全文获取类型
收费全文 | 1988篇 |
免费 | 189篇 |
国内免费 | 7篇 |
出版年
2023年 | 9篇 |
2022年 | 16篇 |
2021年 | 33篇 |
2020年 | 28篇 |
2019年 | 20篇 |
2018年 | 34篇 |
2017年 | 29篇 |
2016年 | 65篇 |
2015年 | 79篇 |
2014年 | 83篇 |
2013年 | 125篇 |
2012年 | 184篇 |
2011年 | 133篇 |
2010年 | 103篇 |
2009年 | 72篇 |
2008年 | 115篇 |
2007年 | 132篇 |
2006年 | 121篇 |
2005年 | 105篇 |
2004年 | 104篇 |
2003年 | 113篇 |
2002年 | 111篇 |
2001年 | 21篇 |
2000年 | 13篇 |
1999年 | 23篇 |
1998年 | 28篇 |
1997年 | 21篇 |
1996年 | 19篇 |
1995年 | 16篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 9篇 |
1991年 | 15篇 |
1990年 | 12篇 |
1989年 | 12篇 |
1988年 | 13篇 |
1987年 | 7篇 |
1986年 | 13篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 15篇 |
1980年 | 9篇 |
1979年 | 10篇 |
1978年 | 6篇 |
1977年 | 13篇 |
1974年 | 6篇 |
1973年 | 7篇 |
1968年 | 4篇 |
排序方式: 共有2184条查询结果,搜索用时 15 毫秒
1.
Daniel A. Vardy Csaba Kari Gerald S. Lazarus Pamela J. Jensen Asher Zilberstein Gregory D. Plowman Ulrich Rodeck 《Journal of cellular physiology》1995,163(2):257-265
Autocrine activation of the epidermal growth factor (EGF) receptor on keratinocytes has been recognized as an important growth regulatory mechanism involved in epithelial homeostasis, and, possibly, hyperproliferative diseases. Insulin-like growth factor (IGF)-1 and insulin have been shown to be paracrine keratinocyte mitogens that bind to the type I IGF receptor which is expressed on actively proliferating keratinocytes in situ. In this report, we demonstrate that IGF-1/insulin induced production of keratinocyte-derived autocrine growth factors that bind to the EGF receptor. Increased steady-state mRNA levels for transforming growth factor alpha (TGF-α) and for amphiregulin (AR) were observed upon incubation of keratinocytes with mitogenic concentrations of IGF-1. IGF-1 also induced production and secretion of TGF-α and AR proteins as detected by immunoassays. An EGF receptor antagonistic monoclonal antibody abolished the mitogenic effect of IGF-1 on cultured keratinocytes. These results suggest that stimulation of keratinocyte growth by IGF-1 requires activation of an EGF receptor-mediated autocrine loop. © 1995 Wiley-Liss, Inc. 相似文献
2.
3.
4.
Pertti J. Martikainen Eeva-Liisa Nurmiaho-Lassila Kari Lounatmaa 《FEMS microbiology letters》1989,59(3):313-317
Abstract The outer membrane (OM) structure of Nitrosospira sp. X101 was studied by different electron microscopic techniques and SDS-PAGE. A crystalline outer membrane protein was visible in freeze-etched cells, occasionally seen also in the thin sectioned cells, but was difficult to see in a negatively-stained preparation. The lattice probably consists of large globular protein subunits with a hexagonal arrangement. The molecular weights of the major proteins in the cell envelope are 35 kDa, 40 kDa and 42 kDa. 相似文献
5.
6.
Kari K. Åkerman 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1997,696(2):394
A simple and reliable method for analyzing the concentrations of clozapine and its biologically active metabolite, norclozapine, in human serum or plasma has been developed. This method is based on reversed-phase high-performance liquid chromatography (HPLC) with automated solid-phase extraction (SPE). For HPLC analysis, samples and standards are prepared with an ASPEC automatic sample preparator using 100 mg Bond-Elut C18 SPE columns. The HPLC assay is an isocratic method with a mobile phase of acetonitrile-methanol-10 mM dipotassium hydrogenphosphate, pH 3.7 (30:2:100, v/v/v) at a flow-rate of 1.5 ml/min with a C18 reversed-phase column. Detection is performed with a diode array detector set at 220 nm and with peak purity analyses at 210–365 nm. The absolute recovery varied from 85 and 95%. The intra-assay coefficients of variation (C.V.s) were from 4.2 and 8.0% and the inter-assay C.V.s were from 1.1. to 9.3% at therapeutic drug concentrations. The detection limit is 15 nmol/l. The method has been developed for use in a clinical laboratory for therapeutic drug monitoring. 相似文献
7.
8.
Attempt to detect recombination between B-F and B-L genes within the chicken B complex by serological typing,in vitro MLR,and RFLP analyses 总被引:1,自引:1,他引:0
Karel Hála Anne-Marie Chaussé Yves Bourlet Olli Lassila Viktor Hasler Charles Auffray 《Immunogenetics》1988,28(6):433-438
In search for recombinants within the chicken major histocompatibility B complex, 1155 animals from crosses between the congenic lines CB (B12) and CC (B4) were tested with alloantibodies and monoclonal antibodies for the B-F (class I), B-L (class II), and B-G (class IV) antigens and by mixed lymphocyte reaction. The absence of detectable recombination was confirmed by restriction fragment length polymorphism analysis with B-L
and B-F probes. Together with previous reports, this indicates that the distance between the B-F and B-L loci is below 0.01 centimorgan. 相似文献
9.
Sera from both human cytomegalovirus (HCMV)-seropositive adults and infants with congenital HCMV infection recognized two major HCMV glycoprotein complexes. However, proliferative responses of peripheral blood mononuclear cells to these complexes varied among seropositive adults and were not detected in any of the infants. Thus, these glycoproteins alone may not be sufficient to develop a subviral HCMV vaccine. 相似文献
10.
A multigene family encodes the human cytomegalovirus glycoprotein complex gcII (gp47-52 complex). 总被引:11,自引:11,他引:0 下载免费PDF全文
The HXLF (HindIII-X left reading frame) gene family is a group of five genes that share one or two regions of homology and are arranged in tandem within the short unique component of the human cytomegalovirus genome (K. Weston and B.G. Barrell, J. Mol. Biol. 192:177-208, 1986). These genes were cloned into an SP6 expression vector in both the sense and antisense orientations. An abundant 1.62-kilobase (kb) bicistronic mRNA, predicted to originate from HXLF1 and HXLF2, was detected in the cytoplasm of infected human fibroblast cells by Northern (RNA) blot analysis. Less abundant RNAs of 1.0 and 0.8 kb, predicted to originate from the HXLF5 and HXLF2 genes, respectively, were also detected. Monocistronic, bicistronic, and polycistronic RNAs synthesized in vitro by using SP6 polymerase were translated in rabbit reticulocyte lysates with or without canine pancreatic microsomal membranes. The HXLF1 or the HXLF1 and HXLF2 translation products were detected when the above mRNAs were used. The HXLF3, HXLF4, and HXLF5 gene products were not detected by in vitro translation of the SP6-derived polycistronic mRNA. Nonglycosylated or glycosylated HXLF1 and HXLF2 gene products were immunoprecipitated by monoclonal antibody 9E10, which is specific for a virion envelope glycoprotein complex designated gcII (gp47-52 complex). In addition, the monoclonal antibody 9E10 immunoprecipitated a diffuse glycoprotein band, designated gp47-52, from HCMV-infected cell lysates. The amino acid composition of gp47-52 purified from viron envelopes has the highest similarity to the predicted amino acid composition of the HXLF1 plus HXLF2 open reading frames, but it is more similar to HXLF2 than to HXLF1. The Northern blot results imply that gp47-52 is synthesized predominantly from the abundant 1.62-kb bicistronic mRNA encoded by the HXLF1 and HXLF2 genes. However, the glycoprotein could also be synthesized by the monocistronic 0.8-kb mRNA encoded by the HXLF2 gene as well as by the mRNAs predicted from the other HXLF genes. 相似文献