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.
Lumpy Skin Disease (LSD) and Foot-and-Mouth Disease (FMD) cause substantial economic losses on the livestock industry. Therefore, vaccinations have been implemented as the control strategy in endemic countries. However, the potential adverse effects of administering vaccines for both diseases simultaneously have not been thoroughly evaluated. The aim of this study was to assess the impact of vaccinating dairy cows with either or both LSD and FMD vaccines on milk production and physiological parameters such as milk temperature, rumination time and body weight. The experimental groups were divided into four according to the injection materials: 1) saline, 2) LSD vaccine, 3) FMD vaccine, and 4) both vaccines. The impact of vaccination on milk yield and physiological parameters was evaluated daily until 12 days post-vaccination, and milk components were analyzed twice, once per week. Among the experimental groups as well as each vaccine group, no statistically significant differences (p < 0.05) were observed at milk yield, milk components, or milk temperature. This suggests that simultaneous vaccination of LSD and FMD can be administered without adverse effects.
Mauremys reevesii (Reeves’ turtle) is an endemic freshwater turtle species found throughout East Asia. Due to a rapid population decline, the International Union for Conservation of Nature (IUCN) and the Korean government have classified this species as Endangered (EN). The reported largest population size of M. reevesii in the Republic of Korea was previously estimated to be approximately 20-30 individuals. Our study assessed the population size and structure of M. reevesii at Geumho Reservoir, Republic of Korea, using a capture-recapture data. A total of 433 M. reevesii were incidentally captured during a 35-week trapping process conducted from March to October 2023. The sex ratio of the captured population exhibited a male bias of 1.3 : 1. Sexual size dimorphism was observed only in body weight. Individuals were recaptured up to 11 times during the study period, with males and females being recaptured at an average of 2.1±2.0 times and 1.5±0.9 times, respectively. The estimated population size of M. reevesii in Geumho Reservoir was approximately 891 turtles. The absence of notable sexual size dimorphism and significant sex ratio differences suggests that the population in this area may have been established relatively recently. Compared to previous records, the population in Geumho Reservoir represents the largest single population of M. reevesii, both within the Republic of Korea and globally.
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 confirmed the fungal community of rice makgeolli sold in the eastern part of Jeollanam-do using ITS 2 sequence-based metagenome analysis. A total of 18 fungi were found in six makgeolli samples, with Saccharomyces cerevisiae being dominant in all samples at high rates ranging from 96.61~99.96%. The six makgeolli samples were classified into three groups based on the PCoA and UPGMA tree analysis results using the Jaccard distance matrix. Network analysis of the relationships among the 18 identified fungal species helped identify a fungus that demonstrated either a positive or negative correlation with the dominant species, Saccharomyces cerevisiae. This study provides important foundational data for understanding the fungal composition in the makgeolli fermentation process.
Malaria remains a significant public health issue, particularly in regions such as the Korean Demilitarized Zone (DMZ). Effective malaria control and prevention require precise prediction of mosquito density across both monitored and unmonitored areas. This study aimed to develop predictive models to estimate the abundance of malaria vector mosquitoes by integrating meteorological and geographical data. Data from mosquito surveillance sites and NASA MODIS land cover datasets acquired between 2009 and 2022 were utilized. Two predictive models, the Gradient Boosted Model (GBM) and Principal Component Regression (PCR), were employed and evaluated. Model performance was assessed using the coefficient of determination (R²). Results showed that PCR outperformed GBM in predictive accuracy, suggesting that PCR is more robust in handling multicollinearity among variables. However, both models did not show practically-usable level of prediction performance. This study provides a preliminary but foundational framework for extending predictive modeling to broader regions, thereby supporting malaria prevention efforts through improved risk mapping.
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.
This study aimed to address the time, cost, and ethical issues associated with traditional animal experiment-based observational methods by utilizing in silico Physiologically Based Pharmacokinetic modeling to predict veterinary drug residues in livestock products and validate them against observational data. Using PK-sim software, we modeled the physiological conditions of pigs to predict the depletion of ceftiofur and spiramycin. We evaluated the ceftiofur (3 mg, 6 mg) and spiramycin models by comparing them with observational data using residuals, MSE, and R-squared values. Specifically, the R-squared values for the ceftiofur models were all negative, indicating poor predictive power. For Ceftiofur (3 mg), the R-squared value was <0 with MSE of 611.3764, and for Ceftiofur (6 mg), it was <0 with MSE of 2447.982, highlighting significant discrepancies. Similar shortcomings were observed in the spiramycin models, with an R-squared value of <0 . These discrepancies can be attributed to inaccuracies in literature data, limited physicochemical data, inadequate consideration of inter-individual differences, mismatches between experimental and model conditions, and limitations of benchmark observational experiments. This underscores the critical importance of enhancing data quality and refining modeling approaches. Future research should focus on validating in silico techniques across diverse animal models and drugs to broaden their applicability in safety assessments. Ultimately, leveraging in silico techniques is crucial for establishing a scientifically robust safety management system for livestock products, overcoming the constraints of current observational experimental methods.