全文获取类型
收费全文 | 1410494篇 |
免费 | 113511篇 |
国内免费 | 3332篇 |
专业分类
耳鼻咽喉 | 18360篇 |
儿科学 | 46548篇 |
妇产科学 | 41045篇 |
基础医学 | 200724篇 |
口腔科学 | 37695篇 |
临床医学 | 125979篇 |
内科学 | 284322篇 |
皮肤病学 | 33354篇 |
神经病学 | 116844篇 |
特种医学 | 53827篇 |
外国民族医学 | 464篇 |
外科学 | 210473篇 |
综合类 | 32764篇 |
现状与发展 | 3篇 |
一般理论 | 487篇 |
预防医学 | 109981篇 |
眼科学 | 31489篇 |
药学 | 98497篇 |
1篇 | |
中国医学 | 3348篇 |
肿瘤学 | 81132篇 |
出版年
2021年 | 10844篇 |
2019年 | 11661篇 |
2018年 | 16568篇 |
2017年 | 12665篇 |
2016年 | 14255篇 |
2015年 | 15999篇 |
2014年 | 22550篇 |
2013年 | 33382篇 |
2012年 | 45368篇 |
2011年 | 47907篇 |
2010年 | 28150篇 |
2009年 | 27041篇 |
2008年 | 44301篇 |
2007年 | 46806篇 |
2006年 | 47374篇 |
2005年 | 45842篇 |
2004年 | 43733篇 |
2003年 | 41678篇 |
2002年 | 40174篇 |
2001年 | 72996篇 |
2000年 | 74523篇 |
1999年 | 61560篇 |
1998年 | 16992篇 |
1997年 | 15429篇 |
1996年 | 15584篇 |
1995年 | 14789篇 |
1994年 | 13395篇 |
1993年 | 12584篇 |
1992年 | 45835篇 |
1991年 | 43479篇 |
1990年 | 41486篇 |
1989年 | 39550篇 |
1988年 | 36178篇 |
1987年 | 35352篇 |
1986年 | 32861篇 |
1985年 | 31277篇 |
1984年 | 23824篇 |
1983年 | 20023篇 |
1982年 | 12209篇 |
1981年 | 10780篇 |
1979年 | 20700篇 |
1978年 | 14577篇 |
1977年 | 12084篇 |
1976年 | 11365篇 |
1975年 | 11619篇 |
1974年 | 13988篇 |
1973年 | 13533篇 |
1972年 | 12633篇 |
1971年 | 11469篇 |
1970年 | 10910篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
101.
D.-Y. LIN I.-S. SHEEN C.-M. CHU & Y.-F. LIAW 《Alimentary pharmacology & therapeutics》1996,10(6):961-966
Background : The clinical course of chronic hepatitis B is variable. Patients with hepatic decompensation, bridging necrosis or an alpha-fetoprotein level greater than 100 ng/mL during an exacerbation of hepatitis have a high risk of developing cirrhosis. This study was conducted to evaluate the effect of colchicine in the prevention of cirrhosis in such patients.
Methods : Patients with risk factor(s) were randomized to receive either colchicine 5 mg/week or no specific treatment, the end point being development of cirrhosis.
Results : After a follow up period of 4 years, the treatment group had a marked reduction in exacerbations of acute hepatitis (32% vs. 63%/patient/year, P <0.005). Seven out of 38 patients in the treatment group and 10 out of 27 patients in the control group developed cirrhosis. The calculated cumulative incidence of cirrhosis by the end of first, second, third and fourth years in the treatment group was 8.7, 18.6, 32 and 32%, respectively. The corresponding figures in the control group were 30, 35.5, 46.3 and 73.2%, respectively, with a P -value of 0.057.
Conclusions : The results suggest that colchicine may prevent cirrhosis in chronic hepatitis B patients with risk factor(s), possibly by suppressing exacerbations of hepatitis through an anti-inflammatory effect. 相似文献
Methods : Patients with risk factor(s) were randomized to receive either colchicine 5 mg/week or no specific treatment, the end point being development of cirrhosis.
Results : After a follow up period of 4 years, the treatment group had a marked reduction in exacerbations of acute hepatitis (32% vs. 63%/patient/year, P <0.005). Seven out of 38 patients in the treatment group and 10 out of 27 patients in the control group developed cirrhosis. The calculated cumulative incidence of cirrhosis by the end of first, second, third and fourth years in the treatment group was 8.7, 18.6, 32 and 32%, respectively. The corresponding figures in the control group were 30, 35.5, 46.3 and 73.2%, respectively, with a P -value of 0.057.
Conclusions : The results suggest that colchicine may prevent cirrhosis in chronic hepatitis B patients with risk factor(s), possibly by suppressing exacerbations of hepatitis through an anti-inflammatory effect. 相似文献
102.
103.
104.
105.
Birth weight on 12,644 singleton infants from 6,196 sibships born in Maryland between 1980 and 1984 were used to estimate the effects of nine maternal and infant covariates on the sibship correlation in birth weight. Assuming a homogeneous correlation across all families, the estimated intraclass correlation was 0.4664 (+/- 0.0099). This high sibship correlation makes it possible to predict, with reasonable accuracy, the birth weight of a child given information on previous sibs, as well as covariates on the mother and/or infant pertinent to a given pregnancy. The reduction in variance associated with incorporating information on the nine covariates used here was approximately equal to that obtained by conditioning on a single previous sib. Testing for heterogeneity in correlation among different groups of families showed that a crude measure of parity (first live birth vs. other), time between births, mother's marital status, and maternal age at the birth of the last child significantly influenced the sibship correlation in birth weight. 相似文献
106.
107.
H Bussey C Quandt R Rospond W Loesch 《The Journal of the American Board of Family Practice / American Board of Family Practice》1988,1(4):282-287
One of our patients had trouble maintaining therapeutic and safe levels of theophylline, even though we were careful in planning and monitoring her drug regimen. This case report shows how we were able to use principles of pharmacokinetics to distinguish among plausible explanations for her experience. We discovered that she was not taking the drug consistently as prescribed and that supervised administration resolved apparent contradictions between doses and serum levels. We believe that physicians can use the same information and methods that we used to get better and safer results from theophylline therapy. 相似文献
108.
A rotating contact lens holder for the three-mirror Goldmann lens permits circular examination of the fundus or chamber angle without having to change the position of the fingers on the edge of the lens. The contact lens holder consists of an outer polygonal ring hold by the thumber and index finger. An inner rotating ring holds the contact lens. Continuous rotation of the contact lens is performed with the free middle Finger. This device permits circular examination of the retina without interruption of fixation. The instrument improves not only the speed but also the reliability of the examination. 相似文献
109.
Six patients who injured their wrists had radiographs documenting a dorsal, 5- to 10-mm oblong fragment of bone immediately proximal to the base of the fourth and/or fifth metacarpal bones. The fragment was seen on the pronation oblique and/or lateral projections, but not on the posteroanterior projection. The radiographic appearance of the fragment was remarkably similar in all cases. In the one patient in which it was performed, pluridirectional tomography demonstrated that the fragment originated from the dorsal surface of the hamate. Five of the six patients also had associated posterior dislocation of the fourth and/or fifth metacarpals. We conclude that this fragment represents a coronal fracture through the body of the hamate resulting from posterior dislocation or subluxation of the fourth and/or fifth metacarpal. 相似文献
110.
A case is presented which demonstrates the potential utility of the extracranial-intracranial bypass procedure for the treatment of vasospasm after subarachnoid hemorrhage. Extracranial-intracranial bypass surgery offers another alternative to the treatment of patients with vasospasm who have failed aggressive medical management. 相似文献