首页 | 官方网站   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   1288篇
  免费   78篇
  国内免费   2篇
医药卫生   1368篇
  2023年   8篇
  2022年   11篇
  2021年   15篇
  2020年   19篇
  2019年   21篇
  2018年   15篇
  2017年   26篇
  2016年   28篇
  2015年   33篇
  2014年   24篇
  2013年   34篇
  2012年   72篇
  2011年   64篇
  2010年   49篇
  2009年   24篇
  2008年   61篇
  2007年   71篇
  2006年   77篇
  2005年   67篇
  2004年   54篇
  2003年   43篇
  2002年   41篇
  2001年   41篇
  2000年   85篇
  1999年   63篇
  1998年   15篇
  1997年   20篇
  1996年   14篇
  1995年   11篇
  1994年   14篇
  1993年   9篇
  1992年   25篇
  1991年   10篇
  1990年   14篇
  1989年   10篇
  1988年   10篇
  1987年   13篇
  1986年   11篇
  1985年   10篇
  1984年   14篇
  1983年   18篇
  1982年   14篇
  1981年   7篇
  1979年   13篇
  1977年   4篇
  1975年   10篇
  1974年   8篇
  1973年   10篇
  1972年   7篇
  1971年   6篇
排序方式: 共有1368条查询结果,搜索用时 15 毫秒
61.
62.
We investigated the influence of symptoms and signs on the detection of Chlamydia trachomatis, Mycoplasma genitalium and Ureaplasma urealyticum organisms (ureaplasmas) in men with non-gonococcal urethritis (NGU). Two hundred and forty-two men attending the Jefferiss Wing at St Mary's Hospital for a sexual health assessment were evaluated, of whom 169 had NGU. Urethral inflammation was diagnosed if there were either > or =5 polymorphonuclear leucocytes (PMNLs) per high-power field (HPF) in five or more microscope fields of a Gram-stained urethral smear, or > or =10 PMNLs per HPF in five or more fields of a Gram-stained thread from 15-20 mL of a first-passed urine (FPU) specimen. C. trachomatis was diagnosed by direct immunofluoresence, M. genitalium by a polymerase chain reaction assay and ureaplasmas by culture. On multivariate analysis, to control for potential confounding by age, ethnicity, sexual lifestyle and co-infection, an urethral discharge remained significantly associated with the detection of C. trachomatis and M. genitalium in men with acute urethritis [OR 12.3, 95% CI (2.39-63.5) and OR 35.2, 95% CI (3.9-319.6), respectively], but dysuria or penile irritation did not. The detection of ureaplasmas was not associated with any clinical feature. In addition, on multivariate analysis men with NGU who were either symptomatic or had an observable discharge were more likely to have C. trachomatis or M. genitalium detected [(OR 6.92, 95% CI 1.41-33.9) and (OR 5.18, 95% CI 0.99-27.1), respectively], but not ureaplasmas (OR 1.19, 95% CI 0.33-4.35). The findings suggest that in men with acute NGU, symptoms or signs, and in particular a urethral discharge, are associated with the detection of C. trachomatis and M. genitalium, but not ureaplasmas. Currently, there is no precise answer to the question of whether all men attending a GUM clinic need to be screened for NGU, but if clinically asymptomatic NGU is found not to be associated with a sexually transmitted pathogen, the UK clinical guidelines requiring the preparation of a urethral smear from such men would need to be revised.  相似文献   
63.
Evaluation of remifentanil as single drug for awake fiberoptic intubation   总被引:14,自引:0,他引:14  
BACKGROUND: Awake fiberoptic intubation is the standard of care for difficult airway management. Quality and success of this technique depend on the experience of the intubating physician and the proper preparation of the patient. The aim of this study was to compare remifentanil (R) as single agent to the combination of fentanyl (F) and midazolam (M), which have been the drugs for analgesia and sedation for this procedure. METHODS: Seventy-four adult patients requiring nasotracheal intubation were randomly assigned to one of two groups. In group I, (n=37) R was administered in incremental dosages (0.1-0.25-0.5 microg/kg/min) by an infusion pump according to comfort, level of sedation and respiratory depression. In group II, (n=37) analgesia and sedation was achieved by F 1.5 microg/kg and doses of between 1 and 10 mg M, titrated to the individual needs. Patient reactions like grimacing, movement and coughing during intubation were assessed, as well as patient recall of the procedure. Haemodynamic and respiratory parameters were continuously recorded. RESULTS: Group I patients better tolerated nasal tube passage (P<0.001) and laryngeal tube advancement (P<0.001) than group II. Remifentanil better suppressed hemodynamic response to nasal intubation (P<0.001). No significant difference in respiratory data was recorded. In group I more recall of the procedure was observed (six vs. zero patients, P<0.05). CONCLUSION: Remifentanil in high doses, as the single agent for patient preparation for awake fiberoptic intubation seems to improve intubating conditions, quality and reliability of the procedure. However, a higher incidence of recall is to be expected.  相似文献   
64.
Huwiler-Müntener K  Jüni P  Junker C  Egger M 《JAMA》2002,287(21):2801-2804
Context  The evaluation of the methodologic quality of randomized controlled trials (RCTs) is central to evidence-based health care. Important methodologic detail may, however, be omitted from published reports, and the quality of reporting is therefore often used as a proxy measure for methodologic quality. We examined the relationship between reporting quality and methodologic quality of published RCTs. Methods  Study of 60 reports of placebo-controlled trials published in English-language journals from 1985 to 1997. Reporting quality was measured using a 25-item scale based on the 1996 issue of the Consolidated Standards of Reporting Trials (CONSORT). Concealment of allocation, appropriate blinding, and analysis according to the intention-to-treat principle were indicators of methodologic quality. Methodologic quality was compared between groups of trials defined by reporting quality scores of low, intermediate, and high. Reporting quality scores were compared between groups defined by high and low methodologic quality. Results  Among 23 trials of low reporting quality (median score, 9 [range, 3.5-10.5]), allocation concealment was unclear for all but 1 trial, but there were 16 trials (70%) with adequate blinding and 9 trials (39%) that had been analyzed according to the intention-to-treat principle. Among 18 trials of high reporting quality (median score, 18 [range 16.5-22.0]), there were 8 trials (44%) with adequate allocation concealment, 16 trials (89%) with adequate blinding, and 13 trials (72%) analyzed according to the intention-to-treat principle. The median reporting score was 15.0 for the 33 trials that were analyzed according to intention-to-treat principle and 14.5 for the 14 trials with on-treatment analyses (P = .67). Conclusions  Similar quality of reporting may hide important differences in methodologic quality, and well-conducted trials may be reported badly. A clear distinction should be made between these 2 dimensions of the quality of RCTs.   相似文献   
65.
Influence of endurance exercise on respiratory muscle performance   总被引:4,自引:0,他引:4  
PURPOSE: During high-intensity, exhaustive, constant-load exercise above 85% of maximal oxygen consumption, the diaphragm of healthy subjects can fatigue. Although a decrease in trans-diaphragmatic pressure is the most objective measure of diaphragmatic fatigue, possible extra-diaphragmatic muscle fatigue would not be detected by this method. The aim of the present study was to investigate the impact of exhaustive, constant-load cycling exercise at different intensities on global respiratory performance determined by the time to exhaustion while breathing against a constant resistance. METHODS: Ten healthy, male subjects performed an exhaustive cycling endurance test at 65, 75, 85, and 95% of peak oxygen consumption (VO2peak). Before cycling (to) as well as at 10 min (t10) and 45 min (t45) after cycling, respiratory performance was determined. RESULTS: Breathing endurance was equivalently reduced after exhaustive cycling at either 65% (8.4 +/- 4.1 min [t0] vs 3.9 +/- 2.8 min [t10]), 75% (9.9 +/- 6.1 vs 4.4 +/- 2.8 min), 85% (9.3 +/- 6.0 vs 3.8 +/- 2.9 min), or 95% VO2peak (8.5 +/- 5.1 vs 4.0 +/- 2.5 min) and, therefore, was independent of exercise intensity. CONCLUSION: This result contradicts previous findings, possibly due to the fact that extra-diaphragmatic muscles are tested in addition to the diaphragm during resistive breathing.  相似文献   
66.
Background. 35% of preterm infants with intraventricular hemorrhage develop ventricular dilatation. The posthemorrhagic ventricular dilatation can persist, be transient or be progressive. Finally 1–2% of all very low birthweight (VLBW <1500 g) infants require shunt placement for the treatment of the posthemorrhagic hydrocephalus. Outcome. The neurodevelopmental outcome is extremely poor in children surviving progressive posthemorrhagic ventricular dilatation. Therapy. There are no uniform guidelines for the treatment of preterm infants with progressive posthemorrhagic ventricular dilatation. Randomised multicenter trials demonstrated, that inhibition of cerebrospinal fluid production with acetazolamide and furosemide or early cerebrospinal fluid tapping did not reduce the need for shunt placement and may worsen the outcome or can be associated with adverse side-effects. Preterm infants with posthemorrhagic ventricular dilatation should be treated by standard therapy with uniform guidelines for cerebrospinal fluid tapping and shunt placement.  相似文献   
67.
68.
69.
Despite ambivalent situations in the cardiovascular business, Jeffrey Frazier of John Goodman & Associates identifies four operational trends that are affecting the growth of heart programs.  相似文献   
70.
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-23

京公网安备 11010802026262号