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   69718篇
  免费   5118篇
  国内免费   123篇
耳鼻咽喉   608篇
儿科学   2841篇
妇产科学   1958篇
基础医学   8952篇
口腔科学   789篇
临床医学   10271篇
内科学   12121篇
皮肤病学   944篇
神经病学   6439篇
特种医学   1467篇
外科学   6752篇
综合类   853篇
一般理论   120篇
预防医学   9364篇
眼科学   1028篇
药学   4942篇
中国医学   74篇
肿瘤学   5436篇
  2023年   315篇
  2022年   441篇
  2021年   1212篇
  2020年   795篇
  2019年   1241篇
  2018年   1448篇
  2017年   1160篇
  2016年   1220篇
  2015年   1444篇
  2014年   1983篇
  2013年   3163篇
  2012年   4585篇
  2011年   4878篇
  2010年   2755篇
  2009年   2424篇
  2008年   4423篇
  2007年   4698篇
  2006年   4541篇
  2005年   4687篇
  2004年   4479篇
  2003年   4244篇
  2002年   3896篇
  2001年   999篇
  2000年   864篇
  1999年   916篇
  1998年   851篇
  1997年   733篇
  1996年   607篇
  1995年   594篇
  1994年   555篇
  1993年   461篇
  1992年   584篇
  1991年   561篇
  1990年   504篇
  1989年   495篇
  1988年   506篇
  1987年   486篇
  1986年   440篇
  1985年   439篇
  1984年   431篇
  1983年   371篇
  1982年   345篇
  1981年   326篇
  1980年   265篇
  1979年   283篇
  1978年   226篇
  1977年   161篇
  1976年   194篇
  1974年   218篇
  1973年   179篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Congenital heart disease is a rare but important finding in adults who experience sudden death. Examination of the congenitally malformed heart has historically been considered esoteric and best left to those with expertise. The Cardiac Risk in the Young cardiovascular pathology laboratory based at St George's University of London has now received over 6,000 cases. Of these, 21 congenitally malformed hearts were retained for research and educational purposes. Hearts were assessed using sequential segmental analysis, and causes of death were adjudicated based on thorough macroscopic examination and histology. Congenital malformations that were encountered included atrial septal defects, ventricular septal defects, tetralogy of Fallot, and transposition of the great arteries in both its regular and congenitally corrected variants. Findings also included hearts with mirror-imaged and isomeric atrial appendages. Direct causes of death included myocardial fibrosis, pulmonary hypertension, and hemorrhage. A small but notable proportion did not reveal a substrate for arrhythmia, raising the question of whether the terminal event was due to the congenital heart disease itself, or an underlying channelopathy. Here, we demonstrate the value of simple sequential segmental analysis in describing and categorizing the cases, with the concept of the “morphological method” serving to identify the distinguishing features of the cardiac components. Clin. Anat. 33:394–404, 2020. © 2019 Wiley Periodicals, Inc.  相似文献   
33.
34.
35.
Ninety-seven inpatients with tardive dyskinesia (average AIMS score = 13), the majority of whom were schizophrenic, were studied. Forty patients were Caucasian, and 57 were African-American. The APOE genotypes of these patients were compared to previously published genotypes of controls and with previously published studies of APOE genotypes in patients with schizophrenia. There were no significant differences in APOE allele frequencies comparing the African-American tardive dyskinesia population and the African-American control groups. In contrast, significant (< 0.05) P values were obtained comparing the Caucasian tardive dyskinesia population to the Caucasian controls, when comparing allele frequencies and genotypic frequencies. This study suggests that Caucasians bearing an APOE2 allele are at increased risk of developing tardive dyskinesia, whereas African-Americans are not. APOE genotype-specific risks of both tardive dyskinesia and Alzheimer's disease that vary across populations could be due to recruitment of patients or controls or could be due to modifying effects of differing genetic or environmental backgrounds. The mechanism by which the APOE2 allele increases risk of tardive dyskinesia is not known. Further information about the mechanisms of increased risk of tardive dyskinesia could result in stratification of prescribing practices weighing the costs of medications against the relative risk of side effects.  相似文献   
36.
37.
PURPOSE: To determine the maximum tolerated dose, dose-limiting toxicities, and pharmacokinetic characteristics of doxorubicin encapsulated in a low temperature sensitive liposome (LTSL) when given concurrently with local hyperthermia to canine solid tumors. EXPERIMENTAL DESIGN: Privately owned dogs with solid tumors (carcinomas or sarcomas) were treated. The tumors did not involve bone and were located at sites amenable to local hyperthermia. LTSL-doxorubicin was given (0.7-1.0 mg/kg i.v.) over 30 minutes during local tumor hyperthermia in a standard phase I dose escalation study. Three treatments, given 3 weeks apart, were scheduled. Toxicity was monitored for an additional month. Pharmacokinetics were evaluated during the first treatment cycle. RESULTS: Twenty-one patients were enrolled: 18 with sarcomas and 3 with carcinomas. Grade 4 neutropenia and acute death secondary to liver failure, possibly drug related, were the dose-limiting toxicities. The maximum tolerated dose was 0.93 mg/kg. Other toxicities, with the possible exception of renal damage, were consistent with those observed following free doxorubicin administration. Of the 20 dogs that received > or = 2 doses of LTSL-doxorubicin, 12 had stable disease, and 6 had a partial response to treatment. Pharmacokinetic variables were more similar to those of free doxorubicin than the marketed liposomal product. Tumor drug concentrations at a dose of 1.0 mg/kg averaged 9.12 +/- 6.17 ng/mg tissue. CONCLUSION: LTSL-doxorubicin offers a novel approach to improving drug delivery to solid tumors. It was well tolerated and resulted in favorable response profiles in these patients. Additional evaluation in human patients is warranted.  相似文献   
38.
39.
40.
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