Computational simulations and high-temperature measurements of velocities near the surface of a mold were carried out by using the rod deflection method to study the effects of various operating parameters on the flow...Computational simulations and high-temperature measurements of velocities near the surface of a mold were carried out by using the rod deflection method to study the effects of various operating parameters on the flow field in slab continuous casting(CC)molds with narrow widths for the production of automobile exposed panels.Reasonable agreement between the calculated results and measured subsurface velocities of liquid steel was obtained under different operating parameters of the CC process.The simulation results reveal that the flow field in the horizontal plane located 50 mm from the meniscus can be used as the characteristic flow field to optimize the flow field of molten steel in the mold.Increases in casting speed can increase the subsurface velocity of molten steel and shift the position of the vortex core downward in the downward circulation zone.The flow field of liquid steel in a 1040 mm-wide slab CC mold can be improved by an Ar gas flow rate of 7 L·min^−1 and casting speed of 1.7 m·min^−1.Under the present experimental conditions,the double-roll flow pattern is generally stable at a submerged entry nozzle immersion depth of 170 mm.展开更多
BACKGROUND Increased homocysteine levels are associated with the risk of cardiovascular disease(CVD)and death.However,their prevention has not been effective in decreasing CVD risk.This study investigated the individu...BACKGROUND Increased homocysteine levels are associated with the risk of cardiovascular disease(CVD)and death.However,their prevention has not been effective in decreasing CVD risk.This study investigated the individual and combined associations of hyperhomocysteinemia and hypertension with incident CVD events and all-cause death in the Chinese elderly population without a history of CVD.METHODS This prospective study was conducted among 1,257 elderly participants(mean age:69 years).A questionnaire survey,physical examinations,and laboratory tests were conducted to collect baseline data.Hyperhomocysteinemia was defined as homocysteine level≥15μmol/L.H-type hypertension was defined as concomitant hypertension and hyperhomocysteinemia.Multivariate Cox regression analysis was used to evaluate individual and combined associations of hyperhomocysteinemia and hypertension with the risks of incident CVD events and all-cause death.RESULTS Over a median of 4.84-year follow-up,hyperhomocysteinemia was independently associated with incident CVD events and all-cause death.The hazard ratios(HRs)were 1.45(95%CI:1.01−2.08)for incident CVD events and 1.55(95%CI:1.04−2.30)for all-cause death.After adjustment for confounding factors,H-type hypertension had the highest HRs for incident CVD events and all-cause death.The fully adjusted HRs were 2.44 for incident CVD events(95%CI:1.28−4.65),2.07 for stroke events(95%CI:1.01−4.29),8.33 for coronary events(95%CI:1.10−63.11),and 2.31 for all-cause death(95%CI:1.15−4.62).CONCLUSIONS Hyperhomocysteinemia was an independent risk factor,and when accompanied by hypertension,it contrib-uted to incident CVD events and all-cause death in the Chinese elderly population without a history of CVD.展开更多
BACKGROUND Chronic pulmonary aspergillosis(CPA)is a rare syndrome that is often accompanied by gradual lung tissue destruction.Voriconazole is usually employed as the first-line agent for CPA treatment.However,some pa...BACKGROUND Chronic pulmonary aspergillosis(CPA)is a rare syndrome that is often accompanied by gradual lung tissue destruction.Voriconazole is usually employed as the first-line agent for CPA treatment.However,some patients can develop hepatotoxicity and often were forced to stop voriconazole treatment.AIM To record the improving trend of liver function and the therapeutic effects in patients after lowering the trough concentration of voriconazole.METHODS This study retrospectively analyzed 12 adult CPA patients who developed hepatotoxicity during the voriconazole treatment.In these patients,the oral dose was reduced to 3/4 or 1/2 of the standard dose(4 mg/kg,twice daily),and the lower limit of voriconazole trough concentration was maintained more than 0.5μg/m L.The trend of remission of liver toxicity after drug reduction in 12 patients was recorded.During the same period,25 patients who received standard doses served as the control group.Data from the two groups were collected and analyzed for different parameters such as demographic characteristics,underlying pulmonary disorders,laboratory tests,and therapeutic effect.The differences between the two groups were statistically compared.RESULTS Hepatotoxicity occurred in 12 patients within 28-65 d after oral voriconazole treatment.Hepatotoxicity was mainly manifested by the significantly increased level of gamma-glutamyltransferase and a slight increase of alanine aminotransferase and aspartate aminotransferase.The oral dose of voriconazole was reduced to approximately 3 mg/kg in seven patients and approximately 2 mg/kg in five patients.The average trough concentrations for the 12 patients before and after voriconazole oral dose reduction were 3.17±1.47μg/m L(1.5-6.0μg/m L)and 1.70±0.78μg/m L(0.6-3.3μg/m L),respectively(P=0.02).After lowering the trough concentrations,the hepatotoxicity was alleviated in all the patients.However,gamma-glutamyltransferase levels declined slowly.After 4 mo of treatment,7 of the 12 patients were successfully treated in the low trough concentrations group(41.7%).Similarly,8 of the 25 patients in the standard treatment dose group(32.0%)were effectively treated.There was no statistical difference between the groups(P=0.72).CONCLUSION Reducing the lower limit of the voriconazole trough concentration to 0.5μg/m L can alleviate the hepatotoxicity and maintained certain clinical efficacy in CPA patients;however,patients should be closely monitored.展开更多
基金This work was financially supported by the Hunan Valin Lianyuan Iron&Steel Co.,Ltd.,China(No.18H00582).The authors are grateful to Hunan Valin Lianyuan Iron&Steel Co.,Ltd.,China for their assistance with the industrial measurement of velocities near the mold surface.
文摘Computational simulations and high-temperature measurements of velocities near the surface of a mold were carried out by using the rod deflection method to study the effects of various operating parameters on the flow field in slab continuous casting(CC)molds with narrow widths for the production of automobile exposed panels.Reasonable agreement between the calculated results and measured subsurface velocities of liquid steel was obtained under different operating parameters of the CC process.The simulation results reveal that the flow field in the horizontal plane located 50 mm from the meniscus can be used as the characteristic flow field to optimize the flow field of molten steel in the mold.Increases in casting speed can increase the subsurface velocity of molten steel and shift the position of the vortex core downward in the downward circulation zone.The flow field of liquid steel in a 1040 mm-wide slab CC mold can be improved by an Ar gas flow rate of 7 L·min^−1 and casting speed of 1.7 m·min^−1.Under the present experimental conditions,the double-roll flow pattern is generally stable at a submerged entry nozzle immersion depth of 170 mm.
基金This study was supported by the Commission of Science and Technology of Beijing(D121100004912002)the Beijing Natural Science Foundation(No.7152068)the Project for Collaboration between Basis and Clinic of Capital Medical University(No.17JL69).
文摘BACKGROUND Increased homocysteine levels are associated with the risk of cardiovascular disease(CVD)and death.However,their prevention has not been effective in decreasing CVD risk.This study investigated the individual and combined associations of hyperhomocysteinemia and hypertension with incident CVD events and all-cause death in the Chinese elderly population without a history of CVD.METHODS This prospective study was conducted among 1,257 elderly participants(mean age:69 years).A questionnaire survey,physical examinations,and laboratory tests were conducted to collect baseline data.Hyperhomocysteinemia was defined as homocysteine level≥15μmol/L.H-type hypertension was defined as concomitant hypertension and hyperhomocysteinemia.Multivariate Cox regression analysis was used to evaluate individual and combined associations of hyperhomocysteinemia and hypertension with the risks of incident CVD events and all-cause death.RESULTS Over a median of 4.84-year follow-up,hyperhomocysteinemia was independently associated with incident CVD events and all-cause death.The hazard ratios(HRs)were 1.45(95%CI:1.01−2.08)for incident CVD events and 1.55(95%CI:1.04−2.30)for all-cause death.After adjustment for confounding factors,H-type hypertension had the highest HRs for incident CVD events and all-cause death.The fully adjusted HRs were 2.44 for incident CVD events(95%CI:1.28−4.65),2.07 for stroke events(95%CI:1.01−4.29),8.33 for coronary events(95%CI:1.10−63.11),and 2.31 for all-cause death(95%CI:1.15−4.62).CONCLUSIONS Hyperhomocysteinemia was an independent risk factor,and when accompanied by hypertension,it contrib-uted to incident CVD events and all-cause death in the Chinese elderly population without a history of CVD.
文摘BACKGROUND Chronic pulmonary aspergillosis(CPA)is a rare syndrome that is often accompanied by gradual lung tissue destruction.Voriconazole is usually employed as the first-line agent for CPA treatment.However,some patients can develop hepatotoxicity and often were forced to stop voriconazole treatment.AIM To record the improving trend of liver function and the therapeutic effects in patients after lowering the trough concentration of voriconazole.METHODS This study retrospectively analyzed 12 adult CPA patients who developed hepatotoxicity during the voriconazole treatment.In these patients,the oral dose was reduced to 3/4 or 1/2 of the standard dose(4 mg/kg,twice daily),and the lower limit of voriconazole trough concentration was maintained more than 0.5μg/m L.The trend of remission of liver toxicity after drug reduction in 12 patients was recorded.During the same period,25 patients who received standard doses served as the control group.Data from the two groups were collected and analyzed for different parameters such as demographic characteristics,underlying pulmonary disorders,laboratory tests,and therapeutic effect.The differences between the two groups were statistically compared.RESULTS Hepatotoxicity occurred in 12 patients within 28-65 d after oral voriconazole treatment.Hepatotoxicity was mainly manifested by the significantly increased level of gamma-glutamyltransferase and a slight increase of alanine aminotransferase and aspartate aminotransferase.The oral dose of voriconazole was reduced to approximately 3 mg/kg in seven patients and approximately 2 mg/kg in five patients.The average trough concentrations for the 12 patients before and after voriconazole oral dose reduction were 3.17±1.47μg/m L(1.5-6.0μg/m L)and 1.70±0.78μg/m L(0.6-3.3μg/m L),respectively(P=0.02).After lowering the trough concentrations,the hepatotoxicity was alleviated in all the patients.However,gamma-glutamyltransferase levels declined slowly.After 4 mo of treatment,7 of the 12 patients were successfully treated in the low trough concentrations group(41.7%).Similarly,8 of the 25 patients in the standard treatment dose group(32.0%)were effectively treated.There was no statistical difference between the groups(P=0.72).CONCLUSION Reducing the lower limit of the voriconazole trough concentration to 0.5μg/m L can alleviate the hepatotoxicity and maintained certain clinical efficacy in CPA patients;however,patients should be closely monitored.
