The occurrence of fractures in the vessel wall has been a major problem for human blood vessel cryopreservation. The large volumetric expansion of water during crystallization produces great inner stresses. To solve t...The occurrence of fractures in the vessel wall has been a major problem for human blood vessel cryopreservation. The large volumetric expansion of water during crystallization produces great inner stresses. To solve these complicated heat transfer and thermal stress problems, a model and an analytic method are presented in this paper, with which transient temperature field, the transient stress field inside the blood vessels during freezing can be calculated and analyzed, and the probable cracks or fractures can be predicted. The analytic results of sheep thoracic artery are consistent with the experimental observations of fractures.展开更多
The damage caused by thermal stress during rewarming vitrified biosamples is one of the major obstacles for clinical purposes.Magnetic warming is a highly effective approach to overcome this hurdle and can achieve rap...The damage caused by thermal stress during rewarming vitrified biosamples is one of the major obstacles for clinical purposes.Magnetic warming is a highly effective approach to overcome this hurdle and can achieve rapid and spatially homogeneous heating.The current research investigates the effects of magnetic warming on the histological and biomechanical properties of the vitrified umbilical arteries(UAs)through experiments and simulation.The results of experiments show that,for the case of magnetic warming comparing with the conventional water bath,magnetic warming presents better preservation of extracellular matrix(ECM),collagen fibers,elastic fibers,and muscle fibers of the umbilical artery.There is no significant difference between magnetothermal and fresh UAs(p>0.05)in the elastic modulus and the ultimate stress.The theoretical results reveal that the maximum temperature difference Tmax inside the biosample is 1.117±0.649℃,and the maximum thermal stressmax is 0.026±0.016 MPa.However,for the case of conventional water bath,Tmax is 32.342±0.967℃andmax is 1.453±0.047 MPa.Moreover,we have arrived at the same conclusion by simulation as theoretical calculation have.Therefore,magnetic warming can effectively reduce the thermal stress damage of biological samples during the warming period due to more uniform and rapid warming.These results confirm that magnetothermal can significantly improve the mechanical properties of large size cryopreserved tissues or organs such as UAs.展开更多
文摘The occurrence of fractures in the vessel wall has been a major problem for human blood vessel cryopreservation. The large volumetric expansion of water during crystallization produces great inner stresses. To solve these complicated heat transfer and thermal stress problems, a model and an analytic method are presented in this paper, with which transient temperature field, the transient stress field inside the blood vessels during freezing can be calculated and analyzed, and the probable cracks or fractures can be predicted. The analytic results of sheep thoracic artery are consistent with the experimental observations of fractures.
基金the National Natural Science Foundation of China(Nos.51576132,52076140)the National Science and Technology Major Project on Important Infectious Diseases Prevention and Control(2018ZX10734404).
文摘The damage caused by thermal stress during rewarming vitrified biosamples is one of the major obstacles for clinical purposes.Magnetic warming is a highly effective approach to overcome this hurdle and can achieve rapid and spatially homogeneous heating.The current research investigates the effects of magnetic warming on the histological and biomechanical properties of the vitrified umbilical arteries(UAs)through experiments and simulation.The results of experiments show that,for the case of magnetic warming comparing with the conventional water bath,magnetic warming presents better preservation of extracellular matrix(ECM),collagen fibers,elastic fibers,and muscle fibers of the umbilical artery.There is no significant difference between magnetothermal and fresh UAs(p>0.05)in the elastic modulus and the ultimate stress.The theoretical results reveal that the maximum temperature difference Tmax inside the biosample is 1.117±0.649℃,and the maximum thermal stressmax is 0.026±0.016 MPa.However,for the case of conventional water bath,Tmax is 32.342±0.967℃andmax is 1.453±0.047 MPa.Moreover,we have arrived at the same conclusion by simulation as theoretical calculation have.Therefore,magnetic warming can effectively reduce the thermal stress damage of biological samples during the warming period due to more uniform and rapid warming.These results confirm that magnetothermal can significantly improve the mechanical properties of large size cryopreserved tissues or organs such as UAs.
