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   166158篇
  免费   16041篇
  国内免费   10255篇
耳鼻咽喉   1412篇
儿科学   2107篇
妇产科学   1743篇
基础医学   23460篇
口腔科学   2931篇
临床医学   19974篇
内科学   22581篇
皮肤病学   1792篇
神经病学   8009篇
特种医学   5732篇
外国民族医学   69篇
外科学   15897篇
综合类   28785篇
现状与发展   33篇
一般理论   12篇
预防医学   12207篇
眼科学   3828篇
药学   19191篇
  154篇
中国医学   9721篇
肿瘤学   12816篇
  2024年   683篇
  2023年   2586篇
  2022年   6591篇
  2021年   8417篇
  2020年   6251篇
  2019年   5468篇
  2018年   5644篇
  2017年   5316篇
  2016年   4919篇
  2015年   7327篇
  2014年   9082篇
  2013年   8918篇
  2012年   12480篇
  2011年   13144篇
  2010年   9462篇
  2009年   7556篇
  2008年   9013篇
  2007年   9035篇
  2006年   8142篇
  2005年   7384篇
  2004年   5786篇
  2003年   5753篇
  2002年   5012篇
  2001年   4139篇
  2000年   3422篇
  1999年   3005篇
  1998年   1846篇
  1997年   1963篇
  1996年   1408篇
  1995年   1335篇
  1994年   1206篇
  1993年   819篇
  1992年   1031篇
  1991年   949篇
  1990年   836篇
  1989年   761篇
  1988年   685篇
  1987年   590篇
  1986年   554篇
  1985年   442篇
  1984年   372篇
  1983年   306篇
  1982年   273篇
  1981年   231篇
  1980年   198篇
  1979年   200篇
  1978年   192篇
  1977年   211篇
  1976年   191篇
  1974年   156篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
The availability of the primary amino acid sequence for a large number of molecules provides a fruitful opportunity for their cellular localization by utilizing the procedure of antipeptide antibody formation. This procedure permits a synthetic peptide sequence to be attached to a carrier molecule for the purpose of inoculating an animal to raise specific antibodies against the selected protein sequence. In this report we describe a number of steps that can be taken to increase the likelihood that the selected peptide sequence will be specific and antigenic. In addition, we describe how the peptides are synthesized, purified and coupled to keyhold limpet hemocyanin. The preparation of the antibody and its characterization are also presented in this method report. The immunocytochemical staining at both the light and ultrastructural level with serotonin (5-HT1A) receptor antipeptide antibodies is discussed. The advantages and disadvantages of this procedure are summarized.  相似文献   
92.
93.
94.
95.
96.
This study investigated whether previous contact with mental illness affected the attitudes to mental illness (AMI) of general student nurses in Hong Kong — the contact hypothesis. We employed a quasi-experimental design. We compared the attitudes to mental illness of students who had previous contact with mental illness through having taken a psychiatric secondment with those who had not taken a psychiatric secondment. Also, we compared the AMI of: students who had taken other courses related to mental illness with those who had not; those who had a family history of mental illness with those who had not; and those who lived with a mentally ill relative with those who did not. We found that previous contact with mental illness had no significant effect on the attitudes to mental illness of the students. In other words our findings do not support the contact hypothesis. Our sample expressed positive general attitudes to mental illness when presented with general issues about mental illness. However, their attitudes were less positive when presented with specific issues about mental illness that might impinge upon their daily lives. We discuss the implications of these findings for mental health nursing practice, education and research.  相似文献   
97.
Anthracycline-resistant HL-60/AR cells and their drug-sensitive HL-60/S counterparts were characterized by karyotypic analysis and examined for the overexpression of DNA and mRNA sequences coding for P-glycoprotein (Pgp). The HL-60/S cells were karyotypically stable over a 5-year period of study (1986-1991), except for an additional small Giemsa-positive band noted at 7q22 in cultures harvested in 1987, but not in 1986. This change did not affect drug sensitivity. The drug-resistant HL-60/AR cells examined in 1986, 1987, and 1991 demonstrated a very stable karyotype. The most striking feature was a large homogeneously staining region in the long arm of chromosome 7 (7q11.2), and translocation of the remainder of the long arm to another centromere. Other changes in the HL-60/AR cells included inversion in 9q, partial deletion of the short arm of chromosome 10p, addition of material to the p arm of der(16), loss of chromosome 22, and the appearance of a new marker chromosome. Both HL-60/S and the HL-60/AR cells were found not to amplify DNA or mRNA sequences coding for the Pgp. Thus, although the HL-60/AR cells possess the classical multidrug resistance phenotype and demonstrate a homogeneously staining region near the region of the MDR1 gene, their resistance is due to mechanisms other than those coded for by MDR1.  相似文献   
98.
俞蓉倩 《护理研究》2007,21(16):1468-1468
在崇尚医学美学的今天,手术室护理人员通过数届"护理审美"活动的研讨,我院神经外科专科组成员针对放置体位规范化的要求和对美学的理解,敢于在日常护理工作中发现问题,探究原因,自行设计新式约束带,改进以往在放置神经外科侧卧位时,约束病人的不规范,以及约束病人肢体时重复劳动的烦琐,给临床护理工作带来了便捷.  相似文献   
99.
Antibiotic use during major head and neck surgery.   总被引:2,自引:0,他引:2       下载免费PDF全文
The appropriate use of prophylactic antimicrobial therapy in patients undergoing major contaminated surgery is an important issue for the head and neck surgeon. A series of five sequential, prospective, randomized, double-blind clinical trials of antibiotics for patients undergoing major contaminated oncologic head and neck surgery are reviewed and summarized. The information generated from the study of these 547 patients indicates that a number of drugs or drug combinations have similar efficacy when employed in adequate dosage. The bacteriologic spectrum of the prophylactic drug should include oral microflora, especially anaerobic bacteria. The administration of antibiotics effective against gram-negative aerobic bacteria may be unnecessary. Perioperative antibiotic administration should be initiated prior to surgery. To date, no evidence exists to support prolonged administration of antibiotics beyond the first 24 hours following surgery.  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