全文获取类型
收费全文 | 85797篇 |
免费 | 6141篇 |
国内免费 | 3562篇 |
专业分类
耳鼻咽喉 | 371篇 |
儿科学 | 1516篇 |
妇产科学 | 860篇 |
基础医学 | 13569篇 |
口腔科学 | 1727篇 |
临床医学 | 7144篇 |
内科学 | 14793篇 |
皮肤病学 | 1073篇 |
神经病学 | 7856篇 |
特种医学 | 1330篇 |
外国民族医学 | 15篇 |
外科学 | 5000篇 |
综合类 | 14624篇 |
现状与发展 | 22篇 |
预防医学 | 4991篇 |
眼科学 | 1004篇 |
药学 | 10798篇 |
27篇 | |
中国医学 | 3172篇 |
肿瘤学 | 5608篇 |
出版年
2024年 | 957篇 |
2023年 | 1323篇 |
2022年 | 2503篇 |
2021年 | 3321篇 |
2020年 | 2681篇 |
2019年 | 2254篇 |
2018年 | 2138篇 |
2017年 | 2443篇 |
2016年 | 2744篇 |
2015年 | 3086篇 |
2014年 | 5177篇 |
2013年 | 5770篇 |
2012年 | 5441篇 |
2011年 | 6069篇 |
2010年 | 4807篇 |
2009年 | 4662篇 |
2008年 | 4794篇 |
2007年 | 4646篇 |
2006年 | 4164篇 |
2005年 | 3914篇 |
2004年 | 3206篇 |
2003年 | 2728篇 |
2002年 | 2095篇 |
2001年 | 1791篇 |
2000年 | 1547篇 |
1999年 | 1327篇 |
1998年 | 1237篇 |
1997年 | 1077篇 |
1996年 | 923篇 |
1995年 | 736篇 |
1994年 | 706篇 |
1993年 | 588篇 |
1992年 | 508篇 |
1991年 | 475篇 |
1990年 | 399篇 |
1989年 | 311篇 |
1988年 | 301篇 |
1987年 | 294篇 |
1986年 | 259篇 |
1985年 | 364篇 |
1984年 | 328篇 |
1983年 | 210篇 |
1982年 | 249篇 |
1981年 | 191篇 |
1980年 | 165篇 |
1979年 | 112篇 |
1978年 | 91篇 |
1977年 | 84篇 |
1976年 | 72篇 |
1975年 | 63篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Weiner SM Prasauskas V Lebrecht D Weber S Peter HH Vaith P 《Clinical and experimental immunology》2001,125(2):316-322
A previous case report described the formation of a complex between a monoclonal IgA with cryolabile properties and C-reactive protein (CRP). Our study provides the first evidence for the frequent occurrence of CRP in cryoglobulins (Cg) of all three types according to Brouet's classification. We performed a systematic immunochemical analysis of cryoglobulins from 18 patients by Western blotting and in 15 of 18 cryoprecipitates a single band (23 KD), immunoreactive with anti-CRP antibody, was demonstrable irrespective of the clonal composition of the cryoglobulins. This band was detectable in 4/5 of type I, in 6/8 of type II, and in 5/5 of type III cryoprecipitates, classified according to Brouet et al. In addition, the complement proteins C1q and C3 were present in nearly all CRP-containing cryoglobulins, presumably reflecting previous activation of the classical complement pathway at least. All three CRP-negative cryoprecipitates were derived from sera with low cryoglobulin content (1-2 g/l). Longitudinal investigation of 23 cryoprecipitates from seven patients confirmed that successful detection of CRP by Western blotting depends on the protein concentration of the cryoglobulins. Since complexed CRP was previously shown to be an effective activator of complement, via C1q binding, CRP may modulate pathophysiologic effects mediated by cryoglobulins in vivo. 相似文献
102.
Mohammad Aftabuddin Ichiro Yamadori Tadashi Yoshino Eisaku Kondo Tadaatsu Akagi 《Pathology international》1995,45(6):422-429
The relationship between the number of apoptotic cells and the expression of apoptosis-related antigens was examined In 56 cases of non-Hodgkin's lymphomas and in 10 cases of reactive hyperplastic lymph nodes (RHL). Apoptosis was visually quantified by the in situ end-labeling (ISEL) method, and the expression of Fas, Ley antigens and bcl-2 protein was examined by Immunohistochemistry. The expression of Ley antigen was observed in germinal centers of RHL and 45% of non-Hodgkin's lymphomas. The apoptotic cell count (AC) in follicular lymphomas was significantly less than that in diffuse lymphomas. The distribution pattern of apoptotic cells In follicular lymphomas was inverse to that in RHL. In follicular lymphomas, AC was lower in follicles than in inter-follicular areas. In contrast, AC was higher in follicles than in Interfollicular areas in RHL. Ley antigen-positive lymphomas showed a significantly higher AC than the negative cases. The Fas antigen-positive lymphomas showed a higher AC than the negative cases. However, AC in bcl-2 protein-positive and negative cases was not significantly different. These results suggest that Ley and Fas antigens appear to be involved in the apoptotic tendency of tumor cells in non-Hodgkin's lymphomas, whereas bcl-2 does not necessarily. 相似文献
103.
104.
Yukichi Tanaka 《Virchows Archiv : an international journal of pathology》1987,410(2):125-132
Summary The present study concerns the immunocytochemical localization of S-100 protein and subunits in the cells of human lymphoreticular tissue and their related tumours. The subunit is mainly localized in dendritic cells, most likely the dendritic reticulum cells (DRCs) located within the germinal centers, while the subunit is mainly localized in the interdigitating reticulum cells (IRCs) in the paracortical area and in Histiocytosis X cells. No immunoreactivity for either subunit was found in the majority of normal lymphocytes, macrophages, malignant lymphoma cells, or xanthoma cells.The DRCs and IRCs are generally considered to show different distribution in the lymphoid tissues and demonstrate some difference in their immunocytochemical and enzyme-histochemical features. It is suggested that S-100 subunits can be used as useful markers for these two types of dendritic cells and investigation of these subunits may provide more information for the study of human lymphoreticular system. 相似文献
105.
Kritaya Kongsuwan Michael A. Johnson Christopher T. Prideaux Michael Sheppard 《Virus genes》1993,7(3):297-303
To localize the gene encoding the 60 kD glycoprotein (gp60) of infectious laryngotracheitis virus (ILTV), a library of the ILTV genome was constructed in the gt11 expression vector. Twelve recombinant bacteriophages expressing gp60 epitopes as fusion products with -galactosidase were detected by immunoscreening with monoclonal antibodies specific for gp60. The ILTV DNA sequence contained in one of these recombinants 24-4 was used as a hybridization probe for mapping the insert sequence on the viral genome. The gene for the gp60 was located at map unit 0.72–0.77 in the unique long region (UL) of the ILTV genome. The DNA sequence of the 1.2 kb insert of 24-4 containing the gp60 epitope was determined. The majority of deduced gp60 amino acid sequence has no homology with any of the known alphaherpesvirus glycoproteins.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession number X 121209. 相似文献
106.
107.
目的在前期的研究中,DAZAP2基因在多发性骨髓瘤(Multiple myeloma,MM)患者中表达明显下调,可能为MM的负性基因.须进一步获得DAZAP2蛋白,制备抗体,从而在蛋白水平上研究DAZAP2的表达、结构和功能.方法将原核重组质粒pQE30-DAZAP2转化大肠杆菌,阳性菌株经1 mmol/LIPTG诱导表达目的蛋白,再经过纯化和透析结果IPTG诱导4hr时,得到大量重组目的蛋白,占可溶蛋白的20%左右,经过Ni—NTA层析柱纯化。获得分子量为17kD的DAZAP2蛋白浓度为0.97mg/m1.结论DAZAP2蛋白获得高效表达,并且建立快速简便的纯化方法,目的蛋白可以用于下一步的实验. 相似文献
108.
A simple quantitative protein A micro-immunoprecipitation method; assay of antibodies to the N and H antigens of poliovirus 总被引:7,自引:0,他引:7
Staphylococcus aureus (Cowan strain I) was used to absorb immune complexes from antiserum to poliovirus to which labeled N or H poliovirus antigens had been added, and the radioactivity in the pelleted organisms and in the supernatant was measured. Excellent agreement was obtained between values calculated separately from the pellet and supernatant readings, validating the use of supernatant measurements from a microtitration plate method. 相似文献
109.
凝血酶对人重组内皮细胞衍生IL—8融合蛋白转换作用 总被引:3,自引:0,他引:3
本文报道利用基因工程技术在大肠杆菌中表达出入内皮细胞衍生IL-8(EDhIL-8)与细菌蛋白lacZ 的融合蛋白lac-hIL-8和lac-T-hIL-8,后者含有一个人工合成凝血酶切点。EDhIL-8上含有一个凝血酶切点,凝血酶可以将lac-hIL-8及以前表达的MS2-hIL-8水解为有生物活性的天然IL-8,而对含有两个凝血酶切点的lac-T-hIL-8无水解作用。这些结果提示凝血酶的功能不仅依赖于所识别的氨基酸,而且依赖于这些氨基酸形成的构象。 相似文献
110.
To solve the problems existing in passive biochip systems, we designed a novel active biochip system. This system introduces negative pressure and controlling devices to adjust the antigen-antibody reaction on the nitrocellulose membrane. Computational simulation demonstrated that this system is a rapid, stable, robust and practical system that may enhance the efficiency of antigen-antibody reactions and improve the repeatability and accuracy of biochip analysis. 相似文献