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   931831篇
  免费   66342篇
  国内免费   1342篇
耳鼻咽喉   12960篇
儿科学   24360篇
妇产科学   23232篇
基础医学   132886篇
口腔科学   28246篇
临床医学   80530篇
内科学   183234篇
皮肤病学   19226篇
神经病学   72181篇
特种医学   36799篇
外国民族医学   79篇
外科学   152100篇
综合类   18042篇
现状与发展   1篇
一般理论   234篇
预防医学   61744篇
眼科学   21307篇
药学   72523篇
  3篇
中国医学   2162篇
肿瘤学   57666篇
  2018年   8967篇
  2017年   7028篇
  2016年   7761篇
  2015年   8860篇
  2014年   11987篇
  2013年   17500篇
  2012年   24080篇
  2011年   25036篇
  2010年   14807篇
  2009年   14271篇
  2008年   24604篇
  2007年   25686篇
  2006年   26480篇
  2005年   25423篇
  2004年   24559篇
  2003年   23604篇
  2002年   23148篇
  2001年   54724篇
  2000年   56545篇
  1999年   46947篇
  1998年   10730篇
  1997年   9464篇
  1996年   9593篇
  1995年   8926篇
  1994年   8278篇
  1993年   7593篇
  1992年   35487篇
  1991年   33911篇
  1990年   32734篇
  1989年   31869篇
  1988年   28991篇
  1987年   28249篇
  1986年   26288篇
  1985年   25144篇
  1984年   17832篇
  1983年   15141篇
  1982年   7795篇
  1981年   6771篇
  1979年   15781篇
  1978年   10598篇
  1977年   9052篇
  1976年   7871篇
  1975年   8628篇
  1974年   10466篇
  1973年   9858篇
  1972年   9357篇
  1971年   8852篇
  1970年   8426篇
  1969年   7924篇
  1968年   7200篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
A pineal hormone melatonin (1 mg/kg, 24 days) facilitated the formation of tolerance to haloperidol and eliminated the changes produced by it in the processes of microsomal oxidation in rats. Pinealectomy yielded the opposite result. After pinealectomy the normalizing effect of the hormone on the condition of the liver monoxygenase system and the effects of haloperidol weakened.  相似文献   
994.
Interaction of midazolam and morphine in the spinal cord of the rat   总被引:11,自引:1,他引:10  
The antinociceptive properties, as measured by the tail-flick and hot-plate tests, and the motor effects of an intrathecally-administered benzodiazepine agonist midazolam, alone, and in combination with morphine, was examined in rats. Midazolam alone produced a weak but dose-dependent (20-60 micrograms) antinociceptive effect in addition to a clear motor dysfunction at larger doses (60-100 micrograms). An inactive dose of intrathecally-administered midazolam (20 micrograms) produced a leftward shift in the dose-response curve for intrathecally administered morphine, in the thermal antinociceptive tests. This supra-additive effect was antagonized by naloxone (1 mg/kg). The data suggest a synergistic interaction between mu- and GABAA-receptors in the spinal processing of thermally-evoked pain.  相似文献   
995.
996.
Binding profile of SM-9018, a novel antipsychotic candidate   总被引:3,自引:0,他引:3  
The present study employed various receptor-binding assays to clarify the biochemical characteristics of SM-9018. SM-9018 possessed very high affinity for 5-HT2, D2 and 5-HT1A receptors (Ki = 0.61, 1.4 and 2.9 nM, respectively), and it had moderate affinity for alpha 1 and D1 receptors (Ki = 17 and 41 nM, respectively). However, SM-9018 had only negligible affinity for alpha 2, opiate, glutamate, phencyclidine, benzodiazepine and GABAA receptors. These results suggest that SM-9018 may be a novel antipsychotic agent with binding affinity for 5-HT2 and 5-HT1A receptors.  相似文献   
997.
We examined the involvement of GABAergic neuronal systems in benzodiazepine-induced passive avoidance deficit. Chlordiazepoxide impaired the passive avoidance response dose dependently when it was given prior to training. Post-training administration of muscimol improved the performance of chlordiazepoxide-pretreated mice. The effects of muscimol were antagonized completely by the GABAA antagonist, bicuculline, and the muscarinic acetylcholine receptor antagonist, scopolamine, but not by the benzodiazepine receptor antagonist, flumazenil, when the latter was administered immediately after training. It appears from these results that the GABAergic neuronal system plays an important role in the benzodiazepine-induced passive avoidance deficit by interacting with the cholinergic neuronal system.  相似文献   
998.
Morocco's severe financial problems have threatened its health-for-all goals. Restrictions have affected the recruitment and replacement of health personnel, the purchase and maintenance of equipment and buildings, hospital catering services and drug procurement. Several methods have been used to try and ease this crisis, rationalization and better deployment of resources, mobilization of national resources, and mobilization of external resources. In attaining the 1st, restrictions on the credits allocated to the Ministry of Public health have forced it to work out better ways of using its resources. These have included plans for better administrative and financial management of hospitals, improvements in drug procurement and distribution, new methods of personnel management, and efforts at improving information facilities and analytical capabilities at the central and local levels. To mobilize internal resources several steps were taken. These included revising too-low hospital charges, and charging people with social security coverage or those able to pay directly, raising funds through private charities, and the establishment of alternative, less expensive types of health centers. Morocco's continued need for funds to achieve health-for-all goals led it to also receive substantial assistance from international agencies (including the World Bank, UNICEF, UNFPA, and USAID) and friendly countries. External assistance cannot provide definitive solutions however, because of 1) the use of foreign experts and the payment of salaries abroad, 2) the purchase of products from the countries providing assistance, and 3) the unpredictability of external support and the danger programs may have to be abandoned. In times of financial crisis it is necessary to continue to budget adequately in order to reach health objectives.  相似文献   
999.
Volunteers trained by a social worker did a telephone screening of 716 elderly persons waiting for elective surgery to determine in advance of admission their need for social services. On the basis of their findings patients were given a risk rating by a social worker. While the survey was experienced positively by patients, volunteers, and social workers, the results do not establish its value in terms of shortened length of stay. Aging females living alone required the greatest amount of social work and had the longest length of stay. This group requires further study, along with the connection between intensity of illness with social problem vulnerability. The study raises other important questions critical to programming for an increasingly older population.  相似文献   
1000.
Job-exposure matrices were constructed and applied in the estimation of past exposures in a case-referent study nested within a cohort of Finnish woodworkers. The objective was to avoid bias in the risk estimates because of a misclassification of exposures. The matrices were constructed separately for each plant under study and each calendar year of follow-up. The level of exposure was incorporated in the matrices, since rather comprehensive data on exposures were available. The individual work histories were converted to exposure histories by a computer program which calculated several exposure indicators (eg, level and dose, with and without allowance for a latency period). The comparison between several indicators was thought to provide additional information for the final evaluation of results. The use of the plant- and period-specific job exposure matrices may be considered in cohort and nested case-referent studies on occupational hazards as an alternative to other procedures used in the estimation of exposures. Specific matrices may find broader applicability along with the increasing availability of detailed hygienic data.  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