重度腹外伤后并发腹腔高压综合征的诊断及治疗

目的总结分析重度腹外伤后并发腹腔高压综合征的诊断及治疗经验.方法分析2例重度腹外伤伴失血性休克并发ACS病例,根据临床表现确定ACS诊断后,及时行腹腔减压,分别以腹壁覆盖及塑料袋缝合暂时性关腹.结果及时认识治疗ACS并行腹腔减压适量延长切口,结果满意,病患恢复平稳.结论对ACS的认识是及时诊断及治疗的关键,开腹减压以保证患者平稳渡过水肿期,选择合适的材料,有利于患者的康复.     

商用车车身底部尘土污染分析及优化

针对某商用车发动机舱冷却气流导致严重的扬尘问题进行分析研究,通过风扇不同转速下的车底扬尘模拟实验来确定导致扬尘的最低转速,对车底风速进行测试,确定扬尘风速的临界点。通过计算流体动力学仿真,在保证散热性能的前提下,比较了延长护风圈和加导流板两种方案,发现延长50 mm的护风圈和增加10°的导流板扬尘效果最为显著。在两者共同作用下,车底风速降至扬尘临界点以下以及扬尘颗粒数减少75%。通过实车道路测试验证优化方案效果。     

基于APDL的可扩展式车厢的模态分析

利用ANSYS10.0软件,通过APDL语言建立了以梁单元和壳单元以及实体单元为基本单元的可扩展式车厢骨架有限元模型,并对该车厢骨架进行静态分析和模态分析。计算结果可为车厢骨架结构设计、改进和轻量化提供理论依据。     

具有时滞效应二室模型的药物动力学分析

本文利用非平衡态统计物理学方法,探讨了含有时滞效应的二室模型中药物浓度动力学行为.结果表明,在引入适当的滞情况下,可以出现在中央室聚集和在两室中振荡的现象。这是某种给药方式而使药物在体内分布的一种由二室模型得出的新的结果;分析结果也表明,这种时滞效应不可能被包含在相应的速率常数之中.     

室内火灾过程的计算机模拟

针对典型的建筑单室结构及火灾荷载,通过对火灾过程多变量的分析,建立了可燃性固体水平表面火焰蔓延的三维动态数学模型。通过实验和计算数据的对比分析,对数学模型进行了验证。实现了对室内火灾发展过程的三维场模拟研究。     

分解者亚系统能量流动的数学分析

依据房室模型和微分方程理论,对绿色农业生态系统中的分解者亚系统的能量流动过程进行了数学分析,建立了数学模型。稳定性分析结果表明,在绿色农业生态系统中,分解者亚系统能量流动过程中的平衡态是渐进稳定的。即该平衡态的稳定性机制为负反馈机制,该系统具有抵抗干扰和保持系统平衡态的自我调节能力,以确保能量流动的正常进行。最后,通过解微分方程,给出了该系统能量流动的数学模拟公式。     

Bioaccumulation processes in ecosystems

The fate of environmental pollutants — the various isotopes of elements, and inorganic or organic compounds — is a fundamental aspect of ecology and ecotoxicology, and bioaccumulation is a phenomenon often discussed in this context. Human activities have drastically altered natural concentrations of many substances in the environment and added numerous new chemicals. An understanding of the processes of bioaccumulation is important for several reasons. 1) Bioaccumulation in organisms may enhance the persistence of industrial chemicals in the ecosystem as a whole, since they can be fixed in the tissues of organisms. 2) Stored chemicals are not exposed to direct physical, chemical, or biochemical degradation. 3) Stored chemicals can directly affect an individual's health. 4) Predators of those organisms that have bioaccumulated harmful substances may be endangered by food chain effects. While former theories on the processes of bioaccumulation focused on single aspects that affect the extent of accumulation (such as the trophic level within the food chain or the lipophilicity of the chemical), modern theories are based on compartmental kinetics and the integration of various environmental interactions. Concepts include results from quantitative structure-activity relationships (QSAR), pharmacokinetics, ecophysiology and general biology, molecular genetic aspects and selection, and finally the structure of communities and man-made alterations in them.     

Autophagy and other vacuolar protein degradation mechanisms

Autophagic degradation of cytoplasm (including protein, RNA etc.) is a non-selective bulk process, as indicated by ultrastructural evidence and by the similarity in autophagic sequestration rates of various cytosolic enzymes with different half-lives. The initial autophagic sequestration step, performed by a poorly-characterized organelle called a phagophore, is subject tofeedback inhibition by purines and amino acids, the effect of the latter being potentiated by insulin and antagonized by glucagon. Epinephrine and other adrenergic agonists inhibit autophagic sequestration through a prazosin-sensitive ₁-adrenergic mechanism. The sequestration is also inhibited by cAMP and by protein phosphorylation as indicated by the effects of cyclic nucleotide analogues, phosphodiesterase inhibitors and okadaic acid.Asparagine specifically inhibits autophagic-lysosomal fusion without having any significant effects on autophagic sequestration, on intralysosomal degradation or on the endocytic pathway. Autophaged material that accumulates in prelysosomal vacuoles in the presence of asparagine is accessible to endocytosed enzymes, revealing the existence of an amphifunctional organelle, the amphisome. Evidence from several cell types suggests that endocytosis may be coupled to autophagy to a variable extent, and that the amphisome may play a central role as a collecting station for material destined for lysosomal degradation.Protein degradation can also take place in a salvage compartment closely associated with the endoplasmic reticulum (ER). In this compartment unassembled protein chains are degraded by uncharacterized proteinases, while resident proteins roturn to the ER and assembled secretory and membrane proteins proceed through the Golgi apparatus. In thetrans-Golgi network some proteins are proteolytically processed by Ca²⁺-dependent proteinases; furthermore, this compartment sorts proteins to lysosomes, various membrane domains, endosomes or secretory vesicles/granules. Processing of both endogenous and exogenous proteins can occurr in endosomes, which may play a particularly important role in antigen processing and presentation. Proteins in endosomes or secretory compartments can either be exocytosed, or channeled to lysosomes for degradation. The switch mechanisms which decide between these options are subject to bioregulation by external agents (hormones and growth factors), and may play an important role in the control of protein uptake and secretion.     

肝脏FDG代谢模型的参数估计

利用房室模型进行肝脏[18F]氟代脱氧葡萄糖([18F]2-fluoro-2-deoxy-D-glucose,FDG)代谢的动力学研究是进行人体功能信息的建模和研究肝脏葡萄糖代谢率的重要手段。动力学研究需要得到血液中的示踪剂浓度随时间变化曲线,将其作为模型的输入,估计出肝脏FDG代谢模型的动力学参数。然而,肝脏存在肝动脉输入和肝门静脉输入。研究分别采用动脉和门静脉的双输入方式和动脉的单输入方式作为血液输入曲线,用这两个输入函数分别进行了肝脏FDG代谢的动力学研究,比较了用两种方法所得到的结果。结果显示,在人体肝脏的FDG代谢研究中,用两种输入曲线得到的结果存在明显的不同,并且用双输入曲线得到的结果更加准确。     

大亚湾海域马尾藻对放射性核素110mAg 迁移转化的数值模拟

应用潮波方程和扩散方程计算出放射性核素110 mAg在大亚湾的浓度分布,使用库室模型描述海洋生态系统动力学微分方程组,建立了海洋生物库室简化模型,得出大亚湾海域马尾藻对放射性核素110 mAg的迁移转化在各网格处达到动态平衡时的浓度规律. 模拟结果与实测数据基本一致,说明模型的建立及参数的选取是恰当的. 该方法为预测核电站废水排放中放射性核素的对海洋生物的影响提供了科学依据.