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   1273581篇
  免费   96243篇
  国内免费   1593篇
耳鼻咽喉   16425篇
儿科学   41313篇
妇产科学   35164篇
基础医学   191080篇
口腔科学   34927篇
临床医学   119094篇
内科学   249599篇
皮肤病学   27480篇
神经病学   102664篇
特种医学   47072篇
外国民族医学   265篇
外科学   179948篇
综合类   26014篇
现状与发展   3篇
一般理论   584篇
预防医学   105774篇
眼科学   28147篇
药学   93367篇
  6篇
中国医学   2028篇
肿瘤学   70463篇
  2018年   13702篇
  2017年   10520篇
  2016年   11489篇
  2015年   13248篇
  2014年   18231篇
  2013年   27827篇
  2012年   38050篇
  2011年   40457篇
  2010年   23305篇
  2009年   22519篇
  2008年   38187篇
  2007年   40838篇
  2006年   40444篇
  2005年   39546篇
  2004年   37993篇
  2003年   36353篇
  2002年   35237篇
  2001年   56335篇
  2000年   57363篇
  1999年   48372篇
  1998年   13525篇
  1997年   12317篇
  1996年   12736篇
  1995年   11998篇
  1994年   11189篇
  1993年   10484篇
  1992年   38390篇
  1991年   37877篇
  1990年   36653篇
  1989年   35465篇
  1988年   32891篇
  1987年   32205篇
  1986年   30697篇
  1985年   28957篇
  1984年   22095篇
  1983年   19316篇
  1982年   11446篇
  1981年   10416篇
  1979年   21069篇
  1978年   15515篇
  1977年   12879篇
  1976年   11935篇
  1975年   12889篇
  1974年   15699篇
  1973年   15461篇
  1972年   14591篇
  1971年   13627篇
  1970年   12848篇
  1969年   12143篇
  1968年   11295篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
PURPOSE: Educational interventions to reduce the use of abbreviations and dosage designations that were deemed unsafe at a level 1 trauma center are described. SUMMARY: Strategies to reduce the use of unsafe abbreviations at Detroit Receiving Hospital were studied. Six abbreviations and dosage designations were deemed as unsafe by the site's medication-use and patient medical safety committees: (1) U for units, (2) microg for microgram, (3) TIW for three times a week, (4) the degree symbol for hour, (5) trailing zeros after a decimal point, and (6) the lack of leading zeros before a decimal point. Data on abbreviation use was collected starting in September 2003 by examining copies of patients' order sheets, which are sent from nursing units to the pharmacy for processing. Data were collected during three 24-hour periods each month, with 7-10 days between each period. A data collection sheet was developed to assist in documenting the number of opportunities for each unsafe abbreviation and the actual incidence of each. Educational strategies were developed and implemented starting in October 2003 to decrease the use of the unsafe abbreviations. These strategies included inservice education programs for the medical, pharmacy, and nursing staffs; laminated pocket cards; patient chart dividers; stickers; and interventions by pharmacists and nurses during medication prescribing. During the eight-month evaluation period, 20,160 orders were reviewed, representing 27,663 opportunities to use a designated unsafe abbreviation. Educational interventions successfully reduced the overall incidence of unsafe abbreviations from 19.69% to 3.31%. CONCLUSION: Educational interventions markedly reduced the use of unsafe abbreviations in medication orders over an eight-month evaluation period.  相似文献   
993.
994.
Immunity against the opportunistic fungal pathogen Pneumocystis.   总被引:2,自引:0,他引:2  
Species of the genus Pneumocystis exist as opportunistic fungal pathogens and are associated with severe pneumonia and pulmonary complications in immunocompromised individuals. Although prophylactic therapy for Pneumocystis has significantly decreased the overall incidence of infection, more than 80% of cases in current patient populations are considered breakthrough cases. In the HIV-infected population, in the years following the initiation of highly active antiretroviral therapy (HAART), significant reductions in the incidence of Pneumocystis infection were observed, although trends over the last several years suggest that the incidence of Pneumocystis has plateaued rather than decreased. Furthermore, with the more prominent usage of immunosuppressive therapies, the frequency of Pneumocystis infection in the HIV-negative population, such as those with hematologic malignancies and those who have undergone transplantation, has risen significantly. Investigating host defense mechanisms against P. carinii has historically been problematic due to the difficulty in achieving continuous in vitro propagation of proliferating Pneumocytis organisms. Nevertheless, clinical and experimental studies have documented that host defense against Pneumocystis involves a concerted effort between innate, cell-mediated (T lymphocyte) and humoral (B lymphocyte) responses. However, the pulmonary environment is a tissue site where heightened inflammatory responses can often lead to inflammation-mediated injury, thereby contributing to the pathogenesis of Pneumocystis infection. Accordingly, clearance of Pneumocystis from the pulmonary environment is dependent on a delicate equilibrium between the inflammatory response and immune-mediated clearance of the organism. Furthermore, innate and adaptive responses against Pneumocystis are strikingly similar to those against other medically-important fungi, thus providing additional evidence that Pneumocystis exists as a fungal organism.  相似文献   
995.
BACKGROUND: The impact of exercise programmes for heart failure on those close to the patient is largely unknown. We examined the effect of a hospital and home-based exercise intervention on burden, anxiety and depression of informal caregivers. DESIGN: The study was a randomized, controlled trial. Heart failure patients were randomized to a seated 12-week hospital-based exercise programme. Caregiver measures were gathered at baseline, 3 months later and 6 months following baseline. METHODS: Sixty caregivers (mean age 63.4 years, 65% female) of heart failure patients (n = 82, mean age 80.5 years, 44% female) participating in a trial of an exercise intervention were recruited. Caregiver burden, anxiety and depression were assessed. RESULTS: There were no differences in caregiver burden, depression or anxiety between the two groups of caregivers at baseline (caregiver burden, patient control 33.1 versus patient exercise 34.1; anxiety 4.1 versus 5.5; depression 2.8 versus 3.8). At 3 months there were no differences between caregivers in the two groups on outcomes. At 6-month follow-up caregivers of heart failure patients in the exercise group had burden scores that were significantly worse than the control group. There were no differences between the carers of exercise and control groups in anxiety and depression. Levels of anxiety and depression in the entire carer sample were marginally higher than reference values in a healthy non-clinical sample. CONCLUSION: The present exercise interventions for frail older patients did not benefit caregivers and was associated with an increase in caregiver burden. We suggest that future exercise interventions for heart failure patients should actively incorporate informal caregivers into research designs.  相似文献   
996.
997.
The drug addict     
  相似文献   
998.
999.
1000.
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