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.
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.
Bone-related diseases (e.g., osteoporosis) represent a significant health challenge, prompting research for effective therapeutic agents, particularly from natural sources. The edible mushroom, Mycoleptodonoides aitchisonii has attracted interest due to its wide range of biological activities. Cytotoxicity assays revealed no significant toxicity of the M. aitchisonii water extract (MAWE) up to 50 μg/mL. MAWE significantly promoted dose-dependent osteoblast differentiation with ALP activity and mineralization increase by 109.17 % and 23 %, respectively, compared with the differentiation-only group. Moreover, MAWE significantly upregulated osteoblast-related gene expressions, including that of type I collagen (COL1A), osterix (Osx), and osteopontin (OPN). Furthermore, MAWE treatment significantly increased AMPK phosphorylation. This effect was further confirmed by demonstrating that the AMPK inhibitor compound C suppressed AMPK phosphorylation, and subsequent MAWE treatment restored it. In summary, these results demonstrate that MAWE possesses potent osteoblast differentiation-promoting efficacy, primarily through AMPK signaling pathway activation.
The objective of this study was to assess the effects of gypsum application on dry matter yield (DMY), mineral content of alfalfa (Medicago sativa L.), and soil properties in reclaimed tidal land in South Korea. The experiment was conducted in Seokmun, located on the west coast of South Korea, which is reclaimed with approximately 70 cm depth of degraded island soil. Treatments consisted of a control with no gypsum application (G0), 2 ton ha-1 (G2), and 4 ton ha-1 (G4) of gypsum application. The first harvest was carried out when the alfalfa reached 10% flowering, and subsequent harvests were conducted at 35-day intervals. Over the three-year experimental periods (2019-2021), the total DMY of G2 treatment was significantly higher than those of G0 and G4 (p<0.05). Although both G2 and G4 gypsum application treatments lowered soil pH, the G4 treatment increased the electrical conductivity (EC) content of the soil. Additionally, gypsum application affected the mineral contents of alfalfa, resulting in reduced concentration of sodium (Na) and Magnesium (Mg). Therefore, this present study suggests that a gypsum application rate of 2 ton ha-1 is optimal for improving alfalfa dry matter yield and mineral balance, as well as enhancing soil chemical properties in reclaimed tidal land in South Korea.
Background: Dairy cows exposed to heat stress have reduced milk production, milk quality, and conception rates, leading to lower profits. This study was conducted to analyze the effect of heat stress according to Temperature-Humidity Index (THI) on the milk production of Korean Holstein cows. Methods: Monthly maximum temperature and average relative humidity data from January 2017 to August 2024 were obtained from 62 observation points used by the Korea Meteorological Administration to calculate the national average. Using this data, the THI, a key indicator for assessing heat stress in Korean Holstein cows, was calculated. Additionally, data from 240,088 Korean Holstein cows, collected through tests conducted by the Dairy Cattle Improvement Center of the NH-Agri Business Group, were analyzed. Results: Comparative analysis of the relationship between THI and milk production revealed that milk yield remained relatively stable until THI reached the “very severe” heat stress threshold (THI ≥ 79). Beyond this level, milk production showed a tendency to decline. Conversely, when THI dropped below this threshold, milk yield tended to recover. Notably, the temperature in September, typically considered part of the autumn season, has been rising in recent years, with THI values now approaching the very severe stress level (THI ≥ 79). Conclusions: These findings suggest that establishing an appropriate farm environment and implementing systematic THI management are essential for mitigating the decline in milk production, as well as the associated economic losses, caused by rising domestic temperatures due to global warming.