全文获取类型
收费全文 | 2328篇 |
免费 | 131篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 57篇 |
妇产科学 | 85篇 |
基础医学 | 278篇 |
口腔科学 | 28篇 |
临床医学 | 505篇 |
内科学 | 390篇 |
皮肤病学 | 33篇 |
神经病学 | 186篇 |
特种医学 | 30篇 |
外科学 | 174篇 |
综合类 | 20篇 |
一般理论 | 3篇 |
预防医学 | 327篇 |
眼科学 | 13篇 |
药学 | 174篇 |
中国医学 | 2篇 |
肿瘤学 | 142篇 |
出版年
2024年 | 4篇 |
2023年 | 19篇 |
2022年 | 28篇 |
2021年 | 44篇 |
2020年 | 33篇 |
2019年 | 65篇 |
2018年 | 56篇 |
2017年 | 37篇 |
2016年 | 48篇 |
2015年 | 57篇 |
2014年 | 56篇 |
2013年 | 112篇 |
2012年 | 178篇 |
2011年 | 206篇 |
2010年 | 129篇 |
2009年 | 113篇 |
2008年 | 173篇 |
2007年 | 176篇 |
2006年 | 179篇 |
2005年 | 169篇 |
2004年 | 154篇 |
2003年 | 109篇 |
2002年 | 127篇 |
2001年 | 17篇 |
2000年 | 12篇 |
1999年 | 12篇 |
1998年 | 24篇 |
1997年 | 28篇 |
1996年 | 18篇 |
1995年 | 12篇 |
1994年 | 16篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
排序方式: 共有2476条查询结果,搜索用时 15 毫秒
71.
C3d binding to the circumsporozoite protein carboxy-terminus deviates immunity against malaria 总被引:5,自引:0,他引:5
Bergmann-Leitner ES Scheiblhofer S Weiss R Duncan EH Leitner WW Chen D Angov E Khan F Williams JL Winter DB Thalhamer J Lyon JA Tsokos GC 《International immunology》2005,17(3):245-255
The immunogenicity of recombinant protein or anti-viral DNA vaccines can be significantly improved by the addition of tandem copies of the complement fragment C3d. We sought to determine if the efficacy of a circumsporozoite protein (CSP)-based DNA vaccine delivered to mouse skin by gene gun was improved by using this strategy. Instead, we found that C3d suppressed the protective immunity against Plasmodium berghei malaria infection and deviated immunity, most notably by suppressing the induction of antibodies specific for the CSP C-terminal flanking sequence and by suppressing the induction of CSP-specific IL-4-producing spleen cells. We further showed that C3d bound to the C-terminal flanking sequence of the CSP, which may explain the immune deviation observed in CS/C3d chimeric antigen. We have thus identified C3d-mediated epitope masking and shifting of both the humoral and cellular immune responses as a potential novel escape mechanism, which plasmodia may use to divert the induction of protective immunity. 相似文献
72.
73.
Jackie Parkes Nichola McCullough Ann Madden & Elaine McCahey 《Journal of advanced nursing》2009,65(11):2311-2323
Title. The health of children with cerebral palsy and stress in their parents.
Aim. This paper is a report of a study conducted to describe the health of children with cerebral palsy and investigate predictors of stress in their parents.
Background. Children with severe cerebral palsy tend to have poorer health than their able-bodied peers, and their parents are more likely to be stressed and have poorer health.
Method. A cross-sectional survey with home visits using standard questionnaires was administered to parents in 2004–05. A total of 102/199 (51%) children and parents participated. The children were compared with a normative sample.
Results. Children with cerebral palsy had poorer physical health, and 79% of parents reported that their child had moderate to severe pain. Their poorer health, in comparison with the normal sample and measured by the Child Health Questionnaire, was related to feeding problems and seizures, general health perceptions to intellectual and feeding impairment, and family activities with severe motor, intellectual and feeding impairment. Poorer psychological well-being on the hyperactivity domain of the Strengths & Difficulties Questionnaire was related to feeding difficulties, on the prosocial domain to more severe forms of all child impairments, and on the social impairment scale to intellectual impairment. Children with psychological problems had statistically significantly increased odds (OR = 7·2, 95% CIs 2·6–20·3) of having parents with high stress.
Conclusion. Children with cerebral palsy and associated impairments are at higher risk of poorer health and family well-being. A family-centred approach to the care of children with cerebral palsy and their families is essential to ensure both receive adequate care and support. 相似文献
Aim. This paper is a report of a study conducted to describe the health of children with cerebral palsy and investigate predictors of stress in their parents.
Background. Children with severe cerebral palsy tend to have poorer health than their able-bodied peers, and their parents are more likely to be stressed and have poorer health.
Method. A cross-sectional survey with home visits using standard questionnaires was administered to parents in 2004–05. A total of 102/199 (51%) children and parents participated. The children were compared with a normative sample.
Results. Children with cerebral palsy had poorer physical health, and 79% of parents reported that their child had moderate to severe pain. Their poorer health, in comparison with the normal sample and measured by the Child Health Questionnaire, was related to feeding problems and seizures, general health perceptions to intellectual and feeding impairment, and family activities with severe motor, intellectual and feeding impairment. Poorer psychological well-being on the hyperactivity domain of the Strengths & Difficulties Questionnaire was related to feeding difficulties, on the prosocial domain to more severe forms of all child impairments, and on the social impairment scale to intellectual impairment. Children with psychological problems had statistically significantly increased odds (OR = 7·2, 95% CIs 2·6–20·3) of having parents with high stress.
Conclusion. Children with cerebral palsy and associated impairments are at higher risk of poorer health and family well-being. A family-centred approach to the care of children with cerebral palsy and their families is essential to ensure both receive adequate care and support. 相似文献
74.
75.
David Berrigan Nancy Potischman Kevin W Dodd Michael Nicar Geraldine McQuillan Jackie A Lavigne J Carl Barrett Rachel Ballard-Barbash 《Cancer epidemiology, biomarkers & prevention》2007,16(5):1017-1022
The insulin-like growth factor (IGF) axis, particularly IGF-I and IGF binding protein-3 (IGFBP-3), has been the subject of much attention because of its role in juvenile growth and their association with cancers at several sites. However, epidemiologic studies of IGF-I and IGFBP-3 have had mixed results and several authors have speculated that quality control (QC), sample storage history, and other methodologic concerns could play a role in this heterogeneity. This article documents the results of storage history and QC efforts for a study of IGF-I and IGFBP-3 in 6,226 serum samples from the National Health and Nutrition Examination Survey III (NHANES III). The study was carried out on site at Diagnostic Systems Laboratories in Webster, Texas, using the IGF-I ELISA (DSL 10-5600) and the IGFBP-3 immunoradiometric assay (DSL 6600). A run-in study of assay performance suggested that plates, days, and weeks significantly affected the variance of both assays. Analysis of samples with different storage histories also indicated strong effects of storage history. Serum samples disbursed to laboratories for measurement of diverse analytes and then returned for storage showed reductions in serum IGF-I level averaging 43% and reductions in IGFBP-3 of 25% compared with samples shipped immediately to the repository for long-term storage at -80 degrees C. Therefore, the main study was carried out using samples that had been shipped directly to the National Center for Health Statistics/NHANES collection center for storage. Laboratory analyses of NHANES III and QC samples were carried out over approximately 10 months. QC was monitored through repeated testing of blood samples from six individuals, with two individuals tested twice on each plate. Assay performance was stable over the entire study and coefficients of variation averaged 2% to 3% within plates and approximately 14% for IGF-I and approximately 11.5% for IGFBP-3 over the entire study. Coefficients of variation varied significantly among individual QC subjects, ranging from 12.3% to 17.6% for IGF-I and 8.9% to 12.8% for IGFBP-3. Based on Levy-Jennings plots, approximately 5% of the plates used for IGF-I in the main study were out of compliance. Finally, location on a plate had small but significant effects on IGF-I level. Together, these results highlight the need for care in large studies of putative biomarkers for cancer risk and illustrate some probable sources of heterogeneity in past epidemiologic studies of the IGF axis and cancer. 相似文献
76.
Angela Curtis Jackie Morton Chariklia Balafa Sheila MacNeil David J Gawkrodger Nicholas D Warren Gareth S Evans 《Toxicology in vitro》2007,21(5):809-819
This study was carried out to assess the effects of chromium and nickel upon isolated keratinocytes as an in vitro model of human skin. Keratinocytes were isolated from healthy volunteer skin samples of unknown metal sensitivity (n=10) and were compared with cells from patient biopsies of known metal sensitivity (n=7). Cells were dosed with a concentration range of nickel and chromium (0-10,000 microM) and cellular mitochondrial activity, viability, metal uptake and cytokine release were measured. Responses of primary versus passaged keratinocytes were also compared. Toxicity data from primary and passaged keratinocytes was statistically analysed by the non-linear Hill Plot model. Results showed that hexavalent chromium was significantly more cytotoxic, associated more with keratinocytes and induced a dose dependant release of IL-1alpha compared to nickel. Significant differences were observed between primary and passaged keratinocytes with regard to the toxicity of chromium and nickel and variation of response. No differences were observed in the cytotoxicity or cytokine release induced by chromium or nickel for the known sensitised biopsy patient samples (n=4) compared to patch test negative controls (n=3). The results from this study suggest human keratinocytes in vitro respond very differently to chromium and nickel. 相似文献
77.
Marie-Claude Léveillé Jackie Carnegie Nongnuj Tanphaichitr 《Journal of assisted reproduction and genetics》1992,9(1):45-52
Human proteins normally used to supplement human in vitro fertilization—embryo transfer (IVF-ET) culture media were tested for their effects on mouse embryo development from the zygote stage. These proteins included follicular and luteal-phase maternal sera, fetal cord sera, and both human and bovine serum albumin. Our results revealed that both maternal and fetal cord sera did not permit mouse blastocyst formation. Furthermore, predialysis of the human maternal sera and removal of IgG by protein A column chromatography did not improve their support of mouse embryonic development to the blastocyst stage. Similar detrimental effects were observed with maternal sera from term-pregnant IVF-ET patients. Interestingly, these serum samples had supported the in vitro growth of the human zygotes which resulted in these patients' pregnancies. Only some batches of human serum albumin supported mouse blastocyst formation, whereas all sources of bovine serum albumin were effective in this regard. These results raise the question of the suitability of the mouse embryo culture system as a quality control for the testing of protein supplements for human IVF-ET. 相似文献
78.
Ryan A Carter J Lucas J Berger J 《The American journal of hospice & palliative care》2002,19(3):171-180
The majority of dying patients continue to receive care in acute, tertiary settings. This has generated the development of hospital-based palliative care (HBPC). The Symptom Management and Palliative Care Program (SMPCP) at LAC+USC Medical Center provides HBPC. The SMPCP operates as an interdisciplinary consultative service, assessing inpatients, and documenting recommendations for primary physicians. Over a 28-month period the SMPCP provided clinical recommendations, education, and research for patients, family members, and hospital staff Demographic, clinical, psychosocial, financial, and outcome information was collected on 265 patients. The SMPCP documented the attainment of defined quality end-points, including pain control within 24 hours, a Do Not Resuscitate (DNR) discussion with patient and family within 72 hours, and control of nausea and vomiting within 24 hours. Team members also documented impediments to implementing recommendations and the success of interventions to overcome impediments. Results indicated that the SMPCP achieved a high rate of quality end-point attainment when impediments were not present. The most significant impediments resulted from behaviors by primary physicians. The SMPCP's ability to overcome barrier behaviors improved the rate of end-point attainment, confirming the importance of palliative care at the end of life. 相似文献
79.
80.
New Zealand's health care sector has undergone almost continual restructuring since the early 1980s. In the latest set of reforms, 21 district health boards (DHBs) have been established with responsibility for promoting health, purchasing services for their populations and delivering publicly owned health services. Boards will be governed by a mix of elected and appointed members, will be responsible for arranging the delivery of primary and community health services, and will own and run public hospitals and related facilities. We clarify the differences and continuities between earlier reforms and the 2000/01 structures, as well as the current reforms' potential strengths and weaknesses. The paper discusses whether the DHB model was the only feasible option for restructuring and whether the dynamics of the new system may lead to further changes, particularly on the purchaser side of the system. Given that DHBs face potential conflict between their purchasing and provision roles, and given the potential advantages that primary care organisations may have as purchasers, we conclude that it is possible that all or part of the purchasing function of DHBs might eventually shift to primary care organisations, leaving the DHBs as hospital-based provider organisations. 相似文献