br />

Resistant Rickets with Analogs of 1 -25-Dihydroxyvitam<strong>in</strong> D 3 ,” J. Biol. Chem. 2001, 276, 29148-29156.<br />

Posner, G. H.; Jeon, H.B.; Parker, M.H.; Krasav<strong>in</strong>, M.; Paik, I.-K.; Shapiro, T. A., “Antimalarial Simplified 3-Aryltrioxanes: Synthesis<br />

and Precl<strong>in</strong>ical Efficacy/Toxicity Test<strong>in</strong>g <strong>in</strong> Rodents,” J. Med. Chem., 2001, 44, 3054-3058.<br />

Posner, G.H.; Crawford, K.R.; Peleg, S.; Welsh, J.E.; Romu, S.; Gewirtz, D.A.; Gupta, M.S.; Dolan, P.; Kensler, T.W., “A Non-Calcemic<br />

Sulfone Version of The Vitam<strong>in</strong> D3 Analog Seocalcitol (EB 1089): Chemical Synthesis, Biological Evaluation, and Potency<br />

Enhancement of the Anticancer Drug Adriamyc<strong>in</strong>,” Bioorg. Med. Chem., 2001, 9, 2365-2371.<br />

Somjen, D.; Waisman, A.; Lee, J.K.; Posner, G.H.; Kaye, A.M., “A Noncalcemic Analog of 1,25-Dihydroxyvitam<strong>in</strong> D 3 (JKF)<br />

Upregulates The Induction of Creat<strong>in</strong>e K<strong>in</strong>ase B by 17-Beta-estradiol <strong>in</strong> Osteoblast-like ROS 17/2.8 Cells and <strong>in</strong> Rat Diaphysis,” J.<br />

Steroid Biochem. Mol. Biol., 2001, 77, 205-212.<br />

Szpilman, A.M.; Korsh<strong>in</strong>, E.E.; Hoos, R.; Posner, G.H.; Bachi, M.D., “Iron(II)-Induced Cleavage of Antimalarial Beta-Sulfonyl<br />

Endoperoxides. Evidence for the Generation of Potentially Cytotoxic Carbocations,” J. Org. Chem., 2001, 66, 6531-6540.<br />

O’Neill, P.M.; Miller, A.; Bishop, L.P.D.; H<strong>in</strong>dley, S.; Maggs, J.L.; Ward, S.A.; Roberts, S.M.; Sche<strong>in</strong>man, F.; Hoos, R.; Posner, G.H.;<br />

Park, B.K., “Synthesis, Antimalarial Activity, Biomimetic Iron(II) <strong>Chemistry</strong>, and the <strong>in</strong> vitro Metabolism of Novel, Potent C-10-<br />

Phenoxy Derivatives of Dihydroartemis<strong>in</strong><strong>in</strong>,” J. Med. Chem., 2001, 44, 58-68.<br />

Guyton, K.Z.; Kensler, T.W.; Posner, G.H., “Cancer Chemoprotection Us<strong>in</strong>g Natural Vitam<strong>in</strong> D 3 and Synthetic Analogs,” Annu. Rev.<br />

Pharm. Toxicol. 2001, 41, 421-442.<br />

White, M.C.; Burke, M.; Peleg, S.; Bren, H.; Posner, G.H., “Conformationally Restricted Hybrid Analogs of the Hormone 1,25-<br />

Dihydroxyvitam<strong>in</strong> D 3 : Design, Synthesis, and Biological Evaluation,” Bioorg. Med. Chem., 2001, 9, 1691-1699.<br />

Posner, G.H.; Halford, B.; Dolan, P.; Kensler, T.W.; White, J.; Jones, G., “Conceptually New Low-Calcemic Oxime Analogs of the<br />

Hormone 1-alpha, 25-Dihydroxyvitam<strong>in</strong> D3: Synthesis and Biological Test<strong>in</strong>g,” J. Med. Chem., 2002, 45, 000.<br />

Korsh<strong>in</strong>, E.K.; Hoos, R.; Szpilman, A.M., Konstant<strong>in</strong>ovski, L.; Posner, G.H.; Bachi, M.D., “An Efficient Synthesis of Bridged-Bicyclic<br />

Peroxides Structurally Related to Antimalarial Y<strong>in</strong>gzhaosu A based on Homolytic Co-Oxidation of Thiols and Monoterpenes,”<br />

Tetrahedon, 2002, 58, 2449-2469.<br />

18<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


Harris J. Silverstone<br />

Theoretical <strong>Chemistry</strong><br />

hjsilverstone@jhu.edu<br />

My ma<strong>in</strong> research <strong>in</strong>terests are quantum problems that cannot be solved <strong>in</strong><br />

simple closed form, but that can be solved by <strong>in</strong>f<strong>in</strong>ite series expansions,<br />

especially divergent asymptotic expansions. Atoms <strong>in</strong> external electric and<br />

magnetic fields are prime examples. When the external field is regarded as<br />

a perturbation, the result<strong>in</strong>g series are asymptotically divergent.<br />

Divergent series are <strong>in</strong>terest<strong>in</strong>g when they are “summable.” That is, when<br />

there is a procedure for f<strong>in</strong>d<strong>in</strong>g directly from the series the mathematical function that<br />

the series represents. There is often a related, sometimes physical, quantity that is<br />

“exponentially small” and that governs the rate of divergence of the series. In the case<br />

of the electric field, the exponentially small quantity is the ionization rate. A new<br />

development is a higher-order summation technique called hyperasymptotics that<br />

uses the exponentially small subseries to sum the divergent series. The exponentially<br />

small subseries are <strong>in</strong>timately connected with the “connection formula” problem <strong>in</strong><br />

semiclassical methods <strong>in</strong> quantum mechanics, such as the JWKB method.<br />

The hyperasymptotics research is <strong>in</strong> collaboration with Professor Gabriel<br />

Álvarez of the Departamento de Física Téorica II, Universidad Complutense,<br />

Madrid, Spa<strong>in</strong>, and with Professor Christopher J. Howls of the Faculty of<br />

Mathematical Studies, <strong>University</strong> of Southampton, UK.<br />

Research now complete provided a detailed feature-by-feature analysis of the<br />

photoionization cross section of hydrogen <strong>in</strong> an electric field <strong>in</strong> terms of expansions<br />

over resonances. Extension of the expansion to <strong>in</strong>f<strong>in</strong>ite fields led to a complete<br />

understand<strong>in</strong>g of the “Bender-Wu” branch cuts of the anharmonic oscillator, a<br />

somewhat serendipitous result. Earlier work used perturbation expansions to<br />

elucidate the transition between classical, semiclassical and quantum mechanics. Still<br />

earlier work concerned electron correlation (how electrons avoid each other) <strong>in</strong> atoms<br />

and molecules, the evaluation of molecular <strong>in</strong>tegrals us<strong>in</strong>g expansions generated from<br />

Fourier-transforms, and the use of piecewise-polynomial expansions for electronic<br />

wave functions.<br />

A separate research <strong>in</strong>terest, <strong>in</strong> collaboration with Professor Betty Jean<br />

Gaffney of the Department of Biological Science, Florida State <strong>University</strong>, has been the<br />

simulation of electron magnetic resonance spectra for high-sp<strong>in</strong> iron <strong>in</strong> heme prote<strong>in</strong>s<br />

and <strong>in</strong> enzymes.<br />

Ph.D., California Institute<br />

of Technology<br />

NSF Postdoctoral Fellow,<br />

Yale <strong>University</strong><br />

Alfred P. Sloan Research<br />

Fellowship<br />

Selected publications <strong>in</strong>clude:<br />

Connection formula, hyperasymptotics, and Schröd<strong>in</strong>ger eigenvalues: dispersive hyperasymptotics and the anharmonic oscillator;<br />

Gabriel Álvarez, Christopher J. Howls, and Harris J. Silverstone <strong>in</strong> Toward the Exact WKB Analysis of Differential Equations, L<strong>in</strong>ear or<br />

Non-L<strong>in</strong>ear, edited by Christopher J. Howls, Takahiro Kawai, and Yoshitsugu Takei (Kyoto <strong>University</strong> Press, Kyoto, 2000).<br />

Large-field behavior of the LoSurdo-Stark resonances <strong>in</strong> atomic hydrogen; Gabriel Álvarez and Harris J. Silverstone;<br />

Phys. Rev. A 50, 4679-4699 (1994).<br />

Simulation methods for loop<strong>in</strong>g transitions; Betty J. Gaffney and Harris J. Silverstone; J. Magn. Reson. 134, 57-66 (1998).<br />

Anharmonic oscillator discont<strong>in</strong>uity formulae up to second-exponentially-small order; Gabriel Álvarez, Christopher J. Howls, and<br />

Harris J. Silverstone; J. Phys. A 35, 4003-4016 (2002).<br />

Dispersive hyperasymptotics and the anharmonic oscillator; Gabriel Álvarez, Christopher J. Howls, and Harris J. Silverstone;<br />

J. Phys. A 35, 4017-4042 (2002).<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

19


Joel R. Tolman<br />

Biophysical <strong>Chemistry</strong><br />

jtolman@jhu.edu<br />

Ph.D., Yale <strong>University</strong><br />

Human Frontier<br />

Postdoctoral Fellow,<br />

<strong>University</strong> of Toronto<br />

Postdoctoral, École<br />

Polytechnique Fédérale de<br />

Lausanne<br />

With<strong>in</strong> the past two decades, Nuclear Magnetic Resonance spectroscopy<br />

(NMR) has become a powerful technique for the study of<br />

macromolecular structure and dynamics <strong>in</strong> the solution state. Research<br />

<strong>in</strong> my lab will be concerned with both the development and application<br />

of novel NMR techniques for study<strong>in</strong>g the complex <strong>in</strong>teractions that<br />

underlie biological function. Of particular <strong>in</strong>terest are studies of molecular dynamics,<br />

the nature of <strong>in</strong>termolecular recognition and the quaternary organization of multidoma<strong>in</strong><br />

prote<strong>in</strong> systems.<br />

The full repertoire of multidimensional NMR methodology will be employed<br />

to study these problems, <strong>in</strong>clud<strong>in</strong>g sp<strong>in</strong> relaxation, scalar coupl<strong>in</strong>g, NOE, and<br />

hydrogen exchange experiments. However, the primary approach will be centered<br />

around recently developed techniques for the measurement of Residual Dipolar<br />

Coupl<strong>in</strong>gs (RDCs) <strong>in</strong> macromolecules. These RDCs, which are normally averaged to<br />

zero <strong>in</strong> solution, are made observable by <strong>in</strong>troduc<strong>in</strong>g a very weak degree of alignment<br />

of the biomolecule relative to the magnetic field. This alignment is typically achieved<br />

by dissolv<strong>in</strong>g the prote<strong>in</strong> or nucleic acid along with a suitable co-solute, such as<br />

bacteriophage particles. The result<strong>in</strong>g RDCs are relatively easily measured and<br />

represent an abundant source of highly precise <strong>in</strong>formation on the relative<br />

orientations of different <strong>in</strong>ternuclear ‘bonds’ with<strong>in</strong> the molecule. Intrigu<strong>in</strong>gly, RDCs<br />

also exhibit sensitivity to molecular motions on the nsec-sec timescales, dur<strong>in</strong>g which<br />

many functionally important motions occur. These motional timescales have<br />

traditionally been very difficult to access experimentally, and thus a major objective<br />

will be to develop RDC-based techniques to enable the study of these motions.<br />

One of the applications of these techniques will be to <strong>in</strong>vestigate the<br />

quaternary organization of tetrameric ubiquit<strong>in</strong>. Tetramers of the prote<strong>in</strong> ubiquit<strong>in</strong><br />

can assume a multi-faceted role <strong>in</strong> cellular signal-transduction mechanisms, which<br />

depends on how they are l<strong>in</strong>ked together. A major goal will be to ga<strong>in</strong> <strong>in</strong>sights <strong>in</strong>to<br />

the nature of this important and versatile signal through studies of its solution state<br />

conformations. In addition, efforts are ongo<strong>in</strong>g to develop methodology for the<br />

simultaneous determ<strong>in</strong>ation of both the 3-dimensional structure and a detailed<br />

description of the dynamics of a prote<strong>in</strong>. A closely related objective is to develop the<br />

capability of us<strong>in</strong>g NMR to rapidly determ<strong>in</strong>e the backbone fold of a prote<strong>in</strong> to<br />

moderate resolution, which would represent an important contribution to current<br />

structural genomics <strong>in</strong>itiatives.<br />

Selected publications <strong>in</strong>clude:<br />

Tolman, J.R., “Dipolar Coupl<strong>in</strong>gs as a Probe of Molecular Dynamics and Structure <strong>in</strong> Solution,”<br />

Curr. Op<strong>in</strong>. Struct. Biol. 2001, 11, 532-539.<br />

Al-Hashimi, H.M.; Tolman, J.R.; Majumdar, A.; Gor<strong>in</strong>, A.; and Patel, D.J., “Determ<strong>in</strong><strong>in</strong>g<br />

Stoichiometry <strong>in</strong> Homomultimeric Nucleic Acid Complexes Us<strong>in</strong>g Magnetic Field Induced Residual<br />

Dipolar Coupl<strong>in</strong>gs,” J. Am. Chem. Soc. 2001, 123, 5806-5807.<br />

Tolman, J.R.; Al-Hashimi, H.M.; Kay, L.E.; and Prestegard, J.H., “Structural and Dynamic Analysis<br />

of Residual Dipolar Coupl<strong>in</strong>g Data for Prote<strong>in</strong>s,” J. Am. Chem. Soc. 2001, 123, 1416-1424.<br />

Tolman, J.R.; Flanagan, J.M.; Kennedy, M.A.; and Prestegard, J.H., “NMR Evidence for Slow<br />

Collective Motions <strong>in</strong> Cyanometmyoglob<strong>in</strong>,” Nature Struct. Biol. 1997, 4, 292-297.<br />

20 <strong>Graduate</strong> <strong>Study</strong> <strong>in</strong> <strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


Organic <strong>Chemistry</strong>; Photochemistry and Photobiology;<br />

Characterization of Reactive Intermediates<br />

jtoscano@jhu.edu<br />

John P. Toscano<br />

Most photochemical reactions take place through very short-lived<br />

<strong>in</strong>termediates such as s<strong>in</strong>glet or triplet excited states, radicals, carbenes,<br />

nitrenes, and nitrenium ions. A thorough understand<strong>in</strong>g of these<br />

<strong>in</strong>termediates is not only of basic scientific concern, but also has direct<br />

relevance to many critical issues <strong>in</strong> photochemistry and photobiology. The<br />

Toscano group’s ma<strong>in</strong> research <strong>in</strong>terests <strong>in</strong>volve the application of time-resolved<br />

spectroscopic techniques to the study of these <strong>in</strong>termediates with particular emphasis<br />

on the use of newly developed methods <strong>in</strong> time-resolved <strong>in</strong>frared spectroscopy.<br />

Nitric oxide (NO), a diatomic radical known previously as a noxious<br />

environmental pollutant, is now known to be <strong>in</strong>volved <strong>in</strong> a wide range of important<br />

bioregulatory processes <strong>in</strong>clud<strong>in</strong>g neurotransmission, blood clott<strong>in</strong>g, and blood<br />

pressure control. In addition, macrophages have been shown to kill cancerous tumor<br />

cells and <strong>in</strong>tracellular parasites by releas<strong>in</strong>g large amounts of NO. Deficiencies <strong>in</strong><br />

these processes caused by a poor endogenous supply of NO are often treatable with<br />

NO-releas<strong>in</strong>g drugs. Diazeniumdiolates (1) are an <strong>in</strong>terest<strong>in</strong>g class of such drugs<br />

presently under development. Recent efforts to make diazeniumdiolates more<br />

effective pharmaceuticals have concentrated on us<strong>in</strong>g derivatives of such compounds<br />

to deliver NO specifically to a targeted site. Given the large number of biological<br />

phenomena now known to be mediated by NO, such target<strong>in</strong>g will be critical to the<br />

success of most medical applications.<br />

We have begun to develop photochemical precursors to diazeniumdiolates<br />

that can be used as effective and potentially selective NO-releas<strong>in</strong>g agents. S<strong>in</strong>ce<br />

<strong>in</strong>itial experiments <strong>in</strong> other laboratories with classical photoprotect<strong>in</strong>g groups (P)<br />

gave unexpected and disappo<strong>in</strong>t<strong>in</strong>g results, we are presently clarify<strong>in</strong>g reaction<br />

pathways so that more efficient phototriggered NO-releas<strong>in</strong>g drugs can be rationally<br />

designed. In addition, if diazeniumdiolates are to enjoy rout<strong>in</strong>e medical use, their<br />

basic photochemistry must be understood so that phototoxicity issues may be<br />

anticipated and avoided.<br />

Recent Publications Include:<br />

Toscano, J. P. “Structure and Reactivity of Organic Intermediates as Revealed by Time-Resolved IR Spectroscopy” Adv. Photochem.<br />

2001, 26, 41-91.<br />

Sr<strong>in</strong>ivasan, A.; Kebede, N.; Saavedra, J. E.; Nikolaitchik, A. V.; Brady, D. A.; Yourd, E.; Davies, K. M.; Keefer, L. K.; Toscano, J. P.<br />

“<strong>Chemistry</strong> of the Diazeniumdiolates. 3. Photoreactivity” J. Am. Chem. Soc. 2001, 123, 5465-5472.<br />

Srivastava, S.; Ruane, P. H.; Toscano, J. P.; Sullivan, M. B.; Cramer, C. J.; Chiapper<strong>in</strong>o, D.; Reed, E. C.; Falvey, D. E. “Structures of<br />

Reactive Nitrenium Ions: Time-Resolved Infrared Laser Flash Photolysis and Computational Studies of Substituted N-Methyl-N-aryl-<br />

Nitrenium Ions” J. Am. Chem. Soc. 2000, 122, 8271-8278.<br />

Wang, Y.; Toscano, J. P. “Time-resolved IR Studies of 4-Diazo-3-Isochromanone: Direct K<strong>in</strong>etic Evidence for a Non-Carbene Route to<br />

Ketene” J. Am. Chem. Soc. 2000, 122, 4512-4513.<br />

Ph.D., Yale <strong>University</strong><br />

NIH Postdoctoral Fellow,<br />

Ohio State <strong>University</strong><br />

Camille and Henry Dreyfus<br />

New Faculty Award<br />

NSF CAREER Award<br />

Camille Dreyfus Teacher-<br />

Scholar Award<br />

Alfred P. Sloan Research<br />

Fellowship<br />

“Controlled Photochemical Release of Nitric Oxide from O 2 -Benzyl Substituted Diazeniumdiolates” Ruane, P.H.; Bushan, K.M.;<br />

Pavlos, C.M.; D’Sa, R.A.; Toscano, J. P. J. Am. Chem. Soc. 2002, <strong>in</strong> press.<br />

“Solvent Dependence of the 2-Napthyl (carbomethoxy)carbene S<strong>in</strong>glet-Triplet Energy Gap” Wang, Y.; Hadad, C.M.; Toscano, J. P.<br />

J. Am. Chem. Soc. 2002, 124, 1761-1767.<br />

O<br />

R2N N<br />

+ h<br />

N<br />

O<br />

P<br />

O<br />

R2N N<br />

+<br />

N<br />

O<br />

+<br />

P<br />

H 2 O<br />

pH 7.4<br />

R 2 NH + 2 NO + OH P<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

21


Craig A. Townsend<br />

Bioorganic <strong>Chemistry</strong><br />

townsend@jhunix.hcf.jhu.edu<br />

Research programs <strong>in</strong> Dr. Townsend’s group are broadly <strong>in</strong> the area of<br />

bioorganic chemistry with specific <strong>in</strong>terests <strong>in</strong> natural product biosynthesis,<br />

the enzymology and molecular biology of secondary metabolism and<br />

molecular medic<strong>in</strong>e. Underly<strong>in</strong>g these studies are <strong>in</strong>terests <strong>in</strong> reaction<br />

mechanism and synthesis, notably biomimetic synthesis, mechanistic<br />

enzymology, prote<strong>in</strong> structure and prote<strong>in</strong> eng<strong>in</strong>eer<strong>in</strong>g, exploration of the genetic<br />

organization and over-expression of biosynthetic enzymes, and the study of and the<br />

design and synthesis of fatty acid synthase <strong>in</strong>hibitors lead<strong>in</strong>g to practical treatments<br />

<strong>in</strong> cancer, tuberculosis and obesity.<br />

Recent publications <strong>in</strong>clude:<br />

Khaleeli, N.; Li, R.-F.; Townsend, C. A. “Orig<strong>in</strong> of the -Lactam Carbons <strong>in</strong> Clavulanic Acid from an Unusual Thiam<strong>in</strong>e Pyrophosphate-<br />

Mediated Reaction,” J. Amer. Chem. Soc. 1999, 121, 9223-9224. [See ‘Perspectives’ article: Science 2000, 287, 818-819.]<br />

Challis, G. L.; Ravel, J.; Townsend, C. A. “Predictive, Structure-Based Model of Am<strong>in</strong>o Acid Recognition by Non-Ribosomal Peptide<br />

Synthetase Adenylation Doma<strong>in</strong>s,” <strong>Chemistry</strong> & Biology 2000, 7, 211-224.<br />

Ph.D., Yale <strong>University</strong><br />

Postdoctoral,<br />

Eidgenössiche<br />

Teschnische Hochschule<br />

Alfred P. Sloan Research<br />

Fellowship<br />

Camille Dreyfus - Teacher<br />

Scholar Award<br />

Loftus, T. M.; Jaworsky D.; Frehywot, G. L.; Townsend, C. A.; Ronnett, G.; Lane, M. D.; Kuhajda, F. J. “Inhibitors of Fatty Acid<br />

Synthase Induce Weight Loss: A L<strong>in</strong>k Between Fatty Acid Synthesis and Feed<strong>in</strong>g Behavior,” Science 2000, 288, 2379-2381.<br />

Jones, P. B.; Parrish, N. M.; Houston, T. A.; Stapon, A. S.; Bansal, N. P.; Dick, J. D.; Townsend, C. A. “A New Class of Anti-<br />

Tuberculosis Agents,” J. Med. Chem. 2000, 43, 3304-3314.<br />

Li. R.-F.; Stapon, A.; Blanchfield, J. T.; Townsend, C. A. “Three Unusual Reactions Mediate Carbapenem and Carbapenam<br />

Biosynthesis,” J. Amer. Chem. Soc. 2000, 122, 9296-9297.<br />

Miller, M. T.; Bachmann, B. O.; Townsend, C. A.; Rosenzweig, A. C. “Stucture of ß-Lactam Synthetase Reveals How to Synthesize<br />

Antibiotics Instead of Asparag<strong>in</strong>e,” Nature Struct. Biol. 2001, 8, 684-689.<br />

Udwary, D.W.; Casillas, L.K.; Townsend, C.A. “Synthesis of 11-Hydroxyl O-Methylsterigmatocyst<strong>in</strong> and the Role of a Cytochrome P-<br />

450 <strong>in</strong> the F<strong>in</strong>al Step of Aflatox<strong>in</strong> Biosynthesis,” J. Amer. Chem. Soc. 2002, 124, 5294-5303.<br />

Maryland Chemist of the<br />

Year (1992)<br />

ACS Arthur C. Cope<br />

Scholar Award<br />

22<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


David R. Yarkony<br />

Theoretical <strong>Chemistry</strong><br />

yarkony@jhu.edu<br />

Accord<strong>in</strong>g to the Born-Oppenheimer approximation nuclei move on a s<strong>in</strong>gle<br />

potential energy surface created by the faster mov<strong>in</strong>g electrons. This<br />

approximation is at the heart of our description of most chemical processes.<br />

From prote<strong>in</strong> fold<strong>in</strong>g to tribology to catalysis the Born Oppenheimer<br />

approximation rules. So why study nonadiabatic processes, processes <strong>in</strong><br />

which the Born-Oppenheimer approximation breaks down. The answer is simple <strong>in</strong><br />

the absence of nonadiabatic processes life on earth, as we know it would not exist.<br />

Light harvest<strong>in</strong>g, vision and essential upper atmospheric processes depend on<br />

electronically nonadiabatic steps. Of course this has been known for decades. What<br />

is unusual and excit<strong>in</strong>g is that <strong>in</strong> the last 10 years our way of th<strong>in</strong>k<strong>in</strong>g about<br />

electronically nonadiabatic processes has begun to change, and change dramatically.<br />

The chang<strong>in</strong>g face of nonadiabatic chemistry is the consequence of a reth<strong>in</strong>k<strong>in</strong>g of the<br />

role of surface <strong>in</strong>tersections (conical <strong>in</strong>tersections) of states of the same symmetry<br />

these processes. Once little more than a theoretical curiosity today conical<br />

<strong>in</strong>tersections of two states of the same symmetry are now understood to be an<br />

essential part of nonadiabatic processes. This change <strong>in</strong> paradigm can dramatically<br />

change the predicted/expected rate of a nonadiabatic process. My research group has<br />

helped lead this revolution. Over the last decade we have developed the tools for<br />

study<strong>in</strong>g conical <strong>in</strong>tersections that def<strong>in</strong>e the state of the art <strong>in</strong> this area and as a result<br />

have lead the way <strong>in</strong> advanc<strong>in</strong>g the computational description of this s<strong>in</strong>gular<br />

consequence of the separation of nuclear and electronic time scales. More recently we<br />

have attacked the problem of nonadiabatic processes <strong>in</strong>volv<strong>in</strong>g heavy atoms <strong>in</strong> which<br />

the sp<strong>in</strong>-orbit <strong>in</strong>teraction and Kramers’ degeneracy play an essential role. Our work<br />

<strong>in</strong> this area has provided the first ever location of a conical <strong>in</strong>tersection <strong>in</strong> a<br />

polyatomic molecule based on ab <strong>in</strong>itio wave functions with the sp<strong>in</strong>-orbit <strong>in</strong>teraction<br />

<strong>in</strong>cluded <strong>in</strong> the Hamiltonian.<br />

We are currently build<strong>in</strong>g on our expertise <strong>in</strong> the description of the<br />

electronic structure aspects of nonadiabatic processes by develop<strong>in</strong>g fully quantum<br />

mechanical wave packet methods to quantify the role of conical <strong>in</strong>tersections <strong>in</strong><br />

nonadiabatic dynamics.<br />

In summary, nonadiabatic chemistry is an important field with a bright new<br />

future and we expect to cont<strong>in</strong>ue to play a lead<strong>in</strong>g role <strong>in</strong> this area.<br />

Recent publications<br />

Nuclear Dynamics near conical <strong>in</strong>tersections <strong>in</strong> the adiabatic representation: I. The effects of local topography on <strong>in</strong>terstate transition: David<br />

R. Yarkony, J.Chem. Phys., 114, 2601-2613 (2001).<br />

Ph.D., <strong>University</strong> of<br />

California, Berkeley<br />

Postdoctoral,<br />

Massachusetts Institute of<br />

Technology<br />

Fellow, American Physical<br />

Society<br />

Alfred P. Sloan Research<br />

Fellowship<br />

Conical <strong>in</strong>tersections: The New Conventional Wisdom – Feature Article, D. R. Yarkony, J. Phys. Chem. A 105, 6277-6293 (2001).<br />

On the Effects of Sp<strong>in</strong>-Orbit Coupl<strong>in</strong>g on Conical Intersection Seams <strong>in</strong> Molecules with an Odd<br />

Number of Electrons. I: Locat<strong>in</strong>g the Seam; Spiridoula Matsika and David R. Yarkony, J. Chem.<br />

Phys. 115, 2038-2050 (2001).<br />

On the Effects of Sp<strong>in</strong>-Orbit Coupl<strong>in</strong>g on Conical Intersection Seams <strong>in</strong> Molecules with an Odd<br />

Number of Electrons. II: Characteriz<strong>in</strong>g the local topography of the seam; Spiridoula Matsika and<br />

David R. Yarkony, J. Chem. Phys. 115,5066-5075, (2001).<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

23


Instrumentation<br />

The department is well equipped with <strong>in</strong>strumentation to perform<br />

modern chemical research. Rout<strong>in</strong>e <strong>in</strong>strumentation is housed <strong>in</strong><br />

the Instruments Facility <strong>in</strong> Remsen Hall and is ma<strong>in</strong>ta<strong>in</strong>ed by staff<br />

with<strong>in</strong> the department. In addition, there is a large variety of<br />

custom-built equipment <strong>in</strong> <strong>in</strong>dividual research laboratories.<br />

Our nuclear magnetic resonance facilities <strong>in</strong>cludes a 500 MHz<br />

Varian Unity <strong>in</strong>strument with full three-channel, gradients capability, a<br />

Varian 400 MHz spectrometer upgraded to a Unity console, and a 300<br />

MHz Bruker AMX. The lower-field NMRs are used for more rout<strong>in</strong>e synthetic<br />

chemistry applications, while the high-field NMR is primarily dedicated<br />

to multi-dimensional analysis of prote<strong>in</strong>s and nucleic acids. In<br />

addition, the undergraduate <strong>in</strong>structional laboratories house a Varian<br />

Mercury 200 MHz spectrometer that is also available for research use.<br />

In a jo<strong>in</strong>t <strong>in</strong>itiative by the Departments of Biology, Biophysics, and<br />

<strong>Chemistry</strong>, the Krieger School of Arts and Sciences has commissioned the<br />

development of a Nuclear Magnetic Resonance Center for the study of the<br />

structure and dynamics of biological macromolecules. This facility will be<br />

constructed <strong>in</strong> connection with the new chemistry build<strong>in</strong>g, at a site<br />

bridg<strong>in</strong>g the chemistry and biology departments. The first <strong>in</strong>strument to<br />

be housed <strong>in</strong> this facility, a 600 MHz spectrometer, has recently been<br />

ordered.<br />

In addition to the NMR <strong>in</strong>itiative, the department has recently<br />

received fund<strong>in</strong>g to establish a state of the art small molecule x-ray<br />

diffraction facility. This staffed facility, used for detailed molecular level<br />

structural characterization of new organic or <strong>in</strong>organic compounds, will<br />

be available fo graduate student use.<br />

24 <strong>Graduate</strong> <strong>Study</strong> <strong>in</strong> <strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


Instrumentation<br />

The department has significantly upgraded its mass spectrometric<br />

<strong>in</strong>strumentation with the acquisition of the follow<strong>in</strong>g<br />

systems: (1) A Kratos laser desorption time-of-flight (MALDI-TOF) mass<br />

spectrometer with l<strong>in</strong>ear and reflectron modes, (2) A Shimadzu gas<br />

chromatograph mass spectrometer with both electron-impact and electron<br />

ionization, and (3) A Thermoquest/F<strong>in</strong>negan electrospray ionization mass<br />

spectrometer (ESI-MS), fitted with a liquid chromatograph and with the<br />

capability for multiple mass spectral analyses. These <strong>in</strong>struments<br />

compliment our VG 70S high-resolution GC-mass spectrometer, which is<br />

capable of FAB, DCI, EI, and CI spectrometry. The department also<br />

ma<strong>in</strong>ta<strong>in</strong>s a Bruker EMX 10 /2.7 EPR spectrometer (X band and low<br />

temperature)<br />

In addition to computers and workstations dispersed throughout<br />

all the <strong>in</strong>dividual research groups, a dedicated computer lab is housed <strong>in</strong><br />

Remsen Hall, with access available to all students, staff, and faculty.<br />

Many of the faculty research laboratories have purchased or<br />

constructed highly specialized <strong>in</strong>strumentation tailored to their specific<br />

research objectives. These <strong>in</strong>clude the follow<strong>in</strong>g: several molecular beam<br />

apparatus, negative ion photoelectron spectrometers, ultra-high vacuum<br />

surface analysis chambers with Auger electron and X-ray photoelectron<br />

spectrometers, an atomic-force microscope, a time-resolved <strong>in</strong>frared<br />

spectrometer, numerous laser systems (Nd:YAG, excimer, dye, optical<br />

parametric oscillator, argon ion), a phase fluorimeter, a fluorescence<br />

microscope, and nanophase material generators.<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

25


Useful Information<br />

Student Activities<br />

As <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>’s ma<strong>in</strong> campus, the<br />

Homewood Campus provides students with an<br />

environment that successfully balances academics and<br />

extracurricular activities. A strong Student Activities Office<br />

oversees and advises over 160 student groups represent<strong>in</strong>g<br />

students <strong>in</strong>volved <strong>in</strong> cultural, religious, recreation, sports,<br />

government, and special <strong>in</strong>terests. Homewood is home to the JHU<br />

<strong>Graduate</strong> Representative Organization (GRO). This graduate<br />

student group won the 2001 National Association of <strong>Graduate</strong>-<br />

Professional Students (NAGPS) award for Outstand<strong>in</strong>g National<br />

<strong>Graduate</strong> Student Organization.<br />

In addition to the various student organizations, the<br />

campus hosts other notable events, such as symposia featur<strong>in</strong>g<br />

well-known speakers, various cultural and sport<strong>in</strong>g activities, and<br />

the annual <strong>Johns</strong> Hopk<strong>in</strong>s Spr<strong>in</strong>g Fair. This popular attraction is the<br />

largest student run fair <strong>in</strong> the country with 150,000 visitors over the<br />

course of three days.<br />

Two new enhancements to campus life are the new Matt<strong>in</strong> Center for Student<br />

Arts and Activities, and a state-of-the-art Athletic Recreation Center. The Matt<strong>in</strong><br />

Center offers a substantial home for student groups and organizations, while<br />

provid<strong>in</strong>g a direct connection to the area’s cultural arts, such as the Baltimore<br />

Museum of Art, which is located adjacent to the center. The new Athletic Recreation<br />

Center is a 63,000 square foot facility hous<strong>in</strong>g a fully equipped gymnasium for<br />

students, faculty and staff.<br />

After Graduation<br />

Many of our students do postdoctoral work, and have won prestigious postdoctoral<br />

fellowships from the Sloan Foundation, American Cancer Society, NIH, and the<br />

National Research Council. In the last few years they have gone on to Universities<br />

such as Yale, Stanford, MIT, Berkeley, Caltech, the <strong>University</strong> of Chicago, and<br />

Harvard, national laboratories such as the NIH, NIST, the Air Force Hanscom<br />

Laboratory, and Brookhaven, or research laboratories at companies such as DuPont,<br />

Merck, and SmithKl<strong>in</strong>e Beecham. Some go abroad for further study; former students<br />

are currently <strong>in</strong> England, Japan, and Switzerland.<br />

Alumni of the department are scattered across the country and around the<br />

world <strong>in</strong> academic, government, and <strong>in</strong>dustrial positions. In the last few years, our<br />

graduates have taken faculty positions at the <strong>University</strong> of Ill<strong>in</strong>ois, <strong>University</strong> of<br />

California at Riverside, Ohio State <strong>University</strong>, Harvard <strong>University</strong>, Bryn Mawr<br />

College, Hood College, and many other colleges and universities. Recent graduates<br />

are now work<strong>in</strong>g for a number of pharmaceutical and chemical companies (Upjohn,<br />

Pfizer, Hoechst-Roussel, Glaxo, Bristol-Meyers Squibb, Dow, Allied, 3M, Enichem<br />

Americas, Hoechst-Celanese, to name a few). As a regular part of our colloquium<br />

schedule, we <strong>in</strong>vite former students back to describe their work and meet with<br />

graduate students.<br />

Hous<strong>in</strong>g<br />

Near the university there is a wide selection of liv<strong>in</strong>g quarters. Many graduate<br />

students, s<strong>in</strong>gle and married, take advantage of the affordable apartment build<strong>in</strong>gs<br />

adjacent to the Homewood campus. Most of the apartments <strong>in</strong> the immediate<br />

vic<strong>in</strong>ity are with<strong>in</strong> easy walk<strong>in</strong>g distance (< 0.5 miles) of the chemistry build<strong>in</strong>gs.<br />

Additional s<strong>in</strong>gle rooms and apartments are generally available <strong>in</strong> areas readily<br />

accessible by car or bus. The <strong>University</strong> ma<strong>in</strong>ta<strong>in</strong>s a hous<strong>in</strong>g office to help students<br />

f<strong>in</strong>d suitable accommodations (Hous<strong>in</strong>g Office, 3339 North Charles Street, Baltimore,<br />

MD 21218, 410-516-7960). The <strong>Chemistry</strong> department also has an <strong>in</strong>formal system <strong>in</strong><br />

place to aide students <strong>in</strong> f<strong>in</strong>d<strong>in</strong>g suitable hous<strong>in</strong>g.<br />

26 <strong>Graduate</strong> <strong>Study</strong> <strong>in</strong> <strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>


Useful Information<br />

The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

FACULTY<br />

E-MAIL<br />

Zanvyl Krieger School of Arts & Sciences 410-516-8212<br />

<strong>Graduate</strong> Admissions Office - 410-516-8174<br />

Office of F<strong>in</strong>ancial Aid - 410-516-8724<br />

Kit H. Bowen<br />

Paul J. Dagdigian<br />

David E. Draper<br />

kitbowen@jhu.edu<br />

pjdagdigian@jhu.edu<br />

draper@jhu.edu<br />

Office of the Registrar - <strong>Graduate</strong> Information -<br />

410-516-8081<br />

D. Howard Fairbrother howardf@jhu.edu<br />

David P. Goldberg<br />

dpg@jhu.edu<br />

Department of <strong>Chemistry</strong><br />

Telephone - 410-516-7429<br />

Fax - 410-516-8420<br />

E-Mail - chem.grad.adm@jhu.edu<br />

Web Site - http://www.jhu.edu/~chem<br />

Research Professor<br />

JOHN P. DOERING<br />

Experimental Chemical Physics<br />

Emeritus Faculty<br />

DWAINE O. COWAN<br />

Organic and Physical <strong>Chemistry</strong><br />

ALSOPH H. CORWIN<br />

Biological Organic <strong>Chemistry</strong><br />

Marc Greenberg<br />

Tamara L Hendrickson<br />

Kenneth D. Karl<strong>in</strong><br />

Thomas Lectka<br />

Gerald J. Meyer<br />

Douglas Poland<br />

Gary H. Posner<br />

Harris J. Silverstone<br />

Joel R. Tolman<br />

John P. Toscano<br />

Craig A. Townsend<br />

David R. Yarkony<br />

mgreenberg@jhu.edu<br />

hendrick@jhu.edu<br />

karl<strong>in</strong>@jhu.edu<br />

lectka@jhu.edu<br />

meyer@jhu.edu<br />

poland@jhu.edu<br />

ghp@jhu.edu<br />

hjsilverstone@jhu.edu<br />

jtolman@jhu.edu<br />

jtoscano@jhu.edu<br />

townsend@jhu.edu<br />

yarkony@jhu.edu<br />

JOHN W. GRYDER<br />

Inorganic and Physical <strong>Chemistry</strong><br />

WALTER S. KOSKI<br />

Physical <strong>Chemistry</strong><br />

BROWN L. MURR<br />

Organic <strong>Chemistry</strong><br />

ALEX NICKON<br />

Physical-Organic and Stereochemistry<br />

DEAN W. ROBINSON<br />

Physical <strong>Chemistry</strong><br />

Jo<strong>in</strong>t Appo<strong>in</strong>tments<br />

JEREMY BERG<br />

Biophysics, School of Medic<strong>in</strong>e<br />

BLAKE HILL<br />

Biology, Kreiger School of Arts and Sciences<br />

ALBERT MILDVAN<br />

Biological <strong>Chemistry</strong>, School of Medic<strong>in</strong>e<br />

LAWRENCE PRINCIPE<br />

History of Science Medic<strong>in</strong>e and Technology/<strong>Chemistry</strong>,<br />

Kreiger School of Arts and Sciences<br />

MICHAEL YU<br />

Material Science and Eng<strong>in</strong>eer<strong>in</strong>g,<br />

Whit<strong>in</strong>g School of Eng<strong>in</strong>eer<strong>in</strong>g<br />

<strong>Graduate</strong> <strong>Study</strong> <strong>in</strong><br />

<strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong><br />

27


Baltimore Map & Directions to Campus<br />

Directions to Homewood Campus<br />

3400 North Charles Street<br />

Baltimore, Maryland 21218<br />

From I-95 (southbound) or from I-695 (the Baltimore Beltway):<br />

Take the beltway toward Towson to exit 25. Take Charles<br />

Street south for about 7 miles (when Charles Street splits<br />

a block after Loyola College and Cold Spr<strong>in</strong>g Lane, take<br />

the right fork). As you approach the university and cross<br />

<strong>University</strong> Parkway, cont<strong>in</strong>ue southbound but be sure to<br />

jog right onto the service road. After you pass the university<br />

on the right, turn right onto Art Museum Drive. Just<br />

after the Baltimore Museum of Art, bear right at the traffic<br />

island onto Wyman Park Drive. Take an almost immediate<br />

right through the university gates. A visitors' lot<br />

and park<strong>in</strong>g meters will be on the left.<br />

From I-95 (northbound):<br />

Take exit 53 onto I-395 north toward downtown<br />

Baltimore, then take the exit to Mart<strong>in</strong> Luther K<strong>in</strong>g Jr.<br />

Boulevard and follow the directions from Mart<strong>in</strong> Luther<br />

K<strong>in</strong>g Junior Boulevard below.<br />

From Maryland 295 (the Baltimore-Wash<strong>in</strong>gton Parkway):<br />

Enter<strong>in</strong>g Baltimore, the parkway becomes Russell Street.<br />

Stay on Russell Street until (with the new Baltimore<br />

Ravens stadium to your right and Oriole Park at Camden<br />

Yards loom<strong>in</strong>g before you) you reach the right-hand exit<br />

marked Mart<strong>in</strong> Luther K<strong>in</strong>g Jr. Boulevard (look carefully<br />

for this; the signs are small). This exit will put you very<br />

briefly on a service road parallel to Russell Street. Stay to<br />

the left and take the ramp marked Mart<strong>in</strong> Luther K<strong>in</strong>g Jr.<br />

Boulevard. Follow the directions (below) from Mart<strong>in</strong><br />

Luther K<strong>in</strong>g Jr. Boulevard.<br />

From Mart<strong>in</strong> Luther K<strong>in</strong>g Jr. Boulevard:<br />

Take K<strong>in</strong>g Boulevard north until it ends at Howard Street<br />

(rema<strong>in</strong> <strong>in</strong> one of the middle lanes of K<strong>in</strong>g Boulevard to<br />

avoid a premature forced right or left turn). Turn left at<br />

Howard Street and proceed about 2 miles. One block<br />

past 29th Street, turn left at the traffic island (just before<br />

the Baltimore Museum of Art) onto Wyman Park Drive.<br />

Take an almost immediate right through the university<br />

gates. A visitors' lot and park<strong>in</strong>g meters will be on the<br />

left.<br />

From the Jones Falls Expressway (I-83) southbound:<br />

Take the 28th Street exit and go left on 28th Street. Turn<br />

left on North Howard Street. One block past 29th Street,<br />

turn left at the traffic island (just before the Baltimore<br />

Museum of Art) onto Wyman Park Drive. Take an almost<br />

immediate right through the university gates. A visitors'<br />

lot and park<strong>in</strong>g meters will be on the left.<br />

From Baltimore's Penn Station:<br />

From Penn Station, you can catch the Hopk<strong>in</strong>s shuttle<br />

bus which will take you to the Homewood, Peabody, or<br />

medical campuses. There is no charge to take the shuttle.<br />

If you opt to take a taxi, the fee should be quite modest.<br />

The university is very close to the tra<strong>in</strong> station.<br />

28 <strong>Graduate</strong> <strong>Study</strong> <strong>in</strong> <strong>Chemistry</strong> at The <strong>Johns</strong> Hopk<strong>in</strong>s <strong>University</strong>

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