테트로도톡신(tetrodotoxin, TTX)은 강력한 해양생물 유 래 신경독소로, 수산물 내 TTX를 검출하기 위해 기존에 주로 사용되는 mouse bioassay (MBA)와 LC-MS/MS 기법 은 낮은 검출한계와 동물 윤리 문제 등의 한계가 있어 이 를 대체할 새로운 시험법 개발이 필요합니다. Neuro-2a assay는 대표적인 세포기반 대체 시험법으로, 이 방법은 마우스 신경모세포인 Neuro-2a 세포주에 ouabain (O)과 veratridine (V)을 처리하여 과도한 Na+ 유입으로 인한 세 포 사멸을 유도한 후, Na+ 채널 억제제인 TTX가 Na+ 유 입을 차단해 세포를 보호하는 원리를 이용해 TTX를 정량 합니다. 본 연구에서는 Neuro-2a assay를 국내 실험실 환경에 적용하기 위해 TTX 처리 조건과 O/V 농도 등의 매 개변수를 최적화하였습니다. 그 결과, 최적 O/V 농도로 600/60 μM를 설정하였으며, S자형 용량-반응 곡선이 도출 되는 8가지 농도(50-0.195 ng/mL)를 확인하였습니다. 또한, 24번의 반복 실험을 통해 데이터의 신뢰도를 평가할 수 있는 6가지 data criteria를 확립하였으며, 이 중 EC50 값 은 약 3.824-1.268 ng/mL로 나타났습니다. 실험실 간 변동 성 비교 결과, COV+와 Bottom OD값을 제외한 모든 품 질 관리 기준(quality control criteria)과 데이터 기준(data criteria)의 변동계수(CVs)는 1.31-14.92%로 도출되어, 실험 의 적정성과 재현성이 확인되었습니다. 본 연구는 국내에 서 활용 가능한 TTX 검출용 Neuro-2a assay의 최적 조 건과 신뢰성을 평가할 수 있는 quality control criteria와 data criteria를 제시하였습니다. 아울러, TTX뿐만 아니라 유사체인 4,9-anhydroTTX에 대한 TEF 값을 0.2098로 산 출하여, TTX뿐 아니라 다양한 유사체의 검출이 가능함 을 확인하였습니다. 향후, 본 시험법은 국내 수산물 내 TTX 검출을 위한 MBA 대체법으로 활용될 것으로 기대 됩니다.

도모익산(domoic acid) 군 독소는 기억상실성 패류중독 (amnesic shellfish poison, ASP)을 유발하는 해양생물독소 이다. 도모익산은 주로 규조류 Pseudonitzchia sp. 에서 생 성되어 이매패류의 체내에 축적되어 독화된다. 우리나라 연안에서는 봄철과 가을철에 Pseudonitzchia sp.의 출현이 보고되고 있으며, 수산물 내 도모익산 군 독소의 함량 기 준을 설정하여 관리하고 있다. WHO와 EFSA에서는 선제 적 안전관리를 위하여 인체노출안전기준안을 제안하여 관 리하고 있다. 본 연구는 도모익산 군 독소의 이화학적 특 성, 분석법, 인체 노출 사례와 국내외 관리 현황 등의 자 료를 검토하여 도모익산 군 독소의 체계적인 모니터링과 안전관리의 기반을 마련하고자 수행되었다.

마비성 패류 독소(Paralytic shellfish poisoning, PSP)는 유해 조류에 의해 생성되며, 독소에 노 출된 수산물을 섭취하였을 때 중독이 발생한다. 수산물 중 PSP를 검출하는 표준 시험법인 Mouse bioassay (MBA)는 낮은 검출한계와 동물 윤리 문제로 대체 시험법의 개발 필요성이 대 두되고 있다. 이러한 대체 시험법 중, PSP가 신경 세포막의 Na+ 채널을 차단하는 기전을 이 용한 마우스 뇌신경 모세포종 세포 기반 시험법(Neuro-2a assay)의 표준화를 위한 노력이 대두 되고 있다. Neuro-2a assay의 원리는 Neuro-2a 세포주에 Na+/K+ ATPase 억제제인 Ouabain (O)과 Na+ 채널 활성화제인 Veratridine (V)을 처리하여 과도한 Na+ 유입으로 인한 세포사멸을 유도한 상태에서, Na+ 채널 억제제인 PSP를 처리하게 되면 Na+ 유입이 차단되어 세포가 생존 하는 것을 측정하는 것이다. 본 연구에서는 PSP 검출을 위한 Neuro-2a assay를 국내 연구 환 경에 맞게 다양한 매개변수를 개선하여 최적 시험법을 확립하고자 하였다. 고려한 매개변수 들은 세포밀도, 배양 조건 및 PSP 처리 조건 등으로, 그 결과는 아래와 같다. 초기 세포밀도 는 40,000 cells/well로, 세포 배양시간 및 처리시간은 각각 24시간으로 설정하였다. 또한 최적 O/V 농도는 500/50 μM로 설정하였다. 본 연구에서 PSP 중 Saxitoxin (STX)에 대해서 O/V 처 리가 된 상태에서 S자형 용량-반응 그래프가 도출되는 8가지 농도(368~47,056 fg/μl)를 확인 하였고, Neuro-2a assay의 실험실 간 변동성 비교를 통해, 실험의 적정성 확인을 위한 5가지 Quality Control Criteria와 실험 데이터의 신뢰가능 범위(Data Criteria) 6가지를 설정하였다. 확 립된 조건으로 Neuro-2a assay를 진행한 결과 반수영향농도(EC50) 값은 약 1,800~3,500 fg/μl 로 나타났다. 실험실 간 변동성 비교 결과, Quality Control Criteria 값 및 Data criteria 값의 변 동계수(coefficients of variation (CVs))가 1.98~29.15% 범위로 산출되어 실험의 적정성 및 재현 성이 확인되었다. 본 연구를 통해 우리나라에서 활용할 수 있는 PSP 검출용 Neuro-2a assay 시험법의 최적 조건 및 5가지 Quality control 기준을 제시하였고, PSP 중 대표적인 독소인 STX 을 대상으로 Neuro-2a assay를 실시한 결과 유의한 EC50 값을 산출할 수 있었으며, 향후 국 내 수산물을 대상으로 MBA를 대체할 수 있는 PSP 검출법으로 활용될 것으로 기대된다.

The air dilution olfactory method to measure complex odors needs to store and carry odor samples from the field sampling until the analysis in laboratories. Until the analysis of sample in the laboratory, odor dilution factor (odor sensitivity) in the sample bag may decrease over time depending on the characteristics of each odor substances. This is one of the limitation for the air dilution olfactory method. Thus, the air dilution device enable to measure without loss in complex odors of samples. Recently, many studies on the performance test of on-site air dilution devices, i.e., field olfactometer, has been conducted to figure out the feasibility of the field olfactometers. In this study, seven odor samples were collected from five odor emission source sites. And comparative analysis with the air dilution olfactory method was carried out to assess the field applicability of the olfactometer. As results, the performance of the field olfactometer used in this study is regared as the affordable method. The dilution factors from between two methods showed the similar values, indicating low values of standard deviations. In order to ensure the accuracy and precision of measurement data using the field olfactometer, methodology minimized variables (that may affect measurement) needs to establish.

Agrophotovoltaic (APV) system is an integrated system producing crops as well as solar energy. Because crop production underneath Photovoltaic (PV) modules requires delicate management of crops, smart farming equipment such as real-time remote monitoring sensors (e.g., soil moisture sensors) and micro-climate monitoring sensors (e.g., thermometers and irradiance sensors) is installed in the APV system. This study aims at introducing a decision support system (DSS) for smart farming in an APV system. The proposed DSS is devised to provide a mobile application service, satellite image processing, real-time data monitoring, and performance estimation. Particularly, the real-time monitoring data is used as an input of the DSS system for performance estimation of an APV system in terms of production yields of crops and monetary benefit so that a data-driven function is implemented in the proposed system. The proposed DSS is validated with field data collected from an actual APV system at the Jeollanamdo Agricultural Research and Extension Services in South Korea. As a result, farmers and engineers enable to efficiently produce solar energy without causing harmful impact on regular crop production underneath PV modules. In addition, the proposed system will contribute to enhancement of the smart farming technology in the field of agriculture.

Agrophotovoltaic (APV) system is an integrated system producing crops as well as solar energy. Because crop production underneath Photovoltaic (PV) modules requires delicate management of crops, smart farming equipment such as real-time remote monitoring sensors (e.g., thermometers, irradiance sensors, and soil moisture sensors) is installed in the APV system. This study aims at introducing a simulation-based decision support system (DSS) for smart farming in an APV system. The proposed DSS is devised to provide a mobile application service, satellite image processing, real-time data monitoring, and simulation-based performance estimation. Particularly, an agent-based simulation (ABS) is used to mimic functions of an APV system so that a data-driven function and digital twin environment are implemented in the proposed system. The ABS model is validated with field data collected from an actual APV system at the Jeollanamdo Agricultural Research and Extension Services in South Korea. As a result, farmers and engineers enable to efficiently produce solar energy without causing harmful impact on regular crop production underneath PV modules. In addition, the proposed system will contribute to enhancement of the digital twin technology in the field of agriculture.

Iron-based amorphous powder attracts increasing attention because of its excellent soft magnetic properties and low iron loss at high frequencies. The development of an insulating layer on the surface of the amorphous soft magnetic powder is important for minimizing the eddy current loss and enhancing the energy efficiency of highfrequency devices by further increasing the electrical resistivity of the cores. In this study, a hybrid insulating coating layer is investigated to compensate for the limitations of monolithic organic or inorganic coating layers. Fe2O3 nanoparticles are added to the flexible silicon-based epoxy layer to prevent magnetic dilution; in addition TiO2 nanoparticles are added to enhance the mechanical durability of the coating layer. In the hybrid coating layer with optimal composition, the decrease in magnetic permeability and saturation magnetization is suppressed.

The removal of organic carbon and nutrients (i.e. N and P) from wastewater is essential for the protection of the water environment. Especially, nitrogen compounds cause eutrophication in the water environment, resulting in bad water quality. Conventional nitrogen removal systems require high aeration costs and additional organic carbon. Microbial electrochemical system (MES) is a sustainable environmental system that treats wastewater and produces energy or valuable chemicals by using microbial electrochemical reaction. Innovative and cost-effective nitrogen removal is feasible by using MESs and increasing attention has been given to the MES development. In this review, recent trends of MESs for nitrogen removal and their mechanism were conclusively reviewed and future research outlooks were also introduced.

This study investigated the Texture Profile Analysis and Sensory characteristics analysis of 6 different Pork Meat-substituted Soybean Curd (PMSC) products with different gluten-fiber (GF) contentst. PMSC types were PMSC-GF 5%, PMSC-GF 10%, PMSC-GF 15%, PMSC-GF 20%, PMSC-GF 25%, and PMSC-GF 30%. The lightness (ΔL value) of cooked PMSC was decreased, whereas the redness (Δa value) and yellowness (Δb value) of cooked PMSC was not changed. Texturometer (TA XT Plus, England) was used for objective test and hardness, springiness, cohesiveness and chewiness of sensory characteristics were measured. PMSC with GF 5% to 15% were characterized high hardness score but PMSC with GF 20% to 30% were not significantly different. PMSC-GF 30% was the highest score in springiness and PMSC-GF 5% was the lowest. PMSC-GF 25% and 30% were high cohesiveness score but was not significantly different (p<0.05). Fourteen sensory descriptors were developed to evaluate the sensory characteristics of PMSC. The sensory characteristics of PMSC were sweetness, saltiness, springiness, hardness, chewiness, meat flavor, odor, loose particle and so on. Six different PMSC showed no significant difference in the attributes of loose particle. But PMSC-GF 5% and PMSC-GF 10% showed significant difference in the attributes of hardness. PMSC-GF 25% and PMSC-GF 30% showed no significant difference in the attributes of hardness. PMSC-GF 30% was the highest springiness score and PMSC-GF 5%, PMSC-GF 10% and PMSC-GF 15% showed no significant difference in the attributes of springiness. Overall consumer acceptance was surveyed. PMSC-GF 5%, PMSC-GF 10% and PMSC-GF 15% showed no significant difference in the attributes of color. PMSC-GF 25% and PMSC-GF 30% was the highest in the attributes of springiness and high moistureness, taste acceptance and overall acceptance. PMSC-GF 5%, PMSC-GF 10% and PMSC-GF 15% showed no significant difference in overall consumer preference but PMSC-GF 25% and PMSCGF 30% showed significant difference. Consequently it is indicated that texture of cooked PMSC-GF 25% and PMSC-GF 30% is very important sensory characteristics.

This study tested a hypothesis that the bacterial immunosuppresants enhance BtI susceptibility of two mosquitoes, the forest mosquito (Aedes albopictus) and the house mosquito (Culex pipiens pallens). Three symbiotic bacteria Xenorhabdus nematophila (Xn), X. hominickii (Xh), and Photorhabdus temperata subsp. temperata (Ptt) were isolated from their symbiotic nematodes and cultured in nutrient broth to allow them to produce the secondary metabolites. BtI gave significant toxicities to A. albopictus and C. pipiens pallens larvae: 50% of lethal concentration to be 2.9 × 105 spores/mL and 2.2 × 105 spores/mL at 16 h after treatment, respectively. Addition of each bacteria-cultured broth significantly enhanced BtI toxicity to the mosquito larvae by lowering LC50 values of BtI to A. albopictus larvae (1.5 × 105 to Xn, 1.7 × 105 to Xh, and 1.9 × 105 to Ptt, respectively) and to C. pipiens pallens larvae (1.2 × 105 to Xn, 1.3 × 105 to Xh, and 1.5 × 105 to Ptt, respectively). Based on these results, we developed a new mosquitocidal Bt formulation called ‘Dip-Kill’, which consisted of 80% Xn-cultured broth, 10% BtI (1010 spores/mL), and 10% preservative. Only 400 ppm of Dip-Kill showed 100% mortality to fourth instar larvae of A. albopictus and C. pipiens pallens 16 h after treatment.

아키텍처 혁신은 급진적 혁신과 달리 기술적 불연속성의 정도는 낮지만 제품 아키텍처의 변경을 통한 기술적 성능개선 폭은 큰 혁신으로 이해되고 있다. 신생 산업의 초 기, 급진적 혁신 제품의 개발에 성공한 기업은 이후, 열등한 아키텍처 효율성 문제를 극복하 지 않으면 더 이상 기술적 성능 개선이 둔화되는 시점에 도달하게 된다. 이 지점에서는 급진 적 혁신 단계에서의 열등하지만 창의성이 깃든 제품 아키텍처의 창출 경험은 오히려 아키텍 처 혁신의 장애물로 작용하게 될 수 있다. 본 연구는 아키텍처 혁신 전후의 시장 요구변화와 이에 대한 기술적 해결 전략을 단계모델의 관점과 문제해결 모델의 관점이 결합된 분석틀의 구축을 통해 이해해보고자 하였다. 한국의 중소기업 자화전자(주)는 산업 초창기 휴대폰에 장착되는 진동모터의 급진적 혁신에 성공 후 아키텍처 혁신과 연관된 장애물들을 극복함으로써 마침내 자신이 개발한 진동모터의 본격적 확산에 성공할 수 있었다. 본 연구는 진동모 터의 개발과정에 대한 능동적 참여관찰을 통해 단일 사례를 종단적으로 깊이 연구함으로서, 이 과정이 어떻게 진행되었는지를 이해하고자 하였다.

Evolution of resistance to entomopathogenic bacterium, Bacillus thuringiensis (Bt), can potentially reduce the efficacy of insecticidal proteins from Bt to insect pests in fields. Bt resistance is involved in modification of the toxin binding to its specific midgut membrane receptors, such as cadherin, aminopeptidase N, alkaline phosphatase, and ABC transporters. The beet armyworm, Spodoptera exigua, is one of major lepidopteran insect pest in Korea and showed highly susceptible to Cry1Ca. We investigated the Cry1Ca toxicity with respect to its binding affinity to a Bt receptor, cadherin compared with Cry1Ac. RNA interference (RNAi) of a cadherin of S. exigua (SeCad1) significantly suppressed the Cry1Ca to the toxic level of Cry1Ac. Binding affinity of Cry1Ca to brush border membrane vesicle (BBMV) of S. exigua midgut was significantly lost after SeCad1 RNAi. Binding affinity of Cry1Ac to BBMV was much low compared to that of Cry1Ca and less sensitive to SeCad1 RNAi. Direct binding assay of Cry toxins to SeCad1 was assessed using a recombinant cadherin repeat 10-11 (rCR10-11) of SeCad1. The addition to rCR10-11 to Cry1Ca significantly enhanced the toxicity under SeCad1 RNAi. However, the synergistic effect of rCR10-11 on toxicity of Cry1Ac was not much significant with poor binding affinity of Cry1Ac compared to Cry1Ca. These results indicate that the differential toxicity of Cry toxins against S. exigua is caused by the different affinities to the Bt receptor, cadherin.