目的:观察微创超薄与计算机辅助设计与制造(Computer Aided Design/Computer Aided Manufacturing,CAD/CAM)全瓷贴面修复前牙间隙的美学效果及对口腔菌群微环境的影响。方法:选取笔者医院2023年2月-2025年2月收治的94例(共135颗患牙)前...目的:观察微创超薄与计算机辅助设计与制造(Computer Aided Design/Computer Aided Manufacturing,CAD/CAM)全瓷贴面修复前牙间隙的美学效果及对口腔菌群微环境的影响。方法:选取笔者医院2023年2月-2025年2月收治的94例(共135颗患牙)前牙间隙患者为研究对象,采用随机数字表法分为两组。微创组47例(67颗患牙),采用微创超薄贴面修复;研究组47例(68颗患牙),采用CAD/CAM全瓷贴面修复。比较两组患者炎症反应、口腔菌群微环境、牙体美观度、修复效果及并发症发生率。结果:治疗后1个月,研究组肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)水平低于微创组(P<0.05);研究组牙卟啉单胞菌、具核梭杆菌、伴放线放线杆菌数量均低于微创组(P<0.05)。治疗后6个月,研究组红色美学指数评分(Pink Esthetic Score,PES)、改良版美国公共卫生服务(United States Public Health Service,USPHS)评分均高于微创组(P<0.05)。研究组并发症发生率低于微创组(P<0.05)。结论:CAD/CAM全瓷贴面修复前牙间隙修复效果和安全性良好,不仅对患者口腔菌群微环境影响较小,有利于减轻修复后炎症反应,还能明显提升牙体美观度。展开更多
The Lower Cambrian shales in the Sichuan Basin are considered one of the most promising shale gas resources in China.However,large-scale commercial development has not been achieved due to the relatively low and signi...The Lower Cambrian shales in the Sichuan Basin are considered one of the most promising shale gas resources in China.However,large-scale commercial development has not been achieved due to the relatively low and significantly variable gas contents of the drilled shales.Excitingly,the first major breakthrough in deep and ultra-deep Lower Cambrian shale gas was made recently in the well Z201 in the southern Sichuan Basin,with a gas yield exceeding 73×10^(4)m^(3)/d.The success of well Z201 provides a favorable geological case to reveal the distinct enrichment mechanism of deep and ultra-deep Lower Cambrian shale gas.In this study,at drilling site of well Z201,fresh shale core samples with different gasin-place contents were collected,and their geochemical,pore development and water-bearing characteristics were analyzed systematically.The results showed that the Z201 organic-rich shales reached an overmature stage,with an average Raman maturity of 3.70%.The Z201 shales with high gas-in-place contents are mainly located in the Qiongzhusi 12section and the upper Qiongzhusi 11section,with an average gas-in-place content of 10.08 cm^(3)/g.Compared to the shales with low gas-in-place contents,the shales with high gas-in-place contents exhibit higher total organic carbon contents,greater porosities,and lower water saturations,providing more effective pore spaces for shale gas enrichment.The effective pore structures of the deep and ultra-deep Lower Cambrian shales are the primary factors affecting their gas-in-place contents.Similar to the shales with high gas-in-place contents of well Z201,the deep and ultra-deep Lower Cambrian shales in the Mianyang-Changning intracratonic sag,especially in the Ziyang area,generally developed in deep-water shelf facies with high total organic carbon contents and thick sedimentary thickness,providing favorable conditions for the development and preservation of effective pores.Therefore,they are the most promising targets for Lower Cambrian shale gas exploration.展开更多
[Objectives]This study was conducted to investigate the effects of soil selenium(Se)content and exogenous Se supplementation on crop Se levels and provide a theoretical basis for the production of Se-enriched agricult...[Objectives]This study was conducted to investigate the effects of soil selenium(Se)content and exogenous Se supplementation on crop Se levels and provide a theoretical basis for the production of Se-enriched agricultural products.[Methods]Thirty three representative townships in Xiayi County,Ningling County,and Yongcheng City were selected.Soil Se content and its impact on wheat Se level were measured.The effects of exogenous Se supplementation on the Se content of crops including soybean,wheat,peanut,corn,sweet potato,grape,crisp pear and apple were also investigated.[Results]Showed that the soil Se content in 18 townships of Xiayi County ranged from 0.08 to 0.34 mg/kg,and Se-adequate areas,Se-deficient areas and severely Se-deficient areas accounted for 27.78%,66.67%,and 0.055%of the total,respectively.In Ningling County,the soil Se content in 11 townships ranged from 0.13 to 0.23 mg/kg,and among them,Se-adequate areas and Se-deficient areas comprised 18.18%and 81.82%,respectively.In Yongcheng City,the soil Se content in 4 townships ranged from 0.16 to 0.23 mg/kg,and Se-adequate areas and Se-deficient areas constituted 75.00%and 25.00%,respectively.The soil Se content in 33 townships across Xiayi County,Ningling County,and Yongcheng City ranged from 0.07 to 0.34 mg/kg.However,the Se levels in wheat from all 33 townships fail to meet the standard for Se-enriched agricultural products.It indicates that relying solely on soil Se supply is insufficient for crops to achieve the Se level required for Se-enriched agricultural products.Exogenous Se supplementation could effectively increase the Se content in soybean,wheat,peanut,corn,sweet potato,grape,crisp pear,and apple.Among these,soybean,wheat and peanut showed the highest Se levels after supplementation,all exceeding 0.10 mg/kg and meeting the industry standard for Se-enriched agricultural products.[Conclusions]The results of this study indicates that exogenous Se supplementation can serve as a key measure for producing Se-enriched agricultural products.展开更多
The significance of purine base content as an important nutrition indicator in foods arises from its potential to trigger hyperuricemia or gout via high-purine diet.Livestock meats,including pork,generally contain mod...The significance of purine base content as an important nutrition indicator in foods arises from its potential to trigger hyperuricemia or gout via high-purine diet.Livestock meats,including pork,generally contain moderate to high total purine content(TP).Recent research revealed substantial variations within and across pig breeds,implying genetic factors influencing this trait.Thus,this study aimed to unravel the genetic underpinnings governing purine base content in pork.The heritability estimates(h~2)for the four purine traits ranged from 0.14 to 0.35.A total of 14,36,19 and 25 quantitative trait loci(QTLs)were identified for guanine,adenine,hypoxanthine,and TP,respectively.Our comprehensive gene set enrichment analysis and gene network analysis revealed 15 promising candidate genes intricately interwoven within diverse purine metabolism pathways,such as purine ribonucleotide metabolic process,purine nucleotide metabolism and transport,and purine salvage pathways,all contributing to TP.Strikingly,most genetic variants significantly associated with TP displayed analogous effects on multiple purine bases.Two distinct and highly significant QTLs(P<10^(–12))emerged on Sus scrofa chromosome(SSC)12:one impacting guanine content and the other concurrently influencing adenine and hypoxanthine levels.The peak of the guanine QTL on SSC12 resided 1.1 kb downstream of the transmembrane protein 238 like(TMEM238L)gene and is encapsulated within a genomic segment characterized by the histone modification H3K27me3.Focused fine-mapping for the SSC12 QTL associated with adenine and hypoxanthine levels narrowed its scope to around 172 kb,encompassing the growth arrest specific 7(GAS7)and myosin heavy chain 13(MYH13)genes.However,the observed QTL effect was not attributed to any missense mutations within the two genes.This pioneering study unveils the genetic variations and candidate genes associated with purine content in livestock,laying a robust foundation for the selective breeding of pig lines with reduced purine base content.展开更多
Background:Investigators from low-,middle-,and high-income countries representing 6 continents contributed to the development of the Global Adolescent and Child Physical Activity Questionnaire(GAC-PAQ).The GAC-PAQ is ...Background:Investigators from low-,middle-,and high-income countries representing 6 continents contributed to the development of the Global Adolescent and Child Physical Activity Questionnaire(GAC-PAQ).The GAC-PAQ is designed to assess physical activity(PA)across all key domains(i.e.,school,chores,work/volunteering,transport,free time,outdoor time).It aimed to address multiple gaps in global PA surveillance(e.g.,omission of important PA domains,insufficient cultural adaptation,underrepresentation of rural areas in questionnaire validation studies).The purpose of this study was to assess the content validity of the GAC-PAQ among PA experts,8-to 17-year-olds,and one of their parents/guardians,and to discuss changes made to the questionnaire based on participants'feedback.Methods:Sixty-two experts in PA measurement and/or surveillance from 24 countries completed an online survey that included both closed-and open-ended questions about the content validity of the GAC-PAQ.The proportion of experts who agreed or strongly agreed with the items was calculated.Child-parent/guardian dyads from 15 countries(n=250;10-40 per country)participated in a structured cognitive interview to assess the clarity of the questions and response options,and they were encouraged to provide suggestions to improve clarity and facilitate completion of the questionnaire.Participating countries are:Aotearoa New Zealand,Brazil,Canada,China,Colombia,Czech Republic,India,Malawi,Mexico,Nepal,Nigeria,Spain,Sweden,Thailand,and the United Arab Emirates.Interviews were conducted in 13 different languages and structured by PA domain.Generic images were included to help participants in answering questions about PA intensity.Results:Expert agreement with the items for each domain exceeded 75%,and their qualitative feedback was used to revise the questionnaire before cognitive interviews.In general,participants found the questionnaire to be comprehensive.Adolescents(12-17 years)found it easier than children(8-11 years)to answer the questions.Several children struggled to answer questions about the duration and intensity of activities and/or concepts related to travel modes,active trips,and organized activities.Many parents/guardians were unsure about the frequency,duration,and intensity of their children's or adolescents'PA at school and/or recommended using more culturally relevant and appropriate images.Some participants misunderstood the concept of activities that“make you stronger”(intended to assess resistance activities)and/or struggled to differentiate between work,volunteering,and chores.Conclusion:Participants'feedback was used to develop a revised,simplified,and culturally adapted GAC-PAQ,which will be pilot-tested in all15 countries in an App that will include country-specific images and narration in local languages.Further research is needed to assess the reliability and validity of the revised GAC-PAQ.展开更多
Iron is an essential mineral element that plays important roles in plant growth,development,and human health.Peanut is a valuable source of iron for human nutrition.Improving iron content in peanut seeds can enhance b...Iron is an essential mineral element that plays important roles in plant growth,development,and human health.Peanut is a valuable source of iron for human nutrition.Improving iron content in peanut seeds can enhance both yield potential and nutritional value.In this study,the seed iron content of the 401 peanut germplasm accessions was estimated and substantial variation among these accessions was observed,ranging from 9.02 to 50.60 mg/kg.The seed iron content of valencia type accessions was significantly higher than that of Peruvian,Virginia,and Irregular types.Landraces showed the highest average iron content,followed by advanced cultivars,breeding lines and interspecific hybrid cultivars.Accessions with red seed coat exhibited significantly higher iron content compared with those with pink seed coat.Correlation analysis revealed that the seed iron content significantly negatively correlated with hundred seed weight(HSW),resveratrol and oleic acid.Eight accessions with high iron content were identified with an average iron content of 32.46 mg/kg,including two elite genotypes that Zh.h4280 showed high resveratrol levels(1057.34μg/kg)and Zh.h1976 exhibited large seeds(HSW over 90g).Association analysis identified four markers,one of which,AHGS2053 stably explained with 5.75%–5.84%phenotypic variation.Accessions containing the favorable allele AHGS2053-250bp exhibited significantly higher iron content compared to those with alternative alleles.The results provide valuable germplasm resources and associated markers for breeding programs targeting high iron content in peanuts.展开更多
Sichuan sausages with moisture contents of 40%,45%,50%,and 60% were stored at-18℃for durations of 0,2,4,6,and 8 weeks to evaluate the effect of moisture content on the quality attributes of Sichuan sausages during fr...Sichuan sausages with moisture contents of 40%,45%,50%,and 60% were stored at-18℃for durations of 0,2,4,6,and 8 weeks to evaluate the effect of moisture content on the quality attributes of Sichuan sausages during frozen storage.Product indicators including pH,colour,thiobarbituric acid reactive substances(TBARS),total volatile basic nitrogen(TVB-N),texture,electronic nose(E-nose)response,and water-holding capacity(thawing and cooking losses)were determined.The results indicated that as storage time increased,water retention in Sichuan sausages with different moisture contents decreased,while the degree of protein and lipid oxidation increased.This led to an increase in pH value,a colour shift from red-bright to grey-brown,and a deterioration in palatability.Among the samples,sausages with 50% moisture content exhibited the lowest thawing and cooking losses,indicating superior water-holding capacity.After 8 weeks of storage,TBARS and TVB-N values for the 50% moisture group were 19.5%and 2.5%lower,respectively,than those of the 40%and 45%moisture groups,indicating a reduced degree of oxidation.Furthermore,Sichuan sausage with 50%moisture content demonstrated an appropriate pH and colour difference,along with excellent texture and flavour,as evidenced by its higher toughness and satisfactory hardness.In conclusion,Sichuan sausage with 50% moisture content demonstrated the highest overall quality under frozen storage conditions.展开更多
This paper provides a systematic review of the histochemical localization,content characteristics,and influencing factors of saponins in Pseudostellaria heterophylla based on an extensive literature survey.It provides...This paper provides a systematic review of the histochemical localization,content characteristics,and influencing factors of saponins in Pseudostellaria heterophylla based on an extensive literature survey.It provides an in-depth analysis and summary of the effects of biological factors,environmental conditions,agronomic practices,processing methods,and continuous cropping obstacles on the synthesis of P.heterophylla saponins,as well as their underlying mechanisms.Based on identified gaps in the current literature,future research directions and prospects are proposed.The findings of this review offer valuable insights for advancing the understanding of the saponin biosynthesis mechanisms in P.heterophylla and for enhancing its quality.展开更多
Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study invest...Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study investigates their coupled effects using inclinedflume experiments and Discrete Element Method(DEM)simulations,covering three gravel sizes(2-5 mm,5-7 mm,7-10 mm)and four ice-content levels(0%,20%,40%,60%).Run-out distance,velocity,energy components,flow regime(Savage number),and segregation indexαwere quantified.Increasing ice content significantly enhances mobility,but with diminishing marginal effectiveness.From 0%to 40%ice content,run-out distance increases by 41%-86%,whereas the additional increase from 40%to 60%contributes only 12%-23%.Particle-size ratio strongly governs segregation intensity.Fine-gravel groups reach segregation indices ofα=0.92-0.98,indicating nearly complete upward migration of ice,whereas medium-gravel and coarse-gravel groups exhibit much weaker segregation,stabilizing atα=0.68-0.74 and 0.60-0.69.Savage number analyses reveal marked flow-regime transitions.At 0%ice content,Savage numbers reach 1.0-1.5,indicating a collisional regime.Increasing ice content suppresses collisionality,with Savage numbers decreasing to 0.03-0.07 at 60%ice content,consistent with dense-regime flow.DEM energy analyses confirm this regime shift:for finegravel mixtures,collision energy decreases by 14%,while sliding-friction energy increases by 33%as ice content increases from 0%to 60%,reflecting enhanced overburden effects imposed by upward-segregated ice layers.Medium and coarse mixtures exhibit weaker or opposite energy-shift patterns,demonstrating strong size dependence.Mechanistically,large particle-size contrasts promote strong segregation and form dense basal rock layers that increase basal friction and reduce mobility.When particle sizes are similar or ice content is high,segregation remains limited,allowing ice to mix into the basal layer,thereby reducing basal friction and enhancing mobility.This research quantitatively demonstrates how composition controls particle spatial distribution,flow regime,and energy dissipation,offering new mechanistic insights into the propagation and deposition behaviors of rock-ice avalanches and improving hazard assessment in vulnerable high-mountain regions.展开更多
This paper uses a complete washing and sieving method and accurately determines the clay mass contents in the loess deposits at the eight regions of Xianyang,Ili,Xi'an,Yan'an,Lvliang,Linfen,Xining,and Lanzhou ...This paper uses a complete washing and sieving method and accurately determines the clay mass contents in the loess deposits at the eight regions of Xianyang,Ili,Xi'an,Yan'an,Lvliang,Linfen,Xining,and Lanzhou in China.The method uses nylon cloth sieves with apertures from 0.0008 mm to 0.048 mm and standard steel sieves with apertures from 0.063 mm to 28 mm.It uses a rotary vibration machine to wash and sieve the loess into many clay,silt,sand,and gravel subgroups.The masses of the separated materials construct the complete mass-based particle size distribution(PSD)curves for the tested loesses.The results show that the Xianyang,Ili,Xi'an,Yan'an,Lvliang,Linfen,Xining,and Lanzhou loesses contain 65.28%,56.73%,56.76%,38.7%,31.78%,30.55%,30.1%,and 26.29%clay in mass.These clay contents are 1.3-14.9 times higher than the clay contents from the past publications for the eight types of loess.On the other hand,the plasticity data in past publications show that loess belongs to the clay type of soil.The clay contents in the publications are underestimated,which is caused by the inseparability of fine soils(or clay and silt mixture)from the existing PSD test methods.Macro-photographs,micro-photographs and SEM photographs present the separated materials of individual clay,silt,sand,and gravel particles.Particle sizes measured from the SEM photographs confirm their particle sizes within their size limits.The clay particles exhibit strong internal cohesion,while the silt,sand,and gravel particles are individual and non-cohesive.Atterberg limits test results further demonstrate the clay particles'high plasticity features and the silt particles'non-plasticity features.展开更多
Ketosis,a common metabolic disease during early lactation,is associated with high circulating levels ofβ-hydroxybutyrate(BHB).A portion of BHB that reaches the mammary gland is utilized as precursor for synthesis of ...Ketosis,a common metabolic disease during early lactation,is associated with high circulating levels ofβ-hydroxybutyrate(BHB).A portion of BHB that reaches the mammary gland is utilized as precursor for synthesis of fatty acids.Recent findings from nonruminant studies revealed that long chain fatty acyl-CoA ligase 4(ACSL4)could play a role in the regulation of cellular fatty acid metabolism,but the mechanisms by which ACSL4 mediates cellular lipid metabolism in response to BHB remains unclear.To achieve the aims,we conducted in vivo or in vitro analyses using bovine mammary gland biopsies and the immortalized mammary epithelial cell line(MAC-T).The in vivo study(n=6 cows per group)involved healthy cows(plasma BHB<0.60 mmol L^(–1))or ketotic cows(plasma BHB>2.0 mmol L^(–1))from which mammary gland tissue was biopsied.In vitro,MAC-T cells were challenged with 0,0.3,0.6,1.2,or 2.4 mmol L^(–1)BHB for 24 h to determine an optimal dose.Subsequently,MAC-T were incubated with 1.2 mmol L^(–1)BHB for 0,3,6,12,24,or 48 h.Furthermore,MAC-T cells were treated with small interfering ACSL4(siACSL4)for 24 h or ACSL4 overexpression plasmid(pcACSL4)for 36 h followed by a challenge with 1.2 mmol L^(–1)BHB for 24 h.Results showed that increased mRNA and protein abundance of lipogenic genes were linked to both mammary gland and in vitro challenge with BHB.BHB increased fatty acid content by activating ACSL4 expression,whereas inhibition of ACSL4 reduced BHB-induced reactive oxygen species(ROS)overproduction,enhancement of mitochondrial membrane potential,increase in fatty acid content,and lipid droplet accumulation.Furthermore,we also elevated ACSL4 expression with an overexpression plasmid to clarify its molecular role in response to BHB challenge.ACSL4 overexpression enhances BHB-induced lipid droplet accumulation by increased fatty acid content.Overall,the information showed that ACSL4 is crucial for the process of producing fatty acids from exogenous BHB.Reduced ACSL4 decreased fatty acid content and lipid droplet accumulation,improved mitochondrial function,directed more fatty acids towards oxidation.Thus,ACSL4 plays an important role in determining the fate of intracellular fatty acids and BHB in BMECs.展开更多
The Yellow Sea and Bohai Sea are among the global shelf seas susceptible to typhoons every year.Using observations and high-resolution numerical simulations,the current study investigates the dramatic changes in tempe...The Yellow Sea and Bohai Sea are among the global shelf seas susceptible to typhoons every year.Using observations and high-resolution numerical simulations,the current study investigates the dramatic changes in temperature and ocean heat content(OHC)of the Yellow Sea and Bohai Sea caused by Super Typhoon Maysak in early September 2020,which is representative of northward/northeastward-bypassing typhoons with centers just to the east of the study area.Temperature shows spatially coherent cooling in the upper mixed layer but warming in the subsurface layer in the majority of the offshore waters,due to wind-enhanced vertical mixing.In lower layers from the thermocline to sea bottom,temperature experiences significant warming in northeastern coastal waters of the Shandong Peninsula and in regions just off the Subei Shoal,but significant cooling in western coastal waters of the Korean Peninsula and southern coastal waters of the Shandong Peninsula.Significant temperature warming/cooling in lower layers is caused by coastal downwelling/upwelling.The total OHC of the study area decreases rapidly during Typhoon Maysak(2020)’s passage,which is generated comparably by latent heat loss at the sea surface and southward heat advection out of the study area at the southern boundary.Reduced shortwave radiation contributes positively but secondarily to the decreasing OHC during the first day.A numerical experiment suggests that Typhoon Maysak(2020)-induced OHC decline could have greatly affected the regional climate evolution in the following seasons.More studies are needed to fully understand the impacts of typhoons on regional climate changes in shelf seas at different time scales.展开更多
Slope units are divided according to the real topography and have clear geological characteristics,making them ideal units for evaluating the susceptibility to geological disasters.Based on the results of automaticall...Slope units are divided according to the real topography and have clear geological characteristics,making them ideal units for evaluating the susceptibility to geological disasters.Based on the results of automatically and manually corrected hydrological slope unit division,the Longhua District,Shenzhen City,Guangdong Province,was selected as the study area.A total of 15 influencing factors,namely Fluctuation,slope,slope aspect,curvature,topographic witness index(TWI),stream power index(SPI),topographic roughness index(TRI),annual average rainfall,distance to water system,engineering rock group,distance to fault,land use,normalized difference vegetation index(NDVI),nighttime light,and distance to road,were selected as evaluation indicators.The information volume model(IV)and random points were used to select non-geological disaster units,and then the random forest model(RF)was used to evaluate the susceptibility to geological disasters.The automatic slope unit and the hydrological slope unit were compared and analyzed in the random forest and information volume random forest models.The results show that the area under the curve(AUC)values of the automatic slope unit evaluation results are 0.931 for the IV-RF model and 0.716 for the RF model,which are 0.6%(IV-RF model)and 1.9%(RF model)higher than those for the hydrological slope unit.Based on a comparison of the evaluation methods based on the two types of slope units,the hydrological slope unit evaluation method based on manual correction is highly subjective,is complicated to operate,and has a low evaluation accuracy,whereas the evaluation method based on automatic slope unit division is efficient and accurate,is suitable for large-scale efficient geological disaster evaluation,and can better deal with the problem of geological disaster susceptibility evaluation.展开更多
As environmental concerns drive shifts in construction materials,rock is increasingly considered as an alternative to sand,reinforcing the importance of understanding its dynamic properties.This study investigates the...As environmental concerns drive shifts in construction materials,rock is increasingly considered as an alternative to sand,reinforcing the importance of understanding its dynamic properties.This study investigates the effect of water content on the small-strain dynamic properties of basalt samples using free-free laboratory testing.Free-free testing,which requires minimal equipment and preparation,provides an efficient and low-cost method for determining key dynamic properties,including three wave velocities(V_(s),V_(p),and V_(c)),material damping ratios,and Poisson's ratios.These properties are crucial for numerical modeling in earthquake analyses and geotechnical site characterization.The test consists of three components:(1)direct travel-time measurement,(2)torsional resonance testing,and(3)compressional resonance testing.A total of 20 rock samples were tested under systematically controlled water contents,ranging from fully dried to saturated,to quantify the effects on Poisson's ratio and material damping ratios.The results showed significant increases in both parameters with rising water content.The Poisson's ratio increased by up to 320%for aphanitic basalt and 150%for vesicular basalt,while the damping ratio rose up to 30-fold(D_(c,min))and 16-fold(D_(s,min)).These findings highlight the critical need to incorporate consideration of water content when characterizing dynamic rock properties for seismic and geotechnical analyses.The practical applicability of this research lies in improving in situ property interpretation and enhancing seismic design reliability by providing engineers with precise relationships between water content and dynamic rock behavior.展开更多
Urban forests are highly multifunctional and provide numerous ecological functions.Plant functional traits individually or jointly influence the ecological multifunctionality of tree species(TS-EMF)and can also modify...Urban forests are highly multifunctional and provide numerous ecological functions.Plant functional traits individually or jointly influence the ecological multifunctionality of tree species(TS-EMF)and can also modify TSEMF in response to environmental changes.However,there has been limited exploration of multitrait combinations for predicting TS-EMF across seasons and of trait thresholds that enhance TS-EMF.Here,for 10 dominant tree species in urban forests of Northeast China,14 traits were measured and four aboveground and three belowground ecological functions assessed in three seasons.Ecological functions and TS-EMF differed significantly throughout the seasons(P<0.05).Synergistic relationships were found between carbon sequestration and oxygen release,between cooling and humidification,and between organic carbon accumulation and nutrient cycling.Notably,aboveground multifunctionality played a leading role in TS-EMF.With seasonal changes,resource allocation shifted toward traits related to resource acquisition rather than conservation to maintain TS-EMF.The combination of traits that predicted TS-EMF varied by type,accounting for up to 66.45%of the variation.TS-EMF was primarily driven by leaf structure in spring and by nutrient accumulation in autumn.Leaf carbon content(LCC)consistently served as a stabilizing factor for predicting TS-EMF across seasons.At 36.5-36.8 mg g^(-1),LCC had its optimal effect on TS-EMF.Other traits in combination that positively influence total TS-EMF include leaf nitrogen content(3.43-3.45 mg g^(-1)),leaf phosphorus content(0.80-0.83 mg g^(-1)),and leaf area(65.86-68.43 cm^(2)).Within these specified trait thresholds,Morus alba and Quercus mongolica were identified as key species.These findings suggest that the trade-off between various ecological functions can be managed by altering plant traits across seasons.This approach could provide a theoretical foundation for enhancing the TS-EMF of urban forests through trait-based management,offering practical guidance for selecting tree species.展开更多
Extreme climate events(e.g.,heatwaves and droughts)are becoming increasingly frequent due to global climate change,which inevitably affects tree growth and various other ecological processes.While the impacts of droug...Extreme climate events(e.g.,heatwaves and droughts)are becoming increasingly frequent due to global climate change,which inevitably affects tree growth and various other ecological processes.While the impacts of droughts on these processes have been widely evaluated,the effects of heatwaves on tree growth and soil water content(SWC)remain poorly understood,particularly those related to thinning treatment.In this study,we evaluated the impacts of the 2021 Pacific Northwest Heatwave and thinning on forest growth and SWC,as well as assessed how thinning might mitigate the heatwave's impacts in lodgepole pine forests in British Columbia,Canada.We measured meteorological data(air temperature,rainfall,solar radiation(SR),relative humidity(RH),and wind speed(W_(s)),sap flow,SWC,soil temperature(T_(s)),and tree diameters at the breast height(DBH)during the growing season(June–September)in the control(27,000 stems·ha^(-1)),lightly thinned(4,500 stems·ha^(-1)),and heavily thinned(1,100 stems·ha^(-1))experimental plots from 2018 to 2024.We found that thinning persistently and significantly(p<0.05)increased individual tree growth,with the most pronounced effects in the heavily thinned stands.The 2021 Pacific Northwest Heatwave led to an exceptionally hot growing season,significantly(p<0.05)reducing forest growth and SWC across all plots.Forest growth recovered in 2022 in the thinned plots but remained suppressed in the unthinned plots,suggesting that thinning effectively mitigated the impact of the heatwave on forest growth,while the heatwave's impacts were persistent in the unthinned plots.Our study highlights that thinning is a practical management strategy for improving tree growth and supporting climate change adaptation to extreme climate events.展开更多
文摘目的:观察微创超薄与计算机辅助设计与制造(Computer Aided Design/Computer Aided Manufacturing,CAD/CAM)全瓷贴面修复前牙间隙的美学效果及对口腔菌群微环境的影响。方法:选取笔者医院2023年2月-2025年2月收治的94例(共135颗患牙)前牙间隙患者为研究对象,采用随机数字表法分为两组。微创组47例(67颗患牙),采用微创超薄贴面修复;研究组47例(68颗患牙),采用CAD/CAM全瓷贴面修复。比较两组患者炎症反应、口腔菌群微环境、牙体美观度、修复效果及并发症发生率。结果:治疗后1个月,研究组肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)水平低于微创组(P<0.05);研究组牙卟啉单胞菌、具核梭杆菌、伴放线放线杆菌数量均低于微创组(P<0.05)。治疗后6个月,研究组红色美学指数评分(Pink Esthetic Score,PES)、改良版美国公共卫生服务(United States Public Health Service,USPHS)评分均高于微创组(P<0.05)。研究组并发症发生率低于微创组(P<0.05)。结论:CAD/CAM全瓷贴面修复前牙间隙修复效果和安全性良好,不仅对患者口腔菌群微环境影响较小,有利于减轻修复后炎症反应,还能明显提升牙体美观度。
基金supported by the National Natural Science Foundation of China(41925014).
文摘The Lower Cambrian shales in the Sichuan Basin are considered one of the most promising shale gas resources in China.However,large-scale commercial development has not been achieved due to the relatively low and significantly variable gas contents of the drilled shales.Excitingly,the first major breakthrough in deep and ultra-deep Lower Cambrian shale gas was made recently in the well Z201 in the southern Sichuan Basin,with a gas yield exceeding 73×10^(4)m^(3)/d.The success of well Z201 provides a favorable geological case to reveal the distinct enrichment mechanism of deep and ultra-deep Lower Cambrian shale gas.In this study,at drilling site of well Z201,fresh shale core samples with different gasin-place contents were collected,and their geochemical,pore development and water-bearing characteristics were analyzed systematically.The results showed that the Z201 organic-rich shales reached an overmature stage,with an average Raman maturity of 3.70%.The Z201 shales with high gas-in-place contents are mainly located in the Qiongzhusi 12section and the upper Qiongzhusi 11section,with an average gas-in-place content of 10.08 cm^(3)/g.Compared to the shales with low gas-in-place contents,the shales with high gas-in-place contents exhibit higher total organic carbon contents,greater porosities,and lower water saturations,providing more effective pore spaces for shale gas enrichment.The effective pore structures of the deep and ultra-deep Lower Cambrian shales are the primary factors affecting their gas-in-place contents.Similar to the shales with high gas-in-place contents of well Z201,the deep and ultra-deep Lower Cambrian shales in the Mianyang-Changning intracratonic sag,especially in the Ziyang area,generally developed in deep-water shelf facies with high total organic carbon contents and thick sedimentary thickness,providing favorable conditions for the development and preservation of effective pores.Therefore,they are the most promising targets for Lower Cambrian shale gas exploration.
基金Supported by Shangqiu Science and Technology Project(20240036).
文摘[Objectives]This study was conducted to investigate the effects of soil selenium(Se)content and exogenous Se supplementation on crop Se levels and provide a theoretical basis for the production of Se-enriched agricultural products.[Methods]Thirty three representative townships in Xiayi County,Ningling County,and Yongcheng City were selected.Soil Se content and its impact on wheat Se level were measured.The effects of exogenous Se supplementation on the Se content of crops including soybean,wheat,peanut,corn,sweet potato,grape,crisp pear and apple were also investigated.[Results]Showed that the soil Se content in 18 townships of Xiayi County ranged from 0.08 to 0.34 mg/kg,and Se-adequate areas,Se-deficient areas and severely Se-deficient areas accounted for 27.78%,66.67%,and 0.055%of the total,respectively.In Ningling County,the soil Se content in 11 townships ranged from 0.13 to 0.23 mg/kg,and among them,Se-adequate areas and Se-deficient areas comprised 18.18%and 81.82%,respectively.In Yongcheng City,the soil Se content in 4 townships ranged from 0.16 to 0.23 mg/kg,and Se-adequate areas and Se-deficient areas constituted 75.00%and 25.00%,respectively.The soil Se content in 33 townships across Xiayi County,Ningling County,and Yongcheng City ranged from 0.07 to 0.34 mg/kg.However,the Se levels in wheat from all 33 townships fail to meet the standard for Se-enriched agricultural products.It indicates that relying solely on soil Se supply is insufficient for crops to achieve the Se level required for Se-enriched agricultural products.Exogenous Se supplementation could effectively increase the Se content in soybean,wheat,peanut,corn,sweet potato,grape,crisp pear,and apple.Among these,soybean,wheat and peanut showed the highest Se levels after supplementation,all exceeding 0.10 mg/kg and meeting the industry standard for Se-enriched agricultural products.[Conclusions]The results of this study indicates that exogenous Se supplementation can serve as a key measure for producing Se-enriched agricultural products.
基金support from the National Natural Science Foundation of China(32272855)STI 2030-Major Projects,China(2023ZD0404501)。
文摘The significance of purine base content as an important nutrition indicator in foods arises from its potential to trigger hyperuricemia or gout via high-purine diet.Livestock meats,including pork,generally contain moderate to high total purine content(TP).Recent research revealed substantial variations within and across pig breeds,implying genetic factors influencing this trait.Thus,this study aimed to unravel the genetic underpinnings governing purine base content in pork.The heritability estimates(h~2)for the four purine traits ranged from 0.14 to 0.35.A total of 14,36,19 and 25 quantitative trait loci(QTLs)were identified for guanine,adenine,hypoxanthine,and TP,respectively.Our comprehensive gene set enrichment analysis and gene network analysis revealed 15 promising candidate genes intricately interwoven within diverse purine metabolism pathways,such as purine ribonucleotide metabolic process,purine nucleotide metabolism and transport,and purine salvage pathways,all contributing to TP.Strikingly,most genetic variants significantly associated with TP displayed analogous effects on multiple purine bases.Two distinct and highly significant QTLs(P<10^(–12))emerged on Sus scrofa chromosome(SSC)12:one impacting guanine content and the other concurrently influencing adenine and hypoxanthine levels.The peak of the guanine QTL on SSC12 resided 1.1 kb downstream of the transmembrane protein 238 like(TMEM238L)gene and is encapsulated within a genomic segment characterized by the histone modification H3K27me3.Focused fine-mapping for the SSC12 QTL associated with adenine and hypoxanthine levels narrowed its scope to around 172 kb,encompassing the growth arrest specific 7(GAS7)and myosin heavy chain 13(MYH13)genes.However,the observed QTL effect was not attributed to any missense mutations within the two genes.This pioneering study unveils the genetic variations and candidate genes associated with purine content in livestock,laying a robust foundation for the selective breeding of pig lines with reduced purine base content.
基金supported by a Project Grant(Grant No.PJT183705)an Early Career Investigator Prize(Grant No.ECP 184184)from the Canadian Institutes of Health Research+7 种基金a Prentice Institute Research Affiliate Fund Grant from the Prentice Institute for Global Population and Economy(Grant No.G00004116)a Te Herenga Waka Victoria University of Wellington Division of Science Health Engineering Architecture and Design Innovation Faculty Strategic Research Grant(Grant No.FSRG-SHEADI-10724)The Thailand Physical Activity Knowledge Development Centre(TPAK)/Thai Health Promotion Foundation provided funding for the cognitive interviews and pilot study in Thailand(Grant No.66-P1-0473)The University Pablo de Olavide provided a scholarship for 2 undergraduate students working on the project(codes PPI2207 and PPI2308)In the Czech Republicthe study was supported by Palacky University IGA(Grant No.IGA_FTK_2023_017)supported by the Division of Intramural Research at the National Institute on Minority Health and Health Disparities of the National Institutes of Healthsupported by the Key Project of the National Philosophy and Social Science Foundation of China(23&ZD197)。
文摘Background:Investigators from low-,middle-,and high-income countries representing 6 continents contributed to the development of the Global Adolescent and Child Physical Activity Questionnaire(GAC-PAQ).The GAC-PAQ is designed to assess physical activity(PA)across all key domains(i.e.,school,chores,work/volunteering,transport,free time,outdoor time).It aimed to address multiple gaps in global PA surveillance(e.g.,omission of important PA domains,insufficient cultural adaptation,underrepresentation of rural areas in questionnaire validation studies).The purpose of this study was to assess the content validity of the GAC-PAQ among PA experts,8-to 17-year-olds,and one of their parents/guardians,and to discuss changes made to the questionnaire based on participants'feedback.Methods:Sixty-two experts in PA measurement and/or surveillance from 24 countries completed an online survey that included both closed-and open-ended questions about the content validity of the GAC-PAQ.The proportion of experts who agreed or strongly agreed with the items was calculated.Child-parent/guardian dyads from 15 countries(n=250;10-40 per country)participated in a structured cognitive interview to assess the clarity of the questions and response options,and they were encouraged to provide suggestions to improve clarity and facilitate completion of the questionnaire.Participating countries are:Aotearoa New Zealand,Brazil,Canada,China,Colombia,Czech Republic,India,Malawi,Mexico,Nepal,Nigeria,Spain,Sweden,Thailand,and the United Arab Emirates.Interviews were conducted in 13 different languages and structured by PA domain.Generic images were included to help participants in answering questions about PA intensity.Results:Expert agreement with the items for each domain exceeded 75%,and their qualitative feedback was used to revise the questionnaire before cognitive interviews.In general,participants found the questionnaire to be comprehensive.Adolescents(12-17 years)found it easier than children(8-11 years)to answer the questions.Several children struggled to answer questions about the duration and intensity of activities and/or concepts related to travel modes,active trips,and organized activities.Many parents/guardians were unsure about the frequency,duration,and intensity of their children's or adolescents'PA at school and/or recommended using more culturally relevant and appropriate images.Some participants misunderstood the concept of activities that“make you stronger”(intended to assess resistance activities)and/or struggled to differentiate between work,volunteering,and chores.Conclusion:Participants'feedback was used to develop a revised,simplified,and culturally adapted GAC-PAQ,which will be pilot-tested in all15 countries in an App that will include country-specific images and narration in local languages.Further research is needed to assess the reliability and validity of the revised GAC-PAQ.
基金supported by the National Key Research and Development Program of China(2023YFD1200200)the earmarked funds for CARS(No.CARS-13)+2 种基金the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2025-OCRI)the National Program for Crop Germplasm Protection of China(22250402)the National Crop Germplasm Resources Center(NCGRC-2025-036)。
文摘Iron is an essential mineral element that plays important roles in plant growth,development,and human health.Peanut is a valuable source of iron for human nutrition.Improving iron content in peanut seeds can enhance both yield potential and nutritional value.In this study,the seed iron content of the 401 peanut germplasm accessions was estimated and substantial variation among these accessions was observed,ranging from 9.02 to 50.60 mg/kg.The seed iron content of valencia type accessions was significantly higher than that of Peruvian,Virginia,and Irregular types.Landraces showed the highest average iron content,followed by advanced cultivars,breeding lines and interspecific hybrid cultivars.Accessions with red seed coat exhibited significantly higher iron content compared with those with pink seed coat.Correlation analysis revealed that the seed iron content significantly negatively correlated with hundred seed weight(HSW),resveratrol and oleic acid.Eight accessions with high iron content were identified with an average iron content of 32.46 mg/kg,including two elite genotypes that Zh.h4280 showed high resveratrol levels(1057.34μg/kg)and Zh.h1976 exhibited large seeds(HSW over 90g).Association analysis identified four markers,one of which,AHGS2053 stably explained with 5.75%–5.84%phenotypic variation.Accessions containing the favorable allele AHGS2053-250bp exhibited significantly higher iron content compared to those with alternative alleles.The results provide valuable germplasm resources and associated markers for breeding programs targeting high iron content in peanuts.
基金Supported by National Modern Agricultural Industry Technology System Sichuan Pig Innovation Team(SCCXTD-2026-8)Sichuan Science and Technology Program(2025ZYD0049)"Challenge and Leadership"Project for Key Core Technologies of Sui Ning in Sichuan(2025SNKBZ19).
文摘Sichuan sausages with moisture contents of 40%,45%,50%,and 60% were stored at-18℃for durations of 0,2,4,6,and 8 weeks to evaluate the effect of moisture content on the quality attributes of Sichuan sausages during frozen storage.Product indicators including pH,colour,thiobarbituric acid reactive substances(TBARS),total volatile basic nitrogen(TVB-N),texture,electronic nose(E-nose)response,and water-holding capacity(thawing and cooking losses)were determined.The results indicated that as storage time increased,water retention in Sichuan sausages with different moisture contents decreased,while the degree of protein and lipid oxidation increased.This led to an increase in pH value,a colour shift from red-bright to grey-brown,and a deterioration in palatability.Among the samples,sausages with 50% moisture content exhibited the lowest thawing and cooking losses,indicating superior water-holding capacity.After 8 weeks of storage,TBARS and TVB-N values for the 50% moisture group were 19.5%and 2.5%lower,respectively,than those of the 40%and 45%moisture groups,indicating a reduced degree of oxidation.Furthermore,Sichuan sausage with 50%moisture content demonstrated an appropriate pH and colour difference,along with excellent texture and flavour,as evidenced by its higher toughness and satisfactory hardness.In conclusion,Sichuan sausage with 50% moisture content demonstrated the highest overall quality under frozen storage conditions.
基金Supported by Open Fund Project of the Engineering Technology Research Center of Characteristic Medicinal Plants of Fujian(PP202003).
文摘This paper provides a systematic review of the histochemical localization,content characteristics,and influencing factors of saponins in Pseudostellaria heterophylla based on an extensive literature survey.It provides an in-depth analysis and summary of the effects of biological factors,environmental conditions,agronomic practices,processing methods,and continuous cropping obstacles on the synthesis of P.heterophylla saponins,as well as their underlying mechanisms.Based on identified gaps in the current literature,future research directions and prospects are proposed.The findings of this review offer valuable insights for advancing the understanding of the saponin biosynthesis mechanisms in P.heterophylla and for enhancing its quality.
基金funded by the Natural Science Foundation of China(Grants No 42277127)。
文摘Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study investigates their coupled effects using inclinedflume experiments and Discrete Element Method(DEM)simulations,covering three gravel sizes(2-5 mm,5-7 mm,7-10 mm)and four ice-content levels(0%,20%,40%,60%).Run-out distance,velocity,energy components,flow regime(Savage number),and segregation indexαwere quantified.Increasing ice content significantly enhances mobility,but with diminishing marginal effectiveness.From 0%to 40%ice content,run-out distance increases by 41%-86%,whereas the additional increase from 40%to 60%contributes only 12%-23%.Particle-size ratio strongly governs segregation intensity.Fine-gravel groups reach segregation indices ofα=0.92-0.98,indicating nearly complete upward migration of ice,whereas medium-gravel and coarse-gravel groups exhibit much weaker segregation,stabilizing atα=0.68-0.74 and 0.60-0.69.Savage number analyses reveal marked flow-regime transitions.At 0%ice content,Savage numbers reach 1.0-1.5,indicating a collisional regime.Increasing ice content suppresses collisionality,with Savage numbers decreasing to 0.03-0.07 at 60%ice content,consistent with dense-regime flow.DEM energy analyses confirm this regime shift:for finegravel mixtures,collision energy decreases by 14%,while sliding-friction energy increases by 33%as ice content increases from 0%to 60%,reflecting enhanced overburden effects imposed by upward-segregated ice layers.Medium and coarse mixtures exhibit weaker or opposite energy-shift patterns,demonstrating strong size dependence.Mechanistically,large particle-size contrasts promote strong segregation and form dense basal rock layers that increase basal friction and reduce mobility.When particle sizes are similar or ice content is high,segregation remains limited,allowing ice to mix into the basal layer,thereby reducing basal friction and enhancing mobility.This research quantitatively demonstrates how composition controls particle spatial distribution,flow regime,and energy dissipation,offering new mechanistic insights into the propagation and deposition behaviors of rock-ice avalanches and improving hazard assessment in vulnerable high-mountain regions.
基金supported by grants from the Research Grant Council of the Hong Kong Special Administra-tive Region,China(Project Nos.HKU 17207518 and R5037-18).
文摘This paper uses a complete washing and sieving method and accurately determines the clay mass contents in the loess deposits at the eight regions of Xianyang,Ili,Xi'an,Yan'an,Lvliang,Linfen,Xining,and Lanzhou in China.The method uses nylon cloth sieves with apertures from 0.0008 mm to 0.048 mm and standard steel sieves with apertures from 0.063 mm to 28 mm.It uses a rotary vibration machine to wash and sieve the loess into many clay,silt,sand,and gravel subgroups.The masses of the separated materials construct the complete mass-based particle size distribution(PSD)curves for the tested loesses.The results show that the Xianyang,Ili,Xi'an,Yan'an,Lvliang,Linfen,Xining,and Lanzhou loesses contain 65.28%,56.73%,56.76%,38.7%,31.78%,30.55%,30.1%,and 26.29%clay in mass.These clay contents are 1.3-14.9 times higher than the clay contents from the past publications for the eight types of loess.On the other hand,the plasticity data in past publications show that loess belongs to the clay type of soil.The clay contents in the publications are underestimated,which is caused by the inseparability of fine soils(or clay and silt mixture)from the existing PSD test methods.Macro-photographs,micro-photographs and SEM photographs present the separated materials of individual clay,silt,sand,and gravel particles.Particle sizes measured from the SEM photographs confirm their particle sizes within their size limits.The clay particles exhibit strong internal cohesion,while the silt,sand,and gravel particles are individual and non-cohesive.Atterberg limits test results further demonstrate the clay particles'high plasticity features and the silt particles'non-plasticity features.
基金supported by the grants from the National Key Research and Development Program of China(2023YFD1800804 and 2023YFD1801100)the National Natural Science Foundation of China(32172926)the China Agriculture Research System(CARS-36)。
文摘Ketosis,a common metabolic disease during early lactation,is associated with high circulating levels ofβ-hydroxybutyrate(BHB).A portion of BHB that reaches the mammary gland is utilized as precursor for synthesis of fatty acids.Recent findings from nonruminant studies revealed that long chain fatty acyl-CoA ligase 4(ACSL4)could play a role in the regulation of cellular fatty acid metabolism,but the mechanisms by which ACSL4 mediates cellular lipid metabolism in response to BHB remains unclear.To achieve the aims,we conducted in vivo or in vitro analyses using bovine mammary gland biopsies and the immortalized mammary epithelial cell line(MAC-T).The in vivo study(n=6 cows per group)involved healthy cows(plasma BHB<0.60 mmol L^(–1))or ketotic cows(plasma BHB>2.0 mmol L^(–1))from which mammary gland tissue was biopsied.In vitro,MAC-T cells were challenged with 0,0.3,0.6,1.2,or 2.4 mmol L^(–1)BHB for 24 h to determine an optimal dose.Subsequently,MAC-T were incubated with 1.2 mmol L^(–1)BHB for 0,3,6,12,24,or 48 h.Furthermore,MAC-T cells were treated with small interfering ACSL4(siACSL4)for 24 h or ACSL4 overexpression plasmid(pcACSL4)for 36 h followed by a challenge with 1.2 mmol L^(–1)BHB for 24 h.Results showed that increased mRNA and protein abundance of lipogenic genes were linked to both mammary gland and in vitro challenge with BHB.BHB increased fatty acid content by activating ACSL4 expression,whereas inhibition of ACSL4 reduced BHB-induced reactive oxygen species(ROS)overproduction,enhancement of mitochondrial membrane potential,increase in fatty acid content,and lipid droplet accumulation.Furthermore,we also elevated ACSL4 expression with an overexpression plasmid to clarify its molecular role in response to BHB challenge.ACSL4 overexpression enhances BHB-induced lipid droplet accumulation by increased fatty acid content.Overall,the information showed that ACSL4 is crucial for the process of producing fatty acids from exogenous BHB.Reduced ACSL4 decreased fatty acid content and lipid droplet accumulation,improved mitochondrial function,directed more fatty acids towards oxidation.Thus,ACSL4 plays an important role in determining the fate of intracellular fatty acids and BHB in BMECs.
基金supported by the National Key Research and Development Program of China(Grant Nos.2022YFF0801400 and 2021YFF0704002)the Shandong Provincial Natural Science Foundation(Grant No.ZR2024LQX002)the National Science Foundation of China(Grant No.42176016).
文摘The Yellow Sea and Bohai Sea are among the global shelf seas susceptible to typhoons every year.Using observations and high-resolution numerical simulations,the current study investigates the dramatic changes in temperature and ocean heat content(OHC)of the Yellow Sea and Bohai Sea caused by Super Typhoon Maysak in early September 2020,which is representative of northward/northeastward-bypassing typhoons with centers just to the east of the study area.Temperature shows spatially coherent cooling in the upper mixed layer but warming in the subsurface layer in the majority of the offshore waters,due to wind-enhanced vertical mixing.In lower layers from the thermocline to sea bottom,temperature experiences significant warming in northeastern coastal waters of the Shandong Peninsula and in regions just off the Subei Shoal,but significant cooling in western coastal waters of the Korean Peninsula and southern coastal waters of the Shandong Peninsula.Significant temperature warming/cooling in lower layers is caused by coastal downwelling/upwelling.The total OHC of the study area decreases rapidly during Typhoon Maysak(2020)’s passage,which is generated comparably by latent heat loss at the sea surface and southward heat advection out of the study area at the southern boundary.Reduced shortwave radiation contributes positively but secondarily to the decreasing OHC during the first day.A numerical experiment suggests that Typhoon Maysak(2020)-induced OHC decline could have greatly affected the regional climate evolution in the following seasons.More studies are needed to fully understand the impacts of typhoons on regional climate changes in shelf seas at different time scales.
文摘Slope units are divided according to the real topography and have clear geological characteristics,making them ideal units for evaluating the susceptibility to geological disasters.Based on the results of automatically and manually corrected hydrological slope unit division,the Longhua District,Shenzhen City,Guangdong Province,was selected as the study area.A total of 15 influencing factors,namely Fluctuation,slope,slope aspect,curvature,topographic witness index(TWI),stream power index(SPI),topographic roughness index(TRI),annual average rainfall,distance to water system,engineering rock group,distance to fault,land use,normalized difference vegetation index(NDVI),nighttime light,and distance to road,were selected as evaluation indicators.The information volume model(IV)and random points were used to select non-geological disaster units,and then the random forest model(RF)was used to evaluate the susceptibility to geological disasters.The automatic slope unit and the hydrological slope unit were compared and analyzed in the random forest and information volume random forest models.The results show that the area under the curve(AUC)values of the automatic slope unit evaluation results are 0.931 for the IV-RF model and 0.716 for the RF model,which are 0.6%(IV-RF model)and 1.9%(RF model)higher than those for the hydrological slope unit.Based on a comparison of the evaluation methods based on the two types of slope units,the hydrological slope unit evaluation method based on manual correction is highly subjective,is complicated to operate,and has a low evaluation accuracy,whereas the evaluation method based on automatic slope unit division is efficient and accurate,is suitable for large-scale efficient geological disaster evaluation,and can better deal with the problem of geological disaster susceptibility evaluation.
文摘As environmental concerns drive shifts in construction materials,rock is increasingly considered as an alternative to sand,reinforcing the importance of understanding its dynamic properties.This study investigates the effect of water content on the small-strain dynamic properties of basalt samples using free-free laboratory testing.Free-free testing,which requires minimal equipment and preparation,provides an efficient and low-cost method for determining key dynamic properties,including three wave velocities(V_(s),V_(p),and V_(c)),material damping ratios,and Poisson's ratios.These properties are crucial for numerical modeling in earthquake analyses and geotechnical site characterization.The test consists of three components:(1)direct travel-time measurement,(2)torsional resonance testing,and(3)compressional resonance testing.A total of 20 rock samples were tested under systematically controlled water contents,ranging from fully dried to saturated,to quantify the effects on Poisson's ratio and material damping ratios.The results showed significant increases in both parameters with rising water content.The Poisson's ratio increased by up to 320%for aphanitic basalt and 150%for vesicular basalt,while the damping ratio rose up to 30-fold(D_(c,min))and 16-fold(D_(s,min)).These findings highlight the critical need to incorporate consideration of water content when characterizing dynamic rock properties for seismic and geotechnical analyses.The practical applicability of this research lies in improving in situ property interpretation and enhancing seismic design reliability by providing engineers with precise relationships between water content and dynamic rock behavior.
基金supported by the National Natural Science Foundation(32130068,32271634,and 32071597)CAS Key Laboratory of Forest Ecology and Silviculture,Institute of Applied Ecology,Chinese Academy of Sciences(KLFES-2025)。
文摘Urban forests are highly multifunctional and provide numerous ecological functions.Plant functional traits individually or jointly influence the ecological multifunctionality of tree species(TS-EMF)and can also modify TSEMF in response to environmental changes.However,there has been limited exploration of multitrait combinations for predicting TS-EMF across seasons and of trait thresholds that enhance TS-EMF.Here,for 10 dominant tree species in urban forests of Northeast China,14 traits were measured and four aboveground and three belowground ecological functions assessed in three seasons.Ecological functions and TS-EMF differed significantly throughout the seasons(P<0.05).Synergistic relationships were found between carbon sequestration and oxygen release,between cooling and humidification,and between organic carbon accumulation and nutrient cycling.Notably,aboveground multifunctionality played a leading role in TS-EMF.With seasonal changes,resource allocation shifted toward traits related to resource acquisition rather than conservation to maintain TS-EMF.The combination of traits that predicted TS-EMF varied by type,accounting for up to 66.45%of the variation.TS-EMF was primarily driven by leaf structure in spring and by nutrient accumulation in autumn.Leaf carbon content(LCC)consistently served as a stabilizing factor for predicting TS-EMF across seasons.At 36.5-36.8 mg g^(-1),LCC had its optimal effect on TS-EMF.Other traits in combination that positively influence total TS-EMF include leaf nitrogen content(3.43-3.45 mg g^(-1)),leaf phosphorus content(0.80-0.83 mg g^(-1)),and leaf area(65.86-68.43 cm^(2)).Within these specified trait thresholds,Morus alba and Quercus mongolica were identified as key species.These findings suggest that the trade-off between various ecological functions can be managed by altering plant traits across seasons.This approach could provide a theoretical foundation for enhancing the TS-EMF of urban forests through trait-based management,offering practical guidance for selecting tree species.
基金supported by the British Columbia Ministry of Forces through long-term annual contracts with University of British Columbia(Okanagan)(No.RE25SIR242)the Natural Sciences and Engineering Research Council of Canada(NSERC),Discovery Grants Program(No.RGPIN-2021-02628)+1 种基金supported by the China Postdoctoral Science Foundation(No.2024M760387)Heilongjiang Postdoctoral Financial Assistance(No.LBH-Z24062)。
文摘Extreme climate events(e.g.,heatwaves and droughts)are becoming increasingly frequent due to global climate change,which inevitably affects tree growth and various other ecological processes.While the impacts of droughts on these processes have been widely evaluated,the effects of heatwaves on tree growth and soil water content(SWC)remain poorly understood,particularly those related to thinning treatment.In this study,we evaluated the impacts of the 2021 Pacific Northwest Heatwave and thinning on forest growth and SWC,as well as assessed how thinning might mitigate the heatwave's impacts in lodgepole pine forests in British Columbia,Canada.We measured meteorological data(air temperature,rainfall,solar radiation(SR),relative humidity(RH),and wind speed(W_(s)),sap flow,SWC,soil temperature(T_(s)),and tree diameters at the breast height(DBH)during the growing season(June–September)in the control(27,000 stems·ha^(-1)),lightly thinned(4,500 stems·ha^(-1)),and heavily thinned(1,100 stems·ha^(-1))experimental plots from 2018 to 2024.We found that thinning persistently and significantly(p<0.05)increased individual tree growth,with the most pronounced effects in the heavily thinned stands.The 2021 Pacific Northwest Heatwave led to an exceptionally hot growing season,significantly(p<0.05)reducing forest growth and SWC across all plots.Forest growth recovered in 2022 in the thinned plots but remained suppressed in the unthinned plots,suggesting that thinning effectively mitigated the impact of the heatwave on forest growth,while the heatwave's impacts were persistent in the unthinned plots.Our study highlights that thinning is a practical management strategy for improving tree growth and supporting climate change adaptation to extreme climate events.
