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   4593篇
  免费   358篇
  国内免费   15篇
耳鼻咽喉   52篇
儿科学   171篇
妇产科学   126篇
基础医学   495篇
口腔科学   81篇
临床医学   648篇
内科学   915篇
皮肤病学   40篇
神经病学   282篇
特种医学   195篇
外科学   535篇
综合类   79篇
一般理论   2篇
预防医学   473篇
眼科学   179篇
药学   398篇
中国医学   10篇
肿瘤学   285篇
  2021年   70篇
  2020年   45篇
  2019年   51篇
  2018年   64篇
  2017年   61篇
  2016年   48篇
  2015年   67篇
  2014年   104篇
  2013年   123篇
  2012年   177篇
  2011年   200篇
  2010年   137篇
  2009年   107篇
  2008年   159篇
  2007年   182篇
  2006年   200篇
  2005年   184篇
  2004年   171篇
  2003年   198篇
  2002年   181篇
  2001年   143篇
  2000年   139篇
  1999年   113篇
  1998年   51篇
  1997年   46篇
  1996年   51篇
  1995年   49篇
  1994年   53篇
  1993年   45篇
  1992年   96篇
  1991年   136篇
  1990年   116篇
  1989年   125篇
  1988年   86篇
  1987年   106篇
  1986年   86篇
  1985年   89篇
  1984年   50篇
  1983年   51篇
  1982年   51篇
  1979年   62篇
  1978年   53篇
  1977年   36篇
  1975年   35篇
  1974年   41篇
  1973年   41篇
  1972年   44篇
  1971年   44篇
  1969年   33篇
  1968年   34篇
排序方式: 共有4966条查询结果,搜索用时 15 毫秒
61.
T R Swift  F T Nichols 《Neurology》1984,34(2):212-215
We found that patients with thoracic outlet syndrome have: (1) low-set, "droopy" shoulders and long swan neck; (2) pain in the neck, shoulder, chest, arms, or hands; (3) aggravation of symptoms by downward traction and relief by propping up the arms; (4) occurrence in women; (5) absence of abnormal vascular, neurologic, and electrical findings; (6) a Tinel's sign over the brachial plexus; and (7) T-2 vertebra visible above the shoulders on lateral cervical spine films. In our experience, droopy shoulder syndrome has accounted for most cases of thoracic outlet syndrome but is largely unrecognized by physicians. Recognition of this syndrome should lead to a better understanding of the underlying pathophysiology and prevent unnecessary surgery.  相似文献   
62.
The Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) global pandemic significantly impacted CF clinical research within the Cystic Fibrosis Foundation Therapeutics Development Network (CFF TDN). A Research Electronic Data Capture (REDCap) survey was developed and sent to network sites to monitor and understand the impact on research teams, ongoing and anticipated clinical research, and specific clinical and research procedures. Key findings indicated an early impact on participant enrollment, research team stability, and procedures such as spirometry and sputum induction. These trends steadily improved over the months as research activities began to recover across the TDN. While SARS-CoV-2 created a significant challenge it also highlights new opportunities to expand CF research with greater focus on data collection outside of research centers and increased access for remote participation.  相似文献   
63.
Chronic Azithromycin (AZM) is a common treatment for lung infection. Among adults at risk of cardiac events, AZM use has been associated with cardiovascular harm. We assessed cardiovascular safety of AZM among children with CF, as a secondary analysis of a placebo-controlled, clinical trial, in which study drug was taken thrice-weekly for a planned 18 months. Safety assessments using electrocardiogram (ECG) occurred at study enrollment, and then after 3 weeks and 18 months of participation. Among 221 study participants with a median of 18 months follow-up, increased corrected QT interval (QTc) of ≥30 msec was rare, at 3.4 occurrences per 100 person-years; and incidence of QTc prolongation was no higher in the AZM arm than the placebo arm (1.8 versus 5.4 per 100 person-years). No persons experienced QTc intervals above 500 msec. Long-term chronic AZM use was not associated with increased QT prolongation.  相似文献   
64.
Highly effective CFTR modulator drug therapy is increasingly available to those with cystic fibrosis. Multiple observational research studies are now being conducted to better understand the impacts of this important therapeutic milestone on long-term outcomes, patient care needs, and future research priorities. PROMISE is a large, multi-disciplinary academic study focused on the broad impacts of starting elexacaftor/tezacaftor/ivacaftor in the US population age 6 years and older. The many areas of investigation and rationale for each are discussed by organ systems, along with recognition of remaining important questions that will not be addressed by this study alone. Knowledge gained through this and multiple complementary studies around the world will help to understand important health outcomes, clinical care priorities, and research needs for a large majority of people treated with these or similarly effective medications targeting the primary cellular impairment in cystic fibrosis.  相似文献   
65.
The association of atopic diseases with endometriosis   总被引:1,自引:0,他引:1  
Comparisons of the incidence of health-related problems were conducted between women with demonstrable endometriosis (N = 88) and a control group (N = 88). Increased incidence of respondents' reports of allergic manifestations (p less than .005) were found. Directions for further research are suggested.  相似文献   
66.
67.
68.
Objective: The purpose of this study was to determine the epidemiology of sexually transmitted diseases (STDs) among pregnant adolescents.Methods: Charts of all patients (n = 735) who attended the Maternal and Infant Care Clinic at University Hospital, Newark, NJ, between July 1, 1991, and June 30, 1992, were reviewed for STDs which included gonorrhea, chlamydia, syphilis, and human immunodeficiency virus (HIV). At the first prenatal visit, each registrant had endocervical specimens obtained to detect gonorrhea and chlamydia. A serum sample was obtained for syphilis screening. HIV testing was made available to all patients and testing was done on a voluntary basis. The same STD screening that was done at the initial visit was repeated at 28 and 36 weeks.Results: Twenty-five percent of patients tested positive for one or more STDs. The mean patient age was 17.3 years. The mean gestational age at first visit was 19.5 weeks. The mean number of visits was 7.3. The following STDs were identified: 4.8% of patients tested positive for gonorrhea, 20.9% tested positive for chlamydia, and 1.7% tested positive for syphilis. Twenty-one percent of patients had a positive STD diagnosed at the initial visit. Another 4.8% of patients had an STD diagnosed at some time after the initial visit when the initial screen was negative for STDs. An additional 1% of patients who initially tested positive for an STD had subsequent screening which revealed another STD (different organism). Seven patients tested HIV positive. Sixty-one percent of patients with STDs agreed to HIV testing. One patient had HIV coexistent with another STD.Conclusions: Pregnant adolescents are at risk for multiple STDs. HIV testing should be offered. STD screening should be repeated in the third trimester in adolescent patients.  相似文献   
69.
This article discusses a number of medical conditions that are common to aquatic athletes. Exercise-induced asthma is particularly prevalent in swimmers because swimming is among the activities tolerated best by asthmatics. The healthcare professional frequently must evaluate and manage respiratory infections and infectious mononucleosis in swimmers, particularly in regard to the safe timing of return to training and competition. Dilutional sports pseudoanemia must be differentiated from the true anemias that are due mostly to iron-deficiency and intravascular hemolysis. Finally, the evaluation, management, and prevention of otitis externa, external auditory canal exostoses, and dermatologic disorders in swimmers are reviewed.  相似文献   
70.
Cerebral lateralization: relationship of language and ideomotor praxis   总被引:2,自引:0,他引:2  
Meador KJ  Loring DW  Lee K  Hughes M  Lee G  Nichols M  Heilman KM 《Neurology》1999,53(9):2028-2031
OBJECTIVE: To determine the relationship of language lateralization and hand preference to praxis performance following left and right hemispheric amobarbital-induced inactivations. BACKGROUND: Patients who are aphasic from left cerebral dysfunction also frequently exhibit ideomotor apraxia in which they make temporal, spatial, and postural errors of learned skilled movements. However, hemispheric lateralization of the systems mediating ideomotor praxis in patients with atypical cerebral language dominance (i.e., bilateral or right hemispheric language function) remains uncertain. METHODS: Subjects included 90 patients with intractable seizures who were undergoing the intracarotid amobarbital procedure (IAP) as part of their preoperative evaluation for epilepsy surgery. Hand preference was determined by the Benton Handedness Questionnaire. Praxis was assessed by the subject's performance when pantomiming the use of four pictured tools. RESULTS: During left IAP, patients with typical language dominance made more ideomotor apraxic errors than did patients with atypical language dominance. During right IAP, patients with atypical language dominance made more ideomotor apraxic errors than did patients with typical language dominance. Overall, patients with atypical language dominance made fewer ideomotor apraxic errors than did patients with typical language dominance. These relationships were present irrespective of hand preference. CONCLUSIONS: Language dominance is more closely associated with the laterality of temporal and spatial movement representations (i.e., ideomotor praxis dominance) than is hand preference. Patients with atypical language dominance exhibit more bilateral cerebral distribution of both language and praxis function.  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