全文获取类型
收费全文 | 64119篇 |
免费 | 6707篇 |
国内免费 | 4931篇 |
专业分类
耳鼻咽喉 | 492篇 |
儿科学 | 666篇 |
妇产科学 | 603篇 |
基础医学 | 7460篇 |
口腔科学 | 1233篇 |
临床医学 | 8632篇 |
内科学 | 10173篇 |
皮肤病学 | 642篇 |
神经病学 | 3569篇 |
特种医学 | 2553篇 |
外国民族医学 | 52篇 |
外科学 | 6467篇 |
综合类 | 11160篇 |
现状与发展 | 19篇 |
一般理论 | 5篇 |
预防医学 | 4449篇 |
眼科学 | 1885篇 |
药学 | 6972篇 |
40篇 | |
中国医学 | 3429篇 |
肿瘤学 | 5256篇 |
出版年
2024年 | 266篇 |
2023年 | 1171篇 |
2022年 | 2724篇 |
2021年 | 3412篇 |
2020年 | 2605篇 |
2019年 | 2245篇 |
2018年 | 2262篇 |
2017年 | 2093篇 |
2016年 | 1983篇 |
2015年 | 2984篇 |
2014年 | 3712篇 |
2013年 | 3185篇 |
2012年 | 4900篇 |
2011年 | 5286篇 |
2010年 | 3158篇 |
2009年 | 2453篇 |
2008年 | 3361篇 |
2007年 | 3305篇 |
2006年 | 3174篇 |
2005年 | 3131篇 |
2004年 | 2034篇 |
2003年 | 1972篇 |
2002年 | 1644篇 |
2001年 | 1409篇 |
2000年 | 1440篇 |
1999年 | 1655篇 |
1998年 | 1077篇 |
1997年 | 1041篇 |
1996年 | 767篇 |
1995年 | 704篇 |
1994年 | 684篇 |
1993年 | 445篇 |
1992年 | 572篇 |
1991年 | 442篇 |
1990年 | 401篇 |
1989年 | 375篇 |
1988年 | 348篇 |
1987年 | 287篇 |
1986年 | 242篇 |
1985年 | 204篇 |
1984年 | 117篇 |
1983年 | 72篇 |
1982年 | 72篇 |
1981年 | 55篇 |
1980年 | 33篇 |
1979年 | 48篇 |
1978年 | 19篇 |
1977年 | 30篇 |
1976年 | 33篇 |
1975年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
Zhang Gu-sheng章谷生 Hu Fang-yuan胡方远 Ye Qing-zhen叶庆祯 Yan Yong-tang严咏棠Immunology Laboratory Shanghai Institute of Biologicat Products Shanghai 《中华医学杂志(英文版)》1986,99(4):343-346
Neurotropin (NSP) is an extract isolated from
the skin of rabbits inoculated with vaccinia virus.
The present study examines the possible action of
NSP on the number and function of immunocompe
tent cells in mice. The experiment showed that NSP
had no effect on both T and B lymphocytes of nor-
malimmunized mouse spleen. The degree of plaque
forming cell reaction and titre of specific antibody
showed no significant differences when the NSP
treated group and controls were compared. How-
ever, NSP exhibited promotive effect on specific
antigen binding cells in the early stage of immune
responses. It was also noted that the rosette forming
capacity of human T lymphocytes in vitro was restor-
ed markedly by NSP. These results suggest that
NSP possesses certain immunostimulating activity,
particularly on the specific antigen binding cells and
human T lymphocytes. 相似文献
33.
X Dong M He X Song B Lu Y Yang S Zhang N Zhao L Zhou Y Li X Zhu R Hu 《Diabetic medicine》2007,24(12):1482-1486
AIMS: Our aim was to assess performances of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease (MDRD) formulae in estimating glomerular filtration rate (GFR) in Chinese diabetic populations and their association with vascular risks. METHODS: A total of 1009 patients with Type 2 diabetes were categorized into low estimated GFR groups (GFR < 60 ml/min/1.73 m(2)) and control groups by the two equations. The performances of these formulae were assessed at different stages of kidney function. Carotid artery intima-media thickness (IMT) and the prevalence of diabetic retinopathy or albuminuria were compared among the groups. The ability of these formulae to identify established vascular risk markers using sensitivity, specificity, positive and negative predictive values were also compared. RESULTS: The prevalence of low estimated GFR was 32.7% with the Cockcroft-Gault formula and 5.2% with the MDRD formula, respectively. In low estimated GFR subjects by the MDRD formula, IMT was significantly thicker than those by the Cockcroft-Gault formula (1.2 mm vs. 1.0 mm; P < 0.05), with a higher prevalence of albuminuria (78.4 vs. 52.8%, P < 0.05) and diabetic retinopathy (46.5 vs. 30.5%; P < 0.05). The Cockcroft-Gault formula gave a specificity of 71.7% and a sensitivity of 37.0%, and the MDRD formula gave a specificity of 96.6% and a sensitivity of 7.9% in estimating low GFR relevant for established vascular risks. CONCLUSIONS: These formulae performed differently in Chinese diabetic populations. The simplified MDRD formula is minimally superior to the Cockcroft-Gault formula for its high specificity and positive predictive values in estimating low GFR relevant for vascular risks. 相似文献
34.
以曼氏血吸虫的虫卵和成虫免疫家兔后所产生的特异性抗体,可用以日本血吸虫虫卵、尾蚴和成虫为抗原分别进行的COP,CHR和ELACIEP测出,表明两种人体血吸虫存有显著的交叉抗原成分。应用此种血清交叉反应性,以检测抗异种人体血吸虫的抗体,似有效而可取的,可用以辅助诊断援外回国人员是否感染国外人体血吸虫病。 相似文献
35.
Bent H. Hellum Zhuohan Hu Odd Georg Nilsen 《Basic & clinical pharmacology & toxicology》2009,105(1):58-63
Abstract: The aim of this study was to evaluate in vitro the dose‐dependent induction potential of six commonly used trade herbal products on CYP2C19 and CYP2E1 metabolic activities in cultured human hepatocytes. S‐mephenytoin and chlorzoxazone were used as specific CYP substrates, respectively, and rifampicin was used as a positive induction control for both enzymes. The hepatocytes were exposed to herbal extracts in increasing and biological relevant concentrations for 72 hrs and CYP substrate metabolites were quantified by validated HPLC methodologies. The major findings were that St John's wort was the most potent CYP‐modulating herb, showing a dose‐dependent induction/inhibition of both CYP2C19 and CYP2E1, with induction at low dosages and inhibition at higher. Ginkgo biloba showed an induction/inhibition profile towards CYP2C19 which was similar but weaker than that observed for St John's wort. If cooperative mechanisms are involved is still an open question. Common sage induced CYP2C19 in a log‐linear dose‐dependent manner with increasing concentrations. Common valerian was a weak inducer of CYP2C19, while horse chestnut and cone flower were characterized as non‐inducers of CYP2C19. Only St John's wort showed an inductive effect towards CYP2E1. In addition to St John's wort, Gingko biloba and common sage should be considered as possible candidates for clinically relevant drug‐herb interactions with selected CYP2C19 substrates. 相似文献
36.
Qiong Xu Junqi Ling Gary S P Cheung Yan Hu 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(4):e109-e113
OBJECTIVE: The aim of this study was to evaluate the sealing ability of 4 different obturation techniques by using a glucose leakage test. STUDY DESIGN: Eighty extracted single-rooted maxillary incisors were selected for the study. The teeth were decoronated and the root canals prepared using ProFile rotary instruments to an apical dimension of size 40 (0.06 taper). The specimens were then randomly divided into 4 experimental groups (n = 15) and filled with gutta-percha and sealer by using either cold lateral compaction, warm vertical compaction, Thermafil, or the E & Q Plus system. Another 10 teeth each served as the positive and negative controls. A glucose leakage model was used for quantitative evaluation of the coronal-to-apical microleakage at 24 hours, 1, 2, 3, 5, 8, and 12 weeks. RESULTS: No significant difference in the cumulative amount of leakage was found among the 4 groups at 24 hours and 1 week (Kruskal-Wallis test, P > .05). Lateral compaction showed significantly more leakage than the other 3 techniques at longer intervals (Mann-Whitney U test, P < .008). No significant difference was found between vertical compaction, Thermafil, and E & Q Plus at all observation times. CONCLUSIONS: Warm vertical compaction, Thermafil, and the E & Q Plus system showed a better sealing result than cold lateral compaction of gutta-percha at extended observation periods. The glucose leakage method used in this study was able to provide a nondestructive, quantitative, and long-term evaluation of the sealing ability of root canal fillings. 相似文献
37.
我们自2000年10月至2008年12月采用大承气汤加黄连应用与肛周常见疾病术后病人,治疗其术后大小便潴留,里急后重等症状,取得了满意的疗效,现报告如下. 相似文献
38.
8年间剖宫产率及指证变化的临床分析 总被引:3,自引:1,他引:2
近年来,我国各地的剖宫产率均呈明显的上升趋势,部分地区的剖宫产率甚至高达60%。居高不下的剖宫产率已引起了广大产科工作者和全社会的广泛关注。对我院近8年来剖宫产病例的临床资料进行回顾性分析,以寻求剖宫产率逐年上升的原因及探讨降低剖宫产率的途径与方法。 相似文献
39.
40.
After a comprehensive rernew of the literature on syphilitic
aortitis, Longcope, (1) stated in 1913; ": . . . the presence of spiro:
chetes in these lesions, as might be expected, cannot by any means be
constantly demonstrated with Levaaiti stain. . . . . . . That these
organisms are ''Treponema pallidum seems almost certain thouS:h actual
proof of such by culture from the arterial lesions, a most difficult task,
or direct inoculation into animals, has not as yet been accomplished." 相似文献