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   12597篇
  免费   688篇
  国内免费   61篇
耳鼻咽喉   180篇
儿科学   256篇
妇产科学   201篇
基础医学   1699篇
口腔科学   1476篇
临床医学   991篇
内科学   2470篇
皮肤病学   288篇
神经病学   886篇
特种医学   525篇
外科学   1133篇
综合类   100篇
一般理论   4篇
预防医学   1462篇
眼科学   210篇
药学   942篇
中国医学   138篇
肿瘤学   385篇
  2023年   116篇
  2022年   268篇
  2021年   435篇
  2020年   286篇
  2019年   404篇
  2018年   466篇
  2017年   321篇
  2016年   336篇
  2015年   407篇
  2014年   593篇
  2013年   716篇
  2012年   985篇
  2011年   1002篇
  2010年   603篇
  2009年   475篇
  2008年   661篇
  2007年   687篇
  2006年   556篇
  2005年   512篇
  2004年   441篇
  2003年   360篇
  2002年   326篇
  2001年   248篇
  2000年   218篇
  1999年   174篇
  1998年   149篇
  1997年   102篇
  1996年   102篇
  1995年   75篇
  1994年   69篇
  1993年   73篇
  1992年   65篇
  1991年   96篇
  1990年   85篇
  1989年   115篇
  1988年   102篇
  1987年   90篇
  1986年   57篇
  1985年   59篇
  1984年   48篇
  1983年   38篇
  1982年   37篇
  1981年   43篇
  1980年   38篇
  1979年   35篇
  1978年   31篇
  1977年   33篇
  1975年   30篇
  1974年   33篇
  1973年   19篇
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
41.
Maternal and Child Health Journal - Dietary patterns can influence maternal and child health outcomes. The study aims to characterize dietary patterns during pregnancy as well as to identify their...  相似文献   
42.
The association between obesity and vitamin A has been studied. Some studies point to the anti-obesity activity related to this vitamin, carotenoids with provitamin A activity, and carotenoid conversion products. This performance has been evaluated in respect of adipogenesis, metabolic activity, oxidation processes, secretory function, and oxidative stress modulation, showing a new property attributed to vitamin A in preventing and treating obesity. However, vitamin A and its precursors are highly sensitive and easily degraded when subjected to heat, the presence of light, and oxygen, in addition to losses related to the processes of digestion and absorption. In this context, encapsulation presents itself as an alternative capable of increasing vitamin A’s stability in the face of unfavorable conditions in the environment, which can reduce its functionality. Considering that vitamin A’s status shows a strong correlation with obesity and is an innovative theme, this article addresses the associations between vitamin A’s consumption and its precursors, encapsulated or not, and its physiological effects on obesity. The present narrative review points out those recent studies that demonstrate that vitamin A and its encapsulated precursors have the most preserved functionality, which guarantees better effects on obesity therapy.  相似文献   
43.
44.
45.
The objective of this study was to investigate the impact of male age, semen quality and days of ejaculatory abstinence on embryo morphokinetics. A total of 1,220 zygotes obtained from 139 couples in a private in vitro fertilisation centre were analysed. The timing of specific events from the point of insemination, such as timings to pronuclei appearance and fading, to two, three, four, five, six, seven and eight cells and to blastulation were recorded. Multivariate linear regression analysis was used to evaluate the influence of paternal factors on embryo morphokinetic events. Paternal age was positively correlated with delayed cell cleavage and blastulation, and negatively associated with implantation rate, and clinical pregnancy and live–birth chances. The ejaculatory abstinence was inversely correlated with the implantation rate. Inverse relationships were observed between semen parameters (sperm count, progressive sperm motility, total motile sperm count and morphology) and the timing of specific events during embryo development. Sperm morphology was also positively associated with implantation rate and pregnancy and live–birth chances. Increased paternal age and ejaculatory abstinence, and poor semen quality correlate with delayed cell cleavage and blastulation and negatively impact intracytoplasmic sperm injection outcomes.  相似文献   
46.
47.
48.
Taking a patient-oriented approach to developing lifestyle interventions includes incorporating the patient into the program’s design, delivery, and evaluation. This commentary assumes that a patient-oriented approach has not yet been implemented and tested in exercise-based interventions designed for pregnant women. We outline and define a patient-oriented approach to conduct exercise-based research and review previous physical activity interventions designed for pregnant women to determine whether a patient-oriented approach was applied. In addition, pregnant women living with obesity may have unique barriers to engaging in prenatal exercise interventions that have not been previously addressed, such as having experienced weight stigma before pregnancy in healthcare and fitness settings. We propose suggestions for future trials to effectively take a patient-oriented approach when designing and implementing prenatal exercise interventions to address patient-informed barriers and incorporate suggested facilitators for physical activity. Given that prenatal activity levels are low and pregnant women may have unique barriers to engaging in exercise interventions, a patient-oriented approach may be an effective strategy to improve inclusivity and equity and, as a result, increase uptake and adherence to the intervention.  相似文献   
49.
50.
A four years-old boy with Xanthogranulomatous pyelonephritis was surgically treated at the Pediatric Surgery Unit of the Santa Casa de Misericórdia of Maceió. Comments are made upon pathology, pre-operative diagnostic difficulties, differential diagnosis, and the rare occurrence in children.  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