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   1567篇
  免费   140篇
  国内免费   15篇
耳鼻咽喉   19篇
儿科学   120篇
妇产科学   65篇
基础医学   233篇
口腔科学   23篇
临床医学   154篇
内科学   278篇
皮肤病学   35篇
神经病学   129篇
特种医学   67篇
外科学   176篇
综合类   54篇
一般理论   4篇
预防医学   117篇
眼科学   73篇
药学   122篇
中国医学   1篇
肿瘤学   52篇
  2023年   12篇
  2022年   6篇
  2021年   9篇
  2020年   7篇
  2019年   14篇
  2018年   21篇
  2017年   12篇
  2016年   17篇
  2015年   28篇
  2014年   24篇
  2013年   71篇
  2012年   62篇
  2011年   74篇
  2010年   38篇
  2009年   50篇
  2008年   63篇
  2007年   80篇
  2006年   70篇
  2005年   72篇
  2004年   64篇
  2003年   78篇
  2002年   54篇
  2001年   59篇
  2000年   76篇
  1999年   59篇
  1998年   57篇
  1997年   49篇
  1996年   28篇
  1995年   31篇
  1994年   30篇
  1993年   36篇
  1992年   28篇
  1991年   52篇
  1990年   24篇
  1989年   25篇
  1988年   26篇
  1987年   23篇
  1986年   14篇
  1985年   25篇
  1984年   18篇
  1983年   20篇
  1982年   14篇
  1981年   10篇
  1980年   8篇
  1979年   9篇
  1977年   9篇
  1975年   5篇
  1969年   9篇
  1968年   9篇
  1966年   5篇
排序方式: 共有1722条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
The regulation of toxic substances present in the environment requires that carcinogens be distinguished from noncarcinogens on the strength of the available toxicological and epidemiological evidence for carcinogenicity. In this article, we consider the difficulties associated with establishing strong evidence against carcinogenicity. In particular, the ability of both animal and human studies to detect small increases in tumor occurrence rates is evaluated in statistical terms. Consideration is also given to resolving apparent conflicts between the toxicological and the epidemiological sources of data.  相似文献   
6.
Murdoch Eaton DG, Wertheim D, Oozeer R, Dubowitz LMS, Dubowitz V. Reversible changes in cerebral activity associated with acidosis in preterm neonates. Acta Paediatr 1994;83:486–92. Stockholm. ISSN 0803–5253
Computerized online EEG monitoring in ventilated preterm infants less than 32 weeks' gestation enabled evaluation of the effect of acidosis on cerebral function. All episodes of acidosis were found to be associated with changes in the levels of cerebral activity. In 21 of the 32 episodes, EEG activity returned to pre-acidosis levels after therapeutic intervention. The duration of EEG abnormality was related to the severity of acidosis. However, the time to recovery of the EEG after therapeutic procedures was not related to duration of the EEG change.  相似文献   
7.
This study examined the effects of the Coenzyme Athletic Performance System (CAPS) on endurance performance to exhaustion. CAPS contains 100 mg coenzyme Q10, 500 mg cytochrome C, 100 mg inosine, and 200 IU vitamin E. Eleven highly trained male triathletes were given three daily doses of either CAPS or placebo (dicalcium phosphate) for two 4-week periods using a double-blind crossover design. A 4-week washout period separated the two treatment periods. An exhaustive performance test, consisting of 90 minutes of running on a treadmill (70% VO2max) followed by cycling (70% VO2max) until exhaustion, was conducted after each treatment period. The mean (+/- SEM) time to exhaustion for the subjects using CAPS (223 +/- 17 min) was not significantly different (p = 0.57) from the placebo trial (215 +/- 9 min). Blood glucose, lactate, and free fatty acid concentrations at exhaustion did not differ between treatments (p < 0.05). CAPS had no apparent benefit on exercise to exhaustion.  相似文献   
8.
BACKGROUND: Seborrhoeic dermatitis (SD) is a common dermatosis in human immunodeficiency virus (HIV)-positive patients, many of whom do not respond satisfactorily to conventional topical treatments such as corticosteroids and antifungals. OBJECTIVE: A pilot study to investigate the efficacy and tolerability of pimecrolimus cream 1% in HIV-positive patients with facial SD. METHODS: In a single-centre study, 21 HIV-infected patients with mild to severe SD were treated twice daily with pimecrolimus cream 1% for 14 days. Thereafter, treatment was discontinued and patients followed up for 5 weeks. Skin involvement at baseline and on days 7, 14, 21, 35 and 49 was assessed using a four-point clinical score and digital photography. MAIN OUTCOME MEASURES: Efficacy and safety of pimecrolimus cream 1% treatment and incidence of relapse in the follow-up phase. Results Marked improvement was seen in clinical parameters at day 7, with >or= 90% patients clear of symptoms at day 14. Relapse was observed at day 35 but signs were milder than at baseline. All patients responded to therapy, despite their immunological status. Pimecrolimus did not alter CD4(+) and CD8(+) T-cell counts or viral load during the treatment period. CONCLUSION: Pimecrolimus cream represents a new, effective therapeutic option for facial SD in HIV patients.  相似文献   
9.
10.
D Murdoch  D McTavish 《Drugs》1992,43(1):123-140
Fosinopril is a phosphinic acid prodrug which, after oral administration, undergoes rapid hydrolysis to its active diacid, the angiotensin converting enzyme (ACE) inhibitor fosinoprilat. Unlike other ACE inhibitors, fosinoprilat has a compensatory dual route of elimination and is cleared by the liver and kidneys. Thus, in patients with diminished renal function increased hepatic clearance of fosinoprilat is noted and, similarly, in patients with diminished hepatic function increased renal clearance seems to occur. Because of this compensatory elimination, fosinopril therapy for all patients can begin with the same recommended dosage. Fosinopril 10 to 40mg administered once daily is an effective antihypertensive regimen that has shown efficacy similar to that of enalapril 5 to 10 mg/day, propranolol 80 to 160 mg/day, hydrochlorothiazide 25 to 50 mg/day and sustained release nifedipine 40 mg/day in preliminary clinical trials. Generally, fosinopril is well tolerated and adverse events associated with the drug are usually mild and similar to those associated with other ACE inhibitors. Thus, fosinopril appears to be a useful alternative to certain 'established' agents used for treating patients with essential hypertension.  相似文献   
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