全文获取类型
收费全文 | 1338434篇 |
免费 | 112521篇 |
国内免费 | 6371篇 |
专业分类
耳鼻咽喉 | 16705篇 |
儿科学 | 43005篇 |
妇产科学 | 36556篇 |
基础医学 | 183618篇 |
口腔科学 | 36273篇 |
临床医学 | 120686篇 |
内科学 | 278501篇 |
皮肤病学 | 31886篇 |
神经病学 | 110499篇 |
特种医学 | 55534篇 |
外国民族医学 | 274篇 |
外科学 | 210338篇 |
综合类 | 31529篇 |
现状与发展 | 2篇 |
一般理论 | 414篇 |
预防医学 | 106644篇 |
眼科学 | 28086篇 |
药学 | 93704篇 |
5篇 | |
中国医学 | 2227篇 |
肿瘤学 | 70840篇 |
出版年
2018年 | 13373篇 |
2017年 | 10631篇 |
2016年 | 12795篇 |
2015年 | 14300篇 |
2014年 | 19945篇 |
2013年 | 29734篇 |
2012年 | 36236篇 |
2011年 | 38881篇 |
2010年 | 24369篇 |
2009年 | 23902篇 |
2008年 | 36361篇 |
2007年 | 38774篇 |
2006年 | 39898篇 |
2005年 | 38486篇 |
2004年 | 36723篇 |
2003年 | 35818篇 |
2002年 | 33832篇 |
2001年 | 66052篇 |
2000年 | 67917篇 |
1999年 | 56587篇 |
1998年 | 16723篇 |
1997年 | 15017篇 |
1996年 | 16014篇 |
1995年 | 16232篇 |
1994年 | 15099篇 |
1993年 | 14154篇 |
1992年 | 47098篇 |
1991年 | 45747篇 |
1990年 | 43971篇 |
1989年 | 41815篇 |
1988年 | 38758篇 |
1987年 | 38081篇 |
1986年 | 35860篇 |
1985年 | 34635篇 |
1984年 | 26359篇 |
1983年 | 22108篇 |
1982年 | 13847篇 |
1981年 | 12447篇 |
1980年 | 11718篇 |
1979年 | 23544篇 |
1978年 | 17072篇 |
1977年 | 14385篇 |
1976年 | 13182篇 |
1975年 | 13722篇 |
1974年 | 16093篇 |
1973年 | 15396篇 |
1972年 | 14173篇 |
1971年 | 13037篇 |
1970年 | 11880篇 |
1969年 | 11101篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Epidemiologic studies have demonstrated that trans fat intake increases the risk of some chronic diseases. We hypothesize that trans fat intake would increase the risk of cardiovascular disease and type 2 diabetes mellitus by changing the lipid profile in plasma, the secretion of adipokines in adipose tissue, and the insulin sensitivity. Accordingly, the major objective of present study was to investigate the effect of dietary intake of trans fat on lipid profile, insulin sensitivity, and adipokine levels in plasma. Two groups of Wistar rats were fed a diet containing 4.5% trans fat or a control diet containing no trans fat for 16 weeks. Fasting glucose level was monitored every 2 weeks. At the end of feeding experiment, blood, heart, kidney, liver, omental adipose tissue, and semitendinosus muscle were collected. The trans fat content in organs, lipid profile, adipokine, insulin, and glucose levels in plasma were analyzed. The trans fat content in adipose tissue, heart, kidney, liver, and muscle of rats fed trans fat were 169.9, 0.6, 1.2, 1.7, and 2.5 mg/g samples, respectively. The trans fat content in these organs contributed to 15.9%, 1.2%, 2.3%, 4.3%, and 6.1% of the total fat, respectively. The plasma glucose level, insulin level, and insulin sensitivity index were not significantly different between the trans fat and control groups. The results indicated that trans fat intake might not be related to insulin resistance. However, lipid profile and plasma adipokine levels were significantly changed after trans fat feeding. The trans fat fed group showed significantly lower total cholesterol and high-density lipoprotein cholesterol levels than the control group. The decreased high-density lipoprotein cholesterol level may indicate the detrimental effect of trans fat intake on lipid profile. Adiponectin and resistin levels were significantly higher in the trans fat group than the control group. Leptin levels were significantly lower in the trans fat group than the control group. The results indicated that dietary intake of trans fat can significantly change the adipokine levels, but the possible links between adipokine level change caused by trans fat intake and metabolic effects of this change need further investigations. 相似文献
992.
993.
994.
995.
Alok D. Gandhi Rohit A. Patel Robert E. Brolin 《Surgery for obesity and related diseases》2009,5(2):144-149
BackgroundMesenteric internal hernia (MIH) is the most common cause of small bowel obstruction (SBO) after laparoscopic Roux-en-Y gastric bypass. Because MIH is a potentially life-threatening complication, we hypothesized that elective repair of MIH before developing acute SBO could decrease morbidity in this population.MethodsThe records of 702 consecutive patients undergoing primary laparoscopic Roux-en-Y gastric bypass from January 2002 and August 2007 were retrospectively reviewed to determine the incidence and etiology of SBO. During the last 9 months of the study, we offered elective laparoscopy to any patient who presented to us with symptoms of intermittent SBO.ResultsOf the 702 patients, 27 (3.8%) developed acute SBO. Of these 27 patients, 15 (55%) had obstruction related to an MIH. Nearly all patients had a typical history of intermittent abdominal pain, nausea, and bloating before developing acute SBO. Elective laparoscopy was offered to 11 patients with symptoms of intermittent SBO. Two patients who refused subsequently underwent operations for acute SBO. MIH was found at elective laparoscopic exploration in all cases. Of the 9 patients undergoing elective surgery, 3 (33%) had small bowel volvulus.ConclusionSBO due to MIH after laparoscopic Roux-en-Y gastric bypass is typically preceded by symptoms of intermittent obstruction. Patients who have these herald symptoms should promptly be offered elective laparoscopic exploration. Elective repair of MIH can be performed safely and expeditiously. 相似文献
996.
997.
998.
Ying-Ying Huang Aaron C.-H. Chen James D. Carroll Michael R. Hamblin 《Dose-response》2009,7(4):358-383
The use of low levels of visible or near infrared light for reducing pain, inflammation and edema, promoting healing of wounds, deeper tissues and nerves, and preventing cell death and tissue damage has been known for over forty years since the invention of lasers. Despite many reports of positive findings from experiments conducted in vitro, in animal models and in randomized controlled clinical trials, LLLT remains controversial in mainstream medicine. The biochemical mechanisms underlying the positive effects are incompletely understood, and the complexity of rationally choosing amongst a large number of illumination parameters such as wavelength, fluence, power density, pulse structure and treatment timing has led to the publication of a number of negative studies as well as many positive ones. A biphasic dose response has been frequently observed where low levels of light have a much better effect on stimulating and repairing tissues than higher levels of light. The so-called Arndt-Schulz curve is frequently used to describe this biphasic dose response. This review will cover the molecular and cellular mechanisms in LLLT, and describe some of our recent results in vitro and in vivo that provide scientific explanations for this biphasic dose response. 相似文献
999.
1000.