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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
591

Estudo Eletroquímico de Catalisadores de Pt-Mo e Pt-Cd para a Oxidação Eletroquímica de Etileno Glicol para a possível Aplicação em Células a Combustível Diretas a Álcool / Electrochemical Study of Pt-Mo and Pt-Cd Catalysts for Electrochemical Oxidation of Ethylene Glycol for possible Application in Direct Fuel Cells to Alcohol

Coutinho, José William Diniz 13 March 2017 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-05-10T17:56:20Z No. of bitstreams: 1 JoseCoutinho.pdf: 2076269 bytes, checksum: f50c622c02cff2de6c220fbd2cf046e2 (MD5) / Made available in DSpace on 2017-05-10T17:56:20Z (GMT). No. of bitstreams: 1 JoseCoutinho.pdf: 2076269 bytes, checksum: f50c622c02cff2de6c220fbd2cf046e2 (MD5) Previous issue date: 2017-03-13 / The electrooxidation of ethylene glycol and its partial oxidation products was studied in platinum-containing electrocatalysts supported on high surface carbon Vulcan XC-72, molybdenum and cadmium (90:10, 80:20, 70:30) in medium acid. All catalysts prepared were synthesized by the alcohol reduction method with 20% metallic charge on the carbon substrate. X-ray diffraction (XRD) analysis showed that the bi-metallic catalysts of PtMo / C and PtCd / C presented cubic face-centered structures and no angular displacement was observed, making it impossible to identify the molybdenum in the catalyst And revealing the absence of alloying characteristics in these catalysts. Results of Transmission Electron Microscopy (MET) revealed that bi-metallic nanoparticles have sizes between 2.0 nm and 4.0 nm. The results of cyclic voltammetry, at room temperature, showed that the presence of Mo and Cd favor the initiation of oxidation at lower potentials than those observed for platinum. However, chronoamperometry data, at a constant potential of 0.50 V and ambient temperature, did not show significant variations in the catalytic current. On the other hand, with the increase in temperature from 25 ° C to 55 ° C, differences in current were observed, with the Pt90Mo10 electrode having the best results. Data obtained by High Performance Liquid Chromatography (HPLC) showed that Glycolide is the main by-product formed by the oxidation of ethylene glycol after electrolysis at 0.50 V. / A eletrooxidação de etileno glicol e de seus produtos parciais de oxidação foi estudado em eletrocatalisadores contendo platina, suportados em carbono de alta área superficial Vulcan XC-72, em molibdênio e cadmio (90:10, 80:20, 70:30) em meio ácido. Todos os catalisadores preparados foram sintetizados pelo método de redução por álcool com 20% de carga metálica sobre o substrato de carbono. As análises por meio da técnica de Difração de Raios-X (DRX) demostraram que os catalisadores bi metálicos de PtMo/C e PtCd/C apresentaram estruturas cúbicas de face centrada e não se verificou nenhum deslocamento angular, impossibilitando a identificação do molibdênio e cádmio nos catalisadores e revelando a ausência de caráter de liga nesses eletro catalisadores. Os resultados de Micrografia Eletrônica de Transmissão (MET) revelaram que as nano partículas bi metálicas possuem tamanhos entre 2,0 nm e 4,0 nm. Os resultados de voltametria cíclica, a temperatura ambiente, mostraram que a presença de Mo e Cd favorecem o início da oxidação para potenciais mais baixos do que os observados para a platina. No entanto, os dados de cronoamperometria, a um potencial constante de 0,50 V e a temperatura ambiente, não mostraram variações significativas na corrente catalítica. Por outro lado, com o aumento da temperatura de 25 °C para 55 °C foram observados diferenças na corrente sendo o eletrodo de Pt90Mo10 com os melhores resultados. Dados obtidos por Cromatografia Líquida de Alta Eficiência (CLAE) mostraram que o Glicoladeído é o principal subproduto formado pela oxidação do etileno glicol após eletrólise a 0,50 V.
592

Targeting c-Met for therapy

Wong, Julin January 2011 (has links)
c-Met is a tyrosine receptor kinase which is activated by its only ligand, the hepatocyte growth factor (HGF). Activation of c-Met leads to a wide spectrum of biological activities such as motility, angiogenesis, morphogenesis, cell survival and cell regeneration. c-Met and HGF knock-out mice are embryonic lethal. During embryogenesis, c-Met is required for liver, kidney and skeletal muscles development. In adult tissues, c-Met is involved in wound healing and hepatocyte regeneration. c-Met is abnormally activated in many tumours types. Aberrant c-Met activation was found to induce tumour development, tumour cell migration and invasion, and the worst and final step in cancer progression, metastasis. In addition, c-Met activation in cells was also shown to confer resistance to apoptosis induced by UV damage or chemotherapeutic drugs. c-Met is thus an attractive target for drug development. This study describes the development of monoclonal antibodies against c-Met as therapeutic molecules in cancer treatment/diagnostics. Antibodies were raised against the a-chain of c-Met. 21 hybridoma clones were single-cell cloned and subjected to preliminary monoclonal antibody characterisation. 11 monoclonal antibodies were finally selected for ascites production and antibody purification. These purified antibodies were characterised by Western blotting, immunofluorescence staining, functional assays (ERK phosphorylation and cell scatter) and for their ability to recognise native c-Met by flow cytometry. Some of the anti-a-chain c-Met antibodies perform better in Western blotting and immunofluorescence staining than the presently-available commercial antibodies. The Mab 2.1 and 13.1 bind strongly to native c-Met in flow cytometry and may be potential candidates for antibody therapy and cancer diagnostics.
593

Acceptance and Commitment Therapy and Posttraumatic Stress Disorder Symptoms in Women

DeLateur, Rachel 01 January 2018 (has links)
The purpose of this study was to analyze the effectiveness of acceptance and commitment therapy (ACT) in a group setting for 8 weeks on the symptoms of posttraumatic stress disorder (PTSD) for women diagnosed with PTSD due to childhood trauma who have not served in the military. ACT was developed using contextualism with relational frame theory being the foundation for contextualism. Women diagnosed with PTSD due to childhood trauma were found to have higher rates of attempted suicide, higher rates of mental health disorders, as well as higher rates of medical disorders than those who were not diagnosed with PTSD. The PTSD symptoms were measured using the PTSD checklist-civilian (PCL-C). The PCL-C was completed during Session 1 and Session 8 of ACT group therapy. There was a total of 24 PCL-C score sheets utilized for this study and only the score sheets of women diagnosed with PTSD due to childhood trauma who did not have a thought disorder were included. The research design was considered a pre-experimental design and the statistical design used was ANOVA with repeated measures using subject x trials. Cohen's estimate of small effect size was used. Secondary data analysis was conducted using archival data from a community mental health agency. According to the statistical measure of the repeated ANOVA the null hypothesis was rejected as there was sufficient evidence to support that using ACT in a group setting for 8 weeks can decrease PTSD symptoms as measured by the PCL-C. This study contributes to social change by decreasing symptoms of PTSD, therefore decreasing suicidal thoughts, as well as behaviors, and lead to an increase in overall functioning and prosocial behaviors.
594

Préparation de tensioactifs par aldolisation de cétoses non protégés / Aldolisation of unprotected ketoses to surfactants

Zhu, Biwen 20 September 2018 (has links)
Dans ce manuscrit, une voie atome économique d'un robuste amphiphile polyols à base de alkyle chaîne liée à liaison C-C ont été développés, ce qui est plus stable pour des applications plus larges. Ce processus implique l'utilisation de matières premières renouvelables et relativement peu coûteuses. Des cétoses tels que la 1,3-dihydroxyacétone et le D-fructose ont été utilisés comme substrats avec des aldéhydes comme agents d'alkylation sans aucune étape de protection-déprotection. La synthèse a été divisée en deux étapes, dans la première étape, les cétoses déprotonées réagissent avec les électrophiles aldéhydes pour former les intermédiaires hydroxycétones. Ensuite, une seconde étape d'hydrogénation avec un catalyseur du ruthénium sur alumine sous pression d'hydrogène a donné accès aux polyols alkylés. Le rendement global de ce procédé en deux étapes est modéré compte tenu de la difficulté de faire réagir une partie fortement hydrophobe avec une partie fortement hydrophile. Ensuite, ces adduits de tétraols obtenus avec la 1,3-dihydroxyacétone ont également été évalués en tant que tensioactifs en effectuant des tests physico-chimiques (CMC, point Krafft et Phase Inverse Temperature). Les résultats ont montré que ces nouveaux agents tensioactifs liés à la liaison C-C sont aussi efficaces que d'autres agents tensioactifs disponibles dans le commerce en diminuant la tension de surface, ce qui est une propriété très attrayante pour des applications potentielles / In this manuscript, an atom economic route of C-C bond based surfactants has been developed. They are more stable for broader applications. This process involves the use of renewable and relatively low cost raw materials. Ketoses such as 1,3-dihydroxyacetone and D-fructose were used as substrates with aldehydes as alkylation agents without any protection-deprotection step. The synthesis has been divided into two steps, in the first step the deprotonated ketoses react with the aldehydes electrophiles to form the hydroxyketone intermediates. Then, a second step of hydrogenation with Ruthenium on alumina catalyst under hydrogen pressure gave access to the alkylated polyols. The overall yield of this two-step process is moderate considering the difficulty of reacting a highly hydrophobic part with a highly hydrophilic part. Then these tetraols adducts obtained with 1,3-dihydrdoxyacetone were also evaluated as surfactants by making physico-chemical tests (CMC, Krafft point and Phase Inverse Temperature). Results have exhibited this novel C-C bond connected surfactants perform as efficient as other commercially available surfactants in decreasing the surface tension which is a very attractive property for potential applications
595

Correlates of protective immunity in individuals who are exposed to Hepatitis C but appear uninfected

Elliott, Lisa, Medicine, UNSW January 2006 (has links)
The hepatitis C virus (HCV) currently infects 3% of the world???s population, with chronic infection in 50-80% of exposed individuals. A small subset of individuals who are exposed to HCV do not develop anti-HCV antibodies, persistent viraemia or chronic hepatitis despite generating HCV-specific CD4+ and CD8+ T cells. These individuals are believed to develop an immune response which rapidly clears viraemia prior to the induction of an antibody response. Circumstantial evidence supports the likelihood that some of these individuals may generate these same responses and outcomes on repeated occasions of HCV infection. HCV-specific cellular immune responses in seronegative subjects have been the subject of only limited prior study, in part due to the lack of appropriate recombinant antigens and assay systems. Therefore, this thesis described the development and validation of an interferon-? (IFN-?) ELISPOT assay using overlapping peptides (n=441). Using this assay, HCV-specific cellular immune responses were detected in 5/10 (50%) of chronically infected subjects. Responses were identified more frequently, and were directed against more regions of the HCV genome, than with traditional assay systems. This IFN-? ELISPOT assay, a comparable interleukin (IL)-2 ELISPOT assay, and a multiplex in vitro cytokine production assay were then used to evaluate HCV-specific cellular immune responses in three cohorts of seronegative subjects at high-risk of exposure to HCV ??? babies born to infected mothers, multiply-transfused subjects with thalassaemia, and high risk injecting drug users. Cellular immune responses were evaluated in 23 infants born to HCV-antibody positive women. Responses were not detected in infants born to HCV-PCR negative mothers. IFN-? production was detected in 1/11 infants born to viraemic mothers using the ELISPOT assay, with cytokine production observed in an additional 3/5 infants studied using the in vitro cytokine production assay. HCV-specific cellular immune responses were assessed in a cohort of multiply transfused subjects with thalassaemia using assays for cytotoxic T lymphocyte activity, IFN-? and IL-2 ELISPOT, as well as lymphocyte proliferation and in vitro cytokine production. Responses were detected in 6/13 chronically infected subjects (46%), 4/7 subjects who had cleared infection (71%), and 14/17 seronegative subjects (82%). The seronegative subjects had responses which were broader and higher in magnitude than those with chronic HCV infection, although lower and narrower than in subjects who had cleared prior HCV infection. IFN-? and IL-2 ELISPOT assays, in additional to in vitro cytokine production assays, were performed on 41 injecting drug users (IDUs), with responses detected in 6 (15%). Seronegative IDUs with HCV-specific cellular immune responses had been injecting for a mean of 7.7 years, and reported multiple risk factors for exposure to HCV. The combined data from these three cohorts indicate that the HCV-specific cellular immune responses detected in seronegative subjects were generally broad in specificity. Cytokine production was generally Th1-biased, a pattern which has previously been associated with an increased likelihood of clearance in primary infection. The findings also suggest that responses can be maintained for decades after exposure, and may provide protection against repeated exposures. In summary, cellular immunity against HCV is evident in some seronegative high risk subjects, suggesting that the cellular immune responses may efficiently facilitate viral clearance. Understanding the mechanisms of this immune response pattern will allow better understanding of the host response to HCV and may provide key insights into vaccine design.
596

Model studies of the cub-histidine-tyrosine centre in cytochrome c oxidase

Lee, Sang Tae, Chemistry, Faculty of Science, UNSW January 2005 (has links)
This thesis reports the synthesis and copper coordination chemistry of covalently-linked aryl-imidazole derivatives designed as models for the crosslinked imidazole-phenol sidechains of the His-Tyr cofactor in the CcO. Three new imidazole- (HL1 - HL3) and three new indole- (HL4 - H2L6) containing tripodal ligands were synthesised. The conjugate addition of an imidazole to activated quinone derivatives was developed as a new route to organic models for the Tyr His cofactor. Two monodentate imidazole-aryl, Im-hq(OH)2 and Im-ArOH, and an imidazole-quinone, Im bq were obtained using this route. The X-ray crystal structure of Im-hq(OH)2.EtOH was determined. The route was also used to give new chelating ligands, H2L10 and HL12, containing a cross-linked imidazole-phenol surrogate for the Tyr244-His240 cofactor. Copper complexes of Im-hq(OH)2, Im-bq, Im-ArOH, H2L10-HL12, and HL1-H2L6 were prepared, and the X-ray crystal structures of [Cu(terpy)(Im-bq)][BF4]2 and five other copper complexes were determined. The physiochemical properties of the copper complexes were characterized by FT-IR, UV-Vis-NIR, EPR and (spectro)electrochemical studies. Key results include: the oxidation of Im-ArO- anion affords the semiquinone radical, Im-sq(4OH)(1O??????), in a hydrous solvent. However, the oxidations of neutral Im-ArOH and [Cu(tpa)(Im-ArOH)]2+ produce the corresponding phenoxy radical species that rapidly and reversibly dimerise to give quinol cyclohexadienone, QCHD, dimers. Significantly [Cu(tpa)(Im-sq(4OH)(1O??????))]2+ was EPR silent, perhaps due to antiferromagnetic coupling between the Cu(II) (S=1/2) and semiquinonyl radical (S=1/2) centres. Deprotonation of the hydroquinone in [Cu(tpa)(Im-hq(OH)2]2+ produces the hydroquinone dianion which reduces the Cu(II) centre. The semiquinone radical is coordinatively labile and dissociates from the Cu(I) centre. The biological implications of these results are mentioned.
597

The role of c-Myb in mammary gland development and tumourigenesis

Miao, Yu Rebecca January 2009 (has links)
c-Myb/MYB is an established and key player in hematopoietic malignancies but more recently a strong case for c-Myb as an oncogene in breast cancer has emerged. c-Myb and its transcriptional target genes have direct bearing on tumour initiation and progression and thus this has opened new opportunities to the development of therapeutic approaches in a range of cancer types with the aim of treating cancer at its various stages. In this study, the requirement of c-Myb during mammary gland tumourigenesis is being examined. In addition a direct therapeutic approach to targeting c-Myb-driven gene grp78/GRP78 in the context of primary and metastatic breast cancer was assessed. / The first aim of this study is to examine the expression of c-Myb during normal mammary gland development. The expression of c-Myb is extensively characterised in a temporal and spatial fashion. Nuclear staining of c-Myb by immunohistochemisty was found to be most elaborately expressed in the ductal epithelium during early mammary gland development. Mouse mammary gland lacking c-myb showed disorganised ductal structure in virgin mice, but did not affect subsequent pregnancy and lactation. / To extend the view that c-Myb is involved in mammary tumourigenesis c-myb-transduced immortalised mammary epithelial cells and two mammary tumour prone transgenic mouse models were examined. NMuMG cells transduced with c-myb showed enhanced proliferation and reduced Annexin V staining consistent with the protection from apoptosis. This reduced apoptosis is consistent with, and perhaps contingent upon, the elevated expression observed for bcl-2 and grp78. The data assembled by expression studies raised the possibility that c-Myb is essential for the establishment of mammary gland tumor in both MMTV-Neu and MMTV-PyMT spontaneous mammary gland tumor models. Loss of c-Myb expression in these models significantly delayed and in most instances completely abolished the onset of mammary gland tumours in both models. Preliminary evidence also indicated that Stat3 phosphorylation may underpin the elevated c-Myb expression in mouse mammary tumour cells. / The focus of my thesis then shifted to examining ways to exploit elevated c-Myb target gene GRP78 expression on the cell surface of mammary tumour cells. To do this I employed a GRP78 binding pro-apoptotic chimera peptide that specifically binds to GRP78 where I examined its efficacy against primary and metastatic breast cancer models. My results demonstrated the anti-tumour activity of the GRP78-chimera peptide both in vitro and in vivo. More importantly, the peptide is also effective at prolonging disease-free survival in mice with established metastatic disease. / Evidence obtained within these studies suggests that c-Myb plays an important role in mammary gland development and tumourgenesis. Although it may be difficult to directly target c-Myb in malignant disease, alternative anti-tumoural therapy may be developed against c-Myb-regulated target genes that are also implicated in mammary tumours. Collectively my thesis studies have advanced our understanding of c-Myb in mammary cancer initiation, progression and as a direct or indirect therapeutic target.
598

C-uppsats inlagd av Peter andersson : Hur upplevs påtvingad behandling?

Andersson, Peter January 2009 (has links)
<p><strong>Abstract:</strong></p><p><strong> </strong></p><p>Denna uppsats söker upplevelsen av påtvingad behandling. Den är gjord på ett behandlingshem i Mellansverige som bedriver behandling efter § 12 LVU med särskilda befogenheter i vård av unga. Behandlingshemmet lyder under SIS (Statens institutionsstyrelse). Underlaget består av fem intervjuer med elever som blir behandlade för narkotika- och alkoholmissbruk samt lättare eller grövre kriminalitet. Metoden som använts för att analysera intervjuerna är fenomenologiskt inspirerad som innebär att man söker efter essensen i upplevda erfarenheter.</p><p>Resultatet visar på sex viktiga teman. Dessa är:<em> </em>Allas problem (ett ”vi” på institutionen), frihetslängtan, passivitet/uppgivenhet, vad eleverna ser som behandling, personalkontakt, aktivitetsbrist. Uppsatsen argumenterar för hur dessa teman utgör individens upplevelse av en behandling på en låsbar institution. Resultatet pekar mot att det idag behöver ses över hur väl denna behandlingsform fungerar utifrån de intagnas perspektiv.</p><p> </p><p><strong> </strong></p><p><strong> </strong></p><p><strong>Sökord: </strong> LVU, Tvång, Ungdomar, Upplevelse, SIS, Fenomenologi, Behandling, Missbruk, Kriminalitet, Motivation, Forced treatment.</p>
599

Prototype of a Fragmented Document Editor

Jutterström, Jenny January 2009 (has links)
<p>Signifikant Svenska AB supplies an information system called Assert, developed to facilitate the aftermarket sales in the manufacturing and subcontractor domains. The information system offers companies and organizations the possibility to gather their product information in a joint database in order to increase the information availability and distribution.</p><p>The management of the documents is an important part of the customer need and can be improved in order to also support document maintenance directly in Assert. At the moment, users only have the possibility to add and view documents in the database. By also providing users the possibility to create documents, update document contents, effectively reuse document sections and ease the translation of documents within Assert, the document management will be better facilitated.</p><p>The purpose of this thesis is to develop a prototype which shows the concept and benefits when providing the possibility to share document contents between several documents. The prototype is developed in C#/WPF and provides a word processor with features to reuse document contents and translation management.</p>
600

Detektering och felkorrigering av fel i flashminnen

Karlsson, Andrea January 2004 (has links)
No description available.

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