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   1337篇
  免费   72篇
  国内免费   3篇
医药卫生   1412篇
  2023年   8篇
  2022年   9篇
  2021年   29篇
  2020年   14篇
  2019年   51篇
  2018年   29篇
  2017年   20篇
  2016年   27篇
  2015年   24篇
  2014年   39篇
  2013年   46篇
  2012年   68篇
  2011年   75篇
  2010年   52篇
  2009年   36篇
  2008年   51篇
  2007年   66篇
  2006年   63篇
  2005年   45篇
  2004年   55篇
  2003年   59篇
  2002年   46篇
  2001年   44篇
  2000年   44篇
  1999年   37篇
  1998年   18篇
  1997年   10篇
  1996年   7篇
  1995年   12篇
  1994年   9篇
  1993年   9篇
  1992年   39篇
  1991年   33篇
  1990年   28篇
  1989年   29篇
  1988年   20篇
  1987年   22篇
  1986年   19篇
  1985年   14篇
  1984年   13篇
  1983年   8篇
  1982年   6篇
  1979年   12篇
  1978年   6篇
  1977年   5篇
  1975年   6篇
  1972年   7篇
  1968年   6篇
  1967年   10篇
  1966年   8篇
排序方式: 共有1412条查询结果,搜索用时 31 毫秒
1.
Journal of Thrombosis and Thrombolysis - Multidisciplinary pulmonary embolism (PE) response teams have garnered widespread adoption given the complexities of managing acute PE and provide a...  相似文献   
2.

Background

Pump speed optimization in patients implanted with a ventricular assist device represents a major challenge during the follow-up period. We present our findings on whether combined invasive hemodynamic ramp tests and cardiopulmonary exercise testing (CPX) can help optimize patient management.

Methods

Eighteen patients implanted with a HeartMate 3 (HM3) device underwent ramp tests with right heart catheterization (including central venous pressure [CVP], pulmonary artery pressure, pulmonary capillary wedge pressure [PCWP], and blood pressure) and echocardiography. Data were recorded at up to 4 speed settings. Speed changes were in steps of 200 revolutions/min (rpm). Evaluation of functional capacity by CPX was conducted according to the modified Bruce protocol.

Results

Only 30% of patients had normal PCWPs at their original rpm settings. In going from lowest to highest speeds, cardiac output improved by 0.25 ± 0.35 L/min/step (total change, 1.28 ± 0.3 L/min), and PCWP decreased by 1.9 ± 0.73 mm Hg/step (total change, 6 ± 1.6 mm Hg). CVP and systolic blood pressure did not change significantly with rpm. The rpm assessment was adjusted based on test results to achieve CVPs and PCWPs as close to normal limits as possible, which was feasible in all patients. On CPX, all patients demonstrated good performance (peak VO2, 16.8 ± 3.5 mL/kg/min).

Conclusion

Hemodynamic ramp testing provides an objective means of optimizing rpm, and has the potential to provide good exercise tolerance.  相似文献   
3.
Transcatheter aortic valve implantation (TAVI) or replacement has rapidly changed the treatment of patients with severe symptomatic aortic stenosis. It is now the standard of care for patients believed to be inoperable or at high surgical risk, and a reasonable alternative to surgical aortic valve replacement for those at intermediate surgical risk. Recent clinical trial data have shown the benefits of this technology in patients at low surgical risk as well. This update of the 2012 Canadian Cardiovascular Society TAVI position statement incorporates clinical evidence to provide a practical framework for patient selection that does not rely on surgical risk scores but rather on individual patient evaluation of risk and benefit from either TAVI or surgical aortic valve replacement. In addition, this statement features new wait time categories and treatment time goals for patients accepted for TAVI. Institutional requirements and recommendations for operator training and maintenance of competency have also been revised to reflect current standards. Procedural considerations such as decision-making for concomitant coronary intervention, antiplatelet therapy after intervention, and follow-up guidelines are also discussed. Finally, we suggest that all patients with aortic stenosis might benefit from evaluation by the heart team to determine the optimal individualized treatment decision.  相似文献   
4.
Patients with active cancer are at an increased risk of arterial and venous thromboembolism (VTE) and bleeding events. Historically, in patients with cancer, low molecular weight heparins have been preferred for treatment of VTE, whereas warfarin has been the standard anticoagulant for stroke prevention in patients with atrial fibrillation (AF). More recently, direct oral anticoagulants (DOACs) have been demonstrated to reduce the risk of venous and arterial thromboembolism in large randomized clinical trials of patients with VTE and AF, respectively, thus providing an attractive oral dosing option that does not require routine laboratory monitoring. In this review, we summarize available clinical trial data and guideline recommendations, and outline a practical approach to anticoagulation management of VTE and AF in cancer.  相似文献   
5.
6.
7.
ObjectivesThe purpose of this study was to assess the concordance between transcatheter aortic valve implantation angles generated by the “double S-curve” and “cusp-overlap” techniques.BackgroundThe “double S-curve” and “cusp-overlap” methods aim to define optimal fluoroscopic projections for transcatheter aortic valve replacement (TAVR) with a self-expandable device.MethodsThe study included 100 consecutive patients undergoing TAVR with self-expanding device planned by multidetector computed tomography. TAVR was performed using the double S-curve model, as a view in which both the aortic valve annulus and delivery catheter planes are displayed perpendicularly on fluoroscopy. Optimal projection according to the cusp-overlap technique was retrospectively generated by overlapping the right and left cups on the multidetector computed tomography annular plane. The angular difference between methods was assessed in spherical 3 dimensions and on the left and right anterior oblique (RAO) and cranial and caudal (CAU) axes.ResultsThe double S-curve and cusp-overlap methods provided views located in the same quadrant, mostly the RAO and CAU, in 92% of patients with a median 3-dimensional angular difference of 10.0° (interquartile range: 5.5° to 17.9°). The 3-dimensional deviation between the average angulation obtained by each method was not statistically significant (1.49°; p = 0.349). No significant differences in average coordinates were noted between the double S-curve and cusp-overlap methods (RAO: 14.7 ± 15.2 vs. 12.9 ± 12.5; p = 0.36; and CAU: 27.0 ± 9.4 vs. 26.9 ± 10.4; p = 0.90). TAVR using the double S-curve was associated with 98% device success, low complication rate, and absence of moderate-to-severe paravalvular leak.ConclusionsThe double S-curve and cusp-overlap methods provide comparable TAVR projections, mostly RAO and CAU. TAVR using the double S-curve model is associated with a high rate of device success and low rate of procedural complications.  相似文献   
8.
9.
Typical enteropathogenic Escherichia coli strains (tEPEC) cause attaching/effacing lesions in eukaryotic cells and produce the bundle-forming pilus (BFP), which interweaves and aggregates bacteria, resulting in the localized adherence (LA) pattern on eukaryotic cells. Previously, we identified tEPEC strains (serotype O119:H6) that exhibited LA simultaneously with an aggregative adherence (AA)-like pattern (LA/AA-like+). Remarkably, AA is characteristically produced by strains of enteroaggregative E. coli (EAEC), another diarrheagenic E. coli pathovar. In one LA/AA-like?+?strain (Ec404/03), we identified a conjugative plasmid containing the pil operon, which encodes the Pil fimbriae. Moreover, a pil operon associated with an AA pattern and plasmid transfer had been previously described in the EAEC C1096 strain. In this study, we investigated the occurrence of the two pilS alleles (pilSEc404 and pilSC1096) in tEPEC strains of different serotypes, origins and years of isolation. We also examined the potential relationship of pilS with the AA-like phenotype, its ability to be transferred by conjugation, and occurrence among strains of the other E. coli pathovars. The pilS alleles were found in 90 (55.2%) of 163 tEPEC strains, with pilSEc404 occurring more often (30.7%) than pilSC1096 (25.1%). About 21 tEPEC serotypes carried pilS. The pilS alleles were found in tEPEC strains from Chile, Peru and different Brazilian cities, with the oldest strain being isolated in 1966. No absolute correlation was found between the presence of pilS and the AA-like pattern. Conjugative pilS transfer was detected in 26.2% of pilSEc404+ strains and in 65.1% of pilSC1096+ strains, but only pilSEc404+ transconjugants were AA-like+, thus suggesting that the latter allele might need a different genetic background to express this phenotype. pilS was found in all other E. coli pathovars, where it was most prevalent in enterotoxigenic E. coli. More studies are needed to understand the mechanisms involved in the regulation of Pil expression and production.  相似文献   
10.
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