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   3476105篇
  免费   271753篇
  国内免费   6302篇
耳鼻咽喉   50630篇
儿科学   111944篇
妇产科学   96006篇
基础医学   489721篇
口腔科学   102899篇
临床医学   314464篇
内科学   670708篇
皮肤病学   73352篇
神经病学   289829篇
特种医学   139270篇
外国民族医学   1260篇
外科学   523561篇
综合类   83747篇
现状与发展   4篇
一般理论   1445篇
预防医学   276953篇
眼科学   82962篇
药学   259316篇
  7篇
中国医学   6505篇
肿瘤学   179577篇
  2018年   35500篇
  2016年   31005篇
  2015年   35404篇
  2014年   49327篇
  2013年   75192篇
  2012年   101664篇
  2011年   106979篇
  2010年   63187篇
  2009年   59787篇
  2008年   101850篇
  2007年   108141篇
  2006年   109342篇
  2005年   106877篇
  2004年   103572篇
  2003年   99764篇
  2002年   98308篇
  2001年   156477篇
  2000年   162002篇
  1999年   137597篇
  1998年   39971篇
  1997年   36167篇
  1996年   35545篇
  1995年   34367篇
  1994年   32321篇
  1993年   30198篇
  1992年   110837篇
  1991年   107154篇
  1990年   104004篇
  1989年   100401篇
  1988年   93330篇
  1987年   92076篇
  1986年   87431篇
  1985年   83818篇
  1984年   63583篇
  1983年   54561篇
  1982年   32980篇
  1981年   29490篇
  1980年   27793篇
  1979年   60536篇
  1978年   42644篇
  1977年   35953篇
  1976年   33725篇
  1975年   35837篇
  1974年   44124篇
  1973年   42087篇
  1972年   39327篇
  1971年   36594篇
  1970年   34170篇
  1969年   31887篇
  1968年   29173篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
There is a recognized need for the early detection of gestational diabetes, and a single blood test, if reliable, would be advantageous. Because serum albumin and total protein are glycosylated and have short life spans, we investigated the usefulness of glycosylated albumin and glycosylated protein in the detection of gestational diabetes. We studied five groups, each with 20 subjects: nonpregnant and pregnant controls, nonpregnant and pregnant insulin-dependent diabetic (IDDM) patients, and gestational diabetic patients. All patients with no history of diabetes had an oral glucose tolerance test to define their carbohydrate status. Our results showed that percent glycosylated albumin and percent glycosylated protein were significantly elevated in both groups of IDDM patients compared with the other groups. However, gestational diabetic patients had glycosylated albumin and glycosylated protein values similar to those of both control groups. Both glycosylated albumin and glycosylated protein correlated well with HbA1c determinations. Thus, glycosylated albumin and glycosylated protein may be a good index of glycemic control, but they are of little value in the diagnosis of gestational diabetes because of a lack of sensitivity: 8 and 3% for glycosylated albumin and glycosylated protein, respectively.  相似文献   
993.
Secretory antibodies protect mucosal surfaces against transmission of many viruses. Human T-lymphotropic Virus, Type I (HTLV-I) is transmitted via blood products and via sexual contact across mucosal surfaces. We investigated the presence of HTLV-I-specific antibodies in whole saliva samples from 10 seronegative and 28 seropositive volunteers from a hospital in southern Japan. Antibodies directed to HTLV-I antigens were found in the salivas from 22 of 28 (79%) of the seropositive subjects. None of the seronegative individuals showed evidence of salivary antibodies. Antibodies directed to the envelope antigens of the virus were found in 21 of 22 positive saliva samples. Secretory antibodies may be important in preventing mucosal transmission.  相似文献   
994.
995.
996.
In order to ascertain the adequacy of ovarian stimulation protocols with a type of follicular puncture, 126 women undergoing in vitro fertilization received either combination clomiphene/hMG or hMG alone according to a randomized test protocol. Within both groups patients for whom a pelvic examination was required had laparoscopies, while others had transvaginal ultrasonically guided punctures as far as possible. Clomiphene/hMG was more efficient than hMG alone as assessed from the cleavage rate (68% vs. 54%; p less than 0.01) and the pregnancy per attempt rate (16% vs. 5%; p less than 0.05). Laparoscopic punctures were more efficient than ultrasonically guided punctures (mean number of recovered oocytes: 4.8 +/- 2.6 vs. 3 +/- 2.5; p less than 0.001), but slightly better results were achieved by this latter method in ongoing pregnancy per puncture rate (18% vs. 8%; NS). With ultrasonically guided punctures, stimulation by clomiphene/hMG allowed better oocyte recoveries (3.8 +/- 2.5 vs. 2.3 +/- 1.9, p less than 0.05). Such results constitute an argument for preferential use of the clomiphene/hMG stimulation protocol with ultrasonically guided punctures.  相似文献   
997.
998.
999.
1000.
J D Carroll  W H Gaasch 《Herz》1981,6(3):131-137
Following surgical correction of chronic aortic regurgitation, left ventricular (LV) volume falls to normal or near normal in most patients; this change generally occurs within the first week after surgery. During the ensuing six months, a significant regression of LV hypertrophy occurs, but most patients do not achieve a normal LV mass. The systolic ejection fraction may increase while the LV end-diastolic pressure almost uniformly falls to normal. Postoperative studies of LV volume mass and function should be aimed at identifying those patients which do not undergo these favorable changes so that medical therapy can be directed at this high risk group.  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