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   5702篇
  免费   533篇
  国内免费   12篇
耳鼻咽喉   40篇
儿科学   120篇
妇产科学   161篇
基础医学   932篇
口腔科学   67篇
临床医学   611篇
内科学   1007篇
皮肤病学   151篇
神经病学   761篇
特种医学   218篇
外科学   651篇
综合类   66篇
一般理论   4篇
预防医学   648篇
眼科学   188篇
药学   350篇
中国医学   5篇
肿瘤学   267篇
  2023年   30篇
  2022年   53篇
  2021年   108篇
  2020年   68篇
  2019年   107篇
  2018年   116篇
  2017年   115篇
  2016年   114篇
  2015年   139篇
  2014年   154篇
  2013年   250篇
  2012年   372篇
  2011年   354篇
  2010年   223篇
  2009年   180篇
  2008年   309篇
  2007年   311篇
  2006年   269篇
  2005年   323篇
  2004年   283篇
  2003年   267篇
  2002年   255篇
  2001年   128篇
  2000年   110篇
  1999年   121篇
  1998年   77篇
  1997年   54篇
  1996年   62篇
  1995年   60篇
  1994年   50篇
  1993年   44篇
  1992年   86篇
  1991年   84篇
  1990年   56篇
  1989年   64篇
  1988年   68篇
  1987年   70篇
  1986年   65篇
  1985年   50篇
  1984年   38篇
  1983年   33篇
  1982年   28篇
  1981年   32篇
  1980年   30篇
  1979年   45篇
  1975年   27篇
  1973年   30篇
  1972年   26篇
  1971年   30篇
  1969年   25篇
排序方式: 共有6247条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Transcranial Doppler (TCD) is an accepted modality for the evaluation of cerebral blood flow velocities. OBJECTIVES: The purpose of this study was to test the feasibility of bedside TCD measurement in the emergency department (ED) with critically ill, intubated patients. METHODS: A prospective convenience sample of patients presenting to a university hospital over a two-month period underwent TCD evaluation of the middle cerebral artery. Intubated patients with head trauma and any patient requiring tracheal intubation were eligible. A 2-MHz Doppler probe was positioned over the temporal bone to acquire blood flow velocities. An emergency medicine resident and research assistant obtained measurements. Continuous TCD tracings were recorded on a video cassette recorder tape for quality assurance review and data collection. Vital signs and therapeutic interventions were also recorded. Flow velocities were measured in cm/s; the peak Resistance Index (RI) was calculated for each patient. RESULTS: A total of 30 patients were enrolled in the study. Adequate tracings were obtained in 25 patients (83%) without a disruption of resuscitation. Tracings could not be obtained in five patients; they were listed as TCD failures. However, in two of these patients, adequate flow velocity tracings were obtained after resuscitation. Four patients were evaluated during tracheal intubation. One patient was monitored successfully during cardiopulmonary resuscitation. The median time required for data acquisition was 1.9 minutes. The mean highest RI for those who expired was 0.84. For those who survived, the mean highest RI was 0.52. The difference of 0.32 was statistically significant (p = 0.04). CONCLUSIONS: Noninvasive blood flow velocity monitoring of the middle cerebral artery using TCD is feasible in the ED when performed at the bedside on intubated patients with traumatic brain injury and others during tracheal intubation and resuscitation.  相似文献   
5.
We conducted a randomized, double-blind, crossover trial of two anticholinergic agents--trihexyphenidyl and tridihexethyl chloride (a quaternary anticholinergic that does not cross the blood-brain barrier)--in patients with acquired nystagmus and measured visual acuity and nystagmus before and at the end of 1 month on each medication. Of the 10 patients admitted to the study, only five completed trials of both drugs due to intolerance of medication or intercurrent illness. Of six patients who completed the trial of trihexyphenidyl, only one showed improvement. Of six patients who completed a trial of tridihexethyl chloride, four showed improvement. We conclude that (1) trihexyphenidyl is not a reliable treatment for acquired nystagmus, although occasional patients may benefit; (2) anticholinergic agents may suppress nystagmus by peripheral rather than central mechanisms; and (3) the side effects of anticholinergic agents limit their effectiveness in the treatment of nystagmus.  相似文献   
6.
Operative mortality, postoperative morbidity and follow up data were analyzed retrospectively from 122 consecutive patients, over 65 years old undergoing elective aortocoronary bypass grafting for symptomatic relief of angina pectoris at the Plains Health Centre, Regina, Saskatchewan, from January 1980 to December 1985. There were two in-hospital deaths (operative mortality 1.6%). Definite perioperative myocardial infarction occurred in 12 patients (9.8%). The 120 survivors were followed for a mean of 32 months. There were three deaths during follow-up, giving a five-year probability of survival of 93%. Twenty-three clinical events (including deaths) occurred during follow-up, giving a five-year probability of event free survival of 72%. Ninety percent of patients say they are pleased with their operation. Seventy-eight percent are currently angina free. These data illustrate the effectiveness of aortocoronary bypass grafting in low risk elderly patients with symptomatic coronary artery disease.  相似文献   
7.
8.
9.
10.
Early intervention with budesonide is an effective strategy for mild persistent asthma, which has been shown to provide additional clinical benefits at a low incremental cost using USA cost data. The present authors analysed whether this strategy would be cost-effective using cost data for other countries. Based on the 3-yr prospective, randomised, double-blind inhaled Steroid Treatment As Regular Therapy (START) in early asthma study (comparing budesonide and placebo combined with usual asthma therapy), the cost-effectiveness was estimated separately for eight different countries, from both healthcare payer and societal perspectives, of adding budesonide to usual asthma therapy. Local unit costs were applied to data for the total trial population. Incremental cost-effectiveness ratios (ICER) were estimated as cost per symptom-free day (SFD) gained. Budesonide increased SFDs by an average of 14.1 days annually. From a healthcare payer perspective, budesonide would reduce the total cost of asthma care in Australia. In Sweden, Canada, France, Spain, UK, China and the USA, the ICER ranged from US$2.4-11.3 per SFD. From a societal perspective, budesonide would be cost-saving in Australia, Canada and Sweden. In conclusion, for countries where costs with budesonide are higher, the policy implication has to be determined by that health system's willingness to pay for an additional symptom-free day. However, where budesonide therapy increases symptom-free days and reduces total costs, the policy conclusion clearly favours early intervention.  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