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

Abstract

This study introduces a novel divertor target design scheme for stellarators, grounded in mathematical treatments and tailored to control of toroidal heat load distributions. Initially, a differential equation characterizing toroidally uniform heat load distribution has been formulated in a two-dimensional (2D) slab configuration, and its analytic solution has been obtained. Subsequently, a numerical scheme has been developed to adapt the analytic solution into the 3D surface shape of stellarator target. The effectiveness of this design scheme has been validated through simulations of the Chinese First Quasi-axisymmetric Stellarator (CFQS) using a suite of codes including HINT, FLARE and EMC3-EIRENE, where a toroidally uniform heat load distribution has been achieved with an island configuration. Further, the effects of input parameters on the target shape and heat load distribution have been studied. The robustness of the designed target has been investigated by simulation results with varying magnetic island configurations, confirming that the toroidal uniformity of heat load distribution is insensitive to changes in island configurations. Moreover, the designed target has been assessed with gas puffing of neon, which shows that neon injections effectively reduce the heat loads without altering the toroidal uniformity of heat load distributions. The proposed scheme highlights the importance of theoretical and mathematical foundations of target design, offering an advantageous alternative/complement to traditional schemes.

• Book : 65(1)
• Pub. Date : 2025
• Page : pp.016023
• 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 :

• Book : 378(pa)
• Pub. Date : 2025
• Page : pp.124844
• Keyword :

Background:

Lung adenocarcinoma, the predominant subtype of lung cancer, presents a significant challenge to public health due to its notably low five-year survival rate. Recent epidemiological data highlights a concerning trend: patients with pulmonary adenocarcinoma and comorbid diabetes exhibit substantially elevated mortality rates compared to those without diabetes, suggesting a potential link between hyperinsulinemia in diabetic individuals and accelerated progression of pulmonary adenocarcinoma. Insulin Receptor (IR) is a tyrosine-protein kinase on the cell surface, and its over-expression is considered the pathological hallmark of hyperinsulinemia in various cancer cell types. Research indicates that IR can translocate to the nucleus of lung adenocarcinoma cells to promote their proliferation, but its precise molecular targets remain unclear. This study aims to silence IRs in lung adenocarcinoma cells and identify key genes within the ERK pathway that may serve as potential molecular targets for intervention.

Methods:

Gene expression data from lung adenocarcinoma and para cancer tissues were retrieved from the Gene Expression Omnibus (GEO) database and assessed through 'pheatmap', GO annotation, KEGG analysis, R calculations, Cytoscape mapping, and Hub gene screening. Significant genes were visualized using the ggplot2 tool to compare expression patterns between the two groups. Additionally, survival analysis was performed using the R 'survminer' and 'survival' packages, along with the R 'pathview' package for pathway visualization. Marker genes were identified and linked to relevant signaling pathways. Validation was conducted utilizing real-time quantitative polymerase chain reaction and immunoblotting assays in an A549 lung cancer cell model to determine the roles of these marker genes in associated signaling cascades.

Results:

The study examined 58 lung adenocarcinoma samples and paired para-neoplastic tissues. Analysis of the GSE32863 dataset from GEO revealed 1040 differentially expressed genes, with 421 up-regulated and 619 down-regulated. Visualization of these differences identified 172 significant alterations, comprising 141 up-regulated and 31 down-regulated genes. Functional enrichment analysis using Gene Ontology (GO) revealed 56 molecular functions, 77 cellular components, and 816 biological processes. KEGG analysis identified 17 strongly enriched functions, including cytokine interactions and tumor necrosis factor signaling. Moreover, the ERK signaling pathway was associated with four Hub genes (FGFR4, ANGPT1, TEK, and IL1B) in cellular biological processes. Further validation demonstrated a positive correlation between IL-1B expression in the ERK signaling pathway and lung cancer through real-time fluorescence quantitative enzyme- linked reaction with immunoblotting assays.

Conclusion:

In IR-silenced lung adenocarcinoma, the expression of the IL-1B gene exhibited a positive correlation with the ERK signaling pathway.

• Book : 26(1)
• Pub. Date : 2025
• Page : pp.24-35
• Keyword :

• Book : 1070(p1)
• Pub. Date : 2025
• Page : pp.170000
• Keyword :

• Book : 1070(p1)
• Pub. Date : 2025
• Page : pp.170027
• Keyword :

• Book : 1071()
• Pub. Date : 2025
• Page : pp.170074
• Keyword :

• Book : 1070(p2)
• Pub. Date : 2025
• Page : pp.169994
• Keyword :