新型冠状病毒感染者末次核酸阴性前后的传染性分析

目的研究新型冠状病毒(新冠病毒)感染者末次核酸阴性前后密切接触者(密接)的感染率, 评估动态核酸检测结果在判断新冠病毒感染者传染性中的作用。方法采用回顾性队列研究的方法, 收集新冠病毒感染者的动态核酸检测结果。选择新冠病毒感染者在首次核酸检测阳性前有核酸阴性结果者为研究对象, 对感染者的密接以及密接的密接(次密接)进行持续隔离医学观察, 评估密接和次密接的发病风险。结果共纳入宁波市2起本土疫情的89例新冠病毒感染者, 均为确诊病例。追踪调查了5 609名密接, 密接的总感染率为0.20%。感染者末次核酸阴性前的密接无感染, 末次核酸阴性后的密接感染率为1.33%, 且均为与指示病例共同居住生活者。感染者涉及的所有次密接均未感染。结论新冠病毒感染者末次核酸阴性前无传染性, 末次核酸阴性后开始具有传染性。     

基于人群的身体活动水平与脑卒中发病风险的队列研究

目的 探讨≥40岁成年人身体活动水平对脑卒中发病的影响。方法 通过宁波市2015年具有人群代表性的成年人慢性病监测调查获得身体活动和人口特征基线数据,利用2015-2019年宁波市慢性病监测信息协同管理系统获得脑卒中发病数据,将数据库进行匹配形成队列。身体活动按照每周身体活动量（METs）分为低、中等和高强度身体活动。采用Cox回归分析计算不同身体活动分类脑卒中的发病风险。结果 2015年基线调查共纳入3 353名研究对象,截至2019年12月31日,随访时间（50.28±2.54）个月,共发生脑卒中事件31人,累积发病率为242/10万。多因素Cox回归分析结果显示,在控制性别、年龄、文化程度、吸烟情况、饮酒情况、BMI、是否高血压等因素后,身体活动强度越高,脑卒中发病风险越低,平均降低37.9%（HR=0.621,95%CI：0.393~0.983）。与低强度身体活动者相比,高强度身体活动者脑卒中发病风险降低了63.1%（HR=0.369,95%CI：0.139~0.976）,而中等强度身体活动者与低强度身体活动者的脑卒中发病风险差异无统计学意义（HR=0.712,95%CI：0.323~1.569）。结论 身体活动强度越高,脑卒中发病风险越低,应加强社区支持性环境建设,提高人群身体活动水平。     

宁波市蚊类种群1999～2002年的年际动态变化

目的　通过调查不同年份蚊虫种群的密度 ,以了解宁波地区蚊虫种群的年际变化规律 ,从而为蚊虫种群的有效控制提供理论依据。方法　采取定点定时的方法 ,利用直流电动捕蚊器捕捉蚊虫 ,然后分种统计捕获的蚊虫数。结果　宁波地区的优势蚊种为中华按蚊、淡色库蚊和三带喙库蚊 ,其中中华按蚊占捕获蚊虫总数的 42 .0 1%。 1999～ 2 0 0 2年蚊类种群密度波动较大 ,其中波动幅度最大的是淡色库蚊。 3种优势蚊种的季节分布呈单峰型 ,总体上最高峰在 6～ 8月 ,其中中华按蚊的高峰期出现在 4～ 5月 ,淡色库蚊的高峰期出现在 7～ 8月 ,三带喙库蚊则出现在 9～ 10月。结论　根据蚊虫种群密度的年际变化和季节消长规律 ,宁波地区蚊虫种群的控制工作重点是在每年的 4～ 5月 ,消灭各类孳生地中的蚊幼 ,以降低全年的蚊虫种群密度     

Imagerie protonique pour la protonthérapie : état de l’art

Proton therapy allows a highly precise tumour volume irradiation with a low dose delivered to the healthy tissues. The steep dose gradients observed and the high treatment conformity require a precise knowledge of the proton range in matter and the target volume position relative to the beam. Thus, proton imaging allows an improvement of the treatment accuracy, and thereby, in treatment quality. Initially suggested in 1963, radiographic imaging with proton is still not used in clinical routine. The principal difficulty is the lack of spatial resolution, induced by the multiple Coulomb scattering of protons with nuclei. Moreover, its realization for all clinical locations requires relatively high energies that are previously not considered for clinical routine. Abandoned for some time in favor of X-ray technologies, research into new imaging methods using protons is back in the news because of the increase of proton radiation therapy centers in the world. This article exhibits a non-exhaustive state of the art in proton imaging.     

A Fatal Case of Thrombotic Microangiopathy Without Schistocytosis and Absent Biochemical Markers of Hemolysis

Thrombotic microangiopathy (TMA) is characterized by microangiopathic hemolytic anemia with thrombocytopenia. In addition to the primary TMA syndromes, microangiopathic hemolytic anemia with thrombocytopenia can be seen in many systemic diseases. Transplant associated TMA (TA-TMA) affects patients following stem cell or solid organ transplant. A 48-year-old male who underwent autologous stem cell transplant for nonsecretory multiple myeloma was admitted to our hospital with worsening anemia, thrombocytopenia, renal dysfunction and hepatosplenomegaly. Initial blood work revealed rare schistocytes and normal lactate dehydrogenase and haptoglobin levels. He underwent an extensive workup looking for an infectious, inflammatory or malignant etiology but a definitive diagnosis could not be reached. Over his prolonged stay at the hospital, he suffered from multiorgan failure and eventually passed away. An autopsy revealed TMA involving all clinically affected organ systems and was deemed to be the cause of his demise. The absence of typical blood work suggestive of hemolysis does not rule out a diagnosis of TA-TMA. Knowledge of this rare disease entity will help physicians identify and treat this life-threatening condition early and effectively.     

Alu Methylation and Risk of Cancer: A Meta-analysis

BackgroundThe association between Alu methylation and risk of cancer remains uncertain. This meta-analysis was conducted to elucidate this issue.Materials and MethodsPubMed and Web of Science up to December 31, 2018, and the reference lists of studies, as well as those presented in relevant meta-analyses and reviews were systematically searched. Standardized mean difference (SMD) in Alu methylation level between cases and controls were pooled using random effects model and assessed heterogeneity between strata by stratified factors using meta-regression model. Sensitivity analysis and publication bias test were also conducted.ResultsTwenty-five articles, including 2719 cases and 3018 controls were included in the meta-analysis. The significant difference in Alu methylation level between cancer cases and controls was greater in tissue (SMD = −1.89, 95% CI: −2.72, −1.05) than blood (SMD = −0.46, 95% CI: −0.82, −0.09), and heterogeneity was found in materials (P = 0.038). In tissue samples, Alu hypomethylation was found in carcinoma (SMD = −2.50, 95% CI: −3.51, −1.48), while not in non-carcinoma. The inverse associations were consistently found in subgroups stratified by data sources and quality score in tissue samples, and publication year was considered to be the potential source of between-study heterogeneity. Moreover, reduced Alu methylation level was found in the European subgroup, detection method of SIRPH and COBRA, and original data source in blood samples.ConclusionsAlu hypomethylation was associated with increased risk of cancer, which could be a potential biomarker for cancer.     

宁波市城乡结合部儿童道路交通伤害干预效果评价

目的:探索城乡结合部儿童道路交通伤害干预模式,为儿童道路交通伤害干预有效途径提供参考。方法:选择宁波市城乡结合部中小学生为对象,建立并实施健康教育、技能培训和环境改变综合干预对策,通过一年半的干预,比较干预前后伤害发生及知信行等方面变化。结果:干预后中小学生伤害知识得分均较干预前上升,差别均有统计学意义(P<0.05);干预后被调查高年级小学生和初中生经常在马路上打闹的发生率均有明显下降(分别从1.3%和1.9%下降至0.6%和0.8%);干预前后道路交通伤害发生率无统计学差异(P>0.05)。结论:以健康教育为主、技能培训和环境改变为辅的伤害干预方式在5所学校实施取得了一定效果,可为城市城乡结合部儿童道路交通伤害干预提供参考。