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   3488527篇
  免费   295434篇
  国内免费   13443篇
耳鼻咽喉   47632篇
儿科学   110641篇
妇产科学   90245篇
基础医学   555747篇
口腔科学   94262篇
临床医学   319795篇
内科学   618800篇
皮肤病学   92248篇
神经病学   300287篇
特种医学   136261篇
外国民族医学   293篇
外科学   532557篇
综合类   103049篇
现状与发展   24篇
一般理论   2415篇
预防医学   299504篇
眼科学   79140篇
药学   239306篇
  26篇
中国医学   9397篇
肿瘤学   165775篇
  2021年   55708篇
  2020年   35531篇
  2019年   58578篇
  2018年   72179篇
  2017年   55046篇
  2016年   60663篇
  2015年   74775篇
  2014年   109076篇
  2013年   174578篇
  2012年   98446篇
  2011年   99280篇
  2010年   118707篇
  2009年   122720篇
  2008年   85942篇
  2007年   89933篇
  2006年   99346篇
  2005年   94977篇
  2004年   96336篇
  2003年   86687篇
  2002年   76527篇
  2001年   103499篇
  2000年   96220篇
  1999年   96073篇
  1998年   64992篇
  1997年   62935篇
  1996年   61001篇
  1995年   56445篇
  1994年   50644篇
  1993年   47296篇
  1992年   68184篇
  1991年   65433篇
  1990年   62005篇
  1989年   61146篇
  1988年   56922篇
  1987年   55668篇
  1986年   53118篇
  1985年   52685篇
  1984年   48475篇
  1983年   44585篇
  1982年   41871篇
  1981年   39552篇
  1980年   37263篇
  1979年   40925篇
  1978年   36432篇
  1977年   32985篇
  1976年   30260篇
  1975年   29157篇
  1974年   30684篇
  1973年   29790篇
  1972年   28040篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
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   
104.
105.
106.
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   
107.
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   
108.
109.
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   
110.
The current study explored the influence of three methods of parental emotion discourse (structured story-telling, reminiscing, and picture book) and their relation to preschoolers’ emotion understanding. Thirty-seven families participated in the study. Analyses showed that the structured story-telling method produced more emotion words, was high in unique emotion words, and was high for both emotion labelling and explanations. All three methods showed some potential to predict preschooler’s emotion understanding. Structured story-telling was best at predicting role-taking, while reminiscing and the picture book both were better at predicting situation knowledge. Additional studies are needed to further explore the influence of different methods of assessing emotion discourse to enhance validity and reliability of research in this field.  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