全文获取类型
收费全文 | 1122篇 |
免费 | 56篇 |
国内免费 | 96篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 63篇 |
妇产科学 | 10篇 |
基础医学 | 144篇 |
口腔科学 | 27篇 |
临床医学 | 155篇 |
内科学 | 244篇 |
皮肤病学 | 12篇 |
神经病学 | 68篇 |
特种医学 | 134篇 |
外科学 | 43篇 |
综合类 | 51篇 |
预防医学 | 96篇 |
眼科学 | 7篇 |
药学 | 135篇 |
中国医学 | 1篇 |
肿瘤学 | 79篇 |
出版年
2021年 | 15篇 |
2019年 | 10篇 |
2018年 | 9篇 |
2017年 | 7篇 |
2016年 | 11篇 |
2015年 | 11篇 |
2014年 | 15篇 |
2013年 | 44篇 |
2012年 | 35篇 |
2011年 | 28篇 |
2010年 | 38篇 |
2009年 | 34篇 |
2008年 | 35篇 |
2007年 | 70篇 |
2006年 | 42篇 |
2005年 | 41篇 |
2004年 | 15篇 |
2003年 | 23篇 |
2002年 | 21篇 |
2001年 | 28篇 |
2000年 | 28篇 |
1999年 | 31篇 |
1998年 | 45篇 |
1997年 | 40篇 |
1996年 | 32篇 |
1995年 | 39篇 |
1994年 | 34篇 |
1993年 | 43篇 |
1992年 | 24篇 |
1991年 | 25篇 |
1990年 | 36篇 |
1989年 | 41篇 |
1988年 | 49篇 |
1987年 | 39篇 |
1986年 | 27篇 |
1985年 | 32篇 |
1984年 | 18篇 |
1983年 | 10篇 |
1982年 | 12篇 |
1981年 | 9篇 |
1980年 | 13篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 8篇 |
1974年 | 7篇 |
1971年 | 5篇 |
1968年 | 5篇 |
1967年 | 5篇 |
1961年 | 5篇 |
1945年 | 4篇 |
排序方式: 共有1274条查询结果,搜索用时 15 毫秒
41.
Effects of therapy with cholestyramine on progression of coronary arteriosclerosis: results of the NHLBI Type II Coronary Intervention Study 总被引:20,自引:0,他引:20
J F Brensike R I Levy S F Kelsey E R Passamani J M Richardson I K Loh N J Stone R F Aldrich J W Battaglini D J Moriarty 《Circulation》1984,69(2):313-324
In the National Heart, Lung and Blood Institute Type II Coronary Intervention Study, patients with Type II hyperlipoproteinemia and coronary artery disease (CAD) were placed on a low-fat, low-cholesterol diet and then were randomly allocated to receive either 6 g cholestyramine four times daily or placebo. This double-blind study evaluated the effects of cholestyramine on the progression of CAD as assessed by angiography. Diet alone reduced the low-density lipoprotein cholesterol 6% in both groups. After randomization, low-density lipoprotein cholesterol decreased another 5% in the placebo group and 26% in the cholestyramine-treated group. Coronary angiography was performed in 116 patients before and after 5 years of treatment. CAD progressed in 49% (28 of 57) of the placebo-treated patients vs 32% (19 of 59) of the cholestyramine-treated patients (p less than .05). When only definite progression was considered, 35% (20 of 57) of the placebo-treated patients vs 25% (15 of 59) of the cholestyramine-treated patients exhibited definite progression; the difference was not statistically significant. However, when this analysis was performed with adjustment for baseline inequalities of risk factors, effect of treatment was more pronounced. Of lesions causing 50% or greater stenosis at baseline, 33% of placebo-treated and 12% of cholestyramine-treated patients manifested lesion progression (p less than .05). Similar analyses with other end points (percent of baseline lesions that progressed, lesions that progressed to occlusion, lesions that regressed, size of lesion change, and all cardiovascular end points) all favored the cholestyramine-treated group, but were not statistically significant. Thus, although the sample size does not allow a definitive conclusion to be drawn, this study suggests that cholestyramine treatment retards the rate of progression of CAD in patients with Type II hyperlipoproteinemia. 相似文献
42.
BRCA1 and BRCA2 are major breast cancer susceptibility genes. Nineteen single nucleotide polymorphisms (SNPs) at 18 loci have been associated with breast cancer. We aimed to determine whether these predict breast cancer incidence in women with BRCA1/BRCA2 mutations. BRCA1/2 mutation carriers identified through the Manchester genetics centre between 1996 and 2011 were included. Using published odds ratios (OR) and risk allele frequencies, we calculated an overall breast cancer risk SNP score (OBRS) for each woman. The relationship between OBRS and age at breast cancer onset was investigated using the Cox proportional hazards model, and predictive ability assessed using Harrell's C concordance statistic. In BRCA1 mutation carriers we found no association between OBRS and age at breast cancer onset: OR for the lowest risk quintile compared to the highest was 1.20 (95% CI 0.82–1.75, Harrell's C = 0.54), but in BRCA2 mutation carriers the association was significant (OR for the lowest risk quintile relative to the highest was 0.47 (95% CI 0.33–0.69, Harrell's C = 0.59). The 18 validated breast cancer SNPs differentiate breast cancer risks between women with BRCA2 mutations, but not BRCA1. It may now be appropriate to use these SNPs to help women with BRCA2 mutations make maximally informed decisions about management options. 相似文献
43.
44.
Abstract: The prevalence of Parkinson’s disease (PD) is expected to double over the next 20 years owing to the increase in life expectancy. This progressive disease has several implications relating to oral health, and many are manageable with proper awareness and knowledge about the disease. This article reviews the epidemiology, pathophysiology, and characteristics of PD, as well as the treatments and oral health considerations to enable dental hygienists to undertake an informed approach to patient management strategies and provide optimal care. 相似文献
45.
J Tang DJ Humes E Gemmil NT Welch SL Parsons JA Catton 《Annals of the Royal College of Surgeons of England》2013,95(5):323-328
Introduction
The high mortality and morbidity associated with resection for oesophagogastric malignancy has resulted in a conservative approach to the postoperative management of this patient group. In August 2009 we introduced an enhanced recovery after surgery (ERAS) pathway tailored to patients undergoing resection for oesophagogastric malignancy. We aimed to assess the impact of this change in practice on standard clinical outcomes.Methods
Two cohorts were studied of patients undergoing resection for oesophagogastric malignancy before (August 2008 – July 2009) and after (August 2009 – July 2010) the implementation of the ERAS pathway. Data were collected on demographics, interventions, length of stay, morbidity and in-hospital mortality.Results
There were 53 and 55 oesophagogastric resections undertaken respectively for malignant disease in each of the study periods. The median length of stay for both gastric and oesophageal resection decreased from 15 to 11 days (Mann– Whitney U, p<0.001) following implementation of the ERAS pathway. There was no significant increase in morbidity (gastric resection 23.1% vs 5.3% and oesophageal resection 25.9% vs 16.7%) or mortality (gastric resection no deaths and oesophageal resection 1.8% vs 3.6%) associated with the changes. There was a significant decrease in the number of oral contrast studies used following oesophageal resection, with a reduction from 21 (77.8%) in 2008–2009 to 6 (16.7%) in 2009–2010 (chi-squared test, p<0.0001).Conclusions
The introduction of an enhanced recovery programme following oesophagogastric surgery resulted in a significant decrease in length of median patient stay in hospital without a significant increase in associated morbidity and mortality. 相似文献46.
JEFF S. HEALEY M.D. M.Sc. LORNE J. GULA M.D. DAVID H. BIRNIE M.D. LAWRENCE STERNS M.D. STUART J. CONNOLLY M.D. JOHN SAPP M.D. EUGENE CRYSTAL M.D. CHRIS SIMPSON M.D. DEREK V. EXNER M.D. M.P.H. TERESA KUS M.D. FRANCOIS PHILIPPON M.D. GEORGE WELLS Ph.D. ANTHONY SL. TANG M.D. 《Journal of cardiovascular electrophysiology》2012,23(12):1313-1316
Comparing ICD Implantation with and Without Intraoperative Defibrillation Testing. Introduction: The need to perform defibrillation testing (DT) at the time of implantable cardioverter defibrillator (ICD) insertion is controversial. In the absence of randomized trials, some regions now perform more than half of ICD implants without DT. Methods: During the last year of enrolment in the Resynchronization for Ambulatory Heart Failure Trial, a substudy randomized patients to ICD implantation with versus without DT. Results: Among 252 patients screened, 145 were enrolled; 75 randomized to DT and 70 to no DT. Patients were similar in terms of age (65.9 ± 9.3 years vs 67.9 ± 8.9 years); LVEF (24.7 ± 4.6% vs 23.6 ± 4.6%), QRS width (154.8 ± 23.5 vs 155.8 ± 23.6 ms), and history of atrial fibrillation (5% vs 6%). All 68 patients in the DT arm tested according to the protocol achieved a successful DT (≤25 J); 96% without requiring any system modification. No patient experienced perioperative stroke, myocardial infarction, heart failure (HF), intubation or unplanned ICU stay. The length of hospital stay was not prolonged in the DT group: 20.2 ± 26.3 hours versus 21.3 ± 23.0 hours, P = 0.79. One patient in the DT arm had a failed appropriate shock and no patient suffered an arrhythmic death. The composite of HF hospitalization or all‐cause mortality occurred in 10% of patients in the no‐DT arm and 19% of patients in the DT arm (HR = 0.53, 95% CI: 0.21–1.31, P = 0.14). Conclusions: In this randomized trial, perioperative complications, failed appropriate shocks, and arrhythmic death were all uncommon regardless of DT. There was a nonsignificant increase in the risk of death or HF hospitalization with DT. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1313‐1316, December 2012) 相似文献
47.
48.
MA Suckow SL Voytik-Harbin LA Terril SF Badylak 《Journal of investigative surgery》2013,26(5):277-287
Small instestinal submucosa (SIS) is an easily produced material that has been used experimentally for tissue engineering. To evaluate the ability of SIS to facilitate bone growth within a long-bone defect, a segment of the radius was surgically removed in adult, female Sprague-Dawley rats. The defect was either left unfilled or implanted with SIS, demineralized cortical bone (DMCB), or ovalbumin. The defect was evaluated radiographically and histologically after 3, 6, 12, and 24 weeks. Tissue remodeling within the defect was evident by week 3 in SIS- and DMCB-treated rats. Filling was characterized initially by infiltration of mononuclear cells and extracellular material in SIS-implanted rats and multifocal remodeling bone particles and cartilage formation in DMCB implanted rats. Cartilage was observed as early as 3 weeks and bone as early as 6 weeks in SIS-implanted rats. Filling of the defect arose from multiple foci in DMCB-implanted rats, but was contiguous with and parallel to the ulnar shaft in SIS-implanted rats, suggesting that defect repair by SIS may be conductive rather than inductive. Rats in which the defect was left unfilled demonstrated slow but progressive filling of the defect, characterized by mononuclear cell infiltrates and fibrous extracellular material. In summary, SIS facilitated rapid filling of a longbone defect. These results suggest that SIS may be useful as a bone repair material. 相似文献
49.
50.