Journals
2026 EN
Dinwiddie Laura E. · Baggett Jared M. · Kofler James M.
+11 more
Abstract Background Computed tomography (CT) is an essential imaging modality for disease diagnosis, treatment efficacy, and image‐based guidance of various medical procedures. The locally deposited radiation dose in tissues, as estimated by the computed tomography dose index (CTDI), can vary considerably across exposures delivered by CT scanners from different vendors, even if the scans are performed using similar technique factors, such as tube potential and tube current. The volumetric CTDI (CTDI vol ) is a common dose metric that reports an average radiation dose (in mGy) delivered to a specific volume within a test phantom. The CTDI vol is important in dosimetry applications as the organ absorbed dose within the patient has been shown to scale in near‐linear proportion, creating a basis for comparing organ doses across different scan protocols and scanner models. Purpose To develop a database of tube current‐time product (mAs) normalized CTDI vol values for currently utilized CT scanner models for each of the four primary CT vendors for use in the MIRDct organ dosimetry software available at MIRDsoft.org. This data forms the basis of the MIRDct code, which reports organ doses across a range of computational phantoms based upon axial organ dose coefficient libraries generated through Monte Carlo radiation transport for a reference CT scanner. Organ doses delivered by alternate CT scanner vendors and models may then be reported using ratios of normalized CTDI vol values under similar technique factors. Methods Scanners were selected from four major CT manufacturers: Philips Healthcare, GE Healthcare, Canon Medical Systems, and Siemens Healthineers. Technique parameters were also selected for each scanner that closely matched values used in the generation of an equivalent CT source term (small to large bowtie filters; 80–140‐kVp tube voltage; and 10‐mm to 40‐mm beam collimation). For each scanner chosen, the appropriate technique factors and protocols were selected, and the console‐reported CTDI vol values were recorded and normalized to a set value of 100 mAs. The normalized CTDI vol data collected for use within the MIRDct code were analyzed for noticeable patterns, features, and trends, and were compared to similar normalized CTDI vol datasets used within the National Cancer Institute NCICT software and the Virtual Phantoms, Inc. VirtualDose software. Results For all given CT scanner and technique factor combinations, there was strong agreement in normalized CTDI vol values across all three codes: between 0% and 12% difference for the compared scanners. Ratios of CTDI vol values for various CT scanner vendors and models to the corresponding CTDI vol values for the MIRDct reference scanner (Cannon Aquilion One Genesis) were also compared on the basis of either the 16‐cm head PMMA phantom or the 32‐cm body PMMA phantom. The mean quotient of these normalized CTDI vol ratios (head ratios to body ratios) was found to be approximately 1.06, and thus either ratio may be applied in reporting patient organ dose by MIRDct. Conclusions A database of normalized CTDI vol (mGy/100 mAs) was created for 17 models of CT scanners from four manufacturers at varying tube potentials, collimations, x‐ray bowtie filters, and phantom sizes for use in the MIRDct software.
Journals
2026 EN
Salih Hadi · Samadzadeh Sara · Bereuter Charlotte
+37 more
ABSTRACT Introduction Optical coherence tomography (OCT)‐derived retina measurements are markers for neuroaxonal visual pathway status. High‐quality OCT scans are essential for reliable measurements, but their acquisition is particularly challenging in eyes with severe visual impairment, as often observed in neuromyelitis optica spectrum disorders (NMOSD). Objective To investigate OCT quality issues in real‐world data from the international Collaborative Retrospective Study on Retinal OCT in Neuromyelitis Optica (CROCTINO). Methods We evaluated the quality of peripapillary and macular OCT scans, using Heidelberg Spectralis SD‐OCT, Carl Zeiss Cirrus HD‐OCT, or Topcon SD‐OCT across 22 centers. Experienced graders applied OSCAR‐IB criteria for OCT quality. Eyes were classified as severely visually impaired or not based on a 1.0 logMAR cut‐off. Quality outcomes were compared using the Chi‐square test. Results A total of 3075 OCT scans (1630 peripapillary, 1445 macular) from 539 people with NMOSD and related conditions were evaluated. Macular scans were rejected more often than peripapillary scans due to quality issues (20.1% vs. 14.5%, p < 0.001). Rejection rates were higher in eyes with severe visual impairment (peripapillary: 28.9%, macular: 41.6%) compared to eyes without severe visual impairment (peripapillary: 10.7%, p < 0.001; macular: 14.6%, p < 0.001). Conclusion Our study revealed that approximately one in six scans was rejected due to low quality, with higher rejection rates in eyes with severe visual impairment. As scan quality can bias quantitative outcomes and artificial intelligence applications, these findings emphasize the unmet need for standardized OCT practices tailored to NMOSD and other conditions involving severe visual impairment.
Journals
2026 EN
Kiefer David · Sonkaya Yade · Krause Dietmar
+5 more
Objective Axial spondyloarthritis (axSpA) is often associated with persistent pain despite effective anti‐inflammatory treatment. Digital health applications (DHAs) provide innovative approaches to address multidimensional aspects of persistent pain through psychological and behavioral strategies. The aim of this study was to assess the impact of a DHA using acceptance and commitment therapy (ACT) on disease outcomes, including the West Haven‐Yale Multidimensional Pain Inventory (MPI), in patients with axSpA experiencing persistent pain despite stable pharmacological therapy. Methods This unblinded, multicentric, randomized controlled trial compared an intervention group (IG) receiving the ACT app with a standard of care (SOC) group. The ACT app provided behavioral therapy. The primary outcome was MPI pain‐related life interference; secondary outcomes included pain severity, affective distress, and other patient‐reported outcomes after 12 weeks. Linear models estimating the effect of the ACT app on the change of MPI pain‐related life interference and affective distress were calculated. Results A total of 136 patients were randomized to IG (n = 73) with the ACT app and SOC (n = 63) without the ACT app. In the IG, 44 actively used the ACT app. All lessons in the ACT app were completed by 19 IG patients (43%). Baseline characteristics, including MPI scores, were comparable between groups. IG showed a reduction in pain‐related life interference as well as in other outcomes. The improvements in pain‐related life interference (β with −0.36, 95% confidence interval [CI]: −0.73 to 0.01) and affective distress related to the disease (−0.4; 95% CI −0.84 to 0.03) were greater compared with SOC. Conclusion The ACT app demonstrated a meaningful reduction in pain‐related life interference, supporting that DHAs might become a complementary tool in managing pain for patients with axSpA. Studies about improving adherence to DHAs are warranted.
Journals
2026 EN
Zhou Yuxing · Hao LiYing · Wang RunZhi
+1 more
ABSTRACT The resilience and robustness of model predictive control are typically contingent upon an adequately extended prediction horizon, yet it is constrained in real‐time applications by limited computational resources. To tackle this issue, this paper introduces a finite‐time Lyapunov‐based model predictive control (FTLMPC) approach, independent of the prediction horizon, for unmanned surface vehicles (USVs) subject to external disturbances and denial‐of‐service (DoS) attacks. Firstly, a finite‐time auxiliary control system is integrated within the FTLMPC framework. This system incorporates a finite‐time extended state observer (FTESO) for precise disturbance estimation and a finite‐time backstepping control law to guarantee zero tracking errors. Consequently, FTLMPC ensures finite‐time stability during each DoS attack interval, effectively preventing error accumulation despite the presence of disturbances and DoS attacks. Secondly, a novel compensation scheme is introduced to mitigate the information loss induced by DoS attacks, wherein the compensation signal is solely derived from the control signal at the moment of the last successful transmission, thus minimizing reliance on the prediction horizon. It enables flexible adaptation of the prediction horizon and control performance according to the available computational resources. Finally, the simulation results validate the superior control performance of the proposed strategy.
Journals
2026 EN
Neherin Kashfia · Holloway Kristopher · Song Yingduo
+4 more
ABSTRACT Reprogramming somatic cells into induced pluripotent stem cells (iPSCs) resets the epigenetic landscapes that mark the aging clock, and consequently cells differentiated from iPSCs resemble fetal cells rather than adult or aged cells. The lack of proper cellular aging in cells differentiated from iPSCs presents a unique challenge in iPSC‐based modeling of age‐associated diseases such as neurodegeneration. To address this challenge, we seek to introduce cellular senescence, a hallmark of aging, into iPSC‐based models in a robust and temporally controlled manner. An inducible CRISPR interference (CRISPRi) is used to suppress the expression of TERF2, a key component of the telomere protecting Shelterin complex. We demonstrate that suppression of TERF2 robustly activates the DNA damage response, p53/p21 signaling, and cellular senescence in iPSCs in a highly homogeneous and synchronous manner. Applying this inducible CRISPRi‐TERF2 system to differentiation of iPSCs to neural progenitor cells (NPCs), we show efficient activation of senescence‐associated phenotypes in NPCs. This inducible cell model allows isogenic comparisons of the same cell populations over the course of differentiation with or without the activation of cellular senescence in a synchronous and homogeneous manner, and has broad applications in investigating the role of cellular senescence in the progression of age‐related diseases.
Journals
2026 EN
Sanap Avinash · Ashok Akshaya · Raundal Kaustubh
+3 more
ABSTRACT Regenerative medicine is evolving exponentially due to the wide range of therapeutic applications of mesenchymal stromal cells (MSCs), including wound healing. Although the translation of tissue‐derived primary MSCs (tMSCs) into clinical practice remains scarce despite preclinical success. The primary causes are donor‐associated and batch‐to‐batch variations, replicative senescence, and the inability of large‐scale manufacturing. Recent studies show that the induced MSCs (iMSCs) derived from reprogrammed induced pluripotent stem cells (iPSCs) offer distinct advantages over conventional tMSCs. This review aims to provide a comprehensive comparative analysis of the cellular characteristics, secretome composition (including growth factors, cytokines, and exosome cargo), regenerative capacities, and therapeutic potentials of tMSCs and iMSCs, with a specific focus on their applications in wound healing and tissue regeneration. The iMSCs surpass tMSCs by providing superior regenerative, immunomodulatory, and angiogenic benefits, along with unmatched consistency and scalability. iMSCs and their derivatives have exhibited remarkable capacities to promote angiogenesis, ECM production, re‐epithelialization, tissue regeneration, and scarless wound healing in diabetic, cutaneous, mucosal, and burn wounds. These advantages position iMSCs as a next‐generation cell therapy for managing both acute and chronic wounds, promising improved clinical outcomes and broader applicability.
Journals
2026 EN
Rigatos G. · Busawon K. · Siano P.
+3 more
ABSTRACT Coaxial rotor 6‐DOF UAVs can find use in several defence and civilian tasks. In this article, two different control methods are proposed for the control of this type of drones: (i) nonlinear optimal control and (ii) multi‐loop flatness‐based control. The dynamic model of the coaxial rotor drone is formulated and differential flatness properties are proven about it. To apply the nonlinear optimal control method, the dynamic model of the coaxial rotor drone undergoes approximate linearization with first‐order Taylor‐series expansion and through the computation of the associated Jacobian matrices. To apply multi‐loop flatness‐based control, the dynamic model of the UAV is decomposed in two subsystems connected in chained form. This means that the state vector of the second subsystem becomes virtual control input to the first subsystem, while the virtual control input of the first subsystem becomes a setpoints vector for the second subsystem. The two proposed control schemes ensure stabilization and precise flight‐path tracking for the coaxial rotor UAV. Both control methods avoid changes of state variables and complicated state‐space model transformations.
Journals
2026 EN
Şenaslan İbrahim · Bilgiç Boğaç
ABSTRACT This paper presents a method for improving the performance of a vehicle suspension system using an adaptive fuzzy dual PID controller optimized with a genetic algorithm. The fuzzy dual PID controller utilizes fuzzy logic to adapt to changing conditions and improve control, while the genetic algorithm optimizes the controller parameters to further enhance performance. The study uses velocity and position PID controllers because velocity PID controls acceleration well and position PID controls position well, and the incorporation of an adaptive fuzzy combination of two controllers ensures optimal performance of the suspension system under all operating conditions. To avoid the issue of suspension distance narrowing and to prevent instability in the controller, the low‐pass filtered displacement response of unsprung mass is utilized as the reference for the position PID controller. Quantitatively, according to the ISO‐8608 road entry for the goal function, the dual PID achieved a 53.35% improvement over the passive state, 6.57% better than dual PD, 33.06% over the Velocity PID, and 32.93% over the Position PID. These significant, quantifiable results confirm that the proposed adaptive fuzzy dual PID structure offers a robust and highly effective solution for advancing active vehicle suspension control technology.
Journals
2026 EN
Gulgonul Senol
ABSTRACT This study presents an analytical method for tuning PI controllers in first‐order with time delay (FOTD) systems, leveraging the Lambert W function. The Lambert W function enables exact pole placement, yielding direct analytical expressions for PI gains. The proposed approach identifies a critical condition that achieves a step response without overshoot and with minimum settling time, while also providing explicit tuning rules for systems where controlled overshoot is specified. The method demonstrates strong agreement with established empirical Chien‐Hrones‐Reswick tuning rules for both non‐overshooting and overshooting cases, bridging the gap between theoretical analysis and empirical results.
Journals
2026 EN
Quan Nguyen Vinh · Son Nguyen Ngoc
ABSTRACT This paper presents a hybrid control strategy for a non‐inverting Buck–Boost DC–DC converter used in photovoltaic energy management. The converter employs two independent Buck and Boost stages, enabling decoupled control loops and fast tracking of rapidly varying reference signals. A combined PI–SMC framework is proposed, where the outer loop regulates the output voltage using a PI controller, and the inner loop controls the inductor current via a smooth Sliding Mode Control (SMC) law based on an arctan(s) switching function. This smooth SMC formulation effectively reduces chattering and high‐frequency oscillations while improving tracking accuracy and robustness. Simulation results show short settling time, fast recovery under abrupt input and load variations, and stable performance across the full Buck–Boost operating range. Quantitative NRMSE (Normalized Root Mean Square Error) analysis confirms high tracking quality, with the output voltage exceeding 90% and the inductor current reaching about 98%. Experimental implementation on a TMS320F28379 DSP further validates the proposed method. The results demonstrate improved disturbance rejection and reduced sensitivity to parameter uncertainties, making the approach well suited for practical renewable‐energy power converters.