Spatial and spectral beam characteristics in a terahertz broadband sub-wavelength imaging system using a solid immersion lens.

This study focuses on the spatial and spectral beam characteristics in a terahertz (THz) broadband sub-wavelength imaging system using a solid immersion lens (SIL). Previously, we demonstrated a broadband sub-wavelength THz imaging system by integrating a SIL with a THz time-domain spectrometer (TDS). Key parameters that influence beam characteristics and, consequently, imaging performance, such as SIL misalignment tolerances and beam propagation from the SIL, constitute the primary focus of this investigation. Numerical simulations demonstrate that the system can tolerate millimeter-level transverse and longitudinal SIL position displacements, underscoring its robustness for sub-wavelength imaging in a wide frequency range. Additionally, numerical simulations of beam propagation characteristics reveal that the system achieves sub-wavelength imaging resolution up to 1 mm from the SIL at 0.5 THz, highlighting its potential for non-destructive testing of subsurface structures. These findings gain experimental validation through imaging stacked utility knife blades with sub-wavelength structures ranging from 0.2 to 2 THz.

Antioxidant and Anti-Obesity Effects of Juglans mandshurica in 3T3-L1 Cells and High-Fat Diet Obese Rats.

Juglans mandshurica Maxim. walnut (JMW) is well-known for the treatment of dermatosis, cancer, gastritis, diarrhea, and leukorrhea in Korea. However, the molecular mechanism underlying its anti-obesity activity remains unknown. In the current study, we aimed to determine whether JMW can influence adipogenesis in 3T3-L1 preadipocytes and high-fat diet rats and determine the antioxidant activity. The 20% ethanol extract of JMW (JMWE) had a total polyphenol content of 133.33 ± 2.60 mg GAE/g. Considering the antioxidant capacity, the ABTS and DPPH values of 200 µg/ml of JMWE were 95.69 ± 0.94 and 79.38 ± 1.55%, respectively. To assess the anti-obesity activity of JMWE, we analyzed the cell viability, fat accumulation, and adipogenesis-related factors, including CCAAT-enhancer-binding protein alpha (C/EBPα), sterol regulatory element-binding protein-1c (SREBP1c), peroxisome proliferator-activated receptor-gamma (PPARγ), fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC). We found that total lipid accumulation and triglyceride levels were reduced, and the fat accumulation rate decreased in a dose-dependent manner. Furthermore, JMWE suppressed adipogenesis-related factors C/EBPα, PPARγ, and SREBP1c, as well as FAS and ACC, both related to lipogenesis. Moreover, animal experiments revealed that JMWE could be employed to prevent and treat obesity-related diseases. Hence, JMWE could be developed as a healthy functional food and further explored as an anti-obesity drug.