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   158867篇
  免费   10790篇
  国内免费   637篇
耳鼻咽喉   1769篇
儿科学   3915篇
妇产科学   2617篇
基础医学   20949篇
口腔科学   3391篇
临床医学   15570篇
内科学   33638篇
皮肤病学   3242篇
神经病学   14607篇
特种医学   7015篇
外国民族医学   14篇
外科学   25226篇
综合类   1974篇
一般理论   109篇
预防医学   11812篇
眼科学   3308篇
药学   10139篇
中国医学   238篇
肿瘤学   10761篇
  2023年   885篇
  2022年   1485篇
  2021年   3375篇
  2020年   2079篇
  2019年   3118篇
  2018年   3593篇
  2017年   2799篇
  2016年   3137篇
  2015年   3587篇
  2014年   5091篇
  2013年   6853篇
  2012年   10340篇
  2011年   11003篇
  2010年   6311篇
  2009年   6017篇
  2008年   9745篇
  2007年   10194篇
  2006年   10101篇
  2005年   10152篇
  2004年   9308篇
  2003年   8617篇
  2002年   8268篇
  2001年   2152篇
  2000年   1840篇
  1999年   2126篇
  1998年   1933篇
  1997年   1557篇
  1996年   1341篇
  1995年   1256篇
  1994年   1129篇
  1993年   1024篇
  1992年   1295篇
  1991年   1189篇
  1990年   1031篇
  1989年   977篇
  1988年   914篇
  1987年   887篇
  1986年   884篇
  1985年   871篇
  1984年   927篇
  1983年   799篇
  1982年   962篇
  1981年   863篇
  1980年   732篇
  1979年   657篇
  1978年   649篇
  1977年   536篇
  1976年   515篇
  1974年   511篇
  1973年   449篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
W C Hsiao  P Braun  E R Becker  S R Thomas 《JAMA》1987,258(6):799-802
This article describes the design and methods of a study currently under way to develop a Resource-Based Relative Value Scale (RBRVS); an alternative basis for establishing the payment rate for the services and procedures (S/Ps) of physicians in medical and surgical specialties. Physician resource inputs to be measured include (1) S/P time, (2) pre-S/P and post-S/P times, (3) intensity, (4) practice costs, including malpractice premiums, and (5) the cost of specialty training. These five factors will be combined to produce an RBRVS denominated in nonmonetary units. In the initial phase of the study, data on time and intensity will be obtained through a national survey of physicians who perform these S/Ps. In the second, consensus phase of the project, the investigators will convene a panel of representatives of the medical profession, third-party payers, consumers, and other interested parties to examine areas of agreement and disagreement as to how an RBRVS should be used for policy purposes. The final results of this study are expected by the summer of 1988.  相似文献   
22.
Summary An infant girl is described who had cor triatriatum and partial anomalous pulmonary venous connection of the left pulmonary veins to the coronary sinus, the first report of this combination of lesions. The infant also had a Dandy-Walker malformation and multiple facial and intrathoracic hemangiomas. The cardiac diagnosis was made by two-dimensional echocardiography. Cardiac catheterization and angiography confirmed the findings and also demonstrated a persistent left superior vena cava draining to the coronary sinus. The infant underwent successful surgical repair. Partial anomalous pulmonary venous connection and left superior vena cava not infrequently are associated with cor triatriatum. Although two-dimensional echocardiography is sensitive for the detection of cor triatriatum, preoperative cardiac catheterization is necessary to identify unequivocally systemic and pulmonary venous connections.  相似文献   
23.
The purpose of this study was to determine whether blood lipid and lipoprotein concentrations varied in 5 men with advanced HIV-1 infection after 12 months of aerobic exercise training. Prior to exercise, the mean baseline cholesterol and high-density lipoprotein cholesterol (HDL-C) serum concentration were each lower, and mean baseline triglyceride concentration was higher compared to a healthy population norm. Consistent exercise training for 12 months failed to significantly (p > .05) alter cholesterol or HDL-C. Triglyceride concentration was significantly (p < .05) elevated above baseline (63 mg/dL) regardless of exercise compliance. The results suggest that long-term exercise training cannot correct lipid profile abnormality, particularly hypertriglyceridemia, common to individuals with advanced HIV-1 infection.  相似文献   
24.
25.
Studies of adults suggest that metered-dose inhalers with spacers are as effective as hand-held nebulizers for bronchodilator delivery. We studied 13 children with acute asthma. They received two puffs every 2 minutes from metered-dose inhalers with spacers (range, 4 to 14 puffs) titrated until improvement stopped. Peak expiratory flow increased 34% for metered-dose inhalers with spacers after the first 2 puffs and increased 87% for metered-dose inhalers with spacers after dose titration. After titration, respiratory rate decreased by 12%, heart rate increased by 2%, and breath sounds improved in 92% of the patients. We concluded that the metered-dose inhalers with spacers are an effective device for the treatment of asthma in the pediatric emergency department and that the use of metered-dose inhalers with spacers with titration can achieve significant bronchodilation in the treatment of patients with acute asthma.  相似文献   
26.
27.
Acoustic analysis of a reading passage was used to identify the abnormal phonatory events associated with adductor spasmodic dysphonia (ADSD) pre- and postinjection of Botulinum Toxin A (Botox). Thirty-one patients (age 22 to 74 years) diagnosed with ADSD were included for study. All patients were new recipients of Botox, and the examination of their voice occurred before and after their initial injection of Botox. Acoustic events were identified from reading samples of the Rainbow Passage produced by each of the patients. These events were examined from sentences containing primarily voiced sound segments. Dependent variables included the number of phonatory breaks, frequency shifts, and aperiodic segments--all variables previously defined by the investigators. Additionally, calculated variables were made of the percentage of time these events occurred relative to the duration of the cumulative voiced segments. A sex- and age-matched control group (+/-2 years) was included for statistical comparison. Results indicated that those with ADSD produced more aberrant acoustic events than the controls. Aperiodicity was the predominant acoustic event produced during the reading, followed by frequency shifts and phonatory breaks. Within the ADSD group, the number of atypical acoustic events decreased following Botox injection. It is important that the occurrence of specific abnormal acoustic events was sufficient to differentiate the disordered speakers from the controls following as well as preceding initial Botox injection, as indicated by discriminant function analysis. This paper complements our previous work using this acoustic analysis method for defining the abnormal events present in the voice of those with ADSD and further suggests that these measures can be used in conjunction with perceptual impressions to differentiate speakers on the basis of initial severity.  相似文献   
28.
29.
30.
The literature suggests that pain in the elderly, especially among seniors with dementia, is under-assessed and under-treated.This qualitative study solicited the perspectives of seniors, front-line nursing staff, nursing-home administrators, and informal caregivers of seniors with dementia on the current status of pain assessment and management. The views of these participants complement the research findings reported in the literature. While some of their explanations and potential solutions concerning under-treatment of pain in seniors echo views that have been presented in the literature, the participants also pointed to factors and avenues that have been given less formal consideration (e.g., systemic barriers to effective assessment and treatment of pain).They also highlighted the need for pain-control strategies beyond medication. The implications of these findings are discussed.  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