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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.
191

A cell level automated approach for quantifying antibody staining in immunohistochemistry images. A structural approach for quantifying antibody staining in colonic cancer spheroid images by integrating image processing and machine learning towards the implementation of computer aided scoring of cancer markers.

Khorshed, Reema A.A. January 2013 (has links)
Immunohistological (IHC) stained images occupy a fundamental role in the pathologist¿s diagnosis and monitoring of cancer development. The manual process of monitoring such images is a subjective, time consuming process that typically relies on the visual ability and experience level of the pathologist. A novel and comprehensive system for the automated quantification of antibody inside stained cell nuclei in immunohistochemistry images is proposed and demonstrated in this research. The system is based on a cellular level approach, where each nucleus is individually analyzed to observe the effects of protein antibodies inside the nuclei. The system provides three main quantitative descriptions of stained nuclei. The first quantitative measurement automatically generates the total number of cell nuclei in an image. The second measure classifies the positive and negative stained nuclei based on the nuclei colour, morphological and textural features. Such features are extracted directly from each nucleus to provide discriminative characteristics of different stained nuclei. The output generated from the first and second quantitative measures are used collectively to calculate the percentage of positive nuclei (PS). The third measure proposes a novel automated method for determining the staining intensity level of positive nuclei or what is known as the intensity score (IS). The minor intensity features are observed and used to classify low, intermediate and high stained positive nuclei. Statistical methods were applied throughout the research to validate the system results against the ground truth pathology data. Experimental results demonstrate the effectiveness of the proposed approach and provide high accuracy when compared to the ground truth pathology data.
192

Optimering av PTAH-färgning för visualisering av ischemiska förändringar i myokardiet / Optimization of PTAH staining protocol for myocardial infarction diagnosis

Persson, Jenny January 2023 (has links)
Akut hjärtinfarkt är globalt sett en vanlig dödsorsak. Hjärtinfarkter behöver inte ge tydliga symptom och dödsorsaken kan därmed vara okänd fram till en klinisk obduktion och att histopatolgiska studier av hjärtmuskelvävnad genomförs. Fosforwolframsyra-hematoxylin (PTAH) är en färgningsmetod som kan användas vid visualisering av hjärtinfarkt genom att färga myokardceller, fibrin, kontraktionsband och cellkärnor blå medan kollagen färgas rosa till rödbrunt. Syftet med examensarbetet var att optimera PTAH-färgningsprotokoll för att underlätta diagnosticering av hjärtinfarkt. Tre olika färgningsprotokoll, två med PTAH med Mallory Bleach (#1 och #2) och ett med PTAH med refixering i Bouins lösning (#3), jämfördes vid inkubering över natt i rumstemperatur samt 3-4 h i värmeskåp vid 56 ºC. Vävnader som färgades in var från paraffininbäddade klossar vilka tillhörde utsvarade fall med konstaterad hjärtinfarkt. Dessa snittades och värmdes fast på oladdade samt laddade objektglas. Efter färgning graderades infärgning efter kategorierna vävnadsdifferentiering och cellkomponenter med en poängskala från 0, ej bedömbar, till 3, optimal. Det protokoll med högst poäng optimerades för att hitta bästa inkuberingstid i PTAH-lösning, därefter implementerades protokollet genom att bekräfta korrekt infärgning vid upprepade infärgningar av hjärtmuskelvävnad. Protokoll #3 visade på högst poäng efter infärgning vid jämförelsen med protokoll #1 och #2 och under optimering framgick inkubering under 4 h i värmeskåp vid 56 ºC som mest gynnsam, då denna inkuberingstid även visade på mindre känslighet vid dehydrering. Slutsatsen blev att PTAH-färgning efter protokoll #3 med refixering i Bouins lösning med 4 h i värmeskåp gav bäst resultat, men färgnyansen varierar med tid mellan dödsfallet och obduktionen. / Acute myocardial infarction (MI) is a common cause of death globally. MI without symptoms or with atypical symptoms is usually first detected at clinical autopsy with histological analyses of the myocardium. Phosphtungstic acid haematoxylin (PTAH) is a method to visualize MI by staining myocytes, fibrin, contraction bands and nuclei blue while collagen stains reddish brown. The aim of this degree project is to optimize PTAH staining protocol for MI diagnosis. Three different staining protocols, two protocols with PTAH staining and Mallory Bleach solution and one protocol with PTAH staining with refixation in Bouin’s solution (#1-3), where compared along with incubation overnight in room temperature and at different hours in heat (56 ºC). Paraffin embedded tissues from myocardium from different autopsy cases diagnosed with MI were cut before mounting and heating on non-charged as well as charged slides. After staining, results were evaluated using scores 0-3 for two parameters; differences in tissues and cell components. Highest evaluated protocol where optimized to find the ultimate incubation in PTAH staining solution. For implementations, additional myocardial tissues from other cases were stained to confirm repeated results. Protocol #3 was evaluated higher in comparison with #1-2 and optimized to 4 h incubation in PTAH-solution in heating with staining results less sensitive to dehydration. In conclusion, staining protocol #3 with 4 h heating was optimal, however, vulnerable to prolonged morgue storage time losing the insensitivity of colour.
193

Visual Performance of Scleral and Soft Contact Lenses in Normal Eyes

Nixon, Alex D. 09 July 2014 (has links)
No description available.
194

Studies on the spread of Verticicladiella procera by soil-borne and insect-borne propagules

Lewis, Katherine JoAnn January 1985 (has links)
Studies were undertaken to determine the dispersal mechanisms of Verticicladiella procera Kendrick, the causal agent of Procera Root Disease (PRD). Propagule germinability in artificially infested soil decrease rapidly under natural and controlled conditions. Colonization of seedlings in artificially infested soil was rare and symptoms were not displayed by colonized seedlings. Natural populations of V. procera were closely associated with colonized root tissue. Colonization of field planted seedlings was related to proximity to root collars of diseased trees and insect activity on the seedlings. Insects (Coleoptera) contaminated with V. procera were found in plantations both with and without PRD. The percent of weevils and bark beetles contaminated with V. procera was 64 and 0.76 respectively. Verticicladiella procera was transmitted to white pine bolts in the field and under controlled conditions following visitation by contaminated insects. Verticicladiella procera was associated with larval galleries and frass in trap bolts and was observed fruiting in insect galleries in root systems of diseased trees. This evidence suggests that transmission by insects, especially weevils, is the more important mechanism for dispersal and that soil-borne propagules have a minor role in pathogen spread. / M.S.
195

Evaluation of simple, noninvasive methods for sampling and quantification of skin bacteria

Dziedzic, Kamila January 2024 (has links)
The increased incidence of diabetes mellitus has underscored the importance of effective management strategies, particularly in preventing complications such as diabetic foot ulcers (DFU). Chronic infections associated with DFU pose significant health risks, including lower limb amputations, highlighting the urgent need for non-invasive methods to assess skin microbiota changes. This study aimed to evaluate simple methods of sampling and quantifying skin bacteria, comparing techniques such as Gram staining, DAPI staining, fluorescence in situ hybridization (FISH), and polymerase chain reaction (PCR). Furthermore, the study investigated bacterial abundance variations across different sampling sites on the foot. Skin bacteria were sampled from healthy human volunteers using tape stripping (TPS) and swabbing. Gram-staining of the samples showed that most bacteria were found on the heel of the foot, and only Gram-positive bacteria were found on the skin of healthy study participants. However, Gram-staining showed artifacts in the form of bubbles under the microscope, which interfered with bacteria counting. PCR provided results indicating the presence of Staphylococcal species on the skin of healthy feet. DAPI staining showed images of bacteria like the ones stained with Gram staining. After using FISH-probe it was found that only a few bacteria hybridized with the probe and further optimization of the protocol is required. The study evaluated various techniques for sampling and quantifying skin bacteria and compared the number of bacteria present on the foot of healthy individuals, which may be used to identify infections before they develop into more serious conditions.
196

Comparison And Optimization Of The Thinprep™5000 Processor For Detecting Abnormal Cells In Bladder Irrigation Fluid

Forsman, Alva January 2024 (has links)
Background: Urine cytology has introduced the use of the ThinPrep™ method, originally for gynecologic applications, years ago. It has demonstrated numerous clinically proven advantages, compared to conventional methods. However, the preparation of bladder irrigation fluid has faced several difficulties at the Cytology laboratory at Gävle Hospital, Sweden. The current method, based on the Cytospin® with MegaFunnel™ technique, is soon to be replaced by the ThinPrep™ method at the current lab. The purpose was to compare the ThinPrep™ and the Cytospin® with MegaFunnel™ preparatory techniques. Additionally, investigations for potential improvements of the ThinPrep™ method tailored for the Cytology laboratory at Gävle Hospital was conducted. Material and method: Bladder irrigation fluid was processed using both techniques. The slides were then evaluated by five cytotechnicians and two specialized doctors based on distribution of cells on the smear, the background and assessability for diagnosis. Further investigation of the ThinPrep™ method was conducted for the purpose of optimization. Results: The ThinPrep™ technique showed significant, diagnostical and statistical, improvement in the preparation of bladder irrigation fluid. It successfully detected highly malignant cells, which the conventional method failed to identify. Optimization testing indicated that the method is best suited with appropriate UroCyte™-filters, and the added step of sample-washing removed inflammatory cells and lightened the staining of the smear. Conclusion: The ThinPrep™ technology was proven superior to the conventional Cytospin® technology, providing a cleaner background, clearer staining and – enhanced safety in diagnostic procedure.
197

An investigation into the influence of the Tiffany Studios in the ecclesiastical stained glass windows commissioned in Indianapolis, Indiana between 1880-1930

Dluzak, Catherine M. January 1999 (has links)
This thesis investigates the influence of the Tiffany Studios in ecclesiastical stained glass windows of Indianapolis, Indiana. The Tiffany Studios was a leading stained glass manufacturer at the turn of the century and popularized the use of opalescent glass in stained glass commissions. The following study will briefly look at the history of stained glass, discuss the life of Louis Comfort Tiffany, characterize the work of the Tiffany Studios, and evaluate the ecclesiastical stained glass windows located in Center Township commissioned between 1880-1930. The evidence contained within the stained glass summaries suggests that Tiffany Studios did influence the commission of stained glass windows in Indianapolis during the period under review. / Department of Architecture
198

The effects of various combinations of different classes of anticancer drugs and tyrosine kinase inhibitors on the human MCF-7 breast carcinoma cell line

Abrahams, Beynon January 2014 (has links)
Magister Scientiae (Medical Bioscience) - MSc(MBS) / This study investigated the effects of TKIs on the growth and proliferation of MCF-7 breast carcinoma cells in culture. MCF-7 cells were exposed to different concentrations of TKIs alone and in combination with each other. Inhibition of cell growth by TKIs used individually occurred in a dose- and time-dependent manner. When EGFR Inhibitor I, EGFR Inhibitor II/BIBX1382 and the multi-specific EGFR/ErbB-2/ErB-4 Inhibitor were used in combination with each other at equimolar log dose concentrations, the combined effects on cell growth was significantly different to inhibitors used individually as reflected in a decreased EC50 (IC50) during combination treatments. Generally, for the combinations with DOX, CPL and the TKIs, synergistic as well as antagonistic effects were observed at isoeffective concentrations with resultant decreases in dose reduction indices (DRIs) implying greater efficacies with the respective combinations. In this study, conventional PCR was used to detect and illustrate the presence of the EGFR gene in the samples, while RT-qPCR was used to determine the mRNA expression levels of this gene in MCF-7 breast carcinoma cells
199

Mechanisms Causing Ferric Staining in the Secondary Water System of Brigham City, Utah

Wallace, Robert Derring 26 May 2007 (has links)
Water from Mantua reservoir has, during some years, exhibited reddish-brown staining when used by Brigham City for irrigation. I propose that seasonal fluctuations in the reservoir chemistry create an environment conducive to dissolving iron from the iron-rich sediments, which subsequently precipitate during irrigation, resulting in a staining event. These conditions are produced by chemical and biological decomposition of organic matter, coupled with isolation of the hypolimnetic waters, which results in seasonal low concentrations of dissolved oxygen in these waters. Under these specific circumstances, anaerobic conditions develop creating a geochemical environment that causes iron and manganese reduction from Fe(III) to Fe(II) and Mn(IV) to Mn(II), respectively. These reducing conditions facilitate reduction-oxidation (redox) chemical reactions that convert insoluble forms of iron and manganese found in the reservoir sediments into more soluble forms. Consequently, relatively high amounts of dissolved iron and manganese are generated in the bottom waters immediately adjacent to the benthic sediments of the reservoir. Water withdrawn from a bottom intake pipe during these periods introduces iron-rich water into the distribution system. When this water is exposed to oxygen, reoxidation shifts redox equilibrium causing precipitation of soluble Fe(II) and Mn(III) back to highly insoluble Fe(III) and Mn(IV). The precipitant appears on contact surfaces as the aforementioned ferric stain. This research focuses specifically on the iron chemistry involved and evaluates this hypothesis using various measurements and models including field data collection, computer simulations, and bench-scale testing to validate the processes proposed.
200

3D-electron microscopic characterization of interstitial cells in the human bladder upper lamina propria

Neuhaus, Jochen, Schröppel, Birgit, Dass, Martin, Zimmermann, Hans, Wolburg, Hartwig, Fallier-Becker, Petra, Gevaert, Thomas, Burkhardt, Claus J., Minh Do, Hoang, Stolzenburg, Jens-Uwe 19 February 2018 (has links)
1) Aims To explore the ultrastructure of interstitial cells in the upper lamina propria of the human bladder, to describe the spatial relationships and to investigate cell-cell contacts. 2) Methods Focused ion beam scanning electron microscopy (FIB-SEM), 3-View SEM and confocal laser scanning microscopy were used to analyze the 3D ultrastructure of the upper lamina propria in male and female human bladders. 3) Results 3View-SEM image stacks as large as 59µm x 59µm x 17µm (xyz) at a resolution of 16nm x 16nm x 50 nm and high resolution (5nm x 5nm x 10nm) FIB-SEM stacks could be analyzed. Interstitial cells with myoid differentiation (mIC) and fibroblast like interstitial cells (fIC) were the major cell types in the upper lamina propria. The flat, sheet-like ICs were oriented strictly parallel to the urothelium sheet-like morphology. No spindle shaped cells were present. We furthermore identified one branched cell (bIC) with several processes contacting urothelial cells by penetrating the basal membrane. This cell did not make any contacts to other ICs within the upper lamina propria. We found no evidence for the occurrence of telocytes in the upper lamina propria. 4) Conclusions Comprehensive 3D-ultrastructural analysis of the human bladder confirmed distinct subtypes of interstitial cells. We provide evidence for a foremost unknown direct connection between a branched interstitial cell and urothelial cells of which the functional role has still to be elucidated. 3D-ultrastructure analyses at high resolution are needed to further define the subpopulations of lamina propria cells and cell-cell interactions.

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