RESUMEN
Antennas play a crucial role in designing an efficient communication system. However, reducing the maximum sidelobe level (SLL) of the beam pattern is a crucial challenge in antenna arrays. Pattern synthesis in smart antennas is a major area of research because of its widespread application across various radar and communication systems. This paper presents an effective technique to minimize the SLL and thus improve the radiation pattern of the linear antenna array (LAA) using the chaotic inertia-weighted Wild Horse optimization (IERWHO) algorithm. The wild horse optimizer (WHO) is a new metaheuristic algorithm based on the social behavior of wild horses. The IERWHO algorithm is an improved Wild Horse optimization (WHO) algorithm that combines the concepts of chaotic sequence factor, nonlinear factor, and inertia weights factor. In this paper, the method is applied for the first time in antenna array synthesis by optimizing parameters such as inter-element spacing and excitation to minimize the SLL while keeping other constraints within the boundary limits, while ensuring that the performance is not affected. For performance evaluation, the simulation tests include 12 benchmark test functions and 12 test functions to verify the effectiveness of the improvement strategies. According to the encouraging research results in this paper, the IERWHO algorithm proposed has a place in the field of optimization.
Asunto(s)
Algoritmos , Animales , Caballos , Dinámicas no Lineales , Simulación por ComputadorRESUMEN
The occurrence of antibiotics in the feces of elderly individuals in Shenzhen, China, was investigated by monitoring 78 compounds to understand the adverse effects and its association with antibiotic residues in animal products collected from local markets. In total, 18 compounds belonging to 5 classes of antibiotics were identified in 74 of 140 fecal samples. Furthermore, 17.9% of the fecal samples contained at least two antibiotics, and 14.3% of the samples showed antibiotic concentrations higher than 100 µg/kg. Cephalothin exhibited the highest detection frequency (22.1%), followed by azithromycin (15.7%) and tilmicosin (12.9%). Oxytetracycline, norfloxacin, and azithromycin showed extremely high concentrations (> 1000 µg/kg). Eight antibiotics were detected in the animal products, with detection frequencies ranging from 4.8 to 40.0%. Five antibiotics exhibited similar detection frequencies and strong correlations between the human fecal and animal product samples. Health risk assessment based on hazard quotients showed that ciprofloxacin in animal products and human feces posed a medium and high risk, respectively. The hazard quotients of oxytetracycline, norfloxacin, and azithromycin in the feces were greater than 1, indicating a high health risk. These findings suggest that the elderly individuals were frequently exposed to antibiotics via the food chain and faced health risks posed by these antibiotics.
Asunto(s)
Oxitetraciclina , Contaminantes Químicos del Agua , Animales , Humanos , Anciano , Antibacterianos/análisis , Norfloxacino , Azitromicina , China , Medición de Riesgo , Contaminantes Químicos del Agua/análisis , Heces/química , Monitoreo del AmbienteRESUMEN
Salinomycin (SAL) and lasalocid (LAS) are widely used as ionophore antibiotics for coccidiosis control. However, their common use as feed additives has led to the occurrence of feed cross-contamination, which has toxic effects on non-target animals. There have been few reports on multiple-residue detection for SAL and LAS in recent years. In this study, two single-chain antibody fragments (scFvs) capable of specifically recognizing SAL and LAS were constructed. Using LAS-scFv and SAL-scFv as parent antibodies, a complete bispecific single-chain diabody (scDb) against both LAS and SAL was built using splicing by overlap extension polymerase chain reaction (SOE-PCR). In addition, the key amino acid sites and interaction energy of antibody variable regions for small-molecule recognition were preliminarily studied by homology modeling and molecular docking. Finally, IC50 values of 12.9 and 8.6 ng/mL, with a linear range of 6.9-24.0 and 4.7-16.0 ng/mL, were obtained for LAS-scFv and SAL-scFv, respectively. An indirect competitive enzyme-linked immunosorbent assay (icELISA) method was established using scDb to obtain an IC50 of 3.5 ng/mL for LAS and 4.1 ng/mL for SAL, which showed better sensitivity and specificity than those of the parent scFv antibodies. The recoveries of LAS and SAL in chicken liver were 89.2-92.7%(CV<4.7%) and 88.6-90.2% (CV<6.8%)), respectively.