全文获取类型
收费全文 | 909篇 |
免费 | 64篇 |
出版年
2024年 | 2篇 |
2023年 | 8篇 |
2022年 | 19篇 |
2021年 | 34篇 |
2020年 | 15篇 |
2019年 | 10篇 |
2018年 | 27篇 |
2017年 | 30篇 |
2016年 | 38篇 |
2015年 | 64篇 |
2014年 | 49篇 |
2013年 | 82篇 |
2012年 | 110篇 |
2011年 | 61篇 |
2010年 | 46篇 |
2009年 | 50篇 |
2008年 | 46篇 |
2007年 | 45篇 |
2006年 | 36篇 |
2005年 | 30篇 |
2004年 | 16篇 |
2003年 | 21篇 |
2002年 | 20篇 |
2001年 | 2篇 |
1999年 | 12篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1983年 | 2篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1979年 | 5篇 |
1977年 | 4篇 |
1975年 | 3篇 |
1974年 | 6篇 |
1973年 | 2篇 |
1970年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有973条查询结果,搜索用时 15 毫秒
41.
Sharma R Srivastava S Bajpai VK Balapure AK 《In vitro cellular & developmental biology. Animal》2002,38(5):293-297
A repertoire of hormonal signals including estrogen regulate the growth, differentiation, and functioning of diverse target tissues, including the ovary, the mammary gland, and skeletal tissue. A serum-free culture system derived from rabbit endometrium explants has been devised and is reported here to explore estrogen action in vitro. The system involves aseptically harvesting the uterus from a virgin rabbit, dissecting the endometrium, explanting it into 1- to 2-mm(3) pieces weighing approximately 1-2 mg each, and incubating these pieces in serum-free Medium-199. The culture is carried out for a period of 4 d in a humidified CO(2) incubator at 37 degrees C with 5% CO(2). The effect of extraneously added estrogen (1 microg/ml) was investigated by histological and ultrastructural procedures. It was observed that estrogen could induce specific changes, such as abundant mitochondria, rough endoplasmic reticulum, golgi complex, and intracellular collagen deposition, in both the epithelial and the fibroblast cell components of the explanted tissue. The study, therefore, indicates that the proposed system is an ideal tool for exploring and demonstrating estrogen responsiveness under in vitro conditions. 相似文献
42.
Khanna S Venojarvi M Roy S Sharma N Trikha P Bagchi D Bagchi M Sen CK 《Free radical biology & medicine》2002,33(8):1089-1096
43.
Identification and Characterization of Two Quiescent Porin Genes, nmpC and ompN, in Escherichia coli BE 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Alexej Prilipov Prashant S. Phale Ralf Koebnik Christine Widmer Jurg P. Rosenbusch 《Journal of bacteriology》1998,180(13):3388-3392
The genomic DNA of the BE strain of Escherichia coli has been scrutinized to detect porin genes that have not been identified so far. Southern blot analysis yielded two DNA segments which proved highly homologous to, yet distinct from, the ompC, ompF, and phoE porin genes. The two genes were cloned and sequenced. One of them, designated ompN, encodes a porin which, due to low levels of expression, has eluded prior identification. The functional properties (single-channel conductance) of the OmpN porin, purified to homogeneity, closely resemble those of the OmpC porin from E. coli K-12. The second DNA fragment detected corresponds to the nmpC gene, which, due to an insertion of an IS1 element in its coding region, is not expressed in E. coli BE. 相似文献
44.
The Product of the Herpes Simplex Virus Type 1 UL25 Gene Is Required for Encapsidation but Not for Cleavage of Replicated Viral DNA 总被引:16,自引:13,他引:3
下载免费PDF全文
![点击此处可从《Journal of virology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Alistair R. McNab Prashant Desai Stan Person Lori L. Roof Darrell R. Thomsen William W. Newcomb Jay C. Brown Fred L. Homa 《Journal of virology》1998,72(2):1060-1070
The herpes simplex virus type 1 (HSV-1) UL25 gene contains a 580-amino-acid open reading frame that codes for an essential protein. Previous studies have shown that the UL25 gene product is a virion component (M. A. Ali et al., Virology 216:278–283, 1996) involved in virus penetration and capsid assembly (C. Addison et al., Virology 138:246–259, 1984). In this study, we describe the isolation of a UL25 mutant (KUL25NS) that was constructed by insertion of an in-frame stop codon in the UL25 open reading frame and propagated on a complementing cell line. Although the mutant was capable of synthesis of viral DNA, it did not form plaques or produce infectious virus in noncomplementing cells. Antibodies specific for the UL25 protein were used to demonstrate that KUL25NS-infected Vero cells did not express the UL25 protein. Western immunoblotting showed that the UL25 protein was associated with purified, wild-type HSV A, B, and C capsids. Transmission electron microscopy indicated that the nucleus of Vero cells infected with KUL25NS contained large numbers of both A and B capsids but no C capsids. Analysis of infected cells by sucrose gradient sedimentation analysis confirmed that the ratio of A to B capsids was elevated in KUL25NS-infected Vero cells. Following restriction enzyme digestion, specific terminal fragments were observed in DNA isolated from KUL25NS-infected Vero cells, indicating that the UL25 gene was not required for cleavage of replicated viral DNA. The latter result was confirmed by pulsed-field gel electrophoresis (PFGE), which showed the presence of genome-size viral DNA in KUL25NS-infected Vero cells. DNase I treatment prior to PFGE demonstrated that monomeric HSV DNA was not packaged in the absence of the UL25 protein. Our results indicate that the product of the UL25 gene is required for packaging but not cleavage of replicated viral DNA. 相似文献
45.
46.
Integrating Phosphoproteome and Transcriptome Reveals New Determinants of Macrophage Multinucleation
47.
Rebecca A. Drummond Amanda L. Collar Muthulekha Swamydas Carlos A. Rodriguez Jean K. Lim Laura M. Mendez Danielle L. Fink Amy P. Hsu Bing Zhai Hatice Karauzum Constantinos M. Mikelis Stacey R. Rose Elise M. N. Ferre Lynne Yockey Kimberly Lemberg Hye Sun Kuehn Sergio D. Rosenzweig Xin Lin Prashant Chittiboina Sandip K. Datta Thomas H. Belhorn Eric T. Weimer Michelle L. Hernandez Tobias M. Hohl Douglas B. Kuhns Michail S. Lionakis 《PLoS pathogens》2015,11(12)
Candida is the most common human fungal pathogen and causes systemic infections that require neutrophils for effective host defense. Humans deficient in the C-type lectin pathway adaptor protein CARD9 develop spontaneous fungal disease that targets the central nervous system (CNS). However, how CARD9 promotes protective antifungal immunity in the CNS remains unclear. Here, we show that a patient with CARD9 deficiency had impaired neutrophil accumulation and induction of neutrophil-recruiting CXC chemokines in the cerebrospinal fluid despite uncontrolled CNS Candida infection. We phenocopied the human susceptibility in Card9
-/- mice, which develop uncontrolled brain candidiasis with diminished neutrophil accumulation. The induction of neutrophil-recruiting CXC chemokines is significantly impaired in infected Card9
-/- brains, from both myeloid and resident glial cellular sources, whereas cell-intrinsic neutrophil chemotaxis is Card9-independent. Taken together, our data highlight the critical role of CARD9-dependent neutrophil trafficking into the CNS and provide novel insight into the CNS fungal susceptibility of CARD9-deficient humans. 相似文献
48.
49.
Na-Young Ha Prashant Sharma Gwanghun Kim Yuri Kim Chan-Ki Min Myung-Sik Choi Ik-Sang Kim Nam-Hyuk Cho 《PLoS neglected tropical diseases》2015,9(3)
BackgroundScrub typhus is an acute febrile disease caused by Orientia tsutsugamushi infection. Recently, the rapid increase of scrub typhus incidence in several countries within the endemic region has become a serious public health issue. Despite the wide range of preventative approaches that have been attempted in the past 70 years, all have failed to develop an effective prophylactic vaccine. Currently, the selection of the proper antigens is one of the critical barriers to generating cross-protective immunity against antigenically-variable strains of O. tsutsugamushi.Conclusions/SignificanceImmunization of ScaA proteins provides protective immunity in mice when challenged with the homologous strain and significantly enhanced protective immunity against infection with heterologous strains. To our knowledge, this is the most promising result of scrub typhus vaccination trials against infection of heterologous strains in mouse models thus far. 相似文献
50.
Domain swapping mechanism is a specialised mode of oligomerization of proteins in which part of a protein is exchanged in a non-covalent manner between constituent subunits. This mechanism is highly affected by several physiological conditions. Here, we present a detailed analysis ofthe effect of pH on different regions of the domain swapped oligomer by considering examples which are known to be sensitive to pH in transiting from monomeric to domain-swapped dimeric form. The energetic calculations were performed using a specialized method which considers changes in pH and subsequent changes in the interactions between subunits. This analysis provides definitive hints about the pH-dependence switch from monomer to domain-swapped oligomer and the steps that may be involved in the swapping mechanism. 相似文献