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   65000篇
  免费   2211篇
  国内免费   456篇
耳鼻咽喉   390篇
儿科学   693篇
妇产科学   586篇
基础医学   7024篇
口腔科学   4558篇
临床医学   4565篇
内科学   11994篇
皮肤病学   1337篇
神经病学   5138篇
特种医学   1583篇
外国民族医学   1篇
外科学   12266篇
综合类   3209篇
现状与发展   1篇
一般理论   5篇
预防医学   4962篇
眼科学   1138篇
药学   3900篇
  17篇
中国医学   2329篇
肿瘤学   1971篇
  2024年   95篇
  2023年   586篇
  2022年   980篇
  2021年   1949篇
  2020年   1175篇
  2019年   5063篇
  2018年   5302篇
  2017年   3354篇
  2016年   964篇
  2015年   933篇
  2014年   1653篇
  2013年   1776篇
  2012年   1318篇
  2011年   1575篇
  2010年   1347篇
  2009年   1057篇
  2008年   1048篇
  2007年   1005篇
  2006年   920篇
  2005年   734篇
  2004年   611篇
  2003年   630篇
  2002年   452篇
  2001年   501篇
  2000年   384篇
  1999年   379篇
  1998年   223篇
  1997年   220篇
  1996年   177篇
  1995年   180篇
  1994年   152篇
  1993年   140篇
  1992年   132篇
  1991年   122篇
  1990年   76篇
  1989年   86篇
  1987年   82篇
  1985年   2825篇
  1984年   3372篇
  1983年   2859篇
  1982年   3324篇
  1981年   3018篇
  1980年   2509篇
  1979年   2496篇
  1978年   2061篇
  1977年   1529篇
  1976年   1992篇
  1975年   1511篇
  1974年   1322篇
  1973年   1271篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
正This study investigated the effects of N-acetylcysteine(NAC)and ascorbic acid(AA)on hemin-induced K562 cell erythroid differentiation and the role of reactive oxygen species(ROS)in this process.Hemin increased ROS levels in a concentration-dependent manner,whereas NAC and AA had opposite effects.Both NAC and AA eliminated transient increased ROS levels after hemin treatment,inhibited hemin-induced  相似文献   
994.
995.
996.
997.
Intra-articular fractures of the calcaneus typically occur in individuals working on ladders, scaffolding or roofs. Male individuals in their productive age are most at risk. The functional problems that frequently persist are a well-known risk since they may obstruct a safe resumption of the former job. According to the data of the National Institute for Sickness and Invalidity Insurance the number of calcaneal fractures in Belgium have stabilised over the last ten years. These figures indicate the necessity for a better prevention policy. Scientific literature about the problem of impairment and disability in these cases is rare and lacks uniformity. A retrospective study was therefore performed on 65 private insurance compensation patients who were treated for intra-articular calcaneal fractures. The mean period of work incapacity was 260.5 days and the mean percentage of impairment was 12.3%. A large group (86.2%) were able to resume their former activities including the height workers. More than half of the patients (57%) needed a supportive device. Working at heights and falls from a height were a significant risk factor for long-term work incapacity. The figures are compared with the limited literature and further discussed.  相似文献   
998.
《药学学报(英文版)》2021,11(8):2469-2487
Lipid-based formulations (LBFs) have demonstrated a great potential in enhancing the oral absorption of poorly water-soluble drugs. However, construction of in vitro and in vivo correlations (IVIVCs) for LBFs is quite challenging, owing to a complex in vivo processing of these formulations. In this paper, we start with a brief introduction on the gastrointestinal digestion of lipid/LBFs and its relation to enhanced oral drug absorption; based on the concept of IVIVCs, the current status of in vitro models to establish IVIVCs for LBFs is reviewed, while future perspectives in this field are discussed. In vitro tests, which facilitate the understanding and prediction of the in vivo performance of solid dosage forms, frequently fail to mimic the in vivo processing of LBFs, leading to inconsistent results. In vitro digestion models, which more closely simulate gastrointestinal physiology, are a more promising option. Despite some successes in IVIVC modeling, the accuracy and consistency of these models are yet to be validated, particularly for human data. A reliable IVIVC model can not only reduce the risk, time, and cost of formulation development but can also contribute to the formulation design and optimization, thus promoting the clinical translation of LBFs.  相似文献   
999.
Background and aimsCholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP) are crucial proteins in reverse cholesterol transport. There are insufficient data on regulating these proteins by insulin therapy in type 1 diabetes mellitus (T1DM). We aimed to assess prospectively the impact of insulin therapy initiation on transfer proteins serum levels in adults with newly diagnosed T1DM.Methods and results57 adults with newly diagnosed T1DM were enrolled in the InLipoDiab1 Study. All participants were treated with subcutaneous insulin in the model of intensive insulin therapy since the diagnosis of diabetes. Serum PLTP and CETP concentrations were measured at diagnosis, after three weeks, six months, and after one year of insulin treatment, using the immunoenzymatic method ELISA.A significant decrease in PLTP and CETP concentrations were demonstrated during twelve months of insulin therapy in newly diagnosed T1DM. The dynamics of changes in the level of these proteins varied depending on the occurrence of remission after a year of the disease. In the group without remission, a significant decrease in PLTP and CETP levels appeared after six months of follow-up. The remission group was characterized by a decrease in proteins concentration only after one year of treatment. In the non-remission group, significant negative correlations were found between the daily dose of insulin and levels of PLTP and CETP.ConclusionExogenous insulin is an inhibitor of lipid transfer proteins involved in high-density lipoprotein cholesterol metabolism in the first year of treatment.  相似文献   
1000.
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