Effect of Sterilisation and Storage on The Composition of Dentine Suhad Al-Nasrawi, Nick Silikas, Alison Qualtrough and Helen Chen Statement of problem: Extracted teeth are used for pre-clinical teaching and in dental materials research. They are considered to pose a biological hazard and a potential cause of cross infection so proper sterilisation and storage are important requirements. Although autoclaving and formalin sterilization/ storage are recommended by the Centres for Disease Control and Prevention, high-pressure steam and formalin and other storages may affect the chemical properties of dental tissues, and researches outcomes. That may influence trend of researcher toward these procedures. Aim: • Investigate the influence of sterilisation and storage on: • Dentine chemical composition. • Dentine response to acid etching. • Dentine fluoride uptake. Objective: Surface elemental analysis of stored /sterilised dentine before and after acid etching using scanning electron microscopy equipped with an energy dispersive spectroscopy (SEM-EDX) under low vacuum mode, without coating at 10KV. Postgraduate Students’ Perceptions of Use of E-Libraries as a Source of Information at King Saud University, Saudi Arabia Faiz Alotaibi Providing an affordable access to various information sources is one of the essential goals in the environment of higher education. One of these valuable and accessible channels is the information provided by e-Libraries. Generally, the university seeks to provide sources of information in various forms to serve scientific and humanitarian disciplines in various faculties of the university. However, these services must cope with the modern information systems and technologies and in order to meet the intended user’s expectations. For the reasons of sustainability on using e-library services, this research aims to investigate the factors and perception of postgraduate students in using the service provided by e-library at King Saud University in Saudi Arabia. The objectives of this research are: a) To examine key factors (i.e. micro and macro) that influence postgraduate students’ acceptance and usage of e- library services as a source of information. b) To determine the postgraduate students’ perceptions of (i.e. perceived usefulness and perceived ease of use) and attitudes towards the e-library services as a source of information at King Saud University in Saudi Arabia. c) To develop a model to define the information literate student with reference to their engagement with and usage of the e-library. d) formulated to discover the context and meaning of the students’ experience as it influences their acceptance and usage of e-library. e) To formulate recommendations to promote the acceptance and effective use of e-libraries by postgraduate students. The source of data for this study will be purposive sample of number of postgraduate (taught and research) students drawn (core subject disciplines with e-learning programs) from King Saud University, in Saudi Arabia. It is estimated that King Saud University has almost 8000 postgraduate students. The study will apply a mixed methodology approach to collect data. The first stage of date collection will involve use of questionnaires focusing on perceived usefulness and ease of use together with a user experience (and information literacy) inventory to explore the experience as well as acceptance of e-library service. The second stage will involve use of semi-structured comprehensive interview formulated to discover the context and meaning of the students’ experience as it influences their acceptance and usage of e-library.
Formulating theophylline as a long acting inhalable nanosized dry powder by freeze-drying double emulsion technique Mohammad Alyami , Lindsay Marshal, James Brown, Dan Kirby, Deborah Lowry The delivery of nanoparticles deep into the lungs continues to be complex and many techniques fail in terms of either efficiency or stability. The poor stability of particles in aqueous medium is an actual barrier for the clinical use of dispersion systems. However, the emergence of freeze-drying, which now has a number of applications especially in pharmaceutical and food industries, has improved the long-term stability storage of numerous products. The method is based on the lyophilisation of double emulsions W/O/W, containing variable concentrations of trehalose sugar as a lyoprotectant in the inner and outer aqueous phase (0, 4, 7, 10%, respectively. Where second solvent W2 was made of various 1, 2, or 4% of poly vinyl alcohol, functions as a stabilizing layer on the surface. The study results showed of a product of good reconstitutibility and relatively high encapsulation efficiency of 15%. The size of lyophilized particles was below 500 nm measured by dynamic light scattering technique. Using PVA was found to be more effective and capable of producing nano-aggregates of size, density, flowability, yield and reconstitutibility in the range ideal for inhaled therapy. Nevertheless, the aerosolization efficiency of nano-aggregates produced by FD is excellent, manifested in the higher emitted dose 51.5 % and 14% fine particle fraction with > 7.2 micron mass median aerodynamic diameter MMAD and 6.96 Geometric standard deviation. Thus, this technique is a reproducible and simple approach to prepare sterilized, submicron unilamellar liposomes with relatively high encapsulation efficiency, excellent long-term storage stability and inhalable particles. The fabrication of surface modified silica nanoparticles for improved cellular and vascular biocompatibility Cai Astley, Debra Whitehead, Yvonne Alexander, Fiona Wilkinson, May Azzawi Advancements in nanoparticle fabrication techniques have resulted in their increased utilisation for biomedical applications, including diagnostic imaging, drug delivery and novel therapeutics. Nanoparticles that are comprised of multiple materials result in a combination of their associated nanoscale properties, providing the opportunity to design multifunctionality. Critically, nanoparticle surface interaction with biological media affects their toxicity. Silica nanoparticles (SiNPs) are widely reported to be biocompatible, however, this has been shown to be surface charge dependant 1 . The hydroxyl groups protruding from the silica surface generate reactive oxygens species (ROS) and these can interfere with cell signalling pathways and affect cell viability and function. Cerium oxide (CeO 2) nanoparticles have been of particular interest due to their antioxidant properties. The free radical scavenging ability of ceria is due to the ratio of trivalent Ce 3+ / tetravalent Ce 4+ ions. Ceria nanoparticles act as a superoxide dismutase (SOD) mimetic, conferring therapeutic potential for the treatment of reactive oxygen species (ROS)-related conditions. Our group has demonstrated that attenuated vasodilator responses induced by SiNP incubation, can be partially restored after coating in ceria 2 . The aim of the present study is to fabricate and characterise SiNPs with various surface coatings in varied biological media and to assess ROS generation using fluorescent assay techniques. We demonstrate that surface modification of 50nm/ 80nm PEG-coated SiNPs with ceria nanoparticles leads to a 2 or 3-fold reduction in ROS species generation, in comparison to PEG-coated or amine-modified SiNPs, respectively. Our findings highlight the importance of surface modification of silica nanoparticles for future clinical applications.