The pharmaceutical biochemistry group: where pharmaceutical chemistry meets biology and drug delivery

Successful drug discovery and development of new therapeutics is a long, expensive multidisciplinary process needing innovation and the integration of smart cutting edge science and technology to overcome the challenges in taking a drug from the bench to the bedside. The research activities of the Pharmaceutical Biochemistry group span the drug discovery and development process, providing an interface that brings together pharmaceutical chemistry, biochemistry, structural biology, computational chemistry and biopharmaceutics. Formulation and drug delivery are brought into play at an earlier stage when facing the perennial challenge of transforming a potent molecule in vitro into a therapeutic agent in vivo. Concomitantly, drug delivery results can be understood at a molecular level. This broad range of interdisciplinary research activities and competences enables us to address key challenges in modern drug discovery and development, provides a powerful collaborative platform for other universities and the pharmaceutical industry and an excellent training platform for pharmacists and pharmaceutical scientists who will later be involved in drug discovery and development.     

Embedded divide-and-conquer algorithm on hierarchical real-space grids: parallel molecular dynamics simulation based on linear-scaling density functional theory

A linear-scaling algorithm has been developed to perform large-scale molecular-dynamics (MD) simulations, in which interatomic forces are computed quantum mechanically in the framework of the density functional theory. A divide-and-conquer algorithm is used to compute the electronic structure, where non-additive contribution to the kinetic energy is included with an embedded cluster scheme. Electronic wave functions are represented on a real-space grid, which is augmented with coarse multigrids to accelerate the convergence of iterative solutions and adaptive fine grids around atoms to accurately calculate ionic pseudopotentials. Spatial decomposition is employed to implement the hierarchical-grid algorithm on massively parallel computers. A converged solution to the electronic-structure problem is obtained for a 32,768-atom amorphous CdSe system on 512 IBM POWER4 processors. The total energy is well conserved during MD simulations of liquid Rb, showing the applicability of this algorithm to first principles MD simulations. The parallel efficiency is 0.985 on 128 Intel Xeon processors for a 65,536-atom CdSe system.     

Laboratory investigation of indirect tensile strength using roofing polyester waste fibers in hot mix asphalt

The vast quantity of waste materials (such as roofing polyester waste fibers) accumulating throughout the world is creating costly disposal problem. The use of these materials was proved to be economical, environmentally sound and effective in increasing the performance properties of the asphalt mixture in recent years. The primary objective of this research was to determine whether homogeneously dispersed roofing waste polyester fibers improve the indirect tensile strength (ITS) and moisture susceptibility properties of asphalt concrete mixtures containing various lengths and percentages of the fiber in various aggregate sources. The experimental design included the use of three aggregate sources, two lengths (0.635 cm (1/4 in.) and 1.270 cm (1/2 in.)) of this fiber, and two fiber contents (0.35% and 0.50% by weight of total mixture). The results of the experiments found that, in general, the addition of the polyester fiber was beneficial in improving the wet tensile strength and tensile strength ratio (TSR) of the modified mixture, increasing the toughness value in both dry and wet conditions, and increasing the void content, the asphalt content, the unit weight, and the Marshall stability.     

Essential Oils from Exotic Eucalyptus: Leaf Oils of Eucalyptus Youmonii,Eucalyptus Macrorhyncha,Eucalyptus Macarthuri,and Eucalyptus Cinera from Northwest Himalays (India)

Analyses of oils obtained by hydrodistillation of foliage of E. youmonii, E. macrorhyncha, and E. macarthuri from India revealed that the three oils are chemically alike, but for the quantitative differences of the main components. The eudesmol (α- and β-) content in E. macrorhyncha and E. macarthuri is rather similar (15.38% and 18.91% respectively), but much higher in E. youmonii (50.04%). The 1,8-cineol content in E. youmonii (30.70%) and E. macrorhyncha (29.83%) are alike while geranyl acetate (23.84%) content in E. macarthuri is highest amongst the three. E. cinerea oil contains cineol (64.65%), α-terpineol (11.56%) and limonene (12.51%) as the major components. On the whole E. macrorhyncha, E. macarthuri and E. cinerea oils are rich in monoterpenoids (71.16%, 71.90% and 94.55%) whereas that of E. youmonii is rich in sesquiterpenoids (53.37%).     

Non-destructive Evaluation and Development of a New Wire Rope Tester Using Parallely Magnetized NdFeB Magnet Segments

A new wire rope tester based on principle of magnetic flux leakage is constructed. Two rings of NdFeB are cut in axial direction into 32 equal arc segments such that each arc segment subtends an angle of 22.5° at the centre. These arc segments are then parallely magnetized in magnetizer. A ferromagnetic cylinderical yoke is constructed by hinging two ferromagnetic half cylinders along one axial edge. A fixture consisting of a wooden square base, wooden mandrel, stepped and slotted Aluminium cylinder and Aluminium fillers is made to assemble the NdFeB magnets in a ring on both the ends of the ferromagnetic yoke. A Hall effect sensor is instrumented inside the yoke in the middle at radial distance of 34 mm from the axis of the yoke. A ferromagnetic wire rope with a defect is inserted in the novel wire rope tester. It has been successfully shown by performing Non-destructive testing that whenever a defect in a wire rope passes below the Hall-effect sensor instrumented in the wire rope tester developed in this work, a signal is generated indicating the defect.     

Preparation of microwave radiation induced graft copolymers and their applications as reinforcing material in phenolic composites

Flax fiber was modified through grafting of binary vinyl monomers mixtures such as methyl methacrylate (MMA)/vinyl acetate (VA), MMA/acrylamide (AAm), and MMA/styrene (Sty) under the influence of microwave radiations. 24.64% grafting was found at 210 W microwave power under optimum reaction conditions. Graft copolymers obtained were characterized with FTIR spectroscopy, scanning electron microscopy, and TGA/DTA techniques. Graft copolymers were found to be moisture retardant with better tensile strength. Phenolic composites using graft copolymers vis‐à‐vis flax as reinforcing material were subjected for the evaluation of different mechanical properties such as wear resistance, tensile strength, compressive strength, modulus of rupture (MOR), modulus of elasticity (MOE), and stress at the limit of proportionality (SP). Composites reinforced with graft copolymers showed better mechanical properties in comparison to composites reinforced with flax. Phenolic composites reinforced with Flax‐g‐poly(MMA/Sty) showed maximum wear resistance followed by reinforcement with flax, Flax‐g‐poly (MMA/AAm), and Flax‐g‐poly(MMA/VA). Composites reinforced with Flax‐g‐poly(MMA/Sty) and flax fibers have been found to show 150 N tensile strength with extension of 3.94 and 2.17 mm, respectively. It has also been found that composites reinforced with Flax‐g‐poly(MMA/Sty) showed maximum compressive strength (1,000 N) with compression of 3.71 mm in comparison to other graft copolymers and flax fibers reinforcement. Reinforcement of phenolic resin with Flax‐g‐poly(MMA/Sty) and flax fibers could improve the MOR and MOE. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

Exploiting hierarchical parallelisms for molecular dynamics simulation on multicore clusters

Many computer vision applications, such as object recognition and content-based image retrieval could function more reliably and effectively if regions of interest were isolated from their background. A new method for regions of interest extraction from color image based on visual saliency in HSV color space is proposed in this paper. Color saliency is calculated by a two-dimensional sigmoid function using the saturation component and brightness component, and we can identify regions with vivid color. Discrete Moment Transform (DMT)-based saliency can determine large areas of interest. A visual saliency map is obtained by combining color saliency and DMT-based saliency, which is denoted the S image. A criterion for the local homogeneity called the E image is calculated in the image. Based on S image and E image, the high visual saliency object seed points set and low visual saliency object seed points set are determined. The seeded regions growing and merging are used to extract regions of interest. Experimental results demonstrate the effectiveness and efficiency of the method for the natural color images.