全文获取类型
| 收费全文 | 1343304篇 |
| 免费 | 98629篇 |
| 国内免费 | 3273篇 |
专业分类
| 耳鼻咽喉 | 18976篇 |
| 儿科学 | 39670篇 |
| 妇产科学 | 38406篇 |
| 基础医学 | 191773篇 |
| 口腔科学 | 36498篇 |
| 临床医学 | 118962篇 |
| 内科学 | 258576篇 |
| 皮肤病学 | 25922篇 |
| 神经病学 | 110314篇 |
| 特种医学 | 54739篇 |
| 外国民族医学 | 226篇 |
| 外科学 | 211230篇 |
| 综合类 | 33799篇 |
| 现状与发展 | 4篇 |
| 一般理论 | 592篇 |
| 预防医学 | 100174篇 |
| 眼科学 | 31797篇 |
| 药学 | 98122篇 |
| 29篇 | |
| 中国医学 | 2739篇 |
| 肿瘤学 | 72658篇 |
出版年
| 2021年 | 12109篇 |
| 2019年 | 12132篇 |
| 2018年 | 16701篇 |
| 2017年 | 12581篇 |
| 2016年 | 14262篇 |
| 2015年 | 16540篇 |
| 2014年 | 23291篇 |
| 2013年 | 34180篇 |
| 2012年 | 46723篇 |
| 2011年 | 48404篇 |
| 2010年 | 28893篇 |
| 2009年 | 26797篇 |
| 2008年 | 44728篇 |
| 2007年 | 48089篇 |
| 2006年 | 47372篇 |
| 2005年 | 46565篇 |
| 2004年 | 44877篇 |
| 2003年 | 42250篇 |
| 2002年 | 40596篇 |
| 2001年 | 49312篇 |
| 2000年 | 49884篇 |
| 1999年 | 42866篇 |
| 1998年 | 14461篇 |
| 1997年 | 13021篇 |
| 1996年 | 12475篇 |
| 1995年 | 11774篇 |
| 1994年 | 11075篇 |
| 1992年 | 34836篇 |
| 1991年 | 34448篇 |
| 1990年 | 33676篇 |
| 1989年 | 32565篇 |
| 1988年 | 30374篇 |
| 1987年 | 29682篇 |
| 1986年 | 28305篇 |
| 1985年 | 27525篇 |
| 1984年 | 21418篇 |
| 1983年 | 18358篇 |
| 1982年 | 11938篇 |
| 1979年 | 21026篇 |
| 1978年 | 15424篇 |
| 1977年 | 13004篇 |
| 1976年 | 11927篇 |
| 1975年 | 12996篇 |
| 1974年 | 15904篇 |
| 1973年 | 15377篇 |
| 1972年 | 14499篇 |
| 1971年 | 13483篇 |
| 1970年 | 12850篇 |
| 1969年 | 12272篇 |
| 1968年 | 11228篇 |
排序方式： 共有10000条查询结果，搜索用时 13 毫秒
21.
Background
Highly cross-linked polyethylene (HXLPE) liners in total hip arthroplasty (THA) have demonstrated decreased wear rates, resilience to cup orientation, and reduced osteolysis compared to conventional polyethylene. Sequential irradiation and annealing below the melting temperature is unique compared to most HXLPE which is irradiated and remelted. This study purpose is to provide minimum 5-year femoral head penetration rates of sequentially annealed HXLPE in primary THA.Methods
A retrospective review of a prospectively collected database identified 198 consecutive, cementless primary THAs utilizing sequentially annealed HXLPE (X3; Stryker, Mahwah, NJ). Operative technique was standardized. Radiographs were analyzed utilizing the Martell method with minimum 5-year and 1-year radiographs as baseline to minimize the initial bedding-in period.Results
Seventy-seven hips with minimum 5-year follow-up were analyzed. Mean steady state linear and volumetric head penetration rates were 0.095 mm/y and 76 mm3/y, respectively. Volumetric head penetration was significantly less for 32-mm compared to 36-mm (P = .028). In addition, less head penetration was observed for ceramic 32-mm heads at nearly half the rate compared to cobalt-chromium 36-mm heads (P ≥ .092). No correlations existed between penetration rates and age, body mass index, University of California Los Angeles Activity Level, polyethylene thickness, cup inclination, or anteversion (P ≥ .10). No radiographic osteolysis was observed.Conclusion
Surprisingly, linear head penetration rates of sequentially annealed HXLPE were nearly identical to the osteolysis threshold for conventional polyethylene and greater than reports of irradiated and remelted HXLPE. Furthermore, these data corroborate reports that HXLPE is resilient to cup orientation and demographic variables. Longer term follow-up is recommended. 相似文献22.
23.
24.
Bo Yang Elizabeth L. Norton Terry Shih Linda Farhat Xiaoting Wu Whitney E. Hornsby Karen M. Kim Himanshu J. Patel G. Michael Deeb 《The Journal of thoracic and cardiovascular surgery》2019,157(4):1313-1321.e2
Objective
To compare perioperative and long-term outcomes in patients undergoing hemiarch and aggressive arch replacement for acute type A aortic dissection (ATAAD).Methods
From 1996 to 2017, we compared outcomes of hemiarch (n = 322) versus aggressive arch replacements (zones 2 and 3 arch replacement with implantation of 2-4 arch branches, n = 150) in ATAAD. Indications for aggressive arch were arch aneurysm >4 cm or intimal tear in the aortic arch that was not resectable by hemiarch replacement, or dissection of arch branches with malperfusion.Results
Patients in the aggressive arch group were significantly younger (mean age: 57 vs 61 years old) and had significantly longer hypothermic circulatory arrest, cardiopulmonary bypass, and aortic crossclamp times. There were no significant differences in perioperative outcomes between hemiarch and aggressive arch groups, including 30-day mortality (5.3% vs 7.3%, P = .38) and postoperative stroke rate (7% vs 7%, P = .96). Over 15 years, Kaplan–Meier survival was similar between hemiarch and aggressive arch groups (log-rank P = .55, 10-year survival 70% vs 72%). Given death as a competing factor, incidence rates of reoperation over 15 years (2.1% vs 2.0% per year, P = 1) and 10-year cumulative incidence of reoperation (14% vs 12%, P = .89) for arch and distal aorta pathology were similar between the 2 groups.Conclusions
Both hemiarch and aggressive arch replacement are appropriate approaches for select patients with ATAAD. Aggressive arch replacement should be considered for an arch aneurysm >4 cm or an intimal tear at the arch unable to be resected by hemiarch replacement, or dissection of the arch branches with malperfusion. 相似文献25.
26.
Aasha I. Hoogland Hailey W. Bulls Brian D. Gonzalez Brent J. Small Lianqi Liu Joseph Pidala Heather S.L. Jim Asmita Mishra 《Journal of pain and symptom management》2019,57(5):952-960.e1
Context
Quality of life (QoL) is increasingly recognized as an important outcome of cancer treatment. Previous studies have examined clinical predictors of QoL, but with the increasing prevalence of wearable sensors that monitor sleep and activity patterns, further investigation into whether these behaviors are predictive of post-treatment QoL is now feasible. Among patients receiving aggressive cancer treatment such as hematopoietic cell transplantation (HCT), analysis of circadian rhythms (24-hour patterns of sleep and activity) via wearable sensors is limited.Objective
To evaluate the relationship between overall QoL and circadian rhythms in patients receiving allogeneic HCT.Methods
Patients wore an ActiGraph GT3X (Pensacola, FL) activity monitor for at least 72 hours before the initiation of conditioning chemotherapy and transplantation and completed a QoL (Functional Assessment of Cancer Therapy-General [FACT-G]) assessment. QoL assessments were also completed 1, 3, and 6 months after HCT.Results
Patients (n = 45, M age = 55) were mostly male (66%) with a total FACT-G score of 80.96 (SD = 16.05) before HCT. Mixed models revealed robust cross-sectional associations between overall QoL and multiple circadian rhythmicity parameters, including durations of high physical activity, overall circadian rhythmicity, and earlier starts of daily activity (P's < .01). Recovery of QoL after transplant was predicted by longer pre-transplant durations of high physical activity (P = .04) and earlier evening retirement (P = .04).Conclusion
Our findings suggest that wearable sensor information is a promising method of predicting recovery of QoL after HCT. Additional studies are needed to confirm these findings in a larger sample. 相似文献27.
Brian Darrith Nicholas B. Frisch Matthew W. Tetreault Michael P. Fice Chris N. Culvern Craig J. Della Valle 《The Journal of arthroplasty》2019,34(2):221-227
Background
Although some prior work supports the safety of same-day arthroplasty performed in a hospital, concerns remain when these procedures are performed in a free-standing ambulatory surgery center. The purpose of this study is to compare 90-day complication rates between matched cohorts that underwent inpatient vs outpatient arthroplasty at an ambulatory surgery center.Methods
A single-surgeon cohort of 243 consecutive patients who underwent outpatient arthroplasty was matched with 243 inpatients who had the same procedure. One-to-one nearest-neighbor matching with respect to gender, age, American Society of Anesthesiologists Score, and body mass index was utilized. The 486 primary arthroplasties included 178 unicondylar knees (36.6%), 146 total hips (30.0%), 92 total knees (18.9%), and 70 hip resurfacings (14.5%). Ninety-day outcomes including reoperation, readmission, unplanned clinic or emergency department visits, and major and minor complications were compared using a 2-sample proportions test.Results
The 2 cohorts were similar in distribution of demographic variables, demonstrating successful matching. The inpatient and outpatient cohorts both had readmission rates of 2.1% (P = 1.0). With the number of subjects studied, there were no statistically significant differences in rates of major complications (2.1% vs 2.5%, P = 1.0), minor complications (7.0% vs 7.8%, P = .86), reoperations (0.4% vs 2.1%, P = .22), emergency department visits (1.6% vs 2.5%, P = .52), or unplanned clinic visits (3.3% vs 5.8%, P = .19).Conclusion
This study suggests that arthroplasty procedures can be performed safely in an ambulatory surgery center among appropriately selected patients without an increased risk of complications. 相似文献28.
Katherine M. Stenson Benjamin O. Patterson Matthew Joe Grima Jorg L. De Bruin Peter J.E. Holt Ian Loftus 《Journal of vascular surgery》2019,69(1):53-62.e1
Background
Endovascular aneurysm sealing (EVAS) represents a novel approach to the treatment of abdominal aortic aneurysms. It uses polymer technology to achieve an anatomic seal within the sac of the aneurysm. This cohort study reports the early clinical outcomes, technical refinements, and learning curve during the initial EVAS experience at a single institution.Methods
Results from 150 consecutive EVAS cases for intact, infrarenal abdominal aortic aneurysms are reported here. These cases were undertaken between March 2013 and July 2015. Preoperative, perioperative, and postoperative data were collected for each patient prospectively.Results
The median age of the cohort was 76.6 years (interquartile range, 70.2-80.9 years), and 87.3% were male. Median aneurysm diameter was 62.0 mm (IQR, 58.0-69.0 mm). Adverse neck morphology was seen in 69 (46.0%) patients, including aneurysm neck length <10 mm (17.3%), neck diameter >32 mm or <18 mm (8.7%), and neck angulation >60 degrees (15.3%). Median follow-up was 687 days (IQR, 463-897 days); 37 patients (24.7%) underwent reintervention. The rates of unresolved endoleak are 1.3% type IA, 0.7% type IB, and 2.7% type I. There were no type III endoleaks. There have been seven secondary ruptures in this cohort; all but one of these patients survived after reintervention. Only one rupture occurred in an aneurysm that had been treated within the manufacturer's instructions for use (IFU).Conclusions
The rate of unresolved endoleaks is satisfactorily low. The incidence of secondary rupture is of concern; however, when the IFU are adhered to, the rate is very low. The results of this study suggest that working within the IFU yields better clinical results. 相似文献29.
30.
Sevan Komshian Alik Farber Virendra I. Patel Philip P. Goodney Marc L. Schermerhorn Elizabeth A. Blazick Douglas W. Jones Denis Rybin Gheorghe Doros Jeffrey J. Siracuse 《Journal of vascular surgery》2019,69(2):405-413