An Agent Based Model for Simulating the Spread of Sexually Transmitted Infections

This work uses agent-based modelling (ABM) to simulate sexually transmitted infection (STIs) spread within a population of 1000 agents over a 10-year period, as a preliminary investigation of the suitability of ABM methodology to simulate STI spread. The work contrasts compartmentalized mathematical models that fail to account for individual agents, and ABMs commonly applied to simulate the spread of respiratory infections. The model was developed in C++ using the Boost 1.47.0 libraries for the normal distribution and OpenGL for visualization. Sixteen agent parameters interact individually and in combination to govern agent profiles and behaviours relative to infection probabilities. The simulation results provide qualitative comparisons of STI mitigation strategies, including the impact of condom use, promiscuity, the form of the friend network, and mandatory STI testing. Individual and population-wide impacts were explored, with individual risk being impacted much more dramatically by population-level behaviour changes as compared to individual behaviour changes.     

Optimal Control Strategy of Plasmodium vivax Malaria Transmission in Korea

ObjectiveTo investigate the optimal control strategy for Plasmodium vivax malaria transmission in Korea.MethodsA Plasmodium vivax malaria transmission model with optimal control terms using a deterministic system of differential equations is presented, and analyzed mathematically and numerically.ResultsIf the cost of reducing the reproduction rate of the mosquito population is more than that of prevention measures to minimize mosquito-human contacts, the control of mosquito-human contacts needs to be taken for a longer time, comparing the other situations. More knowledge about the actual effectiveness and costs of control intervention measures would give more realistic control strategies.ConclusionMathematical model and numerical simulations suggest that the use of mosquito-reduction strategies is more effective than personal protection in some cases but not always.     

薯蓣皂苷元无定形固体分散体制备及体内外评价

目的 制备薯蓣皂苷元无定形固体分散体（diosgenin amorphous solid dispersion,Dio-ASD），提高Dio溶出度和生物利用度。方法 应用分子模拟技术分析Dio与载体之间相互作用并通过抑晶实验验证，构建Dio与载体混溶性曲线相图，理论预测二者混溶性；以Soluplus为载体，应用共沉淀法制备Dio-ASD；通过溶出度测定、差示扫描量热分析（differential scanning calorimetry,DSC）、X-射线粉末衍射（X-ray powder diffraction,XRPD）、扫描电镜分析（scanning electron microscopy,SEM）、傅里叶红外光谱（Fourier transform infrared spectroscopy,FT-IR）对Dio-ASD进行体外评价；采用UPLC-MS/MS方法测定大鼠体内Dio血药浓度，计算药动学参数，对Dio-ASD进行体内评价。结果 分子模拟结果显示Soluplus与Dio之间能形成疏水键和氢键相互作用，结合能强于其他载体，且Soluplus对Dio的抑晶作用最强。构建了...     

基于社会接触网络的大规模人群天花传播并行仿真

天花生物恐怖是世界各国面临的重大潜在威胁.本文利用并行仿真的技术手段,研究天花在大规模城市人群中的传播规律并对环形接种和大规模疫苗接种这两种主要的天花疫苗接种策略进行有效性分析,结果表明环形接种措施能够有效控制天花疫情的扩散,在天花疫苗储备不足的情况下可以优先考虑采用该措施.     

舱外航天服视野设计中的虚拟视域仿真建模

目的探讨一种用于舱外航天服视野设计和分析的虚拟视域仿真建模方法。方法利用Solidworks软件建立三维人体模型,在对软件进行二次开发的基础上,充分利用软件提供的聚光源特性,建立了模拟人眼视锥及人眼运动的仿真算法,从而在Solidworks软件中实现人穿着舱外服后的虚拟视域仿真分析。结果将所建立的模型用于舱外服视野分析,其结果与人-服试验过程视野工效测试结果相一致。结论该模型可应用于舱外航天服设计过程中,对于其它具有工效要求的产品设计具有参考意义。     

Three Meals a Day is Passé at Progressive Hospital

Modern medical simulation technology (MST) debuted in 1960 with the development of Resusci Annie (Laerdal 2007), which assisted students in the acquisition of proper ventilation and compression techniques used during basic life support. Following a steady stream of subsequent technological advances and innovations, MST manufacturers are now able to offer training aids capable of facilitating innovative learning in such diverse areas as human patient simulators, simulated clinical environments, virtual procedure stations, virtual medical environments, electronic tutors, and performance recording. The authors list a number of the most popular MSTs presently available while citing evaluative efforts undertaken to date regarding the efficacy of MST to the medical profession. They conclude by proposing a variety of simulation innovations of prospective interest to both medical and technology personnel while offering healthcare administrators a series of recommended considerations when planning to integrate MST into existing medical systems.     

某市精神分裂症的医疗保障状况分析

目的:为缩小城镇职工、城镇居民医保精神分裂症患者之间保障水平的差异提供意见.方法:首先分析城镇居民医疗保险、城镇职工基本医疗保险患者灾难性卫生支出发生率,然后进行政策模拟分析城居保患者灾难性卫生支出发生率的改善情况.结果:精神分裂症患者极易发生灾难性卫生支出,且城镇居民医疗保险患者发生率更高,是否享受大病救助对城镇居民医疗保险患者的灾难性支出发生率的影响较明显.结论:提高城镇居民医疗保险患者的补偿水平,以提高不同保障制度的公平性;对基本医疗保险和大病救助做好定位,积极推进重特大疾病医疗救助和城镇居民医疗保险的衔接.     

Cellular- and micro-dosimetry of heterogeneously distributed tritium

Abstract

Purpose: The assessment of radiotoxicity for heterogeneously distributed tritium should be based on the subcellular dose and relative biological effectiveness (RBE) for cell nucleus. In the present work, geometry-dependent absorbed dose and RBE were calculated using Monte Carlo codes for tritium in the cell, cell surface, cytoplasm, or cell nucleus.

Materials and methods: Penelope (PENetration and Energy LOss of Positrins and Electrons) code was used to calculate the geometry-dependent absorbed dose, lineal energy, and electron fluence spectrum. RBE for the intestinal crypt regeneration was calculated using a lineal energy-dependent biological weighting function. RBE for the induction of DNA double strand breaks was estimated using a nucleotide-level map for clustered DNA lesions of the Monte Carlo damage simulation (MCDS) code.

Results: For a typical cell of 10 μm radius and 5 μm nuclear radius, tritium in the cell nucleus resulted in much higher RBE-weighted absorbed dose than tritium distributed uniformly. Conversely, tritium distributed on the cell surface led to trivial RBE-weighted absorbed dose due to irradiation geometry and great attenuation of beta particles in the cytoplasm. For tritium uniformly distributed in the cell, the RBE-weighted absorbed dose was larger compared to tritium uniformly distributed in the tissue.

Conclusions: Cellular- and micro-dosimetry models were developed for the assessment of heterogeneously distributed tritium.     

Muscle contributions to center of mass acceleration adapt to asymmetric walking in healthy subjects

Symmetrical limb movement requires complex muscle coordination patterns. Consequently, coordination impairments lead to asymmetric gait patterns, as often seen in stroke subjects. Split-belt walking has previously been used to induce limping-like walking in able-bodied adults. The goal of this study is to analyze how muscle coordination patterns that control the centre of mass are modulated during an asymmetric gait pattern imposed on healthy subjects. These modulations can be uniquely related to the biomechanics of limping as no pathology is present. Forward simulations of limping-like walking (split-belt) and corresponding symmetric conditions (tied-belt) were generated for twelve healthy subjects. Our results show that the differences between ‘fast’ and ‘slow’ leg contributions during split-belt walking are not attributable to simple differences in speed between the belts, because most split-belt muscle contributions differ from tied-belt walking. Different types of modulations, inducing increased, decreased or even reversed asymmetry (e.g. plantarflexors, biceps femoris short head, and quadriceps respectively), underlie limping-like walking in healthy subjects. In general, these patterns present large similarities with adaptations previously described in hemiplegic subjects. However, differences were found with gluteus medius and biceps femoris short head contributions in hemiplegic subjects, suggesting that the latter are not just related to limping, but to concomitant deficits.     

Geometrical optimization of an annulus Compton suppression system using Monte Carlo simulation

We are planning to construct a Compton-suppression system permitting accurate and precise determinations of radioactivity of low-level environmental samples. An annulus guard detector (NaI) and a plug-in detector (NaI) are being used as suppression detectors with an HPGe primary detector. The geometry of the Compton suppression spectrometer was optimized by simulation with PENELOPE for obtaining the highest suppression factor (SF) for a point source. The results of the simulations show that the ultimate value of the suppression factor is 7.87±0.18, obtained when the source is located at 57% of an annuls guard detector.