全文获取类型
收费全文 | 344篇 |
免费 | 24篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 21篇 |
妇产科学 | 5篇 |
基础医学 | 50篇 |
口腔科学 | 12篇 |
临床医学 | 40篇 |
内科学 | 67篇 |
皮肤病学 | 18篇 |
神经病学 | 14篇 |
特种医学 | 36篇 |
外科学 | 39篇 |
综合类 | 18篇 |
预防医学 | 17篇 |
眼科学 | 6篇 |
药学 | 22篇 |
肿瘤学 | 7篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 7篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 14篇 |
2013年 | 25篇 |
2012年 | 14篇 |
2011年 | 10篇 |
2010年 | 17篇 |
2009年 | 24篇 |
2008年 | 16篇 |
2007年 | 9篇 |
2006年 | 12篇 |
2005年 | 20篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 8篇 |
1999年 | 2篇 |
1998年 | 17篇 |
1997年 | 20篇 |
1996年 | 20篇 |
1995年 | 15篇 |
1994年 | 10篇 |
1993年 | 13篇 |
1992年 | 3篇 |
1990年 | 1篇 |
1989年 | 8篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有381条查询结果,搜索用时 15 毫秒
81.
82.
83.
Jahn A Floyd S Mwinuka V Mwafilaso J Mwagomba D Mkisi RE Katsulukuta A Khunga A Crampin AC Branson K McGrath N Fine PE 《Tropical medicine & international health : TM & IH》2008,13(1):129-138
Objective To assess factors related to recorded vaccine uptake, which may confound the evaluation of vaccine impact.
Methods Analysis of documented vaccination histories of children under 5 years and demographic and socio-economic characteristics collected by a demographic surveillance system in Karonga District, Malawi. Associations between deviations from the standard vaccination schedule and characteristics that are likely to be associated with increased mortality were determined by multivariate logistic regression.
Results Approximately 78% of children aged 6–23 months had a vaccination document, declining to <50% by 5 years of age. Living closer to an under-5 clinic, having a better educated father, and both parents being alive were associated with having a vaccination document. For a small percentage of children, vaccination records were incomplete and/or faulty. Vaccination uptake was high overall, but delayed among children living further from the nearest under-5 clinic or from poorer socio-economic backgrounds. Approximately 9% of children had received their last dose of DPT with or after measles vaccine. These children were from relatively less educated parents, and were more likely to have been born outside the health services.
Conclusions Though overall coverage in this community was high and variation in coverage according to child or parental characteristics small, there was strong evidence of more timely coverage among children from better socio-economic conditions and among those who lived closer to health facilities. These factors are likely to be strong confounders in the association of vaccinations with mortality, and may offer an alternative explanation for the non-specific mortality impact of vaccines described by other studies. 相似文献
Methods Analysis of documented vaccination histories of children under 5 years and demographic and socio-economic characteristics collected by a demographic surveillance system in Karonga District, Malawi. Associations between deviations from the standard vaccination schedule and characteristics that are likely to be associated with increased mortality were determined by multivariate logistic regression.
Results Approximately 78% of children aged 6–23 months had a vaccination document, declining to <50% by 5 years of age. Living closer to an under-5 clinic, having a better educated father, and both parents being alive were associated with having a vaccination document. For a small percentage of children, vaccination records were incomplete and/or faulty. Vaccination uptake was high overall, but delayed among children living further from the nearest under-5 clinic or from poorer socio-economic backgrounds. Approximately 9% of children had received their last dose of DPT with or after measles vaccine. These children were from relatively less educated parents, and were more likely to have been born outside the health services.
Conclusions Though overall coverage in this community was high and variation in coverage according to child or parental characteristics small, there was strong evidence of more timely coverage among children from better socio-economic conditions and among those who lived closer to health facilities. These factors are likely to be strong confounders in the association of vaccinations with mortality, and may offer an alternative explanation for the non-specific mortality impact of vaccines described by other studies. 相似文献
84.
Characterization of a new non-Hodgkin's lymphoma cell line (NCEB-1) with a chromosomal (11:14) translocation [t(11:14)(q13;q32)] 总被引:2,自引:2,他引:2
Saltman DL; Cachia PG; Dewar AE; Ross FM; Krajewski AS; Ludlam C; Steel CM 《Blood》1988,72(6):2026-2030
A new cell line, NCEB-1, was established by Epstein-Barr virus (EBV) transformation of peripheral blood mononuclear cells from a patient with centroblastic-centrocytic diffuse lymphoma expressing IgM lambda. The transformed cells were lymphoblastoid, with many cells showing a plasmacytoid morphology. The NCEB-1 cells had cytoplasmic Ig (CyIg), with loss of the surface Ig (SIg) expression. Cytogenetic analysis of the cell line demonstrated two clones with variations: a hypodiploid clone, with a complex karyotype including a t(11;14)(q13;q32) similar to the original tumor cells, and a near tetraploid clone with the same markers. Southern blot analysis of DNA from the patient's neoplastic cells and NCEB-1 demonstrated identical Ig heavy chain gene rearrangement, confirming the origin of the cell line. The cell line was not tumorigenic when tested in an in vitro assay using immunosuppressed mice. NCEB-1 has been in continuous culture for 9 months and will be valuable for the in vivo study of non-Hodgkin's lymphoma and EBV transformation. 相似文献
85.
Sarah Wilke MSc Martijn A Spruit PhD Emiel FM Wouters PhD MD Jos MGA Schols PhD MD Frits ME Franssen PhD MD Daisy JA Janssen PhD MD 《International journal of nursing practice》2015,21(3):239-248
We aimed to identify baseline and longitudinal determinants of change in disease‐specific health status in patients with advanced chronic obstructive pulmonary disease (COPD). Demographic and clinical characteristics as well as disease‐specific health status (St George's Respiratory Questionnaire, SGRQ) were assessed in 105 outpatients with advanced COPD at baseline and at 4, 8 and 12 months. Eighty‐five patients (81.0%) had complete SGRQ data at baseline and 12 months and were included in analyses. Stepwise multiple regression analysis revealed that lower SGRQ total score, higher depression scores and longer time needed to complete the Timed Up and Go (TUG) test at baseline, as well as increase in time needed to complete the TUG test and increase in dyspnoea during the 1‐year follow‐up period, were predictors of deterioration in disease‐specific health status. The current study reinforces the stimulation of physical mobility and the targeting of dyspnoea as components for treatment programs to optimize disease‐specific health status in patients with advanced COPD. 相似文献
86.
Uckun FM; Steinherz PG; Sather H; Trigg M; Arthur D; Tubergen D; Gaynon P; Reaman G 《Blood》1996,88(11):4288-4295
We examined the prognostic impact of CD2 antigen expression for 651 patients with T-lineage acute lymphoblastic leukemia (ALL), who were enrolled in front-line Childrens Cancer Group treatment studies between 1983 and 1994. There was a statistically significant correlation between the CD2 antigen positive leukemic cell content of bone marrow and probability of remaining in bone marrow remission, as well as overall event-free survival (EFS) (P = .0003 and P = .002, log-rank tests for linear trend). When compared with patients with the highest CD2 expression level (> 75% positivity), the life table relative event rate (RER) was 1.22 for patients with intermediate range CD2 expression level (30% to 75% positivity) and 1.81 for "CD2-negative" patients (< 30% positivity). At 6 years postdiagnosis, the EFS estimates for the three CD2 expression groups (low positivity to high positivity) were 52.8%, 65.5%, and 71.9%, respectively. CD2 expression remained a significant predictor of EFS after adjustment for the effects of other covariates by multivariate regression, with a RER of 1.47 for CD2- negative patients (P = .04). Analysis of T-lineage ALL patients shows a significant separation in EFS after adjustment for the National Cancer Institute (NCI) age and white blood cell (WBC) criteria for standard and high-risk ALL (P = .002, RER = 1.67). The determination of CD2 expression on leukemic cells helped identify patients with the better and poorer prognoses in both of these risk group subsets. For standard risk T-lineage ALL, CD2-negative patients had a worse outcome (P = .0007, RER = 2.92) with an estimated 5-year EFS of 55.9% as compared with 78.3% for the CD2-positive patients. Thus, CD2 negativity in standard risk T-lineage ALL identified a group of patients who had a worse outcome than high-risk T-lineage ALL patients who were CD2 positive. The percentage of CD2 antigen positive leukemic cells from T- lineage ALL patients is a powerful predictor of EFS after chemotherapy. This prognostic relationship is the first instance in which a biological marker in T-lineage ALL has been unequivocally linked to treatment outcome. 相似文献
87.
We investigated the effects of granulocyte-macrophage colony- stimulating factor, interleukin-3, stem cell factor, interleukin-6, and granulocyte colony-stimulating factor (G-CSF) alone, and in combination, on the clonogenic potential of normal and aplastic anemia (AA) bone marrow mononuclear cells (BMMC and CD34+ cells. AA BMMC consistently produced a significantly lower absolute number of colonies than normal, but, when account was taken of the reduced proportion of CD34+ cells in AA BM, there was no significant difference in terms of cloning efficiency (CE). However, when removed from the influence of accessory cells, the CE of AA CD34+ cells decreased significantly more than normal, indicating a defect in their function, either in terms of dependence on accessory cell-derived factors or susceptibility to cell damage when sorted. Of the factors studied, G-CSF had the most significant effect on the response of CD34+ cells from both groups when removed from their accessory cells. This was particularly true for AA CD34+ cells, whose response to cytokine stimuli containing G-CSF enabled them to match the response of normal CD34+ cells. 相似文献
88.
89.
ANNEMARIE M VISSER VINCENT WV JADDOE LIDIA R ARENDS HENNING TIEMEIER ALBERT HOFMAN HENRIETTE A MOLL ERIC AP STEEGERS MONIQUE MB BRETELER WILLEM FM ARTS 《Developmental medicine and child neurology》2010,52(11):1014-1020
Aim To examine the incidence of paroxysmal epileptic and non‐epileptic disorders and the associated prenatal and perinatal factors that might predict them in the first year of life in a population‐based cohort. Method This study was embedded in the Generation R Study, a population‐based prospective cohort study from early fetal life onwards. Information about the occurrence of paroxysmal events, defined as suddenly occurring episodes with an altered consciousness, altered behaviour, involuntary movements, altered muscle tone, and/or a changed breathing pattern, was collected by questionnaires at the ages of 2, 6, and 12 months. Information on possible prenatal and perinatal determinants was obtained by measurements and questionnaires during pregnancy and after birth. Results Information about paroxysmal events in the first year of life was available in 2860 participants (1410 males, 1450 females). We found an incidence of paroxysmal disorders of 8.9% (n=255) in the first year of life. Of these participants, 17 were diagnosed with febrile seizures and two with epilepsy. Non‐epileptic events included physiological events, apnoeic spells, loss of consciousness by causes other than epileptic seizures or apnoeic spells, parasomnias, and other events. Preterm birth (p<0.001) and low Apgar score at 1 minute (p<0.05) were significantly associated with paroxysmal disorders in the first year of life. Continued maternal smoking during pregnancy and preterm birth were significantly associated with febrile seizures in the first year of life (p<0.05). Interpretation Paroxysmal disorders are frequent in infancy. They are associated with preterm birth and a low Apgar score. Epileptic seizures only form a minority of the paroxysmal events in infancy. In this study, children whose mothers continued smoking during pregnancy had a higher reported incidence of febrile seizures in the first year of life. These findings may generate various hypotheses for further investigations. 相似文献
90.
Edward M Manno Alejandro A Rabinstein Eelco FM Wijdicks Allen W Brown William D Freeman Vivien H Lee Stephen D Weigand Mark T Keegan Daniel R Brown Francis X Whalen Tuhin K Roy Rolf D Hubmayr 《Critical care (London, England)》2008,12(6):R138-10