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   3388824篇
  免费   248717篇
  国内免费   8566篇
耳鼻咽喉   46940篇
儿科学   113349篇
妇产科学   93898篇
基础医学   477488篇
口腔科学   93863篇
临床医学   307996篇
内科学   665528篇
皮肤病学   79373篇
神经病学   276575篇
特种医学   131645篇
外国民族医学   1282篇
外科学   509747篇
综合类   69885篇
现状与发展   6篇
一般理论   1243篇
预防医学   259846篇
眼科学   76588篇
药学   249891篇
  9篇
中国医学   6845篇
肿瘤学   184110篇
  2019年   26247篇
  2018年   37367篇
  2017年   28683篇
  2016年   33004篇
  2015年   36920篇
  2014年   50795篇
  2013年   77004篇
  2012年   102912篇
  2011年   109322篇
  2010年   65733篇
  2009年   62470篇
  2008年   102666篇
  2007年   109306篇
  2006年   110615篇
  2005年   106490篇
  2004年   103084篇
  2003年   99652篇
  2002年   96488篇
  2001年   162020篇
  2000年   166764篇
  1999年   140833篇
  1998年   40487篇
  1997年   36009篇
  1996年   36150篇
  1995年   34834篇
  1994年   32284篇
  1993年   30271篇
  1992年   110221篇
  1991年   106456篇
  1990年   103398篇
  1989年   99886篇
  1988年   91645篇
  1987年   89946篇
  1986年   84161篇
  1985年   80464篇
  1984年   60249篇
  1983年   50988篇
  1982年   30054篇
  1981年   27125篇
  1979年   53461篇
  1978年   37588篇
  1977年   32082篇
  1976年   29778篇
  1975年   31799篇
  1974年   37423篇
  1973年   35686篇
  1972年   33334篇
  1971年   30726篇
  1970年   28633篇
  1969年   27001篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
55.
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   
56.
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   
57.
58.
59.
Background: Traumatic brain injury (TBI) results in verbal recall deficits and impaired processing of emotion encoded in facial appearance, prosody and the linguistic content of messages. Emotion facilitates memory (emotional memory advantage) for non-brain injured (NBI) individuals but the impact of emotion on verbal recall for linguistically encoded stimuli in TBI has not been explored.

Aims: The purpose of this study was to determine the effects of stimulus emotional content on verbal recall of words and paragraphs in TBI compared to NBI individuals.

Methods and procedures: Six 10-item lists, each with five emotional and five neutral words, and six paragraphs (three emotional, three neutral) were counterbalanced and presented in random order to 20 individuals with TBI and 44 NBI. The number of words from lists and the number of content units from paragraphs were compared for the two groups.

Outcomes and results: The NBI participants recalled more words from the lists and content units from the paragraphs than the individuals with TBI. Both groups recalled significantly more emotional than neutral words. NBI but not TBI participants had significantly greater recall for information in paragraphs with emotional content.

Conclusions: Participants with TBI showed impaired recall of words and paragraph content. Emotion facilitated word and paragraph content recall for neurotypical individuals but emotional memory advantage was limited to words for the TBI participants.  相似文献   

60.
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