Salmonella spp.는 식중독의 주요 원인균으로, 신속하고 정확한 검출 방법이 요구된다. 본 연구에서는 간소화된 direct multiplex real-time PCR 방법인 FS Finder SL키트 의 분석법 활용 가능성을 평가하고, 평판배지법과의 검출 성능을 비교하였다. 또한, real-time PCR의 검출 효율을 평 가하기 위해 FS Finder SL 키트에서 제공하는 세 가지 전 처리 방법(Method 1, 2, 3)을 비교 분석하였다. 실험 결과, 세 가지 전처리 방법을 이용한 direct multiplex real-time PCR 방법은 Salmonella spp.를 100% 검출할 수 있었으며, Ct 값 비교를 통한 통계적 분석에서도 세 방법 간 유의한 차이가 없는 것으로 나타났다(P>0.05). 반면, 선택 배지를 이용한 검출에서는 2 log CFU/g 이상으로 접종된 샘플에 서만 Salmonella spp.가 검출되었으나 real-time PCR법의 경우 0-3 log CFU/g 범위의 샘플에서 모두 검출이 가능 하였다. 또한, 실험에 사용된 세 가지 즉석섭취식품군(알 가공품, 닭가슴살 제품, 편의점 도시락)에서 자연균총의 영 향을 평가한 결과, 도시락 샘플의 일반세균수가 3.56±0.18 log CFU/g으로 가장 높았으며, 알가공품과 닭가슴살 제품 에서는 검출되지 않았다. 결론적으로 FS Finder SL 키트 를 활용한 real-time PCR 방법은 기존의 평판배지법보다 높은 검출 감도를 보였으며, 검출까지의 소요 시간을 대 폭 단축할 수 있었다. 특히, 복합적인 식품 매트릭스에서 도 신속하고 정밀한 검출이 가능함을 확인하였다. 본 연 구는 즉석섭취식품 중 Salmonella spp. 검출을 위한 효율 적인 direct multiplex real-time PCR 분석법의 적용 가능 성을 제시하며, 향후 식품안전 관리 시스템에서 활용될 수 있는 기초 자료를 제공한다.
The electric discharge experiment, known as the Miller-Urey experiment, is one of the experiments to understand the origin of life on Earth. The experiment involved simulating the Earth’s early atmosphere by introducing methane(CH4), ammonia(NH3), and nitrogen(N2) gases, and applying energy through electric discharge. Resulting solution was found to contain amino acids such as glycine(C2H5NO2), alanine( C3H7NO2), histidine(C6H9N3O2), proline(C5H9NO2), and valine(C5H11NO2). These amino acids were compared with the results of the recent experiment (Parker et al. 2014). Interestingly, the electric discharge produced C2 swan band and CN emission and it was newly found in gas phase. These two emission bands are commonly observed in comets.
국내의 도심지 도로는 대부분 시공 후 신속하게 개통할 수 있는 연성포장인 아스팔트 포장으로 시공되어 있다. 그러나 도심지 특성상 인구 밀도의 집중으로 인해 대중교통인 버스의 교통량이 증가하여 중앙버스정류장에 시공된 아스팔트 포 장에 피로하중이 쌓여 심각한 포장 파손이 자주 발생한다. 서울시에서는 최근에 중앙버스정류장의 포장 파손을 억제하기 위해 아스팔트 포장을 콘크리트 포장으로 신속하게 전환할 수 있는 프리캐스트 콘크리트 포장(Precast concrete pavement)을 중앙버스정류장에 적용하고 있다. 본 연구에서는 시공된 중앙버스정류장 중 가장 오랜 기간 공용한 구간을 선정하여 현장 조사를 수행하였으며 프리캐스트 콘크리트 포장의 공용상태와 손상 형태 및 유형을 분석하였다. 현장 조 사를 수행한 중앙버스정류장은 연장이 72m이며 12개의 패널로 구성되어 있다. 현장 조사를 통한 분석 결과 접속부에서 는 아스팔트 포장에 소성변형 및 균열 등의 손상이 관찰되었으며 본선의 경우 그라우트 홀의 균열 또는 탈락, 패널의 균 열 등이 손상 유형으로 분석되었다. 또한, 줄눈부에서는 스폴링 및 단차 등이 손상 유형으로 확인되어 일반적인 현장타 설 줄눈 콘크리트 포장의 손상 유형과 유사한 것을 알 수 있었다.
This study aims to examine total factor productivity (TFP) and its determinants in offshore fisheries under the worsening fishing environment and to propose policy improvement based on the estimation results. We identified a decline in TFP of offshore fisheries from 2012 to 2020 employing the global Malmquist productivity index (GMPI), with the primary cause being the regression of the production possibility frontier due to the reduction of fishery resources. Moreover, utilizing the system generalized method of moments (GMM), we found that the determinants, such as the cessation of operations in Japan’s EEZ, vessel age, fishing experience, and oil prices, contribute to a decrease in the TFP of offshore fisheries. Therefore, this study suggests implementing a total allowable catch (TAC)-centered fishery resource management policy, along with reducing loan interest rates and extending the repayment period for the vessel modernization project. Furthermore, it is necessary to improve the TFP of offshore fisheries by providing regular training for fishermen, implementing the tax-free petroleum stockpiling project, and developing alternative fishing grounds.
PURPOSES : This study was conducted to prevent slip accidents on manhole covers located on sidewalks and local roads as well as to propose reasonable slip resistance management standards for manhole covers. METHODS : Using field surveys, test groups were classified based on the patterns and wear amounts of the manhole covers. Standards for measuring the equipment and methods for slip resistance were established, and the slip resistance values were compared and analyzed for each manhole cover test group. RESULTS : According to the slip resistance test results, micro-protrusions on the non-slip manhole covers were found to be effective in improving slip resistance. However, in areas without microprotrusions, the improvement in slip resistance was minimal and yielded results similar to those of standard manhole covers. In addition, among the pattern types of standard manhole covers, the radial pattern was found to be the most susceptible to slipping. Under the current wear measurement standards, the change in slip resistance at different wear stages was found to be relatively small. Moreover, manhole covers had the lowest slip resistance among road surface structures, indicating the need to establish management standards for them. CONCLUSIONS : To prevent pedestrian slip accidents on sidewalks and local roads, it is necessary to ensure that the slip resistance standards of manhole covers are higher than those of sidewalks.
iRAP(international Road Assessment Program)에서는 최근 다양한 유형의 도로 정밀자료를 바탕으로 한 AiRAP(Accelerated intelligent Road Assessment Program)을 개발하여 여러 국가별 RAP에 확대 적용해나가고 있는 단계에 있다. 2023년부터 국내 도로 여건을 고려한 한국형 도로안전도 평가 프로그램 개발 연구가 진행 중에 있으며, 개발되는 평가항목 및 기준, 평가기술 등에 적합한 도로안전도 평가 기초데이터 역시 유형 및 범위에 변화가 필요해짐에 따라 이를 충족하는 기초데이터 수집이 가능한 도로안전도 조사장비 개발이 기획 되었다. 이에 따라 본 연구에서는 고사양의 360도 도로영상 촬영장치와 360도 128채널 LiDAR 센서, 정밀 GPS 시스템, 휴대용 운영장 치 등을 갖춘 도로안전도 조사장비를 일반 차량에 탈부착이 가능한 형태로 개발하고자 하였다. 본 개발 장비로 취득 가능한 도로영상 및 점군데이터를 활용하여 AiRAP 자동분석을 통한 도로안전도 평가가 가능한데, 이를 통해 객관적이고 신뢰성 높은 평가가 가능할 것으로 기대된다.
감정적 맥락이 기억에 미치는 영향을 이해하는 것은 인간의 인지 능력을 종합적으로 이해하는데 매우 중요하다. 이전 연구에서는 주로 시각적 자극에 초점을 맞춰 이러한 관계를 탐구했다면, 본 연구는 음성으로 제시되는 감정 맥락으로 탐구의 영역을 확장하여 언어적 맥락의 각성도와 정서가가 기억에 미치는 영향을 조사하고 특히 서열 위치 효과를 완화하는지에 주목하였다. 연구 1에서는 단어 목록의 중반부에 제시되는 음성 감정 맥락의 각성도가 단어 음성 기억에 어떤 영향을 주는지 알아보았다. 실험 결과, 각성도가 낮은 맥락에 노출되었을 때 목록 후반부의 기억력 이 저하되는 것으로 나타났다. 연구 2에서는 각성도 수준을 통제했을 때 목록의 중반부에 제시되는 음성 감정 맥락 의 정서가가 단어 음성 기억에 미치는 영향을 조사했다. 실험 결과, 부정적 맥락은 함께 제시되는 단어의 기억력을 저하시킨다는 사실을 발견했다. 연구 결과는 음성을 통해 제시되는 감정 맥락이 음성 자극의 기억 처리를 촉진하지 못한다는 것을 시사한다. 특히 부정적 정서 맥락은 서열 위치 효과를 강화하는 것으로 나타났다. 즉, 맥락과 기억 자극이 음성으로 동일할 경우 부정적 감정 맥락은 과제 수행에 간섭으로 작용하여 감정 맥락의 기억 향상 효과를 유발하지 못하는 경향을 보인다. 이는 청각적으로 전달되는 감정 맥락이 언어 기억 과정에 미치는 영향을 이해하는 데 중요한 통찰을 제공한다.
PURPOSES : Snow-removal performance is performed in this study to assess the feasibility of replacing calcium-chloride solution with sodium chloride solution at the minimum temperature of -5 ℃ during snowfall. METHODS : The atmospheric temperature distribution in Seoul was analyzed. The manufacturing, storage, and indoor melting performance of calcium-chloride and sodium-chloride solutions were evaluated, and on-site snow-removal performance was evaluated based on the solution type. RESULTS : According to the results of the melting performance test at -5°C, the melting capacity of the sodium chloride solution was expressed at a level exceeding 90% of that of the calcium chloride solution, indicating a similar melting performance between the two solutions. Additionally, based on the snow removal performance test using aqueous solutions, the snow removal performance of the sodium chloride solution was found to be approximately 96% compared to that of the calcium chloride solution, indicating minimal differences in snow removal performance due to changes in the type of solution. CONCLUSIONS : Similar snow-removal performance was achieved when the sodium chloride solution was used instead of calciumchloride aqueous solution at temperatures exceeding -5 ℃.
We conducted research on the removal performance of various odor substances using a deodorizing agent, hypochlorite ion (OCl-), in odor emission sites where various odor-causing substances occur simultaneously. In experiments treating odor gases containing mixtures of aldehydes (acetaldehyde, n-butyl aldehyde, iso-valeraldehyde, propionaldehyde), sulfur compounds (hydrogen sulfide, methyl mercaptan, and dimethyl sulfide), and nitrogen compounds (ammonia and trimethyl amine), it was demonstrated that the introduced odor substances could be simultaneously removed when electrolyzed water was used. The overall removal efficiency was found to be significantly higher than when water alone was used. Particularly, it showed simultaneous effectiveness against acidic, neutral, and alkaline odor substances such as ammonia and hydrogen sulfide. Considering the positive aspects with regard to chemical safety, the use of salt instead of chemicals, and the continuous regeneration of the oxidizing agent, this environmentally friendly deodorization technology is expected to contribute to securing excellent odor removal capabilities and wide-ranging deodorization applications.
PURPOSES : The number of snowfall and the amount of snowfall are gradually increasing, and due to the characteristics of Seoul, which has a lot of traffic, it is difficult to respond quickly with a snow removal method that relies on snow removal vehicles. Therefore, it is necessary to develop an IoT based eco-friendly snow removal system that can respond to unexpected heavy snow in winter. In this study, the low temperature operation and snow removal performance of the IoT road condition snow removal detector and the snow removal system using CNT and PCM are evaluated in the climatic environment chamber. METHODS : To make artificial snow, it consists of an climatic environment chamber that can simulate a low temperature environment and equipment that can supply compressed air and cold water. Depending on the usage characteristics of the climatic environment chamber, use an air-water type snow maker. In order to make artificial snow, wet temperature, which takes into account the actual air temperature and the amount of moisture in the air, acts as the most important variable and is suitable for making snow, below –1.5 ℃. The lower the water temperature, the easier it is to freeze, so the water source was continuously supplied at 0 ℃ to 4 ℃. One of the two different pipes is connected to the water tank to supply water, and the other pipe is connected to the compressor to supply high-pressure air. Water is dispersed by compressed air in the form of many small droplets. The sprayed microscopic water particles freeze quickly in the low temperature environmental climatic chamber air and naturally fall to the floor, forming snow. Based on the KS C IEC 60068-2-1 cold resistance test standard, an integrated environmental test procedure was prepared to apply to IoT-based snow removal systems and performance evaluation was performed accordingly. The IoT based eco-friendly snow removal system is needed to in winter, so visual check and inspect the operation at the climatic chamber before setting up it to the actual site. In addition, grid type equipment was manufactured for consistent and reliable snow removal performance evaluation under controlled environmental conditions. RESULTS : The IoT-based eco-friendly snow removal system normally carried out the task of acquiring data and images without damaging the appearance or freezing in a low temperature environment. It showed clear snow removal performance in areas where PCM and CNT heating technology were applied to the concrete slab. This experiment shows that normal snow removal tasks can be carried out in low temperature environments in winter. CONCLUSIONS : The integrated environmental test procedures and grid type evaluation equipment are applied to low temperature operation and snow removal performance evaluation of snow removal systems. In the climatic environment chamber, where low temperature environments can be simulated, artificial snow is created regardless of the season to derive quantitative experimental results on snow removal performance. PCM and CNT heating technology showed high snow removal performance. The system is expected to be applied to road site situations to preemptively respond to unexpected heavy snow in winter.
We used the measurement data derived from a proton transfer reaction time-offlight mass spectrometry (PTR-ToF-MS) to ascertain the source profile of volatile organic compounds (VOCs) from 4 major industrial classifications which showed the highest emissions from a total of 26 industrial classifications of A industrial complex. Methanol (MOH) was indicated as the highest VOC in the industrial classification of fabricated metal manufacture, and it was followed by dichloromethane (DM), ethanol (EN) and acetaldehyde (AAE). In the industrial classification of printing and recording media, the emission of ethylacetate (EA) and toluene (TOL) were the highest, and were followed by acetone (ACT), ethanol (EN) and acetic acid (AA). TOL, MOH, 2-butanol (MEK) and AAE were measured at high concentrations in the classification of rubber and plastic manufacture. In the classification of sewage, wastewater and manure treatment, TOL was the highest, and it was followed by MOH, H2S, and ethylbenzene (EBZ). In future studies, the source profiles for various industrial classifications which can provide scientific evidence must be completed, and then specified mitigation plans of VOCs for each industrial classification should be established.
This study aimed to investigate the protective effect of enzymatically modified stevia (EMS) on C2C12 cell-based model of dexamethasone (DEX)-induced muscle atrophy to provide baseline data for utilizing EMS in functional health products. C2C12 cells with DEX-induced muscle atrophy were treated with EMS (10, 50, and 100 μg/mL) for 24 h. C2C12 cells were treated with EMS and DEX to test their effects on cell viability and myotube formation (myotube diameter and fusion index), and analyze the expression of muscle strengthening or degrading protein markers. Schisandra chinensis Extract, a common functional ingredient, was used as a positive control. EMS did not show any cytotoxic effect at all treatment concentrations. Moreover, it exerted protective effects on C2C12 cell-based model of DEX-induced muscle atrophy at all concentrations. In addition, the positive effect of EMS on myotube formation was confirmed based on the measurement and comparison of the fusion index and myotube diameter when compared with myotubes treated with DEX alone. EMS treatment reduced the expression of muscle cell degradation-related proteins Fbx32 and MuRF1, and increased the expression of muscle strengthening and synthesis related proteins SIRT1 and p- Akt/Akt. Thus, EMS is a potential ingredient for developing functional health foods and should be further evaluated in preclinical models.
세리신은 누에고치에서 추출한 단백질로 많은 건강상의 이점을 가지고 있다. 본 연구는 화장품 소재로서 누에고치에서 유래된 세리신 표준품의 항주름 활성 및 항염증 활성을 평가하기 위해 수행되었다. 세리신의 항산화 효과는 DPPH 및 ABTS 측정법에 의해 측정되었다. 또한 대식세포인 Raw 264.7 cell에서 의 세포 생존율을 확인하였으며, lipoplyscaccharide를 이용하여 유도된 염증반응을 이용하여 세리신의 항 염증 효과를 조사하였다. 그 결과 세리신은 DPPH, ABTS에서 항산화 활성을 보였으며 세포 독성을 가지지 않은 1,000 μg/mL의 농도에서 NO를 억제하였다. 종합하여 세리신은 항산화 활성을 가지며 항노화 및 항 염증 화장품의 우수한 소재가 될 수 있음을 보여준다.
본 연구는 Tetraselmis suecica와 T. tetrathele의 영양물질 증진효과를 가져올 수 있는 배양시스템 구축을 위하여, 발광다이오드 (LED)의 파장별(청색; 450 nm, 황색; 590 nm, 적색; 630 nm) 탄수화물, 단백질, 지질 함량을 측정하였다. 두 종 모두 단백질 비율(42~69%)이 가장 높았으며, 생장속도가 낮았던 황색파장에서 탄수화물, 단백질, 지질의 높은 함량을 보였고, 생장속도가 가장 높았던 적색파장에서는 낮은 함량을 보였다. 이러한 결과는 세포 분열 속도의 감소로 인해 단백질 합성과 함께 세포의 화학적 조성과 효소 활동에 변화를 주어 지질과 탄수화물 함량이 증가한 것으로 생각된다. 따라서, T. suecica와 T. tetrathele의 유용한 생화학적 물질의 증대를 위해 대수생장기 초 기와 중기는 적색 LED 그리고 대수생장기 후기에는 황색 LED를 주사하는 2단계 LED 배양을 제안하였다.