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   1008668篇
  免费   77273篇
  国内免费   2638篇
耳鼻咽喉   13122篇
儿科学   34986篇
妇产科学   28915篇
基础医学   147336篇
口腔科学   27933篇
临床医学   91014篇
内科学   196266篇
皮肤病学   23105篇
神经病学   80155篇
特种医学   38911篇
外国民族医学   305篇
外科学   151109篇
综合类   23779篇
一般理论   388篇
预防医学   78829篇
眼科学   22967篇
药学   73002篇
  3篇
中国医学   2050篇
肿瘤学   54404篇
  2018年   10830篇
  2017年   8465篇
  2016年   9633篇
  2015年   10887篇
  2014年   14772篇
  2013年   22499篇
  2012年   29624篇
  2011年   31538篇
  2010年   18877篇
  2009年   17743篇
  2008年   29258篇
  2007年   30951篇
  2006年   31443篇
  2005年   30133篇
  2004年   29452篇
  2003年   28299篇
  2002年   27334篇
  2001年   47290篇
  2000年   48378篇
  1999年   40590篇
  1998年   11297篇
  1997年   10189篇
  1996年   10236篇
  1995年   9828篇
  1994年   9141篇
  1993年   8535篇
  1992年   32456篇
  1991年   31644篇
  1990年   31188篇
  1989年   30050篇
  1988年   27340篇
  1987年   27494篇
  1986年   25623篇
  1985年   24762篇
  1984年   18531篇
  1983年   15635篇
  1982年   9368篇
  1981年   8448篇
  1979年   17021篇
  1978年   12316篇
  1977年   10407篇
  1976年   9855篇
  1975年   10314篇
  1974年   12471篇
  1973年   11993篇
  1972年   11026篇
  1971年   10246篇
  1970年   9534篇
  1969年   8857篇
  1968年   8255篇
排序方式: 共有10000条查询结果,搜索用时 343 毫秒
121.
Die Ophthalmologie - Die Filtrationsverfahren sind im Gegensatz zu allen anderen Glaukomoperationen mit einer biomikroskopisch sichtbaren Wundheilung assoziiert, sodass eine Vielzahl von...  相似文献   
122.
123.

Objectives

Short successive periods of skeletal muscle disuse have been suggested to substantially contribute to the observed loss of skeletal muscle mass over the life span. Hospitalization of older individuals due to acute illness, injury, or major surgery generally results in a mean hospital stay of 5 to 7 days, during which the level of physical activity is strongly reduced. We hypothesized that hospitalization following elective total hip arthroplasty is accompanied by substantial leg muscle atrophy in older men and women.

Design and participants

Twenty-six older patients (75 ± 1 years) undergoing elective total hip arthroplasty participated in this observational study.

Measurements

On hospital admission and on the day of discharge, computed tomographic (CT) scans were performed to assess muscle cross-sectional area (CSA) of both legs. During surgery and on the day of hospital discharge, a skeletal muscle biopsy was taken from the m. vastus lateralis of the operated leg to assess muscle fiber type–specific CSA.

Results

An average of 5.6 ± 0.3 days of hospitalization resulted in a significant decline in quadriceps (?3.4% ± 1.0%) and thigh muscle CSA (?4.2% ± 1.1%) in the nonoperated leg (P < .05). Edema resulted in a 10.3% ± 1.7% increase in leg CSA in the operated leg (P < .05). At hospital admission, muscle fiber CSA was smaller in the type II vs type I fibers (3326 ± 253 μm2 vs 4075 ± 279 μm2, respectively; P < .05). During hospitalization, type I and II muscle fiber CSA tended to increase, likely due to edema in the operated leg (P = .10).

Conclusions

Six days of hospitalization following elective total hip arthroplasty leads to substantial leg muscle atrophy in older patients. Effective intervention strategies are warranted to prevent the loss of muscle mass induced by short periods of muscle disuse during hospitalization.  相似文献   
124.

Objectives

This study aimed to explore the genetic diversity of Streptococcus pneumoniae isolates in a Tunisian pneumology hospital.

Methods

A total of 141 S. pneumoniae strains isolated between 2009–2016 in the microbiology laboratory at A. Mami Hospital of Pneumology were investigated. Antimicrobial susceptibility testing was performed the disk diffusion method. MICs of penicillin G, amoxicillin and cefotaxime were determined by Etest. Serotyping was inferred from the results of multiplex PCR targeting 40 serotypes. Sequence types (STs) were determined by multilocus sequence typing (MLST).

Results

Among the 141 S. pneumoniae isolates, 98 (69.5%) were resistant to erythromycin. Evaluation of β-lactam susceptibility showed that 90 strains (63.8%) were non-susceptible to penicillin, whereas 48 (34.0%) had decreased susceptibility to amoxicillin and 21 (14.9%) to cefotaxime. Twenty-five serotypes were detected, and 10 isolates were classified as non-typeable. Vaccine coverage was 56.7%, 60.3% and 75.2% for pneumococcal conjugate vaccine 7 (PCV7), PCV10 and PCV13, respectively. Overall, 73 STs were identified, including 23 described for the first time. The most frequent STs were ST179 (n?=?17), ST3772 (n?=?14), ST2918 (n?=?10) and ST4003 (n?=?5), related to serotypes 19F, 19A, 14 and 23F, respectively. Moreover, 110 strains were classified within 45 STs. Three international antimicrobial-resistant clones were found, including Denmark14-ST230 (n?=?22), Spain9V-ST156 (n?=?22) and Portugal19F-ST177 (n?=?20).

Conclusion

This study emphasises the clonal and international dissemination of antimicrobial-resistant S. pneumoniae clones. Significant differences in genetic variation were documented by MLST within the various serotypes identified.  相似文献   
125.
126.
127.
128.
129.
130.
ABSTRACT

A monocausal bacteriological understanding of infectious disease orients tuberculosis control efforts towards antimicrobial interventions. A bias towards technological solutions can leave multistranded public health and social interventions largely neglected. In the context of globalising biomedical approaches to infectious disease control, this ethnography-inspired review article reflects upon the implementation of rapid diagnostic technology in low- and middle-income countries. Fieldwork observations in Vietnam provided a stimulus for a critical review of the global rollout of tuberculosis diagnostic technology. To address local needs in tuberculosis control, health managers in resource-poor settings are readily cooperating with international donors to deploy novel diagnostic technologies throughout national tuberculosis programme facilities. Increasing investment in new diagnostic technologies is predicated on the supposition that these interventions will ameliorate disease outcomes. However, suboptimal treatment control persists even when accurate diagnostic technologies are available, suggesting that promotion of singular technological solutions can distract from addressing systemic change, without which disease susceptibility, propagation of infection, detection gaps, diagnostic delays, and treatment shortfalls persist.  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