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   1317844篇
  免费   97913篇
  国内免费   1614篇
耳鼻咽喉   17160篇
儿科学   42616篇
妇产科学   36165篇
基础医学   197278篇
口腔科学   36624篇
临床医学   123028篇
内科学   257427篇
皮肤病学   28576篇
神经病学   107820篇
特种医学   49237篇
外国民族医学   265篇
外科学   185906篇
综合类   25951篇
现状与发展   3篇
一般理论   599篇
预防医学   108243篇
眼科学   29170篇
药学   96244篇
  31篇
中国医学   2098篇
肿瘤学   72930篇
  2019年   10610篇
  2018年   14713篇
  2017年   11376篇
  2016年   12618篇
  2015年   14119篇
  2014年   19235篇
  2013年   29730篇
  2012年   40409篇
  2011年   43181篇
  2010年   24745篇
  2009年   23384篇
  2008年   40894篇
  2007年   43750篇
  2006年   43070篇
  2005年   42159篇
  2004年   40482篇
  2003年   38939篇
  2002年   37754篇
  2001年   58053篇
  2000年   59605篇
  1999年   49519篇
  1998年   13902篇
  1997年   12637篇
  1996年   12966篇
  1995年   12193篇
  1994年   11386篇
  1993年   10670篇
  1992年   38476篇
  1991年   37903篇
  1990年   36681篇
  1989年   35539篇
  1988年   32914篇
  1987年   32251篇
  1986年   30736篇
  1985年   29057篇
  1984年   22248篇
  1983年   19450篇
  1982年   11589篇
  1979年   21166篇
  1978年   15550篇
  1977年   12962篇
  1976年   12005篇
  1975年   12960篇
  1974年   15729篇
  1973年   15511篇
  1972年   14607篇
  1971年   13628篇
  1970年   12879篇
  1969年   12149篇
  1968年   11320篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
105.
106.
107.
More than 500 abandoned uranium (U) mines within the Navajo Nation contribute U, arsenic (As) and other metals to groundwater, soil and potentially air through airborne transport. The adverse cardiovascular health effects attributed to cumulative exposure to these metals remains uncertain. The aim of this study was to examine whether environmental exposure to these metals may promote or exacerbate the oxidation of low-density lipoprotein (LDL) cholesterol in this Native American population. The correlation of cardiovascular biomarkers (oxidized LDL (oxLDL) and C-reactive protein (CRP)) from a Navajo cohort (n = 252) with mean annual As and U intakes from water and urine metals was estimated using linear regression. Proof-of-concept assays were performed to investigate whether As and U directly oxidize human LDL. Mean annual As intake from water was positively and significantly associated with oxLDL, but not CRP in this study population, while U intake estimates were negatively associated with oxLDL. In an acellular system, As, but not U, directly oxidized the apolipoprotein B-100 component of purified human LDL. Neither metal promoted lipid peroxidation of the LDL particle. Both the population and lab results are consistent with the hypothesis that As promotes oxidation of LDL, a crucial step in vascular inflammation and chronic vascular disease. Conversely, for outcomes related to U, negative associations were observed between U intake and oxLDL, and U only minimally altered human LDL in direct exposure experiments. Only urine U was correlated with CRP, whereas no other metals in water or urine were apparently reliable predictors of this inflammatory marker.  相似文献   
108.
The objective of this study was to examine the association of ethnoracial background and immigrant status to cannabis use among students in Ontario, Canada. Data were derived from the Ontario Student Drug Use and Health Survey, a school-based, province-wide survey of students in Grades 7–12. The survey utilized a stratified two-stage cluster design. Analyses were based on a pooled subsample of 12,527 students in Grades 9–12 during the 2011 and 2013 survey cycles and included adjustments for the complex sample design. Results indicate that youth who were of South Asian or East/Southeast Asian background were at lower odds of cannabis use than those who were White, Black, or mixed-race backgrounds. Youth who were of mixed-race background (i.e., White and another group) were at higher odds of cannabis use than youth who were of White background. The association between ethnoracial background and cannabis use also varied for some foreign-born and native-born youth. These findings suggest that ethnoracial background should be an important consideration in investigations of cannabis use among foreign- relative to native-born youth.  相似文献   
109.
110.

Objectives

The availability of suicide prevention training programs for pharmacists is unknown and may depend on state training requirements. This study’s objectives were to: 1) report state training requirements for pharmacist suicide education; and 2) describe educational resources that are available to prepare pharmacists for interactions with patients at risk of suicide.

Methods

Each state’s board of pharmacy was contacted from July to November 2017 to determine whether that state required pharmacists to complete suicide prevention training. A scoping literature review completed in August 2017 identified suicide prevention resources for pharmacy professionals. A systematic search of 5 databases and Google yielded publications and online resources that were screened for full review. Two coders reviewed articles and resources that met inclusion criteria and extracted data on program format and length, intended audience (i.e., students, practicing pharmacists), learning methods, topics covered, and outcomes assessed.

Results

Only Washington State requires pharmacists to obtain suicide prevention training. Sixteen suicide education programs and resources targeted pharmacists, including 8 in-person courses, 6 online courses, and 2 written resources. Five resources exclusively targeted pharmacists and 2 exclusively targeted student pharmacists. Most programs included information on suicide statistics, how to identify individuals at risk of suicide, how to communicate with someone who is suicidal, and how to refer patients to treatment resources. The long-term effectiveness of the programs at improving outcomes was not reported.

Conclusion

Although only 1 state requires pharmacists to obtain training on suicide prevention, there are several resources available to help prepare pharmacists to interact with individuals at risk of suicide.  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