This paper deals with options on assets, such as stocks or indexes, which pay cash dividends. Pricing methods which consider discrete dividends are usually computationally expensive and become infeasible when one cons...This paper deals with options on assets, such as stocks or indexes, which pay cash dividends. Pricing methods which consider discrete dividends are usually computationally expensive and become infeasible when one considers multiple dividends paid during the option lifetime. This is the case of long-term options and options on indexes. The first purpose of this paper is to assess efficient and accurate numerical procedures which yield consistent prices for both European and American options when the underlying asset pays discrete dividends. The authors then analyze some methodologies to extract information on implied volatilities and dividends from quoted option prices. Implied dividends can also be computed using a modified version of the well-known put-call parity relationship. This technique is straightforward, nevertheless, its use is limited to European options, and when dealing with equities, most traded options are of American type. As an alternative, the numerical inversion of pricing methods, such as efficient interpolated binomial method, can be used. This paper applies different procedures to obtain implied volatilities and dividends of listed stocks of the Italian derivatives market （IDEM）.展开更多
This study examines the nexus between the good and bad volatilities of three technological revolutions—financial technology(FinTech),the Internet of Things,and artificial intelligence and technology—as well as the t...This study examines the nexus between the good and bad volatilities of three technological revolutions—financial technology(FinTech),the Internet of Things,and artificial intelligence and technology—as well as the two main conventional and Islamic cryptocurrency platforms,Bitcoin and Stellar,via three approaches:quantile cross-spectral coherence,quantile-VAR connectedness,and quantile-based non-linear causality-in-mean and variance analysis.The results are as follows:(1)under normal market conditions,in long-run horizons there is a significant positive cross-spectral relationship between FinTech's positive volatilities and Stellar’s negative volatilities;(2)Stellar’s negative and positive volatilities exhibit the highest net spillovers at the lower and upper tails,respectively;and(3)the quantile-based causality results indicate that Bitcoin’s good(bad)volatilities can lead to bad(good)volatilities in all three smart technologies operating between normal and bull market conditions.Moreover,the Bitcoin industry’s negative volatilities have a bilateral cause-and-effect relationship with FinTech’s positive volatilities.By analyzing the second moment,we found that Bitcoin's negative volatilities are the only cause variable that generates FinTech's good volatility in a unidirectional manner.As for Stellar,only bad volatilities have the potential to signal good volatilities for cutting-edge technologies in some middle quantiles,whereas good volatilities have no significant effect.Hence,the trade-off between Bitcoin and cutting-edge technologies,especially FinTech-related advancements,appear more broadly and randomly compared with the Stellar-innovative technologies nexus.The findings provide valuable insights for FinTech companies,blockchain developers,crypto-asset regulators,portfolio managers,and high-tech investors.展开更多
Auxin is a phytohormone that is critical for plant growth and development.The molecular mechanisms underlying auxin biosynthesis,transport,and signaling are well understood.However,the complex mechanism by which auxin...Auxin is a phytohormone that is critical for plant growth and development.The molecular mechanisms underlying auxin biosynthesis,transport,and signaling are well understood.However,the complex mechanism by which auxin regulates plant volatile biosynthesis has seldom been studied.A growing array of unique auxin-related plant volatiles have recently been discovered.This study comprehensively reviews recent findings on auxin and auxin-related genes and their roles in the formation of plant volatiles.This study highlights the implications of exogenous auxin application,genes involved in auxin signaling transduction,and hormonal crosstalk during volatile compound biosynthesis in plants.Plant hormones facilitate the integration of multiple volatile signals to enable specific and appropriate responses to environmental changes.This will improve our overall understanding of the role of auxins in plant volatile compound metabolic pathways.Recent studies have delineated the considerable advancements in elucidating the intricate methods by which plants employ auxin regulatory pathways to modulate the release of volatile chemicals during development and growth,along with prospective research paths.展开更多
During 13 to 16 January 2026,with 148 participating nations,rising global relevance and a marked increase in visitor quality,Heimtextil 2026 stood for stability and reliability in a volatile market environment.Once ag...During 13 to 16 January 2026,with 148 participating nations,rising global relevance and a marked increase in visitor quality,Heimtextil 2026 stood for stability and reliability in a volatile market environment.Once again,3,000 exhibitors from across the globe placed their trust in the industry’s central platform in Frankfurt,presenting current collections,materials and textile solutions for holistic interior design to approximately 47,000 buyers.Under the motto“Lead the Change”,Heimtextil brought evolving market dynamics,Artificial Intelligence(AI)and new business opportunities to life.The focus was on progressive design approaches,visionary talents,functional textiles and new hospitality concepts shaping the future of interior design.A tangible sense of confidence and a clear commitment to Heimtextil as a strong industry partner resonated throughout the exhibition halls.展开更多
This paper investigates the impact of market quality on volatility asymmetry of CSI 300 index futures by using short-and long-run causality measures proposed by Dufour et al.(2012).We use a high-frequency-based noise ...This paper investigates the impact of market quality on volatility asymmetry of CSI 300 index futures by using short-and long-run causality measures proposed by Dufour et al.(2012).We use a high-frequency-based noise variance estimator as the comprehensive proxy for market quality and find that volatility asymmetry is closely related to market quality.Specifically,in the period of poor market quality,the volatility asymmetry will vanish or even be reversed,which is mainly due to the sharp decline of the leverage effects.Moreover,the volatility feedback effect will be enhanced while the leverage effect will be weakened if the noise variance is taken into consideration in the causal analysis.Finally,we use other market quality indices as auxiliary variables in the robustness analysis and get similar results.展开更多
Furniture is identified as a vital volatile organic compound(VOC)emission source in the indoor environment.Leather has become the most common raw and auxiliary fabric material for upholstered furniture,particularly wi...Furniture is identified as a vital volatile organic compound(VOC)emission source in the indoor environment.Leather has become the most common raw and auxiliary fabric material for upholstered furniture,particularly with extensive consumption in sofas,due to its abundant resources and efficient functions.Despite being widely traded across the world,little research has been conducted on the VOCs released by leathermaterials and their health risk assessment in the indoor environment.Accordingly,this study investigated the VOC emissions of leather with different grades and the health risk of the inhalation exposure.Based on the ultra-fast gas phase electronic nose(EN)and GC-FID/Qtof,the substantial emissions of aliphatic aldehyde ketones(Aks),particularly hexanal,appear to be the cause of off-flavor in medium and low grade(MG and LG)sofa leathers.The health risk assessment indicated that leather materials barely pose non-carcinogenic and carcinogenic effects to residents.Given the abundance of VOC sources and the accumulation of health risks in the indoor environment,more stringent specifications concerning qualitative and quantitative content should be extended to provide VOC treatment basic for the manufacturing industry and obtain better indoor air quality.展开更多
Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ...Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ozone pollution as its major precursors.This study analyzed VOC characteristics of roadside,suburban,and rural sites in Hong Kong to investigate their compositions,concentrations,and source contributions.Herewe showthat the TVOC concentrations were 23.05±13.24,12.68±15.36,and 5.16±5.48 ppbv for roadside,suburban,and rural sites between May 2015 to June 2019,respectively.By using Positive Matrix Factorization(PMF)model,six sources were identified at the roadside site over five years:Liquefied petroleum gas(LPG)usage(33%–46%),gasoline evaporation(8%–31%),aged air mass(11%–28%),gasoline exhaust(5%–16%),diesel exhaust(2%–16%)and fuel filling(75–9%).Similarly,six sources were distinguished at the suburban site,including LPG usage(30%–33%),solvent usage(20%–26%),diesel exhaust(14%–26%),gasoline evaporation(8%–16%),aged air mass(4%–11%),and biogenic emissions(2%–5%).At the rural site,four sources were identified,including aged airmass(33%–51%),solvent usage(25%–30%),vehicular emissions(11%–28%),and biogenic emissions(6%–12%).The analysis further revealed that fuel filling and LPG usage were the primary contributors to OFP and OH reactivity at the roadside site,while solvent usage and biogenic emissions accounted for almost half of OFP and OH reactivity at the suburban and rural sites,respectively.These findings highlight the importance of identifying and characterizing VOC sources at different sites to help policymakers develop targeted measures for pollution mitigation in specific areas.展开更多
VOCs(Volatile organic compounds)exert a vital role in ozone and secondary organic aerosol production,necessitating investigations into their concentration,chemical characteristics,and source apportionment for the effe...VOCs(Volatile organic compounds)exert a vital role in ozone and secondary organic aerosol production,necessitating investigations into their concentration,chemical characteristics,and source apportionment for the effective implementation of measures aimed at preventing and controlling atmospheric pollution.FromJuly to October 2020,onlinemonitoringwas conducted in the main urban area of Shijiazhuang to collect data on VOCs and analyze their concentrations and reactivity.Additionally,the PMF(positive matrix factorization)method was utilized to identify the VOCs sources.Results indicated that the TVOCs(total VOCs)concentration was(96.7±63.4μg/m^3),with alkanes exhibiting the highest concentration of(36.1±26.4μg/m^3),followed by OVOCs(16.4±14.4μg/m^3).The key active components were alkenes and aromatics,among which xylene,propylene,toluene,propionaldehyde,acetaldehyde,ethylene,and styrene played crucial roles as reactive species.The sources derived from PMF analysis encompassed vehicle emissions,solvent and coating sources,combustion sources,industrial emissions sources,as well as plant sources,the contribution of which were 37.80%,27.93%,16.57%,15.24%,and 2.46%,respectively.Hence,reducing vehicular exhaust emissions and encouraging neighboring industries to adopt low-volatile organic solvents and coatings should be prioritized to mitigate VOCs levels.展开更多
Optoelectronic memristor is generating growing research interest for high efficient computing and sensing-memory applications.In this work,an optoelectronic memristor with Au/a-C:Te/Pt structure is developed.Synaptic ...Optoelectronic memristor is generating growing research interest for high efficient computing and sensing-memory applications.In this work,an optoelectronic memristor with Au/a-C:Te/Pt structure is developed.Synaptic functions,i.e.,excita-tory post-synaptic current and pair-pulse facilitation are successfully mimicked with the memristor under electrical and optical stimulations.More importantly,the device exhibited distinguishable response currents by adjusting 4-bit input electrical/opti-cal signals.A multi-mode reservoir computing(RC)system is constructed with the optoelectronic memristors to emulate human tactile-visual fusion recognition and an accuracy of 98.7%is achieved.The optoelectronic memristor provides potential for developing multi-mode RC system.展开更多
Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely limited.Here we conducted in situ field measurements of BVOCs...Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely limited.Here we conducted in situ field measurements of BVOCs emissions from representative mature evergreen trees by using dynamic branch enclosures at four altitude gradients(600-1690ma.s.l.)in the Nanling Mountains of southern China.Composition characteristics as well as seasonal and altitudinal variations were analyzed.Standardized emission rates and canopyscale emission factors were then calculated.Results showed that BVOCs emission intensities in the wet season were generally higher than those in the dry season.Monoterpenes were the dominant BVOCs emitted from most broad-leaved trees,accounting for over 70%of the total.Schima superba,Yushania basihirsuta and Altingia chinensis had relatively high emission intensities and secondary pollutant formation potentials.The localized emission factors of isoprene were comparable to the defaults in the Model of Emissions of Gases and Aerosols fromNature(MEGAN),while emission factors of monoterpenes and sesquiterpenes were 2 to 58 times of those in the model.Our results can be used to update the current BVOCs emission inventory in MEGAN,thereby reducing the uncertainties of BVOCs emission estimations in forested regions of southern China.展开更多
Edible oils derived from aquatic products are rich in lipids beneficial to human health.However,the volatile flavor characteristics of flesh oil and liver oil from Doederleinia berycoides remain unclear.In this study,...Edible oils derived from aquatic products are rich in lipids beneficial to human health.However,the volatile flavor characteristics of flesh oil and liver oil from Doederleinia berycoides remain unclear.In this study,flesh oil and liver oil were extracted from Doederleinia berycoides,revealing different fatty acid compositions and contents.Lipidomics analysis identified a total of 124 differential lipids between the flesh oil and liver oil,including 42 glycerophospholipids(GPs),33 glycerolipids(GLs),23 free fatty acids(FAs),13 sphingolipids(SPs),10 sterols(STs),and 3 prenol lipids(PRs).Analysis using HS-GC-IMS identified 12 key volatile compounds that significantly contributed to the distinct volatile flavors of the flesh and liver oils.The volatile flavors originated from these volatile compounds,which had different Relative Odor Activity Values(ROAVs).Further results from HSSPME-GC-MS showed that the volatile flavors of the flesh oil and liver oil were respectively attributed to 64 and 35 volatile compounds,each with unique key volatile compounds exhibiting different ROAVs.There were significant positive or negative correlations between 18 key differential lipids and 24 volatile compounds in both flesh oil and liver oil.Therefore,the complex lipid profiles are responsible for the unique volatile flavors of flesh oil and liver oil,and the differential lipids play a central role in their volatile flavor formation.These findings provide a foundation for understanding the volatile flavor differences in fish oils and hold promise for further exploration of the molecular mechanisms underlying oil volatile flavors.展开更多
Volatile aromatic aldehydes,including benzaldehyde(BzH),4-fluorobenzaldehyde(4-F-BzH),4-isobutylbenzaldehyde(4-iBu-BzH),3-trifluoromethylbenzaldehyde(3-CF_(3)-BzH),p-methoxybenzaldehyde(4-MeO-BzH),and o-trifluoromethy...Volatile aromatic aldehydes,including benzaldehyde(BzH),4-fluorobenzaldehyde(4-F-BzH),4-isobutylbenzaldehyde(4-iBu-BzH),3-trifluoromethylbenzaldehyde(3-CF_(3)-BzH),p-methoxybenzaldehyde(4-MeO-BzH),and o-trifluoromethylbenzaldehyde(2-CF_(3)-BzH),are crucial raw materials for the synthesis of various pesticides and pharmaceuticals[1].展开更多
Assessing the impact of anthropogenic volatile organic compounds(VOCs)on ozone(O_(3))formation is vital for themanagement of emission reduction and pollution control.Continuousmeasurement of O_(3)and the major precurs...Assessing the impact of anthropogenic volatile organic compounds(VOCs)on ozone(O_(3))formation is vital for themanagement of emission reduction and pollution control.Continuousmeasurement of O_(3)and the major precursorswas conducted in a typical light industrial city in the YRD region from 1 May to 25 July in 2021.Alkanes were the most abundant VOC group,contributing to 55.0%of TVOCs concentration(56.43±21.10 ppb).OVOCs,aromatics,halides,alkenes,and alkynes contributed 18.7%,9.6%,9.3%,5.2%and 1.9%,respectively.The observational site shifted from a typical VOC control regime to a mixed regime from May to July,which can be explained by the significant increase of RO_(x)production,resulting in the transition of environment from NOx saturation to radical saturation with respect to O_(3)production.The optimal O_(3)control strategy should be dynamically changed depending on the transition of control regime.Under NOx saturation condition,minimizing the proportion of NOx in reduction could lead to better achievement of O_(3)alleviation.Under mixed control regime,the cut percentage gets the top priority for the effectiveness of O_(3)control.Five VOCs sources were identified:temperature dependent source(28.1%),vehicular exhausts(19.9%),petrochemical industries(7.2%),solvent&gasoline usage(32.3%)and manufacturing industries(12.6%).The increase of temperature and radiation would enhance the evaporation related VOC emissions,resulting in the increase of VOC concentration and the change of RO_(x)circulation.Our results highlight determination of the optimal control strategies for O_(3)pollution in a typical YRD industrial city.展开更多
Tomato is an important economic crop all over the world.Volatile flavors in tomato fruit are key factors influencing consumer liking and commercial quality.However,the regulatory mechanism controlling the volatile fla...Tomato is an important economic crop all over the world.Volatile flavors in tomato fruit are key factors influencing consumer liking and commercial quality.However,the regulatory mechanism controlling the volatile flavors of tomatoes is still not clear.Here,we integrated the metabolome and transcriptome of the volatile flavors in tomato fruit to explore the regulatory mechanism of volatile flavor formation,using wild and cultivated tomatoes with significant differences in flavors.A total of 35 volatile flavor compounds were identified,based on the solid phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS).The content of the volatiles,affecting fruit flavor,significantly increased in the transition from breaker to red ripe fruit stage.Moreover,the total content of the volatiles in wild tomatoes was much higher than that in the cultivated tomatoes.The content variations of all volatile flavors were clustered into 10 groups by hierarchical cluster and Pearson coefficient correlation(PCC)analysis.The fruit transcriptome was also patterned into 10 groups,with significant variations both from the mature green to breaker fruit stage and from the breaker to red ripe fruit stage.Combining the metabolome and the transcriptome of the same developmental stage of fruits by co-expression analysis,we found that the expression level of 1182 genes was highly correlated with the content of volatile flavor compounds,thereby constructing two regulatory pathways of important volatile flavors.One pathway is tetrahydrothiazolidine N-hydroxylase(SlTNH1)-dependent,which is regulated by two transcription factors(TFs)from the bHLH and AP2/ERF families,controlling the synthesis of 2-isobutylthiazole in amino acid metabolism.The other is lipoxygenase(Sl LOX)-dependent,which is regulated by one TF from the HD-Zip family,controlling the synthesis of hexanal and(Z)-2-heptenal in fatty acid metabolism.Dual-luciferase assay confirmed the binding of b HLH and AP2/ERF to their structural genes.The findings of this study provide new insights into volatile flavor formation in tomato fruit,which can be useful for tomato flavor improvement.展开更多
New pollutants have become a significant concern in China's efforts toward ecological and environmental protection.Trichloromethane(TCM,CHCl_3),one of these new pollutants,is primarily released into soil and groun...New pollutants have become a significant concern in China's efforts toward ecological and environmental protection.Trichloromethane(TCM,CHCl_3),one of these new pollutants,is primarily released into soil and groundwater through various industrial activities.Over the past four decades,researchers have consistently focused on the remediation of TCM-contaminated soil and groundwater using microorganisms and iron-based materials,which hold significant potential for practical application.Understanding the remediation process and the factors influencing TCM degradation through these two methods is crucial for advancing both theoretical research and practical implementation.This review focuses on the degradation mechanisms of TCM in soil and groundwater by microorganisms and iron-based materials.It summarizes the active microorganisms and modified iron-based materials with high TCM degradation capabilities,discusses enhancement measures for both methods in the remediation process,and finally,outlines the challenges faced by these methods.The goal is to provide theoretical references for efficient remediation of TCM-contaminated soil and groundwater.展开更多
Ubiquitous contamination of the soil environment with volatile organic compounds(VOCs)has raised considerable concerns.However,there is still limited comprehensive surveying of soil VOCs on a national scale.Herein,65 ...Ubiquitous contamination of the soil environment with volatile organic compounds(VOCs)has raised considerable concerns.However,there is still limited comprehensive surveying of soil VOCs on a national scale.Herein,65 species of VOCswere simultaneously determined in surface soil samples collected from 63 chemical industrial parks(CIPs)across China.The results showed that the total VOC concentrations ranged from 7.15 to 1842 ng/g with a mean concentration of 326 ng/g(median:179 ng/g).Benzene homologs and halogenated hydrocarbons were identified as the dominant contaminant groups.Positive correlations between many VOC species indicated that these compounds probably originated from similar sources.Spatially,the hotspots of VOC pollution were located in eastern and southern China.Soils with higher clay content and a higher fraction of total organic carbon(TOC)content were significantly associated with higher soil VOC concentrations.Precipitation reduces the levels of highly water-soluble substances in surface soils.Both positive matrix factorization(PMF)and principal component analysis-multiple linear regression(PCA-MLR)identified a high proportion of industrial sources(PMF:59.2%and PCA-MLR:66.5%)and traffic emission sources(PMF:32.3%and PCA-MLR:33.5%).PMF,which had a higher R^(2) value(0.7892)than PCA-MLR(0.7683),was the preferred model for quantitative source analysis of soil VOCs.The health risk assessment indicated that the non-carcinogenic and carcinogenic risks of VOCs were at acceptable levels.Overall,this study provides valuable data on the occurrence of VOCs in soil from Chinese CIPs,which is essential for a comprehensive understanding of their environmental behavior.展开更多
The present study monitored bacterial succession,physicochemical properties,and volatile organic compounds(VOCs)changes in smoked chicken legs with modified atmosphere packaging(MAP,60% CO_(2) and 40%N_(2))during a 25...The present study monitored bacterial succession,physicochemical properties,and volatile organic compounds(VOCs)changes in smoked chicken legs with modified atmosphere packaging(MAP,60% CO_(2) and 40%N_(2))during a 25-day storage period at 4℃.After 15 days of storage,S erratia proteamaculans and Pseudomonas fragi became the predominant bacteria.Furthermore,physicochemical properties changed significantly,as evidenced by an increase in thiobarbituric acid reactive substances and b*(yellowness)value,and a decrease in hardness.A total of 65 VOCs were identified during storage.Correlation between bacterial succession and quality indicators(including VOCs and physicochemical properties)allowed the identification of 26 core dominant bacteria,including S.proteamaculans,Psychrobacter alimentarius,Pseudomonas putida,and Pseudomonas poae,which were positively related to spoilage VOCs(e.g.,1-octen-3-ol,1-pentanol,and 3-methyl-1-butanol)and could be defined as specific spoilage organisms(SSOs).The results of this study provide a systematic approach to predict SSOs in smoked chicken legs during storage,which can also provide a basis for product safety.展开更多
Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in China.In vine tea processing,a large amount of broken tea is produced,which has low commercial value.Methods:This study investigat...Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in China.In vine tea processing,a large amount of broken tea is produced,which has low commercial value.Methods:This study investigates the influence of different extraction methods(room temperature water extraction,boiling water extraction,ultrasonic-assisted room temperature water extraction,and ultrasonic-assisted boiling water extraction,referred to as room temperature water extraction(RE),boiling water extraction(BE),ultrasonic assistance at room temperature water extraction(URE),and ultrasonic assistance in boiling water extraction(UBE))on the yield,dihydromyricetin(DMY)content,free amino acid composition,volatile aroma components,and antioxidant properties of vine tea extracts.Results:A notable influence of extraction temperature on the yield of vine tea extracts(P<0.05),with BE yielding the highest at 43.13±0.26%,higher than that of RE(34.29±0.81%).Ultrasound-assisted extraction significantly increased the DMY content of the extracts(P<0.05),whereas DMY content in the RE extracts was 59.94±1.70%,that of URE reached 66.14±2.78%.Analysis revealed 17 amino acids,with L-serine and aspartic acid being the most abundant in the extracts,nevertheless ultrasound-assisted extraction reduced total free amino acid content.Gas chromatography-mass spectrometry analysis demonstrated an increase in the diversity and quantity of compounds in the vine tea water extracts obtained through ultrasonic-assisted extraction.Specifically,69 and 68 volatile compounds were found in URE and UBE extracts,which were higher than the number found in RE and BE extracts.In vitro,antioxidant activity assessments revealed varying antioxidant capacities among different extraction methods,with RE exhibiting the highest DPPH scavenging rate,URE leading in ABTS•+free radical scavenging,and BE demonstrating superior ferric ion reducing antioxidant activity.Conclusion:The findings suggest that extraction methods significantly influence the chemical composition and antioxidant properties of vine tea extracts.Ultrasonic-assisted extraction proved instrumental in elevating the DMY content in vine tea extracts,thereby enriching its flavor profile while maintaining its antioxidant properties.展开更多
To explore the effects of relative humidity(RH)on the quality of walnut kernels and establish a rapid,effective method/model for identifying their deterioration degree,walnut kernels were stored at 45℃for 90 days und...To explore the effects of relative humidity(RH)on the quality of walnut kernels and establish a rapid,effective method/model for identifying their deterioration degree,walnut kernels were stored at 45℃for 90 days under different RH conditions(35%,50%,65%and 80%)in this study.Every 15 days,changes in the kernels'color,acid values(AV),peroxide values(POV),fatty acid composition,contents of total phenols and soluble quinones,synchronous fluorescence spectra,and the compositions/contents of volatile organic compounds(VOCs)were analyzed.Partial least squares discriminant analysis(PLS-DA)and variable importance in projection(VIP)were used to conduct differential analysis of VOCs.The deterioration degree of walnut kernels was predicted using Pearson correlation analysis and a Back Propagation Neural Network(BPNN)model.The results showed that RH had a significant effect on the quality of walnut kernels,with 65%RH being the suitable storage condition for them.According to gas chromatography-mass spectrometry(GC-MS)analysis,a total of 40,34,23 and 17 characteristic VOCs were identified in the walnut kernels stored at RH of 35%,50%,65%and 80%,respectively.Among these VOCs,hexanal,1-octen-3-ol,4,5-dimethyltetrahydrofuran-2-one and DL-pantolactone were identified as potential volatile deterioration markers(PVDMs).Based on the POV limit standard of 1.0 mmol/kg for walnut oil,the threshold concentrations of these four PVDMs were 500-1000,50-100,10-15,and 30-60μg/100g,respectively.This research provides a reference for the quality monitoring and evaluation of walnut kernels during storage.展开更多
Cyclic volatile methyl siloxanes(cVMSs)are widely used in industrial and consumer products because of their thermal stability,low reactivity,and reduced surface tension[1].Their extensive use has resulted in environme...Cyclic volatile methyl siloxanes(cVMSs)are widely used in industrial and consumer products because of their thermal stability,low reactivity,and reduced surface tension[1].Their extensive use has resulted in environmental pollution globally.Recognized as very persistent and very bioaccumulative(vPvB),compounds such as octamethylcyclotetrasiloxane(D4),decamethylcyclopentasiloxane(D5),and dodecamethylcyclohexasiloxane(D6)are regulated in the European Union[2]and are monitored worldwide.展开更多
文摘This paper deals with options on assets, such as stocks or indexes, which pay cash dividends. Pricing methods which consider discrete dividends are usually computationally expensive and become infeasible when one considers multiple dividends paid during the option lifetime. This is the case of long-term options and options on indexes. The first purpose of this paper is to assess efficient and accurate numerical procedures which yield consistent prices for both European and American options when the underlying asset pays discrete dividends. The authors then analyze some methodologies to extract information on implied volatilities and dividends from quoted option prices. Implied dividends can also be computed using a modified version of the well-known put-call parity relationship. This technique is straightforward, nevertheless, its use is limited to European options, and when dealing with equities, most traded options are of American type. As an alternative, the numerical inversion of pricing methods, such as efficient interpolated binomial method, can be used. This paper applies different procedures to obtain implied volatilities and dividends of listed stocks of the Italian derivatives market （IDEM）.
文摘This study examines the nexus between the good and bad volatilities of three technological revolutions—financial technology(FinTech),the Internet of Things,and artificial intelligence and technology—as well as the two main conventional and Islamic cryptocurrency platforms,Bitcoin and Stellar,via three approaches:quantile cross-spectral coherence,quantile-VAR connectedness,and quantile-based non-linear causality-in-mean and variance analysis.The results are as follows:(1)under normal market conditions,in long-run horizons there is a significant positive cross-spectral relationship between FinTech's positive volatilities and Stellar’s negative volatilities;(2)Stellar’s negative and positive volatilities exhibit the highest net spillovers at the lower and upper tails,respectively;and(3)the quantile-based causality results indicate that Bitcoin’s good(bad)volatilities can lead to bad(good)volatilities in all three smart technologies operating between normal and bull market conditions.Moreover,the Bitcoin industry’s negative volatilities have a bilateral cause-and-effect relationship with FinTech’s positive volatilities.By analyzing the second moment,we found that Bitcoin's negative volatilities are the only cause variable that generates FinTech's good volatility in a unidirectional manner.As for Stellar,only bad volatilities have the potential to signal good volatilities for cutting-edge technologies in some middle quantiles,whereas good volatilities have no significant effect.Hence,the trade-off between Bitcoin and cutting-edge technologies,especially FinTech-related advancements,appear more broadly and randomly compared with the Stellar-innovative technologies nexus.The findings provide valuable insights for FinTech companies,blockchain developers,crypto-asset regulators,portfolio managers,and high-tech investors.
基金supported by the National Natural Science Foundation of China(Grant Nos.W2433051,32272663,32302520,and 32060655)National Key Research and Development Program(Grant No.2023YFD2300800)+3 种基金the Guangzhou Science and Technology Project(Grant No.202206010023)Yunnan Provincial Science and Technology Department Local Universities Joint Project(Grant No.202101BA070001-166)China Litchi and Longan Industry Technology Research System(CARS-32-08),Talent Introduction Project of Kunming University(Grant No.XJ20220003)Yunnan Provincial Natural Science Basic Research Fund General Program(Grant No.202501AT070058).
文摘Auxin is a phytohormone that is critical for plant growth and development.The molecular mechanisms underlying auxin biosynthesis,transport,and signaling are well understood.However,the complex mechanism by which auxin regulates plant volatile biosynthesis has seldom been studied.A growing array of unique auxin-related plant volatiles have recently been discovered.This study comprehensively reviews recent findings on auxin and auxin-related genes and their roles in the formation of plant volatiles.This study highlights the implications of exogenous auxin application,genes involved in auxin signaling transduction,and hormonal crosstalk during volatile compound biosynthesis in plants.Plant hormones facilitate the integration of multiple volatile signals to enable specific and appropriate responses to environmental changes.This will improve our overall understanding of the role of auxins in plant volatile compound metabolic pathways.Recent studies have delineated the considerable advancements in elucidating the intricate methods by which plants employ auxin regulatory pathways to modulate the release of volatile chemicals during development and growth,along with prospective research paths.
文摘During 13 to 16 January 2026,with 148 participating nations,rising global relevance and a marked increase in visitor quality,Heimtextil 2026 stood for stability and reliability in a volatile market environment.Once again,3,000 exhibitors from across the globe placed their trust in the industry’s central platform in Frankfurt,presenting current collections,materials and textile solutions for holistic interior design to approximately 47,000 buyers.Under the motto“Lead the Change”,Heimtextil brought evolving market dynamics,Artificial Intelligence(AI)and new business opportunities to life.The focus was on progressive design approaches,visionary talents,functional textiles and new hospitality concepts shaping the future of interior design.A tangible sense of confidence and a clear commitment to Heimtextil as a strong industry partner resonated throughout the exhibition halls.
基金The work was supported by the Humanities and Social Sciences grant of the Chinese Ministry of Education(No.17YJA790033).
文摘This paper investigates the impact of market quality on volatility asymmetry of CSI 300 index futures by using short-and long-run causality measures proposed by Dufour et al.(2012).We use a high-frequency-based noise variance estimator as the comprehensive proxy for market quality and find that volatility asymmetry is closely related to market quality.Specifically,in the period of poor market quality,the volatility asymmetry will vanish or even be reversed,which is mainly due to the sharp decline of the leverage effects.Moreover,the volatility feedback effect will be enhanced while the leverage effect will be weakened if the noise variance is taken into consideration in the causal analysis.Finally,we use other market quality indices as auxiliary variables in the robustness analysis and get similar results.
基金supported by the National Key Research and Development Program of China (No.2019YFC1904501).
文摘Furniture is identified as a vital volatile organic compound(VOC)emission source in the indoor environment.Leather has become the most common raw and auxiliary fabric material for upholstered furniture,particularly with extensive consumption in sofas,due to its abundant resources and efficient functions.Despite being widely traded across the world,little research has been conducted on the VOCs released by leathermaterials and their health risk assessment in the indoor environment.Accordingly,this study investigated the VOC emissions of leather with different grades and the health risk of the inhalation exposure.Based on the ultra-fast gas phase electronic nose(EN)and GC-FID/Qtof,the substantial emissions of aliphatic aldehyde ketones(Aks),particularly hexanal,appear to be the cause of off-flavor in medium and low grade(MG and LG)sofa leathers.The health risk assessment indicated that leather materials barely pose non-carcinogenic and carcinogenic effects to residents.Given the abundance of VOC sources and the accumulation of health risks in the indoor environment,more stringent specifications concerning qualitative and quantitative content should be extended to provide VOC treatment basic for the manufacturing industry and obtain better indoor air quality.
基金supported by Hong Kong Environment Protection Department(Quotation Ref.18-06532)Hong Kong Innovation and Technology Fund(ITS/193/20FP)Hong Kong Research Grants Council(No.26304921).
文摘Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ozone pollution as its major precursors.This study analyzed VOC characteristics of roadside,suburban,and rural sites in Hong Kong to investigate their compositions,concentrations,and source contributions.Herewe showthat the TVOC concentrations were 23.05±13.24,12.68±15.36,and 5.16±5.48 ppbv for roadside,suburban,and rural sites between May 2015 to June 2019,respectively.By using Positive Matrix Factorization(PMF)model,six sources were identified at the roadside site over five years:Liquefied petroleum gas(LPG)usage(33%–46%),gasoline evaporation(8%–31%),aged air mass(11%–28%),gasoline exhaust(5%–16%),diesel exhaust(2%–16%)and fuel filling(75–9%).Similarly,six sources were distinguished at the suburban site,including LPG usage(30%–33%),solvent usage(20%–26%),diesel exhaust(14%–26%),gasoline evaporation(8%–16%),aged air mass(4%–11%),and biogenic emissions(2%–5%).At the rural site,four sources were identified,including aged airmass(33%–51%),solvent usage(25%–30%),vehicular emissions(11%–28%),and biogenic emissions(6%–12%).The analysis further revealed that fuel filling and LPG usage were the primary contributors to OFP and OH reactivity at the roadside site,while solvent usage and biogenic emissions accounted for almost half of OFP and OH reactivity at the suburban and rural sites,respectively.These findings highlight the importance of identifying and characterizing VOC sources at different sites to help policymakers develop targeted measures for pollution mitigation in specific areas.
基金supported by the Natural Science Foundation of Hebei Province(Nos.D2019106042,D2020304038,and D2021106002)the National Natural Science Foundation of China(No.22276099)+1 种基金the State Environmental Protection Key Laboratory of Formation and Prevention of Urban Air Pollution Complex(No.2021080544)the Environmental Monitoring Research Foundation of Jiangsu Province(No.2211).
文摘VOCs(Volatile organic compounds)exert a vital role in ozone and secondary organic aerosol production,necessitating investigations into their concentration,chemical characteristics,and source apportionment for the effective implementation of measures aimed at preventing and controlling atmospheric pollution.FromJuly to October 2020,onlinemonitoringwas conducted in the main urban area of Shijiazhuang to collect data on VOCs and analyze their concentrations and reactivity.Additionally,the PMF(positive matrix factorization)method was utilized to identify the VOCs sources.Results indicated that the TVOCs(total VOCs)concentration was(96.7±63.4μg/m^3),with alkanes exhibiting the highest concentration of(36.1±26.4μg/m^3),followed by OVOCs(16.4±14.4μg/m^3).The key active components were alkenes and aromatics,among which xylene,propylene,toluene,propionaldehyde,acetaldehyde,ethylene,and styrene played crucial roles as reactive species.The sources derived from PMF analysis encompassed vehicle emissions,solvent and coating sources,combustion sources,industrial emissions sources,as well as plant sources,the contribution of which were 37.80%,27.93%,16.57%,15.24%,and 2.46%,respectively.Hence,reducing vehicular exhaust emissions and encouraging neighboring industries to adopt low-volatile organic solvents and coatings should be prioritized to mitigate VOCs levels.
基金supported by the"Science and Technology Development Plan Project of Jilin Province,China"(Grant No.20240101018JJ)the Fundamental Research Funds for the Central Universities(Grant No.2412023YQ004)the National Natural Science Foundation of China(Grant Nos.52072065,52272140,52372137,and U23A20568).
文摘Optoelectronic memristor is generating growing research interest for high efficient computing and sensing-memory applications.In this work,an optoelectronic memristor with Au/a-C:Te/Pt structure is developed.Synaptic functions,i.e.,excita-tory post-synaptic current and pair-pulse facilitation are successfully mimicked with the memristor under electrical and optical stimulations.More importantly,the device exhibited distinguishable response currents by adjusting 4-bit input electrical/opti-cal signals.A multi-mode reservoir computing(RC)system is constructed with the optoelectronic memristors to emulate human tactile-visual fusion recognition and an accuracy of 98.7%is achieved.The optoelectronic memristor provides potential for developing multi-mode RC system.
基金supported by the National Natural Science Foundation of China (NSFC)Projects (Nos.42205105,42121004,and 42077190)the Science and Technology Project of Shaoguan (No.210811164532141)+3 种基金the National Key R&D Program of China (2022YFC3700604)the Science and Technology Program of Guangzhou City (No.202201010400)the Fundamental Research Funds for the Central Universities (No.21622319)the Research Center of Low Carbon Economy for Guangzhou Region (No.22JNZS50).
文摘Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely limited.Here we conducted in situ field measurements of BVOCs emissions from representative mature evergreen trees by using dynamic branch enclosures at four altitude gradients(600-1690ma.s.l.)in the Nanling Mountains of southern China.Composition characteristics as well as seasonal and altitudinal variations were analyzed.Standardized emission rates and canopyscale emission factors were then calculated.Results showed that BVOCs emission intensities in the wet season were generally higher than those in the dry season.Monoterpenes were the dominant BVOCs emitted from most broad-leaved trees,accounting for over 70%of the total.Schima superba,Yushania basihirsuta and Altingia chinensis had relatively high emission intensities and secondary pollutant formation potentials.The localized emission factors of isoprene were comparable to the defaults in the Model of Emissions of Gases and Aerosols fromNature(MEGAN),while emission factors of monoterpenes and sesquiterpenes were 2 to 58 times of those in the model.Our results can be used to update the current BVOCs emission inventory in MEGAN,thereby reducing the uncertainties of BVOCs emission estimations in forested regions of southern China.
基金supported by the R&D Projects in Key Areas of Guangdong Province(2023B0202080003)the National Natural Science Foundation of China(32472272,32302135,32072291)+1 种基金“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2023C02006)Youth S&T Talent Support Programme of Guangdong Provincial Association for Science and Technology(SKXRC202401)。
文摘Edible oils derived from aquatic products are rich in lipids beneficial to human health.However,the volatile flavor characteristics of flesh oil and liver oil from Doederleinia berycoides remain unclear.In this study,flesh oil and liver oil were extracted from Doederleinia berycoides,revealing different fatty acid compositions and contents.Lipidomics analysis identified a total of 124 differential lipids between the flesh oil and liver oil,including 42 glycerophospholipids(GPs),33 glycerolipids(GLs),23 free fatty acids(FAs),13 sphingolipids(SPs),10 sterols(STs),and 3 prenol lipids(PRs).Analysis using HS-GC-IMS identified 12 key volatile compounds that significantly contributed to the distinct volatile flavors of the flesh and liver oils.The volatile flavors originated from these volatile compounds,which had different Relative Odor Activity Values(ROAVs).Further results from HSSPME-GC-MS showed that the volatile flavors of the flesh oil and liver oil were respectively attributed to 64 and 35 volatile compounds,each with unique key volatile compounds exhibiting different ROAVs.There were significant positive or negative correlations between 18 key differential lipids and 24 volatile compounds in both flesh oil and liver oil.Therefore,the complex lipid profiles are responsible for the unique volatile flavors of flesh oil and liver oil,and the differential lipids play a central role in their volatile flavor formation.These findings provide a foundation for understanding the volatile flavor differences in fish oils and hold promise for further exploration of the molecular mechanisms underlying oil volatile flavors.
基金supported by National Natural Science Foundation of China(22361031,22308260).
文摘Volatile aromatic aldehydes,including benzaldehyde(BzH),4-fluorobenzaldehyde(4-F-BzH),4-isobutylbenzaldehyde(4-iBu-BzH),3-trifluoromethylbenzaldehyde(3-CF_(3)-BzH),p-methoxybenzaldehyde(4-MeO-BzH),and o-trifluoromethylbenzaldehyde(2-CF_(3)-BzH),are crucial raw materials for the synthesis of various pesticides and pharmaceuticals[1].
基金supported by the National Natural Science Foundation of China(Nos.42005086,91844301,and 41805100)the National Key Research and Development Programof China(No.2022YFC3703500)+2 种基金China Postdoctoral Science Foundation(No.2023M733028)the Key Research and Development Program of Zhejiang Province(Nos.2021C03165 and 2022C03084)the Ecological and Environmental Scientific Research and Achievement Promotion Project of Zhejiang Province(No.2020HT0048).
文摘Assessing the impact of anthropogenic volatile organic compounds(VOCs)on ozone(O_(3))formation is vital for themanagement of emission reduction and pollution control.Continuousmeasurement of O_(3)and the major precursorswas conducted in a typical light industrial city in the YRD region from 1 May to 25 July in 2021.Alkanes were the most abundant VOC group,contributing to 55.0%of TVOCs concentration(56.43±21.10 ppb).OVOCs,aromatics,halides,alkenes,and alkynes contributed 18.7%,9.6%,9.3%,5.2%and 1.9%,respectively.The observational site shifted from a typical VOC control regime to a mixed regime from May to July,which can be explained by the significant increase of RO_(x)production,resulting in the transition of environment from NOx saturation to radical saturation with respect to O_(3)production.The optimal O_(3)control strategy should be dynamically changed depending on the transition of control regime.Under NOx saturation condition,minimizing the proportion of NOx in reduction could lead to better achievement of O_(3)alleviation.Under mixed control regime,the cut percentage gets the top priority for the effectiveness of O_(3)control.Five VOCs sources were identified:temperature dependent source(28.1%),vehicular exhausts(19.9%),petrochemical industries(7.2%),solvent&gasoline usage(32.3%)and manufacturing industries(12.6%).The increase of temperature and radiation would enhance the evaporation related VOC emissions,resulting in the increase of VOC concentration and the change of RO_(x)circulation.Our results highlight determination of the optimal control strategies for O_(3)pollution in a typical YRD industrial city.
基金supported by the National Natural Science Foundation of China(Grant Nos.32120103010,32002050)Beijing Joint Research Program for Germplasm Innovation and New Variety Breeding(Grant No.G20220628003-03)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences。
文摘Tomato is an important economic crop all over the world.Volatile flavors in tomato fruit are key factors influencing consumer liking and commercial quality.However,the regulatory mechanism controlling the volatile flavors of tomatoes is still not clear.Here,we integrated the metabolome and transcriptome of the volatile flavors in tomato fruit to explore the regulatory mechanism of volatile flavor formation,using wild and cultivated tomatoes with significant differences in flavors.A total of 35 volatile flavor compounds were identified,based on the solid phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS).The content of the volatiles,affecting fruit flavor,significantly increased in the transition from breaker to red ripe fruit stage.Moreover,the total content of the volatiles in wild tomatoes was much higher than that in the cultivated tomatoes.The content variations of all volatile flavors were clustered into 10 groups by hierarchical cluster and Pearson coefficient correlation(PCC)analysis.The fruit transcriptome was also patterned into 10 groups,with significant variations both from the mature green to breaker fruit stage and from the breaker to red ripe fruit stage.Combining the metabolome and the transcriptome of the same developmental stage of fruits by co-expression analysis,we found that the expression level of 1182 genes was highly correlated with the content of volatile flavor compounds,thereby constructing two regulatory pathways of important volatile flavors.One pathway is tetrahydrothiazolidine N-hydroxylase(SlTNH1)-dependent,which is regulated by two transcription factors(TFs)from the bHLH and AP2/ERF families,controlling the synthesis of 2-isobutylthiazole in amino acid metabolism.The other is lipoxygenase(Sl LOX)-dependent,which is regulated by one TF from the HD-Zip family,controlling the synthesis of hexanal and(Z)-2-heptenal in fatty acid metabolism.Dual-luciferase assay confirmed the binding of b HLH and AP2/ERF to their structural genes.The findings of this study provide new insights into volatile flavor formation in tomato fruit,which can be useful for tomato flavor improvement.
基金financially supported by the National Natural Science Foundation of China(Nos.42177239 and 41991330)the“14th Five Year Plan”of Independent Deployment Project of Nanjing Institute of Soil Research,Chinese Academy of Sciences(No.ISSASIP2213)。
文摘New pollutants have become a significant concern in China's efforts toward ecological and environmental protection.Trichloromethane(TCM,CHCl_3),one of these new pollutants,is primarily released into soil and groundwater through various industrial activities.Over the past four decades,researchers have consistently focused on the remediation of TCM-contaminated soil and groundwater using microorganisms and iron-based materials,which hold significant potential for practical application.Understanding the remediation process and the factors influencing TCM degradation through these two methods is crucial for advancing both theoretical research and practical implementation.This review focuses on the degradation mechanisms of TCM in soil and groundwater by microorganisms and iron-based materials.It summarizes the active microorganisms and modified iron-based materials with high TCM degradation capabilities,discusses enhancement measures for both methods in the remediation process,and finally,outlines the challenges faced by these methods.The goal is to provide theoretical references for efficient remediation of TCM-contaminated soil and groundwater.
基金supported by the Medical and Health Projects in Zhejiang Province(No.2022PY049)the Basic Scientific Research Project of Hangzhou Medical College(No.YS2021006)Key Discipline of Zhejiang Province in Public Health and Preventive Medicine(First Class,Category A),Hangzhou Medical College.
文摘Ubiquitous contamination of the soil environment with volatile organic compounds(VOCs)has raised considerable concerns.However,there is still limited comprehensive surveying of soil VOCs on a national scale.Herein,65 species of VOCswere simultaneously determined in surface soil samples collected from 63 chemical industrial parks(CIPs)across China.The results showed that the total VOC concentrations ranged from 7.15 to 1842 ng/g with a mean concentration of 326 ng/g(median:179 ng/g).Benzene homologs and halogenated hydrocarbons were identified as the dominant contaminant groups.Positive correlations between many VOC species indicated that these compounds probably originated from similar sources.Spatially,the hotspots of VOC pollution were located in eastern and southern China.Soils with higher clay content and a higher fraction of total organic carbon(TOC)content were significantly associated with higher soil VOC concentrations.Precipitation reduces the levels of highly water-soluble substances in surface soils.Both positive matrix factorization(PMF)and principal component analysis-multiple linear regression(PCA-MLR)identified a high proportion of industrial sources(PMF:59.2%and PCA-MLR:66.5%)and traffic emission sources(PMF:32.3%and PCA-MLR:33.5%).PMF,which had a higher R^(2) value(0.7892)than PCA-MLR(0.7683),was the preferred model for quantitative source analysis of soil VOCs.The health risk assessment indicated that the non-carcinogenic and carcinogenic risks of VOCs were at acceptable levels.Overall,this study provides valuable data on the occurrence of VOCs in soil from Chinese CIPs,which is essential for a comprehensive understanding of their environmental behavior.
基金funded by the National Natural Science Foundation of China(U22A20547)the Major Science and Technology Projects of Heilongjiang Province(2021ZX12B05 and 2020ZX07B02)。
文摘The present study monitored bacterial succession,physicochemical properties,and volatile organic compounds(VOCs)changes in smoked chicken legs with modified atmosphere packaging(MAP,60% CO_(2) and 40%N_(2))during a 25-day storage period at 4℃.After 15 days of storage,S erratia proteamaculans and Pseudomonas fragi became the predominant bacteria.Furthermore,physicochemical properties changed significantly,as evidenced by an increase in thiobarbituric acid reactive substances and b*(yellowness)value,and a decrease in hardness.A total of 65 VOCs were identified during storage.Correlation between bacterial succession and quality indicators(including VOCs and physicochemical properties)allowed the identification of 26 core dominant bacteria,including S.proteamaculans,Psychrobacter alimentarius,Pseudomonas putida,and Pseudomonas poae,which were positively related to spoilage VOCs(e.g.,1-octen-3-ol,1-pentanol,and 3-methyl-1-butanol)and could be defined as specific spoilage organisms(SSOs).The results of this study provide a systematic approach to predict SSOs in smoked chicken legs during storage,which can also provide a basis for product safety.
基金supported by the Key Research and Development Program of Hunan Province of China(No.2022NK2036)Xiangxi Prefecture Science and Technology Plan Project"School-Local Integration"Special Project(No.2022001)the scientific research project of Hunan Provincial Department of Education(No.22B0520).
文摘Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in China.In vine tea processing,a large amount of broken tea is produced,which has low commercial value.Methods:This study investigates the influence of different extraction methods(room temperature water extraction,boiling water extraction,ultrasonic-assisted room temperature water extraction,and ultrasonic-assisted boiling water extraction,referred to as room temperature water extraction(RE),boiling water extraction(BE),ultrasonic assistance at room temperature water extraction(URE),and ultrasonic assistance in boiling water extraction(UBE))on the yield,dihydromyricetin(DMY)content,free amino acid composition,volatile aroma components,and antioxidant properties of vine tea extracts.Results:A notable influence of extraction temperature on the yield of vine tea extracts(P<0.05),with BE yielding the highest at 43.13±0.26%,higher than that of RE(34.29±0.81%).Ultrasound-assisted extraction significantly increased the DMY content of the extracts(P<0.05),whereas DMY content in the RE extracts was 59.94±1.70%,that of URE reached 66.14±2.78%.Analysis revealed 17 amino acids,with L-serine and aspartic acid being the most abundant in the extracts,nevertheless ultrasound-assisted extraction reduced total free amino acid content.Gas chromatography-mass spectrometry analysis demonstrated an increase in the diversity and quantity of compounds in the vine tea water extracts obtained through ultrasonic-assisted extraction.Specifically,69 and 68 volatile compounds were found in URE and UBE extracts,which were higher than the number found in RE and BE extracts.In vitro,antioxidant activity assessments revealed varying antioxidant capacities among different extraction methods,with RE exhibiting the highest DPPH scavenging rate,URE leading in ABTS•+free radical scavenging,and BE demonstrating superior ferric ion reducing antioxidant activity.Conclusion:The findings suggest that extraction methods significantly influence the chemical composition and antioxidant properties of vine tea extracts.Ultrasonic-assisted extraction proved instrumental in elevating the DMY content in vine tea extracts,thereby enriching its flavor profile while maintaining its antioxidant properties.
基金Anhui Province Scientific and Technological Research Project(202423110050025)National Key Research and Development Project(2023YFD2100400)。
文摘To explore the effects of relative humidity(RH)on the quality of walnut kernels and establish a rapid,effective method/model for identifying their deterioration degree,walnut kernels were stored at 45℃for 90 days under different RH conditions(35%,50%,65%and 80%)in this study.Every 15 days,changes in the kernels'color,acid values(AV),peroxide values(POV),fatty acid composition,contents of total phenols and soluble quinones,synchronous fluorescence spectra,and the compositions/contents of volatile organic compounds(VOCs)were analyzed.Partial least squares discriminant analysis(PLS-DA)and variable importance in projection(VIP)were used to conduct differential analysis of VOCs.The deterioration degree of walnut kernels was predicted using Pearson correlation analysis and a Back Propagation Neural Network(BPNN)model.The results showed that RH had a significant effect on the quality of walnut kernels,with 65%RH being the suitable storage condition for them.According to gas chromatography-mass spectrometry(GC-MS)analysis,a total of 40,34,23 and 17 characteristic VOCs were identified in the walnut kernels stored at RH of 35%,50%,65%and 80%,respectively.Among these VOCs,hexanal,1-octen-3-ol,4,5-dimethyltetrahydrofuran-2-one and DL-pantolactone were identified as potential volatile deterioration markers(PVDMs).Based on the POV limit standard of 1.0 mmol/kg for walnut oil,the threshold concentrations of these four PVDMs were 500-1000,50-100,10-15,and 30-60μg/100g,respectively.This research provides a reference for the quality monitoring and evaluation of walnut kernels during storage.
基金supported by the Shanghai 3-year Public Health Action Plan(grant number:GWVI-11.1-39).
文摘Cyclic volatile methyl siloxanes(cVMSs)are widely used in industrial and consumer products because of their thermal stability,low reactivity,and reduced surface tension[1].Their extensive use has resulted in environmental pollution globally.Recognized as very persistent and very bioaccumulative(vPvB),compounds such as octamethylcyclotetrasiloxane(D4),decamethylcyclopentasiloxane(D5),and dodecamethylcyclohexasiloxane(D6)are regulated in the European Union[2]and are monitored worldwide.
