Bayesian analysis of non-linear differential equation models with application to a gut microbial ecosystem

Process models specified by non-linear dynamic differential equations contain many parameters, which often must be inferred from a limited amount of data. We discuss a hierarchical Bayesian approach combining data from multiple related experiments in a meaningful way, which permits more powerful inference than treating each experiment as independent. The approach is illustrated with a simulation study and example data from experiments replicating the aspects of the human gut microbial ecosystem. A predictive model is obtained that contains prediction uncertainty caused by uncertainty in the parameters, and we extend the model to capture situations of interest that cannot easily be studied experimentally.     

miRNAs生物合成过程的调控

miRNAs是一类短的(20-23nt)非编码的单链RNA分子,在转录后水平上通过抑制靶基因的表达而影响生物体的生长、发育以及癌症发生。miRNAs的成熟需要一系列大型蛋白复合体参与的协同加工,目前对miRNAs生物合成过程调控的研究还处于初始阶段。本文主要综述了影响miRNAs的生物合成过程及活性的因素以及相关调控机制。癌症的发生通常伴随着异常的miRNAs表达谱,miRNAs生物合成调控机制的深入研究必将为癌症的基因治疗技术以及新型疗法的开发提供重要的理论基础和指导意义。     

Development of a three-zone simulated moving bed process based on partial-discard strategy for continuous separation of valine from isoleucine with high purity,high yield,and high product concentration

The issue of separating valine from isoleucine has been a major concern in the biotechnological process for production of valine. To address this issue, an optimal three-zone simulated moving bed (SMB) process for continuous separation of valine was developed in this study. It was first found that an Amberchrom-CG161C resin was highly suitable for the adsorbent of such SMB process. The adsorption isotherm and mass-transfer parameters of valine and isoleucine on the Amberchrom-CG161C adsorbent were then determined through multiple frontal experiments. The determined parameters were used in the next stage of optimizing the SMB for valine separation, which was performed on the basis of genetic algorithm. For the optimized SMB process, a partial-discard strategy was applied to the raffinate port in order to make a further improvement in the valine product concentration. Finally, the optimized SMB based on the partial-discard strategy was tested experimentally using the self-assembled SMB equipment. The experimental results showed that the developed process in this study was highly effective in continuous separation of valine from isoleucine while ensuring the attainment of high product concentration. The experimental data for the SMB effluent histories and the SMB column profiles were also in close agreement with the model predictions.     

重组药物工艺经济分析

随着生物制药行业环境的变化和大剂量产品的出现,生产成本的压力日益凸现。从经济的角度探讨了重组药物上游及下游工艺设计和优化对投资和运转成本的影响,对于生物制药企业降低成本,提高竞争力有积极意义。     

大型人工湿地生态可持续性评价

大型人工湿地现已广泛应用于湖滨带、河滨带水质净化及湿地生态修复,这些人工湿地的生态可持续性评价对于其科学管理调控及长期可持续运行具有重要意义。运用综合指标评价及层次分析法,根据人工湿地生态系统的特点,提出并建立了适合评价人工湿地可持续性运行的指标体系,建立的评价指标包括生态特征与功能、水质净化功能及经济社会功能三项一级指标,及对应的14个二级指标。运用建立的评价指标体系对南四湖湖滨带新薛河大型人工湿地示范工程的生态可持续性运行了评价,评价结果显示:植物多样性、氨氮去除能力、生物入侵抵抗力、野生动物栖息地、COD去除能力是影响大型人工湿地运行效果的主要制约因素;新薛河人工湿地生态可持续性综合指数为0.6862,处于"良"级,其中生态特征功能可持续性指数最高,为0.7732;水质净化功能和社会经济功能指数分别为0.6190,0.6492。由结果可知,南四湖新薛河大型人工湿地具有重要的生态修复功能,水质净化功能方面应加强植物定期收割及植被管理,同时经济社会功能还有待加强,植物经济效益及旅游娱乐效益还有待深入开发。建立的人工湿地可持续性运行的评价指标体系具有较强的针对性,可用于其他大型人工湿地的生态可持续性评价。     

解淀粉芽孢杆菌3-2发酵羽毛产氨基酸

【目的】建立废弃羽毛液体发酵工艺,优化发酵条件,提高羽毛降解率及氨基酸产量,研发新型、高效复合氨基酸肥料。【方法】利用解淀粉芽孢杆菌3-2发酵羽毛,探究温度、发酵时间、羽毛含量、单一碳源、复合碳氮源、金属离子等对废弃羽毛降解效果以及发酵液中氨基酸种类和含量的影响。【结果】废弃羽毛降解率与氨基酸总产量呈负相关。随着发酵时间延长,羽毛降解率增加,当发酵温度为37°C、羽毛添加量为1%、以乳糖为外加碳源、添加Mg2+时,羽毛降解率最高,达到81.92%。随着羽毛添加量增加,氨基酸总含量也增加(在20%范围以内),当发酵温度为37°C、降解时间为108 h、羽毛添加量为10%、乳糖添加量为0.5%、不添加复合碳氮源、不添加金属离子时,氨基酸的种类最全(富含17种氨基酸),总含量最高,达到20.861 g/kg。【结论】利用解淀粉芽孢杆菌3-2发酵废弃羽毛生产氨基酸复合肥料是一种可靠、环保、经济的方法,获得的氨基酸肥料营养齐全。研究结果为新型复合氨基酸肥料的研发提供技术支撑。     

基于分布式水文模型的水源涵养不同功能评估方法——以渭河涵养区为例

为了实现水源涵养量计算和不同功能的综合评估,基于分布式水文模型(WEP-L)提出了一种新方法,即利用WEP-L模型计算次降水过程中降水量和地表产流、冠层截留量的差值作为水源涵养量,并分别评估削洪(地表径流量)、补枯(地下径流量)、维持植被生态系统用水(植被蒸腾量)等不同水源涵养功能的评估方法。为了验证该方法的合理性,以渭河流域咸阳站以上区域为例,对比了该方法和InVEST模型方法的计算结果,由于两种方法在评估内容和使用模型上都存在差异,为了保证计算结果的可比性,先对比了基于相同评价内容的WEP-L模型法I和InVEST模型方法,再对比了基于不同评价内容的WEP-L模型法I和WEP-L模型法II,结论如下:基于相同评价内容的WEP模型法I和InVEST模型法计算结果数值接近,研究区2000-2018年水源涵养量年均值分别为12.43 mm(5.76亿m³)和12.08 mm(5.6亿m³),两种方法所得结果空间分布特征相似,稍有差异之处与InVEST模型的参数没有经过本地化处理有关;基于不同评价内容的WEP-L模型法Ⅰ和WEP-L模型法II计算结果数值相差较大,研究区2000-2018年水源涵养量均值分别为12.43 mm和432.57 mm,空间分布特征上有差异的地方分布于研究区的北部、东部及东北部,主要与两种方法评价时是否考虑蒸散发有关。WEP-L模型法II评估结果中削洪、补枯、维持植被生态系统用水等功能多年变化趋势分别为:2006-2010年期间增加、2012年以后下降以及增加。2012年后补枯功能和维持植被生态系统用水功能之间可能存在权衡关系。通过不同方法计算结果差异原因分析,证明了基于WEP-L模型的不同涵养功能评估方法的合理性,其结果也可为渭河涵养区水资源和生态保护策略的制定提供更多依据。     

Gene microarray analysis of expression profiles in Suberoyllanilide hyroxamic acid-treated Dendritic cells

Objective

The purpose of this study is to provide a further theoretical basis for the role of Suberoyllanilide hyroxamic acid (SAHA) affect on Dendritic cells (DCs).