A radioimmunoassay combined with solid-phase extraction for the determination (pg ml-1) of AR-C15849XX) in human plasma.
A radioimmunoassay has been developed for the determination of AR-C15849KF, a CCK-8 analogue, in human plasma. The method incorporates solid-phase sample extraction, is suitable for the determination of the analyte at pg ml-1 concentrations and is based on a method developed and validated for dog plasma. The solid-phase extraction, using ion-exchange aminopropyl and octadecyl sorbents sequentially, was retained for this procedure to remove matrix interferences in the plasma and to enhance method sensitivity. The calibration range is 10-500 pg ml-1, using a 1 ml sample of undiluted human plasma. The method has been successfully used to generate early human pharmacokinetic data during a programme of exploratory development.
A radioimmunoassay combined with solid-phase extraction for the determination of a novel anti-obesity agent, ARL 15849XX, in dog plasma.
A radioimmunoassay has been developed for the determination of ARL 15849XX, a cholecystokinin-8 (CCK-8) analogue, in dog plasma. The method incorporates solid-phase sample extraction and is suitable for the determination of the analyte at picogram per millilitre concentrations. The antiserum was raised in Suffolk-cross sheep following primary and booster immunisations with an immunogen prepared by conjugating ARL 16935XX, an analogue of ARL 15849KF, to bovine serum albumin. The radioligand was prepared by the no-carrier-added 125I iodination of a non-sulphated derivative, ARL 15745XX. The solid-phase extraction procedure, carried out using ion-exchange aminopropyl and octadecyl sorbents sequentially, was introduced to remove matrix interferences in the plasma and to enhance the method sensitivity. The calibration range is 20-1000 pg ml-1, using a 1 ml sample of undiluted dog plasma.
Analysis of the stress wave effect during coal breakage by a high-pressure abrasive air jet
In view of the defects of borehole collapse, inhibition of gas desorption and migration of gas existing in hydraulic fracturing and other hydraulic permeability–increasing measures for soft coal seams with low-permeability technology is proposed for coal breakage by a high-pressure abrasive gas jet for relieving pressure and increasing permeability. The comparative analysis of gas jet flow field structure between convergent nozzle and Laval nozzle has been given by numerical simulation. For Laval nozzle, the expansion wave and compression wave alternate and move forward steadily in gas jet and vanish when potential core length reaches maximum. So, the Laval nozzle can form more stable flow filed structure of gas jet and avoid shock wave in gas jet. Furthermore, a high-speed camera is adopted to analyze the jet structure and verify the conclusion of numerical simulation. Based on thermodynamic theory, this article calculates and analyzes the critical local sound velocity and pressure generated from the stress wave during the process of coal breakage by the gas jet. Furthermore, experimental coal breakage by a high-pressure abrasive gas jet is carried out. The high-pressure abrasive gas jet impacts the coal body as a quasi-static load and a dynamic load and forms corrosion pits on the surface of the coal body. Penetrating cracks are formed within the coal in the pattern of the loaded stress wave which leads to coal breakage. The effects of porosity and permeability on the propagation of the stress wave in coal are analyzed by establishing the dispersion equation for the spread of the stress wave in coal. The results show that porosity has a significant effect on wave velocity and that the attenuation of the stress wave is intensified with an increase in porosity. Moreover, the stress wave attenuation is more obvious at high frequency. The effect of permeability on the wave velocity is not significant at low frequencies. In contrast, at high frequency and relatively low permeability, the wave velocity increases with the permeability, and the attenuation of the wave velocity initially increases and then decreases. When the permeability is greater than 10−11 m2, the wave velocity is not affected by the permeability. However, the stress wave is not attenuated.