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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.
151

Vliv rozptýlené výztuže na průběh zrání polymercementových hmot / Dispersed reinforcement influence on the maturation of polymercement materials

Zaťko, Petr January 2017 (has links)
The diploma thesis is focused on polymercement materials with dispersed reinforcement. The aim of this work is development of suitable polymercement mixture and monitoring of the impact of dispersed reinforcement on the course of maturation of these materials and physico-mechanical properties. The effect of high temperatures on the properties of the mortar is also examined. Emphasis is placed on the use of alternative resources and byproducts. Mixed binder of cement and slag and admixture of microsilica was used. Recycled cellulose was used as dispersed reinforcement and was compared with commercial polypropylene fibers.
152

A unique serpin P1′ glutamate and a conserved β-sheet C arginine are key residues for activity, protease recognition and stability of serpinA12 (vaspin)

Ulbricht, David, Pippel, Jan, Schultz, Stephan, Meier, René, Sträter, Norbert, Heiker, John T. 06 March 2019 (has links)
SerpinA12 (vaspin) is thought to be mainly expressed in adipose tissue and has multiple beneficial effects on metabolic, inflammatory and atherogenic processes related to obesity. KLK7 (kallikrein 7) is the only known protease target of vaspin to date and is inhibited with a moderate inhibition rate. In the crystal structure, the cleavage site (P1-P1′) of the vaspin reactive centre loop is fairly rigid compared with the flexible residues before P2, possibly supported by an ionic interaction of P1′ glutamate (Glu379) with an arginine residue (Arg302) of the β-sheet C. A P1′ glutamate seems highly unusual and unfavourable for the protease KLK7. We characterized vaspin mutants to investigate the roles of these two residues in protease inhibition and recognition by vaspin. Reactive centre loop mutations changing the P1′ residue or altering the reactive centre loop conformation significantly increased inhibition parameters, whereas removal of the positive charge within β-sheet C impeded the serpin–protease interaction. Arg302 is a crucial contact to enable vaspin recognition by KLK7 and it supports moderate inhibition of the serpin despite the presence of the detrimental P1′ Glu379, which clearly represents a major limiting factor for vaspin-inhibitory activity. We also show that the vaspin-inhibition rate for KLK7 can be modestly increased by heparin and demonstrate that vaspin is a heparin-binding serpin. Noteworthily, we observed vaspin as a remarkably thermostable serpin and found that Glu379 and Arg302 influence heat-induced polymerization. These structural and functional results reveal the mechanistic basis of how reactive centre loop sequence and exosite interaction in vaspin enable KLK7 recognition and regulate protease inhibition as well as stability of this adipose tissue-derived serpin.
153

Cluster-Based Analysis Of Retinitis Pigmentosa Candidate Modifiers Using Drosophila Eye Size And Gene Expression Data

James Michael Amstutz (10725786) 01 June 2021 (has links)
<p>The goal of this thesis is to algorithmically identify candidate modifiers for <i>retinitis pigmentosa</i> (RP) to help improve therapy and predictions for this genetic disorder that may lead to a complete loss of vision. A current research by (Chow et al., 2016) focused on the genetic contributors to RP by trying to recognize a correlation between genetic modifiers and phenotypic variation in female <i>Drosophila melanogaster</i>, or fruit flies. In comparison to the genome-wide association analysis carried out in Chow et al.’s research, this study proposes using a K-Means clustering algorithm on RNA expression data to better understand which genes best exhibit characteristics of the RP degenerative model. Validating this algorithm’s effectiveness in identifying suspected genes takes priority over their classification.</p><p>This study investigates the linear relationship between <i>Drosophila </i>eye size and genetic expression to gather statistically significant, strongly correlated genes from the clusters with abnormally high or low eye sizes. The clustering algorithm is implemented in the R scripting language, and supplemental information details the steps of this computational process. Running the mean eye size and genetic expression data of 18,140 female <i>Drosophila</i> genes and 171 strains through the proposed algorithm in its four variations helped identify 140 suspected candidate modifiers for retinal degeneration. Although none of the top candidate genes found in this study matched Chow’s candidates, they were all statistically significant and strongly correlated, with several showing links to RP. These results may continue to improve as more of the 140 suspected genes are annotated using identical or comparative approaches.</p>
154

Emerging Exposure Issues in Inhalation Toxicology

Li Xia (15355489) 29 April 2023 (has links)
<p>  </p> <p>Inhalation is a primary route of environmental and occupational exposures. Inhalation toxicology studies have thoroughly demonstrated the efficacy and adverse effects of a large number of chemicals, metals, pharmaceuticals, and agrochemicals. With the rapid development of new technologies and emergence of prominent subpopulations, some emerging exposure issues have arisen. To better protect public health, it is necessary to address these numerous emerging issues related to inhalation toxicology including 1) exposures to complex and unknown chemical emissions generated as we resolve infrastructure needs, 2) real-world exposure scenarios such as nanoparticle (NP) mixtures that may induce unique toxicity, and 3) variations in toxicity responses that occur in vulnerable and prevalent subpopulations following exposures. We designed three aims 1) to characterize differential representative composite manufacturing emissions (CMEs) and toxicity assessment of inhalation exposure to CMEs, 2) to examine the contribution of variable iron and manganese NP components in welding fumes to pulmonary toxicity, and 3) to evaluate metabolic syndrome (MetS)-induced variations in NP-Biocorona (NP-BC) composition following inhalation and modulation of pulmonary toxicity. Overall, this proposal aimed to characterize the emerging and complex exposures occurring in the real world and elucidate the mechanisms of differential pulmonary toxicity and susceptibility associated with CMEs, different metal NP components in welding fumes, and underlying diseases such as MetS. The conclusions from this project can help to improve the application of water infrastructure repairing technology and the utilization of welding and understand the mechanism of susceptibility to NP exposure among individuals with underlying diseases. Furthermore, the findings from these evaluations have supported and improved worldwide regulation, which promotes a safer utilization of novel materials, newly developed medicines, and complex chemicals.</p>
155

Comportamiento Óptico y Térmico de un Concentrador Solar Lineal con reflector estacionario y Foco Móvil

Pujol Nadal, Ramon 30 July 2012 (has links)
El concentrador solar Fixed Mirror Solar Concentrator (FMSC) apareció en los años 70 con la finalidad de reducir costes en la producción de energía termoeléctrica. Este diseño consiste en un concentrador de reflector estacionario y foco móvil, presenta buena integrabilidad en cubiertas, y es capaz de alcanzar temperaturas entre 100 y 200ºC manteniendo una eficiencia aceptable. En esta tesis se expone una metodología para determinar el comportamiento del FMSC. Se ha desarrollado una herramienta de cálculo basada en el método de ray-tracing, que simula el trazado de los rayos solares en el sistema óptico. Con esta herramienta se ha analizado el comportamiento óptico y térmico del FMSC, y de la versión con espejos curvos Curved Slats Fixed Mirror Solar Concentrator (CSFMSC). Se ha realizado un análisis paramétrico para conocer la influencia de los distintos parámetros en el modificador de ángulo (IAM), y para obtener los diseños óptimos a una temperatura de 200ºC para tres climas en diferentes latitudes. Se han comparado los valores teóricos obtenidos mediante ray-tracing con dos prototipos ensayados, obteniendo un buen ajuste en ambos casos. Los ensayos han sido utilizados para determinar la curva de rendimiento de uno de los prototipos. Se ha hecho uso del método propuesto en la norma EN-12975-2:2006, combinado con valores de IAM obtenidos mediante ray-tracing. Se prueba que esta combinación puede ser útil para obtener la curva de rendimiento de colectores complejos con un modelo biaxial para el IAM. / The Fixed Mirror Solar Concentrator (FMSC) appeared during the 70s with the aim of reducing costs in the production of electricity in solar thermal power plants. This design consists of a concentrator with fixed reflector and moving receiver, has a very good integrability into building roofs and can reach temperatures between 100 and 200ºC with an acceptable efficiency. In this Thesis a methodology is presented for the determination of the behaviour of the FMSC. A simulation tool based on the forward ray-tracing method has been developed. The optical and thermal behaviour of the FMSC and its curved mirror variation called the Curved Slats Fixed Mirror Solar Concentrator (CSFMSC), have been analyzed with this tool. A parametric analysis has been carried out in order to determine the influence of the different parameters on the Incidence Angle Modifier (IAM) and to determine the optimal designs at a temperature of 200ºC for three different climates at different latitudes. The theoretical values obtained from the ray-tracing code have been compared with two experimental prototypes. The experimental and numerical results obtained show a good fit. The efficiency curve of one of the prototypes has been determined from the experimental tests. The methodology proposed in the norm EN-12975-2:2006 has been used in combination with IAM values obtained by ray-tracing. It has been shown that this combination can be effectively used to obtain the efficiency curve of complex collectors with a bi-axial IAM model.

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