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1
Cuadrado, Regina Aznar. "Binarity and the origin of subdwarf B stars." Thesis, Queen's University Belfast, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.483466.
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Cousins, Derek John. "Excitations in '3HE-B at ultra-low temperatures." Thesis, Lancaster University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364359.
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鍾厚添 and Hau-tim Chung. "Low level hepatitis B virus carriers: its detection by polymerase chain reaction based assays and its clinicalsignificance." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B31981616.
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Shaw, Neil Scott. "Experiments in superfluid '3He-B at ultra-low temperatures." Thesis, Lancaster University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242873.
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Bonnefoy, Jean-Yves. "The low affinity receptor for IgE on human B lymphocytes : detection, biochemical characterization and regulation." Lyon 1, 1987. http://www.theses.fr/1987LYO1T147.
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Chung, Hau-tim. "Low level hepatitis B virus carriers : its detection by polymerase chain reaction based assays and its clinical significance /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17537873.
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Rahm, Andreas. "Quantum turbulence in ³He-B at ultra-low temperatures." Thesis, Lancaster University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289041.
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De, Faria Sergio Manuel Maciel. "Very low bit rate video coding using geometric transform motion compensation." Thesis, University of Essex, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309768.
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Kratzert, Daniel. "Charge Density Distribution in Low-Valent Tetrels." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://hdl.handle.net/11858/00-1735-0000-001C-63A3-B.
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Woods, Nathan Michael. "PHASE-LOCKED PIV INVESTIGATION OF THE EFFECTS OF THE BLOWING RATIO OF A PULSED VORTEX GENERATOR JET IN A LOW-PRESSURE TURBINE." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1190066085.
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Burridge, Amanda. "Proteomic responses of Arabidopsis thaliana to low dose B/y radiation." Thesis, University of the West of England, Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.522522.
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Jackson, Leila J. "The dynamic regulation of the low affinity IGE receptor by toll like receptor and B cell receptor agonists /." Connect to full text via ProQuest. Limited to UCD Anschutz Medical Campus, 2008.
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Thesis (Ph.D. in Immunology) -- University of Colorado Denver, 2008.Typescript. Includes bibliographical references (leaves 122-129). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;
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Rapacchi, Stanislas. "Low b-values diffusion weighted imaging of the in vivo human heart." Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10012/document.
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L'Imagerie par Résonance Magnétique pondérée en Diffusion (IRM-D) permet l'accès à l'information structurelle des tissus au travers de la lecture du mouvement brownien des molécules d'eau. Ses applications sont nombreuses en imagerie cérébrale, tant en milieu clinique qu'en recherche. Néanmoins le mouvement physiologique créé une perte de signal supplémentaire au cours de l'encodage de la diffusion. Cette perte de signal liée au mouvement limite les applications de l'IRM-D quant à l'imagerie cardiaque. L'utilisation de faibles valeurs de pondération (b) réduit cette sensibilité mais permet seulement l'imagerie du mouvement incohérent intra-voxel (IVIM) qui contient la circulation sanguine et la diffusion des molécules d'eau. L'imagerie IVIM possède pourtant de nombreuses applications en IRM de l'abdomen, depuis la caractérisation tissulaire à la quantification de la perfusion, mais reste inexplorée pour l'imagerie du coeur. Mon travail de thèse correspond à l'évaluation des conditions d'application de l'IRM-D à faibles valeurs de b pour le coeur humain, afin de proposer des contributions méthodologiques et d'appliquer les techniques développées expérimentalement. Nous avons identifié le mouvement cardiaque comme une des sources majeures de perte de signal. Bien que le mouvement global puisse être corrigé par un recalage non-rigide, la perte de signal induite par le mouvement perdure et empêche l'analyse précise par IRM-D du myocarde. L'étude de cette perte de signal chez un volontaire a fourni une fenêtre temporelle durable où le mouvement cardiaque est au minimum en diastole. Au sein de cette fenêtre optimale, la fluctuation de l'intensité atteste d'un mouvement variable résiduel. Une solution de répéter les acquisitions avec un déclenchement décalé dans le temps permet la capture des minimas du mouvement, c.-à-d. des maximas d'intensité en IRM-D. La projection du maximum d'intensité dans le temps (TMIP) permet ensuite de récupérer des images pondérées en diffusion avec un minimum de perte de signal lié au mouvement. Nous avons développé et évalué différentes séquences d'acquisition combinées avec TMIP : la séquence d'imagerie écho-planaire classique par écho de spin (SE-EPI) peut être adaptée mais souffre du repliement d'image ; une séquence Carr-Purcell-Meiboom-Gill combinée avec une préparation d'encodage de diffusion est plus robuste aux distorsions spatiales mais des artefacts de bandes noires empêchent son applicabilité ; finalement une séquence double-SE-EPI compensant les courants de Foucault et pleinement optimisée produit des images IRM-D moins artefactées. Avec cette séquence, l'IRM-D-TMIP permet la réduction significative de la perte de signal liée au mouvement pour l'imagerie cardiaque pondérée en diffusion. L'inconvénient avec TMIP vient de l'amplification du bruit positif d'intensité. Afin de compenser cette sensibilité du TMIP, nous séparons le bruit d'intensité des fluctuations lentes liées au mouvement grâce à une nouvelle approche basée sur l'analyse en composantes principales (PCA). La décomposition préserve les détails anatomiques tout en augmentant les rapports signal et contraste-à-bruit (SNR, CNR). Avec l'IRM-D-PCATMIP, nous augmentons à la fois l'intensité finale et la qualité d'image (SNR) en théorie et expérimentalement. Les bénéfices ont été quantifiés en simulation avant d'être validés sur des volontaires. De plus la technique a montré des résultats reproductibles sur des patients post-infarctus aigue du myocarde, avec un contraste cohérent avec la position et l'étendue de la zone pathologique. Contrairement à l'imagerie cérébrale, l'imagerie IRM-D par faibles valeurs de pondération in vivo doit être différentiée des analyses IRM-D ex-vivo. Ainsi l'IRM-D-PCATMIP offre une technique sans injection pour l'exploration du myocarde par imagerie IVIM. Les premiers résultats sont encourageants pour envisager l'application sur un modèle expérimental d'une maladie cardiovasculaire [etc...]Diffusion weighted magnetic resonance imaging (DW-MRI, or DWI) enables the access to the structural information of body tissues through the reading of water molecules Brownian motion. Its applications are many in brain imaging, from clinical practice to research. However physiological motion induces an additional signal-loss when diffusion encoding is applied. This motion-induced signal-loss limits greatly its applications in cardiac imaging. Using low diffusion-weighting values (b) DWI reduces this sensitivity but permits only the imaging of intravoxel incoherent motion (IVIM), which combines both water diffusion and perfusion. IVIM imaging has many applications in body MRI, from tissue characterization to perfusion quantification but remains unexplored for the imaging of the heart. The purpose of this work was to evaluate the context of low b-values DWI imaging of the heart, propose methodological contributions and then apply the developed techniques experimentally. We identified cardiac motion as one of the major sources of motion-induced signal loss. Although bulk motion can be corrected with a non-rigid registration algorithm, additional signal-loss remains uncorrected for and prevents accurate DWI of the myocardium. The study of diffusion-weighted signal-loss induced by cardiac motion in a volunteer provided a time-window when motion is at minimum in diastole. Within this optimal time-window, fluctuation of intensity attests of variable remaining physiological motion. A solution to repeat acquisition with shifted trigger-times ease the capture of motion amplitude minima, i.e. DWI-intensity maxima. Temporal maximum intensity projection (TMIP) finally retrieves diffusion weighted images of minimal motion-induced signal-loss. We evaluated various attempts of sequence development with TMIP: usual spin-echo echo-planar imaging (se-EPI) sequence can be improved but suffers aliasing issues; a balanced steady-state free-precession (b-SSFP) combined with a diffusion preparation is more robust to spatial distortions but typical banding artifacts prevent its applicability; finally a state-of-the-art double-spin-echo EPI sequence produces less artifacted DWI results. With this sequence, TMIP-DWI proves to significantly reduce motion-induced signal-loss in the imaging of the myocardium. The drawback with TMIP comes from noise spikes that can easily be highlighted. To compensate for TMIP noise sensitivity, we separated noise spikes from smooth fluctuation of intensity using a novel approach based on localized principal component analysis (PCA). The decomposition was made so as to preserve anatomical features while increasing signal and contrast to noise ratios (SNR, CNR). With PCATMIP-DWI, both signal-intensity and SNR are increased theoretically and experimentally. Benefits were quantified in a simulation before being validated in volunteers. Additionally the technique showed reproducible results in a sample of acute myocardial infarction (AMI) patients, with a contrast matching the extent and location of the injured area. Contrarily to brain imaging, in vivo low b-values DWI should be differentiated from ex vivo DWI pure diffusion measurements. Thus PCATMIP-DWI might provide an injection-free technique for exploring cardiac IVIM imaging. Early results encourage the exploration of PCATMIP-DWI in an experimental model of cardiac diseases. Moreover the access to higher b values would permit the study of the full IVIM model for the human heart that retrieves and separates both perfusion and diffusion information
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Baird, Allison Michelle. "Analysis of Low Zone Tolerance in Normal and B Cell-Deficient Mice." eScholarship@UMMS, 1996. https://escholarship.umassmed.edu/gsbs_diss/142.
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This thesis investigates the role of B cells as antigen-specific antigen-presenting cells (APC) in self tolerance to low concentrations of soluble self proteins and in acquired tolerance to low doses of soluble foreign protein antigens. Experiments were performed in normal and B cell-deficient animals, and tolerance induction was measured by T cell proliferation assays. T cell proliferation was reduced in B cell-deficient mice, indicating that B cells may be involved in efficient activation of naive T cells in response to protein antigen both in vivo and in vitro. To study acquired tolerance induced by low doses of soluble foreign protein antigen, normal and B cell-deficient adult mice were injected intravenously with repeated low doses (10 μg) of deaggregated ovalbumin (OVA), and then challenged with OVA in complete Freund's adjuvant. In animals treated with deaggregated OVA, the in vitro proliferative responses of LN T cells to OVA were significantly reduced, and production of the Th1 cytokine, IFN-γ, in response to OVA was lost. This occurred in both normal and B cell-deficient treated animals, indicating that B cell antigen presentation was not required for this phenomenon. B cells were also unnecessary for self tolerance of T cells to the transgenic self antigen, hen egg lysozyme (HEL), in a transgenic mouse strain with very low serum lysozyme concentration. Partial low zone tolerance induced by deaggregated, low-dose OVA was selective for the Th1 response, as measured by in vitro proliferation and IL-2 and IFN-γ production, because antibody responses of normal mice to this T cell-dependent antigen were largely unaffected. Both treated and untreated animals produced equivalent titers of anti-OVA antibodies, predominantly of the IgG1 and IgG2b isotypes, following challenge with OVA in complete Freund's adjuvant. Tolerance to low levels of the transgenic HEL self protein in mice expressing different MHC molecules was also addressed. Transgenic mice that were H-2b/b in the class II region were not tolerant to the transgenic self protein, whereas transgenic mice of the H-2b/k were tolerant.
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Parker, Catriona Anne. "The response of tumour cells to hypoxia and reoxygenation : roles and interactions of p53 and NF#kappa#B." Thesis, University of Sheffield, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246997.
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Sum, Siu-man Simon, and 岑紹文. "The development and assessment of assays for quantitation of hepatitisB virus DNA (HBV DNA) and the clinical significance of low HBV DNAlevel in patients with chronic hepatitis B." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B3013836X.
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Porter, Kirsty Michelle. "Causes, consequences and public health implications of low B-vitamin status in ageing." Thesis, Ulster University, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.763930.
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The ageing population is predicted to exceed two billion by 2050; maintaining good health in older age has, thus, become a major global health priority. Ageing involves physiological changes, impairment in digestive function and the increased need for the use of prescribed drugs which can lead to lower status of folate and the metabolically related B-vitamins (vitamins B I2, B6, riboflavin). Deficiencies in these vitamins are increasingly linked with a number of chronic diseases of ageing. In particular, dementia affects 46.8 million globally, figures that are expected to triple by 2050, generating substantial societal and economic impacts. One-carbon metabolism is proposed as a critical pathway associated with health throughout life, especially in ageing. However, studies considering the association of one-carbon metabolism tend to focus on folate and vitamin B 12, few have considered all the relevant B-vitamins which are interlinked within one-carbon metabolism. The overall aim of this thesis therefore, was to investigate the causes, consequences and public health implications of low B-vitamin status in ageing with a particular focus on cognitive health. Results arising from new analysis of the Trinity, Ulster and Department of Agriculture (TUDA) Ageing cohort study (n 5186) indicated that the use of proton pump inhibitors (PPI), widely taken by older people, is associated with significantly lower status of B12 as previously reported, but also with lower status of vitamin B6 and riboflavin, vitamins which have not previously been linked with PPI use. Likewise, metformin use was associated with a significant increase in the risk of vitamin B12 deficiency and more than doubled the risk of vitamin B6 deficiency, in older people with or at-risk of diabetes (HbAic<42mmol/mol). The thesis showed that older adults with or at-risk of diabetes were at a 25% higher risk of vitamin B6 deficiency, and a 67% increased risk of cognitive dysfunction, with some evidence that low status of vitamin B6 may be driving the cognitive dysfunction in these patients. In a follow up study of almost 600 participants, 5 years after the initial investigation (i.e. TUDA+5), low status of vitamin B6 (OR: 1.75, P 0.008) and riboflavin (OR 1.63, P 0.018) were found to be significant predictors of accelerated cognitive decline, as measured by RBANS. The totality of the evidence in this thesis supports the wider public health benefits of optimising B-vitamin status, through natural food sources, fortified foods and supplements, to alleviate B-vitamin depletion in those on long term prescribed drugs and as a means of maintaining cognitive health in ageing. In conclusion, results from this thesis suggest that updating food fortification policies worldwide to optimise all the relevant B-vitamins could offer a cost-effective strategy for maintaining better health in ageing and preventing adverse outcomes.
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Jackson, Colleen. "SiC and B₄C as electrocatalyst support materials for low temperature fuel cells." Doctoral thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/27313.
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Supported nano-catalyst technologies are key for increasing the catalyst utilisation and achieving economically feasible platinum metal loadings in hydrogen polymer electrolyte fuel cells (PEFCs). High surface area carbons are commonly utilised as support materials for platinum due to low cost, large surface areas and high conductivity. However, PEFCs using this technology undergo oxidation of carbon supports, significantly reducing the lifetime of the fuel cell. In this work, silicon carbide and boron carbide are investigated as alternative catalyst support materials to carbon, for the oxygen reduction reaction for low temperature fuel cells. Electrochemical testing, accelerated degradation studies as well as advanced characterisation techniques were used to clarify the structure-property relationships between catalyst morphology, metal-support interaction, ORR activity and surface adsorption onto the Pt nanoparticles. Extended X-ray Absorption Fine Structure (EXAFS) analysis gave insights into the shape of the clustered nanoparticles while X-ray Photoelectron Spectroscopy (XPS) and in-situ X-ray Absorption Near-Edge Spectroscopy (XANES) analysis provided information into how the metal-support interaction influences surface adsorption of intermediate species. Electronic metal-support interactions between platinum and the carbide supports were observed which influenced the electrochemical characteristics of the catalyst, in some cases increasing the oxygen reduction reaction activity, hydrogen oxidation reaction activity and Pt stability on the surface of the support.
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Chrostowski, Marta. "Growth of doped epitaxial silicon at low temperature by PECVD for photovoltaic applications." Thesis, Institut polytechnique de Paris, 2020. http://www.theses.fr/2020IPPAX018.
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Cette thèse a pour objectif l’évaluation de l’épitaxie de silicium à basse température (< 200°C) par RF-PECVD, en tant qu’alternative à la diffusion pour la formation de l’émetteur d’une cellule solaire à base de silicium cristallin (c-Si). La croissance par épitaxie de couches intrinsèques, de type n et de type p sur des substrats de c-Si (100) a été confirmée par ellipsométrie. Étonnamment, les couches dopées de silicium epitaxié (epi-Si) présentent un paramètre de maille hors du plan supérieur à celui du substrat, et sont totalement contraintes. Des concentrations en bore et phosphore de 3 et 3,5.1019 at/cm3, respectivement, ont été obtenues d’après des mesures SIMS. Cependant, lors de la croissance des couches, des complexes B-H sont formés et un recuit est nécessaire pour activer les atomes de bore. Après recuit, une efficacité de dopage de 60% est démontrée, avec une mobilité de l’ordre de 20 cm2/Vs. Nous mettons également en avant une corrélation entre l’évolution après recuit de la structure, des propriétés électriques et de la concentration en hydrogène. Finalement, des mesures DRX ont montré que l’énergie fournie par un recuit à 350°C induit une relaxation de la structure des couches epi-Si, et donc l’apparition de défauts, confirmée par TEM et mesures PL à basse températureThis PhD thesis aims at evaluating low temperature silicon epitaxy (< 200°C) by RF-PECVD as an alternative to diffusion for the formation of the emitter layer of crystalline silicon (c-Si) solar cells. The epitaxial growth of intrinsic, n-type and p-type films grown on (100) c-Si substrates has been confirmed by ellipsometry. Surprisingly, the as-grown doped epitaxial silicon (epi-Si) films present a larger out-of-plane lattice parameter than the substrate, and are fully strained. Boron and phosphorus concentration of 3 and 3.5x1019 at/cm3, respectively, were achieved as deduced from SIMS measurements. However, in the as-grown state B-H complexes are formed and annealing is required to activate boron atoms. After annealing, we reached a doping efficiency of approximately 60%. As expected, the activation of boron leads to a drop of the mobility to ~20 cm2/Vs. Moreover, we put forward a correlation between the evolution upon annealing of the structure, electrical properties and the hydrogen content. Finally, XRD measurements have shown that by providing energy, annealing at 350°C induces the relaxation of the epi-Si structure, thus the apparition of defects, confirmed by TEM and low temperature PL
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De, Waal Bernadine. "Stochastic optimization of subprime residential mortgage loan funding and its risks / by B. de Waal." Thesis, North-West University, 2010. http://hdl.handle.net/10394/4396.
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The subprime mortgage crisis (SMC) is an ongoing housing and nancial crisis that was
triggered by a marked increase in mortgage delinquencies and foreclosures in the U.S. It
has had major adverse consequences for banks and nancial markets around the globe
since it became apparent in 2007. In our research, we examine an originator's (OR's)
nonlinear stochastic optimal control problem related to choices regarding deposit inflow
rates and marketable securities allocation. Here, the primary aim is to minimize liquidity
risk, more speci cally, funding and credit crunch risk. In this regard, we consider two
reference processes, namely, the deposit reference process and the residential mortgage loan
(RML) reference process. This enables us to specify optimal deposit inflows as well as
optimal marketable securities allocation by using actuarial cost methods to establish an
ideal level of subprime RML extension. In our research, relationships are established in
order to construct a stochastic continuous-time banking model to determine a solution for
this optimal control problem which is driven by geometric Brownian motion.
In this regard, the main issues to be addressed in this dissertation are discussed in Chapters
2 and 3.
In Chapter 2, we investigate uncertain banking behavior. In this regard, we consider
continuous-time stochastic models for OR's assets, liabilities, capital, balance sheet as well
as its reference processes and give a description of their dynamics for each stochastic model
as well as the dynamics of OR's stylized balance sheet. In this chapter, we consider RML
and deposit reference processes which will serve as leading indicators in order to establish
a desirable level of subprime RMLs to be extended at the end of the risk horizon.
Chapter 3 states the main results that pertain to the role of stochastic optimal control in
OR's risk management in Theorem 2.5.1 and Corollary 2.5.2. Prior to the stochastic control
problem, we discuss an OR's risk factors, the stochastic dynamics of marketable securities
as well as the RML nancing spread method regarding an OR. Optimal portfolio choices
are made regarding deposit and marketable securities inflow rates given by Theorem 3.4.1
in order to obtain the ideal RML extension level. We construct the stochastic continuoustime
model to determine a solution for this optimal control problem to obtain the optimal
marketable securities allocation and deposit inflow rate to ensure OR's stability and security.
According to this, a spread method of RML financing is imposed with an existence condition given by Lemma 3.3.2. A numerical example is given in Section 3.5 to illustrates the main issues raised in our research.Thesis (M.Sc. (Applied Mathematics))--North-West University, Potchefstroom Campus, 2011.
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Dikmen, Bora. "Numerical Studies Of The Electronic Properties Of Low Dimensional Semiconductor Heterostructures." Phd thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605473/index.pdf.
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An efficient numerical method for solving Schrödinger'
s and Poisson'
s equations using a basis set of cubic B-splines is investigated. The method is applied to find both the wave functions and the corresponding eigenenergies of low-dimensional semiconductor structures. The computational efficiency of the method is explicitly shown by the multiresolution analysis, non-uniform grid construction and imposed boundary conditions by applying it to well-known single electron potentials. The method compares well with the results of analytical solutions and of the finite difference method.
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Reighter, Greg. "TELEMETRY CONSIDERATIONS WITH OPERATIONAL STEALTH VEHICLES." International Foundation for Telemetering, 1998. http://hdl.handle.net/10150/607357.
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International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, CaliforniaInstrumenting the operational B-2 Strategic Bomber presents some unique problems. For example, the requirement to remain operational dictates that the aircraft must retain its stealth characteristics. This means traditional antennas cannot simply be attached to the airframe. A solution to this problem is an antenna designed with stealth, or Low Observable (LO), attributes. Stealth is not an absolute; it is relative. Therefore, antenna design becomes a balancing act between the LO relativity, antenna directivity, and antenna gain. Weapons testing is an additional concern, where instrumented ordinances transmit data that must be monitored real-time prior to launch. Stealth vehicles must carry weapons internally, restricting the Radio Frequency (RF) transmission of telemetered data from the weapon. With the development of future stealthy conveyances, such as the F-22, Joint Strike Fighter (JSF), ground, and ocean-going craft, these concerns will become even more prevalent.
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Matthews, Carolyn J. "Quantum turbulence and aerogel experiments at ultra low temperatures in superfluid ³He-B." Thesis, Lancaster University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441787.
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Thaci, Louise Ann. "Flow cytometry for monitoring the response to chemotherapy in low grade B-cell disorders." Thesis, Ulster University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646857.
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Low Grade B-cell Disorders (LO-BCDs) have been found to be formed from B cells with clonal proliferations arising as B cells differentiate. There are 5 main groups of particular interest in this research project: Chronic Lymphocytic Leukaemia (CLL), Follicular Cell Lymphoma (FCL), Low Grade Lymphoma - unspecified (LOL) Mantle Cell Lymphoma (MCL) and Multiple Myeloma (MM). Currently, bone marrow analysis provides clear indication of relapse, though the procedure is invasive. Immunophenotyping of peripheral blood can identify minute numbers of T cells involved in the pathogenesis of relapse and is non-invasive. This study aimed to investigate which T cells were present and whether the methods employed could be used to replace the need for bone marrow analysis to confirm infection and relapse. The literature review provides an overview of normal cell development and the production of neoplastic cells that develop into LG-BCDs. A brief review of the chemotherapy treatments available is discussed and the methods of diagnosis, and confirmation of the disorders, including an introduction to flow cytometry is given. The preparation of controls, antibodies and reagents used in the study were validated according to good scientific practice and a reliable standard operating procedure for analysis was generated. The optimum method of sample storage using a preservative was investigated and implemented. Patients were recruited at any stage or grade of disease including those not on any treatment (watch and wait), those on treatment and/or post autologous stem cell transplants with maintenance chemotherapy. Patients were identified by LG-BCD type, treatment, and current status (stable, relapsed, partial or complete remission and minimal residual disease). The study presented in this thesis found that irrespective of LG-BCD type both naive and memory cells were detectable at increased levels in patients with relapse and that during infection cytotoxic T cells were raised, regardless of chemotherapy treatment. These cells could be used to discern between infection and relapse which would therefore influence the management of the patient. A population of naive cells (IFNy+) were found to function as memory cells which could have the potential to influence neoplastic B cells to proliferate and differentiate increasing the possibility of disease progression and relapse. Natural killer cells were also identified as present during infection though this could not be confirmed upon further investigation. Further study of a larger number of LG-BCD patients is crucial for confirming the involvement of these T cells which may be used to influence the management of treatment to improve patient's quality of life and prevent hospitalisation due to infection or relapse. Keywords: Thalidomide, lenalidomide, rituximab, chemotherapy, low grade B-cell disorder, flow cytometry, immunophenotyping, infection, relapse.
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Pothana, Kartheek. "Low dose UV-B induced keratinocyte exosomes protect Schwann cells against high glucose injury." Wright State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=wright1610380812991387.
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Enrico, Michael Paul. "Ballistic excitation scattering processes in superfluid '3He-B and spin-lattice relaxation in copper down to 7#mu#K." Thesis, Lancaster University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261014.
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Toledo, Júnior Alceu de Oliveira. "MARCADORES BIOQUÍMICOS NAS DISLIPIDEMIAS E NO RISCO CARDIOVASCULAR: ANÁLISE COMPARATIVA À FÓRMULA DE MARTIN." Universidade Estadual de Ponta Grossa, 2018. http://tede2.uepg.br/jspui/handle/prefix/2712.
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Este estudo tem como objetivo avaliar comparativamente perfis de marcadores bioquímicos que melhor caracterizem e/ou associem-se às dislipidemias, na modalidade diagnóstica por ampliar a estratificação do risco cardiovascular ou no seu monitoramento para melhor condução. Para isso avaliamos o perfil lipídico composto por colesterol total, triglicérides, colesterol da lipoproteína de alta densidade e da lipoproteína de baixa densidade; esta com a fórmula de Martin, e ainda o colesterol em conteúdo que não faz parte das lipoproteínas de alta densidade, correlacionando-os com os marcadores: lipoproteína a, apoproteína B e colesterol da lipoproteína de baixa densidade; com uso do método homogêneo. Foram selecionados 1012 pacientes, segmentados por faixas etárias, sexo e condição de uso ou não de inibidores de produção hepática do colesterol. Para ampliar o poder dessa análise agrupada os exames realizados foram separados em subgrupos, considerando-se valores obtidos e metodologias utilizadas; correlacionando-se os resultados. A pesquisa foi realizada com variáveis qualitativas e quantitativas, procedendo-se ao uso de testes estatísticos não paramétricos para sua compreensão, distribuição e análise agrupada. Nossos resultados mostraram evidências que o risco cardiovascular não se associa apenas ao colesterol da lipoproteína de baixa densidade obtido pela fórmula de Martin, mas a outras variáveis, sob associação às seguintes análises comparativas: que o uso da apoproteína B amplia o diagnóstico de inclusão das dislipidemias em 43% usando valores referenciais sexo-independentes e com uma nova faixa de monitoramento em 84 mg/dL. Que o colesterol da lipoproteína de baixa densidade obtido pelo método homogêneo apresenta discordância analítica em +3,5% e tendo estratificação diagnóstica 48% superior. E que a lipoproteína a apresenta-se superior a 30 mg/dL em 26% dos pacientes, porém com prevalência e segmentação específicas nas mulheres entre 51 a 60 anos, sendo necessária sua análise numa aparente discordância, superior a 10 mg/dL, quando da comparação de resultados entre a fórmula de Martin e o método homogêneo.
This study aims to comparatively evaluate the profiles of biochemical markers that best characterize and / or associate with dyslipidemias, in the diagnostic modality by increasing the stratification of cardiovascular risk or its monitoring for better conduction. For this, we evaluated the lipid profile composed of total cholesterol, triglycerides, high density lipoprotein cholesterol and low density lipoprotein; and the cholesterol in non-high density lipoprotein content, correlating them with the markers: lipoprotein A, apoprotein B and low density lipoprotein cholesterol; using the homogeneous method. A total of 1012 patients were selected, segmented by age, sex and condition of use or inhibition of hepatic cholesterol production. In order to increase the power of this group analysis the exams were separated into subgroups, considering the obtained values and methodologies used; correlating the results. The research was carried out with qualitative and quantitative variables, using nonparametric statistical tests for their comprehension, distribution and grouped analysis. Our results showed evidence that cardiovascular risk is not only associated with the low density lipoprotein cholesterol obtained by Martin's formula, but other variables, in association with the following comparative analyzes: that the use of apoprotein B expands the diagnosis of inclusion of dyslipidemias in 43 % using genderindependent baseline values and with a new monitoring range of 84 mg/dL. That the low density lipoprotein cholesterol obtained by the homogeneous method presents an analytical disagreement at + 3.5% and having a 48% higher diagnostic stratification. In addition, lipoprotein a levels were higher than 30 mg/dL in 26% of the patients, but with a specific prevalence and segmentation in women between the ages of 51 and 60 years, with an apparent disagreement of more than 10 mg/dL when of the comparison of results between the Martin formula and the homogeneous method.
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Dagobert, Tristan. "Évaluation d’algorithmes stéréoscopiques de haute précision en faible B/H." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLN046/document.
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Cette thèse étudie la précision en vision stéréo, les méthodes de détection dites a contrario et en présente une application à l'imagerie satellitaire. La première partie a été réalisée dans le cadre du projet DGA-ANR-ASTRID "STÉRÉO". Son but est de définir les limites effectives des méthodes de reconstruction stéréo quand on contrôle toute la chaîne d’acquisition à la précision maximale, que l’on acquiert des paires stéréo en rapport B/H très faible et sans bruit. Pour valider ce concept, nous créons des vérités terrains très précises en utilisant un rendeur. En gardant les rayons calculés durant le rendu, nous avons une information très dense sur la scène 3D. Ainsi nous créons des cartes d'occultations, de disparités dont l'erreur de précision est inférieure à 10e-6. Nous avons mis à la disposition de la communauté de recherche des images de synthèse avec un SNR supérieur à 500 : un ensemble de 66 paires stéréo dont le B/H varie de1/2500 à 1/50. Pour évaluer les méthodes de stéréo sur ce nouveau type de données, nous proposons des métriques calculant la qualité des cartes de disparités estimées, combinant la précision et la densité des points dont l'erreur relative est inférieure à un certain seuil. Nous évaluons plusieurs algorithmes représentatifs de l'état de l'art, sur les paires créées ainsi sur les paires de Middlebury, jusqu'à leurs limites de fonctionnement. Nous confirmons par ces analyses, que les hypothèses théoriques sur le bien-fondé du faible B/H en fort SNR sont valides, jusqu'à une certaine limite que nous caractérisons. Nous découvrons ainsi que de simples méthodes de flux optique pour l'appariement stéréo deviennent plus performantes que des méthodes variationnelles discrètes plus élaborées. Cette conclusion n'est toutefois valide que pour des forts rapports signal à bruit. L'exploitation des données denses nous permet de compléter les vérités terrain par une détection très précise des bords d'occultation. Nous proposons une méthode de calcul de contours vectoriels subpixéliens à partir d'un nuage de points très dense, basée sur des méthodes a contrario de classification de pixels. La seconde partie de la thèse est dédiée à une application du flot optique subpixélien et des méthodes a contrario pour détecter des nuages en imagerie satellitaire. Nous proposons une méthode qui n'exploite que l'information visible optique. Elle repose sur la redondance temporelle obtenue grâce au passage répété des satellites au-dessus des mêmes zones géographiques. Nous définissons quatre indices pour séparer les nuages du paysage : le mouvement apparent inter-canaux, la texture locale, l'émergence temporelle et la luminance. Ces indices sont modélisés dans le cadre statistique des méthodes a contrario qui produisent un NFA (nombre de fausses alarmes pour chacun). Nous proposons une méthode pour combiner ces indices et calculer un NFA beaucoup plus discriminant. Nous comparons les cartes de nuages estimées à des vérités terrain annotées et aux cartes nuageuses produites par les algorithmes liés aux satellites Landsat-8 etSentinel-2. Nous montrons que les scores de détection et de fausses alarmes sont supérieurs à ceux obtenus avec ces algorithmes, qui pourtant utilisent une dizaine de bandes multi-spectralesThis thesis studies the accuracy in stereo vision, detection methods calleda contrario and presents an application to satellite imagery. The first part was carried out within the framework of the project DGA-ANR-ASTRID"STEREO". His The aim is to define the effective limits of stereo reconstruction when controlling the entire acquisition chain at the maximum precision, that one acquires stereo pairs in very low baseline and noise-free. To validate thisconcept, we create very precise ground truths using a renderer. By keeping the rays computed during rendering, we have very dense information on the 3Dscene. Thus we create occultation and disparity maps whose precision error is less than 10e-6. We have made synthetic images available to the research community with an SNR greater than 500: a set of 66 stereo pairs whoseB/H varies from 1/2500 to 1/50. To evaluate stereo methods onthis new type of data, we propose metrics computing the quality of the estimated disparity maps, combining the precision and the density of the points whose relative error is less than a certain threshold. We evaluate several algorithmsrepresentative of the state of the art, on the pairs thus created and on theMiddlebury pairs, up to their operating limits. We confirm by these analyzesthat the theoretical assumptions about the merit of the low B/H in highSNR are valid, up to a certain limit that we characterize. We thus discover that simple optical flow methods for stereo matching become more efficient than more sophisticated discrete variational methods. This conclusion, however, is only valid for high signal-to-noise ratios. The use of the dense data allows us to complete the ground truths a subpixel detection of the occlusion edges. We propose a method to compute subpixel vector contours from a very dense cloud ofpoints, based on pixel classification a contrario methods. The second part of the thesis is devoted to an application of the subpixelian optical flowand a contrario methods to detect clouds in satellite imagery. We propose a method that exploits only visible optical information. It is based onthe temporal redundancy obtained by the repeated passages of the satellites overthe same geographical zones. We define four clues to separate the clouds fromthe landscape: the apparent inter-channel movement, Local texture, temporal emergence and luminance. These indices are modeled in the statistical framework of a contrario methods which produce an NFA (number of false alarms for each). We propose a method for combining these indices and computing a much more discriminating NFA. We compare the estimated cloud maps to annotated ground truths and the cloud maps produced by the algorithms related to the Landsat-8and Sentinel-2 satellites. We show that the detection and false alarms scores are higher than those obtained with these algorithms, which however use a dozen multi-spectral bands
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Skoglund, Andersson Camilla. "Low density lipoprotein (LDL) heterogeneity : implications for cardiovascular disease and genetic influence /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-490-9/.
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Riveline, Michael. "Probing the parton evolution in DIS at low x[subscript]B[subscript]J using jet observables." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0026/NQ50298.pdf.
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Mulholland, Michael Edward. "Synthesis, Characterization, and Application of Low and Reduced Band Gap Thieno[3,4-b]pyrazine-based Materials." Diss., North Dakota State University, 2013. https://hdl.handle.net/10365/27039.
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Conjugated polymers are a class of materials receiving significant interest due to their unique combination of optical and electronic properties found in inorganics with the flexibility and processability of traditional organic plastics. These materials have become popular in application to electronic devices such as organic photovoltaics (OPVs), organic light-emitting diodes (OLEDs), sensors, electrochromics and field effect transistors (FETs). As the energetic gap between frontier orbitals, the band gap (Eg) is largely responsible for the energetic transitions of these materials and thus tuning of this parameter is of great interest. A popular method to reducing Eg is through the use of fused ring systems such as thieno[3,4-b]pyrazines (TPs). These TP-based materials have been previously applied to solar cells. However, all exhibited limited efficiency (<5% PCE). In an effort to improve the efficacy of TPs in electronic devices, the scope of available TP materials was expanded in an effort to study the effect of changing both side chain and comonomer has on the material properties. In an effort to study the effect of side chains Rasmussen and coworkers introduced a new method in 2008 toward synthesis of 2nd generation TPs with expanded electronic tuning. To further develop this work, preparation of new electron-withdrawing TPs were generated. Application of 1st and 2nd generation TPs in the production of homopolymeric and copolymeric materials was performed, along with characterization of their optical and electronic properties. Select materials with altering side chain and comonomeric unit were then applied to OPV devices and efficiencies were evaluated based on the changed parameter.
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Dollery, Stephen. "Identification and characterization of low pH-triggered conformational changes in the herpes simplex virus glycoprotein B." VCU Scholars Compass, 2011. http://scholarscompass.vcu.edu/etd/176.
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Herpesviruses can enter host cells by pH-dependent endocytic pathways in a cell-specific manner. The role of pH in herpesvirus endocytosis is unclear. Herpes simplex virus (HSV) is a paradigm for virus membrane fusion via a complex of glycoproteins. HSV glycoproteins B, D and the heterodimer H-L are necessary and sufficient for membrane fusion. This work analyzes the structure and function of HSV glycoproteins B, D, and H-L at neutral pH, and at the physiological low-pH encountered during endocytic entry. It is demonstrated that mildly acidic low pH triggers specific conformational changes in HSV gB at a pH of 5.7 to 6.0. The antigenic structure of gB functional region I that is critical for fusion is specifically altered by mildly acidic pH both in vitro and during entry into host cells. Point mutations within gB functional region 1 that block membrane fusion still allow conformational changes in region 1. This suggests that specific hydrophobic residues are essential for fusion domain insertion into the host cell membrane but not conformational change. The detected conformational changes were reversible, similar to other class III fusion glycoproteins. Exposure to mildly acidic pH directly triggered the fusion function of HSV glycoproteins and caused gB, but not other glycoproteins, to become more hydrophobic. The oligomeric conformation of gB is altered at a similar pH range. In addition, several approaches were used to monitor gB throughout glycoprotein synthesis and maturation. It is shown that gB may cotranslationally fold and oligomerize as it is synthesized on the ribosome. As gB matures it then alters conformation and/or binding partner to form antigenically distinct populations of gB within the cell and virion. I conclude that intracellular low pH induces changes in gB conformation that, together with additional triggers such as receptor-binding, are essential for virion-cell fusion during herpesviral entry by endocytosis.
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Johnson-Groh, Mara, Christian Marois, Rosa Robert J. De, Eric L. Nielsen, Julien Rameau, Sarah Blunt, Jeffrey Vargas, et al. "Integral Field Spectroscopy of the Low-mass Companion HD 984 B with the Gemini Planet Imager." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/623816.
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We present new observations of the low-mass companion to HD 984 taken with the Gemini Planet Imager (GPI) as a part of the GPI Exoplanet Survey campaign. Images of HD 984 B were obtained in the J (1.12-1.3 mu m) and H (1.50-1.80 mu m) bands. Combined with archival epochs from 2012 and 2014, we fit the first orbit to the companion to find an 18 au (70-year) orbit with a 68% confidence interval between 14 and 28 au, an eccentricity of 0.18 with a 68% confidence interval between 0.05 and 0.47, and an inclination of 119 degrees with a 68% confidence interval between 114 degrees and 125 degrees. To address the considerable spectral covariance in both spectra, we present a method of splitting the spectra into low and high frequencies to analyze the spectral structure at different spatial frequencies with the proper spectral noise correlation. Using the split spectra, we compare them to known spectral types using field brown dwarf and low-mass star spectra and find a best-fit match of a field gravity M6.5 +/- 1.5 spectral type with a corresponding temperature of 2730(-180)(+120)K. Photometry of the companion yields a luminosity of log(L-bol/L-circle dot) = -2.88 +/- 0.07 dex with DUSTY models. Mass estimates, again from DUSTY models, find an age-dependent mass of 34 +/- 1 to 95 +/- 4 M-Jup. These results are consistent with previous measurements of the object.
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Schuh, Fabian [Verfasser], and Johannes B. [Akademischer Betreuer] Huber. "Digital Communications for Low Latency and Applications for Constant Envelope Signalling / Fabian Schuh. Gutachter: Johannes B. Huber." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2016. http://d-nb.info/1083259539/34.
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Carey, Heather Christine. "Processing structure and properties of rapidly solidified Nd-Fe-B permanent magnet materials with low Nd contents." Thesis, University of Sheffield, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321851.
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Nardini, Elena. "Characterization of genetic events involving IgH switch regions in gastric low grade MALT lymphomas and B CLL." Thesis, Open University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251405.
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Patel, Ashok Bakul. "The development of high cooling power and low ultimate temperature superfluid Stirling refrigerators by Ashook B. Patel." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/80596.
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Griffiths, Ulla Kou. "Haemophilus influenzae type b vaccine in low- and middle-income countries : impact, costs and incremental cost-utility." Thesis, London School of Hygiene and Tropical Medicine (University of London), 2012. http://researchonline.lshtm.ac.uk/2869500/.
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Haemophilus influenzae type b (Hib) is an infectious bacterium transmitted from person to person through close contact. Hib can cause meningitis, pneumonia and a number of rarer forms of disease, primarily in children less than five years. Hib conjugate vaccines became available during the early 1990s and high-income countries quickly introduced this vaccine into their routine programmes and have now achieved a near disappearance of Hib disease. However, relatively high vaccine prices and uncertainties about Hib disease burden led to a slow uptake in low- and middle-income countries. The aim of this PhD is to fill gaps in knowledge about the value of Hib vaccination, in terms of whether or not it is a cost-effective intervention in low- and middle-income countries. Moreover, since economic evaluation involves gathering evidence about numerous criteria that may be considered in isolation by policy makers, such as vaccine efficacy, disease burden, meningitis sequelae prevalence and cold chain expansion costs, specific objectives are also to address some of the unanswered questions about key inputs and determinants of cost-effectiveness. The framework of the PhD is shaped around a decision-analytic model designed to estimate the cost-utility of Hib vaccination. The methodology, collection and analysis of data inputs needed to populate the model represent a number of sub-studies, which are all contributions to new evidence. These include a meta-analysis of Hib vaccine efficacy, calculation of Disability Adjusted Life Years due to Hib disease, estimation of treatment costs of Hib disease, assessment of productivity costs due to meningitis sequelae, and calculation of systems costs of introducing Hib vaccine. Case studies from two countries are included in the sub-studies; productivity costs of meningitis sequelae are investigated in Senegal and systems costs of Hib vaccine introduction are estimated in Ethiopia. Cost-utility results generated from the decision-analytic model are presented for two low-income countries; India and Uzbekistan, and one middle-income country; Belarus. This PhD thesis is the first attempt to combine evidence on disease burden, costs and impact of Hib vaccine across multiple countries using a consistent framework and comparable input parameters. As a result, new insights into the relative cost-utility in countries with different economic and epidemiological circumstances are obtained.
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Delporte, Cédric. "Etude des modifications de l'apolipoprotéine B-100 induites par la myéloperoxydase à l'aide de la chromatographie liquide couplée à la spectrométrie de masse." Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209655.
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Les maladies cardiovasculaires constituent la première cause de décès dans le monde et l’athérosclérose est le premier facteur causal de ces maladies. Parmi les multiples facteurs de risque athéromateux, un facteur est souvent décrit :la modification des lipoprotéines de basse densité (LDLs). Bien que le phénomène d’athérogénèse ne soit pas encore complètement résolu, il est actuellement admis que les LDLs natives passent la paroi vasculaire et s’accumulent au niveau sous-endothélial où elles sont oxydées et endocytées par les macrophages. Une théorie plus récente indique que les LDLs peuvent être également modifiées dans la circulation.Néanmoins, le processus par lequel ces lipoprotéines sont modifiées reste hautement controversé. Depuis quelques années, le modèle de modification des LDLs par la myéloperoxydase est apparu comme un modèle physiopathologique contrairement au modèle longuement utilisé de l’oxydation des LDLs par le cuivre. La myéloperoxydase est une enzyme présente dans les granules primaires des neutrophiles mais qui lors d’inflammations chroniques, comme dans l’athérosclérose, peut se retrouver dans le milieu extracellulaire et former un oxydant puissant qui attaque les protéines, les lipides ou les acides nucléiques. Les LDLs modifiées par la myéloperoxydase ne sont plus reconnues par le récepteur membranaire spécifique pour les LDLs. De plus, très peu d’études ont décrit à ce jour les modifications apportées par la myéloperoxydase aux LDLs.
Dans ce contexte, nous avons étudié la spécificité de la myéloperoxydase à modifier les LDLs. Dans ce modèle, la partie protéique de la lipoprotéine est majoritairement touchée. C’est pourquoi nous avons développé et optimisé des méthodes d’analyse par spectrométrie de masse de l’apolipoprotéine B-100, la seule protéine de la LDL. De plus, l’activité de la myéloperoxydase à la surface des LDLs a également été investiguée.
Les résultats de ce travail montrent que la myéloperoxydase s’attaque de manière spécifique aux LDLs et que le modèle chimique utilisant de l’acide hypochloreux pour mimer l’action de la myéloperoxydase n’est pas parfait. Enfin, nous avons également observé des changements dans l’activité enzymatique lorsque la myéloperoxydase est adsorbée à la surface des LDLs.
Doctorat en Sciences biomédicales et pharmaceutiques
info:eu-repo/semantics/nonPublished
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Guerrini, Luca. "Process optimization for polyhydroxyalkanoate production by mixed microbial cultures within the B-PLAS project." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/24409/.
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Polyhydroxyalkanoates (PHA) are biodegradable polyesters with comparable properties to some petroleum-based polyolefins. Within the context of the B-PLAS process, the PHA production is integrated with a wastewater treatment process aimed at recovering energy and C through platform molecules such as volatile fatty acids (VFAs). Eventually, selected mixed microbial cultures (MMCs) are provided with a fermentation broth under an aerobic dynamic feeding regime to produce PHA-enriched biomass. In this study, an anoxic/aerobic selection and accumulation process has been explored and compared on a bench scale with the standard
and most studied full aerobic alternative. A final setup for both the bench-scale experiments and the B-PLAS pilot plant has also been proposed, allowing to achieve, on-demand, a higher dried biomass PHA content (>50%) compared to the analogous aerobic setup. In addition, the selected population has been proven to respond positively to reduced oxygenation conditions, opening new possibilities to maximise the production of the pilot plant while reducing the oxygenation-related costs and streamlining the process scheme.
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Pons, Maria J., Delfino Vubil, Elisabet Guiral, Dinis Jaintilal, Oscar Fraile, Sara M. Soto, Betuel Sigauque, et al. "Characterisation of extended-spectrum b-lactamases among Klebsiella pneumoniae isolates causing bacteraemia and urinary tract infection in Mozambique." Elsevier B.V, 2015. http://hdl.handle.net/10757/347017.
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The aim of this study was to determine the prevalence of extended-spectrum b-lactamase (ESBL)- producing Klebsiella pneumoniae isolated from urinary tract and bloodstream infections in a rural hospital in Manhic¸a, Mozambique. ESBLs were investigated among ceftriaxone-non-susceptible K. pneumoniae clinical isolates recovered between 2004 and 2009. Characterisation of blaCTX-M, blaSHV, blaOXA and blaTEM genes was performed by PCR and sequencing. Epidemiological relationships were established by phylogenetic analysis, repetitive extragenic palindromic PCR (REP-PCR), pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST), whilst plasmid transferability was evaluated by conjugation. In addition,the presence of class 1 and 2 integrons was studied.A total of 19 K. pneumoniae were analysed. The blaCTX-M-15 gene was found in all strains. Other ESBL genes were found concomitantly, including blaSHV-5, blaSHV-2, blaSHV-2A, blaSHV-12 and blaSHV-38. In addition, other b-lactamases such as blaTEM-1 and blaOXA-30 were also detected. REP-PCR identified 15 different epidemiological profiles. MLST analysis also showed great variability of sequence types. The blaCTX-M-15 gene showed a high transfer capacity. The presence of class 1 integrons was high. High levels of multidrug resistance were also found. In conclusion, these data show the dominance of the CTX-M-type ESBL, particularly CTX-M-15, supporting its worldwide dissemination, including in areas with limited access to third-generation cephalosporins. This finding is a matter of concern for clinical management as third-generation cephalosporins are an alternative for treating severe cases of multidrug-resistant infections in this community.Revisión por pares
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Bamji-Mirza, Michelle. "Defining an Intracellular Role of Hepatic Lipase in the Formation of Very Low Density Lipoproteins and High Density Lipoproteins." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20134.
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Hepatic lipase (HL) plays a pivotal role in the catabolism of apolipoprotein (apo)B-containing lipoproteins and high density lipoprotein (HDL) particles through its reported catalytic and non-catalytic extracellular functions. The current study tested the hypothesis that HL expression might impair formation and secretion of hepatic derived very low density lipoproteins (VLDL) and apoA-I (nascent HDL). Stable or transient expression of human HL (hHL) in McA-RH7777 cells resulted in decreased incorporation of [3H]glycerol into cell-associated and secreted (VLDL-associated) 3H-triacylglcyerol (TAG) relative to control cells. Stable expression of catalytically-inactive hHL (hHLSG) also resulted in decreased secretion of VLDL-associated 3H-TAG whereas cell-associated 3H-TAG levels were unchanged. Expression of hHL or hHLSG increased cell-associated 35S-apoB100 with relatively no change in secreted 35S-apoB100. Importantly, hHL or hHLSG expression resulted in reduced 3H-TAG associated with the microsomal lumen
lipid droplets (LLD), and increased relative expression of ApoB and genes involved in lipogenesis and fatty acyl oxidation. Transient expression of hHL in HL-null primary hepatocytes, mediated by adenoviral gene transfer, resulted in decreased steady-state
levels of cell-associated and secreted apoA-I and reduced rates of synthesis and secretion
of 35S-apoA-I. HL-null hepatocytes exhibited increased levels of secreted 35S-apoA-I relative to wildtype hepatocytes while cell-associated 35S-apoA-I levels were normal.
Transient expression of a hHL chimera (hHLmt), in which the C-terminus of hHL was replaced with mouse HL sequences, exerted an inhibitory effect on apoA-I production similar to that of hHL even though hHLmt was secreted less effectively than hHL with impaired exit from the endoplasmic reticulum (ER) as compared with hHL. In contrast, stable expression of hHL in McA-RH7777 cells resulted in a dose-dependent increase in cell-associated and secreted 35S-apoA-I levels. These studies demonstrate that hHL has an intracellular (but non-catalytic) role in reducing the content of the LLD and ultimately the buoyancy of secreted VLDL particles, and that the N-terminal sequences of ER-residing hHL directly or indirectly modulates the production and secretion of apoA-I (nascent HDL) from hepatocytes.
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Tovar, Thais Tristão. "Estudo da Hepatite B oculta em doadores de sangue de Vitória, Espírito Santo." Universidade Federal do Espírito Santo, 2012. http://repositorio.ufes.br/handle/10/5755.
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Hepatite_B_Oculta_2012.pdf: 1487094 bytes, checksum: 098e451e5a2e2af112aa8508df956a77 (MD5)
Previous issue date: 2012-02-29Occult hepatitis B (OHB) is defined as the presence of low levels of HBV DNA in the liver or serum of individuals testing hepatitis B surface antigen (HBsAg) negative. In most cases of OHB, sera are positive for hepatitis B core antibody. The literature contains quite a few studies on the prevalence of OHB in Brazil, as well as in the worldwide population. Such reports, often controversial, demonstrate that the OHB prevalence varies among healthy individuals or patients with diseases unrelated to the liver and patients with chronic liver disease. Despite efforts, it is necessary a better understanding of: the reasons for the persistence of low levels of HBV-DNA in the absence of detectable HBsAg, the potential risk of OHB transmission and its role in the progression and aggravation of some liver diseases. Therefore, it is interesting to know the prevalence of OHB indifferent population samples which allows de monitoring of carriers of the occult infection, followed prospectively in order to try to surprise the possible effects of the presence of low levels of HBV-DNA in these individuals. In this study we investigated the presence of Occult Hepatitis B in peripheral blood obtained from 520 healthy donors of Vitoria, Espirito Santo, with the aim of guiding policies to include or not the sensitive HBV-DNA nucleic acid amplification technique (NAT) screening in blood donations with a detection limit of 54UI/mL. In order to enable the molecular detection we had also developed a method that screens plasma samples in pools which is capable of detecting the presence of HBV in the ratio of 1:40.Through the technique of nested-PCR we found that 0,2% (1/520) had occult HBV in serum samples. Despite the low prevalence of OHB detected in the study, a considerable number of patients with occult HBV infection may not have been detected if the blood units were only tested for serological markers of HBV infection. So it is important to know the prevalence of OHB in one or more additional population groups, in order to follow up carriers of occult infection prospectively to determine possible effects of the presence of HBV-DNA in low concentrations in these individuals
A Hepatite B Oculta (HBO) é definida pela presença do DNA do VHB com carga viral geralmente baixa (<200UI/mL), no fígado ou soro de pessoas com antígeno de superfície (HBsAg) indetectável. Na maioria dos casos de HBO há positividade para o anticorpo contra o antígeno core da Hepatite B (anti-HBc). Na literatura constam poucos estudos sobre a prevalência da HBO no Brasil, bem como na população mundial. Existem relatos, muitas vezes controversos, que reportam frequências variáveis da HBO em indivíduos sem doença ou portadores de doença não relacionada com o fígado e em hepatopatas crônicos. Apesar dos esforços, faz-se necessário ainda uma melhor compreensão das razões para a persistência da baixa viremia do VHB na ausência de HBsAg detectável, do potencial risco de transmissão da HBO e do seu papel na progressão e agravamento de algumas hepatopatias. No estudo investigou-se a presença de HBO em 520 doadores de sangue de Vitória, Espírito Santo, com o objetivo de nortear políticas para incluir ou não a triagem molecular NAT (Nucleic Acid Amplification Technique ) de bolsas de sangue. Para viabilizar a detecção molecular desenvolveu-se também uma metodologia de extração em pool de amostrascapaz de detectar a presença do VHB na proporção de 1:40 com limite de detecção de 54UI/mL. Através da técnica de nested-PCR detectou-se a presença do VHB oculto em 0,2% (1/520) das amostras. Apesar da baixa prevalência de HBO detectada no estudo, um número considerável de portadores da infecção oculta podem não estar sendo detectados, se apenas a pesquisa de marcadores sorológicos da presença do VHB esta sendo realizada nas bolsas de sangue. Sendo assim é importante conhecer a prevalência da HBO em diferentes amostras da população para que se possa ter em mãos portadores da infecção oculta acompanhados prospectivamente a fim de tentar surpreender possíveis efeitos da presença do DNA do VHB em baixas concentrações nesses indivíduos
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Harrison, Nicola. "Magnetic properties and microstructure of intermediate and low rare earth content Ndâ‚‚Feâ‚â‚„B-based nanocomposite magnets." Thesis, University of Sheffield, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443883.
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Gubay, Finn. "Higher derivative corrections to the low-energy effective action of type IIA/B string theory and M-theory." Thesis, King's College London (University of London), 2012. https://kclpure.kcl.ac.uk/portal/en/theses/higher-derivative-corrections-to-the-lowenergy-e-ective-action-of-type-iiab-string-theory-and-mtheory(775e2c55-d7de-4d43-89f4-b995fa13b640).html.
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The type IIA and type IIB supergravity actions in d = 10 dimensions are the low-energy effective theories of type IIA and IIB string theory. In addition, the unique eleven dimensional supergravity theory is the low-energy effective action of M-theory. Higher order corrections to the low-energy effective actions of these supergravity theories contain perturbative and non-perturbative effects of the corresponding string theories and, as such, understanding the structure of the higher order terms provides an insight into the perturbative and non-perturbative formulations of string theory. The U-duality groups of type IIA/B string theory and M-theory compactified on a torus to d < 10 dimensions puts powerful constraints on the higher derivative terms in the effective actions of these theories. In particular, the higher derivative terms in d = 10 - n dimensions are required to possess coefficient functions that transform as En+1 (Z) automorphic forms. These automorphic forms are complex mathematical objects that encode all the perturbative and non-perturbative features of type II string theory and M-theory compactified on an torus to d dimensions. We investigate the structure of the higher derivative terms and their associated automorphic forms in the effective actions of type IIA/B string theory and M-theory. Constraints on automorphic forms appearing in d dimensions by dimensional reduction of arbitrary higher derivative terms in the type IIA, type IIB and M-theory effective actions to d dimensions are obtained. The behaviour of higher derivative terms in the d dimensional type II effective action in specic limits of various parameters is analysed. We derive a group theoretical interpretation for each limit. A general formula is given for a class of automorphic forms in these limits.
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Brinkmann, Jan Ole [Verfasser]. "Vessel function of the atherosclerotic low-density-lipoprotein-receptor-deficient apolipoprotein-B-100-only mouse / Jan Ole Brinkmann." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2008. http://d-nb.info/102325784X/34.
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Nagara, Srinivasa Prasanna Srivatsa [Verfasser], Anne E. B. [Akademischer Betreuer] Nielsen, Anne E. B. [Gutachter] Nielsen, Roderich [Akademischer Betreuer] Moessner, Roderich [Gutachter] Moessner, and Jan C. [Gutachter] Budich. "Special states in quantum many-body spectra of low dimensional systems / Srivatsa Nagara Srinivasa Prasanna ; Gutachter: Anne E. B. Nielsen, Roderich Moessner, Jan C. Budich ; Anne E. B. Nielsen, Roderich Moessner." Dresden : Technische Universität Dresden, 2021. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa2-758538.
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Maisonet, Mildred, Ruby Yadav, and Edward Leinaar. "Role of PFOA and PFOS on Serum Apolipoprotein B, NHANES, 2005-2006." Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etsu-works/27.
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Background: Exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) have been associated with higher circulating concentrations of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C). ApoB is the primary apolipoprotein component of LDL-C, and acts as a ligand for LDL-C receptors in various cells throughout the body. Circulating concentrations of ApoB are considered to be a better indicator of heart disease risk than TC or LDL-C. Objectives: Explore associations of concentrations of PFOA and PFOS with serum ApoB in adults. Methods: We analyzed data from 2744, 20-80 years old participants in the 2005–2006 National Health and Nutrition Examination Survey (NHANES). Linear regression models were used to estimate adjusted predicted means of serum ApoB (in g/L) for quartiles of PFOA and PFOS (in ng/mL) to describe patterns of associations. Results: Adjusted predicted mean concentrations of serum ApoB did not appear to vary meaningfully with increasing concentrations of PFOA (Q1 1.11, Q2 1.02, Q3 1.01, Q4 1.02) or increasing concentrations of PFOS (Q1 1.06, Q2 1.05, Q3 1.07, Q4 0.99) in study participants. Conclusions: Exposure to PFOA or PFOS does not appear to alter Apo B concentrations in adults.
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Hayes, William Michael. "Neutron detection, the Kibble mechanism and the decay of quantum turbulence in superfluid '3He-B at very low temperatures." Thesis, Lancaster University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242837.
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Heilos, Anna [Verfasser], and Bernd [Gutachter] Engels. "Mechanistic Insights into the Inhibition of Cathepsin B and Rhodesain with Low-Molecular Inhibitors / Anna Heilos ; Gutachter: Bernd Engels." Würzburg : Universität Würzburg, 2019. http://d-nb.info/1180982304/34.
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