全文获取类型
收费全文 | 116375篇 |
免费 | 44487篇 |
国内免费 | 2336篇 |
专业分类
耳鼻咽喉 | 1885篇 |
儿科学 | 4805篇 |
妇产科学 | 1035篇 |
基础医学 | 19598篇 |
口腔科学 | 5631篇 |
临床医学 | 17367篇 |
内科学 | 28807篇 |
皮肤病学 | 7935篇 |
神经病学 | 15484篇 |
特种医学 | 3547篇 |
外国民族医学 | 15篇 |
外科学 | 17768篇 |
综合类 | 6632篇 |
现状与发展 | 13篇 |
一般理论 | 24篇 |
预防医学 | 6896篇 |
眼科学 | 2296篇 |
药学 | 9864篇 |
52篇 | |
中国医学 | 3333篇 |
肿瘤学 | 10211篇 |
出版年
2024年 | 102篇 |
2023年 | 601篇 |
2022年 | 1677篇 |
2021年 | 3543篇 |
2020年 | 6502篇 |
2019年 | 12014篇 |
2018年 | 11419篇 |
2017年 | 12595篇 |
2016年 | 13141篇 |
2015年 | 13631篇 |
2014年 | 13997篇 |
2013年 | 14381篇 |
2012年 | 7300篇 |
2011年 | 7292篇 |
2010年 | 11032篇 |
2009年 | 7088篇 |
2008年 | 4206篇 |
2007年 | 2980篇 |
2006年 | 2968篇 |
2005年 | 2384篇 |
2004年 | 2146篇 |
2003年 | 2162篇 |
2002年 | 1948篇 |
2001年 | 1811篇 |
2000年 | 1507篇 |
1999年 | 1055篇 |
1998年 | 380篇 |
1997年 | 415篇 |
1996年 | 335篇 |
1995年 | 263篇 |
1994年 | 237篇 |
1993年 | 153篇 |
1992年 | 253篇 |
1991年 | 237篇 |
1990年 | 213篇 |
1989年 | 186篇 |
1988年 | 167篇 |
1987年 | 150篇 |
1986年 | 122篇 |
1985年 | 98篇 |
1984年 | 77篇 |
1983年 | 61篇 |
1982年 | 35篇 |
1981年 | 34篇 |
1980年 | 27篇 |
1979年 | 46篇 |
1978年 | 26篇 |
1977年 | 23篇 |
1976年 | 28篇 |
1974年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Jing‐Ping Zhang Limin Zheng Jiang‐Hai Wang Karl‐Eric Magnusson Xin Liu 《Phytotherapy research : PTR》2009,23(6):844-850
Ganoderma sinensis has been used widely in Oriental countries for the prevention and treatment of various diseases including cancer. Previous studies have shown that the lipid extract from Ganoderma exhibits direct cytotoxicity against tumor cells. Here, it is reported that the lipid extract from germinating G. sinensis spores, at lower concentrations that have no direct tumoricidal activity, induce potent antitumor immune responses in human monocytes/macrophages. Upon stimulation with the lipid extract, monocytes/macrophages exhibited markedly increased production of proinflammatory cytokines and surface expression of costimulatory molecules. Conditioned medium from stimulated cells effectively suppressed the growth of tumor cells. Apparently, the lipid extract triggered macrophage activation via a mechanism different from that associated with LPS. Moreover, it was observed that the lipid extract could partially re‐establish the antitumor activity of the immunosuppressive tumor‐associated macrophages. These results indicated that in addition to its direct tumoricidal activity, the lipid extract from G. sinensis spores could exert antitumor activity by stimulating the activation of human monocytes/macrophages. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
22.
Fu-Wei Wang Yu-Wen Chiu Ming-Shium Tu Ming-Yueh Chou Chao-Ling Wang Hung-Yi Chuang 《International archives of occupational and environmental health》2009,82(7):819-825
Purpose There has been increasing interest in the occupational health of workers in small enterprises, especially in developing countries.
This study examines the association between psychosocial job characteristics and fatigue, and attempts to identify risk factors
for fatigue among workers of small enterprises in southern Taiwan.
Methods A structured questionnaire was administered to workers receiving regular health examinations between August 2005 and January
2006. The questionnaire collected demographic information and data on working conditions, personal health status and life
styles. It also collected information on psychosocial job characteristics, fatigue and psychological distress using three
instruments.
Results A total of 647 workers with mean age of 43.7 were completed. Probable fatigue was found in 34.6% of the sample. Fatigue was
found by multiple logistic regressions to be associated with the lack of exercise, working in shifts, depression score and
lack of social support at workplace.
Conclusions This study found associations between life style, psychosocial job characteristics and fatigue. Because the high prevalence
of probable fatigue was found in such small enterprises, the authors suggest that a short interview with some quick questionnaires
in health checkup for these small enterprise workers are helpful to early detect psychosocial and fatigue problems. 相似文献
23.
24.
25.
Henry Ho‐Lung Chan 《Clinical & experimental optometry》2005,88(6):410-414
The first‐order kernel analysis in multifocal electroretinogram (mfERG) using low contrast stimulation is suggested as a way to detect the inner retinal responses in animal studies. In this case report, this protocol is applied to human patients with glaucoma to demonstrate the possibility of using mfERG as a tool to detect glaucomatous damage. Two patients with glaucoma were recruited and had mfERG measurements with the 103‐scaled hexagonal stimulus pattern at low (50 per cent) contrast. Their responses were analysed and compared with those from normal subjects with the mfERG measured under the same condition. In the normal subjects, there were obvious oscillatory components on the ascending and descending limbs of the first‐order kernel response to 50 per cent contrast. In the glaucomatous patients, the oscillatory component on the descending limb was obviously diminished. In addition, this component was significantly diminished in the quadrant with a glaucomatous visual field defect. This suggests that the low‐contrast stimulation condition in mERG measurement may provide a good way to detect glaucomatous damage and this may help in clinical diagnosis of glaucoma. 相似文献
26.
E. Wieczerzak E. Jankowska S. Rodziewicz‐Motowido A. Giedo J. giewka Z. Grzonka M. Abrahamson A. Grubb D. Brmme 《Chemical biology & drug design》2005,66(Z1):1-11
Abstract: We have designed and synthesized a new series of azapeptides which act as potential inhibitors of cathepsin B and/or cathepsin K. Their structures are based upon the inhibitory sites of natural cysteine protease inhibitors, cystatins. For the synthesized azapeptides, the equilibrium constants for dissociation of inhibitor–enzyme complex, Ki, were determined. Comparison of these values indicated that all of the azainhibitors act much stronger toward cathepsin B. Z‐Arg‐Leu‐His‐Agly‐Ile‐Val‐OMe ( 7 ) proved to be approximately 500 times more potent for cathepsin B than for cathepsin K. To be able to explain the obtained experimental values we used the molecular dynamics procedures to analyze the interactions between cathepsin B and compound 7 . We also determined the structure of the most potent and selective cathepsin B azainhibitor by means of NMR studies and theoretical calculations. In this report, we describe SAR studies of azapeptide inhibitors indicating the influence of the conformational flexibility of the examined compounds on inhibition of cathepsins B and K. 相似文献
27.
28.
29.
1 The internal anal sphincter (IAS) has a spontaneous tone and is the main contributor to the maintenance of faecal continence. The spontaneous resting tone exhibited by the sphincter can be modified by neurotransmitters from the autonomic and enteric nervous systems. 2 In this review, the influence of the sympathetic and parasympathetic nervous systems on IAS tone are discussed and the putative roles of nitric oxide, carbon monoxide, vasoactive intestinal peptide and adenosine triphosphate in non‐adrenergic non‐cholinergic transmission are considered. 3 Faecal incontinence is a common condition that places a heavy financial burden on the health service and severely affects patients’ quality of life. Resting anal pressure is reduced in patients with faecal incontinence and agents that increase sphincter tone tend to relieve symptoms. The results of clinical studies of the use of phenylephrine to treat faecal incontinence are reviewed. 4 It is concluded that the IAS is a potential target for drug development for the treatment of faecal incontinence. 相似文献
30.