Authors:Tack-Jin Kim, Yong-Kwang Jeong, Jun-Gill Kang, Yongju Jung, Do-Hee Ahn, and Han-Soo Lee
The spontaneous reduction of Eu3+ to Eu2+ was examined when EuCl3 was added into a pyroprocessing media of LiCl molten salt at 923 K. The amount of Eu2+ was calculated by measuring the total charge consumed to oxidize Eu2+ ions to Eu3+ ions. The concentration ratio of Eu2+ to Eu3+ was estimated to be about 0.40 in the media. In addition, it is confirmed that the reduction of Eu3+ to Eu2+ is caused by the oxidation power of Cl− to Cl2. The coexistence of Eu3+ and Eu2+ in the LiCl molten salt system was examined by UV–Visible and luminescence spectroscopy. The molar absorptivities of Eu3+ and Eu2+, calculated from UV–Visible absorption spectra, were 423 and 1954 M−1 cm−1, respectively.
Authors:Hye Park, Min Hong, Sun Hwang, Young Park, Ka Kwon, Jang Yoon, Sook Shin, Jae Kim, and Yong Park
Pseudomonas aeruginosa is one of the causative pathogens of bovine mastitis. Most P. aeruginosa strains possess the type III secretion system (TTSS), which may increase somatic cell counts (SCCs) in milk from mastitis-affected cows. Moreover, most of P. aeruginosa cells can form biofilms, thereby reducing antibiotic efficacy. In this study, the presence and effect of TTSS-related genotypes on increase of SCCs among 122 P. aeruginosa isolates obtained from raw milk samples from mastitis-affected cows and their antibiotic susceptibility at planktonic and biofilm status were investigated. Based on the presence of TTSS-related genes a total of 82.7% of the isolates were found to harbour exoU and/or exoS genes, including the invasive (exoU-/exoS+, 69.4%), cytotoxic (exoU+/exoS-, 8.3%) and cytotoxic/invasive strains (exoU+/ exoS+, 5.0%). Milk containing exoS-positive isolates had higher SCCs than those containing exoS-negative isolates. The majority of isolates showed gentamicin, amikacin, meropenem and ciprofloxacin susceptibility at planktonic status. However, the susceptibility was decreased at the biofilm status. Based on minimum biofilm eradication concentration (MBEC)/minimum inhibitory concentration (MIC) ratios, the range of change in antibiotic susceptibility varied widely depending on the antibiotics (from ≥ 3.1-fold to ≥ 475.0-fold). In conclusion, most P. aeruginosa isolates studied here had a genotype related to increase in SCCs. The efficiency of antibiotic therapy against P. aeruginosa-related bovine mastitis could be improved by analysing both the MBEC and the MIC of isolates.
Authors:Dong-Yong Chung, Heui-Seung Seo, Jae-Won Lee, Han-Beom Yang, Eil-Hee Lee, and Kwang-Wook Kim
A feasibility and basic study to find a possibility to develop such a process for recovering U alone from spent fuel by using
the methods of an oxidative leaching and a precipitation of U in high alkaline carbonate media was newly suggested with the
characteristics of a highly enhanced proliferation-resistance and more environmental friendliness. This study has focused
on the examination of an oxidative leaching of uranium from SIMFUEL powders contained 16 elements (U, Ce, Gd, La, Nd, Pr,
Sm, Eu, Y, Mo, Pd, Ru, Zr, Ba, Sr, and Te) using a Na2CO3 solution with hydrogen peroxide. U3O8 was dissolved more rapidly than UO2 in a carbonate solution. However, in the presence of H2O2, we can find out that the leaching rates of the reduced SIMFUEL powder are faster than the oxidized SIMFUEL powder. In carbonate
solutions with hydrogen peroxide, uranium oxides were dissolved in the form of uranyl peroxo-carbonato complexes. UO2(O2)x(CO3)y2−2x−2y, where x/y has 1/2, 2/1.
Authors:Sung Jae Kim, Van Giap Nguyen, Cheong Ung Kim, Bong Kyun Park, Thi-My Le Huynh, Sook Shin, Woo Kyung Jung, Yong Ho Park, and Hee Chun Chung
Porcine epidemic diarrhoea virus (PEDV) is one of the major pathogens causing acute enteritis, which is characterised by vomiting and watery diarrhoea and commonly leads to high rates of mortality and morbidity in suckling piglets. Chitosan has been regarded as a promising natural disinfectant. In this study, the disinfectant effect and mammalian-cell toxicity of chitosan were evaluated against PEDV using Vero cells. A 0.01% solution of chitosan was determined to be an effective disinfectant. In addition, no evidence of toxicity was observed during the cell toxicity test; on the contrary, chitosan promoted cell proliferation. In conclusion, chitosan is a promising candidate for an effective and safe disinfectant against PEDV as well as other coronaviruses.