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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.
211

Strukturelle Ansätze für die Stereorekonstruktion / Stuctural approaches for stereo-reconstruction

Shlezinger, Dmytro 15 August 2005 (has links) (PDF)
Die Dissertation beschäftigt sich mit Labeling Problemen. Dieses Forschungsgebiet bildet einen wichtigen Teil der strukturellen Mustererkennung, in der die Struktur des zu erkennenden Objektes explizit berücksichtigt wird. Die entwickelte Theorie wird auf die Aufgabe der Stereorekonstruktion angewendet. / The thesis studies the class of labeling problems. This theory contributes to the new stream in pattern recognition in which structure is explicitly taken into account. The developed theory is applied to practical problem of stereo reconstruction.
212

A study on the deviant behaviour of secondary school students

Lee, Yuk-chi., 李玉芝. January 1994 (has links)
published_or_final_version / Social Work / Master / Master of Social Sciences
213

Protein Structure Characterization by Solid-State NMR: Structural Comparison of Mouse and Human alpha-Synuclein Fibrils, Sparse 13C Labeling Schemes, and Stereospecific Assignment of Val and Leu Prochiral Methyl Groups

Lv, Guohua 28 March 2013 (has links)
No description available.
214

Nutritional Labeling on Menus in Full-Service Restaurants: Consumer Attitudes and Intended Usage

Foster, Charles R. 08 1900 (has links)
Dining out has become an important part of the American lifestyle, greater frequencies as well as increased portion sizes have led to concern. The number of Americans that are classified as overweight or obese has also increased considerably, and the foodservice industry has become a target. Mandatory labeling of menu items has been avoided to this point, but the subject has moved to the forefront and continues to be debated. This study surveyed 502 patrons at a student-run restaurant in Texas. Respondents provided information concerning their health and dining habits as well as their attitudes toward and intended usage of nutritional information (NI) on menus in full-service restaurants. Gender, education levels, age, and household income affect the attitudes toward and intended usage of NI. Exercise frequency, the current use of nutritional information on packaged foods, and the practice of healthy eating habits are all related to the intended use of NI while dining out.
215

Efeito da adição de n-acetilcisteína ao tratamento com clozapina na perfusão cerebral de pacientes com esquizofrenia refratária / Effects of adjunct n-acetylcysteine to the treatment with clozapine in resting state cerebral perfusion of subjects with refractory schizophrenia

Souza, Roberto Mascarenhas 31 May 2019 (has links)
A esquizofrenia continua sendo um dos transtornos mais desafiadores para a clínica psiquiátrica, apesar dos estudos atuais que tentam elucidar sua fisiopatologia e buscar novas opções de tratamento. A n-acetilcisteína (NAC) é uma droga utilizada há mais de 30 anos na clínica médica no tratamento da intoxicação por acetaminofeno e como mucolítico na DPOC, entre outros. Evidências recentes apoiam o seu uso no tratamento de diversos transtornos neuropsiquiátricos, como depressão, transtorno afetivo bipolar, dependência química e esquizofrenia. A droga tem como provável mecanismo de ação um aumento na atividade antioxidante através do aumento nos níveis de glutationa (GSH) e modulação da neurotransmissão glutamatérgica. Nas duas últimas décadas, o estudo dos mecanismos neurobiológicos subjacentes aos transtornos psiquiátricos, bem como a investigação dos possíveis mecanismos e regiões cerebrais influenciados por substâncias psicofarmacológicas, recebeu importante contribuição das técnicas de neuroimagem funcional. Apesar disto, até o momento existem poucos estudos que avaliaram os mecanismos centrais relacionados às propriedades antipsicóticas da NAC em humanos. Este estudo tem o objetivo de investigar os efeitos da NAC em indivíduos portadores de esquizofrenia refratária em uso exclusivo de clozapina através de medidas de sintomas positivos e negativos e da avaliação da perfusão cerebral através de ressonância magnética nuclear utilizando a técnica de arterial spin labeling (ASL). Foram avaliados 20 sujeitos com esquizofrenia refratária em uso de clozapina em um estudo com distribuição aleatória, duplo-cego e controlado por placebo, utilizando a dose de 2000mg por dia de NAC. Do total da amostra, 14 tiveram as imagens perfusão sanguínea cerebral analisadas. O estudo teve a duração de oito semanas, com avaliações a cada quatro semanas e realização das RMN no início e ao final do período. Não foram observadas diferenças estatisticamente significativas entre os grupos placebo e NAC nas escalas BPRS e PANSS-N. O grupo que recebeuNAC apresentou mais efeitos colaterais, porém no geral a medicação foi bem tolerada. Também não se observou diferenças no FSC das diversas ROI analisadas. A NAC não produziu mudanças estatisticamente significativas nas escalas de sintomas e no FSC nesta amostra, apesar de outros estudos mostrarem diferenças significativas favorecendo a NAC. O presente estudo não mostrou melhora do FSC, mesmo após oito semanas, o que pode significar que a ASL pode não ser um método adequado para avaliar os efeitos cerebrais desta droga / Schizophrenia continues to be one of the most challenging psychiatric disorders in the clinical practice, despite recent studies that attempt to elucidate its pathophysiology and search for new treatment options. N-acetylcysteine (NAC) is a drug that has been used for more than 30 years in clinical medicine, in situations like acetaminophen intoxication and as mucolytic in COPD, among others. Recent studies support its therapeutic use in neuropsychiatric disorders such as depression, bipolar disorder, substance abuse and schizophrenia. The mechanism of action of NAC seems to occur in antioxidant activity, through the increase of glutathione levels (GSH) and in the modulation of glutamatergic neurotransmission. In the last two decades, the study of the neurobiological mechanisms underlying psychiatric disorders, as well as the investigation of the possible mechanisms and brain areas influenced by psychopharmacological substances received a significant contribution of functional neuroimaging techniques. Despite this, there are few studies that have evaluated the central mechanisms related to the antipsychotic properties of NAC in humans. This study aims to investigate the effects of NAC in subjects with refractory schizophrenia, exclusively on clozapine use, through measure of positive and negative symptoms and the evaluation of cerebral perfusion by magnetic resonance imaging, using the arterial spin labeling technique (ASL) . Twenty subjects with refractory schizophrenia were evaluated in a randomized, double-blind, placebo-controlled study using a dose of 2000mg per day of NAC. From the total sample, 14 had cerebral perfusion images analyzed. The study had a duration of eight weeks, with evaluations at each four weeks and MRI sessions before the beginning of NAC and at the end of the period. The results did not show statistically significant differences between placebo and NAC groups onthe BPRS and PANSS-N scales. The NAC group presented more side effects, although the medication was well tolerated in general. There were also no differences in the cerebral blood flow (CBF) among the regions of interest analyzed. Although there was no difference regarding symptoms scales the CBF in this sample, other studies found differences favoring NAC. The present study did not show changes of the CBF, which might mean that ASL is not an adequate technic to evaluate neurochemical effects of this drug
216

Strukturelle Ansätze für die Stereorekonstruktion

Shlezinger, Dmytro 18 July 2005 (has links)
Die Dissertation beschäftigt sich mit Labeling Problemen. Dieses Forschungsgebiet bildet einen wichtigen Teil der strukturellen Mustererkennung, in der die Struktur des zu erkennenden Objektes explizit berücksichtigt wird. Die entwickelte Theorie wird auf die Aufgabe der Stereorekonstruktion angewendet. / The thesis studies the class of labeling problems. This theory contributes to the new stream in pattern recognition in which structure is explicitly taken into account. The developed theory is applied to practical problem of stereo reconstruction.
217

Application of center-out k-space trajectories to three-dimensional imaging of structure and blood transport in the human brain

Shrestha, Manoj 05 September 2016 (has links)
A novel non-invasive imaging method of unique k-space trajectory named “3D center-out EPI with cylindrical encoding” was developed and implemented for fast imaging of the human brain. The method based on a variant of 3D hybrid EPI combines advantages of the Cartesian and the radial encoding to achieve ultra-short echo time independent of spatial resolution and reasonably short echo train length yielding a quality image of high signal-to-noise ratio. Unlike rectilinear sampling, the method offers not only less motion and flow artifacts but enables also the undersampling capability. As a result, the method improves temporal resolution by shortening the measurement time. Nonetheless, artifacts induced from long-term drifts of the magnetic field as well as geometrical distortions caused by B0 inhomogeneity were removed with the average phase of the k-space center lines and an additional field map scan. Compared to other cylindrical k-space trajectories based on echo-planar imaging, which lead to progressively increasing echo time upon increasing the spatial resolution, the proposed method offers more benefits. As a significant application, imaging readout of the novel technique was applied to true 3D cine imaging which was later used in the combination of pseudo-continuous arterial spin labeling module in order to track a short arterial spin labeling (ASL) bolus of well-defined length along the fast passage through the large vessel compartment of the brain. Parametric maps of ASL signal change, estimated time-to-peak and ASL bolus width were extracted in order to characterize the macrovascular compartments of the brain-feeding arteries. Consequently, bolus dispersion within a single arterial branch was also assessed.
218

Příprava rekombinantních forem extracelulární domény myších leukocytárních receptorů z rodiny NKR-P1. / Preparation of recombinant forms of the extracellular part of mouse leukocyte receptors from NKR-P1 family.

Adámek, David January 2012 (has links)
Mouse NK cell receptors belonging to NKR-P1 family plays role in activation, inhibition and cytokine secretion by these cells. Aim of this thesis is preparation of extracellular parts of C57BL/6 mouse strain activating receptors mNKR-P1A and mNKR-P1C. Production vectors with coding sequences of both proteins were prepared. Next, optimization of production in E. coli was done and appropriate in vitro refolding and purification protocol were developed. Purified proteins were characterized by mass spectrometry and labeled by a fluorescent dye. Primary screening for potential ligand was performed. Further work will involve structural characterization of the receptors and identification of their ligands. These data may help to clarify the function of NK cells.
219

Biochemical applications of DsRed-monomer utilizing fluorescence and metal-binding affinity

Goulding, Ann Marie 09 March 2011 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The discovery and isolation of naturally occurring fluorescent proteins, FPs, have provided much needed tools for molecular and cellular level studies. Specifically the cloning of green fluorescent protein, GFP, revolutionized the field of biotechnology and biochemical research. Recently, a red fluorescent protein, DsRed, isolated from the Discosoma coral has further expanded the pallet of available fluorescent tools. DsRed shares only 23 % amino acid sequence homology with GFP, however the X-ray crystal structures of the two proteins are nearly identical. DsRed has been subjected to a number of mutagenesis studies, which have been found to offer improved physical and spectral characteristics. One such mutant, DsRed-Monomer, with a total of 45 amino acid substitutions in native DsRed, has shown improved fluorescence characteristics without the toxic oligomerization seen for the native protein. In our laboratory, we have demonstrated that DsRed proteins have a unique and selective copper-binding affinity, which results in fluorescence quenching. This copper-binding property was utilized in the purification of DsRed proteins using copper-bound affinity columns. The work presented here has explored the mechanism of copper-binding by DsRed-Monomer using binding studies, molecular biology, and other biochemical techniques. Another focus of this thesis work was to demonstrate the applications of DsRed-Monomer in biochemical studies based on the copper-binding affinity and fluorescence properties of the protein. To achieve this, we have focused on genetic fusions of DsRed-Monomer with peptides and proteins. The work with these fusions have demonstrated the feasibility of using DsRed-Monomer as a dual functional tag, as both an affinity tag and as a label in the development of a fluorescence assay to detect a ligand of interest. Further, a complex between DsRed-Monomer-bait peptide/protein fusion and an interacting protein has been isolated taking advantage of the copper-binding affinity of DsRed-Monomer. We have also demonstrated the use of non-natural amino acid analogues, incorporated into the fluorophore of DsRed-Monomer, as a tool for varying the spectral properties of the protein. These mutations demonstrated not only shifted fluorescence emission compared to the native protein, but also improved extinction coefficients and quantum yields.
220

Food label knowledge : a comparison between a developing and developed country context / Susara Carolina Havenga

Havenga, Susara Carolina January 2014 (has links)
The aim of this study was to determine and compare the subjective and objective food label knowledge of consumers from Potchefstroom (South Africa) and Fayetteville (Arkansas, USA), therefore in a developing and developed country context. The question was asked whether the knowledge of consumers in such contexts differed and whether consumers’ demographics are associated with their food label knowledge. No specific research on food label knowledge has been done in a comparative context between a developing and developed country previously. A quantitative study using purposive sampling was conducted among respondents in these contexts by means of interviewer-administered questionnaires. Descriptive and inferential statistics were applied. The total study sample (N = 713) included respondents from South Africa (a developing country) and the United States of America (a developed country) with specific reference to respondents from Potchefstroom (n = 400) and Fayetteville (n = 313). The researcher strived to include respondents from each ethnic, demographic, gender and age group. No differences were found regarding respondents’ subjective knowledge (SK) of food labels. With respect to respondents from Potchefstroom and Fayetteville, practically significant differences regarding objective knowledge (OK) were found only within the factors of locating information (OK-L) and manipulating information (OK-M) with a similar pattern for symbol information (OK-S), although respondents from Fayetteville had higher mean scores for OK-L, OK-M and OK-S, which indicates that respondents from Fayetteville were more knowledgeable on these factors than respondents from Potchefstroom. Within the study populations, better OK was only observed among respondents from Potchefstroom who were young and well educated, whereas respondents from Fayetteville had high levels of knowledge regardless of demographic variables. It was observed that respondents from Potchefstroom were not as knowledgeable (OK-L, OK-M and OK-S) as respondents from Fayetteville. The results from this study serve as evidence for a need to improve food label knowledge in the Potchefstroom context, and raise the question about similar needs in other developing countries. It can be concluded that educational efforts should be developed and implemented to increase objective food label knowledge among consumers from developing country contexts, as OK may have an impact on health. Development of consumer education programmes should focus on the vulnerabilities identified with regard to age and education groups as well as the problems identified regarding label and symbol information provided, whereby consumers might acquire optimal food label knowledge to use these labels for improved decision-making and health. This research about food label knowledge in South Africa and the United States of America, may serve as a foundation for future studies to be conducted in developing and developed country contexts. This might result in a better understanding about factors that contribute to consumers’ confusion, distrust and lack of understanding of food label information, which may hinder food label knowledge in developing country contexts. Demographic, label-reading and health-related factors that may contribute to increased knowledge could also be further explored in addressing specific needs among particular groups in developing country contexts regarding their food label knowledge. / M Consumer Sciences, North-West University, Potchefstroom Campus, 2015

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