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排序方式: 共有142条查询结果,搜索用时 15 毫秒
81.
82.
Silver PG Beck SL Wallace TC Meade C Myers SC James DE Kuehnel R 《Science (New York, N.Y.)》1995,268(5207):69-73
The M(w) = 8.3 deep (636 kilometers) Bolivian earthquake of 9 June 1994 was the largest deep-focus earthquake ever recorded. Seismic data from permanent stations plus portable instruments in South America show that rupture occurred on a horizontal plane and extended at least 30 by 50 kilometers. Rupture proceeded at 1 to 3 kilometers per second along the down-dip azimuth of the slab and penetrated through more than a third of the slab thickness. This extent is more than three times that expected for a metastable wedge of olivine at the core of the slab, and thus appears to be incompatible with an origin by transformational faulting. These large events may instead represent slip on preserved zones of weakness established in oceanic lithosphere at the Earth's surface. 相似文献
83.
Wallace AR 《Science (New York, N.Y.)》1912,35(900):487-488
84.
Abrupt climate change 总被引:4,自引:0,他引:4
Alley RB Marotzke J Nordhaus WD Overpeck JT Peteet DM Pielke RA Pierrehumbert RT Rhines PB Stocker TF Talley LD Wallace JM 《Science (New York, N.Y.)》2003,299(5615):2005-2010
Large, abrupt, and widespread climate changes with major impacts have occurred repeatedly in the past, when the Earth system was forced across thresholds. Although abrupt climate changes can occur for many reasons, it is conceivable that human forcing of climate change is increasing the probability of large, abrupt events. Were such an event to recur, the economic and ecological impacts could be large and potentially serious. Unpredictability exhibited near climate thresholds in simple models shows that some uncertainty will always be associated with projections. In light of these uncertainties, policy-makers should consider expanding research into abrupt climate change, improving monitoring systems, and taking actions designed to enhance the adaptability and resilience of ecosystems and economies. 相似文献
85.
86.
Wallace HA 《Science (New York, N.Y.)》1939,89(2303):140-143
87.
88.
Wallace S Vaughn K Stewart BW Viswanathan T Clausen E Nagarajan S Carrier DJ 《Journal of agricultural and food chemistry》2008,56(11):3966-3972
Silymarin encompasses a group of flavonolignans that are extracted from Silybum marianum (Asteraceae) fruits. The silymarins have previously been reported to lower low-density lipoprotein (LDL) levels associated with high-fat diets. The present study reports the efficacy of the silymarins in inhibiting oxidized low-density lipoprotein (oxLDL) generation and subsequent scavenger receptor (SR) mediated monocyte adherence to oxLDL. The flavonolignans that comprise silymarin include silichristin (SC), silidianin (SD), silibinin (SBN), and isosilibinin (IS). These flavonolignans (300 microM) lowered oxLDL generation, measured by the thiobarbituric acid-reacting substances (TBARS) assay, by 60.0, 28.1, 60.0, and 30.1%, respectively. SBN treatment of LDL in the presence of copper sulfate (CuSO 4) resulted in a significant dose-dependent inhibition of monocyte adhesion. Inhibition was paralleled by a decrease in binding of anti-oxLDL antibodies recognized by U937 monocyte Fc gamma receptors (FcgammaR). These results showed that silymarin and SBN, likely through antioxidant and free radical scavenging mechanisms of action, inhibit the generation of oxLDL and oxidation-specific neoepitopes recognized by SR and FcgammaR expressed on monocytes/macrophages. 相似文献
89.
Wallace LJ White FH Gore HL 《Journal of the American Veterinary Medical Association》1966,149(7):881-883
Edwardsiella tarda was isolated from a sea lion and 2 alligators on 3 separate occasions. The 3 isolates were not serologically identical. Specific pathologic effects of E. tarda could not be determined. 相似文献
90.
OBJECTIVE: To determine the clinical and pathologic findings in dogs with primary bicipital tenosynovitis. ANIMALS: 19 dogs with 20 shoulder joints treated surgically for bicipital tenosynovitis and 8 shoulder joints from 4 clinically normal dogs. PROCEDURE: Histologic abnormalities of tendon sheaths of the biceps brachii in affected dogs were determined by use of comparison with findings in clinically normal dogs. Specimens were graded for inflammation, fibrosis, villous hypertrophy, vascular prominence, and synovial cell proliferation. Histopathologic results were statistically evaluated for relationship with clinical findings and treatment before surgery. RESULTS: Synovial villous hypertrophy and vascular prominence were the most consistent histologic findings in 16 and 14 of 20 affected joints, respectively. Evidence of inflammation was lacking in 6 joints. Ten joints had inflammatory cell infiltration of the tendon sheath. Plasma cells and lymphocytes were the most common infiltrates; however, the type and amount of inflammatory cell infiltrate were variable. Fibrosis of the tendon sheath was seen in 8 joints, and synovial cell proliferation was seen in 11 joints. Other changes included accumulation of hemosiderin, focal calcification, osseous metaplasia, lysis of collagen, and fibrocartilaginous metaplasia. No significant relationship was detected between histopathologic findings and clinical findings or treatment before surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Inflammation was more variable than hypothesized and may not be a consistent pathophysiologic feature of bicipital tenosynovitis. In some dogs, this disease may be the result of a degenerative process rather than an inflammatory process. 相似文献