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        검색결과 56

        1.
        2023.11 구독 인증기관·개인회원 무료
        Radiation workers, especially those dealing with Uranium isotopes, can potentially intake Uranium -containing materials through their respiratory and digestive systems. According to the “Regulations on the Measurement and Calculation of Internal Exposure” from Nuclear Safety and Security Commission (NSSC), those who intend to work in or enter the nuclear facilities with a risk of exceeding 2 mSv exposure per year should be examined the internal exposure. However, when it comes to in-vitro bioassay, Uranium intake through drinking water can affect the quantitative analysis. The International Commission on Radiological Protection (ICRP) reported in ICRP Publication 23 (Report on the Task Group on Reference Man) that the reference man excretes Uranium in the urine (0.05-0.5 μg/day) and feces (1.4-1.8 μg/day). Korea Atomic Energy Research Institute (KAERI) set the 90.5 ng/day as the 238U background of workers handing Uranium based on the daily Uranium intake of Koreans. In this research, we examined the possible effects of Uranium in drinking water on internal exposure by analyzing the concentration of Uranium in bottled waters from various water sources sold in the domestic market and a water from the water purifier. The 238U concentration results of analyzing 11 bottled waters and 1 purified water, were ranged from 0 to 10.2 μg/L. All the results were satisfied the standard of 30 μg/L according to “Regulations for Drinking Water Quality Standards and Inspection” enacted by the Ministry of Environment. However, various concentrations were shown depending on the water sources. Assuming that these concentrations of water are consumed by drinking 1 L per day, the internal dose assessment result is 0 to 0.94 mSv. On the other hand, if it is assumed to be inhaled, it can be an overestimated because the dose coefficient of inhalation, Type M is higher than that of ingestion, f1=0.02 which are the values recommended by ICRP Publication 78 (Individual Monitoring for Internal Exposure of Workers) when the Uranium compound is unspecified. In case of two workers at KAERI, the daily excretion of urine was 151 and 120 ng/day respectively in the first quarter monitoring. However after changing the kind of drinking water in the second quarter monitoring, it dropped to 17.4 and 15.4 ng/day respectively. Through this study, it is confirmed that the Uranium background in urine can be analyzed differently depending on the kind of drinking water consumed by each worker. Depending on the Uranium concentration of drinking water, the internal exposure dose assessment can be overestimated or underestimated. Therefore, the Uranium concentration and intake amount according to the kind of drinking water should be considered for in-vitro bioassays of Uranium handlers. Furthermore, if necessary, the Uranium isotope ratio analysis in urine and the handling information should be comprehensively considered. In addition, in order to exclude the effect of intake through the digestive system, replacing the kind of drinking water can be considered. The additional analysis such as in-vivo bioassay and 24 hours urine analysis rather than spot samples can be also recommended.
        2.
        2023.11 구독 인증기관·개인회원 무료
        KEPCO KPS is the contractor for the full system decontamination (FSD) of Kori Unit 1 and under preparation such as modification, lay out for equipment installation, setting up tie-in/out point for chemical injection and way to pressurize the system, of its successful performance. In this research, KPS introduced how KPS has designed and prepared for the FSD project and how will the chemical decontamination process be implemented. As described in the previous research, chemical decontamination process is planned to be conducted for three cycles and each cycle is consisted of oxidation, reduction, decomposition, and purification. Oxidation and reduction process were conducted at 90°C. Chemical decomposition and purification process were conducted at 40°C due to the damage of IX by the heat. If the decontamination result does not meet the target DF and the dose rate, additional cycle can be conducted. Expected volume of process water for FSD is 200 m3. Three systems have been designated as decontamination targets: reactor coolant system (RCS), residual heat removal system (RHRS), chemical volume control system (CVCS). For the steady flow rate, existed plant equipment such as reactor coolant pump (RCP) will be operated and modifications on some components will be conducted. Due to the limited space for installation, decontamination equipment and other resources are distributed to three different places. KPS designed the layout of equipment installed inside the containment vessel. The layout contains the information of shielding for highly radiated equipment such as IX and filter skid.
        3.
        2023.10 구독 인증기관·개인회원 무료
        Although ethylformate and phosphine fumigants are widely used for pest quarantine, studies related to their mechanism of action and metabolic physiological changes in Drosophila models are still unclear. In this study, we investigated how key metabolites altered by fumigants and cold treatment are associated with and affect insect physiology by comparative metabolome analysis. Fumigant treatment significantly altered cytochrome P450 and glutathione metabolites involved in the detoxification mechanism and showed lower expression of PGF2α involved in the immune response compared to the control. Additionally, most of the metabolites functioned in metabolic pathways related to the biosynthesis of amino acids, nucleotides and cofactors.
        5.
        2022.10 구독 인증기관·개인회원 무료
        In this research, KPS manufactured Full System Decontamination (FSD) equipment, which is consisted of Oxidizing Agent Manufacturing System (OAMS), Chemical Injection System (CIS), RadWaste Treatment System (RWTS), Chemical Waste Decomposition & Treatment System (CWDS) and conducted demonstration test to prepare Decontamination and Decommissioning (D&D) project of Kori nuclear power plant in Korea. Each equipment of FSD was modularized due to the limited size of equipment hatch of Kori nuclear power plant. To simulate the expected circumstances in nuclear power plant such as usage of heater or position of each equipment, additional equipment was used. The chemical concentration and flow rate of process water for FSD were used as mentioned in the previous study by KHNP CRI. FSD was conducted for three cycles and each cycle was consisted of oxidation, reduction, chemical decomposition and purification. Oxidation and reduction process were conducted at 90°C. Chemical decomposition and purification process were conducted at 40°C due to the damage of UV lamp and IX by the heat. Total volume of process water for FSD demonstration test was 2.5 m2. KPS conducted decontamination performance review by calculating thickness reduction and weight loss of installed specimen. Operational review was conducted as if FSD test was conducted in the field based on the result of demonstration test. One of the most prioritized features is the workers’ safety. Also, the appropriate position of equipment needs to be considered to meet the required specification of component.
        8.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        우리나라 정원의 식물 이용 현황을 알아보고자 전국 36개 정원을 대상으로 정원식물을 조사하였다. 정원은 6가지 유형 으로 구분하였다. 그 결과, 36개소 정원에는 정원식물 712종 류가 식재되고 있었다. 교목, 관목, 초본의 비중은 평균 1:2:7 이었다. 개별 정원(10×10㎡)에서 교목은 평균 2.5종으로 12.6%, 관목은 4.1종 20.7%, 초본은 13.2종 66.7%를 차지했다. 식재 빈도 상위 5%에 40여 종이 포함되었으며, 맥문동, 일본조팝나 무, 수국, 회양목, 단풍나무, 옥잠화, 에키네시아, 산철쭉이 대 표적이었다. 양지형 정원에는 관목이 상대적으로 적고 초본이 많았으며 다른 유형보다 20~40% 이상 다양했다. 그늘형은 초 본보다 교목이 많았으며, 건조형 및 습지형과 마찬가지로 식 재 다양성이 20% 감소했다. 옥상정원의 도시형 정원은 초본 이 전체의 80~90%를 차지하고, 해안형 정원에는 목본과 초본 이 1:1로 목본 중심의 식재 특성을 보였다. 결과적으로 정원 유형에 따라 식재 다양성과 구성 비율이 명확한 차이를 나타 냈다.
        4,000원
        12.
        2018.11 구독 인증기관·개인회원 무료
        The early-onset familial Alzheimer's disease (EOFAD/ FAD), the less common type of Alzheimer's disease (AD) currently affects a vast number of individuals worldwide. This type is being inherited as an autosomal dominant fashion. Missense mutations on Amyloid precursor protein (APP) and Presenilins 1 and 2 (PSEN1 & PSEN2) are known as major genetic factors in FAD. Conversely, missense mutations on microtubule-associated protein tau (MAPT) are also thought to involve. Up to date, several triple-transgenic animal models with muted forms of the human APP, PSENs and MAPT have been reported. Compared to other animals, canines are more emotional and their disease signs can be easily diagnosed. This attempt was to develop a triple transgenic canine model for the AD. We have obtained the coding sequences of APP, PSEN1 and MAPT from Dana-Farber/Harvard Cancer Center DNA resource core at HMS and incorporated several common AD mutations. The transgenic construct is composed of hNSE (ENO2) promoter-driven three AD genes fused together with modified 2A sequences. It was transfected into the canine fetal fibroblasts which were then used to perform somatic cell nuclear transfer (SCNT). The viable transgenic embryos were obtained after in vitro culture and the GFP was detected. In this study, we have successfully produced viable triple transgenic canine cloned embryos using SCNT technique. These transgenic canine embryos will be further developed into canines with FAD. The transgenic canines will be a good candidate in the AD research field.
        13.
        2018.04 구독 인증기관·개인회원 무료
        The effect of the ionization energy on the common house mosquito, Culex pipiens, pupa was investigated as the hatching rate, longevity and detoxification enzyme activity. The longevity of adult emerging in the pupa decreased depending on the exposure dose of Gray (Gy) in Cx. pipiens. The hatching rate of the F1 generation egg derived from Cx. pipiens pupa treated up to 70 Gy did not show any difference with the control, but the eggs did not hatch 100% at 120 Gy exposure. These results showed that Cx. pipiens was sterilized at 120 Gy. Several detoxifying enzyme (GST, non-specific esterase and MFO) activity of Cx. pipiens adult emerged from pupa irradiated with 120 Gy was investigated. The difference in activity was observed in female than in male irradiated with electron beam. As a result, electron beam irradiation seems to affect enzyme activity as well as induce infertility of Cx. pipiens.
        14.
        2018.04 구독 인증기관·개인회원 무료
        최근 봄철 기온이 높아짐에 따라 마늘 뿌리응애 피해가 늘어나고 있는 실정이다. 이러한 뿌리응애 피해를 최소하 하고자 발생양상과 22종의 약제에 대하여 살비효과를 조사하였다. 마늘 재배시기 중 뿌리응애의 발생은 충북 보은 등 5지역에서 2015년부터 2017년까지 3년간 3월부터 6월까지 뿌리응애 발생밀도를 조사하여 발생양상을 확인하였다. 뿌리응애는 2016년에 가장 많이 발생하였으며, 발생시기는 월동 후 3월 상순부터 발생하여 6월 중순경까지 지속적으로 밀도가 높아지는 양상을 나타내었다. 조사된 5지역 중 가장 높은 밀도로 조사된 보은지역은 6월 상순경 주당 13.3마리가 발생하였다. 뿌리응애에 대하여 우수한 살비효과를 나타낸 약제는 분무처리시 약제처리 10일 후에서 dimethoate, azocyclotin, abamectin, hexythiazox, cabosulfan, spirotetramat, benfuracarb가 90% 이상의 살비효과를 나타내었다
        18.
        2017.04 구독 인증기관·개인회원 무료
        The diamondback moth (DBM), Plutella xylostella, is a globally distributed and important economic pest. Chemical control is the primary approach to regulate populations of this pest. Chlorantraniliprole is the first commercial insecticide that belongs to the new chemical class of diamide insecticides. In this study, the resistant strain was observed 1578-fold resistance to chlorantraniliprole. Point mutation (G4946E) in ryanodine receptor (RyR) showed a high frequency. Enzyme assays indicated that glutathione S-transferase (GST) activity in the resistant strain was 2.4 times higher compared with the susceptible strain, whereas no difference was seen for P450 and esterase. In addition, the expression of two GSTs genes was up-regulated. These findings pave the way for the complete understanding of the mechanisms of diamide insecticides resistance in insects.
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