全文获取类型
收费全文 | 247383篇 |
免费 | 20421篇 |
国内免费 | 8297篇 |
专业分类
耳鼻咽喉 | 1574篇 |
儿科学 | 8019篇 |
妇产科学 | 1918篇 |
基础医学 | 24156篇 |
口腔科学 | 6556篇 |
临床医学 | 26914篇 |
内科学 | 58079篇 |
皮肤病学 | 3343篇 |
神经病学 | 27087篇 |
特种医学 | 7826篇 |
外国民族医学 | 12篇 |
外科学 | 21515篇 |
综合类 | 34269篇 |
现状与发展 | 41篇 |
一般理论 | 9篇 |
预防医学 | 17959篇 |
眼科学 | 2842篇 |
药学 | 17083篇 |
193篇 | |
中国医学 | 10998篇 |
肿瘤学 | 5708篇 |
出版年
2024年 | 245篇 |
2023年 | 4809篇 |
2022年 | 6376篇 |
2021年 | 11829篇 |
2020年 | 12063篇 |
2019年 | 9383篇 |
2018年 | 9349篇 |
2017年 | 9239篇 |
2016年 | 9611篇 |
2015年 | 9382篇 |
2014年 | 17669篇 |
2013年 | 20000篇 |
2012年 | 14553篇 |
2011年 | 15899篇 |
2010年 | 12479篇 |
2009年 | 12089篇 |
2008年 | 12162篇 |
2007年 | 11849篇 |
2006年 | 10560篇 |
2005年 | 8887篇 |
2004年 | 7576篇 |
2003年 | 6525篇 |
2002年 | 5369篇 |
2001年 | 4674篇 |
2000年 | 3808篇 |
1999年 | 3222篇 |
1998年 | 2801篇 |
1997年 | 2428篇 |
1996年 | 2160篇 |
1995年 | 2247篇 |
1994年 | 2055篇 |
1993年 | 1732篇 |
1992年 | 1688篇 |
1991年 | 1502篇 |
1990年 | 1198篇 |
1989年 | 1029篇 |
1988年 | 974篇 |
1987年 | 884篇 |
1986年 | 760篇 |
1985年 | 914篇 |
1984年 | 753篇 |
1983年 | 483篇 |
1982年 | 572篇 |
1981年 | 513篇 |
1980年 | 404篇 |
1979年 | 333篇 |
1978年 | 255篇 |
1977年 | 221篇 |
1976年 | 212篇 |
1975年 | 81篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
41.
《Nutrition, metabolism, and cardiovascular diseases : NMCD》2022,32(4):908-917
Background and aimsReducing dietary cholesterol is generally acceptable for the prevention of cardiovascular disease (CVD). Eggs are nutrient-dense and common food items across the world, while rich in cholesterol. The potential effects of egg intake on cardiovascular health remain uncertainty and have been under debate in past decades.Methods and resultsA nationwide cohort of 20,688 participants aged 16–110 years without CVD at baseline were derived from the China Family Panel Studies. Egg consumption was assessed by a semi-quantitative food frequency questionnaire. We adopted stratified Cox proportional hazards model with random intercepts for provinces to evaluate associations of egg intake with CVD incidence. During a median follow-up of 6.0 years, we identified 2395 total CVD incidence and mean egg consumption was 3 times/week. Egg intakes were associated lower risks of CVD incidence in the multivariate-adjusted model. Compared with the non-consumers, the corresponding HRs (95% confidence interval) for total CVD events were 0.84 (0.74–0.94) for 1–2 times per week, 0.78 (0.69–0.88) for 3–6/week, and 0.83 (0.72–0.95) for ≥7/week. Similar relationships were found in hypertension. Approximately non-linear relationships were observed between egg consumption with total CVD and hypertension incidence, identifying the lowest risk in 3–6 times/week. Subgroup analyses estimated lower risks of total CVD and hypertension in females only, with significant effect modification by sex (P for interaction = 0.008 and 0.020).ConclusionEgg consumption may be associated with lower risks of CVD incidence among Chinese adults. Our findings could have implications in CVD prevention and might be considered in the development of dietary guidelines. 相似文献
42.
《Revista de gastroenterologia de Mexico》2022,87(2):159-169
Introduction and aimsCirrhosis is the common outcome of liver diseases. It can be decompensated and lead to the development of complications, such as encephalopathy. Hyperammonemia that develops due to liver dysfunction is etiopathologically related to hepatic encephalopathy. Caffeine increases the activity of the urea cycle in the liver, augmenting ammonia degradation. By antagonizing adenosine receptors, it also has a hepatoprotective effect, impeding the formation of fibrosis, as well as having a stimulating effect on the central nervous system. The present study analyzed the effects of caffeine on the progression of cholestatic liver fibrosis and hepatic encephalopathy.Materials and methodsAn experimental model of cholestatic liver fibrosis, through common bile duct ligature, and of hepatic encephalopathy, through the administration of a high-protein diet, was constructed. Male Wistar rats (n = 32) were equally divided into 4 groups. The experiment lasted 28 days, with the administration of 50 mg/kg/day of caffeine. Laboratory tests, histologic analyses of the liver and encephalon, open field tests (OFTs), and daily behavioral analyses were carried out.ResultsThe ligated animals treated with caffeine had lower mean transaminase levels and improved histologic aspects of the liver and encephalon. The untreated ligated animals were clearly lethargic and apathetic at the last week of the experiment, confirmed by reduced exploratory activity during the OFT.ConclusionCaffeine improved the microarchitecture of the liver and encephalon of the cirrhotic animals and prevented the decrease in exploratory behavior of the animals during the OFT. 相似文献
43.
姚峰 《中国工业医学杂志》2022,35(2):191-191