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   173221篇
  免费   19045篇
  国内免费   10048篇
耳鼻咽喉   1617篇
儿科学   3165篇
妇产科学   1667篇
基础医学   11981篇
口腔科学   3231篇
临床医学   23803篇
内科学   18056篇
皮肤病学   2061篇
神经病学   5357篇
特种医学   6414篇
外国民族医学   16篇
外科学   13468篇
综合类   42168篇
现状与发展   36篇
一般理论   4篇
预防医学   20812篇
眼科学   3060篇
药学   19480篇
  272篇
中国医学   15838篇
肿瘤学   9808篇
  2024年   861篇
  2023年   2683篇
  2022年   5917篇
  2021年   7563篇
  2020年   6603篇
  2019年   4269篇
  2018年   4663篇
  2017年   5567篇
  2016年   4723篇
  2015年   7540篇
  2014年   9503篇
  2013年   11408篇
  2012年   14848篇
  2011年   15625篇
  2010年   13315篇
  2009年   11810篇
  2008年   12023篇
  2007年   11854篇
  2006年   10566篇
  2005年   8364篇
  2004年   6496篇
  2003年   6113篇
  2002年   4962篇
  2001年   4203篇
  2000年   2860篇
  1999年   1556篇
  1998年   857篇
  1997年   858篇
  1996年   766篇
  1995年   621篇
  1994年   550篇
  1993年   414篇
  1992年   268篇
  1991年   236篇
  1990年   214篇
  1989年   222篇
  1988年   195篇
  1987年   159篇
  1986年   147篇
  1985年   128篇
  1984年   95篇
  1983年   86篇
  1982年   72篇
  1981年   81篇
  1980年   50篇
  1979年   28篇
  1978年   27篇
  1977年   42篇
  1976年   32篇
  1971年   23篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
OBJECTIVE: To study the expression of neuron-specific enolase (NSE) and olfactory marker protein (OMP) in the developing olfactory mucosa of human fetuses. METHOD: The expression of NSE and OMP in the olfactory mucosa of 6 human fetuses (12, 16, 20, 24, 28 and 34 weeks) was studied using the technique of immunohistochemistry. RESULTS: NSE immunological positive reactions were seen in all 6 fetal mucosa from gestational 12 (G12) to G34, with plenty of positive-stained dual-pole neuron cells. At G12, the positive cells aligned tightly, the cell bodies were localized in the lower portion of olfactory epithelium and the positive-stained area occupied upper 2/3 of fetal nasal mucosa. With the development, the positive cells gradually became multilayer, but the density and the relative area of positive-cells reduced. At G34, the positive cells were located only in upper 1/3 of nasal mucosa. OMP-positive reactions were localized in a few dual-pole neurons at G12, the number was much less than NSE-positive cells in the same fetus. With the development, the OMP-positive cells gradually increased with most of the cell bodies located in the upper portion of epithelium, but number still relatively less than the NSE-positive cells at the same age. CONCLUSION: At G12, there were lots of olfactory neuron in the olfactory mucosa and only a few olfactory neurons had became mature. With the development, the olfactory epithelial area reduced but the number of mature olfactory neurons increased. At the last trimester, fetal olfactory sensor was almost matured.  相似文献   
102.
目的为提高手术安全性,在L2~S2选择性脊神经后根切断(SPR)手术时,对肛门括约肌进行肌电图(EMG)监测,并评价其作用。方法在SPR手术监测中,当对S2后根小束进行电刺激时,采用针状电极记录双侧肛门括约肌的反应情况,有明显反应的后根小束予以保留。手术后随访患者踝痉挛改善情况和括约肌功能变化情况。结果所有患者手术后踝痉挛均有明显改善,无大小便功能障碍发生。结论SPR手术包括S2后根时,术中括约肌EMG监测对保证疗效,保护括约肌功能,提高手术安全,具有重要意义。  相似文献   
103.
“跳起来摘桃子”,有人如此形容华西医院这些年的发展。5年前,华西医院拥有开放床位3466张,规模的扩大和管理相对滞后之间的矛盾随着医院发展逐渐凸现出来,医院管理者职业化建设的要求也越来越迫切。2004年春,本着“把时间还给医生,把医生还给病人”的宗旨,该院启动医院管理“运营创新”项目,探索了一条和时下流行的“MBA培训”不同的建设路径,并命名其为“专科经营助理培训项目”。一年后的2005年5月,随着27名“专科经营助理”上岗,该院专科经营助理培训和专科经营制度也被正式导入,并与信息化建设、财务成本制度改革、薪酬制度改革等共同构成了该院的“运营创新”体系。“他们是医院的眼睛,能发现问题,他们进入科室后,可使教授、博士生导师从不熟悉的行政业务中解脱出来,更多地考虑战略问题,把战术问题交给专科经营助理来完成。”事后,华西医院院长石应康这样评价该院专科经营助理的工作。这究竞是怎样一个群体?其日常工作和职能分工如何来界定?4年下来,这个群体工作情况又怎样?作为先行先试者,华西医院有关人士作出了若干解答。  相似文献   
104.
医院用血液制品HCV污染情况的调查   总被引:1,自引:0,他引:1  
目的调查医院治疗用血液制品HCV污染情况.方法临床治疗所用的血液制品,在输完后留容器之残液备检.采用酶标免疫法(ELISA)检测.对ELISA检测之阳性标本及在阴性标本中随机抽取9份,采用逆转录双PCR方法检测HCV_RNA.结果血浆白蛋白抗_HCV阳性率458%,新鲜血浆阳性率26%.两种方法检测同一标本,ELISA检测阳性的血液制品中,用PCR证实,并非都有病毒复制;而在ELISA检测的阴性标本中,仍旧有较高的PCR阳性检出.结论血液制品存在着HCV污染,抗_HCV对于HCV感染的诊断价值很高.检测血液制品中的抗_HCV,合理使用血液成份,可防止HCV在医院内传播.  相似文献   
105.
The public sector in Britain has been subjected to over a decade of major reform aimed at breaking up public service monopolies, at containing costs while at the same time opening services up to greater consumer choice. Health and social services have not been exempt from this revolution in the organization and management of public sector services. The long-standing policy of care in the community is being subjected to market principles and the introduction of a ‘contract culture’ very similar to the NHS reforms introduced in 1991. This paper reviews the origins of these developments in the doctrines of ‘new public management’, a movement which has proved attractive to policy-makers in many countries. Local authority social services departments have been identified as the lead agency for the development of a mixed economy of care following a review of community care policy by the government's health adviser, Sir Roy Griffiths, and a subsequent white paper. This paper examines the limited empirical evidence available on how managers and providers are meeting the challenge bestowed upon them, and concludes that most authorities are moving ahead cautiously if at all. Only a handful of authorities studied have embraced the reforms with any degree of enthusiasm. The paper concludes with an assessment of the reforms from two perspectives: a pessimistic one and an optimistic one. There are many worrying features of the reforms, not least among these being a lack of clarity over their intended purpose. Tensions and contradictions are plentiful, which places in jeopardy the certainty of the reforms in becoming user led rather than provider driven. A more optimistic scenario is that the changes are leading to a loosening up of services and practices which have often suffered from sclerotic tendencies, paternalism and sometimes complacency. If the reform process is skilfully handled and not rushed and if the ends are clearly established and communicated then users and carers could prove to be the principal beneficiaries.  相似文献   
106.
The ability of a peptide hormone to affect many different intracellular targets is thought to be possible because of the modular organization of signal transducing molecules in the cell. Evidence for the presence of signaling modules in metazoan cells, however, is incomplete. Herein we show, with morphology and cell fractionation, that all the components of a mitogen-activated protein kinase pathway are concentrated in caveolae of unstimulated human fibroblasts. Addition of platelet-derived growth factor to either the intact cell or caveolae isolated from these cells stimulates tyrosine phosphorylation and activates mitogen-activated protein kinases in caveolae. The molecular machinery for kinase activation, therefore, is preorganized at the cell surface of quiescent cells.  相似文献   
107.
The development and implementation of effective community support systems are goals of many public mental health authorities who are attempting to shift the focus and dollars for mental health services from inpatient to community care. This article presents the results of a survey which asked 90 community mental health agency case managers to assess the community support and residential needs of over 1400 of their clients. Medication monitoring and therapy were rated high priority needs. Psychosocial treatment, day and vocational activities also ranked high. Survey responses regarding residential services indicated a need for more supported and supervised options.The study reported was a collaborative effort by county and agency staff.  相似文献   
108.
Research shows that clients with automatic thoughts (dysfunctional thinking) often do not think of alternative explanations in relation to negative events. Furthermore, these automatic thoughts are characterized by a broad global, self-evaluative and ambiguous nature that could make disputing (or changing the ways they think) the most difficult part of the therapeutic process. This paper proposes a two-stage practise-based disputing model, guided by research, that aims to 'bring' an automatic thought to a specific, objective, quantifiable and concrete level at which not only is the particular aspect(s) of the automatic thought that causes emotional disturbances finely focused, but the disputing is also likely to be effective and manageable. Furthermore, it will also generate alternative explanations that are helpful in reducing emotional disturbances and in facilitating problem solving approach. In this paper, the authors use a case example to discuss the rationale that underpins the conceptualization of the model and to illustrate the process in which the strategies of the model are effectively used.  相似文献   
109.
原发性骨质疏松症 (Op)是骨构建和骨重建中 ,骨形成和骨吸收恒常调节失衡引发的一种缓慢的、渐进的骨吸收亢进症 ,是一类综合征。多种病因可以引起 ,现今一般认为和机体遗传、个体生活习惯、生理状态与生存环境等多种因素综合影响有关。因Op病因的多源性和发病机理的复杂性 ,现今尚在不断阐明中 ,多主张综合治疗处理。凡是骨密度(BMD)有明显减低或骨吸收生化标志有明显上升者 ,无论伴有或不伴有非暴力性骨折 ,均应给予治疗处理。一、Op的治疗原则和许多慢性非传染性流行性疾病类似 :(1 )去除病因 ,阻止骨量减少和骨质量劣化进程。 (2 )增…  相似文献   
110.
Leukotriene B4 (LTB4) and the protein kinase C activator, 4-beta-phorbol dibutyrate (PDBu), both induced a pronounced and concentration-dependent stimulation of hydrogen peroxide (H2O2) generation by purified guinea pig peritoneal eosinophils in the concentration range 1 nM-1 microM. The LTB4 response was inhibited competitively by the specific LTB4 receptor antagonist, U-75302, with a KB of 25 nM, while the concentration-response curves for both stimuli were shifted rightwards (3.8-fold and 2.8-fold for LTB4 and PDBu, respectively) by the competitive protein kinase C inhibitor, 1-O-hexadecyl-2-O-methylglycerol at a concentration of 300 microM. LTB4 appears, therefore, to induce respiratory burst in eosinophils via a receptor-mediated mechanism involving protein kinase C.  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