Circulating fluidized bed combustion(CFBC)is known for its ability to significantly reduce the emission of NO_(x)and SO2 from coal combustion.However,the fly ash produced from CFBC(CFBFA)is impractical for use as a co...Circulating fluidized bed combustion(CFBC)is known for its ability to significantly reduce the emission of NO_(x)and SO2 from coal combustion.However,the fly ash produced from CFBC(CFBFA)is impractical for use as a construction material due to its low pozzolanic activity.The present work evaluated two methods for zeolite synthesis from CFBFA,namely a low-temperature hydrothermal method and an alkali fusion followed by hydrothermal method,in order to provide another method to recycle CFBFA.Various synthesis conditions were systematically investigated to optimize the process.展开更多
Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’...Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’s disease.In this review,we summarize the changes in short-chain fatty acid levels and the abundance of short-chain fatty acid-producing bacteria in various samples from patients with Parkinson’s disease,highlighting the critical role of gut homeostasis imbalance in the pathogenesis and progression of the disease.Focusing on the nervous system,we discuss the molecular mechanisms by which short-chain fatty acids influence the homeostasis of both the enteric nervous system and the central nervous system.We identify key processes,including the activation of G protein-coupled receptors and the inhibition of histone deacetylases by short-chain fatty acids.Importantly,structural or functional disruptions in the enteric nervous system mediated by these fatty acids may lead to abnormalα-synuclein expression and gastrointestinal dysmotility,which could serve as an initiating event in Parkinson’s disease.Furthermore,we propose that short-chain fatty acids help establish communication between the enteric nervous system and the central nervous system via the vagal nerve,immune circulation,and endocrine signaling.This communication may shed light on their potential role in the transmission ofα-synuclein from the gut to the brain.Finally,we elucidate novel treatment strategies for Parkinson’s disease that target short-chain fatty acids and examine the challenges associated with translating short-chain fatty acid-based therapies into clinical practice.In conclusion,this review emphasizes the pivotal role of short-chain fatty acids in regulating gut-brain axis integrity and their significance in the pathogenesis of Parkinson’s disease from the perspective of the nervous system.Moreover,it highlights the potential value of short-chain fatty acids in early intervention for Parkinson’s disease.Future research into the molecular mechanisms of short-chain fatty acids and their synergistic interactions with other gut metabolites is likely to advance the clinical translation of innovative short-chain fatty acid-based therapies for Parkinson’s disease.展开更多
In this paper,we present a necessary and sufficient condition for hyponormal block Toeplitz operators T on the vector-valued weighted Bergman space with symbolsΦ(z)=G^(*)(z)+F(z),where F(z)=∑^(N)_(i)=1 A_(i)z^(i)and...In this paper,we present a necessary and sufficient condition for hyponormal block Toeplitz operators T on the vector-valued weighted Bergman space with symbolsΦ(z)=G^(*)(z)+F(z),where F(z)=∑^(N)_(i)=1 A_(i)z^(i)and G(z)=∑^(N)_(i)=1 A_(−i)z^(i),A_(i)ae culants.展开更多
Objectives:Although immune checkpoint inhibitors(ICIs)and targeted therapies have reshaped treatment non-small cell lung cancer(NSCLC)paradigms,prognosis remains poor for many patients due to delayed diagnosis and res...Objectives:Although immune checkpoint inhibitors(ICIs)and targeted therapies have reshaped treatment non-small cell lung cancer(NSCLC)paradigms,prognosis remains poor for many patients due to delayed diagnosis and resistance mechanisms.Liquid biopsy offers a minimally invasive approach to monitoring tumor evolution.Among circulating biomarkers,circulating tumor cells(CTCs)and cancer-associated macrophage-like cells(CAM-Ls)may provide complementary prognostic insights.The study aimed to evaluate the prognostic role of CTC and CAM-Ls dynamic in metastatic NSCLC patients.Methods:We retrospectively analyzed 77 patients with metastatic NSCLC who underwent CTC and CAM-L evaluation via the CellSearch^(■)system at baseline(T0)and after three months of first-line treatment(T1)including chemotherapy,targeted therapy,or ICIs.Survival outcomes were analyzed using Kaplan-Meier and Cox regression analyses.Results:Conversion to CTC-negative status at T1 was associated with improved outcomes,with median overall survival(OS)and progression-free survival(PFS)of 33 and 18 months,respectively,vs.10 and 6 months in persistently positive patients(both p<0.001).CTC negativity at T1 remained an independent prognostic factor for OS(HR:6.68)and PFS(HR:5.91,both p<0.0001).CAM-L positivity at T1 also correlated with longer OS(30 vs.12 months)and PFS(13 vs.6 months,both p<0.0001),particularly among ICI-treated patients.Combined CTC and CAM-L assessment further refined risk stratification.Conclusions:Dynamic monitoring of CTCs and CAM-Ls provides actionable prognostic information in metastatic NSCLC.CTC-negative status predicted longer OS and PFS,while CAM-L positivity at T1 was associated with improved outcomes,particularly in ICI-treated patients.Combined assessment of both biomarkers may directly inform therapeutic decision-making,through early detection of outcomes.展开更多
Objective:We investigated the clinical value of a novel circulating tumor cell(CTC)detection method—subtraction enrichment combined with immunostaining and fluorescence in situ hybridization(SEi FISH)—in ovarian can...Objective:We investigated the clinical value of a novel circulating tumor cell(CTC)detection method—subtraction enrichment combined with immunostaining and fluorescence in situ hybridization(SEi FISH)—in ovarian cancer(OC).This study evaluated the diagnostic and prognostic significance of chromosome 8aneuploidy in CTCs and circulating tumor endothelial cells(CTECs)for preoperative diagnosis,treatment efficacy assessment,and recurrence monitoring.Methods:A total of 331 patients were enrolled,including 56 with newly diagnosed primary OC,265 with benign ovarian tumors,and 10 with borderline tumors.Peripheral blood CTCs and CTECs were detected using SEi FISH;their quantity and ploidy characteristics were analyzed in relation to clinical indicators.To assess dynamic CTC changes during disease progression and treatment response,72 patients were followed longitudinally,of whom 19 experienced recurrence.Results:The CTC detection rate in OC patients was 92.9%,with significantly higher counts than that in the benign tumor group(median 5 vs.2).Receiver operating characteristic analysis demonstrated good diagnostic performance for total CTCs[area under the curve(AUC)=0.699],with triploid CTCs achieving the highest efficacy(AUC=0.792),surpassing carbohydrate antigen 125(CA125)(AUC=0.702).Postoperative follow-up showed that70%of patients exhibited concurrent decreases in CTCs and CA125 levels,indicating disease improvement.In30%of patients,CTC levels did not correlate with changes in CA125 levels.Individual case evidence suggests that CTC alterations may serve as an early indicator of recurrence or metastasis.Among the 19 recurrent cases,73.7%showed elevated CTCs at recurrence that decreased following treatment.In four patients,CTCs reflected disease progression earlier than CA125,indicating higher sensitivity for recurrence monitoring.Conclusions:CTCs with chromosome 8 aneuploidy demonstrate significant clinical value in the preoperative diagnosis,treatment efficacy evaluation,and recurrence monitoring of OC.Dynamic CTC changes may serve as a more sensitive indicator than CA125 for disease surveillance,supporting the translational potential of CTC-based biomarkers in OC.展开更多
Cervical cancer related to human papillomavirus(HPV)is a leading cause of cancer-related mortality among women worldwide.Cancer cells release fragments of their DNA,known as circulating tumor DNA(ctDNA),which can be d...Cervical cancer related to human papillomavirus(HPV)is a leading cause of cancer-related mortality among women worldwide.Cancer cells release fragments of their DNA,known as circulating tumor DNA(ctDNA),which can be detected in bodily fluids.A PubMed search using the terms“ctHPV”or“circulating tumor DNA”and“cervical cancer”,limited to the past ten years,identified 104 articles,complemented by hand-searching for literature addressing medico-legal implications.Studies were evaluated for relevance and methodological quality.Detection and characterization of circulating tumor HPV DNA(ctHPV DNA)have emerged as promising tools for assessing prognosis and disease recurrence in cervical cancer.Detection techniques include polymerase chain reaction(PCR),digital droplet PCR(ddPCR),and next-generation sequencing(NGS).This review summarizes current knowledge on ctHPV DNA in cervical cancer and explores its clinical and medico-legal implications,including management of discordant results,diagnostic errors,liability,and data protection compliance.展开更多
Climate models are essential for understanding past,present,and future changes in atmospheric circulation,with circulation modes providing key sources of seasonal predictability and prediction uncertainties for both g...Climate models are essential for understanding past,present,and future changes in atmospheric circulation,with circulation modes providing key sources of seasonal predictability and prediction uncertainties for both global and regional climates.This study assesses the performance of models participating in phase 6 of the Coupled Model Intercomparison Project in simulating interannual variability modes of Northern Hemisphere 500-hPa geopotential height during winter and summer,distinguishing predictable(potentially predictable on seasonal or longer timescales)and unpredictable(intraseasonal and essentially unpredictable at long range)components,using reanalysis data and a variance decomposition method.Although most models effectively capture unpredictable modes in reanalysis,their ability to reproduce dominant predictable modes-specifically the Pacific-North American pattern,Arctic Oscillation,and Western Pacific Oscillation in winter,and the East Atlantic and North Atlantic Oscillations in summer-varies notably.An optimal ensemble is identified to distinguish(a)predictable-external modes,dominated by external forcing,and(b)predictable-internal modes,associated with slow internal variability,during the historical period(1950-2014)and the SSP5-8.5 scenario(2036-2100).Under increased radiative forcing,the leading winter/summer predictable-external mode exhibits a more uniform spatial distribution,remarkably larger trend and annual variance,and enhanced height-sea surface temperature(SST)covariance under SSP5-8.5 compared to historical conditions.The dominant winter/summer predictable-internal modes also exhibit increased variance and height-SST covariance under SSP5-8.5,along with localized changes in spatial configuration.Minimal changes are observed in spatial distribution or variance for dominant winter/summer unpredictable modes under SSP5-8.5.This study,from a predictive perspective,deepens our understanding of model uncertainties and projected changes in circulations.展开更多
Wind-induced circulation is the main form of lake flow for shallow lakes and plays an important role in algae population distribution.This study constructed a three-dimensional hydrodynamic model(EFDC)of the plateau l...Wind-induced circulation is the main form of lake flow for shallow lakes and plays an important role in algae population distribution.This study constructed a three-dimensional hydrodynamic model(EFDC)of the plateau lake Erhai,China using accuracy wind field observation,runoff data and monthly algae data during 2022–2023.The model successfully reproduced the circulation characteristics of Erhai under prevailing wind directions.The results showed that the lake flow velocity in Lake Erhai is higher in winter than in summer,with lower velocities near shore particularly in the northern and central parts of the lake.There is a negative correlation between algal biomass and flow velocity(FV)in different zones,with lower FV favoring the accumulation of algal biomass,particularly for Microcystis,Dolichospermum,and Peridinium.Additionally,due to buoyancy,cyanobacteria are highly affected by wind direction and tend to accumulate in downwind regions of the prevailing wind direction.This study demonstrates that wind-induced circulation is a crucial factor affecting the spatial distribution of dominant algae populations in shallow plateau lakes with weak hydrodynamic force.Further,the risk of bloom occurrence in Lake Erhai will be higher due to the background of global climate change and the lake’s wind speed decline.In conclusion,we suggest implementing targeted zoning measures to control algal blooms and establishing stricter regulations for nitrogen and phosphorus control to counterbalance the promotion of algal bloom accumulation in low-velocity zones caused by reduced wind speed.展开更多
This study investigates the relationship between atmospheric stratification (i.e., static stability given by N^(2)) and the vertical energy transfer of stationary planetary waves, and further illustrates the underlyin...This study investigates the relationship between atmospheric stratification (i.e., static stability given by N^(2)) and the vertical energy transfer of stationary planetary waves, and further illustrates the underlying physical mechanism. Specifically, for the simplified case of constant stratospheric N^(2), the refractive index square of planetary waves has a theoretical tendency to increase first and then decrease with an increased N^(2), whereas the group velocity weakens. Mechanistically, this behavior can be understood as an intensified suppression of vertical isentropic surface displacement caused by meridional heat transport of planetary waves under strong N^(2) conditions. Observational analysis corroborates this finding, demonstrating a reduction in the vertical-propagation velocity of waves with increased N^(2). A linear, quasi- geostrophic, mid-latitude beta-plane model with a constant background westerly wind and a prescribed N^(2) applicable to the stratosphere is used to obtain analytic solutions. In this model, the planetary waves are initiated by steady energy influx from the lower boundary. The analysis indicates that under strong N^(2) conditions, the amplitude of planetary waves can be sufficiently increased by the effective energy convergence due to the slowing vertical energy transfer, resulting in a streamfunction response in this model that contains more energy. For N^(2) with a quasi-linear vertical variation, the results bear a resemblance to the constant case, except that the wave amplitude and oscillating frequency show some vertical variations.展开更多
Based on high-altitude and ground observation data and physical quantity field data,the diagnostic analysis of a heavy rainfall process in Hulunbuir City from July 18 to 20,2025 was conducted from the aspects of circu...Based on high-altitude and ground observation data and physical quantity field data,the diagnostic analysis of a heavy rainfall process in Hulunbuir City from July 18 to 20,2025 was conducted from the aspects of circulation patterns,influencing systems,dynamic conditions,moisture conditions and convective conditions,and the causes of the occurrence and development of this process were revealed.The study shows that the superposition of the upper-level trough,the ground cyclone,and the low-level jet stream formed strong water vapor transport,strong warm advection,and strong dynamic uplift in Hulunbuir,thereby leading to this heavy rainfall event.The forecasting ideas for short-term heavy rainfall were pointed out to provide certain scientific references for future forecasting and prediction work.展开更多
Clouds play an important role in global atmospheric energy and water vapor budgets, and the low cloud simulations suffer from large biases in many atmospheric general circulation models. In this study, cloud microphys...Clouds play an important role in global atmospheric energy and water vapor budgets, and the low cloud simulations suffer from large biases in many atmospheric general circulation models. In this study, cloud microphysical processes such as raindrop evaporation and cloud water accretion in a double-moment six-class cloud microphysics scheme were revised to enhance the simulation of low clouds using the Global-Regional Integrated Forecast System(GRIST)model. The validation of the revised scheme using a single-column version of the GRIST demonstrated a reasonable reduction in liquid water biases. The revised parameterization simulated medium-and low-level cloud fractions that were in better agreement with the observations than the original scheme. Long-term global simulations indicate the mitigation of the originally overestimated low-level cloud fraction and cloud-water mixing ratio in mid-to high-latitude regions,primarily owing to enhanced accretion processes and weakened raindrop evaporation. The reduced low clouds with the revised scheme showed better consistency with satellite observations, particularly at mid-and high-latitudes. Further improvements can be observed in the simulated cloud shortwave radiative forcing and vertical distribution of total cloud cover. Annual precipitation in mid-latitude regions has also improved, particularly over the oceans, with significantly increased large-scale and decreased convective precipitation.展开更多
To solve the problem of circulating power of dual active bridge(DAB)DC-DC converter over a wide voltage conversion ratio,this paper proposes a novel synchronous PWM(S-PWM)modulation.Existence of circulating power incr...To solve the problem of circulating power of dual active bridge(DAB)DC-DC converter over a wide voltage conversion ratio,this paper proposes a novel synchronous PWM(S-PWM)modulation.Existence of circulating power increases current stress of devices and decreases efficiency,especially under light load conditions.Several modulation methods have been proposed to overcome the problem.They can reduce or eliminate either input or output side circulating power.In contrast,S-PWM not only eliminates both sides circulating power and reduces current stress,but also achieves zero-current-switching(ZCS)turn-on for all switches and ZCS turn-off for most across the full power range.No auxiliary or snubber circuits are increased.In addition,the control can be simplified so the transmitted power is related to only one variable.The S-PWM has four cases under different gain and power conditions.The detailed operation principle and modes of DAB under S-PWM are analyzed in the paper.In addition,four modulations in literature are discussed,and corresponding comparative analyses with S-PWM are given.Finally,a laboratory prototype is built to verify advantages and effectiveness of the proposed modulation.展开更多
The present study compares the Atlantic Meridional Overturning Circulation(AMOC)in the North Atlantic from two simulations by an oceanic general circulation model with 1°×1°and 0.1°×0.1°r...The present study compares the Atlantic Meridional Overturning Circulation(AMOC)in the North Atlantic from two simulations by an oceanic general circulation model with 1°×1°and 0.1°×0.1°resolution,respectively,which explores the sensitivity of AMOC to the resolution.The ocean model is the latest version of the LASG/IAP Climate System Model(LICOM3),and it is forced with atmospheric data from phase 2 of the Ocean Model Intercomparison Project(OMIP2).Comprehensive comparison between the two simulations indicates that the simulated AMOC is highly sensitive to the spatial resolution.The high-resolution model(LICOM-H)simulates a deeper mixed-layer depth(MLD),due to increased surface salinity,than that in the low-resolution model(LICOML)in the Labrador Sea,and it also has stronger AMOC strength(the maximum climatic mean AMOC from 1958 to 2018 is 23.4 Sv for LICOM-H and 21.2 Sv for LICOM-L)and larger variability of AMOC index(2.3 Sv for LICOM-H and 1.7 Sv for LICOM-L).These differences can mainly be attributed to two main dynamic processes that benefit from high resolution.Firstly,LICOM-H can simulate much stronger boundary currents(~0.6 m s^(-1))than LICOM-L(0.3 m s^(-1))in the upper ocean,which leads to saltier and warmer seawater being transported to the Labrador Sea,where it enhances deep convection.Secondly,in LICOM-H,the stronger variability of AMOC is related to the higher sensitivity of the MLD and transformation to the prescribed atmospheric forcing in the Labrador Sea.展开更多
Summer rainfall in the Yangtze River basin(YRB)is favored by two key factors in the lower troposphere:the tropical anticyclonic anomaly over the western North Pacific and the extratropical northeasterly anomalies to t...Summer rainfall in the Yangtze River basin(YRB)is favored by two key factors in the lower troposphere:the tropical anticyclonic anomaly over the western North Pacific and the extratropical northeasterly anomalies to the north of the YRB.This study,however,found that approximately 46%of heavy rainfall events in the YRB occur when only one factor appears and the other is opposite signed.Accordingly,these heavy rainfall events can be categorized into two types:the extratropical northeasterly anomalies but tropical cyclonic anomaly(first unconventional type),and the tropical anticyclonic anomaly but extratropical southwesterly anomalies(second unconventional type).Anomalous water vapor convergence and upward motion exists for both types,but through different mechanisms.For the first type,the moisture convergence and upward motion are induced by a cyclonic anomaly over the YRB,which appears in the mid and lower troposphere and originates from the upstream region.For the second type,a mid-tropospheric cyclonic anomaly over Lake Baikal extends southward and results in southwesterly anomalies over the YRB,in conjunction with the tropical anticyclonic anomaly.The southwesterly anomalies transport water vapor to the YRB and lead to upward motion through warm advection.This study emphasizes the role of mid-tropospheric circulations in inducing heavy rainfall in the YRB.展开更多
BACKGROUND:Prolonged on-scene Advanced Life Support(ALS) in out-of-hospital cardiac arrest(OHCA) patients may enhance return of spontaneous circulation(ROSC),but the optimal duration of cardiopulmonary resuscitation(C...BACKGROUND:Prolonged on-scene Advanced Life Support(ALS) in out-of-hospital cardiac arrest(OHCA) patients may enhance return of spontaneous circulation(ROSC),but the optimal duration of cardiopulmonary resuscitation(CPR) without initial prehospital ROSC remains unclear.We investigated the association between on-scene CPR duration and outcomes using nationwide data.METHODS:This prospective,multi-regional study(2015–2022) included medical cause OHCA patients who underwent Smart ALS(SALS).Data from emergency medical services(EMS) records,SALS logs,and hospital outcomes were analyzed.Logistic regression models were developed for prehospital ROSC,survival to discharge,and good neurological outcome(Cerebral Performance Category [CPC] 1–2).RESULTS:Among 98,569 patients,34,989 were SALS-eligible and 16,052 received SALS.Predictors of ROSC included younger age,male sex,public arrest,witnessed arrest,bystander CPR,shockable rhythm,and shorter response/scene times.Longer on-scene CPR reduced probabilities of ROSC,survival,and neurological recovery at hospital discharge.Model AUROCs were 0.697(95%CI 0.676–0.717) for ROSC,0.836(95%CI 0.810–0.861) for survival,and 0.925(95%CI 0.904–0.946) for neurological outcome.CONCLUSION:On-scene CPR duration is a critical prognostic factor in OHCA.The proposed models highlight on-scene predictors that may inform decisions about CPR continuation and support individualized resuscitation strategies.External validation in other EMS systems is warranted.展开更多
High-sulfur iron concentrates emit SO_(2)into the flue gas during pellet induration.To investigate the effect of the SO_(2)cycle on pellet quality in the grate-kiln process,sulfur balance analysis,thermodynamic calcul...High-sulfur iron concentrates emit SO_(2)into the flue gas during pellet induration.To investigate the effect of the SO_(2)cycle on pellet quality in the grate-kiln process,sulfur balance analysis,thermodynamic calculations,and pellet production experiments under simulated flue gas circulation conditions were conducted.The results indicated that SO_(2)circulation inhibited desulfurization and deteriorated pellet strength.SO_(2)absorption increased the pellet sulfur content to 0.70 wt.%during the downdraft drying phase,and the absorption could be aggravated by the moisture.The desulfurization rate of the preheating process was also decreased to 16.67%,resulting from the refractory sulfate generation.Sulfur content of the roasted pellets dropped to 0.13 wt.%because of the aluminosilicate generation.The finished pellet sulfur content further decreased to 0.08 wt.%due to the fresh air during the cooling process.Eventually,optimization measures were proposed when high-sulfur iron concentrates were used for oxidized pellet preparation.展开更多
Influenza A virus(IAV) has a wide host range,including wild birds,poultry,various mammals,and even humans(Xu et al.2024).Currently,two subtypes of canine influenza virus(CIV),H3N8 and H3N2,are primarily circulating in...Influenza A virus(IAV) has a wide host range,including wild birds,poultry,various mammals,and even humans(Xu et al.2024).Currently,two subtypes of canine influenza virus(CIV),H3N8 and H3N2,are primarily circulating in dogs.The H3N8 CIV was introduced from horses into dogs in 2004(Crawford et al.2005),while the H3N2 CIV originated from chickens in Asia in 2007(Song et al.2008).In China,H3N2 is the predominant CIV subtype,with a prevalence rate of up to 5.63% in the canine population,as reported by Chen et al.(2023).CIV infection typically manifests with symptoms such as coughing,sneezing,runny nose,and fever but is rarely fatal.However,co-infection with other pathogens(e.g.,Streptococcus,Mycoplasma or canine parainfluenza virus) can exacerbate symptoms and lead to lethal outcomes(Yondo et al.2023).展开更多
The Yili River Basin in Northwest China is a crucial ecological security barrier,yet it faces frequent droughts amid global climate change,posing significant threats to food security and ecological stability.However,t...The Yili River Basin in Northwest China is a crucial ecological security barrier,yet it faces frequent droughts amid global climate change,posing significant threats to food security and ecological stability.However,the spatiotemporal variations and driving mechanisms of drought in the basin remain unclear.Based on the monthly Standardized Precipitation Evapotranspiration Index(SPEI),this study employed the Run-Length theory to identify drought events in the basin during 1980-2020,applied statistical and time-series analyses to investigate the spatiotemporal variations,trends,periodicity,and persistence of drought,and explored the underlying drivers associated with meteorological factors and large-scale atmospheric circulation patterns.The results showed that droughts in the Yili River Basin are more severe in spring and summer.Droughts in the central and southwestern regions exhibit greater severity,with shorter durations and stronger intensity.Drought conditions have generally worsened(Sen’s slope=−0.146/10 yr),with notable intensification since 2005,especially in the northwestern region.Spring droughts(Sen’s slope=−0.213/10 yr)and summer droughts(Sen’s slope=−0.169/10 yr)have intensified at most stations,while autumn and winter droughts have eased.In the future,droughts are expected to alleviate overall,but summer droughts may continue to intensify.The Yili River Basin exhibits two primary drought periods of 9 yr and 21 yr,with primary periods in autumn(20 yr)and winter(20 yr)being longer than those in spring(10 yr)and summer(17 yr).Finally,droughts are impacted by both meteorological factors and large-scale atmospheric circulation patterns.Rising temperatures and uneven precipitation have intensified droughts.The SPEI exhibits a co-phase relationship with the North Atlantic Oscillation and an antiphase relationship with the East Central Tropical Pacific Sea Surface Temperature.Therefore,close monitoring and mitigation are necessary for spring and summer droughts,with a focus on the central and southwestern areas in autumn and winter.展开更多
The algebraic reconstruction technique(ART),multiplicative algebraic reconstruction technique(MART),and simultaneous iterative reconstruction technique(SIRT)are computational methodologies extensively utilized within ...The algebraic reconstruction technique(ART),multiplicative algebraic reconstruction technique(MART),and simultaneous iterative reconstruction technique(SIRT)are computational methodologies extensively utilized within the field of computerized ionospheric tomography(CIT)to facilitate three-dimensional reconstruction of the ionospheric morphology.However,reconstruction accuracy elicits recurrent disputes over its practical application,and people usually attribute this issue to incomplete and uneven coverage of the measurements.The Thermosphere Ionosphere Electrodynamics General Circulation Model(TIEGCM)offers a reasonable physics-based ionospheric background and is widely utilized in ionospheric research.We use the TIEGCM simulations as the targeted ionosphere because the current measurements are far from able to realistically reproduce the ionosphere in detail.Optimized designations of satellite measurements are conducted to investigate the limiting performance of CIT methods in ionospheric reconstruction.Similar to common practice,electron density distributions from outputs of the International Reference Ionosphere(IRI)model are used as the iterative initial value in CIT applications.The outcomes suggest that despite data coverage,iterative initial conditions also play an essential role in ionospheric reconstruction.In particular,in the longitudinal sectors where the iterative initial height of the F2-layer peak electron density(hmF2)differs substantially from the background densities,none of the three CIT methods can reproduce the exact background profile.When hmF2 is close but the ionospheric F2-layer peak density(NmF2)is different between the targeted background and initial conditions,the MART performs better than the ART and SIRT,as evidenced by the correlation coefficients of MART being above 0.97 and those of ART and SIRT being below 0.85.In summary,this investigation reveals the potential uncertainties in traditional CIT reconstruction,particularly when realistic hmF2 or NmF2 values differ substantially from the initial CIT conditions.展开更多
The movement of global ocean circulation in the Earth’s main magnetic field generates a measurable induced magnetic field(about 2 nT at geomagnetic satellite altitudes).However,this ocean circulation-induced magnetic...The movement of global ocean circulation in the Earth’s main magnetic field generates a measurable induced magnetic field(about 2 nT at geomagnetic satellite altitudes).However,this ocean circulation-induced magnetic field has not been previously estimated or incorporated into geomagnetic field models,potentially causing leakage into the core field model.Here,we present a method to account for the circulation-induced magnetic field during geomagnetic field modeling.First,a forward model of the circulation-induced magnetic field is constructed by numerically solving electromagnetic induction equations based on a realistic ocean circulation model.Then,this forward model is subtracted from the observed data.Finally,the core and lithospheric fields,magnetospheric and Earth’s mantle-induced fields,and the ocean tide-induced magnetic field are co-estimated.Applying our method to over 20 years of MSS-1,Swarm,CryoSat-2,and CHAMP satellite magnetic data,we derive a new multisource geomagnetic field model(MGFM).We find that incorporating a forward model of the circulation-induced magnetic field marginally improves the fit to the data.Furthermore,we demonstrate that neglecting the circulation-induced magnetic field in geomagnetic field modeling results in leakage into the core field model.The highlights of the MGFM model include:(i)a good agreement with the widely used CHAOS model series;(ii)the incorporation of magnetic fields induced by both ocean tides and circulation;and(iii)the suppression of leakage of the circulation-induced magnetic field into the core field model.展开更多
文摘Circulating fluidized bed combustion(CFBC)is known for its ability to significantly reduce the emission of NO_(x)and SO2 from coal combustion.However,the fly ash produced from CFBC(CFBFA)is impractical for use as a construction material due to its low pozzolanic activity.The present work evaluated two methods for zeolite synthesis from CFBFA,namely a low-temperature hydrothermal method and an alkali fusion followed by hydrothermal method,in order to provide another method to recycle CFBFA.Various synthesis conditions were systematically investigated to optimize the process.
基金supported by the National Key R&D Program of China,No.2021YFC2501200(to PC).
文摘Short-chain fatty acids,metabolites produced by the fermentation of dietary fiber by gut microbiota,have garnered significant attention due to their correlation with neurodegenerative diseases,particularly Parkinson’s disease.In this review,we summarize the changes in short-chain fatty acid levels and the abundance of short-chain fatty acid-producing bacteria in various samples from patients with Parkinson’s disease,highlighting the critical role of gut homeostasis imbalance in the pathogenesis and progression of the disease.Focusing on the nervous system,we discuss the molecular mechanisms by which short-chain fatty acids influence the homeostasis of both the enteric nervous system and the central nervous system.We identify key processes,including the activation of G protein-coupled receptors and the inhibition of histone deacetylases by short-chain fatty acids.Importantly,structural or functional disruptions in the enteric nervous system mediated by these fatty acids may lead to abnormalα-synuclein expression and gastrointestinal dysmotility,which could serve as an initiating event in Parkinson’s disease.Furthermore,we propose that short-chain fatty acids help establish communication between the enteric nervous system and the central nervous system via the vagal nerve,immune circulation,and endocrine signaling.This communication may shed light on their potential role in the transmission ofα-synuclein from the gut to the brain.Finally,we elucidate novel treatment strategies for Parkinson’s disease that target short-chain fatty acids and examine the challenges associated with translating short-chain fatty acid-based therapies into clinical practice.In conclusion,this review emphasizes the pivotal role of short-chain fatty acids in regulating gut-brain axis integrity and their significance in the pathogenesis of Parkinson’s disease from the perspective of the nervous system.Moreover,it highlights the potential value of short-chain fatty acids in early intervention for Parkinson’s disease.Future research into the molecular mechanisms of short-chain fatty acids and their synergistic interactions with other gut metabolites is likely to advance the clinical translation of innovative short-chain fatty acid-based therapies for Parkinson’s disease.
文摘In this paper,we present a necessary and sufficient condition for hyponormal block Toeplitz operators T on the vector-valued weighted Bergman space with symbolsΦ(z)=G^(*)(z)+F(z),where F(z)=∑^(N)_(i)=1 A_(i)z^(i)and G(z)=∑^(N)_(i)=1 A_(−i)z^(i),A_(i)ae culants.
基金funded by Sapienza University PNRR-RT_SPOKE_1—ROME TECHNOPOLE—Spoke 1—B83C22002820006—ECS00000024 and FO R.O.onlus.
文摘Objectives:Although immune checkpoint inhibitors(ICIs)and targeted therapies have reshaped treatment non-small cell lung cancer(NSCLC)paradigms,prognosis remains poor for many patients due to delayed diagnosis and resistance mechanisms.Liquid biopsy offers a minimally invasive approach to monitoring tumor evolution.Among circulating biomarkers,circulating tumor cells(CTCs)and cancer-associated macrophage-like cells(CAM-Ls)may provide complementary prognostic insights.The study aimed to evaluate the prognostic role of CTC and CAM-Ls dynamic in metastatic NSCLC patients.Methods:We retrospectively analyzed 77 patients with metastatic NSCLC who underwent CTC and CAM-L evaluation via the CellSearch^(■)system at baseline(T0)and after three months of first-line treatment(T1)including chemotherapy,targeted therapy,or ICIs.Survival outcomes were analyzed using Kaplan-Meier and Cox regression analyses.Results:Conversion to CTC-negative status at T1 was associated with improved outcomes,with median overall survival(OS)and progression-free survival(PFS)of 33 and 18 months,respectively,vs.10 and 6 months in persistently positive patients(both p<0.001).CTC negativity at T1 remained an independent prognostic factor for OS(HR:6.68)and PFS(HR:5.91,both p<0.0001).CAM-L positivity at T1 also correlated with longer OS(30 vs.12 months)and PFS(13 vs.6 months,both p<0.0001),particularly among ICI-treated patients.Combined CTC and CAM-L assessment further refined risk stratification.Conclusions:Dynamic monitoring of CTCs and CAM-Ls provides actionable prognostic information in metastatic NSCLC.CTC-negative status predicted longer OS and PFS,while CAM-L positivity at T1 was associated with improved outcomes,particularly in ICI-treated patients.Combined assessment of both biomarkers may directly inform therapeutic decision-making,through early detection of outcomes.
基金sponsored by the Peking University People’s Hospital Research and Development Fund(No.RDZH2024-06)the National Key Research and Development Program of China(No.2022YFC2704204)。
文摘Objective:We investigated the clinical value of a novel circulating tumor cell(CTC)detection method—subtraction enrichment combined with immunostaining and fluorescence in situ hybridization(SEi FISH)—in ovarian cancer(OC).This study evaluated the diagnostic and prognostic significance of chromosome 8aneuploidy in CTCs and circulating tumor endothelial cells(CTECs)for preoperative diagnosis,treatment efficacy assessment,and recurrence monitoring.Methods:A total of 331 patients were enrolled,including 56 with newly diagnosed primary OC,265 with benign ovarian tumors,and 10 with borderline tumors.Peripheral blood CTCs and CTECs were detected using SEi FISH;their quantity and ploidy characteristics were analyzed in relation to clinical indicators.To assess dynamic CTC changes during disease progression and treatment response,72 patients were followed longitudinally,of whom 19 experienced recurrence.Results:The CTC detection rate in OC patients was 92.9%,with significantly higher counts than that in the benign tumor group(median 5 vs.2).Receiver operating characteristic analysis demonstrated good diagnostic performance for total CTCs[area under the curve(AUC)=0.699],with triploid CTCs achieving the highest efficacy(AUC=0.792),surpassing carbohydrate antigen 125(CA125)(AUC=0.702).Postoperative follow-up showed that70%of patients exhibited concurrent decreases in CTCs and CA125 levels,indicating disease improvement.In30%of patients,CTC levels did not correlate with changes in CA125 levels.Individual case evidence suggests that CTC alterations may serve as an early indicator of recurrence or metastasis.Among the 19 recurrent cases,73.7%showed elevated CTCs at recurrence that decreased following treatment.In four patients,CTCs reflected disease progression earlier than CA125,indicating higher sensitivity for recurrence monitoring.Conclusions:CTCs with chromosome 8 aneuploidy demonstrate significant clinical value in the preoperative diagnosis,treatment efficacy evaluation,and recurrence monitoring of OC.Dynamic CTC changes may serve as a more sensitive indicator than CA125 for disease surveillance,supporting the translational potential of CTC-based biomarkers in OC.
文摘Cervical cancer related to human papillomavirus(HPV)is a leading cause of cancer-related mortality among women worldwide.Cancer cells release fragments of their DNA,known as circulating tumor DNA(ctDNA),which can be detected in bodily fluids.A PubMed search using the terms“ctHPV”or“circulating tumor DNA”and“cervical cancer”,limited to the past ten years,identified 104 articles,complemented by hand-searching for literature addressing medico-legal implications.Studies were evaluated for relevance and methodological quality.Detection and characterization of circulating tumor HPV DNA(ctHPV DNA)have emerged as promising tools for assessing prognosis and disease recurrence in cervical cancer.Detection techniques include polymerase chain reaction(PCR),digital droplet PCR(ddPCR),and next-generation sequencing(NGS).This review summarizes current knowledge on ctHPV DNA in cervical cancer and explores its clinical and medico-legal implications,including management of discordant results,diagnostic errors,liability,and data protection compliance.
基金supported by the National Natural Science Foundation of China(Grant Nos.U2342210 and 42275043)the National Institute of Natural Hazards,Ministry of Emergency Management of China(Grant Nos.J2223806,ZDJ2024-25 and ZDJ2025-34)。
文摘Climate models are essential for understanding past,present,and future changes in atmospheric circulation,with circulation modes providing key sources of seasonal predictability and prediction uncertainties for both global and regional climates.This study assesses the performance of models participating in phase 6 of the Coupled Model Intercomparison Project in simulating interannual variability modes of Northern Hemisphere 500-hPa geopotential height during winter and summer,distinguishing predictable(potentially predictable on seasonal or longer timescales)and unpredictable(intraseasonal and essentially unpredictable at long range)components,using reanalysis data and a variance decomposition method.Although most models effectively capture unpredictable modes in reanalysis,their ability to reproduce dominant predictable modes-specifically the Pacific-North American pattern,Arctic Oscillation,and Western Pacific Oscillation in winter,and the East Atlantic and North Atlantic Oscillations in summer-varies notably.An optimal ensemble is identified to distinguish(a)predictable-external modes,dominated by external forcing,and(b)predictable-internal modes,associated with slow internal variability,during the historical period(1950-2014)and the SSP5-8.5 scenario(2036-2100).Under increased radiative forcing,the leading winter/summer predictable-external mode exhibits a more uniform spatial distribution,remarkably larger trend and annual variance,and enhanced height-sea surface temperature(SST)covariance under SSP5-8.5 compared to historical conditions.The dominant winter/summer predictable-internal modes also exhibit increased variance and height-SST covariance under SSP5-8.5,along with localized changes in spatial configuration.Minimal changes are observed in spatial distribution or variance for dominant winter/summer unpredictable modes under SSP5-8.5.This study,from a predictive perspective,deepens our understanding of model uncertainties and projected changes in circulations.
基金supported by the Open Research Fund of Key Laboratory for Lake Pollution Control of the Ministry of Ecology and Environment(No.2024HPYKFZD04)the Fundamental Research Funds for the Central Publicinterest Scientific Institution(No.2025YSKY-04)the National Natural Science Foundation of China(Nos.U1902207 and 42207265).
文摘Wind-induced circulation is the main form of lake flow for shallow lakes and plays an important role in algae population distribution.This study constructed a three-dimensional hydrodynamic model(EFDC)of the plateau lake Erhai,China using accuracy wind field observation,runoff data and monthly algae data during 2022–2023.The model successfully reproduced the circulation characteristics of Erhai under prevailing wind directions.The results showed that the lake flow velocity in Lake Erhai is higher in winter than in summer,with lower velocities near shore particularly in the northern and central parts of the lake.There is a negative correlation between algal biomass and flow velocity(FV)in different zones,with lower FV favoring the accumulation of algal biomass,particularly for Microcystis,Dolichospermum,and Peridinium.Additionally,due to buoyancy,cyanobacteria are highly affected by wind direction and tend to accumulate in downwind regions of the prevailing wind direction.This study demonstrates that wind-induced circulation is a crucial factor affecting the spatial distribution of dominant algae populations in shallow plateau lakes with weak hydrodynamic force.Further,the risk of bloom occurrence in Lake Erhai will be higher due to the background of global climate change and the lake’s wind speed decline.In conclusion,we suggest implementing targeted zoning measures to control algal blooms and establishing stricter regulations for nitrogen and phosphorus control to counterbalance the promotion of algal bloom accumulation in low-velocity zones caused by reduced wind speed.
基金supported by the National Natural Science Foundation of China(Grant No.42261134532,42405059,and U2342212)。
文摘This study investigates the relationship between atmospheric stratification (i.e., static stability given by N^(2)) and the vertical energy transfer of stationary planetary waves, and further illustrates the underlying physical mechanism. Specifically, for the simplified case of constant stratospheric N^(2), the refractive index square of planetary waves has a theoretical tendency to increase first and then decrease with an increased N^(2), whereas the group velocity weakens. Mechanistically, this behavior can be understood as an intensified suppression of vertical isentropic surface displacement caused by meridional heat transport of planetary waves under strong N^(2) conditions. Observational analysis corroborates this finding, demonstrating a reduction in the vertical-propagation velocity of waves with increased N^(2). A linear, quasi- geostrophic, mid-latitude beta-plane model with a constant background westerly wind and a prescribed N^(2) applicable to the stratosphere is used to obtain analytic solutions. In this model, the planetary waves are initiated by steady energy influx from the lower boundary. The analysis indicates that under strong N^(2) conditions, the amplitude of planetary waves can be sufficiently increased by the effective energy convergence due to the slowing vertical energy transfer, resulting in a streamfunction response in this model that contains more energy. For N^(2) with a quasi-linear vertical variation, the results bear a resemblance to the constant case, except that the wave amplitude and oscillating frequency show some vertical variations.
文摘Based on high-altitude and ground observation data and physical quantity field data,the diagnostic analysis of a heavy rainfall process in Hulunbuir City from July 18 to 20,2025 was conducted from the aspects of circulation patterns,influencing systems,dynamic conditions,moisture conditions and convective conditions,and the causes of the occurrence and development of this process were revealed.The study shows that the superposition of the upper-level trough,the ground cyclone,and the low-level jet stream formed strong water vapor transport,strong warm advection,and strong dynamic uplift in Hulunbuir,thereby leading to this heavy rainfall event.The forecasting ideas for short-term heavy rainfall were pointed out to provide certain scientific references for future forecasting and prediction work.
基金National Natural Science Foundation of China(42375153,42105153,42205157)Development of Science and Technology at Chinese Academy of Meteorological Sciences(2023KJ038)。
文摘Clouds play an important role in global atmospheric energy and water vapor budgets, and the low cloud simulations suffer from large biases in many atmospheric general circulation models. In this study, cloud microphysical processes such as raindrop evaporation and cloud water accretion in a double-moment six-class cloud microphysics scheme were revised to enhance the simulation of low clouds using the Global-Regional Integrated Forecast System(GRIST)model. The validation of the revised scheme using a single-column version of the GRIST demonstrated a reasonable reduction in liquid water biases. The revised parameterization simulated medium-and low-level cloud fractions that were in better agreement with the observations than the original scheme. Long-term global simulations indicate the mitigation of the originally overestimated low-level cloud fraction and cloud-water mixing ratio in mid-to high-latitude regions,primarily owing to enhanced accretion processes and weakened raindrop evaporation. The reduced low clouds with the revised scheme showed better consistency with satellite observations, particularly at mid-and high-latitudes. Further improvements can be observed in the simulated cloud shortwave radiative forcing and vertical distribution of total cloud cover. Annual precipitation in mid-latitude regions has also improved, particularly over the oceans, with significantly increased large-scale and decreased convective precipitation.
文摘To solve the problem of circulating power of dual active bridge(DAB)DC-DC converter over a wide voltage conversion ratio,this paper proposes a novel synchronous PWM(S-PWM)modulation.Existence of circulating power increases current stress of devices and decreases efficiency,especially under light load conditions.Several modulation methods have been proposed to overcome the problem.They can reduce or eliminate either input or output side circulating power.In contrast,S-PWM not only eliminates both sides circulating power and reduces current stress,but also achieves zero-current-switching(ZCS)turn-on for all switches and ZCS turn-off for most across the full power range.No auxiliary or snubber circuits are increased.In addition,the control can be simplified so the transmitted power is related to only one variable.The S-PWM has four cases under different gain and power conditions.The detailed operation principle and modes of DAB under S-PWM are analyzed in the paper.In addition,four modulations in literature are discussed,and corresponding comparative analyses with S-PWM are given.Finally,a laboratory prototype is built to verify advantages and effectiveness of the proposed modulation.
基金supported by the National Natural Science Foundation of China [grant number 92358302]。
文摘The present study compares the Atlantic Meridional Overturning Circulation(AMOC)in the North Atlantic from two simulations by an oceanic general circulation model with 1°×1°and 0.1°×0.1°resolution,respectively,which explores the sensitivity of AMOC to the resolution.The ocean model is the latest version of the LASG/IAP Climate System Model(LICOM3),and it is forced with atmospheric data from phase 2 of the Ocean Model Intercomparison Project(OMIP2).Comprehensive comparison between the two simulations indicates that the simulated AMOC is highly sensitive to the spatial resolution.The high-resolution model(LICOM-H)simulates a deeper mixed-layer depth(MLD),due to increased surface salinity,than that in the low-resolution model(LICOML)in the Labrador Sea,and it also has stronger AMOC strength(the maximum climatic mean AMOC from 1958 to 2018 is 23.4 Sv for LICOM-H and 21.2 Sv for LICOM-L)and larger variability of AMOC index(2.3 Sv for LICOM-H and 1.7 Sv for LICOM-L).These differences can mainly be attributed to two main dynamic processes that benefit from high resolution.Firstly,LICOM-H can simulate much stronger boundary currents(~0.6 m s^(-1))than LICOM-L(0.3 m s^(-1))in the upper ocean,which leads to saltier and warmer seawater being transported to the Labrador Sea,where it enhances deep convection.Secondly,in LICOM-H,the stronger variability of AMOC is related to the higher sensitivity of the MLD and transformation to the prescribed atmospheric forcing in the Labrador Sea.
基金supported by the National Natural Science Foundation of China(Grant No.42275041)the Hainan Province Science and Technology Special Fund(Grant No.SOLZSKY2025006).
文摘Summer rainfall in the Yangtze River basin(YRB)is favored by two key factors in the lower troposphere:the tropical anticyclonic anomaly over the western North Pacific and the extratropical northeasterly anomalies to the north of the YRB.This study,however,found that approximately 46%of heavy rainfall events in the YRB occur when only one factor appears and the other is opposite signed.Accordingly,these heavy rainfall events can be categorized into two types:the extratropical northeasterly anomalies but tropical cyclonic anomaly(first unconventional type),and the tropical anticyclonic anomaly but extratropical southwesterly anomalies(second unconventional type).Anomalous water vapor convergence and upward motion exists for both types,but through different mechanisms.For the first type,the moisture convergence and upward motion are induced by a cyclonic anomaly over the YRB,which appears in the mid and lower troposphere and originates from the upstream region.For the second type,a mid-tropospheric cyclonic anomaly over Lake Baikal extends southward and results in southwesterly anomalies over the YRB,in conjunction with the tropical anticyclonic anomaly.The southwesterly anomalies transport water vapor to the YRB and lead to upward motion through warm advection.This study emphasizes the role of mid-tropospheric circulations in inducing heavy rainfall in the YRB.
基金supported by Soonchunhyang University research fund。
文摘BACKGROUND:Prolonged on-scene Advanced Life Support(ALS) in out-of-hospital cardiac arrest(OHCA) patients may enhance return of spontaneous circulation(ROSC),but the optimal duration of cardiopulmonary resuscitation(CPR) without initial prehospital ROSC remains unclear.We investigated the association between on-scene CPR duration and outcomes using nationwide data.METHODS:This prospective,multi-regional study(2015–2022) included medical cause OHCA patients who underwent Smart ALS(SALS).Data from emergency medical services(EMS) records,SALS logs,and hospital outcomes were analyzed.Logistic regression models were developed for prehospital ROSC,survival to discharge,and good neurological outcome(Cerebral Performance Category [CPC] 1–2).RESULTS:Among 98,569 patients,34,989 were SALS-eligible and 16,052 received SALS.Predictors of ROSC included younger age,male sex,public arrest,witnessed arrest,bystander CPR,shockable rhythm,and shorter response/scene times.Longer on-scene CPR reduced probabilities of ROSC,survival,and neurological recovery at hospital discharge.Model AUROCs were 0.697(95%CI 0.676–0.717) for ROSC,0.836(95%CI 0.810–0.861) for survival,and 0.925(95%CI 0.904–0.946) for neurological outcome.CONCLUSION:On-scene CPR duration is a critical prognostic factor in OHCA.The proposed models highlight on-scene predictors that may inform decisions about CPR continuation and support individualized resuscitation strategies.External validation in other EMS systems is warranted.
基金supported by the Science and Technology Innovation Program of Hunan Province(Nos.2023RC1025 and 2024RC3022)the Technology Special Program Project of China Minmetals Corporation(No.2021ZXA04)the Major Scientific Research Projects of Inner Mongolia Baotou Steel Union Co.,Ltd.(No.HKF202300356).
文摘High-sulfur iron concentrates emit SO_(2)into the flue gas during pellet induration.To investigate the effect of the SO_(2)cycle on pellet quality in the grate-kiln process,sulfur balance analysis,thermodynamic calculations,and pellet production experiments under simulated flue gas circulation conditions were conducted.The results indicated that SO_(2)circulation inhibited desulfurization and deteriorated pellet strength.SO_(2)absorption increased the pellet sulfur content to 0.70 wt.%during the downdraft drying phase,and the absorption could be aggravated by the moisture.The desulfurization rate of the preheating process was also decreased to 16.67%,resulting from the refractory sulfate generation.Sulfur content of the roasted pellets dropped to 0.13 wt.%because of the aluminosilicate generation.The finished pellet sulfur content further decreased to 0.08 wt.%due to the fresh air during the cooling process.Eventually,optimization measures were proposed when high-sulfur iron concentrates were used for oxidized pellet preparation.
基金supported by the National Key Research and Development Program of China (2021YFD1800200)the National Natural Science Foundation of China (32170539)。
文摘Influenza A virus(IAV) has a wide host range,including wild birds,poultry,various mammals,and even humans(Xu et al.2024).Currently,two subtypes of canine influenza virus(CIV),H3N8 and H3N2,are primarily circulating in dogs.The H3N8 CIV was introduced from horses into dogs in 2004(Crawford et al.2005),while the H3N2 CIV originated from chickens in Asia in 2007(Song et al.2008).In China,H3N2 is the predominant CIV subtype,with a prevalence rate of up to 5.63% in the canine population,as reported by Chen et al.(2023).CIV infection typically manifests with symptoms such as coughing,sneezing,runny nose,and fever but is rarely fatal.However,co-infection with other pathogens(e.g.,Streptococcus,Mycoplasma or canine parainfluenza virus) can exacerbate symptoms and lead to lethal outcomes(Yondo et al.2023).
基金Under the auspices of the Third Xinjiang Scientific Expedition Program(No.2022xjkk0600)。
文摘The Yili River Basin in Northwest China is a crucial ecological security barrier,yet it faces frequent droughts amid global climate change,posing significant threats to food security and ecological stability.However,the spatiotemporal variations and driving mechanisms of drought in the basin remain unclear.Based on the monthly Standardized Precipitation Evapotranspiration Index(SPEI),this study employed the Run-Length theory to identify drought events in the basin during 1980-2020,applied statistical and time-series analyses to investigate the spatiotemporal variations,trends,periodicity,and persistence of drought,and explored the underlying drivers associated with meteorological factors and large-scale atmospheric circulation patterns.The results showed that droughts in the Yili River Basin are more severe in spring and summer.Droughts in the central and southwestern regions exhibit greater severity,with shorter durations and stronger intensity.Drought conditions have generally worsened(Sen’s slope=−0.146/10 yr),with notable intensification since 2005,especially in the northwestern region.Spring droughts(Sen’s slope=−0.213/10 yr)and summer droughts(Sen’s slope=−0.169/10 yr)have intensified at most stations,while autumn and winter droughts have eased.In the future,droughts are expected to alleviate overall,but summer droughts may continue to intensify.The Yili River Basin exhibits two primary drought periods of 9 yr and 21 yr,with primary periods in autumn(20 yr)and winter(20 yr)being longer than those in spring(10 yr)and summer(17 yr).Finally,droughts are impacted by both meteorological factors and large-scale atmospheric circulation patterns.Rising temperatures and uneven precipitation have intensified droughts.The SPEI exhibits a co-phase relationship with the North Atlantic Oscillation and an antiphase relationship with the East Central Tropical Pacific Sea Surface Temperature.Therefore,close monitoring and mitigation are necessary for spring and summer droughts,with a focus on the central and southwestern areas in autumn and winter.
基金supported by the National Key R&D Program of China (Grant No. 2022YFF0503702)the National Natural Science Foundation of China (Grant No. 42074186)
文摘The algebraic reconstruction technique(ART),multiplicative algebraic reconstruction technique(MART),and simultaneous iterative reconstruction technique(SIRT)are computational methodologies extensively utilized within the field of computerized ionospheric tomography(CIT)to facilitate three-dimensional reconstruction of the ionospheric morphology.However,reconstruction accuracy elicits recurrent disputes over its practical application,and people usually attribute this issue to incomplete and uneven coverage of the measurements.The Thermosphere Ionosphere Electrodynamics General Circulation Model(TIEGCM)offers a reasonable physics-based ionospheric background and is widely utilized in ionospheric research.We use the TIEGCM simulations as the targeted ionosphere because the current measurements are far from able to realistically reproduce the ionosphere in detail.Optimized designations of satellite measurements are conducted to investigate the limiting performance of CIT methods in ionospheric reconstruction.Similar to common practice,electron density distributions from outputs of the International Reference Ionosphere(IRI)model are used as the iterative initial value in CIT applications.The outcomes suggest that despite data coverage,iterative initial conditions also play an essential role in ionospheric reconstruction.In particular,in the longitudinal sectors where the iterative initial height of the F2-layer peak electron density(hmF2)differs substantially from the background densities,none of the three CIT methods can reproduce the exact background profile.When hmF2 is close but the ionospheric F2-layer peak density(NmF2)is different between the targeted background and initial conditions,the MART performs better than the ART and SIRT,as evidenced by the correlation coefficients of MART being above 0.97 and those of ART and SIRT being below 0.85.In summary,this investigation reveals the potential uncertainties in traditional CIT reconstruction,particularly when realistic hmF2 or NmF2 values differ substantially from the initial CIT conditions.
基金supported by the National Natural Science Foundation of China(42250101,42250102)the Macao Foundation.
文摘The movement of global ocean circulation in the Earth’s main magnetic field generates a measurable induced magnetic field(about 2 nT at geomagnetic satellite altitudes).However,this ocean circulation-induced magnetic field has not been previously estimated or incorporated into geomagnetic field models,potentially causing leakage into the core field model.Here,we present a method to account for the circulation-induced magnetic field during geomagnetic field modeling.First,a forward model of the circulation-induced magnetic field is constructed by numerically solving electromagnetic induction equations based on a realistic ocean circulation model.Then,this forward model is subtracted from the observed data.Finally,the core and lithospheric fields,magnetospheric and Earth’s mantle-induced fields,and the ocean tide-induced magnetic field are co-estimated.Applying our method to over 20 years of MSS-1,Swarm,CryoSat-2,and CHAMP satellite magnetic data,we derive a new multisource geomagnetic field model(MGFM).We find that incorporating a forward model of the circulation-induced magnetic field marginally improves the fit to the data.Furthermore,we demonstrate that neglecting the circulation-induced magnetic field in geomagnetic field modeling results in leakage into the core field model.The highlights of the MGFM model include:(i)a good agreement with the widely used CHAOS model series;(ii)the incorporation of magnetic fields induced by both ocean tides and circulation;and(iii)the suppression of leakage of the circulation-induced magnetic field into the core field model.
