Soil respiration is the key process driving CO_(2) exchange between forest soils and the atmosphere and regulated by soil organic carbon(SOC)characteristics and extracellular enzyme activities.However,the direction an...Soil respiration is the key process driving CO_(2) exchange between forest soils and the atmosphere and regulated by soil organic carbon(SOC)characteristics and extracellular enzyme activities.However,the direction and magnitude of the effects of stand density on labile SOC fractions,extracellular enzymes,and soil respiration across plantation ages remain unclear.We constructed enhanced soil respiration models using heterogeneous soil data under density regulation to better characterize soil processes.Study plots encompassing stand-density gradients were implemented in Larix principis-rupprechtii plantations spanning three age-class strata.During the growing season,systematic measurements were conducted on soil respiration rates,labile organic carbon fractions,and extracellular enzyme activities.A process-driven soil respiration model was developed by integrating nonlinear mixed-effects modeling frameworks with measured data.The moderate density stands showed increases in soil respiration(Rs),microbial biomass carbon(MBC),light fraction organic carbon(LFOC),β-1,4-glucosidase(BGC),andβ-N-acetyl glycosaminidase+leucine aminopeptidase(NAG+LAP).In 36a and 48a stands,the moderate-density stands NAG+LAP had a~35%increase compared to other density levels,while readily oxidized carbon(ROC)concentrations showed a significant~30%-50%reduction.All labile organic carbon components were stable with age,so that soil microorganisms were promoted to acquire C,N,and P.Temperature,moisture,MBC,BGC,and NAG+LAP were essential factors that affected soil respiration.Stand density has important impacts on soil respiration as it regulates the soil organic carbon and activities of extracellular enzymes.The roles of temperature,microbial biomass carbon,soil organic carbon and dissolved organic carbon are complex and directly affect autotrophic and heterotrophic respiration and regulate soil respiration by influencing microbial C and N acquisition.A mixed-effects model with nested stand density and age mathematically optimized the soil respiration model,enabling enhanced characterization of covariation patterns of soil respiration with related soil carbon pool variables.展开更多
Conventional ultrasound(US)evaluation of enthesitis in psoriatic arthritis(PsA)is limited by its inability to quantify metabolic alterations such as hypoxia,a key driver of disease activity.We introduce an oxygenation...Conventional ultrasound(US)evaluation of enthesitis in psoriatic arthritis(PsA)is limited by its inability to quantify metabolic alterations such as hypoxia,a key driver of disease activity.We introduce an oxygenation-integrated multimodal photoacoustic/ultrasound(PA/US)imaging framework designed to quantify entheseal oxygen saturation(SO_(2))for assessing entheseal disease activity in PsA.In this cross-sectional study,25 PsA patients underwent bilateral PA/US imaging of 12 entheses,where ultrasound lesions were scored using the Outcome Measures in Rheumatology scoring system,and PA-derived SO_(2) levels,quantified via dual-wavelength PA imaging,were classified into hyperoxia or hypoxia groups using k-means clustering.This approach provides metabolic insights complementary to conventional ultrasonic assessment.A composite score integrating hypoxia with US parameters was validated against clinical disease activity indices(Disease Activity Score 28-C-reactive protein,DAS28-CRP;Disease Activity Index for Psoriatic Arthritis,DAPSA).Among 300 entheses,103(34.3%)exhibited PA positivity,with 40(38.8%)classified as hypoxia.Hypoxia scores independently predicted DAS28-CRP(β=0.618,p=0.001)and DAPSA(β=0.612,p<0:001).The hypoxia-optimized PAUS score demonstrated superior correlation with disease activity indices compared to conventional US(DAS28-CRP:r=0.615,p=0.001 versus r=0.474,p=0.017;DAPSA:r=0.743,p<0:001 versus r=0.567,p=0.003),alongside superior diagnostic accuracy for minimal disease activity(area under the curve,AUC 0.776 versus 0.614,p=0.008)and low disease activity(AUC 0.853 versus 0.772,p=0.009).This multimodal scoring system enhances the stratification of PsA disease activity by providing unique metabolic insights,offering a potential tool for therapeutic monitoring and guiding treat-to-target strategies.展开更多
基金supported by the National Key Research and Development Program of China(2023YFD2200403)National Natural Science Foundation of China(No.32260382)the Natural Science Foundation of Guangxi(2025GXNSFBA069250).
文摘Soil respiration is the key process driving CO_(2) exchange between forest soils and the atmosphere and regulated by soil organic carbon(SOC)characteristics and extracellular enzyme activities.However,the direction and magnitude of the effects of stand density on labile SOC fractions,extracellular enzymes,and soil respiration across plantation ages remain unclear.We constructed enhanced soil respiration models using heterogeneous soil data under density regulation to better characterize soil processes.Study plots encompassing stand-density gradients were implemented in Larix principis-rupprechtii plantations spanning three age-class strata.During the growing season,systematic measurements were conducted on soil respiration rates,labile organic carbon fractions,and extracellular enzyme activities.A process-driven soil respiration model was developed by integrating nonlinear mixed-effects modeling frameworks with measured data.The moderate density stands showed increases in soil respiration(Rs),microbial biomass carbon(MBC),light fraction organic carbon(LFOC),β-1,4-glucosidase(BGC),andβ-N-acetyl glycosaminidase+leucine aminopeptidase(NAG+LAP).In 36a and 48a stands,the moderate-density stands NAG+LAP had a~35%increase compared to other density levels,while readily oxidized carbon(ROC)concentrations showed a significant~30%-50%reduction.All labile organic carbon components were stable with age,so that soil microorganisms were promoted to acquire C,N,and P.Temperature,moisture,MBC,BGC,and NAG+LAP were essential factors that affected soil respiration.Stand density has important impacts on soil respiration as it regulates the soil organic carbon and activities of extracellular enzymes.The roles of temperature,microbial biomass carbon,soil organic carbon and dissolved organic carbon are complex and directly affect autotrophic and heterotrophic respiration and regulate soil respiration by influencing microbial C and N acquisition.A mixed-effects model with nested stand density and age mathematically optimized the soil respiration model,enabling enhanced characterization of covariation patterns of soil respiration with related soil carbon pool variables.
基金supported by the National Natural Science Foundation of China(62325112)the National Key Research and Development Program of China(2023YFC2411700,2023YFC2411705)+2 种基金the National Natural Science Foundation of China(U22A2023)the National High-Level Hospital Clinical Research Funding(2022-PUMCH-C-009,2022-PUMCH-B-064,2022-PUMCH-D-002)the National Basic Research Program of China(973 Program,2014CB541801).
文摘Conventional ultrasound(US)evaluation of enthesitis in psoriatic arthritis(PsA)is limited by its inability to quantify metabolic alterations such as hypoxia,a key driver of disease activity.We introduce an oxygenation-integrated multimodal photoacoustic/ultrasound(PA/US)imaging framework designed to quantify entheseal oxygen saturation(SO_(2))for assessing entheseal disease activity in PsA.In this cross-sectional study,25 PsA patients underwent bilateral PA/US imaging of 12 entheses,where ultrasound lesions were scored using the Outcome Measures in Rheumatology scoring system,and PA-derived SO_(2) levels,quantified via dual-wavelength PA imaging,were classified into hyperoxia or hypoxia groups using k-means clustering.This approach provides metabolic insights complementary to conventional ultrasonic assessment.A composite score integrating hypoxia with US parameters was validated against clinical disease activity indices(Disease Activity Score 28-C-reactive protein,DAS28-CRP;Disease Activity Index for Psoriatic Arthritis,DAPSA).Among 300 entheses,103(34.3%)exhibited PA positivity,with 40(38.8%)classified as hypoxia.Hypoxia scores independently predicted DAS28-CRP(β=0.618,p=0.001)and DAPSA(β=0.612,p<0:001).The hypoxia-optimized PAUS score demonstrated superior correlation with disease activity indices compared to conventional US(DAS28-CRP:r=0.615,p=0.001 versus r=0.474,p=0.017;DAPSA:r=0.743,p<0:001 versus r=0.567,p=0.003),alongside superior diagnostic accuracy for minimal disease activity(area under the curve,AUC 0.776 versus 0.614,p=0.008)and low disease activity(AUC 0.853 versus 0.772,p=0.009).This multimodal scoring system enhances the stratification of PsA disease activity by providing unique metabolic insights,offering a potential tool for therapeutic monitoring and guiding treat-to-target strategies.
