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Changes in the molecular structure of collagen fibrils isolated from solutions of native tropocollagen (TC) and of soluble collagen, obtained by enzymic (ESC) and alkaline-salt (ASC) methods, were studied by electron microscopy. It was found that, under certain conditions, it is possible to derive native-like fibrils (NF), segments with long spacings (SLS) and fibrils with long spacings (FLS)_from collagen solutions, these being very similar to structures precipitated from TC. Despite the fact that more structures with clear cross-striations can be isolated from ESC than from ASC, neither enzymic nor alkali-salt treatments cause substantial changes in the molecular structure of solubilized collagen, this determining its orderly aggregation. The data obtained permit the recommendation of new artificial materials for food and medical uses. 相似文献
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A triple-product acousto-optic processor output was studied analytically and numerically. The processor is capable of detecting the carrier frequency and the modulation envelope of a signal. 相似文献
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Johnson GP Calo VM Gaither KP 《IEEE transactions on visualization and computer graphics》2008,14(6):1420-1427
A stand-alone visualization application has been developed by a multi-disciplinary, collaborative team with the sole purpose of creating an interactive exploration environment allowing turbulent flow researchers to experiment and validate hypotheses using visualization. This system has specific optimizations made in data management, caching computations, and visualization allowing for the interactive exploration of datasets on the order of 1TB in size. Using this application, the user (co-author Calo) is able to interactively visualize and analyze all regions of a transitional flow volume, including the laminar, transitional and fully turbulent regions. The underlying goal of the visualizations produced from these transitional flow simulations is to localize turbulent spots in the laminar region of the boundary layer, determine under which conditions they form, and follow their evolution. The initiation of turbulent spots, which ultimately lead to full turbulence, was located via a proposed feature detection condition and verified by experimental results. The conditions under which these turbulent spots form and coalesce are validated and presented. 相似文献
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Disease detection in body cavities, such as the detection of abnormal growths in the colon path, has been illustrated here using an image fiber guided catheter based multispeckle modality endoscopic system. An all fiber-optic approach for the illumination and imaging of the inner cavity walls is adopted here. An endoscope probe to carry the illumination fibers as well as the imaging lens-image fiber unit is designed and custom fabricated in order to operate the probe in its various direction sensitive configurations. This is facilitated by the selection of suitable optical elements such as beam combiner and biprism at the probe proximal end. Experimental investigations were carried out using the endoscope system employing phantom model of colon as the test specimen that has normal and abnormal (representing growth) regions and the obtained results indicated the system effectiveness in identifying the abnormal growths at an early stage. 相似文献
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Ciriello VM 《Applied ergonomics》2007,38(1):1-5
In the development of our present manual materials handling (MMH) guidelines (Snook, S.H., Ciriello, V.M., 1991. The design of manual tasks: revised tables of maximum acceptable weights and forces. Ergonomics 34, 1197-1213), the assumption was made that the effects of frequency on maximum acceptable weights (MAWs) of lifting with a large box (hand distance, 38 cm from chest) were similar to that of lifting with a small box (hand distance, 17 cm from chest). The first purpose of the present experiment was to investigate this assumption with female industrial workers. The second purpose was to study the effects of extended horizontal reach lifting (hand distance, 44.6 cm from chest) on MAWs as a confirmation of the results of a previous studies on this variable with males (Ciriello, V.M., Snook, S.H., Hughes, G.J., 1993. Further studies of psychophysically determined maximum acceptable weights and forces. Hum. Factors 35(1), 175-186; Ciriello, V.M., 2003. The effects of box size, frequency, and extended horizontal reach on maximum acceptable weights of lifting. Int. J. Ind. Ergon. 32, 115-120). Lastly, we studied the effects of high frequency (20 lifts/min) on MAWs of lifting. Ten female industrial workers performed 15 variations of lifting using our psychophysical methodology whereby the subjects were asked to select a workload they could sustain for 8h without "straining themselves or without becoming unusually tired weakened, overheated or out of breath". The results confirmed that MAWs of lifting with the large box was significantly effected by frequency. The frequency factor pattern in this study was similar to the frequency pattern from a previous study using the small box (Ciriello, V.M., Snook, S.H., 1983. A study of size distance height, and frequency effects on manual handling tasks. Hum. Factors 25(5), 473-483) for all fast frequencies down to one lift every 2 min with deviations of 7%, 15%, and 13% for the one lift every 5 and 30 min tasks and the one lift in 8h task, respectively. The effects of lifting with an extended horizontal reach decreased MAW 22% and 18% for the mid and center lift and the effects of the 20 lifts/min frequency resulted in a MAW that was 47% of a 1 lift/min MAW. Incorporating these results in future guidelines should improve the design of MMH tasks for female workers. 相似文献
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Vivanco F Mas S Darde VM De la Cuesta F Alvarez-Llamas G Barderas MG 《Proteomics. Clinical applications》2007,1(9):1102-1122
The characterization of patients with acute coronary syndromes (ACS) at the molecular and cellular levels provides a novel vision for understanding the pathological and clinical expression of the disease. Recent advances in proteomic technologies permit the evaluation of systematic changes in protein expression in many biological systems and have been extensively applied to cardiovascular diseases (CVD). The cardiovascular system is in permanent intimate contact with blood, making blood-based biomarker discovery a particularly worthwhile approach. Thus, proteomics can potentially yield novel biomarkers reflecting CVD, establish earlier detection strategies, and monitor response to therapy. Here we review the different proteomic strategies used in the study of atherosclerosis and the novel proteins differentially expressed and secreted by atherosclerotic lesions which constitute novel potential biomarkers (HSP-27, Cathepsin D). Special attention is paid to MS-Imaging of atheroma plaque and the generation, for the first time, of 2-D images of lipids, showing the distribution of these molecules in the different areas of the atherosclerotic lesions. In addition new potential biomarkers have been identified in plasma (amyloid A1α, transtherytin), circulating cells (protein profile in monocytes from ACS patients) and individual cells constituents of atheroma plaques (endothelial, VSMC, macrophages) which provide novel insights into vascular pathophysiology. 相似文献