1,608 research outputs found

    Pulmonary Embolism Complicating Permanent Cardiac Pacing

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    Pulmonary embolism arising from intracardiac electrodes in permanently-paced patients, is fortunately rare. The serious nature of the complication is illustrated by a case report

    Epidemiology of urethral stricture at Tygerberg Hospital

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    Over a 12-month period, 120 consecutive male patients with confirmed urethral stricture were prospectively studied with regard to the epidemiology of the disease. Specific urethritis is the main aetiological factor (45%) and internal and external trauma account for an alarming 38,3% of cases. The prevalence is highest among 40 - 50-year-old coloured men who have had little schooling, multiple sexual partners and who have a low annual income. The incidence can be reduced by upliftment of moral and educational standards of the local population, and by emphasising the potential dangers of catheterisation and instrumentation to m.edical personnel

    Potential applications of biomolecular archaeology to the ecohistory of sea turtles and groupers in Levant coastal antiquity

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    Humans have been exploiting marine resources along the Levantine coast for millennia. Advances in biomolecular archaeology present novel opportunities to understand the exploitation of these taxa in antiquity. We discuss the potential insights generated by applying collagen peptide fingerprinting, ancient DNA analysis, and stable isotope analysis to groupers (Serranidae) and sea turtles (Chelonia mydas and Caretta caretta) in the Levant. When combined with traditional zooarchaeological techniques, biomolecular archaeology offers utility to further investigate human impacts on marine ecosystems

    InterPack2003-35151 CONSTRUCTING A TRADE-OFF SURFACE FOR EXTRUDED HEAT SINKS EXPOSED TO FORCED CONVECTION

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    ABSTRACT In modern electronic components power densities are being increased continuously while the size and weight decrease. The effective dissipating of the heat produced by these components has now become a major design problem. Ordinary heat sinks often used to dissipate this heat, can in many instances no longer be used. Heat sinks therefore need to be designed and optimized for specific applications. The design of these heat sinks requires a difficult trade-off between conflicting parameters, e.g. mass or material cost, maximum temperature and pressure drop. Since these parameters influence one another, optimum designs require the use of mathematical optimization techniques. In the case of heat sinks, the thermal engineer would typically like to optimize the design simultaneously for three design parameters. The parameters are maximum heat sink temperature, mass and pressure drop. In the formulation of such an optimization problem, where more than one design criterion is important, the engineer currently has to assign the relative importance of each design criteria before starting the optimization. A better approach is to perform a range of optimization problems where the relative importance of the design criteria is varied systematically to obtain a trade-off surface of optimum heat sinks. This surface can then be used to investigate the influence of the different design criteria on each other and to select the optimum heat sink for a specific application. In this study such a trade-off surface is created for an extruded heat sink exposed to forced convection. The constructing of this surface is obtained by combining a semi-empirical simulation program, QFin 3.0 with the DYNAMIC-Q optimization method

    Gain of 20q11.21 in human pluripotent stem cells impairs TGF-β-dependent neuroectodermal commitment

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    Gain of 20q11.21 is one of the most common recurrent genomic aberrations in human pluripotent stem cells. Although it is known that overexpression of the antiapoptotic gene Bcl-xL confers a survival advantage to the abnormal cells, their differentiation capacity has not been fully investigated. RNA sequencing of mutant and control hESC lines, and a line transgenically overexpressing Bcl-xL, shows that overexpression of Bcl-xL is sufficient to cause most transcriptional changes induced by the gain of 20q11.21. Moreover, the differentially expressed genes in mutant and Bcl-xL overexpressing lines are enriched for genes involved in TGF-beta- and SMAD-mediated signaling, and neuron differentiation. Finally, we show that this altered signaling has a dramatic negative effect on neuroectodermal differentiation, while the cells maintain their ability to differentiate to mesendoderm derivatives. These findings stress the importance of thorough genetic testing of the lines before their use in research or the clinic

    Studies on tuberculosis in dogs, and on a case of human tuberculosis contracted from a dog

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    1. Apparently this is the first case on record in which tuberculosis of the skin in man was contracted from an infected dog through a wound. The infection probably occurred when handling the heavily infected lymph nodes and serous membranes of dog No. I at post-mortem. 2. In view of the rather obscure nature of the lesions, and the fact that this case was complicated with nervous distemper, tuberculosis was not suspected in this dog, until diagnosed histologically. 3. The nodule on the finger, which remained completely circumscribed, was successfully excised approximately three months after infection. 4. In the two dogs with natural tuberculosis the infection was of the nature of an incomplete primary complex in the abdominal cavity. 5. Although large doses of tubercle bacilli were injected into two; dogs intravenously, the disease was much milder, and less widespread than in the two natural cases. 6. In all the dogs clusters of macrophages and epithelioids dominated the picture in the lesions, whereas neutrophiles appeared to play an insignificant part. There was no evidence of Langhans giant cells and calcification, and in the liver, spleen and lungs no caseation was observed. 7. In view of the morphology of the tubercle bacilli, the nature of their growth in culture media, and of their behaviour in rabbits, it was concluded that the human type of organism was involved in all these cases.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

    Texture and mineralogy influence on durability: The Macigno sandstone

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    The behaviour of ornamental stones in response to environmental changes or interactions is crucial when dealing with the conservation of cultural heritage.Weathering factors affect each rock differently, depending on structure, mineralogy, and extraction and implementation techniques. This work focuses on the Macigno sandstone, a dimension stone often employed in Tuscany over the centuries. A thorough mineralogical (optical microscopy, scanning electron microscopy and X-ray powder diffraction) and petrophysical characterization (i.e. mercury intrusion porosimetry, X-ray computed tomography, hygroscopic adsorption behaviour, ultrasounds, image analysis and capillary uptake) was made of the sandstone type extracted in the area of Greve in Chianti. The lithotype shows mineralogical (i.e. presence of mixed-layer phyllosilicates) and microporosimetric features, leading to a high susceptibility to relative humidity variation. Moreover, the influence of swelling minerals is related to weathering due to saline solution. The joint application of petrographic and petrophysical techniques allows an understanding of the characteristic weathering pattern of exfoliation (i.e. detachment of multiple thin stone layers, centimetre scale, that are sub-parallel to the stone surface)

    In vitro comparison of the anti-proliferative effects of galenia africana on human skin cell lines

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    Malignant melanoma is the major cause of skin cancer-related deaths. Surgery in combina-tion with radiotherapy, immunotherapy or chemotherapy is used to eradicate cancer cells, however, this treatment option is limited by the tolerance of the surrounding healthy tissue. The extracts from Galenia africana have been shown to possess anti-cancer flavonoid compounds and can be a safer and cost-effective alternative treatment. The study aimed to compare the anti-proliferative effects of G. africana on human skin cells (HaCaT) and human malignant melanoma cells (A375). The cells were exposed to various concentrations of the G. africana extract at different times. In vitro assays were employed to determine cell viability and cytotoxicity. Hoechst 33342 staining was performed to observe the nuclear changes, including apoptosis. G. africana significantly reduced the cell viability of the A375 cells in a dose and time-dependent manner, while having no effect on the HaCaT cells. The A375 cells displayed nuclear condensation, brightly stained nuclei and nuclear fragmentation indicative of apoptosis

    Enlisting the help of non-specialist personnel to prevent hearing loss.

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    Non-specialist personnel (i.e. not trained in ear and hearing care or EHC), as well as community members, can be trained to contribute to the prevention of hearing loss. Indeed, this can help overcome several obstacles to the prevention of hearing loss, such as the lack of information on ear diseases and hearing loss, the important gaps in the availability of EHC personnel, particularly in low- and middle-income countries, as well as the delays in identification and intervention caused by a lack of EHC services at primary and community levels
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