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   305篇
  免费   24篇
耳鼻咽喉   1篇
儿科学   3篇
妇产科学   7篇
基础医学   14篇
口腔科学   9篇
临床医学   92篇
内科学   74篇
皮肤病学   10篇
神经病学   18篇
外科学   30篇
一般理论   2篇
预防医学   21篇
眼科学   1篇
药学   44篇
肿瘤学   3篇
  2023年   2篇
  2022年   1篇
  2017年   6篇
  2016年   9篇
  2015年   13篇
  2014年   6篇
  2013年   12篇
  2012年   1篇
  2011年   4篇
  2010年   17篇
  2009年   19篇
  2008年   2篇
  2007年   4篇
  2006年   5篇
  2005年   5篇
  2004年   2篇
  2003年   3篇
  2001年   6篇
  2000年   3篇
  1999年   5篇
  1998年   15篇
  1997年   14篇
  1996年   28篇
  1995年   14篇
  1994年   12篇
  1993年   15篇
  1992年   15篇
  1991年   14篇
  1990年   5篇
  1989年   9篇
  1988年   8篇
  1987年   7篇
  1986年   7篇
  1985年   4篇
  1984年   4篇
  1983年   7篇
  1982年   5篇
  1981年   4篇
  1980年   4篇
  1979年   2篇
  1978年   1篇
  1973年   1篇
  1972年   1篇
  1971年   3篇
  1969年   1篇
  1967年   1篇
  1958年   1篇
  1955年   1篇
  1947年   1篇
排序方式: 共有329条查询结果,搜索用时 15 毫秒
21.
22.
To determine the optimal ventricular stimulation sequence, an 11-step programmed electrical stimulation (PES) protocol was completed, even if a ventricular arrhythmia (VA) was induced with earlier steps. The protocol consisted of one, two, and three extrastimuli during sinus rhythm (SR), and at two drive pacing rates (VP1 and VP2) plus rapid burst and ramp pacing. By analyzing the 79 completed protocols that induced the clinical arrhythmia, the following were determined: (1) the frequency of induced clinical and nonclinical VA with each stimulation step; (2) the yield ratio (YR) of each step, defined as the probability of inducing clinical versus nonclinical arrhythmia; (3) the cumulative yield of induced clinical and nonclinical arrhythmia with two widely used stimulation sequences, i.e., triple extrastimuli delivered early in the stimulation protocol (MMC sequence) and triple extrastimuli delayed until after double extrastimuli failed to induce the clinical arrhythmia (B sequence); (4) the relative efficiency of these sequences were determined. The percentage of induced clinical and nonclinical arrhythmia with SR + 3 extrastimuli, VP1 + 2 extrastimuli, and VP2 + 2 extrastimuli were (53%, 5%), (36%, 5%), and (41%, 9%), respectively. The cumulative yield of induced clinical VA with the MMC-type sequence reached 55% by the third step of the protocol, whereas 50% was attained only at the eighth step of the B-type sequence. The cumulative percentage of induced nonclinical VA with either sequence was similar during the early steps of the protocol. The MMC sequence was more efficient, requiring overall 36% of potential steps for clinical arrhythmia induction, compared with 48% for the B sequence (P less than 0.001). For questionable arrhythmia states, e.g., syncope of unknown origin and nonsustained VT, a modified sequence is proposed that may further reduce the induction of uninterpretable arrhythmias.  相似文献   
23.
24.
25.
A case of cholelithiasis is reported occurring in a boy aged two years and seven months. The patient presented with biliary colic, and cholecystectomy was performed. Detailed analysis of the stone, including electron-probe studies, showed it to be an example of a polybilirubinate stone, containing also calcium, carbonate, and phosphate, with some sulphur, sodium, and magnesium. There were also traces of chlorine, aluminium, copper, nickel, and manganese.  相似文献   
26.
A case of extensive gastric duplication in an adult is presented, illustrating one of the two common symptoms, and emphasising that surgical excision, where possible, Is the treatment of choice.  相似文献   
27.
Background: It is known that patients with lifesaving devices such as implantable cardioverter-defibrillators (ICDs) may be alarmed and worried by recalls or alerts related to their ICDs.
Objectives: This study aimed to determine whether counseling has any short- or long-term benefits, and to look for characteristics that identify those most worried and those most in need of counseling.
Methods: Among 100 patients with recall or alert ICDs, 14 were pacer dependent; 50 had ICDs for 1° prevention and 22 were women. Patients completed a survey indicating how worried they were on learning of the recall or alert (0–10 scale). After counseling and advice in accordance with manufacturer guidelines, patients were asked to indicate their level of worry, and were again asked after 6 months.
Results: For all patients, the "worry level" at the initial interview was 5.0 ± 3.7, falling to 2.2 ± 3.0 after counseling (P < 0.001) and 1.4 ± 2.3 after 6 months (P < 0.001 vs both earlier levels). There were no significant differences between those implanted for 1° versus 2° prevention or for pacer dependency. Women were initially more worried than men, but not for the long term. The 49 patients whose ICDs could be managed by reprogramming or software fix had significant reduction in worry after counseling and at 6 months compared to others. The 18 patients recommended for operative intervention remained more concerned after counseling (3.5 ± 3.3 vs 1.9 ± 2.9, P = 0.043).
Conclusions: Patients' concerns resulting from ICD recalls or alerts can be reduced by appropriate counseling. Those patients whose ICDs could be reprogrammed to safer parameters had the most reduction in worry levels.  相似文献   
28.
29.
The “fair benefits” approach to international research is designed to produce results that all can agree are fair without taking a stand on divisive questions of justice. But its appealing veneer of collaboration masks ambiguities at both a conceptual and an operational level. An attempt to put it into practice would look a lot like an auction, leaving little reason to think the outcomes will satisfy even minimal conditions of fairness.  相似文献   
30.
Opinions vary regarding the need to perform defibrillation testing prior to hospital discharge in recipients of state-of-the-art cardioverter defibrillators (ICDs). Our protocol is to perform predischarge ICD testing 1 day after implant. This report includes 682 consecutive implants. Adverse observations at testing were grouped into (1) risk of defibrillation failure, (2) surgical complications, (3) sensing/pacing issues or narrow defibrillation margin warranting closer follow-up, or (4) findings correctable by device reprogramming. Among the 682 patients, 63% had single-chamber and 37% dual-chamber or biventricular ICDs. In 48 patients (7%) there were 69 concerns and/or interventions, with overlaps among the four categories, including one failure to defibrillate (0.15%), and six other patients at risk. Surgical complications included 11 hematomas (1.6%), and six lead dysfunctions. Closer follow-up was indicated in 19 patients (2.7%), for high pacing thresholds in seven, sensing issues in seven, and <10 J defibrillation margin in five. Device reprogramming was needed in 31 patients (4.5%), for tachycardia detection and therapy settings in 12, and for pacing/sensing functions in 22 patients. In eight patients ventricular fibrillation could not be induced. There was no morbidity or mortality due to testing. The state-of-the-art ICDs delivering biphasic shocks are remarkably reliable. The routine pre-hospital discharge defibrillation testing of such ICDs may be optional and left to the physicians' discretion.  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