首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4053篇
  免费   250篇
  国内免费   95篇
耳鼻咽喉   73篇
儿科学   86篇
妇产科学   39篇
基础医学   574篇
口腔科学   210篇
临床医学   370篇
内科学   707篇
皮肤病学   115篇
神经病学   138篇
特种医学   439篇
外科学   539篇
综合类   39篇
预防医学   148篇
眼科学   112篇
药学   426篇
中国医学   67篇
肿瘤学   316篇
  2023年   35篇
  2022年   90篇
  2021年   143篇
  2020年   73篇
  2019年   80篇
  2018年   119篇
  2017年   94篇
  2016年   134篇
  2015年   202篇
  2014年   232篇
  2013年   275篇
  2012年   354篇
  2011年   303篇
  2010年   193篇
  2009年   162篇
  2008年   190篇
  2007年   190篇
  2006年   163篇
  2005年   140篇
  2004年   115篇
  2003年   78篇
  2002年   77篇
  2001年   79篇
  2000年   59篇
  1999年   49篇
  1998年   78篇
  1997年   82篇
  1996年   78篇
  1995年   67篇
  1994年   51篇
  1993年   56篇
  1992年   20篇
  1991年   22篇
  1990年   16篇
  1989年   42篇
  1988年   27篇
  1987年   39篇
  1986年   15篇
  1985年   28篇
  1984年   15篇
  1983年   29篇
  1982年   22篇
  1981年   19篇
  1980年   22篇
  1979年   4篇
  1978年   5篇
  1977年   9篇
  1976年   5篇
  1975年   7篇
  1973年   4篇
排序方式: 共有4398条查询结果,搜索用时 15 毫秒
61.
62.
Although lupus erythematosus is known to be more common among women of color, the study populations in previous reports were predominantly Caucasian and there is scarce information on Asian patients. Therefore, we performed a retrospective study using a nationwide population-based cohort in South Korea. The average annual incidence of cutaneous lupus was 4.36/100 000. Among 634 patients with cutaneous lupus, 20.8% had systemic disease: cutaneous lupus was diagnosed before systemic lupus in 4.26% and after systemic lupus in 8.52%. More female patients than male patients developed systemic lupus erythematosus. The average time to progression to systemic lupus was 1.53 ± 1.46 years.  相似文献   
63.
64.
65.
66.
67.
Numerous medications are used to treat hyperpigmentation. However, several reports have indicated that repeated application of some agents, such as rhododendrol (RD), raspberry ketone (RK) and monobenzone (MB), can be toxic to melanocytes. Although these agents had severe side effects in human trials, no current in vitro methods can predict the safety of such drugs. This study assessed the in vitro effects of five depigmentary compounds including leukoderma‐inducing agents. In particular, we determined the effects of different concentrations and exposure times of different depigmentary agents on cell viability and melanogenesis in the presence and absence of ultraviolet B (UVB) radiation. Concentrations of RD, RK and MB that inhibit melanogenesis are similar to concentrations that are cytotoxic; however, concentrations of rucinol (RC) and AP736 that inhibit melanogenesis are much lower than concentrations that are cytotoxic. Furthermore, the concentrations that cause toxic effects depend on exposure duration, and prolonged exposure to RD, RK and MB had more cytotoxic effects than prolonged exposure to RC and AP736. The cytotoxic effects of RD and RK appear to be mediated by apoptosis due to increased expression of caspase‐3 and caspase‐8; UVB radiation increased the cytotoxicity of these agents and also increased caspase activity. Our results indicate that different leukoderma‐inducing compounds have different effects on the viability of normal epidermal melanocytes and suggest that the in vitro assay used here can be used to predict whether an investigational compound that induces leukoderma may lead to adverse effects in human trials.  相似文献   
68.
69.
The purpose of this study was to investigate the relationship between weight status and recreational drug use in Korean adolescents. A total of 72,399 adolescent students (38,152 boys and 34,247 girls) from the middle first to high third grade participated in the 5th Korea Youth Risk Behaviour Web-based Survey (KYRBWS-V) project in 2009. They were assessed for body mass index (BMI) and recreational drug abuse. The associations between BMI and recreational drug use were examined using multivariable logistic regression analysis after adjusting for the covariate variables of age, smoking frequency and cigarette consumption, frequency of alcohol consumption and severe alcohol intoxication, amount of alcohol consumed, parents’ education level, economic status, sedentary activities during the week, mental stress, sleep duration, frequency of vigorous and moderate physical activities, and muscular strength exercises during the week. For boys, the odds ratio (OR) (95% confidence interval [CI]) between overweight and drug use were 0.990 (0.723–1.356; p = 0.950) for almost none, 0.939 (0.521–1.693; p = 0.834) for past use, and 0.791 (0.385–1.624; p = 0.523) for present use. The OR (95% CI) between obesity and drug use was 0.731(0.508–1.052; p = 0.091) for almost none, 0.755 (0.389–1.465; p = 0.407) for past use, and 0.701 (0.314–1.565; p = 0.386) for present use. For girls, the OR (95% CI) between overweight and drug use was 1.112 (0.702–1.763; p = 0.650) for almost none, 1.103 (0.464–2.619; p = 0.825) for past use, and 0.927 (0.267–3.218; p = 0.905) for present use. The OR (95% CI) between obesity and drug abuse was 0.594 (0.261–1.352; p = 0.215) for almost none, 1.318 (0.462–3.764; p = 606) for past use, and <0.001(<0.001–<0.001; p = 0.998) for present use. We concluded that recreational drug use had no correlation with overweight and obesity in Korean adolescents.  相似文献   
70.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号