White-matter tracts play a pivotal role in transmitting sensory and motor information,facilitating interhemispheric communication and integrating different brain regions.Meanwhile,sensorimotor disturbance is a common ...White-matter tracts play a pivotal role in transmitting sensory and motor information,facilitating interhemispheric communication and integrating different brain regions.Meanwhile,sensorimotor disturbance is a common symptom in patients with major depressive disorder(MDD).However,the role of aberrant sensorimotor white-matter system in MDD remains largely unknown.Herein,we investigated the topological structure alterations of white-matter morphological brain networks in 233 MDD patients versus 257 matched healthy controls(HCs)from the DIRECT consortium.White-matter networks were derived from magnetic resonance imaging(MRI)data by combining voxel-based morphometry(VBM)and three-dimensional discrete wavelet transform(3D-DWT)approaches.Support vector machine(SVM)analysis was performed to discriminate MDD patients from HCs.The results indicated that the network topological changes in node degree,node efficiency,and node betweenness were mainly located in the sensorimotor superficial white-matter system in MDD.Using network nodal topological properties as classification features,the SVM model could effectively distinguish MDD patients from HCs.These findings provide new evidence to highlight the importance of the sensorimotor system in brain mechanisms underlying MDD from a new perspective of white-matter morphological network.展开更多
The possibility of baryons cooled by a millicharged dark matter(mDM)via mDM–baryons scattering has recently been proposed to explain the observation discrepancy from the experiment to detect the global epoch of reion...The possibility of baryons cooled by a millicharged dark matter(mDM)via mDM–baryons scattering has recently been proposed to explain the observation discrepancy from the experiment to detect the global epoch of reionization signature(EDGES).In this sense,we analyze the Jeans instability of self-gravitational systems in the background of mDM under kinetic regime that the collisionless Boltzmann equation and Poisson equation have been combined to obtain the modified dispersion relation.It is shown that the effect of mDM is significant on the dynamics of gravitational collapse,i.e.,the presence of mDM makes the self-gravitational systems more difficult to collapse relatively.展开更多
Microorganisms constitute an essential component in the indoor environment,which is closely related to hu-man health.However,there is limited evidence regarding the associations between indoor airborne microbiome and ...Microorganisms constitute an essential component in the indoor environment,which is closely related to hu-man health.However,there is limited evidence regarding the associations between indoor airborne microbiome and systemic inflammation,as well as whether this association is modified by indoor particulate matter and the underlying mechanisms.In this prospective repeated-measure study among 66 participants,indoor airborne mi-crobiome was characterized using amplicon sequencing and qPCR.Indoor fine particulate matter(PM_(2.5))and inhalable particulate matter(PM10)were measured.Systemic inflammatory biomarkers were assessed,including white blood cell(WBC),neutrophil(NEUT),monocyte,eosinophil counts,and their proportions.Targeted serum amino acid metabolomics were conducted to explore the underlying mechanisms.Linear mixed-effect models re-vealed that bacterial and fungal Simpson diversity were significantly associated with decreased WBC and NEUT.For example,for each interquartile range increase in the bacterial Simpson diversity,WBC and NEUT changed by-4.53%(95%CI:-8.25%,-0.66%)and-5.95%(95%CI:-11.3%,-0.27%),respectively.Notably,increased inflammatory risks of airborne microbial exposure were observed when indoor PM_(2.5) and PM10 levels were below the WHO air quality guidelines.Mediation analyses indicated that dopamine metabolism partially mediated the anti-inflammatory effects of fungal diversity exposure.Overall,our study indicated protection from a diverse indoor microbial environment on cardiovascular health and proposed an underlying mechanism through amino acid metabolism.Additionally,health risks associated with microbial exposure deserve more attention in con-texts of low indoor particulate matter pollution.Further research is necessary to fully disentangle the complex relationships between indoor microbiome,air pollutants,and human health.展开更多
Intracerebral hemorrhage is the most dangerous subtype of stroke,characterized by high mortality and morbidity rates,and frequently leads to significant secondary white matter injury.In recent decades,studies have rev...Intracerebral hemorrhage is the most dangerous subtype of stroke,characterized by high mortality and morbidity rates,and frequently leads to significant secondary white matter injury.In recent decades,studies have revealed that gut microbiota can communicate bidirectionally with the brain through the gut microbiota–brain axis.This axis indicates that gut microbiota is closely related to the development and prognosis of intracerebral hemorrhage and its associated secondary white matter injury.The NACHT,LRR,and pyrin domain-containing protein 3(NLRP3)inflammasome plays a crucial role in this context.This review summarizes the dysbiosis of gut microbiota following intracerebral hemorrhage and explores the mechanisms by which this imbalance may promote the activation of the NLRP3 inflammasome.These mechanisms include metabolic pathways(involving short-chain fatty acids,lipopolysaccharides,lactic acid,bile acids,trimethylamine-N-oxide,and tryptophan),neural pathways(such as the vagus nerve and sympathetic nerve),and immune pathways(involving microglia and T cells).We then discuss the relationship between the activated NLRP3 inflammasome and secondary white matter injury after intracerebral hemorrhage.The activation of the NLRP3 inflammasome can exacerbate secondary white matter injury by disrupting the blood–brain barrier,inducing neuroinflammation,and interfering with nerve regeneration.Finally,we outline potential treatment strategies for intracerebral hemorrhage and its secondary white matter injury.Our review highlights the critical role of the gut microbiota–brain axis and the NLRP3 inflammasome in white matter injury following intracerebral hemorrhage,paving the way for exploring potential therapeutic approaches.展开更多
Dissolved organic matter(DOM)represents the largest pool of reactive carbon on the Earth and plays a crucial role in various biogeochemical processes and ecosystem functions.However,it is understudied for a global und...Dissolved organic matter(DOM)represents the largest pool of reactive carbon on the Earth and plays a crucial role in various biogeochemical processes and ecosystem functions.However,it is understudied for a global understanding of DOM molecular properties such as molecular weight,stoichiometry,and oxidation state,and the linkages among them across Earth systems.Here,a meta-analysis of 2707 sites in 204 literatures was conducted by synthesizing four representative molecular properties of DOM,i.e.,mass,double bond equivalent(DBE),modified aromaticity index(AI_(mod)),and nominal oxidation state of carbon(NOSC).By exploring H/C and O/C ratios,we examined the relationships among these DOM properties across waters and land systems,and their geographical patterns and environmental drivers.We found that,compared to land system,the mass,DBE,and AI_(mod) were all significantly higher in water systems,with river sediments exhibiting the highest values.The DOM oxidation state indicated by NOSC was greater on average in wastewater(NOSC=0.226±0.06)and marine water(NOSC=0.133±0.06)than in other habitats.Compared to waters,the mass in land system showed more strongly positive correlations with oxidation states such as NOSC and O/C,and the NOSC showed stronger relations to bioavailability properties such as DBE,AI_(mod),and H/C.Among all the properties,H/C and AI_(mod) contributed to the most variations in global DOM properties.In waters,NOSC monotonically increased towards high latitudes,while DBE and AI_(mod) showed significant hump-shaped patterns indicating peaked unsaturation and aromaticity at mid-latitudes of approximately absolute 30°–50°.The variations in DOM properties were significantly correlated with environmental factors such as annual mean temperature and pH.Collectively,we revealed the spatial distribution and environmental drivers of DOM molecular properties across Earth ecosystems,which could shed light on our comprehensive understanding of DOM characteristics and its dynamics.展开更多
Recent evidence suggests that ferroptosis plays a crucial role in the occurrence and development of white matter lesions.However,the mechanisms and regulatory pathways involved in ferroptosis within white matter lesio...Recent evidence suggests that ferroptosis plays a crucial role in the occurrence and development of white matter lesions.However,the mechanisms and regulatory pathways involved in ferroptosis within white matter lesions remain unclear.Long non-coding RNAs(lnc RNAs)have been shown to influence the occurrence and development of these lesions.We previously identified lnc_011797 as a biomarker of white matter lesions by high-throughput sequencing.To investigate the mechanism by which lnc_011797 regulates white matter lesions,we established subjected human umbilical vein endothelial cells to oxygenglucose deprivation to simulate conditions associated with white matter lesions.The cells were transfected with lnc_011797 overexpression or knockdown lentiviruses.Our findings indicate that lnc_011797 promoted ferroptosis in these cells,leading to the formation of white matter lesions.Furthermore,lnc_011797 functioned as a competitive endogenous RNA(ce RNA)for mi R-193b-3p,thereby regulating the expression of WNK1 and its downstream ferroptosis-related proteins.To validate the role of lnc_011797 in vivo,we established a mouse model of white matter lesions through bilateral common carotid artery stenosis.The results from this model confirmed that lnc_011797 regulates ferroptosis via WNK1 and promotes the development of white matter lesions.These findings clarify the mechanism by which lnc RNAs regulate white matter lesions,providing a new target for the diagnosis and treatment of white matter lesions.展开更多
Hepatic myelopathy is a complication seen in patients with chronic liver failure with physiologic or iatrogenic portosystemic shunting. The main symptom is progressive lower limb dyskinesia. The role of the brain moto...Hepatic myelopathy is a complication seen in patients with chronic liver failure with physiologic or iatrogenic portosystemic shunting. The main symptom is progressive lower limb dyskinesia. The role of the brain motor control center in hepatic myelopathy is unknown. This study aimed to investigate the gray matter changes in patients with hepatic myelopathy secondary to transjugular intrahepatic portosystemic shunt and to examine their clinical relevance. This was a cross-sectional study. Twenty-three liver failure patients with hepatic myelopathy(hepatic myelopathy group), 23 liver failure patients without hepatic myelopathy(non-hepatic myelopathy group) after transjugular intrahepatic portosystemic shunt, and 23 demographically matched healthy volunteers were enrolled from March 2014 to November 2016 at Xijing Hospital, Air Force Military Medical University(Fourth Military Medical University), China. High-resolution magnetization-prepared rapid gradient-echo brain imaging was acquired. Group differences in regional gray matter were assessed using voxel-based morphometry analysis. The relationship between aberrant gray matter and motor characteristics was investigated. Results demonstrated that compared with the non-hepatic myelopathy group, gray matter volume abnormalities were asymmetric, with decreased volume in the left insula(P = 0.003), left thalamus(P = 0.029), left superior frontal gyrus(P = 0.006), and right middle cingulate cortex(P = 0.021), and increased volume in the right caudate nucleus(P = 0.017), corrected with open-source software. The volume of the right caudate nucleus in the hepatic myelopathy group negatively correlated with the lower limb clinical rating of the Fugl-Meyer Assessment(r = –0.53, P = 0.01). Compared with healthy controls, patients with and without hepatic myelopathy exhibited overall increased gray matter volume in both thalami, and decreased gray matter volume in both putamen, as well as in the globus pallidus, cerebellum, and vermis. The gray matter abnormalities we found predominantly involved motor-related regions, and may be associated with motor dysfunction. An enlarged right caudate nucleus might help to predict weak lower limb motor performance in patients with preclinical hepatic myelopathy after transjugular intrahepatic portosystemic shunt. This study was approved by the Ethics Committee of Xijing Hospital, Air Force Military Medical University(Fourth Military Medical University), China(approval No. 20140227-6) on February 27, 2014.展开更多
Water-soluble organic matter（WSOM） represents a critical fraction of fine particles（PM2.5）in the air, but its changing behaviors and formation mechanisms are not well understood yet, partly due to the lack of fast...Water-soluble organic matter（WSOM） represents a critical fraction of fine particles（PM2.5）in the air, but its changing behaviors and formation mechanisms are not well understood yet, partly due to the lack of fast techniques for the ambient measurements. In this study,a novel system for the on-line measurement of water-soluble components in PM2.5, the particle-into-liquid sampler（PILS）–Nebulizer–aerosol chemical speciation monitor（ACSM）, was developed by combining a PILS, a nebulizer, and an ACSM. High time resolution concentrations of WSOM, sulfate, nitrate, ammonium, and chloride, as well as mass spectra, can be obtained with satisfied quality control results. The system was firstly applied in China for field measurement of WSOM. The mass spectrum of WSOM was found to resemble that of oxygenated organic aerosol, and WSOM agreed well with secondary inorganic ions. All evidence collected in the field campaign demonstrated that WSOM could be a good surrogate of secondary organic aerosol（SOA）. The PILS–Nebulizer–ACSM system can thus be a useful tool for intensive study of WSOM and SOA in PM2.5.展开更多
A modified CQESTR model, a simple yet useful model frequently used for estimating carbon sequestration in agricultural soils, was developed and applied to evaluate the effects of intensive cropping on soil organic mat...A modified CQESTR model, a simple yet useful model frequently used for estimating carbon sequestration in agricultural soils, was developed and applied to evaluate the effects of intensive cropping on soil organic matter （SOM） dynamics and mineralization as well as to estimate carbon dioxide emission from agricultural soils at seven sites on the Huang-Huai-Hai Plain of China. The model was modified using site-specific parameters from short- and mid-term buried organic material experiments at four stages of biomass decomposition. The predicted SOM results were validated using independent data from seven long-term （10- to 20-year） soil fertility experiments in this region. Regression analysis on 1 151 pairs of predicted and measured SOM data had an r2 of 0.91 （P≤0.01）. Therefore, the modified model was able to predict the mineralization of crop residues, organic amendments, and native SOM. Linear regression also showed that SOM mineralization rate （MR） in the plow layer increased by 0.22% when annual crop yield increased by 1 t ha^-1 （P ≤ 0.01）, suggesting an improvement in SOM quality. Apparently, not only did the annual soil respiration efftux merely reflect the intensity of soil organism and plant metabolism, but also the SOM MR in the plow layer. These results suggested that the modified model was simple yet valuable in predicting SOM trends at a single agricultural field and could be a powerful tool for estimating C-storage potential and reconstructing C storage on the Huang-Huai-Hai Plain of China.展开更多
Particulate matter emissions from ammonia-based wet flue gas desulfurization(AmmoniaWFGD)systems are composed of a filterable particulate matter and a condensable particulate matter(CPM)portion.However,the CPM part ha...Particulate matter emissions from ammonia-based wet flue gas desulfurization(AmmoniaWFGD)systems are composed of a filterable particulate matter and a condensable particulate matter(CPM)portion.However,the CPM part has been ignored for a long time,which results in an underestim ation of the aerosol problems caused by Ammonia-WFGD systems.In our research,the characteristics of the CPM that emits from an Ammonia-WFGD system are investigated experimentally for the first time,with the US Environmental Protection Agency Method 202 employed as the primary measurement.The influences of some essential desulfurizing parameters are evaluated based on the experimental data.The results show that CPM contributes about 68.8%to the total particulate matter emission.CPM consists mainly of ammonium sulfates/sulfites,with the organic part accounting for less than 4%.CPM is mostly in the submicron fraction,about 71.1%of which originates from the NH3-H2O-SO2 reactions.The appropriate adjustments for the parameters of the flue gas and the desulfurizing solution can inhibit CPM formation to different extents.This indicates that the parameter optimizations are promising in solving CPM emission problems in Ammonia-WFGD systems,in which the pH adjustment alone can abate CPM emission by around 49%.The opposite variations of the parameters need attention because they can cause tremendous CPM emission increase.展开更多
Dissolved organic matter(DOM)in surface waters can vary markedly in character depending on seasonal variations such as rainfall intensity,UV radiations and temperature.Changes in DOM as well as temperature and rainfal...Dissolved organic matter(DOM)in surface waters can vary markedly in character depending on seasonal variations such as rainfall intensity,UV radiations and temperature.Changes in DOM as well as temperature and rainfall intensity over the year can affect the biochemical processes occurring in bank filtration(BF).Identification and characterization of DOM in the surface water could help to optimize the water treatment and provide stable and safe drinking water.This study investigated year-long variations of DOM concentrations and compositions in a surface water of a circulated outdoor pond(research facility)connected to a BF passage.DOM was dominated by humic substances and a changing pattern of DOM in surface water was observed throughout the year.A significant increase of DOM(~38%)in surface water was noted in August compared to November.The fluorescent DOM showed that DOM in summer was enriched with the degradable fraction whilst non-degradable fraction was dominated in winter.A constant(1.7±0.1 mg/L)effluent DOM was recirculated in the system throughout the year.DOM removal through BF varied between 4%to 39%and was achieved within a few meters after infiltration and significantly correlated with influent DOM concentration(R^(2)=0.82,p<0.05).However,no significant(p>0.05)change in the removal of DOM was observed in two subsurface layers(upper and lower).This study highlights the presence of a constant non-degradable DOM in the bank filtrate,which was not affected by temperature,redox conditions and UV radiations.展开更多
Diesel particulate matter （DPM） is considered to be carcinogenic after prolonged exposure. With more diesel- powered equipment used in underground mines, miners＇ exposure to DPM has become an increasing concern. Th...Diesel particulate matter （DPM） is considered to be carcinogenic after prolonged exposure. With more diesel- powered equipment used in underground mines, miners＇ exposure to DPM has become an increasing concern. This paper used computational fluid dynamics method to study the DPM dispersion in a dead-end entry with loading operation. The effects of different push-pull ventilation systems on DPM distribution were evaluated to improve the working conditions for underground miners. The four push-pull systems considered include： long push and short pull tubing; short push and long pull tubing, long push and curved pull tubing, and short push and curved pull tubing. A species transport model with buoyancy effect was used to examine the DPM dispersion pattern with unsteady state analysis. During the 200 s of loading operation, high DPM levels were identified in the face and dead-end entry regions. This study can be used for mining engineer as guidance to design and setup local ventilation, select DPM control strategies and for DPM annual training for underground miners.展开更多
Ambient suspended particulate matter(PM)(primarily with particle diameter 2.5m or less,i.e.,PM2.5)can adversely affect ecosystems and human health.Currently,optical particle sensors based on light scattering dominate ...Ambient suspended particulate matter(PM)(primarily with particle diameter 2.5m or less,i.e.,PM2.5)can adversely affect ecosystems and human health.Currently,optical particle sensors based on light scattering dominate the portable PM sensing market.However,the light scattering method has poor adaptability to different-sized PM and adverse environmental conditions.Here,we design and develop a portable PM sensing microsystem that consists of a micromachined virtual impactor(VI)for particle separation,a thermophoretic deposition chip for particle collection,and an extended-gate field-effect transistor(FET)for particle analysis.This system can realize on-site separation,collection,and analysis of aerosol particles without being influenced by environmental factors.In this study,the design of the VI is thoroughly analyzed by numerical simulation,and mixtures of different-sized silicon dioxide(SiO2)particles are used in an experimental verification of the performance of the VI and FET.Considering the low cost and compact design of the whole system,the proposed PM analysis microsystem has potential for PM detection under a wide range of conditions,such as heavily polluted industrial environments and for point-of-need outdoor and indoor air quality monitoring.展开更多
This review aimed to systematically summarize the epidemiological literature on the cardiorespiratory effects of PM_(2.5)published during the 13^(th) Five-Year Plan period(2016-2020)in China.Original articles publishe...This review aimed to systematically summarize the epidemiological literature on the cardiorespiratory effects of PM_(2.5)published during the 13^(th) Five-Year Plan period(2016-2020)in China.Original articles published between January 1,2016 and June 30,2021 were searched in PubMed,Web of Science,the China National Knowledge Internet Database and Wanfang Database.Random-or fixed-effects models were used to pool effect estimates where appropriate.Of 8558 records identified,145 met the full eligibility criteria.A 10μg/m^(3) increase in short-term PM_(2.5)exposure was significantly associated with increases of 0.70%,0.86%,0.38%and 0.96%in cardiovascular mortality,respiratory mortality,cardiovascular morbidity,and respiratory morbidity,respectively.The specific diseases with significant associations included stroke,ischemic heart disease,heart failure,arrhythmia,chronic obstructive pulmonary disease,pneumonia and allergic rhinitis.The pooled estimates per 10μg/m^(3) increase in long-term PM_(2.5)exposure were 15.1%,11.9%and 21.0%increases in cardiovascular,stroke and lung cancer mortality,and 17.4%,11.0%and 4.88%increases in cardiovascular,hypertension and lung cancer incidence respectively.Adverse changes in blood pressure,heart rate variability,systemic infiammation,blood lipids,lung function and airway infiammation were observed for either short-term or long-term PM_(2.5)exposure,or both.Collectively,we summarized representative exposure-response relationships between short-and long-term PM_(2.5)exposure and a wide range of cardiorespiratory outcomes applicable to China.The magnitudes of estimates were generally smaller in short-term associations and comparable in long-term associations compared with those in developed countries.Ourfindings are helpful for future standard revisions and policy formulation.There are still some notable gaps that merit further investigation in China.展开更多
According to the characteristics of ecosystem and concept of the ecosystem in mining area, the index system of the ecosystem health in mining area was set up, and the evaluation standard was established. Aiming at the...According to the characteristics of ecosystem and concept of the ecosystem in mining area, the index system of the ecosystem health in mining area was set up, and the evaluation standard was established. Aiming at the complexion in which the information lost in index ration, the matter element method was put forward to evaluate the ecosystem health in mining area. Making use of the model set up, the weight was built up by the method of index number heavy, the matter element, clas- sical field, and limit field were set up. The rating hierarchy was calculated by relating function. As a case study in the mining area of Pingyangsi Town, the results show that the ecosystem is good and sustainable from 2003 to 2006, but the healthy degree is not high, and some indexes have depravation.展开更多
Objective Studies of the association of hypertension with long-term exposure to particulate matter less than 2.5μm in diameter(PM2.5)have shown contradictory results and the magnitude of the association is still uncl...Objective Studies of the association of hypertension with long-term exposure to particulate matter less than 2.5μm in diameter(PM2.5)have shown contradictory results and the magnitude of the association is still unclear.Hence,we conducted a meta-analysis of cohort studies to assess the effect of long-term exposure to PM2.5 on incident hypertension.展开更多
Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter （SOM）. In this study, surface softs from field plots in the Bankhead National ...Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter （SOM）. In this study, surface softs from field plots in the Bankhead National Forest, Alabama, USA, were used to investigate possible SOM transformations induced by thinning and burning. Elemental analysis and solid-state 13C cross polarization magic angle spinning nuclear magnetic resonance （13C CPMAS NMR） spectroscopy were used to characterize SOM fractions in whole soils, humic substances, and density fractions. Our data revealed that the changes in SOM fractions due to the repeated burning carried out in the forest ecosystem studied were involved mainly with alkyl C, O-alkyl C, and carbohydrate functional groups, implying that most prominent reactions that occurred involved dehydrogenation, de-oxygenation, and decarboxylation. In addition, burning and thinning might have also affected the distribution and composition of free and occluded particulate SOM fractions. The limited structural changes in SOM fractions suggested that low-intensity prescribed fire in the forest ecosystem studied will not create major structural changes in SOM fractions.展开更多
A long-term simulation experiment was carried out to study the effect of rice-based cropping system,green manure and ground-water level on soil organic matter. Soil organic matter content increased when upland soil wa...A long-term simulation experiment was carried out to study the effect of rice-based cropping system,green manure and ground-water level on soil organic matter. Soil organic matter content increased when upland soil was puddled and cropped under submerged conditions. Among all treatments, soil organic matter contents in the treatments of rice-rice-flooded fallow in winter (WF) were the highest, those in the treatments of rice-rice-astragalus (WG) came the second, and those in the treatments of rice-rice-rape (WR)were the lowest. At the same rate of green manure application, the degrees of organo-mineral complexing in soils of treatments WG and WR were higher than those of treatment WF. After 9-year rice cultivation, the state of combination of humus in heavy fraction varied with treatments. The relative content of loosely bonded humus decreased in the order of WR > WG > WF, and it correlated significantly with Se availability.展开更多
In recent years, cooling technology for liquid xenon(LXe) detectors has advanced driven by the development of dark matter(DM) detectors with target mass in the 100–1000 kg range. The next generation of DM detectors b...In recent years, cooling technology for liquid xenon(LXe) detectors has advanced driven by the development of dark matter(DM) detectors with target mass in the 100–1000 kg range. The next generation of DM detectors based on LXe will be in the 50,000 kg(50 t)range requiring more than 1 k W of cooling power. Most of the prior cooling methods become impractical at this level.For cooling a 50 t scale LXe detector, a method is proposed in which liquid nitrogen(LN2) in a small local reservoir cools the xenon gas via a cold finger. The cold finger incorporates a heating unit to provide temperature regulation. The proposed cooling method is simple, reliable, and suitable for the required long-term operation for a rare event search. The device can be easily integrated into present cooling systems, for example the ‘‘Cooling Bus’ ’employed for the Panda X I and II experiments. It is still possible to cool indirectly with no part of the cooling or temperature control system getting in direct contact with the clean xenon in the detector. Also, the cooling device can be mounted at a large distance, i.e., the detector is cooled remotely from a distance of 5–10 m. The method was tested in a laboratory setup at Columbia University to carry out different measurements with a small LXe detector and behaved exactly as predicted.展开更多
Chronic obstructive pulmonary disease (COPD) is a chronic disease characterized by progressive airflow obstruction, along with pulmonary and systemic inflammation. Outdoor PM has been associated with morbidity and mor...Chronic obstructive pulmonary disease (COPD) is a chronic disease characterized by progressive airflow obstruction, along with pulmonary and systemic inflammation. Outdoor PM has been associated with morbidity and mortality in COPD but less is known about effects of indoor air quality. In former smokers with COPD, we investigated in-home PM effects on pulmonary and systemic inflammation, symptoms, and lung function. Participants underwent in-home air monitoring for two weeks and simultaneous health assessments. Median (IQR) PM2.5 was 9 (7) μg/m3. Increased indoor PM2.5 was associated with increased white blood cells, predominantly neutrophils and lymphocytes, suggesting that even relatively low indoor PM2.5 may elicit a systemic inflammatory response in COPD.展开更多
基金supported by the Zhejiang Medical and Health Science and Technology Project(No.2022KY1055)the Zhejiang Provincial Natural Science Foundation of China(No.LY17H180007)+1 种基金the Key Clinical Specialty Construction Project of Zhejiang Provincethe Key Medical Disciplines of Hangzhou,China.
文摘White-matter tracts play a pivotal role in transmitting sensory and motor information,facilitating interhemispheric communication and integrating different brain regions.Meanwhile,sensorimotor disturbance is a common symptom in patients with major depressive disorder(MDD).However,the role of aberrant sensorimotor white-matter system in MDD remains largely unknown.Herein,we investigated the topological structure alterations of white-matter morphological brain networks in 233 MDD patients versus 257 matched healthy controls(HCs)from the DIRECT consortium.White-matter networks were derived from magnetic resonance imaging(MRI)data by combining voxel-based morphometry(VBM)and three-dimensional discrete wavelet transform(3D-DWT)approaches.Support vector machine(SVM)analysis was performed to discriminate MDD patients from HCs.The results indicated that the network topological changes in node degree,node efficiency,and node betweenness were mainly located in the sensorimotor superficial white-matter system in MDD.Using network nodal topological properties as classification features,the SVM model could effectively distinguish MDD patients from HCs.These findings provide new evidence to highlight the importance of the sensorimotor system in brain mechanisms underlying MDD from a new perspective of white-matter morphological network.
基金the National Natural Science Foundation of China(Grant Nos.11763006 and 11863004)the fund from the Jiangxi Provincial Key Laboratory of Fusion and Information Control(Grant No.20171BCD40005)the Project of Scientific and Technological Innovation Base of Jiangxi Province,China(Grant No.20203CCD46008)。
文摘The possibility of baryons cooled by a millicharged dark matter(mDM)via mDM–baryons scattering has recently been proposed to explain the observation discrepancy from the experiment to detect the global epoch of reionization signature(EDGES).In this sense,we analyze the Jeans instability of self-gravitational systems in the background of mDM under kinetic regime that the collisionless Boltzmann equation and Poisson equation have been combined to obtain the modified dispersion relation.It is shown that the effect of mDM is significant on the dynamics of gravitational collapse,i.e.,the presence of mDM makes the self-gravitational systems more difficult to collapse relatively.
基金supported by the National Key Research and Development Program of China(No.2022YFC3702704)the National Natural Science Foundation of China(Nos.22376005,22076006 and 82073506).
文摘Microorganisms constitute an essential component in the indoor environment,which is closely related to hu-man health.However,there is limited evidence regarding the associations between indoor airborne microbiome and systemic inflammation,as well as whether this association is modified by indoor particulate matter and the underlying mechanisms.In this prospective repeated-measure study among 66 participants,indoor airborne mi-crobiome was characterized using amplicon sequencing and qPCR.Indoor fine particulate matter(PM_(2.5))and inhalable particulate matter(PM10)were measured.Systemic inflammatory biomarkers were assessed,including white blood cell(WBC),neutrophil(NEUT),monocyte,eosinophil counts,and their proportions.Targeted serum amino acid metabolomics were conducted to explore the underlying mechanisms.Linear mixed-effect models re-vealed that bacterial and fungal Simpson diversity were significantly associated with decreased WBC and NEUT.For example,for each interquartile range increase in the bacterial Simpson diversity,WBC and NEUT changed by-4.53%(95%CI:-8.25%,-0.66%)and-5.95%(95%CI:-11.3%,-0.27%),respectively.Notably,increased inflammatory risks of airborne microbial exposure were observed when indoor PM_(2.5) and PM10 levels were below the WHO air quality guidelines.Mediation analyses indicated that dopamine metabolism partially mediated the anti-inflammatory effects of fungal diversity exposure.Overall,our study indicated protection from a diverse indoor microbial environment on cardiovascular health and proposed an underlying mechanism through amino acid metabolism.Additionally,health risks associated with microbial exposure deserve more attention in con-texts of low indoor particulate matter pollution.Further research is necessary to fully disentangle the complex relationships between indoor microbiome,air pollutants,and human health.
基金supported by the Guangdong Basic and Applied Basic Research Foundation,No.2023A1515030045(to HS)Presidential Foundation of Zhujiang Hospital of Southern Medical University,No.yzjj2022ms4(to HS)。
文摘Intracerebral hemorrhage is the most dangerous subtype of stroke,characterized by high mortality and morbidity rates,and frequently leads to significant secondary white matter injury.In recent decades,studies have revealed that gut microbiota can communicate bidirectionally with the brain through the gut microbiota–brain axis.This axis indicates that gut microbiota is closely related to the development and prognosis of intracerebral hemorrhage and its associated secondary white matter injury.The NACHT,LRR,and pyrin domain-containing protein 3(NLRP3)inflammasome plays a crucial role in this context.This review summarizes the dysbiosis of gut microbiota following intracerebral hemorrhage and explores the mechanisms by which this imbalance may promote the activation of the NLRP3 inflammasome.These mechanisms include metabolic pathways(involving short-chain fatty acids,lipopolysaccharides,lactic acid,bile acids,trimethylamine-N-oxide,and tryptophan),neural pathways(such as the vagus nerve and sympathetic nerve),and immune pathways(involving microglia and T cells).We then discuss the relationship between the activated NLRP3 inflammasome and secondary white matter injury after intracerebral hemorrhage.The activation of the NLRP3 inflammasome can exacerbate secondary white matter injury by disrupting the blood–brain barrier,inducing neuroinflammation,and interfering with nerve regeneration.Finally,we outline potential treatment strategies for intracerebral hemorrhage and its secondary white matter injury.Our review highlights the critical role of the gut microbiota–brain axis and the NLRP3 inflammasome in white matter injury following intracerebral hemorrhage,paving the way for exploring potential therapeutic approaches.
基金supported by the National Natural Science Foundation of China(Nos.U24A20578,42225708,42377122,92251304)the Basic Research Program of Jiangsu Province(No.BK20240111)+1 种基金the Key Laboratory of Lake and Watershed Science for Water Security(No.NKL2023-QN04)the Science and Technology Planning Project of Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences(No.NIGLAS2022GS09).
文摘Dissolved organic matter(DOM)represents the largest pool of reactive carbon on the Earth and plays a crucial role in various biogeochemical processes and ecosystem functions.However,it is understudied for a global understanding of DOM molecular properties such as molecular weight,stoichiometry,and oxidation state,and the linkages among them across Earth systems.Here,a meta-analysis of 2707 sites in 204 literatures was conducted by synthesizing four representative molecular properties of DOM,i.e.,mass,double bond equivalent(DBE),modified aromaticity index(AI_(mod)),and nominal oxidation state of carbon(NOSC).By exploring H/C and O/C ratios,we examined the relationships among these DOM properties across waters and land systems,and their geographical patterns and environmental drivers.We found that,compared to land system,the mass,DBE,and AI_(mod) were all significantly higher in water systems,with river sediments exhibiting the highest values.The DOM oxidation state indicated by NOSC was greater on average in wastewater(NOSC=0.226±0.06)and marine water(NOSC=0.133±0.06)than in other habitats.Compared to waters,the mass in land system showed more strongly positive correlations with oxidation states such as NOSC and O/C,and the NOSC showed stronger relations to bioavailability properties such as DBE,AI_(mod),and H/C.Among all the properties,H/C and AI_(mod) contributed to the most variations in global DOM properties.In waters,NOSC monotonically increased towards high latitudes,while DBE and AI_(mod) showed significant hump-shaped patterns indicating peaked unsaturation and aromaticity at mid-latitudes of approximately absolute 30°–50°.The variations in DOM properties were significantly correlated with environmental factors such as annual mean temperature and pH.Collectively,we revealed the spatial distribution and environmental drivers of DOM molecular properties across Earth ecosystems,which could shed light on our comprehensive understanding of DOM characteristics and its dynamics.
基金supported by the Qingdao Medical Health Research Project,No.2023-WJZD212(to XX)。
文摘Recent evidence suggests that ferroptosis plays a crucial role in the occurrence and development of white matter lesions.However,the mechanisms and regulatory pathways involved in ferroptosis within white matter lesions remain unclear.Long non-coding RNAs(lnc RNAs)have been shown to influence the occurrence and development of these lesions.We previously identified lnc_011797 as a biomarker of white matter lesions by high-throughput sequencing.To investigate the mechanism by which lnc_011797 regulates white matter lesions,we established subjected human umbilical vein endothelial cells to oxygenglucose deprivation to simulate conditions associated with white matter lesions.The cells were transfected with lnc_011797 overexpression or knockdown lentiviruses.Our findings indicate that lnc_011797 promoted ferroptosis in these cells,leading to the formation of white matter lesions.Furthermore,lnc_011797 functioned as a competitive endogenous RNA(ce RNA)for mi R-193b-3p,thereby regulating the expression of WNK1 and its downstream ferroptosis-related proteins.To validate the role of lnc_011797 in vivo,we established a mouse model of white matter lesions through bilateral common carotid artery stenosis.The results from this model confirmed that lnc_011797 regulates ferroptosis via WNK1 and promotes the development of white matter lesions.These findings clarify the mechanism by which lnc RNAs regulate white matter lesions,providing a new target for the diagnosis and treatment of white matter lesions.
文摘Hepatic myelopathy is a complication seen in patients with chronic liver failure with physiologic or iatrogenic portosystemic shunting. The main symptom is progressive lower limb dyskinesia. The role of the brain motor control center in hepatic myelopathy is unknown. This study aimed to investigate the gray matter changes in patients with hepatic myelopathy secondary to transjugular intrahepatic portosystemic shunt and to examine their clinical relevance. This was a cross-sectional study. Twenty-three liver failure patients with hepatic myelopathy(hepatic myelopathy group), 23 liver failure patients without hepatic myelopathy(non-hepatic myelopathy group) after transjugular intrahepatic portosystemic shunt, and 23 demographically matched healthy volunteers were enrolled from March 2014 to November 2016 at Xijing Hospital, Air Force Military Medical University(Fourth Military Medical University), China. High-resolution magnetization-prepared rapid gradient-echo brain imaging was acquired. Group differences in regional gray matter were assessed using voxel-based morphometry analysis. The relationship between aberrant gray matter and motor characteristics was investigated. Results demonstrated that compared with the non-hepatic myelopathy group, gray matter volume abnormalities were asymmetric, with decreased volume in the left insula(P = 0.003), left thalamus(P = 0.029), left superior frontal gyrus(P = 0.006), and right middle cingulate cortex(P = 0.021), and increased volume in the right caudate nucleus(P = 0.017), corrected with open-source software. The volume of the right caudate nucleus in the hepatic myelopathy group negatively correlated with the lower limb clinical rating of the Fugl-Meyer Assessment(r = –0.53, P = 0.01). Compared with healthy controls, patients with and without hepatic myelopathy exhibited overall increased gray matter volume in both thalami, and decreased gray matter volume in both putamen, as well as in the globus pallidus, cerebellum, and vermis. The gray matter abnormalities we found predominantly involved motor-related regions, and may be associated with motor dysfunction. An enlarged right caudate nucleus might help to predict weak lower limb motor performance in patients with preclinical hepatic myelopathy after transjugular intrahepatic portosystemic shunt. This study was approved by the Ethics Committee of Xijing Hospital, Air Force Military Medical University(Fourth Military Medical University), China(approval No. 20140227-6) on February 27, 2014.
基金supported by the National Natural Science Foundation of China(Nos.U1301234,21277003)the Ministry of Science and Technology of China(No.2014BAC21B03)the Science and Technology Plan of Shenzhen Municipality
文摘Water-soluble organic matter（WSOM） represents a critical fraction of fine particles（PM2.5）in the air, but its changing behaviors and formation mechanisms are not well understood yet, partly due to the lack of fast techniques for the ambient measurements. In this study,a novel system for the on-line measurement of water-soluble components in PM2.5, the particle-into-liquid sampler（PILS）–Nebulizer–aerosol chemical speciation monitor（ACSM）, was developed by combining a PILS, a nebulizer, and an ACSM. High time resolution concentrations of WSOM, sulfate, nitrate, ammonium, and chloride, as well as mass spectra, can be obtained with satisfied quality control results. The system was firstly applied in China for field measurement of WSOM. The mass spectrum of WSOM was found to resemble that of oxygenated organic aerosol, and WSOM agreed well with secondary inorganic ions. All evidence collected in the field campaign demonstrated that WSOM could be a good surrogate of secondary organic aerosol（SOA）. The PILS–Nebulizer–ACSM system can thus be a useful tool for intensive study of WSOM and SOA in PM2.5.
基金Project supported by the National Key Technologies Research and Development Program of China during the 10th Five-Year Plan Period (No. 2004BA520A14C02) and the Program for Changjiang Scholars and Innovative Research Team in University of China (No. IRT0412).
文摘A modified CQESTR model, a simple yet useful model frequently used for estimating carbon sequestration in agricultural soils, was developed and applied to evaluate the effects of intensive cropping on soil organic matter （SOM） dynamics and mineralization as well as to estimate carbon dioxide emission from agricultural soils at seven sites on the Huang-Huai-Hai Plain of China. The model was modified using site-specific parameters from short- and mid-term buried organic material experiments at four stages of biomass decomposition. The predicted SOM results were validated using independent data from seven long-term （10- to 20-year） soil fertility experiments in this region. Regression analysis on 1 151 pairs of predicted and measured SOM data had an r2 of 0.91 （P≤0.01）. Therefore, the modified model was able to predict the mineralization of crop residues, organic amendments, and native SOM. Linear regression also showed that SOM mineralization rate （MR） in the plow layer increased by 0.22% when annual crop yield increased by 1 t ha^-1 （P ≤ 0.01）, suggesting an improvement in SOM quality. Apparently, not only did the annual soil respiration efftux merely reflect the intensity of soil organism and plant metabolism, but also the SOM MR in the plow layer. These results suggested that the modified model was simple yet valuable in predicting SOM trends at a single agricultural field and could be a powerful tool for estimating C-storage potential and reconstructing C storage on the Huang-Huai-Hai Plain of China.
基金supported by the National Key Research and Development Program of China(No.2016YFC0203703)the National Natural Science Foundation of China(Nos.51576039,51806107 and 21276049)+1 种基金the Scientific Research Foundation of Graduate School of Southeast University(No.YBJJ1610)the Research Innovation Program for College Graduates of Jiangsu Province(No.KYLX16_0283)。
文摘Particulate matter emissions from ammonia-based wet flue gas desulfurization(AmmoniaWFGD)systems are composed of a filterable particulate matter and a condensable particulate matter(CPM)portion.However,the CPM part has been ignored for a long time,which results in an underestim ation of the aerosol problems caused by Ammonia-WFGD systems.In our research,the characteristics of the CPM that emits from an Ammonia-WFGD system are investigated experimentally for the first time,with the US Environmental Protection Agency Method 202 employed as the primary measurement.The influences of some essential desulfurizing parameters are evaluated based on the experimental data.The results show that CPM contributes about 68.8%to the total particulate matter emission.CPM consists mainly of ammonium sulfates/sulfites,with the organic part accounting for less than 4%.CPM is mostly in the submicron fraction,about 71.1%of which originates from the NH3-H2O-SO2 reactions.The appropriate adjustments for the parameters of the flue gas and the desulfurizing solution can inhibit CPM formation to different extents.This indicates that the parameter optimizations are promising in solving CPM emission problems in Ammonia-WFGD systems,in which the pH adjustment alone can abate CPM emission by around 49%.The opposite variations of the parameters need attention because they can cause tremendous CPM emission increase.
基金supported by the German Academic Exchange Service (DAAD)and Higher Education Commission (HEC),Pakistan。
文摘Dissolved organic matter(DOM)in surface waters can vary markedly in character depending on seasonal variations such as rainfall intensity,UV radiations and temperature.Changes in DOM as well as temperature and rainfall intensity over the year can affect the biochemical processes occurring in bank filtration(BF).Identification and characterization of DOM in the surface water could help to optimize the water treatment and provide stable and safe drinking water.This study investigated year-long variations of DOM concentrations and compositions in a surface water of a circulated outdoor pond(research facility)connected to a BF passage.DOM was dominated by humic substances and a changing pattern of DOM in surface water was observed throughout the year.A significant increase of DOM(~38%)in surface water was noted in August compared to November.The fluorescent DOM showed that DOM in summer was enriched with the degradable fraction whilst non-degradable fraction was dominated in winter.A constant(1.7±0.1 mg/L)effluent DOM was recirculated in the system throughout the year.DOM removal through BF varied between 4%to 39%and was achieved within a few meters after infiltration and significantly correlated with influent DOM concentration(R^(2)=0.82,p<0.05).However,no significant(p>0.05)change in the removal of DOM was observed in two subsurface layers(upper and lower).This study highlights the presence of a constant non-degradable DOM in the bank filtrate,which was not affected by temperature,redox conditions and UV radiations.
文摘Diesel particulate matter （DPM） is considered to be carcinogenic after prolonged exposure. With more diesel- powered equipment used in underground mines, miners＇ exposure to DPM has become an increasing concern. This paper used computational fluid dynamics method to study the DPM dispersion in a dead-end entry with loading operation. The effects of different push-pull ventilation systems on DPM distribution were evaluated to improve the working conditions for underground miners. The four push-pull systems considered include： long push and short pull tubing; short push and long pull tubing, long push and curved pull tubing, and short push and curved pull tubing. A species transport model with buoyancy effect was used to examine the DPM dispersion pattern with unsteady state analysis. During the 200 s of loading operation, high DPM levels were identified in the face and dead-end entry regions. This study can be used for mining engineer as guidance to design and setup local ventilation, select DPM control strategies and for DPM annual training for underground miners.
基金supported by the National Natural Science Foundation of China(Nos.91743110,61674114,and 21861132001)the National Key R&D Program of China(Nos.2017YFF0204604 and 2018YFE0118700)+1 种基金Tianjin Applied Basic Research and Advanced Technology(No.17JCJQJC43600),the“111”Project(No.B07014)the Foundation for Talent Scientists of Nanchang Institute for Micro-technology of Tianjin University.
文摘Ambient suspended particulate matter(PM)(primarily with particle diameter 2.5m or less,i.e.,PM2.5)can adversely affect ecosystems and human health.Currently,optical particle sensors based on light scattering dominate the portable PM sensing market.However,the light scattering method has poor adaptability to different-sized PM and adverse environmental conditions.Here,we design and develop a portable PM sensing microsystem that consists of a micromachined virtual impactor(VI)for particle separation,a thermophoretic deposition chip for particle collection,and an extended-gate field-effect transistor(FET)for particle analysis.This system can realize on-site separation,collection,and analysis of aerosol particles without being influenced by environmental factors.In this study,the design of the VI is thoroughly analyzed by numerical simulation,and mixtures of different-sized silicon dioxide(SiO2)particles are used in an experimental verification of the performance of the VI and FET.Considering the low cost and compact design of the whole system,the proposed PM analysis microsystem has potential for PM detection under a wide range of conditions,such as heavily polluted industrial environments and for point-of-need outdoor and indoor air quality monitoring.
基金funded by the National Key Research and Development Program of China(No.2019YFC0214801)National Natural Science Foundation of China(Nos.92043301 and 92143301)。
文摘This review aimed to systematically summarize the epidemiological literature on the cardiorespiratory effects of PM_(2.5)published during the 13^(th) Five-Year Plan period(2016-2020)in China.Original articles published between January 1,2016 and June 30,2021 were searched in PubMed,Web of Science,the China National Knowledge Internet Database and Wanfang Database.Random-or fixed-effects models were used to pool effect estimates where appropriate.Of 8558 records identified,145 met the full eligibility criteria.A 10μg/m^(3) increase in short-term PM_(2.5)exposure was significantly associated with increases of 0.70%,0.86%,0.38%and 0.96%in cardiovascular mortality,respiratory mortality,cardiovascular morbidity,and respiratory morbidity,respectively.The specific diseases with significant associations included stroke,ischemic heart disease,heart failure,arrhythmia,chronic obstructive pulmonary disease,pneumonia and allergic rhinitis.The pooled estimates per 10μg/m^(3) increase in long-term PM_(2.5)exposure were 15.1%,11.9%and 21.0%increases in cardiovascular,stroke and lung cancer mortality,and 17.4%,11.0%and 4.88%increases in cardiovascular,hypertension and lung cancer incidence respectively.Adverse changes in blood pressure,heart rate variability,systemic infiammation,blood lipids,lung function and airway infiammation were observed for either short-term or long-term PM_(2.5)exposure,or both.Collectively,we summarized representative exposure-response relationships between short-and long-term PM_(2.5)exposure and a wide range of cardiorespiratory outcomes applicable to China.The magnitudes of estimates were generally smaller in short-term associations and comparable in long-term associations compared with those in developed countries.Ourfindings are helpful for future standard revisions and policy formulation.There are still some notable gaps that merit further investigation in China.
文摘According to the characteristics of ecosystem and concept of the ecosystem in mining area, the index system of the ecosystem health in mining area was set up, and the evaluation standard was established. Aiming at the complexion in which the information lost in index ration, the matter element method was put forward to evaluate the ecosystem health in mining area. Making use of the model set up, the weight was built up by the method of index number heavy, the matter element, clas- sical field, and limit field were set up. The rating hierarchy was calculated by relating function. As a case study in the mining area of Pingyangsi Town, the results show that the ecosystem is good and sustainable from 2003 to 2006, but the healthy degree is not high, and some indexes have depravation.
文摘Objective Studies of the association of hypertension with long-term exposure to particulate matter less than 2.5μm in diameter(PM2.5)have shown contradictory results and the magnitude of the association is still unclear.Hence,we conducted a meta-analysis of cohort studies to assess the effect of long-term exposure to PM2.5 on incident hypertension.
基金supported by the USDA National Institute of Food and Agriculture(NIFA),Evans Allen Grant,USA(No.224120)the National Science Foundation(NSF-CREST-CFEA),USA(No.1036600)the Agricultural Experimental Station,Alabama A&M University,Alabama,USA(Journal#:660)
文摘Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter （SOM）. In this study, surface softs from field plots in the Bankhead National Forest, Alabama, USA, were used to investigate possible SOM transformations induced by thinning and burning. Elemental analysis and solid-state 13C cross polarization magic angle spinning nuclear magnetic resonance （13C CPMAS NMR） spectroscopy were used to characterize SOM fractions in whole soils, humic substances, and density fractions. Our data revealed that the changes in SOM fractions due to the repeated burning carried out in the forest ecosystem studied were involved mainly with alkyl C, O-alkyl C, and carbohydrate functional groups, implying that most prominent reactions that occurred involved dehydrogenation, de-oxygenation, and decarboxylation. In addition, burning and thinning might have also affected the distribution and composition of free and occluded particulate SOM fractions. The limited structural changes in SOM fractions suggested that low-intensity prescribed fire in the forest ecosystem studied will not create major structural changes in SOM fractions.
文摘A long-term simulation experiment was carried out to study the effect of rice-based cropping system,green manure and ground-water level on soil organic matter. Soil organic matter content increased when upland soil was puddled and cropped under submerged conditions. Among all treatments, soil organic matter contents in the treatments of rice-rice-flooded fallow in winter (WF) were the highest, those in the treatments of rice-rice-astragalus (WG) came the second, and those in the treatments of rice-rice-rape (WR)were the lowest. At the same rate of green manure application, the degrees of organo-mineral complexing in soils of treatments WG and WR were higher than those of treatment WF. After 9-year rice cultivation, the state of combination of humus in heavy fraction varied with treatments. The relative content of loosely bonded humus decreased in the order of WR > WG > WF, and it correlated significantly with Se availability.
基金the Ministry of Science and Technology of China(No.2016YFA0400301)the grants for the XENON Dark Matter Project。
文摘In recent years, cooling technology for liquid xenon(LXe) detectors has advanced driven by the development of dark matter(DM) detectors with target mass in the 100–1000 kg range. The next generation of DM detectors based on LXe will be in the 50,000 kg(50 t)range requiring more than 1 k W of cooling power. Most of the prior cooling methods become impractical at this level.For cooling a 50 t scale LXe detector, a method is proposed in which liquid nitrogen(LN2) in a small local reservoir cools the xenon gas via a cold finger. The cold finger incorporates a heating unit to provide temperature regulation. The proposed cooling method is simple, reliable, and suitable for the required long-term operation for a rare event search. The device can be easily integrated into present cooling systems, for example the ‘‘Cooling Bus’ ’employed for the Panda X I and II experiments. It is still possible to cool indirectly with no part of the cooling or temperature control system getting in direct contact with the clean xenon in the detector. Also, the cooling device can be mounted at a large distance, i.e., the detector is cooled remotely from a distance of 5–10 m. The method was tested in a laboratory setup at Columbia University to carry out different measurements with a small LXe detector and behaved exactly as predicted.
文摘Chronic obstructive pulmonary disease (COPD) is a chronic disease characterized by progressive airflow obstruction, along with pulmonary and systemic inflammation. Outdoor PM has been associated with morbidity and mortality in COPD but less is known about effects of indoor air quality. In former smokers with COPD, we investigated in-home PM effects on pulmonary and systemic inflammation, symptoms, and lung function. Participants underwent in-home air monitoring for two weeks and simultaneous health assessments. Median (IQR) PM2.5 was 9 (7) μg/m3. Increased indoor PM2.5 was associated with increased white blood cells, predominantly neutrophils and lymphocytes, suggesting that even relatively low indoor PM2.5 may elicit a systemic inflammatory response in COPD.
