Vacuum freeze-dried aorta is a satisfactory material for blood vessel grafting. Previous studies have focused on immunity, however, vacuum freeze-drying is a complicated process of heat and mass transfer, and adopting a programmed cooling process may more completely preserve the mechanical properties of the blood vessels. Irradiation, as a method of removing pathogens, lowers the antigenic activity of the blood vessels. In our study, vacuum freeze-drying combined with radiation was used as a treatment for porcine aorta prior to grafting, aimed at deactivating endogenous retrovirus, shielding masses of endothelial cells and lowering the immunogenicity of the blood vessels. As for the mechanical properties, compared with normal aorta, the maximum axial tensile stress (ATS) decreased by 20%, the maximum circumferential tensile stress (CTS) increased by 30% and the maximum puncture stress (PT) decreased by 20%. Our results revealed that 2 months after of grafting, the host cells had migrated into the graft tissue and propagated to initiate endothelialization, the inflammatory reaction was abated and the PT had returned to normal levels.

With the fast development of modern food and beverage industry, fresh-cut vegetables have wider application than before. During the process of sterilization in fresh-cut vegetables, the concentration of chloric disinfectant is usually so high that the common sensor can't be used directly on the product line. In order to solve this problem, we have invented a new detecting apparatus which could detect high concentration of chloric disinfectant directly. In this paper, the working principle, main monitor indicators, application and technical creations of the on-line apparatus have been discussed, and we also carried on the experimental analysis for its performance. The actual demands in factory could be met when the detecting flux is 2L/min, the dilution ratio is 15 and input amount of the disinfectant is 200ml per time, the max of the detecting deviation achieves ±4.8ppm(mg/L). The main detecting range of residual chlorine is 0~300ppm.

At present, the vascular tissue disease has become the major cause to against people’s health, vascular graft is an effective means for the treatment of vascular tissue disease, but the preservation of blood vessels has always been a big challenge. This paper based on the conduct of porcining aortic cryofreeze-drying, with using micro-CT to track the whole drying process, expect to reveal what vascular morphology changes have taken place during the process of cryofreeze-drying, and take a comparative analysis of porcine aortic mechanical properties between freeze-dried after the restoration of water and fresh porcine aortic by the Texture analyzer, so that uncover the effect the process of freeze-dried making on pig arteries mechanical properties. Test results showed that the pig aorta vascular occur stratification in the process of cryofreeze-drying, blood vessels freeze-dried following the resumption of water comparing the mechanical properties with the fresh blood vessels, its maximum axial tensile stress reduced by about 40%, and the largest peripheral tensile stress increase by about 45%, and the biggest puncture stress is about 75 percent of fresh blood vessels.

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