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   28290篇
  免费   2193篇
  国内免费   81篇
耳鼻咽喉   409篇
儿科学   778篇
妇产科学   615篇
基础医学   3563篇
口腔科学   341篇
临床医学   2986篇
内科学   5976篇
皮肤病学   517篇
神经病学   2687篇
特种医学   1299篇
外科学   4562篇
综合类   329篇
一般理论   24篇
预防医学   2082篇
眼科学   475篇
药学   2034篇
中国医学   46篇
肿瘤学   1841篇
  2023年   270篇
  2022年   436篇
  2021年   1171篇
  2020年   656篇
  2019年   997篇
  2018年   1103篇
  2017年   744篇
  2016年   792篇
  2015年   980篇
  2014年   1275篇
  2013年   1597篇
  2012年   2324篇
  2011年   2346篇
  2010年   1256篇
  2009年   1005篇
  2008年   1616篇
  2007年   1604篇
  2006年   1520篇
  2005年   1340篇
  2004年   1201篇
  2003年   1058篇
  2002年   956篇
  2001年   396篇
  2000年   307篇
  1999年   302篇
  1998年   182篇
  1997年   142篇
  1996年   141篇
  1995年   107篇
  1994年   82篇
  1993年   90篇
  1992年   183篇
  1991年   170篇
  1990年   174篇
  1989年   179篇
  1988年   139篇
  1987年   147篇
  1986年   138篇
  1985年   127篇
  1984年   101篇
  1983年   90篇
  1982年   65篇
  1981年   83篇
  1980年   56篇
  1979年   79篇
  1978年   68篇
  1976年   55篇
  1974年   54篇
  1973年   70篇
  1972年   61篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Erosive pustular dermatosis of the scalp (EPDS) is an uncommon chronic inflammatory response to scalp trauma that usually resolves with cicatricial alopecia. It most commonly affects elderly patients with a history of actinic damage. Herein, we describe a 16‐year‐old girl with acrofacial dysostosis type 1 presenting after surgery with crusting purulent scalp lesions, whose clinical presentation and histopathologic findings were consistent with EPDS. A review of the literature on EPDS in children is also detailed.  相似文献   
4.

Researchers have highlighted numerous sociocultural factors that have been shown to underpin human appearance enhancement practices, including the influence of peers, family, the media, and sexual objectification. Fewer scholars have approached appearance enhancement from an evolutionary perspective or considered how sociocultural factors interact with evolved psychology to produce appearance enhancement behavior. Following others, we argue that evidence from the field of evolutionary psychology can complement existing sociocultural models by yielding unique insight into the historical and cross-cultural ubiquity of competition over aspects of physical appearance to embody what is desired by potential mates. An evolutionary lens can help to make sense of reliable sex and individual differences that impact appearance enhancement, as well as the context-dependent nature of putative adaptations that function to increase physical attractiveness. In the current review, appearance enhancement is described as a self-promotion strategy used to enhance reproductive success by rendering oneself more attractive than rivals to mates, thereby increasing one’s mate value. The varied ways in which humans enhance their appearance are described, as well as the divergent tactics used by women and men to augment their appearance, which correspond to the preferences of opposite-sex mates in a heterosexual context. Evolutionarily relevant individual differences and contextual factors that vary predictably with appearance enhancement behavior are also discussed. The complementarity of sociocultural and evolutionary perspectives is emphasized and recommended avenues for future interdisciplinary research are provided for scholars interested in studying appearance enhancement behavior.

  相似文献   
5.
6.
7.
Affinity peptide and protein‐ (APP) based radiotracers are an increasingly popular class of radiotracer in positron emission tomography (PET), which was once dominated by the use of small molecule radiotracers. Radiolabelled monoclonal antibodies (mAbs) are important examples of APPs, yet a preference for smaller APPs, which exhibit fast pharmacokinetics and permit rapid PET aided diagnosis, has become apparent. 18F exhibits favourable physical characteristics for APP radiolabelling and has been described as an ideal PET radionuclide. Notwithstanding, 18F radiolabelling of APP is challenging, and this is echoed in the literature where a number of diverse approaches have been adopted. This review seeks to assess and compare the approaches taken to 18F APP radiolabelling with the intention of highlighting trends within this expanding field. Generic themes have emerged in the literature, namely the use of mild radiolabelling conditions, a preference of site‐specific methodologies with an impetus for short, automated procedures which produce high‐yielding [18F]APPs.  相似文献   
8.
9.
In the “basic” approach, medical expenses are catastrophic if they exceed a prespecified percentage of consumption or income; the approach tells us if expenses cause a large percentage reduction in living standards. The ability‐to‐pay (ATP) approach defines expenses as catastrophic if they exceed a prespecified percentage of consumption less expenses on nonmedical necessities or an allowance for them. The paper argues that the ATP approach does not tell us whether expenses are large enough to undermine a household's ability to purchase nonmedical necessities. The paper compares the income‐based and consumption‐based variants of the basic approach, and shows that if the individual is a borrower after a health shock, the income‐based ratio will exceed the consumption‐based ratio, and both will exceed the more theoretically correct Flores et al. ratio; whereas if the individual continues to be a saver after a health shock, the ordering is reversed and the income‐based ratio may not overestimate Flores et al.'s ratio. Last, the paper proposes a lifetime money metric utility (LMMU) approach defining medical expenses as catastrophic in terms of their lifetime consequences. Under certain assumptions, the LMMU and Flores et al. approaches are identical, and neither requires data on how households finance their medical expenses.  相似文献   
10.
PurposeManagement of head and neck cancers (HNC) in older adults is a common but challenging clinical scenario. We assess the impact of Stereotactic Body Radiation Therapy (SBRT) on survival utilizing the Geriatric-8 (G8) questionnaire.Materials and methods171 HNC patients, deemed medically unfit for definitive treatment, were treated with SBRT ± systemic therapy. G8 questionnaires were collected at baseline, at 4–6 weeks, and at 2–3 months post-treatment. Patients were stratified according to their baseline G8 score: <11 as ‘vulnerable’, 11–14 as ‘intermediate’, and >14 as ‘fit’. Overall survival (OS) was assessed through univariate Kaplan Meier analysis. Repeated measures ANOVA was used to determine if baseline characteristics affected G8 score changes.ResultsMedian follow-up was seventeen months. 60% of patients presented with recurrent HNC, 30% with untreated HNC primaries, and 10% with metastatic non-HNC primaries. Median age was 75 years. Median Charlson Comorbidity Index score was 2. 51% of patients were ‘vulnerable’, 37% were ‘intermediate’, and 12% were ‘fit' at baseline, with median survival of 13.2, 24.3, and 41.0 months, respectively (p = .004). Patients who saw a decrease in their follow-up G8 score (n = 69) had significantly lower survival than patients who had stable or increased follow-up G8 scores (n = 102), with median survival of 8.6 vs 36.0 months (p < .001).ConclusionThe G8 questionnaire may be a useful tool in upfront treatment decision-making to predict prognosis and prevent older patients from receiving inappropriate anti-cancer treatment. Decline in follow-up G8 scores may also predict worse survival and aid in goals of care following treatment.  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