Minimizing soil ammonia（NH_3） and nitrous oxide（N_2O） emission factors（EFs） has significant implications in regional air quality and greenhouse gas（GHG） emissions besides nitrogen（N） nutrient loss.The aim of...Minimizing soil ammonia（NH_3） and nitrous oxide（N_2O） emission factors（EFs） has significant implications in regional air quality and greenhouse gas（GHG） emissions besides nitrogen（N） nutrient loss.The aim of this study was to investigate the impacts of different N fertilizer treatments of conventional urea,polymer-coated urea,ammonia sulfate,urease inhibitor（NBPT,N-（n-butyl） thiophosphoric triamide）-treated urea,and nitrification inhibitor（DCD,dicyandiamide）-treated urea on emissions of NH_3 and GHGs from subtropical wheat cultivation.A field study was established in a Cancienne silt loam soil.During growth season,NH_3 emission following N fertilization was characterized using active chamber method whereas GHG emissions of N_2O,carbon dioxide（CO_2）,and methane（CH_4） were by passive chamber method.The results showed that coated urea exhibited the largest reduction（49%） in the EF of NH_3-N followed by NBPT-treated urea（39%） and DCD-treated urea（24%） over conventional urea,whereas DCD-treated urea had the greatest suppression on N_2O-N（87%） followed by coated urea（76%） and NBPT-treated urea（69%）.Split fertilization of ammonium sulfate-urea significantly lowered both NH_3-N and N_2O-N EF values but split urea treatment had no impact over one-time application of urea.Both NBPT and DCD-treated urea treatments lowered CO_2-C flux but had no effect on CH_4-C flux.Overall,application of coated urea or urea with NPBT or DCD could be used as a mitigation strategy for reducing NH_3 and N_2O emissions in subtropical wheat production in Southern USA.展开更多
BACKGROUND There is an urgent need to risk stratify patients with suspected nonalcoholic fatty liver disease(NAFLD)and identify those with fibrotic nonalcoholic steatohepatitis.This study aims to apply a simple diagno...BACKGROUND There is an urgent need to risk stratify patients with suspected nonalcoholic fatty liver disease(NAFLD)and identify those with fibrotic nonalcoholic steatohepatitis.This study aims to apply a simple diagnostic algorithm to identify subjects with at-risk NAFLD in the general population.AIM To apply a simple diagnostic algorithm to identify subjects with at-risk NAFLD in the general population.METHODS Adult subjects were included from the National Health and Nutrition Examination Survey database(2017-2018)if they had elevated alanine aminotransferase(ALT)and excluded if they had evidence of viral hepatitis or significant alcohol consumption.A fibrosis-4(FIB4)cutoff of 1.3 differentiated patients with low risk vs high risk disease.If patients had FIB4>1.3,a FAST score<0.35 ruled out advanced fibrosis.Patients with FAST>0.35 were referred to a specialist.The same algorithm was applied to subjects with type 2 diabetes mellitus(T2DM).RESULTS Three thousand six hundred and sixty-nine patients were identified who met all inclusion and exclusion criteria.From this cohort,911(28.6%)patients had elevated ALT of which 236(22.9%)patients had elevated FIB4 scores≥1.3.Among patients with elevated FIB4 score,75(24.4%)had elevated FAST scores,ruling in advanced fibrosis.This accounts for 2.0%of the overall study population.Applying this algorithm to 737 patients with T2DM,213(35.4%)patients had elevated ALT,85(37.9%)had elevated FIB4,and 42(46.1%)had elevated FAST scores.This accounts for 5.7%of the population with T2DM.CONCLUSION The application of this algorithm to identify at-risk NAFLD patients in need for specialty care is feasible and demonstrates that the vast majority of patients do not need subspecialty referral for NAFLD.展开更多
基金supported,in part,by a scholarship from the China Scholarship Council(CSC)
文摘Minimizing soil ammonia（NH_3） and nitrous oxide（N_2O） emission factors（EFs） has significant implications in regional air quality and greenhouse gas（GHG） emissions besides nitrogen（N） nutrient loss.The aim of this study was to investigate the impacts of different N fertilizer treatments of conventional urea,polymer-coated urea,ammonia sulfate,urease inhibitor（NBPT,N-（n-butyl） thiophosphoric triamide）-treated urea,and nitrification inhibitor（DCD,dicyandiamide）-treated urea on emissions of NH_3 and GHGs from subtropical wheat cultivation.A field study was established in a Cancienne silt loam soil.During growth season,NH_3 emission following N fertilization was characterized using active chamber method whereas GHG emissions of N_2O,carbon dioxide（CO_2）,and methane（CH_4） were by passive chamber method.The results showed that coated urea exhibited the largest reduction（49%） in the EF of NH_3-N followed by NBPT-treated urea（39%） and DCD-treated urea（24%） over conventional urea,whereas DCD-treated urea had the greatest suppression on N_2O-N（87%） followed by coated urea（76%） and NBPT-treated urea（69%）.Split fertilization of ammonium sulfate-urea significantly lowered both NH_3-N and N_2O-N EF values but split urea treatment had no impact over one-time application of urea.Both NBPT and DCD-treated urea treatments lowered CO_2-C flux but had no effect on CH_4-C flux.Overall,application of coated urea or urea with NPBT or DCD could be used as a mitigation strategy for reducing NH_3 and N_2O emissions in subtropical wheat production in Southern USA.
基金Supported by AHRQ grant,No.R01HS026937(Le P and Payne J)。
文摘BACKGROUND There is an urgent need to risk stratify patients with suspected nonalcoholic fatty liver disease(NAFLD)and identify those with fibrotic nonalcoholic steatohepatitis.This study aims to apply a simple diagnostic algorithm to identify subjects with at-risk NAFLD in the general population.AIM To apply a simple diagnostic algorithm to identify subjects with at-risk NAFLD in the general population.METHODS Adult subjects were included from the National Health and Nutrition Examination Survey database(2017-2018)if they had elevated alanine aminotransferase(ALT)and excluded if they had evidence of viral hepatitis or significant alcohol consumption.A fibrosis-4(FIB4)cutoff of 1.3 differentiated patients with low risk vs high risk disease.If patients had FIB4>1.3,a FAST score<0.35 ruled out advanced fibrosis.Patients with FAST>0.35 were referred to a specialist.The same algorithm was applied to subjects with type 2 diabetes mellitus(T2DM).RESULTS Three thousand six hundred and sixty-nine patients were identified who met all inclusion and exclusion criteria.From this cohort,911(28.6%)patients had elevated ALT of which 236(22.9%)patients had elevated FIB4 scores≥1.3.Among patients with elevated FIB4 score,75(24.4%)had elevated FAST scores,ruling in advanced fibrosis.This accounts for 2.0%of the overall study population.Applying this algorithm to 737 patients with T2DM,213(35.4%)patients had elevated ALT,85(37.9%)had elevated FIB4,and 42(46.1%)had elevated FAST scores.This accounts for 5.7%of the population with T2DM.CONCLUSION The application of this algorithm to identify at-risk NAFLD patients in need for specialty care is feasible and demonstrates that the vast majority of patients do not need subspecialty referral for NAFLD.
