Distribution and chemical speciation of dissolved inorganic arsenic were examined in Yellow Sea and East China Sea. Results demonstrated that:(1) both As(III) and As(V) were detected, with As(V) dominated at 40% stati...Distribution and chemical speciation of dissolved inorganic arsenic were examined in Yellow Sea and East China Sea. Results demonstrated that:(1) both As(III) and As(V) were detected, with As(V) dominated at 40% stations of surface water and 51% stations of bottom water;(2) influenced by the exchange of fresh and sea water, the type of surface sediment and the transport of various water masses, large values in surface water were observed along the coastal region and in the same latitude of Changjiang River Estuary and Hangzhou Bay, and in bottom water found in the southern area where the Taiwan Warm Current and Kuroshio Current influenced;(3) As(III) behaved non-conservatively in Changjiang River Estuary. Man-derived inputs cause substantial positive deviation from the theoretical dilution. The negative correlation of As(V) to salinity in surface water suggested that it behaved conservatively during the transportation along Changjiang River Estuary. While, the occurrence of As(V) up to the linear fit in bottom water indicated the eventual transfer from dissolved phase to particulate phase, which was impossible to be determined without the knowledge of arsenic level and speciation in suspended particulate matter. Further study is needed on the arsenic source/sink relationships based on the distribution profiles.展开更多
Water samples were collected in the coastal area of the Changjiang Estuary on four cruises from August 2002 to May 2003. The seasonal variations of dissolved inorganic arsenic (DIAs) distributions were analyzed. The r...Water samples were collected in the coastal area of the Changjiang Estuary on four cruises from August 2002 to May 2003. The seasonal variations of dissolved inorganic arsenic (DIAs) distributions were analyzed. The results showed that the distributions of DIAs were mainly influenced by the terrestrial input and the intrusion of the Kuroshio Subsurface Water (KSSW). The concentration of the total dissolved inorganic arsenic (TDIAs) decreased consecutively from winter to summer, while it increased in autumn. The distributions of TDIAs showed some relationships with salinity and suspended particulate matter (SPM). The relationships between DIAs speciation (including arsenite [As(Ⅲ)] and arsenate [As(Ⅴ)]), biological activity and the availabilities of the phosphate were investigated in the study area for the cruise August 2002. The ratio of As (Ⅲ)/TDIAs increased with the decrease of phosphate concentrations. In the bottom water, the As(Ⅲ)/TDIAs ratio decreased with the increasing of N/P. The concentration of TDIAs decreased 28.7% approximately after the occurrence of harmful algal blooms (HAB) because of the uptake of arsenate by algae. Further study is needed about the arsenic source/sink relationships in their vertical or horizontal profiles and the uptake mechanism during the occurrence of harmful algal blooms.展开更多
In order to understand the similarity or difference of inorganic As species uptake and transport related to phosphorus in As-hyperaccumulator,uptake and transport of arsenate(As(V))and arsenite(As(III))were studied us...In order to understand the similarity or difference of inorganic As species uptake and transport related to phosphorus in As-hyperaccumulator,uptake and transport of arsenate(As(V))and arsenite(As(III))were studied using Pteris vittata L.under sandculture.Higher concentrations of phosphate were found to inhibit accumulation of arsenate and arsenite in the fronds of P.vittata.The reduction in As accumulation was greater in old fronds than in young fronds,and relatively weak in root and rhizome.Moderateincreases,from 0.05 to 0.3 mmol/L,in phosphate reduced uptake of As(III)more than As(V),while the reverse was observed at highconcentrations of phosphate(1.0 mmol/L).Phosphate apparently reduced As transport and the proportion of As accumulated in frondsof P.vittata when As was supplied as As(V).It may in part be due to competition between phosphorus and As(V)during transport.Incontrast,phosphate had a much smaller effect on As transport when the As was supplied as As(III).Therefore,the results from presentexperiments indicates that a higher concentration of phosphate suppressed As accumulation and transport in P.vittata,especially inthe fronds,when exposed to As(V);but the suppression of phosphate to As transport may be insignificant when P.vittata exposed toAs(III)under sand culture conditions.The finding will help to understand the interaction of P and As during their uptake process in P.vittata.展开更多
A novel 1-methylimidazole ionic liquid modified SBA15 mesoporous silica(1-MIIL@SBA15) was synthesized and applied to selective separation of inorganic arsenic(iAs) in rice by dispersive solid phase extraction(DSPE), f...A novel 1-methylimidazole ionic liquid modified SBA15 mesoporous silica(1-MIIL@SBA15) was synthesized and applied to selective separation of inorganic arsenic(iAs) in rice by dispersive solid phase extraction(DSPE), followed by hydride generation-atomic fluorescence spectrometric(HG-AFS) quantification. The prepared sorbent was characterized by FTIR, FESEM, BET and Zeta potential. Key parameters of adsorption and desorption in DSPE were optimized using standard reference material 1568 b rice flour. Under optimal conditions, the limit of detection was 8.776 ng/kg, relative standard deviation was ≤2.0%, and recoveries of iAs were in the 92.3～94.4% range. This method was successfully applied to the determination of iAs in rice. Under acidic condition, the electrostatic interaction between the positively charged 1-MIIL@SBA15 and anionic iAs played an important role in selective iAs separation, rendering this method suitable for iAs analysis.展开更多
An automatic flow analysis system with on-line liquid nitrogen trap, hydride generation and flame-less atomic absorption spectrophotometry was presented for the determination of inorganic arsenic and antimony in seawa...An automatic flow analysis system with on-line liquid nitrogen trap, hydride generation and flame-less atomic absorption spectrophotometry was presented for the determination of inorganic arsenic and antimony in seawater. The experimental conditions such as acidity of reduction reaction, the amount of sodium borohydride , the flow rate of carry gas (high purity of nitrogen) were tested and selected optimally. The limit detection of the method presented was 0. 15 ug/L for arsenic and 0. 24 μ/L for antimony . During the determination of seawater samples with levels microgram arsenic and antimony pa litre th?variation coefficient would be ±4% for arsenic and ±10% for antimony. The volume needed for one measurement was 9 mL for arsenic and 12 mL for antimony. The frequency of sample determination reached 20 times per hour for arsenic and 15 times per hour for antimony.展开更多
Approximately 94 to 220 million people worldwide are at risk of drinking well water containing arsenic > 10 μg/L, the WHO guideline value. To identify non-compliant domestic wells, assess health risks and reduce e...Approximately 94 to 220 million people worldwide are at risk of drinking well water containing arsenic > 10 μg/L, the WHO guideline value. To identify non-compliant domestic wells, assess health risks and reduce exposure, accurate and rapid on-site inorganic arsenic screening methods are desirable because all domestic wells worldwide need to be tested.Here, the principles, advantages and limitations of commonly used colorimetry, electrochemistry, and biosensing methods are critically reviewed, with the performance compared with laboratory-based benchmark methods. Most commercial kits are based on the classic Gutzeit reaction. Despite being semi-quantitative, the more recent and more expensive products display improved and acceptable accuracy and shorter testing time (~10 min). Carried out by trained professionals, electrochemical methods are also feasible for on-site analysis, although miniaturization is desirable yet challenging. Biosensing using whole bacterial cells or bio-engineered materials such as aptamers is promising, if incorporated with function specific nanomaterials and biomaterials. Since arsenic is frequently found as arsenite in reducing groundwater and subject to oxidation during sampling, transportation and storage, on-site separation and sample preservation are feasible but the specific methods should be chosen based on sample matrix and tested before use. To eliminate arsenic exposure among hundreds of millions of mostly rural residents worldwide, we call for concerted efforts in research community and regulatory authority to develop accurate, rapid, and affordable tests for on-site screening and monitoring of arsenic in drinking water. Access to affordable testing will benefit people who are socioeconomically disadvantaged.展开更多
Arsenic(II)sulfide is a stable inorganic arsenic compound with a different valence from arsenic trioxide,and has been widely applied to treat various diseases with low toxic side effects for a long time.However,its lo...Arsenic(II)sulfide is a stable inorganic arsenic compound with a different valence from arsenic trioxide,and has been widely applied to treat various diseases with low toxic side effects for a long time.However,its low solubility and complicated formulations restrict its further applications in modern medical industry.Meanwhile,as the tumour with the highest incidence rate among women,the low recurrence risk of breast cancer has been confirmed to be closely related to the high infiltration of immune cells.Herein,we synthesized and filtered novel biocompatible PEGylated arsenic(II)sulfide nanocrystals AsS@PEG with a size of 93.14±0.49 nm by the gel method,which displayed excellent anticancer and immune activation activity in breast cancer model.Proteomic analysis suggested that the AsS@PEG induce ferroptosis in cancer cells and further activate antitumour immune responses via B-cell lymphoma 9-like(BCL9L)protein inhibition.Furthermore,mechanism studies revealed notable glutathione peroxidase 4(GPX4)downregulation in cancer cells,dendritic cells(DCs)maturation and subsequent effector CD8^(+)T-cells production induced by the AsS@PEG in the tumour microenvironment.This study highlights biocompatible arsenic(II)sulfide nanocrystals that induce ferroptotic cell death and activate antitumour immune responses,providing insights into the path towards the immunotherapy assisted chemotherapy for breast cancer.展开更多
Lagoons are ecosystems for biodiversity and the livelihoods of coastal communities. The main objective of the study was to analyze the variability of arsenic concentrations in gastropods and bivalves in the Aby and Te...Lagoons are ecosystems for biodiversity and the livelihoods of coastal communities. The main objective of the study was to analyze the variability of arsenic concentrations in gastropods and bivalves in the Aby and Tendo lagoons, taking into account spatial, seasonal and hydrological variations. The study was carried out in four stages spread over two successive hydroclimatic cycles, including two seasons during the rainy season and two more during the dry season. The samples were taken in two areas of the Aby and Tendo lagoons. Arsenic levels were measured by ICP-MS. The results showed that mean arsenic concentrations in the muscles of organisms in Aby Lagoon ranged from 0.01 to 1.26 μg As/g, with a mean and median of 0.17 and 0.06 μg As/g, respectively. Fish had the highest levels of arsenic, followed by crustaceans, while molluscs and plants had lower and comparable concentrations of As. Arsenic concentrations in tilapia and jawbones varied significantly between sites and seasons, with higher concentrations at Tendo and during the rainy season. Arsenic concentrations in gastropods and bivalves were significantly higher than those of other species, with averages of 0.74 and 1.03 mg As/kg, respectively.展开更多
Developing technologies that can be applied simultaneously in battery thermal management(BTM)and thermal runaway(TR)mitigation is significant to improving the safety of lithium-ion battery systems.Inorganic phase chan...Developing technologies that can be applied simultaneously in battery thermal management(BTM)and thermal runaway(TR)mitigation is significant to improving the safety of lithium-ion battery systems.Inorganic phase change material(PCM)with nonflammability has the potential to achieve this dual function.This study proposed an encapsulated inorganic phase change material(EPCM)with a heat transfer enhancement for battery systems,where Na_(2)HPO_(4)·12H_(2)O was used as the core PCM encapsulated by silica and the additive of carbon nanotube(CNT)was applied to enhance the thermal conductivity.The microstructure and thermal properties of the EPCM/CNT were analyzed by a series of characterization tests.Two different incorporating methods of CNT were compared and the proper CNT adding amount was also studied.After preparation,the battery thermal management performance and TR propagation mitigation effects of EPCM/CNT were further investigated on the battery modules.The experimental results of thermal management tests showed that EPCM/CNT not only slowed down the temperature rising of the module but also improved the temperature uniformity during normal operation.The peak battery temperature decreased from 76℃to 61.2℃at 2 C discharge rate and the temperature difference was controlled below 3℃.Moreover,the results of TR propagation tests demonstrated that nonflammable EPCM/CNT with good heat absorption could work as a TR barrier,which exhibited effective mitigation on TR and TR propagation.The trigger time of three cells was successfully delayed by 129,474 and 551 s,respectively and the propagation intervals were greatly extended as well.展开更多
Arsenic is a carcinogenic environmental factor found in food and drinking water around the world.The mechanisms in which arsenic alters homeostasis are not fully understood.Over the past few decades,light has been she...Arsenic is a carcinogenic environmental factor found in food and drinking water around the world.The mechanisms in which arsenic alters homeostasis are not fully understood.Over the past few decades,light has been shed on varying mechanisms in which arsenic induces cancer.Such mechanisms include gut microbe perturbations,genotoxic effects,and epigenetic modification.Gut microbe perturbations have been shown to increase the level of pathogen-associated molecular patterns such as lipopolysaccharide(LPS) leading to uncontained inflammation.Increase in inflammation is the major factor in cirrhosis leading to hepatocellular carcinoma.Alterations in gut permeability and metabolites have also been observed as a fallout of arsenic induced gut microbe modification.The guts proximity and interaction through portal flow make the liver susceptible to gut perturbations and ensuing inflammatory responses.Genotoxic and epigenetic dysregulation induced by arsenic and its toxic metabolites present a more direct mechanism that works synergistically with gut microbe perturbations to induce the incidence of cancers.These pathways combined could be some of the main causes of arsenic-induced carcinogenesis.展开更多
Our previous data have shown that inorganic arsenic concentrations were high in Dianchi Lake,China,where Microcystis blooms often occur.To explore the relationship between arsenic and the growth of Microcystis,the eff...Our previous data have shown that inorganic arsenic concentrations were high in Dianchi Lake,China,where Microcystis blooms often occur.To explore the relationship between arsenic and the growth of Microcystis,the effects of arsenite[As(III)]and arsenate[As(V)]on the growth and toxin production of M.aeruginosa strain FACHB 905 were tested.Results showed that M.aeruginosa FACHB 905 was tolerant to inorganic arsenic and its growth was not inhibited when the concentration of As(III)was below 10-5 mol L-1 or that of As(V)below 10-3 mol L-1.Total microcystin production was stimulated in the presence of 10-7 mol L-1 As(III)and the response of this M.aeruginosa strain to As(III)seemed to be a typical inverted U-shaped hormesis.The content increase of microcystin-LR per cell indicated that the toxicity was enhanced as M.aeruginosa FACHB 905 was exposed to As(V).Considering the relatively high concentration of inorganic arsenic in Dianchi Lake(139μg L-1 in epilimnetic water),the origin of the M.aeruginosa strain,inorganic arsenic favors survival of M.aeruginosa FACHB 905 and may stimulate its microcystin production and cellular toxicity.展开更多
It has been estimated that between 94 million and 220 million people around the world are at risk of consuming drinking water that contain arsenic concentrations higher than 10μg/L(Podgorski and Berg,2020).
p-Arsanilic acid(p-ASA) is widely used in China as livestock and poultry feed additive for promoting animal growth.The use of organoarsenics poses a potential threat to the environment because it is mostly excreted by...p-Arsanilic acid(p-ASA) is widely used in China as livestock and poultry feed additive for promoting animal growth.The use of organoarsenics poses a potential threat to the environment because it is mostly excreted by animals in its original form and can be transformed by UV–Vis light excitation.This work examined the initial rate and efficiency of p-ASA phototransformation under UV-C disinfection lamp.Several factors influencing p-ASA phototransformation,namely,p H,initial concentration,temperature,as well as the presence of Na Cl,NH4+,and humic acid,were investigated.Quenching experiments and LC–MS were performed to investigate the mechanism of p-ASA phototransformation.Results show that p-ASA was decomposed to inorganic arsenic(including As(Ⅲ) and As(V))and aromatic products by UV-C light through direct photolysis and indirect oxidation.The oxidation efficency of p-ASA by direct photosis was about 32%,and those by HOU and1O2 were 19% and 49%,respectively.Cleavage of the arsenic–benzene bond through direct photolysis,HOU oxidation or1O2 oxidation results in simultaneous formation of inorganic As(Ⅲ),As(IV),and As(V).Inorganic As(Ⅲ) is oxidized to As(IV) and then to As(V) by1O2 or HOU.As(IV) can undergo dismutation or simply react with oxygen to produce As(V) as well.Reactions of the organic moieties of p-ASA produce aniline,aminophenol and azobenzene derivatives as main products.The photoconvertible property of p-ASA implies that UV disinfection of wastewaters from poultry and swine farms containing p-ASA poses a potential threat to the ecosystem,especially agricultural environments.展开更多
Inorganic arsenic induces a variety of toxicities including cancer. The mode of action for cancer and non-cancer effects involves the metabolic generation of trivalent arsenicals and their reaction with sulfhydryl gro...Inorganic arsenic induces a variety of toxicities including cancer. The mode of action for cancer and non-cancer effects involves the metabolic generation of trivalent arsenicals and their reaction with sulfhydryl groups within critical proteins in various cell types which leads to the biological response. In epithelial cells, the response is cell death with consequent regenerative proliferation. If this continues for a long period of time, it can result in an increased risk of cancer. Arsenicals do not react with DNA. There is evidence for indirect genotoxicity in various in vitro and in vivo systems, but these involve exposures at cytotoxic concentrations and are not the basis for cancer development. The resulting markers of genotoxicity could readily be due to the cytotoxicity rather than an effect on the DNA itself. Evidence for genotoxicity in humans has involved detection of chromosomal aberrations, sister chromatid exchanges in lymphocytes and micronucleus formation in lymphocytes, buccal mucosal cells, and exfoliated urothelial cells in the urine. Numerous difficulties have been identified in the interpretation of such results, including inadequate assessment of exposure to arsenic, measurement of micronuclei, and potential confounding factors such as tobacco exposure, folate deficiency, and others. Overall, the data strongly supports a non-linear dose response for the effects of inorganic arsenic. In various in vitro and in vivo models and in human epidemiology studies there appears to be a threshold for biological responses, including cancer.展开更多
Seven inorganic amendment materials were added into arsenic(As) contaminated soil at a rate of 0.5%(w/w); the materials used were sepiolite, red mud, iron grit, phosphogypsum, ferrihydrite, iron phosphate, and layered...Seven inorganic amendment materials were added into arsenic(As) contaminated soil at a rate of 0.5%(w/w); the materials used were sepiolite, red mud, iron grit, phosphogypsum, ferrihydrite, iron phosphate, and layered double oxides(LDO). Plant growth trials using rape(edible rape, Brassia campestris L.) as a bio-indicator are commonly used to assess As bioavailability in soils. In this study, B. campestris was grown in a contaminated soil for 50 days. All of the inorganic amendments significantly inhibited the uptake of As by B. campestris. Following soil treatment with the seven aforementioned inorganic ammendments, the As concentrations in the edible parts of B. campestris were reduced by 28.6, 10.5, 8.7, 31.0, 47.4, 25.3, and 28.8%, respectively, as compared with the plants grown in control soil. The most effective amendment was ferrihydrite, which reduced As concentration in B. campestris from 1.84 to 0.97 mg kg–1, compared to control. Furthermore, ferrihydrite-treated soils had a remarkable decrease in both non-specifically sorbed As and available-As by 67 and 20%, respectively, comparing to control. Phosphogypsum was the most cost-effective amendment and it showed excellent performance in reducing the water soluble As in soils by 31% and inhibiting As uptake in B. campestris by 21% comparing to control. Additionally, obvious differences in As transfer rates were observed in the various amendments. The seven amendment materials used in this study all showed potential reduction of As bioavailability and influence on plant growth and other biological processes still need to be further explored in the long term.展开更多
基金The Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA11020102the National Natural Science Foundation of China under contract Nos 41306055 and U1406403
文摘Distribution and chemical speciation of dissolved inorganic arsenic were examined in Yellow Sea and East China Sea. Results demonstrated that:(1) both As(III) and As(V) were detected, with As(V) dominated at 40% stations of surface water and 51% stations of bottom water;(2) influenced by the exchange of fresh and sea water, the type of surface sediment and the transport of various water masses, large values in surface water were observed along the coastal region and in the same latitude of Changjiang River Estuary and Hangzhou Bay, and in bottom water found in the southern area where the Taiwan Warm Current and Kuroshio Current influenced;(3) As(III) behaved non-conservatively in Changjiang River Estuary. Man-derived inputs cause substantial positive deviation from the theoretical dilution. The negative correlation of As(V) to salinity in surface water suggested that it behaved conservatively during the transportation along Changjiang River Estuary. While, the occurrence of As(V) up to the linear fit in bottom water indicated the eventual transfer from dissolved phase to particulate phase, which was impossible to be determined without the knowledge of arsenic level and speciation in suspended particulate matter. Further study is needed on the arsenic source/sink relationships based on the distribution profiles.
基金This research was supported by the National Basic Research Program of China （Nos. 2001CB409703 and G1999043705） the National Natural Science Foundation of China （Nos. 40036010 and 40206017）.
文摘Water samples were collected in the coastal area of the Changjiang Estuary on four cruises from August 2002 to May 2003. The seasonal variations of dissolved inorganic arsenic (DIAs) distributions were analyzed. The results showed that the distributions of DIAs were mainly influenced by the terrestrial input and the intrusion of the Kuroshio Subsurface Water (KSSW). The concentration of the total dissolved inorganic arsenic (TDIAs) decreased consecutively from winter to summer, while it increased in autumn. The distributions of TDIAs showed some relationships with salinity and suspended particulate matter (SPM). The relationships between DIAs speciation (including arsenite [As(Ⅲ)] and arsenate [As(Ⅴ)]), biological activity and the availabilities of the phosphate were investigated in the study area for the cruise August 2002. The ratio of As (Ⅲ)/TDIAs increased with the decrease of phosphate concentrations. In the bottom water, the As(Ⅲ)/TDIAs ratio decreased with the increasing of N/P. The concentration of TDIAs decreased 28.7% approximately after the occurrence of harmful algal blooms (HAB) because of the uptake of arsenate by algae. Further study is needed about the arsenic source/sink relationships in their vertical or horizontal profiles and the uptake mechanism during the occurrence of harmful algal blooms.
基金Project supported by the National Foundation for Distinguished Youthof China(No.40325003)the National Natural Science Foun-dation of China(No.40232022).
文摘In order to understand the similarity or difference of inorganic As species uptake and transport related to phosphorus in As-hyperaccumulator,uptake and transport of arsenate(As(V))and arsenite(As(III))were studied using Pteris vittata L.under sandculture.Higher concentrations of phosphate were found to inhibit accumulation of arsenate and arsenite in the fronds of P.vittata.The reduction in As accumulation was greater in old fronds than in young fronds,and relatively weak in root and rhizome.Moderateincreases,from 0.05 to 0.3 mmol/L,in phosphate reduced uptake of As(III)more than As(V),while the reverse was observed at highconcentrations of phosphate(1.0 mmol/L).Phosphate apparently reduced As transport and the proportion of As accumulated in frondsof P.vittata when As was supplied as As(V).It may in part be due to competition between phosphorus and As(V)during transport.Incontrast,phosphate had a much smaller effect on As transport when the As was supplied as As(III).Therefore,the results from presentexperiments indicates that a higher concentration of phosphate suppressed As accumulation and transport in P.vittata,especially inthe fronds,when exposed to As(V);but the suppression of phosphate to As transport may be insignificant when P.vittata exposed toAs(III)under sand culture conditions.The finding will help to understand the interaction of P and As during their uptake process in P.vittata.
基金Financially supported by the National Natural Science Foundation of China(No.31701708)the Outstanding Youth Foundation Project of Fujian Agriculture and Forestry University of China(No.xjq201710)
文摘A novel 1-methylimidazole ionic liquid modified SBA15 mesoporous silica(1-MIIL@SBA15) was synthesized and applied to selective separation of inorganic arsenic(iAs) in rice by dispersive solid phase extraction(DSPE), followed by hydride generation-atomic fluorescence spectrometric(HG-AFS) quantification. The prepared sorbent was characterized by FTIR, FESEM, BET and Zeta potential. Key parameters of adsorption and desorption in DSPE were optimized using standard reference material 1568 b rice flour. Under optimal conditions, the limit of detection was 8.776 ng/kg, relative standard deviation was ≤2.0%, and recoveries of iAs were in the 92.3～94.4% range. This method was successfully applied to the determination of iAs in rice. Under acidic condition, the electrostatic interaction between the positively charged 1-MIIL@SBA15 and anionic iAs played an important role in selective iAs separation, rendering this method suitable for iAs analysis.
文摘An automatic flow analysis system with on-line liquid nitrogen trap, hydride generation and flame-less atomic absorption spectrophotometry was presented for the determination of inorganic arsenic and antimony in seawater. The experimental conditions such as acidity of reduction reaction, the amount of sodium borohydride , the flow rate of carry gas (high purity of nitrogen) were tested and selected optimally. The limit detection of the method presented was 0. 15 ug/L for arsenic and 0. 24 μ/L for antimony . During the determination of seawater samples with levels microgram arsenic and antimony pa litre th?variation coefficient would be ±4% for arsenic and ±10% for antimony. The volume needed for one measurement was 9 mL for arsenic and 12 mL for antimony. The frequency of sample determination reached 20 times per hour for arsenic and 15 times per hour for antimony.
基金Support was provided by NSFC grants 41831279 and 41772265 to Yan Zhenggrant 2021YFA0715900 from the National Key Research and Development Program of China。
文摘Approximately 94 to 220 million people worldwide are at risk of drinking well water containing arsenic > 10 μg/L, the WHO guideline value. To identify non-compliant domestic wells, assess health risks and reduce exposure, accurate and rapid on-site inorganic arsenic screening methods are desirable because all domestic wells worldwide need to be tested.Here, the principles, advantages and limitations of commonly used colorimetry, electrochemistry, and biosensing methods are critically reviewed, with the performance compared with laboratory-based benchmark methods. Most commercial kits are based on the classic Gutzeit reaction. Despite being semi-quantitative, the more recent and more expensive products display improved and acceptable accuracy and shorter testing time (~10 min). Carried out by trained professionals, electrochemical methods are also feasible for on-site analysis, although miniaturization is desirable yet challenging. Biosensing using whole bacterial cells or bio-engineered materials such as aptamers is promising, if incorporated with function specific nanomaterials and biomaterials. Since arsenic is frequently found as arsenite in reducing groundwater and subject to oxidation during sampling, transportation and storage, on-site separation and sample preservation are feasible but the specific methods should be chosen based on sample matrix and tested before use. To eliminate arsenic exposure among hundreds of millions of mostly rural residents worldwide, we call for concerted efforts in research community and regulatory authority to develop accurate, rapid, and affordable tests for on-site screening and monitoring of arsenic in drinking water. Access to affordable testing will benefit people who are socioeconomically disadvantaged.
基金This work was supported by the National Natural Science Foundation of China(Nos.22207053,91753121,21872069,51761135104,21731004 and 91953201)the Shenzhen Basic Research Program(Nos.JCYJ20170413150538897 and JCYJ20180508182240106)+2 种基金the National Key R&D Program of China(Nos.2017YFA0208200,2016YFB0700600 and 2015CB659300)the Natural Science Foundation of Jiangsu Province(Nos.BK20220764,BK20180008 and BK20202004)The Fundamental Research Funds for the Central Universities,2021 Strategic Research Project of the Science and Technology Commission of the Ministry of Education of China.
文摘Arsenic(II)sulfide is a stable inorganic arsenic compound with a different valence from arsenic trioxide,and has been widely applied to treat various diseases with low toxic side effects for a long time.However,its low solubility and complicated formulations restrict its further applications in modern medical industry.Meanwhile,as the tumour with the highest incidence rate among women,the low recurrence risk of breast cancer has been confirmed to be closely related to the high infiltration of immune cells.Herein,we synthesized and filtered novel biocompatible PEGylated arsenic(II)sulfide nanocrystals AsS@PEG with a size of 93.14±0.49 nm by the gel method,which displayed excellent anticancer and immune activation activity in breast cancer model.Proteomic analysis suggested that the AsS@PEG induce ferroptosis in cancer cells and further activate antitumour immune responses via B-cell lymphoma 9-like(BCL9L)protein inhibition.Furthermore,mechanism studies revealed notable glutathione peroxidase 4(GPX4)downregulation in cancer cells,dendritic cells(DCs)maturation and subsequent effector CD8^(+)T-cells production induced by the AsS@PEG in the tumour microenvironment.This study highlights biocompatible arsenic(II)sulfide nanocrystals that induce ferroptotic cell death and activate antitumour immune responses,providing insights into the path towards the immunotherapy assisted chemotherapy for breast cancer.
文摘Lagoons are ecosystems for biodiversity and the livelihoods of coastal communities. The main objective of the study was to analyze the variability of arsenic concentrations in gastropods and bivalves in the Aby and Tendo lagoons, taking into account spatial, seasonal and hydrological variations. The study was carried out in four stages spread over two successive hydroclimatic cycles, including two seasons during the rainy season and two more during the dry season. The samples were taken in two areas of the Aby and Tendo lagoons. Arsenic levels were measured by ICP-MS. The results showed that mean arsenic concentrations in the muscles of organisms in Aby Lagoon ranged from 0.01 to 1.26 μg As/g, with a mean and median of 0.17 and 0.06 μg As/g, respectively. Fish had the highest levels of arsenic, followed by crustaceans, while molluscs and plants had lower and comparable concentrations of As. Arsenic concentrations in tilapia and jawbones varied significantly between sites and seasons, with higher concentrations at Tendo and during the rainy season. Arsenic concentrations in gastropods and bivalves were significantly higher than those of other species, with averages of 0.74 and 1.03 mg As/kg, respectively.
基金financially supported by the National Key Research and Development Program(Grant No.2022YFE0207400)the National Natural Science Foundation of China(Grant No.U22A20168 and 52174225)。
文摘Developing technologies that can be applied simultaneously in battery thermal management(BTM)and thermal runaway(TR)mitigation is significant to improving the safety of lithium-ion battery systems.Inorganic phase change material(PCM)with nonflammability has the potential to achieve this dual function.This study proposed an encapsulated inorganic phase change material(EPCM)with a heat transfer enhancement for battery systems,where Na_(2)HPO_(4)·12H_(2)O was used as the core PCM encapsulated by silica and the additive of carbon nanotube(CNT)was applied to enhance the thermal conductivity.The microstructure and thermal properties of the EPCM/CNT were analyzed by a series of characterization tests.Two different incorporating methods of CNT were compared and the proper CNT adding amount was also studied.After preparation,the battery thermal management performance and TR propagation mitigation effects of EPCM/CNT were further investigated on the battery modules.The experimental results of thermal management tests showed that EPCM/CNT not only slowed down the temperature rising of the module but also improved the temperature uniformity during normal operation.The peak battery temperature decreased from 76℃to 61.2℃at 2 C discharge rate and the temperature difference was controlled below 3℃.Moreover,the results of TR propagation tests demonstrated that nonflammable EPCM/CNT with good heat absorption could work as a TR barrier,which exhibited effective mitigation on TR and TR propagation.The trigger time of three cells was successfully delayed by 129,474 and 551 s,respectively and the propagation intervals were greatly extended as well.
基金supported by the U.S. National Institutes of Health (Nos.R01DK080440,R01DK104656,R01ES025909,R21AA022482,R21AA024935)the VA Merit Award (Nos.1I01BX002634)+1 种基金Natural Scientific Foundation of China (No.81572443)Yale Liver Center,USA (No.P30 DK34989)
文摘Arsenic is a carcinogenic environmental factor found in food and drinking water around the world.The mechanisms in which arsenic alters homeostasis are not fully understood.Over the past few decades,light has been shed on varying mechanisms in which arsenic induces cancer.Such mechanisms include gut microbe perturbations,genotoxic effects,and epigenetic modification.Gut microbe perturbations have been shown to increase the level of pathogen-associated molecular patterns such as lipopolysaccharide(LPS) leading to uncontained inflammation.Increase in inflammation is the major factor in cirrhosis leading to hepatocellular carcinoma.Alterations in gut permeability and metabolites have also been observed as a fallout of arsenic induced gut microbe modification.The guts proximity and interaction through portal flow make the liver susceptible to gut perturbations and ensuing inflammatory responses.Genotoxic and epigenetic dysregulation induced by arsenic and its toxic metabolites present a more direct mechanism that works synergistically with gut microbe perturbations to induce the incidence of cancers.These pathways combined could be some of the main causes of arsenic-induced carcinogenesis.
基金supported by the State Key Laboratory of Freshwater Ecology and Biotechnology(2009FBZ09)National Major Science and Technology Program of China(2009ZX07104-005-03)the Hubei Key Laboratory of Crop Diseases,Insect Pests and Weeds Control(2011CDIWC-1-1)
文摘Our previous data have shown that inorganic arsenic concentrations were high in Dianchi Lake,China,where Microcystis blooms often occur.To explore the relationship between arsenic and the growth of Microcystis,the effects of arsenite[As(III)]and arsenate[As(V)]on the growth and toxin production of M.aeruginosa strain FACHB 905 were tested.Results showed that M.aeruginosa FACHB 905 was tolerant to inorganic arsenic and its growth was not inhibited when the concentration of As(III)was below 10-5 mol L-1 or that of As(V)below 10-3 mol L-1.Total microcystin production was stimulated in the presence of 10-7 mol L-1 As(III)and the response of this M.aeruginosa strain to As(III)seemed to be a typical inverted U-shaped hormesis.The content increase of microcystin-LR per cell indicated that the toxicity was enhanced as M.aeruginosa FACHB 905 was exposed to As(V).Considering the relatively high concentration of inorganic arsenic in Dianchi Lake(139μg L-1 in epilimnetic water),the origin of the M.aeruginosa strain,inorganic arsenic favors survival of M.aeruginosa FACHB 905 and may stimulate its microcystin production and cellular toxicity.
文摘It has been estimated that between 94 million and 220 million people around the world are at risk of consuming drinking water that contain arsenic concentrations higher than 10μg/L(Podgorski and Berg,2020).
基金supported by the National Natural Science Foundation of China(Nos 51508423 and 21477090)
文摘p-Arsanilic acid(p-ASA) is widely used in China as livestock and poultry feed additive for promoting animal growth.The use of organoarsenics poses a potential threat to the environment because it is mostly excreted by animals in its original form and can be transformed by UV–Vis light excitation.This work examined the initial rate and efficiency of p-ASA phototransformation under UV-C disinfection lamp.Several factors influencing p-ASA phototransformation,namely,p H,initial concentration,temperature,as well as the presence of Na Cl,NH4+,and humic acid,were investigated.Quenching experiments and LC–MS were performed to investigate the mechanism of p-ASA phototransformation.Results show that p-ASA was decomposed to inorganic arsenic(including As(Ⅲ) and As(V))and aromatic products by UV-C light through direct photolysis and indirect oxidation.The oxidation efficency of p-ASA by direct photosis was about 32%,and those by HOU and1O2 were 19% and 49%,respectively.Cleavage of the arsenic–benzene bond through direct photolysis,HOU oxidation or1O2 oxidation results in simultaneous formation of inorganic As(Ⅲ),As(IV),and As(V).Inorganic As(Ⅲ) is oxidized to As(IV) and then to As(V) by1O2 or HOU.As(IV) can undergo dismutation or simply react with oxygen to produce As(V) as well.Reactions of the organic moieties of p-ASA produce aniline,aminophenol and azobenzene derivatives as main products.The photoconvertible property of p-ASA implies that UV disinfection of wastewaters from poultry and swine farms containing p-ASA poses a potential threat to the ecosystem,especially agricultural environments.
文摘Inorganic arsenic induces a variety of toxicities including cancer. The mode of action for cancer and non-cancer effects involves the metabolic generation of trivalent arsenicals and their reaction with sulfhydryl groups within critical proteins in various cell types which leads to the biological response. In epithelial cells, the response is cell death with consequent regenerative proliferation. If this continues for a long period of time, it can result in an increased risk of cancer. Arsenicals do not react with DNA. There is evidence for indirect genotoxicity in various in vitro and in vivo systems, but these involve exposures at cytotoxic concentrations and are not the basis for cancer development. The resulting markers of genotoxicity could readily be due to the cytotoxicity rather than an effect on the DNA itself. Evidence for genotoxicity in humans has involved detection of chromosomal aberrations, sister chromatid exchanges in lymphocytes and micronucleus formation in lymphocytes, buccal mucosal cells, and exfoliated urothelial cells in the urine. Numerous difficulties have been identified in the interpretation of such results, including inadequate assessment of exposure to arsenic, measurement of micronuclei, and potential confounding factors such as tobacco exposure, folate deficiency, and others. Overall, the data strongly supports a non-linear dose response for the effects of inorganic arsenic. In various in vitro and in vivo models and in human epidemiology studies there appears to be a threshold for biological responses, including cancer.
基金the financial support of the National Natural Science Foundation of China (41171255)the National Scientific and Technology Program during 12th Five-Year Plan period, China (2012BAD14B02)
文摘Seven inorganic amendment materials were added into arsenic(As) contaminated soil at a rate of 0.5%(w/w); the materials used were sepiolite, red mud, iron grit, phosphogypsum, ferrihydrite, iron phosphate, and layered double oxides(LDO). Plant growth trials using rape(edible rape, Brassia campestris L.) as a bio-indicator are commonly used to assess As bioavailability in soils. In this study, B. campestris was grown in a contaminated soil for 50 days. All of the inorganic amendments significantly inhibited the uptake of As by B. campestris. Following soil treatment with the seven aforementioned inorganic ammendments, the As concentrations in the edible parts of B. campestris were reduced by 28.6, 10.5, 8.7, 31.0, 47.4, 25.3, and 28.8%, respectively, as compared with the plants grown in control soil. The most effective amendment was ferrihydrite, which reduced As concentration in B. campestris from 1.84 to 0.97 mg kg–1, compared to control. Furthermore, ferrihydrite-treated soils had a remarkable decrease in both non-specifically sorbed As and available-As by 67 and 20%, respectively, comparing to control. Phosphogypsum was the most cost-effective amendment and it showed excellent performance in reducing the water soluble As in soils by 31% and inhibiting As uptake in B. campestris by 21% comparing to control. Additionally, obvious differences in As transfer rates were observed in the various amendments. The seven amendment materials used in this study all showed potential reduction of As bioavailability and influence on plant growth and other biological processes still need to be further explored in the long term.
