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   405228篇
  免费   21991篇
  国内免费   2863篇
耳鼻咽喉   5411篇
儿科学   8790篇
妇产科学   10615篇
基础医学   56704篇
口腔科学   12123篇
临床医学   31940篇
内科学   83981篇
皮肤病学   9129篇
神经病学   29673篇
特种医学   14375篇
外国民族医学   82篇
外科学   62604篇
综合类   10051篇
现状与发展   1篇
一般理论   75篇
预防医学   19117篇
眼科学   9874篇
药学   32486篇
  10篇
中国医学   2258篇
肿瘤学   30783篇
  2021年   3649篇
  2020年   2307篇
  2019年   3612篇
  2018年   5318篇
  2017年   4112篇
  2016年   4324篇
  2015年   4782篇
  2014年   6721篇
  2013年   8537篇
  2012年   11768篇
  2011年   12018篇
  2010年   7190篇
  2009年   6749篇
  2008年   10851篇
  2007年   11717篇
  2006年   11523篇
  2005年   10490篇
  2004年   9810篇
  2003年   9472篇
  2002年   8990篇
  2001年   28295篇
  2000年   28818篇
  1999年   23726篇
  1998年   5304篇
  1997年   4355篇
  1996年   3912篇
  1995年   3553篇
  1994年   3150篇
  1993年   2890篇
  1992年   16079篇
  1991年   14832篇
  1990年   14173篇
  1989年   13981篇
  1988年   12596篇
  1987年   12077篇
  1986年   11118篇
  1985年   10334篇
  1984年   6920篇
  1983年   5613篇
  1982年   2731篇
  1979年   5479篇
  1978年   3354篇
  1977年   2977篇
  1975年   2649篇
  1974年   3070篇
  1973年   2867篇
  1972年   2832篇
  1971年   2782篇
  1970年   2513篇
  1969年   2547篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Endorectal ultrasonography was evaluated in the diagnosis of prostatic cancer, using a high frequency (7,5 MHz) mechanical sectorial endocavitary probe developed by the authors. In a first study, sonograms from a series of 213 patients were interpreted retrospectively without any knowledge of the clinical or pathological findings. Specificity for the diagnosis of cancer (true non-malignant/total non-malignant) reached 79%, whereas sensitivity (true malignant/total malignant) was only 48%. Pathology was available for 132 patients. In a second study, 72 ultrasonically guided biopsies were performed in patients presenting either with a suspicious induration without nodule (47 cases) or a palpable nodule (25 cases). Good quality biopsy specimens, and absence of complication were remarkable. However, the 10 cancer cases (5 diagnosed in each group) did not show sonographically clearly different from the remaining adenoma, prostatitis and normal cases.  相似文献   
92.
Fifty-four patients with 65 superficial malignant lesions were treated by local hyperthermia combined with radiation therapy at the National Cancer Center Hospital, Tokyo. Hyperthermia was delivered with an Aloka Model HMS-020 (2450 MHz) or with a horn-type applicator of BSD-1000 (80-90 MHz). Relatively small tumours, those less than 4 cm in thickness, were treated by using 2450 MHz while 80-90 MHz delivered through the horn-type applicator was used for tumours exceeding 5 cm in thickness. The radiation dose was 4 Gy twice a week or 2 Gy five times a week, the total dose being 40-60 Gy. A total of six to 10 hyperthermia treatments ranging from 40 to 60 min each, with the tumour heated to more than 42.5 degrees C, were given twice a week within 1 h following radiation therapy. Complete response was achieved in 16 of the 30 patients (55 per cent) treated with the 2450 MHz microwave, and partial response in seven others (23 per cent). Tumours treated with the BSD-1000 achieved complete response in 10 out of 33 patients (30 per cent) and partial response in nine others (27 per cent). In five out of nine patients classified as partial responders, however, complete disappearance of tumour cells was noted by post-treatment histological examination. Complete plus partial response rates were thus essentially the same with the Aloka HMS-020 and the BSD-1000, though the rate of complete response was apparently higher with the Aloka unit, probably because it was used on smaller tumours.  相似文献   
93.
94.
The growth of Plasmodium falciparum in erythrocytes from individuals with beta zero-thalassaemia or haemoglobin (Hb) E, or both, was assessed in vitro. A significant inhibitory effect on the growth of the parasite was found only with erythrocytes from individuals doubly heterozygous for beta zeros-thalassaemia and HbE. The inhibitory effect was particularly marked with erythrocytes from splenectomized beta zeros-thalassaemia/HbE patients. The protective effect was related to HbF, Hb levels and shape abnormalities of the variant erythrocytes.  相似文献   
95.
96.
There have only been a few studies on the role of mineral intake in tooth loss. We investigated the association between mineral intake and the prevalence of tooth loss in Japan. We used the baseline data on 1002 pregnant women who were enrolled in the Osaka Maternal and Child Health Study between November 2001 and March 2003. Tooth loss was defined as the previous extraction of one or more teeth. Nutrient intake was assessed by a validated diet history questionnaire. Prevalence odds ratios and confidence intervals were estimated by applying a multiple logistic regression model. The adjusted odds ratio upon comparison of the highest quartile with the lowest quartile of magnesium intake was 0.64 (95% confidence interval, 0.42-0.99), showing a tendency for an inverse dose-response relationship (p for linear trend = 0.05). There were no associations between the level of consumption of calcium, phosphate, iron, zinc, or copper and tooth loss. The present findings suggest that intake of magnesium is related to reduced prevalence of tooth loss among young Japanese women.  相似文献   
97.
98.
99.
We report a 24-year-old woman with an intramedullary conus ependymoma associated with holocord syringohydromyelia and syringobulbia. The tumor was removed and surgery for decompression of the syringohydromyelia was not considered at the first operation. In the follow-up examinations, MRI showed significant and steady improvement of syringohydromyelia. Symptoms associated with syringohydromyelia also disappeared. The cause of syringohydromyelia accompanying intradural spinal cord tumors appears to be either direct blockade of the central canal or secondary interruption of the central canal flow by compression of the perimedullary cerebrospinal fluid flow. As removal of the mass often corrects both these likely causes of the syringohydromyelia, no additional treatment for the drainage of the hydromyelia cavity syrinx is usually necessary.  相似文献   
100.
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