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   1709238篇
  免费   124609篇
  国内免费   3822篇
耳鼻咽喉   21834篇
儿科学   56081篇
妇产科学   46633篇
基础医学   242913篇
口腔科学   48951篇
临床医学   153309篇
内科学   335863篇
皮肤病学   39016篇
神经病学   132583篇
特种医学   64163篇
外国民族医学   243篇
外科学   258539篇
综合类   39249篇
现状与发展   5篇
一般理论   548篇
预防医学   126196篇
眼科学   40492篇
药学   124468篇
  7篇
中国医学   4488篇
肿瘤学   102088篇
  2021年   13088篇
  2019年   13817篇
  2018年   20297篇
  2017年   15433篇
  2016年   16872篇
  2015年   19307篇
  2014年   26654篇
  2013年   38660篇
  2012年   53678篇
  2011年   56427篇
  2010年   33362篇
  2009年   31158篇
  2008年   52421篇
  2007年   55731篇
  2006年   56205篇
  2005年   53452篇
  2004年   51616篇
  2003年   48975篇
  2002年   47142篇
  2001年   91909篇
  2000年   93725篇
  1999年   77095篇
  1998年   19862篇
  1997年   17399篇
  1996年   17513篇
  1995年   16857篇
  1994年   15355篇
  1993年   14156篇
  1992年   57483篇
  1991年   55379篇
  1990年   53062篇
  1989年   50838篇
  1988年   46229篇
  1987年   44998篇
  1986年   42303篇
  1985年   40075篇
  1984年   29433篇
  1983年   24966篇
  1982年   13962篇
  1979年   25562篇
  1978年   17614篇
  1977年   14932篇
  1976年   13910篇
  1975年   14596篇
  1974年   17641篇
  1973年   16970篇
  1972年   15700篇
  1971年   14475篇
  1970年   13445篇
  1969年   12536篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
BACKGROUND: We prospectively evaluated the usefulness of IgA tissue transglutaminase antibodies (IgA tTG) in the initial diagnosis of celiac disease (CD) and compared its diagnostic potential with that of IgA anti-endomysial antibodies (IgA EMA) and anti-IgA and IgG gliadin antibodies (AGA and AGG, respectively). METHODS: Sera of 23 untreated children fulfilling the revised ESPGHAN criteria for diagnosis of CD (Group I; mean age 10.8 y); 19 disease controls (Group II; mean age 8.5 y) presenting with chronic diarrhea, short stature or both; and 22 healthy children (Group III; mean age 8.8 y) were studied. These were tested in a blinded manner for AGA, AGG, IgA tTG (guinea pig as antigen) and IgA EMA. RESULTS: In Group I, IgA EMA was positive in 19, IgA tTG in 17, AGA in 14 and AGG in 17 patients. In Group II, these tests were positive in 1, 0, 2 and 14 patients, respectively and in Group III, in 0, 0, 0 and 1 child, respectively. Analyzing data from Group I and II, IgA EMA, IgA tTG, AGA and AGG had sensitivity rates of 83%, 74%, 61% and 74%, respectively; the specificity rates were 95%, 100%, 89% and 26%; positive predictive values were 95%, 100%, 88% and 55% and negative predictive values were 82%, 74%, 65% and 45%, respectively. CONCLUSION: IgA tTG is useful for the diagnosis of CD, with sensitivity and specificity rates comparable to those of EMA and this test is well suited for use in tropical countries like India.  相似文献   
83.
84.
85.
86.
OBJECTIVES: Pseudotumour cerebri has been previously recognized as a neurological side effect of combined oral contraceptives but has not been diagnosed with a delay of 3 years after initiation of combined oral contraceptives. CASE REPORT: A 19-year-old obese woman developed visual impairment and headache, 4 months after starting combined oral contraceptives. Three years later symptoms deteriorated and she presented with prominent tendon-jerks and congested optical-discs. Normal CSF drained with high pressure from the spinal tap. Pseudotumour cerebri was diagnosed. Headache and visual impairment resolved within 3 weeks after discontinuation of combined oral contraceptives. CONCLUSIONS: Combined oral contraceptives-induced pseudotumour cerebri may remain undetected for years. Young, obese women with visual impairment and headache under combined oral contraceptives should undergo immediate neurological and ophthalmological investigation.  相似文献   
87.
A 41-year-old Chinese lady had a Gr?fenberg ring in utero for 15 years. During that period of time, she had one normal vaginal delivery a year after insertion, followed by an ectopic pregnancy 12 years later. We discuss the possible mechanism of action of the Gr?fenberg ring and sequelae of its prolonged presence in the uterus.  相似文献   
88.
Postpartum fatigue is a normal condition that most women experience. Breastfeeding is often associated in women's minds as contributing to the feeling of overall perceived fatigue, and many women indicate that they have ceased breastfeeding because of fatigue. However, the relationship between feeding choice and perceived fatigue has never been established. Two hundred and fifty-three women participated in a study examining whether perceived fatigue differed for bottle-feeding and breastfeeding women at 3 different times during the postpartum period (2-4 days, 6 weeks, and 12 weeks postpartum). Results showed no significant differences for these 2 groups, suggesting that perceived fatigue during the postpartum period is not dependent on feeding choice. Additional analyses examining other variables with a potential effect were nonsignificant. Because perceived physical fatigue does not appear to be dependent on feeding choice, women should be prepared for the feeling of perceived fatigue during the postpartum period while at the same time be reassured that feeding choice is not correlated.  相似文献   
89.
90.
PURPOSE: Concern over stigma as a consequence of genetic testing has grown in response to the recent increase in genetic research and testing resulting from the Human Genome Project. However, whether a genetic or hereditary basis necessarily confers a stigma to a condition remains unexamined. METHODS: We performed a qualitative interview study with 86 individuals with one of four conditions: deafness or hearing loss, breast cancer, sickle cell disease, and cystic fibrosis. The first two groups were divided approximately between people who ascribed their conditions to a genetic or hereditary cause and those who did not. RESULTS: Respondents interpreted genetic or hereditary causes and nongenetic causes in a variety of ways. Subjects with breast cancer reported the most consistently negative interpretation of genetic cause. This response concerned future ill health, not an enduring sense of stigma. Deaf and hard of hearing subjects provided the most consistently positive comments about a genetic or hereditary basis to their condition, casting familial hearing loss as a vital component of group and individual identity. Respondents with sickle cell disease and cystic fibrosis offered similar and positive interpretations of the genetic cause of their condition insofar as it meant their conditions were not contagious. CONCLUSIONS: Although some subjects report feeling stigmatized as a result of their condition, this stigmatization is not uniformly associated with the condition's cause, genetic or otherwise. Instead, stigma emerges from a variety of sources in the context of the lived experience of a particular condition.  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