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        검색결과 551

        1.
        2026.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Dongjun Park, Minseop Noh, Hyeokchan Kwon, Minyoung Choi, Murtaza Khan, Juil Kim
        파밤나방(Spodoptera exigua)과 왕담배나방(Helicoverpa armigera)은 우리나라를 포함한 전 세계적으로 경제적으로 중요한 농업 해충이며, 이들의 방제는 디아 마이드계 및 피레스로이드계 살충제에 대한 저항성이 빠르게 진화함에 따라 점점 더 어려워지고 있다. 이러한 저항성은 주로 시토크롬P450 모노옥시게네이스 (cytochrome P450 monooxygenases, CYPs)의 과발현에 의해 매개되는 대사적 해독능의 증가에 기인한다. 따라서CYP 활성을 억제하는 것은 살충제 감수성을 회복시키고 저항성 관리를 개선하기 위한 유망한 전략으로 부각되고 있다. 본 연구에서는CYP 억제제로 알려진 아졸계 살균제가 상승제로 작용하여 이들 나비목 해 충의 저항성 집단에 대한 살충제 효능을 증대시킬 수 있는 가능성을 조사하였다. 생물검정 결과, 종 및 살충제 종류에 따라 뚜렷이 구분되는 상승효과가 확인되었다. 파밤나방에서는 아졸계 살균제 프로피코나졸(propiconazole)을 디아마이드계 살충제 클로란트라닐리프롤(chlorantraniliprole)과 함께 처리하였을 때 독성이 유 의하게 증가하여 유충 사망률이 100%에 도달하였다. 반면, 델타메트린(deltamethrin) 저항성 왕담배나방에서는 델타메트린과 헥사코나졸(hexaconazole) 또는 메 트코나졸(metconazole)을 혼용하였을 때 강한 상승효과가 나타났으며, 사망률은 80%를 초과하였다. 아졸계 살균제를 단독 처리하였을 때에는 살충 효과가 거의 없 었으나, 살충제와 함께 처리할 경우 농도 의존적으로 사망률이 뚜렷하게 증가하였고, 이는 살충제 단독 처리구와 비교하여 통계적으로 유의한 차이를 보였다. 이러한 결과는 디아마이드계 및 피레스로이드계 살충제 저항성에CYP 매개 해독작용이 관여함을 강하게 시사하며, 동시에 아졸계 살균제가 효과적인 상승제로 기능할 수 있음을 입증한다. 종합하면, 본 연구는 파밤나방과 담배거세미나방의 저항성 집단에 대한 방제 효율을 향상시키기 위해 아졸계 살균제를 살충제 저항성 관리 프로그 램에 전략적으로 도입할 수 있음을 제안한다.
        4,000원
        10.
        2026.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hyeonho Lee, Heesu Kim, Jisu Kim, Mirae Kim, Jongil Jeong, Jun-Gyu Park, Daehyun Kim
        Background: The rise in annual mean temperatures caused by global warming has increased the risk of heat stress in livestock. Dairy cows are particularly susceptible, with both productivity and reproductive performance adversely affected. Previous studies have reported that THI ≥ 72 is generally considered the onset of heat stress. Against this background, the present study examines conception rate variations of dairy cows in relation to the THI in Jeolla-do region through 2024. Methods: The THI for the Jeolla-do region was collected from the Korea Meteorological Administration Data Portal, and artificial insemination conception records were compiled for 35,053 cows from 39 farms across Gwangju Metropolitan City and eight counties in Jeolla-do region (Gochang, Gwangju, Yeonggwang, Naju, Hampyeong, Muan, Jangseong, and Yeongam). Seasonal artificial insemination conception rates (spring: March-May, summer: June-August, autumn: September-November, and winter: December-February) were compared and analyzed in relation to the regional THI values (n = 35,053). Results: The THI threshold for heat stress in dairy cows (THI ≥ 72) persisted from May through September, and all locations, except Yeongam and Naju, reached their annual maximum THI in August. In Jangseong, THI remained ≥ 72 for the longest period, lasting 175 days. In most locations, the highest monthly conception rate occurred in July. By season, conception rates were highest in summer (June-August) at 58.5% and lowest in autumn (September-November) at 43.5%. Conclusions: The pronounced reduction in conception rates observed in autumn appears to be a consequence of the cumulative heat stress of the summer, which continues to impair reproductive performance even in autumn. Although farms commonly deploy cooling systems such as ventilation fans and sprinklers during the summer, management of heat stress may be neglected in autumn despite animals continuing to experience thermal stress, thus contributing to the observed decline in conception rates. These findings underscore the need for vigilant herd management and heat‑stress mitigation not only in summer but also in autumn. The results can serve as baseline data for future research on the effects of heat stress on dairy cattle and on strategies for its mitigation.
        4,000원
        11.
        2025.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Jae Young Jung, Dong‑gun Kim, Sungkwon Jung, Sujin Kim, Jae‑yeong Kang, Yong‑seong Park, Hongbum Kim, Nam Dong Kim, Pil Kim
        With the increasing demand for flexible electronic devices, smaller and lighter flexible supercapacitors have gained significant research attention. Among the various materials, self-supporting reduced graphene oxide (rGO) paper has emerged as one of the most promising electrode materials for supercapacitors due to its low cost, high chemical/thermal stability, and excellent electrical conductivity. Nevertheless, a major drawback of rGO paper is the limited ion diffusion between stacked rGO layers, hindering the effective formation of electrochemical double-layer at the electrode/electrolyte interface. In this study, we prepared the rGO paper derived from ball-milled followed-by water oxidation process for reducing the sheet size. The smaller-sized rGO sheets facilitated ion transport between graphene layers, promoting efficient electric double-layer formation. Moreover, the increased presence of edge planes in ball-milled rGO sheets achieved high capacitance, further enhancing the performance of rGO as an electrode material. Notably, the 2-BMOX rGO paper obtained from ball-milling and wet-oxidized graphite exhibited a capacitance of 117.9 F/g in cyclic voltammetry (CV) and 128.6 F/g in galvanostatic charge–discharge (GCD) tests, approximately twice that of conventional rGO. Additionally, the capacitance retained 91% of its initial performance after 2,000 cycles, indicating excellent cycling stability.
        4,300원
        12.
        2025.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Jung-Hoe Ahn, Hyun-Il Kim
        목적: 본 연구는 안경원 및 안과의 시력 검사실의 다양한 조도가 피검자의 동공 크기 변화에 미치는 영향을 평가하고 자 하였다. 또한 이러한 동공 크기 변화가 이색검사를 이용한 굴절검사 결과에 미치는 영향을 분석하여 시력 검사실의 적정 조도 수준을 모색하고자 하였다. 방법 : 안질환 관련 수술 경험이 없고 시력과 동공에 영향을 줄 수 있는 전신질환 및 안질환이 없는 성인을 대상 으로 기본 검사(색각 검사, 동공 기능)를 진행하였다. 완전교정 자각식 굴절검사 후에 단안 이색검사를 진행하였다. 4단계의 조도(10, 50, 300, 630 lx)를 설정하고 각 조도에서 적응 후 동공 크기를 측정하였다. 굴절이상 변화는 적 록 차트를 사용하여 교정했으며, 변화가 있는 경우 0.12 D의 구면 렌즈를 추가하여 굴절이상 변화량을 정량화하였 다. 결과 : 각 조도 단계별 굴절이상 값(이색검사 값)의 변화량은 유의한 차이가 있었다(F=37.61, p=0.000*). 뿐만 아니라 동공 크기 증가에 따른 굴절이상 값의 변화량 사이에 유의한 양의 상관관계가 있었다(r=0.178, p=0.006**). 그리고 동공 크기가 증가할수록 굴절이상 값의 변화량도 유의하게 증가하는 것으로 나타났 다(p=0.006**). 특히 어두운 조도 환경(10 lx)에서 밝은 조도 환경으로 변환(630 lx) 시 굴절이상 값의 변화는 +0.24 D 이상으로 가장 두드러졌다. 결론 : 시력 검사실의 조도 변화는 피검자의 동공 크기 변화를 유발하며, 이는 굴절이상 값(이색검사 값)의 변화 에 영향을 미치는 주요 요인 중 하나임을 확인하였다. 따라서 실제 안경 착용자가 일상생활을 영위하는 환경의 조 도는 주로 명소시 상태에 해당하므로 안정적이고 최적의 시력 교정효과를 제공하기 위해서는 최소 50 lx 이상의 조 도 상태에서 최종 굴절이상 값의 결과를 확인하는 것이 적합할 것으로 사료된다.
        4,200원
        13.
        2025.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Merc Emil Matienzo, Ba-Wool Lee, Ji-Hye Ha, Da-Hye Yi, In-Chul Lee, Hyung-Jun Kwon, Chang-Min Lee, Keon Kim, Min-Jung Park, Dong-il Kim
        Plant-derived natural products, recognized for their bioactive properties and minimal side effects, have been widely explored for their potential in obesity management. Identifying plant-based agents that can modulate adipocyte function with low cytotoxicity is essential for developing safe and effective anti-obesity interventions. In this study, Philadelphus schrenkii (Korean mock orange) was identified as a promising candidate following an initial screening for agents that exhibit minimal cytotoxicity and reduced adipocyte differentiation, as assessed by Oil Red O staining. The anti-obesity effects of P. schrenkii methanol extract (PSE) were evaluated by using in vitro and in vivo models. PSE treatment significantly reduced C3H10T1/2 preadipocyte differentiation and upregulated thermogenic markers, including Ucp1 and Dio2, in differentiated cells. Although PSE did not induce weight loss, alter food intake, or improve the serum metabolic profiles in a diet-induced obesity mouse model, it notably enhanced the thermogenic Ucp1 expression in inguinal white adipose tissue (iWAT) and brown adipose tissue. It also mitigated high-fat diet-induced adiposity in iWAT, accompanied by Protein Kinase A signaling activation. These findings suggest that PSE modulates adipose tissue function by suppressing adipogenesis and promoting thermogenic gene expression without weight reduction or metabolic improvement. Based on these effects, PSE may contribute as a supportive agent to plant-based therapeutic strategies against obesity
        4,600원
        19.
        2025.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Myung-Hyun Cho, Phil-Jung Kim
        This study utilized ray tracing and back-ray tracing to optimally design road lighting for optimal visibility for drivers and pedestrians at night. While conventional road lighting focuses on ensuring sufficient brightness, recent developments require diverse characteristics beyond brightness to ensure optimal visibility for drivers and pedestrians, including reduced glare and uniform ground luminance. Existing road lighting was inadequate for drivers and pedestrians due to serious issues such as glare and uneven illumination. To address these issues, moving beyond capacitance-centric design methods and understanding the path light takes to reach the road surface is crucial. Optical simulation, which assumes a sufficient number of rays, is essential for achieving this goal. To achieve these goals, this study explored the application of ray tracing to the design of road lighting reflectors. Design goals such as uniformity of road area per single light, shading angle, and continuous luminance uniformity over long distances were established. Ray tracing was used to design the ideal road lighting conditions. Back-ray tracing was then used to design the road lighting reflectors. By reducing light loss, power consumption was reduced by almost half while achieving the same brightness on the road, and the shading angle was 75 degrees and the brightness uniformity of the road area was 0.6, achieving the ideal design criteria.
        4,000원
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