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   2897780篇
  免费   208872篇
  国内免费   7853篇
耳鼻咽喉   39028篇
儿科学   95914篇
妇产科学   79927篇
基础医学   414713篇
口腔科学   79645篇
临床医学   262756篇
内科学   568229篇
皮肤病学   69852篇
神经病学   235401篇
特种医学   111061篇
外国民族医学   779篇
外科学   433523篇
综合类   56066篇
现状与发展   5篇
一般理论   1073篇
预防医学   221876篇
眼科学   65112篇
药学   213115篇
  8篇
中国医学   5895篇
肿瘤学   160527篇
  2019年   22513篇
  2018年   31935篇
  2017年   24522篇
  2016年   28455篇
  2015年   31935篇
  2014年   43877篇
  2013年   66063篇
  2012年   87586篇
  2011年   92932篇
  2010年   55970篇
  2009年   53623篇
  2008年   86938篇
  2007年   92606篇
  2006年   94383篇
  2005年   90294篇
  2004年   87106篇
  2003年   83959篇
  2002年   81324篇
  2001年   140553篇
  2000年   144252篇
  1999年   121197篇
  1998年   34511篇
  1997年   30562篇
  1996年   31024篇
  1995年   29999篇
  1994年   27544篇
  1993年   25787篇
  1992年   94169篇
  1991年   91160篇
  1990年   88591篇
  1989年   85608篇
  1988年   78348篇
  1987年   76974篇
  1986年   71904篇
  1985年   68744篇
  1984年   51075篇
  1983年   43228篇
  1982年   25417篇
  1981年   22779篇
  1979年   45400篇
  1978年   32133篇
  1977年   27337篇
  1976年   25303篇
  1975年   27330篇
  1974年   32344篇
  1973年   30571篇
  1972年   28859篇
  1971年   26866篇
  1970年   24809篇
  1969年   23811篇
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
41.
42.
43.
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   
44.
45.
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   
46.
47.
48.
49.
50.
G. Berlin  M. Hammar  L. Tapper 《Platelets》2019,30(4):473-479
Platelets are needed to prevent or arrest bleeding and aggregate at the site of injury upon vascular damage. Platelets express receptors for estrogens which might affect the function of the platelets and their hemostatic ability. The aim was to identify possible differences in platelet function related to age, gender, and phases of the menstrual cycle by use of impedance aggregometry with Multiplate. In the first part of the study, platelet function was assessed in 60 healthy individuals (30 men and 30 women) in each of three age groups (20–25, 40–45, and 60–65 years). In the second part of the study, the platelet function was analyzed on four occasions during the menstrual cycle in women without oral contraceptives (OCs) (n = 17) and compared to 19 women on OCs and 18 men of similar age (20–40 years). For the women on OCs, aggregation was analyzed once during the tablet-free week and once late during the period with OCs. The men were sampled once. Women of younger age (<45 years) had significantly higher agonist-induced aggregation response than both men and post-menopausal women (60–65 years). The agonist-induced aggregation response did not differ between phases of the menstrual cycle or OC use. The results suggest that estradiol and/or progesterone affect spontaneous aggregation since it was found to be lowest in the mid-luteal phase. Spontaneous aggregation was significantly lower in women on OCs than in both men and women without OCs. Our findings indicate that fertile age is associated with higher aggregation response capacity of the platelets, possibly to prevent excessive bleeding during menstruation, but this response capacity is not altered during the menstrual cycle or by use of OCs.  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