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Povzetek: Background. Electroporation-based therapies are being explored in glioblastoma (GB) treatment, as means of enhancing drug delivery or achieving nonthermal ablation. Yet, little is known about how sublethal exposure affects the invasive behaviour of GB tumour cells. Materials and methods. Five patient-derived GB cell lines were initially screened for intrinsic invasive potential, and two most invasive (NIB140 CORE and NIB216 CORE) were selected for further experiments with electroporation treatment. Cells in suspension were exposed to bursts of high-frequency biphasic electric pulses resulting in electric field strength of 1 kV/cm, which corresponded to conditions of reversible electroporation. Changes in cell invasion and gene regulation were assessed 24 hours after electroporation using transwell assay and RNA transcriptome analysis, respectively. Results. Reversible electroporation at 1.0 kV/cm enhanced invasion in a cell line-dependent manner. NIB140 CORE showed a consistent and pronounced increase, with a median of 3.74-fold (274%) higher number of invading cells compared to sham control. In contrast, NIB216 CORE exhibited only a modest increase in invasion (1.30-fold; 30%). Transcriptomic profiling identified modulation of genes linked to extracellular matrix organization and ion channel activity in NIB140 CORE, and cytoskeletal remodelling in NIB216 CORE, indicating the activation of invasion-related pathways. Conclusions. These findings highlight a potential risk of pro-invasive responses in GB cells. In tumour ablation with irreversible electroporation, this concern relates to cells in the peripheral zone that may experience only sublethal electric fields, while in electrochemotherapy, a similar risk may arise if permeabilized cells are not effectively eliminated due to insufficient local drug delivery. Nevertheless, the two tested cell lines responded differently, underscoring patientspecific heterogeneity and the need for validation in more physiologically relevant models.
Ključne besede: electroporation, high-frequency electric pulses, glioblastoma, patient-derived cells, invasion
Objavljeno v DiRROS: 17.06.2026; Ogledov: 81; Prenosov: 58
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Povzetek: The emergence of phonon frequency combs exemplifies a rare and intriguing phenomenon in quantum solids. Materials with distinctive phonon band structures are especially promising for hosting such states, as their vibrational dispersion landscape across the Brillouin zone can facilitate the formation of long-lived, collective lattice excitations. In the layered Van der Waals compound InSiTe3, polarization-resolved Raman spectroscopy reveals a pronounced anharmonicity in symmetry-predicted modes and the formation of a self-organized frequency domain structure (coherent-like state), in the range of a localized high-energy A1g phonon mode near 500 cm−1. This strong phonon-phonon coupling manifests itself as an anomalous temperature dependence around 200 K, coinciding with the appearance of higher-order excitations within the phonon density of states gap. These findings position InSiTe3 as an unconventional platform where intrinsic highly structured phonon spectral correlations and unusually strong anharmonic effects coexist, opening new avenues for exploring emergent vibrational phenomena in low-dimensional materials.
Ključne besede: phonon, phonon frequency comb, Layered Van der Waals materials, femtosecond excitation
Objavljeno v DiRROS: 14.05.2026; Ogledov: 161; Prenosov: 143
Celotno besedilo (3,88 MB)
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Povzetek: Huntington’s disease is a neurodegenerative disorder in which neuronal death leads to chorea and cognitive decline. Individuals with ≥40 cytosine–adenine–guanine repeats on the interesting transcript 15 gene develop Huntington’s disease due to a mutated huntingtin protein. While the associated structural and molecular changes are well characterized, the alterations in neurovascular function that lead to the symptoms are not yet fully understood. Recently, the neurovascular unit has gained attention as a key player in neurodegenerative diseases. The mutant huntingtin protein is known to be present in the major parts of the neurovascular unit in individuals with Huntington’s disease. However, a non-invasive assessment of neurovascular unit function in Huntington’s disease has not yet been performed. Here, we investigate neurovascular interactions in presymptomatic (N = 13) and symptomatic (N = 15) Huntington’s disease participants compared to healthy controls (N = 36). To assess the dynamics of oxygen transport to the brain, functional near-infrared spectroscopy, ECG and respiration effort were recorded. Simultaneously, neuronal activity was assessed using EEG. The resultant time series were analysed using methods for discerning time-resolved multiscale dynamics, such as wavelet transform power and wavelet phase coherence. Neurovascular phase coherence in the interval around 0.1 Hz is significantly reduced in both Huntington’s disease groups. The presymptomatic Huntington’s disease group has a lower power of oxygenation oscillations compared to controls. The spatial coherence of the oxygenation oscillations is lower in the symptomatic Huntington’s disease group compared to the controls. The EEG phase coherence, especially in the α band, is reduced in both Huntington’s disease groups and, to a significantly greater extent, in the symptomatic group. Our results show a reduced efficiency of the neurovascular unit in Huntington’s disease both in the presymptomatic and symptomatic stages of the disease. The vasculature is already significantly impaired in the presymptomatic stage of the disease, resulting in reduced cerebral blood flow control. The results indicate vascular remodelling, which is most likely a compensatory mechanism. In contrast, the declines in α and γ coherence indicate a gradual deterioration of neuronal activity. The results raise the question of whether functional changes in the vasculature precede the functional changes in neuronal activity, which requires further investigation. The observation of altered dynamics paves the way for a simple method to monitor the progression of Huntington’s disease non-invasively and evaluate the efficacy of treatments.
Ključne besede: neurovascular unit, time–frequency analysis multiscale, oscillatory analysis, phase coherence, brain oxygenation
Objavljeno v DiRROS: 05.05.2026; Ogledov: 179; Prenosov: 159
Celotno besedilo (2,26 MB)
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Povzetek: Multi-carrier phase difference (MCPD) ranging is promising for low-cost proximity and localization systems, but its performance degrades when devices use inexpensive crystal oscillators. In practice, carrier frequency offset (CFO) can change linearly with carrier frequency, and the difference between the slopes of CFO as a function of carrier frequency, referred to as the carrier frequency offset slope difference (CFOSD), introduces a systematic distance bias.We model MCPD using the standard timing diagram (TD) and derive a closed-form expression for the distance error that reveals a dominant term proportional to both CFOSD and the sampling time offset difference between devices. Two TD design approaches are proposed and validated by simulations with CFOSD sweep and additive noise. The temporal differential correction approach suppresses the effect of CFOSD on distance estimation over a wide CFOSD range and achieves almost zero bias, but at the cost of longer measurement duration, greater sensitivity to timing asynchronization, and a higher required signal-to-noise ratio (SNR). The role switching approach reverses the roles of initiator and reflector across carrier frequencies according to a role pattern, preserves the measurement duration of the standard TD, and reduces CFOSD sensitivity within a method-dependent CFOSD operating range. Experimental results for the standard and role-switching TD designs confirm the signal model, show good agreement between measured and simulated channel impulse responses, and demonstrate that the proposed TD designs substantially reduce distance bias caused by CFOSD while remaining compatible with low-cost implementations.
Ključne besede: asynchronization, carrier frequency offset, channel frequency response
Objavljeno v DiRROS: 24.02.2026; Ogledov: 344; Prenosov: 311
Celotno besedilo (41,90 MB)
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Povzetek: In this study, we investigate the load-bearing capacity of pre-stressed concrete girders under various damage levels. We employed Distributed Acoustic Sensing (DAS) technology to monitor and quantify changes in the girder response as damage levels were incrementally introduced. This approach enabled the real-time measurement of dynamic behavior over the entire length of the girder, allowing for a detailed characterization of damage-induced structural changes. To complement the DASbased approach, we also applied classical acceleration-based damage detection techniques. By integrating these methods, we aimed to cross-validate the results and provide a more comprehensive understanding of damage progression and its impact on structural performance. The experimental campaign, conducted in Ljubljana, ZAG, involved full-scale testing of pre-stressed concrete girders subjected to controlled damage scenarios. This setup ensured a realistic assessment of the girders’ residual capacity and failure mechanisms. The paper presents preliminary results from this experimental study, emphasizing the capability of DAS measurements to detect and characterize damage, while also comparing its performance against traditional methods. By combining advanced sensing technologies with established techniques, this research highlights the potential of DAS as a transformative tool in structural health monitoring.
Ključne besede: distributed acoustic sensing, distributed fiber optic sensing, structural health monitoring, frequency analysis, load test, infrastructure monitoring, bridge monitoring
Objavljeno v DiRROS: 22.01.2026; Ogledov: 482; Prenosov: 298
Celotno besedilo (21,37 MB)
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