The site used for a nuclear facility can be released after decommissioning if the results of dose estimation meet the regulatory requirements and the site release is approved by the regulatory body. RESRAD-ONSITE, developed by the Argonne National Laboratory, is a computer code used to estimate the dose to the residents on radiologically contaminated sites. The dose estimation for site release should consider various exposure pathways, including inhalation, ingestion, and external exposure. This study used RESRAD-ONSITE to evaluate the internal exposure dose and identify radionuclides due to the intake of food produced on radiologically contaminated sites. The upper limit of the clearance level of radionuclides expected to remain at the site was used as the source terms for the dose evaluation. In addition, the amount of food intake per capita was obtained from eight countries using nuclear power generation as of 2020. The default values of RESRAD were used for other parameters except for intake by type of food and source terms. As a result of the dose evaluation, the contaminated water and vegetables showed a great contribution to the exposure dose. The dose due to tritium in drinking water was highest in the third year. In addition, regarding the intake of vegetables, the internal exposure due to 90Sr was the highest in the first year.
Japanese pine sawyer beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae) is considered as a serious pest in pine trees. To develop an eco-friendly strategy to manage this forest insect, we collected entomopathogenic fungi from Korean soil and assessed their virulence against the adults of the insect in laboratory conditions. As a result, two isolates with conidial suspension (1.0×107conidia/ml), showed 87% and 90% mortality 12 days after fungal treatment, respectively. We assessed the potential of the fungi-derived destruxin and protease as additives to the fungal isolates, and they showed insecticidal activity via feeding and spraying treatments. Finally, we produced fungal conidia in massive solid cultures and formulated wettable powders, and now studying optimal conditions of oil-based formulation with two isolates. Based on these results, we are evaluating the control efficacy of the fungal agents against M. alternatus in field conditions.
Earthworms, especially Eisenia andrei, are cultivated for a variety of purposes including waste disposal and compost production. In this study, bacteria from earthworm gut were cultured and the dominant species identified. Subsequently, we isolated bacteriophages able to lyse the isolated gut bacteria. Two dominant genera of gut bacteria, Aeromonas sp. and Citrobacter sp. were identified by using MALDI-TOF MS analysis and a library was constructed to find lytic phages. Phage EF1 showed lytic activity for C. freundii and two Citrobacter isolates, C. braakii and C. murliniae. These 3 species have similar sensitivities to EF1. Several aspects of the life cycle of EF1 were investigated by using C. freundii under optimal growth conditions. EF1 infects C. freundii with a moderate latent period, approximately 25 min, and a large burst size averaging 5 × 109 per infected cell. Moreover, the antimicrobial activity of EF1 was well maintained under diverse conditions including a broad temperature range of 40°C to 50°C and a wide pH range of 4 to 11. In conclusion, the results indicate that earthworm casting contain a wide range of bacteria species, for which there are various corresponding bacteriophages.
An importance of food allergen detection has been growing in food industry. Here, we developed a rapid and easy-to-use detection system for Ara h1, a major allergen in peanut, using gold nanoparticles and switchable linkers. The detection system was performed by two steps. In the first step, Ara h1 was mixed with various concentrations (0.2 - 1.0μg/mL) of biotinylated anti-Ara h1 antibody (i.e., switchable linker, SLs) solutions for 20 min. After mixing, streptavidin coated gold nanoparticle (Abs. 4.0) was added to the mixture solutions with agitation for10 min. Without Ara h1(control), the region of aggregation caused by quantitative relationship between SLs and gold nanoparticle was observed at more than 0.4 μg/mL of SLs. However, under presence of Ara h1, SLs covered with Ara h1 had less ability to react with gold nanoparticles than naked SLs. This resulted in a change of the quantitative relationship mentioned above, which led to shift of the aggregation region. When 10 nM and 40 nM of Ara h1 were added, the aggregation region was appeared from 0.5and 0.8 μg/mLof switchable linkers, respectively. Ara h1 in peanut sample was also detected with this system. 0.4 μg/mL of switchable linkers are mixed with serially diluted peanut extract solutions. As a result, the shift of the aggregation region was observed from undiluted extract to 10 -2 diluted solution. This system could be adapted to detect other harmful/useful bio materials in food.
Oxalic acid has a nematicidal activity against the root-knot nematode Meloidogyne incognita. High producer of oxalic acid was isolated, and then named as Aspergillus niger F22. Oxalic acid production was investigated under various temperatures from 20 – 33oC and rotational speeds in 5 L jar fermenters. Yield of oxalic acid increased with decreasing temperature. The highest yield was obtained at 23oC, showing the yield of oxalic acid of 8.7 g/L, whereas oxalic acid production was least at 33oC. At 20oC, the yield was lower than that of 23oC. At a rotational speed of 300 rpm, serious oxygen depletion was present from 48 - 72 h, resulting in low productivity of 26.2 mg /L·h. When a rotational speed was set at 600 rpm, dissolved oxygen tension was over 40% and oxalic acid production increased up to approximately 55%. Viscosity during the culture differed with temperatures. Viscosity increased with the increment of temperatures. When A. niger F22 was cultured at 23oC, viscosity was 810 cP, which was favorable for oxalic acid production.
Biological control has been tried for integrated pest management. It is often comparable, safe, and environment-friendly, making itself an alternative for chemical agents. Filamentous microorganisms, i.e., fungi and streptomystes, produce many kinds of useful metabolites, and some of them have been developed as a biocontrol agent. However, they still have a long way because of the concern of manufacturing cost. Therefore, process development was intensively studied to meet cost-effectiveness. Operating conditions of bioreactor, e.g., agitation and aeration, had an effect on biological and physiological responses such as mycelial morphology, oxygen and nutrient transfer. Understanding relationship between operating parameters and microbial responses in terms of growth, substrate and oxygen consumption, and production yield was critical for process development. This study dedicated to build strategies for mass production of biological control agent using aerobic filamentous microorganisms.
Lentinus edodes is a popular edible mushroom in South-East Asia. This study was initiated to evaluate the antioxidant activities, tyrosinase inhibitory effects on the fruiting bodies of L. edodes extracted with acetone, methanol and hot water. The antioxidant activities were performed on β-carotene-linoleic acid, reducing power, 1,1-diphenyl-2-picrylhydrazyl free radical scavenging, and ferrous chelating abilities. In addition to this, phenolic acid and flavonoids contents were also analyzed. Methanolic extract of L. edodes showed the strongest β-carotene-linoleic acid inhibition as compare to others extracts. At 8 mg/ml, hot water extract showed a high reducing power of 0.96. The scavenging effects on 1,1-diphenyl-2-picrylhydrazyl radicals, acetonic extract was effective than other extracts. The strongest chelating effect (86.45%) was obtained from the acetonic extract at 1.0 mg/ml concentration. Antioxidant activities of the extracts from the fruiting bodies of L. edodes were increased with the increasing concentration. After application of reverse phase high performance liquid chromatography, coupled to a diode array detector and electrospray ionisation mass spectra, four phenolic compounds namely, naringenin, hesperetin, formononetin and biochanin were identified from acetonic extract. Tyrosinase inhibition of acetonic, methanolic, and hot water extracts of L. edodes were increased with the increasing of concentration. Results revealed that acetonic and methanolic extracts showed good, while hot water showed moderate activities of the tyrosinase inhibition at the concentration tested. This study suggests that fruiting bodies of L. edodes can potentially be used as a readily accessible source of natural antioxidants.
Although whole crop barley are now widely grown as a silage crop in Korea, but silage quality of the whole crop barley produced from farmer's fields have not been published. Therefore, this experiment was conducted to evaluate forage quality of whole crop barley which was participated in Korean quality contest in 2008. These data were classified by region, forage production, added inoculants, planting date and harvest date. Difference on lactic acid of barley silage was detected in the region (p<0.05), however, there no significant differences in other chemical composition. The moisture and lactic acid were significant differences in dry matter yield of barley silage. There is all the difference between silage added inoculants and control. Differences between planting dates in ash and crude protein (CP) were detected in barley silage (p<0.05). From comparison within harvest date, lactic acid ㏊d significant differences among barley silage. Differences in forage quality were observed among whole crop barley for silage. Therefore, nutritional quality as well as lactic acid is important in silage quality contest of whole crop barley.
수평 배향 액정 모드는 양의 유전율 이방성과 음의 유전융 이방성 액정을 사용한 프린지 필드
스위칭과 양의 유전율 이방성 액정을 사용한 인플래인 스위칭 모드가 대표적이다 . 이 대표적인 세 구동
방식의 화질 특성을 비교하기 위하여 각각의 최척화된 위상지연 값 조건하에서 밝기, 명암대비율과 색
특성을 조사하였다. 그 결과 양액정과 음액정을 사용한 프린지 필드 스위칭 모드가 밝기와 명암대비율
면에 있어서 인플래인 스위칭 모드보다 우수한 특성을 보인다. 또한 양액정을 사용한 프린지 필드 스위
칭 모드는 시야각 방향에서 적은 색 변이 특성을 보인다.
The patent ductus arteriosus (PDA) is a vascular structure connecting the proximal descending aorta to the roof of the main pulmonary artery, near the origin of the left branch pulmonary artery. Transcatheter closure has become the treatment of choice for most cases of PDA in both children and adults; however, measurement of the exact size and morphology of the shunt in adult cases using only contrast fluoroscopy is difficult. We report on a case of a 49-year-old woman who underwent transcatheter closure of PDA with intravascular ultrasound (IVUS) guideance. In the current case, IVUS is feasible and helpful for measuring the exact size and shape of the PDA.