To investigate the effect of solution treatment and aging process parameters on the microstructure and mechanical properties of TB18 titanium alloy,process optimization research was conducted based on the mixed-level ...To investigate the effect of solution treatment and aging process parameters on the microstructure and mechanical properties of TB18 titanium alloy,process optimization research was conducted based on the mixed-level orthogonal experiment design of factor levels.Results show that through range analysis,the significance order of process parameters is determined as follows:solution cooling method>solution temperature>aging time>aging temperature>solution time.Considering the strength-ductility matching and engineering application requirements,the benchmark parameters are selected as solution time of 1 h,solution cooling method of air cooling(AC),aging temperature of 525℃,and aging time of 4 h.Furthermore,the effects of solution temperature in the range of 790–870℃ on the impact toughness and micro-fracture characteristics of the alloy were studied.The results reveal that the larger the area of shear lip and fibrous zone,and the smaller the area of radiation zone,the better the toughness of the alloy.With the increase in solution temperature,the length of secondary cracks on the fracture surface increases,the number of dimples increases,and the toughness is enhanced.Based on the collaborative optimization of strength and toughness,the optimal heat treatment process for TB18 alloy is determined as 870℃/1 h,AC+525℃/4 h,AC.展开更多
Objective:To evaluate the performance of interferon gamma release assays and tuberculin skin test in Bacillus Calmette-Guerin vaccinated young children.Methods:A cross-sectional study was conducted in healthy children...Objective:To evaluate the performance of interferon gamma release assays and tuberculin skin test in Bacillus Calmette-Guerin vaccinated young children.Methods:A cross-sectional study was conducted in healthy children younger than 5 years who were recently diagnosed with tuberculosis or had recent exposure to active tuberculosis.QuantiFERON-TB Gold,T-SPOT.TB and tuberculin skin test were performed in each patient.Results:Of the 60 children,median age 3.3 years,17 had tuberculosis and 43 had recent tuberculosis exposure.Overall,15(25.0%)children had tuberculin skin test reaction≥10 mm;8(13.3%)were positive by QuantiFERON-TB Gold In-Tube test,and 12(20.0%)by T-SPOT.TB.Nineteen(31.7%)children had at least one positive test.There was a moderate agreement between interferon gamma release assays and tuberculin skin test.Conclusions:The positive rates of interferon gamma release assays and tuberculin skin test were low in young children who were infected with tuberculosis,supporting the management strategy of not testing children younger than 5 years.展开更多
基金Key Program of National Natural Science Foundation of China(52431001)。
文摘To investigate the effect of solution treatment and aging process parameters on the microstructure and mechanical properties of TB18 titanium alloy,process optimization research was conducted based on the mixed-level orthogonal experiment design of factor levels.Results show that through range analysis,the significance order of process parameters is determined as follows:solution cooling method>solution temperature>aging time>aging temperature>solution time.Considering the strength-ductility matching and engineering application requirements,the benchmark parameters are selected as solution time of 1 h,solution cooling method of air cooling(AC),aging temperature of 525℃,and aging time of 4 h.Furthermore,the effects of solution temperature in the range of 790–870℃ on the impact toughness and micro-fracture characteristics of the alloy were studied.The results reveal that the larger the area of shear lip and fibrous zone,and the smaller the area of radiation zone,the better the toughness of the alloy.With the increase in solution temperature,the length of secondary cracks on the fracture surface increases,the number of dimples increases,and the toughness is enhanced.Based on the collaborative optimization of strength and toughness,the optimal heat treatment process for TB18 alloy is determined as 870℃/1 h,AC+525℃/4 h,AC.
基金supported by the Faculty of Medicine Siriraj Hospital,Mahidol University,Bangkok,Thailand,[Grant Number(IO)R016032002]Oxford Immunotec and Biomed diagnostics(Thailand)provided the T-SPOT.TB test kit
文摘Objective:To evaluate the performance of interferon gamma release assays and tuberculin skin test in Bacillus Calmette-Guerin vaccinated young children.Methods:A cross-sectional study was conducted in healthy children younger than 5 years who were recently diagnosed with tuberculosis or had recent exposure to active tuberculosis.QuantiFERON-TB Gold,T-SPOT.TB and tuberculin skin test were performed in each patient.Results:Of the 60 children,median age 3.3 years,17 had tuberculosis and 43 had recent tuberculosis exposure.Overall,15(25.0%)children had tuberculin skin test reaction≥10 mm;8(13.3%)were positive by QuantiFERON-TB Gold In-Tube test,and 12(20.0%)by T-SPOT.TB.Nineteen(31.7%)children had at least one positive test.There was a moderate agreement between interferon gamma release assays and tuberculin skin test.Conclusions:The positive rates of interferon gamma release assays and tuberculin skin test were low in young children who were infected with tuberculosis,supporting the management strategy of not testing children younger than 5 years.
