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   1634634篇
  免费   133182篇
  国内免费   2721篇
耳鼻咽喉   22071篇
儿科学   55027篇
妇产科学   46814篇
基础医学   231604篇
口腔科学   48138篇
临床医学   143371篇
内科学   320540篇
皮肤病学   35010篇
神经病学   132053篇
特种医学   65647篇
外国民族医学   474篇
外科学   248842篇
综合类   40767篇
现状与发展   3篇
一般理论   558篇
预防医学   124572篇
眼科学   37737篇
药学   124648篇
  4篇
中国医学   3267篇
肿瘤学   89390篇
  2018年   15990篇
  2016年   14085篇
  2015年   16190篇
  2014年   22378篇
  2013年   33292篇
  2012年   45260篇
  2011年   47376篇
  2010年   27922篇
  2009年   26525篇
  2008年   44740篇
  2007年   46967篇
  2006年   47601篇
  2005年   46068篇
  2004年   45382篇
  2003年   43261篇
  2002年   42195篇
  2001年   76165篇
  2000年   78752篇
  1999年   66756篇
  1998年   17928篇
  1997年   16491篇
  1996年   16475篇
  1995年   16159篇
  1994年   15183篇
  1993年   14316篇
  1992年   55646篇
  1991年   53978篇
  1990年   52773篇
  1989年   51036篇
  1988年   47385篇
  1987年   46713篇
  1986年   44414篇
  1985年   42985篇
  1984年   32140篇
  1983年   27635篇
  1982年   16190篇
  1981年   14493篇
  1980年   13608篇
  1979年   30526篇
  1978年   21121篇
  1977年   17819篇
  1976年   16736篇
  1975年   17612篇
  1974年   21523篇
  1973年   20714篇
  1972年   18884篇
  1971年   17805篇
  1970年   16320篇
  1969年   15281篇
  1968年   13979篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
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   
82.
83.
A 19-item survey instrument was designed and mailed by the Infectious Diseases Society of America to its membership to determine the media preferred by infectious diseases physicians for continuing medical education on general topics and on antimicrobial resistance. The objective of the survey was to offer the developers of educational programs knowledge on which to base more-effective ways to deliver educational materials to physicians in this specialty.  相似文献   
84.
OBJECTIVE: To assess the effects of adding combined estradiol/norethisterone acetate therapy (CENT) to goserelin acetate treatment (GA) of dysfunctional uterine bleeding (DUB) in perimenopausal women. METHODS: In a randomized, placebo-controlled, double-blind trial followed by an open follow-up study, 31 perimenopausal women with DUB were recruited from gynecological outpatient departments of two Dutch hospitals and randomized for treatment with either GA/placebo or GA/CENT for 6 months followed by 18 months of GA/CENT for all. The main outcome measures were abdominal pain, number of bleeding days, double-layer endometrial thickness (DET), Greene climacteric score (GCS), visual analog scale for well-being, bone mineral density (BMD) and mammographic density (BI-RAD score). RESULTS: Abdominal pain, number of bleeding days and DET decreased in both groups, the between-group difference in decrease not being statistically significant. GCS initially showed significant improvement in the GA/CENT group. BMD decreased significantly in the GA/placebo group (-4.1%) compared with the GA/CENT group (-0.3%). Another 18 months of GA/CENT did not result in a lasting difference in BMD between groups. BI-RAD scores did not differ significantly between or within the two groups. CONCLUSIONS: Adding CENT to GA treatment for DUB in perimenopausal women initially prevented BMD loss and improved climacteric complaints, while having no negative impact on vaginal bleeding, abdominal pain or BI-RAD scores. However, prolonged treatment did not result in a lasting prevention of bone loss.  相似文献   
85.
86.
87.
88.
OBJECTIVES: To identify and describe current women's thoughts about the menopause, hormone treatment (HT) and perceptions about breast cancer. METHODS: Between December 2004 and January 2005, 4201 postmenopausal women in seven European countries were interviewed via a standardized computer-aided telephone interview protocol. RESULTS: Almost all women reported to have experienced climacteric symptoms, and 63% of the women rated them as being severe. Only 52% of women were aware of the benefits of HT for relief of climacteric symptoms. Although 84% felt that severe symptoms should be treated, only 40% had used HT at some point in time. Thirty-four percent of the women preferring treatment with natural products did so because of the risk of breast cancer associated with HT. HT was recognized by 59% of the women as one of the most important contributors to an increased breast cancer risk. Most women received their information about HT and breast cancer risk from the media. CONCLUSIONS: This European survey reveals that the majority of women experience climacteric symptoms but that their decision whether or not to use HT is highly dependent on their concern about breast cancer risk. An increase in knowledge of the benefits and risks of HT is required for women to make appropriate decisions about hormone use.  相似文献   
89.
Bleeding disorders encountered during administration of hormone replacement therapy (HRT) are reviewed. The incidence of bleeding disorders is dependent on the phase of HRT and the age of the patient. In the diagnosis of these bleedings transvaginal sonography and minihysteroscopy are very important methods. Endometrial thickness can be monitored exactly by transvaginal sonography. Outpatient minihysteroscopy without anesthesia results in higher compliance to HRT after the procedure. In hormonal treatment of bleeding disorders during HRT, the sonographically supported progestogen test is very useful and can reduce endometrium thickness. Operative treatments include myoma and polyp resection as well as endometrial ablation. By these methods a high rate of bleeding-free HRT can be reached. The problem of endometrial cancer during HRT is discussed on the basis of new literature and critical statements. The review shows the importance of individual diagnostic and treatment schedules for bleeding disorders during HRT.  相似文献   
90.
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