全文获取类型
收费全文 | 197篇 |
免费 | 36篇 |
专业分类
233篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 4篇 |
2013年 | 4篇 |
2012年 | 7篇 |
2011年 | 8篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2007年 | 7篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 9篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1975年 | 9篇 |
1974年 | 4篇 |
1973年 | 7篇 |
1972年 | 4篇 |
1971年 | 3篇 |
1968年 | 2篇 |
1934年 | 3篇 |
排序方式: 共有233条查询结果,搜索用时 0 毫秒
1.
Noradrenaline caused a prompt but transient increase in the rate of45Ca2+ efflux from isolated rat islets of Langerhans perifused in Ca2+ depleted medium. The response was modest in size and was unaffected by isosmotic replacement of NaCl with choline chloride or by inclusion of 0.5 mM dibutyryl cAMP in the perifusion medium, suggesting that it was not mediated by Na+: Ca2+ exchange nor by lowered cAMP. Despite its effect on45Ca2+ efflux, noradrenaline treatment did not alter the kinetics of45Ca2+ efflux in response to the muscarinic agonist, carbamylcholine, nor did it change the magnitude of the response to this agent. Simultaneous introduction of 20 mM glucose with noradrenaline prevented a rise in45Ca2+ efflux and indeed resulted in inhibition of45Ca2+ efflux. The data suggest that noradrenaline does not directly activate the mechanisms which regulate Ca2+ extrusion from islets cells, and they do not support a primary role for the Ca2+ efflux response in mediating adrenergic inhibition of insulin secretion. 相似文献
2.
3.
This article presents an industrial case study, examining the application of a novel adaptive biomass estimator to an industrial microfungi production process. It is our intention that this contribution should focus upon the implementation issues of the algorithm, in preference to a rigorous theoretical development. The novel algorithm adopted is developed from Adaptive Inferential Estimation studies of Guilandoust and co-workers. The technique utilizes input-output process measurements obtained at different frequencies, thereby providing more frequent estimates of biomass concentration than are otherwise available from off-line laboratory analyses. The algorithm is particularly suited to the biotechnology industry, as it is capable of utilizing irregular assay measurements with varying delays.Although this article demonstrates the encouraging industrial implications of the adaptive algorithm, like all adaptive techniques currently developed, it is restricted by the inability to perform robust on-line system identification. The ultimate selection of a "suboptimal" "fixed parameter" algorithm for on-line implementation, is therefore directly attributable to these inadequacies. Aspects of data acquisition, data pretreatment, and data quality are critical for real process applications, and while some practical approaches are adopted here, many important implementation problems remain unresolved. (c) 1993 John Wiley & Sons, Inc. 相似文献
4.
C. J. Lord S. K. Bohlander E. A. Hopes C. T. Montague N. J. Hill J. -B. Prins R. J. Renjilian L. B. Peterson L. S. Wicker J. A. Todd P. Denny 《Mammalian genome》1995,6(9):563-570
Development of novel congenic mouse strains has allowed us to better define the location of the diabetogenic locus, Idd3, on Chromosome (Chr) 3. Congenic strains were identified by use of published and newly developed microsatellite markers, their genomes fingerprinted by a rapid, fluorescence-based approach, and their susceptibility to type 1 diabetes evaluated. The maximum interval containing Idd3 is now approximately 4 cM. 相似文献
5.
6.
7.
Inhibition of tumor cell invasion by verapamil. 总被引:3,自引:0,他引:3
K H Yohem J L Clothier S L Montague R J Geary A L Winters M J Hendrix D R Welch 《Pigment cell research / sponsored by the European Society for Pigment Cell Research and the International Pigment Cell Society》1991,4(5-6):225-233
Verapamil, a calcium channel antagonist, inhibits murine B16 melanoma and colon adenocarcinoma C26 tumor metastasis by altering platelet aggregation [Tsuruo, T., et al. (1985) Cancer Chemother. Pharmacol., 14:30-33]. However, the role of calcium homeostasis in regulating several biochemical pathways implicated in other steps of the metastatic cascade suggests that calcium channel antagonists could also inhibit metastasis by other mechanisms. In this report, non-toxic doses of verapamil reversibly decreased human A375M and C8161 melanoma cell invasion and metastasis in a dose-dependent manner. Verapamil reduced cellular invasion and metastases by up to 96% (range 78-96%). Concomitantly, verapamil disrupts microtubule and microfilament organization and inhibits unidirectional cell migration but does not affect cellular adhesion to endothelial monolayers or reconstituted basement membranes. In addition, tumor cells treated with verapamil have a decrease in mRNA of type IV collagenase, a proteinase important in tumor cell degradation of basement membranes. Collectively, these data offer additional evidence regarding the mechanisms of action of verapamil as an anti-metastatic agent. 相似文献
8.
Montague S. Woolf 《The Western journal of medicine》1938,49(6):463-464
9.
The levels of cyclic AMP (cAMP) and activities of adenylate cyclase and protein kinase have been examined in chick skeletal muscle tissue between the 7th and 15th day of its embryonic development. The tissue cAMP levels were found to increase in two main phases; from 8–10 days and from 12–15 days of development. Parallel increases between the 8th and 10th day of development were also found in the basal enzyme activities of both adenylate cyclase and protein kinase. The maximum values of all three parameters coincided with the onset of cell fusion in the tissue. The results are compared with the findings of a similar study carried out on differentiating myoblasts cultured in vitro, and are assessed in terms of the possibility that cAMP levels control the expression of myoblast differentiation. 相似文献
10.
Kaley M. Wilburn Christine R. Montague Bo Qin Ashley K. Woods Melissa S. Love Case W. McNamara Peter G. Schultz Teresa L. Southard Lu Huang H. Michael Petrassi Brian C. VanderVen 《PLoS pathogens》2022,18(2)
There is a growing appreciation for the idea that bacterial utilization of host-derived lipids, including cholesterol, supports Mycobacterium tuberculosis (Mtb) pathogenesis. This has generated interest in identifying novel antibiotics that can disrupt cholesterol utilization by Mtb in vivo. Here we identify a novel small molecule agonist (V-59) of the Mtb adenylyl cyclase Rv1625c, which stimulates 3’, 5’-cyclic adenosine monophosphate (cAMP) synthesis and inhibits cholesterol utilization by Mtb. Similarly, using a complementary genetic approach that induces bacterial cAMP synthesis independent of Rv1625c, we demonstrate that inducing cAMP synthesis is sufficient to inhibit cholesterol utilization in Mtb. Although the physiological roles of individual adenylyl cyclase enzymes in Mtb are largely unknown, here we demonstrate that the transmembrane region of Rv1625c is required during cholesterol metabolism. Finally, the pharmacokinetic properties of Rv1625c agonists have been optimized, producing an orally-available Rv1625c agonist that impairs Mtb pathogenesis in infected mice. Collectively, this work demonstrates a role for Rv1625c and cAMP signaling in controlling cholesterol metabolism in Mtb and establishes that cAMP signaling can be pharmacologically manipulated for the development of new antibiotic strategies. 相似文献