全文获取类型
收费全文 | 3699篇 |
免费 | 262篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 1084篇 |
妇产科学 | 142篇 |
基础医学 | 526篇 |
口腔科学 | 62篇 |
临床医学 | 195篇 |
内科学 | 180篇 |
皮肤病学 | 21篇 |
神经病学 | 42篇 |
特种医学 | 58篇 |
外科学 | 109篇 |
综合类 | 232篇 |
预防医学 | 926篇 |
眼科学 | 4篇 |
药学 | 302篇 |
3篇 | |
中国医学 | 61篇 |
肿瘤学 | 46篇 |
出版年
2023年 | 44篇 |
2022年 | 73篇 |
2021年 | 231篇 |
2020年 | 148篇 |
2019年 | 131篇 |
2018年 | 128篇 |
2017年 | 129篇 |
2016年 | 142篇 |
2015年 | 142篇 |
2014年 | 201篇 |
2013年 | 267篇 |
2012年 | 121篇 |
2011年 | 140篇 |
2010年 | 143篇 |
2009年 | 128篇 |
2008年 | 119篇 |
2007年 | 130篇 |
2006年 | 107篇 |
2005年 | 108篇 |
2004年 | 111篇 |
2003年 | 89篇 |
2002年 | 82篇 |
2001年 | 63篇 |
2000年 | 62篇 |
1999年 | 63篇 |
1998年 | 46篇 |
1997年 | 54篇 |
1996年 | 55篇 |
1995年 | 47篇 |
1994年 | 71篇 |
1993年 | 43篇 |
1992年 | 43篇 |
1991年 | 34篇 |
1990年 | 35篇 |
1989年 | 36篇 |
1988年 | 39篇 |
1987年 | 38篇 |
1986年 | 44篇 |
1985年 | 34篇 |
1984年 | 44篇 |
1983年 | 39篇 |
1982年 | 58篇 |
1981年 | 33篇 |
1980年 | 20篇 |
1979年 | 23篇 |
1978年 | 17篇 |
1977年 | 12篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1973年 | 4篇 |
排序方式: 共有3994条查询结果,搜索用时 31 毫秒
1.
2.
“母乳最好”的宣传话语在目前育龄人群中几乎耳熟能详,但很多信奉科学育儿、希望母乳喂养的都市女性却发现母乳喂养困难重重,其中遭遇“母乳不足”的案例较为多见。回顾历史发现,“母乳不足”的现象全球普遍存在,这个话题在20世纪80年代的英语学术圈曾引起热议。经过十余年讨论后,学者们基本认同大部分遭遇母乳不足的女性并不是真正的“母乳不足”,而是由于种种社会文化因素干扰造成母乳喂养失败的这一结论,其中产后初期的奶瓶介入是重要原因。术语也由insufficient milk syndrome变为perceived insufficient milk,以此来强调“母乳不足”不是一种病理现象,而更多是一种文化感知。 相似文献
3.
4.
本文旨在探讨影响新疆低温乳消费市场的限制性因素及相应的对策。调研通过网络调查问卷和实地调研走访相结合的方式,从乳制品消费结构、消费能力,低温奶认知、低温奶购买意愿、购买便利性、购买偏好及健康饮奶习惯等方面分析影响新疆低温乳消费市场的因素。结果显示:32.93%的消费者不了解乳中生物活性物质(如乳铁蛋白)的热敏性,39.97%的消费者不能区分各类液态乳产品,47.64%的消费者有煮沸巴氏杀菌乳后饮用的习惯;43.21%的消费者"担心未消毒彻底,存在细菌",36.30%的消费者认为"加热后可增加营养价值和香味";72.64%的消费者曾感到"购买巴氏杀菌乳不方便";54.85%的消费者认为本地品牌"更新鲜、更健康"。结果启示:本地乳企应该充分利用在当地的良好品牌信誉度和牧场资源,尽早布局低温奶市场,通过研发高品质低温乳制品、普及科学饮奶理念、改善冷链物流能力、完善购物体验和精细化服务能力等手段,提高生产竞争力,抵御进口乳制品和常温乳对当地乳品市场的冲击,占领区域低温奶消费市场。 相似文献
5.
Background/purpose
Necrotizing enterocolitis (NEC) is a devastating disease of prematurity that develops after feeding, often without warning, and results in diffuse intestinal necrosis leading to sepsis and death in many cases. The lack of improvement in overall survival is influenced by nonspecific diagnostic modalities as well as inexact and nonpersonalized treatment strategies.Methods/Results
Recently, we and others have shown that NEC develops in response to exaggerated bacterial signaling in the premature intestine, as a consequence of elevated expression and activity of the bacterial receptor toll-like receptor 4 (TLR4), which is important for normal gut development. Breast milk is a powerful TLR4 inhibitor, while mutations in TLR4 genes lead to increased NEC risk in humans, providing proof-of-concept for its role in NEC. Recently, a drug discovery approach has revealed a novel class of TLR4 inhibitors which are being developed for personalized approaches to NEC treatment.Conclusion
This review will highlight the current understanding of the role of bacterial signaling in NEC pathogenesis, and will describe advances in diagnosis, prevention and treatment of NEC that may hopefully improve survival for these most fragile patients.Systematic Review
Level of Evidence: Level II. 相似文献6.
Cindy H.T. Yeung Simon Fong Paul R.V. Malik Andrea N. Edginton 《Maternal & child nutrition》2020,16(2)
Despite the many benefits of breast milk, mothers taking medication are often uncertain about the risks of drug exposure to their infants and decide not to breastfeed. Physiologically based pharmacokinetic models can contribute to drug‐in‐milk safety assessments by predicting the infant exposure and subsequently, risk for toxic effects that would result from continuous breastfeeding. This review aimed to quantify breast milk intake feeding parameters in term and preterm infants using literature data for input into paediatric physiologically based pharmacokinetic models designed for drug‐in‐milk risk assessment. Ovid MEDLINE and Embase were searched up to July 2, 2019. Key study reference lists and grey literature were reviewed. Title, abstract and full text were screened in nonduplicate. Daily weight‐normalized human milk intake (WHMI) and feeding frequency by age were extracted. The review process retrieved 52 studies. A nonlinear regression equation was constructed to describe the WHMI of exclusively breastfed term infants from birth to 1 year of age. In all cases, preterm infants fed with similar feeding parameters to term infants on a weight‐normalized basis. Maximum WHMI was 152.6 ml/kg/day at 19.7 days, and weighted mean feeding frequency was 7.7 feeds/day. Existing methods for approximating breast milk intake were refined by using a comprehensive set of literature data to describe WHMI and feeding frequency. Milk feeding parameters were quantified for preterm infants, a vulnerable population at risk for high drug exposure and toxic effects. A high‐risk period of exposure at 2–4 weeks of age was identified and can inform future drug‐in‐milk risk assessments. 相似文献
7.
Kimberly A. Lackey Ryan M. Pace Janet E. Williams Lars Bode Sharon M. Donovan Kirsi M. Jrvinen Antti E. Seppo Daniel J. Raiten Courtney L. Meehan Mark A. McGuire Michelle K. McGuire 《Maternal & child nutrition》2020,16(4)
The novel coronavirus SARS‐CoV‐2 has emerged as one of the most compelling and concerning public health challenges of our time. To address the myriad issues generated by this pandemic, an interdisciplinary breadth of research, clinical and public health communities has rapidly engaged to collectively find answers and solutions. One area of active inquiry is understanding the mode(s) of SARS‐CoV‐2 transmission. Although respiratory droplets are a known mechanism of transmission, other mechanisms are likely. Of particular importance to global health is the possibility of vertical transmission from infected mothers to infants through breastfeeding or consumption of human milk. However, there is limited published literature related to vertical transmission of any human coronaviruses (including SARS‐CoV‐2) via human milk and/or breastfeeding. Results of the literature search reported here (finalized on 17 April 2020) revealed a single study providing some evidence of vertical transmission of human coronavirus 229E; a single study evaluating presence of SARS‐CoV in human milk (it was negative); and no published data on MERS‐CoV and human milk. We identified 13 studies reporting human milk tested for SARS‐CoV‐2; one study (a non‐peer‐reviewed preprint) detected the virus in one milk sample, and another study detected SARS‐CoV‐2 specific IgG in milk. Importantly, none of the studies on coronaviruses and human milk report validation of their collection and analytical methods for use in human milk. These reports are evaluated here, and their implications related to the possibility of vertical transmission of coronaviruses (in particular, SARS‐CoV‐2) during breastfeeding are discussed. 相似文献
8.
Erna Petersen Birna Thorisdottir Inga Thorsdottir Geir Gunnlaugsson Petra Arohonka Iris Erlund Ingibjrg Gunnarsdottir 《Maternal & child nutrition》2020,16(3)
Iodine is an essential nutrient for growth and development during infancy. Data on iodine status of exclusively (EBF) and partially breastfed (PBF) infants as well as breast milk iodine concentration (BMIC) are scarce. We aimed to assess (a) infant iodine nutrition at the age of 5.5 months by measuring urinary iodine concentration (UIC) in EBF (n = 32) and PBF (n = 28) infants and (b) mothers' breast milk iodine concentration (n = 57). Sixty mother–infant pairs from three primary health care centres in Reykjavik and vicinities provided urine and breast milk samples for iodine analysis and information on mothers' habitual diet. The mother–infant pairs were participants of the IceAge2 study, which focuses on factors contributing to infant growth and development, including body composition and breast‐milk energy content. The median (25th–75th percentiles) UIC was 152 (79–239) μg/L, with no significant difference between EBF and PBF infants. The estimated median iodine intake ranged from 52 to 86 μg/day, based on urinary data (assuming an average urine volume of 300–500 ml/day and UIC from the present study). The median (25th–75th percentiles) BMIC was 84 (48–114) μg/L. It is difficult to conclude whether iodine status is adequate in the present study, as no ranges for median UIC reflecting optimal iodine nutrition exist for infants. However, the results add important information to the relatively sparse literature on UIC, BMIC, and iodine intake of breastfed infants. 相似文献
9.
张玲 《中国中医药现代远程教育》2020,(1):131-133
目的探析对剖宫产产妇采取中西医结合护理的效果。方法本次研究72例剖宫产产妇均为本院2018年3月-2018年11月接收,随机分为2组,对照组(n=36)行常规护理,研究组(n=36)开展中西医结合护理,统计各组护理效果。结果在初乳泌乳始动优良率、母乳喂养、乳汁分泌充足及乳房胀痛发生率方面,研究组均优于对照组,差异有统计学意义(P<0.05)。结论中西医结合护理在剖宫产产妇护理中效果突出,有助于改善产妇术后的乳汁分泌情况,值得推广。 相似文献
10.
目的评价牛奶相关症状评分(CoMiSS)在早期识别婴儿牛奶蛋白过敏(CMPA)中的作用。方法 2016年6月至2017年5月对6家儿科门诊疑似CMPA的210例婴儿进行CoMiSS评分,通过开放性食物激发试验(OFC)明确或排除CMPA诊断。同期选取96例健康体检婴儿为对照组。通过ROC曲线评估CoMiSS识别CMPA的灵敏度和特异度,评价其在早期识别婴儿CMPA中的作用。结果 210例疑似CMPA婴儿中,男114例、女96例,中位年龄4.5个月(1~12个月);其中82例确诊CMPA,中位CoMiSS为7.0分(6.0~8.3分);128例非CMPA婴儿的中位CoMiSS为4.0分(3.0~5.0分)。96例对照组中,男42例、女54例,中位年龄4.1个月(1~12个月);中位CoMiSS为 3.0分(2.0~4.0分)。三组间CoMiSS差异有统计学意义(H=152.58,P0.01)。CoMiSS的ROC曲线下面积(AUC)为0.90,最佳诊断界值为5.5,灵敏度为87.8%,特异度为78.1%。结论 CoMiSS评分临床可操作性强,适合儿科推广。建议以CoMiSS≥6分作为早期识别CMPA标准。 相似文献