冲破生存极限:极早产的经济影响作用

Background:Previous assessments of the economic impact of preterm birth focus sed on short term health service costs across the broad spectrum of prematurity.Objective:To estimate the societal costs of extreme preterm birth during the s ixth year after birth.Methods:Unit costs were applied to estimates of health,social and broader resource use made by 241 children born at 20 through 25 compl eted weeks of gestation in the United Kingdom and Republic of Ireland and a comp arison group of 160 children born at full term.Societal costs per child during the sixth year after birth were estimated and subjected to a rigorous sensitivit y analysis.The effects of gestational age at birth on annual societal costs wer e analysed,first in a simple linear regression and then in a multiple linear re gression.Results:Mean societal costs over the 12 month period were ￡9541(sta ndard deviation ￡11,678)for the extreme preterm group and ￡3883(￡1098)for the term group,generating a mean cost difference of ￡5658(bootstrap 95%confi dence interval:￡4203,￡7256)that was statistically significant(P < 0.001).After adjustment for clinical and sociodemographic covariates,sexspecific extre me preterm birth was a strong predictor of high societal costs.Conclusion:The results of this study should facilitate the effective planning of services and m ay be used to inform the development of future economic evaluations of intervent ions aimed at preventing extreme preterm birth or alleviating its effects.

Search for hidden-charm tetraquark with strangeness in e^(+)e^(−)→K^(+)D_(s)^(∗−) D^(∗0 )+ c.c.

We report a search for a heavier partner of the recently observed Z_(cs)(3985)^(-) state,denoted as Z_(cs)^('-),in the process e^(+)e^(−)→K^(+)D_(s)^(∗−) D^(∗0 )+ c.c.,based on e^(*)e^(-)collision data collected at the center-of-mass energies of √s=4.661,4.682 and 4.699 GeV with the BESIII detector.The Z_(cs)^('-) is of interest as it is expected to be a candidate for a hidden-charm and open-strange tetraquark.A partial-reconstruction technique is used to isolate K^(+)recoil-mass spectra,which are probed for a potential contribution from Z_(cs)^('-)→D_(s)^(∗−) D^(∗0 )+ c.c.We find an excess of Z_(cs)^('-)→D_(s)^(*-)-D^(*0)(c.c.)candidates with a significance of 2.1o,after considering systematic uncertainties,at a mass of(4123.5±0.7_(sat)±4.7_(syst.))MeV/c^(2).As the data set is limited in size,the upper limits are evaluated at the 90%confidence level on the product of the Born cross sections(σ^(Borm))and the branching fraction(B)of Z_(cs)^('-)→D_(s)^(*-)-D^(*0),under different assumptions of the Z_(cs)^('-) mass from 4.120 to 4.140 MeV and of the width from 10 to 50 MeV at the three center-of-mass energies.The upper limits of σ^(Born).B are found to be at the level of O(1)pb at each energy.Larger data samples are needed to confirm the Z_(cs)^('-) state and clarify its nature in the coming years.

英格兰和威尔士地区儿童恶性肿瘤与高压输电线距离的关系:一项病例-对照研究

目的 确定英格兰和威尔士地区儿童白血病及其他癌症发病率是否与其出生时家庭地址与高压电线的距离存在关系。设计 病例-对照研究。设置 癌症登记处和国家电力供应网的记录。对象1962-1995年，英格兰和威尔士地区出生的0-14岁的29081名癌症患儿中包括9700名白血病患儿。对照组依照性别、大致相同的出生日期、出生登记处等予以个体匹配。并不强求积极参与。主要结果测定 儿童出生时的家庭地址与当时最近的高架高压输电线问的距离（以下有时简称为距离）。结果 与生活在距输电线超过600米的儿童相比，距输电线200米之内的儿童患白血病的相对危险度为1．69（95％可信区间为1．13-2．53）；200-600米间的发病相对危险度为1．23（1．02-1．49）。白血病发病风险与输电线相互距离的倒数存在显著相关性（P〈0．01）。毗邻输电线未发现增加儿童其他癌症的额外发病风险。结论 儿童白血病发病风险与出生时家庭地址距高压电线的远近存在相关关系，且风险程度超出了以往研究的预期。在英格兰和威尔士地区，出生时生活在距离高压输电线600米内的白血病患儿约占4％。如果这种相关是偶然的，那么在该地区约1％的儿童白血病是由于高压输电线导致的，尽管这种估计在统计学上具有相当的不确定性。没有其他可接受的生物学机制来解释这些流行病学结果；事实上这种联系可能源于偶然或混杂。