The growing sophistication of adversarial ballistic missile threats, along with the development of multilayered defense systems to counter them, has increased the importance of establishing efficient operational concepts. However, existing studies on multilayered defense and weapon allocation have mainly focused on dynamic allocation procedures or time constraints, and have not sufficiently reflected the uncertainty of detection information and its changes over time, which serve as key grounds for decision- making. This study proposes a dynamic command-system-based operational concept for multilayered defense that allows command decisions to be revised in response to changes in detection information, and develops an effectiveness simulation tool to implement it. The proposed operational concept is designed to reflect real operational environments in which detection information is updated progressively over time, enabling the continuous reassessment of existing engagement plans and weapon-target allocation results. In addition, comparative experiments were conducted by varying the timing of information utilization in order to verify the feasibility and effectiveness of the proposed concept. The results show that an early response increases unnecessary allocations and cancellations due to low information accuracy, whereas a delayed response limits interception opportunities because of reduced available response time. A strategy that responds after a certain level of information accuracy has been secured was found to be superior in terms of both resource utilization efficiency and defense effectiveness. These findings demonstrate that an operational concept adaptive to changes in information can have a meaningful impact on actual defense effectiveness, and they provide implications for establishing command-and-control structures and procedures for future multilayered defense systems.
It is challenging to treat canine brucellosis due to the immune evading and stealthy characteristic of the causative bacteria, Brucella (B.) canis. Gold nanoparticle aptamer (AuNP-Apt) conjugated antimicrobial peptide (AMP) is a promising alternative to antibiotics for various bacterial infections. However, the toxicity of AuNP-Apt has been variable throughout research, and the in vivo toxic mechanism has not been fully elucidated. This study evaluated the therapeutic potential against B. canis, and the toxicity of AuNP-Apt conjugated antimicrobial peptide, RW-BP100 (AuNP-AptHis-RW-BP100His), in a mouse model. Intravenous (IV) treatment with AuNP-AptHis-RW-BP100His reduced the bacteria burden and histopathologic lesions. The IV treatment also induced CD4+ T cell differentiation and modulated serum cytokine levels. However, high-dose AuNP-Apt was lethal, resulting in tissue accumulation and vessel embolism. Therefore, AuNP-AptHis-RW-BP100His is a promising therapeutic agent for B. canis treatment, but due to its toxicity, further studies are needed for its utilization in clinical practice.
Amitriptyline hydrochloride (AMT), a tricyclic antidepressant, is known to exhibit antimicrobial effects against a wide range of bacterial species. This study aims to evaluate the effect of AMT on Brucella (B.) abortus infection in RAW 264.7 cells and ICR mice, which has not yet been clearly characterized. The results showed that all tested concentrations of AMT had no direct bactericidal effect on B. abortus survival at any incubation time point. Interestingly, RAW 264.7 cells pre-treated with a non-toxic high concentration of AMT before B. abortus infection showed a significant reduction in the phagocytosis of B. abortus at 20 min post-infection, compared to untreated cells. However, AMT treatment did not affect the intracellular replication of B. abortus compared to the control cells. Based on the reduced bacterial uptake observed in-vitro, an in-vivo experiment was conducted to assess whether daily oral administration of AMT at a dose of 20 mg/kg could inhibit B. abortus growth in ICR mice. The results showed that AMT treatment slightly increased both organ weights and bacterial loads, suggesting possible systemic effects of prolonged AMT exposure. In summary, these preliminary results provide initial insight into the potential effects of AMT on B. abortus infection both in-vitro and in-vivo. Therefore, further study should focus on dose optimization in-vivo and exploration of the underlying cellular mechanisms involved in AMT-mediated inhibition of phagocytosis during Brucella infection.
High-entropy alloys (HEAs) have been reported to have better properties than conventional materials; however, they are more expensive due to the high cost of their main components. Therefore, research is needed to reduce manufacturing costs. In this study, CoCrFeMnNi HEAs were prepared using metal injection molding (MIM), which is a powder metallurgy process that involves less material waste than machining process. Although the MIM-processed samples were in the face-centered cubic (FCC) phase, porosity remained after sintering at 1200°C, 1250°C, and 1275°C. In this study, the hot isostatic pressing (HIP) process, which considers both temperature (1150°C) and pressure (150 MPa), was adopted to improve the quality of the MIM samples. Although the hardness of the HIP-treated samples decreased slightly and the Mn composition was significantly reduced, the process effectively eliminated many pores that remained after the 1275°C MIM process. The HIP process can improve the quality of the alloy.
In 2022, research for native prokaryotic species in Korea reported 10 unrecorded bacterial strains affiliated to phyla Actinomycetota, Bacillota, and Pseudomonadota. The strains formed monophyletic clades with the most closely related species (with ≥98.7% sequence similarity) in the 16S rRNA gene sequencing. Among them, four species of the phylum Actinomycetota, two species of the phylum Bacillota, and four species of the phylum Pseudomonadota have not been reported in Korea, suggesting unrecorded species in Korea. Information on strains such as Gram staining reaction, colony and cell morphology, biochemical characteristics, and isolation sources were provided in the species description.
High-entropy alloys (HEAs) are attracting attention because of their excellent properties and functions; however, they are relatively expensive compared with commercial alloys. Therefore, various efforts have been made to reduce the cost of raw materials. In this study, MIM is attempted using coarse equiatomic CoCrFeMnNi HEA powders. The mixing ratio (powder:binder) for HEA feedstock preparation is explored using torque rheometer. The block-shaped green parts are fabricated through a metal injection molding process using feedstock. The thermal debinding conditions are explored by thermogravimetric analysis, and solvent and thermal debinding are performed. It is densified under various sintering conditions considering the melting point of the HEA. The final product, which contains a small amount of non-FCC phase, is manufactured at a sintering temperature of 1250oC.
Putri Novadhea Salsabilla, So Eun Park, Ye Ram Im, In Soo Jeon, Yu Lim Park, Yu Jin Jeong, Ki Jung Kim, Ga Hyeon Song, Hanna Yang, Jong Cheol Kim, Jae Su Kim