首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1562270篇
  免费   113107篇
  国内免费   16933篇
耳鼻咽喉   21768篇
儿科学   43089篇
妇产科学   43061篇
基础医学   213118篇
口腔科学   43665篇
临床医学   142120篇
内科学   298836篇
皮肤病学   32694篇
神经病学   118757篇
特种医学   61682篇
外国民族医学   531篇
外科学   232669篇
综合类   64228篇
现状与发展   53篇
一般理论   471篇
预防医学   106320篇
眼科学   37760篇
药学   122889篇
  168篇
中国医学   13690篇
肿瘤学   94741篇
  2021年   18385篇
  2020年   13202篇
  2019年   15264篇
  2018年   19362篇
  2017年   16279篇
  2016年   16941篇
  2015年   21587篇
  2014年   28889篇
  2013年   36571篇
  2012年   49765篇
  2011年   53222篇
  2010年   31993篇
  2009年   29174篇
  2008年   45673篇
  2007年   48791篇
  2006年   48949篇
  2005年   47867篇
  2004年   43245篇
  2003年   41292篇
  2002年   39843篇
  2001年   68193篇
  2000年   70108篇
  1999年   60768篇
  1998年   18037篇
  1997年   16902篇
  1996年   15581篇
  1995年   14683篇
  1994年   13597篇
  1992年   44553篇
  1991年   42886篇
  1990年   41882篇
  1989年   40681篇
  1988年   37933篇
  1987年   37299篇
  1986年   35624篇
  1985年   33661篇
  1984年   25172篇
  1983年   21343篇
  1979年   24095篇
  1978年   17166篇
  1977年   14915篇
  1976年   13450篇
  1975年   15324篇
  1974年   18155篇
  1973年   17624篇
  1972年   16855篇
  1971年   15772篇
  1970年   14970篇
  1969年   14378篇
  1968年   13498篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
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   
65.
66.
67.
Pseudoaneurysms in the external carotid artery system are rare, mostly reported in the superficial temporal and facial arteries. The bilateral sagittal split osteotomy has a low incidence of complications requiring emergency interventions. We report the case of a patient with acute bleeding from a pseudoaneurysm of the inferior alveolar artery diagnosed by angiography and treated successfully by super-selective embolization.  相似文献   
68.
聚酰胺—胺树枝状聚合物(PAMAM)作为一种新型超支化大分子聚合物,因其出色的化学和生物学特性,一直被众学者称之为“人工蛋白”。 PAMAM的特点是存在内部空腔,并含有大量的反应性末端基团,这些结构使得PAMAM可以被用作仿生大分子,模拟天然有机基质在牙体组织表面进行仿生矿化,即PAMAM作为有机模板调控矿物质成核以及晶体的生长,以此来建造比传统的异体材料更加理想的牙体修复材料。本文就 PAMAM 诱导牙体硬组织仿生矿化的研究进展作一综述。  相似文献   
69.
Objectives: The steeling effect suggests that early-life adversity can have a beneficial impact later in life. However, little is known about its underlying mechanisms and long-term outcomes . The study aimed to examine the role of early-life adversity (ELA) on successful aging, and whether this relationship can be explained by mental and physical health.

Method: Socio-demographics, early-life adversity (ELA), individual quality of life (iQoL), and mental and physical health of 270 individuals (Mage = 66.82 years, 71.5% female) were assessed. Polynomial regressions and mediation analyses were conducted.

Results: Significant inverse U-shaped associations were found between ELA and iQoL (β = ?.59, p = .005) and between ELA and mental health (β = ?.64, p = .002), but not between ELA and physical health. Furthermore, mental health significantly mediated the relationship between ELA and iQoL (b = ?.84, BCa CI [?1.66, ?.27]).

Conclusion: Highest level of individual quality of life (i.e. successful aging) was related to a moderate amount of ELA. Additionally, mental health significantly mediated this relationship. These findings suggest that some amount of ELA could be beneficial for successful aging. Resource-focused interventions are needed to improve health and promote successful aging for an underdetected, at-risk subgroup with low early-life adversity.  相似文献   

70.
Doxorubicin (DOX) is the most commonly used anticancer drug; however, it has limited use because prolonged administration may result in severe cardiotoxicity. Simvastatin (SIM), generally prescribed for hypercholesterolaemia, has also shown salubrious results in the monotherapy or combinational drug therapy of different cancers in various models. Nanoparticle drug delivery systems are a novel way of improving therapeutics and also improving the absorption and specificity of drugs towards tumour cells. In this study, we exploited this technology to increase drug specificity and minimize imminent adverse effects. In this study, the antitumour activity of the combination formulas of DOX and SIM, either loaded in water (DOX‐SIM‐Solution) or nanoemulsions (NEs) (DOX‐SIM‐NE), was evaluated in a Swiss albino mouse model of Ehrlich ascites carcinoma. The anticancer effect was assessed by quantifying the change in body weight, mean survival time, and percent increase in lifespan (%ILS), determining haematological and serum biochemical parameters (liver function test, kidney function test and lipid profile parameters) as well as studying the histopathological alterations in liver tissues. We observed a clear increase in %ILS of the DOX‐SIM‐Solution group (265.30) that was double the %ILS of the DOX‐SIM‐NE group (134.70). However, DOX‐SIM‐NE had a non‐toxic effect on the haematological parameters, whereas DOX‐SIM‐Solution increased the levels of haemoglobin and lymphocytes. Furthermore, the encapsulation of SIM and DOX into NEs improved the levels of all serum biochemical parameters compared to the DOX‐SIM‐Solution. A reduction in the side effects of DOX‐SIM‐NE on the liver was also established using light microscopy, which revealed that the morphologies of the hepatocytes of the mice were less affected by administration of the DOX‐SIM‐NE treatment than with the DOX‐SIM‐Solution treatment. The study showed that incorporating SIM into the DOX‐loaded‐NE formulation remarkably improved its efficiency and simultaneously reduced its adverse effects.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号