AIM： To analyze occupational health hazards exposure to doses lower than the Chinese occupational health standard in a selected VC polymerization plant in China, and also to elucidate the relationship between genetic...AIM： To analyze occupational health hazards exposure to doses lower than the Chinese occupational health standard in a selected VC polymerization plant in China, and also to elucidate the relationship between genetic polymorphisms and genetic susceptibility on liver lesions of workers exposed to vinyl chloride monomer （VCM）. METHODS： In order to explore the mechanism of VCM- related health effects, we used a case-control design to investigate the association between the genetic polymorphisms of metabolic enzymes and liver lesions in workers occupationally exposed to VCM. Genotypes of CYP2E1, GSTT1, GSTM1, ALDH2 and ADH2 were identified using PCR and PCR-RFLP. RESULTS： Even when the concentration of VCM was lower than the current Chinese occupational health standard, neurasthenia, pharyngeal irritation, liver ultrasonography abnormalities and hemoglobin disorders were significantly higher in exposure subjects compared to non-exposure subjects, and the relative risks （RRand 95% C1） were 1.74 （1.06-2.85）, 1.97 （1.56-2.48）, 10.69 （4.38-26.12）, and 2.07 （1.20-3.57）. CYP2E1 c1c2/c2c2 genotype was significantly associated with liver damages （OR 3.29, 95% CI 1.51-7.20, P〈0.01）. CONCLUSION： The incidences of neurasthenia and liver ultrasonography abnormalities significantly increase when the cumulative exposure dose increases. The genotypes of metabolic enzymes （CYP2E1 c1c2/c2c2, null GSTT1 and ADH2 1-1） play important roles in VCM metabolism. Polymorphisms of CYP 2E1, GSTT1 and ADH2 may be a major reason of genetic susceptibility in VCM-induced hepatic damage.展开更多
A modified selective medium (modified Cetrimide Agar, mCA) consisting of 200 μg/mL benzalkonium chloride (BKC) was developed for the isolation of Pseudomonas aeruginosa from raw milk. Initially, a total of 55 isolate...A modified selective medium (modified Cetrimide Agar, mCA) consisting of 200 μg/mL benzalkonium chloride (BKC) was developed for the isolation of Pseudomonas aeruginosa from raw milk. Initially, a total of 55 isolates were obtained from 14 raw milk samples collected from several dairy plants in Ankara, Turkey. Among these isolates, 19 were identified as Pseudomonas aeruginosa, 28 as Pseudomonas fluorescens, 4 as Acinetobacter baumannii, 2 as Enterobacter intermedium, 1 asEnterobacter agglomerans, and 1 as Escherichia coli using Microbact biochemical test kit. BKC was chosen as a selective agent to suppress growth of competitive flora because it is very effective against a wide range of Gram-negative bacteria while P. aeruginosa is resistant. MICs (minimum inhibitory concentration) for BKC were determined by agar dilution method. The concentration of 200 μg/mL BKC inhibited competitive flora, while 90% of P. aeruginosa strains were resistant. When the results of enumeration of P. aeruginosa and other Gram (-) bacteria in Cetrimide Agar (CA) and mCA were compared, it was observed that mCA was more selective than the standard CA in preventing the growth of competitive flora especially of P. fluorescens.展开更多
The catalytic application of p-toluenesulfonyl chloride for efficient acetylation of various types of alcohols and phenols with acetic anhydride in solvent-free conditions is reported.Also structurally diverse alcohol...The catalytic application of p-toluenesulfonyl chloride for efficient acetylation of various types of alcohols and phenols with acetic anhydride in solvent-free conditions is reported.Also structurally diverse alcohols were formylated using formic acid based on the use of catalytic amount of p-toluenesulfonyl chloride under solvent-free condition.The reactions were carried out in short reaction time and in good to excellent yields at room temperature.展开更多
Corrosion rate and anode polarization curves of electrodeposited RE-Ni-W-P-SiC-PTFE composite coating in various concentrations of phosphoric and ferric chloride were researched. The results show that corrosion rate o...Corrosion rate and anode polarization curves of electrodeposited RE-Ni-W-P-SiC-PTFE composite coating in various concentrations of phosphoric and ferric chloride were researched. The results show that corrosion rate of the composite coatings increases with the increasing concentrations of phosphoric and ferric chloride, and reaches the maximum value when phosphoric concentration is 40% and ferric chloride concentration is 20% (mass fraction, the same below if not mentioned). Anode polarization curves of the composite coatings show that anode polarization current density of the composite coatings heat-treated at 200 ℃ or 500 ℃ is lower than that of other coatings heat-treated at 300 ℃ or 400 ℃, which displays that the composite coatings heat-treated at 200 ℃ or 500 ℃ have better corrosion resistance. Besides, corrosion resistance of the composite coating heat-treated at 500 ℃ is better than that as deposited and RE-Ni-W-P-SiC composite coating heat-treated at 400 ℃, and is also better than that of 316L stainless steel.展开更多
A polystyrene-bonded stannic chloride catalyst was synthesized by the method of lithium polystyryl combined with stannic chloride. This catalyst is a polymeric organometallic compound containing 0.25 mmol Sn (Ⅳ)/g ca...A polystyrene-bonded stannic chloride catalyst was synthesized by the method of lithium polystyryl combined with stannic chloride. This catalyst is a polymeric organometallic compound containing 0.25 mmol Sn (Ⅳ)/g catalyst. The catalyst showed sufficient stability and catalytic activity in organic reaction such as esterification, acetalation and ketal formation, and it could be reused many times without losing its catalytic activity.展开更多
基金Supported by the National Natural Science Foundation of China, No. 30070650 and National Key Basic Research and Development Program of China, No. 2002CB512909
文摘AIM： To analyze occupational health hazards exposure to doses lower than the Chinese occupational health standard in a selected VC polymerization plant in China, and also to elucidate the relationship between genetic polymorphisms and genetic susceptibility on liver lesions of workers exposed to vinyl chloride monomer （VCM）. METHODS： In order to explore the mechanism of VCM- related health effects, we used a case-control design to investigate the association between the genetic polymorphisms of metabolic enzymes and liver lesions in workers occupationally exposed to VCM. Genotypes of CYP2E1, GSTT1, GSTM1, ALDH2 and ADH2 were identified using PCR and PCR-RFLP. RESULTS： Even when the concentration of VCM was lower than the current Chinese occupational health standard, neurasthenia, pharyngeal irritation, liver ultrasonography abnormalities and hemoglobin disorders were significantly higher in exposure subjects compared to non-exposure subjects, and the relative risks （RRand 95% C1） were 1.74 （1.06-2.85）, 1.97 （1.56-2.48）, 10.69 （4.38-26.12）, and 2.07 （1.20-3.57）. CYP2E1 c1c2/c2c2 genotype was significantly associated with liver damages （OR 3.29, 95% CI 1.51-7.20, P〈0.01）. CONCLUSION： The incidences of neurasthenia and liver ultrasonography abnormalities significantly increase when the cumulative exposure dose increases. The genotypes of metabolic enzymes （CYP2E1 c1c2/c2c2, null GSTT1 and ADH2 1-1） play important roles in VCM metabolism. Polymorphisms of CYP 2E1, GSTT1 and ADH2 may be a major reason of genetic susceptibility in VCM-induced hepatic damage.
文摘A modified selective medium (modified Cetrimide Agar, mCA) consisting of 200 μg/mL benzalkonium chloride (BKC) was developed for the isolation of Pseudomonas aeruginosa from raw milk. Initially, a total of 55 isolates were obtained from 14 raw milk samples collected from several dairy plants in Ankara, Turkey. Among these isolates, 19 were identified as Pseudomonas aeruginosa, 28 as Pseudomonas fluorescens, 4 as Acinetobacter baumannii, 2 as Enterobacter intermedium, 1 asEnterobacter agglomerans, and 1 as Escherichia coli using Microbact biochemical test kit. BKC was chosen as a selective agent to suppress growth of competitive flora because it is very effective against a wide range of Gram-negative bacteria while P. aeruginosa is resistant. MICs (minimum inhibitory concentration) for BKC were determined by agar dilution method. The concentration of 200 μg/mL BKC inhibited competitive flora, while 90% of P. aeruginosa strains were resistant. When the results of enumeration of P. aeruginosa and other Gram (-) bacteria in Cetrimide Agar (CA) and mCA were compared, it was observed that mCA was more selective than the standard CA in preventing the growth of competitive flora especially of P. fluorescens.
文摘The catalytic application of p-toluenesulfonyl chloride for efficient acetylation of various types of alcohols and phenols with acetic anhydride in solvent-free conditions is reported.Also structurally diverse alcohols were formylated using formic acid based on the use of catalytic amount of p-toluenesulfonyl chloride under solvent-free condition.The reactions were carried out in short reaction time and in good to excellent yields at room temperature.
基金Project([2002]24) supported by the National Development and Reform Commission of China
文摘Corrosion rate and anode polarization curves of electrodeposited RE-Ni-W-P-SiC-PTFE composite coating in various concentrations of phosphoric and ferric chloride were researched. The results show that corrosion rate of the composite coatings increases with the increasing concentrations of phosphoric and ferric chloride, and reaches the maximum value when phosphoric concentration is 40% and ferric chloride concentration is 20% (mass fraction, the same below if not mentioned). Anode polarization curves of the composite coatings show that anode polarization current density of the composite coatings heat-treated at 200 ℃ or 500 ℃ is lower than that of other coatings heat-treated at 300 ℃ or 400 ℃, which displays that the composite coatings heat-treated at 200 ℃ or 500 ℃ have better corrosion resistance. Besides, corrosion resistance of the composite coating heat-treated at 500 ℃ is better than that as deposited and RE-Ni-W-P-SiC composite coating heat-treated at 400 ℃, and is also better than that of 316L stainless steel.
文摘A polystyrene-bonded stannic chloride catalyst was synthesized by the method of lithium polystyryl combined with stannic chloride. This catalyst is a polymeric organometallic compound containing 0.25 mmol Sn (Ⅳ)/g catalyst. The catalyst showed sufficient stability and catalytic activity in organic reaction such as esterification, acetalation and ketal formation, and it could be reused many times without losing its catalytic activity.
