全文获取类型
收费全文 | 14023篇 |
免费 | 957篇 |
国内免费 | 589篇 |
专业分类
耳鼻咽喉 | 88篇 |
儿科学 | 207篇 |
妇产科学 | 309篇 |
基础医学 | 2854篇 |
口腔科学 | 555篇 |
临床医学 | 1032篇 |
内科学 | 2094篇 |
皮肤病学 | 259篇 |
神经病学 | 1353篇 |
特种医学 | 289篇 |
外国民族医学 | 2篇 |
外科学 | 1214篇 |
综合类 | 1624篇 |
现状与发展 | 1篇 |
预防医学 | 701篇 |
眼科学 | 294篇 |
药学 | 1526篇 |
中国医学 | 142篇 |
肿瘤学 | 1025篇 |
出版年
2023年 | 81篇 |
2022年 | 205篇 |
2021年 | 334篇 |
2020年 | 238篇 |
2019年 | 227篇 |
2018年 | 262篇 |
2017年 | 283篇 |
2016年 | 362篇 |
2015年 | 427篇 |
2014年 | 642篇 |
2013年 | 921篇 |
2012年 | 749篇 |
2011年 | 873篇 |
2010年 | 765篇 |
2009年 | 849篇 |
2008年 | 867篇 |
2007年 | 837篇 |
2006年 | 749篇 |
2005年 | 735篇 |
2004年 | 616篇 |
2003年 | 550篇 |
2002年 | 431篇 |
2001年 | 403篇 |
2000年 | 320篇 |
1999年 | 296篇 |
1998年 | 237篇 |
1997年 | 240篇 |
1996年 | 214篇 |
1995年 | 196篇 |
1994年 | 176篇 |
1993年 | 126篇 |
1992年 | 143篇 |
1991年 | 135篇 |
1990年 | 129篇 |
1989年 | 105篇 |
1988年 | 76篇 |
1987年 | 70篇 |
1986年 | 53篇 |
1985年 | 95篇 |
1984年 | 101篇 |
1983年 | 75篇 |
1982年 | 64篇 |
1981年 | 66篇 |
1980年 | 56篇 |
1979年 | 49篇 |
1978年 | 36篇 |
1977年 | 35篇 |
1976年 | 18篇 |
1975年 | 12篇 |
1974年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Polyclonal antiserum to an Escherichia coli-produced beta-galactosidase/E4 fusion protein of human papillomavirus type 6b (antiserum 256), and affinity purified HPV 11 anti-E4 antibodies were tested for reactivity in Western blots with bacterially expressed trpE/E4 fusion proteins of HPV types 6b, 11, 16, and 18. To further characterize the affinity purified anti-E4 antibodies, a dot-immunobinding assay was performed using overlapping synthetic HPV 11 E1E4 peptides as antigens. Protein extracts of condylomata acuminatum from 18 patients containing HPV type 6 or 11 DNA sequences were tested in Western blots using antiserum 256 or affinity purified HPV 11 anti-E4 antibodies. In the Western blots of the trpE proteins, antiserum 256 identified the HPV types 6b and 11 fusion proteins; the affinity purified HPV 11 anti-E4 antibodies identified only the HPV 11 fusion protein. In the dot-immunobinding assay, three HPV 11 peptides were recognized, each containing a shared 8 amino acid sequence that differs significantly from the corresponding sequences of HPV types 6b, 16, or 18. In the Western blots of protein extracts from 18 condylomata acuminatum samples shown to contain HPV types 6 or 11 DNA, putative E4 gene products were identified in six samples by antiserum 256. The affinity purified HPV 11 anti-E4 antibodies identified putative E4 gene products in one of these same six lesions, which was shown to contain HPV 11 sequences by the Southern blot method. All six samples containing E4 gene products were from women. Three of these women were pregnant, one had serum antibodies to the human immunodeficiency virus, and one was a renal transplant recipient receiving glucocorticoids.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
102.
Tissue-specific tumor suppressor activity of retinoblastoma gene homologs p107 and p130 总被引:6,自引:0,他引:6
下载免费PDF全文
![点击此处可从《Genes & development》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dannenberg JH Schuijff L Dekker M van der Valk M te Riele H 《Genes & development》2004,18(23):2952-2962
The retinoblastoma gene family consists of three genes: RB, p107, and p130. While loss of pRB causes retinoblastoma in humans and pituitary gland tumors in mice, tumorigenesis in other tissues may be suppressed by p107 and p130. To test this hypothesis, we have generated chimeric mice from embryonic stem cells carrying compound loss-of-function mutations in the Rb gene family. We found that Rb/p107- and Rb/p130-deficient mice were highly cancer prone. We conclude that in a variety of tissues tumor development by loss of pRB is suppressed by its homologs p107 and p130. The redundancy of the retinoblastoma proteins in vivo is reflected by the behavior of Rb-family-defective mouse embryonic fibroblasts in vitro. 相似文献
103.
104.
Anti-human thyroid peroxidase and anti-human thyroglobulin antibodies present no cross-reactivity on recombinant peptides.
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Thyroglobulin (Tg) and thyroid peroxidase (TPO) are two antigens largely recognized by the sera from patients with autoimmune thyroid disease (AITD). Recently, the complete mapping of both antigens was established with rabbit polyclonal antibodies by the use of recombinant proteins expressed in prokaryotic vector. Several investigators have argued for the existence of a cross-reactivity of some hetero- and autologous antibodies versus these two proteins. In the present study, using rabbit polyclonal antibody, mouse polyclonal antibody and autoimmune antibody (aAb), we observed no common epitope on human Tg (hTg) and human TPO (hTPO). 相似文献
105.
Stress or heat-shock proteins may be involved in the initiation and perpetuation of autoimmune diseases. In order to investigate a possible role of autoantibodies against the 70-kD family of heat-shock proteins in systemic lupus erythematosus (SLE), sera of SLE patients and healthy subjects were tested for the presence of IgG and IgM antibodies to 70-kD class proteins. These proteins were purified by affinity chromatography on ATP-agarose and used in Western blotting studies. The data obtained revealed that antibodies to the 72-kD and the 73-kD heat-shock proteins occurred with similar frequencies both in healthy subjects and SLE patients. Thus, approximately 20% of the sera in each group contained IgG antibodies, and IgM antibodies were detected in about 30% of the sera tested. Moreover, in SLE patients no association between the occurrence and litre of these antibodies and disease activity was found. These data suggest that antibodies to the 70-kD class heat-shock proteins are naturally occurring and argue therefore against an involvement of these antibodies in the pathogenesis of SLE. 相似文献
106.
目的:观察大鼠7周大负荷游泳训练及人参二醇组皂甙(PDS)对大鼠股四头肌α-肌动蛋白mRNA表达的影响。方法:采用Northernblot分析7周大负荷游泳训练后恢复期大鼠股四头肌α-肌动蛋白mRNA表达水平及PDS对其影响。结果:α-肌动蛋白mRNA杂交信号的扫描积分光密度值(A),运动·盐水组较安静组略强;运动·PDS,扫描积分光密度值(A)显著强于运动·盐水组和安静组,运动·甲睾组与运动·盐水组表达无明显差异。结论:PDS可提高长期耐力运动大鼠股四头肌α-肌动蛋白mRNA表达,从而提高耐力运动能力;长期应用外源性雄激素对耐力训练大鼠股四头肌α-肌动蛋白无明显提高,这可能与外源睾酮对内源性睾酮分泌的抑制有关。 相似文献
107.
Serological distinction of integral plasma membrane proteins as a class of mycobacterial antigens and their relevance for human T cell activation
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J. MEHROTRA D. BISHT V. D. TIWARI S. SINHA 《Clinical and experimental immunology》1995,102(3):626-634
This study pertains to classification and antigenic analysis of mycobacterial plasma membrane proteins in relation to human T cell proliferative responses, using a ‘fast grower’ Mycobacterium fortuitum as model. Membrane vesicles, prepared by sonication and differential centrifugation, were subjected to biphasic Triton X-1 14 extraction for isolation of integral (detergent phase) and peripheral (aqueous phase) proteins. Neither protein pool showed any appreciable overlap serologically. SDS-PAGE showed five prominent bands in peripheral and three in the integral protein pool, whereas immunoblotting with rabbit antisera identified only two major antigens (60 and 67kD) in the former and five (24, 34, 42, 51 and 54kD) in the latter, ELISA with a panel of anti-mycobacterial MoAbs revealed that nine out of 12 previously known antigens were present in the peripheral protein pool. Only two of them (33 and 40 kD) were additionally detected amongst integral proteins. The membrane-associated immunosuppressive moiety lipoarabinomannan was semiquantitatively located in aqueous phase. In bulk T cell proliferation assays, seven out of 10 subjects belonging to a ‘responder’ background (BT-BB leprosy patients and healthy contacts) showed high responses for Myco. fortuitum antigens. Proliferative response with integral proteins was comparable to that with whole membrane, hut it was significantly higher (P < 0.0005) than t he response with peripheral proteins. The distinction and relevance of integral membrane proteins as a class of mycobacterial antigens make them worthy of consideration in a subunit vaccine design. 相似文献
108.
The effect of surface chemistry modification of titanium alloy on signalling pathways in human osteoblasts 总被引:2,自引:0,他引:2
Zreiqat H Valenzuela SM Nissan BB Roest R Knabe C Radlanski RJ Renz H Evans PJ 《Biomaterials》2005,26(36):7579-7586
Establishing and maintaining mature bone at the bone–device interface is critical to the long-term success of prosthesis. Poor cell adhesion to orthopaedic and dental implants results in implant failure. Considerable effort has been devoted to alter the surface characteristics of these biomaterials in order to improve the initial interlocking of the device and skeleton. We investigated the effect of surface chemistry modification of titanium alloy (Ti–6Al–4V) with zinc, magnesium or alkoxide-derived hydroxy carbonate apatite (CHAP) on the regulation of key intracellular signalling proteins in human bone-derived cells (HBDC) cultured on these modified Ti–6Al–4V surfaces. Western blotting demonstrated that modifying Ti–6Al–4V with CHAP or Mg results in modulation of key intracellular signalling proteins. We showed an enhanced activation of Shc, a common point of integration between integrins and the Ras/Mapkinase pathway. Mapkinase pathway was also upregulated, suggesting its role in mediating osteoblastic cell interactions with biomaterials. The signalling pathway involving c-fos (member of the activated protein-1) was also shown to be upregulated in osteoblasts cultured on the Mg and CHAP modified Ti–6Al–4V. Thus surface modification with CHAP or Mg may contribute to successful osteoblast function and differentiation at the skeletal tissue–device interface. 相似文献
109.
S. A. Afanas’ev E. N. Pavlyukova Sh. D. Akhmedov R. S. Karpov 《Bulletin of experimental biology and medicine》2004,138(10):365-368
We studied myocardial biopsy specimens from the right atrium of cardiological patients with different degree of cardiac ischemia obtained during surgery. No inducible HSP70 stress proteins were detected in atrial cardiomyocytes of patients with the WPW syndrome without signs of ischemic injuries of the heart. These proteins were detected in the myocardium of coronary patients. Their expression was more intense in patients with coronary disease paralleled by the development of myocardial dyskinesia. Two-dimensional electrophoresis showed only acid HSP70 but no alkaline isoforms in coronary patients even with pronounced dyskinesia. Presumably, alkaline HSP70 isoforms are present in the myocardium directly involved in the dyskinesia zone.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 10, pp. 412–415, October, 2004 相似文献
110.
Vibrio parahaemolyticus, a universal marine pathogen with available genome sequences, could be used as a bacterial model to clarify the various physiological phenomena of its native and host environments. In the present study, proteomic methodologies were applied to investigate the expression pattern of outer membrane proteins (OMPs) of V. parahaemolyticus at different NaCl concentrations. OmpW, OmpV, elongation factor TU and polar flagellin were determined to be osmoregulation-sensitive OMPs, among which OmpW and OmpV were reported to vary with changed NaCl concentrations in the pattern of osmolarity regulation. Therefore, our results not only expand our knowledge on osmoregulation-related proteins, but also provide a valuable strategy for the screening of salt-sensitive proteins. 相似文献