ABSTRACT
Objective To understand the consulting relationship among students of some teaching class of epidemiology.Methods Data were collected through questionnaire and the network characteristics were analyzed with social network analysis software-NetDraw.Results The consulting network relation of this class was loosening,but there were a few people who have more degree and betweenness than others;some cliques were associated with major and sex.Conclusions Social network analysis can help teacher understand the consulting relationship among students,which may provide the base for making the management strategy on teaching class.
ABSTRACT
Objective To study killing effect of plasmas ozo ne water on microorganisms by plasmas ozone disinfection solution through plasma s ozone resulting from discharge along surface disinfection solution produced by machine and its effect factors. Methods Quantitative solut ion test was used to study killing action of plasmas ozone disinfection water to E. coli and staphyrococcus aureus, and to study its eff ect factors. Results Plasmas ozone water could kill 99.9% E. coli and staphyrococcus aureus after 15 min. The kill ing effect was affected by organism. With the increasing of organism concertrat ion, the killing efficacy increased. Conclusions Plasmas ozone can effectively kill microorgnisms in water and the efficacy was affected by org anism.
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Objective To study efficacy of 2,4-dibromo-5, 5-d imethylhydantoin in killing vegetative forms of bacteria and spores of B. subtil is var.niger, and efficacy of 2,4-dibromo-5,5-dimethylhydantoin in dest roying antigenicity of HBsAg. Methods Neutralizer test and efficacy of so lution of 2,4-dibromo-5,5-dimethylhydantoin in killing vegetative forms of ba cteria and spores. Neutralizer test and efficacy of solution of 2,4-dibromo-5, 5-dimethylhydantoin in destroying HBsAg antigenicity in suspension. Resul ts The killing rate of Staphylococcus aureus and E. coli. was 100 % a fter exposure to its solution containing 4 mg*L-1 and 2 mg*L-1 av ailable bromo after 10 min and 20 min. The killing rate of spores of Bacil lus subtilis var. Niger also was 100% after exposure to its solution co ntainin g 2 000 mg*L-1 available bromo after 30 min. Its solution containing 1 0 00 mg*L-1 available bromo with could destroy HBsAg in su spension for 5 min. Conclusions 2,4-dibromo-5,5-dimethylhydantoi n can effe ctively kill vegetative forms of bacteria and spores of B. subtilis var.ni ger, and can completely destroy the antigenicity of HBsAg in the water.
ABSTRACT
Several epidemic influenza viruses leading to worldwide periodical pandemics all result from the genetic reassortment of different influenza viruses.The novel 2009 A/H1N1 virus is a reassortment virus evolved from swine influenza virus A/H1N1,avian influenza virus H5N1,and human influenza virus A/H1N1.The 8 fragmente genes of the novel A/H1N1 virus had their own evolutionary characteristics.All the pandemic viruses in humans originate from avian influenza viruses and are transferred into humans after reassortment processes in pigs.Pigs as middle host and a mixing vessel of influenza A virus play an important role in the evolution of the 2009 novel A/H1N1 virus.More attention should be paid on the role of swine in the prevention and control of novel H1N1 virus epidemics in future.