Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(...Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(III)nanoparticles with the most commonly identified FRB,Geobacter sulfurreducens PCA,remains poorly understood.Herein,we demonstrated that the synergistic role of outer membrane proteins and periplasmic proteins in the EET process for-Fe_(2)O_(3),Fe3O4,and𝛽α-FeOOH nanoparticles by construction of multiple gene knockout strain.oxpG(involved in the type II secretion system)and omcST(outer membrane c-type cytochrome)medi-ated pathways accounted for approximately 67%of the total reduction of𝛼α-Fe_(2)O_(3) nanoparticles.The residual reduction of𝛼α-Fe_(2)O_(3) nanoparticles in∆oxpG-omcST strain was likely caused by redox-active substances in cell supernatant.Conversely,the reduction of dissolved Fe(III)was almost unaffected in∆oxpG-omcST strain at the same concentration.However,at high dissolved Fe(III)concentration,the reduction significantly decreased due to the formation of Fe(III)nanoparticles,suggesting that this EET process is specific to Fe(III)nanoparticles.Overall,our study provided a more comprehensive understanding for the EET pathways between G.sulfurreducens PCA and different Fe(III)species,enriching our knowledge on the role of microorganisms in iron biogeochemical cycles and remediation strategies of pollutants.展开更多
Persistent toxic substances(PTS)represent a paramount environmental issue in the 21st century.Understanding the concentrations and forms of PTS in the environment is crucial for accurately assessing their environmenta...Persistent toxic substances(PTS)represent a paramount environmental issue in the 21st century.Understanding the concentrations and forms of PTS in the environment is crucial for accurately assessing their environmental health impacts.This article presents a concise overview of the components of PTS,pertinent environmental regulations,and conventional detection methodologies.Additionally,we offer an in-depth review of the principles,development,and practical applications of surface-enhanced Raman scattering(SERS)in environmental monitoring,emphasizing the advancements in detecting trace amounts of PTS in complex environmental matrices.Recent progress in enhancing SERS sensitivity,improving selectivity,and practical implementations are detailed,showcasing innovative materials and methods.Integrating SERS with advanced algorithms are highlighted as pivotal areas for future research.展开更多
Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and s...Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and speciation inmicroalgae remain unclear.Here,we used two strains of Chlamydomonas reinhardtii,namely CC-125(wild type)and CC-503(cell walldeficientmutant),to examine the algal growth,EPS synthesis,As adsorption,absorption and transformation under 10–1000μg/L As(III)and As(V)treatments for 96 h.In both strains,the As absorption increased after the EPS removal,but the growth,As adsorption,and transformation of C.reinhardtii declined.The CC-125 strain was more tolerant to As stress and more efficient in EPS production,As accumulation,and redox transformation than CC-503,irrespective of EPS presence or absence.Three-dimension excitation-emission matrix(3DEEM)and attenuated total reflectance infrared spectroscopy(ATR-IR)analyses showed that As was bound with functional groups in the EPS and cell wall,such as-COOH,NH and-OH in proteins,polysaccharides and amino acids.Together,this study demonstrated that EPS and cell wall acted as barriers to lower the As uptake by C.reinhardtii.However,the cell wall mutant strain wasmore susceptible to As toxicity due to lower EPS induction and higher As absorption.展开更多
Due to their persistence,bioaccumulation,and resistance to degradation,perfluorinated substances(PFASs)have significant impacts on the environment and human health.This study comprehensively analyzed and assessed the ...Due to their persistence,bioaccumulation,and resistance to degradation,perfluorinated substances(PFASs)have significant impacts on the environment and human health.This study comprehensively analyzed and assessed the occurrence characteristics,sources,and potential ecological risks of 13 PFASs in the Yangtze River.The results indicated that the concentrations ofΣPFASs range from 5.1 to 57.7 ng/L,with more severe pollution downstream and perfluorobutane sulfonate(PFBuS)being the main pollutant.ΣPFASs showed a positive correlation with total organic carbon and absorbance under the condition of UV wavelength 254 nm(UV_(254)),and a negative correlation with total dissolved solids.Positive matrix factorization model analysis revealed that the primary sources of PFASs in the study area are food packaging,the electroplating industry,and the manufacturing and processing of fluoropolymer-containing products.The total ecological risk value of PFASs indicated that the ecological risks to algae,invertebrates,and fish are negligible.The annual load of ΣPFASs in the Yangtze River was 39.00 t,with the highest concentrations of pollutants being PFBuS(26.41 t/year),perfluorobutanoic acid(6.47 t/year),and perfluorooctanoic acid(PFOA,3.19t/year).While PFASs have not yet posed a risk to aquatic organisms,the increase in the use of short-chain PFASs substitutes(C4-C7)due to the regulation of PFOA and perfluorooctane sulfonate highlights the need for continued monitoring of short-chain PFASs pollution.展开更多
Spider mites are significant pests in agricultural production.The increasing resistance of spider mites,along with environmental pollution and ecological imbalance caused by their control,is primarily attributed to th...Spider mites are significant pests in agricultural production.The increasing resistance of spider mites,along with environmental pollution and ecological imbalance caused by their control,is primarily attributed to the long-term use of chemical acaricides in agriculture.In contrast,bioactive substances of biological origin offer advantages such as wide availability,environmental friendliness,and low tendency to induce resistance,making them a research hotspot for spider mite control.This review summarizes recent advances in the use of plant-derived active compounds(exemplified by extracts from Veratrum rhizomes),RNA interference(RNAi)technology,and microorganism-derived active substances for controlling spider mites.These bioactive agents exert acaricidal effects by disrupting the nervous system,interfering with metabolic processes,or silencing key genes in mites,demonstrating favorable efficacy and considerable potential for development.However,challenges remain,including poor environmental stability,slow action,high production costs,and insufficient understanding of their effects on non-target organisms.Therefore,future research should focus on the screening and development of novel bioactive substances of biological origin,elucidation of their mechanisms of action,optimization of formulation technologies,and assessment of their ecological safety.These efforts will provide valuable insights for promoting the advancement of bioactive substances and supporting sustainable agricultural development.展开更多
The optical absorption of large molecular compounds HULIS(humic-like substances)can significantly impact the aerosol light absorption and radiative forcing,influencing cloud condensation nuclei formation and thus the ...The optical absorption of large molecular compounds HULIS(humic-like substances)can significantly impact the aerosol light absorption and radiative forcing,influencing cloud condensation nuclei formation and thus the climate and atmospheric environment.This study collected aerosol(PM_(2.5))samples from the summit of Mount Tai in North China to investigate the concentration,molecular composition,and optical properties of HULIS.The average concentration of HULIS in the PM_(2.5) in this study was 1.26±0.54μg/m^(3),comprising for 56%of the water-soluble organic carbon(WSOC),with levels lower than urban areas but higher than other mountainous regions.Mass spectrometry revealed that CHO and CHON components,with high aromaticity and phenolic groups,are major contributors to absorption and fluorescence.These results indicate that HULIS is mainly composed of lignin and proteins/amino sugars,derived from combustion and secondary formation,and possesses a high light absorption capacity(withMAE365(mass absorption efficiency)and AAE(A˚ngstrom exponent)indices of 0.62m^(2)/g and 4.99,respectively).Parallel factor analysis identified three fluorescence components of HULIS,with proportions of 60.8%for less oxygen humic-like substances,21.0%for high oxygen humic-like substances,and 18.2%for protein-like substances.Our study highlights the significance of the light-absorbing capacity and secondary formation of HULIS at Mount Tai,laying the groundwork for investigation into the climate effects,formation mechanisms,and sources of HULIS generation.展开更多
Fermented sour soup is a unique traditional sour food of the Miao and Dong ethnic groups in China.However,due to the commonly used traditional fermentation,the unstable fluctuation of microbial community often leads t...Fermented sour soup is a unique traditional sour food of the Miao and Dong ethnic groups in China.However,due to the commonly used traditional fermentation,the unstable fluctuation of microbial community often leads to some unpleasant inherent off-flavours in rice sour soup.In this study,the microbial composition and volatile flavour components of off-flavour and normal rice sour soup were examined by high-throughput sequencing and headspace solid-phase microextraction coupled with gas chromatography mass spectrometry.Then,based on Pearson correlation coefficients,the correlations between fungi and bacteria and those between core microorganisms and key volatile flavour components were investigated.The dominant fungal genera included Candida,Dekkera,Pichia,Rhizopus,and Issatchenkia,whereas the dominant bacterial genera included Lactobacillus,Pectinatus,Bifidobacterium,Pseudomonas,and Acetobacter.Compared to normal rice sour soup,off-flavoured rice sour soup contained the significantly increased relative abundance of Candida and the significantly decreased relative abundance of Dkkera.In addition,80 volatile flavour compounds detected in off-flavoured rice sour soup,mainly including esters,acids,and alcohols,were different from those detected in normal rice sour soup.Especially,some substances were only detected in off-flavoured rice sour soup,such as 1-hexanol(68-207μg/kg),butyric acid(20-92μg/kg)and heptanoic acid(12-45μg/kg),which might be the main source of off-flavours.These results provide new ideas and strategies of removing or abating odour from fermented rice sour soup.展开更多
Per-and polyfluoroalkyl substances(PFASs)can induce a range of adverse health effects,with the precise molecularmechanisms remaining elusive.Extracellular vesicles(EVs)have demonstrated their potential to elucidate un...Per-and polyfluoroalkyl substances(PFASs)can induce a range of adverse health effects,with the precise molecularmechanisms remaining elusive.Extracellular vesicles(EVs)have demonstrated their potential to elucidate unknown molecular mechanisms.Building upon the close alignment of their biological functions with the observed health effects of PFASs,this study innovatively focuses on proteomic insights from EVs into the molecular mechanisms underlying the systemic health effects of PFASs.Through rat exposure experiments and proteomics technology,it not only demonstrated the occurrence of PFASs in EVs but also revealed the alterations in the serum EVs and the expression of their protein cargos following mixed exposure to PFASs,leading to changes in related pathways.These changes encompass various biological processes,including proteasome activity,immune response,cytoskeletal organization,oxidative stress,cell signaling,and nervous system function.Particularly noteworthy is the uncovering of the activation of the proteasome pathway,highlighting significant key contributing proteins.These novel findings provide a new perspective for exploring the molecularmechanism underlying the systemic health effects of PFASs and offer reliable screening for potential biomarkers.Additionally,comparisons with serum confirmed the potential of serum EVs as biological responders and measurable endpoints for evaluating PFASs-induced toxicity.展开更多
Reclaimed water for irrigation or hydroponic cultivation provides exposure pathways for per-and polyfluoroalkyl substances(PFAS)to enter the human food chain.This study employed hydroponic methods to investigate the b...Reclaimed water for irrigation or hydroponic cultivation provides exposure pathways for per-and polyfluoroalkyl substances(PFAS)to enter the human food chain.This study employed hydroponic methods to investigate the behavior of legacy PFAS and emerging chlorinated polyfluoroalkyl ether sulfonic acids(Cl-PFESAs)in lettuce grown under environment-related exposure levels and assessed the human exposure risks from consuming contaminated lettuce.Overall,PFAS in lettuce were concentration-dependent,with long-chain PFAS tending to accumulate in roots and short-chain PFAS accumulating more in shoots.The enrichment of PFAS in lettuce was jointly influenced by their chain length and polar functional groups.Specifically,the root concentration factors(RCFs)of PFAS generally increased with increasing chain length,and RCF values of most perfluoroalkanesulfonic acids(PFSAs)were significantly higher than those of perfluoroalkyl carboxylic acids(PFCAs)with the same chain length(p<0.01),while the translocation factors(TFs)exhibited opposite trends.RCF values of perfluorooctane sulfonate(PFOS)and its alternatives,Cl-PFESAs,were ranked as follows:8:2 Cl-PFESA(mean:139)>6:2 Cl-PFESA(28.6)>PFOS(25.7),which was attributed to the increased molecular size and hydrophobicity resulting from the insertion of ether bonds and additional CF2 in 8:2 Cl-PFESA.Notably,TF value of 8:2 Cl-PFESA(mean:0.007)was the smallest among all PFAS,indicating 8:2 Cl-PFESA was difficult to transfer to nutritional compartments.Adults and children would exceed the most conservative health-based reference dose(RfD)by consuming approximately 15.9–148 g and 7.92–74.0 g of contaminated lettuce per day,implying high health risks.展开更多
Perfluoroalkyl and polyfluoroalkyl substances(PFASs)pollution with their toxicity,carcinogenicity,and persistence has been concerned worldwide.Research into novel materials for detecting and removing PFASs has increas...Perfluoroalkyl and polyfluoroalkyl substances(PFASs)pollution with their toxicity,carcinogenicity,and persistence has been concerned worldwide.Research into novel materials for detecting and removing PFASs has increased rapidly,particularly in regard to the emergence of well-characterized single-atom materials(SAMs).Owing to the high selectivity,high atom utilization,and abundant active sites of SAMs,these materials exhibit remarkable efficacy in the detection and removal of PFASs.In this work,recent advances in the synthesis of SAMs for the detection and removal PFASs are reviewed.In-depth discussions of the structure-activity relationship and reaction mechanisms have demonstrated the high efficiency,activity,and selectivity of SAMs for the detection,adsorption,and degradation of PFASs.To optimize the application of SAMs in PFASs remediation,this review comprehensively surveys SAMs applications for PFASs and analyzes potential design strategies based on synthesis methods and corresponding properties.Synthesis strategies such as wet-chemistry,which offer ease of operation and high potential for large-scale production,are recommended for the further exploration of specific SAMs for the detection and removal of PFASs.Finally,this review identifies the challenges and opportunities for development of SAMs for the detection and remediation of PFASs,providing an outlook on strategic goals for a green economy and sustainable development.展开更多
Mental health disorders have emerged as a critical global health challenge,profoundly impacting individuals,communities,and societies worldwide.The prevalence of mental health problems has been steadily increasing,wit...Mental health disorders have emerged as a critical global health challenge,profoundly impacting individuals,communities,and societies worldwide.The prevalence of mental health problems has been steadily increasing,with~1 in 8 people,equivalent to 970 million individuals suffering from a mental disorder in 2019(https://vizhub.healthdata.org/gbd-results).Anxiety and depressive disorders are predominant,contributing significantly to the burden of mental health issues,according to the World Health Organization.The COVID-19 pandemic has further exacerbated this situation.It led to a notable upsurge in anxiety and major depressive disorders in 2020.Estimates indicate a 26%rise in anxiety and a 28%increase in depression within that year(https://www.who.int/publications/i/item/WHO-2019-nCoVSci_Brief-Mental_health-2022.1)[1].展开更多
Previous studies have suggested that abnormal hepatobiliary system function may contribute to poor prognosis in patientswith acute coronary syndrome(ACS)and that abnormal hepatobiliary system function may be associate...Previous studies have suggested that abnormal hepatobiliary system function may contribute to poor prognosis in patientswith acute coronary syndrome(ACS)and that abnormal hepatobiliary system function may be associated with per-and polyfluoroalkyl substances(PFAS)exposure.However,there is limited evidence for this association in cardiovascular subpopulations,particularly in the ACS patients.Therefore,we performed this study to evaluate the association between plasma PFAS exposure and hepatobiliary system function biomarkers in patients with ACS.This study included 546 newly diagnosed ACS patients at the Second Hospital of Hebei Medical University,and data on 15 hepatobiliary system function biomarkers were obtained from medical records.Associations between single PFAS and hepatobiliary system function biomarkers were assessed using multiple linear regression models and restricted cubic spline model(RCS),and mixture effects were assessed using the Quantile g-computation model.The results showed that total bile acids(TBA)was negative associated with perfluorohexane sulfonic acid(PFHxS)(-7.69%,95%CI:-12.15%,-3.01%).According to the RCS model,linear associations were found between TBA and PFHxS(P for overall=0.003,P for non-linear=0.234).We also have observed the association between between PFAS congeners and liver enzyme such as aspartate aminotransferase(AST)and α-l-Fucosidase(AFU),but it was not statistically significant after correction.In addition,Our results also revealed an association between prealbumin(PA)and PFAS congeners as well as mixtures.Our findings have provided a piece of epidemiological evidence on associations between PFAS congeners or mixture,and serum hepatobiliary system function biomarkers in ACS patients,which could be a basis for subsequent mechanism studies.展开更多
Gastric cancer is the third leading cause of cancer-related mortality and remains a major global health issue^([1]).Annually,approximately 479,000individuals in China are diagnosed with gastric cancer,accounting for a...Gastric cancer is the third leading cause of cancer-related mortality and remains a major global health issue^([1]).Annually,approximately 479,000individuals in China are diagnosed with gastric cancer,accounting for almost 45%of all new cases worldwide^([2]).展开更多
The current quality standard for polyvinyl alcohol eye drops lacks an impurity assessment,despite the potential impact of raw material impurities on product safety.To strengthen quality control and ensure drug safety,...The current quality standard for polyvinyl alcohol eye drops lacks an impurity assessment,despite the potential impact of raw material impurities on product safety.To strengthen quality control and ensure drug safety,an investigation into the impurity profile of the formulation was conducted,and an HPLC-UV method was developed for impurity quantification.The method validation was performed using an H-type cation exchange column.A total of 116 batches of polyvinyl alcohol eye drops from four manufacturers and two batches of the innovator drug were analyzed.Formic acid was detected exclusively in 0.4 mL samples from Company A and the innovator drug,with concentrations below 0.002%in both cases.Acetic acid was identified in samples from all manufacturers,with levels not exceeding 0.1%.The method demonstrated high specificity and sensitivity,making it well-suited for the quantification of formic and acetic acids in polyvinyl alcohol eye drops.The presence of formic acid was attributed to excipients,whereas acetic acid originated from raw materials and was further generated during pH adjustment in manufacturing.Although the overall impurity levels were low and posed minimal risk to drug safety,manufacturers should remain vigilant regarding impurity control to maintain product quality.展开更多
Although per-and polyfluoroalkyl substances(PFAS)have been frequently linked to cardiovascular and renal disease separately,evidence remains scarce regarding their systematic effect.Therefore,we recruited 546 newly di...Although per-and polyfluoroalkyl substances(PFAS)have been frequently linked to cardiovascular and renal disease separately,evidence remains scarce regarding their systematic effect.Therefore,we recruited 546 newly diagnosed acute coronary syndrome(ACS)patients and detected seven myocardial enzymes and six kidney function biomarkers.Twelve PFASwere also assessedwith ultra-high-performance liquid chromatography-tandem mass spectrometry.Generalized linear model and restricted cubic spline model were applied to single pollutant analysis.Quantile g-computation was used for mixture analysis.Network model was utilized to identify central and bridge nodes of pollutants and phenotypes.In the present study,perfluorohexane sulfonic acid was positively associated with uric acid(UA)(β=0.04,95%confidence interval(CI):0.01,0.07),and perfluorobutanoic acid was negatively associated with estimated glomerular filtration rate(β=-0.04,95%CI:-0.07,-0.01)but positively associated with UA(β=0.03,95%CI:0.01,0.06).In mixture analysis,each quantile increase in the PFAS mixture was significantly associated with UA(β=0.08,95%CI:0.04,0.11).Network analysis revealed that perfluorooctanoate,UA,and myoglobin were denoted as bridge nodes,and the first principal component of lactate dehydrogenase and creatine kinase-myocardial band was identified as the node with the highest strength and expected influence.This study investigates the systematic impact of PFAS exposure through cardiorenal interaction network,which highlights that PFAS may serve as an upstream approach in UA-modulated cardiorenal network to affect cardiorenal system comprehensively.展开更多
In the context of global COVID-19 epidemic preparedness,the extensive use of disposable surgical masks(DSM)may lead to its emergence as a main new source of microplastics in the environment.Nowadays,DSMs have become a...In the context of global COVID-19 epidemic preparedness,the extensive use of disposable surgical masks(DSM)may lead to its emergence as a main new source of microplastics in the environment.Nowadays,DSMs have become a non-negligible source of plastic waste in aquatic environment,however,less research has been done on DSM after biofilm colonization in freshwater environment.The study investigated the microbial community of DSM-associated biofilms by 16S rRNA gene sequencing.Analysis of the microbial community in the middle and inner/outer layers of the DSM showed that the middle layer was different from the remaining two layers and that potential pathogens were enriched only in the middle layer of the DSM.Herein,we focused on the middle layer and explored the characterization properties and extracellular polymeric substances(EPS)components changes during biofilm formation.The results showed that the EPS components varied with the biofilm incubation time.As the formation of biofilm,the protein(PN)and polysaccharide(PS)in EPS showed an overall increasing trend,and the growth of PS was well synchronized with PN.Three fluorescent components of EPS were determined by the three-dimensional excitation emission matrix(3D-EEM),including humic acid-like,fulvic acid-like,and aromatic protein-like components.The percentage of fluorescent components varied with increasing biofilm development time and then stabilized.Fourier transform infrared spectroscopy(FTIR)characterization results elucidated the emergence of oxygen-containing functional groups during biofilm formation.Moreover,the hydrophilicity increased with biofilm development.In conclusion,the environmental behavior and ecological risks of DSM in aquatic environment deserve urgent attention in future studies.展开更多
[Objective] The aim was to provide certain theoretical basis for stuides on the high yield and high quality cultivation of Lycium barbarum L..[Method] Under yield conditions,the accumulation of primary substances and ...[Objective] The aim was to provide certain theoretical basis for stuides on the high yield and high quality cultivation of Lycium barbarum L..[Method] Under yield conditions,the accumulation of primary substances and secondary substances of Lycium barbarum L.was studied under different mulching treatments.[Result] Different mulching methods all had a certain effects on the contents of main primary substances and main secondary substances in Lycium barbarum L.fruit.Among them,carbohydrates and flavonoids contents in Lycium barbarum L.were both obviously increased under straw-film mulching;carotenoid content was decreased relatively;hundred leaf weight,1 000-grain weight and yield of Lycium barbarum L.were increased to a certain extent,but there was no obvious effect on the shape of fruit.Besides,the yield of Lycium barbarum L.had no significant positive correlation with total carbohydrate and polysaccharide,almost had no correlation with flavonoids,and had no significant negative correlation with carotenoid.[Conclusion] The reasonable mulching could improve the yield and quality of Lycium barbarum L..展开更多
This review starts with the description of the quantitative significance of dissolved organic material in general and dissolved humic substances (HS) in particular in various ecosystems. Despite their high quantities,...This review starts with the description of the quantitative significance of dissolved organic material in general and dissolved humic substances (HS) in particular in various ecosystems. Despite their high quantities, the knowledge about the role of HS is still very low and full of old, but still recycled paradigms. HS are thought to be inert or at least refractory and too large to be taken up by aquatic organisms. Instead, I present evidence that dissolved HS that mainly derives from the terrestrial environment, are taken up and directly and/or indirectly interfere with freshwater organisms and, thus, structure biocenoses. Relatively well known is in the meantime the fuelling function of allochthonous HS, which, upon irradiation, release fatty acids, which serve as substrates for microbial growth. This is an indirect effect of HS. Microbes, in turn, are food for mixotrophic algae and (heterotrophic) zooplankton. Thus, non-eutrophicated freshwaters are net-heterotrophic, meaning that respiration exceeds primary production. Furthermore, model calculations exemplify that only a very small portion of the terrestrial production is sufficient to cause net-heterotrophy in these freshwater bodies. But, recent papers show also that due to different stoichiometries the maximal plankton biomass production with algae or mixotrophs is higher than with bacteria. Very recently, several direct effects of HS have been elucidated. Among them are:induction of chaperons (stress shock proteins), induction and modulation of biotransformation enzymes, modulation (mainly inhibition) of photosynthetic oxygen release of aquatic plants, production of an internal oxidative stress, modulation of the offspring numbers in the nematode Caenorhabditis elegans[WTBZ], feminization of fish and amphibs, interference within the thyroid system, and action as chemical attractant to C. elegans. We are still in the phase of identifying the various physiological, biochemical, and molecular-biological effects. Hence, the ecological and ecophysiological significance of these HS-mediated effects still remain somewhat obscure. Nevertheless, HS appear generally to have an impact on the individual as well as on the community and even ecosystem level comparable to that of, for instance, nutrients.展开更多
The changes of pH,redox potential,concentrations of soluble iron ions and Cu^2＋ with the time of bioleaching chalcopyrite concentrates by acidithiobacillus ferrooxidans were investigated under the different condition...The changes of pH,redox potential,concentrations of soluble iron ions and Cu^2＋ with the time of bioleaching chalcopyrite concentrates by acidithiobacillus ferrooxidans were investigated under the different conditions of initial total-iron amount as well as mole ratio of Fe（III） to Fe（II） in the solutions containing synthetic extracellular polymeric substances （EPS）.When the solution potential is lower than 650 mV （vs SHE）,the inhibition of jarosites to bioleaching chalcopyrite is not vital as EPS produced by bacteria can retard the contamination through flocculating jarosites even if concentration of Fe（III） ions is up to 20 g/L but increases with increasing the concentration of Fe（III） ions;jarosites formed by bio-oxidized Fe3＋ ions are more easy to adhere to outside surface of EPS space on chalcopyrite;the EPS layer with jarosites acts as a weak diffusion barrier to further rapidly create a high redox potential of more than 650 mV by bio-oxidizing Fe^2＋ ions inside and outside EPS space into Fe^3＋ ions,resulting in a rapid deterioration of ion diffusion performance of the EPS layer to inhibit bioleaching chalcopyrite severely and irreversibly.展开更多
The extracellular polymeric substances（EPS） of Acidithiobacillus ferrooxidans ATCC 23270,and iron and copper enclosed in EPS were extracted by ultrasonication and centrifugation methods to determine the interaction ...The extracellular polymeric substances（EPS） of Acidithiobacillus ferrooxidans ATCC 23270,and iron and copper enclosed in EPS were extracted by ultrasonication and centrifugation methods to determine the interaction mechanism of Cu2＋,Fe3＋ and EPS during bioleaching chalcopyrite.Generally,Cu2＋ ions can stimulate bacteria to produce more EPS than Fe3＋ ions.The mass ratio of Fe3＋/Cu2＋ enclosed in EPS decreased gradually from about 4：1 to about 2：1 when the concentration of Cu2＋ ions increased from 0.01 to 0.04 mol/L.The amount of iron and copper bound together by EPS in ferrous-free 9K medium containing 1% chalcopyrite was about 2 times of that in 9K medium containing 0.04 mol/L Cu2＋ ions.It was inferred that the EPS with jarosites on the surface of chalcopyrite gradually acted as a weak diffusion barrier for Cu2＋,Fe3＋ ions transference during bioleaching chalcopyrite.展开更多
基金supported by the National Key Research and Development Project(No.2020YFA0907500)the National Natural Science Foundation of China(No.22476206)+1 种基金the supports from the National Young Top-Notch Talents(No.W03070030)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y202011).
文摘Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(III)nanoparticles with the most commonly identified FRB,Geobacter sulfurreducens PCA,remains poorly understood.Herein,we demonstrated that the synergistic role of outer membrane proteins and periplasmic proteins in the EET process for-Fe_(2)O_(3),Fe3O4,and𝛽α-FeOOH nanoparticles by construction of multiple gene knockout strain.oxpG(involved in the type II secretion system)and omcST(outer membrane c-type cytochrome)medi-ated pathways accounted for approximately 67%of the total reduction of𝛼α-Fe_(2)O_(3) nanoparticles.The residual reduction of𝛼α-Fe_(2)O_(3) nanoparticles in∆oxpG-omcST strain was likely caused by redox-active substances in cell supernatant.Conversely,the reduction of dissolved Fe(III)was almost unaffected in∆oxpG-omcST strain at the same concentration.However,at high dissolved Fe(III)concentration,the reduction significantly decreased due to the formation of Fe(III)nanoparticles,suggesting that this EET process is specific to Fe(III)nanoparticles.Overall,our study provided a more comprehensive understanding for the EET pathways between G.sulfurreducens PCA and different Fe(III)species,enriching our knowledge on the role of microorganisms in iron biogeochemical cycles and remediation strategies of pollutants.
基金supported by the National Natural Science Foundation of China(Nos.42077299,and U21A20290)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750400)the Ordos Key Research and Development Program(No.YF20240037).
文摘Persistent toxic substances(PTS)represent a paramount environmental issue in the 21st century.Understanding the concentrations and forms of PTS in the environment is crucial for accurately assessing their environmental health impacts.This article presents a concise overview of the components of PTS,pertinent environmental regulations,and conventional detection methodologies.Additionally,we offer an in-depth review of the principles,development,and practical applications of surface-enhanced Raman scattering(SERS)in environmental monitoring,emphasizing the advancements in detecting trace amounts of PTS in complex environmental matrices.Recent progress in enhancing SERS sensitivity,improving selectivity,and practical implementations are detailed,showcasing innovative materials and methods.Integrating SERS with advanced algorithms are highlighted as pivotal areas for future research.
基金supported by the National Natural Science Foundation of China(Nos.32171623 and 31770548)the National Key Research and Development Program of China(Nos.2016YFD0800306 and 2017YFD0800305).
文摘Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and speciation inmicroalgae remain unclear.Here,we used two strains of Chlamydomonas reinhardtii,namely CC-125(wild type)and CC-503(cell walldeficientmutant),to examine the algal growth,EPS synthesis,As adsorption,absorption and transformation under 10–1000μg/L As(III)and As(V)treatments for 96 h.In both strains,the As absorption increased after the EPS removal,but the growth,As adsorption,and transformation of C.reinhardtii declined.The CC-125 strain was more tolerant to As stress and more efficient in EPS production,As accumulation,and redox transformation than CC-503,irrespective of EPS presence or absence.Three-dimension excitation-emission matrix(3DEEM)and attenuated total reflectance infrared spectroscopy(ATR-IR)analyses showed that As was bound with functional groups in the EPS and cell wall,such as-COOH,NH and-OH in proteins,polysaccharides and amino acids.Together,this study demonstrated that EPS and cell wall acted as barriers to lower the As uptake by C.reinhardtii.However,the cell wall mutant strain wasmore susceptible to As toxicity due to lower EPS induction and higher As absorption.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750000)the National Natural Science Foundation of China(Nos.52270012 and 52470018)the Ministry of Science and Technology of China(Nos.2022YFC3203705 and2021YFC3200904)。
文摘Due to their persistence,bioaccumulation,and resistance to degradation,perfluorinated substances(PFASs)have significant impacts on the environment and human health.This study comprehensively analyzed and assessed the occurrence characteristics,sources,and potential ecological risks of 13 PFASs in the Yangtze River.The results indicated that the concentrations ofΣPFASs range from 5.1 to 57.7 ng/L,with more severe pollution downstream and perfluorobutane sulfonate(PFBuS)being the main pollutant.ΣPFASs showed a positive correlation with total organic carbon and absorbance under the condition of UV wavelength 254 nm(UV_(254)),and a negative correlation with total dissolved solids.Positive matrix factorization model analysis revealed that the primary sources of PFASs in the study area are food packaging,the electroplating industry,and the manufacturing and processing of fluoropolymer-containing products.The total ecological risk value of PFASs indicated that the ecological risks to algae,invertebrates,and fish are negligible.The annual load of ΣPFASs in the Yangtze River was 39.00 t,with the highest concentrations of pollutants being PFBuS(26.41 t/year),perfluorobutanoic acid(6.47 t/year),and perfluorooctanoic acid(PFOA,3.19t/year).While PFASs have not yet posed a risk to aquatic organisms,the increase in the use of short-chain PFASs substitutes(C4-C7)due to the regulation of PFOA and perfluorooctane sulfonate highlights the need for continued monitoring of short-chain PFASs pollution.
文摘Spider mites are significant pests in agricultural production.The increasing resistance of spider mites,along with environmental pollution and ecological imbalance caused by their control,is primarily attributed to the long-term use of chemical acaricides in agriculture.In contrast,bioactive substances of biological origin offer advantages such as wide availability,environmental friendliness,and low tendency to induce resistance,making them a research hotspot for spider mite control.This review summarizes recent advances in the use of plant-derived active compounds(exemplified by extracts from Veratrum rhizomes),RNA interference(RNAi)technology,and microorganism-derived active substances for controlling spider mites.These bioactive agents exert acaricidal effects by disrupting the nervous system,interfering with metabolic processes,or silencing key genes in mites,demonstrating favorable efficacy and considerable potential for development.However,challenges remain,including poor environmental stability,slow action,high production costs,and insufficient understanding of their effects on non-target organisms.Therefore,future research should focus on the screening and development of novel bioactive substances of biological origin,elucidation of their mechanisms of action,optimization of formulation technologies,and assessment of their ecological safety.These efforts will provide valuable insights for promoting the advancement of bioactive substances and supporting sustainable agricultural development.
基金supported by the National Natural Science Foundation of China(Nos.22176112 and 42307134)the Natural Science Foundation of Shandong Province(No.ZR2021MD028)the Natural Science Foundation of Qingdao(No.23–2-1–74-zyyd-jch).
文摘The optical absorption of large molecular compounds HULIS(humic-like substances)can significantly impact the aerosol light absorption and radiative forcing,influencing cloud condensation nuclei formation and thus the climate and atmospheric environment.This study collected aerosol(PM_(2.5))samples from the summit of Mount Tai in North China to investigate the concentration,molecular composition,and optical properties of HULIS.The average concentration of HULIS in the PM_(2.5) in this study was 1.26±0.54μg/m^(3),comprising for 56%of the water-soluble organic carbon(WSOC),with levels lower than urban areas but higher than other mountainous regions.Mass spectrometry revealed that CHO and CHON components,with high aromaticity and phenolic groups,are major contributors to absorption and fluorescence.These results indicate that HULIS is mainly composed of lignin and proteins/amino sugars,derived from combustion and secondary formation,and possesses a high light absorption capacity(withMAE365(mass absorption efficiency)and AAE(A˚ngstrom exponent)indices of 0.62m^(2)/g and 4.99,respectively).Parallel factor analysis identified three fluorescence components of HULIS,with proportions of 60.8%for less oxygen humic-like substances,21.0%for high oxygen humic-like substances,and 18.2%for protein-like substances.Our study highlights the significance of the light-absorbing capacity and secondary formation of HULIS at Mount Tai,laying the groundwork for investigation into the climate effects,formation mechanisms,and sources of HULIS generation.
基金funded by National Natural Science Foundation of China(32360568)Science and Technology Plan Project of Guizhou Province(Qian Ke He Chengguo[2023]Zhongda 011)+2 种基金Guizhou Basic Research Program(Natural Science)Mianshang Project(Qiankehe Basic MS[2025]671)Guizhou Provincial Association of Science and Technology Youth Science and Technology Talent Support Project(GASTYESS202407)Guizhou University Natural Science Specialized(Te Gang)Scientific Research Fund(Gui Da Te Gang He Zi(2022)39).
文摘Fermented sour soup is a unique traditional sour food of the Miao and Dong ethnic groups in China.However,due to the commonly used traditional fermentation,the unstable fluctuation of microbial community often leads to some unpleasant inherent off-flavours in rice sour soup.In this study,the microbial composition and volatile flavour components of off-flavour and normal rice sour soup were examined by high-throughput sequencing and headspace solid-phase microextraction coupled with gas chromatography mass spectrometry.Then,based on Pearson correlation coefficients,the correlations between fungi and bacteria and those between core microorganisms and key volatile flavour components were investigated.The dominant fungal genera included Candida,Dekkera,Pichia,Rhizopus,and Issatchenkia,whereas the dominant bacterial genera included Lactobacillus,Pectinatus,Bifidobacterium,Pseudomonas,and Acetobacter.Compared to normal rice sour soup,off-flavoured rice sour soup contained the significantly increased relative abundance of Candida and the significantly decreased relative abundance of Dkkera.In addition,80 volatile flavour compounds detected in off-flavoured rice sour soup,mainly including esters,acids,and alcohols,were different from those detected in normal rice sour soup.Especially,some substances were only detected in off-flavoured rice sour soup,such as 1-hexanol(68-207μg/kg),butyric acid(20-92μg/kg)and heptanoic acid(12-45μg/kg),which might be the main source of off-flavours.These results provide new ideas and strategies of removing or abating odour from fermented rice sour soup.
基金supported by the Key Research and Development Plan of Zhejiang Province(No.2021C03176)Zhejiang Provincial Natural Science Foundation of China(No.LY23B070001)+2 种基金the Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province(No.20230009)the National Natural Science Foundation of China(No.22106032)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750000).
文摘Per-and polyfluoroalkyl substances(PFASs)can induce a range of adverse health effects,with the precise molecularmechanisms remaining elusive.Extracellular vesicles(EVs)have demonstrated their potential to elucidate unknown molecular mechanisms.Building upon the close alignment of their biological functions with the observed health effects of PFASs,this study innovatively focuses on proteomic insights from EVs into the molecular mechanisms underlying the systemic health effects of PFASs.Through rat exposure experiments and proteomics technology,it not only demonstrated the occurrence of PFASs in EVs but also revealed the alterations in the serum EVs and the expression of their protein cargos following mixed exposure to PFASs,leading to changes in related pathways.These changes encompass various biological processes,including proteasome activity,immune response,cytoskeletal organization,oxidative stress,cell signaling,and nervous system function.Particularly noteworthy is the uncovering of the activation of the proteasome pathway,highlighting significant key contributing proteins.These novel findings provide a new perspective for exploring the molecularmechanism underlying the systemic health effects of PFASs and offer reliable screening for potential biomarkers.Additionally,comparisons with serum confirmed the potential of serum EVs as biological responders and measurable endpoints for evaluating PFASs-induced toxicity.
基金supported by the Fundamental Research Funds for Central Non-profit Scientific Institution(No.1610132022015)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750200)the National Natural Science Foundation of China(No.22176198).
文摘Reclaimed water for irrigation or hydroponic cultivation provides exposure pathways for per-and polyfluoroalkyl substances(PFAS)to enter the human food chain.This study employed hydroponic methods to investigate the behavior of legacy PFAS and emerging chlorinated polyfluoroalkyl ether sulfonic acids(Cl-PFESAs)in lettuce grown under environment-related exposure levels and assessed the human exposure risks from consuming contaminated lettuce.Overall,PFAS in lettuce were concentration-dependent,with long-chain PFAS tending to accumulate in roots and short-chain PFAS accumulating more in shoots.The enrichment of PFAS in lettuce was jointly influenced by their chain length and polar functional groups.Specifically,the root concentration factors(RCFs)of PFAS generally increased with increasing chain length,and RCF values of most perfluoroalkanesulfonic acids(PFSAs)were significantly higher than those of perfluoroalkyl carboxylic acids(PFCAs)with the same chain length(p<0.01),while the translocation factors(TFs)exhibited opposite trends.RCF values of perfluorooctane sulfonate(PFOS)and its alternatives,Cl-PFESAs,were ranked as follows:8:2 Cl-PFESA(mean:139)>6:2 Cl-PFESA(28.6)>PFOS(25.7),which was attributed to the increased molecular size and hydrophobicity resulting from the insertion of ether bonds and additional CF2 in 8:2 Cl-PFESA.Notably,TF value of 8:2 Cl-PFESA(mean:0.007)was the smallest among all PFAS,indicating 8:2 Cl-PFESA was difficult to transfer to nutritional compartments.Adults and children would exceed the most conservative health-based reference dose(RfD)by consuming approximately 15.9–148 g and 7.92–74.0 g of contaminated lettuce per day,implying high health risks.
基金supported by Shenzhen Science and Technology Program(NO.JCYJ20210324094000001).
文摘Perfluoroalkyl and polyfluoroalkyl substances(PFASs)pollution with their toxicity,carcinogenicity,and persistence has been concerned worldwide.Research into novel materials for detecting and removing PFASs has increased rapidly,particularly in regard to the emergence of well-characterized single-atom materials(SAMs).Owing to the high selectivity,high atom utilization,and abundant active sites of SAMs,these materials exhibit remarkable efficacy in the detection and removal of PFASs.In this work,recent advances in the synthesis of SAMs for the detection and removal PFASs are reviewed.In-depth discussions of the structure-activity relationship and reaction mechanisms have demonstrated the high efficiency,activity,and selectivity of SAMs for the detection,adsorption,and degradation of PFASs.To optimize the application of SAMs in PFASs remediation,this review comprehensively surveys SAMs applications for PFASs and analyzes potential design strategies based on synthesis methods and corresponding properties.Synthesis strategies such as wet-chemistry,which offer ease of operation and high potential for large-scale production,are recommended for the further exploration of specific SAMs for the detection and removal of PFASs.Finally,this review identifies the challenges and opportunities for development of SAMs for the detection and remediation of PFASs,providing an outlook on strategic goals for a green economy and sustainable development.
基金supported by the National Natural Science Foundation of China(T2241028)STI2030-Major Projects[2021ZD0203000(2021ZD0203003)].
文摘Mental health disorders have emerged as a critical global health challenge,profoundly impacting individuals,communities,and societies worldwide.The prevalence of mental health problems has been steadily increasing,with~1 in 8 people,equivalent to 970 million individuals suffering from a mental disorder in 2019(https://vizhub.healthdata.org/gbd-results).Anxiety and depressive disorders are predominant,contributing significantly to the burden of mental health issues,according to the World Health Organization.The COVID-19 pandemic has further exacerbated this situation.It led to a notable upsurge in anxiety and major depressive disorders in 2020.Estimates indicate a 26%rise in anxiety and a 28%increase in depression within that year(https://www.who.int/publications/i/item/WHO-2019-nCoVSci_Brief-Mental_health-2022.1)[1].
基金supported by the National Natural Science Foundation of China(No.21976050)the Science and Technology Program of Hebei Province(No.21377779D)+3 种基金the Natural Science Foundation of Hebei Province(No.B2020206008)China Postdoctoral Science Foundation(Nos.2023M730317 and 2023T160066)the Fundamental Research Funds for the Central Universities(No.3332023042)the Open Project of Hebei Key Laboratory of Environment and Human Health(No.202301).
文摘Previous studies have suggested that abnormal hepatobiliary system function may contribute to poor prognosis in patientswith acute coronary syndrome(ACS)and that abnormal hepatobiliary system function may be associated with per-and polyfluoroalkyl substances(PFAS)exposure.However,there is limited evidence for this association in cardiovascular subpopulations,particularly in the ACS patients.Therefore,we performed this study to evaluate the association between plasma PFAS exposure and hepatobiliary system function biomarkers in patients with ACS.This study included 546 newly diagnosed ACS patients at the Second Hospital of Hebei Medical University,and data on 15 hepatobiliary system function biomarkers were obtained from medical records.Associations between single PFAS and hepatobiliary system function biomarkers were assessed using multiple linear regression models and restricted cubic spline model(RCS),and mixture effects were assessed using the Quantile g-computation model.The results showed that total bile acids(TBA)was negative associated with perfluorohexane sulfonic acid(PFHxS)(-7.69%,95%CI:-12.15%,-3.01%).According to the RCS model,linear associations were found between TBA and PFHxS(P for overall=0.003,P for non-linear=0.234).We also have observed the association between between PFAS congeners and liver enzyme such as aspartate aminotransferase(AST)and α-l-Fucosidase(AFU),but it was not statistically significant after correction.In addition,Our results also revealed an association between prealbumin(PA)and PFAS congeners as well as mixtures.Our findings have provided a piece of epidemiological evidence on associations between PFAS congeners or mixture,and serum hepatobiliary system function biomarkers in ACS patients,which could be a basis for subsequent mechanism studies.
基金supported by the Natural Science Foundation of Shanghai(23ZR1463600)Shanghai Pudong New Area Health Commission Research Project(PW2021A-69)Research Project of Clinical Research Center of Shanghai Health Medical University(22MC2022002)。
文摘Gastric cancer is the third leading cause of cancer-related mortality and remains a major global health issue^([1]).Annually,approximately 479,000individuals in China are diagnosed with gastric cancer,accounting for almost 45%of all new cases worldwide^([2]).
基金National Drug Sampling Inspection Project(No.NMPA Drug Admin[2024]1).
文摘The current quality standard for polyvinyl alcohol eye drops lacks an impurity assessment,despite the potential impact of raw material impurities on product safety.To strengthen quality control and ensure drug safety,an investigation into the impurity profile of the formulation was conducted,and an HPLC-UV method was developed for impurity quantification.The method validation was performed using an H-type cation exchange column.A total of 116 batches of polyvinyl alcohol eye drops from four manufacturers and two batches of the innovator drug were analyzed.Formic acid was detected exclusively in 0.4 mL samples from Company A and the innovator drug,with concentrations below 0.002%in both cases.Acetic acid was identified in samples from all manufacturers,with levels not exceeding 0.1%.The method demonstrated high specificity and sensitivity,making it well-suited for the quantification of formic and acetic acids in polyvinyl alcohol eye drops.The presence of formic acid was attributed to excipients,whereas acetic acid originated from raw materials and was further generated during pH adjustment in manufacturing.Although the overall impurity levels were low and posed minimal risk to drug safety,manufacturers should remain vigilant regarding impurity control to maintain product quality.
基金supported by the China Postdoctoral Science Foundation(Nos.2023M730317 and 2023T160066)the Fundamental Research Funds for the Central Universities(No.3332023042)+3 种基金the Open Project of Hebei Key Laboratory of Environment and Human Health(No.202301)the Programs of the National Natural Science Foundation of China(No.21976050)the Science and Technology Program of Hebei Province(No.21377779D)the Natural Science Foundation of Hebei Province,China(No.B2020206008).
文摘Although per-and polyfluoroalkyl substances(PFAS)have been frequently linked to cardiovascular and renal disease separately,evidence remains scarce regarding their systematic effect.Therefore,we recruited 546 newly diagnosed acute coronary syndrome(ACS)patients and detected seven myocardial enzymes and six kidney function biomarkers.Twelve PFASwere also assessedwith ultra-high-performance liquid chromatography-tandem mass spectrometry.Generalized linear model and restricted cubic spline model were applied to single pollutant analysis.Quantile g-computation was used for mixture analysis.Network model was utilized to identify central and bridge nodes of pollutants and phenotypes.In the present study,perfluorohexane sulfonic acid was positively associated with uric acid(UA)(β=0.04,95%confidence interval(CI):0.01,0.07),and perfluorobutanoic acid was negatively associated with estimated glomerular filtration rate(β=-0.04,95%CI:-0.07,-0.01)but positively associated with UA(β=0.03,95%CI:0.01,0.06).In mixture analysis,each quantile increase in the PFAS mixture was significantly associated with UA(β=0.08,95%CI:0.04,0.11).Network analysis revealed that perfluorooctanoate,UA,and myoglobin were denoted as bridge nodes,and the first principal component of lactate dehydrogenase and creatine kinase-myocardial band was identified as the node with the highest strength and expected influence.This study investigates the systematic impact of PFAS exposure through cardiorenal interaction network,which highlights that PFAS may serve as an upstream approach in UA-modulated cardiorenal network to affect cardiorenal system comprehensively.
基金Supported by the Natural Science Foundation of Shandong Province(Nos.ZR2022MD115,ZR202111160067)。
文摘In the context of global COVID-19 epidemic preparedness,the extensive use of disposable surgical masks(DSM)may lead to its emergence as a main new source of microplastics in the environment.Nowadays,DSMs have become a non-negligible source of plastic waste in aquatic environment,however,less research has been done on DSM after biofilm colonization in freshwater environment.The study investigated the microbial community of DSM-associated biofilms by 16S rRNA gene sequencing.Analysis of the microbial community in the middle and inner/outer layers of the DSM showed that the middle layer was different from the remaining two layers and that potential pathogens were enriched only in the middle layer of the DSM.Herein,we focused on the middle layer and explored the characterization properties and extracellular polymeric substances(EPS)components changes during biofilm formation.The results showed that the EPS components varied with the biofilm incubation time.As the formation of biofilm,the protein(PN)and polysaccharide(PS)in EPS showed an overall increasing trend,and the growth of PS was well synchronized with PN.Three fluorescent components of EPS were determined by the three-dimensional excitation emission matrix(3D-EEM),including humic acid-like,fulvic acid-like,and aromatic protein-like components.The percentage of fluorescent components varied with increasing biofilm development time and then stabilized.Fourier transform infrared spectroscopy(FTIR)characterization results elucidated the emergence of oxygen-containing functional groups during biofilm formation.Moreover,the hydrophilicity increased with biofilm development.In conclusion,the environmental behavior and ecological risks of DSM in aquatic environment deserve urgent attention in future studies.
基金Supported by National Natural Science Foundation of China(30860227)Natural Science Foundation of Ningxia Province(NZ0603,NZ0639)~~
文摘[Objective] The aim was to provide certain theoretical basis for stuides on the high yield and high quality cultivation of Lycium barbarum L..[Method] Under yield conditions,the accumulation of primary substances and secondary substances of Lycium barbarum L.was studied under different mulching treatments.[Result] Different mulching methods all had a certain effects on the contents of main primary substances and main secondary substances in Lycium barbarum L.fruit.Among them,carbohydrates and flavonoids contents in Lycium barbarum L.were both obviously increased under straw-film mulching;carotenoid content was decreased relatively;hundred leaf weight,1 000-grain weight and yield of Lycium barbarum L.were increased to a certain extent,but there was no obvious effect on the shape of fruit.Besides,the yield of Lycium barbarum L.had no significant positive correlation with total carbohydrate and polysaccharide,almost had no correlation with flavonoids,and had no significant negative correlation with carotenoid.[Conclusion] The reasonable mulching could improve the yield and quality of Lycium barbarum L..
文摘This review starts with the description of the quantitative significance of dissolved organic material in general and dissolved humic substances (HS) in particular in various ecosystems. Despite their high quantities, the knowledge about the role of HS is still very low and full of old, but still recycled paradigms. HS are thought to be inert or at least refractory and too large to be taken up by aquatic organisms. Instead, I present evidence that dissolved HS that mainly derives from the terrestrial environment, are taken up and directly and/or indirectly interfere with freshwater organisms and, thus, structure biocenoses. Relatively well known is in the meantime the fuelling function of allochthonous HS, which, upon irradiation, release fatty acids, which serve as substrates for microbial growth. This is an indirect effect of HS. Microbes, in turn, are food for mixotrophic algae and (heterotrophic) zooplankton. Thus, non-eutrophicated freshwaters are net-heterotrophic, meaning that respiration exceeds primary production. Furthermore, model calculations exemplify that only a very small portion of the terrestrial production is sufficient to cause net-heterotrophy in these freshwater bodies. But, recent papers show also that due to different stoichiometries the maximal plankton biomass production with algae or mixotrophs is higher than with bacteria. Very recently, several direct effects of HS have been elucidated. Among them are:induction of chaperons (stress shock proteins), induction and modulation of biotransformation enzymes, modulation (mainly inhibition) of photosynthetic oxygen release of aquatic plants, production of an internal oxidative stress, modulation of the offspring numbers in the nematode Caenorhabditis elegans[WTBZ], feminization of fish and amphibs, interference within the thyroid system, and action as chemical attractant to C. elegans. We are still in the phase of identifying the various physiological, biochemical, and molecular-biological effects. Hence, the ecological and ecophysiological significance of these HS-mediated effects still remain somewhat obscure. Nevertheless, HS appear generally to have an impact on the individual as well as on the community and even ecosystem level comparable to that of, for instance, nutrients.
基金Project(2010CB630904) supported by the National Basic Research Program of ChinaProject(50621063) supported by the Chinese Science Foundation for Distinguished Group
文摘The changes of pH,redox potential,concentrations of soluble iron ions and Cu^2＋ with the time of bioleaching chalcopyrite concentrates by acidithiobacillus ferrooxidans were investigated under the different conditions of initial total-iron amount as well as mole ratio of Fe（III） to Fe（II） in the solutions containing synthetic extracellular polymeric substances （EPS）.When the solution potential is lower than 650 mV （vs SHE）,the inhibition of jarosites to bioleaching chalcopyrite is not vital as EPS produced by bacteria can retard the contamination through flocculating jarosites even if concentration of Fe（III） ions is up to 20 g/L but increases with increasing the concentration of Fe（III） ions;jarosites formed by bio-oxidized Fe3＋ ions are more easy to adhere to outside surface of EPS space on chalcopyrite;the EPS layer with jarosites acts as a weak diffusion barrier to further rapidly create a high redox potential of more than 650 mV by bio-oxidizing Fe^2＋ ions inside and outside EPS space into Fe^3＋ ions,resulting in a rapid deterioration of ion diffusion performance of the EPS layer to inhibit bioleaching chalcopyrite severely and irreversibly.
基金Project(50621063) supported by the National Natural Science Foundation of ChinaProject(2010CB630903) supported by the National Basic Research Program of China
文摘The extracellular polymeric substances（EPS） of Acidithiobacillus ferrooxidans ATCC 23270,and iron and copper enclosed in EPS were extracted by ultrasonication and centrifugation methods to determine the interaction mechanism of Cu2＋,Fe3＋ and EPS during bioleaching chalcopyrite.Generally,Cu2＋ ions can stimulate bacteria to produce more EPS than Fe3＋ ions.The mass ratio of Fe3＋/Cu2＋ enclosed in EPS decreased gradually from about 4：1 to about 2：1 when the concentration of Cu2＋ ions increased from 0.01 to 0.04 mol/L.The amount of iron and copper bound together by EPS in ferrous-free 9K medium containing 1% chalcopyrite was about 2 times of that in 9K medium containing 0.04 mol/L Cu2＋ ions.It was inferred that the EPS with jarosites on the surface of chalcopyrite gradually acted as a weak diffusion barrier for Cu2＋,Fe3＋ ions transference during bioleaching chalcopyrite.
