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   618篇
  免费   22篇
  国内免费   6篇
儿科学   31篇
妇产科学   45篇
基础医学   77篇
口腔科学   3篇
临床医学   52篇
内科学   53篇
皮肤病学   6篇
神经病学   63篇
特种医学   5篇
外科学   56篇
综合类   49篇
预防医学   83篇
药学   93篇
中国医学   19篇
肿瘤学   11篇
  2023年   13篇
  2022年   22篇
  2021年   18篇
  2020年   20篇
  2019年   14篇
  2018年   15篇
  2017年   19篇
  2016年   15篇
  2015年   18篇
  2014年   21篇
  2013年   31篇
  2012年   29篇
  2011年   32篇
  2010年   25篇
  2009年   32篇
  2008年   30篇
  2007年   26篇
  2006年   19篇
  2005年   16篇
  2004年   14篇
  2003年   16篇
  2002年   20篇
  2001年   14篇
  2000年   9篇
  1999年   12篇
  1998年   7篇
  1997年   11篇
  1996年   12篇
  1995年   5篇
  1994年   6篇
  1993年   7篇
  1992年   3篇
  1991年   5篇
  1990年   3篇
  1989年   4篇
  1988年   5篇
  1987年   3篇
  1986年   8篇
  1985年   7篇
  1984年   9篇
  1983年   6篇
  1982年   10篇
  1981年   11篇
  1980年   10篇
  1976年   4篇
  1975年   3篇
  1974年   1篇
  1973年   1篇
  1971年   1篇
  1969年   1篇
排序方式: 共有646条查询结果,搜索用时 0 毫秒
61.
Objective To describe the association between breastfeeding and ovarian cancer risk in two prospective cohorts. Materials & methods We pooled data from the Nurses’ Health Study and Nurses’ Health Study II. There were 391 cases of epithelial ovarian cancer diagnosed among 149,693 parous women with up to 16 years of follow-up. Data were analyzed using multivariate Cox proportional hazards models, controlling for age, parity, duration of oral contraceptive use, tubal ligation, and age at menarche. Results Ever breastfeeding was associated with a non-significant reduction in ovarian cancer risk compared with never breastfeeding (RR = 0.86, 95% CI 0.70–1.06); the median duration of breastfeeding among women who breastfed was nine months. Breastfeeding of 18 or more months was associated with a significant decrease in ovarian cancer risk compared to never breastfeeding (RR = 0.66, 95% CI 0.46–0.96). For each month of breastfeeding the relative risk decreased by 2% (RR = 0.98 per month, 95% CI 0.97–1.00). Conclusions These data support a linear inverse association between breastfeeding and risk of epithelial ovarian cancer.  相似文献   
62.
Rates of breastfeeding initiation in hospitals with a tertiary neonatal intensive care unit are limited. A follow-up study with prospectively collected data in a Danish university hospital with approximately 5000 annual births was conducted. Between 1 February 2015 and 30 June 2015, 1939 newborns were enrolled in the study. Rates of frequencies for initiation of breastfeeding were calculated. High initiations rates for breastfeeding were found among term-born infants. Newborns of multiparous women had the highest initiation rate of 91.7% and newborns delivered by cesarean section had the lowest initiation rate of 73.3%.  相似文献   
63.
Several preclinical and clinical studies have shown that prenatal stress alters neuronal dendritic development in the prefrontal cortex, together with behavioral disturbances (anxiety). Nevertheless, neither whether these alterations are present during the lactation period, nor whether such findings may reflect the onset of anxiety disorders observed in childhood and adulthood has been studied. The central aim of the present study was to determine the effects of prenatal stress on the neuronal development and behavior of mice offspring during lactation (postnatal days 14 and 21). We studied 24 CF-1 male mice, grouped as follows: (i) control P14 (n = 6), (ii) stressed P14 (n = 6), (iii) control P21 (n = 6) and (iv) stressed P21 (n = 6). On the corresponding days, animals were evaluated with the open field test and sacrificed. Their brains were then stained in Golgi-Cox solution for 30 days. The morphological analysis dealt with the study of 96 pyramidal neurons. The results showed, first, that prenatal stress resulted in a significant (i) decrease in the apical dendritic length of pyramidal neurons in the orbitofrontal cortex at postnatal day 14, (ii) increase in the apical dendritic length of pyramidal neurons in the orbitofrontal cortex at postnatal day 21, and (iii) reduction in exploratory behavior at postnatal day 14 and 21.  相似文献   
64.
65.
The present study was undertaken to evaluate the potential risks of the mucolytic and broncholytic drug, Theophylline derivatives (Mucophylline) maternally administered on the pups. The nursing rats orally administered from 1st postpartum day (PPD) to 21th PPD with two different doses 30.83 mg/kg (low dose) and 66.61 mg/kg (Human equivalent dose (HED)). On the 21th PPD, the postnatal developmental signs, skeletal malformation and the histopathology of neonatal liver, kidney and brain were examined. Our results showed that Mucophylline induced a significant reduction in the neonatal weight and length, delayed, weak and incomplete ossification, wavy ribs and the neonatal liver revealed histopathological changes, pyknotic hepatocytes, cytoplasmic vacuolization, dilated sinusoid and necrotic area. Kidney revealed alternation changes, enlargement of the glomerulus, renal tubules degeneration and lymphatic infiltration. Brain (cerebral cortex and cerebellum) showed neurodegenerative changes, vacuolization of neuropil, congested and dilated blood vessel and dark stain neurons. Our results showed that the activities of non-enzymatic (GSH) and enzymatic (GST, CAT) antioxidants were insignificantly decrease in both neonatal brain and liver tissues of rats administered with 30.83 mg/kg and 61.66 mg/kg of Mucophylline and insignificant increase in MDA levels in both neonatal brain and liver tissues. However, significant reduction (P  0.05) in the content of GR was recorded in neonatal brain tissue of rats administered with 30.83 mg/kg and 61.66 mg/kg of Mucophylline during lactation period in comparison with control. These support and proof the potential risks of the maternal administration of Mucophylline on pups.  相似文献   
66.
卢莉红  赵爱梅 《护士进修杂志》2010,25(23):2158-2159
目的通过咀嚼口香糖的假吃活动和药膳饮食,促进剖宫产术后产妇胃肠功能的快捷恢复,增进泌乳。方法术后2 h或清醒后开始咀嚼口香糖,服用白萝卜、黄芪、陈皮、瘦肉加水熬成的药膳汤。结果肛门排气时间、乳汁充盈时间缩短,产妇体力恢复、舒适感增加。结论 假吃与药膳可促进剖宫产产妇胃肠功能快速恢复,增进泌乳。  相似文献   
67.
68.
Although lactation mastitis (LM) has been extensively researched, the incidence rate of LM remains a salient clinical problem. To reduce this incidence rate and achieve a better prognosis, early and specific quantitative indicators are particularly important. It has been found that milk electrolyte concentrations (chloride, potassium, and sodium) and electrical conductivity (EC) significantly change in the early stages of LM in an animal model. Several studies have evaluated EC for the detection of subclinical mastitis in cows. EC, chloride, and sodium content of milk were more accurate for predicting infection status than were other variables. In the early stages of LM, lactic sodium, chloride, and EC increase, but potassium decreases. However, these indicators have not been reported in the diagnosis of LM in humans. This review summarizes the pathogenesis and the mechanism of LM in terms of milk electrolyte concentration and EC, and aim to provide new ideas for the detection of sub-clinical mastitis in humans.  相似文献   
69.
70.
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