Digital perfusion, evaluated scintigraphically, and hoof wall growth in horses with chronic laminitis treated with egg bar-heart bar shoeing and coronary grooving

Nuclear scintigraphy was used to assess digital perfusion before and after treatment in 10 horses with clinical and radiographic evidence of chronic laminitis. Horses were evaluated for lameness, degree of distal phalanx rotation, and heel-toe hoof wall growth ratio, and randomly divided into two treatment groups. Group 1 horses received only egg bar-heart bar shoeing; Group 2 underwent egg bar-heart bar shoeing and coronary grooving. Horses were re-evaluated for digital perfusion, lameness, degree of distal phalanx rotation, and hoof wall growth at 6 week intervals over the 18 week follow-up period. Prior to treatment, relative scintigraphic activity at the dorsal laminar area was decreased and relative scintigraphic activity at the toe and adjacent solar area was increased. Egg bar-heart bar shoeing was associated with significantly increased dorsal laminar scintigraphic activity and significantly decreased solar scintigraphic activity over the 18 week period. Coronary grooving, in combination with egg bar-heart bar shoeing, resulted in a significantly lower heel-toe hoof wall growth ratio but did not enhance digital perfusion. Seven of 10 (70%) horses were responsive to treatment, defined as an improvement in lameness by at least one grade. Horses that were refractory to treatment had significantly lower dorsal laminar scintigraphic activity and higher palmar coronary scintigraphic activity prior to treatment than horses that responded to treatment. Our results are the first to demonstrate that egg bar-heart bar shoeing is associated with improved dorsal laminar perfusion, and support the use of this technique. In addition, we found that pre-treatment nuclear scintigraphy was predictive of clinical outcome in horses with chronic laminitis treated with corrective shoeing.     

Simulation of deformation and lifetime behavior of a fcc single crystal superalloy at high temperature under low-cycle fatigue loading

This work deals with the formulation of a three-dimensional crystallographic time-incremental lifetime rule for face-centered cubic (fcc) single crystals used for gas-turbine blade applications. The damage contribution rate of each slip system to the total damage is governed by the current values of the resolved shear stress and the slip rate on the corresponding slip system. The damage rule is combined with a crystallographic viscoplastic deformation model. For the nickel-base single-crystal superalloy CMSX4 at 950 °C, various strain- and stress-controlled uniaxial cyclic tests with and without hold-times can be described for different crystal orientations by one set of material parameters. For verification, simulation results for a single-crystal specimen with a notch have been compared with corresponding experimental results. The predicted lifetime is within the factor of two of the measured one.     

Electrochemical method for the detection of lipase activity

A novel electrochemical technique for the general assay of lipase activity is described. The method utilizes a solid-supported lipase substrate, which is formed by dripping and drying a small amount of an ethanol solution of 9-(5'-ferrocenylpentanoyloxy)nonyl disulfide (FPONDS) onto gold modified by a hexanethiol self-assembled monolayer. The redox ferrocene group of FPONDS generates the electrochemical signal, the intensity of which is proportional to the number of FPONDS molecules at the interface. Electrochemical and surface-enhanced infrared absorption spectroscopic data, as well as control experiments with an engineered, deactivated mutant enzyme, demonstrate that the wild-type lipase from Thermomyces lanuginosus is capable of cleaving the ester bonds of FPONDS molecules via an enzymatic hydrolysis mechanism, which includes the adsorption of the lipase onto the substrate surface. The hydrolysis liberates the ferrocene groups from the interface triggering a decay of the electrochemical redox signal. The rate of the electrochemical signal decrease is proportional to the lipase activity/concentration. These data suggest a general method for the direct measure of enzymatic activity of lipases.     

Efficacy of taxol in the orpk mouse model of polycystic kidney disease

Studies on conscious Sprague-Dawley rats using intracerebral dialysis in live animals combined with high-performance liquid chromatography with electrochemical detection showed that administration of apomorphine into the nucleus accumbens decreased the levels of dihydroxyphenylacetic acid and 5-hydroxyindoleacetic acid in the extracellular space of the dorsal striatum throughout the observation period and produced a transient reduction in the level of homovanillic acid in the dialysate from this structure. The studies demonstrated that reversible exclusion of the nucleus accumbens with procaine produced a transient increase in the levels of dopamine metabolites, without an increase in serotonin metabolites, in the extracellular space of the dorsal striatum. These results demonstrate that the nucleus accumbens affects dopamine metabolism in the striatum, this being mediated by the dopamine-reactive system in the nucleus accumbens.     

一种基于相关函数法的超导失超检测方法

提出一种基于相关函数相位差法的高温超导体失超检测方法．利用带通滤波器提取被测信号的电压和电流基波分量,消除谐波对相关函数的干扰;对电压和电流的基波信号作相关运算,测量相位差,提高超导失超检测的灵敏度和抗干扰能力．并通过MATLAB软件中的Simtdink组件进行仿真分析,验证了该方法的可行性．     

hp-Adaptive spectral element solver for reactor modeling

The study, analysis and optimization of chemical reactors has shown a significant increase in complexity of the models used during the last decades. This complexity increased the computational cost of the models demanding the development of efficient solution techniques. This paper discusses the implementation of an hp-adaptive refinement technique applied to a least-squares spectral element formulation as a mathematical framework for reactor modeling. The refinement is based on an estimate of the local Sobolev regularity index of the underlying solution by monitoring the decay rate of its Legendre expansion coefficients. The performance of the method is demonstrated numerically by using an analytical test case.