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   32249篇
  免费   2594篇
  国内免费   71篇
耳鼻咽喉   231篇
儿科学   1054篇
妇产科学   1021篇
基础医学   4151篇
口腔科学   488篇
临床医学   4720篇
内科学   6165篇
皮肤病学   353篇
神经病学   3320篇
特种医学   656篇
外科学   3355篇
综合类   413篇
一般理论   39篇
预防医学   4312篇
眼科学   558篇
药学   1941篇
中国医学   27篇
肿瘤学   2110篇
  2023年   271篇
  2022年   244篇
  2021年   560篇
  2020年   395篇
  2019年   564篇
  2018年   743篇
  2017年   577篇
  2016年   640篇
  2015年   739篇
  2014年   1023篇
  2013年   1444篇
  2012年   2019篇
  2011年   2231篇
  2010年   1214篇
  2009年   1144篇
  2008年   1899篇
  2007年   1987篇
  2006年   1891篇
  2005年   1899篇
  2004年   1862篇
  2003年   1709篇
  2002年   1667篇
  2001年   553篇
  2000年   431篇
  1999年   459篇
  1998年   447篇
  1997年   353篇
  1996年   298篇
  1995年   296篇
  1994年   279篇
  1993年   221篇
  1992年   351篇
  1991年   320篇
  1990年   295篇
  1989年   316篇
  1988年   274篇
  1987年   237篇
  1986年   256篇
  1985年   253篇
  1984年   202篇
  1983年   214篇
  1982年   173篇
  1981年   163篇
  1980年   135篇
  1979年   167篇
  1978年   156篇
  1977年   121篇
  1976年   120篇
  1974年   132篇
  1973年   122篇
排序方式: 共有10000条查询结果,搜索用时 671 毫秒
121.
122.
We present three patients with Treacher Collins or Pierre Robin syndromes who had historical and physical evidence of airway obstruction, difficulty feeding, and sleep disturbances. These preoperative findings correlated with difficult airway management intraoperatively. Based on this experience, we recommend that children with obstructive symptoms have laryngoscopy prior to anaesthetic induction. If the glottic opening is visualized, inhalational induction can proceed. If the glottic structures cannot be visualized, then the anaesthetist must choose between awake oral or nasal intubation, elective tracheostomy, or fiberoptic intubation. In all cases, a tracheostomy tray should be ready and a surgeon experienced in paediatric tracheostomy should be in attendance. After intubation, anaesthesia is best maintained with oxygen and a potent inhalational agent. Extubation should only be done with the patient fully awake and with emergency airway equipment immediately available. Postoperatively, these patients should be transferred to an intermediate care area or intensive care unit where they can be observed closely since delayed complications of airway obstruction are common in this group of patients.  相似文献   
123.
Cardiac contusion following blunt chest trauma remains a diagnostic problem because of a lack of sensitive diagnostic tests. This study evaluated thallous chloride Tl 201 single-photon-emission computed tomography in a series of 48 patients following blunt chest trauma. Of the 48 patients, 23 had normal scans. None of these patients proved to have serious arrhythmias during three days of continuous monitoring. Of 25 patients with abnormal or ambiguous studies, five (20%) developed serious arrhythmias requiring therapy. Single-photon-emission computed tomography scanning thus was sensitive in indicating that group of patients at risk of serious arrhythmias, and may therefore prove to be a useful screening test to determine the need for hospitalization and arrhythmia monitoring following blunt chest trauma.  相似文献   
124.
125.
Morbid obesity: use of vertical banded gastroplasty   总被引:4,自引:0,他引:4  
  相似文献   
126.
On a daily basis, clinicians make decisions regarding therapies to result in the best outcome for their patients. These decisions should be based on the evidence in the literature, indicating a therapy will cause the best outcome. To facilitate this, many professional societies and scientific journals have published technical and scientific reviews, as well as evidence-based standards of care focused on many issues of nutrition support practice. This paper provides an overview of how these reviews and standards of care are derived to promote both the understanding of what they can and cannot do to enhance clinical practice.  相似文献   
127.
Much of the literature on research design in clinical pharmacology and pharmacokinetics emphasizes statistical concerns, thus suggesting that a primary ingredient of a valid research design is an appropriate plan for statistical analysis of data. However, statistical validity is only one of several ways to evaluate an experimental study. The present paper reviews the underlying logic and sources of invalidity of experimental drug research suggesting influences and factors which may deceive or lure an experimenter into erroneous conclusions.  相似文献   
128.
The aim of this study was to investigate the pathological and cellular basis for radiation-induced myelopathy in guinea pigs by monitoring biochemical alterations in levels of myelin basic protein and 2',3'-cyclic nucleotide phosphohydrolase. Guinea pigs were irradiated to the lumbar region with various doses of neutrons or cobalt gamma irradiation. The ED50s for paralysis were 17.2 Gy and 67.5 Gy for neutron and cobalt irradiation, respectively, and was histologically associated with demyelination. In spinal cords taken from animals at the onset of paralysis myelin basic protein levels were decreased in direct relationship to the radiation dose. The lowest doses to cause paralysis led to a 25% decrease in MBP levels. In a separate experiment, alterations in MBP were measured in the spinal cords over the time period leading up to paralysis. Surprisingly, decreases in MBP were found immediately after the end of the 4 week irradiation period. These early changes in MBP were not markedly dose dependent and occurred with nonparalyzing doses. Dose-dependent decreases were found only just before the onset of paralysis. CNPase activity measured in the same specimens showed changes that were essentially similar to those for MBP. In the CSF, MBP levels were essentially constant until onset of paralysis. This study showed that demyelination, as assessed by the levels of the myelin-associated proteins MBP and CNPase, can occur soon after spinal cord irradiation but that profound dose-dependent changes are seen only immediately preceding the onset of paralysis. Although increases in MBP in the CSF were associated with the onset of radiation-induced myelopathy, its assay is unlikely to predict this complication of irradiation.  相似文献   
129.
Childhood sarcoidosis is a rare disorder with protean manifestations. The case of a child with prolonged fever, hepatosplenomegaly, pancytopenia, and systemic necrotizing vasculitis manifesting as fever, rash and skin infarctions, digital pregangrene, and foot drop is reported. This is the first case of systemic necrotizing vasculitis reported in sarcoidosis. The fulminant course of the disease required treatment with intravenous pulsed cyclophosphamide and high doses of corticosteroids. The spectrum of vasculitis in childhood and adult sarcoidosis is reviewed.  相似文献   
130.
Preliminary evaluation of the processes of changing to a low-fat diet   总被引:3,自引:2,他引:1  
The purpose of the present paper is to identify the processesof changing dietary fat consumption using Prochaska's transtheoreticalmodel. This model assigns individuals into a series of stages,emphasizing the cognitive, social and behavioral steps of change.At each of the stages an individual focuses on different processes,or coping strategies, to enable movement to the next stage.Dietary process items were created by a multidisciplinary teamusing the smoking processes as a model. These items were subjectedto a Q-sort and piloted in convenience samples. The processitems were distributed with staging questionnaires to 720 membersof an outdoor folk music festival audience. The final groupof 121 process items was subjected to exploratory factor analysisof principle components with varimax rotation. Eight independentfactors emerged during this factor analysis. The processes measuredby the final 60-item questionnaire relate to the stages of changein the hypothesized manner. Applications of this model to interventionsettings seem possible.  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