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   3174篇
  免费   167篇
  国内免费   26篇
耳鼻咽喉   39篇
儿科学   319篇
妇产科学   47篇
基础医学   375篇
口腔科学   35篇
临床医学   173篇
内科学   620篇
皮肤病学   61篇
神经病学   114篇
特种医学   162篇
外科学   283篇
综合类   255篇
一般理论   2篇
预防医学   283篇
眼科学   70篇
药学   298篇
中国医学   21篇
肿瘤学   210篇
  2021年   67篇
  2020年   55篇
  2019年   56篇
  2018年   69篇
  2017年   43篇
  2016年   77篇
  2015年   67篇
  2014年   108篇
  2013年   185篇
  2012年   200篇
  2011年   194篇
  2010年   125篇
  2009年   100篇
  2008年   141篇
  2007年   148篇
  2006年   140篇
  2005年   116篇
  2004年   92篇
  2003年   99篇
  2002年   91篇
  2001年   84篇
  2000年   60篇
  1999年   47篇
  1998年   67篇
  1997年   50篇
  1996年   28篇
  1995年   23篇
  1994年   22篇
  1993年   22篇
  1992年   51篇
  1991年   52篇
  1990年   53篇
  1989年   51篇
  1988年   46篇
  1987年   44篇
  1986年   38篇
  1985年   37篇
  1984年   18篇
  1982年   18篇
  1981年   17篇
  1980年   18篇
  1979年   30篇
  1978年   24篇
  1977年   28篇
  1975年   16篇
  1974年   19篇
  1973年   22篇
  1972年   21篇
  1970年   25篇
  1969年   18篇
排序方式: 共有3367条查询结果,搜索用时 31 毫秒
1.
Clostridioides (Clostridium) difficile (C. difficile) infection is one of the most common causes of increased morbidity and mortality. Approximately 500 000 C. difficile infections (CDIs) occur each year in the United States, and they result in more than 29 000 deaths. Patients with haematologic diseases are at a higher risk for this infection due to frequent hospitalization and exposure to treatment-associated risk factors. Whilst several currently available antimicrobial agents offer resolution, recurrence of infection remains a major concern. Recent advancement in deciphering C. difficile virulence mechanisms and identification of its allies in contributing to the infection has led to the development of alternative treatment strategies. Here, we will provide a contemporary discussion of how major risk factors in haematologic diseases, such as immunosuppression, chemoradiation, use of antibiotic, proton pump inhibitor and opioid, and deficiency in butyrate and antimicrobial peptides contribute to C. difficile infection. Next, we will highlight different approaches to control and mitigate this infection such as antibiotic stewardship and faecal microbiota transplantation. Finally, we will explore several emerging treatments such as use of pre- and probiotics, immunotherapy and microbiome-sparing agents.  相似文献   
2.
3.
ABSTRACT

Community-based participatory research (CBPR) has captured public health attention and support because it is positioned as an approach that involves researchers and communities as equitable partners in addressing health disparities. However, it is unknown the extent to which CBPR creates a participatory space in the scientific discourse to signal “community voice,” which we define as textual expression of community-centered perspectives on collective roles, interests, and worldviews. In this study, we utilized the culture-centered approach to examine the expression of community voice in the abstracts and public health relevance statements of 253 extramural CBPR projects in the U.S. that received funding from the National Institute of Health and Centers for Disease Control and Prevention in 2009. We found that project abstracts and public health relevance statements contain four textual domains, or potential sites of contest to signal the articulation of community agency and voice within the CBPR projects. These domains include: 1) the rationale for the community health issue, 2) the roles of community partners, 3) community-centered outcomes of the partnership, and 4) elements of participatory research process. The degree of culture-centeredness of the texts is suggested in the extent to which articulations of community agency and voice are signaled across the four domains. We conclude that the dynamics of CBPR may shape culture-centered expressions of problem identification, solution configuration, structural transformations, reflexivity, values, and agency in the project abstracts and public health relevance statements.  相似文献   
4.
5.
6.
7.
8.
The aim of this study was to investigate the morphologic and ultrastructural features of biofilms of slow and fast-growing mycobacteria in different stress conditions, presence and absence of oleic acid albumin dextrose catalase (OADC) enrichment and at different temperatures: 30, 37 and 42?°C. Four hundred mycobacterial isolates were taken. The biomass of each biofilm was quantified using a modified microtiter plate assay method. Isolates were divided into those that formed fully established biofilms, moderately attached biofilms and weakly adherent biofilms by comparison with a known biofilm-forming strain. The large quantity of biofilm was produced by Mycobacterium smegmatis at temperature 37 and 42?°C as compared to 30?°C. Mycobacterium fortuitum and M. avium developed large amount of biofilm at 30?°C as compared to 37 and 42?°C. Mycobacterium tuberculosis developed strong biofilm at 37?°C and no biofilm at 30 and 42?°C in Sauton’s media. The selected non-tuberculous mycobacteria and H37Rv developed strong biofilm in the presence of OADC enrichment in Sauton’s medium. Microscopic examination of biofilms by scanning electron microscopy revealed that poorly adherent biofilm formers failed to colonize the entire surface of the microtiter well. While moderately adherent biofilm formers grew in uniform monolayers but failed to develop a mature three-dimensional structure. SEM analysis of an isolate representative of the group formed fully established biofilms with a textured, multi-layered, three-dimensional structure.  相似文献   
9.
Food insecurity and its most extreme form, hunger, have increased exponentially in the United States since 2006. This essay seeks to contribute to our understanding of hunger by attending to the context of the financial crisis as an organizing frame for understanding local meanings of hunger. Within a broader framework of the culture-centered approach (CCA) that works to identify and develop locally rooted solutions to food insecurity, we describe through locally grounded stories of food insecurity the financial climate where large percentages of U.S. households have been cast into poverty because of the crash of an unregulated economy. These local understandings of hunger in the context of the economy offer entry points for organizing a food-insecure coalition that seeks to address the stigma around food insecurity.  相似文献   
10.
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