Jiafei Chen | Searcharxiv

arXiv2026

Triple-Phase Sequential Fusion Network for Hepatobiliary Phase Liver MRI Synthesis

Gadoxetate disodium-enhanced MRI is essential for the detection and characterization of hepatocellular carcinoma. However, acquisition of the hepatobiliary phase (HBP) requires a prolonged post-contrast delay, which reduces workflow efficiency and increases the risk of motion artifacts. In this study, we propose a Triple-Phase Sequential Fusion Network (TriPF-Net) to synthesize HBP images by leveraging the sequential information from pre-HBP sequences: while T1-weighted imaging serves as the indispensable baseline, the model adaptively integrates arterial-phase (AP) and venous-phase (VP) features when available. By modeling the tissue-specific contrast uptake and excretion dynamics across these three phases, TriPF-Net ensures robust HBP synthesis even under the stochastic absence of one or both dynamic contrast-enhanced sequences. The framework comprises an Enhanced Region-Guided Encoder and a Dynamic Feature Unification Module, optimized with a Region-Guided Sequential Fusion Loss to maintain physiological consistency. In addition, clinical variables, including age, sex, total bilirubin, and albumin, are incorporated to enhance physiological consistency. Compared with conventional methods, TriPF-Net achieved superior performance on datasets from two centers. On the internal dataset, the model achieved an MAE of 10.65, a PSNR of 23.27, and an SSIM of 0.76. On the external validation dataset, the corresponding values were 12.41, 23.11, and 0.78, respectively. This flexible solution enhances clinical workflow and lesion depiction, potentially eliminating the need for delayed HBP acquisition in HCC imaging.

eess.IV↗

arXiv2026

Resonant Coupling Between Electromagnetic Waves and Protein Conformational Dynamics Revealed by Molecular Dynamics Simulations

The biological effects of electromagnetic fields on proteins remain controversial beyond well-established thermal mechanisms, particularly with respect to frequency-dependent responses. Here, we propose that electromagnetic waves can modulate protein conformation through resonant coupling with intrinsic protein dynamics. Molecular dynamics simulations were employed to characterize spontaneous conformational fluctuations in the absence of external fields, and a tiered screening strategy combined with fast Fourier transform analysis was used to identify dominant intrinsic frequencies associated with periodically fluctuating non-covalent atom or residue pairs. Oscillating external electric fields were subsequently applied at resonant and off-resonant frequencies to evaluate conformational responses across diverse protein systems. The results demonstrate that resonant excitation induces significantly enhanced backbone conformational deviations compared to off-resonant conditions, with the effect becoming more pronounced in structurally flexible and multichain proteins. These findings provide atomistic evidence for frequency-specific resonance between electromagnetic fields and protein conformational dynamics, offering mechanistic insight into frequency-dependent electromagnetic effects and a computational framework for electromagnetic wave-based modulation of protein function.

physics.chem-ph↗