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   1584篇
  免费   71篇
  国内免费   30篇
耳鼻咽喉   15篇
儿科学   52篇
妇产科学   9篇
基础医学   251篇
口腔科学   34篇
临床医学   105篇
内科学   293篇
皮肤病学   4篇
神经病学   116篇
特种医学   336篇
外科学   87篇
综合类   32篇
预防医学   71篇
眼科学   8篇
药学   103篇
中国医学   6篇
肿瘤学   163篇
  2022年   4篇
  2021年   17篇
  2020年   10篇
  2019年   10篇
  2018年   15篇
  2017年   7篇
  2016年   12篇
  2015年   20篇
  2014年   23篇
  2013年   22篇
  2012年   38篇
  2011年   61篇
  2010年   22篇
  2009年   35篇
  2008年   64篇
  2007年   73篇
  2006年   70篇
  2005年   80篇
  2004年   81篇
  2003年   50篇
  2002年   67篇
  2001年   57篇
  2000年   31篇
  1999年   38篇
  1998年   59篇
  1997年   49篇
  1996年   71篇
  1995年   60篇
  1994年   36篇
  1993年   43篇
  1992年   24篇
  1991年   29篇
  1990年   30篇
  1989年   40篇
  1988年   42篇
  1987年   30篇
  1986年   28篇
  1985年   39篇
  1984年   24篇
  1983年   24篇
  1982年   27篇
  1981年   25篇
  1980年   14篇
  1979年   7篇
  1978年   8篇
  1977年   27篇
  1976年   19篇
  1975年   15篇
  1969年   2篇
  1875年   2篇
排序方式: 共有1685条查询结果,搜索用时 15 毫秒
1.
Fifty-one patients who had persistent or recurrent neck disease from nasopharyngeal carcinoma after radiotherapy underwent radical neck dissection. The follow-up period ranged from 0.5 to 9 years (median: 2 years). Multiple cervical lymph node involvement was present in 51% of the patients (26 of 51). Malignant cells were detected in 88% of the resected specimens (45 of 51). The clinical sign of fixation of lymph node is the only factor that affects the successful control of neck disease (p = 0.04). Extracapsular extension of the nodal disease was present, and 35% of the lymph nodes were adherent to surrounding structures at operation (18 of 51). There was one hospital mortality and the overall morbidity was minimal. The actuarial survival at 5 years was 38%, and the probability of control of neck disease was 66%. Radical neck dissection is effective in controlling post-irradiation cervical metastasis from nasopharyngeal carcinoma.  相似文献   
2.
3.
4.
We have examined the hypothesis that a variable number of tandem repeats in the third cytoplasmic loop of the dopamine D4 receptor influences clinical response to clozapine using a sample of 189 schizophrenic patients. Alleles of the 48-bp repeat, which range from two to ten copies in the normal human population, were analysed by the polymerase chain reaction using genomic DNA as template. Association between these alleles and response to clozapine was tested using the difference in pre-and post-treatment GAS scores as a measure of response. We found no statistically significant variation between genotypic groups and response by analysis of variance. We conclude that the variation of the number of 48-bp repeats alone does not determine response to clozapine. Larger studies are underway to determine if there is a more subtle relationship with sequence variation within the repeats or at other polymorphic sites within the gene that may provide evidence for a component of clozapine's action being at D4 receptors. © 1995 Wiley-Liss, Inc.  相似文献   
5.
The early results of brachytherapy for persistent and recurrent nasopharyngeal carcinoma in 30 patients is presented. Fifteen patients were treated by intracavitary caesium, 12 patients were treated by interstitial gold grain implant using the split-palate approach and three patients were treated by both intracavitary caesium and interstitial gold grain implant for the first and second relapse in the nasopharynx, respectively. The overall tumour control rate for intracavitary caesium was 5/18 (28%) with median follow-up of 25.2 months, and for interstitial gold grain implant it was 9/14 (64%) with median follow-up of 16.5 months. Interstitial gold grain implantation appears to be effective in the treatment of persistent and recurrent nasopharyngeal carcinoma.  相似文献   
6.
7.
8.
9.
We investigated the age at onset distributions of schizophrenia in men and women and the relationship of age at onset and sex to the familial rates of schizophrenia and manic-depression in data from a Swedish family study of 270 schizophrenic probands. On the logarithmic scale, the age at onset distribution of schizophrenia in both male and female relatives was bimodal, suggesting that broadly defined schizophrenia may be a mixture of 2 (probably related) disorders. The risk of schizophrenia in relatives decreased as a function of the age at onset of the proband, irrespective of the sex of the proband or relative. In contrast, the risk of manic-depression was significantly higher in relatives of female probands with an age at onset in the twenties than in relatives of female probands with earlier or later onset, or in relatives of male probands. This suggests a third disorder related to affective psychosis, with an intermediate age at onset and female preponderance.  相似文献   
10.
By means of a PCR assay, EBV was demonstrated directly in peripheral blood of previously infected individuals. The virus was detected in approximately 80% of specimens from EBV-seropositive individuals, but not in cord-blood lymphocytes by this method. When virus present in peripheral blood was compared to that observed directly in NPC biopsies or throat washings, it was distinct from that seen in biopsies in 4/15 cases (27%) and from that seen in throat washes in 1/22 cases (5%). The throat-wash virus differed from the biopsy virus in 3/20 cases (15%). The prototype F virus was found in 7/10 LCLs (70%) established from NPC patients' peripheral blood, but was only detected in 2/9 specimens (22%) directly analyzed by the PCR assay. This finding suggests selective isolation of prototype F EBV in spontaneous LCLs established from NPC patients.  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