全文获取类型
收费全文 | 1634篇 |
免费 | 207篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 33篇 |
妇产科学 | 22篇 |
基础医学 | 204篇 |
口腔科学 | 15篇 |
临床医学 | 210篇 |
内科学 | 560篇 |
皮肤病学 | 46篇 |
神经病学 | 69篇 |
特种医学 | 69篇 |
外科学 | 336篇 |
综合类 | 27篇 |
一般理论 | 1篇 |
预防医学 | 107篇 |
眼科学 | 15篇 |
药学 | 66篇 |
中国医学 | 1篇 |
肿瘤学 | 65篇 |
出版年
2021年 | 25篇 |
2019年 | 18篇 |
2018年 | 19篇 |
2017年 | 20篇 |
2016年 | 20篇 |
2015年 | 23篇 |
2014年 | 27篇 |
2013年 | 58篇 |
2012年 | 80篇 |
2011年 | 71篇 |
2010年 | 48篇 |
2009年 | 54篇 |
2008年 | 81篇 |
2007年 | 84篇 |
2006年 | 120篇 |
2005年 | 101篇 |
2004年 | 91篇 |
2003年 | 95篇 |
2002年 | 92篇 |
2001年 | 25篇 |
2000年 | 31篇 |
1999年 | 26篇 |
1998年 | 23篇 |
1997年 | 22篇 |
1996年 | 28篇 |
1995年 | 20篇 |
1994年 | 14篇 |
1993年 | 21篇 |
1992年 | 19篇 |
1991年 | 12篇 |
1990年 | 12篇 |
1989年 | 16篇 |
1986年 | 11篇 |
1985年 | 15篇 |
1984年 | 18篇 |
1983年 | 13篇 |
1982年 | 13篇 |
1981年 | 16篇 |
1980年 | 21篇 |
1979年 | 16篇 |
1978年 | 23篇 |
1977年 | 17篇 |
1976年 | 18篇 |
1975年 | 25篇 |
1974年 | 15篇 |
1973年 | 20篇 |
1972年 | 15篇 |
1966年 | 13篇 |
1964年 | 18篇 |
1962年 | 13篇 |
排序方式: 共有1857条查询结果,搜索用时 15 毫秒
31.
32.
Ben-Dor I Maluenda G Iyasu GD Laynez-Carnicero A Hauville C Torguson R Okubagzi P Xue Z Goldstein SA Lindsay J Satler LF Pichard AD Waksman R 《The American journal of cardiology》2012,109(7):1031-1037
Left ventricular systolic dysfunction in patients with severe aortic stenosis (AS) is associated with poor outcome. This analysis was designed primarily to describe the clinical course of a large series of consecutive patients with severe AS and low ejection fraction (EF) (<40%) who, because of high surgical risk, were referred for transcatheter aortic valve implantation consideration. A cohort of 270 patients with severe AS and low EF (<40%) who were referred to participate in a clinical trial of transcatheter aortic valve implantation was studied. Clinical, hemodynamic, and periprocedural complications and follow-up mortality data were collected and compared between patients with low mean transvalvular gradients (≤40 mm Hg, n = 170 [63%]) and high transvalvular gradients (>40 mm Hg, n = 100 [37%]). Patients with low gradients were younger (mean age 79.8 ± 9.1 vs 83.8 ± 7.7 years, p <0.001) and had higher incidences of coronary artery disease and renal failure. Mean aortic valve area was larger (0.73 ± 0.23 vs 0.53 ± 0.18 cm(2), p <0.001), while mean EF (26.4 ± 6.9% vs 30.5% ± 6.6%, p <0.001), cardiac output (3.7 ± 1.1 vs 4.1 ± 1.3 L/min, p = 0.04), and cardiac index (1.9 ± 0.5 vs 2.1 ± 0.6 L/min/m(2), p = 0.04) were lower in patients with lower gradients compared to those with higher gradients, respectively. Mortality was higher in patients with low gradients (53.8%) at a mean follow-up of 151 days compared to those with high gradients (41%) at a mean follow-up of 256 days (p = 0.01). In conclusion, patients with severe AS and low EF with low transvalvular gradients are at higher risk for worse outcomes compared to patients with high transvalvular gradients. Surgery or transcatheter aortic valve implantation treatment and high baseline transvalvular gradient are associated with EF improvement. 相似文献
33.
Waksman R Barbash IM Dvir D Torguson R Ben-Dor I Maluenda G Xue Z Satler LF Suddath WO Kent KM Pichard AD 《The American journal of cardiology》2012,109(9):1288-1294
Data from randomized clinical trials have shown the safety and efficacy of the XIENCE V in selected populations. However, limited data are available comparing the XIENCE V to the first-generation CYPHER sirolimus-eluting stent. This study aimed to assess the long-term safety and clinical efficacy of the XIENCE V everolimus-eluting stent compared to first-generation stents in an unselected patient population. This retrospective analysis included 6,069 patients treated with CYPHER, TAXUS, and XIENCE stents from 2003 to 2009 at our institution. The patients were followed up for ≥1 year after the index procedure. The baseline characteristics were generally comparable among the 3 groups, with the exception of a significantly greater prevalence of diabetes mellitus, systemic hypertension, and a history of angioplasty and coronary bypass surgery among the XIENCE patients. The XIENCE patients also had a twofold greater rate of type C lesions. One-year follow-up data were available for 82% of the patients. The 1-year major adverse cardiovascular events rate was 9.3% for the XIENCE stent versus 9.8% for the CYPHER stent and 11.5% for the TAXUS stent (p = 0.11). Mortality was lower in the XIENCE group than in the CYPHER and TAXUS groups (3.6% vs 4.9% vs 7.2%, respectively, p <0.001), and target lesion revascularization was similar (5.9% vs 5.2% vs 5.6%, respectively; p = 0.34). Stent thrombosis was lower in the XIENCE patients (0.2% vs 1.2% vs 0.7%, p = 0.007). In conclusion, in a contemporary United States clinical practice with an unselected patient population, use of the XIENCE V stent was associated with an improved safety profile and reduction of all-cause mortality and stent thrombosis compared to first-generation drug-eluting stents. The XIENCE V failed to demonstrate superiority for overall major adverse cardiovascular events, Q-wave myocardial infarction, and revascularization rates. 相似文献
34.
Hong YJ Jeong MH Ahn Y Kang JC Mintz GS Kim SW Lee SY Kim SY Pichard AD Satler LF Waksman R Weissman NJ 《The American journal of cardiology》2012,109(11):1576-1581
The aim of this study was to investigate the relation between intravascular ultrasound (IVUS) findings and the no-reflow phenomenon and long-term outcome after percutaneous coronary intervention (PCI) of saphenous vein graft (SVG) lesions. No reflow was defined as Thrombolysis In Myocardial Infarction grade 0, 1, or 2 flow after PCI. Of 311 patients who underwent IVUS before and after stenting, no reflow was observed in 39 patients (13%). Degenerated SVG (62% vs 36%, p = 0.002), IVUS-detected intraluminal mass (82% vs 43%, p <0.001), culprit lesion multiple plaque ruptures (23% vs 6%, p <0.001), and tissue prolapse (51% vs 35%, p = 0.043) were observed more frequently in patients with no reflow. In multivariate logistic regression analysis, an intraluminal mass (odds ratio [OR] 4.84, 95% confidence interval [CI] 1.98 to 10.49, p = 0.001), culprit lesion multiple plaque ruptures (OR 3.46, 95% CI 1.46 to 8.41, p = 0.014), and degenerated SVGs (OR 3.17, 95% CI 1.17 to 6.56, p = 0.024) were the independent predictors of no reflow after PCI. At 5-year clinical follow-up, rates of death (14, 36%, vs 55, 20%, p = 0.036) and myocardial infarction (13, 33%, vs 52, 19%, p = 0.039) were significantly higher in the no-reflow group. However, rate of target vessel revascularization was not significantly different between the 2 groups (15, 38%, vs 90, 33%, p = 0.3). IVUS-detected intraluminal mass, multiple plaque ruptures, and degenerated SVGs were associated with no reflow in SVG lesions after PCI. In conclusion, no reflow was associated with poor long-term clinical outcomes after PCI for SVG lesions. 相似文献
35.
Romaguera R Wakabayashi K Laynez-Carnicero A Sardi G Maluenda G Ben-Dor I Torguson R Kent KM Satler LF Suddath WO Lindsay J Pichard AD Waksman R 《The American journal of cardiology》2012,109(1):75-81
Vascular complications (VCs) occur in 3% to 8% of percutaneous coronary interventions (PCIs). However, only a portion of patients who experience VCs bleed significantly. The aim of this study was to assess the covariates associated with the amount of blood loss in patients experiencing postprocedural VCs as well as the effect of the degree of blood loss on long-term mortality. Overall, 7,718 unselected patients who underwent PCI through femoral access were evaluated. Those experiencing VCs were identified and stratified with regard to the degree of hematocrit (HCT) decrease after the procedure. In total, 444 patients (5.8%) had VCs. Compared to those without VCs, patients with VCs were older and had more extensive co-morbidities. Severe blood loss was most frequent in those who had vascular perforation requiring surgical repair or in those who had retroperitoneal bleeding. Overall, <25% of patients with hematoma had severe blood loss. The raw 1-year mortality was doubled in patients with minimal or moderate HCT decrease and was tripled in those with severe decreases in HCT. Similarly, the rate of definite stent thrombosis was tripled in patients with VCs and moderate or severe decreases in HCT. After adjustment, only patients with VCs and the greater HCT decreases had an increased risk for death at 1 year (hazard ratio 1.80, 95% confidence interval 1.03 to 3.14). Independent predictors of severe HCT decrease included age, female gender, glycoprotein IIb/IIIa inhibitor use, and activated clotting time peak. Bivalirudin and closure devices were independently associated with less frequent severe HCT decrease. In conclusion, VCs do not entail an increased risk for death at 1 year unless associated with severe blood loss. The use of bivalirudin and closure devices seems to reduce the risk for such complications. 相似文献
36.
MacConmara MP Vachharajani N Wellen JR Anderson CD Lowell JA Shenoy S Chapman WC Doyle MB 《HPB : the official journal of the International Hepato Pancreato Biliary Association》2012,14(1):42-48
Background
The inclusion of hepatitis B core antibody-positive (HBcAb+) liver donors is a strategy utilized to increase organ availability. This study examined HBcAb+ transplantation practices to identify specific factors influencing outcomes.Methods
Twenty-five HBcAb+ liver transplants were identified retrospectively among 868 adult transplants performed between 1 January 1997 and 31 December 2009. Twelve (48%) recipients had hepatitis C and five (20%) had hepatitis B. Patient and donor demographics, preoperative morbidity, transplant data and outcomes were examined. Statistical analysis was completed using Student''s t-test or the Kaplan–Meier method. A P-value of <0.05 was considered significant.Results
There was no difference in age, body mass index or comorbidities between HBcAb+ liver recipients and control subjects. Model for End-stage Liver Disease (MELD) scores of >30 were significantly more frequent in HBcAb+ liver recipients (32% vs. 15%; P = 0.04). All patients received immunoglobulin and longterm antiviral therapy as prophylaxis against graft hepatitis B resurgence. No patients who received HBcAb+ livers developed hepatitis B infection on follow-up. Overall survival at 30 days, 1 year and 5 years in HBcAb+ liver recipients was 92%, 74% and 74%, respectively, compared with 96%, 89% and 76%, respectively, in the control group (P = not significant, log-rank test). All except one of the deaths in the HBcAb+ liver recipient group occurred within 90 days postoperatively and in patients with MELD scores >30.Conclusions
The practice of transplanting HBcAb+ grafts incurs low risk for infection using current methods of prophylaxis. The highest mortality risk was in the early postoperative period, specifically in patients with very high MELD scores. This probably reflects the practice of using positive serology grafts in emergent situations. 相似文献37.
Gabriel Maluenda MD Lavinia Mitulescu MD Itsik Ben‐Dor MD Michael A. Gaglia Jr. MD MSc Gaby Weissman MD Rebecca Torguson MPH Lowell F. Satler MD Augusto D. Pichard MD Nelson L. Bernardo MD Ron Waksman MD 《Catheterization and cardiovascular interventions》2012,80(1):29-36
Background : Retroperitoneal hemorrhage (RPH) is a serious but infrequent complication of percutaneous coronary intervention (PCI). This study aimed to describe the clinical outcomes of patients who developed RPH following PCI in the current practice era, with particular focus on treatment strategies and the related prognostic value of abdominal/pelvic computed tomography (CT). Methods : Among 20,904 patients undergoing PCI, we identified 93 RPH (0.45%) confirmed by CT or by unequivocal surgical findings. We identified three groups with RPH for comparison: patients who developed refractory shock (systolic blood pressure <80 mm Hg for ≥30 min despite fluids and vasopressors, n = 16 [17.2%]); patients with transient hypotension (<30 min, n = 34 [36.6%]); and patients without hypotension (n = 43 [46.2%]). The primary endpoint was a composite of in‐hospital mortality, myocardial infarction, and cerebral vascular accident (CVA). Results : Baseline clinical, angiographic, and procedural characteristics were similar among the three groups. Patients who developed refractory shock had significantly more bleeding quantified by abdominal/pelvic CT (P < 0.001), had a higher rate and amount of red blood cell transfusion (P < 0.001), and were managed invasively more frequently (68.7%) than the rest of the population. The primary endpoint trended higher in patients presenting with refractory shock; however, this difference was not statistically significant. The volume of bleeding quantified by CT and the timing of imaging diagnosis did not correlate with the primary endpoint. Red blood cell transfusion, but not clopidogrel discontinuation, was associated with the primary endpoint. Conclusions : RPH remains as a serious complication of PCI and is associated with high rates of mortality and morbidity independently of the therapeutic strategy. In patients who were hemodynamically stable, RPH volume as quantified by non‐contrast abdominal/pelvic CT did not contribute to prognosis. © 2011 Wiley Periodicals, Inc. 相似文献
38.
Manuel A. Gonzalez MD MPH Itsik Ben‐Dor MD Michael A. Gaglia Jr. MD MSc Rebecca Torguson MPH Hirity Shimellis BS Anh Bui MD William O. Suddath MD Augusto D. Pichard MD Lowell F. Satler MD Ron Waksman MD 《Catheterization and cardiovascular interventions》2012,79(5):843-848
Objectives: This study aimed to test whether advanced cardiovascular injection (ACI) via 4 French (Fr) catheters is more advantageous than manual injection with 6 Fr catheters. Background: For coronary angiography, proponents of contrast media ACI believe it utilizes smaller‐diameter catheters when compared with manual injection, without compromising the quality of the angiogram, and has the potential to reduce the amount of contrast used and lessen the use of closure devices. Methods: In a prospective study, 200 consecutive patients referred for elective coronary angiography were randomized to standard 6 Fr catheters with manual injection versus 4 Fr catheters with ACI. The study's primary endpoint is the quality of the coronary angiogram. Secondary endpoints include groin complications, utilization of closure devices, and volume of contrast media. Thirty‐six patients who underwent ad hoc percutaneous coronary intervention were excluded from the analysis. Results: The final analysis included 80 patients treated with 4 Fr catheters with ACI and 84 patients treated with 6 Fr catheters with manual injection. The groups had similar demographic and clinical characteristics. The quality of the angiogram was similar between groups with the exception of more left coronary sinus flush with 4 Fr catheters (3.57 ± 1.1 vs. 2.98 ± 0.9, P < 0.001) and less closure device use with 4 Fr (25 vs. 71.4%, P < 0.01) compared to 6 Fr catheters. The procedure duration, volume of contrast used, vascular complications, and time to ambulation were similar between groups (all P > 0.05). Conclusions: 4 Fr diagnostic catheters with ACI offer similar quality coronary angiograms, similar rates of vascular complications, procedure duration, contrast used, and time to ambulation, but have a significantly lesser need for closure devices compared to the 6 Fr system with manual injection. © 2011 Wiley‐Liss, Inc. 相似文献
39.