全文获取类型
收费全文 | 1726篇 |
免费 | 318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 | 28篇 |
临床医学 | 847篇 |
内科学 | 166篇 |
皮肤病学 | 51篇 |
神经病学 | 14篇 |
特种医学 | 235篇 |
外科学 | 48篇 |
综合类 | 56篇 |
预防医学 | 87篇 |
眼科学 | 5篇 |
药学 | 45篇 |
肿瘤学 | 52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 | 76篇 |
2015年 | 98篇 |
2014年 | 100篇 |
2013年 | 97篇 |
2012年 | 36篇 |
2011年 | 59篇 |
2010年 | 100篇 |
2009年 | 99篇 |
2008年 | 40篇 |
2007年 | 45篇 |
2006年 | 36篇 |
2005年 | 21篇 |
2004年 | 15篇 |
2003年 | 29篇 |
2002年 | 20篇 |
2001年 | 34篇 |
2000年 | 10篇 |
1999年 | 46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 | 14篇 |
排序方式: 共有2052条查询结果,搜索用时 15 毫秒
61.
Hisham Zayan Abdel-Hafez MD Ayman Mohamed Mahran MD Eman RM Hofny MD Dalia Abdel Aziz Attallah MD Doaa Sameer Sayed MD & Hebat-Allah G Rashed MD 《Journal of Cosmetic Dermatology》2009,8(1):52-55
Background Alopecia areata (AA) is an immune-mediated form of hair loss that occurs in all ethnic groups, ages, and both sexes. Helicobacter pylori has been associated with certain extra-digestive dermatological conditions, including chronic urticaria, rosacea, Schönlein-Henoch purpura, Sweet syndrome, systemic sclerosis, and atopic dermatitis.
Objective The causal relation between alopecia areata and H. pylori is discussed. We have screened for the presence of H. pylori in patients with AA in order to determine any potential role in its pathophysiology.
Patients and methods We have prospectively studied 31 patients with AA and 24 healthy volunteers of similar gender for the presence of H. pylori surface antigen (HpSag) in stool.
Results Optical density values for H. pylori infection were positive in 18 of all 31 patients evaluated (58.1%), while in 13 patients, values did not support H. pylori infection (41.9%). While in the control group, 10 of 24 (41.7%) had positive results. Within the group of AA, there was no significant difference between HpSag-positive and HpSag-negative patients.
Conclusions Based on these results, the relation between H. pylori and AA is not supported. We advise that H. pylori detection should not be included in the laboratory workup of AA. 相似文献
Objective The causal relation between alopecia areata and H. pylori is discussed. We have screened for the presence of H. pylori in patients with AA in order to determine any potential role in its pathophysiology.
Patients and methods We have prospectively studied 31 patients with AA and 24 healthy volunteers of similar gender for the presence of H. pylori surface antigen (HpSag) in stool.
Results Optical density values for H. pylori infection were positive in 18 of all 31 patients evaluated (58.1%), while in 13 patients, values did not support H. pylori infection (41.9%). While in the control group, 10 of 24 (41.7%) had positive results. Within the group of AA, there was no significant difference between HpSag-positive and HpSag-negative patients.
Conclusions Based on these results, the relation between H. pylori and AA is not supported. We advise that H. pylori detection should not be included in the laboratory workup of AA. 相似文献
62.
63.
Nash RA; Pineiro LA; Storb R; Deeg HJ; Fitzsimmons WE; Furlong T; Hansen JA; Gooley T; Maher RM; Martin P; McSweeney PA; Sullivan KM; Anasetti C; Fay JW 《Blood》1996,88(9):3634-3641
The safety and potential efficacy of FK506 in combination with a short course of methotrexate (MTX) for the prevention of acute graft-versus- host disease (GVHD) after marrow transplantation from HLA-matched unrelated donors was evaluated in a single-arm Phase II study conducted at two centers. Forty-three patients, 15 to 54 (median 41) years of age, were transplanted for hematologic malignancies. Thirty-seven of 43 evaluable patients had evidence of sustained marrow engraftment. Five patients died before day 17 after transplantation. The median time to an absolute neutrophil count of > 0.5 x 10(5)/L was 21 (range, 14 to 30) days. Nephrotoxicity (serum creatinine concentration > 2 mg/dL or doubling of baseline) occurred in 32 patients (74% cumulative incidence during the first 100 days after transplant). Other adverse effects included hypertension (n = 27), hyperglycemia (n = 27), neurotoxicity (n = 9) and thrombotic thrombocytopenic purpura (n = 2). Severe veno- occlusive disease of the liver occurred in 9 (21%) of the 43 patients. Eighteen patients (42%) developed grades II to IV acute GVHD and five (12%) developed grades III to IV acute GVHD. Twelve of 25 evaluable patients developed extensive chronic GVHD within 1 year of marrow transplantation resulting in an estimate of the probability of developing this complication of 48%. The cumulative incidence of transplant-related mortality during the first 100 days was 37%. Kaplan- Meier estimates of disease-free survival at 2 years for good-risk, poor- risk, and all patients were 65%, 4%, and 32%, respectively. FK506 in combination with a short course of MTX appears active in preventing acute GVHD after marrow transplantation from unrelated donors. Further studies comparing the combination of FK506 and MTX with cyclosporine and MTX for the prevention of acute GVHD are warranted. 相似文献
64.
Lord BI; Woolford LB; Wood LM; Czaplewski LG; McCourt M; Hunter MG; Edwards RM 《Blood》1995,85(12):3412-3415
BB-10010 is a genetically engineered variant of human macrophage inflammatory protein-1 alpha with improved solution properties. We show here that it mobilizes stem cells into the peripheral blood. We investigated the mobilizing effects of BB-10010 on the numbers of circulating 8-day spleen colony-forming units (CFU-S8), CFU-S12, and progenitors with marrow repopulating ability (MRA). A single subcutaneous dose of BB-10010 caused a twofold increase in circulating numbers of CFU-S8, CFU-S12, and MRA 30 minutes after dosing. We also investigated the effects of granulocyte colony-stimulating factor (G- CSF) and the combination of G-CSF with BB-10010 on progenitor mobilization. Two days of G-CSF treatment increased circulating CFU-S8, CFU-S12, and MRA progenitors by 25.7-, 19.8-, and 27.7-fold. A single administration of BB-10010 after 2 days of G-CSF treatment increased circulating CFU-S8, CFU-S12, and MRA even further to 38-, 33-, and 100- fold. Splenectomy resulted in increased circulating progenitor numbers but did not change the pattern of mobilization. Two days of treatment with G-CSF then increased circulating CFU-S8, CFU-S12, and MRA by 64-, 69-, and 32-fold. A single BB-10010 administration after G-CSF treatment further increased them to 85-, 117-, and 140-fold, respectively, compared with control. We conclude that BB-10010 causes a rapid increase in the number of circulating hematopoietic progenitors and further enhances the numbers induced by pretreatment with G-CSF. BB- 10010 preferentially mobilized the more primitive progenitors with marrow repopulating activity, releasing four times the number achieved with G-CSF alone. Translated into a clinical setting, this improvement in progenitor cell mobilization may enhance the efficiency of harvest and the quality of grafts for peripheral blood stem cell transplantation. 相似文献
65.
66.
Activated protein C decreases plasminogen activator-inhibitor activity in endothelial cell-conditioned medium 总被引:12,自引:0,他引:12
van Hinsbergh VW; Bertina RM; van Wijngaarden A; van Tilburg NH; Emeis JJ; Haverkate F 《Blood》1985,65(2):444-451
Confluent cultures of endothelial cells from human umbilical cord were used to study the effect of activated human protein C (APC) on the production of plasminogen activators, plasminogen activator-inhibitor, and factor VIII-related antigen. Addition of APC to the cells in a serum-free medium did not affect the production of tissue-type plasminogen activator (t-PA) or factor VIII-related antigen; under all measured conditions, no urokinase activity was found. However, less plasminogen activator-inhibitor activity accumulated in the conditioned medium in the presence of APC. This decrease was dose dependent and could be prevented by specific anti-protein C antibodies. No decrease was observed with the zymogen protein C or with diisopropylfluorophosphate-inactivated APC. APC also decreased the t-PA inhibitor activity in endothelial cell-conditioned medium in the absence of cells, which suggests that the effect of APC is at least partly due to a direct effect of APC on the plasminogen activator- inhibitor. High concentrations of thrombin-but not of factor Xa or IXa-- had a similar effect on the t-PA inhibitor activity. The effect of APC on the plasminogen activator-inhibitor provides a new mechanism by which APC may enhance fibrinolysis. The data suggest that activation of the coagulation system may lead to a secondary increase of the fibrinolytic activity by changing the balance between plasminogen activator(s) and its (their) fast-acting inhibitor. 相似文献
67.
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
68.
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
69.
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
70.
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