[Characteristics on molecular epidemiology of Brucella melitensis in Jiangxi province]

Objective: To understand the molecular characteristics and correlation among isolated strains of Brucella melitensis (BM) so as to improve the strategies on prevention and control of the disease in Jiangxi province. Methods: A total of 25 strains of BM isolated from human in 17 counties of Jiangxi province were analyzed by multiple locus variable-number tandem repeat analysis (MLVA) method. Results: A total of 25 strains of BM were classified into 24 independent genotypes with similarities between 67.00% and 100.00% and Simpson index between 0.000 and 0.773. There were 3 genotypes in MLVA8, including 60.00% (15/25) as 42 genotype, 32.00% (8/25) as 43 genotype, and 8.00% (2/25) as 63 genotype, respectively. There were 7 genotypes in MLVA11 identified, with 116 genotype and 125 genotype the main genotypes, accounting for 56.00% (14/25) of all the identified strains. Conclusions: Genes from all the 25 strains of BM that isolated from human being were with high genetic diversities, and various, genotypes. However, no obvious epidemiological correlation was noticed among these strains, indicating the complexity of the source of infection on Brucella in Jiangxi province.

Selective removal of copper with polystyrene–1,3-diaminourea chelating resin: synthesis and adsorption studies

In this study, green chloromethylated polystyrene bead–1,3-diaminourea (PS–DU) which was intended to adsorb copper ions was synthesized from chloromethylated polystyrene (PS-Cl) and 1,3-diaminourea (DU).

Study on the adsorption of cadmium(II) from aqueous solution by D152 resin

The feasibility of using D152 resin as an adsorbent for cadmium(II) was examined. The adsorption capacity of D152 resin for cadmium(II) ions was studied as a function of solution pH, temperature and contact time. The optimal pH for the adsorption of cadmium(II) ions was found to be 5.95 in the HAc-NaAc system. The maximum uptake capacity of cadmium(II) was estimated to 378 mg/g D152 resin at 298 K, at an initial pH value of 5.95. The results obtained from equilibrium adsorption studies were conformed to the Langmuir and Freundlich and the correlation coefficients have been evaluated. The apparent adsorption rate constant was k(298 K)=4.01 x 10(-5)s(-1), and the apparent activation energy was 2.78 kJ/mol. Thermodynamic parameters, DeltaS was 108 J/(mol K), heat of adsorption (Delta H) value of 12.8 kJ/mol indicated the endothermic nature of the adsorption process, and a decrease of Gibbs free energy (Delta G) with increasing temperature also indicated the spontaneous nature of the process, respectively. The elution tests were carried out using various mixed reagents. The maximum elution percent of cadmium(II) ions were obtained when the reagent 0.5 mol/L HCl was used.