全文获取类型
收费全文 | 24001篇 |
免费 | 2278篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 208篇 |
儿科学 | 580篇 |
妇产科学 | 588篇 |
基础医学 | 3329篇 |
口腔科学 | 637篇 |
临床医学 | 2527篇 |
内科学 | 4970篇 |
皮肤病学 | 304篇 |
神经病学 | 2530篇 |
特种医学 | 1026篇 |
外国民族医学 | 1篇 |
外科学 | 3094篇 |
综合类 | 663篇 |
一般理论 | 25篇 |
预防医学 | 2161篇 |
眼科学 | 643篇 |
药学 | 1694篇 |
2篇 | |
中国医学 | 38篇 |
肿瘤学 | 1301篇 |
出版年
2021年 | 267篇 |
2020年 | 181篇 |
2019年 | 287篇 |
2018年 | 371篇 |
2017年 | 294篇 |
2016年 | 289篇 |
2015年 | 342篇 |
2014年 | 481篇 |
2013年 | 868篇 |
2012年 | 1129篇 |
2011年 | 1225篇 |
2010年 | 624篇 |
2009年 | 625篇 |
2008年 | 1123篇 |
2007年 | 1196篇 |
2006年 | 1243篇 |
2005年 | 1261篇 |
2004年 | 1231篇 |
2003年 | 1148篇 |
2002年 | 1174篇 |
2001年 | 529篇 |
2000年 | 499篇 |
1999年 | 475篇 |
1998年 | 290篇 |
1997年 | 243篇 |
1996年 | 243篇 |
1995年 | 263篇 |
1994年 | 233篇 |
1993年 | 218篇 |
1992年 | 400篇 |
1991年 | 461篇 |
1990年 | 418篇 |
1989年 | 345篇 |
1988年 | 398篇 |
1987年 | 346篇 |
1986年 | 339篇 |
1985年 | 356篇 |
1984年 | 325篇 |
1983年 | 252篇 |
1982年 | 206篇 |
1981年 | 225篇 |
1980年 | 207篇 |
1979年 | 278篇 |
1978年 | 222篇 |
1977年 | 215篇 |
1976年 | 192篇 |
1975年 | 195篇 |
1974年 | 218篇 |
1973年 | 169篇 |
1972年 | 186篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
Phyllis A Gordon 《Journal of Vascular Nursing》2004,22(1):2-11; quiz 12-3
Diabetes mellitus has been referred to as a vascular disease because of its effect on the vascular endothelial wall. In recent years, research has identified specific effects of hyperglycemia and insulin resistance on the vasculature of the diabetic patient. Atherosclerosis is known to develop earlier in the diabetic patient and is more aggressive due to the metabolic effects of hyperglycemia and insulin resistance. The results of many large, randomized, prospective trials have provided practice changes in the management of the patient with diabetes. Trials such as the Framingham Study identified risk factors associated with atherosclerosis. Additional studies, such as the Diabetes Control and Complications Trial and the United Kingdom Prospective Diabetes Study, provided information about risk factors for diabetes and contributed to treatment recommendations for the person with type 1 or type 2 diabetes. Results of these and many other trials continue to change the recommendations for the person with diabetes to reduce mortality and prevent coronary heart disease, blindness, renal failure, and amputation. This paper will identify the effects of diabetes on the vascular system and outline best practice recommendations on the basis of clinical trials. 相似文献
63.
64.
65.
66.
67.
Percutaneous transhepatic placement of biliary endoprostheses: results in 100 consecutive patients. 总被引:4,自引:0,他引:4
B W Dick R L Gordon J M LaBerge M M Doherty E J Ring 《Journal of vascular and interventional radiology : JVIR》1990,1(1):97-100
One hundred patients with malignant biliary obstruction underwent palliative therapy by means of percutaneous transhepatic placement of 114 biliary endoprostheses. All patients were then followed up for at least 18 months or until death. Retrospective evaluation of the 95 patients who died showed an average survival time of 5.0 months. The five remaining patients have survived an average of 29.8 months. During the 1st week after stent insertion, a second manipulation was performed to improve stent function in nine patients. Overall, 14 (12.3%) of the stents became obstructed and six (5.2%) migrated; 86 patients required no further therapy for biliary obstruction or stent malfunction. The 30-day mortality rate was 12%; none of the deaths were directly attributable to a complication of the stent placement procedure. 相似文献
68.
Dehydroepiandrosterone and dehydroepiandrosterone sulfate are steroids which may be associated with the development of breast cancer. To examine the association between serum levels of dehydroepiandrosterone and dehydroepiandrosterone sulfate and the risk of developing premenopausal breast cancer, we measured hormone levels in 15 women who donated blood to a community-based serum bank in 1974 and who subsequently developed premenopausal breast cancer and in 29 matched controls from the same group of volunteers. The mean serum level of dehydroepiandrosterone among cases was 10% lower than among controls. The risk of developing breast cancer for women in the highest tertile compared with the lowest tertile of serum dehydroepiandrosterone was 0.40 with a suggestion of a dose-response trend with increasing levels. No consistent association between dehydroepiandrosterone sulfate and the risk of premenopausal breast cancer was evident. In contrast to postmenopausal breast cancer, a protective effect of dehydroepiandrosterone against premenopausal breast cancer is suggested, but because of the small sample size, the results of this study need to be replicated by others. 相似文献
69.
Pallav J Shah Manoj Durairaj Ian Gordon John Fuller Alex Rosalion Siven Seevanayagam James Tatoulis Brian F Buxton 《European journal of cardio-thoracic surgery》2004,26(1):118-124
OBJECTIVE: The purpose is to define factors influencing long-term patency of the internal thoracic artery (ITA) to optimize the operative strategy. METHODS: 1482 left internal thoracic artery (LITA) and 636 right internal thoracic artery (RITA) symptom-directed angiograms were studied in 1434 patients. Data were prospectively collected from patients who had primary coronary artery bypass surgery during the period 1982-2002. The mean age of patients was 59 years; 85% were male. The mean period from operation to re-angiogram was 80 months. LITA was grafted to left anterior descending coronary artery (LAD) in 82% of cases, RITA to right coronary artery (RCA) in 40% and circumflex artery in 35% of cases. Graft failure was defined as > or =80% stenosis. RESULTS: 96.3% of LITA and 88.1% of RITA grafts were patent. No patient variables were significantly associated with graft patency (age, gender, diabetes, hypertension, LVEF, NYHA, AMI). Target coronary artery was associated with patency of both LITA and RITA grafts with maximum patency when grafted to LAD (P = 0.02) RITA had the worst patency to RCA, patency for the left system was identical to LITA. Proximal anastomosis to aorta (free RITA) had significantly better patency when compared with in situ RITA to RCA system (P = 0.005) while similar patency when grafted to left system. ITA diameter and target artery diameter were not associated with graft patency. Recent operations had better RITA patency (P = 0.03). The interval from operation to angiogram was not associated with ITA patency (96% patency for LITA and 88% patency for RITA, remained stable when studied at <1, 1-4, 5-9, 10-14 and >15 years). CONCLUSIONS: Even in a patient cohort that had adverse symptoms, excellent LITA and RITA patency was achieved which almost remained constant through all time intervals studied. 相似文献
70.
Gordon Winocur Fergus I M Craik Brian Levine Ian H Robertson Malcolm A Binns Michael Alexander Sandra Black Deirdre Dawson Heather Palmer Tara McHugh Donald T Stuss 《Journal of the International Neuropsychological Society》2007,13(1):166-171
This study provides an overview of the papers emanating from the experimental trial that evaluated a new cognitive rehabilitation program in older adults who were experiencing normal cognitive decline. The main features of the design are summarized, along with evidence that the training produced long-lasting improvement in memory performance, goal management, and psychosocial status. The benefits were attributed to several factors, including the program's emphasis on techniques that promoted efficient strategic processing. Limitations of the program and directions for future research are discussed. 相似文献