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   4227492篇
  免费   341862篇
  国内免费   13881篇
耳鼻咽喉   58814篇
儿科学   135572篇
妇产科学   111024篇
基础医学   653253篇
口腔科学   113588篇
临床医学   384983篇
内科学   763034篇
皮肤病学   106341篇
神经病学   351823篇
特种医学   163961篇
外国民族医学   503篇
外科学   648604篇
综合类   119442篇
现状与发展   23篇
一般理论   2618篇
预防医学   356121篇
眼科学   99191篇
药学   295916篇
  26篇
中国医学   11339篇
肿瘤学   207059篇
  2021年   56037篇
  2020年   35698篇
  2019年   58758篇
  2018年   74153篇
  2017年   56689篇
  2016年   62689篇
  2015年   75641篇
  2014年   110090篇
  2013年   175362篇
  2012年   123076篇
  2011年   128610篇
  2010年   125988篇
  2009年   127049篇
  2008年   114469篇
  2007年   121913篇
  2006年   130435篇
  2005年   125506篇
  2004年   125553篇
  2003年   115730篇
  2002年   104838篇
  2001年   149712篇
  2000年   144558篇
  1999年   134345篇
  1998年   70135篇
  1997年   66237篇
  1996年   64438篇
  1995年   59715篇
  1994年   53786篇
  1993年   50047篇
  1992年   96054篇
  1991年   92650篇
  1990年   89059篇
  1989年   86824篇
  1988年   80020篇
  1987年   78511篇
  1986年   73860篇
  1985年   72978篇
  1984年   61664篇
  1983年   55435篇
  1982年   46021篇
  1981年   43119篇
  1980年   40513篇
  1979年   53100篇
  1978年   44035篇
  1977年   38888篇
  1976年   36268篇
  1975年   36277篇
  1974年   39406篇
  1973年   37638篇
  1972年   35244篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
Journal of Neuro-Oncology - Adjuvant radiation is often used in patients with low grade gliomas with high-risk characteristics with a recommended dose of 45–54 Gy. We used the...  相似文献   
82.
Maternal and Child Health Journal - Early life exposures can have an impact on a child’s developmental trajectory and children born late preterm (34–36 weeks gestational age)...  相似文献   
83.
84.
Troppmair  Teresa  Egger  J.  Krösbacher  A.  Zanvettor  A.  Schinnerl  A.  Neumayr  A.  Baubin  M. 《Der Anaesthesist》2022,71(4):272-280
Die Anaesthesiologie - Die Qualität eines Rettungssystems zeichnet sich auch durch den effizienten Einsatz seiner personellen und Fahrzeugressourcen aus. So können im berechtigten Fall...  相似文献   
85.
86.
Cutaneous leiomyomas are rare benign smooth‐muscle tumors. These lesions are distinguished based on their cell of origin and are subclassified as pilar leiomyoma, angioleiomyoma, and genital‐type leiomyoma. Nipple leiomyoma is the least common genital‐type leiomyoma, arising from the dartoic muscle cell of the nipple. Histologic examination of the lesion is necessary for definitive diagnosis, and these uncommon tumors can pose a diagnostic challenge. We describe herein a series of six nipple leiomyomas with a spectrum of histologic appearances.  相似文献   
87.
BackgroundLittle is known about the extent of ordering low-value services by.PurposeTo compare the rates of low-value back images ordered by primary care physicians (PCMDs) and primary care nurse practitioners (PCNPs).MethodWe used 2012 and 2013 Medicare Part B claims for all beneficiaries in 18 hospital referral ?regions (HRRs) and a measure of low-value back imaging from Choosing Wisely. Models included random clinician effect and fixed effects for beneficiary age, disability, Elixhauser comorbidities, clinician sex, the emergency department setting, back pain visit volume, organization, and region (HRR).FindingsPCNPs (N = 231) and PCMDs (N = 4,779) order low-value back images at similar rates (NP: all images: 26.5%; MRI/CT: 8.4%; MD: all images: 24.5%; MRI/CT: 7.7%), with no detectable significant difference when controlling for covariates.DiscussionPCNPs and PCMDs order low-value back images at an effectively similar rate.  相似文献   
88.
89.
Gold nanoparticles (Au NPs) hold great promise in food, industrial and biomedical applications due to their unique physicochemical properties. However, influences of the gastrointestinal tract (GIT), a likely route for Au NPs administration, on the physicochemical properties of Au NPs has been rarely evaluated. Here, we investigated the influence of GIT fluids on the physicochemical properties of Au NPs (5, 50, and 100?nm) and their implications on intestinal epithelial permeability in vitro. Au NPs aggregated in fasted gastric fluids and generated hydroxyl radicals in the presence of H2O2. Cell studies showed that GIT fluids incubation of Au NPs affected the cellular uptake of Au NPs but did not induce cytotoxicity or disturb the intestinal epithelial permeability.  相似文献   
90.
Introduction: The Hedgehog (HH) pathway constitutes a collection of signaling molecules which critically influence embryogenesis. In adults, however, the HH pathway remains integral to the proliferation, maintenance, and apoptosis of adult stem cells including hematopoietic stem cells.

Areas covered: We discuss the current understanding of the HH pathway as it relates to normal hematopoiesis, the pathology of acute myeloid leukemia (AML), the rationale for and data from combination therapies including HH pathway inhibitors, and ultimately the prospects that might offer promise in targeting this pathway in AML.

Expert opinion: Efforts to target the HH pathway have been focused on impeding this disposition and restoring chemosensitivity to conventional myeloid neoplasm therapies. The year 2018 saw the first approval of a HH pathway inhibitor (glasdegib) for AML, though for an older population and in combination with an uncommonly-used therapy. Several other clinical trials with agents targeting modulators of HH signaling in AML and MDS are underway. Further study and understanding of the interplay between the numerous aspects of HH signaling and how it relates to the augmented survival of AML will provide a more reliable substrate for therapeutic strategies in patients with this poor-risk disease.  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