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目的 以谷胱甘肽-S-转硫酶（GST）为模型，探讨有产物抑制时用积分法分析酶反应过程测定底物量的可靠性。方法 从猪肝制备GST。1-氯-2，4-二硝基苯（CDNB）终浓度为1．0mmol／L，监测GST催化还原型谷胱甘肽（GSH）与CDNB结合产物在340nm吸收变化。用积分法预测反应终点的产物吸收。结果 优化产物抑制常数可使此积分法所得反应终点产物吸收对剩余底物变化不敏感。此积分法测定GSH对常见干扰有抗性。此法测定大鼠肝匀浆中外加GSH回收率大于98％，线性响应上限接近90μmol／L，下限接近2．0μmol／L，所得大鼠肝GSH含量与文献报道一致。结论 有产物抑制时用积分法也可定量底物；用此积分法进行动力学酶法分析具有一定普遍性，而且有明显优势。

Blood flow inside the liver plays a key role in hepatic functions, and abnormal hemodynamics are highly correlated with liver diseases. To date, the flow field in an elementary building block of the organ, the liver lobule, is difficult to determine experimentally in humans due to its complicated structure, with radially branched microvasculature and the technical difficulties that derive from its geometric constraints. Here we established a set of 3D computational models for a liver lobule using porous media theory and analyzed its flow dynamics in normal, fibrotic, and cirrhotic lobules. Our simulations indicated that those approximations of ordinary flow in portal tracts (PTs) and the central vein, and of porous media flow in the sinusoidal network, were reasonable only for normal or fibrotic lobules. Models modified with high resistance in PTs and collateral vessels inside sinusoids were able to describe the flow features in cirrhotic lobules. Pressures, average velocities, and volume flow rates were profiled and the predictions compared well with experimental data. This study furthered our understanding of the flow dynamics features of liver lobules and the differences among normal, fibrotic, and cirrhotic lobules.

The co-gasification behavior and synergistic effect of petroleum coke, biomass, and their blends were studied by thermogravimetric analysis under CO2 atmosphere at different heating rates. The isoconversional method was used to calculate the activation energy. The results showed that the gasification process occurred in two stages： pyrolysis and char gasification. A synergistic effect was observed in the char gasification stage. This effect was caused by alkali and alkaline earth metals in the biomass ash. Kinetics analysis showed that the activation energy in the pyrolysis stage was less than that in the char gasification stage. In the char gasification stage, the activation energy was 129.1–177.8 k J/mol for petroleum coke, whereas it was 120.3–150.5 k J/mol for biomass. We also observed that the activation energy calculated by the Flynn–Wall–Ozawa（FWO） method were larger than those calculated by the Kissinger–Akahira–Sunosen（KAS） method. When the conversion was 1.0, the activation energy was 106.2 k J/mol when calculated by the KAS method, whereas it was 120.3 k J/mol when calculated by the FWO method.

This work deals with the active control of the vibrations of mechanical structures incorporating magnetorheological elastomer. The damping coefficient and shear modulus of the elastomer increase when exposed to a magnetic field. Compared with the vibration control where the elastomer is permanently exposed to a magnetic field, the control of this process through time reduces vibrations more effectively. The experimental study for the vibrations of a sandwich beam filled with an elastomer is conducted, followed by a numerical study using the Abaqus code. The vibration damping is found to be dependent on the loading rate of micro-size ferromagnetic particles in the elastomer.

The importance of tacrolimus in the treatment of myasthenia gravis （MG） as a substitute for corticosteroid-dependent immunosuppressive therapy is increasing. Thus far, however, no population pharmacokinetic （PopPK） analysis of tacrolimus in treating MG patients has been published. This article aimed to construct a PopPK model of tacrolimus for Chinese MG patients with the goal of improving its performance in MG treatment. A total of 253 trough concentration records were obtained from 83 Chinese MG patients. The effects of demographics, lifestyle and health status, biochemical test data, disease progression and treatment-related information （including co-administered medications） as covariates on the various parameters were investigated. The covariate selection was based on biological plausibility, clinical significance, statistical significance and reduction in inter-individual variability （IIV）. Bootstrap and normalized prediction distribution error （NPDE） analysis were performed to validate the final model. A one-compartment PopPK model with first-order elimination and a fixed absorption phase was constructed. The estimated apparent oral clearance （CL/F） and apparent oral volume of distribution （V/F） were 3.6 L/h and 1700 L, respectively, in the MG patients. Hematocrit and blood urea nitrogen were identified as two covariates that significantly influenced the CL/F. Immunoglobulin treatment （PRO） also had the potential to influence V/F, which was consistent with the clinical observations and the high protein-binding property of tacrolimus. Other covariates including age, weight, gender and co-administered medications had no obvious influence on CL/F or V/F. The first PopPK model of tacrolimus in MG patients was established. The identified covariates were of biological plausibility and clinical importance to help individualize the dosing schedule in MG patients.

Background： Both lower urinary tract dysfunction and urinary symptoms are prevalent in patients with multiple sclerosis （MS）. Although the significance of identifying and treating urinary symptoms in MS is currently well-known, there is no information about the real prevalence and therapeutic effect of urinary symptoms in patients with MS. The purpose of this study was to analyze the major symptoms and urodynamic abnormalities, and observe the therapeutic effect in different MS characteristics. Methods： We enrolled 126 patients with urological dysfunction who were recruited between July 2008 and January 2015 in Beijing Tian Tan Hospital, Capital Medical University and conducted overactive bladder system score （OABSS）, urodynamic investigation, and expanded disability status scale （EDSS）. Changes of urinary symptoms and urodynamic parameters were investigated. Results： Urgency was the predominant urinary symptom, and detrusor overactivity was the major bladder dysfunction. There was a positive correlation between EDSS and OABSS. Clinically isolated syndrome （CIS） had lowest EDSS and OABSS. CIS exhibited significant improvements in OABSS, maximum urinary flow rate （Qmax）, and bladder volume at the first desire to voiding and maximum bladder volume after the treatment （P 〈 0.05）. Relapsing-remitting MS showed significant improvements in the OABSS, Qmax, and bladder volume at the first desire to voiding, maximum bladder volume and bladder compliance after the treatment （P 〈 0.05）. Progressive MS exhibited significant increase in the bladder volume at the first desire to voiding, the detrusor pressure at maximum flow rate （PdetQmax）, and bladder compliance after the treatment （P 〈 0.05）. Conclusions： Urodynamic parameters examined are important in providing an accurate diagnosis, guiding management decisions of MS. Early and effective treatment may improve the bladder function and the quality of life at the early stages of MS.

The pyrolysis and oxy-fuel combustion characteristics of Polish bituminous coal were studied using non-isothermal thermogravimetric analysis. Pyrolysis tests showed that the mass loss profiles were almost similar up to 870°C in both N2 and CO2 atmospheres, while further mass loss occurred in CO2 atmosphere at higher temperatures due to char-CO2 gasification. Replacement of N2 in the combustion environment by CO2 delayed the combustion of bituminous coal. At elevated oxygen levels, TG/DTG profiles shifted through lower temperature zone, ignition and burnout temperatures decreased and mass loss rate significantly increased and complete combustion was achieved at lower temperatures and shorter times. Kinetic analysis for the tested coal was performed using Kissinger-Akahira-Sunose (KAS) method. The activation energies of bituminous coal combustion at the similar oxygen content in oxy-fuel with that of air were higher than that in air atmosphere. The results indicated that, with O2 concentration increasing, the activation energies decreased.

Based on Chua’s chaotic oscillation circuit, a fifth-order chaotic circuit with two memristors is designed and its corresponding dimensionless mathematic model is established. By using conventional dynamical analysis methods, stability analysis of the equilibrium set of the circuit is performed, the distribution of stable and unstable regions corresponding to the memristor initial states is achieved, and the complex dynamical behaviors of the circuit depending on the circuit parameters and the memristor initial states are investigated. The theoretical analysis and numerical simulation results demonstrate that the proposed chaotic circuit with two memristors has an equilibrium set located on the plane constituted by the inner state variables of two memristors. The stability of the equilibrium set depends on both the circuit parameters and the initial states of the two memristors. Rich nonlinear dynamical phenomena, such as state transitions, transient hyperchaos and so on, are expected.

Dissolution kinetics of nickel from lateritic ore in nitric acid solution was investigated. Experimental parameters used were stirring speed (100-600 r/min), temperature (40-96 °C), nitric acid concentration (0.1-2 mol/L) and particle size (<106 µm). The shrinking core model was applied to the results of experiments investigating the effects of leaching temperature in the range of 40-90 °C and nitric acid concentration in range of 0.1-2 mol/L on nickel dissolution rate. The kinetic analysis shows that the nickel dissolution from lateritic ore could be described by diffusion model. The activation energy (Ea) for the dissolution reaction is calculated as 79.52 kJ/mol.

By using the radiosonde measurements collected at Shouxian,China,we examined the dynamics and thermodynamics of single- and two-layer clouds formed at low and middle levels.The analyses indicated that the horizontal wind speed above the cloud layers was higher than those within and below cloud layers.The maximum balloon ascent speed（5.3 m s^-1） was located in the vicinity of the layer with the maximum cloud occurrence frequency（24.4%）,indicating an upward motion（0.1-0.16 ms^-1）.The average thickness,magnitude and gradient of the temperature inversion layer above single-layer clouds were117±94 m,1.3±1.3℃ and 1.4±1.5℃（100 m）^-1,respectively.The average temperature inversion magnitude was the same（1.3℃） for single-low and single-middle clouds;however,a larger gradient[1.7±1.8℃（100 m）^-1]and smaller thickness（94±67 m） were detected above single-low clouds relative to those above single-middle clouds[0.9±0.7℃（100 m）^-1 and157±120 m].For the two-layer cloud,the temperature inversion parameters were 106±59 m,1.0±0.9℃ and 1.0±1.0℃（100 m）^-1 above the upper-layer cloud and 82 ± 60 m,0.6±0.9℃ and 0.7±0.6℃（100 m）^-1 above the low-layer cloud.Absolute differences between the cloud-base height（cloud-top height） and the lifting condensation level（equilibrium level）were less than 0.5 km for 66.4%（36.8%） of the cases analyzed in summer.