全文获取类型
收费全文 | 1743篇 |
免费 | 320篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 58篇 |
妇产科学 | 281篇 |
基础医学 | 77篇 |
口腔科学 | 27篇 |
临床医学 | 846篇 |
内科学 | 168篇 |
皮肤病学 | 52篇 |
神经病学 | 14篇 |
特种医学 | 236篇 |
外科学 | 48篇 |
综合类 | 56篇 |
预防医学 | 87篇 |
眼科学 | 5篇 |
药学 | 44篇 |
肿瘤学 | 70篇 |
出版年
2024年 | 4篇 |
2023年 | 43篇 |
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 34篇 |
2019年 | 18篇 |
2018年 | 57篇 |
2017年 | 90篇 |
2016年 | 77篇 |
2015年 | 98篇 |
2014年 | 101篇 |
2013年 | 97篇 |
2012年 | 36篇 |
2011年 | 58篇 |
2010年 | 101篇 |
2009年 | 99篇 |
2008年 | 43篇 |
2007年 | 45篇 |
2006年 | 37篇 |
2005年 | 22篇 |
2004年 | 17篇 |
2003年 | 35篇 |
2002年 | 22篇 |
2001年 | 36篇 |
2000年 | 10篇 |
1999年 | 47篇 |
1998年 | 93篇 |
1997年 | 109篇 |
1996年 | 105篇 |
1995年 | 93篇 |
1994年 | 63篇 |
1993年 | 48篇 |
1992年 | 21篇 |
1991年 | 23篇 |
1990年 | 9篇 |
1989年 | 32篇 |
1988年 | 31篇 |
1987年 | 18篇 |
1986年 | 26篇 |
1985年 | 29篇 |
1984年 | 13篇 |
1983年 | 13篇 |
1982年 | 18篇 |
1981年 | 12篇 |
1980年 | 15篇 |
1979年 | 4篇 |
1978年 | 16篇 |
1977年 | 15篇 |
1976年 | 13篇 |
1975年 | 13篇 |
排序方式: 共有2071条查询结果,搜索用时 15 毫秒
61.
Virginia Schmied PhD MA RM Sarah Beake MA RM RN Athena Sheehan PhD MN RM Christine McCourt PhD BA Fiona Dykes PhD MA RM 《分娩》2011,38(1):49-60
Abstract: Background: Both peer and professional support have been identified as important to the success of breastfeeding. The aim of this metasynthesis was to examine women’s perceptions and experiences of breastfeeding support, either professional or peer, to illuminate the components of support that they deemed “supportive.” Methods: The metasynthesis included studies of both formal or “created” peer and professional support for breastfeeding women but excluded studies of family or informal support. Qualitative studies were included as well as large‐scale surveys if they reported the analysis of qualitative data gathered through open‐ended responses. Primiparas and multiparas who initiated breastfeeding were included. Studies published in English, in peer‐reviewed journals, and undertaken between January 1990 and December 2007 were included. After assessment for relevance and quality, 31 studies were included. Meta‐ethnographic methods were used to identify categories and themes. Results: The metasynthesis resulted in four categories comprising 20 themes. The synthesis indicated that support for breastfeeding occurred along a continuum from authentic presence at one end, perceived as effective support, to disconnected encounters at the other, perceived as ineffective or even discouraging and counterproductive. A facilitative approach versus a reductionist approach was identified as contrasting styles of support that women experienced as helpful or unhelpful. Conclusions: The findings emphasize the importance of person‐centered communication skills and of relationships in supporting a woman to breastfeed. Organizational systems and services that facilitate continuity of caregiver, for example continuity of midwifery care or peer support models, are more likely to facilitate an authentic presence, involving supportive care and a trusting relationship with professionals. (BIRTH 38:1 March 2011) 相似文献
62.
Marie Tarrant RN MPH PhD Kendra M. Wu BSc MSc MMedSc Daniel Y. T. Fong PhD Irene L. Y. Lee RN RM MHA MPHC Emmy M. Y. Wong RN MN PhD Alice Sham RN RM MSc MBA Christine Lam RN RM MMW IBCLC Joan E. Dodgson RN MPH PhD 《分娩》2011,38(3):238-245
Abstract: Background: The World Health Organization (WHO) developed the Baby‐Friendly Hospital Initiative to improve hospital maternity care practices that support breastfeeding. In Hong Kong, although no hospitals have yet received the Baby‐Friendly status, efforts have been made to improve breastfeeding support. The aim of this study was to examine the impact of Baby‐Friendly hospital practices on breastfeeding duration. Methods: A sample of 1,242 breastfeeding mother‐infant pairs was recruited from four public hospitals in Hong Kong and followed up prospectively for up to 12 months. The primary outcome variable was defined as breastfeeding for 8 weeks or less. Predictor variables included six Baby‐Friendly practices: breastfeeding initiation within 1 hour of birth, exclusive breastfeeding while in hospital, rooming‐in, breastfeeding on demand, no pacifiers or artificial nipples, and information on breastfeeding support groups provided on discharge. Results: Only 46.6 percent of women breastfed for more than 8 weeks, and only 4.8 percent of mothers experienced all six Baby‐Friendly practices. After controlling for all other Baby‐Friendly practices and possible confounding variables, exclusive breastfeeding while in hospital was protective against early breastfeeding cessation (OR: 0.61; 95% CI: 0.42–0.88). Compared with mothers who experienced all six Baby‐Friendly practices, those who experienced one or fewer Baby‐Friendly practices were almost three times more likely to discontinue breastfeeding (OR: 3.13; 95% CI: 1.41–6.95). Conclusions: Greater exposure to Baby‐Friendly practices would substantially increase new mothers’ chances of breastfeeding beyond 8 weeks postpartum. To further improve maternity care practices in hospitals, institutional and administrative support are required to ensure all mothers receive adequate breastfeeding support in accordance with WHO guidelines. (BIRTH 38:3 September 2011) 相似文献
63.
Catherine Angell RM BSc PhD Jo Alexander RM MTD PhD Jane A. Hunt RGN RSCN PhD 《分娩》2011,38(4):346-353
Abstract: Background: Breastfeeding is the optimal feeding method for human infants. In the United Kingdom some women do not initiate breastfeeding, and many commence formula milk feeding after a brief period of breastfeeding. Infant feeding perceptions may develop early in life, and this research aimed to explore infant feeding awareness among primary school children as a first step toward informing appropriate health education interventions. Method: Fifty‐six children aged 5/6, 7/8, and 10/11 years were recruited from three schools in southern England. Children were shown a series of drawings, and were read a story about a hungry newborn baby. A creative method, “draw, write and tell,” was developed for this research. Children were asked to finish the story, showing how they thought the baby might be fed. They were given the opportunity to verbally interpret their work. A constant comparison method was used to analyze the data. Results: Children were aware of formula milk, breastfeeding, and solid foods. Formula milk feeding was referred to more frequently than breastfeeding. Some children combined feeding methods. Children appeared to have gained their awareness in various settings. Conclusions: Children have a range of perceptions around infant feeding. They appear receptive to new ideas on the subject while of primary school age. An opportunity for education in primary schools arises to present breastfeeding to children as a normal way to feed a baby, but it is vital that education is evidence based and any interventions are evaluated. (BIRTH 38:4 December 2011) 相似文献
64.
Carol Bedwell LLB RM Research Midwife Therese Dowswell PhD Research Fellow James P. Neilson MD FRCOG Professor of Obstetrics Gynaecology Tina Lavender PhD RM Professor of Midwifery 《Midwifery》2011,27(5):e141
Objective
to assess the effects of transcutaneous electrical nerve stimulation (TENS) for pain relief in labour.Search methods
studies were identified from a search of the Cochrane Pregnancy and Childbirth Group’s Trials Register (November 2008).Selection criteria
randomised controlled trials comparing women receiving TENS for pain relief in labour vs routine care or placebo devices. All types of TENS machines were included.Data collection and analysis
two review authors assessed all trials identified by the search strategy, carried out data extraction and assessed risk of bias.Results
14 studies including 1256 women were included: 11 examined TENS applied to the back, two to acupuncture points and one to the cranium. Overall, there was little difference in satisfaction with pain relief or in pain ratings between TENS and control groups, although women receiving TENS to acupuncture points were less likely to report severe pain (risk ratio 0.41, 95% confidence interval 0.32–0.55). The majority of women using TENS would use it again in a future labour. There was no evidence that TENS had any impact on interventions and outcomes in labour. There was little information on outcomes for mothers and infants. No adverse events were reported.Conclusions
there is only limited evidence that TENS reduces pain in labour and it does not seem to have any impact on other outcomes for mothers or infants. The use of TENS at home in early labour has not been evaluated. Although the guidelines of the National Institute for Health and Clinical Excellence recommend that TENS should not be offered to women in labour, women appear to be choosing it and midwives are supporting them in their choice. Given the absence of adverse effects and the limited evidence base, it seems unreasonable to deny women that choice. More robust studies of effectiveness are needed. 相似文献65.
Della A. Forster Dip.App.Sci. BHealth.Sci. MMid PhD Senior Research Fellow Midwifery Consultant Kerri McEgan RN RM Unit Manager Rachael Ford BNurs Clinical Midwife Research Scholarship Fellow Anita Moorhead RN RM Clinical Midwifery Consultant Gillian Opie MBBS Neonatal Paediatrician Susan Walker MBBS MD Associate Professor Director of Perinatal Medicine Cath McNamara BA Grad Cert Diab Ed Diabetic Educator 《Midwifery》2011,27(2):209-214
Objective
infants of women with diabetes in pregnancy are at increased risk of hypoglycaemia. If the infant's blood glucose is low and the mother is unable to breast feed/provide sufficient expressed breast milk, infants are often given formula. Some hospitals encourage women with diabetes to express breast milk before birth. However, there is limited evidence for this practice, including its impact on labour and birth, e.g. causing premature birth may be a concern. A pilot study was undertaken to establish the feasibility of conducting an adequately powered randomised controlled trial to evaluate this practice.Design
consecutive eligible women with pre-existing or gestational diabetes (requiring insulin), planning to breast feed and attending the study hospital were offered participation. Inclusion criteria: 34-36 weeks of gestation; singleton pregnancy; cephalic presentation; and able to speak, read and write in English. Exclusion criteria: history of spontaneous preterm birth, antepartum haemorrhage, placenta praevia and suspected fetal compromise. Women were encouraged to express colostrum twice a day from 36 weeks of gestation, and advised how to store the colostrum, which was frozen for their infant's use after birth. They were asked to keep a diary documenting their expressing. Data: demographic questionnaire, telephone interview at six and 12 weeks postpartum and medical record data.Setting
a public, tertiary, women's hospital in Melbourne, Australia.Participants
43 women with diabetes in pregnancy (requiring insulin).Findings
cardiotocographs were undertaken after the first expressing episode and none of the infants showed any sign of fetal compromise. Forty per cent of infants received formula in the 24 hours postpartum. The proportion of infants receiving any breast milk at six weeks was 90%, and this decreased to 75% at 12 weeks. No women showed evidence of hypoglycaemia post expressing. The intervention was positively received by most women; 95% said that they would express antenatally again if the practice proved to be beneficial. The amount of colostrum varied according to the number of expressions, the length of time in the study and the time spent expressing, with a median of 14 days expressing and 39.6 ml of colostrum obtained.Key conclusions
the small number of women in this pilot was not an adequate number to examine safety or efficacy, but this study does provide evidence that it would be feasible and desirable to conduct a randomised controlled trial of antenatal milk expressing for women with diabetes requiring insulin in pregnancy.Implications for practice
it is important that this widespread practice undergoes rigorous evaluation to assess both efficacy and safety. Until such evidence is available, the authors suggest that the routine encouragement of antenatal milk expressing in women with diabetes in pregnancy should cease. 相似文献66.
Devendra Kumar Pandey Tabarak Malik Abhijit Dey Joginder Singh RM Banik 《African journal of traditional, complementary, and alternative medicines》2014,11(2):439-446
Background
Gloriosa superba produces an array of alkaloids including colchicine, a compound of interest in the treatment of various diseases. The tuber of Gloriosa superba is a rich source of colchicine which has shown anti-gout, anti-inflammatory, and anti-tumor activity. However, this promising compound remains expensive and Gloriosa superba is such a good source in global scale. Increase in yield of naturally occurring colchicine is an important area of investigation.Materials and Methods
The effects of inoculation by four arbuscular mycorrhizal (AM), fungi, Glomus mossae, Glomus fasciculatum, Gigaspora margarita and Gigaspora gilmorei either alone or supplemented with P-fertilizer, on colchicine concentration in Gloriosa superba were studied. The concentration of colchicine was determined by high-performance thin layer chromatography.Results
The four fungi significantly increased concentration of colchicine in the herb. Although there was significant increase in concentration of colchicine in non-mycorrhizal P-fertilized plants as compared to control, the extent of the increase was less compared to mycorrhizal plants grown with or without P-fertilization. This suggests that the increase in colchicine concentration may not be entirely attributed to enhanced P-nutrition and improved growth. Among the four AM fungi Glomus mossae was found to be best. The total colchicine content of plant (mg / plant) was significantly high in plants inoculated with Glomus mossae and 25 mg kg−1phosphorus fertilizer (348.9 mg /plant) while the control contain least colchicine (177.87 mg / plant).Conclusion
The study suggests a potential role of AM fungi in improving the concentration of colchicine in Gloriosa superba tuber. 相似文献67.
JD Roberts JC Herkert J Rutberg SM Nikkel ACP Wiesfeld D Dooijes RM Gow JP van Tintelen MH Gollob 《Clinical genetics》2013,83(5):452-456
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease that predominantly affects the right ventricle and is associated with ventricular arrhythmias that may lead to sudden cardiac death. Mutations within at least seven separate genes have been identified to cause ARVC, however a genetic culprit remains elusive in approximately 50% of cases. Although negative genetic testing may be secondary to pathogenic mutations within undiscovered genes, an alternative explanation may be the presence of large deletions or duplications involving known genes. These large copy number variants may not be detected with standard clinical genetic testing which is presently limited to direct DNA sequencing. We describe two cases of ARVC possessing large deletions involving plakophilin‐2 (PKP2) identified with microarray analysis and/or multiplex ligation‐dependent probe amplification (MLPA) that would have been classified as genotype negative with standard clinical genetic testing. A deletion of the entire coding region of PKP2 excluding exon 1 was identified in patient 1 and his son. In patient 2, MLPA analysis of PKP2 revealed deletion of the entire gene with subsequent microarray analysis demonstrating a de novo 7.9 Mb deletion of chromosome 12p12.1p11.1. These findings support screening for large copy number variants in clinically suspected ARVC cases without clear disease causing mutations following initial sequencing analysis. 相似文献
68.
Follicular density in ovarian biopsy of infertile women: a novel method to assess ovarian reserve 总被引:4,自引:15,他引:4
Lass A; Silye R; Abrams DC; Krausz T; Hovatta O; Margara R; Winston RM 《Human reproduction (Oxford, England)》1997,12(5):1028-1031
The ageing ovary appears to be characterized by depletion of primordial
follicles. The relationship between infertility and the number of follicles
in the ovarian cortex is not known. Moreover, there are no accurate markers
or clinical methods to predict the decline in ovarian reserve. This study
investigates the correlation between early follicular follicle stimulating
hormone, ovarian size and follicular density in 60 infertile women aged
19-45 years (mean = 34.4 +/- 5.5). An ovarian biopsy was taken from each
patient while performing diagnostic laparoscopy (n = 28) or laparotomy for
tubal surgery or myomectomy (n = 32). The median number of follicles was
similar in tubal and unexplained infertility patients (9.5 versus 5.5).
Increasing age showed a significant negative correlation with follicular
density and ovarian volume (r = -0.46, P = 0.0003;. r = -0.43, P = 0.0016,
respectively). In women > or = 35 years of age the ovarian volume showed
a strong correlation with follicular density (r = 0.71, P < 0.0001). Our
results indicate that infertile women in their late thirties and over have
a decreased ovarian reserve which could possibly be predicted by ovarian
volume measurement. Ovarian biopsy may have a place as part of infertility
evaluation in older women.
相似文献
69.
Objective
to review the literature around what is considered to be a good midwife and in particular what women value in a midwife, in order to identify the gaps in the evidence for future research.Design
this paper reviews the research in the area of interest over the past 30 years. The literature search focused on the concept of good midwife using synonyms and antonyms. The inclusion criteria included language (English or Italian). The examined databases were Medline, Maternity and Infant Care, Applied Social Sciences Index and Abstract and CINAHL.Setting
studies conducted in high-income countries were taken into account. A focused review of papers which explicitly investigated what a good midwife means and a thematic analysis on what women value in a midwife were carried out.Participants
different standpoints have been considered (midwives, student midwives, women and their partners), focusing in particular on women viewpoint.Findings
the literature review reveals information about what is considered to be a good midwife from a range of perspectives and what women value in a midwife. A good midwife should possess several attributes: theoretical knowledge, professional competencies, personal qualities, communication skills and moral/ethical values. According to the thematic analysis around what childbearing women value in a midwife, frequent key-themes emerging from the literature were: support, possibility of choice, feeling in control and having appropriate information.Key conclusions
the meaning of good midwife might change according to different actors involved in midwifery care and there is no agreement on the definition of what constitutes a good midwife. Furthermore, it is not clear if what women value in a good midwife corresponds to the midwives' perception of themselves as good professionals. There is a dearth of information around women's expectations and experiences specifically of a good midwife, and even less around whether this changes according to where they give birth.Implications for practice
this literature review seeks to stimulate debate and reflection among midwives and professionals involved in the childbearing event, in order to fulfil women's expectations of their midwife and increase their satisfaction with the birth experience. The identification of the gaps in the evidence provided the starting point and allowed the development of research questions and methodology for an ongoing doctoral research. On the basis of the gaps in the evidence, the doctoral research will explore and seek to explain nulliparous women's expectations and experiences of a good midwife in the context of different planned place of birth, using a Grounded Theory methodology. It is also expected that the findings of this literature review will stimulate additional research in this area to ultimately inform midwifery practice and midwifery educational programmes. 相似文献70.