Background:Liver diseases are a major contributor to both morbidity and mortality.Conditional knockout animals are always produced through crossing floxed animals with a tissue-specific Cre animal.The use of floxed ra...Background:Liver diseases are a major contributor to both morbidity and mortality.Conditional knockout animals are always produced through crossing floxed animals with a tissue-specific Cre animal.The use of floxed rat resource has rapidly increased,but the liver-specific Cre rat lines for studying liver diseases and interested genes are limited,especially in a spatially and temporally restricted manner.Methods:RNA sequencing and real-time polymerase chain reaction(PCR)were used to screen and confirm the presence of liver-specific genes.Apoa4-Cre rats and Cyp2c11-Cre rats were produced by CRISPR/Cas9 knockin.Rosa26-imCherry rats were employed to hybridize with the Cre rats to obtain the Apoa4-Cre/Rosa26-imCherry and Cyp2c11-Cre/Rosa26-imCherry rats.The temporal and spatial patterns of Cre expression were determined by the observation of red fluorescence on tis-sue sections.Hematoxylin-eosin stain was used to evaluate the liver histopathologic changes.The blood biochemical analysis of several liver enzymes and liver lipid profile was performed to evaluate the liver function of Cre rats.Results:Apoa4 and Cyp2c11 were identified as two liver-specific genes.Apoa4-Cre and Cyp2c11-Cre rats were produced and hybridized with Rosa26-imCherry rats.The red fluorescence indicated that the Cre recombinases were specially expressed in the juvenile and adult liver and not in other organs of two hybridized rats.All the blood biochemical parameters except low-density lipoprotein(LDL)did not change signifi-cantly in the Cre rats.No histological alterations were detected in the livers of the Cre rats.Conclusions:Liver-specific Apoa4-Cre and Cyp2c11-Cre rats have been established successfully and could be used to study gene knockout,specifically in juvenile and adult liver.展开更多
The TiB+TiC dual-reinforced B_(4)C/TC4 composite was in-situ fabricated via incorporating 0.5wt%B_(4)C reinforcement during the laser melting deposition process.Different heat treatments of annealing and solid solutio...The TiB+TiC dual-reinforced B_(4)C/TC4 composite was in-situ fabricated via incorporating 0.5wt%B_(4)C reinforcement during the laser melting deposition process.Different heat treatments of annealing and solid solution were used to regulate the microstructure,mechanical properties,and corrosion properties of B_(4)C/TC4 composite.Results show that with the increase in temperature from 500℃to 800°C,partial lamellarα-Ti in the as-deposited sample is gradually transformed into equiaxedα-Ti,accompanied by the disappearance of basketweave microstructure.At 1100°C,a small portion of TiC phase suffers fusion.This composite exhibits the optimal combination of strength and plasticity after annealing at 500℃for 4 h followed by furnace cooling,which is attributed to the stress release effect and the refined basketweave microstructure.However,this composite shows a decline in corrosion resistance after various heat treatments due to grain coarsening and micro-galvanic corrosion.展开更多
基金CAMS Innovation Fund for Medical Sciences(CIFMS),Grant/Award Number:2021-I2M-1-035National Natural Science Foundation of China,Grant/Award Number:31970508。
文摘Background:Liver diseases are a major contributor to both morbidity and mortality.Conditional knockout animals are always produced through crossing floxed animals with a tissue-specific Cre animal.The use of floxed rat resource has rapidly increased,but the liver-specific Cre rat lines for studying liver diseases and interested genes are limited,especially in a spatially and temporally restricted manner.Methods:RNA sequencing and real-time polymerase chain reaction(PCR)were used to screen and confirm the presence of liver-specific genes.Apoa4-Cre rats and Cyp2c11-Cre rats were produced by CRISPR/Cas9 knockin.Rosa26-imCherry rats were employed to hybridize with the Cre rats to obtain the Apoa4-Cre/Rosa26-imCherry and Cyp2c11-Cre/Rosa26-imCherry rats.The temporal and spatial patterns of Cre expression were determined by the observation of red fluorescence on tis-sue sections.Hematoxylin-eosin stain was used to evaluate the liver histopathologic changes.The blood biochemical analysis of several liver enzymes and liver lipid profile was performed to evaluate the liver function of Cre rats.Results:Apoa4 and Cyp2c11 were identified as two liver-specific genes.Apoa4-Cre and Cyp2c11-Cre rats were produced and hybridized with Rosa26-imCherry rats.The red fluorescence indicated that the Cre recombinases were specially expressed in the juvenile and adult liver and not in other organs of two hybridized rats.All the blood biochemical parameters except low-density lipoprotein(LDL)did not change signifi-cantly in the Cre rats.No histological alterations were detected in the livers of the Cre rats.Conclusions:Liver-specific Apoa4-Cre and Cyp2c11-Cre rats have been established successfully and could be used to study gene knockout,specifically in juvenile and adult liver.
基金Tianjin Municipal Natural Science Foundation(23JCYBJC00040)National Natural Science Foundation of China(52175369)。
文摘The TiB+TiC dual-reinforced B_(4)C/TC4 composite was in-situ fabricated via incorporating 0.5wt%B_(4)C reinforcement during the laser melting deposition process.Different heat treatments of annealing and solid solution were used to regulate the microstructure,mechanical properties,and corrosion properties of B_(4)C/TC4 composite.Results show that with the increase in temperature from 500℃to 800°C,partial lamellarα-Ti in the as-deposited sample is gradually transformed into equiaxedα-Ti,accompanied by the disappearance of basketweave microstructure.At 1100°C,a small portion of TiC phase suffers fusion.This composite exhibits the optimal combination of strength and plasticity after annealing at 500℃for 4 h followed by furnace cooling,which is attributed to the stress release effect and the refined basketweave microstructure.However,this composite shows a decline in corrosion resistance after various heat treatments due to grain coarsening and micro-galvanic corrosion.
