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Synthesis, Purification, and Structural and Dynamic Studies of the Amino-Proximate Transmembrane Domain of CREP-1, a Diverged Microsomal Delta-12-DesaturaseGibbons, William Johnathan, Jr. 26 November 2002 (has links)
No description available.
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Development of transmission mode desorption electrospray ionization (TM-DESI)Chipuk, Joseph Eugene 19 August 2010 (has links)
A new era of high-throughput mass spectrometry emerged with the nearly simultaneous introduction of two ambient ionization techniques: desorption electrospray ionization (DESI) and direct analysis in real time (DART). The ability to integrate near instantaneous sample analysis with the specificity of mass spectrometry opened up a broad range of applications. While some of these involve the direct analysis of bulk materials, many others require the collection and deposition of samples onto suitable substrates.
This dissertation details the development of a new mode of operation for DESI. Instead of depositing a sample onto a continuous surface, the sample is either collected by or deposited onto a mesh substrate. Analytes either adsorb to the mesh strands or become suspended within the confines of the mesh in macroscale droplets. The samples are then analyzed by scrolling the mesh orthogonally into the path of an electrospray plume positioned coaxial to the inlet capillary of the mass spectrometer, thereby resulting in the transmission of the ionizing plume directly through the material.
The transmission mode results in desorption and ionization typical of DESI, but with the added benefits of a simpler experimental geometry and the convenient analysis of both dry (i.e., following evaporation of the deposition solvent) and wet (i.e., solvated) samples. The simplification of the experimental arrangement increases method robustness and reproducibility, while the inclusion of a mesh substrate introduces new possibilities for sample collection and introduction, due to the intricate chemistry between the mesh material, analytes, and deposition/electrospray solvent system.
However, the most important benefit lies in the development of surface-enhanced TM-DESI, whereby mesh substrates are derivatized to specifically capture and concentrate targeted analytes directly from solution. Following removal of matrix interferences by sample rinsing and subsequent cleavage of a photolabile linker, the mesh is analyzed directly by TM-DESI-MS. The technique has the potential to overcome interferences that have typically required chromatographic separations using LC-MS or have been insurmountable using ambient ionization methods. The impact of the surface-enhanced method could be tremendous as it may ultimately unite the competing metrics of analytical speed and specificity for ambient ionization mass spectrometry. / text
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Bridgehead substituted scorpionates providing helically chiral complexesBell, Nicola Louise January 2013 (has links)
Tripodal borate ligands, including Tp and Tm, are some of the most widely used in organometallic chemistry and were originally prepared, as anions, from the reaction of the relevant heterocycle with an alkali metal borohydride. However, an alternate route, allowing access to zwitterionic, charge-neutral, scorpionates was recently developed within the Bailey group using tris(dimethylamino)borane as the boron source. This thesis describes the expansion of the borane synthetic route to create new, charge-neutral, zwitterionic, tris(methimazolyl)borate (ZTm) ligands containing B-N, B-O and B-C coordinate bonds. Unusual reactivity with isonitrile donors is also presented which has allowed access to boron substituted anionic Tm ligands from the charge-neutral starting material, (HNMe2)ZTm. Attempts to control the helical chirality of ZTm complexes, by using chiral imidazoline donors on the central boron are also described. The borane synthetic route has allowed access to the novel ligand ZThp, the first example of a tripod based on 2-hydroxypyridine ligand arms. As with Tm, this ligand exhibits helical chirality upon complexation and demonstrates how individual atom hybridisation within the ligand arms affects the helicity and thus the chirality of flexible scorpionate ligands. Coordination studies of both zwitterionic and boron-substituted anionic Tm ligands have shown a tendency for the formation of ‘sandwich’ complexes of the form L2M with some metal precursors, whilst the formation of the corresponding ‘half-sandwich’ complexes of these ligands with ruthenium and rhodium was found to be disfavoured.
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A study based on Kano model to improve satisfaction of students at university libraries in SwedenVerhoeven, Peter, Sha, Nana January 2017 (has links)
This paper designed the questionnaire for the case and combines the Kano Model with the LibQUAL+TM model to understand the students’ perception and expectation of the library service quality in Sweden. Also, find a specific way to improve the satisfaction of the students.
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Susceptibilité de la muqueuse intestinale aux xénobiotiques : implication dans la physiopathologie des maladies inflammatoires chroniques de l’intestin (MICI) : exemple du gène Rac1 / Susceptibility of intestinal mucosa to xenobiotics : role in the physiopathology of inflammatory bowel diseases (IBD) : example of Rac1 geneBourgine, Joanna 24 October 2011 (has links)
Les Maladies Inflammatoires Chroniques de l’Intestin (MICI) regroupent la maladie de Crohn (MC) et la Rectocolite Hémorragique (RCH), deux maladies qui se caractérisent par l’inflammation de la paroi d’une partie du tube digestif, source de lésions destructrices (ulcérations). Ces pathologies complexes sont influencées par de multiples facteurs génétiques et environnementaux. D’une part, de nombreux gènes de susceptibilité pour ces maladies ont été identifiés, mais ils ne permettent d’expliquer qu’une fraction mineure du développement des MICI. D’autre part, certaines études montrent qu’un dysfonctionnement du processus de prise en charge des xénobiotiques dans la muqueuse digestive peut jouer un rôle dans l’initiation et/ou la progression des MICI. Notre travail a consisté, dans un premier temps, en l’étude du profil d’expression de gènes codant pour des protéines impliquées dans le métabolisme et le transport des xénobiotiques. Une stratégie de RT-PCR quantitative en temps réel, permettant l’analyse simultanée de l’expression de 377 gènes, a été utilisée. Cette analyse a été réalisée sur des échantillons de muqueuse intestinale de sujets témoins et de patients atteints de MC, ainsi que sur cinq lignées de cellules épithéliales intestinales.Cette étude a permis d’identifier les systèmes de prise en charge des xénobiotiques présents dans la muqueuse intestinale saine. Des profils d’expression différents ont été mis en évidence entre les tissus intestinaux sains et inflammatoires, mais également entre les tissus intestinaux et les lignées cellulaires intestinales, ce qui suggère des différences majeures dans les processus de prise en charge cellulaire des xénobiotiques, et, par conséquent des différences de susceptibilité à l’effet des composés toxiques exogènes. Dans un second temps, la petite protéine G, Rac1, a été étudiée. Cette protéine est impliquée dans la réparation des ulcérations de l’épithélium intestinal et a récemment été identifiée comme la cible des métabolites actifs des médicaments thiopuriniques, largement prescrits dans le traitement des MICI. La nature et l’étendue de la variabilité de la séquence nucléotidique du gène Rac1 a été évaluée, chez des volontaires sains et des patients atteints de MICI, à l’aide d’une stratégie basée sur le couplage de l’analyse du polymorphisme de conformation de fragments d’ADN simple brin générés par réaction de polymérisation en chaine (PCR-SSCP) et du séquençage. Des études in silico et in vitro des conséquences fonctionnelles des polymorphismes d’intérêts ont ensuite été effectuées dans des lignées cellulaires intestinales (HT29 et Caco-2) et lymphocytaires (Jurkat). Cela nous a conduits à mieux caractériser le promoteur de Rac1 par une analyse de délétion séquentielle et par des techniques de ChIP et d’EMSA.Cette étude nous a permis de démontrer pour la première fois l’existence de polymorphismes génétiques fonctionnels de Rac1 et d’identifier son promoteur minimal, ainsi que des facteurs de transcription à l’origine de la régulation de cette protéine. / Crohn’s disease (CD) and Ulcerative colitis (UC) are chronic inflammatory bowel diseases (IBD) of the gastrointestinal tract. These are multifactorial polygenic diseases with probable genetic heterogeneity. An emerging concept suggesting that dysfunction(s) of the processing of xenobiotics in the intestinal mucosa may be an important event in the initiation and progression of IBD has been discussed. Firstly, in this study, a precise and reliable characterization of the global expression profile of genes which code enzymes, transporters and nuclear factors involved in the processing of xenobiotics has been performed in intestinal epithelium of controls or patients with IBD, and in 5 intestinal cell lines. A quantitative real-time RT-PCR analysis using TaqMan Low Density Arrays (TLDA) was performed to simultaneously measure the expression of 377 genes.This work has identified genes encoding proteins that are involved in the metabolism and the disposition of xenobiotics in the healthy intestinal mucosa. Different genes expression profile between healthy and inflammatory intestinal tissues and between healthy intestinal tissues and intestinal cell lines were found. These tissues will consequently display distinctive susceptibility toward environmental chemicals and their toxic effects.Secondly, the small G protein, Rac1, which regulates cutaneous and mucosal intestinal wound healing and is identified as a target of active metabolites of thiopurine drugs, used in the treatment of IBD, has been studied. We searched for sequence variations by analysing the nucleotide sequence of the promoter and the coding sequence of Rac1 in genomic DNA from healthy volunteers and patients with IBD, using a PCR-single strand conformation polymorphism (SSCP) strategy and sequencing. The functional consequences of variations, that have been identified, were then analysed in silico and in vitro, in human intestinal cell lines (HT29 and Caco-2) and leukemia T-lymphocyte cell line (Jurkat). Via various deletion constructs, a putative regulatory region was identified and characterized further by chromatin immunoprecipitation and electrophoretic mobility shift assays.This work provides the first evidence that a functional genetic polymorphism of Rac1 activity exists. Furthermore, this study characterizes the proximal promoter of Rac1 gene and demonstrates the presence of consensus binding sites for numerous transcription factors, which could influence gene expression.
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Quel niveau de qualité de traitement peut être obtenu par un système d'irradiation robotisé guidé par l'image en radiothérapie (CyberKnife TM) / Treatment’s Quality Level Can Be Obtained by an Image-Guided Robotized Irradiation System in Radiotherapy CyberknifeTMAl Khawaja, Mohamad Safa 09 November 2011 (has links)
Le CyberKnifeTM est composé d’un accélérateur linéaire de 6 MV monté sur un bras robotisé, avec 6 axes de rotation et d’un système d’imagerie permettant de guider le faisceau d’irradiation sur la cible à traiter. Le but est d'améliorer la précision du traitement et la réduction de l’irradiation des organes critiques environnants. Le traitement est réalisé par la convergence « isotrope » d’une centaine d’orientation pour créer jusqu’à 1200 mini faisceaux dirigés sur la cible avec une précision sub-millimétrique. Cet ensemble est complété par une table de traitement montée sur un bras robotisé qui offre 6 degrés de liberté supplémentaires, permettant d’améliorer encore la précision du traitement et de lever d’éventuelles limitations. Grâce à son sous système SynchronyTM, le CyberKnifeTM est capable de traiter les tumeurs abdo-thoraciques, qui bougent avec la respiration en déplaçant dynamiquement le LINAC afin de compenser le mouvement respiro-induit. La forte dose utilisée dans ce genre de traitement hypofractionné, rend toute erreur même minimale inacceptable et impose une très grande précision géométrique, tout en assurant une précision dosimétrique maximale.Notre travail est consacrée à évaluer la qualité de traitement en termes des précisions géométrique et dosimétrique, pour les différents modes de suivi disponibles dans le système en statique, et en dynamique avec suivi respiratoire. Dans cette étude, nous avons utilisé différents types de détecteurs, et trois plateformes afin de simuler des simples mouvements respiratoires, des mouvements réels provenant des patients traités et enfin des mouvements complexes avec hystérésis / The CyberKnifeTM consists of 6MV LINAC mounted on a robotic arm, with six degree of freedom and is coupled to an image guiding system, allowing us to guide the irradiation beams toward the target. The aim is to improve the treatment accuracy and to reduce the irradiation of critical surrounding organs. The treatment is realized by the isotropic convergence of hundreds of orientations for creating up to 1200 mini-beams, which are orientated to the target with submillimetric accuracy. This group is completed by a treatment couch, which is also mounted on a robotized arm, that offers 6 additional degrees of freedom, allowing an additional improvement of accuracy, and eliminates the possible limitations. Using its subsystem SynchronyTM, the CyberKnifeTM is capable of treating the abdo -thoracic tumors, which move with respiration, by moving dynamically the LINAC to compensate the respiratory motion of the tumors. The high dose level, which is used in this kind of hypofractionated treatment, makes the smallest error unacceptable, and needs a very high geometric accuracy with keeping a maximal dosimetric accuracy. Our work is dedicated to evaluate the quality of treatment, in the terms of dosimetric and geometric accuracies. For the different modes of tracking, which are available in the system in static mode, and dynamic mode with respiratory motion tracking. By using different kinds of detectors (ionization chambers, radiochromic films) and three different platforms, which allow simulating simple respiratory motion, real respiratory motion coming from real treated patients, and finally complex motion with hysteresis
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C-Band TM Smart AntennaRyken, Marv 10 1900 (has links)
ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / This paper addresses the system requirements of the C-Band TM antenna that will take the place of the S-Band TM antenna used in applications on munitions and targets that require a quasi-omni directional antenna pattern. For these applications, the C-Band TM effective radiated power (ERP) must be approximately 3 dB higher than the S-Band TM ERP to achieve the same system performance due mainly to weather and environmental differences. From a systems stand-point, this will be a problem for the following reasons: power amplification at higher frequencies is usually less efficient, there is a limit on prime power due to battery capabilities, and a more complex corporate feed at C-Band as compared to S-Band will produce more loss. This means that a more fruitful approach would be to use smart antenna ideas to achieve the required higher ERP as compared to current approaches of using higher power transistors and more battery power. Several smart antenna ideas are introduced in this paper, switchable driven element antenna is described including active amplification at each element.
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Characterization of circulating free DNA in healthy and diseased individuals / Maniesh van der VaartVan der Vaart, Maniesh January 2009 (has links)
Thesis (Ph.D. (Biochemistry))--North-West University, Potchefstroom Campus, 2009.
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Characterization of circulating free DNA in healthy and diseased individuals / Maniesh van der VaartVan der Vaart, Maniesh January 2009 (has links)
Thesis (Ph.D. (Biochemistry))--North-West University, Potchefstroom Campus, 2009.
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Dengue em área com Stegomyia albopicta e ausencia de Stegomyia aegypti, Paraná, BrasilMello, Angela Maron de January 2005 (has links)
Orientador : Ennio Luz / Dissertaçao (mestrado) - Universidade Federal do Paraná, Setor de Ciencias Biológicas, Programa de Pós-Graduaçao em Ciencias Biológicas (Microbiologia, Parasitologia e Patologia Básica). Defesa: Curitiba, 2005 / Inclui bibliografia / Resumo: Dengue é uma arbovirose que vem contribuindo com milhões de casos por ano, preocupando a saúde pública no mundo. É um agravo originário da Ásia onde há dois vetores envolvidos na sua transmissão Stegomyia aegypti e Stegomyia albopicta. No continente americano o vetor apontado como responsável pela transmissão é Stegomyia aegypti muito embora haja indícios no México do papel do Stegomyia albopicta em epidemias daquele país. No Brasil, no estado do Paraná em 2002, na região litorânea houve a notificação de quatro casos de dengue confirmados por sorologia, imunoglobulina M, nos municípios de Paranaguá, Morretes e Pontal do Paraná. Em outro município do litoral, Guaraqueçaba, em área rural ocorreu uma epidemia de doença febril aguda com 191 casos, no período de junho a setembro de 2002. Nesses quatro municípios Stegomyia albopicta é o único vetor detectado pela vigilância entomológica de rotina, no período de 1997-2003. Foi realizado um estudo sorológico para pesquisa de outros casos de dengue na população dos municípios de Morretes, Paranaguá, Pontal do Paraná. Em Guaraqueçaba foram coletadas amostras por domicílio onde houve caso.Nos resultados laboratoriais foram encontradas 51 pessoas com sorologia positiva para dengue, pesquisa de imunoglobulina G pela técnica do Ensaio Imunoenzimático, com uma prevalência geral de 18,8 e nos municípios respectivamente 10,5; 25,8; 11,7 e Guaraqueçaba uma incidência de 23,3 todos por cem habitantes. Na espacialização dos dados utilizando o método de Kernel para análise verificou-se que todos os casos positivos, tanto os com imunoglobulina M quantos os com imunoglobulina G estavam circunscritos dentro de um raio de mil metros confirmando o vínculo epidemiológico.Conclusão: As sorologias positivas para dengue confirmam que houve a circulação do vírus da dengue nos municípios de Morretes, Pontal do Paraná, Paranaguá e Guaraqueçaba, em 2002. O único vetor detectado naquela área vem sendo Stegomyia albopicta portanto as evidências apontam para este espécie como o possível vetor para realizar a transmissão. / Abstract:The Dengue Fever is an arboviruses which has been contributing with thousands of cases by year, worrying the public health in the world. The disease is originary from Asia where there are two important vectors responsible for the transmission. In the Americas the aggravate situation started in eigthy decade, with the number of cases increasing in several countries, specially in Brazil. In the Americas a single vector Stegomyia aegypti has been pointed as responsible for although, there are evidences in Mexico concerning the role of Stegomyia albopicta on dengue epidemic in that country. In Brazil, on the coast of Paraná state Stegomyia albopicta is the unique vector identified since 1997. In 2002 three cases of dengue fever were confirmed by sorology in three sites of that region. At the same time, a fourth site was notified with 191 cases of dengue fever with symptoms such as migraine headache, arthralgia, myalgia and inappetence. A local entomological survey has confirmed only the presence of Stegomyia albopicta. An epidemiological study based on serology for immunoglobulin G, in the cites of Morretes, Paranaguá and Pontal do Paraná has confirmed respective prevalence of 10,5; 25,8; 11,7 and incidence of 23,3 in Guaraqueçaba. A spatial analysis using Kernel method has been verified a clear aggregation of the cases immunoglobulin "M" and immunoglobulin "G" positive cases, circumscribed to an area smaller than a thousand meters, confirming the epidemiologic link. According to the results there has been a circulation of Dengue Fever virus among regions on the coast of Paraná State in 2002, in which Stegomyia albopicta was the main possible vector to accomplish the transmission
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