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   4967篇
  免费   401篇
  国内免费   60篇
耳鼻咽喉   40篇
儿科学   141篇
妇产科学   210篇
基础医学   634篇
口腔科学   74篇
临床医学   427篇
内科学   1297篇
皮肤病学   113篇
神经病学   612篇
特种医学   157篇
外科学   446篇
综合类   6篇
一般理论   3篇
预防医学   295篇
眼科学   54篇
药学   340篇
中国医学   9篇
肿瘤学   570篇
  2024年   18篇
  2023年   141篇
  2022年   284篇
  2021年   431篇
  2020年   250篇
  2019年   273篇
  2018年   320篇
  2017年   202篇
  2016年   232篇
  2015年   257篇
  2014年   263篇
  2013年   311篇
  2012年   412篇
  2011年   343篇
  2010年   187篇
  2009年   139篇
  2008年   231篇
  2007年   239篇
  2006年   199篇
  2005年   166篇
  2004年   143篇
  2003年   130篇
  2002年   98篇
  2001年   16篇
  2000年   6篇
  1999年   20篇
  1998年   24篇
  1997年   14篇
  1996年   11篇
  1995年   11篇
  1994年   12篇
  1993年   9篇
  1992年   2篇
  1991年   5篇
  1990年   3篇
  1989年   3篇
  1988年   5篇
  1987年   4篇
  1986年   3篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1982年   2篇
  1981年   3篇
  1979年   3篇
排序方式: 共有5428条查询结果,搜索用时 15 毫秒
991.
992.
Clinical Rheumatology - The pediatric syndrome characterized by periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) and adult Behçet’s disease share some...  相似文献   
993.
AIM: To investigate in vitro the therapeutic effect and mechanisms of silybin in a cellular model of hepatic steatosis.METHODS: Rat hepatoma Fa O cells were loaded with lipids by exposure to 0.75 mmol/L oleate/palmitate for 3 h to mimic liver steatosis. Then, the steatotic cells were incubated for 24 h with different concentrations(25 to 100 μmol/L) of silybin as phytosome complex with vitamin E. The effects of silybin on lipid accumulation and metabolism, and on indices of oxidative stress were evaluated by absorption and fluorescence microscopy, quantitative real-time PCR, Western blot, spectrophotometric and fluorimetric assays.RESULTS: Lipid-loading resulted in intracellular triglyceride(TG) accumulation inside lipid droplets, whose number and size increased. TG accumulation was mediated by increased levels of peroxisome proliferator-activated receptors(PPARs) and sterol regulatory element-binding protein-1c(SREBP-1c). The lipid imbalance was associated with higher production of reactive oxygen species(ROS) resulting in increased lipid peroxidation, stimulation of catalase activity and activation of nuclear factor kappa-B(NF-κB). Incubation of steatotic cells with silybin 50 μmol/L significantly reduced TG accumulation likely by promoting lipid catabolism and by inhibiting lipogenic pathways, as suggested by the changes in carnitine palmitoyltransferase 1(CPT-1), PPAR and SREBP-1c levels. The reduction in fat accumulation exerted by silybin in the steatotic cells was associated with the improvement of the oxidative imbalance caused by lipid excess as demonstrated by the reduction in ROS content, lipid peroxidation, catalase activity and NF-κB activation.CONCLUSION: We demonstrated the direct antisteatotic and anti-oxidant effects of silybin in steatotic cells, thus elucidating at a cellular level the encouraging results demonstrated in clinical and animal studies.  相似文献   
994.
995.
The mutational analysis of potassium (KCNQ2, KCNQ3), sodium (SCN1A, SCN2A), and chloride (CLCN2) ion channels was performed in three children with typical features of the recently described syndrome of migrating partial seizures in infancy. Mutational analysis was performed by PCR and automatic sequencing. The coding regions, including the exon-intron boundaries, were amplified in the patients using appropriate primers sets. No mutations associated to migrating partial seizures have been found. Mutational screening of CLCN2 gene, revealed a homozygous mutation G2003C (exon 17), leading to a Ser/Thr substitution at the codon 668, in two of the three patients. The same variation has been found in 38 out of 100 control alleles. The identification of the genetic basis of this new epileptic encephalopathy requires further studies that might be enforced by familial cases.  相似文献   
996.
Drug-eluting stents are largely used in coronary arteries and more recently in tibial arteries owing to their potentially better outcomes compared with bare metal stents. A patient with polyarteritis nodosa and critical limb ischemia and a dorsal foot ulcer was previously unsuccessfully treated with multiple angioplasties and subsequently underwent implantation of a drug-eluting stent in the pedal artery. At 6 months, stent patency on color Doppler ultrasound and complete healing of the foot ulcer were observed.  相似文献   
997.
998.
The concept of ideal tumor surgery is to remove the neoplastic tissue without damaging adjacent normal structures. High-intensity focused ultrasound (HIFU) was developed in the 1940s as a viable thermal tissue ablation approach. In clinical practice, HIFU has been applied to treat a variety of solid benign and malignant lesions, including pancreas, liver, prostate, and breast carcinomas, soft tissue sarcomas, and uterine fibroids. More recently, magnetic resonance guidance has been applied for treatment monitoring during focused ultrasound procedures (magnetic resonance–guided focused ultrasound, MRgFUS). Intraoperative magnetic resonance imaging provides the best possible tumor extension and dynamic control of energy deposition using real-time magnetic resonance imaging thermometry. We introduce the fundamental principles and clinical indications of the MRgFUS technique; we also report different treatment options and personal outcomes.  相似文献   
999.
Abstract

The aim of the present study is to understand how the attitudes towards food labelling in the Chilean population have changed after the introduction of the Chilean law on food labelling and advertising. A computer-assisted telephone interview was conducted in 2012 and 2016, employing the same procedures. The difference in outcomes between 2012 and 2016 was assessed using a logistic regression model. One hundred and sixty-seven subjects responded to both the 2012 and 2016 survey editions (respondents). For both the unadjusted and adjusted analyses, the respondents in 2016 were more likely to be involved in a programme to lose weight and to consider food labelling the most effective intervention introduced to date to promote healthy nutrition. However, no significant differences were reported in both self-reported and objectively assessed understandings of front-of-pack-labelling. Evidence suggests a positive perception among Chileans regarding the effectiveness of the new law.  相似文献   
1000.
Our aim was to explore health workers’ perceptions of providing sexuality and contraception care for female adolescents within family health centers. We interviewed 26 volunteer health workers and analyzed the interviews using thematic analysis. We identified three main themes: (a) “adolescents and sexuality,” with the subthemes “initiation rite,” “me like the others,” and “just for fun”; (b) “adolescents and contraception,” with the subthemes “omnipotent adolescents,” “aware adolescents,” and “women's responsibility”; and (c) “health workers and adolescents,” with the subthemes “to put in order,” “to catch,” and “to teach to take care of themselves.” Our results provided an interesting picture of health workers’ perceptions of their work with Italian female adolescents regarding sexuality and contraception.  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