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   57847篇
  免费   1848篇
  国内免费   1842篇
耳鼻咽喉   379篇
儿科学   1256篇
妇产科学   1601篇
基础医学   3492篇
口腔科学   965篇
临床医学   6572篇
内科学   7289篇
皮肤病学   394篇
神经病学   1385篇
特种医学   2595篇
外国民族医学   2篇
外科学   4040篇
综合类   11344篇
一般理论   5篇
预防医学   8034篇
眼科学   927篇
药学   4121篇
中国医学   4066篇
肿瘤学   3070篇
  2023年   106篇
  2022年   160篇
  2021年   202篇
  2020年   151篇
  2019年   140篇
  2018年   246篇
  2017年   202篇
  2016年   284篇
  2015年   286篇
  2014年   468篇
  2013年   725篇
  2012年   1129篇
  2011年   3809篇
  2010年   2225篇
  2009年   1374篇
  2008年   1743篇
  2007年   1464篇
  2006年   1571篇
  2005年   2512篇
  2004年   7146篇
  2003年   6660篇
  2002年   5273篇
  2001年   4095篇
  2000年   2741篇
  1999年   3039篇
  1998年   2099篇
  1997年   1798篇
  1996年   1063篇
  1995年   899篇
  1994年   1027篇
  1993年   1587篇
  1992年   1153篇
  1991年   947篇
  1990年   617篇
  1989年   439篇
  1988年   316篇
  1987年   272篇
  1986年   260篇
  1985年   136篇
  1984年   97篇
  1983年   78篇
  1982年   65篇
  1981年   65篇
  1980年   74篇
  1979年   71篇
  1978年   64篇
  1977年   54篇
  1975年   49篇
  1974年   48篇
  1973年   59篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
RELATIONSHIP BETWEEN CORNEAL DELLEN AND TEARFILM BREAKUP TIME   总被引:1,自引:0,他引:1  
The BUT of 51 strabismus patients were measured before and after operation. The average pre-op BUT was 28.75 seconds(10.96"-91.80"). The post-op BUT in all operated eyes were reduced significantly, no matter what procedures had been performed and whether dellen appeared or not(P<0.01). The BUT in the group complicated dellen reduced from 23.22"(pre-op) to 8.61"(post-op). The incidence of dellen was 22.54% in this study. The incidence of dellen after rectus resection procedure(47.75%) was much higher than that after rectus recession(5.13%)(P<0.01). This study showed that dellen was closelyre related to the BUT and occurred more often in the eyes on which resection procedure was performed. It is considered that excessive lacrimation and elevation of the bulbar conjunctiva near the limbus may disturb the stability of the precornea tearfilm and cause the tearfilm break up earlier. Local corneal dehydration and dellen formation may be caused by reduced BUT. The incidence of dellen after operation may be higher if the cornea was carefully observed.  相似文献   
952.
本文测定绝育术后盆腔痛患者44例、输卵管绝育术后行输卵管复通术11例和正常妇女15例血浆与腹腔液中的甾体激素及前列腺素水平。结果发现:血中E_2与PGF_(2α)呈明显正相关,与TXB_2呈负相关,而P则与PGF_(2α)呈明显负相关;腹腔液中E_2与PGF_(2α)、TXB_2呈负相关。盆腔痛患者,包括异位症、无明显病变盆腔痛和盆腔静脉瘀血症3组的某种PG水平高于其他组。结果表明:血与腹腔液中PGs受甾体激素的影响,绝育术后慢性盆腔痛与PGs有关。  相似文献   
953.
The WHO workshop on the impact of the environment on reproductive health is summarized. Topics include the nature of environmental factors affecting reproductive health, environmental factors blamed for declining sperm quantity and quality, the effects of natural and man-made disasters on reproductive health, chemical pollutants, how the environment damages reproductive health, and research needs for better research methodologies and surveillance data. Recommendations are made to: 1) promote international research collaboration with an emphasis on consistency of methodological approaches for assessing developmental and reproductive toxicity, on development of improved surveillance systems and data bases, an strengthening international disaster alert and evaluation systems; 2) promote research capabilities for multidisciplinary studies, for interactive studies of the environment and cellular processes, and for expansion of training and education; and 3) take action on priority problems of exposure to chemical, physical, and biological agents, of exposure to pesticides among specific populations, and of inadequate screening methods for identification of environmental chemicals. The costs of environmental injury to reproduction include subfertility, intrauterine growth retardation, spontaneous abortion, and various birth defects. Developed country's primary threats are from chemical pollution, radiation, and stress. There is a large gap in knowledge. Caution is urged in understanding the direct relationship between environmental causes and infertility. Sexual health is difficult to assess and research is suggested. Exposure to excessive vitamin A and toxic chemicals are cited as agents probably having serious effects on malformations. Sperm quality has declined over the decades; there is speculation about the potential causes. The effects of radiation such as at Chernobyl are described. Toxic chemical exposure such as in Bhopal, India killed thousands. Neurological damage is reported for fetuses and infants exposed to methyl mercury. There is the beginning of evidence that complications of pregnancy may be related to pollution levels surrounding industrial plants. Reproductive health is affected through chromosome damage and cell destruction, prenatal death, altered growth, fetal abnormalities, postnatal death, functional learning deficits, and premature aging.  相似文献   
954.
955.
An audit was undertaken of the case notes of all new outpatients referred to the haematology department at the Leeds General Infirmary over a one-year period. The source, reason for referral, final diagnosis and outcome were determined in each case, along with essential biographical details. The results show that general practitioners initiated over half of all referrals, often prompted by written comments from a hematologist on a full blood count advising them that further tests were required. Almost a third came from other departments at the study hospital and the remainder originated from hospitals outside the district. Most general practitioner referrals were made with a request for a diagnosis. Hospital initiated referrals were more likely to have a final diagnosis of a malignant haematological disease, whereas those from general practice tended to have benign or self-limiting conditions. Ninety-one per cent of patients referred had an abnormality. There were low numbers of both clinic defaulters and those patients required to be re-referred to other specialties. These results suggest that the high quality of referrals is largely due to the general practitioner's decision to refer patients based on the full blood count result. This often occurs after discussion with haematology medical staff. The possible impact of the government's White Paper proposals on this outpatient service is discussed.  相似文献   
956.
957.
958.
959.
960.
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