검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 37

        2.
        2022.05 구독 인증기관·개인회원 무료
        At high temperatures, molten salt has heat transfer properties like water. Molten salt has the characteristics of a strong natural circulation tendency, large heat capacity, and low thermal conductivity. Unlike sodium, molten salt does not react explosively exothermically with air. However, molten salt has a strong tendency to corrode materials, and its properties are easily changed by a sensitive reaction to oxygen and moisture. Therefore, it is necessary to study material corrosion properties and chemical control methods for nuclear fuel salts, which are eutectic mixtures. In this study, the optimal operation method of the thermal convection loop is established to perform the experiments on the molten salt. The process describes briefly as follows. The operation step consists of preparation, purification, transportation, and operation. In the preparation, the step checks the entire structure and equipment (TC, blower, vacuum pump, etc.). And melt the salt mixture at a high temperature (670°C) slowly in the purification step. Before injecting the molten salt, the surface temperature of the entire loop must retain temperature (about 500°C) constantly. Completely melted molten salt in the melting pot is flow along the pipe of the thermal convection loop in the transportation step. Lastly, the convection of molten salt goes to keep by the temperature difference. The thermal convection loop can be utilized for various experiments such as corrosion tests, component analyses, chemistry control, etc.
        3.
        2022.05 구독 인증기관·개인회원 무료
        Molten salt used in the multipurpose molten salt experiment must be of high purity. Depending on the purpose of the experiment, only the base component of the molten salt be used, or a component simulating a nuclear fission product be added to the base component and used. In all cases, an increase in the concentration of impurities such as oxygen and moisture may lead to an erroneous interpretation when analyzing the experimental results. Therefore, molten salt should be purified before use. In this study, the purification of molten salt is described for multi-purpose molten salt experiments. The salt mixture is selected as MgCl2-NaCl and is quantified at a mixing ratio of 43mol%:57mol%. The salt mixture is treated in a glove box environment because of must minimize the reaction of adsorbing oxygen and moisture when the salt mixture is exposed to the atmosphere. MgCl2 is more likely to contain water than NaCl, the purification of the NaCl-MgCl2 mixture is established according to the purification process for removing water from MgCl2. A process for purifying the salt mixture briefly consists as follows: drying moisture, melting salts, purification, removing HCl, and stabilization. Through the process be able to obtain high-purity molten salt and more accurate experiment results.
        4.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        배스(Micropterus salmoides)는 수생태계에서 최상위단계에 위치하는 생태계교란 어종으로 심각한 담수생태계의 불균형을 초래하고 있다. 배스의 퇴치 및 관리를 위한 다양한 시도를 하고 있지만 효과적인 방안은 없는 상황이므로 배스의 고유한 특성에 기반한 개체군 감소의 효율성을 극대화할 수 있는 방식을 모색하였다. 본 연구에서는 배스의 Transcriptom 분석으로 Unigene contigs는 182,887개, 그리고 정자-난자 인식 단백질인 IZUMO1과 Zona pellucida sperm-binding protein의 유전자에서 CRISPR/Cas9 system을 적용할 최종 Target sequence는 12종을 산출하였다. 각 Target sequence를 인식할 수 있는 12종의 sgRNA를 합성한 후 후속 연구에 사용할 12종의 Cas9-sgRNA ribonucleoprotein (RNP) complex를 제작하였다. 본 연구에서는 차세대염기서열 분석법으로 정자-난자 인식 단백질을 암호화하는 유전자를 탐색하였고, CRISPR/Cas9 system으로 유전자를 편집하여 번식행동은 하지만 수정란을 형성하지 못하는 생식세포를 생산하는 불임개체를 유도하기 위한 조성물 개발 과정을 확립하였다. 그리고 배스와 동일한 수계에 있는 고유 생물종의 서식에는 영향을 미치지 않는 생태교란종 관리 방안으로서의 유용성을 검증하기 위한 후속 연구의 귀중한 기초 자료를 확보하는데 기여했다고 판단된다.
        5,800원
        8.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A pregnancy diagnosis is an important standard for control of livestock’s reproduction in paricular dairy cattle. High reproductive performance in dairy animals is a essential condition to realize of high life-time production. Pregnancy diagnosis is crucial to shortening the calving interval by enabling the farmer to identify open animals so as to treat or re-breed them at the earliest opportunity. MicroRNAs are short RNA molecules which are critically involved in regulating gene expression during both health and disease. This study is sought to establish the feasible of circulating miRNAs as biomarkers of early pregnancy in cattle. We applied Illumina small-RNA sequencing to profile miRNAs in plasma samples collected from 12 non-pregnant cows (“open” cows: samples were collected before insemination (non-pregnant state) and after pregnancy check at the indicated time points) on weeks 0, 4, 8, 12 and 16. Using small RNA sequencing we identified a total of 115 miRNAs that were differentially expressed weeks 16 relative to non-pregnancy (“open” cows). Weeks 8, 12 and 16 of pregnancy commonly showed a distinct increase in circulating levels of miR-221 and miR-320a. Through genome-wide analyses we have successfully profiled plasma miRNA populations associated with pregnancy in cattle. Their application in the field of reproductive biology has opened up opportunities for research communities to look for pregnancy biomarker molecules in dairy cattle.
        4,000원
        10.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        저염분 순치기간에 먹이를 섭취함으로서 얻을 수 있는 초기 유생의 생리적 변화는 다음과 같이 요약할 수 있다. 하루 동안의 순치기간에 염분농도에 따른 유생의 생존율은 차이를 보였지만 각 염분구간별 먹이섭취 유무에 따른 생존효과는 유사하였다. 그러나 먹이섭취 시 유생이 에너지원으로 활용할 수 있는 cholesterol, triglyceride의 증가가 있었으며 삼투압에 영향을 미칠 수 있는 glucose 농도가 유의적으로 증가하였다. 또한 저염분 순치기간 동안에 스트레스, 조직손상 및 대사작용의 지표가 되는 BUN과 creatine의 감소가 있었다. 먹이섭취로 인한 소화효소의 활성이 먹이를 섭취한 실험구 모두에서 증가하였다. 그러므로 유생발달과 함께 중요한 소화, 순환, 생식기관이 형성되며 탈피 성장을 위한 신진대사가 빠르게 진행되는 유생시기에 저염분 순치가 효율적으로 이루어져 향후 지속적인 성장을 유도하기 위해서는 먹이를 섭취하는 것이 더 효과적인 것으로 판단되었다.
        4,000원
        11.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to compare the effects of respiratory exercise on cardiopulmonary function and muscle activity of rectus abdominis in smokers and non-smokers with elderly people. All the participants were older than 65 years, and twenty non-smokers, and twenty smokers participated. Non-smokers and smokers were randomly divined into 10 feedback breathing exercises (FBE) and a balloonblowing exercise (BBE) group. The FBE and the BBE were performed three times a week for four weeks. Forced vital capacity (FVC), forced expiratory volume at one second (FEV1), forced expiratory volume at one second/forced vital capacity (FEV1/FVC), peak expiratory flow (PEF), and vital capacity (VC) were measured as pulmonary function. EMG was used to measure the activity of the rectus abdominis. In the FBE and BBE groups, FEV1 was significantly lower in non-smokers compared to smokers at two and four weeks (p<.05), FEV1/FVC, PEF and VC were significantly lower in non-smokers compared to smokers to pre-test, two weeks, four weeks and six weeks (p<.05). Muscle activity of rectus abdominis was significantly difference in the BBE group at pre-test, two weeks, four weeks, and six weeks (p<.05). These results suggest that respiratory exercise was effective in improving pulmonary function and rectus muscle activity.
        4,000원
        12.
        2015.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study compared the ability of feedback breathing training (FBT) and balloon blowing training to enhance the breathing of elderly people. The subjects were randomly and evenly divided into a feedback breathing training group (FBTG) and a balloon blowing training group (BBTG). Each group trained 3 times a week for 4 weeks, with the training suspended during the last 2 weeks. Pulmonary function measurements were obtained before the test and 2, 4 and 6 weeks after the test: forced vital capacity (FVC), forced expiratory volume at one second (FEV1), FEV1/FVC, peak expiratory flow (PEF) and vital capacity (VC). A repeatedmeasures ANOVA was conducted for the significance test. The FBT resulted in a significant increase in the FVC, FEV1/FVC, PEF, and VC of the elderly smokers after 4 weeks and a significant decrease in the FVC, FEV1/FVC, and PEF after 6 weeks. The BBT resulted in a significant increase in the FVC, FEV1, FEV1/FVC, PEF, and VC of the elderly smokers after 4 weeks and a significant decrease in the FVC, FEV1/FVC, and PEF after 6 weeks. In conclusion, An at home breathing rehabilitation program, in addition to balloon blowing, could increase the breathing performance of elderly people.
        4,000원
        13.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Phasianus colchicus is not only a beautiful bird but also a great value in science and under the threat of endanger. Hence, the aim of this study was to isolate the pheasant male germ cells (mGCs) and then induce them into elongated sperm-like cells in vitro. The mGCs were purified and enriched by a two-step plating method based on the different adherence velocities of mGCs and somatic cells. The percentage of the c-kit positive cells and c-kit negative cells examined by flow cytometry analysis (FCA) was 92.87% and 2.57%, respectively. Subsequently, the mGCs were induced for 48h in DMEM/F12 medium supplemented factors such as retinol acid, testosterone and bovine FSH, followed by 5 weeks in culture. We found that some elongated sperm-like cells appeared initially in vitro under inducement of stimulated factors. The elongated sperm-like cells showed in the expression of changed morphology and post-transcriptional marker such as spermatid associated (SPERT), spermatid perinuclear RNA binding protein (STRBP), round spermatid basic protein 1 (RSBN1) and SPER1L. Moreover, in DNA content identified assay, induced cells showed that the 1C DNA population markedly increased in differentiated group but it was not change in undifferentiated group. Successful in vitro differentiation of pheasant testicular germline cells into spermatids appears to offer extremely attractive potential for the conservation of endangered birds and treatment of male infertility.
        4,000원
        14.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to examine the effects of auditory biofeedback training and kicking training on walking times in patients with hemiplegia to determine if the effects of such training would be maintained even after stopping the intervention. Thirty hemiplegia patients were selected and randomly assigned to a control group of 10 patients to receive general exercise treatment; an auditory biofeedback training group of 10 patients to receive auditory biofeedback training, along with general exercise; and a kicking training group to receive kicking training, along with general exercise. All the patients received their respective training 12 times in total, three times per week for four weeks. In addition, all those in the control and experimental groups received the same general exercise treatment 12 times in total, three times per week for four weeks, and underwent follow-up tests thereafter. The patients’10m walking times were measured using a stopwatch. The significance was analyzed using repeated-ANOVAs. In cases where there were interactions between measuring times and groups, in each group were examined using repeated-ANOVAs. In cases where there were differences, post-hoc tests were conducted using repeated of contrast test. The 10m walking times of the control and experimental groups were significant differences in 10m walking times were shown between measurement times(p<.05), and significant differences in the interactions between measuring times and groups were shown between the groups(p <.05). However, no significant differences in 10m walking times were shown between the groups(p>.05). The auditory biofeedback training group showed significant decreases in walking times four weeks after the beginning of the intervention(p<.05) and significant increases eight weeks after the beginning of the intervention(p<.05). The kicking training group showed significant decreases in walking time four weeks after the beginning of the intervention(p<.05) and maintained the walking times without showing any significant differences eight weeks after the beginning of the intervention(p>.05). The walking speeds of only the kicking training group were maintained until eight weeks after the beginning of the intervention.
        4,000원
        15.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to examine the effects of auditory biofeedback training and kicking training on walking times in patients with hemiplegia to determine if the effects of such training would be maintained even after stopping the intervention. Thirty hemiplegia patients were selected and randomly assigned to a control group of 10 patients to receive general exercise treatment; an auditory biofeedback training group of 10 patients to receive auditory biofeedback training, along with general exercise; and a kicking training group to receive kicking training, along with general exercise. All the patients received their respective training 12 times in total, three times per week for four weeks. In addition, all those in the control and experimental groups received the same general exercise treatment 12 times in total, three times per week for four weeks, and underwent follow-up tests thereafter. The patients’10m walking times were measured using a stopwatch. The significance was analyzed using repeated-ANOVAs. In cases where there were interactions between measuring times and groups, in each group were examined using repeated-ANOVAs. In cases where there were differences, post-hoc tests were conducted using repeated of contrast test. The 10m walking times of the control and experimental groups were significant differences in 10m walking times were shown between measurement times(p<.05), and significant differences in the interactions between measuring times and groups were shown between the groups(p <.05). However, no significant differences in 10m walking times were shown between the groups(p>.05). The auditory biofeedback training group showed significant decreases in walking times four weeks after the beginning of the intervention(p<.05) and significant increases eight weeks after the beginning of the intervention(p<.05). The kicking training group showed significant decreases in walking time four weeks after the beginning of the intervention(p<.05) and maintained the walking times without showing any significant differences eight weeks after the beginning of the intervention(p>.05). The walking speeds of only the kicking training group were maintained until eight weeks after the beginning of the intervention.
        4,000원
        20.
        1998.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        청둥오리의 압란유의 기능성 특성을 알아보기 위하여 흰쥐를 모델로 하여 streptozotocin(STZ)을 투여하여 당뇨병을 유발시킨 다음, 혈액 중의 당 농도, 지질의 변화 및 동맥경화 지표와의 상관관계를 검토하였고, 또한 Sarcoma-180을 쥐에 이식하여 이에 대한 항암 효과를 실험하였다. STZ로 당뇨병을 유발시킨 흰쥐를 청둥오리의 압란유를 15일간 투여하였던 바 혈중의 당 농도는 정상상태로 유지되었고 phospholipid 및 triglyceride의 함량은 STZ를 처리한 압란유의 경우에는 증가하였으나, STZ 처리군에 압란유를 투여하였을 때 감소되었다. 혈중 total cholesterol, LDL+VLDL의 cholesterol 및 동맥경화의 지표는 STZ 처리군에서는 증가하였으나, 시료를 150㎎/㎏ 투여시에는 감소하였다. 한편 Sarcoma-180에 대한 성장억제율은 압란유를 150㎎/㎏ 투여시 63.89%로 나타났고 수명연장 실험에서는 압란유의 경우 15.4%로 나타났다.
        4,000원
        1 2