全文获取类型
收费全文 | 2128篇 |
免费 | 111篇 |
国内免费 | 33篇 |
出版年
2024年 | 1篇 |
2023年 | 22篇 |
2022年 | 32篇 |
2021年 | 51篇 |
2020年 | 52篇 |
2019年 | 61篇 |
2018年 | 57篇 |
2017年 | 38篇 |
2016年 | 30篇 |
2015年 | 43篇 |
2014年 | 75篇 |
2013年 | 136篇 |
2012年 | 65篇 |
2011年 | 73篇 |
2010年 | 65篇 |
2009年 | 64篇 |
2008年 | 92篇 |
2007年 | 103篇 |
2006年 | 106篇 |
2005年 | 85篇 |
2004年 | 98篇 |
2003年 | 76篇 |
2002年 | 96篇 |
2001年 | 111篇 |
2000年 | 90篇 |
1999年 | 70篇 |
1998年 | 65篇 |
1997年 | 39篇 |
1996年 | 39篇 |
1995年 | 34篇 |
1994年 | 25篇 |
1993年 | 47篇 |
1992年 | 29篇 |
1991年 | 25篇 |
1990年 | 14篇 |
1989年 | 24篇 |
1988年 | 27篇 |
1987年 | 11篇 |
1986年 | 14篇 |
1985年 | 19篇 |
1984年 | 16篇 |
1983年 | 8篇 |
1982年 | 17篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1970年 | 1篇 |
排序方式: 共有2272条查询结果,搜索用时 0 毫秒
1.
2.
N. L. Klyachko 《Russian Journal of Plant Physiology》2006,53(5):702-709
This lecture is devoted to the relative contribution of various levels of regulation of the actin cytoskeleton functioning in the cell. Regulation at the levels of gene expression, mRNA and protein synthesis and stability, processes of actin polymerization/depolymerization and actin structures reorganization is briefly considered. Novel information about the pathways of signal transduction to the actin cytoskeleton with the involvement of Arp2/3 complex and RIC proteins is highlighted. 相似文献
3.
The family of flaviviruses is one of the most medically important groups of emerging arthropod-borne viruses. Host cell cytoskeletons have been reported to have close contact with flaviviruses during virus entry, intracellular transport, replication, and egress process, although many detailed mechanisms are still unclear. This article provides a brief overview of the function of the most prominent flaviviruses-induced or-hijacked cytoskeletal structures including actin, microtubules and intermediate filaments, mainly focus on infection by dengue virus, Zika virus and West Nile virus. We suggest that virus interaction with host cytoskeleton to be an interesting area of future research. 相似文献
4.
Nazar J. Hussein Thomas Mbimba Asaad A. Al-Adlaan Mohammad Y. Ansari Fatima A. Jaber Scott McDermott Takhar Kasumov Fayez F. Safadi 《Journal of cellular biochemistry》2020,121(1):284-298
Trafficking protein particle complex 9 (TRAPPC9) is a major subunit of the TRAPPII complex. TRAPPC9 has been reported to bind nuclear factor κB kinase subunit β (IKKβ) and NF-kB-inducing kinase (NIK) where it plays a role in the canonical and noncanonical of nuclear factor-κB (NF-kB) signaling pathways, receptively. The role of TRAPPC9 in protein trafficking and cytoskeleton organization in osteoclast (OC) has not been studied yet. In this study, we examined the mRNA expression of TRAPPC9 during OC differentiation. Next, we examined the colocalization of TRAPPC9 with cathepsin-K, known to mediate OC resorption suggesting that TRAPPC9 mediates the trafficking pathway within OC. To identify TRAPPC9 protein partners important for OC-mediated cytoskeleton re-organization, we conducted immunoprecipitation of TRAPPC9 in mature OCs followed by mass spectrometry analysis. Our data showed that TRAPPC9 binds various protein partners. One protein with high recovery rate is L-plastin (LPL). LPL localizes at the podosomes and reported to play a crucial role in actin aggregation thereby actin ring formation and OC function. Although the role of LPL in OC-mediated bone resorption has not fully reported in detail. Here, first, we confirmed the binding of LPL to TRAPPC9 and, then, we investigated the potential regulatory role of TRAPPC9 in LPL-mediated OC cytoskeleton reorganization. We assessed the localization of TRAPPC9 and LPL in OC and found that TRAPPC9 is colocalized with LPL at the periphery of OC. Next, we determined the effect of TRAPPC9 overexpression on LPL recruitment to the actin ring using a viral system. Interestingly, our data showed that TRAPPC9 overexpression promotes the recruitment of LPL to the actin ring when compared with control cultures. In addition, we observed that TRAPPC9 overexpression reorganizes actin clusters/aggregates and regulates vinculin recruitment into the OC periphery to initiate podosome formation. 相似文献
5.
《Developmental cell》2023,58(15):1399-1413.e5
- Download : Download high-res image (260KB)
- Download : Download full-size image
6.
Cell and molecular biology of bryophytes: ultimate limits to the resolution of phylogenetic problems 总被引:1,自引:0,他引:1
JEFFREY G. DUCKETT F.L.S. KAREN S. RENZAGLIA 《Botanical journal of the Linnean Society. Linnean Society of London》1988,98(3):225-246
Ultrastructure, biochemistry and 5S rRNA sequences link tracheophytes, bryophytes and charalean green algae, but the precise interrelationships between these groups remain unclear. Further major clarification now awaits primary sequence data. These are also needed to determine directionality in possible evolutionary trends within the bryophytes, but are unlikely to overturn current schemes of classification or phylogeny. Comparative ultrastructural studies of spermatogenesis, sporogenesis, the cytoskeleton and plastids reinforce biochemical and morphogenetic evidence for the wide phyletic discontinuities between mosses, hepatics and hornworts, and also rule out direct lines of descent between them. Direct ancestral lineages from charalean algae to bryophytes and to tracheophytes are also unlikely. EM studies of gametophyte/sporophyte junctions, plus immunological investigations of bryophyte cytoskeletons, are likely to accentuate the differences between mosses, hepatirs and hornworts. Other priorities for systematics include elucidation of oil body ultrastructure, analysis of the changes in nuclear proteins during spermatogenesis and a detailed comparison of bryophyte and charalean plastids. The combined evidence from ultrastrueture, biochemistry, morphology and morphogenesis warrants general acceptance of the polyphyletic origin of the bryophytes. Ultrastructural attributes should be more widely used in bryophyte systematics. 相似文献
7.
A purified head fraction was prepared from bovine epididymal spermatozoa and was utilized to identify the solubility characteristics and major polypeptide components of the postacrosomal sheath. Sperm heads extracted in nonionic-detergent-containing or high-salt-containing solutions retained an intact postacrosomal sheath, but it was readily solubilized by high pH extraction solutions. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a major polypeptide of 58,000 daltons (58-kD) in the high pH extract solution. Antibodies to the 58-kD polypeptide specifically reacted with the postacrosomal segment by immunofluorescence and by electron microscopic immunohistochemistry were shown to bind the postacrosomal sheath. We conclude that this 58-kD polypeptide is a constituent of the postacrosomal sheath and that its distribution is restricted to the postacrosomal segment. 相似文献
8.
9.
Michael S. Goligorsky David N. Menton Keith A. Hruska 《The Journal of membrane biology》1986,92(2):151-162
Summary In order to examine the possibility of parathyroid hormone-mediated ultrastructural rearrangements in target epithelium, isolated canine renal proximal tubular cells were grown on a collagen-coated semipermeable membrane in a defined medium. Scanning and transmission electron microscopy of these monolayers revealed abundant microvilli. Exposure of the proximal tubular cells to parathyroid hormone resulted in a biphasic changes involving: (1) dramatic shortening and rarefaction of microvilli within 1 min; and (2) recovery of microvillar topography after 5 min. A similar shortening of microvilli was observed following exposure to ionomycin, whereas incubation with cyclic AMP resulted in an elongation of microvilli. Parathyroid hormone stimulated cyclic AMP production and increased cytoplasmic free calcium concentration in cultured proximal tubular cells. Pretreatment of cells with a calmodulin inhibitor abolished the effect of parathyroid hormone on brush border topography. Shortening of microvilli was associated with a disappearance of microvillar core filaments. Staining of F-actin with fluoresceinphalloidin showed that parathyroid hormone resulted in fragmentation of stress fibers. It is concluded that parathyroid hormoneinduced cell activation involves cytoplasmic-free calcium, calmodulin, and the cytoskeleton. 相似文献
10.
Richard E. Williamson 《Planta》1985,163(1):1-8
The mechanism by which sub-cortical actin bundles and membranous organelles are immobilised in the cortical cytoplasm of the alga Chara was studied by perfusing cells with a solution containing 1% Triton X-100. Light and scanning electron microscopy and the release of starch grains and chlorophyll-protein complexes indicated that the detergent extensively solubilised the chloroplasts. However, the sub-cortical actin bundles remained in situ even though they were originally separated from the plasma membrane by the chloroplasts. A fibrous layer between chloroplasts and plasma membrane became readily visible after detergent extraction of the cells and could be released by low-ionic-strength ethylenediaminetetraacetic acid, thioglycollate and trypsin. The same treatments applied to cells not subject to detergent extraction released the membrane-bound organelles and actin bundles and no fibrous meshwork was visible on subsequent extraction with Triton. It is, therefore, concluded that a detergent-insoluble cortical cytoskeleton exists and contributes to the immobility of the actin and cortical organelles in the cells.Abbreviation EDTA
ethylenediaminetetraacetic acid 相似文献