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   36202篇
  免费   3851篇
  国内免费   733篇
耳鼻咽喉   116篇
儿科学   4434篇
妇产科学   3377篇
基础医学   3012篇
口腔科学   401篇
临床医学   4059篇
内科学   4242篇
皮肤病学   201篇
神经病学   1772篇
特种医学   913篇
外国民族医学   4篇
外科学   2573篇
综合类   3937篇
现状与发展   2篇
一般理论   5篇
预防医学   6174篇
眼科学   699篇
药学   3008篇
  21篇
中国医学   903篇
肿瘤学   933篇
  2023年   689篇
  2022年   767篇
  2021年   1527篇
  2020年   1483篇
  2019年   1699篇
  2018年   1565篇
  2017年   1642篇
  2016年   1585篇
  2015年   1457篇
  2014年   2425篇
  2013年   3070篇
  2012年   2001篇
  2011年   2238篇
  2010年   1758篇
  2009年   1679篇
  2008年   1682篇
  2007年   1632篇
  2006年   1402篇
  2005年   1229篇
  2004年   1054篇
  2003年   954篇
  2002年   731篇
  2001年   682篇
  2000年   536篇
  1999年   454篇
  1998年   382篇
  1997年   337篇
  1996年   333篇
  1995年   281篇
  1994年   310篇
  1993年   254篇
  1992年   237篇
  1991年   225篇
  1990年   194篇
  1989年   173篇
  1988年   176篇
  1987年   147篇
  1986年   154篇
  1985年   226篇
  1984年   208篇
  1983年   173篇
  1982年   164篇
  1981年   150篇
  1980年   140篇
  1979年   105篇
  1978年   86篇
  1977年   68篇
  1976年   66篇
  1975年   47篇
  1973年   40篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Increased survival of infants born preterm, especially those born extremely preterm (<28 weeks’ gestation), has meant that more are reaching later childhood and adulthood. As preterm birth is associated with a higher risk of neurodevelopmental deficits, the aim of this review was to determine whether or not the advances in perinatal care that led to improved survival have also had a positive impact on long-term neurodevelopment. Studies examining temporal changes in neurodevelopment are limited, and only from high-income countries. However, based on available published data, there is no definite trend of improved neurodevelopment at school age for neurosensory, cognitive, academic achievement, motor or executive function with time. Cerebral palsy rates, however, may be decreasing. More research is needed into the potential contributors for the trends observed, and also for other outcomes such as mental health and behavior.  相似文献   
92.
《Archives de pédiatrie》2020,27(4):189-195
BackgroundAccording to the INPES 2014 health barometer, the prevalence of smoking in pregnant women in France is the highest in Europe : 17.8% of expectant mothers who smoke continue to do so during pregnancy. Several epidemiological studies have confirmed multiple risks for tobacco-exposed infants (low birth weight; digestive, respiratory, neurological, and psychological disorders; obesity; type 1 diabetes).PurposeThis study compared a cohort of infants exposed to tobacco in utero (T + ) with those unexposed (T−). Birth weight, diet, presence of colic (ROME III criteria) and regurgitations (Vandenplas scale) were specifically analyzed.MethodsThis observational, cross-sectional, and multicenter survey was conducted in France by pediatricians and general practitioners from September 2016 to February 2017. Infants with a chronic pathology and those with parents under 18 years of age were excluded. The data were collected by the physician and by the mother through a self-administered questionnaire.ResultsA total of 452 physicians recruited 759 T+ and 741 T- infants in the study. The mean birth weight of T+ infants was significantly lower (3.1 ± 0.5 kg [WHO z-score -0.476 ± 1.081]) than that of T− infants (3.3 ± 0.5 kg [0.033 ± 0.965]; P < 0.001). At the time of leaving the maternity facility, 47.7% of T+ infants were breastfed by their mother compared with 70.1% of T− infants. The median reported duration of breastfeeding was 1 month vs. 2 months for T+ and T− infants, respectively. Colic was significantly more common in T+ than in T− infants: 25.6% vs. 12.3% according to the ROME III criteria, and 45.7% vs. 29.7% according to the doctor's opinion (P < 0.001 for both). In the T+ group, cases of regurgitation (63.6% vs. 56.5%; P = 0.005), respiratory disorder (6.3% vs. 2.4%, P < 0.001), and bronchiolitis (6.5% vs. 3.0%; P = 0.001) were also more frequent.ConclusionThis study confirms that maternal smoking during pregnancy is associated with health risks; exposed infants had significantly more digestive/respiratory symptoms and lower birth weight than unexposed infants. Preventive and educational actions need to be further strengthened in the face of this public health problem.  相似文献   
93.
94.
95.
96.
Responsive feeding (RF) has been recognized as necessary to prevent all forms of malnutrition including stunting and childhood obesity. Specific RF guidelines have been developed, but it is unclear how RF behaviours can be monitored systematically. Therefore, developing valid and reliable abbreviated and pragmatic RF scales is an important global priority. This is challenging, as RF is a construct with multiple dimensions including recognizing and responding to hunger and satiety cues, providing a nurturing environment during feeding episodes, and understanding how feeding needs evolve as a function of the developmental stage of the young child. Further, RF is embedded within the responsive parenting framework that in addition to RF includes sleep, soothing and play routines and the interconnections between them. A recent pioneer study conducted in a rural area of Cambodia validated an 8‐item RF scale through direct feeding observations of 6‐ to 23‐month‐old infants at home, as part of two cross‐sectional surveys conducted before and after a complementary feeding intervention. It is important for similar research to be conducted elsewhere to find out if it is possible or not to develop a core RF scale that is valid and reliable and that has adequate specificity and sensitivity for application in community studies and population surveys globally. As highlighted in this article, different definitions of RF have been used in the field; thus, it is important to reach consensus on a single definition to help move this research area forward.  相似文献   
97.
ObjectivesTo explore the relationships among potentially modifiable factors related to childbirth and effective breastfeeding initiation at approximately 36 hours after birth and duration and exclusivity at hospital discharge, 2 weeks, 2 months, and 6 months after birth in primiparous women and to explore whether modifiable and nonmodifiable secondary factors and covariates influenced the relationships among factors related to childbirth and these breastfeeding outcomes.DesignA prospective, longitudinal, cohort study.SettingThe postpartum units of two general hospitals in eastern Canada.ParticipantsNinety-seven mother–infant dyads.MethodsWe recorded demographic, childbirth, obstetric history, and breastfeeding data through chart review. A breastfeeding observation was completed at approximately 36 hours after birth by unit nurses. Participants maintained breastfeeding logs in hospital and for 6 months after birth and completed three self-report questionnaires before discharge. We analyzed outcomes using backward stepwise linear and logistic regression.ResultsOne childbirth factor, labor induced with oxytocin, was negatively associated with effective initiation of breastfeeding, and none was related to breastfeeding duration and exclusivity at any time point. Maternal weight; professional support; and newborn’s gestational age at birth, 5-minute Apgar score, weight loss, LATCH score, and active feeds (newborn actively suckled at the breast) were significantly associated with breastfeeding outcomes.ConclusionInduction of labor with oxytocin should be used judiciously; when used, nurses must be hypervigilant to assess the mother–infant dyad for breastfeeding issues and to intervene to prevent or remediate them.  相似文献   
98.
99.
Progesterone is the main hormone in the luteal phase. It plays a key role in preparing the uterus for a possible pregnancy, and in maintaining it after it has occurred. In assisted reproduction treatments, there is usually a luteal phase deficiency, so it is necessary to supplement this critical phase to obtain the best results, not only of implantation but also of ongoing pregnancy. Among all the available options, exogenously administered progestogens are the most used, as they have proven their efficacy and safety. This review will address the most relevant aspects of luteal phase support with progesterone in the different scenarios an embryo transfer can be performed, such as the stimulated cycle, the artificial cycle, or the natural cycle. Although there is no evidence of the perfect protocol for all patients, recent studies point to the need of individualizing luteal phase support according to the needs of each patient.  相似文献   
100.
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