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   27458篇
  免费   1830篇
  国内免费   329篇
耳鼻咽喉   47篇
儿科学   660篇
妇产科学   660篇
基础医学   4206篇
口腔科学   390篇
临床医学   2949篇
内科学   2304篇
皮肤病学   363篇
神经病学   4856篇
特种医学   237篇
外国民族医学   1篇
外科学   1281篇
综合类   2082篇
一般理论   2篇
预防医学   6019篇
眼科学   46篇
药学   2675篇
  8篇
中国医学   331篇
肿瘤学   500篇
  2024年   90篇
  2023年   430篇
  2022年   848篇
  2021年   1182篇
  2020年   986篇
  2019年   921篇
  2018年   863篇
  2017年   931篇
  2016年   1011篇
  2015年   863篇
  2014年   1450篇
  2013年   2516篇
  2012年   1220篇
  2011年   1419篇
  2010年   1051篇
  2009年   1103篇
  2008年   1157篇
  2007年   1102篇
  2006年   1118篇
  2005年   907篇
  2004年   737篇
  2003年   713篇
  2002年   613篇
  2001年   484篇
  2000年   403篇
  1999年   374篇
  1998年   307篇
  1997年   302篇
  1996年   257篇
  1995年   250篇
  1994年   204篇
  1993年   196篇
  1992年   188篇
  1991年   185篇
  1990年   170篇
  1989年   157篇
  1988年   150篇
  1987年   130篇
  1986年   191篇
  1985年   301篇
  1984年   265篇
  1983年   201篇
  1982年   239篇
  1981年   232篇
  1980年   227篇
  1979年   213篇
  1978年   150篇
  1977年   153篇
  1976年   145篇
  1975年   103篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Background: Traumatic brain injury (TBI) results in verbal recall deficits and impaired processing of emotion encoded in facial appearance, prosody and the linguistic content of messages. Emotion facilitates memory (emotional memory advantage) for non-brain injured (NBI) individuals but the impact of emotion on verbal recall for linguistically encoded stimuli in TBI has not been explored.

Aims: The purpose of this study was to determine the effects of stimulus emotional content on verbal recall of words and paragraphs in TBI compared to NBI individuals.

Methods and procedures: Six 10-item lists, each with five emotional and five neutral words, and six paragraphs (three emotional, three neutral) were counterbalanced and presented in random order to 20 individuals with TBI and 44 NBI. The number of words from lists and the number of content units from paragraphs were compared for the two groups.

Outcomes and results: The NBI participants recalled more words from the lists and content units from the paragraphs than the individuals with TBI. Both groups recalled significantly more emotional than neutral words. NBI but not TBI participants had significantly greater recall for information in paragraphs with emotional content.

Conclusions: Participants with TBI showed impaired recall of words and paragraph content. Emotion facilitated word and paragraph content recall for neurotypical individuals but emotional memory advantage was limited to words for the TBI participants.  相似文献   

2.
BackgroundA majority of youth with Autism Spectrum Disorder (ASD) have disrupted sleep patterns, but there has been limited research examining factors associated with sleep in this population. Objective: The objective of this study was to compare demographic and lifestyle behaviors with sleep quality in youth with ASD. Methods: A total of 49 children (12.44 years; 78% male) with ASD wore the Actigraph GT9X accelerometer over seven days and nights to assess moderate to vigorous physical activity (MVPA), sedentary behavior (SB), total sleep duration, and sleep efficiency. Parents reported their child’s weekly amount of screen time and demographic information. Participants were classified according to whether they met sleep criteria for duration and efficiency (8–9 h of sleep duration and ≥85% sleep efficiency). T-tests and ANOVA were used to compare demographic and lifestyle factors between the groups. Results: Participants who meet both sleep duration and efficiency criteria had greater minutes of MVPA per day (113.65 min/day) than participants who only met sleep efficiency criteria (40.27 min/day) and participants who did not meet either sleep criteria (67.5 min/day; p < 0.0001). Additionally, participants who met both sleep criteria had fewer minutes of SB compared to those who only met sleep efficiency criteria (384.79 vs 526.05 min/day; p = 0.02). Conclusions: Youth who had indicators of good sleep quality had greater amounts of MVPA and lower amounts of SB. Studies should further examine the relationship between sleep and health behaviors in youth with ASD to determine causal mechanisms, leading to more effective sleep interventions.  相似文献   
3.
目的探究组织气氛在护士吞咽障碍知识水平与护理行为之间的中介效应。方法2019年6-7月,便利抽样法选取15个省市33所医院及医疗机构神经科、康复科具有吞咽障碍护理经验的231名护士为研究对象采用脑卒中吞咽障碍知识水平问卷、脑卒中吞咽障碍护理行为问卷及团队创新气氛量表对其进行调查。结果护士吞咽障碍知识水平总分为(56.69±13.50)分、护理行为得分为(140.65土32.02)分、组织气氛得分为(157.63±26.56)分。组织气氛与吞咽障碍知识水平(r=0.49,P<0.01)、护理行为(r=0.50,P<0.01)均呈正相关。组织气氛在知识水平和护理行为之间起中介作用,中介效应占总效应的83.18%。结论组织气氛在护士吞咽障碍知识水平与护理行为之间起中介作用,临床管理者可在提升护士吞咽障碍知识水平的基础上,通过提高组织气氛水平推进其护理行为。  相似文献   
4.
The Theory of Rational Addictions, by Gary Becker & Kevin Murphy (1988), was a rational choice model that became a standard tool for economists modeling addictive behavior. The approach differs from other theories of addiction by modeling addictive behavior as the gradual implementation of a rational, forward‐looking plan, where consumption at any point in time is partly motivated by the immediate payoff of consumption and partly by the effects this consumption has on the individual in the future. This makes addictive behavior a subset of rational behavior, requiring no more specific government policies or attention than any other consumption choice. Later work by economists extended the theory in different ways, allowing it to match an increasing number of consumption patterns, and searched for ways to test the forward‐looking assumption in different types of market data. While the work was successful as a contribution to rational choice theory, with possible statistical applications, there are several reasons to dismiss its usefulness as an explanation of real‐world addictive behavior and its ability to assess the welfare effects of addictions.  相似文献   
5.
Food-grade titanium dioxide (E171) is widely used as a food additive, and it is known that after oral consumption, E171 is translocated into the bloodstream reaching the highest titanium level at 6 h. E171 is accumulated in some organs triggering toxicity, but the effects on the blood parameters after oral consumption have been less studied. Recently, evidence shows that oral exposure to E171 induces behavioral signs of anxiety and depression. The relation between blood alterations and psychiatric disorders has been previously demonstrated. However, the oral exposure to E171 effects on alterations in blood parameters and effects linked to alterations in animal behavior has not been explored. In this short communication, we aimed to investigate the effects of E171 on specific blood parameters (hematocrit, hemoglobin, number of erythrocytes, and leukocytes) and anxiety and compulsive-like behavior in males and females orally exposed to ~5 mg/kg for 4 weeks. The results showed that E171 decreased hematocrit and hemoglobin in male but not in female mice while leukocyte and erythrocyte count remained unaltered. Oral consumption of E171 decreased the levels of anxiety-like behavior in females but not in male mice, while compulsive-like behavior was increased in both male and female mice.  相似文献   
6.
ABSTRACT

Objectives: The present study investigated the relationships of enculturation and depressive symptoms with health risk behavior engagement in Mexican-American college students and examined how these relationships differed by gender. Previous research has noted consistent gender differences in health risk behavior (e.g. alcohol use, substance use, and risky sexual behavior) among Latina/os, and emphasized the role of U.S. acculturation in this difference. Research examining the role of heritage cultural retention (i.e. enculturation), and including the added influence of mental health variables, such as depressive symptoms, is currently lacking. This study sought to address this gap.

Design: A large sample (N?=?677) of Mexican-American college students from four universities (located in New York, California, Florida, and Texas) completed an online questionnaire assessing health risk behaviors and corresponding variables.

Results: We found that males who endorsed more behavioral enculturation and depressive symptoms were more likely to engage in health risk behavior than all others in the sample. Contrary to previous literature, no relationship was found between behavioral enculturation and health risk behavior in females.

Conclusion: The current study found behavioral enculturation to be associated with depressive symptoms, and in turn with health risk behaviors among the males in our sample. Additional research will be needed to identify the mechanism underlying the relationship between enculturation and depressive symptoms as well as between depressive symptoms and risky behavior.  相似文献   
7.
目的了解广东省家庭医生式服务试点地区居民健康行为及影响因素,为开展健康教育提供依据。方法2015年7—10月抽样选取1010名家庭医生式服务试点地区居民进行问卷调查,以吸烟、饮酒、早餐、吃水果、锻炼及睡眠等6项行为为调查内容,同时选用P-CAT量表测量基层医疗服务质量。结果 6项行为方式共赋值12分,被调查者平均得分(8.72?0.65)分,得分从高到低依次为吃早餐、限酒、不吸烟、体育锻炼、吃水果和睡眠。多重线性回归分析结果显示:女性、已婚或慢性病患者的健康行为优于各对应组;收入对健康行为有正面影响;基层医疗服务可及性、服务提供综合性对健康行为有正向影响。结论试点地区居民整体健康行为较好。健康教育和健康促进应聚焦于合理膳食、锻炼及睡眠等健康行为;男性、单身或离异及低收入群体是重点关注的对象;提高基层医疗服务可及性和服务提供综合性有利于促进居民的健康行为。  相似文献   
8.
9.
10.
目的了解上海市浦东新区小学生超重肥胖的现状以及学生的营养知识、态度和饮食行为,为开展学生营养知识宣传与相关行为干预提供依据。方法按照分层整群随机抽样的方法,抽取浦东新区6 824名小学生测量身高和体重;随机整群抽取1 122名小学生和家长进行有关的问卷调查,剔除不合格问卷,获得有效问卷1 089份,有效率为97.1%。结果浦东新区小学生超重和肥胖检出率分别为22.0%和10.7%,总超重率为32.7%,其中男生超重、肥胖检出率为24.5%和13.2%,总超重肥胖率为37.8%,女生超重、肥胖检出率为19.0%和7.7%,总超重率为26.7%,男生超重率高于女生,差异有统计学意义(χ~2=30.111,P0.01),男生肥胖率高于女生,差异有统计学意义(χ~2=55.004,P0.01)。全体学生的营养知识水平偏低,平均得分为(4.68±1.166)分,学生对合理膳食的基本要求、钙元素和维生素C的良好来源等知识掌握比较好,但对于相对专业的营养知识掌握较差。学生对零食、饮料的食用频率较高,1周吃8~14次分别达到10.1%和10.6%,豆类食用频率相对较少。结论上海市浦东新区小学生超重及肥胖检出率已超过全国平均水平,小学生整体的营养知识水平不高,零食、饮料和油炸烧烤等食品食用频率较高。针对这些问题,应结合当地的实际情况积极采取各项措施,培养科学合理的饮食行为。  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