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   210236篇
  免费   15274篇
  国内免费   744篇
耳鼻咽喉   2284篇
儿科学   5482篇
妇产科学   4304篇
基础医学   27107篇
口腔科学   4510篇
临床医学   20002篇
内科学   44885篇
皮肤病学   2754篇
神经病学   20302篇
特种医学   6951篇
外国民族医学   13篇
外科学   32921篇
综合类   3411篇
现状与发展   2篇
一般理论   291篇
预防医学   19062篇
眼科学   4372篇
药学   14393篇
  1篇
中国医学   384篇
肿瘤学   12823篇
  2023年   842篇
  2022年   1403篇
  2021年   3440篇
  2020年   2105篇
  2019年   3390篇
  2018年   3967篇
  2017年   3212篇
  2016年   3411篇
  2015年   4069篇
  2014年   6095篇
  2013年   8822篇
  2012年   13128篇
  2011年   14322篇
  2010年   8099篇
  2009年   7305篇
  2008年   13590篇
  2007年   14426篇
  2006年   13922篇
  2005年   14394篇
  2004年   13808篇
  2003年   12902篇
  2002年   12436篇
  2001年   1875篇
  2000年   1460篇
  1999年   2047篇
  1998年   2828篇
  1997年   2437篇
  1996年   2205篇
  1995年   1953篇
  1994年   1755篇
  1993年   1655篇
  1992年   1209篇
  1991年   1150篇
  1990年   1053篇
  1989年   952篇
  1988年   1011篇
  1987年   1018篇
  1986年   998篇
  1985年   1081篇
  1984年   1478篇
  1983年   1461篇
  1982年   1814篇
  1981年   1639篇
  1980年   1555篇
  1979年   812篇
  1978年   958篇
  1977年   932篇
  1976年   831篇
  1975年   682篇
  1974年   666篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Molecular chaperones assist in the biosynthesis and processing of proteins. Most chaperones are induced by physiological stresses. We have shown that dietary energy restriction decreases the mRNA and protein levels of many endoplasmic reticulum chaperones in the livers of mice. Here, we have investigated the response of chaperone mRNA to feeding. Control and 50% energy-restricted C3B10RF1 mice were deprived of food for 24 h, fed, and killed 0, 1.5, 5 or 12 h after feeding. Chaperone mRNAs were strongly induced as early as 1.5 h after feeding in control and energy-restricted mice. The integrated levels of these mRNA over 24 h were significantly lower in energy-restricted mice. The mRNA response to energy intake was mirrored over the course of days in the level of chaperone protein. A similar but smaller response to feeding was found in kidney and muscle. Puromycin and cycloheximide failed to inhibit the feeding response, suggesting that feeding releases chaperone expression from an unstable inhibitor. Studies with dibutyryl-cAMP- and glucagon-supplemented, normal and streptozotocin-diabetic mice suggest that glucagon and insulin may be mediators of the feeding response. Adrenalectomy enhanced the feeding induction, but dexamethasone administration had no effect. Thus, postprandial changes in insulin and glucagon may link chaperone gene expression to feeding, possibly in several tissues including liver.  相似文献   
102.
PURPOSE: To review the role of recombinant factor VIIa in anesthetic practice. SOURCE: A review of the published literature. MAIN FINDINGS: The mechanism of action of rFVIIa suggests enhancement of hemostasis limited to the site of injury without systemic activation of the coagulation cascade. In addition to its indication for use in patients with hemophilia, use of rFVIIa for treatment of uncontrolled massive hemorrhage in various peroperative settings appears to be rational, safe, and effective. Published results suggest that in trauma patients rFVIIa may play a role as an adjunctive hemostatic measure in addition to surgical hemostatic techniques There is preliminary evidence that hemorrhagic complications (eg. epistaxis, vaginal bleeding) associated with profound thrombocytopenia can be reversed with rFVIIa even at platelet counts below 10,000 per microL. Various case reports outlining the successful treatment with recombinant factor VIIa of patents experiencing intractable bleeding after valve replacement surgery, and with severe hemorrhage during therapy with left ventricular assist device, indicate the potential therapeutic efficacy of this agent in cardiac surgical procedures. Additionally, rFVIIa has been used successfully for treatment of massive postoperative bleeding following general surgery. CONCLUSIONS: rFVIIa is a novel hemostatic agent that shows promise in non-hemophiliac patents of a significant therapeutic role in variety of coagulopathic and hemorrhagic conditions in clinical situations ranging from thrombocytopenia, disseminated intravascular coagulation and transfusion-related coagulopathy, as well as in patients experiencing massive blood loss undergoing orthotopic liver transplantation, cardiac, orthopedic and genitourinary surgery.  相似文献   
103.
104.
Eight lymphatic fluid collections were drained percutaneously. There were no immediate or late complications. Seven patients had follow-up; 1 required surgical drainage of a residual or recurrent lymphocele, and another had reaccumulated fluid in a lymphocele which was detected on autopsy. The remaining lymphatic collections responded to percutaneous drainage. Percutaneous drainage is safe and can be an effective tool in the management of lymphatic collections.  相似文献   
105.
This article begins by challenging the widely held view in neoliberal discourse that there is a necessary trade-off between higher efficiency and lower reduction of inequalities: the article empirically shows that the liberal, U.S. model has been less efficient economically (slower economic growth, higher unemployment) than the social model in existence in the European Union and in the majority of its member states. Based on the data presented, the authors criticize the adoption of features of the liberal model (such as deregulation of their labor markets, reduction of public social expenditures) by some European governments. The second section analyzes the causes for the slowdown of economic growth and the increase of unemployment in the European Union--that is, the application of monetarist and neoliberal policies in the institutional frame of the European Union, including the Stability Pact, the objectives and modus operandi of the European Central Bank, and the very limited resources available to the European Commission for stimulating and distributive functions. The third section details the reasons for these developments, including (besides historical considerations) the enormous influence of financial capital in the E.U. institutions and the very limited democracy. Proposals for change are included.  相似文献   
106.
Dimethyl isosorbide (DMI), which is currently under investigation for its potential use as a pharmaceutical vehicle and drug permeation enhancer, is a water-miscible liquid with relatively low viscosity. The solubilization behavior of DMI as a cosolvent for nonpolar drugs was characterized via dielectric constant measurements of binary solvent systems containing DMI and either water, propylene glycol (PG), or polyethylene glycol (PEG). Evidence from the dielectric constant profiles and NMR studies suggest that DMI undergoes complexation with water and PG, but not with PEG, through hydrogen bonding interactions. The solvent complexation exhibited a major effect on the solubilities of prednisone, dexamethasone, and prednisolone in the mixed solvent systems. Maximum solubility of each drug was found to occur near a DMI/water or DMI/PG concentration ratio of 1:2. In the DMI–PEG mixed system, while there is no apparent interaction between DMI and PEG molecules, the solubility of prednisone was found to increase with decreasing dielectric constant.  相似文献   
107.
108.
109.
Infantile Digital Fibroma Treated With Mohs Micrographic Surgery   总被引:2,自引:0,他引:2  
John G. Albertini  MD  Maj  USAF  MC  Michael Jude Welsch  MD  CPT  USA  MC  Leo A. Conger  MD  LTC  USA  MC  Lester F. Libow  MD  COL  USA  MC    Dirk M. Elston  MD  COL  USA  MC 《Dermatologic surgery》2002,28(10):959-961
BACKGROUND: Infantile digital fibroma (IDF) is a rare benign fibrous tumor of childhood that frequently recurs despite local excision. Conservative, nonsurgical management may result in regression and/or joint deformity. OBJECTIVE: To describe the histologic features of IDF and discuss a case excised using Mohs micrographic surgery (MMS). METHODS: Case report and review of the clinical, histologic, and ultrastructural features. RESULTS: Characteristic inclusion bodies of actin were identified with hematoxylin and eosin, Masson's trichrome, and rapid actin immunostain. The tumor was debulked and the majority was removed after one stage of MMS, except where the deep margin approached the joint space. The defect healed by secondary intention. At 2 years the patient had no recurrence or functional joint deformity. CONCLUSION: MMS is a surgical treatment option for IDF.  相似文献   
110.
Central post stroke pain is often difficult to manage satisfactorily with conventional treatment modalities for pain. In the last decade functional neurosurgery has offered hope with motor cortex stimulation achieving significant alleviation of pain in some patients. Unfortunately this has led to the neglect of chronic stimulation of deep grey matter as another modality of treating this condition. In this article we present our experience with motor cortex stimulation and that with deep grey matter stimulation in patients with post stroke pain. We argue that both modalities have a significant role and that what is required are better methods of identifying particular patients who are more likely to respond to one or the other.  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