全文获取类型
收费全文 | 678篇 |
免费 | 51篇 |
国内免费 | 61篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 48篇 |
妇产科学 | 9篇 |
基础医学 | 82篇 |
口腔科学 | 25篇 |
临床医学 | 109篇 |
内科学 | 154篇 |
皮肤病学 | 16篇 |
神经病学 | 17篇 |
特种医学 | 93篇 |
外科学 | 36篇 |
综合类 | 19篇 |
预防医学 | 46篇 |
眼科学 | 4篇 |
药学 | 54篇 |
1篇 | |
中国医学 | 2篇 |
肿瘤学 | 74篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 15篇 |
2020年 | 8篇 |
2019年 | 14篇 |
2018年 | 23篇 |
2017年 | 10篇 |
2016年 | 14篇 |
2015年 | 14篇 |
2014年 | 27篇 |
2013年 | 34篇 |
2012年 | 26篇 |
2011年 | 26篇 |
2010年 | 36篇 |
2009年 | 30篇 |
2008年 | 34篇 |
2007年 | 54篇 |
2006年 | 18篇 |
2005年 | 20篇 |
2004年 | 14篇 |
2003年 | 5篇 |
2002年 | 8篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 16篇 |
1998年 | 34篇 |
1997年 | 37篇 |
1996年 | 23篇 |
1995年 | 22篇 |
1994年 | 29篇 |
1993年 | 20篇 |
1992年 | 5篇 |
1991年 | 10篇 |
1990年 | 3篇 |
1989年 | 18篇 |
1988年 | 18篇 |
1987年 | 11篇 |
1986年 | 4篇 |
1985年 | 11篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1980年 | 8篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1976年 | 11篇 |
1975年 | 5篇 |
1966年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有790条查询结果,搜索用时 50 毫秒
41.
Arianne C Lim Kitty WM Bloemenkamp Kees Boer Johannes J Duvekot Jan Jaap HM Erwich Tom HM Hasaart Pieter Hummel Ben WJ Mol Jos PM Offermans Charlotte M van Oirschot Job G Santema Hubertina CJ Scheepers Willem A Schöls Frank PHA Vandenbussche Maurice GAJ Wouters Hein W Bruinse 《BMC pregnancy and childbirth》2007,7(1):1-6
Background
Adequate vitamin D concentrations during pregnancy are necessary to neonatal calcium homeostasis, bone maturation and mineralization. The aim of study is to evaluate serum vitamin D concentrations in mothers and their newborns and effect of vitamin D deficiency on pregnancy outcomes.Methods
552 pregnant women were recruited from Tehran University educating hospitals in the winter of 2002. Maternal and cord blood samples were taken at delivery. The serum was assayed for 25-hydroxyvitamin D3, calcium, phosphorus and parathyroid hormone.Results
The prevalence of vitamin D deficiency in maternal and cord blood samples were 66.8% and 93.3%, respectively (<35 nmol/l). There was significant correlation between maternal and cord blood serum concentrations of vitamin D. In mothers with vitamin D deficiency, cord blood vitamin D concentrations was lower than those from normal mothers (P = .001). Also, a significant direct correlation was seen between maternal vitamin D intake and weight gain during pregnancy.Conclusion
Consideration to adequate calcium and vitamin D intake during pregnancy is essential. Furthermore, we think it is necessary to reconsider the recommendation for vitamin D supplementation for women during pregnancy. 相似文献42.
Comparative Study of Automotive, Aircraft and Biogenic Emissions of Aldehydes and Aromatic Compounds
C. S. Guimarães D. Custodio R. C. S. de Oliveira L. S. Varandas G. Arbilla 《Bulletin of environmental contamination and toxicology》2010,84(2):180-184
Air samples were collected in three well characterized locations in the city of Rio de Janeiro, Brazil: downtown, the idle and taxi way areas of the national airport and an urban forest, where the main emissions are from vehicular, aircraft and biogenic sources, respectively. Aldehydes and BTEX concentrations show a characteristic profile which may be attributed to the emission sources. Formaldehyde/acetaldehyde ratios, in the early morning, were 1.39, 0.62 and 2.22 in downtown, airport and forest, respectively. Toluene/benzene ratios, for downtown, airport and forest areas, were 1.11, 1.82 and 1.06, respectively. The results show that the impact of the urban emissions on the forest is negligible as well as the impact of aircraft emissions over the urban area. 相似文献
43.
Loyola W Custodio LA Felipe I Conchon-Costa I Carvalho PG Quirino GF Silva LF Gaziri LC 《International immunopharmacology》2012,12(2):378-383
The activities of dectin-1 and mannose receptors on phagocytosis of Candida albicans and the production of TNF-α by macrophages from mice pretreated for 3 days with extract of Artocarpus intergrifolia seeds (jack extract), Artin M or jacalin were studied. Macrophages from these mice were coincubated with C. albicans CR15 (yeast), in the presence of mannose (50mM) plus mannan (100 μg) or laminarin (1mg). Phagocytosis was significantly enhanced to 52% in macrophages from mice pretreated intraperitoneally for 3 days with jack extract (500 μg/250 μl PBS). Reduction in phagocytosis from 52% to 34% (P<0.05) occurred in the presence of mannose receptor inhibitors and from 52% to 16% (P<0.01) in the presence of dectin-1 inhibitor laminarin, whereas only 20% of control macrophages phagocytosed blastoconidia. Similar results were verified for pretreatment of mice with Artin M (2.5 μg/250 μl PBS), but not for jacalin (25 μg/250 μl PBS). Macrophages from mice pretreated 3 days previously with jack extract or Artin M and then coincubated for 2h with C. albicans presented a significant increase in TNF-α production, correlating with significantly less transition of yeast to filamentous forms compared to pretreatment with jacalin. These results suggest that Artin M, but not jacalin present in jack extract significantly increased TNF-α production and the activity of mannose and dectin-1 receptors. 相似文献
44.
Judith HM Helmink Jessie JM Meis Inge de Weerdt Femke N Visser Nanne K de Vries Stef PJ Kremers 《The international journal of behavioral nutrition and physical activity》2010,7(1):49
Background
The number of patients with diabetes is increasing. BeweegKuur (Dutch for 'Exercise Therapy') is a Dutch lifestyle intervention which aims to effectively and feasibly promote physical activity and better dietary behaviour in primary health care to prevent diabetes. 相似文献45.
Emma Howarth Theresa HM Moore Nicky Stanley Harriet L. MacMillan Gene Feder Alison Shaw 《Health & social care in the community》2019,27(2):271-292
Children who grow up in homes affected by domestic violence and abuse (DVA) are at risk of poor outcomes across the lifespan, yet there is limited evidence on the acceptability and effectiveness of interventions for them. A recent review of child‐focused interventions highlighted a gap in understanding the factors influencing the willingness of parents and children to engage with these programmes. We conducted a systematic review of qualitative evidence on the experiences of receiving and delivering interventions with the aim of identifying factors at different levels of the social–ecological context that may influence parent and child readiness to take up interventions. We searched literature till April 2016 and found 12 reports of eight programmes. Two authors independently screened papers for inclusion, extracted data and identified the first‐ and second‐order constructs. The third‐order constructs were derived and fitted to the ecological framework to inform a picture of readiness to engage with interventions. Three key findings emerged from this review: (a) parent and child readiness is influenced by a complex interplay of individual, relationship and organisational factors, highlighting that individual readiness to take up child‐focussed interventions must be viewed in an ecological context; (b) the specific process through which women become ready to engage in or facilitate child‐focussed interventions may differ from that related to uptake of safety‐promoting behaviours and requires parents to be aware of the impact of DVA on children and to focus on children's needs; (c) there are distinct but interlinked processes through which parents and children reach a point of readiness to engage in an interventions aimed at improving child outcomes. We discuss the implications of these findings for both practice and research. 相似文献
46.
Annette?AM?GerritsenEmail author Inge?Bramsen Walter?Devillé Loes?HM?van Willigen Johannes?E?Hovens Henk?M?van der Ploeg 《BMC public health》2004,4(1):7
Background
This article discusses the design of a study on the prevalence of health problems (both physical and mental) and the utilisation of health care services among asylum seekers and refugees in the Netherlands, including factors that may be related to their health and their utilisation of these services. 相似文献47.
Patients being evaluated as potential renal transplant recipients routinely undergo voiding cystourethrography. Eight patients were encountered in whom extraperitoneal extravasation was noted from the region of the ureterovesical junction during voiding (seven patients) or during filling (one patient). Extravasation was bilateral in six patients and unilateral in two. The patients neither experienced symptoms related to the extravasation, required treatment, nor had sequelae. Five of the eight patients have subsequently received renal transplants and their bladders were observed to be normal at surgery. Cystoscopy was also performed in two of these five patients and was unremarkable. After transplantation, these patients' bladders functioned normally and gave rise to no symptoms. 相似文献
48.
Eelco AB Over GC Wanda Wendel-Vos Matthijs van den Berg Heleen H Hamberg-van Reenen Luqman Tariq Rudolf T Hoogenveen Pieter HM van Baal 《Cost effectiveness and resource allocation : C/E》2012,10(1):1-7
Background
Counseling in combination with pedometer use has proven to be effective in increasing physical activity and improving health outcomes. We investigated the cost-effectiveness of this intervention targeted at one million insufficiently active adults who visit their general practitioner in the Netherlands.Methods
We used the RIVM chronic disease model to estimate the long-term effects of increased physical activity on the future health care costs and quality adjusted life years (QALY) gained, from a health care perspective.Results
The intervention resulted in almost 6000 people shifting to more favorable physical-activity levels, and in 5100 life years and 6100 QALYs gained, at an additional total cost of EUR 67.6 million. The incremental cost-effectiveness ratio (ICER) was EUR 13,200 per life year gained and EUR 11,100 per QALY gained. The intervention has a probability of 0.66 to be cost-effective if a QALY gained is valued at the Dutch informal threshold for cost-effectiveness of preventive intervention of EUR 20,000. A sensitivity analysis showed substantial uncertainty of ICER values.Conclusion
Counseling in combination with pedometer use aiming to increase physical activity may be a cost-effective intervention. However, the intervention only yields relatively small health benefits in the Netherlands. 相似文献49.
Background
Physical activity has been associated with a decreased risk for breast cancer. The biological mechanismn(s) underlying the association between physical activity and breast cancer is not clear. Most prominent hypothesis is that physical activity may protect against breast cancer through reduced lifetime exposure to endogenous hormones either direct, or indirect by preventing overweight and abdominal adiposity. In order to get more insight in the causal pathway between physical activity and breast cancer risk, we designed the Sex Hormones and Physical Exercise (SHAPE) study. Purpose of SHAPE study is to examine the effects of a 1-year moderate-to-vigorous intensity exercise programme on endogenous hormone levels associated with breast cancer among sedentary postmenopausal women and whether the amount of total body fat or abdominal fat mediates the effects. 相似文献50.
Gabriella M van Dijk Cindy Veenhof Francois Schellevis Harry Hulsmans Jan PJ Bakker Henk Arwert Jos HM Dekker Guus J Lankhorst Joost Dekker 《BMC musculoskeletal disorders》2008,9(1):95