全文获取类型
收费全文 | 11208篇 |
免费 | 627篇 |
国内免费 | 66篇 |
专业分类
耳鼻咽喉 | 98篇 |
儿科学 | 283篇 |
妇产科学 | 209篇 |
基础医学 | 1358篇 |
口腔科学 | 654篇 |
临床医学 | 801篇 |
内科学 | 3236篇 |
皮肤病学 | 164篇 |
神经病学 | 1261篇 |
特种医学 | 261篇 |
外科学 | 1442篇 |
综合类 | 44篇 |
一般理论 | 5篇 |
预防医学 | 493篇 |
眼科学 | 179篇 |
药学 | 708篇 |
中国医学 | 35篇 |
肿瘤学 | 670篇 |
出版年
2023年 | 105篇 |
2022年 | 214篇 |
2021年 | 394篇 |
2020年 | 226篇 |
2019年 | 327篇 |
2018年 | 384篇 |
2017年 | 236篇 |
2016年 | 281篇 |
2015年 | 317篇 |
2014年 | 437篇 |
2013年 | 534篇 |
2012年 | 764篇 |
2011年 | 850篇 |
2010年 | 432篇 |
2009年 | 391篇 |
2008年 | 671篇 |
2007年 | 669篇 |
2006年 | 639篇 |
2005年 | 586篇 |
2004年 | 520篇 |
2003年 | 458篇 |
2002年 | 431篇 |
2001年 | 208篇 |
2000年 | 202篇 |
1999年 | 180篇 |
1998年 | 90篇 |
1997年 | 69篇 |
1996年 | 72篇 |
1995年 | 64篇 |
1994年 | 53篇 |
1993年 | 47篇 |
1992年 | 115篇 |
1991年 | 70篇 |
1990年 | 90篇 |
1989年 | 69篇 |
1988年 | 61篇 |
1987年 | 70篇 |
1986年 | 61篇 |
1985年 | 55篇 |
1984年 | 49篇 |
1983年 | 57篇 |
1982年 | 28篇 |
1981年 | 19篇 |
1979年 | 28篇 |
1978年 | 22篇 |
1976年 | 20篇 |
1975年 | 26篇 |
1974年 | 27篇 |
1972年 | 20篇 |
1970年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Clerici M Cogliati M Rizzardini G Colombo F Fossati S Rhodes J Bray D Piconi S 《Clinical immunology (Orlando, Fla.)》2000,97(3):211-220
The immunomodulatory properties of tucaresol (compound 589C80) were tested on in vitro antigen- and mitogen-stimulated proliferation and cytokine production by peripheral blood mononuclear cells (PBMC) of HIV-infected individuals and healthy controls (HC). Results showed that tucaresol: (1) increases influenza A virus-, gp 160 peptide-, and HLA alloantigen-stimulated proliferation as well as interleukin (IL)-2 and interferon gamma (IFN gamma) production by PBMC of HIV-infected individuals with higher CD4 counts (>500/microl) but had only a marginal immunomodulatory effect on PBMC of patients with lower CD4 counts (<500/microl); (2) did not modify IL-10 production; (3) augmented CD25 expression on mitogen-stimulated T cells of HC but not of HIV-infected individuals; and (4) marginally increased CTL activity. The immunomodulatory properties of tucaresol were confirmed by PCR analyses; additional data showed that tucaresol costimulated CD3-dependent triggering of T cells and that this stimulation was independent of CD28 costimulation. The immunomodulatory effects of tucaresol on T cell functions are characterized by a bell-shaped dose response curve; the action of the compound is optimal in the 100 to 300 microM range. Analyses of mitogen-stimulated apoptosis demonstrated that the lack of effect of tucaresol at higher doses is not the result of increased cell death, suggesting a role of functional impairment. These data confirm that tucaresol can stimulate T helper cell function and enhance the production of type 1 cytokines, thus eliciting cell-mediated immunity, and warrant its potential utility in the therapy of HIV infection. 相似文献
73.
74.
75.
Age and sex influence on oxidative damage and functional status in human skeletal muscle 总被引:3,自引:0,他引:3
Fanò Giorgio Mecocci Patrizia Vecchiet Jacopo Belia Silvia Fulle Stefania Polidori M. Cristina Felzani Giorgio Senin Umberto Vecchiet Leonardo Beal M. Flint 《Journal of muscle research and cell motility》2001,22(4):345-351
A reduction in muscle mass, with consequent decrease in strength and resistance, is commonly observed with advancing age. In this study we measured markers of oxidative damage to DNA, lipids and proteins, some antioxidant enzyme activities as well Ca2+ transport in sarcoplasmic reticulum membranes in muscle biopsies from vastus lateralis of young and elderly healthy subjects of both sexes in order to evaluate the presence of age- and sex- related differences. We found a significant increase in oxidation of DNA and lipids in the elderly group, more evident in males, and a reduction in catalase and glutathione transferase activities. The experiments on Ca2+ transport showed an abnormal functional response of aged muscle after exposure to caffeine, which increases the opening of Ca2+ channels, as well a reduced activity of the Ca2+ pump in elderly males. From these results we conclude that oxidative stress play an important role in muscle aging and that oxidative damage is much more evident in elderly males, suggesting a gender difference maybe related to hormonal factors.This revised version was published online in September 2005 with corrections to the Cover Date. 相似文献
76.
77.
Colombo T Frapolli R Bombardelli E Morazzoni P Riva A D'Incalci M Zucchetti M 《Journal of chromatography. B, Biomedical sciences and applications》1999,736(1-2):135-141
An HPLC assay was developed to determine the paclitaxel analogue 13-(N-tert.-butoxycarbonyl-beta-isobutylisoserinyl)-14-hydroxyb accatin-1,14-carbonate (IDN5109) and its epimer in mouse plasma. The method involves solid-phase extraction on cyano cartridges (recovery >75%), HPLC separation on symmetry shield column, a mobile phase of NaH2PO4 (10 mM) pH 5.2, acetonitrile (47:53) and detection at 227 nm. Retention times of IDN5109, its epiform and internal standard were 15, 24 and 25.5 min, respectively. The assay was linear from 0.10 to 10 microg/ml (r2 = 0.999), with a C.V. <5% and accuracy in the range of 95-107%. LOQ was 50 ng/ml for both compounds. Using this method IDN5109 pharmacokinetic was determined in mice. 相似文献
78.
Transcranial magnetic stimulation of the occipital pole interferes with verbal processing in blind subjects 总被引:6,自引:0,他引:6
Recent neuroimaging studies in blind persons show that the occipital cortex, including the primary visual cortex (V1), is active during language-related and verbal-memory tasks. No studies, however, have identified a causal link between early visual cortex activity and successful performance on such tasks. We show here that repetitive transcranial magnetic stimulation (rTMS) of the occipital pole reduces accuracy on a verb-generation task in blind subjects, but not in sighted controls. An analysis of error types revealed that the most common error produced by rTMS was semantic; phonological errors and interference with motor execution or articulation were rare. Thus, in blind persons, a transient 'virtual lesion' of the left occipital cortex interferes with high-level verbal processing 相似文献
79.
Somasundaram P Ren G Nagar H Kraemer D Mendoza L Michael LH Caughey GH Entman ML Frangogiannis NG 《The Journal of pathology》2005,205(1):102-111
Mast cells and macrophages infiltrate healing myocardial infarcts and may play an important role in regulating fibrous tissue deposition and extracellular matrix remodelling. This study examined the time-course of macrophage and mast cell accumulation in healing infarcts and studied the histological characteristics and protease expression profile of mast cells in a canine model of experimental infarction. Although macrophages were more numerous than mast cells in infarct granulation tissue, macrophage density decreased during maturation of the scar, whereas mast cell numbers remained persistently elevated. During the inflammatory phase of infarction, newly recruited leucocytes infiltrated the injured myocardium and appeared to be clustered in close proximity to degranulating cardiac mast cells. During the proliferative phase of healing, mast cells had decreased granular content and were localized close to infarct neovessels. In contrast, macrophages showed no selective localization. Mast cells in healing canine infarcts were alcian blue/safranin-positive cells that expressed both tryptase and chymase. In order to explain the pro-inflammatory and angiogenic actions of tryptase--the major secretory protein of mast cells--its effects on endothelial chemokine expression were examined. Chemokines are chemotactic cytokines that play an important role in leucocyte trafficking and angiogenesis and are highly induced in infarcts. Tryptase, a proteinase-activated receptor (PAR)-2 agonist, induced endothelial expression of the angiogenic chemokines CCL2/MCP-1 and CXCL8/IL-8, but not the angiostatic chemokine CXCL10/IP-10. Endothelial PAR-2 stimulation with the agonist peptide SLIGKV induced a similar chemokine expression profile. Mast cell tryptase may exert its angiogenic effects in part through selective stimulation of angiogenic chemokines. 相似文献
80.
Ohne Zusammenfassung 相似文献