全文获取类型
收费全文 | 634篇 |
免费 | 33篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 19篇 |
妇产科学 | 20篇 |
基础医学 | 70篇 |
口腔科学 | 10篇 |
临床医学 | 59篇 |
内科学 | 134篇 |
皮肤病学 | 7篇 |
神经病学 | 40篇 |
特种医学 | 10篇 |
外科学 | 124篇 |
综合类 | 1篇 |
预防医学 | 109篇 |
药学 | 41篇 |
中国医学 | 1篇 |
肿瘤学 | 20篇 |
出版年
2023年 | 5篇 |
2022年 | 9篇 |
2021年 | 21篇 |
2020年 | 11篇 |
2019年 | 13篇 |
2018年 | 22篇 |
2017年 | 11篇 |
2016年 | 13篇 |
2015年 | 20篇 |
2014年 | 15篇 |
2013年 | 28篇 |
2012年 | 74篇 |
2011年 | 57篇 |
2010年 | 27篇 |
2009年 | 32篇 |
2008年 | 36篇 |
2007年 | 45篇 |
2006年 | 47篇 |
2005年 | 46篇 |
2004年 | 30篇 |
2003年 | 29篇 |
2002年 | 23篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1972年 | 1篇 |
排序方式: 共有668条查询结果,搜索用时 15 毫秒
1.
Ren Drucker-Colín Leticia Verdugo-Díaz Milagros Mndez Jos Carrillo-Ruiz Consuelo Morgado-Valle Arturo Hernndez-Cruz Gabriel Corkidi 《Molecular and cellular neurosciences》1994,5(6)
Adrenal chromaffin cells in vitro respond to nerve growth factor (NGF) by expressing neuronal traits. Low frequency magnetic (LFM) field stimulation, while inducing a variety of effects on several cell types, has never been studied as to its effects on chromaffin cell cultures. The purpose of this study was to compare the effects of LFM field stimulation with that of NGF on the morphological phenotype, on noradrenaline (NA) release, and on membrane excitability of cultured chromaffin cells. We also tested the effects of grafting LFM and NGF-treated chromaffin cells into the caudate nucleus of rats with 6-hydroxydopamine lesions of the nigrostriatal pathway. The results of this study showed that LFM field stimulation produced neurite growth of cultured chromaffin cells in a manner similar to that of NGF exposure. The combination of the two procedures did not induce changes above those observed by NGF alone. Both NGF- and LFM-treated chromaffin cells released [3H]NA equally in response to a depolarizing concentration of KCl. On the other, Na+ current density of LFM field stimulation increased, but to a lesser extent than that seen in NGF-treated cells. In addition both types of cells when transplanted into nigrostriatal-lesioned animals induced a similar decrease in the motor asymmetries produced by the lesion. When NGF- or LFM-treated chromaffin cells where compared to untreated control cells, no significant differences were observed in [3H]NA release, on Na+ current densities, or on postgraft motor asymmetries. The results are discussed in terms of the fact that LFM-stimulated cells can be differentiated in a manner similar to NGF-treated cells, by acquiring sympathetic like traits which in turn can diminish motor asymmetries when grafted into nigrostriatal-lesioned rats. 相似文献
2.
Community-academic partnerships in the training of doctors offer unique learning opportunities of great importance. Such partnerships can induce a paradigm shift such that physicians view community as a teaching resource and partner rather than as a passive recipient of services or solely as a placement site. The authors describe a model of a community-academic partnership in New York City, begun in 1995, in which, for training and service, pediatric residents are integrally involved in a community-based program. Principles adapted from the Community-Campus Partnerships for Health's principles of partnership provide a framework for portraying the essential elements of developing and maintaining the partnership. The authors explain the clashes that may arise between partners and show how the principles of partnership guide partnership members in working and learning within a setting that by its nature entails conflict and inequality. This report is based on the knowledge gained from the structured reflections of both members of this partnership: the residency program at a large academic health center and the community-based social service organization. Such partnerships provide the training ground for the development of physicians who understand the social and cultural determinants of health and constructively use community agencies' input in promoting child health and well-being. Within this framework, community-based organizations are not solely service providers but become educators of physicians-in-training who, with new knowledge gained through the partnership, more effectively contribute to the overall health of the communities they serve. 相似文献
3.
The influence of dietary choline availability on cognition is currently being suggested by animal and human studies which have focused mainly on the early developmental stages. The aim of this review is to systematically search through the available rodent (rats and mice) research published during the last two decades that has assessed the effect of dietary choline interventions on cognition and related attentional and emotional processes for the entire life span. The review has been conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines covering peer-reviewed studies included in PubMed and Scopus databases. After excluding duplicates and applying the inclusion/exclusion criteria we have reviewed a total of 44 articles published in 25 journals with the contribution of 146 authors. The results are analyzed based on the timing and duration of the dietary intervention and the behavioral tests applied, amongst other variables. Overall, the available results provide compelling support for the relevance of dietary choline in cognition. The beneficial effects of choline supplementation is more evident in recognition rather than in spatial memory tasks when assessing nonpathological samples whilst these effects extend to other relational memory tasks in neuropathological models. However, the limited number of studies that have evaluated other cognitive functions suggest a wider range of potential effects. More research is needed to draw conclusions about the critical variables and the nature of the impact on specific cognitive processes. The results are discussed on the terms of the theoretical framework underlying the relationship between the brain systems and cognition. 相似文献
4.
Daniel López-Padilla Francisco García-Río Adolfo Alonso-Arroyo Nuria Arenas Valls Alicia Cerezo Lajas Marta Corral Blanco Virginia Gallo González Milagros Llanos Flores María Martínez Redondo Natalia Martos Gisbert Elena Ojeda Castillejo Marta Padilla Bernáldez Marta Pérez Gallán Vania Prudencio Ribera Luis Puente Maestu Beatriz Recio Moreno Elena Rodríguez Jimeno Ana Sánchez Azofra José Ignacio de Granda-Orive 《Archivos de bronconeumologia》2021,57(2):146-147
5.
Eva Tabernero Huguet Borja Ortiz de Urbina Antia Beatriz González Quero Elena Garay Llorente Joseba Andia Iturrate Silvia Pérez Fernández Ana Gómez Larrauri Milagros Iriberri Pascual 《Archivos de bronconeumologia》2021,57(5):345-350
IntroductionNECPAL is a tool for identification of patients with advanced chronic disease in need of palliative care. The main objective of the study is to know the prevalence of patients with palliative needs in an acute respiratory ward in a Spanish tertiary hospital using NECPAL. A second objective of the study is to know the annual mortality rate of these patients.Materials and methodsCross sectional study and prospective monitoring of a cohort identified as palliative patients with the NECPAL tool for 12 months. Patient identification was performed in patients admitted to the respiratory ward of our hospital for longer than 3 days. We have assessed the annual vital status (deceased or not deceased) of patients and have recorded demographics, clinical and functional data, as well as the use of healthcare resources.ResultsWe monitored a cohort of 363 patients. Of them, 87 patients (24.3%) (IC 95% 19–30) were identified as NECPAL positive. 60% of patients (n = 64) died within 12 months of their admission. There was no significant difference in the mortality ratio of oncologic versus non oncologic patients. In a multivariable analysis, mortality was associated with demand by patients or relatives for palliative care and with the presence of specific disease progression markers or indicators.Conclusionsprevalence of patients with palliative needs in acute respiratory wards is high (one out of four patients). 60% of the patients identified as NECPAL positive in our cohort died in the first 12 months. Training of healthcare professionals as well as availability of appropriate resources are indispensable factors to improve care of this population. 相似文献
6.
Diosque P Padilla AM Cimino RO Cardozo RM Negrette OS Marco JD Zacca R Meza C Juarez A Rojo H Rey R Corrales RM Nasser JR Basombrío MA 《The American journal of tropical medicine and hygiene》2004,71(5):590-593
We studied the seroprevalence of antibodies against Trypanosoma cruzi in the human population along with domiciliary infestation by triatomine bugs in an area endemic for Chagas disease in the Chaco Province of Argentina. In addition, we carried out parasitologic surveys in patients, dogs, wild mammals, and vectors. The mean seroprevalence in humans was 27.81% (109 of 392) and 24.14% (63 of 261) in 1-15-year-old children. The minimum domiciliary infestation rate was 13.33%, with certain areas reaching 53.85%. The prevalence was 15.09% (16 of 106) in dogs and 35.71% (10 of 28) in opossums. Infection with T. cruzi was detected in 30.10% (59 of 196) of the Triatoma infestans tested. Compared with nationwide studies, our data suggest that 1) there are zones requiring immediate sanitary action, and 2) nationwide estimates are based on very heterogeneous epidemiologic situations. This heterogeneity emphasizes the importance of in-depth studies of restricted areas to provide additional information for a better understanding of the present status of Chagas disease in Argentina. 相似文献
7.
8.
Drug use patterns and infection with sexually transmissible agents among young adults in a high-risk neighbourhood in New York City 总被引:1,自引:0,他引:1
Friedman SR Flom PL Kottiri BJ Zenilman J Curtis R Neaigus A Sandoval M Quinn T Des Jarlais DC 《Addiction (Abingdon, England)》2003,98(2):159-169
Aims To determine relationships between drug use ‘hardness’ (defined in increasing order of hardness as no drug use, marijuana use, non‐injected heroin or cocaine use, crack smoking and injection drug use) and prevalences of several sexually transmissible infections among young adults in a high‐risk neighbourhood. Drug users, particularly injection drug users and crack smokers, may be a core group for some sexually transmitted infections. Design Cross‐sectional survey and assays of young adults from (a) a household probability sample and (b) a targeted sample of youth who have used injected drugs, crack, other cocaine or heroin. Setting Bushwick, an impoverished New York City minority neighbourhood with major drug markets. Participants A total of 363 18–24‐year‐olds from a household probability sample; 165 Bushwick 18–24‐year‐olds who have used injected drugs, crack, other cocaine or heroin. Measurements Drug use by self‐report; serum‐ and urine‐based assays for HIV, hepatitis B and C, syphilis, gonorrhoea, chlamydia and herpes simplex (type 2). Findings Household‐sample prevalences: HIV, hepatitis C and syphilis, 1%; gonorrhoea 3%; chlamydia 5%; past or present hepatitis B infection 8%; herpes simplex (type 2) 18%. In combined household and targeted samples, hepatitis C and HIV were concentrated among drug injectors. Herpes simplex (type 2), syphilis and hepatitis B increased among women with ‘hardest drug ever used’. Conclusions Using ‘harder’ drugs is associated with some but not all of these infections. Prevention efforts should help youth avoid unsafe sex and higher‐risk drugs. 相似文献
9.
10.