全文获取类型
收费全文 | 1285043篇 |
免费 | 98129篇 |
国内免费 | 2020篇 |
专业分类
耳鼻咽喉 | 18525篇 |
儿科学 | 44512篇 |
妇产科学 | 35095篇 |
基础医学 | 183037篇 |
口腔科学 | 34279篇 |
临床医学 | 111775篇 |
内科学 | 259465篇 |
皮肤病学 | 28212篇 |
神经病学 | 100821篇 |
特种医学 | 51305篇 |
外国民族医学 | 660篇 |
外科学 | 197092篇 |
综合类 | 27082篇 |
现状与发展 | 1篇 |
一般理论 | 380篇 |
预防医学 | 96426篇 |
眼科学 | 28024篇 |
药学 | 95201篇 |
2篇 | |
中国医学 | 2486篇 |
肿瘤学 | 70812篇 |
出版年
2018年 | 13407篇 |
2017年 | 10146篇 |
2016年 | 11089篇 |
2015年 | 12603篇 |
2014年 | 17465篇 |
2013年 | 26538篇 |
2012年 | 36551篇 |
2011年 | 38625篇 |
2010年 | 23081篇 |
2009年 | 22045篇 |
2008年 | 37058篇 |
2007年 | 39634篇 |
2006年 | 39840篇 |
2005年 | 38709篇 |
2004年 | 37815篇 |
2003年 | 36638篇 |
2002年 | 35964篇 |
2001年 | 64068篇 |
2000年 | 66582篇 |
1999年 | 56494篇 |
1998年 | 15150篇 |
1997年 | 13770篇 |
1996年 | 14212篇 |
1995年 | 13472篇 |
1994年 | 12774篇 |
1993年 | 11801篇 |
1992年 | 44575篇 |
1991年 | 43494篇 |
1990年 | 42231篇 |
1989年 | 40130篇 |
1988年 | 36919篇 |
1987年 | 36248篇 |
1986年 | 33629篇 |
1985年 | 32292篇 |
1984年 | 24150篇 |
1983年 | 20275篇 |
1982年 | 11729篇 |
1981年 | 10693篇 |
1980年 | 9530篇 |
1979年 | 21356篇 |
1978年 | 14824篇 |
1977年 | 12539篇 |
1976年 | 11698篇 |
1975年 | 12630篇 |
1974年 | 14676篇 |
1973年 | 14129篇 |
1972年 | 12952篇 |
1971年 | 11735篇 |
1970年 | 11062篇 |
1969年 | 10028篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
191.
P V Fragola C Autore G Ruscitti A Picelli M Borzi D Cannata M Sangiorgi 《Giornale italiano di cardiologia》1988,18(1):52-54
Eighty-nine first-degree relatives of 22 patients with an established diagnosis of hypertrophic cardiomyopathy underwent electrocardiographic and echocardiographic screening. Scalar electrocardiogram was abnormal in 30/89 (33.7%) relatives. Of these thirty, eleven had definite evidence of hypertrophic cardiomyopathy at echo; one had borderline hypertrophy and was considered neither affected nor unaffected; four had questionable signs of hypertrophy. The remaining 14 relatives had normal echo-cardiograms. Fifty-nine relatives (66.3%) had normal electrocardiograms; at echo 3 were considered to have borderline hypertrophy, 16 had questionable signs of hypertrophy and 40 were normal. In relatives of patients with hypertrophic cardiomyopathy an abnormal electrocardiogram may reflect different morphologic conditions: a real hypertrophic cardiomyopathy or a myocardial hypertrophy of uncertain significance. Furthermore, in these categories of subjects, an abnormal electrocardiogram with normal echo must be considered with caution. 相似文献
192.
193.
Brachial artery hemodynamic response to acute converting enzyme inhibition by enalaprilat in essential hypertension 总被引:1,自引:0,他引:1
To assess the vascular involvement of renin-angiotensin system inhibition in human hypertension, acute effects of intravenous enalaprilat on brachial artery diameter, blood flow, and blood velocity were investigated in hypertensive patients by pulsed Doppler technique and compared with effects of saline vehicle. Compared with saline vehicle, enalaprilat reduced blood pressure (P less than 0.001) and increased brachial arterial diameter (P less than 0.01) and brachial blood flow (P less than 0.01). Enalaprilat effect on arterial pulse pressure was dependent on preinjection pulse pressure (r = -0.76; P less than 0.001), but its effect on mean blood pressure was not dependent on preinjection mean blood pressure. On the other hand, enalaprilat effect on arterial blood flow was negatively correlated with preinjection blood pressure (r = -0.64; P less than 0.02). The findings point to different responses of large and small arteries to intravenous enalaprilat. 相似文献
194.
W. S. L. Stebbings M. J. G. Farthing J. R. Puddefoot Elizabeth Anderson G. P. Vinson J. M. A. Northover R. F. M. Wood 《Journal of cancer research and clinical oncology》1988,114(2):208-211
Summary To evaluate the potential effect of androgens on the development and growth of human colorectal adenomas, the prevalence and concentration of cytosolic androgen receptors (AR) were analysed in 26 adenomas and 19 samples of normal colonic mucosa by a hybrid ligand receptor-binding assay. AR were detected in 7 of the adenomas (26.9%), and in 6 of the normal mucosa samples (31.6%). In the adenomas, AR levels demonstrated were low, ranging from 6 to 31 fmol/mg cytosol protein, and dissociation constants (Kds) ranged from 0.17–2.7x10-9
M. Of 13 adenomas excised from men, 6 (46%) had positive receptor activity, whereas only 1 of 13 (7.7%) from women was positive (P=0.03, Fisher's exact test). There was no correlation between AR titre and patient age, or between adenoma size and histological type or degree of dysplasia. In normal mucosa, AR levels ranged from 7 to 33 fmol/mg and Kds ranges from 0.24–3.1x10-9
M. There was no significant difference between either AR prevalence or levels in the adenomas and normal mucosa. The sex difference was exclusive to the adenoma. Endogenous androgen may play a role in adenoma development early in the promotional process. 相似文献
195.
196.
Endocarditis due to Kingella species 总被引:1,自引:0,他引:1
197.
Using indirect immunohistochemistry and an antiserum raised against rat corticotrophin-releasing factor (CRF) we have outlined an asymmetric network of cells and varicose fibers in sheep adrenal cortex. This network was not associated with the larger splanchnic nerves, but was occasionally found in small bundles or with blood vessels; in most instances fibers were found weaving independently through cortical parenchyma. A plexus of fibers was found in the zona reticularis, with a few fibers ramifying into adjacent medulla. Uni or bipolar cells were found throughout the cortex, with the greatest frequency at the corticomedullary junction; a multipolar-type cell was also found in this area. Staining of varicose structures and most cells was abolished by incubation with excess rat CRF 1-41, but not by ovine CRF or a range of other peptides. Though the immunoreactive species has not as yet been identified, it may thus share homology with sequences present in rat but not ovine CRF. 相似文献
198.
In an attempt to identify a cause for the alteration in breathing pattern seen when conventional respiratory apparatus is applied to the face, we have studied the effects of causing the subject to focus attention on breathing by counting breaths in threes for 5 min. We used the respiratory inductance plethysmograph in 18 naive subjects who were unaware that their breathing was being measured. In the control periods, distraction was provided by a recorded story played through head-phones. The experiment was repeated with the rim of a facemask applied to the face. Focusing attention on breathing caused a prolongation of inspiration at a constant mean inspiratory flow, and lengthening of expiration. Tidal volume but not ventilation was increased. The facemask rim caused no significant change. It is concluded that conscious awareness of breathing could account for a major part of the effect of conventional respiratory apparatus. 相似文献
199.
J J Rodrigues N J Shaikh D A Gadkari S R Prasad S George P Yergolkar L V Hungund 《The Southeast Asian journal of tropical medicine and public health》1988,19(2):323-326
Brain tissues from 38 patients with a clinical suspicion of encephalitis or encephalopathy were examined by two immunoenzymatic techniques for the detection of arboviral antigen. Group B arboviral antigen was identified in 23 of these tissues. This simple method could be used for the diagnosis of the causal agent of encephalitis. 相似文献