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   2392660篇
  免费   186714篇
  国内免费   9797篇
耳鼻咽喉   30646篇
儿科学   78190篇
妇产科学   65442篇
基础医学   339465篇
口腔科学   65910篇
临床医学   225357篇
内科学   474333篇
皮肤病学   52820篇
神经病学   198515篇
特种医学   92311篇
外国民族医学   622篇
外科学   352277篇
综合类   55309篇
现状与发展   3篇
一般理论   838篇
预防医学   200607篇
眼科学   51838篇
药学   172162篇
  11篇
中国医学   4916篇
肿瘤学   127599篇
  2018年   26431篇
  2017年   20375篇
  2016年   23271篇
  2015年   26340篇
  2014年   36567篇
  2013年   55981篇
  2012年   72207篇
  2011年   77251篇
  2010年   46552篇
  2009年   44266篇
  2008年   71233篇
  2007年   75558篇
  2006年   76845篇
  2005年   74260篇
  2004年   70799篇
  2003年   68138篇
  2002年   65351篇
  2001年   109608篇
  2000年   112701篇
  1999年   94591篇
  1998年   28204篇
  1997年   25352篇
  1996年   25946篇
  1995年   25545篇
  1994年   23927篇
  1993年   22426篇
  1992年   77369篇
  1991年   75529篇
  1990年   72886篇
  1989年   69259篇
  1988年   64373篇
  1987年   63093篇
  1986年   59935篇
  1985年   57610篇
  1984年   43897篇
  1983年   37020篇
  1982年   22912篇
  1981年   20462篇
  1980年   19157篇
  1979年   39709篇
  1978年   28768篇
  1977年   23897篇
  1976年   22736篇
  1975年   23472篇
  1974年   28123篇
  1973年   27179篇
  1972年   25117篇
  1971年   23275篇
  1970年   21393篇
  1969年   19808篇
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
991.
Following the outbreak of poliomyelitis in Gazankulu in 1982, the immunisation services in Gazankulu were thoroughly examined. As a result of this, a comprehensive immunisation policy for Gazankulu was accepted in November 1986. The broad aim of the policy is to provide effective immunisation to all Gazankulu residents against tuberculosis, diphtheria, pertussis, tetanus, poliomyelitis and measles. A specific objective is that by the end of 1987, 85% of under-5s should have been vaccinated against these six diseases and by the end of 1990 this percentage should be 97%. The detailed strategies to reach these objectives are highlighted. Within the framework of the objectives, the policy allows different areas to formulate individual strategies. Programme monitoring and community involvement are two crucial aspects of the policy and these are discussed in detail. The early successes and difficulities in implementing this policy are discussed.  相似文献   
992.
A 4.5-year follow-up retrospective study on the use of epiphysiodesis procedure for juvenile hallux valgus deformity and metatarsus primus adductus deformity shows a good reduction of deformity in nine patients with minimal change in one patient that can be explained due to the timing of the procedure. This is a minor operation for juvenile bunion deformities, using epiphyseal arrest techniques. The only complication to this procedure was one case with a noted metatarsus primus elevatus due to incomplete epiphyseal arrest from dorsal to plantar. This procedure has been found to be a safe and effective way of dealing with juvenile hallux valgus deformity when metatarsus primus adductus is the deforming force. It should be stated that in all cases a follow-up biomechanical examination and casting for orthotics took place and to date no complications, other than what has been previously mentioned, has occurred. I shall continue to perform this procedure where indicated and shall report my findings as they become available.  相似文献   
993.
The second documented case of renal aspergilloma due to Aspergillusflavus is presented. The merits of the medical therapy thatfailed are discussed. Pathological examination showed a nidusof aspergillus around suture material persisting from a pyelolithotomyoperation 2 years before in India. We argue that this was thereason for the failure of the medical therapy. This is the firstcase of its kind reported.  相似文献   
994.
995.
996.
997.
Results of prevention programs with adolescents   总被引:3,自引:0,他引:3  
Programs for preventing smoking and alcohol and drug abuse have radically changed in the past decade. Instead of being regarded as a health or discipline problem that involves only a few deviant adolescents, drug use has begun to be viewed as social behavior that is functional for adolescents, not capricious, and is normative for that population. The most successful prevention programs have sought to delay the onset of tobacco use. Based on theoretical and etiological research, these programs target factors that have repeatedly been predictive of adolescent smoking, alcohol and drug use. The programs teach adolescents (1) why people their age smoke tobacco or use alcohol and drugs; (2) how these meanings get established by peers, older role models and advertising; (3) how to resist these influences to smoke or to use alcohol and drugs; and (4) life skills and competencies to counterbalance the functions that drug use serves. Because of the association with the onset of smoking and the onset of using other drugs, these strategies are being studied for alcohol use and other drugs. In addition, elected peer leaders are trained to conduct these activities with their classmates and act as new role models for non-use. Evaluations of these approaches are optimistic. Studies in northern California and Minnesota reveal 50-70% reductions in the onset of smoking. Botvin's 'Life Skills Training' program demonstrates success in delaying heavy alcohol and marijuana use.  相似文献   
998.
Summary: Fifty-seven isolates of Basidiobolus from reptiles and amphibians, and 7 other obtained from the American Type Culture Collection (ATCC) in Maryland were studied for their extracellular enzyme activities on solid media. The Conidiobolus isolates studied included 4 recovered from Nigerian soil and additional 4 obtained from the ATCC All these isolates produced active extracellular lipase and protease and failed to exhibit amylase, deoxyribonuclease and ribonuclease activities. The significance of the findings is discussed.
Zusammenfassung: Fünfundsiebzig Basidiobolus-Isolate aus Reptilien und Amphibien und sieben weitere aus der American Type Culture Collection (ATCC) in Maryland wurden auf Aktivtäten extrazellulärer Enzyme auf festen Medien untersucht Die untersuchten Conidiobolus-Isolate schlossen vier aus nigerianischen Böden und vier weitere aus der ATCC ein. Alle Isolate zeigten extrazellulär Lipase- und Proteaseaktivität Amylase-, Desoxyribonuclease- und Ribonucleaseaktivität war jedoch nicht nachzuweisen. Die Bedeutung dieser Befunde wird diskutiert.  相似文献   
999.
1000.
Two hundred and thirty pregnancies were studied in 196 diabetic women. Seven women with babies found to have major malformations had a higher median first trimester haemoglobin A1 (12.9%) than the median HbA1 (10.8%) in those with normal babies (p = 0.06). No relationship was found between the occurrence of minor malformations and first trimester maternal haemoglobin A1. Two of the seven congenital malformations were diagnosed antenatally at a time when therapeutic abortion could be offered. Expert antenatal ultrasound scanning should be offered to all pregnant diabetic women as poor glycaemic control at the time of conception and organogenesis, as evidenced by raised first trimester HbA1, predisposes to congenital malformation.  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