收费全文 | 1202732篇 |
免费 | 85728篇 |
国内免费 | 2774篇 |
耳鼻咽喉 | 15747篇 |
儿科学 | 39037篇 |
妇产科学 | 34709篇 |
基础医学 | 169331篇 |
口腔科学 | 32040篇 |
临床医学 | 104898篇 |
内科学 | 242330篇 |
皮肤病学 | 28536篇 |
神经病学 | 98793篇 |
特种医学 | 44240篇 |
外国民族医学 | 396篇 |
外科学 | 176788篇 |
综合类 | 26562篇 |
现状与发展 | 3篇 |
一般理论 | 400篇 |
预防医学 | 96024篇 |
眼科学 | 26642篇 |
药学 | 83914篇 |
33篇 | |
中国医学 | 2865篇 |
肿瘤学 | 67946篇 |
2021年 | 9891篇 |
2019年 | 10922篇 |
2018年 | 15518篇 |
2017年 | 11478篇 |
2016年 | 12711篇 |
2015年 | 14180篇 |
2014年 | 19594篇 |
2013年 | 29206篇 |
2012年 | 40686篇 |
2011年 | 42475篇 |
2010年 | 24772篇 |
2009年 | 23163篇 |
2008年 | 39001篇 |
2007年 | 41262篇 |
2006年 | 41517篇 |
2005年 | 40241篇 |
2004年 | 38341篇 |
2003年 | 36321篇 |
2002年 | 35046篇 |
2001年 | 60050篇 |
2000年 | 61482篇 |
1999年 | 50730篇 |
1998年 | 13766篇 |
1997年 | 12540篇 |
1996年 | 12687篇 |
1995年 | 11980篇 |
1994年 | 10859篇 |
1993年 | 10149篇 |
1992年 | 37473篇 |
1991年 | 35658篇 |
1990年 | 33951篇 |
1989年 | 32396篇 |
1988年 | 29594篇 |
1987年 | 28730篇 |
1986年 | 26913篇 |
1985年 | 25537篇 |
1984年 | 19423篇 |
1983年 | 16270篇 |
1982年 | 9905篇 |
1981年 | 8750篇 |
1979年 | 16844篇 |
1978年 | 11899篇 |
1977年 | 9807篇 |
1976年 | 9293篇 |
1975年 | 9534篇 |
1974年 | 11608篇 |
1973年 | 11194篇 |
1972年 | 10485篇 |
1971年 | 9479篇 |
1970年 | 9137篇 |
Background
Catheter ablation of ventricular tachycardia (VT) can reduce the burden of ventricular arrhythmia (VA) but its effect on health care utilization and costs after such therapy is poorly known. We sought to compare the rates of cardiovascular (CV)-related hospitalizations, survival, and health care costs in patients with recurrent VT treated either with VT ablation or with medical therapy.Methods
One-hundred implantable cardioverter-defibrillator patients with structural heart disease who underwent VT ablation were included. Propensity score-matched patients with recurrent VT treated with medical therapy were identified from a prospective registry of approximately 7000 de novo implantable cardioverter-defibrillator patients. Outcomes and costs were ascertained using health administrative databases.Results
Among patients who underwent VT ablation, the cumulative rates of VA-related hospitalizations were lower in the 2 years after their ablation procedure compared with the year before (rate ratio, 0.3; 95% confidence interval [CI], 0.22-0.43). Rates of CV-related hospitalization and hospitalization because of VA post index date were similar between the VT ablation and medical therapy groups (hazard ratio [HR], 0.94; 95% CI, 0.57-1.54 and HR, 1.04; 95% CI, 0.57-1.91, respectively). Health care costs in the VT ablation patients were not increased post-ablation compared with the medical management group. The risk of all-cause mortality was lower among patients in the VT ablation group relative to the medical therapy group (HR, 0.64; 95% CI, 0.4-0.99).Conclusions
Patients who underwent VT ablation experienced a significant reduction in their rate of VA-related hospitalizations. Patients treated with VT ablation had similar rates of CV-related hospitalization compared with those treated with medical therapy without increased health care-related costs. 相似文献Objective
To assess a 6-month nutritional and physical activity intervention program on the nutritional status of overweight or obese and not very active 8-14 years old children by means of a controlled pre-post design (ACTIVA’T program).Method
Pre-post study in 8-14 years old overweight or obese and low active children from Vilafranca del Penedès (Barcelona, Spain) randomized in control group (n = 51, 47.1% girls, nutritional intervention and ≤3 h/wk physical activity) and ACTIVA’T group (n = 45, 37.8% girls, nutritional and physical activity ≥5 h/wk intervention). Body mass index, waist/height index, and diet quality by means of KIDMED test at the beginning and at the end of the program were assessed. During the intervention, each participant was accompanied by a relative (father or mother) who performed the same activities as the children.Results
Dietary recommendations have positively changed the habits of both ACTIVA’T and control group. The reversion in the prevalence of overweight and obesity was 93.8% and 58.6%, respectively, in the ACTIVA’T group, compared to 25.0% and 35.8% in the control group. Abdominal obesity was decreased from 42.2% to 17.8% in the ACTIVA’T group and from 47.1% to 27.5% in the control group.Conclusions
The program ACTIVA’T (nutritional education and physical activity promotion) improves the quality of diet and reverses the prevalence of overweight and obesity in the underactive child population. 相似文献Introduction
There are limited randomized data comparing radical cystectomy (RC) with bladder-sparing tri-modality therapy (TMT) in the treatment of muscle-invasive bladder cancer (MIBC). Both strategies are thought to have similar survival outcomes with different morbidity profiles. We compare the effectiveness of TMT and RC using decision-analytic modeling and the endpoint of quality-adjusted life years (QALYs).Patients and Methods
Using a Markov model, we simulated the lifetime outcomes after TMT versus RC ± neoadjuvant chemotherapy for 67-year-old patients with clinical stage T2-T4aN0M0 MIBC. Model probabilities and utilities were extracted from the literature. The incremental effectiveness was reported in QALYs and sensitivity analyses were performed.Results
For all patients with MIBC, although the model showed identical survival, TMT was the most effective strategy with an incremental gain of 0.59 QALYs over RC (7.83 vs. 7.24 QALYs, respectively). When limiting the model to favorable, contemporary cohorts in both the TMT and RC strategies, TMT remained more effective with an incremental gain of 1.61 QALYs (9.37 vs. 7.76 QALYs, respectively). One-way sensitivity analyses demonstrated the model was sensitive to the quality of life parameters (ie, the utilities) for RC and TMT. When testing the 95% confidence interval of the RC utility parameter the model demonstrated an incremental gain with TMT from ?0.54 to 4.23 QALYs. Probabilistic sensitivity analysis demonstrated that TMT was more effective than RC for 63% of model iterations.Conclusions
This modeling study found that treatment of MIBC with organ-sparing TMT in appropriately-selected patients may result in a gain of QALYs relative to RC. 相似文献Background
In November 2017, the World Health Organization received initial reports of suspected diphtheria cases in camps established for displaced Rohingyas in Cox’s Bazar district, Bangladesh. By January 11, 2018, over 4,000 suspected cases of diphtheria and 30 deaths were reported. The Bangladesh government and partners implemented a diphtheria vaccination campaign in December 2017. Outbreak response staff reported anecdotal evidence of vaccine hesitancy. Our assessment aimed to understand vaccination barriers and opportunities to enhance vaccine demand among displaced Rohingyas in Bangladesh.Methods
In January 2018, we conducted a qualitative assessment consisting of nine focus group discussions and 15 key informant interviews with displaced Rohingyas in three camps. Participants included mothers and fathers with under five-year-old children, community volunteers, majhis (camp leaders), Islamic religious leaders, traditional and spiritual healers, and teachers. We recruited participants using purposive sampling, and analyzed the data thematically.Results
Across focus groups and in-depth interviews, trusted information sources cited by participants included religious leaders, elders, village doctors, pharmacists, majhis, and mothers trained by non-governmental organizations to educate caregivers. Treatment of diphtheria and measles was usually sought from multiple sources including traditional and spiritual healers, village doctors, pharmacies, and health clinics. Major barriers to vaccination included: various beliefs about vaccination causing people to become Christian; concerns about multiple vaccines being received on the same day; worries about vaccination side effects; and, lack of sensitivity to cultural gender norms at the vaccination sites.Conclusion
Although vaccination was understood as an important intervention to prevent childhood diseases, participants reported numerous barriers to vaccination. Strengthening vaccine demand and acceptance among displaced Rohingyas can be enhanced by improving vaccination delivery practices and engaging trusted leaders to address religious and cultural barriers using community-based channels. 相似文献Prolonged mechanical ventilation (MV) is a major complication following cardiac surgery. We conducted a secondary analysis of the Transfusion Requirements in Cardiac Surgery (TRICTS) III trial to describe MV duration, identify factors associated with prolonged MV, and examine associations of prolonged MV with mortality and complications.
MethodsFour thousand, eight hundred and nine participants undergoing cardiac surgery at 71 hospitals worldwide were included. Prolonged MV was defined based on the Society of Thoracic Surgeons definition as MV lasting 24 hr or longer. Adjusted associations of patient and surgical factors with prolonged MV were examined using multivariable logistic regression. Associations of prolonged MV with complications were assessed using odds ratios, and adjusted associations between prolonged MV and mortality were evaluated using multinomial regression. Associations of shorter durations of MV with survival and complications were explored.
ResultsProlonged MV occurred in 15% (725/4,809) of participants. Prolonged MV was associated with surgical factors indicative of complexity, such as previous cardiac surgery, cardiopulmonary bypass duration, and separation attempts; and patient factors such as critical preoperative state, left ventricular impairment, renal failure, and pulmonary hypertension. Prolonged MV was associated with perioperative but not long-term complications. After risk adjustment, prolonged MV was associated with perioperative mortality; its association with long-term mortality among survivors was weaker. Shorter durations of MV were not associated with increased risk of mortality or complications.
ConclusionIn this substudy of the TRICS III trial, prolonged MV was common after cardiac surgery and was associated with patient and surgical risk factors. Although prolonged MV showed strong associations with perioperative complications and mortality, it was not associated with long-term complications and had weaker association with long-term mortality among survivors.
Study registrationwww.ClinicalTrials.gov (NCT02042898); registered 23 January 2014. This is a substudy of the Transfusion Requirements in Cardiac Surgery (TRICS) III trial.
相似文献