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   4138篇
  免费   363篇
  国内免费   20篇
耳鼻咽喉   47篇
儿科学   108篇
妇产科学   85篇
基础医学   546篇
口腔科学   83篇
临床医学   625篇
内科学   713篇
皮肤病学   22篇
神经病学   419篇
特种医学   289篇
外科学   580篇
综合类   111篇
预防医学   384篇
眼科学   49篇
药学   364篇
中国医学   1篇
肿瘤学   95篇
  2021年   35篇
  2019年   39篇
  2018年   41篇
  2017年   41篇
  2016年   44篇
  2015年   44篇
  2014年   73篇
  2013年   78篇
  2012年   120篇
  2011年   139篇
  2010年   80篇
  2009年   86篇
  2008年   123篇
  2007年   162篇
  2006年   140篇
  2005年   120篇
  2004年   114篇
  2003年   135篇
  2002年   122篇
  2001年   131篇
  2000年   134篇
  1999年   121篇
  1998年   83篇
  1997年   77篇
  1996年   74篇
  1995年   83篇
  1994年   62篇
  1993年   68篇
  1992年   98篇
  1991年   112篇
  1990年   119篇
  1989年   129篇
  1988年   140篇
  1987年   110篇
  1986年   115篇
  1985年   123篇
  1984年   84篇
  1983年   82篇
  1982年   61篇
  1981年   49篇
  1980年   68篇
  1979年   70篇
  1978年   60篇
  1977年   72篇
  1976年   59篇
  1975年   54篇
  1974年   57篇
  1973年   46篇
  1972年   30篇
  1971年   28篇
排序方式: 共有4521条查询结果,搜索用时 9 毫秒
11.
The federal Medicare Diagnosis Related Group payment mechanism is undergoing constant change. Significant interest has been generated at the health policy level regarding reimbursement for patients with complications and comorbidities. The purpose of this study was to analyze hospital resource consumption for patients in the seventeen urology non-complicating condition (CC) stratified Diagnostic Related Groups (DRGs), currently 45 percent of urology DRGs. We analyzed 185 Medicare patients in these non-CC stratified urology DRGs and found that patients with more CCs per patient had higher total hospital costs per patient, financial risk under DRGs, a greater percentage of outliers, and a higher mortality, than patients in these same DRGs with fewer CCs per patient. These findings suggest that the current DRG system is inequitable to some patients and certain hospitals vis-a-vis non-CC stratified urology DRGs. The Health Care Financing Administration has not significantly changed the complicating condition urology DRG classification, as of its recent May, 1988 legislation. Financial disincentives to treat these patients may affect both their access and quality of care in the future.  相似文献   
12.
Neurological sequelae of hypothyroidism are well recognized and relatively common. Neurological symptoms occurring as a presenting feature of this illness are, however, uncommon. Here we report three patients who presented in such a way and in whom the diagnosis was only suspected because of slow relaxing reflexes.  相似文献   
13.
14.
Although optic neuropathy is a known complication of systemic lupus erythematosus, its association with other connective tissue diseases is less well documented. We describe 3 previously asymptomatic women presenting with optic neuropathy in whom changes highly suggestive of primary Sj?gren's syndrome (SS) were found by minor salivary gland biopsy 1-6 years after initial presentation. Typical symptoms of SS were absent initially and developed slowly, while serologic abnormalities were consistently present. Optic neuropathy may be a presenting neurologic feature of SS and may antedate typical signs and symptoms of SS. Primary SS should be considered in the differential diagnosis of optic neuropathy.  相似文献   
15.
A plan was developed and implemented to reduce costs per unit of service in three departments (pulmonary, cardiology, and neurology services), which resulted in a 19% reduction in cost per RVU over two years. These savings were attained primarily by a reduction of supplies and the redesign of work practices, which resulted in a reduction of both personnel and purchased service expenses. The departments have continued to improved the quality of services provided while reducing the costs of these services through this proactive approach to cost-containment.  相似文献   
16.
17.
PURPOSE: Some researchers (F. R. Vellutino, F. M. Scanlon, & M. S. Tanzman, 1994) have argued that the different domains comprising language (e.g., phonology, semantics, and grammar) may influence reading development in a differential manner and at different developmental periods. The purpose of this study was to examine proposed causal relationships among different linguistic subsystems and different measures of reading achievement in a group of children with reading disabilities. METHODS: Participants were 279 students in 2nd to 3rd grade who met research criteria for reading disability. Of those students, 108 were girls and 171 were boys. In terms of heritage, 135 were African and 144 were Caucasian. Measures assessing pre-reading skills, word identification, reading comprehension, and general oral language skills were administered. RESULTS: Structural equation modeling analyses indicated receptive and expressive vocabulary knowledge was independently related to pre-reading skills. Additionally, expressive vocabulary knowledge and listening comprehension skills were found to be independently related to word identification abilities. CONCLUSION: Results are consistent with previous research indicating that oral language skills are related to reading achievement (e.g., A. Olofsson & J. Niedersoe, 1999; H. S. Scarborough, 1990). Results from this study suggest that receptive and expressive vocabulary knowledge influence pre-reading skills in differential ways. Further, results suggest that expressive vocabulary knowledge and listening comprehension skills facilitate word identification skills.  相似文献   
18.
The in-vitro activity of PD 131628, the active metabolite of the prodrug PD 131112, was compared with that of ciprofloxacin and members of other groups of antimicrobial agents against 701 recent clinical isolates and strains with known mechanisms of resistance. The MIC90s of PD 131628 against the Enterobacteriaceae were between 0.008 and 0.5 mg/L; PD 131628 was one- to four-fold more active than ciprofloxacin against these strains and was four-fold more active than ciprofloxacin against Pseudomonas aeruginosa. Against the Gram-positive species tested, PD 131628 was two- to four-fold more active than ciprofloxacin, inhibiting all strains of Staphylococcus aureus and Streptococcus pneumoniae with 0.5 mg/L or less. PD 131628 was very active against Neisseria spp., Haemophilus influenzae and Moraxella catarrhalis, with MIC90s ranging from 0.004 to 0.008 mg/L. Organisms with decreased susceptibility to other quinolones had decreased susceptibility to PD 131628, but there was no cross-resistance between this class of antimicrobial and other classes. The protein binding of PD 131628 was at most 25% across a broad range of concentrations. The addition of 70% human serum had little effect on the MICs, but caused a two- to eight-fold increase in MBCs.  相似文献   
19.
20.
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