Objective Post tuberculosis lung disease(PTLD)manifests in various forms,including tuberculosisassociated chronic obstructive pulmonary disease(TB-COPD),yet the clinical features of PTLD remain undercharacterized.This...Objective Post tuberculosis lung disease(PTLD)manifests in various forms,including tuberculosisassociated chronic obstructive pulmonary disease(TB-COPD),yet the clinical features of PTLD remain undercharacterized.This study aimed to assess longitudinal changes in lung function over a 5-year period and to identify predictors of airflow obstruction in a cohort of patients treated for active pulmonary TB.Methods Patients with active pulmonary TB were enrolled in this study and were followed during treatment,at treatment completion and five years post-treatment.Assessments included lung function and chest CT,analyzing longitudinal trends and airflow obstruction risk factors.Results Among 53 patients(mean age 36.9±13.9 years;64.2%male),7 patients(13.2%)exhibited airflow obstruction.At the 5-year follow-up,the mean FEV_(1)/FVC declined significantly(76.27%±12.04%vs.80.23%±11.02%,P<0.001)and 9 patients(17.0%)exhibited airflow obstruction.Seven of these patients predominantly showed air trapping consistent with small airway disease on chest CT,aligning with TB-COPD phenotype.Notably,four young-to-middle-aged patients(<60 years old)had persistent obstruction over the five years.Conclusion The initial test revealed that 13.2%of patients presented with airflow obstruction.By the 5-year follow-up,this proportion had increased to 17.0%,with most cases demonstrating imaging findings aligning with TB-COPD,even among younger,non-smoking individuals.These findings emphasize the importance of long-term follow-up and routine lung function assessments in TB survivors.展开更多
The mass of high-speed trains can be reduced using the brake disk prepared with SiC network ceramic frame reinforced 6061 aluminum alloy composite （SiCn/Al）. The thermal and stress analyses of SiCn/Al brake disk dur...The mass of high-speed trains can be reduced using the brake disk prepared with SiC network ceramic frame reinforced 6061 aluminum alloy composite （SiCn/Al）. The thermal and stress analyses of SiCn/Al brake disk during emergency braking at a speed of 300 km/h considering airflow cooling were investigated using finite element （FE） and computational fluid dynamics （CFD） methods. All three modes of heat transfer （conduction, convection and radiation） were analyzed along with the design features of the brake assembly and their interfaces. The results suggested that the higher convection coefficients achieved with airflow cooling will not only reduce the maximum temperature in the braking but also reduce the thermal gradients, since heat will be removed faster from hotter parts of the disk. Airflow cooling should be effective to reduce the risk of hot spot formation and disc thermal distortion. The highest temperature after emergency braking was 461 °C and 359 °C without and with considering airflow cooling, respectively. The equivalent stress could reach 269 MPa and 164 MPa without and with considering airflow cooling, respectively. However, the maximum surface stress may exceed the material yield strength during an emergency braking, which may cause a plastic damage accumulation in a brake disk without cooling. The simulation results are consistent with the experimental results well.展开更多
基金supported by the National Science and Technology Major Project for the Prevention and Control of Emerging and Major Infectious Diseases[2025ZD01908702]Peking University Medicine Fund of Fostering Young Scholars’Scientific&Technological innovation[BMU2024YFJHP014]supported by Fundamental Research Funds for the Central Universities+1 种基金Key Clinical Projects of Peking University Third Hospital[BYSYZD2022014]Peking University Third Hospital[2025024].
文摘Objective Post tuberculosis lung disease(PTLD)manifests in various forms,including tuberculosisassociated chronic obstructive pulmonary disease(TB-COPD),yet the clinical features of PTLD remain undercharacterized.This study aimed to assess longitudinal changes in lung function over a 5-year period and to identify predictors of airflow obstruction in a cohort of patients treated for active pulmonary TB.Methods Patients with active pulmonary TB were enrolled in this study and were followed during treatment,at treatment completion and five years post-treatment.Assessments included lung function and chest CT,analyzing longitudinal trends and airflow obstruction risk factors.Results Among 53 patients(mean age 36.9±13.9 years;64.2%male),7 patients(13.2%)exhibited airflow obstruction.At the 5-year follow-up,the mean FEV_(1)/FVC declined significantly(76.27%±12.04%vs.80.23%±11.02%,P<0.001)and 9 patients(17.0%)exhibited airflow obstruction.Seven of these patients predominantly showed air trapping consistent with small airway disease on chest CT,aligning with TB-COPD phenotype.Notably,four young-to-middle-aged patients(<60 years old)had persistent obstruction over the five years.Conclusion The initial test revealed that 13.2%of patients presented with airflow obstruction.By the 5-year follow-up,this proportion had increased to 17.0%,with most cases demonstrating imaging findings aligning with TB-COPD,even among younger,non-smoking individuals.These findings emphasize the importance of long-term follow-up and routine lung function assessments in TB survivors.
基金Projects (50872018, 50902018) supported by the National Natural Science Foundation of ChinaProject (1099043) supported by the Science and Technology in Guangxi Province, ChinaProject (090302005) supported by the Basic Research Fund for Northeastern University, China
文摘The mass of high-speed trains can be reduced using the brake disk prepared with SiC network ceramic frame reinforced 6061 aluminum alloy composite （SiCn/Al）. The thermal and stress analyses of SiCn/Al brake disk during emergency braking at a speed of 300 km/h considering airflow cooling were investigated using finite element （FE） and computational fluid dynamics （CFD） methods. All three modes of heat transfer （conduction, convection and radiation） were analyzed along with the design features of the brake assembly and their interfaces. The results suggested that the higher convection coefficients achieved with airflow cooling will not only reduce the maximum temperature in the braking but also reduce the thermal gradients, since heat will be removed faster from hotter parts of the disk. Airflow cooling should be effective to reduce the risk of hot spot formation and disc thermal distortion. The highest temperature after emergency braking was 461 °C and 359 °C without and with considering airflow cooling, respectively. The equivalent stress could reach 269 MPa and 164 MPa without and with considering airflow cooling, respectively. However, the maximum surface stress may exceed the material yield strength during an emergency braking, which may cause a plastic damage accumulation in a brake disk without cooling. The simulation results are consistent with the experimental results well.
