• Book : 521(p1)
• Pub. Date : 2025
• Page : pp.113566
• Keyword :

• Book : 161()
• Pub. Date : 2025
• Page : pp.101684
• Keyword :

• Book : 10(1)
• Pub. Date : 2025
• Page : pp.101676
• Keyword :

A metasurface inspired circularly polarized (CP) compact patch antenna with high gain for fifth-generation communication systems is designed and implemented in this article. The proposed structure features a corner truncated patch antenna and a metasurface of 3×3 double sided identical circular metallic patches. The attribute that puts this design distinct is that it minimizes the impact of scattering and edge diffraction at millimeter wave frequencies. The metasurface above a patch with an air gap is designed using the similar substrate material with the same thickness, resulting in a simplified antenna design with high gain and low cost. The antenna’s overall dimension is , with a peak gain of 11.5 dBic and a 3-dB axial ratio bandwidth of 28.45 - 28.88 GHz. The simulated and experimental results show that the metasurface-inspired antenna has better impedance matching and radiation efficiency between 28.23 - 30.01 GHz. Additionally, the experimental results of the proposed antenna exhibits stable right-hand circular polarization in the desired frequency range and a flat gain response with a little variation. The proposed antenna design could be well suited for millimeter-wave communication systems, in scenarios requiring robust long-range performance and high data throughput.

• Book : 37(2)
• Pub. Date : 2025
• Page : pp.867
• Keyword :

• Book : 50()
• Pub. Date : 2025
• Page : pp.100897
• Keyword :

ABSTRACT

This study aimed to explore the effect of toll‐like receptor 4 (TLR4)/nuclear factor‐kappa B (NF‐κB)/NOD‐like receptor thermal protein domain‐associated protein 3 (NLRP3) signalling on Henoch-Schonlein purpura nephritis (HSPN). We established a HSPN rat model in a high‐altitude hypoxic (HH) environment. Renal tissue lesions were observed by haematoxylin and Eosin (H&E) staining and terminal deoxynucleotidyl transferase‐mediated dUTP nick end labelling (TUNEL), CD20‐postive B cells and CD68‐postive macrophage cells were detected by immunohistochemistry, T‐cell activation was detected by flow cytometry and toll‐like receptor 4 (TLR4)/nuclear factor‐kappa B (NF‐κB)/NOD‐like receptor thermal protein domain associated protein 3 (NLRP3) signalling was detected by western blot. TAK‐242 inhibited the expression of TLR4/NF‐κB/NLRP3 signalling related‐proteins, decreased the levels of 24 h urinary protein, serum creatinine, circular immune complex (CIC) and kidney immunoglobulin A (IgA), and improved renal histopathological damage in HH‐HSPN rats. Furthermore, TAK‐242 attenuated the infiltration of CD20 and CD68 into the kidney and increased the percentage of CD3+, CD4+ and CD4+/CD8+ cells in the blood of HH‐HSPN rats. The study revealed that suppressing TLR4/NF‐κB/NLRP3 signalling improved renal function and histopathological damage, and this improvement was related to inhibiting the inflammatory response and enhancing immune competence.

• Book : 52(1)
• Pub. Date : 2025
• Page : pp.e70008
• Keyword :

• Book : 140()
• Pub. Date : 2025
• Page : pp.104148
• Keyword :

• Book : 65(1)
• Pub. Date : 2025
• Page : pp.010401
• Keyword :

Abstract

Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) has emerged as a powerful imaging technique sensitive to tissue molecular composition, pH, and metabolic processes in situ. CEST MRI uniquely probes the physical exchange of protons between water and specific molecules within tissues, providing a window into physiological phenomena that remain invisible to standard MRI. However, given the very low concentration (millimolar range) of CEST compounds, the effects measured are generally only on the order of a few percent of the water signal. Consequently, a few critical challenges, including correction of motion artifacts and magnetic field (B0 and B1⁺) inhomogeneities, have to be addressed in order to unlock the full potential of CEST MRI. Motion, whether from patient movement or inherent physiological pulsations, can distort the CEST signal, hindering accurate quantification. B0 and B1⁺ inhomogeneities, arising from scanner hardware imperfections, further complicate data interpretation by introducing spurious variations in the signal intensity. Without proper correction of these confounding factors, reliable analysis and clinical translation of CEST MRI remain challenging. Motion correction methods aim to compensate for patient movement during (prospective) or after (retrospective) image acquisition, reducing artifacts and preserving data quality. Similarly, B0 and B1⁺ inhomogeneity correction techniques enhance the spatial and spectral accuracy of CEST MRI. This paper aims to provide a comprehensive review of the current landscape of motion and magnetic field inhomogeneity correction methods in CEST MRI. The methods discussed apply to saturation transfer (ST) MRI in general, including semisolid magnetization transfer contrast (MTC) and relayed nuclear Overhauser enhancement (rNOE) studies.

• Book : 38(1)
• Pub. Date : 2025
• Page : pp.e5294
• Keyword :

Abstract

Articular cartilage (AC) is a specialized connective tissue that covers the ends of long bones and facilitates the load‐bearing of joints. It consists of chondrocytes distributed throughout an extracellular matrix and organized into three zones: superficial, middle, and deep. Nuclear magnetic resonance (NMR) techniques can be used to characterize this layered structure. In this study, devoted to a better understanding of the NMR response of this complex tissue, 20 specimens excised from femoral and tibial cartilage of bovine samples were analyzed by the low‐field single‐sided NMR‐MOUSE‐PM10. A multiparametric depth‐wise analysis was performed to characterize the laminar structure of AC and investigate the origin of the NMR dependence on depth. The depth dependence of the single parameters T1, T2, and D has been described in literature, but their simultaneous measurement has not been fully exploited yet, as well as the extent of their variability. A novel parameter, α, evaluated by applying a double‐quantum‐like sequence, has been measured. The significant decrease in T1, T2, and D from the middle to the deep zone is consistent with depth‐dependent composition and structure changes of the complex matrix of fibers confining and interacting with water. The α parameter appears to be a robust marker of the layered structure with a well‐reproducible monotonic trend across the zones. The discrimination of cartilage zones was reinforced by a multivariate principal component analysis statistical analysis. The large number of samples allowed for the identification of the smallest number of parameters or their combination able to classify samples. The first two components clustered the data according to the different zones, highlighting the sensitivity of the NMR parameters to the structural and compositional variations of AC. Using two parameters, the best result was obtained by considering T1 and α. Single‐sided NMR devices, portable and low‐cost, provide information on NMR parameters related to tissue composition and structure.

• Book : 38(1)
• Pub. Date : 2025
• Page : pp.e5287
• Keyword :