To study the effects of paraphenylenediamine （PPD） and linear alkylbenzene sulphonate （LAS） alone and in combination on the skin. Methods Forty-eight guinea pigs were divided equally into 4 groups and exposed to P...To study the effects of paraphenylenediamine （PPD） and linear alkylbenzene sulphonate （LAS） alone and in combination on the skin. Methods Forty-eight guinea pigs were divided equally into 4 groups and exposed to PPD （4 mg/kg）, LAS （12 mg/kg） and PPD （4 mg/kg） plus LAS （12 mg/kg） for 30 days. The biochemical parameters such as acid phosphatase, gtutathione-s-transferase, glutathione peroxidase, glutathione, lipid peroxidafion and histamine contents in exposed skin were estimated. The histopathological examination of the exposed skin was also carried out. Results The skin enzymes, lipid peroxidation, and histamine increased while glutathione decreased in skin. The simultaneously exposed group showed additive toxic effects. The histopathological examination showed severe hyperkeratosis, thickening of collagen fibres and vacuolisation of epidermal cells in PPD plus LAS exposed skin. Conclusion The findings of the present study suggest that simultaneous exposure to PPD and LAS has additive toxic effects.展开更多
In this study, P（St-MAA） seed latex particles were first prepared via soap-free emulsion polymerization of styrene （St） and methacrylic acid （MAA）, then the seed particles were allowed to swell with St at room t...In this study, P（St-MAA） seed latex particles were first prepared via soap-free emulsion polymerization of styrene （St） and methacrylic acid （MAA）, then the seed particles were allowed to swell with St at room temperature, and the P（St-MAA）/P（St- NaSS） core/shell latex particles were then synthesized via seeded emulsion copolymerization of St and sodium styrene sulphonate （NaSS） using AIBN as initiator in the presence of N,N^-methylenebisacrylamide （BAA, water-soluble crosslinker）. Results showed that the polymerization could be carried out smoothly when the ratio of BAA to total monomers was less than 3 mol%, the narrow dispersed P（St-MAA） seed particles with the diameter of 150 nm and the P（St-MAA）/P（St-NaSS） core/shell latexes with the particle size of about 200 nm were synthesized. When the 25/75 mole ratio of NaSS/（St ＋ MAA） and 2 tool% of BAA were used in the seeded emulsion polymerization, the resulted P（St-MAA）/P（St-NaSS） latex product showed a low weight loss after water extraction, and the NaSS unit content in the whole particle and in the shell reached 11.7 mol% and 34.6 mol%, resoectivelv.展开更多
Poly(styrene-co-sodium styrene sulphonate)(P(St-NaSS)) latex particles were prepared using the mixture of ethanol and water as continuous phase in the presence of surfactant by dispersion--emulsion combined polymeriza...Poly(styrene-co-sodium styrene sulphonate)(P(St-NaSS)) latex particles were prepared using the mixture of ethanol and water as continuous phase in the presence of surfactant by dispersion--emulsion combined polymerization.The influence of recipes on polymerization process as well as the content of sulphonate group in the purified products was investigated.Results showed that the copolymerization could be performed smoothly.When the mole ratio of NaSS/St/divinyl benzene(DVB) was 25/75/2 and the weight ratio ...展开更多
Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo g...Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metaI ions, in most of the studied chelates, and that the two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metal ions, in most of the studied chelates, and that the two ligands L1 and L2 were coordinated either in the enol or the keto form. IR spetra also showed that Fe(III)-, Ni(II)-, Mn(II)-, VO(II)-L1 and Cu(II)-L2 chelates behaved in a bidentate manner, in contrast with the two (1:1) M:L cobalt chelates with the two ligands are tridentate.TG analysis indicated the presence of three to twelve water molecules of hydration eliminated on heating up to 150℃ and one or two coordinated water molecules removed at 150~180℃.The octahedral structure is proposed fOr all the chelates, except Cu(II)-L2 and Ni(II)-L1 chelates which have square planar geometry, based on their electronic spectra展开更多
The gray phosphate coating was formed on AZ91D magnesium alloy from the zinc phosphating bath containing sodium metanitrobenzene sulphonate in about 4 min. The structure, surface morphologies and phase compositions of...The gray phosphate coating was formed on AZ91D magnesium alloy from the zinc phosphating bath containing sodium metanitrobenzene sulphonate in about 4 min. The structure, surface morphologies and phase compositions of the phosphate coatings were observed and analyzed by using SEM, XRD and EDS. It is shown that the phosphate coating becomes denser and has less micro holes with increasing the concentration of sodium metanitrobenzene sulphonate in the bath in the range of 2.0 to 6.0 g/L. The addition of sodium metanitrobenzene sulphonate greatly increases the micro cathode sites for the formation of the phosphate coating and decreases the porosity of the coating.展开更多
The synthesis, properties and dispersion mechanism of sulphonated acetone-formaldehyde superplasticizer （SAF） were presented. This superplasticizer was synthesized by the reaction among acetone, formaldehyde, sodium...The synthesis, properties and dispersion mechanism of sulphonated acetone-formaldehyde superplasticizer （SAF） were presented. This superplasticizer was synthesized by the reaction among acetone, formaldehyde, sodium sulfite and pyrosulfite. The structure and property were respectively characterized by IR and surface tension measurement. Performance of SAF in cement was evaluated by paste flow as well as heat calorimetry. The dispersion mechanism was identified via adsorption and zeta potential measurement. The results show that cement paste mixed with SAF shows good fluidity. SAF exerts little retarding effect on cement paste and it behaves like a typical polycondensate superplasticizer. The main dispersion mechanism of SAF is attributed to electrostatic repulsion.展开更多
Oil-based drilling fluid(OBDF)is used to drill through high permeable pay zone to prevent possible damage to the formation.However,the oil based drilling fluid leaves behind filter cake residue and oilwet surfaces whi...Oil-based drilling fluid(OBDF)is used to drill through high permeable pay zone to prevent possible damage to the formation.However,the oil based drilling fluid leaves behind filter cake residue and oilwet surfaces which hinder cement bonding.Spacer fluid is usually introduced to clean up the wellbore prior to cementing job.This work presents a spacer fluid designed with environment-friendly anionic methyl ester sulphonate(MES)surfactant and evaluated through a series of experimental tests to ascertain its effectiveness to clean wellbore.Addition of methyl ester sulphonate to confected waterbased drilling fluid at high amount(0.15 g and 0.20 g)showed good rheological properties,compatibility with OBDF and cement and low contact angle on steel and sandstone in the range of 21.9°-34.7°.Furthermore,results show that it requires less amount of MES spacer fluid to revert oil-wet OBDF aqueous phase to water external continuous phase,validating the low contact angle measurements.Cleaning efficiencies for two best performing MES spacer fluids achieved 83.27%and 94.3%respectively.Shear bond strength were measured to be 1.3 MPa and 1.05 MPa for steel and sandstone respectively,above the minimum allowable shear bond strength for oil well cementing.Hence,MES spacer fluid can be used to clean up wellbores in high permeable formations and in well completion,where strong cement bonding is required.展开更多
Spectrophotometric study was carried out, for the first time, to investigate the reaction between the vasodilator pentoxifylline hydrochloride (POX) and 1,2-naphthoquinone-4-sulphonate (NQS) reagent. The reaction occu...Spectrophotometric study was carried out, for the first time, to investigate the reaction between the vasodilator pentoxifylline hydrochloride (POX) and 1,2-naphthoquinone-4-sulphonate (NQS) reagent. The reaction occurs in alkaline medium to activate the nucleophilic substitution reaction producing an orange-colored product measured spectrophometrically at λ<sub>max</sub> 472 nm. The variables affecting the reaction were carefully studied and the conditions were optimized. The kinetics of the reaction was investigated and its activation energy was found to be 0.262 cal/mol. Owing to its low activation energy, the reaction proceeded easily and was successfully used for simple and rapid assay of POX. The stoichiometry of the reaction was determined (1:1), and the reaction mechanism was suggested. To develop a high-throughput methodology used in quality control laboratory, a comparative study of the reaction using the conventional spectrophotometric versus microwell assay was applied. Under the optimum reaction conditions, the initial rate and fixed time methods were utilized for constructing the calibration graphs for determination of POX concentrations. The linear range was 10 - 120 μg/ml with good correlation coefficients (0.9987 - 0.9998). The LOD was 2.5 and 3.4 μg/ml for initial rate and fixed time methods, respectively. The intra- and inter-day accuracy and precision of the developed methods were satisfactory, where RSD was ≤3.94%. The present methods have been successfully applied to the determination of POX in its pharmaceutical tablets, and the percentage recovery values were 97.9% - 101.9%. Therefore, we strongly recommend the proposed methods for determination of POX in quality control laboratories.展开更多
Using bis(p-methoxyphenyl)telluroxide(BMPTO)as the catalyst, phenylsulphonyl acetonitrile condensed easily with aromatic aldehydes at room temperature to give -cyano- ,β-unsaturated sulphones in high yields.
Recently, functional molecules such as Polydopamine(PDA), Hyaluronic Acid(HA) and heparin have been widely studied in the field of surface modification of magnesium(Mg) alloy stents for better degradation behavior and...Recently, functional molecules such as Polydopamine(PDA), Hyaluronic Acid(HA) and heparin have been widely studied in the field of surface modification of magnesium(Mg) alloy stents for better degradation behavior and biocompatibility, but their further application is limited by undesirable anticoagulant function, uncontrollable degradation and easy bleeding, respectively.Regarding to this consideration, a magnesium Fluoride/Polydopamine/Sulphonated hyaluronic acid(Mg F2/PDA/S-HA) composite coating was successfully prepared by applying S-HA with sulfur content of 9.71 wt% on the surface of ZE21B alloy in this study. The results showed that the composite coating with a unique mesh structure not only inherited the anticoagulant effect of sulfonic acid group and the excellent cyto-compatibility of S-HA with high sulfur content, but also significantly improved the corrosion performance of ZE21B alloy.These results indicate a great application potential of the composite coating in the field of cardiovascular biomaterials.展开更多
文摘To study the effects of paraphenylenediamine （PPD） and linear alkylbenzene sulphonate （LAS） alone and in combination on the skin. Methods Forty-eight guinea pigs were divided equally into 4 groups and exposed to PPD （4 mg/kg）, LAS （12 mg/kg） and PPD （4 mg/kg） plus LAS （12 mg/kg） for 30 days. The biochemical parameters such as acid phosphatase, gtutathione-s-transferase, glutathione peroxidase, glutathione, lipid peroxidafion and histamine contents in exposed skin were estimated. The histopathological examination of the exposed skin was also carried out. Results The skin enzymes, lipid peroxidation, and histamine increased while glutathione decreased in skin. The simultaneously exposed group showed additive toxic effects. The histopathological examination showed severe hyperkeratosis, thickening of collagen fibres and vacuolisation of epidermal cells in PPD plus LAS exposed skin. Conclusion The findings of the present study suggest that simultaneous exposure to PPD and LAS has additive toxic effects.
文摘In this study, P（St-MAA） seed latex particles were first prepared via soap-free emulsion polymerization of styrene （St） and methacrylic acid （MAA）, then the seed particles were allowed to swell with St at room temperature, and the P（St-MAA）/P（St- NaSS） core/shell latex particles were then synthesized via seeded emulsion copolymerization of St and sodium styrene sulphonate （NaSS） using AIBN as initiator in the presence of N,N^-methylenebisacrylamide （BAA, water-soluble crosslinker）. Results showed that the polymerization could be carried out smoothly when the ratio of BAA to total monomers was less than 3 mol%, the narrow dispersed P（St-MAA） seed particles with the diameter of 150 nm and the P（St-MAA）/P（St-NaSS） core/shell latexes with the particle size of about 200 nm were synthesized. When the 25/75 mole ratio of NaSS/（St ＋ MAA） and 2 tool% of BAA were used in the seeded emulsion polymerization, the resulted P（St-MAA）/P（St-NaSS） latex product showed a low weight loss after water extraction, and the NaSS unit content in the whole particle and in the shell reached 11.7 mol% and 34.6 mol%, resoectivelv.
文摘Poly(styrene-co-sodium styrene sulphonate)(P(St-NaSS)) latex particles were prepared using the mixture of ethanol and water as continuous phase in the presence of surfactant by dispersion--emulsion combined polymerization.The influence of recipes on polymerization process as well as the content of sulphonate group in the purified products was investigated.Results showed that the copolymerization could be performed smoothly.When the mole ratio of NaSS/St/divinyl benzene(DVB) was 25/75/2 and the weight ratio ...
文摘Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metaI ions, in most of the studied chelates, and that the two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metal ions, in most of the studied chelates, and that the two ligands L1 and L2 were coordinated either in the enol or the keto form. IR spetra also showed that Fe(III)-, Ni(II)-, Mn(II)-, VO(II)-L1 and Cu(II)-L2 chelates behaved in a bidentate manner, in contrast with the two (1:1) M:L cobalt chelates with the two ligands are tridentate.TG analysis indicated the presence of three to twelve water molecules of hydration eliminated on heating up to 150℃ and one or two coordinated water molecules removed at 150~180℃.The octahedral structure is proposed fOr all the chelates, except Cu(II)-L2 and Ni(II)-L1 chelates which have square planar geometry, based on their electronic spectra
基金Project(2004CB619301) supported by the National Basic Research and Development Program and Project 985-Automotive Engineering of Jilin University
文摘The gray phosphate coating was formed on AZ91D magnesium alloy from the zinc phosphating bath containing sodium metanitrobenzene sulphonate in about 4 min. The structure, surface morphologies and phase compositions of the phosphate coatings were observed and analyzed by using SEM, XRD and EDS. It is shown that the phosphate coating becomes denser and has less micro holes with increasing the concentration of sodium metanitrobenzene sulphonate in the bath in the range of 2.0 to 6.0 g/L. The addition of sodium metanitrobenzene sulphonate greatly increases the micro cathode sites for the formation of the phosphate coating and decreases the porosity of the coating.
基金Funded by the Western Region Traffic Construction Technology Program of the Ministry of Communications of China(No.2007319811130)
文摘The synthesis, properties and dispersion mechanism of sulphonated acetone-formaldehyde superplasticizer （SAF） were presented. This superplasticizer was synthesized by the reaction among acetone, formaldehyde, sodium sulfite and pyrosulfite. The structure and property were respectively characterized by IR and surface tension measurement. Performance of SAF in cement was evaluated by paste flow as well as heat calorimetry. The dispersion mechanism was identified via adsorption and zeta potential measurement. The results show that cement paste mixed with SAF shows good fluidity. SAF exerts little retarding effect on cement paste and it behaves like a typical polycondensate superplasticizer. The main dispersion mechanism of SAF is attributed to electrostatic repulsion.
文摘Oil-based drilling fluid(OBDF)is used to drill through high permeable pay zone to prevent possible damage to the formation.However,the oil based drilling fluid leaves behind filter cake residue and oilwet surfaces which hinder cement bonding.Spacer fluid is usually introduced to clean up the wellbore prior to cementing job.This work presents a spacer fluid designed with environment-friendly anionic methyl ester sulphonate(MES)surfactant and evaluated through a series of experimental tests to ascertain its effectiveness to clean wellbore.Addition of methyl ester sulphonate to confected waterbased drilling fluid at high amount(0.15 g and 0.20 g)showed good rheological properties,compatibility with OBDF and cement and low contact angle on steel and sandstone in the range of 21.9°-34.7°.Furthermore,results show that it requires less amount of MES spacer fluid to revert oil-wet OBDF aqueous phase to water external continuous phase,validating the low contact angle measurements.Cleaning efficiencies for two best performing MES spacer fluids achieved 83.27%and 94.3%respectively.Shear bond strength were measured to be 1.3 MPa and 1.05 MPa for steel and sandstone respectively,above the minimum allowable shear bond strength for oil well cementing.Hence,MES spacer fluid can be used to clean up wellbores in high permeable formations and in well completion,where strong cement bonding is required.
文摘Spectrophotometric study was carried out, for the first time, to investigate the reaction between the vasodilator pentoxifylline hydrochloride (POX) and 1,2-naphthoquinone-4-sulphonate (NQS) reagent. The reaction occurs in alkaline medium to activate the nucleophilic substitution reaction producing an orange-colored product measured spectrophometrically at λ<sub>max</sub> 472 nm. The variables affecting the reaction were carefully studied and the conditions were optimized. The kinetics of the reaction was investigated and its activation energy was found to be 0.262 cal/mol. Owing to its low activation energy, the reaction proceeded easily and was successfully used for simple and rapid assay of POX. The stoichiometry of the reaction was determined (1:1), and the reaction mechanism was suggested. To develop a high-throughput methodology used in quality control laboratory, a comparative study of the reaction using the conventional spectrophotometric versus microwell assay was applied. Under the optimum reaction conditions, the initial rate and fixed time methods were utilized for constructing the calibration graphs for determination of POX concentrations. The linear range was 10 - 120 μg/ml with good correlation coefficients (0.9987 - 0.9998). The LOD was 2.5 and 3.4 μg/ml for initial rate and fixed time methods, respectively. The intra- and inter-day accuracy and precision of the developed methods were satisfactory, where RSD was ≤3.94%. The present methods have been successfully applied to the determination of POX in its pharmaceutical tablets, and the percentage recovery values were 97.9% - 101.9%. Therefore, we strongly recommend the proposed methods for determination of POX in quality control laboratories.
文摘Using bis(p-methoxyphenyl)telluroxide(BMPTO)as the catalyst, phenylsulphonyl acetonitrile condensed easily with aromatic aldehydes at room temperature to give -cyano- ,β-unsaturated sulphones in high yields.
基金funded by the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U1804251)National Key Research and Development Program of China (2017YFB0702500, 2018YFC1106703, and 2016YFC1102403)Top Doctor Program of Zhengzhou University (grant number 32210475)。
文摘Recently, functional molecules such as Polydopamine(PDA), Hyaluronic Acid(HA) and heparin have been widely studied in the field of surface modification of magnesium(Mg) alloy stents for better degradation behavior and biocompatibility, but their further application is limited by undesirable anticoagulant function, uncontrollable degradation and easy bleeding, respectively.Regarding to this consideration, a magnesium Fluoride/Polydopamine/Sulphonated hyaluronic acid(Mg F2/PDA/S-HA) composite coating was successfully prepared by applying S-HA with sulfur content of 9.71 wt% on the surface of ZE21B alloy in this study. The results showed that the composite coating with a unique mesh structure not only inherited the anticoagulant effect of sulfonic acid group and the excellent cyto-compatibility of S-HA with high sulfur content, but also significantly improved the corrosion performance of ZE21B alloy.These results indicate a great application potential of the composite coating in the field of cardiovascular biomaterials.
