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   3755054篇
  免费   330886篇
  国内免费   16644篇
耳鼻咽喉   52668篇
儿科学   115440篇
妇产科学   95716篇
基础医学   583782篇
口腔科学   102507篇
临床医学   344223篇
内科学   678558篇
皮肤病学   97819篇
神经病学   320862篇
特种医学   149336篇
外国民族医学   378篇
外科学   591085篇
综合类   114256篇
现状与发展   93篇
一般理论   2312篇
预防医学   307142篇
眼科学   87452篇
药学   261125篇
  25篇
中国医学   11371篇
肿瘤学   186434篇
  2021年   56370篇
  2020年   37584篇
  2019年   58955篇
  2018年   75022篇
  2017年   57929篇
  2016年   64004篇
  2015年   78006篇
  2014年   115032篇
  2013年   179917篇
  2012年   100285篇
  2011年   100864篇
  2010年   122531篇
  2009年   127793篇
  2008年   87827篇
  2007年   91346篇
  2006年   102094篇
  2005年   96367篇
  2004年   97644篇
  2003年   88383篇
  2002年   77345篇
  2001年   134386篇
  2000年   128192篇
  1999年   121785篇
  1998年   70138篇
  1997年   66675篇
  1996年   64098篇
  1995年   59637篇
  1994年   53287篇
  1993年   49662篇
  1992年   86766篇
  1991年   82599篇
  1990年   78437篇
  1989年   77028篇
  1988年   71056篇
  1987年   69329篇
  1986年   65372篇
  1985年   64811篇
  1984年   56117篇
  1983年   50334篇
  1982年   44385篇
  1981年   41380篇
  1980年   38971篇
  1979年   46400篇
  1978年   39267篇
  1977年   35564篇
  1976年   32261篇
  1975年   31278篇
  1974年   32920篇
  1973年   31525篇
  1972年   29442篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
MicroRNAs (miRNAs) play important roles in prostate cancer development. However, it remains unclear how individual miRNAs contribute to the initiation and progression of prostate cancer. Here we show that a basal layer‐enriched miRNA is required for prostate tumorigenesis. We identify miR‐205 as the most highly expressed miRNA and enriched in the basal cells of the prostate. Although miR‐205 is not required for normal prostate development and homeostasis, genetic deletion of miR‐205 in a Pten null tumor model significantly compromises tumor progression and does not promote metastasis. In Pten null basal cells, loss of miR‐205 attenuates pAkt levels and promotes cellular senescence. Furthermore, although overexpression of miR‐205 in prostate cancer cells with luminal phenotypes inhibits cell growth in both human and mouse, miR‐205 has a minimal effect on the growth of a normal human prostate cell line. Taken together, we have provided genetic evidence for a requirement of miR‐205 in the progression of Pten null‐induced prostate cancer.  相似文献   
102.
103.
Secondary tricuspid regurgitation (TR) caused by right ventricular enlargement in the setting of left heart disease/pulmonary hypertension has been well described. In contrast, that associated with right atrial enlargement—atrial functional TR (AF‐TR)—remains largely underappreciated. AF‐TR most often occurs in the setting of lone atrial fibrillation, although it is also seen in its absence (idiopathic AF‐TR). Several recent studies have found that the prevalence, hemodynamic significance, and prognosis of AF‐TR are not inconsequential, suggesting increased physician awareness of this novel clinical entity is warranted. This article discusses the pathogenesis, echocardiographic findings, and treatment of this underappreciated cause of secondary TR.  相似文献   
104.
We review the spectrum of cutaneous disorders associated with inflammatory and neoplastic plasmacytic pathology. Because plasma cells are derived from B‐lymphocytes our overview includes discussion of certain lymphoplasmacytic proliferations. It is structured along histopathological lines, addressing conditions characterized by (a) cutaneous plasma cell infiltrates, (b) deposits of plasma cell products or their derivatives in the skin and (c) miscellaneous, poorly understood cutaneous complications of plasmacytic disorders. Lesions arising primarily in the skin and those due to cutaneous involvement by multisystem disorders are addressed. The range includes a spectrum of tumefactive and circulatory manifestations. We highlight key clinical and pathological features of the different conditions and outline recent advances in our understanding of these entities. By emphasizing the dermatopathological characteristics of this spectrum of disorders we hope to hone the diagnostic accuracy of practitioners in the field.  相似文献   
105.
106.
BackgroundThe aim of this study was to estimate the prevalence of dental prosthetic treatment and to investigate the demographic, social, economic and medical factors associated with the use of fixed and removable dentures in a representative sample of adults living in France.MethodsThe data were obtained from the 2002–2003 Decennial Health Survey, a cross-sectional study of a representative sample of the population living in France, which included 29,679 adults. Information was collected by interview. The variables collected were fixed denture, removable denture, age, gender, number of children, area of residence, nationality, educational attainment, family social status, employment status, annual household income per capita, supplementary insurance, chronic disease, eyesight problems/glasses, hearing problems/hearing aids. Multinomial logistic regression models were used to study the relationship between prosthetic treatment and demographic, socioeconomic and medical characteristics unadjusted, adjusted for age and adjusted for all the characteristics.ResultsThe prevalence of prosthetic treatment was 34.6% (95% confidence interval (CI): [34.1; 35.2]) for fixed prosthetic dentures and 13.8% (95% CI: [13.4; 14.2]) for removable prosthetic dentures. We showed a gradient between educational attainment and removable dentures; the odds ratio adjusted for all the variables (aOR) associated with no or primary education compared to post-secondary education was 2.56; 95% CI: [2.09; 3.13]. When annual household income per capita was low, subjects were less likely to report fixed dentures (aOR = 0.68; 95% CI: [0.62; 0.75]) than those with high annual household income per capita. Individuals without insurance less often reported fixed dentures than those with private insurance. Those reporting chronic disease were less likely to report fixed dentures (aOR = 0.87; 95% CI: [0.79; 0.95]) but more likely to report removable dentures (aOR = 1.29; 95% CI: [1.17; 1.43]) than those without chronic disease.ConclusionThis study reveals social, economic and medical inequalities in fixed and removable prosthetic treatment among adults in France.  相似文献   
107.
108.
109.
Introduction: Pharmacovigilance is essential to monitoring the safety profiles of authorized medicines. Compared with small-molecule drugs, biological drugs are more complex, more susceptible to structural variability due to manufacturing processes, and have the potential to induce immune-related reactions, underscoring the importance of safety monitoring for these products. Although highly similar to reference products, biosimilars are not expected to be structurally identical. For these reasons, proper reporting of potential adverse drug reactions (ADRs) using distinguishable names and batch numbers is essential for accurate tracing of all biological drugs. To address the need for robust pharmacovigilance, the European Parliament and Council of the European Union provided legislation regarding pharmacovigilance of biologics in 2010.

Areas covered: This narrative review examines the current state of pharmacovigilance for biologics in the European Union (EU) and discusses relevant information on pharmacovigilance of biosimilars, the current EU pharmacovigilance system, and areas that could be improved.

Expert opinion: Although steps have been taken to improve pharmacovigilance of biologics in the EU, several enhancements can still be made, including additional training for healthcare professionals on ADR reporting, the use of 2D barcodes that enhance traceability, and an open discussion of potentially missed opportunities in the pharmacovigilance of biosimilars.  相似文献   

110.
ABSTRACT

This project examined 55 picture books featuring transgender, gender expansive or genderqueer protagonists or narrators published between 2008 and 2018. The purpose of the study was to determine how this genre of children’s literature supports and challenges four gender assumptions: the gender binary, gender essentialism, sex/gender congruency and gender stability. Additionally, this critical analysis explored misgendering within this genre and themes of social rejection and acceptance. Protagonists and narrators were permitted a degree of gender nonconformity, however, the majority of picture books missed opportunities for a more complete exploration of gender possibilities.  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