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   41232篇
  免费   7295篇
  国内免费   111篇
耳鼻咽喉   272篇
儿科学   1243篇
妇产科学   2096篇
基础医学   3206篇
口腔科学   585篇
临床医学   17694篇
内科学   6684篇
皮肤病学   224篇
神经病学   2780篇
特种医学   940篇
外科学   4178篇
综合类   426篇
一般理论   12篇
预防医学   4132篇
眼科学   481篇
药学   1679篇
中国医学   27篇
肿瘤学   1979篇
  2023年   847篇
  2022年   229篇
  2021年   572篇
  2020年   804篇
  2019年   594篇
  2018年   1461篇
  2017年   1591篇
  2016年   1717篇
  2015年   1809篇
  2014年   2079篇
  2013年   2613篇
  2012年   1634篇
  2011年   1915篇
  2010年   1726篇
  2009年   1928篇
  2008年   1784篇
  2007年   1796篇
  2006年   1716篇
  2005年   1585篇
  2004年   1530篇
  2003年   1443篇
  2002年   1391篇
  2001年   969篇
  2000年   799篇
  1999年   878篇
  1998年   836篇
  1997年   908篇
  1996年   867篇
  1995年   793篇
  1994年   632篇
  1993年   546篇
  1992年   632篇
  1991年   567篇
  1990年   578篇
  1989年   535篇
  1988年   427篇
  1987年   432篇
  1986年   450篇
  1985年   442篇
  1984年   370篇
  1983年   348篇
  1982年   277篇
  1981年   292篇
  1980年   208篇
  1979年   304篇
  1978年   255篇
  1977年   199篇
  1976年   225篇
  1974年   190篇
  1972年   221篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Since the mid-1970s, the Margaret Sanger Center of Planned Parenthood of New York City has prepared nurses and nurse midwives from less developed countries to be family-planning nurse practitioners. These nurse practitioners then provide services to patients, train other staff, and manage integrated family-planning clinics. More than 120 nurses and nurse midwives have arrived in groups of 10 at the Sanger Center, with 72 attending since 1981. Each course lasts 10 weeks. The core curriculum provides trainees with skills in women's health care including contraception, in training and advocacy, and in management of clinics. Whether, in the current period of scarce resources, cross-cultural training programs of this type remain a worthwhile investment, and if so, which of their components are most important to this success, is assessed.  相似文献   
32.
33.
34.
Monoclonal antibodies against human and bovine 2′:3′-cyclic nucleotide 3′-phosphodiesterase (CNPase) were generated by fusing FOX-NY myeloma cells with spleen cells from RBF/Dn mice previously immunized with the purified brain antigens. The enzyme isolated from bovine brain was quite basic, with an isoelectric point of 9.71 and both the bovine and human enzymes consisted of a closely spaced doublet at approximately 44 and 46 kDa on SDS-PAGE. Six monoclonals were identified as strongly recognizing the enzyme on both ELISA plates and on immunoblots of whole brain protein. Four monoclonals very weakly cross-reacted with guinea pig myelin basic protein. In contrast with two previous reports, some of our monoclonal antibodies did immunostain 2 or 3 protein bands in peripheral nerve, two bands closely corresponding to those immunostained in central nervous system (CNS) myelin, the Wolfgram protein fraction and in acetone powders of whole brain. Each of the 6 monoclonals reacting strongly on immunoblots recognized the enzyme in from 2 to 5 of the species examined (human, bovine, rat, mouse and rabbit). In addition, all 6 monoclonals that immunostained the enzyme in whole brain, myelin and Wolfgram protein immunoblots recognized both CNP1 (44 kDa) and CNP2 (46 kDa). The two closely spaced protein bands observed on SDS-PAGE and previously stained on immunoblots of CNS CNPase using polyvalent rabbit anti-bovine CNPase antisera, and now different monoclonal antibodies, appear to be immunologically related and to contain highly conserved sequences.  相似文献   
35.
The most common cause of illness in infancy and childhood is acute infection of the respiratory tract. Several recent studies have reported that life-threatening respiratory disease in infancy, such as pneumonia and bronchiolitis, is directly related to the smoking habits of parents. The effects of smoking are more hazardous to youngsters because babies and young children breathe more rapidly than adults. Because of this higher breathing rate, they inhale more air—and more pollution—in comparison to their total body weight. The harmful effects of cigarette smoking on infants and children and recommendations for specific interventions to minimize or eliminate this health hazard are discussed.  相似文献   
36.
37.
This paper describes a complex set of patient and nursing data from 83 psychiatric wards. It explains how the data were collected and organized into a meaningful format using a quality league-table. The patient and nursing characteristics of high quality psychiatric wards ranking above the 74th percentile and the characteristics of low quality wards falling below the 26th percentile are compared and examined in detail. Startling similarities and differences in patient activity, nursing activity, and nursing quality in high and low quality wards are highlighted. Finally, some implications of the findings for nursing practice, management, and education are considered.  相似文献   
38.
Prolactin (PRL) and other trophic factors rapidly activate a nuclear pool(s) of protein kinase C (nPKC) in purified splenocyte nuclei. The PRL also enhanced [2-3H]glycerol incorporation into nuclear mono- and triacylglycerol. An assay was devised which not only probed the ability of the hormone to activate protein kinase C (PKC) but also demonstrated the presence of nuclear substrates. Using this methodology, a biphasic concentration-response curve to PRL was observed. Heterologous species of PRL and various growth factors also activated nPKC. The PRL-induced nPKC stimulation was antagonized by various immunomodulators, G protein-coupling inhibitors, PKC inhibitors, a calmodulin inhibitor, and a peripheral benzodiazepine agonist and antagonist. A monoclonal antibody to PKC, anti-rat PRL antiserum and a monoclonal anti-rat PRL receptor antibody antagonized PRL-induced PKC-dependent nuclear phosphorylation, further implicating nPKC and a PRL receptor-mediated activation process. Nuclear PKC may be a major target for trophic regulation in response to both positive and negative growth signals.  相似文献   
39.
This paper reviews the evolution of U.S. policy toward medical technology in areas such as cost containment, regulation of devices and drugs, and third party reimbursement. In addition the authors chronicle the diffusion of major medical technologies, procedures, and organizational innovations in the United States. Finally, the article provides tentative observations on the effect of recent policy changes and concludes with some recommendations for the future.  相似文献   
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