Serine protease 50(PRSS50/TSP50)is highly expressed in spermatocytes.Our study investigated its role in testicular development and spermatogenesis.Initially,PRSS50 knockdown was observed to impair DNA synthesis in spe...Serine protease 50(PRSS50/TSP50)is highly expressed in spermatocytes.Our study investigated its role in testicular development and spermatogenesis.Initially,PRSS50 knockdown was observed to impair DNA synthesis in spermatocytes.To further explore this,we generated PRSS50 knockout(Prss50^(−/−))mice(Mus musculus),which exhibited abnormal spermatid nuclear compression and reduced male fertility.Furthermore,dysplastic seminiferous tubules and decreased sex hormones were observed in 4-week-old Prss50^(−/−)mice,accompanied by meiotic progression defects and increased apoptosis of spermatogenic cells.Mechanistic analysis indicated that PRSS50 deletion resulted in increased phosphorylation of extracellular signal-regulated protein kinases 1 and 2(ERK1/2)and elevated levels of MAP kinase phosphatase 3(MKP3),a specific ERK antagonist,potentially accounting for testicular dysplasia in adolescent Prss50−/−mice.Taken together,these findings suggest that PRSS50 plays an important role in testicular development and spermatogenesis,with the MKP3/ERK signaling pathway playing a significant role in this process.展开更多
Corrosion of reinforcement has a significant effect on the deformation of reinforced concrete beams by deteriorating the bond-slip characteristics, diminishing the cross-sectional area of reinforcement, and causing cr...Corrosion of reinforcement has a significant effect on the deformation of reinforced concrete beams by deteriorating the bond-slip characteristics, diminishing the cross-sectional area of reinforcement, and causing cracking. The traditional way of quantifying the load capacity and simulating deflection is the moment-curvature(M/χ) approach. The problem is that the M/χ approach is semi-empirical after cracking as it is strain-based and cannot allow for tension stiffening. This paper introduces the new displacement-based moment-rotation(M/θ) approach which directly simulates the development of cracks and hence allows for tension stiffening. This M/θ approach is then used to predict the load-deflection behavior of reinforced concrete beams with corrosion effect by incorporating the corrosion-affected bond-slip model. The bond-slip model only considers the corrosion effect but ignores the confinement effect. It is used here as an example to describe the procedure of how to quantify the corrosion effect on reinforced concrete beam behavior. The load-deflection curves obtained from the numerical simulation show a good agreement with test results. For reinforced concrete beams with confinement, the only difference is to replace the bond-slip model with the one which includes both corrosion and stirrup effects. Additionally, the paper shows how to use the M/θ approach with the bond-slip model to predict the real corrosion level of reinforcement in some tests in which only the theoretical corrosion levels are provided.展开更多
基金supported by the Research Foundation of Jilin Provincial Science&Technology Development(20210204164YY,YDZJ202201ZYTS524,20230204067YY,20230204069YY)Jilin Province Development and Reform Commission(2022C044-3)Fundamental Research Funds for the Central Universities(135131002)。
文摘Serine protease 50(PRSS50/TSP50)is highly expressed in spermatocytes.Our study investigated its role in testicular development and spermatogenesis.Initially,PRSS50 knockdown was observed to impair DNA synthesis in spermatocytes.To further explore this,we generated PRSS50 knockout(Prss50^(−/−))mice(Mus musculus),which exhibited abnormal spermatid nuclear compression and reduced male fertility.Furthermore,dysplastic seminiferous tubules and decreased sex hormones were observed in 4-week-old Prss50^(−/−)mice,accompanied by meiotic progression defects and increased apoptosis of spermatogenic cells.Mechanistic analysis indicated that PRSS50 deletion resulted in increased phosphorylation of extracellular signal-regulated protein kinases 1 and 2(ERK1/2)and elevated levels of MAP kinase phosphatase 3(MKP3),a specific ERK antagonist,potentially accounting for testicular dysplasia in adolescent Prss50−/−mice.Taken together,these findings suggest that PRSS50 plays an important role in testicular development and spermatogenesis,with the MKP3/ERK signaling pathway playing a significant role in this process.
基金Project supported by the National Natural Science Foundation of China(No.51478422)。
文摘Corrosion of reinforcement has a significant effect on the deformation of reinforced concrete beams by deteriorating the bond-slip characteristics, diminishing the cross-sectional area of reinforcement, and causing cracking. The traditional way of quantifying the load capacity and simulating deflection is the moment-curvature(M/χ) approach. The problem is that the M/χ approach is semi-empirical after cracking as it is strain-based and cannot allow for tension stiffening. This paper introduces the new displacement-based moment-rotation(M/θ) approach which directly simulates the development of cracks and hence allows for tension stiffening. This M/θ approach is then used to predict the load-deflection behavior of reinforced concrete beams with corrosion effect by incorporating the corrosion-affected bond-slip model. The bond-slip model only considers the corrosion effect but ignores the confinement effect. It is used here as an example to describe the procedure of how to quantify the corrosion effect on reinforced concrete beam behavior. The load-deflection curves obtained from the numerical simulation show a good agreement with test results. For reinforced concrete beams with confinement, the only difference is to replace the bond-slip model with the one which includes both corrosion and stirrup effects. Additionally, the paper shows how to use the M/θ approach with the bond-slip model to predict the real corrosion level of reinforcement in some tests in which only the theoretical corrosion levels are provided.
