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   30270篇
  免费   2498篇
  国内免费   61篇
耳鼻咽喉   331篇
儿科学   811篇
妇产科学   447篇
基础医学   3814篇
口腔科学   657篇
临床医学   3486篇
内科学   6573篇
皮肤病学   399篇
神经病学   2793篇
特种医学   986篇
外国民族医学   3篇
外科学   4574篇
综合类   550篇
一般理论   29篇
预防医学   2721篇
眼科学   622篇
药学   2039篇
  4篇
中国医学   15篇
肿瘤学   1975篇
  2023年   262篇
  2022年   477篇
  2021年   1030篇
  2020年   558篇
  2019年   802篇
  2018年   929篇
  2017年   636篇
  2016年   679篇
  2015年   769篇
  2014年   1103篇
  2013年   1282篇
  2012年   2049篇
  2011年   2018篇
  2010年   1066篇
  2009年   894篇
  2008年   1577篇
  2007年   1525篇
  2006年   1392篇
  2005年   1282篇
  2004年   1228篇
  2003年   1091篇
  2002年   912篇
  2001年   632篇
  2000年   629篇
  1999年   553篇
  1998年   265篇
  1997年   198篇
  1996年   202篇
  1995年   214篇
  1994年   176篇
  1993年   188篇
  1992年   472篇
  1991年   437篇
  1990年   438篇
  1989年   424篇
  1988年   354篇
  1987年   348篇
  1986年   302篇
  1985年   305篇
  1984年   220篇
  1983年   211篇
  1982年   170篇
  1981年   149篇
  1980年   151篇
  1979年   237篇
  1978年   169篇
  1977年   140篇
  1976年   161篇
  1974年   149篇
  1973年   164篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
The clinicopathologic features of 17 cases of an unusual variant of chorioamnionitis distinguished by a pure or predominantly chronic inflammatory infiltrate in the fetal membranes rather than the usual acute inflammatory reaction are reported. In six cases, there was an equal (one case) or minor (five cases) component of acute inflammation in the fetal membranes as well. Concomitant villitis, found in 11 cases, was almost uniformly lymphohistiocytic and destructive, but it varied greatly in severity. Immunoperoxidase stains for cytomegalovirus, herpes simplex I and II, and Toxoplasma gondii; Warthin-Starry, Gomori methenamine silver, Dieterle, Gram and acid fast stains; placental or amniotic fluid culture; and limited maternal serologic studies failed to identify a specific infectious etiology in any case. Seven women had experienced at least one previous spontaneous abortion, fetal death in utero, or preterm birth. No patient reported a history of fever, rash, or flu-like syndrome during pregnancy. Serious antenatal complications were numerous. Preterm birth occurred in 13 cases. Gestational age ranged from 25 to 42 weeks (mean 32 weeks) and birth weight ranged from 740 to 3,230 g (mean 2,100 g). When expressed as a percentile for gestational age, 47% of infants had a birth weight at or below the 25th percentile, and 76% were at or below the 50th percentile. Two infants were born with gross anomalies, and one infant died in the neonatal period.  相似文献   
33.
In order to determine the effects of the Fowler-Stephens orchiopexy (FSO) on fertility, young rats underwent simulated FSO, FSO and concurrent contralateral orchiectomy (FSO/OR), unilateral orchiectomy (OR), or sham operation (controls). Twelve weeks after the operation, each male rat was mated to two proven-fertile female rats for 17 days (three ovulatory cycles). Two weeks later, both male and female rats were killed. No pregnancy resulted from the matings of the FSO/OR males. In contrast, pregnancy ensued in 13 of 16 (81%) females in the FSO group, 9 of 14 (64%) in the OR group, and 11 of 12 (92%) in the control group. There were no fertile males in the FSO/OR group. In the FSO group, eight of eight males induced pregnancy in at least one female; in the OR group, six of seven (86%) males were fertile as were all six males in the control group. No differences in litter size or fetal weight were observed between fertile females in various groups.  相似文献   
34.
35.
Neonatal septicaemia (NNS) is a major cause of neonatal morbidity and mortality. Neonatal septicaemia was studied to determine the incidence, common bacterial aetiology and antibiotic susceptibility in Qatif Central Hospital, Saudi Arabia. Of 1,797 babies admitted into the unit over a 3 year period, 144 (8.0%) had documented neonatal septicaemia consisting of 94 (65%) late onset and 50 (35%) early onset septicaemia. The incidence was 8.2/1000 of the total live births in the hospital.

Gram negative bacteria were encountered in 66.2%, gram positive bacteria in 29.2% and Candida albicans in 4.4% of the case. Klebsiella spp., E. coli, and Pseudomonas accounted for 81.8 % of the gram negative while Staphylococcus epidermidis, Staphylococcus aureus and group B Beta haemolytic Streptococcus accounted for 73.9% of the gram positive bacteria.

Most of Gram negative bacteria had a high sensitivity to Aminoglycosides and third generation Cephalosporins. Coagulase negative staphylococci were frequently resistant to most antibiotics but always sensitive to Vancomycin. The overall mortality rate was 18.7%.  相似文献   
36.
A new technique in the treatment of stress urinary incontinence utilizes a sling fashioned from a rectangular island of buried vaginal epithelium. We developed a model to study the natural history of vaginal wall covered by an epithelial flap in 12 rabbits sacrificed at intervals to 26 weeks. Histopathologic examination demonstrated an immediate acute inflammatory reaction. This early response was followed by formation of an epithelial lining of the potential space overlying the buried vaginal tissue. Acute inflammatory cells continued to enter this lumen until week 20, when granulomas were first detected. Histopathologic examination at twenty-six weeks showed stratified squamous epithelium lining the lumen. No deleterious inflammatory sequelae were detected, and no dysplastic or malignant changes were identified. These results suggest that buried vaginal epithelium is a safe (short term) tissue alternative for sling creation.  相似文献   
37.
38.
39.
40.
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