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排序方式: 共有1114条查询结果,搜索用时 33 毫秒
21.
PJ Johnson SC Tyagi LC Katwa VK Ganjam LA Moore JM Kreeger NT Messer 《Canadian Metallurgical Quarterly》1998,142(15):392-396
Samples of connective tissue obtained from the hoof of six laminitic and eight non-laminitic adult horses were analysed zymographically to investigate whether connective tissue matrix metalloproteinases are activated or induced during laminitis. The activity or matrix metalloproteinases was substantially greater in the tissues from the laminitic horses than in the tissues from the non-laminitic horses. A comparison of the collagenolytic activity in the laminitic and control tissues showed that collagenolytic activities corresponding to the 92 kDa (P < 0.001), 72 kDa (P < 0.01) and 66 kDa (P < 0.01) bands were induced in the laminitic tissues. 相似文献
22.
A cigarette which heats rather than burns tobacco (Premier) was introduced in 1988, but was unacceptable due to unpleasant taste and low nicotine intake. We examined availability of nicotine from a new version (Eclipse), in the same four subjects as our earlier Premier study. Average blood nicotine boosts of 23.7 and 17.8 ng/ml were obtained from smoking a first and second Eclipse. This substantially exceeds intake from Premier (boost 13 ng/ml) and that obtained by heavy smokers from conventional brands (boost 12-15 ng/ml). Eclipse (or similar product) may be the best option for averting Peto's dire warnings of rising millions of annual smoking deaths in the 2020s, and its potential for large-scale, long-term switching warrants further study. 相似文献
23.
VK Boppana 《Canadian Metallurgical Quarterly》1995,692(1-2):195-202
A highly sensitive and selective high-performance liquid chromatographic method was developed for the determination of granisetron and its active metabolite, 7-hydroxygranisetron (7OH-G) in human plasma. Granisetron is a selective 5-hydroxytryptamine receptor antagonist used in the treatment of cytotoxic drug-induced emesis. The method involves isolation of granisetron, 7OH-G and the internal standards from plasma by solid-phase extraction prior to reversed-phase ion-pair chromatographic separation on an octyl silica column with subsequent quantification of analytes simultaneously either with electrochemical (7OH-G) or fluorescence (granisetron) detectors which are placed in series. The recovery of granisetron and 7OH-G from human plasma was quantitative. Using 1 ml of plasma, the limits of quantification for granisetron and 7OH-G were 0.1 and 0.25 ng/ml, respectively. Linear responses in analyte/internal standard peak-area ratios were observed for analyte concentrations ranging from 0.1 to 50 ng/ml plasma. Precision and accuracy were within 13% across the calibration range for both granisetron and 7OH-G. The method was sufficiently sensitive, accurate and precise to support pharmacokinetic studies for granisetron and 7OH-G, in both normal and patient populations. 相似文献
24.
Yu. N. Dragoshanskii V. V. Shulika A. P. Potapov O. F. Denisov 《The Physics of Metals and Metallography》2006,101(6):519-523
It has been shown that the formation of nitride-oxide magnetically active electrically insulating coatings on ribbons of iron-based soft magnetic alloys using the method of ion-plasma deposition and subsequent magnetic annealing in an ac magnetic field leads to a substantial improvement of their static and dynamic magnetic properties. 相似文献
25.
Peter Potapov Matthew C. Hansen Stephen V. Stehman Thomas R. Loveland Kyle Pittman 《Remote sensing of environment》2008,112(9):3708-3719
Estimation of forest cover change is important for boreal forests, one of the most extensive forested biomes, due to its unique role in global timber stock, carbon sequestration and deposition, and high vulnerability to the effects of global climate change. We used time-series data from the MODerate Resolution Imaging Spectroradiometer (MODIS) to produce annual forest cover loss hotspot maps. These maps were used to assign all blocks (18.5 by 18.5 km) partitioning the boreal biome into strata of high, medium and low likelihood of forest cover loss. A stratified random sample of 118 blocks was interpreted for forest cover and forest cover loss using high spatial resolution Landsat imagery from 2000 and 2005. Area of forest cover gross loss from 2000 to 2005 within the boreal biome is estimated to be 1.63% (standard error 0.10%) of the total biome area, and represents a 4.02% reduction in year 2000 forest cover. The proportion of identified forest cover loss relative to regional forest area is much higher in North America than in Eurasia (5.63% to 3.00%). Of the total forest cover loss identified, 58.9% is attributable to wildfires. The MODIS pan-boreal change hotspot estimates reveal significant increases in forest cover loss due to wildfires in 2002 and 2003, with 2003 being the peak year of loss within the 5-year study period. Overall, the precision of the aggregate forest cover loss estimates derived from the Landsat data and the value of the MODIS-derived map displaying the spatial and temporal patterns of forest loss demonstrate the efficacy of this protocol for operational, cost-effective, and timely biome-wide monitoring of gross forest cover loss. 相似文献
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This paper presents the validation aspects of a unified numerical framework based on SPH formulation and devoted to the modeling of fluid–structure interaction problems involving large motion of the fluid and large deformation with a possible failure of the structure. The fluid domain is modeled according to an updated Lagrangian formulation. The solid domain (3D and shell models) uses the total Lagrangian formulation. The fluid–structure interaction is treated via a unilateral contact algorithm adapted to SPH context. The SPH framework is verified on academic test cases and validated by simulating an experiment involving the reservoir leakage. 相似文献
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29.
The frequent difficulties encountered in the diagnosis of pediatric sarcomas, caused by the lack of observable differentiation at the light microscopic level, has led to the routine use of immunohistochemistry in pediatric surgical pathology. To a large degree the advent of this staining technique has led to the correct assessment of many perplexing lesions that previously would have been given inconclusive diagnoses. However, with increased usage and testing, it has become apparent that there are few, if any, "magic bullets" in immunohistochemistry for pediatric pathologists. Thus, it behooves diagnosticians to be careful in the usage of this technique, to be aware of possible discrepancies in its results, and to remember the ancillary nature of its application. The following article will review selected markers commonly used in pediatric surgical pathology, from both previous reports and the author's perspective, and will briefly consider several new phenotypic markers which have potential utility with childhood sarcomas. 相似文献
30.
In 41 preparations of the m. pectoralis major it has been stated by means of anatomical methods that the vascular "hilus" is projected on the upper third of its middle part and represented by the thoracic branch of the thoracoacromial artery. The latter has several variants dividing into branches of the successive orders. It has been stated that the muscle has a wide network of anastomoses at the macro-microscopic level. For plastic purposes, it is expedient to use the external and middle parts of the m. pectoralis major which have more favourable conditions of the blood supply. Owing to the data obtained and the technique, developed on 25 corpses, for cutting out and graft transplantation in the thoracic cavity, it has been possible to operate 9 patients. 相似文献