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   11890篇
  免费   993篇
  国内免费   245篇
耳鼻咽喉   105篇
儿科学   69篇
妇产科学   162篇
基础医学   1364篇
口腔科学   211篇
临床医学   627篇
内科学   3138篇
皮肤病学   495篇
神经病学   1947篇
特种医学   494篇
外科学   665篇
综合类   784篇
现状与发展   1篇
一般理论   3篇
预防医学   1728篇
眼科学   181篇
药学   570篇
中国医学   299篇
肿瘤学   285篇
  2024年   37篇
  2023年   283篇
  2022年   471篇
  2021年   546篇
  2020年   571篇
  2019年   572篇
  2018年   433篇
  2017年   499篇
  2016年   418篇
  2015年   490篇
  2014年   689篇
  2013年   942篇
  2012年   496篇
  2011年   589篇
  2010年   484篇
  2009年   527篇
  2008年   537篇
  2007年   513篇
  2006年   437篇
  2005年   404篇
  2004年   356篇
  2003年   315篇
  2002年   263篇
  2001年   229篇
  2000年   194篇
  1999年   139篇
  1998年   184篇
  1997年   159篇
  1996年   136篇
  1995年   140篇
  1994年   113篇
  1993年   104篇
  1992年   97篇
  1991年   81篇
  1990年   80篇
  1989年   57篇
  1988年   50篇
  1987年   46篇
  1986年   62篇
  1985年   71篇
  1984年   75篇
  1983年   34篇
  1982年   60篇
  1981年   41篇
  1980年   36篇
  1979年   19篇
  1978年   15篇
  1977年   9篇
  1976年   11篇
  1974年   4篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Objectives: The steeling effect suggests that early-life adversity can have a beneficial impact later in life. However, little is known about its underlying mechanisms and long-term outcomes . The study aimed to examine the role of early-life adversity (ELA) on successful aging, and whether this relationship can be explained by mental and physical health.

Method: Socio-demographics, early-life adversity (ELA), individual quality of life (iQoL), and mental and physical health of 270 individuals (Mage = 66.82 years, 71.5% female) were assessed. Polynomial regressions and mediation analyses were conducted.

Results: Significant inverse U-shaped associations were found between ELA and iQoL (β = ?.59, p = .005) and between ELA and mental health (β = ?.64, p = .002), but not between ELA and physical health. Furthermore, mental health significantly mediated the relationship between ELA and iQoL (b = ?.84, BCa CI [?1.66, ?.27]).

Conclusion: Highest level of individual quality of life (i.e. successful aging) was related to a moderate amount of ELA. Additionally, mental health significantly mediated this relationship. These findings suggest that some amount of ELA could be beneficial for successful aging. Resource-focused interventions are needed to improve health and promote successful aging for an underdetected, at-risk subgroup with low early-life adversity.  相似文献   

2.
3.
在这篇文章中,应用圆形分布法计算了泰安市1984—1985两年流行出血热的发病平均日期,分别为1984年11月5号和1985年11月11号,两年合计的平均发病日期为11月9号。另外,还分析了发病的年龄和职业。这将为预防工作提供准确的科学数据。  相似文献   
4.
After the interaction of estrogen with the ligand binding domain (LBD) of mouse estrogen receptor‐α (mERα) and hormone‐responsive elements of target genes, many nuclear proteins are recruited to regulate the expression of specific genes. Because it is not known which brain proteins interact with LBD or whether these proteins vary with age and sex, we used pull‐down assay and far Western blotting to detect five nuclear proteins of 160, 140, 87, 60, and 46 kD in the mouse brain. These interacting proteins were identified as PELP1, RIP140, PGC1α, BAF60, and ADA3, respectively. The level of PELP1, RIP140, PGC1α, and BAF60 decreased drastically in old compared with adult male mice, whereas the ADA3 level showed no significant change. PELP1, PGC1α, and BAF60 levels were lower in old male compared with female mice. Thus we report the identification and interaction of five nuclear proteins with mERα‐LBD, indicating their role in estrogen signaling and brain functions during aging. © 2009 Wiley‐Liss, Inc.  相似文献   
5.
Aim:   In the last three decades, the segment of population aged 60 years and older has more than doubled in Brazil. People aged 80 years and older are expected to be the fastest-growing segment in the near future. This aim of this study was to analyze the legal structures currently in place in Brazil and to provide a framework for care policies and practices towards older-adults.
Methods:   This article focuses on past and present major socioeconomic burdens on this segment of the Brazilian population as well as on public achievements to overcome inequities.
Results:   Both the public health and the social security systems have been directed to provide preferential assistance to the aged. Nonetheless, the elderly remain the most impoverished segment of Brazil and carry the burden of an overall lack of specialized services. Moreover, socioeconomic inequalities and population diversity in Brazil affects elderly care, adding complexity to this unique scenario.
Conclusion:   Brazil has adopted legal hallmarks that substantially shifted public practices towards the elderly segment from a philanthropic status to a legitimate right for care and assistance. The demographic transition that took place provides an opportunity for innovative solutions in public policies for older adults in a developing economic environment.  相似文献   
6.
The present paper deals with a Finnish long-term prospective study, the objective of which is to shed light on adjustment to retirement and old age. In this phase, only the preliminary findings of the initial survey carried out in 1982 are available. For the purposes of the study, a random sample of 200 individuals was drawn from among Turku inhabitants born in 1920. Another sample, consisting of 189 persons of the same age, was drawn from rural municipalities in the neighborhood of Turku. An extensive structured psychosocial interview could be conducted with a total of 339 subjects. The research methods used included e.g. the 36-item version of Goldberg's General Health Questionnaire (GHQ). Relatively little mental disturbance was revealed in the interview, and no major differences occurred between the urban and the rural sample. Somewhat over one-third of both samples were probable psychiatric cases as defined according to the GHQ.  相似文献   
7.
Evidence of the effect of exercise on bone loss comes mainly from studies in voluntary postmenopausal women, and no population-based, long-term interventions have been performed. The purpose of this population-based, randomized, controlled trial was to determine the effect of long-term impact exercise on bone mass at various skeletal sites in elderly women with low bone mineral density (BMD) at the radius and hip. Participants ( n =160) were randomly assigned to 30 months either of supervised and home-based impact exercise training or of no intervention. The primary outcome measures were femoral neck, trochanter and total hip BMD, and the secondary outcomes were bone density measures at the radius and calcaneum. Outcomes were assessed at baseline, 12 months and 30 months using blinded operators. The analyses were performed on an intention-to-treat analysis. Mean femoral neck and trochanter BMD decreased in the control group [–1.1%, 95% confidence interval (CI) –0.1% to –2.1% and –1.6%, 95% CI –0.4% to –2.7%], while no change occurred in the exercise group. Mean trochanter BMC decreased more in the control group (–7.7%, 95% CI –9.7% to –5.6% vs. –2.9%, 95% CI –5.3 to –0.9). There were six falls that resulted in fractures in the exercise group and 16 in the control group during the 30-month intervention ( P =0.019). A significant bone loss occurred in both groups at the radius and calcaneum. In multivariate analysis, weight gain was associated with increased BMD and BMC at all femur sites both in the exercise group and in the pooled groups. In conclusion, impact exercise had no effect on BMD, while there was a positive effect on BMC at the trochanter. Exercise may prevent fall-related fractures in elderly women with low bone mass.There was no conflict of interest.  相似文献   
8.
目的 评价诊断中老年男子部分雄激素缺乏综合征(PADAM)的游离睾酮指数(FTI).方法 对129例45岁以上健康男性的FTI进行年龄相关分析.以推算的游离睾酮(CFT)值为依据,对FTI进行有效性检验.结果 男子在中老年期FTI与增龄呈明显的负相关.FTI敏感性97.78%,特异性58.33%.结论 计算简单的FTI可用于PADAM病人的筛选和随访,尤其对70岁以上男子是血清FT较为有效的参数.  相似文献   
9.
当归对衰老小鼠脑组织细胞凋亡及胸腺指数的影响   总被引:2,自引:0,他引:2  
目的:研究当归的抗衰老作用及作用机制。方法:用D—半乳糖诱导小鼠制成衰老模型,同时给予不同剂量的当归水煎剂,观察当归对脑组织细胞凋亡及胸腺指数的影响。结果:当归能明显抑制小鼠脑组织细胞凋亡,提高胸腺指数。结论:当归具有抗衰老作用。  相似文献   
10.
苯作业工人白细胞降低者的总估校正现患率   总被引:7,自引:0,他引:7  
选择乡镇工业苯作业工人4次外周血白细胞计数中的间隔半年的两次数据,应用俘获再俘获法,计算其白细胞降低者的总估校正现患率(ACPR)。结果苯接触组为36.8l%(29.14%~44.48%),对照组为12.71%(7.20%~18.22%)具有显著差异,其相对危险度为2,9。用常规法求得的4次检出率分别是:苯接触组为26.37%,18.73%,27.93%,36.76%;对照组为6。85%,7.38%,7.94%,15.00%。均在其ACPR之95%可信限内,可见ACPR计算方法简便、结果准确,值得推广。对于稳定的人群,可用其每年一次的健康监护资料计算ACPR。  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