우리나라에 축산물을 수출한 국가들이 2022년과 2023년 에 제출한 2019-2022년 국가별 잔류물질검사프로그램(NRP) 자료를 바탕으로 축산물 유형별, 국가별로 잔류허용기준 을 위반한 동물용의약품과 환경오염물질의 현황을 분석하 였다. 가장 많이 위반된 잔류물질은 네오마이신 2 4 1건, 페 니실린G 183건, 겐타마이신 151건, 세프티오퍼 113건, 니카 바진 103건 등이였고 축산물별로는 소고기, 돼지고기, 가 금육, 우유, 계란 등의 순서로 나타났다. 잔류 위반이 가 장 많았던 소고기에서는 페니실린G, 세프티오퍼, 플루니신 , 네오마이신, 벤질페니실린, 멜록시캄, 플로르페니콜, 질 파테롤 등 전염병 치료에 사용되는 항생제와 해열제 및 성장 촉진에 사용되는 동물용의약품이 주로 검출되었지만 , 돼지고기에서는 성장촉진을 목적으로 사용되는 락토파민 과 항생제인 독시사이클린, 클로람페니콜, 벤질페니실린, 난드롤론, 티오라실, 스트렙토마이신 및 임신 촉진에 사용 되는 호르몬이 가장 흔하게 검출된 것으로 나타났다. 가 금육에서는 콕시듐증 치료에 사용되는 항생제인 니카바진 이 가장 많이 위반되었으며, 스트렙토마이신, 아미노글리 코사이드 항생제, 벤질페니실린, 독시사이클린 및 기타 항 생제가 그 뒤를 이었다. 동물용의약품의 잔류 위반은 많 은 국가에서 보고되고 있으나, 다이옥신과 PCB와 같은 환 경오염 물질의 잔류는 주로 유럽 국가에서 보고되었다. 국 가별 잔류물질의 차이는 각국에서 사육되는 가축과 사육 관리 방식의 차이에 의한 것으로, 소고기의 잔류 수준이 높은 것은 소는 다른 동물에 비해 질병 발생 시 개체별로 치료되기 때문일 것으로 추정된다. 본 연구 결과는 수입 축산물의 안전성 확보를 위하여 국가별, 축산물별로 중점 적으로 검사가 필요한 물질을 제시함으로써 매년 실시하 는 수입 축산물 잔류물질검사를 보다 과학적이고 효율적 으로 수행할 수 있는 기반을 제공하였다.

Gentamicin is an aminoglycoside antibiotic effective against aerobic gram-negative bacteria and is also used in veterinary medicine, particularly in the swine and bovine industries. However, no gentamicin product is currently approved for treating equine diseases in Korea. The present study aims to examine the time-dependent residue of gentamicin in horses after intravenous injection (IV) via jugular vein. The test product was injected at 6.6 mg/kg BW via jugular vein in nine horses. Blood was collected from the horse's jugular vein at 15 minutes, 30 minutes, 1, 4, 8, 12, 24 and 48 hours after injection. To purify the gentamicin in serum, 100μL of 20 mM HFBA in DW, 100 μL of 30% trichloroacetic acid and 300 μL of 20 mM heptafluorobutyric acid (HFBA) in acetonitrile (ACN) were added to 500 μL of serum and supernatant was applied to LC-MS/MS after centrifugation. LC-MS/MS-8050 analyzed the level of gentamicin in serum with Electrospray ionization (ESI) and multiple reaction monitoring (MRM) positive mode. Gentamicin C1 was 478 m/z and product ions were 322, 157 m/z. Precursor ion of Gentamicin C1a was 450 m/z and product ions were 322, 160 m/z. Precursor ion of Gentamicin C2 and C2a was 464 m/z and product ions were 322, 160 m/z. The LC column was a C18 and mobile phase composed of 20 mM HFBA in 5% ACN and 20 mM HFBA in 50% ACN. The amount of gentamicin was calculated by adding four components of gentamicin (C1, C1a, C2 and C2a). The pharmacokinetic parameters of gentamicin were calculated by the WinNonlin program. The Cmax of gentamicin in horse serum was 93 ± 17 μg/kg and the Tmax was 0.25 ± 0 hours. The T1/2 was 6.41 ± 2.32 hours and the CLt was 0.05 ± 0.01L/hr/kg. The Vd was shown as 0.44 ± 0.13 L/kg and the MRT was 1.98 ± 0.55 hours. In conclusion, our data provides useful pharmacokinetic parameters for gentamicin in horses following IV injection.

Additive manufacturing makes it possible to improve the mechanical properties of alloys through segregation engineering of specific alloying elements into the dislocation cell structure. In this study, we investigated the mechanical and microstructural characteristics of CoNi-based medium-entropy alloys (MEAs), including the refractory alloying element Mo with a large atomic radius, manufactured via laser-powder bed fusion (L-PBF). In an analysis of the printability depending on the processing parameters, we achieved a high compressive yield strength up to 653 MPa in L-PBF for (CoNi)85Mo15 MEAs. However, severe residual stress remained at high-angle grain boundaries, and a brittle μ phase was precipitated at Mo-segregated dislocation cells. These resulted in hot-cracking behaviors in (CoNi)85Mo15 MEAs during L-PBF. These findings highlight the need for further research to adjust the Mo content and processing techniques to mitigate cracking behaviors in L-PBF-manufactured (CoNi)85Mo15 MEAs.

This study developed conductive inks composed of carbon black (CB) and silver nanowires (Ag NWs) for cost-effective screen-printing on fabrics. The Ag NW density within the CB matrix was precisely controlled, achieving tunable electrical conductivity with minimal Ag NW usage. The resulting inks were successfully patterned into shapes such as square grids and circles on textile surfaces, demonstrating excellent conductivity and fidelity. Adding 19.9 wt% Ag NWs reduced sheet resistance by ~92% compared to CB-only inks, highlighting the effectiveness and potential of this hybrid approach for cost-effective, high-performance textile-based electronics. The one-dimensional morphology of Ag NWs facilitated the formation of conductive percolation networks, creating efficient electron pathways within the CB matrix even at low loadings. This work advances the field of CB-based conductive inks and provides a scalable and practical method for producing functional, patterned electronic textiles.

This study was conducted to investigate changes in immunoglobulin G (IgG) concentration, nutrient content, and microbial communities of fresh and heat-treated Holstein colostrum collected from a colostrum bank operated by a local agricultural technology center in Gyeongsangbuk-do, South Korea. Of the 16 colostrum samples, 8 were heated at 60℃ for 30 min under a pressure of 0.9–1 bar. The colostrum samples were stored at −70℃ until use, at which time they were thawed at 50–55℃ in a water bath to analyze IgG levels, chemical composition, and microbiome, which was identified by 16S rRNA gene sequencing using the Illumina MiSeq-PE250 platform. The IgG concentrations were similar in fresh and heat-treated colostrum. The fat, protein, and lactose contents also did not differ in these samples. However, somatic cell count (SCC) was lower in heat-treated colostrum than those in fresh colostrum (p<0.05). At the phylum level for the microbiome of fresh colostrum, Proteobacteria (44.16%) was the most abundant taxa, followed by Bacteroidota (33.26%), Firmicutes (10.04%), Actinobacteriota (7.14%), and a marginal difference in the order of abundance was observed in heat-treated colostrum. At the genus level, bacteria belonging to Sphingomonas, Delftia, Ochrobactrum, Simplicispira, and Lactobacillus were more abundant (p<0.05) in the heat-treated colostrum, while the abundance of Acinetobacter in the fresh colostrum was four times more (p<0.05) than that in the heat-treated colostrum. Our results demonstrated that heating does not affect IgG level and colostrum composition but reduces SCC (p<0.05), suggesting that heat-treated colostrum can potentially be put to further use (e.g., feeding Hanwoo calves) without compromising its quality. Differences in the microbiome between the fresh and heat-treated colostrum were limited. Further studies are required to extensively investigate the quality and safety of colostrum collected from dairy farms to ensure better utilization and processing at a local agricultural technology center.

In this study, an simultaneous LC-MS/MS multi-residue analytical method was developed and validated for the residues of six neonicotinoid insecticides (acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam) in honey. Sample preparation included a combination of QuEChERS extraction kit and liquid-liquid extraction method to effectively extract pesticide components from the honey matrix and optimized analytical conditions to achieve high sensitivity and selectivity. The limits of detection (LOD) and the limits of quantitation (LOQ) were set in the range of 6-15 ng/mL and 19-44 ng/mL, respectively and the correlation coefficient (R²) was greater than 0.99, confirming good linearity. In addition, the intra-day recoveries for each pesticide were 75-104%, and the coefficient of variation (CV) was less than 20%, which met the guideline recommended by the Ministry of Food and Drug Safety. The LC-MS/MS method developed in this study is expected to be used as a multi-residue analysis method for 6 neonicotinoid pesticides in honey.

We investigated the effects of supercritical-CO2 treatment on the pore structure and consequent H2 adsorption behavior of single-walled carbon nanohorns (SWCNHs) and SWCNH aggregates. High-resolution transmission electron microscopy and adsorption characterization techniques were employed to elucidate the alterations in the SWCNH morphology and aggregate pore characteristics induced by supercritical-CO2 treatment. Our results confirm that supercritical-CO2 treatment reduces the interstitial pore surface area and volume of SWCNH aggregates, notably affecting the adsorption of N2 (77 K), CO2 (273 K), and H2 (77 K) gasses. The interstitial porosity strongly depends on the supercritical-CO2 pressure. Supercritical-CO2 treatment softens the individual SWCNHs and opens the core of SWCNH aggregates, producing a partially orientated structure with interstitial ultramicropores. These nanopores are formed by the diffusion and intercalation of CO2 molecules during treatment. An increase in the amount of H2 adsorbed per interstitial micropore of the supercritically modified SWCNHs was observed. Moreover, the increase in the number and volume of ultramicropores enable the selective adsorption of H2 and CO2 molecules. This study reveals that supercritical-CO2 treatment can modulate the pore structure of SWCNH aggregates and provides an effective strategy for tailoring the H2 adsorption properties of nanomaterials.

Electrical and thermal transport properties of a polycrystalline carrier-doped wide-gap semiconductor LaCu1-δ S0.5Se0.5O (δ = 0.01), in which the CuCh (Ch = S, Se) layer works as conducting layer, were measured at temperatures 473~673 K. The presence of δ = 0.01 copper defects dramatically reduces the electrical resistivity (ρ) to approximately one part per million compared to that of δ = 0 at room temperature. The polycrystalline δ = 0.01 sample exhibited ρ of 1.3 × 10-3 Ωm, thermal conductivity of 6.0 Wm-1 K-1, and Seebeck coefficient (S) of 87 μVK-1 at 673 K. The maximum value of the dimensionless figure of merit (ZT) of the δ = 0.01 sample was calculated to be 6.4 × 10-4 at T = 673 K. The ZT value is far smaller than a ZT ~ 0.01 measured for a nominal LaCuSeO sample. The smaller ZT is mainly due to the small S measured for LaCu1-δS0.5Se0.5O (δ = 0.01). According to the Debye model, above 300 K phonon thermal conductivity in a pure lattice is inversely proportional to T, while thermal conductivity of the δ = 0.01 sample increases with increasing T.

Black ice, a thin and nearly invisible ice layer on roads and pavements, poses a significant danger to drivers and pedestrians during winter due to its transparency. We propose an efficient black ice detection system and technique utilizing Global Positioning System (GPS)-reflected signals. This system consists of a GPS antenna and receiver configured to measure the power of GPS L1 band signal strength. The GPS receiver system was designed to measure the signal power of the Right-Handed Circular Polarization (RHCP) and Left-Handed Circular Polarization (LHCP) from direct and reflected signals using two GPS antennas. Field experiments for GPS LHCP and RHCP reflection measurements were conducted at two distinct sites. We present a Normalized Polarized Reflection Index (NPRI) as a methodological approach for determining the presence of black ice on road surfaces. The field experiments at both sites successfully detected black ice on asphalt roads, indicated by NPRI values greater than 0.1 for elevation angles between 45o and 55o. Our findings demonstrate the potential of the proposed GPS-based system as a cost-effective and scalable solution for large-scale black ice detection, significantly enhancing road safety in cold climates. The scientific significance of this study lies in its novel application of GPS reflection signals for environmental monitoring, offering a new approach that can be integrated into existing GPS infrastructure to detect widespread black ice in real-time.

This study proposes a soil moisture retrieval method from ground reflection signals received by Global Positioning System (GPS) antenna modules consisting of an up-looking (UP) right-hand circular polarization (RHCP) and two down-looking (DW) RHCP and left-hand circular polarization (LHCP) signals. Field experiments at four different surface types (asphalt, grassland, dry soil, and moist soil) revealed that the DW RHCP and LHCP signals are affected by antenna height and multipath interference signals. The strength differences between the DW LHCP and UP RHCP signals were in good agreement with the DW LHCP signals. Methodologically, this study applied a spectrum analysis to the detrended surface-reflected signals for RHCP and LHCP. The study indicated that the down-looking antenna exhibited greater sensitivity to reflected GPS signals than the up-looking antenna. We demonstrated the feasibility of estimating soil moisture using GPS signals, by comparing LHCP signals received by the down-looking antenna with theoretical values. This study presents a novel method for estimating soil moisture in vegetated areas, leveraging the advantage of crosspolarization comparisons to achieve stronger signal strength than single-polarization reflection signals. With further research, including long-term observations and detailed analysis, the proposed method has the potential to enhance performance significantly.

In order to predict the process window of laser powder bed fusion (LPBF) for printing metallic components, the calculation of volumetric energy density (VED) has been widely calculated for controlling process parameters. However, because it is assumed that the process parameters contribute equally to heat input, the VED still has limitation for predicting the process window of LPBF-processed materials. In this study, an explainable machine learning (xML) approach was adopted to predict and understand the contribution of each process parameter to defect evolution in Ti alloys in the LPBF process. Various ML models were trained, and the Shapley additive explanation method was adopted to quantify the importance of each process parameter. This study can offer effective guidelines for fine-tuning process parameters to fabricate high-quality products using LPBF.

In the study, a variation of Haemaphysalis longicornis, a major vector of fever-causing conditions, was statistically analyzed to identify the spatial and climatic factors affecting the time-dependent variations of its population. The survey occurred in different habitats in South Korea. In addition, we developed a predictive model by using a probability function to find the peak occurrence time annually. As a result, the numbers of adults and nymphs were found to be related to temperature and relative humidity and their population peaked at the end of May in all habitats except deciduous forests. This study is expected to provide information on habitat types, times, and climate patterns that require attention to help control H. longicornis populations.

This study presents the results of mosquito surveillance monitoring in Chungnam Province from 2017 to 2020. A total of 130,750 mosquitoes were collected, and we analyze variations of mosquito populations with emphasis on the most abundant species. We also provide the field survey data based on the different habitats in Chungnam Province.

국내에서 유통되는 한약재 오공(蜈蚣)의 정·위품 유통 현황 파악과 유전자 감별법 개발을 위해 서로 다른 6개 유통사에서 오공으로 판매중인 전형약재를 구매하여 각 약재 포장 단위별 크기, 색깔, 무늬 등 형태적으로 차이가 있는 개체를 분류하여 국내에서 채집된 왕지네 표본 2개체를 포함 총 30개 시료를 대상으로 DNA 바코드 분석을 실시하였다. 확보한 미토콘드리아 COI 염기서열 정보와 기 등재된 NCBI GenBank 염기서열 정보를 이용하여 계통 분석을 실시한 결과, 28개 약재 시료 중 국산 및 중국산 전형약재 유통품 13 개체는 모두 대한민국약전외한약 (생약)규격집에 정품 기원종으로 수재된 Scolopendra subspinipes mutilans로 확인되었으며, 이들은 국내 채집 왕지네 개체들과 함께 하나의 단계통군을 형성하였다. 하지만 인도네시아산 전형약재 유통품 15 개체의 경우 4개의 그룹으로 구분되었는데, 그 중 3개 그룹은 S. dehaani, S. subspinipes, 그리고 명확한 종을 알 수 없는 Scolopendra sp.로 Scolopendra 속으로 확인되었고 나머지 그룹을 형성하는 한 개체는 Scolopendra 속에 속하지 않고 Rhysida singaporiensis와 89%의 유사도를 보였다. COI 바코드 분석을 통해 국내 유통되는 오공은 원산지가 한국 또는 중국인 경우 모두 정품 기원종으로 확인되었으며, 원산지가 인도네시아인 경우에는 모두 위품인 것으 로 확인되었다. 또한 위품으로 확인된 유통약재는 총 4개의 종으로 분류되었고, 대부분은 정품인 Scolopendra속 의 분류군이었으며 Rhysida속과 가까운 분류군도 오공으로 수입되어 유통되고 있는 것으로 확인되었다.