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   4342篇
  免费   189篇
  国内免费   12篇
耳鼻咽喉   103篇
儿科学   192篇
妇产科学   210篇
基础医学   677篇
口腔科学   31篇
临床医学   260篇
内科学   980篇
皮肤病学   69篇
神经病学   384篇
特种医学   69篇
外科学   186篇
综合类   26篇
预防医学   371篇
眼科学   112篇
药学   578篇
中国医学   13篇
肿瘤学   282篇
  2024年   7篇
  2023年   31篇
  2022年   203篇
  2021年   302篇
  2020年   104篇
  2019年   134篇
  2018年   142篇
  2017年   129篇
  2016年   152篇
  2015年   153篇
  2014年   200篇
  2013年   283篇
  2012年   361篇
  2011年   371篇
  2010年   197篇
  2009年   147篇
  2008年   233篇
  2007年   304篇
  2006年   272篇
  2005年   255篇
  2004年   187篇
  2003年   184篇
  2002年   143篇
  2001年   12篇
  2000年   4篇
  1999年   3篇
  1998年   5篇
  1997年   10篇
  1996年   6篇
  1995年   4篇
  1992年   1篇
  1988年   1篇
  1981年   1篇
  1978年   1篇
  1977年   1篇
排序方式: 共有4543条查询结果,搜索用时 312 毫秒
991.
Treating the elderly is often problematic, especially when congenital heart disease is diagnosed. The aim of this study is to present the case of a 72-year old woman with depression syndrome, paroxysmal atrial fibrillation and past cerebral stroke, in whom persistent ductus arteriosus Botalli was diagnosed. Due to exacerbation of the depressive syndrome, she did not give her consent to further diagnostics, possible interventional procedures and treatment with oral anticoagulants. After intermission of the therapy she was treated with dabigatran. The patient is still undergoing outpatient treatment and so far, no cerebrovascular episodes have been recorded.  相似文献   
992.
993.
The study is aimed at presenting new diagnostic and therapeutic proposals for patients with alcohol use disorders. The revised ICD-11 which is currently being updated is coming closer to American standards in disease classification. The latest update of the American DSM-5 has been a notable step forward as it integrates alcohol abuse and alcohol dependence into a single disorder called alcohol use disorder. Recent developments in research into diagnostic tools have brought changes in the approach to therapy. According to most international guidelines, the form of treatment should be customised to the individual patient, with consideration given to his/her mental and physical condition, personality and natural setting. A significant change is the recommendation of a harm reduction strategy as a useful alternative to total abstinence in alcohol dependence treatment for some patients.  相似文献   
994.
The process of angiogenesis is quite well-known nowadays. Some medicines and extracts affecting this process are already used routinely in supporting the conventional treatment of many diseases that are considered angiogenic such as cancer. However, we must be aware that the area of currently used drugs of this type is much narrower than the theoretical possibilities existing in therapeutic angiogenesis. Plant substances are a large and diverse group of compounds that are found naturally in fruits, vegetables, spices, and medicinal plants. They also have different anticancer properties. The aim of this literature review article is to present the current state of knowledge concerning the molecular targets of tumor angiogenesis and the active substances (polyphenols, alkaloids, phytohormones, carbohydrates, and terpenes) derived from natural sources, whose activity against cancer angiogenesis has been confirmed.  相似文献   
995.
996.
997.
998.
We describe here the successful coupling of real-time polymerase chain reaction (PCR) and high-resolution melting (HRM) analysis to rapidly identify 15 forensically important species of blowfly from the family Calliphoridae (Diptera), which occur in Poland. Two short regions (119 and 70 base pairs, respectively) of cytochrome oxidase gene subunit I with sufficient sequence diversity were selected. In the case of lacking taxa (e.g., reference species) these amplicons can be synthesized using sequences deposited in gene banks. The technique utilizes low template DNA concentration and is highly reproducible. The melting profile was not altered up to a 10,000-fold difference in DNA template concentration (ranging from 5 pg to 50 ng). The several HRM runs performed on different specimens from Poland belonging to the same species and on different days resulted in only minor variations in the amplification curves and in melting temperatures of the peaks. Intraspecific variation in a larger scale was tested using synthesized oligonucleotides from cosmopolitan Lucilia illustris originating from Poland, France, Great Britain, India, and USA. As HRM PCR analysis is sensitive to even single base changes, all geographic variants of this species were identified. This technique is also cost-effective and simple, and it may even be used by non-geneticists. A working protocol was ultimately constructed for the purpose of rapid and accurate species identification in most countries in Europe regardless of which stage or which part of a blowfly was collected.  相似文献   
999.
Background and purposeSporadic amyotrophic lateral sclerosis (sALS) is a devastating neurodegenerative disease, which results from complex genetic and environmental interactions. Recent studies have reported an association between several polymorphisms of the PON1 and PON2 genes and risk of sALS. The aim of the present study was to identify an association between the – A162G polymorphism of the promoter region of the human PON1 gene and the risk of sALS in a Polish population.Material and methodsWe included 259 patients with a diagnosis of definite or probable sALS (76 bulbar onset, 183 limb onset) and 694 healthy controls matched for age and sex. The diagnosis of ALS was established according to El Escorial criteria. The polymorphism was studied by Single Nucleotide Polymorphism Real-Time Polymerase Chain Reaction analysis.ResultsNo overall difference in the PONI – A162G genotype and allele distribution was seen between cases and controls (all p > 0.05). There was, however, a difference in the A allele frequency when the bulbar onset group was compared to the controls (p = 0.03), but this significance disappeared after the Bonferroni correction.ConclusionsThe results did not show that the – A162G polymorphism of the PON1 gene is a risk factor of sALS in a Polish population; it may affect, however, bulbar onset of the disease.  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