Search Results (1,267)

Unknown time-varying parameters, along with mismatched and matched disturbances, exist in hydraulic systems, worsening position tracking performance and even destabilizing systems. To address this issue, this article proposes an adaptive full-state prescribed performance position tracking control for hydraulic systems subject both to unknown time-varying parameters and to mismatched and matched disturbances. First, a smooth nonlinear term is skillfully introduced into the controller design so that it can simultaneously cope with both unknown time-varying parameters and disturbances. Next, by integrating the adaptive technique and the prescribed performance function, an adaptive full-state prescribed performance position tracking controller is developed for hydraulic systems in which both the transient and steady performance of all the control errors can be prescribed. A stability analysis then confirms both the prescribed transient performance and the asymptotic steady performance of all the control errors. Finally, the superiority of the proposed controller is also validated by comparison with simulation results. Full article

Background/Objectives: The complexity of acute pancreatitis (AP) extends beyond its immediate complications. This study aimed to evaluate both exocrine and endocrine pancreatic dysfunctions following a first episode of AP, assessed at diagnosis and during a 6-month follow-up period. Methods: A prospective analysis was conducted on patients with a first episode of AP. Pancreatic endocrine function was evaluated using fasting glucose and glycated hemoglobin (HbA1c) levels, while pancreatic exocrine function was assessed through fecal elastase-1 (FE-1) testing and the novel Pancreatic Exocrine Insufficiency Questionnaire (PEI-Q). Results: Altogether, data from 112 time-point observations were analyzed with respect to endocrine and exocrine insufficiency after a first episode of AP, with 60 patients enrolled at baseline, 33 (55%) completing the first follow-up, and 19 (31.67%) completing the second follow-up. Based on PEI-Q scores, 75% of patients showed pancreatic exocrine insufficiency (PEI) at baseline. This rate decreased significantly to 33.3% at 2 months, with a further slight decline to 26.3% at 6 months. In contrast, FE-1 testing identified PEI in only 23% of patients at baseline, with a similar progressive improvement in time. Regarding the endocrine function, hyperglycemia was noted at baseline (mean serum glucose 120.75 ± 49.89 mg/dL), with a decreasing trend and normalization observed at follow-up. Conclusions: The pancreas has a remarkable recovery potential, with both exocrine and endocrine dysfunctions seen during the hospitalization for AP being transient. However, follow-up after AP is essential, as pancreatic insufficiency can significantly impact patients’ quality of life. Full article

To achieve rapid detection of stainless steel passivation quality, a time-domain impedance method was investigated based on a potential step transient with a portable three-electrode probe. A comparison of the effects of signal analysis and transient parameters was conducted, and the results were compared with those obtained in a bulk solution with a general three-electrode system. The measured transient current with the probe offered a higher signal-to-noise ratio, with minimal deviation from the frequency-domain impedance observed at a step amplitude of 0–100 mV. Measurements using the three-electrode probe under different stabilization times indicated that, after 30 s of stabilization, the measurement deviation was less than 1%, enabling a rapid assessment. Comparative testing of surfaces with varying passivation quality revealed that the pitting potential increases with increasing time-domain impedance, demonstrating the method’s capability to distinguish passivated surfaces with different corrosion resistances. Full article

Limbal dermoids are congenital, benign, choristomatous growths affecting the corneal-limbal junction. Conventional excision techniques often result in persistent epithelial defects, corneal thinning, and vascularization due to sectoral limbal stem cell deficiency. This study investigated a novel surgical approach for limbal dermoid excision, utilizing Bowman’s membrane lenticule and autologous limbal stem cell transplantation, aimed at improving epithelial healing and visual outcomes. Thirty-four subjects (24 females, 10 males; mean age 8.33 ± 6.47 years) with limbal dermoids underwent the procedure. After dermoid excision, a Bowman’s membrane lenticule was placed over the defect and tucked 1 mm beneath the surrounding tissue. Sectoral limbal reconstruction was then performed using the AutoSLET technique. Pre- and postoperative assessments included visual acuity, corneal thickness, and epithelialization time. Statistical analysis employed paired t-tests. The mean epithelialization time was 3.36 ± 0.74 weeks, indicating rapid healing. Best-corrected visual acuity (BCVA) significantly improved from a preoperative mean of 0.136 ± 0.121 decimal units to a postoperative mean of 0.336 ± 0.214 decimal units (p < 0.001). Corneal thickness also demonstrated a significant increase, rising from a preoperative mean of 294 ± 49.68 microns to a postoperative mean of 484 ± 5.037 microns (p < 0.001). There is a transient edema below the Bowman lenticule observed in many cases, which resolves with deposition of granulation tissue. The findings suggest that the combined use of Bowman’s membrane lenticule and autologous limbal stem cell transplantation offers a promising surgical strategy for limbal dermoid excision. This technique promotes rapid epithelialization and leads to significant improvements in visual acuity and corneal thickness compared to conventional methods. The utilization of Bowman’s membrane as a natural basement membrane and the direct application of limbal stem cells facilitate enhanced epithelial healing and visual rehabilitation. While the study is limited by its small sample size, the results demonstrate the potential of this novel approach in managing limbal dermoids effectively. Full article

This paper proposes a coordinated control strategy for grid-forming inverters (GFMs) to address two critical challenges in evolving power systems. These are the active harmonic mitigation under nonlinear loading conditions and dynamic overcurrent control during grid disturbances. The proposed framework integrates a shunt active filter (SAF) mechanism within the GFM control structure to achieve a real-time suppression of harmonic distortions from the inverter and grid currents. In parallel, a virtual impedance-based dynamic current limiting strategy is incorporated to constrain fault current magnitudes, ensuring the protection of power electronic components and maintaining system stability. The SAF operates in a current-injection mode aligned with harmonic components, derived via instantaneous reference frame transformations and selective harmonic extraction. The virtual impedance control (VIC) dynamically modulates the inverter’s output impedance profile based on grid conditions, enabling adaptive response during fault transients to limit overcurrent stress. A detailed analysis is performed for the coordinated control of the grid-forming inverter. Supported by simulations and analytical methods, the approach ensures system stability while addressing overcurrent limitations and active harmonic filtering under nonlinear load conditions. This establishes a viable solution for the next-generation inverter-dominated power systems where reliability, power quality, and fault resilience are paramount. Full article

The no-insulation (NI) technique improves the stability and defect-tolerance of high-temperature superconducting (HTS) coils by enabling current redistribution, thereby reducing the risk of quenching. NI–HTS coils are widely applied in DC systems such as high-field magnets and superconducting field coils for electric machines. However, the presence of turn-to-turn contact resistance makes current distribution uneven, rendering traditional simulation methods unsuitable. To address this, a finite element method (FEM) based on the T–A formulation is proposed. This model solves coupled equations for the magnetic vector potential (A) and current vector potential (T), incorporating turn-to-turn contact resistance and anisotropic conductivity. The thin-strip approximation simplifies second-generation HTS materials as one-dimensional conductors, and a homogenization technique further reduces computational time by averaging the properties between turns, although it may limit the resolution of localized inter-turn effects. To verify the model’s accuracy, simulation results are compared against the H formulation, distributed circuit network (DCN) model, and experimental data. The proposed T–A model accurately reproduces key transient characteristics, including magnetic field evolution and radial current distribution, in both circular and racetrack NI coils. These results confirm the model’s potential as an efficient and reliable tool for transient electromagnetic analysis of NI–HTS coils. Full article

This paper analyzes the transient voltage stability of the dual-source DC power system. The system’s equivalent model is first established. Subsequently, the effect mechanisms of line parameters and voltage-source rectifiers’ current control inner loops on the system’s transient voltage instability are investigated. It indicates that these factors reduce the power supply capacity of the source, increasing the risk of transient instability in the system. Then, considering the influence of fault depths, the influence of different large disturbances on the transient voltage stability is investigated. Furthermore, the critical cutting voltage and critical cutting time for DC power systems are determined and then validated on the MATLAB R2023b/Simulink platform. Finally, based on the mixed potential function theory, the impact of system parameter variations on stability boundaries is analyzed quantitatively. Simulation verification is conducted on the MATLAB R2023b/Simulink platform, and experimental verification is conducted on the RT-LAB Hardware-in-the-Loop platform. The results of the quantitative analysis and experiments corroborate the conclusions drawn from the mechanistic analysis, underscoring the critical role of line parameters and converter control parameters in the system’s transient voltage stability. Full article

The sudden increase of fluxes of quasi-trapped energetic electrons under the Earth’s radiation belt (ERB) has remained a puzzling phenomenon for decades. It is known as enhancements of forbidden energetic electrons (FEEs). The FEE enhancements are occasionally observed by low-Earth orbit NOAA/POES satellites. Previously, no strong correlation was established between FEEs and geomagnetic activity, while external control of FEE occurrence by solar activity and interplanetary parameters was revealed on a long time-scale. Two important questions are still open: (1) key parameters of the mechanism and (2) solar wind drivers or triggers. In the present study we conducted detailed analysis of three FEE events that occurred during the greatest geomagnetic storms, which dramatically affected space weather. The FEE enhancements occurred under northward IMF and, thus, Bz and convection electric fields could have been neither driver nor trigger. We found that an abrupt and significant change in solar wind pressure is a key solar wind driver of the FEE enhancements observed. The characteristic time of FEE injection from the inner edge of the ERB at L-shell 1.2 to the forbidden zone at L < 1.1 was estimated to be 10–20 min. In the mechanism of ExB drift, this characteristic time corresponds to the radial inward transport of electrons caused by a transient electric field with the magnitude ~10 mV/m. Full article

Transcranial magnetic stimulation combined with electroencephalography (TMS-EEG) has emerged as a transformative tool for probing cortical dynamics with millisecond precision. This review examines the state-dependent nature of TMS-EEG, a critical yet underexplored dimension influencing measurement reliability and clinical applicability. By integrating TMS’s neuromodulatory capacity with EEG’s temporal resolution, this synergy enables real-time analysis of brain network dynamics under varying neural states. We delineate foundational mechanisms of TMS-evoked potentials (TEPs), discuss challenges posed by temporal and inter-individual variability, and evaluate advanced paradigms such as closed-loop and task-embedded TMS-EEG. The former leverages real-time EEG feedback to synchronize stimulation with oscillatory phases, while the latter aligns TMS pulses with task-specific cognitive phases to map transient network activations. Current limitations—including hardware constraints, signal artifacts, and inconsistent preprocessing pipelines—are critically analyzed. Future directions emphasize adaptive algorithms for neural state prediction, phase-specific stimulation protocols, and standardized methodologies to enhance reproducibility. By bridging mechanistic insights with personalized neuromodulation strategies, state-dependent TMS-EEG holds promise for advancing both basic neuroscience and precision medicine, particularly in psychiatric and neurological disorders characterized by dynamic neural dysregulation. Full article

As semiconductor technologies continue to scale aggressively, electromigration (EM) has become critical in modern VLSI design. Since traditional EM assessment methods fail to accurately capture the complex behavior of multi-segment interconnects, recent physics-based models have been developed to provide a more accurate representation of EM-induced stress evolution. However, numerical methods for these models result in large-scale systems, which are computationally expensive and impractical for complex interconnect structures. Model order reduction (MOR) has emerged as a key enabler for scalable EM analysis, with moment-matching (MM) techniques offering a favorable balance between efficiency and accuracy. However, conventional Krylov-based approaches often suffer from limited frequency resolution or high computational cost. Although the extended Krylov subspace (EKS) improves frequency coverage, its symmetric structure introduces significant overhead in large-scale scenarios. This work introduces a novel MOR technique based on the asymmetric extended Krylov subspace (AEKS), which improves upon the conventional EKS by incorporating a sparsity-aware and computationally efficient projection strategy. The proposed AEKS-based moment-matching framework dynamically adapts the Krylov subspace construction according to matrix sparsity, significantly reducing runtime without sacrificing accuracy. Experimental evaluation on IBM power grid benchmarks demonstrates the high accuracy of our method in both frequency-domain and transient EM simulations. The proposed approach delivers substantial runtime improvements of up to 15× over full-order simulations and 100× over COMSOL, while maintaining relative errors below 0.5%, even under time-varying current inputs. Full article

Background/Objectives: Interferon alpha (IFNα) remains a cornerstone in the management of Philadelphia-negative myeloproliferative neoplasms (Ph-neg MPNs), yet its immunomolecular impact over time is not fully elucidated. The aim of the study was to explore how IFNα therapy dynamically reshapes immune and gene profiles in Ph-neg MPNs and assess their potential as treatment-related biomarkers. Methods: This single-center, prospective, observational study included a translational substudy conducted within a previously established clinical cohort of 44 IFNα-treated patients, selecting a representative subset of 18 individuals stratified by treatment duration. Cytokine profiling (ELISA) and gene expression (RT-qPCR) analysis were performed using plasma and peripheral blood mononuclear cells (PBMCs), respectively. Results: Patients with prolonged exposure showed reduced pro-inflammatory cytokines and downregulation of inflammatory-signalling STAT1/STAT3 expression. In contrast, those with intermediate exposure exhibited transient TH2/regulatory cytokine peaks and upregulation of immunomodulatory genes such as CXCL10, SOCS3, and TNFAIP3. Spearman correlations revealed functional associations between cytokine and gene expression patterns including notable links such as STAT1–IL-13 and MYB–IL-13. Conclusions: These results describe a sequential immune reprogramming driven by IFNα, supporting the development of dynamic immunomolecular biomarkers of response in Ph-neg MPNs. Full article

Objectives: To evaluate the immediate and short-term changes in intraocular pressure (IOP) following intravitreal injection (IVI) of anti-vascular endothelial growth factor (VEGF) agents and to identify the clinical and procedural factors associated with IOP elevation after treatment. Methods: This retrospective study included 118 eyes from 115 patients who underwent IVI with anti-VEGF agents at Osaka Metropolitan University Hospital between September 2024 and January 2025. IOP was measured at three time points, namely before injection, within 1 min after injection, and at 30 min, in selected eyes with a post-injection IOP ≥ 25 mmHg. Differences in IOP elevation were analyzed according to the disease type and anti-VEGF agent. Univariate and multivariate linear regression analyses were performed to identify clinical factors associated with IOP elevation. Results: Mean IOP significantly increased from 13.9 ± 3.3 mmHg at baseline to 39.2 ± 12.4 mmHg immediately after injection (p < 0.001), with 79.7% of eyes showing an IOP ≥ 25 mmHg. Among those remeasured, IOP decreased to 17.7 ± 6.5 mmHg at 30 min. Significant differences in IOP elevation were observed among anti-VEGF agents (p < 0.001), with aflibercept at 2 mg and 8 mg showing greater increases than other agents. Multivariate analysis identified higher baseline IOP, history of glaucoma, absence of prior vitrectomy, and use of aflibercept (2 mg or 8 mg) as significant risk factors for greater post-injection IOP elevation. Conclusions: Transient IOP elevation ≥ 25 mmHg was observed in the majority of eyes after IVI but typically resolved within 30 min. Aflibercept use, high baseline IOP, glaucoma history, and absence of prior vitrectomy were associated with greater IOP elevation. Careful monitoring and attention to injection volume may be warranted, particularly in high-risk patients. Full article

Fusarium wilt, caused by Fusarium solani, is a devastating disease that leads to significant losses in ginger (Zingiber officinale) crops worldwide. To explore the molecular mechanisms underlying F. solani infection and disease progression, we performed a comparative transcriptome analysis of ginger rhizomes during storage, comparing inoculated and non-inoculated samples. A total of 647 and 6398 DEGs were identified in the 1.5- and 2-day infection groups, respectively. KEGG analysis revealed that most DEGs were enriched in the plant–pathogen interaction pathway, with both PTI and ETI being activated. Six DEGs in this pathway were validated by qRT-PCR at two time points, showing a strong correlation with FPKM values from the transcriptome data. Furthermore, transient expression analysis in Nicotiana benthamiana leaves demonstrated that overexpressing ZoCEBiP1 helped scavenge excess ROS, thereby reducing disease severity. Transcriptional profiling of DEGs in the plant–pathogen interaction pathway revealed significant changes in genes involved in ROS and NO metabolism. In F. solani-infected ginger rhizomes, levels of H₂O₂ and O₂⁻ were elevated, along with increased activities of antioxidant enzymes (POD, CAT, SOD, and APX) and higher NO content and NOS activity. These findings elucidated the early defense response of ginger rhizomes to F. solani infection and provided insights for developing effective strategies to manage fungal diseases. Full article

Vibrational analysis of peptides in solution and the theoretical determination of the effects of the microenvironment on infrared and Raman spectra are of key importance in many fields of chemical interest. In this work, we present a computational study combining static quantum mechanical calculations with ab initio molecular dynamics simulations to investigate the vibrational behavior of three peptide models in both the gas phase and in explicit water, under non-periodic boundary conditions. The vibrational spectra of the main amide bands, namely amide I-III and A, were analyzed using a time–frequency approach based on the wavelet transform, which allows the resolution of transient frequency shifts and mode couplings along the trajectories. This combined approach enabled us to perform a time-resolved vibrational analysis revealing how vibrational frequencies, especially of the C=O and N–H stretching modes, evolve over time due to dynamical microsolvation. These fluctuations modulate vibrational couplings and lead to spectral broadening and frequency shifts that correlate with the local structuring of the solvent. In conclusion, our results highlight how the proposed protocol allows for the direct connection between vibrational modes and local structural changes, providing a link from the spectroscopic observable to the structure, the peptide backbone, and its microenvironment. Full article

Virtual synchronous generator (VSG) control has been increasingly utilized for the grid integration of the voltage source inverter (VSI). Under large disturbances, such as voltage sags and grid faults, the VSG synchronization dynamic is highly nonlinear and cannot be evaluated by small-signal-based approaches. Conventionally, the equal area criterion (EAC) is utilized to analyze the transient stability of a synchronous machine or a VSG. However, it is found that the EAC is only valid under special scenarios when the damping effect is ignored. In this case, the EAC will provide conservative predictions and therefore put stringent requirements on the fault-clearing time. This paper reveals that the motion of a pendulum is essentially the same as the VSG swing equation. Due to this, the phase portrait approach, which was used to predict the pendulum motion, can be similarly applied for the VSG transient stability study. Based on the analogical phase portrait analysis, a damping coefficient tuning guideline is proposed, which always guarantees the synchronization stability as long as an equilibrium exists. The aforementioned theoretical findings are finally verified through a grid-connected VSG under the hardware-in-loop (HIL) environment. Full article