Fracture is a very common failure mode of the composite materials,which seriously affects the reliability and service-life of composite materials.Therefore,the study of the fracture behavior of the composite materials...Fracture is a very common failure mode of the composite materials,which seriously affects the reliability and service-life of composite materials.Therefore,the study of the fracture behavior of the composite materials is of great significance and necessity,which demands an accurate and efficient numerical tool in general cases because of the complexity of the arising boundary-value or initial-boundary value problems.In this paper,a phase field model is adopted and applied for the numerical simulation of the crack nucleation and propagation in brittle linear elastic two-phase perforated/particulate composites under a quasi-static tensile loading.The phase field model can well describe the initiation,propagation and coalescence of the cracks without assuming the existence and the geometry of the initial cracks in advance.Its numerical implementation is realized within the framework of the finite element method(FEM).The accuracy and the efficiency of the present phase field model are verified by the available reference results in literature.In the numerical examples,we first study and discuss the influences of the hole/particle size on the crack propagation trajectory and the force-displacement curve.Then,the effects of the hole/particle shape on the crack initiation and propagation are investigated.Furthermore,numerical examples are presented and discussed to show the influences of the hole/particle location on the crack initiation and propagation characteristics.It will be demonstrated that the present phase field model is an efficient tool for the numerical simulation of the crack initiation and propagation problems in brittle two-phase composite materials,and the corresponding results may play an important role in predicting and preventing possible hazardous crack initiation and propagation in engineering applications.展开更多
Fine particulate matter(particulate matter with a diameter of 2.5μm or less;PM2.5)causes millions of premature deaths globally1,but not all particles are equally harmful2-4.Current air-pollution control strategies,pr...Fine particulate matter(particulate matter with a diameter of 2.5μm or less;PM2.5)causes millions of premature deaths globally1,but not all particles are equally harmful2-4.Current air-pollution control strategies,prioritizing PM2.5 mass reduction,have provided considerable health benefits but further refinements based on differences in the toxicity of various emission sources may provide greater benefits5-7.Here we integrated field measurements with air-quality modelling to assess the unequal toxicities of PM2.5 from various anthropogenic sources.展开更多
A hydrodynamic model is used to study Kelvin-Helmholtz(KH)instability of the interface between two particle-laden inviscid fluids moving with two different uniform mean velocities.Explicit eigen-equation is derived to...A hydrodynamic model is used to study Kelvin-Helmholtz(KH)instability of the interface between two particle-laden inviscid fluids moving with two different uniform mean velocities.Explicit eigen-equation is derived to study the effect of suspended particles on the growth rate of KH instability.For dusty gases with negligible volume fraction of heavy particles and small particle-to-fluid mass ratio,the real and imaginary parts of leading-order asymptotic expression derived by the present model for the growth rate are shown to be identical to the earlier results derived by the classical Saffman model established for dusty gases.Beyond the known results,explicit leading-order asymptotic expressions for the effect of suspended particles on the growth rate are derived for several typical cases of basic interest.It is shown that the suspended particles can decrease or increase the growth rate of KH instability depending on the Stokes numbers of the particles and whether the particles are heavier or lighter than the clean fluid.Compared to the mass density of the clean fluid,our results based on leading-order asymptotic solutions show that heavier particles and lighter particles have opposite effects on the growth rate of KH instability,while the effect of neutrally buoyant particles on the growth rate of KH instability is negligible.展开更多
BACKGROUND Pediatric perforated appendicitis(PPA)is a severe acute condition requiring surgical intervention and postoperative antibiotic therapy.Antibiotic selection differs significantly among pediatric centers,and ...BACKGROUND Pediatric perforated appendicitis(PPA)is a severe acute condition requiring surgical intervention and postoperative antibiotic therapy.Antibiotic selection differs significantly among pediatric centers,and an ideal postoperative antiinfective approach for PPA management has yet to be established.AIM To examine the spectrum of pathogenic bacteria in pediatric PPA and to summarize the postoperative experience with carbapenem(CBP)and cephalosporin(CPS)antibiotics.METHODS We retrospectively analyzed medical records of 65 children(43 boys,22 girls;mean age 6.92±3.41 years)with PPA who underwent surgery at our hospital between December 2019 and August 2022.Data were collected in September 2023.Based on postoperative antibiotic selection,patients were divided into CBP(32 cases)and CPS(33 cases)groups.Chi-square and T-tests compared recovery outcomes,while univariate and multivariate regression models identified independent factors affecting postoperative recovery.RESULTS There were no significant differences between the two groups in gender,age,weight,height,body mass index,baseline ear temperature,or heart rate(P>0.05).Escherichia coli(40.00%)and Pseudomonas aeruginosa(24.62%)were the most common pathogens in PPA.Postoperative analysis showed significantly shorter C-reactive protein(CRP)recovery times in the CPS group than in the CBP group[(6.18±1.84)vs(8.12±3.48)days,P=0.009].Univariate logistic regression indicated CPS selection(OR=0.32,95%CI:0.10-0.97,P=0.044)was significantly associated with a higher CRP recovery rate within 7 days.Multivariate analysis confirmed CPS selection(OR=3.49,95%CI:1.19-10.24,P=0.023)as an independent factor affecting CRP recovery within 7 days postoperatively.CONCLUSION The choice of CBP or CPS independently affects CRP recovery within 7 days.CBP offers no advantage over CPS in treating PPA,with CPS also demonstrating favorable clinical outcomes.展开更多
The risk of exposure to particulate matter(PM)has been consistently highlighted globally owing to its detrimental effects on the respiratory and cardiovascular systems and in the development of lung cancer.Additionall...The risk of exposure to particulate matter(PM)has been consistently highlighted globally owing to its detrimental effects on the respiratory and cardiovascular systems and in the development of lung cancer.Additionally,PM promotes cancer cell metastasis;however,research elucidating the precise mechanisms underlying this phenomenon and the strategies to inhibit it remains limited.The aim of this study was to elucidate the mechanism underlying PM-induced cancer metastasis and investigate the preventive role of ginsenoside Rg3.We treated macrophages with PM and confirmed an increase in the expression and secretion of chemokines,such as CCL3,CCL4,and CCL5.This effect was mediated by the MAPK and NF-kB pathways,and Rg3 inhibited this process by suppressing chemokine expression.These chemokines regulate the expression of epithelial-mesenchymal transition(EMT)markers in cancer cells,including Snail,Slug,ZEB1,and E-cadherin.The regulated EMT markers increased the motility of cancer cells in vitro.Furthermore,an increase in CCL3,CCL4,and CCL5 in the bronchoalveolar lavage fluid(BALF)was confirmed in a PM inhalation mouse model,and Rg3 reduced PM-induced cancer metastasis.The study findings suggest the potential use of Rg3 as a therapeutic agent to prevent PM-induced cancer metastasis.展开更多
Objective Emerging evidence suggests that exposure to ultrafine particulate matter(UPM,aerodynamic diameter<0.1μm)is associated with adverse cardiovascular events.Previous studies have found that Shenlian(SL)extra...Objective Emerging evidence suggests that exposure to ultrafine particulate matter(UPM,aerodynamic diameter<0.1μm)is associated with adverse cardiovascular events.Previous studies have found that Shenlian(SL)extract possesses anti-inflammatory and antiapoptotic properties and has a promising protective effect at all stages of the atherosclerotic disease process.In this study,we aimed to investigated whether SL improves UPM-aggravated myocardial ischemic injury by inhibiting inflammation and cell apoptosis.Methods We established a mouse model of MI+UPM.Echocardiographic measurement,measurement of myocardialinfarct size,biochemical analysis,enzyme-linked immunosorbent assay(ELISA),histopathological analysis,Transferase dUTP Nick End Labeling(TUNEL),Western blotting(WB),Polymerase Chain Reaction(PCR)and so on were used to explore the anti-inflammatory and antiapoptotic effects of SL in vivo and in vitro.Results SL treatment can attenuate UPM-induced cardiac dysfunction by improving left ventricular ejection fraction,fractional shortening,and decreasing cardiac infarction area.SL significantly reduced the levels of myocardial enzymes and attenuated UPM-induced morphological alterations.Moreover,SL significantly reduced expression levels of the inflammatory cytokines IL-6,TNF-α,and MCP-1.UPM further increased the infiltration of macrophages in myocardial tissue,whereas SL intervention reversed this phenomenon.UPM also triggered myocardial apoptosis,which was markedly attenuated by SL treatment.The results of in vitro experiments revealed that SL prevented cell damage caused by exposure to UPM combined with hypoxia by reducing the expression of the inflammatory factor NF-κB and inhibiting apoptosis in H9c2 cells.Conclusion Overall,both in vivo and in vitro experiments demonstrated that SL attenuated UPMaggravated myocardial ischemic injury by inhibiting inflammation and cell apoptosis.The mechanisms were related to the downregulation of macrophages infiltrating heart tissues.展开更多
Particulate photocatalytic systems using nanoscale photocatalysts have been developed as an attractive promising route for solar energy utilization to achieve resource sustainability and environmental harmony.Dynamic ...Particulate photocatalytic systems using nanoscale photocatalysts have been developed as an attractive promising route for solar energy utilization to achieve resource sustainability and environmental harmony.Dynamic obstacles are considered as the dominant inhibition for attaining satisfactory energy-conversion efficiency.The complexity in light absorption and carrier transfer behaviors has remained to be further clearly illuminated.It is challenging to trace the fast evolution of charge carriers involved in transfer migration and interfacial reactions within a micro–nano-single-particle photocatalyst,which requires spatiotemporal high resolution.In this review,comprehensive dynamic descriptions including irradiation field,carrier separation and transfer,and interfacial reaction processes have been elucidated and discussed.The corresponding mechanisms for revealing dynamic behaviors have been explained.In addition,numerical simulation and modeling methods have been illustrated for the description of the irradiation field.Experimental measurements and spatiotemporal characterizations have been clarified for the reflection of carrier behavior and probing detection of interfacial reactions.The representative applications have been introduced according to the reported advanced research works,and the relationships between mechanistic conclusions from variable spatiotemporal measurements and photocatalytic performance results in the specific photocatalytic reactions have been concluded.This review provides a collective perspective for the full understanding and thorough evaluation of the primary dynamic processes,which would be inspired for the improvement in designing solar-driven energy-conversion systems based on nanoscale particulate photocatalysts.展开更多
Objective Several epidemiological observational studies have related particulate matter(PM)exposure to Inflammatory bowel disease(IBD),but many confounding factors make it difficult to draw causal links from observati...Objective Several epidemiological observational studies have related particulate matter(PM)exposure to Inflammatory bowel disease(IBD),but many confounding factors make it difficult to draw causal links from observational studies.The objective of this study was to explore the causal association between PM_(2.5)exposure,its absorbance,and IBD.Methods We assessed the association of PM_(2.5)and PM_(2.5)absorbance with the two primary forms of IBD(Crohn’s disease[CD]and ulcerative colitis[UC])using Mendelian randomization(MR)to explore the causal relationship.We conducted two-sample MR analyses with aggregated data from the UK Biobank genome-wide association study.Single-nucleotide polymorphisms linked with PM_(2.5)concentrations or their absorbance were used as instrumental variables(IVs).We used inverse variance weighting(IVW)as the primary analytical approach and four other standard methods as supplementary analyses for quality control.Results The results of MR demonstrated that PM_(2.5)had an adverse influence on UC risk(odds ratio[OR]=1.010;95%confidence interval[CI]=1.001–1.019,P=0.020).Meanwhile,the results of IVW showed that PM_(2.5)absorbance was also causally associated with UC(OR=1.012;95%CI=1.004–1.019,P=0.002).We observed no causal relationship between PM_(2.5),PM_(2.5)absorbance,and CD.The results of sensitivity analysis indicated the absence of heterogeneity or pleiotropy,ensuring the reliability of MR results.Conclusion Based on two-sample MR analyses,there are potential positive causal relationships between PM_(2.5),PM_(2.5)absorbance,and UC.展开更多
Controlling the adhesion of potentially corrosive substances from flue gas on grate bar is crucial for extending the operational lifespan of the equipment.The adhesive behaviour and mechanism of ultrafine particulate ...Controlling the adhesion of potentially corrosive substances from flue gas on grate bar is crucial for extending the operational lifespan of the equipment.The adhesive behaviour and mechanism of ultrafine particulate matters(UPM)throughout the sintering process were elucidated,and measures to control adhesion on grate bars were developed.Research findings indicated that a small quantity of UPM were found on grate bar during the initial sintering stages(ignition stage and middle stageⅠandⅡ).The main compositions of UPM were FexOy-rich,CaO-rich,and aluminium silicate-rich particles.In contrast,corrosive substances like alkali metal compounds were almost absent.These UPM adhered onto grate bar primarily through inertial impaction.When moving to the final sintering stages(middle stageⅢand temperature rising stage),many UPM rich in corrosive substances like NaCl and KCl adhered to the grate bar.These UPM adhered to grate bar through thermal diffusion and vortex deposition.Solid waste water washing technology can greatly decrease the quantity of UPM(rich in NaCl and KCl)on the grate bar due to vortex deposition and thermal diffusion,and it represents a potentially promising way to control adhesion and corrosion on grate bars.展开更多
Objective The effects of prolonged exposure to persistently elevated atmospheric pollutants,commonly termed air pollution waves,on fertility intentions remain inadequately understood.This study aims to investigate the...Objective The effects of prolonged exposure to persistently elevated atmospheric pollutants,commonly termed air pollution waves,on fertility intentions remain inadequately understood.This study aims to investigate the association between particulate matter(PM)exposure and fertility intentions.Methods In this nationwide cross-sectional study,we analyzed data from 10,747 participants(5496 females and 5251 males).PM waves were defined as periods lasting 3‒6 consecutive days during which the daily average concentrations exceeded China’s Ambient Air Quality Standards Grade II thresholds(PM2.5>75μg/m3 and PM10>150μg/m3).We employed multivariate logistic regression models to assess the association between exposure to PM waves and fertility intentions.Results Significant inverse associations were detected between exposure to PM2.5 wave events(characterized by concentrations exceeding 75μg/m3 for durations of 4‒6 days,P<0.05)and PM10 wave events(defined as concentrations exceeding 150μg/m3 for 6 consecutive days,P<0.05)and fertility intentions among females.In contrast,neither the PM2.5 wave nor the PM10 wave events demonstrated statistically significant correlations with fertility intentions in males(P>0.05 for all comparisons).The potentially susceptible subgroup was identified as females aged 20–30 years.Conclusions Our results provide the first evidence that PM2.5 and PM10 waves are associated with a reduction in female fertility intentions,offering critical insights for the development of public health policies and strategies aimed at individual protection.展开更多
Serious fine particulate matter(PM_(2.5))pollution and rapidly increasing of ground-level ozone(O_(3))concentrations are concern issues in China.To achieve the comprehensive control of PM_(2.5)-O_(3) composite air pol...Serious fine particulate matter(PM_(2.5))pollution and rapidly increasing of ground-level ozone(O_(3))concentrations are concern issues in China.To achieve the comprehensive control of PM_(2.5)-O_(3) composite air pollution,exploring the common sources of PM_(2.5) and VOCs is essential.However,previous researches most carried out either PM_(2.5) or VOCs source appointment.In this study,we applied the ensemble source apportionment method to explore the impacts of common sources on PM_(2.5)-VOCs.Subsequently,we obtained the ensemble source impacts on O_(3) combining the extracted VOCs source profile and ozone formation potential.We found that the focus of environmentalmanagement and source control should be varied accordingly for different pollutants.Vehicle emission was the largest contributor(41%)to PM_(2.5)-VOCs,while industrial emission was the main common source(51%)to O_(3).The result showed that the O_(3) production rate is not only related to the VOCs emission,but also to the reactivity of VOCs.In addition,sensitivity tests revealed that temperature was the main factor affecting O_(3) formation.The study provides a framework to explore the common sources impact on PM_(2.5) and VOCs,which is benefit to address both PM_(2.5) and O_(3) mitigations.展开更多
BACKGROUND Peptic ulcer disease(PUD)during pregnancy is extremely rare.Perforated peptic ulcer(PPU)during pregnancy has high maternal and fetal mortality.Symptoms attributed to pregnancy and other diagnoses make the d...BACKGROUND Peptic ulcer disease(PUD)during pregnancy is extremely rare.Perforated peptic ulcer(PPU)during pregnancy has high maternal and fetal mortality.Symptoms attributed to pregnancy and other diagnoses make the diagnosis of preoperative PPU during pregnancy and puerperium challenging.AIM To identify predictive factors for early diagnosis and treatment,and the association between the diagnosis and maternal/neonatal outcomes.METHODS We searched PubMed,PubMed Central,and Google Scholar.Articles were analyzed following preferred reporting items for systematic reviews and metaanalysis.The search items included:‘ulcer’,‘PUD’,‘pregnancy’,‘puerperium’,‘postpartum’,‘gravid’,‘labor’,‘perforated ulcer’,‘stomach ulcer’,‘duodenal ulcer’,‘peptic ulcer’.Additional studies were extracted by reviewing reference lists of retrieved studies.We included all available full-text cases and case series.Demographic,clinical,obstetric,diagnostic and treatment parameters,and outcomes were collected.RESULTS Forty-three cases were collected.The mean maternal age was 30.9 years;36.6%were multiparous,and 63.4%were nulliparous or primiparous,with multiparas being older than primiparas.Peptic ulcer perforated in 44.2%of postpartum and 55.8%of antepartum patients.Antepartum PPU incidence increased with advancing gestation 2.3%in the first,7%in the second,and 46.5%in the third trimester.The most common clinical findings were abdominal tenderness(72.1%),rigidity(34.9%),and distension(48.8%).Duodenal ulcer predominated(76.7%).In 79.5%,the time from delivery to surgery or vice versa was>24 hours.The maternal mortality during the third trimester and postpartum was 10%and 31.6%,respectively.The trimester of presentation did not influence maternal mortality.The fetal mortality was 34.8%,with all deaths in gestational weeks 24-32.CONCLUSION Almost all patients with PPU in pregnancy or puerperium presented during the third trimester or the first 8 days postpartum.Early intervention reduced fetal mortality but without influence on maternal mortality.Maternal mortality did not depend on the use of X-ray imaging,perforation location,delivery type,trimester of presentation,and maternal age.Explorative laparoscopy was never performed during pregnancy,only postpartum.展开更多
Lithium ion batteries are important for new energy technologies and manufacturing systems.However,enhancing their capacity and cycling stability poses a significant challenge.This study proposes a novel method,i.e.,mo...Lithium ion batteries are important for new energy technologies and manufacturing systems.However,enhancing their capacity and cycling stability poses a significant challenge.This study proposes a novel method,i.e.,modifying current collectors with perforations,to address these issues.Lithium ion batteries with mechanically perforated current collectors are prepared and tested with charge/discharge cycles,revealing superior capacity as well as enhanced electrochemical stability over cycles.Impedance spectroscopy,scanning electron microscopy,and peeling tests are conducted to investigate the underlying mechanisms.Higher peel resistance,minimized interface cracking,and reduced electrical impedance are found in the perforated electrodes after cycles.Investigations indicate that the perforation holes on current collectors allow the active materials coating on the two sides of the current collector to bind together and,thus,lead to enhanced adhesion between the current collector and active layer.Mechanical simulation illustrates the role of perforated current collectors in curbing interface cracking during lithiation,while electrochemical simulation shows that the interfacial cracking hinders the diffusion of lithium ions,thereby increasing battery impedance and reducing the cyclic performance.This investigation reveals the potential of designing non-active battery components to enhance battery performance,advocating a nuanced approach to battery design emphasizing structural integrity and interface optimization.展开更多
BACKGROUND Acute perforated cholecystitis(APC)is a serious complication of acute cholecystitis and is associated with significant morbidity and mortality,particularly in elderly or high-risk patients.While emergency c...BACKGROUND Acute perforated cholecystitis(APC)is a serious complication of acute cholecystitis and is associated with significant morbidity and mortality,particularly in elderly or high-risk patients.While emergency cholecystectomy is the standard of care,it may not be feasible in unstable patients.Percutaneous transhepatic cholecystostomy(PTC)offers a minimally invasive alternative.AIM To evaluate the safety and effectiveness of PTC as an initial treatment modality for APC.METHODS We conducted a retrospective cohort study of patients diagnosed with APC between January 2017 and October 2022 at a single tertiary medical center.All patients underwent PTC as the initial intervention.Data collected included demographics,comorbidities,laboratory and imaging findings,complications,and clinical outcomes over a 24-month follow-up.Patients were stratified into two groups based on whether they subsequently underwent cholecystectomy.RESULTS Thirty patients underwent PTC for APC.Half of the patients(n=15)were stabilized and later underwent cholecystectomy;the remaining 15 were managed non-operatively.Patients in the non-surgical group were significantly older(87.1±6.2 years vs 76.1±7.4 years;P<0.001).Clinical improvement was observed in 61.4%of non-operated patients,with eventual drain removal or closure.Both groups demonstrated significant reductions in white blood cell count and C-reactive protein levels from admission to discharge.No significant differences were found in hospital stay or complication rates.During follow-up,three deaths occurred due to non-biliary causes.Only one patient required repeat drainage.CONCLUSION PTC is a safe and effective initial treatment for APC,particularly in elderly and comorbid patients for whom surgery poses excessive risk.It provides clinical stabilization and may serve either as a bridge to delayed cholecystectomy or as definitive management in selected patients.These findings support the broader use of PTC in the management of APC,although larger prospective studies are warranted.展开更多
Phthalate(PAEs)and Bisphenols(BPs)are plasticizers or additives in consumer products.They are typical endocrine disruptors,and potential health hazards may occur when people are exposed to them through inhalation,inge...Phthalate(PAEs)and Bisphenols(BPs)are plasticizers or additives in consumer products.They are typical endocrine disruptors,and potential health hazards may occur when people are exposed to them through inhalation,ingestion,and dermal contact.The current research on inhalation exposure pays limited attention to the particle distribution of PAEs and BPs in air,although particulate-bound pollutants are usually size-dependent.In this study,we discussed the size resolution of PAEs and BPs in air particles from city waste recycling plants.With paired urine samples of the workers,we also compared the internal and external exposure of PAEs and BPs and related potential health risks.The particulatebound PAEs and BPs concentrated mainly on coarse particles(Dp>2.1μm),with a bimodal distribution,and the peak particle size ranged from 9–10 to 4.7–5.85μm,respectively.Model calculation revealed that the deposition fluxes of PAEs in different respiratory regions followed the sequence of head airways(167±92.8 ng/h)>alveolar region(18.9±9.96 ng/h)>tracheobronchial region(9.20±5.22 ng/h),and the similar trends went for BPs.The daily intakes of PAEs and BPs via dust ingestion were higher than those fromrespiratory inhalation and dermal contact,with mean value of 96 and 0.88 ng/(kg-bw day),respectively.For internal exposure,the estimated daily intakes of PAEs for waste recycling workers were higher than those in e-waste dismantling workers,while the exposure levels of bisphenols were comparable.Overall,the potential health risks from inhalation exposure to particulate-bound PAEs and BPs were low.展开更多
In this research,we introduce an innovative approach that combines the Continuum Damage Mechanics-Finite Element Method(CDM-FEM)with the Particle Swarm Optimization(PSO)-based technique,to predict the Medium-Low-Cycle...In this research,we introduce an innovative approach that combines the Continuum Damage Mechanics-Finite Element Method(CDM-FEM)with the Particle Swarm Optimization(PSO)-based technique,to predict the Medium-Low-Cycle Fatigue(MLCF)life of perforated structures.First,fatigue tests are carried out on three center-perforated structures,aiming to assess their fatigue life under various strengthening conditions.These tests reveal significant variations in fatigue life,accompanied by an examination of crack initiation through the analysis of fatigue fracture surfaces.Second,an innovative fatigue life prediction methodology is applied to perforated structures,which not only forecasts the initiation of fatigue cracks but also traces the progression of damage within these structures.It leverages an elastoplastic constitutive model integrated with damage and a damage evolution model under cyclic loads.The accuracy of this approach is validated by comparison with test results,falling within the three times error band.Finally,we explore the impact of various strengthening techniques,including cross-sectional reinforcement and cold expansion,on the fatigue life and damage evolution of these structures.This is achieved through an in-depth comparative analysis of both experimental data and computational predictions,which provides valuable insights into the behavior of perforated structures under fatigue conditions in practical applications.展开更多
Particulate organic matter(POM)plays a crucial role in the organic composition of lakes;however,its characteristics remain poorly understood.This study aimed to characterize the structure and composition of POM in Lak...Particulate organic matter(POM)plays a crucial role in the organic composition of lakes;however,its characteristics remain poorly understood.This study aimed to characterize the structure and composition of POM in Lake Baiyangdian usingmany kinds of techniques and investigate the effects of different extracted forms of POM on water quality.The suspended particulatematter in the lake had complex compositions,with its components primarily derived from aquatic plants and their detritus.The organic matter content of the suspended particulatematterwas relatively high(organic carbon content 27.29–145.94 g/kg)for the sum of three extractable states(water-extracted organic matter[WEOM],humic acid,and fulvic acid)and one stable bound state(humin).Spatial distribution analysis revealed that the POM content in the water increased from west to east,which was consistent with the water flow pattern influenced by the Baiyangdian water diversion project.Fluorescence spectroscopy analysis of the WEOM showed three prominent peaks with excitation/emission wavelengths similar to those of dissolved organic matter peaks.These peaks were potentially initial products of POM conversion into dissolved organic matter.Furthermore,the intensity of the WEOM fluorescence peak(total fluorescence peak intensity)was negatively correlated with the inorganic nitrogen concentration in water(p<0.01),while the intensity of the HA fluorescence peak showed a positive correlation with the inorganic nitrogen concentration(p<0.01).This suggested that exogenous organic matter inputs led to the diffusion of alkaline dissolved nitrogen from sediment intowater,while degradation processes of aquatic plant debris contributed to the decrease in inorganic nitrogen concentrations in the water column.These findings enhance our understanding of POM characteristics in shallow lakes and the role of POM in shallow lake ecosystems.展开更多
In modern engineering,enhancing boiling heat transfer efficiency is crucial for optimizing energy use and several industrial processes involving different types of materials.This study explores the enhancement of pool...In modern engineering,enhancing boiling heat transfer efficiency is crucial for optimizing energy use and several industrial processes involving different types of materials.This study explores the enhancement of pool boiling heat transfer potentially induced by combining perforated copper particles on a heated surface with a sodium dodecyl sulfate(SDS)surfactant in saturated deionized water.Experiments were conducted at standard atmospheric pressure,with heat flux ranging from 20 to 100 kW/m2.The heating surface,positioned below the layer of freely moving copper beads,allowed the particle layer to shift due to liquid convection and steam nucleation.The study reports on the influence of copper bead diameter(2,3,4,and 5 mm),particle quantity,arrangement,and SDS concentration(20,200,and 500 ppm).It is shown that the combination of 5 mm particles and a 500 ppm SDS concentration can yield a remarkable 139%improvement in heat transfer efficiency.As demonstrated by direct flow visualization,bubble formation occurs primarily in the gaps between the particles and the heated surface,with the presence of SDS reducing bubble size and accelerating bubble detachment.展开更多
Forest ecosystems function as the largest carbon(C)sink in terrestrial ecosystems,and nearly half of the C in forest ecosystems is stored in forest soils.However,the patterns of two main fractions of soil organic C,pa...Forest ecosystems function as the largest carbon(C)sink in terrestrial ecosystems,and nearly half of the C in forest ecosystems is stored in forest soils.However,the patterns of two main fractions of soil organic C,particulate organic C(POC)and mineral-associated organic C(MAOC),across various types of forest ecosystems remain unclear.In this study,soil samples were collected from depths of 0–100 cm at eight sites located between 18°and 48°north latitude in eastern China.The soil samples were then separated into particulate organic matter(POM)and mineral-associated organic matter(MAOM)based on particle size to analyze the distribution of C within each fraction.The results showed that the C stored as POC increased with latitude and decreased with soil depth.Specifically,28.1%,38.5%and 55.6%of C was stored as POC in the topsoil(0–30 cm)of tropical,subtropical and temperate forests,respectively,while 24.0%,24.3%and 38.9%of C was stored as POC in the subsoil(30–100 cm)of the corresponding forests,respectively.MAOC experienced a higher degree of microbial processing(indicated by differences in δ^(13)C,δ^(15)N and C:N between POM and MAOM)than POC,with a more pronounced difference in microbial processing between MAOC and POC at lower latitudes than at higher latitudes.These findings contribute to a comprehensive understanding of the characteristics of forest SOC and offer potential strategies for enhancing forest C sequestration.展开更多
Mesoscale eddies are widespread in the global ocean,significantly influencing the physical,chemical,and biological structures of water column.Based on the CTD data and suspended particulate matter(SPM)data collected a...Mesoscale eddies are widespread in the global ocean,significantly influencing the physical,chemical,and biological structures of water column.Based on the CTD data and suspended particulate matter(SPM)data collected at 36 hydrographic stations during a field cruise in southern Mozambique Channel,combined with satellite altimeter observations,we identified a series of mesoscale eddies traversing the Mozambique Channel.Our hydrographic measurements,coupled with in situ chlorophyll fluorescence data,reveal that these eddies significantly influence thermohaline structure and chlorophyll distribution,which in turn affects primary productivity and SPM concentrations in the upper ocean.The cyclonic eddies facilitate the upwelling of cold subsurface water,leading to a shallowing of the pycnocline and the creation of a low-temperature anomaly with variable salinity anomalies at different depths.Conversely,anticyclonic eddies submerge warm surface water,deepening the pycnocline,and resulting in a high-temperature anomaly accompanied by distinct salinity patterns.Significantly,a coastal anticyclonic eddy was observed to intercept terrestrial material from the Delagoa Bight,redirecting it west of 36°E.This study presents unique and quasi-synchronous CTD datasets capturing mesoscale eddy impacts,and provided valuable insights into SPM variability within the often-neglected southern Mozambique Channel.展开更多
基金the National Natural Science Foundation of China(Grants U1333201 and U1833116)。
文摘Fracture is a very common failure mode of the composite materials,which seriously affects the reliability and service-life of composite materials.Therefore,the study of the fracture behavior of the composite materials is of great significance and necessity,which demands an accurate and efficient numerical tool in general cases because of the complexity of the arising boundary-value or initial-boundary value problems.In this paper,a phase field model is adopted and applied for the numerical simulation of the crack nucleation and propagation in brittle linear elastic two-phase perforated/particulate composites under a quasi-static tensile loading.The phase field model can well describe the initiation,propagation and coalescence of the cracks without assuming the existence and the geometry of the initial cracks in advance.Its numerical implementation is realized within the framework of the finite element method(FEM).The accuracy and the efficiency of the present phase field model are verified by the available reference results in literature.In the numerical examples,we first study and discuss the influences of the hole/particle size on the crack propagation trajectory and the force-displacement curve.Then,the effects of the hole/particle shape on the crack initiation and propagation are investigated.Furthermore,numerical examples are presented and discussed to show the influences of the hole/particle location on the crack initiation and propagation characteristics.It will be demonstrated that the present phase field model is an efficient tool for the numerical simulation of the crack initiation and propagation problems in brittle two-phase composite materials,and the corresponding results may play an important role in predicting and preventing possible hazardous crack initiation and propagation in engineering applications.
文摘Fine particulate matter(particulate matter with a diameter of 2.5μm or less;PM2.5)causes millions of premature deaths globally1,but not all particles are equally harmful2-4.Current air-pollution control strategies,prioritizing PM2.5 mass reduction,have provided considerable health benefits but further refinements based on differences in the toxicity of various emission sources may provide greater benefits5-7.Here we integrated field measurements with air-quality modelling to assess the unequal toxicities of PM2.5 from various anthropogenic sources.
文摘A hydrodynamic model is used to study Kelvin-Helmholtz(KH)instability of the interface between two particle-laden inviscid fluids moving with two different uniform mean velocities.Explicit eigen-equation is derived to study the effect of suspended particles on the growth rate of KH instability.For dusty gases with negligible volume fraction of heavy particles and small particle-to-fluid mass ratio,the real and imaginary parts of leading-order asymptotic expression derived by the present model for the growth rate are shown to be identical to the earlier results derived by the classical Saffman model established for dusty gases.Beyond the known results,explicit leading-order asymptotic expressions for the effect of suspended particles on the growth rate are derived for several typical cases of basic interest.It is shown that the suspended particles can decrease or increase the growth rate of KH instability depending on the Stokes numbers of the particles and whether the particles are heavier or lighter than the clean fluid.Compared to the mass density of the clean fluid,our results based on leading-order asymptotic solutions show that heavier particles and lighter particles have opposite effects on the growth rate of KH instability,while the effect of neutrally buoyant particles on the growth rate of KH instability is negligible.
基金Supported by Jiaxing Science and Technology Plan Project,No.2024AD30035.
文摘BACKGROUND Pediatric perforated appendicitis(PPA)is a severe acute condition requiring surgical intervention and postoperative antibiotic therapy.Antibiotic selection differs significantly among pediatric centers,and an ideal postoperative antiinfective approach for PPA management has yet to be established.AIM To examine the spectrum of pathogenic bacteria in pediatric PPA and to summarize the postoperative experience with carbapenem(CBP)and cephalosporin(CPS)antibiotics.METHODS We retrospectively analyzed medical records of 65 children(43 boys,22 girls;mean age 6.92±3.41 years)with PPA who underwent surgery at our hospital between December 2019 and August 2022.Data were collected in September 2023.Based on postoperative antibiotic selection,patients were divided into CBP(32 cases)and CPS(33 cases)groups.Chi-square and T-tests compared recovery outcomes,while univariate and multivariate regression models identified independent factors affecting postoperative recovery.RESULTS There were no significant differences between the two groups in gender,age,weight,height,body mass index,baseline ear temperature,or heart rate(P>0.05).Escherichia coli(40.00%)and Pseudomonas aeruginosa(24.62%)were the most common pathogens in PPA.Postoperative analysis showed significantly shorter C-reactive protein(CRP)recovery times in the CPS group than in the CBP group[(6.18±1.84)vs(8.12±3.48)days,P=0.009].Univariate logistic regression indicated CPS selection(OR=0.32,95%CI:0.10-0.97,P=0.044)was significantly associated with a higher CRP recovery rate within 7 days.Multivariate analysis confirmed CPS selection(OR=3.49,95%CI:1.19-10.24,P=0.023)as an independent factor affecting CRP recovery within 7 days postoperatively.CONCLUSION The choice of CBP or CPS independently affects CRP recovery within 7 days.CBP offers no advantage over CPS in treating PPA,with CPS also demonstrating favorable clinical outcomes.
基金supported by the KIST Institutional Program(No.2E31700-22-P005)the KRIBB Research Initiative Program(No.KGM5322422)+1 种基金the Technology Innovation Program(No.20008826)funded by the Ministry of Trade,Industry and Energy(MOTIE,Republic of Korea)the National Research Foundation of Korea(NRF)(No.2022R1A2C1091865)funded by the Ministry of Science and ICT(MSIT,Republic of Korea)。
文摘The risk of exposure to particulate matter(PM)has been consistently highlighted globally owing to its detrimental effects on the respiratory and cardiovascular systems and in the development of lung cancer.Additionally,PM promotes cancer cell metastasis;however,research elucidating the precise mechanisms underlying this phenomenon and the strategies to inhibit it remains limited.The aim of this study was to elucidate the mechanism underlying PM-induced cancer metastasis and investigate the preventive role of ginsenoside Rg3.We treated macrophages with PM and confirmed an increase in the expression and secretion of chemokines,such as CCL3,CCL4,and CCL5.This effect was mediated by the MAPK and NF-kB pathways,and Rg3 inhibited this process by suppressing chemokine expression.These chemokines regulate the expression of epithelial-mesenchymal transition(EMT)markers in cancer cells,including Snail,Slug,ZEB1,and E-cadherin.The regulated EMT markers increased the motility of cancer cells in vitro.Furthermore,an increase in CCL3,CCL4,and CCL5 in the bronchoalveolar lavage fluid(BALF)was confirmed in a PM inhalation mouse model,and Rg3 reduced PM-induced cancer metastasis.The study findings suggest the potential use of Rg3 as a therapeutic agent to prevent PM-induced cancer metastasis.
基金supported by CACMS Innovation Fund(No CI2021A04611,CI2021A05106)Scientific and technological innovation project of China Academy of Chinese Medical Sciences(CI2021B015)+1 种基金Scientific and technological innovation project of China Academy of Chinese Medical Sciences(CI2023E001TS01)Fundamental research funds for the central public welfare research institutes(L2022035).
文摘Objective Emerging evidence suggests that exposure to ultrafine particulate matter(UPM,aerodynamic diameter<0.1μm)is associated with adverse cardiovascular events.Previous studies have found that Shenlian(SL)extract possesses anti-inflammatory and antiapoptotic properties and has a promising protective effect at all stages of the atherosclerotic disease process.In this study,we aimed to investigated whether SL improves UPM-aggravated myocardial ischemic injury by inhibiting inflammation and cell apoptosis.Methods We established a mouse model of MI+UPM.Echocardiographic measurement,measurement of myocardialinfarct size,biochemical analysis,enzyme-linked immunosorbent assay(ELISA),histopathological analysis,Transferase dUTP Nick End Labeling(TUNEL),Western blotting(WB),Polymerase Chain Reaction(PCR)and so on were used to explore the anti-inflammatory and antiapoptotic effects of SL in vivo and in vitro.Results SL treatment can attenuate UPM-induced cardiac dysfunction by improving left ventricular ejection fraction,fractional shortening,and decreasing cardiac infarction area.SL significantly reduced the levels of myocardial enzymes and attenuated UPM-induced morphological alterations.Moreover,SL significantly reduced expression levels of the inflammatory cytokines IL-6,TNF-α,and MCP-1.UPM further increased the infiltration of macrophages in myocardial tissue,whereas SL intervention reversed this phenomenon.UPM also triggered myocardial apoptosis,which was markedly attenuated by SL treatment.The results of in vitro experiments revealed that SL prevented cell damage caused by exposure to UPM combined with hypoxia by reducing the expression of the inflammatory factor NF-κB and inhibiting apoptosis in H9c2 cells.Conclusion Overall,both in vivo and in vitro experiments demonstrated that SL attenuated UPMaggravated myocardial ischemic injury by inhibiting inflammation and cell apoptosis.The mechanisms were related to the downregulation of macrophages infiltrating heart tissues.
基金supported by the Project of National Natural Science Foundation of China(22102095,21773153)the National Key Basic Research and Development Program(2018YFB1502001)financial support from the program of China Scholarships Council(No.202306230242).
文摘Particulate photocatalytic systems using nanoscale photocatalysts have been developed as an attractive promising route for solar energy utilization to achieve resource sustainability and environmental harmony.Dynamic obstacles are considered as the dominant inhibition for attaining satisfactory energy-conversion efficiency.The complexity in light absorption and carrier transfer behaviors has remained to be further clearly illuminated.It is challenging to trace the fast evolution of charge carriers involved in transfer migration and interfacial reactions within a micro–nano-single-particle photocatalyst,which requires spatiotemporal high resolution.In this review,comprehensive dynamic descriptions including irradiation field,carrier separation and transfer,and interfacial reaction processes have been elucidated and discussed.The corresponding mechanisms for revealing dynamic behaviors have been explained.In addition,numerical simulation and modeling methods have been illustrated for the description of the irradiation field.Experimental measurements and spatiotemporal characterizations have been clarified for the reflection of carrier behavior and probing detection of interfacial reactions.The representative applications have been introduced according to the reported advanced research works,and the relationships between mechanistic conclusions from variable spatiotemporal measurements and photocatalytic performance results in the specific photocatalytic reactions have been concluded.This review provides a collective perspective for the full understanding and thorough evaluation of the primary dynamic processes,which would be inspired for the improvement in designing solar-driven energy-conversion systems based on nanoscale particulate photocatalysts.
基金supported by the National Natural Science Foundation of China(No.82303169)the Key Research and Development Program of Shaanxi(No.2021ZDLSF02-06).
文摘Objective Several epidemiological observational studies have related particulate matter(PM)exposure to Inflammatory bowel disease(IBD),but many confounding factors make it difficult to draw causal links from observational studies.The objective of this study was to explore the causal association between PM_(2.5)exposure,its absorbance,and IBD.Methods We assessed the association of PM_(2.5)and PM_(2.5)absorbance with the two primary forms of IBD(Crohn’s disease[CD]and ulcerative colitis[UC])using Mendelian randomization(MR)to explore the causal relationship.We conducted two-sample MR analyses with aggregated data from the UK Biobank genome-wide association study.Single-nucleotide polymorphisms linked with PM_(2.5)concentrations or their absorbance were used as instrumental variables(IVs).We used inverse variance weighting(IVW)as the primary analytical approach and four other standard methods as supplementary analyses for quality control.Results The results of MR demonstrated that PM_(2.5)had an adverse influence on UC risk(odds ratio[OR]=1.010;95%confidence interval[CI]=1.001–1.019,P=0.020).Meanwhile,the results of IVW showed that PM_(2.5)absorbance was also causally associated with UC(OR=1.012;95%CI=1.004–1.019,P=0.002).We observed no causal relationship between PM_(2.5),PM_(2.5)absorbance,and CD.The results of sensitivity analysis indicated the absence of heterogeneity or pleiotropy,ensuring the reliability of MR results.Conclusion Based on two-sample MR analyses,there are potential positive causal relationships between PM_(2.5),PM_(2.5)absorbance,and UC.
基金supported by the National Natural Science Foundation of China(No.52274344)the Provincial Natural Science Foundation of Hunan(Nos.2022JJ30723 and 2023JJ20068)the Science and Technology Innovation Program of Hunan Province(2023RC3042).
文摘Controlling the adhesion of potentially corrosive substances from flue gas on grate bar is crucial for extending the operational lifespan of the equipment.The adhesive behaviour and mechanism of ultrafine particulate matters(UPM)throughout the sintering process were elucidated,and measures to control adhesion on grate bars were developed.Research findings indicated that a small quantity of UPM were found on grate bar during the initial sintering stages(ignition stage and middle stageⅠandⅡ).The main compositions of UPM were FexOy-rich,CaO-rich,and aluminium silicate-rich particles.In contrast,corrosive substances like alkali metal compounds were almost absent.These UPM adhered onto grate bar primarily through inertial impaction.When moving to the final sintering stages(middle stageⅢand temperature rising stage),many UPM rich in corrosive substances like NaCl and KCl adhered to the grate bar.These UPM adhered to grate bar through thermal diffusion and vortex deposition.Solid waste water washing technology can greatly decrease the quantity of UPM(rich in NaCl and KCl)on the grate bar due to vortex deposition and thermal diffusion,and it represents a potentially promising way to control adhesion and corrosion on grate bars.
基金supported by grants from the National Key Research and Development Program of China(No.2023YFC2705700)Guangdong Basic and Applied Basic Research Foundation(No.2024A1515012355)+1 种基金the Shenzhen Science and Technology Program(No.JCYJ20220530140609020)the Scientific Research Project of Wuhan Municipal Health Commission(No.WX21Q36).
文摘Objective The effects of prolonged exposure to persistently elevated atmospheric pollutants,commonly termed air pollution waves,on fertility intentions remain inadequately understood.This study aims to investigate the association between particulate matter(PM)exposure and fertility intentions.Methods In this nationwide cross-sectional study,we analyzed data from 10,747 participants(5496 females and 5251 males).PM waves were defined as periods lasting 3‒6 consecutive days during which the daily average concentrations exceeded China’s Ambient Air Quality Standards Grade II thresholds(PM2.5>75μg/m3 and PM10>150μg/m3).We employed multivariate logistic regression models to assess the association between exposure to PM waves and fertility intentions.Results Significant inverse associations were detected between exposure to PM2.5 wave events(characterized by concentrations exceeding 75μg/m3 for durations of 4‒6 days,P<0.05)and PM10 wave events(defined as concentrations exceeding 150μg/m3 for 6 consecutive days,P<0.05)and fertility intentions among females.In contrast,neither the PM2.5 wave nor the PM10 wave events demonstrated statistically significant correlations with fertility intentions in males(P>0.05 for all comparisons).The potentially susceptible subgroup was identified as females aged 20–30 years.Conclusions Our results provide the first evidence that PM2.5 and PM10 waves are associated with a reduction in female fertility intentions,offering critical insights for the development of public health policies and strategies aimed at individual protection.
基金supported by the National Key Research and Development Program of China(Nos.2023YFC3709500,2023YFC3709502 and 2022YFC3703400)the National Natural Science Foundation of China(No.42077191)+1 种基金the Fundamental Research Funds for the Central Universities(No.63233054)Tianjin Science and Technology Plan Project(No.18PTZWHZ00120).
文摘Serious fine particulate matter(PM_(2.5))pollution and rapidly increasing of ground-level ozone(O_(3))concentrations are concern issues in China.To achieve the comprehensive control of PM_(2.5)-O_(3) composite air pollution,exploring the common sources of PM_(2.5) and VOCs is essential.However,previous researches most carried out either PM_(2.5) or VOCs source appointment.In this study,we applied the ensemble source apportionment method to explore the impacts of common sources on PM_(2.5)-VOCs.Subsequently,we obtained the ensemble source impacts on O_(3) combining the extracted VOCs source profile and ozone formation potential.We found that the focus of environmentalmanagement and source control should be varied accordingly for different pollutants.Vehicle emission was the largest contributor(41%)to PM_(2.5)-VOCs,while industrial emission was the main common source(51%)to O_(3).The result showed that the O_(3) production rate is not only related to the VOCs emission,but also to the reactivity of VOCs.In addition,sensitivity tests revealed that temperature was the main factor affecting O_(3) formation.The study provides a framework to explore the common sources impact on PM_(2.5) and VOCs,which is benefit to address both PM_(2.5) and O_(3) mitigations.
文摘BACKGROUND Peptic ulcer disease(PUD)during pregnancy is extremely rare.Perforated peptic ulcer(PPU)during pregnancy has high maternal and fetal mortality.Symptoms attributed to pregnancy and other diagnoses make the diagnosis of preoperative PPU during pregnancy and puerperium challenging.AIM To identify predictive factors for early diagnosis and treatment,and the association between the diagnosis and maternal/neonatal outcomes.METHODS We searched PubMed,PubMed Central,and Google Scholar.Articles were analyzed following preferred reporting items for systematic reviews and metaanalysis.The search items included:‘ulcer’,‘PUD’,‘pregnancy’,‘puerperium’,‘postpartum’,‘gravid’,‘labor’,‘perforated ulcer’,‘stomach ulcer’,‘duodenal ulcer’,‘peptic ulcer’.Additional studies were extracted by reviewing reference lists of retrieved studies.We included all available full-text cases and case series.Demographic,clinical,obstetric,diagnostic and treatment parameters,and outcomes were collected.RESULTS Forty-three cases were collected.The mean maternal age was 30.9 years;36.6%were multiparous,and 63.4%were nulliparous or primiparous,with multiparas being older than primiparas.Peptic ulcer perforated in 44.2%of postpartum and 55.8%of antepartum patients.Antepartum PPU incidence increased with advancing gestation 2.3%in the first,7%in the second,and 46.5%in the third trimester.The most common clinical findings were abdominal tenderness(72.1%),rigidity(34.9%),and distension(48.8%).Duodenal ulcer predominated(76.7%).In 79.5%,the time from delivery to surgery or vice versa was>24 hours.The maternal mortality during the third trimester and postpartum was 10%and 31.6%,respectively.The trimester of presentation did not influence maternal mortality.The fetal mortality was 34.8%,with all deaths in gestational weeks 24-32.CONCLUSION Almost all patients with PPU in pregnancy or puerperium presented during the third trimester or the first 8 days postpartum.Early intervention reduced fetal mortality but without influence on maternal mortality.Maternal mortality did not depend on the use of X-ray imaging,perforation location,delivery type,trimester of presentation,and maternal age.Explorative laparoscopy was never performed during pregnancy,only postpartum.
基金supported by the National Natural Science Foundation of China under Grant Nos.12172205,11872236,and 12072183.
文摘Lithium ion batteries are important for new energy technologies and manufacturing systems.However,enhancing their capacity and cycling stability poses a significant challenge.This study proposes a novel method,i.e.,modifying current collectors with perforations,to address these issues.Lithium ion batteries with mechanically perforated current collectors are prepared and tested with charge/discharge cycles,revealing superior capacity as well as enhanced electrochemical stability over cycles.Impedance spectroscopy,scanning electron microscopy,and peeling tests are conducted to investigate the underlying mechanisms.Higher peel resistance,minimized interface cracking,and reduced electrical impedance are found in the perforated electrodes after cycles.Investigations indicate that the perforation holes on current collectors allow the active materials coating on the two sides of the current collector to bind together and,thus,lead to enhanced adhesion between the current collector and active layer.Mechanical simulation illustrates the role of perforated current collectors in curbing interface cracking during lithiation,while electrochemical simulation shows that the interfacial cracking hinders the diffusion of lithium ions,thereby increasing battery impedance and reducing the cyclic performance.This investigation reveals the potential of designing non-active battery components to enhance battery performance,advocating a nuanced approach to battery design emphasizing structural integrity and interface optimization.
文摘BACKGROUND Acute perforated cholecystitis(APC)is a serious complication of acute cholecystitis and is associated with significant morbidity and mortality,particularly in elderly or high-risk patients.While emergency cholecystectomy is the standard of care,it may not be feasible in unstable patients.Percutaneous transhepatic cholecystostomy(PTC)offers a minimally invasive alternative.AIM To evaluate the safety and effectiveness of PTC as an initial treatment modality for APC.METHODS We conducted a retrospective cohort study of patients diagnosed with APC between January 2017 and October 2022 at a single tertiary medical center.All patients underwent PTC as the initial intervention.Data collected included demographics,comorbidities,laboratory and imaging findings,complications,and clinical outcomes over a 24-month follow-up.Patients were stratified into two groups based on whether they subsequently underwent cholecystectomy.RESULTS Thirty patients underwent PTC for APC.Half of the patients(n=15)were stabilized and later underwent cholecystectomy;the remaining 15 were managed non-operatively.Patients in the non-surgical group were significantly older(87.1±6.2 years vs 76.1±7.4 years;P<0.001).Clinical improvement was observed in 61.4%of non-operated patients,with eventual drain removal or closure.Both groups demonstrated significant reductions in white blood cell count and C-reactive protein levels from admission to discharge.No significant differences were found in hospital stay or complication rates.During follow-up,three deaths occurred due to non-biliary causes.Only one patient required repeat drainage.CONCLUSION PTC is a safe and effective initial treatment for APC,particularly in elderly and comorbid patients for whom surgery poses excessive risk.It provides clinical stabilization and may serve either as a bridge to delayed cholecystectomy or as definitive management in selected patients.These findings support the broader use of PTC in the management of APC,although larger prospective studies are warranted.
基金supported by the National Natural Science Foundation of China(No.22176071)the Natural Science Foundation of Guangdong Province,China(No.2023A1515011879).
文摘Phthalate(PAEs)and Bisphenols(BPs)are plasticizers or additives in consumer products.They are typical endocrine disruptors,and potential health hazards may occur when people are exposed to them through inhalation,ingestion,and dermal contact.The current research on inhalation exposure pays limited attention to the particle distribution of PAEs and BPs in air,although particulate-bound pollutants are usually size-dependent.In this study,we discussed the size resolution of PAEs and BPs in air particles from city waste recycling plants.With paired urine samples of the workers,we also compared the internal and external exposure of PAEs and BPs and related potential health risks.The particulatebound PAEs and BPs concentrated mainly on coarse particles(Dp>2.1μm),with a bimodal distribution,and the peak particle size ranged from 9–10 to 4.7–5.85μm,respectively.Model calculation revealed that the deposition fluxes of PAEs in different respiratory regions followed the sequence of head airways(167±92.8 ng/h)>alveolar region(18.9±9.96 ng/h)>tracheobronchial region(9.20±5.22 ng/h),and the similar trends went for BPs.The daily intakes of PAEs and BPs via dust ingestion were higher than those fromrespiratory inhalation and dermal contact,with mean value of 96 and 0.88 ng/(kg-bw day),respectively.For internal exposure,the estimated daily intakes of PAEs for waste recycling workers were higher than those in e-waste dismantling workers,while the exposure levels of bisphenols were comparable.Overall,the potential health risks from inhalation exposure to particulate-bound PAEs and BPs were low.
基金support from the National Natural Science Foundation of China(No.12472072)the Fundamental Research Funds for the Central Universities,China.
文摘In this research,we introduce an innovative approach that combines the Continuum Damage Mechanics-Finite Element Method(CDM-FEM)with the Particle Swarm Optimization(PSO)-based technique,to predict the Medium-Low-Cycle Fatigue(MLCF)life of perforated structures.First,fatigue tests are carried out on three center-perforated structures,aiming to assess their fatigue life under various strengthening conditions.These tests reveal significant variations in fatigue life,accompanied by an examination of crack initiation through the analysis of fatigue fracture surfaces.Second,an innovative fatigue life prediction methodology is applied to perforated structures,which not only forecasts the initiation of fatigue cracks but also traces the progression of damage within these structures.It leverages an elastoplastic constitutive model integrated with damage and a damage evolution model under cyclic loads.The accuracy of this approach is validated by comparison with test results,falling within the three times error band.Finally,we explore the impact of various strengthening techniques,including cross-sectional reinforcement and cold expansion,on the fatigue life and damage evolution of these structures.This is achieved through an in-depth comparative analysis of both experimental data and computational predictions,which provides valuable insights into the behavior of perforated structures under fatigue conditions in practical applications.
基金supported by the National Key Research and Development Program of China(No.2022YFC3204003)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Wenqiang Zhang,No.2018058).
文摘Particulate organic matter(POM)plays a crucial role in the organic composition of lakes;however,its characteristics remain poorly understood.This study aimed to characterize the structure and composition of POM in Lake Baiyangdian usingmany kinds of techniques and investigate the effects of different extracted forms of POM on water quality.The suspended particulatematter in the lake had complex compositions,with its components primarily derived from aquatic plants and their detritus.The organic matter content of the suspended particulatematterwas relatively high(organic carbon content 27.29–145.94 g/kg)for the sum of three extractable states(water-extracted organic matter[WEOM],humic acid,and fulvic acid)and one stable bound state(humin).Spatial distribution analysis revealed that the POM content in the water increased from west to east,which was consistent with the water flow pattern influenced by the Baiyangdian water diversion project.Fluorescence spectroscopy analysis of the WEOM showed three prominent peaks with excitation/emission wavelengths similar to those of dissolved organic matter peaks.These peaks were potentially initial products of POM conversion into dissolved organic matter.Furthermore,the intensity of the WEOM fluorescence peak(total fluorescence peak intensity)was negatively correlated with the inorganic nitrogen concentration in water(p<0.01),while the intensity of the HA fluorescence peak showed a positive correlation with the inorganic nitrogen concentration(p<0.01).This suggested that exogenous organic matter inputs led to the diffusion of alkaline dissolved nitrogen from sediment intowater,while degradation processes of aquatic plant debris contributed to the decrease in inorganic nitrogen concentrations in the water column.These findings enhance our understanding of POM characteristics in shallow lakes and the role of POM in shallow lake ecosystems.
基金supported by the National Natural Science Foundation of China(Project No.52166004)the National Key Research and Development Program of China(Project No.2022YFC3902000)+2 种基金the Major Science and Technology Special Project of Yunnan Province(Project Nos.202202AG050007202202AG050002)the Research on the Development of Complete Sets of Technology for Extraction of Aromatic Substances from Tobacco Waste and Its Application,Applied Research-Pyrolysis Process Technology Research(2023QT01).
文摘In modern engineering,enhancing boiling heat transfer efficiency is crucial for optimizing energy use and several industrial processes involving different types of materials.This study explores the enhancement of pool boiling heat transfer potentially induced by combining perforated copper particles on a heated surface with a sodium dodecyl sulfate(SDS)surfactant in saturated deionized water.Experiments were conducted at standard atmospheric pressure,with heat flux ranging from 20 to 100 kW/m2.The heating surface,positioned below the layer of freely moving copper beads,allowed the particle layer to shift due to liquid convection and steam nucleation.The study reports on the influence of copper bead diameter(2,3,4,and 5 mm),particle quantity,arrangement,and SDS concentration(20,200,and 500 ppm).It is shown that the combination of 5 mm particles and a 500 ppm SDS concentration can yield a remarkable 139%improvement in heat transfer efficiency.As demonstrated by direct flow visualization,bubble formation occurs primarily in the gaps between the particles and the heated surface,with the presence of SDS reducing bubble size and accelerating bubble detachment.
基金financially supported by the National Natural Science Foundation of China(Nos.42141006,32425038 and 31988102).
文摘Forest ecosystems function as the largest carbon(C)sink in terrestrial ecosystems,and nearly half of the C in forest ecosystems is stored in forest soils.However,the patterns of two main fractions of soil organic C,particulate organic C(POC)and mineral-associated organic C(MAOC),across various types of forest ecosystems remain unclear.In this study,soil samples were collected from depths of 0–100 cm at eight sites located between 18°and 48°north latitude in eastern China.The soil samples were then separated into particulate organic matter(POM)and mineral-associated organic matter(MAOM)based on particle size to analyze the distribution of C within each fraction.The results showed that the C stored as POC increased with latitude and decreased with soil depth.Specifically,28.1%,38.5%and 55.6%of C was stored as POC in the topsoil(0–30 cm)of tropical,subtropical and temperate forests,respectively,while 24.0%,24.3%and 38.9%of C was stored as POC in the subsoil(30–100 cm)of the corresponding forests,respectively.MAOC experienced a higher degree of microbial processing(indicated by differences in δ^(13)C,δ^(15)N and C:N between POM and MAOM)than POC,with a more pronounced difference in microbial processing between MAOC and POC at lower latitudes than at higher latitudes.These findings contribute to a comprehensive understanding of the characteristics of forest SOC and offer potential strategies for enhancing forest C sequestration.
基金Supported by the Taishan Scholar Project of Shandong Province (Nos.TS20190913,tsqn202211054)the Fundamental Research Funds for the Central Universities (No.202241007)the Youth Innovation Team Program in Colleges and Universities of Shandong Province (No.2022KJ045)
文摘Mesoscale eddies are widespread in the global ocean,significantly influencing the physical,chemical,and biological structures of water column.Based on the CTD data and suspended particulate matter(SPM)data collected at 36 hydrographic stations during a field cruise in southern Mozambique Channel,combined with satellite altimeter observations,we identified a series of mesoscale eddies traversing the Mozambique Channel.Our hydrographic measurements,coupled with in situ chlorophyll fluorescence data,reveal that these eddies significantly influence thermohaline structure and chlorophyll distribution,which in turn affects primary productivity and SPM concentrations in the upper ocean.The cyclonic eddies facilitate the upwelling of cold subsurface water,leading to a shallowing of the pycnocline and the creation of a low-temperature anomaly with variable salinity anomalies at different depths.Conversely,anticyclonic eddies submerge warm surface water,deepening the pycnocline,and resulting in a high-temperature anomaly accompanied by distinct salinity patterns.Significantly,a coastal anticyclonic eddy was observed to intercept terrestrial material from the Delagoa Bight,redirecting it west of 36°E.This study presents unique and quasi-synchronous CTD datasets capturing mesoscale eddy impacts,and provided valuable insights into SPM variability within the often-neglected southern Mozambique Channel.
