Foot-and-mouth disease (FMD), which affects cloven-hoofed animals, is economically important because of its highly contagious nature. FMD virus (FMDV), the causative agent of FMD, involves seven serotypes (O, A, Asia1, C, and SAT 1-3). Serotype Asia1 is unique to the Asian territory and is subdivided into nine genetic groups (G-I-IX) based on nucleotide variations in the VP1 sequence. Asia1 Shamir, the most representative Asia1 vaccine, is not highly protective against the Asia1/MOG/05 (G-V) lineage found in North Korea in 2007. Therefore, we investigated whether a chimeric virus strain (Asia1/MOG/Shamir), in which the VP4, VP2, and VP3 sequences of Asia1/MOG/05 were combined with the VP1 sequence of Asia1 Shamir, can simultaneously protect against both viruses. We determined the optimal viral growth conditions for the commercial utilization of this chimeric virus strain. Of the three types of cell culture media, the Cellvento medium resulted in the highest amount of antigen in the samples. The chimeric strain was proliferated in a small bioreactor to produce a test vaccine, and its immunogenicity was evaluated in pigs. The virus neutralization (VN) titer against the Asia1 Shamir virus was > 1/100 after the second immunization with the chimeric vaccine in pigs. In addition, a single dose of the test vaccine resulted in a VN titer of > 1/100 against the Asia1/MOG/05 strain. Taken together, our chimeric vaccine strain provided sufficient protection against the Asia1/MOG/05 and Asia1 Shamir viruses, suggesting its potential as a novel vaccine for both these strains.

This study was aimed to isolate bacterial inoculants producing chitinase and evaluate their application effects on corn silage. Four corn silages were collected from four beef cattle farms to serve as the sources of bacterial inoculants. All isolates were tested against Fusarium graminearum head blight fungus MHGNU F132 to confirm their antifungal effects. The enzyme activities (carboxylesterase and chitinase) were also measured to isolate the bacterial inoculant. Based on the activities of anti-head blight fungus, carboxylesterase, and chitinase, L. buchneri L11-1 and L. paracasei L9-3 were subjected to silage production. Corn forage (cv. Gwangpyeongok) was ensiled into a 10 L mini silo (5 kg) in quadruplication for 90 days. A 2 × 2 factorial design consists of F. graminearum contamination at 1.0104 cfu/g (UCT (no contamination) vs. CT (contamination)) and inoculant application at 2.1 × 105 cfu/g (CON (no inoculant) vs. INO (inoculant)) used in this study. After 90 days of ensiling, the contents of CP, NDF, and ADF increased (p<0.05) by F. graminearum contamination, while IVDMD, acetate, and aerobic stability decreased (p<0.05). Meanwhile, aerobic stability decreased (p<0.05) by inoculant application. There were interaction effects (p<0.05) on IVNDFD, NH3-N, LAB, and yeast, which were highest in UCT-INO, UCT-CON, CT-INO, and CT-CON & INO, respectively. In conclusion, this study found that mold contamination could negatively impact silage quality, but isolated inoculants had limited effects on IVNDFD and yeast.

When decommissioning a nuclear power plant, the structure must be made to a disposable size. In general, the cutting process is essential when dismantling a nuclear power plant. Mainly, thermal cutting method is used to cutting metal structures. The aerosols generated during thermal cutting have a size distribution of less than 1 μm. The contaminated structures are able to generate radioactive aerosols in the decommissioning. Radioactive aerosols of 1 μm or less are deposited in the respiratory tract by workers’ breathing, causing the possibility of internal exposure. Therefore, workers must be protected from the risk of exposure to radioactive aerosols. Prior knowledge of aerosols generated during metal cutting is important to ensure worker safety. In this study, the physical and chemical properties of the aerosol were evaluated by measuring the number and mass concentrations of aerosols generated when cutting SUS304 and SA508 using the laser cutting method. High-resolution aerosol measuring equipment (HR-ELPI+, DEKATI) was used to measure the concentration of aerosols. The HR-ELPI+ is an impactor-type aerosol measuring equipment that measures the aerosol number concentration distribution in the aerodynamic diameter range of 6 nm to 10 um in real-time. And analyze the mass concentration of the aerosol according to the diameter range through the impactor. ICP-MS was used for elemental mass concentration analysis in the aerosol. Analytical elements were Fe, Cr, Ni and Mn. For the evaluation of physical and chemical properties, the MMAD of each element and CMAD were calculated in the aerosol distribution. Under the same cutting conditions, it was confirmed that the number concentration of aerosols generated from both materials had a uni-modal distribution with a peak around 0.1 um. CMAD was calculated to be 0.072 um for both SUS304 and SA508. The trend of the CMAD calculation results is the same even when the cutting conditions are changed. In the case of MMAD, it was confirmed that SUS304 had an MMAD of around 0.1 μm in size for only Fe, Cr and Mn. And SA508, Fe, Cr, Ni and Mn were all confirmed to have MMAD around 0.1 μm in size. The results of this study show that a lot of aerosols in the range of less than 1 μm, especially around 0.1 μm in size, are generated when metal is cut using laser cutting. Therefore, in order to protect the internal exposure of workers to laser metal cutting when decommissioning NPPs, it is necessary to protect from nano-sized aerosols beyond micron size.

본 연구는 제비꽃과 남산제비꽃 종자의 종자휴면을 구명하고 종자 저장에 따른 발아 특성을 알아보는 것을 목표로 하고 있다. 먼저 장기 저장 종자를 대상으로 다양한 배양 온도, 저온층적처리, GA3처리를 수행하였다. 휴면의 유무를 판단하기 위해 종자를 25/15, 20/10, 15/6°C 온도에서 배양하였고 제비 꽃 종자의 최종 발아율이 각각 86, 66, 66%으로 나타났다. 이는 제비꽃 종자에 휴면이 없는 것으로 여겨진다. 남산제비꽃은 최종 발아율이 50% 이하이며, 4주 이내에 거의 발아를 하지 않아 생리적휴면이 있다고 판단된다. 남산제비꽃 종자에 GA3 1000mg･L-1를 처리했을 때 최종 발아율이 100%로 나타났다. 또한 저온층적처리 실험 결과 남산제비꽃 종자가 저온 층적처리 기간이 증가할수록 최종발아율도 증가하였다. 앞의 실험은 장기 저장이 되었던 종자를 사용한 것이며 채종 직후의 제비꽃, 남산제비꽃의 발아양상도 살펴보았다. 제비꽃은 25/15°C에서 1주 만에 모두 발아를 하여 종자 휴면이 없는 것을 다시 확인하였다. 장기 저장 종자에 비해 평균발아일수가 줄어들고 발아속도가 증가하여 제비꽃 종자는 장기 저장 중에 종자의 활력이 감소됨을 알 수 있었다. 바로 채종한 남산제비 꽃 종자도 4주만에 발아가 거의 이루어지지 않고 저온층적처리를 통해 발아율이 향상 되는 것으로 보아 생리적휴면을 가지고 있다고 재확인되었다. 따라서 제비꽃과 남산제비꽃은 장기 저장에 따라 종자의 휴면 유형은 변하지 않지만 종자 활력 에 따라서 최종발아율, 평균 발아일수, 발아속도, 발아균일도가 달라질 수 있다.