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   20331篇
  免费   1843篇
  国内免费   32篇
耳鼻咽喉   225篇
儿科学   577篇
妇产科学   476篇
基础医学   2564篇
口腔科学   453篇
临床医学   2382篇
内科学   3569篇
皮肤病学   219篇
神经病学   1991篇
特种医学   566篇
外科学   2718篇
综合类   573篇
一般理论   24篇
预防医学   2181篇
眼科学   477篇
药学   1544篇
中国医学   17篇
肿瘤学   1650篇
  2022年   136篇
  2021年   268篇
  2020年   184篇
  2019年   264篇
  2018年   347篇
  2017年   261篇
  2016年   300篇
  2015年   336篇
  2014年   436篇
  2013年   679篇
  2012年   1024篇
  2011年   989篇
  2010年   540篇
  2009年   499篇
  2008年   907篇
  2007年   980篇
  2006年   896篇
  2005年   895篇
  2004年   881篇
  2003年   806篇
  2002年   829篇
  2001年   648篇
  2000年   592篇
  1999年   538篇
  1998年   268篇
  1997年   207篇
  1996年   228篇
  1995年   208篇
  1994年   185篇
  1993年   188篇
  1992年   410篇
  1991年   403篇
  1990年   442篇
  1989年   401篇
  1988年   384篇
  1987年   367篇
  1986年   357篇
  1985年   319篇
  1984年   253篇
  1983年   207篇
  1982年   138篇
  1979年   265篇
  1978年   180篇
  1977年   160篇
  1976年   134篇
  1975年   161篇
  1974年   187篇
  1973年   149篇
  1972年   139篇
  1968年   124篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
A modified end-point enzymatic method for the measurement of ammonia in stool water is presented. A protein precipitation step was included in order to inactivate urease and faecal enzymes, which oxidise NADH. The modified method is reliable, with acceptable precision and accuracy, and is linear up to a concentration of 1.5 mmol/l.  相似文献   
102.
The duration of retention of tolerance to ethanol was tested in the alcohol-preferring (P) and alcohol-nonpreferring (NP) rats lines, using ethanol-induced hypothermia as a measure of tolerance. Rats received two injections of ethanol (3.5 g/kg) body wt, IP) and the time between the injections was 1, 2, or 3 days. When one day separated the two injections, tolerance to the hypothermic effect of a second “test” injection was found in both lines. When 2 or 3 days separated the two injections, the P line showed a loss of tolerance and the NP line showed sensitization to ethanol. Sensitization in the NP line grew stronger when the interval between injections was increased from 2 to 3 days. The duration of retention of tolerance to ethanol-induced hypothermia in the P line was shorter than has previously been reported for motor impairment in this line. It appears that the duration of tolerance retention in the P line depends on the test used to measure tolerance. Sensitization to ethanol in the NP line may be associated with low oral ethanol intake. This research was supported, in part, by grants AA08312, AA03243, and AA07611 from the PHS  相似文献   
103.
104.
BACKGROUND: Nurse leaders in Fiji are currently involved in meeting the challenges of being at the forefront of an AusAID supported Health Sector Improvement process. Fiji is experiencing the same shortages of health professionals (including nurses) as is occurring internationally, while simultaneously striving to improve the quality of its health services. PRIMARY ARGUMENT: This paper provides information about the current situation in relation to health services in Fiji, and describes strategies being undertaken by the nurse leaders of Fiji to meet the challenge of leading an exciting reform process. James Cook University, School of Nursing Sciences, has been privileged to support the provision of contemporary leadership and management education for current and future nurse leaders in the Fiji Health Sector as a component of a current education program to educate registered nurses to bachelor level. This paper will provide an overview of the current Fiji Health Sector Improvement Program, with a particular focus on the preparation of nurse leaders. CONCLUSION: There is an ongoing need to understand beliefs and values, and styles of interaction and communication, and indeed, ideas about time. With collaboration between Australian academics and Fiji tutors from the Fiji School of Nursing, the program appears to be remarkably successful.  相似文献   
105.
106.
Post-traumatic cerebrospinal fluid (CSF) rhinorrhoea is a well recognized complication of closed head injury. Most cases occur soon after injury and a delay in presentation of more than 1 month is unusual. A case is reported of CSF rhinorrhoea presenting 15 years after initial trauma which was complicated by meningitis after 12 months. The management of this condition is reviewed.  相似文献   
107.
108.
109.
BACKGROUND: Parallel comparison studies of cognitive therapy and antidepressant medication have suggested that both treatments are effective. However, we cannot determine from these studies whether cognitive therapy and antidepressant medication are effective for the same populations of depressives. A sequential study in which nonresponders to the first treatment are then treated with the second can address this issue. METHOD: Twenty-seven patients meeting DSM-III criteria for major depression or dysthymic disorder and Columbia criteria for atypical depression received cognitive therapy followed by antidepressant medication for cognitive therapy nonresponders. A response rate with the second treatment equal to that expected with placebo would suggest both treatments target the same depressive population. RESULTS: Of the 25 completers of the study, 14 (56%) were judged responders to cognitive therapy alone. Sixty-nine percent (9/13) of the responders maintained their benefits for 6 months or more. Seven of the 11 cognitive therapy nonresponders (63%) responded to antidepressant medication. These results were compared with those of a concurrent double-blind medication study; both its sample and ours were drawn from the same population at the same time: cognitive therapy and antidepressant medication response rates were higher than expected with placebo (28%). CONCLUSION: The results suggest that (1) cognitive therapy and antidepressant medication are effective treatments for differing populations of depressed patients, as the antidepressant medication response of cognitive therapy nonresponders was greater than expected with placebo, and (2) cognitive therapy has a lasting effect.  相似文献   
110.
The objective of the work was to identify changes in antidepressant drug use and determine if the prevalence of antidepressant use has changed over 14 years. A longitudinal analysis comparing antidepressant drug use at 14 yearly intervals from 1978–79 to 1991–92 was undertaken using the longitudinal health screening program of ambulatory elderly participants (Florida Geriatric Research Program). Participants included all subjects screened in the Florida Geriatric Research Program from 1 August 1978 to 31 July 1992. The outcome measures were self-reported antidepressant drug use. Approximately 3.0 per cent (range of 2.3 to 3.2 per cent over 14 yearly intervals) of participants in this program reported the use of an antidepressant drug. There was no statistically significant change in antidepressant use between 1978–79 and 1991–92 (p > 0.6630). Across all study intervals women reported more frequent use of antidepressant drugs than men. In 1991–92, amitriptyline and imipramine represented over 50 per cent of all antidepressant drug use in this elderly population. Less than 6 per cent of all antidepressant drug use was for fluoxetine, the newest selective serotonin uptake inhibitor. The majority of elderly patients are receiving older tertiary amine tricyclic antidepressants such as amitriptyline, imipramine and doxepin that are not the preferred drugs for the elderly. Educational programs are needed to improve antidepressant prescribing for geriatric patients.  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