全文获取类型
收费全文 | 218406篇 |
免费 | 15875篇 |
国内免费 | 764篇 |
专业分类
耳鼻咽喉 | 2506篇 |
儿科学 | 5770篇 |
妇产科学 | 4523篇 |
基础医学 | 28096篇 |
口腔科学 | 4707篇 |
临床医学 | 20916篇 |
内科学 | 46526篇 |
皮肤病学 | 2976篇 |
神经病学 | 20935篇 |
特种医学 | 7337篇 |
外国民族医学 | 13篇 |
外科学 | 34344篇 |
综合类 | 3572篇 |
现状与发展 | 2篇 |
一般理论 | 299篇 |
预防医学 | 19683篇 |
眼科学 | 4507篇 |
药学 | 14687篇 |
1篇 | |
中国医学 | 374篇 |
肿瘤学 | 13271篇 |
出版年
2023年 | 864篇 |
2022年 | 1433篇 |
2021年 | 3522篇 |
2020年 | 2167篇 |
2019年 | 3459篇 |
2018年 | 4060篇 |
2017年 | 3291篇 |
2016年 | 3482篇 |
2015年 | 4167篇 |
2014年 | 6219篇 |
2013年 | 9029篇 |
2012年 | 13391篇 |
2011年 | 14597篇 |
2010年 | 8265篇 |
2009年 | 7452篇 |
2008年 | 13837篇 |
2007年 | 14737篇 |
2006年 | 14224篇 |
2005年 | 14698篇 |
2004年 | 14075篇 |
2003年 | 13203篇 |
2002年 | 12721篇 |
2001年 | 2135篇 |
2000年 | 1742篇 |
1999年 | 2295篇 |
1998年 | 2900篇 |
1997年 | 2507篇 |
1996年 | 2288篇 |
1995年 | 2028篇 |
1994年 | 1821篇 |
1993年 | 1733篇 |
1992年 | 1445篇 |
1991年 | 1388篇 |
1990年 | 1274篇 |
1989年 | 1196篇 |
1988年 | 1207篇 |
1987年 | 1227篇 |
1986年 | 1204篇 |
1985年 | 1275篇 |
1984年 | 1649篇 |
1983年 | 1577篇 |
1982年 | 1896篇 |
1981年 | 1716篇 |
1980年 | 1624篇 |
1979年 | 954篇 |
1978年 | 1065篇 |
1977年 | 1005篇 |
1976年 | 914篇 |
1975年 | 759篇 |
1974年 | 761篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
121.
122.
Skoug John W. Borin Marie T. Fleishaker Joseph C. Cooper Anne M. 《Pharmaceutical research》1991,8(12):1482-1488
The mechanism of release from sustained-release adinazolam mesylate tablets was assessed by the Higuchi equation and by analysis of drug release profiles through 60% released using the Peppas equation. Computed values of the diffusional exponent, n, ranged from 0.59 to 0.66. Values of n in this range are consistent with a mixed mechanism of release, with diffusion of drug through the hydrated polymer matrix and relaxation of this matrix being the principal processes controlling release. The rate of in vitro drug release was increased for half tablets relative to whole tablets and is attributed to an increase in the surface to volume ratio of half tablets of about 16%. This increase in surface-to-volume ratio of half tablets was reflected by an increase in the constant, k, from the Peppas equation of 20–23% and by an increase in the slope of Higuchi plots of 12–18% for four lots of tablets. In vivo/in vitro relationships from two bioavailability studies were thoroughly evaluated. Using either a linear or a quadratic relationship, an in vivo/in vitro correlation exists for sustained-release adinazolam mesylate tablets. 相似文献
123.
124.
125.
Preventing sports injury has rarely been cited as an appropriate action to respond to the obesity epidemic, and in fact a recent letter has suggested that those playing sport are as responsible for their predicament as those who are obese. This opinion piece argues that it is time for better prevention and management of sports injury to be seen as part of the complex solution to preventing obesity, rather than being a self-inflicted problem that governments should continue to ignore. 相似文献
126.
127.
128.
Controlled study of haloperidol, pimozide and placebo for the treatment of Gilles de la Tourette's syndrome 总被引:5,自引:0,他引:5
E Shapiro A K Shapiro G Fulop M Hubbard J Mandeli J Nordlie R A Phillips 《Archives of general psychiatry》1989,46(8):722-730
The results of this controlled study of the treatment of 57 patients with Gilles de la Tourette's syndrome suggested that both haloperidol and pimozide were more effective than placebo, but that haloperidol was slightly more effective than pimozide. Adverse effects occurred more frequently with haloperidol vs placebo than with pimozide vs placebo, but the frequency was not significantly different for haloperidol compared with pimozide. Clinically significant cardiac effects did not occur at a maximum dosage of 0.3 mg/kg or 20 mg/d for pimozide and 10 mg/d for haloperidol. However, the QTc interval was prolonged during pimozide treatment compared with that during haloperidol treatment, although the values for both medications were not in an abnormal range. 相似文献
129.
John P Elliott Hugh S Miller Suzanne Coleman Debbie Rhea Diana Abril Karen Hallbauer Niki B Istwan Gary J Stanziano 《Journal of perinatology》2005,25(10):626-630
OBJECTIVE: To assess the impact of activity restriction (AR) on the incidence of preterm birth in women treated for preterm labor testing negative for fetal fibronectin (fFN). STUDY DESIGN: Women who were diagnosed with preterm labor and tocolyzed with magnesium sulfate were concurrently screened with fFN for the purpose of subsequent management. Included were consenting patients with negative fFN, gestational age 23 0/7-33 6/7 weeks, cervical dilation < or =3 cm, and minimal vaginal bleeding. Patients were randomized to AR or no AR. Primary study outcome was incidence of preterm delivery and interval from randomization to delivery. RESULTS: A total of 73 women with negative fFN were randomized (36 with AR, 37 without AR). The overall preterm birth rate was 40%, with 44.4% of patients with AR and 35.1% of patients without AR delivering preterm, p=0.478. CONCLUSION: Maternal AR did not impact pregnancy outcome. The incidence of preterm birth in symptomatic women testing fFN negative was higher than previously reported. 相似文献
130.
Gil Zalsman Yung-yu Huang Jill M Harkavy-Friedman Maria A Oquendo Steven P Ellis J John Mann 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2005,(1):100-103
Monoamine oxidase A gene promoter (MAOA-uVNTR) and catechol-O-methyltransferase V158M (COMT-V158M) gene functional polymorphisms are reported to be associated with impulsive-aggression, but a biological intermediate effect remains to be determined. This study assessed the association of these polymorphisms with cerebrospinal fluid (CSF) monoamine metabolites as endophenotypes. Ninety-eight Caucasian psychiatric subjects were assessed for Axis I and II diagnosis. Subjects were genotyped for the functional polymorphisms, MAOA-uVNTR and COMT-V158M. CSF was obtained by lumbar puncture. Relationships of the two polymorphism to monoamine metabolites: HVA, 5-HIAA, and MHPG were examined. The higher-expressing MAOA-uVNTR genotype was associated with higher CSF-HVA levels in males only (n = 46) (195.80 pmol/ml, SD = 61.64 vs. 161.13, SD = 50.23, respectively; P = 0.042). No association was found with diagnosis. COMT-V158M had no association with CSF monoamine metabolites. The association of MAOA-uVNTR with dopaminergic activity in males is a preliminary finding that needs to be replicated in a larger sample of Caucasian males and relationships sought with clinical phenotypes. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148-7299:1/suppmat/index.html. 相似文献