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.
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.
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.
The study investigated a method of synthesizing a pitch suitable for making activated carbon using fluid catalytic crackingdecant oil (FCC-DO), a high-purity carbon precursor from oil refining. We kept the reaction time and catalyst amount constant while varying the temperature to investigate its impact on pitch synthesis and the resulting physical and activation properties. Previous research established that materials added during pitch synthesis can affect the properties of both the pitch and resulting activated carbon. This study examined the addition of polyethylene terephthalate (PET) to FCC-DO-based pitch. The results indicated significant changes in properties with PET addition and temperature variation that ensured stable activated carbon quality. At temperatures of 390 °C or higher, the specific surface area of the activated carbon stabilized between 2680 and 2740 m2/ g. Waste PET, a recyclable plastic, was chosen due to its compatibility and thermodynamic suitability for pitch synthesis. Importantly, adding PET didn't generate additional waste or degrade the physical properties of the activated carbon.
많은 연구에 따르면 Tenebrio molitor은 유충 단계에서 플라스틱을 섭취할 수 있다고 보고되었다. 이 연구의 목적은 T. molitor 유충의 성장과 발달에 발포폴리스티렌 섭취가 미치는 영향을 조사하는 것이다. 밀기울을 섭취한 유충의 성장률은 발포폴리스티렌을 섭취한 유충의 성장률보다 더 좋았고(p < 0.001) 발포폴리스티렌을 섭취한 유 충의 번데기로 전환되는 기간은 밀기울을 섭취한 유충의 번데기로 전환되는 기간보다 더 빨랐다(p < 0.001). 하지만 두 처리구간 생존율은 유의미한 차이가 없었다(p = 0.786). 이 결과에 따르면 발포폴리스티렌을 섭취한 유충은 체중 감소와 짧은 발육기간이 특징이지만 생존하는 것에는 문제가 없었다. 따라서 우리는 T. molitor가 플라스틱 폐기물 의 지속 가능하고 친환경적인 제거를 위한 주요 자원이라는 결론을 내렸다.
Antimicrobial resistance significantly threatens human and animal health globally, with considerable mortality and economic impact. This study investigated antimicrobial usage in small animal clinics in South Korea, focusing on understanding the trends in prescriptions for therapeutic and preventive purposes. Data were collected from 12 small animal clinics that were analyzed for antimicrobial prescriptions from 2018–2020. A comprehensive dataset was used, including patient signalment, clinical notes, and prescription details, and statistically analyzed using SPSS software. The results indicated that most antimicrobials (93.1%) were prescribed for the treatment of infectious diseases, with a smaller portion (6.9%) used for preventive measures, such as surgery. High prescription rates were observed for the treatment of cutaneous and otological diseases, which may reflect common diseases in companion animals. The study highlighted a higher prescription rate for adult age groups, possibly because of the higher prevalence in those groups. Overall, this study provides valuable insights into common prescription patterns in veterinary practice and underscores the need for more stringent antimicrobial stewardship to curb the rise of antimicrobial resistance. This suggests that ongoing surveillance and education on appropriate antimicrobial use are crucial for optimizing treatment outcomes and minimizing the development of resistance.
Background: Platelet-derived growth factor receptor alpha (PDGFRα) is essential for various biological processes, including fetal Leydig cell differentiation. The PDGFRαEGFP mouse model, which expresses an eGFP fusion gene under the native Pdgfrα promoter, serves as a valuable resource for exploring PDGFRα’s expression and function in vivo. This study investigates PDGFRα expression in adult testicular cells using PDGFRαEGFP mouse model. Methods: Genotyping PCR and gel electrophoresis were used to confirm the zygosity of PDGFRαEGFP mice. Histological examination and fluorescence imaging were used to identify PDGFRα expression within testicular tissue. Immunohistochemical analysis assessed the co-expression of PDGFRα with c-Kit, ANO-1, and TASK-1 in testicular cells. Results: Genotyping confirmed the heterozygous status of the mice, which is crucial for studies due to the embryonic lethal phenotype observed in homozygotes. Histological and fluorescence imaging revealed that PDGFRα+ cells were primarily located in the interstitial spaces of the testis, specifically within Leydig cells and peritubular myoid cells (PMCs). Immunohistochemical results showed PDGFRα co-localization with c-Kit and ANO-1 in Leydig cells and a complete co-localization with TASK-1 in both Leydig cells and PMCs. Conclusions: The findings demonstrate specific expression of PDGFRα in Leydig cells and PMCs in adult testicular tissue. The co-expression of PDGFRα with c-Kit, ANO-1, and TASK-1 suggests complex regulatory mechanisms, possibly influencing testicular function and broader physiological processes.
The threat of North Korea's long-range firepower is recognized as a typical asymmetric threat, and South Korea is prioritizing the development of a Korean-style missile defense system to defend against it. To address this, previous research modeled North Korean long-range artillery attacks as a Markov Decision Process (MDP) and used Approximate Dynamic Programming as an algorithm for missile defense, but due to its limitations, there is an intention to apply deep reinforcement learning techniques that incorporate deep learning. In this paper, we aim to develop a missile defense system algorithm by applying a modified DQN with multi-agent-based deep reinforcement learning techniques. Through this, we have researched to ensure an efficient missile defense system can be implemented considering the style of attacks in recent wars, such as how effectively it can respond to enemy missile attacks, and have proven that the results learned through deep reinforcement learning show superior outcomes.
장내 미생물 군집은 소화 과정, 면역 시스템, 질병 발생 등 숙주의 다양한 면에 광범위한 영향을 주는 것으로 알려져 있으며, 주요 장내 미생물 종은 숙주의 생리 기능에 핵심적인 역할을 수행한다고 발표된 바 있다. 곤충의 장내 미생물 군집에 관한 연구가 최근 활발히 이루어지고 있으며, 이들 연구는 주로 장내 미생물 군집과 기생충, 병원체 간의 상호작용, 종간의 신호 전달 네트워크, 먹이의 소화 과정 등을 중심으로 이루어지고 있다. 이러한 연구들은 대부분 Illumina MiSeq을 활용하여 16S rRNA 유전자의 V1부터 V9 영역 중 선택된 특정 부분을 대상으로 짧은 서열 정보를 대상으로 진행되었다. 그러나, 최근에는 PacBio HiFi 기술이 상용화되면서 16S rRNA의 전장 분석이 가능할 수 있게 되었다. 이번 연구는 장수말벌(Vespa mandarinia)의 해부를 통해 gut과 carcass 부분을 분리한 뒤, 각 샘플을 Illumina MiSeq과 PacBio HiFi 기술을 활용하여 미생물 군집 간의 차이점을 확인하기 위하여 수행되었다.