Cellular Senescence: Pathogenic Mechanisms in Lung Fibrosis

Pulmonary fibrosis is a chronic and fatal lung disease that significantly impacts the aging population globally. To date, anti-fibrotic, immunosuppressive, and other adjunct therapy demonstrate limited efficacies. Advancing our understanding of the pathogenic mechanisms of lung fibrosis will provide a future path for the cure. Cellular senescence has gained substantial interest in recent decades due to the increased incidence of fibroproliferative lung diseases in the older age group. Furthermore, the pathologic state of cellular senescence that includes maladaptive tissue repair, decreased regeneration, and chronic inflammation resembles key features of progressive lung fibrosis. This review describes regulatory pathways of cellular senescence and discusses the current knowledge on the senescence of critical cellular players of lung fibrosis, including epithelial cells (alveolar type 2 cells, basal cells, etc.), fibroblasts, and immune cells, their phenotypic changes, and the cellular and molecular mechanisms by which these cells contribute to the pathogenesis of pulmonary fibrosis. A few challenges in the field include establishing appropriate in vivo experimental models and identifying senescence-targeted signaling molecules and specific therapies to target senescent cells, known collectively as “senolytic” or “senotherapeutic” agents.     

Numerical simulation of microstructure formation ofAZ91 using mCA method

A stochastic model for simulating the microstructure formation of Mg alloy AZ91 during solidification was developed based on the finite element method（FEM） for macroscopic model of heat transfer calculation and a modified Cellular Automaton （mCA） for microscopic modeling of nucleation, growth of crystal. In this model, the effect of solute redistribution, interface curvature and preferred orientation was considered. A numerical simulation was developed with C＋＋ program language. The computation was carded out to understand the effect of varying processing parameters, such as nucleation parameters and heat transfer coefficient, on the microstructure formation of AZ91. The result of simulation was displayed on screen.     

共晶自生复合材料的晶形转变

自生复合材料的晶形转变受到成分过冷与曲面过冷两个因素的控制.非金属相具有较大的熔化熵且易形成小平面是改变领先相的因素,而领先相的改变则可能是晶形转变的根本原因.     

生态稳定塘系统在城市污水处理中的应用

介绍了生态稳定塘系统在德州市城市污水处理中的应用情况，对工程设计参数及其设计特色作了重点介绍，以资同行借鉴。     

Solving a multi-floor layout design model of a dynamic cellular manufacturing system by an efficient genetic algorithm

This paper presents a mixed-integer programming model for a multi-floor layout design of cellular manufacturing systems (CMSs) in a dynamic environment. A novel aspect of this model is to concurrently determine the cell formation (CF) and group layout (GL) as the interrelated decisions involved in the design of a CMS in order to achieve an optimal (or near-optimal) design solution for a multi-floor factory in a multi-period planning horizon. Other design aspects are to design a multi-floor layout to form cells in different floors, a multi-rows layout of equal area facilities in each cell, flexible reconfigurations of cells during successive periods, distance-based material handling cost, and machine depot keeping idle machines. This model incorporates with an extensive coverage of important manufacturing features used in the design of CMSs. The objective is to minimize the total costs of intra-cell, inter-cell, and inter-floor material handling, purchasing machines, machine processing, machine overhead, and machine relocation. Two numerical examples are solved by the CPLEX software to verify the performance of the presented model and illustrate the model features. Since this model belongs to NP-hard class, an efficient genetic algorithm (GA) with a matrix-based chromosome structure is proposed to derive near-optimal solutions. To verify its computational efficiency in comparison to the CPLEX software, several test problems with different sizes and settings are implemented. The efficiency of the proposed GA in terms of the objective function value and computational time is proved by the obtained results.     

高铁车厢内部紧急情况下人员疏散仿真研究

在引入元胞自动机理论的基础上,模拟分析了紧急情况下人员生理及心理的不同对疏散过程的影响,通过人员动态调整自身行为,并引入人员竞争力,对人员疏散过程建立模型。在疏散过程中,根据存在着一定程度的外部干扰因素,提出疏散干扰度概念。计算机仿真的结果表明,考虑人员竞争力,以及出口疏散干扰的问题,可以更加真实地模拟人员紧急疏散过程和疏散状况。     

能效优先的用户关联与功率控制协同优化机制

在异构蜂窝网络中,针对系统的能效,提出了一种基于效用函数最大化模型的用户关联与功率控制协同优化方案,该方案表示为非线性混合整数问题。为了求得该问题的最优解,设计了一种迭代算法,首先将原问题转换为带参数的多项式形式的问题,在外层循环利用Dinkelbach方法求得最佳的能效因子,然后在内层循环分别求得最佳的用户关联矩阵和传输功率。最终实验结果表明,用户关联与功率控制协同的优化方案在能效和负载平衡方面比固定功率条件下的用户关联策略的性能更优。     

泡沫塑料主要力学性能及其力学模型

描述发泡塑料力学性能的模型,讨论了普通发泡塑料的力学性能以及它和发泡塑料密度的关系。并且比较了硬质聚氨酯(RPUR)和聚氯乙烯(PVC)泡沫塑料的主要力学性能随密度的变化。最后介绍了微孔发泡塑料的几项优良的力学性能。     

内部连接的球形多孔羟基磷灰石支架的制备

采用高分子模板,通过注浆成型制备了球形孔结构的羟基磷灰石(hroxyapatite,HA)支架,研究了支架的微观结构、压缩强度和相容性.结果表明:改变工艺参数可以控制高分子模板中球体间胶黏面的大小,控制所制备的HA多孔体孔内连接的尺寸.制备的支架具有开口、均匀而内部连通的多孔结构,当孔径为200μm、孔隙率为65%时,压缩强度可达8MPa左右.体外生物模拟实验表明:多孔结构HA支架有很好的相容性.随多孔球体孔隙率和尺寸的增加,支架的细胞吸收率逐步增加.     

蜂窝式构件长细比的计算方法

为了进一步研究蜂窝构件稳定承载性能,以现有长细比计算理论为基础,结合蜂窝构件的受力机理和界面特性,提出了蜂窝构件长细比计算中相关参数的计算方法．同时,结合理论推导和数值分析结果,提出了蜂窝构件换算长细比建议计算公式．