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   1329271篇
  免费   114627篇
  国内免费   6350篇
耳鼻咽喉   16684篇
儿科学   42913篇
妇产科学   36537篇
基础医学   182400篇
口腔科学   36250篇
临床医学   120062篇
内科学   276319篇
皮肤病学   31861篇
神经病学   109751篇
特种医学   55491篇
外国民族医学   274篇
外科学   209888篇
综合类   31491篇
现状与发展   2篇
一般理论   414篇
预防医学   105921篇
眼科学   28011篇
药学   93451篇
  5篇
中国医学   2153篇
肿瘤学   70370篇
  2018年   13377篇
  2017年   10631篇
  2016年   12793篇
  2015年   14302篇
  2014年   19948篇
  2013年   29738篇
  2012年   36242篇
  2011年   38888篇
  2010年   24373篇
  2009年   23905篇
  2008年   36365篇
  2007年   38779篇
  2006年   39907篇
  2005年   38488篇
  2004年   36713篇
  2003年   35750篇
  2002年   33763篇
  2001年   65963篇
  2000年   67749篇
  1999年   56271篇
  1998年   15980篇
  1997年   14204篇
  1996年   15221篇
  1995年   16155篇
  1994年   15040篇
  1993年   14074篇
  1992年   47041篇
  1991年   45738篇
  1990年   43951篇
  1989年   41791篇
  1988年   38725篇
  1987年   38060篇
  1986年   35834篇
  1985年   34620篇
  1984年   26329篇
  1983年   22060篇
  1982年   13809篇
  1981年   12405篇
  1980年   11664篇
  1979年   23505篇
  1978年   17020篇
  1977年   14337篇
  1976年   13139篇
  1975年   13694篇
  1974年   16067篇
  1973年   15380篇
  1972年   14167篇
  1971年   13024篇
  1970年   11863篇
  1969年   11092篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
Uptake of colorectal cancer screening remains suboptimal. Mailed fecal immunochemical testing (FIT) offers promise for increasing screening rates, but optimal strategies for implementation have not been well synthesized. In June 2019, the Centers for Disease Control and Prevention convened a meeting of subject matter experts and stakeholders to answer key questions regarding mailed FIT implementation in the United States. Points of agreement included: 1) primers, such as texts, telephone calls, and printed mailings before mailed FIT, appear to contribute to effectiveness; 2) invitation letters should be brief and easy to read, and the signatory should be tailored based on setting; 3) instructions for FIT completion should be simple and address challenges that may lead to failed laboratory processing, such as notation of collection date; 4) reminders delivered to initial noncompleters should be used to increase the FIT return rate; 5) data infrastructure should identify eligible patients and track each step in the outreach process, from primer delivery through abnormal FIT follow-up; 6) protocols and procedures such as navigation should be in place to promote colonoscopy after abnormal FIT; 7) a high-quality, 1-sample FIT should be used; 8) sustainability requires a program champion and organizational support for the work, including sufficient funding and external policies (such as quality reporting requirements) to drive commitment to program investment; and 9) the cost effectiveness of mailed FIT has been established. Participants concluded that mailed FIT is an effective and efficient strategy with great potential for increasing colorectal cancer screening in diverse health care settings if more widely implemented.  相似文献   
62.
Early stage localized prostate cancer (PCa) has an excellent prognosis; however, patient survival drops dramatically when PCa metastasizes. The molecular mechanisms underlying PCa metastasis are complex and remain unclear. Here, we examine the role of a new member of the fatty acid‐binding protein (FABP) family, FABP12, in PCa progression. FABP12 is preferentially amplified and/or overexpressed in metastatic compared to primary tumors from both PCa patients and xenograft animal models. We show that FABP12 concurrently triggers metastatic phenotypes (induced epithelial‐to‐mesenchymal transition (EMT) leading to increased cell motility and invasion) and lipid bioenergetics (increased fatty acid uptake and accumulation, increased ATP production from fatty acid β‐oxidation) in PCa cells, supporting increased reliance on fatty acids for energy production. Mechanistically, we show that FABP12 is a driver of PPARγ activation which, in turn, regulates FABP12''s role in lipid metabolism and PCa progression. Our results point to a novel role for a FABP‐PPAR pathway in promoting PCa metastasis through induction of EMT and lipid bioenergetics.

Abbreviations

AR
androgen receptor
ATP
adenosine triphosphate
CN
copy number
CPT1
carnitine palmitoyltransferase I
CS
citrate synthase
EMT
epithelial–mesenchymal transition
ET
electron transfer‐state
FABP
fatty acid‐binding protein
LD
lipid droplet
OA
oleic acid
PCa
prostate cancer
PPAR
peroxisome proliferator‐activated receptor
PPRE
peroxisome proliferator‐activated receptor response element
TZD
thiazolidinediones
  相似文献   
63.
64.
65.
66.
Benzophenone-3 is a putative endocrine disrupting chemical and common ingredient in sunscreens. The potential of endocrine disrupting chemicals to act as agonists or antagonists in critical hormonally regulated processes, such as mammary gland development and mammary tumorigenesis, demands evaluation of its potential in promoting breast cancer. This study identifies the effects of BP-3 on mammary tumorigenesis with high-fat diet during puberty versus adulthood in Trp53-null transplant BALB/c mice. Benzophenone-3 exposure yielded levels in urine similar to humans subjected to heavy topical sunscreen exposure. Benzophenone-3 was protective for epithelial tumorigenesis in mice fed lifelong low-fat diet, while promotional for epithelial tumorigenesis in mice fed adult high-fat diet. Benzophenone-3 increased tumor cell proliferation, decreased tumor cell apoptosis, and increased tumor vascularity dependent on specific dietary regimen and tumor histopathology. Even in instances of an ostensibly protective effect, other parameters suggest greater risk. Although benzophenone-3 seemed protective on low-fat diet, spindle cell tumors arising in these mice showed increased proliferation and decreased apoptosis. This points to a need for further studies of benzophenone-3 in both animal models and humans as a potential breast cancer risk factor, as well as a more general need to evaluate endocrine disrupting chemicals in varying dietary contexts.  相似文献   
67.
For someone with an outsized influence on a field he helped to create, Dan Callahan was anything but overbearing. Physically compact, thin, and wiry in older age, he spoke at the rapid speed of his mind. Soon after I met him—when I was on the cusp of what would become a year‐long residency at The Hastings Center—I found myself seated in his decidedly quaint living room. Dan told a story that evening, one of many that has stuck in my head. It seemed to encapsulate his moral mindset and, in a way, his broader vision for bioethics. I am sure he has told the story many times to many people, but here it is as I recall it.  相似文献   
68.
69.
A disease-focused course entitled “Understanding Sickle Cell Disease: A Biopsychosocial Approach” addressed the complex nature of SCD using patient-centered, global and interdisciplinary approaches. Sickle cell disease (SCD) is a rare inherited blood disorder that requires multidisciplinary care. Worldwide 20–25 million individuals have SCD, which is associated with a shortened lifespan due to many medical complications and social and behavioral health challenges. Health care professionals often have limited knowledge of SCD as they typically learn about it within the context of their own disciplines. This article provides twelve tips for educators that can be used to develop a similar course on any disease, with considerations for both low- and high-resource countries. The tips were devised from personal experience and available literature. Through these twelve tips, we provide a practical framework for increasing knowledge of complex diseases like SCD using a comprehensive elective course.  相似文献   
70.
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