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   37310篇
  免费   3186篇
  国内免费   1350篇
耳鼻咽喉   427篇
儿科学   843篇
妇产科学   433篇
基础医学   2732篇
口腔科学   1553篇
临床医学   4512篇
内科学   6397篇
皮肤病学   1153篇
神经病学   1626篇
特种医学   1710篇
外科学   2618篇
综合类   6536篇
一般理论   4篇
预防医学   5029篇
眼科学   1260篇
药学   2735篇
  29篇
中国医学   1760篇
肿瘤学   489篇
  2024年   40篇
  2023年   760篇
  2022年   1208篇
  2021年   1723篇
  2020年   1851篇
  2019年   1290篇
  2018年   1169篇
  2017年   1242篇
  2016年   1328篇
  2015年   1262篇
  2014年   2569篇
  2013年   2759篇
  2012年   2371篇
  2011年   2553篇
  2010年   2083篇
  2009年   1972篇
  2008年   1874篇
  2007年   1887篇
  2006年   1607篇
  2005年   1512篇
  2004年   1173篇
  2003年   1052篇
  2002年   879篇
  2001年   851篇
  2000年   671篇
  1999年   504篇
  1998年   466篇
  1997年   377篇
  1996年   259篇
  1995年   355篇
  1994年   298篇
  1993年   204篇
  1992年   222篇
  1991年   204篇
  1990年   161篇
  1989年   171篇
  1988年   152篇
  1987年   143篇
  1986年   118篇
  1985年   102篇
  1984年   78篇
  1983年   49篇
  1982年   47篇
  1981年   36篇
  1980年   31篇
  1979年   41篇
  1978年   25篇
  1977年   27篇
  1976年   28篇
  1975年   18篇
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
1.
DNA损伤是衰老相关疾病领域的研究热点, 可引起细胞周期停滞、凋亡, 加快个体衰老速度、增加衰老相关疾病的患病风险。本文将从细胞衰老和个体衰老两个层面阐述其与衰老之间的研究进展, 并综述其与衰老常见相关疾病(肿瘤、心血管疾病、阿尔茨海默病)及早衰综合征的关系, 为抗衰老研究和临床干预衰老相关疾病提供理论依据。  相似文献   
2.
BackgroundInvasive Fungal Diseases (IFD), account for high morbidity and mortality in immunocompromised and seriously ill patients worldwide. Early, faster and accurate diagnosis with timely and appropriate patient management is critical for improved patient outcome and antifungal stewardship. Clinical/radiological presentations in IFD are non-specific and microscopy/culture based tests have low sensitivity and long turnaround time. Biomarkers have clinical utility for diagnosing IFD but their interpretation is not straight forward.ObjectivesThis review discusses the salient characteristics, clinical usefulness and limitations of common biomarkers such as Galactomannan (GM), 1–3, β D glucan (βDG), mannan, anti-mannan antibody (Mn/antiMn), Cryptococcal antigen test (CrAg), Nucleic Acid Amplification (NAA) tests and next generation sequencing for diagnosing IFD.ContentsFungal biomarkers are useful adjuncts as screening and diagnostic tools for IFD and are much more suited for ‘ruling out’ rather than ‘ruling in’ disease. GM, NAA tests are promising biomarkers for screening of invasive Aspergillosis in high risk asymptomatic patients who are not on antifungal therapy and for diagnosis of breakthrough infections in symptomatic patients. 1–3, β D glucan has limitations both as a ‘rule in’ and ‘rule out’ test and is useful in only specific clinical settings. Two consecutive positive 1-3-βDG tests or combined positivity with GM increases its specificity. Mn/antiMn, T2Candida nano diagnostic panel are promising candidates for diagnosing invasive candidiasis. Combining two or more biomarkers improves the sensitivity for prompt initiation of antifungal therapy and the negative predictive value for suspension of empirical treatment.Serum CrAg test is a good ‘rule in’ rather than a ‘rule out’ test in immunocompetent patients but has good diagnostic accuracy in immunocompromised patients. Detection of single nucleotide polymorphisms by next generation sequencing is useful for fungal characterization and identification of host determinants responsible for increased susceptibility to fungal infections but is still in experimental stages.  相似文献   
3.
4.
A liver abscess is identified as a rare extraintestinal manifestation of Crohn’s disease, with an incidence of approximately 150 in 100,000 patients with this condition. In many of these patients, infectious causes are identified, and the patient’s condition is often noted to improve with antibiotics. An aseptic abscess (AA) is an increasingly recognized entity, especially in patients with inflammatory bowel disease, where repetitive evaluations to identify the infectious cause are futile. The average age of diagnosis for an AA is 29 years. The most common site is the spleen, followed by the lymph nodes and then the liver. In this study, we present a unique case of extensive aseptic liver abscesses extending into the pleural cavity in a young patient with Crohn’s disease.  相似文献   
5.
6.
7.
《Drug discovery today》2022,27(6):1724-1732
The enactment of orphan drug-specific legislation pioneered by the USA was subsequently followed by many regions, including the European Union (EU), Australia, Japan, and Taiwan. Here, we discuss the associated regulations established and their impacts in the aforementioned regions, which are among the first with frameworks specific for orphan drugs. Varied scopes of rare diseases or orphan drugs, diverse incentives, and heterogeneous types of reimbursement systems imply the prioritization of the agencies concerned. The numbers of designated and approved drugs reflect the impact of the regulatory and reimbursement frameworks. A comparison of the frameworks and their impact in the respective regions could provide valuable information for developing and improving related frameworks for countries worldwide.  相似文献   
8.
Bacterial keratitis continues to be one of the leading causes of corneal blindness in the developed as well as the developing world, despite swift progress since the dawn of the “anti-biotic era”. Although, we have expeditiously developed our understanding about the different causative organisms and associated pathology leading to keratitis, extensive gaps in knowledge continue to dampen the efforts required for early and accurate diagnosis, and management in these patients, resulting in poor clinical outcomes. The ability of the causative bacteria to subdue the therapeutic challenge stems from their large genome encoding complex regulatory networks, variety of unique virulence factors, and rapid secretion of tissue damaging proteases and toxins.In this review article, we provide an overview of the established diagnostic techniques and therapeutics for keratitis caused by various bacteria. We extensively report the recent in-roads through novel tools for accurately diagnosing mono- and poly-bacterial corneal infections. Furthermore, we outline the recent progress by our groups and others in understanding the sub-cellular genomic changes that lead to antibiotic resistance in these organisms. Finally, we discuss in detail, the novel therapies and drug delivery systems in development for the efficacious management of bacterial keratitis.  相似文献   
9.
胶质淋巴系统是一个主要由星形胶质细胞水通道蛋白4介导的依靠动脉、静脉周围血管间隙的脑脊液-脑组织液交换流动的系统,是阿尔茨海默病、脑卒中、帕金森病、失眠、抑郁症等脑病的共同特征,是一条新的脑代谢途径,可以清除包括β-淀粉样蛋白、乳酸在内的代谢产物。本文综合分析了全球有关胶质淋巴系统在脑部疾病的研究,得出:胶质淋巴系统可能为神经退行性疾病等发病机制和诊治策略研究带来新视角;胶质淋巴系统有望为一些脑部疾病诊断提供新的有效证据;胶质淋巴系统可能是脑部疾病治疗给药方式的新途径。  相似文献   
10.
目的 观察超声引导下关节腔内注射重组人Ⅱ型肿瘤坏死因子受体-抗体融合蛋白(益赛普)治疗血友病性关节病(HA)的价值。方法 回顾性分析32例接受超声引导下穿刺关节腔注射益赛普的HA患者,对比观察治疗前及治疗后1个月血友病关节健康评分(HJHS)、视觉模拟评分(VAS),以及超声所示目标关节增生滑膜厚度、血流信号、Melchiorre及中国早期血友病性关节病超声检测(HEAD-US-C)评分,评估其治疗价值。结果 对32例均成功完成超声引导下穿刺关节腔及腔内注射益赛普,共对18例膝关节、7例肘关节及7例踝关节进行治疗。术后未出现感染、出血等并发症。治疗后1个月,目标关节HJHS、VAS、Melchiorre评分、HEAD-US-C评分及增生滑膜最大厚度、平均厚度、血流信号均低于治疗前(P均<0.01)。结论 超声引导下关节腔内注射益赛普治疗HA安全、有效。  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