大鼠膈神经传出和传入神经成分在脊髓内的分布

采用HRP追踪法,对成年大鼠膈神经运动纤维的起源和初级传入神经元胞体的位置及在其中枢突脊髓的投射进行了观察。结果表明,膈神经运动纤维在脊髓标记(膈核)主要分布在注射侧C_3-C_5脊髓节段的前角。隔神经感觉纤维初级传入标记的神经元见于注射侧C_3-C_6后根节,其中C_4标记的细胞数最多。     

A micro-mechanics model of dentin mechanical properties

Application of a micro-mechanics cell model to dentin composites for determination of their effective mechanical properties is discussed in this paper. The dilute micro-mechanics model for fibre-reinforced composites is utilized and the corresponding cell model is chosen to consist of a circular hollow cylinder filled with liquid or gas phase, which is surrounded by two circular cylindrical shells, a thin shell and a matrix phase. Each layer of cylindrical shell is here considered as a composite consisting of collagen fibrils, with mineralized hydroxyapatite, loosely connected to their neighbours, and water (or gas in the case of dry dentin composite). Determination of the effective material properties of such a three phase composite is discussed. Using the cell model the effect of porosity, thickness of each cylindrical shell, and mineral content on material properties is analysed. Results obtained from nano-indentation observations are compared with numerical predictions of the analytical model.     

Modeling the development of acquired clinical immunity to Plasmodium falciparum malaria

Individuals living in regions where malaria is endemic develop an acquired immunity to malaria which enables them to remain asymptomatic while still carrying parasites. Field studies indicate that cumulative exposure to a variety of diverse Plasmodium parasites is required for the transition from symptomatic to asymptomatic malaria. This study used a simulation model of the within-host dynamics of P. falciparum to investigate the development of acquired clinical immunity under different transmission conditions and levels of parasite diversity. Antibodies developed to P. falciparum erythrocyte membrane protein 1 (PfEMP1), a clonally variant molecule, were assumed to be a key human immunological response to P. falciparum infection, along with responses to clonally conserved but polymorphic antigens. The time to the development of clinical immunity was found to be proportional to parasite diversity and inversely proportional to transmission intensity. The effect of early termination of symptomatic infections by chemotherapy was investigated and found not to inhibit the host's ability to develop acquired immunity. However, the time required to achieve this state was approximately double that compared to when no treatment was administered. This study demonstrates that an immune response primarily targeted against PfEMP1 has the ability to reduce clinical symptoms of infections irrespective of whether treatment is administered, supporting its role in the development of acquired clinical immunity. The results also illustrate a novel use for simulation models of P. falciparum infections, investigation of the influence of intervention strategies on the development of naturally acquired clinical immunity.     

我国正常生育力男子精浆的微量元素研究

本文报告测试了68例正常生育力成年男子精浆中的锌、铜,铁等微量元素和镁,测试结果如下:锌130±5.64μg/ml,铜1.84±0.158μg/ml,铁0.801±0.104μg/ml,镁103.86±10.01μg/ml。所测得的数值均在正常范围内。在正常范围内的精液,精浆中的锌、镁含量与精液质量(精子密度和活动力)之间无显著差异。但铜的含量与精子活动度关系密切,含量高则活动度差,反之则活动度好。铁的含量与精子密度关系也十分密切,含量高时精子密度也高。     

西藏6个高海拔县藏族人群骨质疏松患病现状及其影响因素研究

目的 了解西藏地区6个高海拔县藏族成年人骨质疏松的患病现状及其影响因素。方法 采用多阶段分层随机抽样,从西藏地区6个高海拔县随机抽取1 309名藏族居民作为研究对象,采用χ2检验和logistic回归方法分析该地区骨质疏松检出率情况及影响因素。结果 西藏地区6个高海拔县成年女性骨质疏松的检出率为3.8％,男性为3.0％;60岁及以上女性骨质疏松的检出率为16.7％,男性为12.8％。Logistic回归分析结果显示:在女性群体中,年龄、从事农牧活动、BMI、绝经与骨质疏松的发生有关。在男性群体中,年龄与骨质疏松的发生有关。结论 西藏地区6个高海拔县60岁及以上男性和女性的骨质疏松的检出率偏低。增龄是该地区藏族成年女性、男性骨质疏松发生的独立危险因素。绝经、BMI偏低是该地区成年女性骨质疏松发生的独立危险因素。从事农牧活动是该地区成年女性骨质疏松发生的保护因素。     

实时荧光RT-PCR法和NASBA方法在呼吸道多病原检测中的应用评价

目的 评价实时荧光RT-PCR和核酸依赖性序列扩增法（NASBA）两种方法在呼吸道多病原检测中的应用价值。方法 收集北京地区急性呼吸道感染病例标本140份,分别采用实时荧光RT-PCR方法和NASBA方法对样本进行平行检测并对两种方法的病原检出限、重复性、检测一致性及检测时间等指标进行比较。结果 两种检测方法批内重复CV值均<5%,重复性较好;实时荧光RT-PCR方法对脊灰毒株核酸和H1N1病毒核酸最低检出限分别为5.62 CCID50 /0.1 ml（107 倍稀释）和10³倍稀释度,NASBA方法最低检出限分别为56.2 CCID50 /0.1 ml（106 倍稀释）和10²倍稀释。实时荧光RT-PCR灵敏度略优于NASBA方法。针对两种方法共同检测呼吸道病原体种类,实时荧光RT-PCR和NASBA方法检测阳性率分别为89.28%（125/140）、70%（98/140）。两种方法对甲型H1N1病毒、肠道病毒及新型冠状病毒的检测结果一致性达100%,对甲型流感病毒、甲型H3N2、副流感病毒1-4型的检测结果基本一致, Kappa 值范围为0.81~1;对冠状病毒229E/HKU1/OC43/NL63、鼻病毒、呼吸道合胞病毒和乙型流感病毒的检测结果一致性较好, Kappa 值范围为0.61~0.80;对人偏肺病毒的检测结果一致性差, Kappa 值仅为0.55。实时荧光RT-PCR方法检测时间为90 min,NASBA方法仅需40 min即可完成。 结论 实时荧光RT-PCR方法灵敏度较高,适合对大批量临床样本进行筛查;NASBA方法检测时间短,不易污染,适用于时限性强但对灵敏度要求不太高的应用场景,如临床上重症呼吸道感染者的快速检测。建议根据不同需求和应用场景,选择合适的检测方法和产品。     

Dietary Aspects to Incorporate in the Creation of a Mobile Image-Based Dietary Assessment Tool to Manage and Improve Diabetes

Diabetes is the seventh leading cause of death in United States. Dietary intake and behaviors are essential components of diabetes management. Growing evidence suggests dietary components beyond carbohydrates may critically impact glycemic control. Assessment tools on mobile platforms have the ability to capture multiple aspects of dietary behavior in real-time throughout the day to inform and improve diabetes management and insulin dosing. The objective of this narrative review was to summarize evidence related to dietary behaviors and composition to inform a mobile image-based dietary assessment tool for managing glycemic control of both diabetes types (type 1 and type 2 diabetes). This review investigated the following topics amongst those with diabetes: (1) the role of time of eating occasion on indicators of glycemic control; and (2) the role of macronutrient composition of meals on indicators of glycemic control. A search for articles published after 2000 was completed in PubMed with the following sets of keywords “diabetes/diabetes management/diabetes prevention/diabetes risk”, “dietary behavior/eating patterns/temporal/meal timing/meal frequency”, and “macronutrient composition/glycemic index”. Results showed eating behaviors and meal macronutrient composition may affect glycemic control. Specifically, breakfast skipping, late eating and frequent meal consumption might be associated with poor glycemic control while macronutrient composition and order of the meal could also affect glycemic control. These factors should be considered in designing a dietary assessment tool, which may optimize diabetes management to reduce the burden of this disease.     

西昌市城区3~14岁儿童身高状况分析

目的 分析西昌市城区儿童身高的特点,为当地儿童健康发展提供参考。方法 2018年4-5月采用分层整群抽样法以西昌市城区19所学校3~14岁儿童作为研究对象。按照《中国儿童生长标准与生长曲线》的要求,统一测量儿童身高,并使用SPSS22.0软件进行数据分析。结果 西昌市城区的儿童中汉族男生3~6岁及9~11岁、彝族男生3~7岁及10~11岁、汉族女生3~7岁及9~10岁、彝族女生3~10岁的身高均高于全国标准(P<0.05);学龄前期男生汉族儿童身高高于彝族(P<0.05);在学龄期与青春期彝汉两个民族身高差异无统计学意义(P>0.05);男生身高在各年龄段均高于女生身高(P<0.05)。结论 西昌市儿童身高普遍高于全国标准身高,家长应重视身高在儿童生长发育中的作用。