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   379155篇
  免费   24164篇
  国内免费   2808篇
耳鼻咽喉   5183篇
儿科学   8198篇
妇产科学   10078篇
基础医学   53098篇
口腔科学   11778篇
临床医学   30098篇
内科学   78350篇
皮肤病学   8543篇
神经病学   27196篇
特种医学   13952篇
外国民族医学   82篇
外科学   60609篇
综合类   9953篇
现状与发展   1篇
一般理论   64篇
预防医学   17442篇
眼科学   9437篇
药学   30969篇
  1篇
中国医学   2193篇
肿瘤学   28902篇
  2021年   2613篇
  2019年   2718篇
  2018年   4517篇
  2017年   3428篇
  2016年   3517篇
  2015年   4018篇
  2014年   5694篇
  2013年   7378篇
  2012年   10022篇
  2011年   10197篇
  2010年   6189篇
  2009年   5845篇
  2008年   9453篇
  2007年   10283篇
  2006年   10205篇
  2005年   9262篇
  2004年   8768篇
  2003年   8514篇
  2002年   8185篇
  2001年   28238篇
  2000年   28779篇
  1999年   23659篇
  1998年   5162篇
  1997年   4247篇
  1996年   3829篇
  1995年   3479篇
  1994年   3108篇
  1993年   2845篇
  1992年   16059篇
  1991年   14819篇
  1990年   14163篇
  1989年   13963篇
  1988年   12587篇
  1987年   12066篇
  1986年   11111篇
  1985年   10332篇
  1984年   6925篇
  1983年   5607篇
  1982年   2722篇
  1979年   5481篇
  1978年   3349篇
  1977年   2974篇
  1975年   2642篇
  1974年   3067篇
  1973年   2871篇
  1972年   2831篇
  1971年   2776篇
  1970年   2516篇
  1969年   2544篇
  1968年   2253篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
131.
132.
133.
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   
134.
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   
135.
136.
Delta hepatitis virus infection in China   总被引:1,自引:0,他引:1  
To assess the prevalence, epidemiological features and prognostic implications of hepatitis D (Delta) in Sichuan Province, The People's Republic of China, 649 sera (515 from HBsAg positive patients and 134 from HBsAg negative subjects) were tested by radioimmunoassay (RIA) for antibody to the hepatitis D virus (anti-HD). Forty-seven sera (7.2%) showed some degree of reactivity. Serial dilutions of these sera indicated that prozoning was not responsible for the equivocal results. Thirty-four of the 47 sera were submitted under code to a second laboratory for independent analysis. According to those results anti-HD antibodies were detected in four of these sera. The overall prevalence of anti-HD in the HBsAg positive patients therefore was 0.8% (4/515). On the basis of clinical, biochemical and histological data 427 HBsAg positive sera were further divided into acute Type B hepatitis, chronic Type B hepatitis, healthy carrier state and hepatocellular carcinoma (HCC) subgroups. Two of 65 (3.1%) anti-HD positive sera belonged to the acute Type B hepatitis group; one of 104 (0.9%), the chronic Type B hepatitis group and one of 246 (0.4%), the healthy carrier group. No antibody was detected in sera from 12 HBsAg positive HCC patients. All HBsAg negative patients were negative for anti-HD antibody. The results of this study indicate that despite a high prevalence of hepatitis B virus infection, positive serology for delta virus is uncommon in Sichuan Province, The People's Republic of China.  相似文献   
137.
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   
138.
139.
140.
Kindling of the visual cortex in cats: comparison with amygdaloid kindling   总被引:3,自引:0,他引:3  
Kindling of the primary visual cortex (VC) was compared with that of the amygdala in cats. VC kindling was basically similar to kindling of the amygdala in that daily electrical stimulation can lead to the development of a generalized convulsion in most subjects, a growth of afterdischarges in their configuration and duration, and a reduction of the afterdischarge threshold. The kindling response of the VC differed from that of the amygdala in a number of respects, i.e., a high afterdischarge threshold, a different pattern of behavioral seizure development, an abrupt growth of electroclinical seizures coincident with the onset of a generalized convulsion, an intersubject variability in seizure susceptibility, and a marked seizure instability. In VC kindling the afterdischarge propagation into the amygdala was not observed until the generalized convulsion developed, and the early involvement of afterdischarge was seen in the pulvinar, lateral geniculate body, and superior colliculus. These data suggest that a neural mechanism different from amygdaloid kindling may participate in VC kindling, and that the subcortical structures of the visual system are involved in the preferential pathway for a seizure generalization from the VC.  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