全文获取类型
收费全文 | 1656753篇 |
免费 | 108752篇 |
国内免费 | 4642篇 |
专业分类
耳鼻咽喉 | 20001篇 |
儿科学 | 54732篇 |
妇产科学 | 42561篇 |
基础医学 | 235567篇 |
口腔科学 | 44011篇 |
临床医学 | 152220篇 |
内科学 | 320861篇 |
皮肤病学 | 30645篇 |
神经病学 | 139734篇 |
特种医学 | 61730篇 |
外国民族医学 | 387篇 |
外科学 | 232739篇 |
综合类 | 32654篇 |
现状与发展 | 2篇 |
一般理论 | 517篇 |
预防医学 | 146481篇 |
眼科学 | 34392篇 |
药学 | 117043篇 |
6篇 | |
中国医学 | 4360篇 |
肿瘤学 | 99504篇 |
出版年
2021年 | 13965篇 |
2019年 | 14451篇 |
2018年 | 41659篇 |
2017年 | 32382篇 |
2016年 | 36247篇 |
2015年 | 19330篇 |
2014年 | 26086篇 |
2013年 | 38405篇 |
2012年 | 59657篇 |
2011年 | 76805篇 |
2010年 | 50001篇 |
2009年 | 40810篇 |
2008年 | 70017篇 |
2007年 | 76242篇 |
2006年 | 52725篇 |
2005年 | 53478篇 |
2004年 | 52736篇 |
2003年 | 51733篇 |
2002年 | 46614篇 |
2001年 | 64821篇 |
2000年 | 66628篇 |
1999年 | 55642篇 |
1998年 | 16093篇 |
1997年 | 14653篇 |
1996年 | 14260篇 |
1995年 | 13490篇 |
1994年 | 12669篇 |
1993年 | 11855篇 |
1992年 | 43629篇 |
1991年 | 42843篇 |
1990年 | 41350篇 |
1989年 | 39256篇 |
1988年 | 36286篇 |
1987年 | 35317篇 |
1986年 | 33656篇 |
1985年 | 32078篇 |
1984年 | 24100篇 |
1983年 | 20446篇 |
1982年 | 12292篇 |
1979年 | 21651篇 |
1978年 | 15361篇 |
1977年 | 12472篇 |
1976年 | 12256篇 |
1975年 | 12571篇 |
1974年 | 15278篇 |
1973年 | 14934篇 |
1972年 | 13727篇 |
1971年 | 12759篇 |
1970年 | 11891篇 |
1969年 | 10836篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
We report a case of intestinal obstruction in a 73-year-old woman caused by ileocolic intussusception. The underlying cause was a giant submucosal ulcerating lipoma (6?×?3.3?×?3.8 cm) extending from the superior mucosal lip of Bauhin’s valve. Abdominal ultrasonography showed a pathognomonic target-like mass appearing as multiple concentric rings. CT scan confirmed the diagnosis. Because of apparent obstruction, a laparotomy with right hemicolectomy and ileocolic anastomosis was performed. Lipomas most frequently occur in the cecum and ascending colon where they represent the most common submucosal mesenchymal tumor. They typically occur in elderly women with an incidence that varies from 0.15 to 0.56 %. Pain, rectal bleeding, and obstruction are typical symptoms. When faced with an intussusception in children, reduction with air per rectum can be performed. In adults, however, malignant cell spreading and seeding is of big concern. Since approximately 20–50 % of all underlying causes are malignant, explorative surgery is favored in adults. 相似文献
102.
103.
104.
105.
106.
David M. Presby Michael C. Rudolph Vanessa D. Sherk Matthew R. Jackman Rebecca M. Foright Kenneth L. Jones Julie A. Houck Ginger C. Johnson Janine A. Higgins P. Darrell Neufer Robert H. Eckel Paul S. MacLean 《Diabetes》2021,70(4):867
Moderate weight loss improves numerous risk factors for cardiometabolic disease; however, long-term weight loss maintenance (WLM) is often thwarted by metabolic adaptations that suppress energy expenditure and facilitate weight regain. Skeletal muscle has a prominent role in energy homeostasis; therefore, we investigated the effect of WLM and weight regain on skeletal muscle in rodents. In skeletal muscle of obesity-prone rats, WLM reduced fat oxidative capacity and downregulated genes involved in fat metabolism. Interestingly, even after weight was regained, genes involved in fat metabolism were also reduced. We then subjected mice with skeletal muscle lipoprotein lipase overexpression (mCK-hLPL), which augments fat metabolism, to WLM and weight regain and found that mCK-hLPL attenuates weight regain by potentiating energy expenditure. Irrespective of genotype, weight regain suppressed dietary fat oxidation and downregulated genes involved in fat metabolism in skeletal muscle. However, mCK-hLPL mice oxidized more fat throughout weight regain and had greater expression of genes involved in fat metabolism and lower expression of genes involved in carbohydrate metabolism during WLM and regain. In summary, these results suggest that skeletal muscle fat oxidation is reduced during WLM and regain, and therapies that improve skeletal muscle fat metabolism may attenuate rapid weight regain. 相似文献
107.
Henry Havel Gregory Finch Pamela Strode Marc Wolfgang Stephen Zale Iulian Bobe Hagop Youssoufian Matthew Peterson Maggie Liu 《The AAPS journal》2016,18(6):1373-1378
Advancing nanomedicines from concept to clinic requires integration of new science with traditional pharmaceutical development. The medical and commercial success of nanomedicines is greatly facilitated when those charged with developing nanomedicines are cognizant of the unique opportunities and technical challenges that these products present. These individuals must also be knowledgeable about the processes of clinical and product development, including regulatory considerations, to maximize the odds for successful product registration. This article outlines these topics with a goal to accelerate the combination of academic innovation with collaborative industrial scientists who understand pharmaceutical development and regulatory approval requirements—only together can they realize the full potential of nanomedicines for patients. 相似文献
108.
Moises Rodriguez-Gonzalez Antonio Moruno Tirado Reza Hosseinpour Jose Santos de Soto 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》2015,42(4):350-356
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic. 相似文献
109.
110.
Eric E Rasmussen Autumn Shafer Malinda J. Colwell Shawna White Narissra Punyanunt-Carter Rebecca L. Densley 《Journal of Children and Media》2016,10(4):443-461
This study explored the relationship between active mediation, exposure to Daniel Tiger’s Neighborhood, and key indicators of preschoolers’ social and emotional development. One hundred and twenty-seven children aged 2–6 either watched or did not watch 10 episodes of Daniel Tiger’s Neighborhood over a two-week period. Results revealed that preschoolers who watched the program exhibited higher levels of empathy, self-efficacy, and emotion recognition when their regular TV-watching experiences are frequently accompanied by active mediation. This was especially true for younger preschoolers and preschoolers from low-income families. Implications for policy-makers, parents, producers of prosocial programming, and educators are discussed. 相似文献