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        검색결과 26

        1.
        2024.04 구독 인증기관·개인회원 무료
        왕피천 수계 내 저서성 대형무척추동물의 군집구조 분석을 위해 총 5개 지점에서 2023년 총 4회(4월, 6월, 8월 11월) 조사를 실시하였다. 조사기간 중 저서성 대형무척추동물은 총 5문 7강 17목 77과 156종 17,179.1개체/㎡가 채집되었다. 수환경 변화에 민감한 E.P.T. 분류군은 전체 156종 중 91종이 출현하여, 전체 출현종의 58.3%를 차지 하였다. 섭식기능군(FFGs) 분석결과, 종 출현 양상은 육식성 포식자(Predator: P)가 51종(32.69%)으로, 개체 출현 양상은 주워먹는 무리(Gathering-collector: GC)가 6,867.2개체/㎡(39.97%)로 높은 비율로 출현하였다. 서식기능 군(FHGs) 분석결과, 붙는 무리(Clinger: CL)가 70종(44.87%), 12,720.6개체/㎡(74.04%)로 가장 높은 비율로 출현 하였다. 군집지수 분석결과, 우점도지수(DI) 0.43, 다양도지수(H′) 3.51, 풍부도지수(R1) 4.59 균등도지수(J′) 0.77 로 나타났다. 생물학적 수질 판정 지수(BMI) 분석결과, 평균 92.36(±0.83)으로 모든 지점에서 “매우 좋음”으로 판정되었다.
        2.
        2023.11 구독 인증기관·개인회원 무료
        KORAD (Korea Radioactive Waste Agency, http://www.korad.or.kr) has stored slightly contaminated ascon (asphalt coated concrete mixture) that was introduced to Gyeongju repository about a decade ago waiting for a final disposal. It is believed to be mainly contaminated by radioisotope 137Cs due to impurities introduced from the outside during the ascon manufacturing process. We studied characteristics of the radioactive waste to see whether this material would be proper enough to be disposed in Gyeongju LILW repository or be other ways to reduce the disposal volume including self-disposal before its final disposal otherwise. KORAD looked into the properness of characteristics of ascon in terms of WAC (Waste Acceptance Criteria) documented by KORAD that includes general chemical and physical properties of asphalt, density, size of grains, content of organic material and possibility of existence of chelate materials that qualitatively limited to be disposed by the criteria. And other associated characteristics such as gas generation and bio degradation were also investigated. Based on the data obtained from the study, we proposed various plausible solutions in associated with operational and disposal safety and economic view points. This study will be used for KORAD’s decision on how to control and safely dispose the spent ascon within a reasonable time period. And also those experiences may be applied for other LILW issues that require treatment or conditioning of radioactive wastes in the future.
        4.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        For fast-built and safe precast concrete (PC) construction, the dry mechanical splicing method is a critical technique that enables a self-sustaining system (SSS) during construction with no temporary support and minimizes onsite jobs. However, due to limited experimental evidence, traditional wet splicing methods are still dominantly adopted in the domestic precast industry. For PC beam-column connections, the current design code requires achieving emulative connection performances and corresponding structural integrity to be comparable with typical reinforced concrete (RC) systems with monolithic connections. To this end, this study conducted the standard material tests on mechanical splices to check their satisfactory performance as the Type 2 mechanical splice specified in the ACI 318 code. Two PC beam-column connection specimens with dry mechanical splices and an RC control specimen as the special moment frame were subsequently fabricated and tested under lateral reversed cyclic loadings. Test results showed that the seismic performances of all the PC specimens were fully comparable to the RC specimen in terms of strength, stiffness, energy dissipation, drift capacity, and failure mode, and their hysteresis responses showed a mitigated pinching effect compared to the control RC specimen. The seismic performances of the PC and RC specimens were evaluated quantitatively based on the ACI 374 report, and it appeared that all the test specimens fully satisfied the seismic performance criteria as a code-compliant special moment frame system.
        4,000원
        5.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 설문을 통해 ‘스마트 그린오피스(Smart Green Office)’에 대해 대중의 인식과 선호도를 알아보고, 활성화를 위한 기반을 마련하고자 수행하였다. 총 195명을 대상으로 설문조사를 진행하였으며, 실내식물에 대한 인식과 ‘스마트 그린오피스’의 인식 및 선호도에 대하여 조사하였다. 설문조사 결과, 설문에 참여한 대부분의 응답자들은 실내식물을 선호하며, 접근성과 필요성에 대해 긍정적으로 답변한 것으로 조사되었다. 응답자들이 실내식물을 통해 ‘공기 질 향상(52.0%)’ 및 ‘스트레스 해소(34.0%)’등 긍정적인 효과를 경험한 적이 있기 때문에 실내식물의 기능을 인지하고 필요성을 크게 인식하는 것으로 판단된다. ‘스마트 그린오피스’의 인지도에 대해 조사한 결과, 알거나 들어본 경험이 있는 사람은 15.4%로 적었으나 개념을 설명한 후, 필요성을 느끼고 설치를 원하는 응답자들 은 90% 이상으로 조사되었다. 응답자들은 ‘공기정화(83.6%)’ 기능 때문에 ‘스마트 그린오피스’ 도입 이 필요하다고 하였으며, 오피스 내 도입 시‘공기정화 식물(70.8%)’로 이루어진 벽면형태(41.0%)’를 선호하는 것으로 조사되었다. 또한, ‘비용 (45.6%)’과 ‘유지 관리(28.2%)’등의 문제가 ‘스마트 그린오피스’ 도입 시 고려하는 점으로 조사되었으며, 설치 시 비용은 ‘200만원 이하(56.4%)’와 ‘200~450 만원(38.5%)’을 선호하는 것으로 조사되었다. ‘스마트 그린오피스’의 인식 및 선호도와 더불어 비활성화에 대한 원인을 조사한 결과, ‘낮은 인지도’ 및 ‘스 마트 그린오피스’의 개념을 인지하지 못한 ‘불필요’가 각각 25.1%와 42.6%로 조사되었으며, ‘적극적인 마케팅 및 홍보 (46.2%)와 ‘실내식물에 대한 관심도 향상(38.0%)’이 이를 해결하기 위한 방법이라고 응답하였다. 따라서, ‘스마트 그린오피스’의 올바른 의미를 알리고, 공기정화 식물로 이루어진 벽면형태의 디자인 개발 및 모델 제시와 같이 ‘스마트 그린오피스’가 활성화될 수 있도록 홍보를 통한 다양한 정보 제공 등 여러 방안 모색이 필요할 것으로 판단된다.
        4,000원
        11.
        2016.04 구독 인증기관·개인회원 무료
        Acetylcholinesterase 1 (AmAChE1) has low catalytic activity and is abundantly expressed in both neuronal and non-neuronal tissues. In previous experiments, we observed that AmAChE1 is rarely expressed in summer while highly expressed in winter. Through additional experiments, the expression of AmAChE1 was suggested to be associated with brood rearing status. Under the assumption that abnormal suppression of brood rearing activity may result in stressful condition in honey bee social community, it was further suggested that AmAChE1 is likely involved in stress management particularly during winter. We hypothesized that the increased docility usually observed in overwintering bees is likely an outcome of stress management in colony, which is mediated by AmAChE1 expression. To verify this, worker bees expressing abundant AmAChE1 were collected in early winter and injected with Amace1 dsRNA to knockdown Amace1. Then, the behavioral activity of the bees was investigated using the EthoVison video tracking system. Honey bees injected with Amace1 dsRNA showed significantly increased motility, which was strongly correlated with the suppressed expression level of AmAChE1 in the abdomen. No apparent reduced expression of AmAChE1 in the head was observed perhaps due to the limited efficacy of RNA interference in the blood-brain-barrier. Our finding suggests that behavioral activity can be regulated, at least, by AmAChE1 expression level in non-neuronal tissue (i.e., fatbody) perhaps via metabolic alteration.
        12.
        2015.12 구독 인증기관 무료, 개인회원 유료
        The aim of the present study was to investigate sex- and age-associated clinico-metabolic characteristics of urinary stone patients. A retrospective review was performed on data from 2,009 consecutive patients presenting with their first urinary stone episode between 2005 and 2013. Of the 2,009 patients, 1,426 (71.0%) satisfied the inclusion criteria and were enrolled in the study. Patients were grouped by age (<60, ≥60 years old) and sex. The medical history and 24 hr urinary chemistry results of each patient were obtained. The mean age of the 165 (11.6%) patients aged 60 or over was 65.5 ± 4.2 years. Body mass index was greater in elderly females than in younger females (p=0.031). After stratification by sex and age, lower urinary excretion of calcium and uric acid was a protective factor for both sexes among the elderly (p<0.05, each, respectively). Low urine pH was a common risk factor for both sexes among the elderly (p=0.013 in males, p=0.047 in females, respectively), whereas lower citrate excretion was a risk factor for only the elderly female group (p=0.004). With regard to urinary metabolic abnormalities, elderly females showed higher incidence of hypocitraturia compared to younger females (p=0.049). In conclusion, this study demonstrated the sex- and age-associated clinico-metabolic characteristics of urinary stone patients. Thus, it is important to tailor metabolic evaluation and medical prevention therapies for patient according to sex and gender characteristics.
        4,000원
        18.
        2010.12 KCI 등재 구독 인증기관·개인회원 무료
        Neurotrophic factors are essential to maintain and organize neurons functionally; thereby neurotrophic factor-like substances or their inducers are expected to be applied to the treatment of neurodegenerative diseases such as stroke. In the present study, we firstly examined the effects of ethanol extracts of Hericium erinaceus (HE, Yamabushitake), on nerve growth factor expression in neuronal cells. HE extract promoted NGF expression in a brain tissue. Here we assessed neuroprotective effects of HE with a transient global cerebral ischemia model. Global cerebral ischemia was induced by occluding both common carotid arteries. Treatment with HE was initiated after ischemia induction and given once a day for 7 consecutive days. Neuronal cell loss in CA1 of hippocampus was significantly decreased and the performance in the Morris water maze was significantly improved in rats administered HE. We conclude that treatment with HE attenuated learning and memory deficits, motor functional disability, and neuronal cell loss induced by global cerebral ischemia. These results suggest that HE may be a potential candidate for the treatment of vascular dementia.
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