全文获取类型
收费全文 | 391篇 |
免费 | 21篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 11篇 |
2015年 | 19篇 |
2014年 | 20篇 |
2013年 | 40篇 |
2012年 | 29篇 |
2011年 | 35篇 |
2010年 | 18篇 |
2009年 | 14篇 |
2008年 | 32篇 |
2007年 | 27篇 |
2006年 | 15篇 |
2005年 | 23篇 |
2004年 | 18篇 |
2003年 | 13篇 |
2002年 | 19篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1984年 | 6篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1964年 | 1篇 |
1910年 | 1篇 |
排序方式: 共有412条查询结果,搜索用时 35 毫秒
11.
Andrew K. Schmucker Nicholas Scott Johnson Ugo Bussy Ke Li Heather S. Galbraith Yu-Wen Chung-Davidson Weiming Li 《Journal of fish biology》2020,96(4):1024-1033
The American eel (Anguilla rostrata) is an imperilled fish hypothesized to use conspecific cues, in part, to coordinate long-distance migration during their multistage life history. Here, holding water and tissue from multiple American eel life stages was collected and analysed for the presence, profile and concentration of bile acids. Distinct bile acid profiles were identified in glass, elver, yellow eel and silver eel holding waters using ultraperformance liquid chromatography high-resolution mass spectrometry and principal component analysis. Taurochenodeoxycholic acid, taurodeoxycholic acid, cholic acid, deoxycholic acid, taurolithocholic acid and taurocholic acid were detected in whole tissue of American glass eels and elvers, and in liver, intestine and gallbladder samples of late-stage yellow eels. Bile acids were not a major component of silver eel washings or tissue. This study is novel because little was previously known about bile acids produced and emitted into the environment by American eels. Future behavioural studies could evaluate whether any bile acids produced by American eels influence conspecific migratory behaviour. 相似文献
12.
13.
Ugo Mellone Beatriz Yáñez Rubén Limiñana A.-Román Muñoz Diego Pavón J.-Miguel González 《Bird Study》2013,60(4):516-521
Capsule Immature Short-toed Snake Eagles hatched in Spain leave their Sahelian wintering grounds to spend the summer in northern Africa. 相似文献
14.
Lavanya Bondada Ramu Rondla Ugo Pradere Peng Liu Chengwei Li Drew Bobeck Tamara McBrayer Philip Tharnish Jerome Courcambeck Philippe Halfon Tony Whitaker Franck Amblard Steven J. Coats Raymond F. Schinazi 《Bioorganic & medicinal chemistry letters》2013,23(23):6325-6330
Herein, we report the synthesis and structure–activity relationship studies of new analogs of boceprevir 1 and telaprevir 2. Introduction of azetidine and spiroazetidines as a P2 substituent that replaced the pyrrolidine moiety of 1 and 2 led to the discovery of a potent hepatitis C protease inhibitor 37c (EC50 = 0.8 μM). 相似文献
15.
Laura Gangoso Pascual López-López Juan Manuel Grande Ugo Mellone Rubén Limi?ana Vicente Urios Miguel Ferrer 《PloS one》2013,8(4)
Background
The adaptive transition between behavioral strategies, such as the shift from migratoriness to sedentariness, remains an outstanding question in evolutionary ecology. Density-dependent variation in the age of first breeding has been proposed as a feasible mechanism through which long-lived migratory birds with deferred sexual maturity should become sedentary to persist on islands. Although this pattern seems to hold for most raptors and herons, a few exceptions have been identified. One of these exceptions is the Eleonora’s falcon, a long-distance migratory bird, which shows one of the most peculiar adaptations in the timing of reproduction and food requirements among raptors.Methodology/Principal Findings
Here, we compiled data concerning demography, banding recoveries and satellite tracking of Eleonora’s falcons to discuss likely explanations for the exceptional behavior of this insular long-distance migratory species.Conclusions/Significance
New data reveal that Eleonora’s falcons do return to the natal colonies in their first year and young birds are able to breed. However, in contrast to previous hypothesis, the highly specialized strategy of this and other ecologically similar species, as well as the virtual lack of food during winter at breeding areas prevent them from becoming sedentary on islands. Although the ultimate mechanisms underlying the process of sedentarization remain poorly understood, the evidence provided reveal the existence of important trade-offs associated with ecological specialization that may become particularly relevant in the present context of global change. 相似文献16.
17.
Activation of MK5/PRAK by the atypical MAP kinase ERK3 defines a novel signal transduction pathway 总被引:7,自引:0,他引:7
Seternes OM Mikalsen T Johansen B Michaelsen E Armstrong CG Morrice NA Turgeon B Meloche S Moens U Keyse SM 《The EMBO journal》2004,23(24):4780-4791
Extracellular signal-regulated kinase 3 (ERK3) is an atypical mitogen-activated protein kinase (MAPK), which is regulated by protein stability. However, its function is unknown and no physiological substrates for ERK3 have yet been identified. Here we demonstrate a specific interaction between ERK3 and MAPK-activated protein kinase-5 (MK5). Binding results in nuclear exclusion of both ERK3 and MK5 and is accompanied by ERK3-dependent phosphorylation and activation of MK5 in vitro and in vivo. Endogenous MK5 activity is significantly reduced by siRNA-mediated knockdown of ERK3 and also in fibroblasts derived from ERK3-/- mice. Furthermore, increased levels of ERK3 protein detected during nerve growth factor-induced differentiation of PC12 cells are accompanied by an increase in MK5 activity. Conversely, MK5 depletion causes a dramatic reduction in endogenous ERK3 levels. Our data identify the first physiological protein substrate for ERK3 and suggest a functional link between these kinases in which MK5 is a downstream target of ERK3, while MK5 acts as a chaperone for ERK3. Our findings provide valuable tools to further dissect the regulation and biological roles of both ERK3 and MK5. 相似文献
18.
Up-regulation of cyclooxygenase-2 and apoptosis resistance by p38 MAPK in hypericin-mediated photodynamic therapy of human cancer cells 总被引:7,自引:0,他引:7
Hendrickx N Volanti C Moens U Seternes OM de Witte P Vandenheede JR Piette J Agostinis P 《The Journal of biological chemistry》2003,278(52):52231-52239
19.
20.
Enhanced activity of the plasma membrane oxidoreductase in circulating lymphocytes from insulin-dependent diabetes mellitus patients 总被引:2,自引:0,他引:2
Lenaz G Paolucci U Fato R D'Aurelio M Parenti Castelli G Sgarbi G Biagini G Ragni L Salardi S Cacciari E 《Biochemical and biophysical research communications》2002,290(5):1589-1592
Circulating human lymphocytes contain a transmembrane oxidoreductase (PMOR) capable of reducing dichlorophenol indophenol (DCIP) by endogenous reductants, presumably NADH. Membranes from lymphocytes obtained from buffy coats contain a NADH DCIP reductase having a K(m) of about 1 microM and almost insensible to dicoumarol. The PMOR of lymphocytes from insulin-dependent diabetic patients is higher than that from age-matched controls and, in addition, has a dicoumarol-sensitive component, lacking in most controls, presumably due to membrane association of DT-diaphorase. The increase of PMOR in diabetes is likely due to overexpression of the enzyme, in view of the very low K(m) for NADH indicating that, in intact cells, the enzyme is practically saturated with the reductant substrate. 相似文献