Novel insight into mechanisms of cholestatic liver injury

Cholestasis results in a buildup of bile acids in serum and in hepatocytes.Early studies into the mechanisms of cholestatic liver injury strongly implicated bile acidinduced apoptosis as the major cause of hepatocellular injury.Recent work has focused both on the role of bile acids in cell signaling as well as the role of sterile inflammation in the pathophysiology.Advances in modern analytical methodology have allowed for more accurate measuring of bile acid concentrations in serum,liver,and bile to very low levels of detection.Interestingly,toxic bile acid levels are seemingly far lower than previously hypothesized.The initial hypothesis has been based largely upon the exposure of μmol/L concentrations of toxic bile acids and bile salts to primary hepatocytes in cell culture,the possibility that in vivo bile acid concentrations may be far lower than the observed in vitro toxicity has far reaching implications in the mechanism of injury.This review will focus on both how different bile acids and different bile acid concentrations can affect hepatocytes during cholestasis,and additionally provide insight into how these data support recent hypotheses that cholestatic liver injury may not occur through direct bile acid-induced apoptosis,but may involve largely inflammatory cell-mediated liver cell necrosis.

Collision-induced Rotational Energy Transfer in an Atom-Diatom System

As a further theoretical study of the collision-induced quantum interference on rotational energy transfer in an atom-diatom system, based on the first-Born approximation of time-dependent perturbation theory, taking into account the anisotropic Lennard-Jones interaction potential and the long-range interaction potential, the differential interference angles in singlet-triplet mixed states of CO A^1Π（v=9）-e3∑-（v=1） system in collision with He, Ne, Ar, and other partners were calculated theoretically. The relationships of differential interference angle versus impact parameters, including collision parameter b and velocity, are obtained.

Remedial Learning： A CALL Approach

Computer Assisted Language Learning （CALL） has been in use as a learner centered method since 1960. In this paper an attempt is made to evolve a Remedial Grammar （RG） which enables the teacher to develop a repertoire of remedial activities based on the errors identified following Error Analysis （EA） for repeated presentation. The error types are considered as teaching/learning points. The present paper argues that CALL is the right model for effective remedial learning. Remedial Gmaster （RGm）, an authoring package is introduced. This is an exclusive mode of error correction in which interlingual, intralingual, developmental, and global errors are dealt with. The syntactical problems due to the subtle difference between simple past and perfect tenses in English language use are discussed and CALL authoring package presented.

Test evaluation for vertical fracture wells in low permeability reservoir

As flow environment is poor in low permeability reservoirs, wells are always fractured in order to gain better economic benefits. Well testing analysis is very necessary for fracturing wells. However, available test analysis methods are of slow fitting speed and low fitting precision. In this paper, we first use a comprehensive evaluation method of analytical well testing, numerical well testing and well testing design. Many dynamic parameters such as fracture length, fracture conductivity, skin factor, etc are obtained. An example to illustrate accurate results of this method is given.

Inverse analysis of thermal conductivities in transient non-homogeneous and non-linear heat conductions using BEM based on complex variable differentiation method

This paper presents a new inverse analysis approach to sensitivity analysis and material property identification in transient non-homogeneous and non-linear heat conduction Boundary Element Method (BEM) analysis based on Complex Variable Differentiation Method (CVDM). In this approach, the material properties are taken as the optimization variables, and the sensitivity coefficients are computed by CVDM. The advantages of using CVDM are that the computation of partial derivatives of an implicit function is reduced to function calculation in a complex domain, and the parameter sensitivity coefficients can be determined in a more accurate way than the traditional Finite Difference Method (FDM). Based on BEM and CVDM in evaluation of the sensitivity matrix of heat flux, the parameter such as thermal conductivity can be accurately identified. Six numerical examples are given to demonstrate the potential of the proposed approach. The results indicate that the presented method is efficient for identifying the thermal conductivity with single or multiple parameters.

NEW DESIGN AND ANALYSIS OF FINITE DIFFERENCE DOMAIN DECOMPOSITION ALGORITHM FOR THE TWO-DIMENSIONAL HEAT EQUATION

It is presented in this paper that the new design and its analysis of finite difference domain decomposition algorithms for the two-dimensional heat equation, and the numerical results have shown the stability and accuracy of the algorithms, where SauFyev asymmetric schemes have been used at the interface points. The Algorithm II in this paper has further extended those developed by Dawson and the others, Zhang and Shen.

Constructal entransy dissipation rate minimization for umbrella-shaped assembly of cylindrical fins

Umbrella-shaped assembly of cylindrical fins is optimized by adopting analytical method and taking dimensionless mean thermal resistance (MTR) as performance index. The optimal construct of umbrella-shaped assembly is obtained. The results show that the heat conductance performance of the assembly becomes ever worse with ever greater number of elemental cylindrical fins,the umbrella-shaped assembly reduces to cylindrical fin in some values of design parameters,and the diameters’ dependence on design parameters is weak for the optimized assembly. An equivalent thermal resistance defined based on entransy dissipation rate (EDR) reflects an average heat transfer effect of the assembly. The constructal design corresponding to the minimum EDR (or MTR) should be adopted for designing an assembly of fins in engineering at the limit safe condition.

An optimization method on runner blades in bulb turbine based on CFD analysis

In this paper an optimization method of the runner blades in a bulb turbine based on CFD analysis is proposed.In the method the main scales of the turbine including guide vane,runner and draft are maintained.Only the runner blades are modified based on the present method.In the optimization method the runner blade is expressed by spline surface with a gather of coordinate points.The B-spline curve is used to keep the modified blades smooth.In order to make the blade optimization simple and ef- ficient,one of the coordinates is fixed and only the angles of the points are changed according to different modification purposes.Three main optimization principles based on flow diagnosis are presented here.These three principles are all based on the CFD analysis of the internal flow in bulb turbine.For the purpose of method verification,the optimization method is used in a model bulb turbine.A three dimensional steady turbulent computation is carried out through the whole passage including the bulb body,guide vanes,runner and draft tube of the bulb turbine under seven different work conditions.An SST k-ωturbulence model is used during the CFD analysis and the performance of the turbine can be achieved.The runner blade is optimized according to the three optimization principles based on flow diagnosis.The CFD analysis is conducted again on the optimized turbine and another modification is needed if the new turbine can’t satisfy the required performance.Comparison of the computational results between the original turbine and an optimized one indicates that the optimization method is practical and does improve the performance of the bulb turbine.

Analytical Approach for Nonlinear Partial Differential Equations of Fractional Order

The purpose of the paper is to present analytical and numerical solutions of a degenerate parabolic equation with time-fractional derivatives arising in the spatial diffusion of biological populations. The homotopy-perturbation method is employed for solving this class of equations, and the time-fractional derivatives are described in the sense of Caputo. Comparisons are made with those derived by Adomian＇s decomposition method, revealing that the homotopy perturbation method is more accurate and convenient than the Adomian＇s decomposition method. Furthermore, the results reveal that the approximate solution continuously depends on the time-fractional derivative and the proposed method incorporating the Caputo derivatives is a powerful and efficient technique for solving the fractional differential equations without requiring linearization or restrictive assumptions. The basis ideas presented in the paper can be further applied to solve other similar fractional partial differential equations.