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   309796篇
  免费   37773篇
  国内免费   210篇
  2016年   3140篇
  2015年   4761篇
  2014年   5477篇
  2013年   7777篇
  2012年   8744篇
  2011年   8721篇
  2010年   6066篇
  2009年   5602篇
  2008年   7777篇
  2007年   8016篇
  2006年   7601篇
  2005年   7530篇
  2004年   7432篇
  2003年   7496篇
  2002年   7124篇
  2001年   11597篇
  2000年   11697篇
  1999年   9716篇
  1998年   3840篇
  1997年   4026篇
  1996年   3994篇
  1995年   3698篇
  1994年   3660篇
  1993年   3658篇
  1992年   8641篇
  1991年   8352篇
  1990年   8189篇
  1989年   8098篇
  1988年   7578篇
  1987年   7530篇
  1986年   6969篇
  1985年   7125篇
  1984年   6038篇
  1983年   5370篇
  1982年   4331篇
  1981年   4154篇
  1980年   3775篇
  1979年   6184篇
  1978年   4838篇
  1977年   4649篇
  1976年   4398篇
  1975年   4764篇
  1974年   5226篇
  1973年   5086篇
  1972年   4714篇
  1971年   4294篇
  1970年   3744篇
  1969年   3779篇
  1968年   3350篇
  1967年   2890篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
995.
996.
997.
Several workers have suggested that cell membranes have a high proton conductance. Our interest in this concept arose from the possibility that the nutrient (submucosal-facing) membrane of the gastric mucosa may have a high proton or hydroxyl ion conductance which would play a role in the regulation of the acid-base balance of the cell. We found that wide changes in the H+ concentration of the fluid bathing the nutrient side of the in vitro frog gastric mucosa did not result in significant changes in p.d. However, a maintained change of the H+ concentration of the bathing fluid would be expected to produce only a temporary change in p.d. Since a diffusion barrier is present on the nutrient side the temporary change in p.d. might be masked. An analysis of this possibility was made on the basis of a conceptual model and as a result of the analysis it is concluded that the proton (and/or OH?) conductance of the nutrient membrane of the frog gastric mucosa is not a significant fraction of its total conductance. The present status of the proton conductance hypothesis with respect to striated muscle and to the secretory membrane of the gastric mucosa is reviewed.  相似文献   
998.
999.
1000.
The aim of the study reported in this article was to investigate staff nurses’ perceptions and experiences about structural empowerment and perceptions regarding the extent to which structural empowerment supports safe quality patient care. To address the complex needs of patients, staff nurse involvement in clinical and organizational decision-making processes within interdisciplinary care settings is crucial. A qualitative study was conducted using individual semi-structured interviews of 11 staff nurses assigned to medical or surgical units in a 600-bed university hospital in Belgium. During the study period, the hospital was going through an organizational transformation process to move from a classic hierarchical and departmental organizational structure to one that was flat and interdisciplinary. Staff nurses reported experiencing structural empowerment and they were willing to be involved in decision-making processes primarily about patient care within the context of their practice unit. However, participants were not always fully aware of the challenges and the effect of empowerment on their daily practice, the quality of care and patient safety. Ongoing hospital change initiatives supported staff nurses’ involvement in decision-making processes for certain matters but for some decisions, a classic hierarchical and departmental process still remained. Nurses perceived relatively high work demands and at times viewed empowerment as presenting additional. Staff nurses recognized the opportunities structural empowerment provided within their daily practice. Nurse managers and unit climate were seen as crucial for success while lack of time and perceived work demands were viewed as barriers to empowerment.  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