Pasteurized milk contains complex microbial communities affected by sterilization and storage conditions.This complex microflora may be the possible reason that pasteurized dairy products are highly prone to spoilage....Pasteurized milk contains complex microbial communities affected by sterilization and storage conditions.This complex microflora may be the possible reason that pasteurized dairy products are highly prone to spoilage.In this study,packaged pasteurized milk products collected from dairy processing factories in China were stored at 0,4,10,15,and 25℃ for 0−15 days and subjected to microbial identification using high-throughput sequencing.Accordingly,6 phyla and 44 genera were identified as the dominant microbiota.Moreover,the changes in nutritional composition of the pasteurized milk,including in 16 free amino acids,7 taste values,and 8 chemical constituents,were analyzed using principal component and multi-factor analyses.The Pearson correlation analysis identified Pseudomonas,Aeromonas,Paenibacillus,and Serratia genera as the core functional microbiota that significantly affects the nutritional composition of pasteurized milk.Hence,the results provide a comprehensive understanding of the safety and shelf-life of stored pasteurized milk.展开更多
Objective:To analyze the effect of high-performance liquid chromatography(HPLC)for the determination of azithromycin and to provide references for related research work.Methods:The mobile phase was ammonixim dihydroge...Objective:To analyze the effect of high-performance liquid chromatography(HPLC)for the determination of azithromycin and to provide references for related research work.Methods:The mobile phase was ammonixim dihydrogen phosphate at 0.067 mol/L(mixed with triethylamine;pH value was adjusted to 6.5).The chromatographic column was Kromasil C18(250 mm × 4.6 mm;5.0μm)and the relative standard deviation(RSD)of the drug content level was 1.25%.The injection volume was set to 20μL,the detection wavelength was set to 210 nm,the external standard method was used to complete the quantitative work,and the theoretical plate number should be more than 1000 according to the drug peak calculation.The effect of HPLC on the determmation of azithromycin was analyzed.Results:The concentration of azithromycin was 1.40-3.40 mg/mL,and the linear relationship was good.RSD of the drug content level was 1.25%.The representative test product had strong stability within 8.0 hours and the method had good repeatability.According to the recovery experiment method,the recovery rates of three standard samples from low to high were 99.87%,100.15%,and 100.62%.The average recovery rate was 100.21%.RSD value was 0.39%.It means that the recovery rate of HPLC is good.Conclusion:In the determination of azithromycin,the use of HPLC to complete the work was of high sensitivity,simple,and fast.The method had good repeatability in the determination of drug components which is worthy of further promotion.展开更多
Aim:To analyze the effective methods of antibiotic ointment to control bacterial growth,and to provide references for the research work of related personnel.Method:In this experiment,membrane filtration method combine...Aim:To analyze the effective methods of antibiotic ointment to control bacterial growth,and to provide references for the research work of related personnel.Method:In this experiment,membrane filtration method combined with centrifugal precipitation method was used to complete the inspection of antibiotic ointment,and the final result was analyzed.Results:The application of membrane filtration method combined with centrifugal precipitation method to complete the test of antibiotic ointment has a significant effect.The test solution is milky white.The possibility if it can exert the effect of eliminating antibacterial components,so that Pseudomonas aeruginosa and Staphylococcus caureus can show an affecting state in the positive test tube,and colonies can be found after observation.Conclusion:The application of membrane filtration method combined with centrifugal precipitation method to complete the inspection of antibiotic ointment can achieve satisfactory results.The method is simple to operate and has high feasibility.It is worthy of further promotion and application.展开更多
To the Editor:Bullous pemphigoid(BP)is a chronic autoimmune blistering disease characterized by the association with autoantibodies to two hemidesmosomal proteins(BP180 and BP230)interfering with the adhesion of basal...To the Editor:Bullous pemphigoid(BP)is a chronic autoimmune blistering disease characterized by the association with autoantibodies to two hemidesmosomal proteins(BP180 and BP230)interfering with the adhesion of basal epidermal keratinocytes.The global incidence of BP is 2.5 to 75 cases/million per year.[1]Genetic,environmental,and stochastic factors contribute to the susceptibility to BP.We performed a retrospective study on BP in Northeast China to evaluate its clinical characteristics.The data of BP patients from Shenyang Seventh People’s Hospital between January 2015 and January 2020 were analyzed,including 464 BP patients from Northeast China.展开更多
基金supported by the National Natural Science Foundation of China(31871831,32172279)Liaoning Provincial Natural Science Foundation regional Joint Fund project(2020-MZLH-34)+1 种基金Shenyang City Youth Science and Technology Innovation Leading Talent Project(RC200495)Shenyang Science and technology innovation platform project(21-103-0-14,21-104-0-28).
文摘Pasteurized milk contains complex microbial communities affected by sterilization and storage conditions.This complex microflora may be the possible reason that pasteurized dairy products are highly prone to spoilage.In this study,packaged pasteurized milk products collected from dairy processing factories in China were stored at 0,4,10,15,and 25℃ for 0−15 days and subjected to microbial identification using high-throughput sequencing.Accordingly,6 phyla and 44 genera were identified as the dominant microbiota.Moreover,the changes in nutritional composition of the pasteurized milk,including in 16 free amino acids,7 taste values,and 8 chemical constituents,were analyzed using principal component and multi-factor analyses.The Pearson correlation analysis identified Pseudomonas,Aeromonas,Paenibacillus,and Serratia genera as the core functional microbiota that significantly affects the nutritional composition of pasteurized milk.Hence,the results provide a comprehensive understanding of the safety and shelf-life of stored pasteurized milk.
文摘Objective:To analyze the effect of high-performance liquid chromatography(HPLC)for the determination of azithromycin and to provide references for related research work.Methods:The mobile phase was ammonixim dihydrogen phosphate at 0.067 mol/L(mixed with triethylamine;pH value was adjusted to 6.5).The chromatographic column was Kromasil C18(250 mm × 4.6 mm;5.0μm)and the relative standard deviation(RSD)of the drug content level was 1.25%.The injection volume was set to 20μL,the detection wavelength was set to 210 nm,the external standard method was used to complete the quantitative work,and the theoretical plate number should be more than 1000 according to the drug peak calculation.The effect of HPLC on the determmation of azithromycin was analyzed.Results:The concentration of azithromycin was 1.40-3.40 mg/mL,and the linear relationship was good.RSD of the drug content level was 1.25%.The representative test product had strong stability within 8.0 hours and the method had good repeatability.According to the recovery experiment method,the recovery rates of three standard samples from low to high were 99.87%,100.15%,and 100.62%.The average recovery rate was 100.21%.RSD value was 0.39%.It means that the recovery rate of HPLC is good.Conclusion:In the determination of azithromycin,the use of HPLC to complete the work was of high sensitivity,simple,and fast.The method had good repeatability in the determination of drug components which is worthy of further promotion.
文摘Aim:To analyze the effective methods of antibiotic ointment to control bacterial growth,and to provide references for the research work of related personnel.Method:In this experiment,membrane filtration method combined with centrifugal precipitation method was used to complete the inspection of antibiotic ointment,and the final result was analyzed.Results:The application of membrane filtration method combined with centrifugal precipitation method to complete the test of antibiotic ointment has a significant effect.The test solution is milky white.The possibility if it can exert the effect of eliminating antibacterial components,so that Pseudomonas aeruginosa and Staphylococcus caureus can show an affecting state in the positive test tube,and colonies can be found after observation.Conclusion:The application of membrane filtration method combined with centrifugal precipitation method to complete the inspection of antibiotic ointment can achieve satisfactory results.The method is simple to operate and has high feasibility.It is worthy of further promotion and application.
文摘To the Editor:Bullous pemphigoid(BP)is a chronic autoimmune blistering disease characterized by the association with autoantibodies to two hemidesmosomal proteins(BP180 and BP230)interfering with the adhesion of basal epidermal keratinocytes.The global incidence of BP is 2.5 to 75 cases/million per year.[1]Genetic,environmental,and stochastic factors contribute to the susceptibility to BP.We performed a retrospective study on BP in Northeast China to evaluate its clinical characteristics.The data of BP patients from Shenyang Seventh People’s Hospital between January 2015 and January 2020 were analyzed,including 464 BP patients from Northeast China.
