<p>In this study we report on the effect of the deposition parameters on the morphology and structural properties of CNTs, synthesized by means of the hot-wire chemical vapour deposition technique. SEM, Raman and XRD results show that the optimum deposition conditions for the HWCVD synthesis of aligned MWCNTs, with diameters between 50 and 150 nm and lengths in the micrometer range are: Furnace temperature of 500 &ordm / C, deposition pressure between 150 and 200 Torr, methane/hydrogen dilution of 0.67 and a substrateto- filament distance of 10 cm.</p>

While much is known about the toxicity of polychlorinated biphenyls (PCBs), there are tens of thousands of natural and synthetic chemicals in the environment that can activate the aryl hydrocarbon receptor (AhR) and thus cause toxicity. Since it would be difficult to conduct studies of the toxicity of each and every compound, here is presented a new model based on first-principles taking into account the basic electronic and electron trans- fer characteristics of PCBs, but can be used to predict the toxicities of other AhR-active compounds. The predictive model is based on Density Functional Theory. The model predicts that the energy gap between highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbitals is the overarching indicator of toxicity of PCBs, but not the only factor. The model explains why chlorination of both para-positions is required for maximum toxic potency. To rank potency of PCBs, the dipole moment in relation to the most chemically active chlorine-sites is critical. The theory is consistent with the accepted toxic equivalency factor (TEF) model for these molecules and is also able to improve on ranking toxic potency of PCBs with similar TEFs. This new model also includes a 13th dioxin-like PCB, PCB 74, not considered in the current TEF model developed by the World Health Organization (WHO). The model was applied to HOMO-LUMO gap mea- surements of a set of PCBs and the measurements are consistent with the model. Values of HOMO-LUMO gap can also be used to predict bio-accumulation of PCBs. The model provides an in silico method to screen a wide range of chemicals to predict their ability to act as an AhR agonist.

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The effect of temperature on the crystal structure of deuterated piperidine has been studied using neutron powder diffraction. Differential scanning calorimetry indicates that there are multiple phases accessible via changes in temperature however there is no evidence of this in the neutron powder diffraction study with only one phase observed in the range 2 – 250 K and under various crystallisation conditions. The effect of pressure up to 2.79 GPa has also been determined. The compression of the structure is facilitated through the closing up of voids in the structure and no phase transition is observed. Differential scanning calorimetry has shown N-methyl and N,N-dimethylformamide both exhibit a thermal event prior to melting. Low temperature neutron powder diffraction has shown these transitions are associated with the onset of methyl group rotation. Neutron powder diffraction studies show formamide exhibits remarkable polymorphism at ambient temperature and pressures between 0.1 GPa and 3.6 GPa, forming four new polymorphs. All the structures consist of N-H…O hydrogen bonded chains. The formation of the various polymorphs can be rationalised in terms of the orientation of the molecules within the hydrogen bonded chains and the resultant structures formed by further hydrogen bonds between the chains. This is in stark contrast to the effect of varying conditions of temperature where only one structure exists from 2 K right up to the melting point. The effect of temperature on the crystal structure of pyrazine in the range 8 – 315 K is described. At temperatures below 90 K the structure undergoes a phase transition to a previously uncharacterised phase, designated phase IV, which is closely related to the previously known phase I. The crystal structure of phase III has been determined at 315 K. The crystal structure of pyrazine has been determined at room temperature at pressures between 0.11 GPa and 9.36 GPa. At 0.94 GPa a transition from phase I to phase IV is observed. This is the same phase as observed at low temperatures. Crystal growth at 215 K results in the formation of two different phases of mesitylene; phase II and a new previously unknown phase designated phase IV. The structure of phase IV has been determined and found to be stable in the range 90 – 221 K. On cooling a crystal of deuterated mesitylene in phase II to 90 K a transition to phase III was observed and the resultant crystal structure is closely related to that of phase II.

Vector-borne diseases such as malaria, leishmaniasis, and African trypanosomiasis are a major scourge to humans and animals in some of the most impoverished nations across the globe. Enabling the transmission of these disease-causing pathogens is a highly sophisticated molecular arsenal of surface proteins. My research focuses on biophysical characterization of these proteins with the ultimate goal of deciphering the molecular crosstalk between pathogen and vector. In support of this goal, I have selected the tsetse fly-transmitted parasites of the genus Trypanosoma, the etiological agent of African sleeping sickness, as a model system. Towards elucidating the molecular mechanism of transmission, I have attempted to characterize structurally three novel proteins; TbFam50.360, TbPSSA2, and TcCISSA and get insight into their functions. Before this study, GARP (Glutamic Acid Rich Protein from T. congolense), and VSG (Variant Surface Glycoprotein from T. brucei) were the only proteins to be structurally characterized in the vector stages of the parasite. Our structural analysis revealed that while the N- terminal region of TbFam50.360 adopted a three-helical structure similar to previously characterized trypanosome surface proteins, ectodomains of both TbPSSA2 and TcCISSA adopted a previously uncharacterized bilobed architecture. The structural analysis further identified putative ligand binding regions in TbFam50.360 and TcCISSA. However, in the absence of binding partners, the exact function of these proteins could not be established. Our lab in conjunction with our collaborators is investigating the binding partners of these proteins within the tsetse. The structures of TbFam50.360, TbPSSA2, and TcCISSA can be added to the repertoire of structurally characterized surface proteins expressed by trypanosomes. The information gained from these first structures of trypanosome surface proteins offer insight into their role in the trypanosome life cycle, and may, in the future, contribute to the control of African trypanosomiasis. / Graduate

Invasion of host erythrocytes is an essential stage in the life cycle of Plasmodium parasites and in development of the pathology of malaria. The stages of erythrocyte invasion, including initial contact, apical reorientation, junction formation, and active invagination, are directed by the coordinated release of specialised apical organelles and their parasite protein contents. Among these proteins, and central to invasion by all species, are two parasite protein families, the reticulocyte-binding protein homologue (RH) and the erythrocyte-binding like (EBL) proteins, that mediate host-parasite interactions. RH5 from Plasmodium falciparum (PfRH5) is the only member of either family demonstrated to be necessary for erythrocyte invasion in all tested strains, through its interaction with the erythrocyte surface protein basigin. Indeed, antibodies targeting either PfRH5 or basigin can block parasite invasion with high efficiency in vitro, making PfRH5 an excellent candidate for a vaccine to protect against the most deadly form of malaria. Here I present crystal structures of PfRH5 in complex with basigin and with two distinct inhibitory antibodies. This is the first structure of any RH protein, revealing a novel fold in which two three-helical bundles come together to form a kite-like architecture. The two immunoglobulin domains of basigin and the inhibitory antibodies bind to one tip of the kite. These findings provide the first structural insights into erythrocyte binding by the Plasmodium RH protein family and identify novel inhibitory epitopes to guide the design of a new generation of vaccines against the blood-stage parasite.

In the first part of this work, we present two methods for improving the shape-threat detection performance of x-ray computed tomography. Our work uses a fixed-gantry system employing 25 x-ray sources. We first utilize Kullback-Leibler divergence and Mahalanobis distance to determine the optimal single-source single-exposure measurement. The second method employs gradient search on Bhattacharyya bound on error rate (P-e) to determine an optimal multiplexed measurement that simultaneously utilizes all available sources in a single exposure. With limited total resources of 10(6) photons, the multiplexed measurement provides a 41.8x reduction in P-e relative to the single-source measurement. In the second part, we consider multiple exposures and develop an adaptive measurement strategy for x-ray threat detection. Using the adaptive strategy, we design the next measurement based on information retrieved from previous measurements. We determine both optimal "next measurement" and stopping criterion to insure a target P-e using sequential hypothesis testing framework. With adaptive single-source measurements, we can reduce P-e by a factor of 40x relative to the measurements employing all sources in sequence. We also observe that there is a trade-off between measurement SNR and number of detectors when we study the performance of systems with reduced detector numbers. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)

Tittle:Influence of drugs from the group SYSADOA for knee osteoarthrosis Objectives:The aim of the thesis is to evaluate the effect of three months use of drugs from the group SASADOA on subjective perception of the difficulties associated with knee osteoarthritis and to determine the intensity of gonarthrosis progression in connection with knee cartilage width. Methods:For the study18 probands were obtained from rehabilitation and orthopedic institutions in Prague. The criterion for recruitmen t was knee joint osteoarthrosis of II. degree. For all participants there was conducted input kinesiology analysis and clinical examination, patient's medical history and filled in WOMAC questionnaire. All participants were sent for an X-ray of the knee. Group of probands was randomly divided into two groups. An experimental group was taking Proenzi 3 plus, a control group was taking placebo. Both groups were taking medications for 12 weeks. After this time the probands arrived to check- up and second filling in of the WOMAC questionnaire. The experimental group that had been taking Proenzi 3 plus received placebo for additional 12 weeks, the control group received Proenzi 3 Plus. After finishing preparations all probands were invited to the last visit where they underwent follow-up examination, the third...

This thesis evaluates the utility of a geochemical technique for the investigation of palaeoenvironmental change in south west England. The method, EDMA (Energy Dispersive X-ray Micro Analysis), is a rapid, non-destructive analysis tool, capable of detecting a large range of geochemical elements. This research examines the most appropriate method of sample preparation for organic soils and peats, and investigates the reliability of results gained from EDMA with respect to conventional bulk geochemical techniques. A detailed study focused on a range of different sedimentary sites in south west England where a variety of palaeoenvironmental changes were thought to occur. Pollen analysis was undertaken on the same sedimentary material, and provided complementary information on the nature and scale of vegetation change through time. Sediments from a coastal valley mire near North Sands, Salcombe, revealed information relating to the processes of sea-level change in this part of south Devon and the subsequent autogenic processes as the sediment accumulated through time. A range of sites were located on the granitic upland of Dartmoor. A raised bog, Tor Royal, provided data relating to the changing nature of the central upland landscape from late Mesolithic times to the present day. Two soligenous sites, Upper Merrivale and Piles Copse, sought to investigate the activities of postulated anthropogenic activity at a much smaller spatial scale, with particular interest placed upon the evidence for deforestation activity and the utilisation of the local mineral resources. The last site, Crift Down, a lowland spring fed valley mire utilised geochemical and palynological fluxes within the peat to investigate processes and activities associated with archaeological evidence for Medieval tinworking in this area of Cornwall. The results from the EDMA investigations, and comparable studies using other geochemical methods including EMMA, AAS and flame photometry, suggest the technique to have greatest applicability as a first stage tool in the analysis of general activities of past environmental change. The technique was found to yield reliable results for the major elements (Si, Al, 5, Fe, Ca, K, Na and Mg), but is generally incapable of providing useful data on heavy metal elements. The data from south west England suggest the method to reflect activity at a range of different scales, and as part of a structured programme of analysis may contribute information to allow a more holistic environmental reconstruction to be made.

The Large Observatory For x-ray Timing (LOFT) is a mission concept which was proposed to ESA as M3 and M4 candidate in the framework of the Cosmic Vision 2015-2025 program. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument and the uniquely large field of view of its wide field monitor, LOFT will be able to study the behaviour of matter in extreme conditions such as the strong gravitational field in the innermost regions close to black holes and neutron stars and the supra-nuclear densities in the interiors of neutron stars. The science payload is based on a Large Area Detector (LAD, > 8m(2) effective area, 2-30 keV, 240 eV spectral resolution, 1 degree collimated field of view) and a Wide Field Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). The WFM is equipped with an on-board system for bright events (e. g., GRB) localization. The trigger time and position of these events are broadcast to the ground within 30 s from discovery. In this paper we present the current technical and programmatic status of the mission.