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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.
71

Different methods for particle diameter determination of low density and high density lipoproteins-Comparison and evaluation

Vaidyanathan, Vidya 15 May 2009 (has links)
Predominance of small dense Low Density Lipoprotein (LDL) is associated with a two to threefold increase in risk for Coronary Heart Disease (CVD). Small, dense HDL (High Density Lipoprotein) particles protect small dense LDL from oxidative stress. Technological advancements have introduced an array of techniques for measuring diameters of LDL and HDL as well as estimating overall particle heterogeneity. However, there is lack of comparative studies between these techniques, and, hence, no conclusive evidence to establish the merits of one method relative to others. The primary purpose of this study was to compare Nondenaturing Gradient Gel Electrophoresis (NDGGE) and Dynamic Laser Light Scattering (DLLS) methods in determining LDL and HDL particle diameter. Our comparison entailed: 1) Evaluating the two methods in terms of their reproducibility 2) Correlating the two methods(in future studies method selection would be driven by time and cost considerations if the two methods correlate), and 3) Evaluating the two methods in terms of their ability to identify bi-modal samples. A secondary purpose of this research was to investigate the effect of refrigerated plasma storage on particle diameter. Reproducibility was measured as Coefficient of Variance (CV). Within and between runs, CV for LDL and HDL for NDGGE were <6% and <15%, respectively and for DLLS, CV within runs were <3% and <5.5%, respectively. No correlation was observed between LDL diameter from the two methods. NDGGE showed two bands for 157 HDL samples of which only 24 samples showed bimodal peaks in DLLS. In order to study the effect of storage, three sample sets of LDL and two sample sets of HDL were used. NDGGE showed a significant difference between mean diameter of fresh and stored LDL and HDL sample for all sets, whereas DLLS showed a significant difference in only one LDL sample set and none for HDL sample sets. We conclude that DLLS may be a better method for measuring LDL diameter because NDGGE overestimated LDL diameter. However, NDGGE was able to resolve subpopulation better in an HDL sample than DLLS. Thus, NDGGE may be a better choice for measuring HDL diameter than DLLS.
72

Molecular epidemiology of nasal carriage in patients with both community and hospital acquired Staphylococcus aureus bacteremia

Hung, Ciha-Hsun 25 August 2003 (has links)
Staphylococcus aureus is one of the most important pathogens both in community- or hospital-acquired infections. The first part of this study analyzed the similarity of molecular types of S. aureus isolates cultured from nares and blood in patients with S. aureus bacteremia (SAB) by pulse-fielded gel electrophoresis (PFGE) of digested chromosomal DNA by Sma I at Kaohsiung Veterans General Hospital from August 1, 2000 through July 31, 2001. The results showed that the PFGE types of 78 (82.1%) paired nare and blood isolates of the 95 SAB patients having nasal carriage of S. aureus were clonally identical; identical in 89.7% patients of nosocomial group and 62.9% in community-acquired group. This provides the powerful evidence in close relationship between nasal carriage of S. aureus and acquisition of it in bacteremia. The data also showed that the rate of methicillin resistance occurred in SAB patients with nasal carriage in isolates of nosocomial SAB was 85.3%, and 31.3% in community-acquired group. The second part of this study analyzed the distribution of PFGE types of 163 nosocomial SAB isolates. The most predominant type was type A and composed 51.5% (84 strains) of 163 nosocomial SAB isolates. They were further divided into 7 subtypes. The second prevailing type was type B, 6.1%(10 strains). The evidence that an endemic stain (type A) occurred in >50% of nosocomial bacteremic isolates demonstrates horizontal dissemination of a single endemic strain of S. aureus in the SAB patients was common in the hospital. These results provide support for strategies to endorse more intensive procedures in infection control and to prevent systemic S. aureus infections by eliminating S. aureus nasal carriage.
73

The bacterial diversity in a KaoPing River constructed wetland for wastewater treatment

Cheng, Shu-Hsun 14 July 2008 (has links)
Constructed wetlands had been used for water treatment worldwide. The efficiency of wastewater treatment in a constructed wetland depends on its design, types of aquatic plants and microbial community present in this wetland. The goal of this study is to analyze the microbial populations in KaoPing River Rail Bridge constructed wetland which was designed to remove the polluted material from municipal sewage and industrial wastewater. Sediment and water samples were collected every 3 months from April, 2007 to April, 2008. The bacterial community diversities were analyzed by PCR-DGGE of the bacterial 16S rRNA gene. Results show approximately 60% BOD, 41% COD, 46% nitrate, 22% total nitrogen, and 97% coliforms were removed by this wetland system. DGGE profiles revealed the bacterial community diversities shifted progressively from the entry to the exit of both A and B systems in this wetland. The microbial populations in water, sediment, biofilms on plants, and soil were quite different from each others. The fecal indicator Escherichia coli was used as a marker to monitor the fecal contamination in all samples. From PCR-DGGE profiles, E. coli could be successfully removed by this wetland system. In conclusion, this constructed wetland is a very successful system for wastewater treatment and is able to remove most of the pollutants before they are discharged into KaoPing River. The results of this study provided useful suggestions for the government to assess the bacterial diversities and the efficiency of this wetland system, to protect people from hazardous risks, and to manage a constructed wetland in the future.
74

Studies of the Diversity of <em>Lactobacillus spp</em>. in Fecal Samples Using PCR and Denaturing Gradient Gel Electrophoresis

Strandgren, Charlotte January 2008 (has links)
<p>Allergic diseases, for example asthma and eczema, are nowadays considered belonging to the most common chronic diseases amongst children in the West, but the cause for this increase in allergy prevalence is unknown. Since studies have indicated a connection between children's exposure of microorganisms during infancy and risk of developing allergic disease, it is suggested that this exposure is a crucial factor in question of allergy development or not. Other studies have established differences in microflora composition between healthy children and children with allergic disease, and several studies have shown that probiotic therapy can give positive results in both prevention and treatment of allergic diseases.</p><p>The aim of this master's thesis was to develop a method, using PCR and denaturing gradient gel electrophoresis, to study the diversity of <em>Lactobacillus spp</em>. in fecal samples retrieved from a study of the probiotic strain<em> L. reuteri</em> ATCC 55730. The developed method was successful in detecting lactobacilli in fecal samples, but three other bacterial genera commonly found in humans were also amplified. Comparison of average numbers of detected bacterial strains and lactobacilli strains between samples belonging to the probiotics and placebo groups, respectively, showed higher numbers for the probiotics group. Also, the only fecal samples that contained <em>L. reuteri</em> belonged to the probiotics group. Although the results are far from statistically significant, they support the theories that probiotics may influence the intestinal microbiota.</p>
75

Information extraction from DNA pulsed-field gel electrophoresis patterns and it's application

Wang, Dayou, January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 120-126). Also available on the Internet.
76

Information extraction from DNA pulsed-field gel electrophoresis patterns and it's application /

Wang, Dayou, January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 120-126). Also available on the Internet.
77

An Investigation of Autoxidation and DNA Thermal Cleavage by Polymethine Cyanine Dyes and Analogs in Aqueous Solutions

Li, Ziyi 16 December 2015 (has links)
Studies on a series of polymethine cyanine dyes and analogs (1-24) show that certain near-infrared cyanines are capable of damaging DNA in the absence of light and external reducing agents. Experimental results imply that in this DNA thermal cleavage, the cyanine reduces Cu(II) to Cu(I) which reacts with O2 to generate the reactive oxygen species (ROS) O2∙- and ∙OH. The formation of these ROS is also thought to be responsible for the irreversible bleaching of the dyes in aqueous solutions. A correlation between structural features and DNA thermal cleavage activity as well as dye bleaching is suggested. Long polymethine chains appear to confer instability to cyanines in aqueous solutions and further contribute to undesired thermal DNA cleavage. These drawbacks can be overcome by introducing an electron-withdrawing group to the polymethine bridge of the cyanine dye.
78

Comparison between four commonly used methods for detection of small M-components in plasma

Jonsson, Susanne January 2008 (has links)
Analysis of M-components is an important part of the diagnosis of monoclonal gammopathies and for the evaluation of disease response during treatment. In this project, two widely used electrophoresis methods and their corresponding immunotyping method were compared to evaluate the sensitivity of each method for the detection of small M-components. The project included 30 plasma samples from patients with identified M-components; 10 samples containing each IgG, IgA and IgM, respectively. All samples were diluted with normal EDTA plasma to achieve M-components of 5,00g/L. The samples were then serially diluted to achieve M-component concentrations of; 5,00, 2,50, 1,25, 0,63, 0,31 and 0,16g/L. All 180 samples were analysed with agarose gel electrophoresis and capillary electrophoresis. The dilutions above and below the detection level of each method were then analysed with immunofixation and immunosubtraction. The results showed good agreement between agarose gel electrophoresis and capillary electrophoresis in the highest concentrations of IgG and IgM. With agarose gel electrophoresis, IgA was detected in the same location as transferrin and the lowest concentration detected were therefore 1,25g/L. Besides the samples containing IgG, immunofixation was the most sensitive method.
79

Untersuchung der Proteinmusterveränderungen renaler Fibroblasten nach TGFß-1-Behandlung / A proteomic analysis of TGFß-1 induced fibroblast transformation during renal fibrosis

Bazra, Souad 11 March 2014 (has links)
No description available.
80

Identification of Multi-drug Resistant Enterococcus spp. as a Potential Nosocomial Pathogen in a Veterinary Teaching Hospital

Steele, Andrea Marie 22 December 2011 (has links)
This thesis presents results from three studies conducted in a veterinary teaching hospital (VTH). Study 1 retrospectively examined a collection of enterococci from clinical infections. Five recurring strains of Enterococcus faecium, and one strain of Enterococcus faecalis were identified using pulsed-field gel electrophoresis (PFGE) as causing clinical infections. Study 2 examined the gastrointestinal tract enterococci as a source of enteroccocal infections in dogs. Enterococcal catheter-associated bacteriuria (CA-bacteriuria) rate was 8%. In 3 of 4 sets of bacteriuria and rectal isolates, CA-bacteriuria isolates were indistinguishable from rectal isolates suggesting that the patient’s fecal enterococci represented the infection source. In all 3 sets of wound and rectal isolates, fecal carriage of the infection isolate was observed. Study 3 examined the prevalence of bacterial species and the overall CA-bacteriuria rate. CA-bacteriuria rate was 24%, with Enterococcus spp., E. coli, Staphylococcus spp., Streptococcus spp. and Enterobacter spp., as the most prevalent bacteria in listed order. / PetTrust

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