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   2059588篇
  免费   146037篇
  国内免费   3142篇
耳鼻咽喉   29553篇
儿科学   62507篇
妇产科学   57472篇
基础医学   296143篇
口腔科学   59924篇
临床医学   176898篇
内科学   402624篇
皮肤病学   42885篇
神经病学   160058篇
特种医学   80642篇
外国民族医学   438篇
外科学   325408篇
综合类   41843篇
现状与发展   2篇
一般理论   516篇
预防医学   145527篇
眼科学   47487篇
药学   158812篇
  3篇
中国医学   4303篇
肿瘤学   115722篇
  2018年   19231篇
  2016年   16442篇
  2015年   18991篇
  2014年   26003篇
  2013年   39093篇
  2012年   53641篇
  2011年   56945篇
  2010年   33734篇
  2009年   31967篇
  2008年   55415篇
  2007年   59440篇
  2006年   60494篇
  2005年   58945篇
  2004年   56939篇
  2003年   55044篇
  2002年   54162篇
  2001年   102719篇
  2000年   106026篇
  1999年   89412篇
  1998年   23272篇
  1997年   20673篇
  1996年   20904篇
  1995年   19601篇
  1994年   18470篇
  1993年   17072篇
  1992年   70455篇
  1991年   68498篇
  1990年   67022篇
  1989年   65276篇
  1988年   60414篇
  1987年   58959篇
  1986年   55839篇
  1985年   53331篇
  1984年   39025篇
  1983年   33562篇
  1982年   18920篇
  1981年   16625篇
  1979年   36014篇
  1978年   24887篇
  1977年   21507篇
  1976年   19644篇
  1975年   21590篇
  1974年   25760篇
  1973年   24520篇
  1972年   23445篇
  1971年   21928篇
  1970年   20592篇
  1969年   19732篇
  1968年   18292篇
  1967年   16179篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
This report examines long-term and short-term benefits of achieving abstinence from opioids in a sample of opioid addicts who were reevaluated 2.5 years following seeking treatment. Extensive assessment of drug use history and drug-associated problems had been obtained when the subjects applied for treatment. At follow-up evaluations, detailed information was obtained on intervening course of drug use, treatment, legal problems, psychological problems, social functioning, occupational functioning, and medical status. The results were as follows: (1) Achieving abstinence from illicit opioids was associated with concurrent improvement in other aspects of functioning including reduction of criminal activity, improved medical status, improved social functioning, and reduced abuse of other psychoactive substances. However, many of these improvements were reversed immediately if relapse to opioid use occurred. (2) Achieving abstinence was associated with being in drug treatment, especially treatment in a methadone maintenance program. (3) Achievement of abstinence was not successfully predicted by client characteristics measured at entrance into treatment. (4) Long-range benefits of abstinence were detectable in social functioning even for those who had relapsed at the time of follow-up reevaluation.  相似文献   
992.
993.
A rare case of craniopharyngioma extending to the cranial base and nasopharynx is reported and eight other cases in the literature are reviewed. The embryology and the clinical features of these tumors are discussed. Tomograms of the skull and computed tomography are the most useful radiological tools of investigation. A nasoseptal or transpalatal approach to surgery, which has been performed in reported cases of cystic nasopharyngeal craniopharyngiomas, was not performed on our patient because of the hard consistency and the diffusely infiltrating aspect of the tumor.  相似文献   
994.
995.
We carried out a nonrandomized, unblinded study to compare the efficacy of rifampin alone with that of rifampin in combination with trimethoprim in the eradication of the Haemophilus influenzae type b (HIB) carrier state among contacts of patients with invasive HIB infection. The study population comprised 17 index patients admitted to hospital with severe HIB infections and 233 contacts, 43 of whom had nasopharyngeal colonization with HIB of the same biotype as that of the index patient. Rifampin in a daily dose of 20 mg/kg (maximum 600 mg) for 4 days eradicated the carrier state in 86% of cases, as did the combination of rifampin at the same dosage and trimethoprim in a daily dose of 5 mg/kg (maximum 160 mg) for 4 days.  相似文献   
996.
997.
998.
The relative free energy of binding the anions Cl- and Br- to the macrotricyclic receptor SC24 in water has been computed by a computer simulation technique. This result and an incidental result for the relative free energy of hydration of the anions are in excellent agreement with experimental data. The simulation approach to ligand-receptor interactions that is described here has significant potential as a predictive tool in chemistry, biochemistry, and pharmacology.  相似文献   
999.
The contents of free and conjugated polyamines in cyst fluids of brain tumours were analysed. The putrescine and N1-acetylspermidine levels in cyst fluids of malignant brain tumours were significantly higher than those of benign tumours. The free spermidine levels in malignant and benign tumours were about the same, while the total spermidine levels were higher in malignant than those in benign tumours. These results suggest that polyamine levels in cyst fluids reflect the altered polyamine metabolism in brain tumours.  相似文献   
1000.
We present some important current applications of reconstructive microsurgery. This field is expanding rapidly and the techniques are finding application in many branches of surgery. There is a pressing need for educational programs and training in microsurgery, as well as for continued research.

Many of the procedures reviewed here have already been shown to substantially reduce costs, shorten hospitalization, and lessen patient disability; and as a result, several conventional procedures have been out-dated. We have stressed the concept that this is team surgery. To cover the needs of replantation and emergency free flaps around the clock, several micro-surgeons must work together in established centers, and the team must possess expertise from all the involved surgical specialities. This may imply revision of many organizational aspects of patient care. Replantation centers would provide the necessary educational bases and give an impetus to the development of microsurgery.  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