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   380508篇
  免费   24274篇
  国内免费   2818篇
耳鼻咽喉   5185篇
儿科学   8227篇
妇产科学   10083篇
基础医学   53239篇
口腔科学   11799篇
临床医学   30175篇
内科学   78697篇
皮肤病学   8765篇
神经病学   27270篇
特种医学   13960篇
外国民族医学   82篇
外科学   60852篇
综合类   9960篇
现状与发展   1篇
一般理论   64篇
预防医学   17510篇
眼科学   9441篇
药学   31074篇
  1篇
中国医学   2194篇
肿瘤学   29021篇
  2021年   2643篇
  2019年   2742篇
  2018年   4578篇
  2017年   3484篇
  2016年   3570篇
  2015年   4056篇
  2014年   5759篇
  2013年   7444篇
  2012年   10119篇
  2011年   10294篇
  2010年   6227篇
  2009年   5883篇
  2008年   9510篇
  2007年   10338篇
  2006年   10262篇
  2005年   9327篇
  2004年   8841篇
  2003年   8557篇
  2002年   8247篇
  2001年   28281篇
  2000年   28822篇
  1999年   23709篇
  1998年   5194篇
  1997年   4262篇
  1996年   3841篇
  1995年   3484篇
  1994年   3112篇
  1993年   2851篇
  1992年   16073篇
  1991年   14832篇
  1990年   14175篇
  1989年   13981篇
  1988年   12594篇
  1987年   12072篇
  1986年   11111篇
  1985年   10335篇
  1984年   6926篇
  1983年   5613篇
  1982年   2724篇
  1979年   5485篇
  1978年   3354篇
  1977年   2979篇
  1975年   2649篇
  1974年   3071篇
  1973年   2870篇
  1972年   2835篇
  1971年   2776篇
  1970年   2517篇
  1969年   2548篇
  1968年   2255篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
In this new radioimmunoassay system for determination of amatoxins in urine and plasma, a novel chemical approach is used for antigen and 125I-tracer production, based on a detoxified alpha-amanitin derivative (aldoamanitin). Total assay time, including data processing, is less than 100 min. The lowest detectable concentration is 1 microgram/L for urine, 0.1 microgram/L for plasma. In the clinically significant range, within-run CVs are less than 8%. This new 125I-based assay is a significant improvement over existing 3H technology in terms of speed, precision, and freedom from interference.  相似文献   
92.
93.
Bilateral cervical lymph node dissection was performed in 71 cases of papillary thyroid carcinoma, considered to be relatively early cases because of mobility, irrespective of the size of tumor or presence of node enlargement. Of these, 33 cases received additional node dissection of the anterosuperior mediastinum through longitudinal sternotomy. The number of lymph nodes examined per subject averaged 89.9, the number of metastatic nodes was 13.8, and metastasis was noted in 88.7% of all cases. Lymph node metastasis tended to be more frequent on the affected side, but was simultaneously scattered over the whole cervical area. As to sites, metastasis of paratracheal nodes on the affected side occurred at a frequency of 66.2%, inferior and superior jugular nodes at 62.0% and 59.0% respectively, pretracheal nodes at 50.7%, and tracheoesophageal nodes at 47.9%. The high incidence of para- and pretracheal nodes suggests that the lymph flow in this direction is of great importance in metastasis. In fact, lymph nodes in the mediastinum, which were directly continuous with these nodes, showed as high as 39.4% metastasis in cases of anterosuperior mediastinal extirpation. This extensive node dissection is considered to be very preferable as at least the agony of survival with carcinoma can be lessened.  相似文献   
94.
95.
96.
Liver histopathology in clinical Reye syndrome   总被引:1,自引:0,他引:1  
Analysis of the liver histopathology in 19 children with clinical Reye syndrome (RS) revealed that nine had diffuse panlobular steatosis, one giant cell hepatitis, one a mild choledochal cyst with inflammation, two multifocal spotty necrosis and one multiple centrilobular necrosis, the other five being normal. Four of the nine patients with diffuse panlobular steatosis showed microvesicular fatty droplets with central nuclei, which was consistent with findings characteristic for typical RS. Two cases showed a periportal area dominant macrovesicular fatty change, which was highly suggestive for metabolic disorder. In the other three cases, the findings were so variable in terms of the size of lipid droplets and the location of nuclei in hepatocytes that it was not possible to provide any clue for defining a diagnosis. These results confirmed the legitimacy of the diagnostic criteria of RS which included a liver biopsy as one of the mandatory conditions. They also indicated that RS-mimicking clinical pictures can be presented by miscellaneous conditions in which liver histology does not necessarily helpful in establishing definite diagnosis.  相似文献   
97.
Our experience with full-length ureteric splintage is reviewed with a note on the technique and its outcome. It is safe, effective and simple, easy to teach and easy to learn. It is recommended as the operation of choice in bilharzial ureteropathy.  相似文献   
98.
Radiation-induced meningioma. 3 cases   总被引:1,自引:0,他引:1  
During the same year (1984), we have seen 3 cases of meningiomas following radiation therapy of the brain for previously diagnosed tumors. A causal relationship between irradiation and meningioma has been postulated. Nevertheless, the coincidental occurrence in same patient of two different histological lesions is possible. The neoplasms developed after irradiation are of mesenchymal origin; they are fibrosarcomas, osteogenic sarcomas and meningiomas.  相似文献   
99.
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