197,365 research outputs found
Canine epithelial skin tumours: Expression of the stem cell markers Lgr5, Lgr6 and Sox9 in light of new cancer stem cell theories
No full textEvidence is accumulating that tumour development is driven by cancer stem cells (CSCs). In order to understand the presence and potential contribution of stem cells (SCs) as tumour-initiating cells in canine cutaneous tumours, we selected three putative SC markers (Lgr5, Lgr6 and Sox9) and investigated their expression pattern, level of protein and mRNA expression, in 43 canine hair follicle (HF) and 18 canine cutaneous epidermal tumours by immunohistochemistry and qRT-PCR, using normal skin samples as controls. Lgr5 protein expression was not detected in epidermal and HF tumours; however, Lgr5 mRNA overexpression was evident in some HF tumours. Sox9 was expressed in several tumour cases, both at the protein and mRNA level. The Lgr6 antibody tested was not suitable for formalin-fixed paraffin-embedded tissue samples, but Lgr6 gene showed higher expression in several samples of both HF and epidermal tumours compared with normal skin. Significantly higher mRNA expression levels of the three SC markers were found in trichoblastomas (TB) compared with basal cell carcinomas (BCC). The present results indicated that canine HF and epidermal tumours might have common tumour-initiating cells. The mRNA expression of the three selected SC markers, especially Lgr5, could be potentially useful in the distinction between canine TB and BCC
Verbesserte Momentenübertragung in Welle-Nabe-Verbindungen durch Press-Presslöt
No full textS.247-258Weit verbreitet unter den Welle-Nabe-Verbindungen sind Pressverbindungen als Untergruppe reibschlüssiger Verbindungen, da diese mit vergleichsweise geringem fertigungstechnischen Aufwand und somit kostengünstig herzustellen sind. Die Festigkeit der Pressverbindung kann durch Kombination mit der stoffschlüssigen Presslötverbindung wesentlich erhöht werden. Bei Press-Presslöt-Verbindungen werden die Fügeflächen der Pressverbindung mit einer dünnen Lotschicht beschichtet und dann durch Längs- bzw. Querpressen gefügt. Die Lotschicht wird nach dem gegenwärtigen Stand der Technik mittels elektrochemischem Abschneiden (Galvanisieren) von Zink oder Kupfer auf die gereinigte Fügefläche von Welle und/oder Nabe aufgebracht. Während des Fügens und des Betriebs bauen sich lokal stofschlüssige Verbindungen im festen Zustand auf. Dadurch erhöhen sich, wie die vorliegenden Versuchsergebnisse zeigen, die übertragbaren Momente gegenüber der reibschlüssigen elementaren Pressverbindung beträchtlich. Wie die durchgeführten Untersuchungen ebenfalls zeigen, lässt sich die Momentenübertragungsfähigkeit einer Press-Presslöt-Verbindung mittels Relativbewegung steigern (Trainieren). Ob dies durch Rutschen der kompletten Verbindung oder durch örtliches Gleiten an den Nabenkanten, etwa durch schwingende Belastung, erfolgt, hat nur quantitativen Einfluss. Die minderfeste Lotschicht in der Verbindung bestimmt den Versagensort und verhindert die Beschädigung des Grundwerkstoffes von Welle und Nabe. Dies verbessert die Lösbarkeit bzw. Wiederverwendbarkeit der Fügeteile gegenüber herkömmlichen Pressverbindungen. Die Dimensionierung der Pressverbindung kann unter Berücksichtigung der verbesserten Reibbeiwerte nach DIN 7190 erfolgen
Intern experience at CH���M Hill, Inc.: an internship report
No full textIncludes author's vita"Submitted to the College of Engineering of Texas A&M University in partial
fulfillment of the requirement for the degree of Doctor of Engineering."Includes bibliographical referencesA review of the author's internship experience with CH���M HILL, Inc.
during the period September 1975 through May 1976 is presented. During this nine month
internship the author worked as an Engineer II in the Industrial Processes discipline of this
large consulting engineering firm... The author's prime responsibility was as one of three
lead design engineers on the design of a large wastewater treatment facility for a pulp mill
in Hoquiam, Washington owned by ITT Rayonier Inc. The work generally consisted of the design
of individual treatment units and associated piping and pumping. The purpose of the project
was to provide wastewater treatment capabilities that would satisfy the effluent limitations
(standards) imposed upon the mill by the State of Washington Department of Ecology and the
U.S. Environmental Protection Agency. The author's assignment also entailed necessary
interaction with the project manager and other CH���M HILL design engineers and support staff
members, the client's representatives, and representatives of two other consulting engineering
firms working on the project. Thus, the internship position at CH���M HILL provided considerable
experience coordinating the author's work with the work of other engineers, guiding the design
and administrative efforts of a support staff, and interacting regularly with the client and
other consulting firms. This broad exposure to a variety of engineering and organizational
problems provided a valuable educational experience
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
Identification of stem cell markers lgr5, lgr6 and sox9 in canine hair follicle and epidermal tumours
No full textEvidence is accumulating that tumours are driven by cancer stem cells. We investigated the expression of three putative stem cell (SC) markers, Lgr5, Sox9, at both protein and mRNA level, and Lgr6 mRNA, in 43 canine hair follicles (HF) and 18 cutaneous epidermal tumors in order to examine the possible contribution of HF SCs in their development and progression. Fisher's exact test was applied to evaluate the significance of the gene and protein expression levels of the investigated molecules and their correlation with histopathological parameters and malignancy. Lgr5 immunolabelling was not detected in any of the tumours analyzed, despite positive staining in the surrounding HFs. The expression of Lgr6 and Lgr5 mRNA was observed in the majority of the cases. Sox9 was expressed in several tumours at both the protein and the mRNA levels. Sox9 positive cells were mainly present among the basaloid neoplastic cells of infundibular keratinizing acanthoma and of squamous cell carcinoma, and in some cases of basal cell carcinoma (BCC) and trichoblastoma. A statistically significant correlation was observed between lack of Sox9 protein expression and histologically assessed malignancy (P=0.0448). The presence of Sox9 positive cells in both epidermal and HF tumours suggests their involvement in the development of these tumours. Our results suggest that Sox9 might represent a marker of HF differentiation and its expression in BCCs might indicate a differentiation of these tumors along the line of the outer root sheath. A significant correlation was observed between absent/low Lgr5 mRNA levels and histologically assessed malignancy (P=0.0001), suggesting a possible transient function of the molecule in the development of the investigated tumors. The highest Lgr6 gene expression level was observed in the trichoblastoma cases, indicating a possible role of the molecule in the development of this type of tumour
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
M-regularity and the fourier-mukai transform
No full textThis is a survey of M-regularity and its applications, expanding on lectures given by the second author at the Seattle conference, in August 2005, and at the Luminy workshop "Geometrie Algebrique Complexe", in October 2005
[Inherited alopecia X in Pomeranians]
No full textFour male Pomeranians that showed alopecia with an age of onset between five months and eight years were investigated.The aim of the investigation was to clarify whether the affected dogs had alopecia X and whether their symptoms might be due to a hereditary defect.The four affected dogs showed hairless patches at the root of the tail, at the back, at the limbs from the thigh to the tarsus and at the abdomen. Within the hairless patches some islets with sparse hair were present. In hairless patches the skin was dark pigmented. Besides the alopecia and hyperpigmentation no other symptoms were found according to anamnestic and clinical examination. History, clinical examinations, laboratory diagnostics, and histopathology of skin biopsies allowed the diagnosis of alopecia X in three affected male dogs.The last one of the affected dogs additionally had slightly reduced thyroid hormone levels. Based on identical symptoms and the close relatedness of all four animals, it was assumed that the fourth affected dog also had alopecia X.The available data possibly indicate a monogenic autosomal dominant inheritance, however a recessive inheritance can not be excluded at this time
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