The fuel fabrication facility has been built and is being operated by KAERI since licensing research reactor fuel fabrication in 2004. After almost 20 years of operation, outdated equipment for fabrication or inspection has been replaced by automated, digitalized ones to assure a higher quality of nuclear fuels. However, the generation of a large amount of radioactive waste is another concern for the replacement in terms of its volume and various types of it that should be categorized before disposal. The regulatory body, NSSC (Nuclear Safety and Security Commission) released a notice related to the classification of radioactive wastes, and most accessory equipment can be classified into the clearance levels, called self-disposal waste. In this study, the practice of self-disposal of metal radioactive waste is carried out to reduce its volume and downgrade its radioactivity. For metal radioactive waste, which is expected to occupy the most amount, analysis status and legal limitations were performed as follows: First, the disposal plan was established after an investigation of the use history for equipment. Second, those were classified by types of materials, and their surface radio-contamination was measured for checking self-disposable or not. After collecting data, the plan for the self-disposal was written and submitted to the Korea Institute of Nuclear Safety (KINS) for approval.

In the design of a spent-fuel (SF) storage, the consideration of burnup credit brings the benefits in safety and economic views. According to it, various SF burnup measurement systems have been developed to estimate high fidelity burnup credit, such as FORK and SMOPY. Recently, there are a few attempts to localize the SF burnup measurement system in South Korea. For the localization of SF burnup measurement systems, it is very important to build the isotope inventory data base (DB) of various kinds of SFs. In this study, we performed DeCART2D/MASTER core follow calculations and McCARD single fuel assembly (FA) burnup analyses for Hanbit unit 3 and confirmed the characteristic of the isotope inventory over burnup. Firstly, the core follow calculations for Cycles 1~7 were performed using DeCART2D/MASTER code system. The core follow calculation is very realistic and practical because it considers the design conditions from its nuclear design report (NDR). Secondly, the Monte Carlo burnup analyses for single FAs were conducted by the McCARD Monte Carlo (MC) transport code. The McCARD code can utilize continuous energy cross section library and treat complex geometric information for particle transport simulation. Accordingly, the McCARD code can provide accurate solutions for burnup analyses without approximations, but it needs huge computing resources and time burden to perform whole-core follow calculations. Therefore, we will confirm the effectiveness of the single McCARD FA burnup analyses by comparing the DeCART2D/MASTER core follow results with the McCARD solution. From the results, the use of single FA burnup analyses for the establishment of the DBs will be justified. Various FAs, that have different 235U enrichments and loading pattern of fuel rods and burnable absorbers, were considered for the burnup analyses. In addition, the results of the sensitivity analyses for power density, initial enrichment, and cooling time will be presented.

Minuartia laricina (L.) Mattf. is a Korean native plant with high potential as a commercial flowering potted plant due to its compactness and long flowering duration. However, because this plant is a groundcover, it is susceptible to lodging and leggy growth. Therefore, this study investigated the effects of plant growth retardants (PGRs) on the inhibition of stem elongation and flowering characteristics of M. laricina. Commercial products, Trimmit, Cycocel, and B-Nine, were used for the exogenous PGR application of paclobutrazol (PBZ), chlormequat chloride (CCC), and daminozide (DMZ), respectively. Application concentrations were 50 and 100 mg·L-1 for PBZ; 100, 500, and 1,000 mg･L-1 for CCC; and 500, 1,000, and 2,000 mg·L-1 for DMZ. Paclobutrazol was the only PGR that inhibited stem elongation. The stem lengths of the plants treated with 50 or 100 mg·L-1 PBZ were 2.2 cm (13%) or 9.8 cm (57%) shorter, respectively, than those of the control. 50 mg·L-1 PBZ retarded stem growth effectively without negatively affecting flowering or other growth parameters, whereas 100 mg·L-1 PBZ caused excessive dwarfing and significantly reduced flowering by 59%. CCC and DMZ applications were ineffective for growth control. Flowering time was accelerated with most PGRs, except for 2,000 mg·L-1 DMZ, reducing the time to flowering by 2–8 days. These results indicate that the stem growth of M. laricina was successfully inhibited with PBZ but not with CCC or DMZ. Thus, we concluded that a single application of 50 mg·L-1 PBZ or similar treatment is effective in miniaturizing M. laricina without causing harm to its growth or aesthetic value, such as the flower number. Additionally, because CCC and DMZ are not persistent in the growing medium, testing multiple application times for these PGRs is crucial.

목적: 상분리가 일어나지 않는 실리콘하이드로겔 콘택트렌즈(silicone hydrogel contact lens, SH-CL) 제조에 적합한 실리콘 모노머의 구조를 알아보고자 한다. 방법 : HEMA(2-hydroxyethyl methacrylate)와 세 종류의 실리콘 모노머, TRIM[3-(trimethoxysilyl)propyl methacrylate, Aldrich], TEMA[2-(trimethylsilyloxy)ethyl methacrylate, TCI], TMMA[(trimethylsilyl) methacrylate, Aldrich]를 활용하여 완전몰드로 SH-CL를 제조하였다. 함수율과 UV-VIS spectrophotomter 를 이용한 광투과율, TGA 분석을 통한 열적안정성 등의 물리적 특성과 FT-IR 분석을 통한 화학적 특성을 알아 보았다. 결과 : 동일한 양의 TRIM, TEMA, TMMA를 사용하여 제작한 SH-CL의 광투과율은 각각 92%, 86%, 80%로 측정되었으며, 함수율은 TRIM을 사용한 SH-CL에서 39.3%로 가장 높게 나타났다. FT-IR 분석 결과 세 종류의 SH-CL 모두 silicone monomer와 HEMA의 중합반응이 잘 이루어졌음을 확인할 수 있었고, TGA 분석을 통해 TRIM monomer의 sol-gel 반응 유무를 확인할 수 있었다. 결론 : Sol-gel 반응에 적합한 구조를 가지고 있어 상분리가 일어나지 않아 투명하고, Si에 극성 작용기인 methoxy기가 연결되어 있는 TRIM monomer가 SH-CL 제조에 적합한 구조임을 확인할 수 있었다.

In Korea livestock farms breeding cattle have been suffering from re-emerging problems of Brucella (B.) abortus infection while steady decline of bovine brucellosis. Therefore, this study underscored the identification and association of etiological agent of brucellosis in cattle in South Korea. The incidence of brucellosis in cattle was analyzed by bacteriological and molecular methods in 187 brucellosis-suspicious farms of 11 regions between 2018 and 2020. Brucella isolates from various specimens were identified by Brucella-specific multiplex PCR. Epidemiological data were collected by local official veterinarians through history taking from farmers and animal data systems. In 230 of 560 cattle (40.9%) and 94 of 187 farms (50.3%), a total of 313 B. abortus were isolated from various specimens, the majority of isolates were from supramammary lymph node (41%). In epidemiological findings, the majority of positive cases were mainly caused by resurgence (43.7%) and unknown (37.2%). Of 94 positive cases isolated B. abortus, abortion in cattle infected by B. abortus occurred in 51 farms (54.3%) where led to resurgence in 30 farms and environmental survival of B. abortus in 9 farms. Consequently, these findings revealed the existence of etiological agent of bovine brucellosis in Korea, which still occurred at low levels in distinct regions where are allowed to call for persistent biosecurity. Thus, we highlight that brucellosis in Korea needs to take more effective control strategies with potential evidence. Moreover it is ultimately important to maintain a constant monitoring for eradication of brucellosis.

본 연구는 기존에 절화용으로 개발되지 않았던 벼룩이울타리를 절화로써의 가치와 가능성을 증명함으로써 새로운 관상식물로 개발하기 위해 수행되었다. 실험은 온도, 보존용액, 절화 수명연장제에 따른 절화 벼룩이울타리의 영향을 구명하고자 절화수명, 수분흡수량, 생체중을 조사하였다. 수확 후 절화는 4, 15, 20, 25°C의 온도 조건에 따른 영향력과 1, 3% sucrose 와 8-hydroxqui-noline sulfate(8-HQS) 10, 50, 100mg･L-1 혼 용보존용액, 절화수명연장제 Chrysal와 Floarlife을 처리하였다. 저장 온도에 따른 실험 결과, 절화 벼룩이울타리는 저온 (4°C)에서의 저장에서의 절화수명이 대조구(7.8일)보다 29일 연장되었다. 온도가 낮을수록 절화의 품질과 수명에 가장 효과적이었다. sucrose와 8-HQS의 효과 확인을 위해 가장 낮은 농도의 당과 살균제를 혼용한 1% sucrose+8-HQS 10mg･L-1를 제외한 나머지 3개의 보존용액 대조구(6.5±0.5일)에 비하여 절화수명이 약 2주 연장되었다. 또한, 절화수명연장제 Chrysal 과 Floarlife는 sucrose와 8-HQS의 혼용보존용액과 절화수명에 유의적인 차이는 없었다. 한편, 모든 실험 조건에서 수분흡수량과 생체중의 급격한 감소는 절화수명의 단축됨과 연관이 있다는 것을 확인하였다.

This study aimed to examine the effect of a mild elevation in serum cholesterol level in a porcine coronary overstretch restenosis model using a balloon angioplasty catheter or drug-eluting coronary stent. Pigs were divided into two groups and were fed a commercial normal diet (CND, n = 4) or a high-fat diet (HFD, n = 4) for 5 weeks. Coronary overstretch injury by balloon angioplasty or stent implantation was induced in the left anterior descending and left circumflex artery after 1 week of feeding. Histopathological analysis was performed at 4 weeks after coronary injury. During the experiment, the total cholesterol level in the HFD group increased by approximately 44.9% (from 65.9 ± 3.21 mg/dL at baseline to 95.5 ± 9.94 mg/dL at 5 weeks). The lumen area in the CND group was reduced in comparison with that in the HFD group after balloon angioplasty. After stent implantation, the injury score showed no significant difference. There were significant differences in the neointimal area (2.7 ± 0.33 mm2 in the CND group vs. 3.3 ± 0.34 mm2 in the HFD group, p<0.05), lumen area (2.6 ± 0.54 mm2 in the CND group vs. 2.0 ± 0.33 mm2 in the HFD group, p<0.05), and percent area stenosis (52.0 ± 7.96% in the CND group vs. 62.4 ± 5.15% in the HFD group, p<0.05). Body weight change was not different between the two groups. Increased serum cholesterol level activated vascular smooth muscle cell proliferation in the porcine coronary overstretch model.

Cryopreservation of boar semen is continually researched in reproductive technologies and genetic resource banking in breed conservation. For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Recently, polymorphisms reported to be significant association with sperm MOT. This study was conducted to evaluate the SNP in the coding region of ESR1 (g.672C>T inexon 1) as a positional controlling for motility and kinematic characteristics of post-thawed boar semen. To results,The g.672C>T was significantly associated with frozen semen motility and kinematic characteristics. g.158 T>C SNP was high significantly associated with MOT, VCL, VSL and VAP Also, the SNP was low significantly associated with ALH.Therefore, we suggest that theSNP in the coding region of ESR1 (g.672C>T in exon 1) may be used as a molecular marker for Duroc boar Post-thawed semen quality.

Estrogen receptor 2 (ESR2) is involved in oestrogen-related apoptosis in cell cycle spermatogenesis but their effects have not yet confirmed in pig. Therefore, this study was performed to investigatetheir association with semen motility and kinematic characteristics. DNA samples from 126 Duroc pigs with records of sperm motility and kinematic characteristics [Total motile spermatozoa (MOT), Curvilinear velocity(VCL), Straight-line velocity(VSL), the ratio between VSL and VCL(LIN), Amplitude of Lateral Head displacement(ALH)] were used in present study. A single nucleotide polymorphism (g.35547A>G) was associated with MOT, VCL, VAP and ALH in Duroc population (p < 0.05). Therefore, we suggest that the porcine ESR2 may be used as a molecular marker for Duroc boar semen quality, although its functional effect was not clear yet. These results will improve the understanding of the functions of the ESR2 in spermatogenesis within the reproductive tracts, and will shed light on ESR2 as a candidate gene in the selection of good sperm quality boars.

We performed a survey for flavivirus infection and distribution of Aedes albopictus that known as Zika and Dengue virus vector using black–light trap and BG-sentinel trap around urban area in Korea. Mosquitoes were collected in 27 cities during March to November (twice a month) year 2016. Total numbers of mosquitoes collected 102,102 including 19 species 8 genera during collecting period. Total 21,467 Ae. albopictus was collected that 20,961(24.3%) by BG-sentinel trap and 506 (3.2%) by Black-light trap in urban area. Trap index(trap/night) of Ae. albopictus was showed highest in Hamyang (TI:992.3) and lowest in Taebaek (TI:0.3) there was only collected by Black-light trap. A total of 894 pools from all collecting Ae. albopictus were performed a Flavivirus detection. Flavivirus was not detected during study period. This study may provide basic information for surveillance of imported diseases (include Zika virus) and vectors in Korea.

Haemaphysalis longicornis is a major vector for Severe fever with thrombocytopenia syndrome (SFTS) throughout Republic of Korea (ROK). The ticks distribute at vast open fields and various kind of habitate. Control of the ticks with pesticides is almost impossible and personal protection such as use of commercial repellents is very critical for control. However occasional toxic effects of the commercial repellents have been reported that include central nervous system depression and urticaria. In our studies, repellency of three plant essential oils was assessed and was compared with two commercial repellents. Lavendual angustifolia demonstrated the highest repellency and higher repellency than DEET when was individually tested, but binary mixture of Cinnamomum zeylinicam and Juniperus verginiana showed significantly higher repellency with synergic effects than mixture of Lavendula angustifolia and Juniperus verginiana. Further study on repellency of the C. zelinicam in field need.

Previous laboratory repellent assessment with three plant essential oils against Haemaphysalis longicornis, a major vector for Severe fever with thrombocytopenia syndrome, revealed high repellency of Lavendual angustifolia and high synergic effects of Cinnamomum zeylinicam and Juniperus verginiana. Based on the previous laboratory repellent assessment field studies on repellency of the three plant oils were carried out with formulations such as cream type and spray type. 10% spray type of Cinnamomum zeylinicam demonstrated > 70% of repellency against H. longicornis. 10% spray type of Lavendual angustifolia showed > 80% of repellency. 10% spray type of binary mixture containing Cinnnamomum zeylinicam and Juniperus verginiana showed > 98% repellency against H. longicornis. Further studies on repellency of cream type of the plant oils might be carried out and compared with two commercial repellents.

Control of the vector mosquitoes is critical for implementation of patient’s decrease. Vector mosquito control has been mainly carried out using pesticides in Republic of Korea (ROK), which has developed the resistance against selected insecticides. Voltage-gated sodium channel (VGSC) and Acethylcholine esterase (AchE) are the target of several classes of insecticides. Genetic mutations of VGSC and AchE have been documented to confer resistances to pyrethroids and organophosphates in mosquitoes, respectively. In our studies, the insecticidal resistable level of An. sinensis from four malaria risk areas near Demilitarized Zone (DMZ) was measured. The partial sequence of An. sinensis voltage gated sodium channel (VGSC) IIS6 domain for Kdr gene and ace1 gene for AchE was sequenced. An. sinensis from two areas demonstrated significantly higher resistance to pyrethroids and mutation rates of Kdr gene were comparatively higher. In all tested areas An. sinensis showed high insecticidal resistance to organophosphates and > 70% of mutation rates of ace1 gene ware higher. Understanding the mechanisms of insecticide resistance among vector mosquitoes populations is very important to efficient and effective vector control.

The Asian tiger mosquito, Aedes albopictus, is considered as potential vector of Zika virus in Republic of Korea (ROK). Vector control during mosquito season is one of critical factors for decline of viral transmission. Total 14 oversea travel-associated Zika cases by mosquito bite were reported throughout ROK from January to September 2016 and vector control and monitoring at surroundings of patient’s residences was carried out during three weeks after confirmation of the virus. Although population density rates of Ae. albopictus were remarkably various according to ecological surroundings, population density of Ae. albopictus near forest was higher than urban. All captured Aedes mosquitoes were used for detection of three flavivirus, Zika, Dengue and Chikunguya, using RT-PCR and any virus was not detected. Population density of Ae. albopictus decreased > 65% on average after vector control and in one area > 95% of population density decreased. Our data might reveal that vector monitoring and control at surroundings near residences of oversea travel-associated Zika patients might effectively prevent viral transmission by mosquito bite and naturalization of the virus in ROK.

Hypocreales entomopathogenic Beauveria bassiana and Metarhizium anisopliae are well-known biological control agents worldwide and have high potential in industrialization. However their thermo-susceptibility limits long-term storage under high temperature conditions and high insecticidal activity after application to target pests. Herein we isolated highly virulent isolates, B. bassiana JEF006 and JEF007 and M. anisopliae JEF003 and 004, and produced in three grains, as substrates for solid cultures, followed by thermotolerance assays to compare the potential of the three substrates. The JEF isolates were exposed to dry and wet heat at 50°C and overall conidia were more stable under dry heat condition rather than wet heat. Of the three grains, Italian millet was superior to the other grains in the production of thermotolerant conidia. Additionally Italian millet did not severely aggregated, which enabled air to penetrate into the substrate well compared to the sorghum and millet. JEF isolates were more thermotolerant when they were kept in oil conditions. The conidia of JEF 007 and 003 wild type and AtMT-based generating random mutants were subjected to SDS-PAGE. A significant relationship between conidial thermotoelrance and detected proteins was observed. This work suggests that Italian millet can be used as an effective substrate to produce more thermotolerant conidia, thus maintaining viability for long times under unfavorable environment and biological activity against target pests.