A synergistic catalytic effect between copper methanesulfonate and acetic acid in tetrahydropyranylation of alcohols and phenol at room temperature under solvent free condition has been described. Both alcohols （prim...A synergistic catalytic effect between copper methanesulfonate and acetic acid in tetrahydropyranylation of alcohols and phenol at room temperature under solvent free condition has been described. Both alcohols （primary, secondary and tertiary） and phenols reacted with 3,4-dihydro-2H-pyran smoothly to afford the corresponding tetrahydropyranyl ethers in good yields.展开更多
Cobalt methanesulfonate in combination with acetic acid catalysed the chemoselective diacetylation of aldehyde with acetic anhydride at room temperature under solvent free conditions. After reaction, cobalt methanesul...Cobalt methanesulfonate in combination with acetic acid catalysed the chemoselective diacetylation of aldehyde with acetic anhydride at room temperature under solvent free conditions. After reaction, cobalt methanesulfonate can be easily recovered and reused many times. The reaction was mild and efficient with good to high yields.展开更多
The synthesis of organolanthanide compounds identified as LnCp^＊（MS）2PzA, Ln = Sm, Tb, Yb （MS = methanesulfonate, Cp^＊ = pentamethylcyclopentadienyl, and PzA = pyrazinamide）, by the reaction of coordination comp...The synthesis of organolanthanide compounds identified as LnCp^＊（MS）2PzA, Ln = Sm, Tb, Yb （MS = methanesulfonate, Cp^＊ = pentamethylcyclopentadienyl, and PzA = pyrazinamide）, by the reaction of coordination compounds Ln（MS）3（PzA）4 with NaCp in THF was reported. The complexes were formulated according to elemental analyses, complexometric titration with EDTA （%Ln）, and ^1H NMR. IR spectroscopy revealed that PzA coordinates with lanthanide （Ⅲ） ions and methanesulfonate coordinates via oxygen atoms in a non-equivalent manner. In preliminary catalytic studies, these compounds were active in styrene polymerization that used MAO as a cocatalyst with an activity of 12.3 kg PS molSm^-1h^-1. Differential scanning calorimetry （DSC） of polystyrene showed that the polymer was mainly atactic.展开更多
Background: Producing rainfed cotton(Gossypium hirsutum L.) with high fiber quality has been challenging in the Texas High Plains because of extended periods of insufficient rainfall during sensitive boll developmenta...Background: Producing rainfed cotton(Gossypium hirsutum L.) with high fiber quality has been challenging in the Texas High Plains because of extended periods of insufficient rainfall during sensitive boll developmental stages.Genetic variation created by Ethyl MethaneSulfonate(EMS) mutagen has successfully improved fiber quality of cotton. However, little is known about the effect of water deficit environments on fiber quality. Three EMS treated populations were advanced from the first to the fourth generation(M1 to M4) as bulk harvested populations. In2014, single-plant divergent selection was applied based on perceived morphological and agronomic differences seen during and at the end of the season.Results: Analyses from these selections in 2014-2016 showed significant(P< 0.05) improvement between and within populations for fiber traits(micronaire, length, strength, uniformity, and elongation) when compared with the original non-treated EMS source; some selections were found to have excellent fiber quality under diverse irrigationregimes.Conclusions: Some of these selections are being considered for germplasm release and could be useful for improving the fiber quality of cotton under water limited conditions, thereby helping to ensure the long-term survival of the cotton industry on the Texas High Plains.展开更多
A series of 5-aminolevulinic acid and its alkylester methanesulfonates was exploited to photodynamic therapy（PDT） of human lymphocytic cells, U-937 in vitro. The PDT efficiency is influenced by the concentration and...A series of 5-aminolevulinic acid and its alkylester methanesulfonates was exploited to photodynamic therapy（PDT） of human lymphocytic cells, U-937 in vitro. The PDT efficiency is influenced by the concentration and incubation time. Generally, for ALA and its alkylester methanesulfonates, the cell survival rate decreases and the accumulation ability of PplX increases with the concentration and incubation time. We found that the longer carbon chain methanesulfonates（C5-S, C6-S, C8-S） exhibit better PDT effect than ALA methanesulfonate. This possibly provides a promising route to the clinical application ofPplX-mediated PDT to cancer cell.展开更多
Ethyl methanesulfonate (EMS) is a stable and effective chemical mutagen. In this study, cucumber (Cucumis sativus L. cv. “Shannong No. 5”) seeds were treated by 1% EMS for 12 h, 24 h and 48 h to optimize EMS mutagen...Ethyl methanesulfonate (EMS) is a stable and effective chemical mutagen. In this study, cucumber (Cucumis sativus L. cv. “Shannong No. 5”) seeds were treated by 1% EMS for 12 h, 24 h and 48 h to optimize EMS mutagenesis and determined median lethal dose of EMS (1% EMS and 24 h) for “Shannong No. 5”. After treated by 1% EMS for 24 h, 541 M1 plants were grown in greenhouse for phenotype investigation. The fertility of M1 cucumbers was very low, and only 79 lines produced seeds after self crossing. 60 independent M2 families comprising 600 M2 plants were investigated for phenotypic alteration, and 11 individual mutant lines were isolated into six groups: short-fruit mutants, long-fruit mutants, small-flower mutants, big-flower mutants, opposite-tendril mutants and clustered-leaf mutants. The mutation frequency was 18.3%. Two selected representatives, short-fruit mutants and clustered-leaf mutants, showed 1:3 of segregation ratio in M2 populations. This ratio is consistent with classic Mendelian model, indicating that the two kinds of mutants may be controlled by a single recessive gene, respectively. Long-fruit phenotype was stably inherited and no segregation was observed in M3 generation, indicating that this mutant line may be homozygous.展开更多
Background:Producing rainfed cotton (Gossypium hirsutum L.) with high fiber quality has been challenging in the Texas High Plains because of extended periods of insufficient rainfall during sensitive boll developmenta...Background:Producing rainfed cotton (Gossypium hirsutum L.) with high fiber quality has been challenging in the Texas High Plains because of extended periods of insufficient rainfall during sensitive boll developmental stages.Genetic variation created by Ethyl MethaneSulfonate (EMS) mutagen has successfully improved fiber quality of cotton.However,little is known about the effect of water deficit environments on fiber quality.Three EMS treated populations were advanced from the first to the fourth generation (M1 to M4) as bulk harvested populations.In2014,single-plant divergent selection was applied based on perceived morphological and agronomic differences seen during and at the end of the season.Results:Analyses from these selections in 2014-2016 showed significant (P < 0.05) improvement between and within populations for fiber traits (micronaire,length,strength,uniformity,and elongation) when compared with the original non-treated EMS source;some selections were found to have excellent fiber quality under diverse irrigation-regimes.Conclusions:Some of these selections are being considered for germplasm release and could be useful for improving the fiber quality of cotton under water limited conditions,thereby helping to ensure the long-term survival of the cotton industry on the Texas High Plains.展开更多
Main observation and conclusion We have developed an efficient synthesis of acrylonitriles via mild base promoted tandem nucleophilic substitution-isomerization ofα-cyanohydrin methanesulfonates with alkenylboronic a...Main observation and conclusion We have developed an efficient synthesis of acrylonitriles via mild base promoted tandem nucleophilic substitution-isomerization ofα-cyanohydrin methanesulfonates with alkenylboronic acids.This transition metal-free protocol works under simple and mild conditions and offers good chemical yields for a wide range of substrates and demonstrates good functional group tolerance.展开更多
This study focuses on using a green reagent scheme of methanesulfonic acid (MSA) and citric acid (CA) to extract valuable metals from the cathodes, aiming to minimize environmental impact during the recycling process....This study focuses on using a green reagent scheme of methanesulfonic acid (MSA) and citric acid (CA) to extract valuable metals from the cathodes, aiming to minimize environmental impact during the recycling process. Leaching studies on LiCoO_(2) identified optimal conditions as follows: 2.4 mol/L MSA, 1.6 mol/L CA, S/L ratio of 80 g/L, leaching temperature of 90oC and leaching time of 6 h. The maximum Co and Li extraction achieved was 92% and 85%, respectively. LiCoO_(2) dissolution in MSA-CA leaching solution is highly impacted by temperature;Avrami equation showed a good fitting for the leaching data. The experimental activation energy of Co and Li was 50.98 kJ/mol and 50.55 kJ/mol, respectively, indicating that it is a chemical reaction-controlled process. Furthermore, cobalt was efficiently recovered from the leachate using oxalic acid, achieving a precipitation efficiency of 99.91% and a high-purity cobalt oxalate product (99.85 wt.%). In the MSA-CA leaching solution, MSA served as a lixiviant, while CA played a key role in reducing Co in LiCoO_(2). The overall organic acid leaching methodology presents an attractive option due to its reduced environmental impact.展开更多
A new hydrometallurgical process based on the methanesulfonic acid system was proposed to extract the bismuth efficiently from by-products of lead smelting.The bismuth extraction process included electrorefining,oxida...A new hydrometallurgical process based on the methanesulfonic acid system was proposed to extract the bismuth efficiently from by-products of lead smelting.The bismuth extraction process included electrorefining,oxidation leaching,and electrodeposition.The optimum conditions of the bismuth extraction process were determined by a single-factor test.The bismuth plate with a purity of 99.8%was obtained under the optimum conditions.Cyclic voltammetry and linear sweep voltammetry were applied to investigating the cathode reaction mechanism of electrorefining.The results show that lead deposition,bismuth deposition,and hydrogen evolution occur at the cathode,and the reactions of metals deposition are irreversible and diffusion-controlled.In addition,decreasing the temperature and acidity can improve the purity of the cathodic product(lead powder)in the electrorefining process.展开更多
The availability of the B73 inbred reference genome sets the stage for high-throughput functional charac- terization of maize genes on a whole-genome scale. Among the 39 324 protein-coding genes predicted, the vast ma...The availability of the B73 inbred reference genome sets the stage for high-throughput functional charac- terization of maize genes on a whole-genome scale. Among the 39 324 protein-coding genes predicted, the vast majority are untapped due to the lack of suitable high-throughput reverse genetic resources. We have generated a gene-indexed maize mutant collection through ethyl methanesulfonate mutagenesis and de- tected the mutations by combining exome capture and next-generation sequencing. A total of 1086 mutated MI plants were sequenced, and 195 268 CG〉TA-type point mutations, including stop gain/loss, missplice, start gain/loss, and various non-synonymous protein mutations as well as 4610 InDel mutations, were identified. These mutations were distributed on 32 069 genes, representing 82% of the predicted protein-coding genes in the maize genome. We detected an average of 180 mutations per mutant line and 6.1 mutations per gene. As many as 27 214 mutations of start codons, stop codons, or missplice sites were identified in 14 101 genes, among which 6232 individual genes harbored more than two such muta- tions. Application of this mutant collection is exemplified by the identification of the ent-kaurene synthase gene, which encodes a key enzyme in the gibberellin biosynthesis pathway. This gene-indexed genome- wide mutation collection provides an important resource for functional analysis of maize genes and may bring desirable allelic variants for genetic breeding in maize.展开更多
Methanesulfonic acid(MSA) has been identified as one of the most important intermediate products of DMS reactions in the atmosphere.Although considerable amounts of MSA have been found in the ma-rine boundary layer,li...Methanesulfonic acid(MSA) has been identified as one of the most important intermediate products of DMS reactions in the atmosphere.Although considerable amounts of MSA have been found in the ma-rine boundary layer,little is known about the interaction of gaseous MSA with sea salt particles.To understand the fate of MSA in the atmosphere and its potential importance in atmospheric chemistry,the heterogeneous reactions of gaseous MSA with micron-scale NaCl and sea salt particles were studied using diffuse reflectance infrared Fourier transform spectrometry,X-ray photoelectron spectroscopy,and scanning electron microscopy.The CH3SO3Na and CH3SO3-were the major products of the condensed phase of the reaction of gaseous MSA with NaCl and with sea salt particles.The steady-state uptake coefficient was determined to be(5.94±2.32)×10-7(1 σ) for the reaction of gaseous MSA with NaCl particles and(2.23±1.25)×10-7(1 σ) for the reaction of gaseous MSA with sea salt parti-cles.The heterogeneous reaction of MSA with NaCl particles was found to be first-order for MSA.The reaction mechanisms were discussed.展开更多
Background Methanesulfonic acid sodium salt （Dipyrone）, an antipyretic and analgesic drug, has been demonstrated to improve cerebral ischemia through the inhibition of mitochondrial cell death cascades. The aim of t...Background Methanesulfonic acid sodium salt （Dipyrone）, an antipyretic and analgesic drug, has been demonstrated to improve cerebral ischemia through the inhibition of mitochondrial cell death cascades. The aim of this study was to evaluate the potential photoprotective activity of methanesulfonic acid sodium salt in a model of light-induced retinopathy. Methods One hundred mice were assigned randomly into vehicle （V）, methanesulfonic acid sodium salt （D）, light damage model plus vehicle （MV） and light damage model plus methanesulfonic acid sodium salt （MD） groups （n=25 each）. In the MD group, methanesulfonic acid sodium salt （100 mg/kg） was administered by intraperitoneal injection 30 minutes before light exposure. Twenty-four hours after light exposure, hematoxylin and eosin staining and transmission electron microscopy （TEM） were used for histological evaluation. The thickness of the outer plus inner-segment and outer nuclear layer was measured on sections parallel to the vertical meridian of the eye at a distance of 1000 I^m from the optic nerve. Electroretinography （ERG） test was performed to assess the functional change. The morphology of mitochondria was also revealed by TEM. Finally, the expression of cytochrome c （CytC） and the relative apoptotic proteins were detected by Western blotting, and the interaction between mitochondrial proteins was investigated by co-immunoprecipitation. Results The photoreceptor inner and outer segments of the MV group were significantly disorganized than the MD group. The thicknesses of the outer plus inner-segment layers and the outer nuclear layer, and the amplitudes of the a and b waves of the scotopic ERG response markedly decreased in the MV group compared to those in the MD group （P 〈0.05）. TEM examination revealed that the mitochondria of the MV group were distinctly swollen and contained disrupted cristae. In contrast, the morphology of mitochondria in the MD group was unaffected. Western blotting analysis showed that CytC, apoptosis proteinase activating factor-1 （Apaf-1）, caspase 3, p53, p53-upregulated modulator of apoptosis （PUMA）, Bax, and Bad were increased, whereas the anti-apoptotic proteins Bcl-2 and Bcl-XL were significantly decreased in the MV group than the MD group. Co-immunoprecipitation detection revealed that PUMA immunoreactivity precipitated by Bcl-XL decreased, whereas Bax immunoreactivity precipitated by Bcl-XL increased in the MD group compared to those in the MV group. Conclusion Methanesulfonic acid sodium salt is an effective photoprotective agent against light-induced retinopathy through the inhibition of CytC-mediated mitochondrial impairment.展开更多
Four kinds of polythiophenes have been doped with CH3SO3H in CHCl3 under air,oxygen,and nitrogen. In the doping of two types of poly(3-hexylthiophene)s,P3HexTh(Zn/Ni)and P3HexTh(Fe)with different contents of a head-to...Four kinds of polythiophenes have been doped with CH3SO3H in CHCl3 under air,oxygen,and nitrogen. In the doping of two types of poly(3-hexylthiophene)s,P3HexTh(Zn/Ni)and P3HexTh(Fe)with different contents of a head-to-tail unit,the p-doping occurs at a similar rate.The reaction between poly(3-dodecylthiophene),P3DodTh,and the acid takes place more rapidly.P3OBuTh with a butoxy substituent undergoes more facile p-doping and receives photochemical reaction with CHCl3,and this reaction obeys a pseudo-first-order rate law with a rate constant kobs of 1.42×10-5s-1at room tempera- ture.展开更多
Methanesulfonic acid （MSA） was successfully immobilized in silica, leading to a novel and environmentally friendly solid acid catalyst SMSA. The most important feature of SMSA is that anhydrous formic acid is used t...Methanesulfonic acid （MSA） was successfully immobilized in silica, leading to a novel and environmentally friendly solid acid catalyst SMSA. The most important feature of SMSA is that anhydrous formic acid is used to hydrolysis of tetraethylorthosili- cate （TEOS）. No water was added in the whole preparation. Therefore, MSA could be anchored in silica matrix more effec- tively instead of being dissolved in water. This new organic/inorganic hybrid catalyst was characterized by powder X-ray dif- fraction （XRD）, energy dispersive spectrum （EDS）, N2 adsorption-desorption analyzer, thermogravimetric analysis （TGA-DSC） and pyridine-FTIR. The catalytic activity was tested by alkylation of olefins and aromatics. High concentration acid sites, both Lewis and Brcnsted, abundant porosity and large surface area enabled the highest activity for SMSA, among MCM-22. ZSM-5 and industrial acidity clay.展开更多
A novel approach is designed to optimize the synthesis of sulfonic-functionalized silica material. Results from 29Si and 27AI NMR suggest that the AI acts as the bridging atom connecting the methanesulfonate and silic...A novel approach is designed to optimize the synthesis of sulfonic-functionalized silica material. Results from 29Si and 27AI NMR suggest that the AI acts as the bridging atom connecting the methanesulfonate and silica matrix. Further pyridine-FTIR spectra followed by catalytic activity tests demonstrate that compared with previous methods, our new approach results in higher Lewis acid site concentration, higher thermal stability and superior catalytic activity. Moreover, the whole catalysis preparation procedure is environmentally friendly. Specifically, the silica matrix is synthesized through hydrolysis of tetrae- thylorthosilicate employing formic acid as hydro-catalyst, in which no surfactant species or precursors were involved.展开更多
A green protocol for the preparation of amidoalkyl naphthols from three-component one-pot condensation of 2-naphthol, aldehydes, amides or urea in the presence of silica supported methanesulfonic acid under thermal so...A green protocol for the preparation of amidoalkyl naphthols from three-component one-pot condensation of 2-naphthol, aldehydes, amides or urea in the presence of silica supported methanesulfonic acid under thermal sol- vent-free conditions has been described. The catalyst is stable, efficient, easily prepared, and reusable. The remarkable features of this methodology are short reaction time, excellent yields, simple experimental and work-up procedures.展开更多
文摘A synergistic catalytic effect between copper methanesulfonate and acetic acid in tetrahydropyranylation of alcohols and phenol at room temperature under solvent free condition has been described. Both alcohols （primary, secondary and tertiary） and phenols reacted with 3,4-dihydro-2H-pyran smoothly to afford the corresponding tetrahydropyranyl ethers in good yields.
文摘Cobalt methanesulfonate in combination with acetic acid catalysed the chemoselective diacetylation of aldehyde with acetic anhydride at room temperature under solvent free conditions. After reaction, cobalt methanesulfonate can be easily recovered and reused many times. The reaction was mild and efficient with good to high yields.
基金Project supported by the Fundacā de Amparo à Pesquisa do Estado de Sāo Paulo and CNPq Conselho Nacional de Desenvolvimento Científico e Teenológico
文摘The synthesis of organolanthanide compounds identified as LnCp^＊（MS）2PzA, Ln = Sm, Tb, Yb （MS = methanesulfonate, Cp^＊ = pentamethylcyclopentadienyl, and PzA = pyrazinamide）, by the reaction of coordination compounds Ln（MS）3（PzA）4 with NaCp in THF was reported. The complexes were formulated according to elemental analyses, complexometric titration with EDTA （%Ln）, and ^1H NMR. IR spectroscopy revealed that PzA coordinates with lanthanide （Ⅲ） ions and methanesulfonate coordinates via oxygen atoms in a non-equivalent manner. In preliminary catalytic studies, these compounds were active in styrene polymerization that used MAO as a cocatalyst with an activity of 12.3 kg PS molSm^-1h^-1. Differential scanning calorimetry （DSC） of polystyrene showed that the polymer was mainly atactic.
基金funded by the Ogallala Aquifer Program with a collaborative project between Texas Tech University and USDA-ARS,PA,Cropping System Research Laboratory,Lubbock,TXUSDA-ARS(Project 3096-21000-019-00-D)(MU)
文摘Background: Producing rainfed cotton(Gossypium hirsutum L.) with high fiber quality has been challenging in the Texas High Plains because of extended periods of insufficient rainfall during sensitive boll developmental stages.Genetic variation created by Ethyl MethaneSulfonate(EMS) mutagen has successfully improved fiber quality of cotton. However, little is known about the effect of water deficit environments on fiber quality. Three EMS treated populations were advanced from the first to the fourth generation(M1 to M4) as bulk harvested populations. In2014, single-plant divergent selection was applied based on perceived morphological and agronomic differences seen during and at the end of the season.Results: Analyses from these selections in 2014-2016 showed significant(P< 0.05) improvement between and within populations for fiber traits(micronaire, length, strength, uniformity, and elongation) when compared with the original non-treated EMS source; some selections were found to have excellent fiber quality under diverse irrigationregimes.Conclusions: Some of these selections are being considered for germplasm release and could be useful for improving the fiber quality of cotton under water limited conditions, thereby helping to ensure the long-term survival of the cotton industry on the Texas High Plains.
基金Supported Partly by the Academic Frontier Promotion Grant from the Ministry of Education,Science,Sports and Culture,Japan and the Exchange Program Between the Japan Society of the Promotion of Science and the Chinese Academy of Sciences
文摘A series of 5-aminolevulinic acid and its alkylester methanesulfonates was exploited to photodynamic therapy（PDT） of human lymphocytic cells, U-937 in vitro. The PDT efficiency is influenced by the concentration and incubation time. Generally, for ALA and its alkylester methanesulfonates, the cell survival rate decreases and the accumulation ability of PplX increases with the concentration and incubation time. We found that the longer carbon chain methanesulfonates（C5-S, C6-S, C8-S） exhibit better PDT effect than ALA methanesulfonate. This possibly provides a promising route to the clinical application ofPplX-mediated PDT to cancer cell.
文摘Ethyl methanesulfonate (EMS) is a stable and effective chemical mutagen. In this study, cucumber (Cucumis sativus L. cv. “Shannong No. 5”) seeds were treated by 1% EMS for 12 h, 24 h and 48 h to optimize EMS mutagenesis and determined median lethal dose of EMS (1% EMS and 24 h) for “Shannong No. 5”. After treated by 1% EMS for 24 h, 541 M1 plants were grown in greenhouse for phenotype investigation. The fertility of M1 cucumbers was very low, and only 79 lines produced seeds after self crossing. 60 independent M2 families comprising 600 M2 plants were investigated for phenotypic alteration, and 11 individual mutant lines were isolated into six groups: short-fruit mutants, long-fruit mutants, small-flower mutants, big-flower mutants, opposite-tendril mutants and clustered-leaf mutants. The mutation frequency was 18.3%. Two selected representatives, short-fruit mutants and clustered-leaf mutants, showed 1:3 of segregation ratio in M2 populations. This ratio is consistent with classic Mendelian model, indicating that the two kinds of mutants may be controlled by a single recessive gene, respectively. Long-fruit phenotype was stably inherited and no segregation was observed in M3 generation, indicating that this mutant line may be homozygous.
文摘Background:Producing rainfed cotton (Gossypium hirsutum L.) with high fiber quality has been challenging in the Texas High Plains because of extended periods of insufficient rainfall during sensitive boll developmental stages.Genetic variation created by Ethyl MethaneSulfonate (EMS) mutagen has successfully improved fiber quality of cotton.However,little is known about the effect of water deficit environments on fiber quality.Three EMS treated populations were advanced from the first to the fourth generation (M1 to M4) as bulk harvested populations.In2014,single-plant divergent selection was applied based on perceived morphological and agronomic differences seen during and at the end of the season.Results:Analyses from these selections in 2014-2016 showed significant (P < 0.05) improvement between and within populations for fiber traits (micronaire,length,strength,uniformity,and elongation) when compared with the original non-treated EMS source;some selections were found to have excellent fiber quality under diverse irrigation-regimes.Conclusions:Some of these selections are being considered for germplasm release and could be useful for improving the fiber quality of cotton under water limited conditions,thereby helping to ensure the long-term survival of the cotton industry on the Texas High Plains.
基金the Scientific Research Foundation of Yancheng Institute of Technology(No.1542036)the National Natural Science Foundation of China for financial support(No.NSFC-21472018)+2 种基金the National Science Foundation(NSF,Grant No.CHE-1401700)the Open Fund of Jiangsu Collaborative Innovation Center for Ecological Building Material and Environmental Protection Equipments and Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province(No.JH201832)the Funding for School-Level Research Projects of Yancheng Institute of Technology(No.xjr2020011).
文摘Main observation and conclusion We have developed an efficient synthesis of acrylonitriles via mild base promoted tandem nucleophilic substitution-isomerization ofα-cyanohydrin methanesulfonates with alkenylboronic acids.This transition metal-free protocol works under simple and mild conditions and offers good chemical yields for a wide range of substrates and demonstrates good functional group tolerance.
文摘This study focuses on using a green reagent scheme of methanesulfonic acid (MSA) and citric acid (CA) to extract valuable metals from the cathodes, aiming to minimize environmental impact during the recycling process. Leaching studies on LiCoO_(2) identified optimal conditions as follows: 2.4 mol/L MSA, 1.6 mol/L CA, S/L ratio of 80 g/L, leaching temperature of 90oC and leaching time of 6 h. The maximum Co and Li extraction achieved was 92% and 85%, respectively. LiCoO_(2) dissolution in MSA-CA leaching solution is highly impacted by temperature;Avrami equation showed a good fitting for the leaching data. The experimental activation energy of Co and Li was 50.98 kJ/mol and 50.55 kJ/mol, respectively, indicating that it is a chemical reaction-controlled process. Furthermore, cobalt was efficiently recovered from the leachate using oxalic acid, achieving a precipitation efficiency of 99.91% and a high-purity cobalt oxalate product (99.85 wt.%). In the MSA-CA leaching solution, MSA served as a lixiviant, while CA played a key role in reducing Co in LiCoO_(2). The overall organic acid leaching methodology presents an attractive option due to its reduced environmental impact.
基金financial supports from the National Key Research and Development Program of China(No.2018YFC1900403)。
文摘A new hydrometallurgical process based on the methanesulfonic acid system was proposed to extract the bismuth efficiently from by-products of lead smelting.The bismuth extraction process included electrorefining,oxidation leaching,and electrodeposition.The optimum conditions of the bismuth extraction process were determined by a single-factor test.The bismuth plate with a purity of 99.8%was obtained under the optimum conditions.Cyclic voltammetry and linear sweep voltammetry were applied to investigating the cathode reaction mechanism of electrorefining.The results show that lead deposition,bismuth deposition,and hydrogen evolution occur at the cathode,and the reactions of metals deposition are irreversible and diffusion-controlled.In addition,decreasing the temperature and acidity can improve the purity of the cathodic product(lead powder)in the electrorefining process.
文摘The availability of the B73 inbred reference genome sets the stage for high-throughput functional charac- terization of maize genes on a whole-genome scale. Among the 39 324 protein-coding genes predicted, the vast majority are untapped due to the lack of suitable high-throughput reverse genetic resources. We have generated a gene-indexed maize mutant collection through ethyl methanesulfonate mutagenesis and de- tected the mutations by combining exome capture and next-generation sequencing. A total of 1086 mutated MI plants were sequenced, and 195 268 CG〉TA-type point mutations, including stop gain/loss, missplice, start gain/loss, and various non-synonymous protein mutations as well as 4610 InDel mutations, were identified. These mutations were distributed on 32 069 genes, representing 82% of the predicted protein-coding genes in the maize genome. We detected an average of 180 mutations per mutant line and 6.1 mutations per gene. As many as 27 214 mutations of start codons, stop codons, or missplice sites were identified in 14 101 genes, among which 6232 individual genes harbored more than two such muta- tions. Application of this mutant collection is exemplified by the identification of the ent-kaurene synthase gene, which encodes a key enzyme in the gibberellin biosynthesis pathway. This gene-indexed genome- wide mutation collection provides an important resource for functional analysis of maize genes and may bring desirable allelic variants for genetic breeding in maize.
基金Supported by the National Natural Science Foundation of China (Grant No. 40490265)the National Basic Research Priorities Program (Grant No. 2002CB410802)
文摘Methanesulfonic acid(MSA) has been identified as one of the most important intermediate products of DMS reactions in the atmosphere.Although considerable amounts of MSA have been found in the ma-rine boundary layer,little is known about the interaction of gaseous MSA with sea salt particles.To understand the fate of MSA in the atmosphere and its potential importance in atmospheric chemistry,the heterogeneous reactions of gaseous MSA with micron-scale NaCl and sea salt particles were studied using diffuse reflectance infrared Fourier transform spectrometry,X-ray photoelectron spectroscopy,and scanning electron microscopy.The CH3SO3Na and CH3SO3-were the major products of the condensed phase of the reaction of gaseous MSA with NaCl and with sea salt particles.The steady-state uptake coefficient was determined to be(5.94±2.32)×10-7(1 σ) for the reaction of gaseous MSA with NaCl particles and(2.23±1.25)×10-7(1 σ) for the reaction of gaseous MSA with sea salt parti-cles.The heterogeneous reaction of MSA with NaCl particles was found to be first-order for MSA.The reaction mechanisms were discussed.
文摘Background Methanesulfonic acid sodium salt （Dipyrone）, an antipyretic and analgesic drug, has been demonstrated to improve cerebral ischemia through the inhibition of mitochondrial cell death cascades. The aim of this study was to evaluate the potential photoprotective activity of methanesulfonic acid sodium salt in a model of light-induced retinopathy. Methods One hundred mice were assigned randomly into vehicle （V）, methanesulfonic acid sodium salt （D）, light damage model plus vehicle （MV） and light damage model plus methanesulfonic acid sodium salt （MD） groups （n=25 each）. In the MD group, methanesulfonic acid sodium salt （100 mg/kg） was administered by intraperitoneal injection 30 minutes before light exposure. Twenty-four hours after light exposure, hematoxylin and eosin staining and transmission electron microscopy （TEM） were used for histological evaluation. The thickness of the outer plus inner-segment and outer nuclear layer was measured on sections parallel to the vertical meridian of the eye at a distance of 1000 I^m from the optic nerve. Electroretinography （ERG） test was performed to assess the functional change. The morphology of mitochondria was also revealed by TEM. Finally, the expression of cytochrome c （CytC） and the relative apoptotic proteins were detected by Western blotting, and the interaction between mitochondrial proteins was investigated by co-immunoprecipitation. Results The photoreceptor inner and outer segments of the MV group were significantly disorganized than the MD group. The thicknesses of the outer plus inner-segment layers and the outer nuclear layer, and the amplitudes of the a and b waves of the scotopic ERG response markedly decreased in the MV group compared to those in the MD group （P 〈0.05）. TEM examination revealed that the mitochondria of the MV group were distinctly swollen and contained disrupted cristae. In contrast, the morphology of mitochondria in the MD group was unaffected. Western blotting analysis showed that CytC, apoptosis proteinase activating factor-1 （Apaf-1）, caspase 3, p53, p53-upregulated modulator of apoptosis （PUMA）, Bax, and Bad were increased, whereas the anti-apoptotic proteins Bcl-2 and Bcl-XL were significantly decreased in the MV group than the MD group. Co-immunoprecipitation detection revealed that PUMA immunoreactivity precipitated by Bcl-XL decreased, whereas Bax immunoreactivity precipitated by Bcl-XL increased in the MD group compared to those in the MV group. Conclusion Methanesulfonic acid sodium salt is an effective photoprotective agent against light-induced retinopathy through the inhibition of CytC-mediated mitochondrial impairment.
文摘Four kinds of polythiophenes have been doped with CH3SO3H in CHCl3 under air,oxygen,and nitrogen. In the doping of two types of poly(3-hexylthiophene)s,P3HexTh(Zn/Ni)and P3HexTh(Fe)with different contents of a head-to-tail unit,the p-doping occurs at a similar rate.The reaction between poly(3-dodecylthiophene),P3DodTh,and the acid takes place more rapidly.P3OBuTh with a butoxy substituent undergoes more facile p-doping and receives photochemical reaction with CHCl3,and this reaction obeys a pseudo-first-order rate law with a rate constant kobs of 1.42×10-5s-1at room tempera- ture.
文摘Methanesulfonic acid （MSA） was successfully immobilized in silica, leading to a novel and environmentally friendly solid acid catalyst SMSA. The most important feature of SMSA is that anhydrous formic acid is used to hydrolysis of tetraethylorthosili- cate （TEOS）. No water was added in the whole preparation. Therefore, MSA could be anchored in silica matrix more effec- tively instead of being dissolved in water. This new organic/inorganic hybrid catalyst was characterized by powder X-ray dif- fraction （XRD）, energy dispersive spectrum （EDS）, N2 adsorption-desorption analyzer, thermogravimetric analysis （TGA-DSC） and pyridine-FTIR. The catalytic activity was tested by alkylation of olefins and aromatics. High concentration acid sites, both Lewis and Brcnsted, abundant porosity and large surface area enabled the highest activity for SMSA, among MCM-22. ZSM-5 and industrial acidity clay.
文摘A novel approach is designed to optimize the synthesis of sulfonic-functionalized silica material. Results from 29Si and 27AI NMR suggest that the AI acts as the bridging atom connecting the methanesulfonate and silica matrix. Further pyridine-FTIR spectra followed by catalytic activity tests demonstrate that compared with previous methods, our new approach results in higher Lewis acid site concentration, higher thermal stability and superior catalytic activity. Moreover, the whole catalysis preparation procedure is environmentally friendly. Specifically, the silica matrix is synthesized through hydrolysis of tetrae- thylorthosilicate employing formic acid as hydro-catalyst, in which no surfactant species or precursors were involved.
文摘A green protocol for the preparation of amidoalkyl naphthols from three-component one-pot condensation of 2-naphthol, aldehydes, amides or urea in the presence of silica supported methanesulfonic acid under thermal sol- vent-free conditions has been described. The catalyst is stable, efficient, easily prepared, and reusable. The remarkable features of this methodology are short reaction time, excellent yields, simple experimental and work-up procedures.
