基于质谱的蛋白质绝对定量研究策略和建议

科学家已经研究获得了大量的蛋白质/多肽潜在生物标志物,这些生物标志物需要经过验证和确证才能进一步转化到临床应用.针对蛋白质/多肽的绝对定量研究在标志物验证和确证过程中起到关键作用.传统的蛋白质定量方法,如酶联免疫吸附试验(ELISA)技术存在蛋白质抗体难以获得、不同抗体批次之间存在差异、基于抗体的检测存在交叉反应等问题...     

Towards optimal allocation of computer resources: Trade-offs between uncertainty quantification,discretization and model reduction

The computational complexity of numerical models can be broken down into contributions ranging from spatial, temporal and stochastic resolution, e.g., spatial grid resolution, time step size and number of repeated simulations dedicated to quantify uncertainty. Controlling these resolutions allows keeping the computational cost at a tractable level whilst still aiming at accurate and robust predictions. The objective of this work is to introduce a framework that optimally allocates the available computational resources in order to achieve highest accuracy associated with a given prediction goal. Our analysis is based on the idea to jointly consider the discretization errors and computational costs of all individual model dimensions (physical space, time, parameter space). This yields a cost-to-error surface which serves to aid modelers in finding an optimal allocation of the computational resources (ORA). As a pragmatic way to proceed, we propose running small cost-efficient pre-investigations in order to estimate the joint cost-to-error surface, then fit underlying complexity and error models, decide upon a computational design for the full simulation, and finally to perform the designed simulation at near-optimal costs-to-accuracy ratio. We illustrate our approach with three examples from subsurface hydrogeology and show that the computational costs can be substantially reduced when allocating computational resources wisely and in a situation-specific and task-specific manner. We conclude that the ORA depends on a multitude of parameters, assumptions and problem-specific features and, hence, ORA needs to be determined carefully prior to each investigation.     

Visualization and quantification of water movement in porous cement-based materials by real time thermal neutron radiography:Theoretical analysis and experimental study

Water movement in porous cement-based materials is of great importance when studying their deterioration processes and durability.Many traditional methods based on mass changes,electricity or nuclear magnetic resonances are available for studying water transport in cement-based materials.In this research,an advanced technique i.e.thermal neutron radiography was utilized to achieve visualization and quantification of time dependent water movement including water penetration and moisture vapor in porous cemen...     

Inverse identification of the release location,temporal rates,and sensor alarming time of an airborne pollutant source

With an accidental release of an airborne pollutant, it is always critical to know where, when, and how the pollutant has been released. Then, emergency measures can be scientifically advised to prevent any possible harm. This investigation proposes an inverse model to identify the release location, the temporal rate profile, and the sensor alarming time from the start of a pollutant release. The first step is to implement the inverse operation to the cause–effect matrix to obtain the release rate profiles for discrete candidate scenarios with concentration information provided by one sensor. The second step is to interpret the occurrence probability of each solution in the first step with the Bayesian model by matching the concentration at the other sensor. The proposed model was applied to identify a single pollutant source in a two‐dimensional enclosure using measurement data and in a three‐dimensional aircraft cabin with simulated data. The results show that the model is able to correctly determine the pollutant source location, the temporal rate profile, and the sensor alarming time. The known conditions for input into the inverse model include a steady flow field and the valid temporal concentrations at two different locations.     

Comparison of the wound-activated transformation of caulerpenyne by invasive and noninvasive Caulerpa species of the Mediterranean

The invasive green alga, Caulerpa taxifolia, that has spread rapidly after its introduction into the Mediterranean and the North American Pacific, reacts to wounding by transforming its major metabolite caulerpenyne (1). This wound-activated reaction involves the transformation of the bis-enol acetate moiety of 1, releasing reactive 1,4-dialdehydes. The ability to perform this transformation is found also in both the noninvasive Mediterranean C. prolifera and the invasive C. racemosa. Trapping experiments, as well as transformation of the model substrate geranyl acetate, suggest that all three investigated Caulerpa spp. rely on esterases that act upon wounding of the algae by subsequently removing the three acetate residues of caulerpenyne. The resulting reactive 1,4-dialdehyde oxytoxin 2 (9) can be identified by liquid chromatography–mass spectrometry and is unstable in the wounded tissue. Caulerpenyne transformation occurs rapidly, and severe tissue damage caused degradation of more than 50% of the stored caulerpenyne within 1 min in all three algae. Prevention of the enzymatic reaction before extraction, by shock freezing the tissue with liquid nitrogen, was used for the determination of the caulerpenyne content in intact algae. It gives about twofold higher values compared to an established methanol extraction protocol. The speed and mechanism of the wound-activated transformation, as well as the caulerpenyne content in intact tissue of invasive and noninvasive Caulerpa spp., are comparable. Thus, this enzymatic , transformation, despite being fast and efficient, is likely not the key for the success of the investigated invasive species.     

对高校奖学金评定量化方法的探索

研究了一套高校奖学金评定的量化方法，提出了“附加分”的新概念，目的在于使高等院校的奖学金评定工作更加公平、公正、公开，充分发挥奖学金鼓励先进、鞭策后进、促进大学生全面素质提高的作用。     

城市照明规划研究(英文)

文章通过对城市照明总体规划、城市照明详细规划设计内容的确定,结合实践中的认识,对城市照明总体规划、城市照明详细规划设计及城市照明规划的定量方面进行了研究。     

感觉量化分析在包装设计中的应用

通过对量化分析的研究,初步阐述了感觉量化的概念及意义,并在此基础之上进一步探讨了如何有效地利用感觉量化理论来分析包装设计,从而进一步全面地构建了包装设计的理论体系.     

Optimization of extraction and determination of emodin from Polygonum cuspidatum Sieb. et Zucc. products by HPLC-DAD

A uniform experimental design procedure was used to investigate the effects of some operating parameters on the extraction of emodin from Polygonum cuspidatum Sieb. et Zucc. products. Variables tested were volume ratio of material to solvent, size of material, extraction time and temperature and composition of extraction solvent （mixtures of acetone-water）. Each variable was tested at seven levels; 7 experiments were performed in random order. Analyses of the extracts were performed by high-performance liquid chromatography with diode array detection（HPLC-DAD）. Analytical responses were processed by using a forward regression analysis, in order to find polynomial function describing the relationship between variables and responses. For all the analytes the experimental conditions for providing the highest extraction yield inside the experimental domain considered were found. Finally, a simple, rapid and accurate analytical method was developed for the determination of emodin by high performance liquid chromatography. The separation is achieved within 25 rain on an ODS column using methanol and water as gradient mobiles. Emodin can be quantified by using external standard method detecting at 436 nm. Good linearity is obtained with correlation coefficient exceeding 0.9986 and the detection limit and the quantification limit are 1.53 and 3.23 mg/L respectively. This method shows good reproducibility for the quantification of the emodin with intra-day and inter-day relative standard deviation less than 2.3% and 5.6% respectively. Under optimized extraction conditions, the recovery of the standard is 96.5%. The validated method is successfully applied to quantify the emodin in seven Polygonum cuspidatum sieb. Et zucc. products, which provided an idea for the pre-treatment of determination of active compounds in traditional Chinese medicines.     

Turbo码不同译码算法中的量化性能分析

针对Turbo码的不同译码方法，提出了不同情况下的中间变量的量化方式。在已完成接收比特、附加信息和输出似然值的量化情况下，着重讨论了不同译参政方式的中间变量的量化范围、量化级别和量化方法对译码性能的影响。仿真结果表明，对于改进的Turbo码的译码算法（LOG-MAP，MAX-LOG-MAP，SOVA），中间变量的量化可以不采用非均匀量化，而且中间变量量化的级别也可以大大减小，不仅降低译码复杂度，而且减少了硬件实现时所需要的存储空间。