Objective To investigate air bacteria pollution and the rule of microbes spread in some markets in Guangzhou, aiming at prevention and forecast airborne pathogenic microbes. Bacteria and Staphylococcus aureus were collected to provide reference on evaluation and of the spread of through the air in public. Methods Gravity exposure of microbial media plates was used to sample the airborne bacteria in eight different markets in Guangzhou on a given day, from 2003 to 2005. The simulated experiment in the laboratory was conducted based on the results of natural sampling stations. Results Samples taken at different times showed wide variations with quantities of airborne bacteria (total count) and Staphylococcus aureus ranged from 95 to 1.5?104 cfu per petri dish and from 2 to 1.2?104 cfu per petri dish respectively. Movement of airborne bacteria in the market obeyed quadratic equation pattern. The spread distance of airborne bacteria was among 24 to 26 meters. Maximum airborne bacteria were detected from 17:00 o'clock to 19:00 o'clock in a day. Conclusion The count of market airborne bacteria is markedly more than the limits stipulated in the related national standard GB 9670-1996. Live fowls sold in the markets are the main carriers of bacteria and the potential pollution resource of pathogenic bacteria.

Objective To test the toxicity of genetically engineered strain R32 released to the environment.Methods Acute,chronic and cumulative toxicity test on mice,micronucleus assay of mice bone marrow cell and mice sperm malformation test were conducted to assess the toxicity of strain R32.Results R32 did not cause acute,chronic,cumulative and genetical toxic effect on mice before it absorbed heavy metal chromium.Although the mice bone marrow micronucleus frequency increased and some cumulative toxic effect emerged after R32 absorbed chromium,it did not cause acute and chronic toxicity effect on mice and mice sperm malformation rate did not increase neither.Furthermore,whether R32 absorbed heavy metal chromium or not,the effect of its secretion was not significant in all experiments compared with the control.Conclusion R32 can not cause toxic effect on mice before it absorbed chromium.Whether R32 absorbed chromium or not,the effect of its secretion was not significant in all toxicological experiments conducted in the present paper.Large content of R32 may cause some cumulative toxic effect in mice after it absorbed chromium.

Insect viruses are attractive as biological control agents and could be a feasible alternative to chemical insecticides in the management of insect infestations. This review describes recent advances in the development of wild-type and genetically modified viruses as insecticides. A new strategy of application of insect viruses in China is reviewed. Also, the assessment of biosafety of genetically modified Helicoverpa armigera Nucleopolyhedovirus (HearNPV) is emphasized as a case-study.

Objective To observe the various influence of Imipenem/Cilastatin(IPM) and Cefoperazone(CPZ) on Gram-negative bacterial endotoxin release in severely burned patients.Methods Patients were divided into IPM group and CPZ group randomly. The bacterial cultures and microbial drug-sensitivities of burn wound swabs and subeschar tissues were performed on the 1st and 3rd day, At the same time, the levels of LPS in plasma were detected in seven burned patients administrated with IPM and six with CPZ at the time 0?2?4?12?24?48?72h of antibiotics administration.Results Patients were infected by Gram-negative bacterial. The counting of bacteria in subeschar tissues decreased 10~100 times after the administration of antibiotics 3 days; Plasma LPS levels elevated to the peak value at 2h after infusion of IPM or CPZ , and then showed significant decrease. The magnitude of increased LPS in CPZ group was higher than that in IPM group; The LPS levels of 72h were lower significantly than that of 0h.Conclusion IPM and CPZ could effectively control Gram-negative bacterial infection and induce the releases of LPS from bacteria, of which the former induced less LPS release than the latter; The levels of LPS came down with the decreasing of bacterial counting.

Adult ; Female ; Health Knowledge, Attitudes, Practice ; Health Promotion ; Humans ; Lead ; Male ; Middle Aged ; Occupational Exposure ; prevention & control ; Occupational Health ; Occupational Health Services ; Stearates ; Young Adult

The purpose of risk assessment is to evaluate the permissible exposure level under specific risk factors.To extrapolate the human acceptable daily intake (ADI) and/or reference dose (RfD), the traditional method uses the no-observed-adverse-effect level ( NOAEL ) to quantify toxicity after being divided by uncertainty factor.There are many limitations with NOAEL method in safety evaluation,for it relies too much on experimental design.Benchmark dose ( BMD) approach is a more reliable method with many advantages.BMD approach and its analysis software, the advantages of BMD over NOAEL, the application and methodological perfection in risk assessment of long-team exposure toxicity are presented in this review.

0.05).The serum PICP of tubercular meningitis children after 4 neeks glucocorticoid therapy (108.85?46.13) ?g/L was significantly lower than that in control group((154.38)?47.98) ?g/L and glucocorticoid- pretreatment (152.99?44.78) ?g/L (P

Effects of Cr 6+ concentration and culture time on four heavy metal removing strains,stability of these four strains removing Cr 6+,configuration changes inside or outside their cells,effects of Cr 6+ on soluble reductive sugar inside their cells,and effect of several factors on these strains had been studied,and the Cr 6+ resistance mechanisms of these strains have been discussed elementarily. The results showed that the Lethality of these strains caused by Cr 6+ was similar with one another, namely, increasing at first, then decreasing, and finally increasing again as culture time passed. Acclimatization of Candida sp. was better than Sporobolomycetaceae sp.,and the Cr 6+ resistance of Sporobolomycetaceae sp. 7-3 was the best of the four. The research also demonstrated that the metabolic activity of these strains had been influenced by Cr 6+ in a certain extent. Scanning electron microscopy,transmission electron microscopy,and atomic force microscopy observations approved that removal of Cr 6+ by Candida sp. was depended on both surface adsorption and intracellular accumulation. Effects of Cr 6+ concentration, pH, culture time, nitrogen source, carbon source and adsorption time on these strains are not the same.

A biosurfactant-producing strain(S_6)was isolated from oil-containing wastewater in oxidation ditch and identified as Pseudomonas aeruginosa based on physiological and biochemical experiments and 16S rDNA sequence analysis.Infrared spectrum analysis revealed that S_6 produced glucolipid in the process of metabolism.It was observed that S_6 decreased the surface tension of water from 72 mN/m to 33.9 mN/m with the critical micelle concentration(CMC)of 50mg/L.The measurement of oil displacement and surface tension demonstrated that the fermented liquid had stable surface activity at varying range of salinity,pH,amount of dissolved oxygen.The optimal culture condition was obtained through orthogonal experiment:glucose 10g/L,urea 5g/L,KH_2PO_4 1g/L,liquor of microelement 2mL,pH 8.0,water 1000mL;and the biosurfactant production under optimal culture condition was 0.173g/L.

The mechanism of chromium accumulation and microstructure transformation of the fused yeast were studied in this paper.The result showed that the process of Cr6+ reduction and adsorption was accom-panied by the H+ consumption.The main adsorptive groups on the strain surface included amino,hydroxyl,phosphate group and amide,among which phosphate group played vital role in the chromium accumulation.The removal rate of chromium and reduction rate of hexavalent chromium declined 70% and 46%,respec-tively,when phosphate group was masked.During the adsorption process the chromium ions complexed on the surface of fused yeast was transported into the cell wall and combined with inclusion to form steady spe-cies and this took 90 min to reach the equilibrium.The biosorption and reduction of Cr on the cell surface would alter microstructure of cell surface,reduce cell membrane potential and increase cell membrane per-meability.