全文获取类型
收费全文 | 190篇 |
免费 | 32篇 |
专业分类
222篇 |
出版年
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 9篇 |
2013年 | 17篇 |
2012年 | 8篇 |
2011年 | 13篇 |
2010年 | 5篇 |
2009年 | 7篇 |
2008年 | 11篇 |
2007年 | 8篇 |
2006年 | 9篇 |
2005年 | 11篇 |
2004年 | 11篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 7篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1961年 | 1篇 |
1959年 | 1篇 |
1953年 | 2篇 |
排序方式: 共有222条查询结果,搜索用时 15 毫秒
51.
Mira Malcov Dalit Ben-Yosef Tova Glaser Ruth Shalgi 《Molecular reproduction and development》1997,48(1):119-126
Resumption of meiosis at fertilization is mediated by increased levels of calcium which activate several calcium-dependent enzymes. Calpain, a neutral calcium-activated thiol protease, is present in the cytoplasm of many cells. Its activation is associated with limited autolysis and relocalization in the cell. Calpain is thought to participate in the regulation of mitosis and resumption of meiosis in Xenopus oocytes. In this study we followed the activation and localization of calpain during maturation and fertilization in rat eggs using a polyclonal antibody raised against chicken muscle calpain. A band of 80 kDa was detected in GV oocytes and its level increased in unfertilized MII eggs. At the early stages of fertilization, we observed a transient decrease in the level of calpain which was regained at the pronuclear stage. Adding Ca2+ to lysate of MII eggs resulted in an additional band, representing the degraded fragment of the activated protein. In eggs activated by ionomycin, calpain level decreased, followed by an increase in a dynamic similar to that observed in fertilized eggs. Egg activation also led to changes in calpain localization. A homogenous distribution was observed in GV and in MII eggs, while in activated eggs it was localized predominantly overlying the metaphase plate. In the current study we demonstrate the presence of calpain in the rat egg. During maturation, calpain level increases; however, during egg activation, in response to [Ca2+]i changes, calpain undergoes autolysis, translocation, and fluctuation in its level. We therefore suggest a correlation between calpain activation and fertilization. Mol. Reprod. Dev. 48:119–126, 1997. © 1997 Wiley-Liss, Inc. 相似文献
52.
53.
The abundance of caveolae in adipocytes suggests a possible cell-specific role for these structures, and because these cells take up and release fatty acids as their quantitatively most robust activity, modulation of fatty acid movement is one such role that is supported by substantial in vitro and in vivo data. In addition, caveolae are particularly rich in cholesterol and sphingolipids, and indeed, fat cells harbor more cholesterol than any other tissue. In this article, we review the role of adipocyte caveolae with regard to these important lipid classes. 相似文献
54.
55.
Biomechanical plasticity and within-species growth form diversity are traits that can facilitate invasion by non-native plant
species. We support this argument with evidence from the invasion of coastal habitats in northern Florida, USA, by Schinus terebinthifolius and describe some of the consequences of this invasion for overtopped saltmarsh plants. In crowded stands, Schinus grows more like a vine than a tree, with stem height : diameter ratios nearly twice than those observed in open-grown individuals
but with no changes in wood density or the modulus of elasticity of stem material. When extracted from the surrounding vegetation,
the formerly crowded Schinus stems buckle under their own weight. Schinus crowns also extend much further over adjacent saltmarsh than crowns of Juniperus virginiana, the only other tree species abundant in the study site. Along forest edges, the above-ground biomass of saltmarsh plants
overtopped by Schinus crowns was reduced by more than an order of magnitude. The biomechanical plasticity of Schinus allows it to adapt its growth form to suit habitat conditions and can dominate the edges of salt marshes as a sprawling shrub
and maritime forests as either a free-standing tree or a woody vine, depending on stand crowding 相似文献
56.
Functional phosphorylation sites in the C-terminal region of the multivalent multifunctional transcriptional factor CTCF 总被引:1,自引:0,他引:1
57.
Maja Neiman Claudia Fredolini Henrik Johansson Janne Lehtiö Per‐Åke Nygren Mathias Uhlén Peter Nilsson Jochen M. Schwenk 《Proteomics》2013,13(23-24):3406-3410
The increasing availability of antibodies toward human proteins enables broad explorations of the proteomic landscape in cells, tissues, and body fluids. This includes assays with antibody suspension bead arrays that generate protein profiles of plasma samples by flow cytometer analysis. However, antibody selectivity is context dependent so it is necessary to corroborate on‐target detection over off‐target binding. To address this, we describe a concept to directly verify interactions from antibody‐coupled beads by analysis of their eluates by Western blots and MS. We demonstrate selective antibody binding in complex samples with antibodies toward a set of chosen proteins with different abundance in plasma and serum, and illustrate the need to adjust sample and bead concentrations accordingly. The presented approach will serve as an important tool for resolving differential protein profiles from antibody arrays within plasma biomarker discoveries. 相似文献
58.
59.
Dror Fixler Smadar Yitzhaki Alexander Axelrod Tova Zinman Asher Shainberg 《Bioelectromagnetics》2012,33(8):634-640
The purpose of this study was to determine the effect of extremely low frequency and weak magnetic fields (WMF) on cardiac myocyte Ca2+ transients, and to explore the involvement of potassium channels under the WMF effect. In addition, we aimed to find a physical explanation for the effect of WMF on cardiac myocyte Ca2+ transients. Indo‐1 loaded cells, which were exposed to a WMF at 16 Hz and 40 nT, demonstrated a 75 ± 4% reduction in cytosolic Ca2+ transients versus control. Treatment with the KATP channel blocker, glibenclamide, followed by WMF at 16 Hz exposure, blocked the reduction in cytosolic calcium transients while treatment with pinacidil, a KATP channel opener, or chromanol 293B, a selective potassium channel blocker of the delayed rectifier K+ channels, did not inhibit the effect. Based on these finding and the ion cyclotron resonance frequency theory, we further investigated the effect of WMF by changing the direct current (DC) magnetic field (B0). When operating different DC magnetic fields we showed that the WMF value changed correspondingly: for B0 = 44.5 µT, the effect was observed at 17.05 Hz; for B0 = 46.5 µT, the effect was observed at 18.15 Hz; and for B0 = 49 µT the effect was observed at 19.1 Hz. We can conclude that the effect of WMF on Ca2+ transients depends on the DC magnetic field level. Bioelectromagnetics 33:634–640, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
60.