Search Results (462)

Objectives: Saccharomyces boulardii CNCM I-745, a probiotic yeast, is effectively used for the treatment of acute diarrhea as well as for the prevention and treatment of traveller‘s diarrhea and diarrhea under tube feeding. The underlying mechanisms are not fully elucidated. Both antitoxic and regulatory effects on the intestinal barrier, mediated either by the yeast or yeast-derived substrates, have been discussed. Methods: To examine the effects of Saccharomyces boulardii released substrates (S.b.S) on gastrointestinal (GI) barrier function, a murine small intestinal organoid cell model under stress was used. Stress was induced by lipopolysaccharide (LPS) exposure or withdrawal of growth factors from cell culture medium (GF_Red). Stressed organoids were treated with S.b.S (200 µg/mL), and markers of GI barrier and inflammatory response were assessed. Results: GF_Red-induced stress was characterized by disturbances in selected tight junction (TJ) (p < 0.05), adherent junction (AJ) (p < 0.001), and mucin (Muc) formation (p < 0.01), measured by gene expressions, whereby additional S.b.S treatment was found to reverse these effects by increasing Muc2 (from 0.22 to 0.97-fold change, p < 0.05), Occludin (Ocln) (from 0.37 to 3.5-fold change, p < 0.0001), and Claudin (Cldn)7 expression (from 0.13 ± 0.066-fold change, p < 0.05) and by decreasing Muc1, Cldn2, Cldn5, and junctional adhesion molecule A (JAM-A) expression (all p < 0.01). Further, S.b.S normalized expression of nucleotide binding oligomerization domain (Nod)2- (from 44.5 to 0.51, p < 0.0001) and matrix metalloproteinase (Mmp)7-dependent activation (from 28.3 to 0.02875 ± 0.0044 ** p < 0.01) of antimicrobial peptide defense and reduced the expression of several inflammatory markers, such as myeloid differentiation primary response 88 (Myd88) (p < 0.01), tumor necrosis factor α (Tnfα) (p < 0.01), interleukin (IL)-6 (p < 0.01), and IL-1β (p < 0.001). Conclusions: Our data provide new insights into the molecular mechanisms by which Saccharomyces boulardii CNCM I-745-derived secretome attenuates inflammatory responses and restores GI barrier function in small intestinal organoids. Full article

Coffee is one of the most widely consumed beverages globally, with over 60% of Americans drinking it daily. This review examines coffee’s multifaceted impact on health and well-being, drawing on decades of research. Overall, the consensus is that moderate coffee intake is more beneficial than harmful across a wide range of health outcomes. Numerous large-scale, prospective cohort studies from around the world have consistently shown that moderate coffee consumption—typically three to five cups per day—is associated with reduced overall mortality and lower risk of major diseases such as cardiovascular diseases, diabetes, stroke, respiratory conditions, cognitive decline, and potentially several types of cancer, including liver and uterine cancers. Both caffeinated and decaffeinated coffee have shown benefits. The addition of sugar and cream to coffee may attenuate coffee’s positive health effects. Despite historical concerns, coffee consumption is not linked to increased risks of cancer, hypertension, or arrhythmia. However, some concerns remain. For pregnant women, coffee consumption should be limited to lower amounts, such that the daily intake of caffeine does not exceed 200 mg/day. Also, excessive caffeinated coffee intake may cause anxiety or sleep disturbances. Coffee’s health-promoting mechanisms include improved glucose balancing, increased physical activity, increased fat oxidation, improved lung function, and reduced inflammation. Beyond mortality and chronic diseases, coffee consumption affects many aspects of well-being: it supports hydration, boosts mental acuity, enhances physical performance, and may aid bowel recovery after surgery. While the field is well-studied via long-term observational cohorts, future research should focus on randomized controlled trials, Mendelian randomization studies, and granular analyses of coffee types and additives. Full article

Nonlinear narrowband low-frequency noise generated during tractors’ operation significantly affects operators’ comfort and working efficiency. Traditional linear active noise control algorithms often struggle to effectively suppress such complex acoustic disturbances. To address this challenge, this paper proposes a momentum-enhanced Volterra filter-based active noise control (ANC) algorithm that improves both the modeling capability of nonlinear acoustic paths and the convergence performance of the system. The proposed approach integrates the nonlinear representation power of the Volterra filter with a momentum optimization mechanism to enhance convergence speed while maintaining robust steady-state accuracy. Simulations are conducted under second- and third-order nonlinear primary paths, followed by performance validation using multi-tone signals and real in-cabin tractor noise recordings. The results demonstrate that the proposed algorithm achieves superior performance, reducing the NMSE to approximately −35 dB and attenuating residual noise energy by 3–5 dB in the 200–800 Hz range, compared to FXLMS and VFXLMS algorithms. The findings highlight the algorithm’s potential for practical implementation in nonlinear and narrowband active noise control scenarios within complex mechanical environments. Full article

Objectives: Saffron, a traditional Chinese medicine, is renowned for its pharmacological effects in promoting blood circulation, resolving blood stasis, regulating menstruation, detoxification, and alleviating mental disturbances. Trans-crocetin, its principal bioactive component, exhibits significant anti-hypoxic activity. The clinical development and therapeutic efficacy of trans-crocetin are limited by its instability, poor solubility, and low bioavailability. Conversion of trans-crocetin into trans-sodium crocetinate (TSC) enhances its solubility, stability, and bioavailability, thereby amplifying its anti-hypoxic potential. Methods: This study integrates network pharmacology with in vivo and in vitro validation to elucidate the molecular targets and mechanisms underlying TSC’s therapeutic effects against high-altitude acute lung injury (HALI), aiming to identify novel treatment strategies. Results: TSC effectively reversed hypoxia-induced biochemical abnormalities, ameliorated lung histopathological damage, and suppressed systemic inflammation and oxidative stress in HALI rats. In vitro, TSC mitigated CoCl₂-induced hypoxia injury in human pulmonary microvascular endothelial cells (HPMECs) by reducing inflammatory cytokines, oxidative stress, and ROS accumulation while restoring mitochondrial membrane potential. Network pharmacology and pathway analysis revealed that TSC primarily targets the EGFR/PI3K/AKT/NF-κB signaling axis. Molecular docking and dynamics simulations demonstrated stable binding interactions between TSC and key components of this pathway. ELISA and RT-qPCR confirmed that TSC significantly downregulated the expression of EGFR, PI3K, AKT, NF-κB, and their associated mRNAs. Conclusions: TSC alleviates high-altitude hypoxia-induced lung injury by inhibiting the EGFR/PI3K/AKT/NF-κB signaling pathway, thereby attenuating inflammatory responses, oxidative stress, and restoring mitochondrial function. These findings highlight TSC as a promising therapeutic agent for HALI. Full article

Disturbance rejection in localized continuous linear systems remains challenging due to the interplay between spatial constraints, exact invariance conditions, and discretization effects. Existing methods either lack rigorous guarantees for exact rejection in continuous time or fail to address the subtleties of weak rejection in discrete-time implementations. In this work, we first establish necessary and sufficient conditions for exact disturbance rejection in the continuous-time output case, deriving control laws that enforce output invariance. For the discrete-time output scenario, we resolve the weak rejection problem by proving that—under stabilizability assumptions and an optimal discretization step—the system can achieve practical disturbance attenuation. Our results unify these two regimes, providing explicit design criteria for robust control in localized linear systems. Full article

Autonomic imbalance is one of the major pathological disturbances in chronic heart failure (CHF). Additionally, enhanced oxidative stress and inflammation are considered to be the main contributors to the disease progression. A growing body of evidence suggests cholinergic stimulation as a potential therapeutic approach in CHF, since it corrects the autonomic imbalance and alters the inflammatory response via the cholinergic anti-inflammatory pathway. Although previous research has provided some insights into the potential mechanisms behind these effects, there is a gap in knowledge regarding different cholinergic stimulation methods and their specific mechanisms of action. In the present study, an isoprenaline model (5 mg/kg/day s.c. for 7 days, followed by 4 weeks of CHF development) was used. Afterwards, rats received pyridostigmine (22 mg/kg/day in tap water for 14 days) or no treatment. Pyridostigmine treatment prevented the progression of CHF, decreasing chamber wall thinning (↑ PWDd, ↑ PWDs) and left ventricle dilatation (↓ LVIDd, ↓ LVIDs), thus improving cardiac contractile function (↑ EF). Additionally, pyridostigmine improved antioxidative status (↓ TBARS, ↓ NO₂⁻; ↑ CAT, ↑ GSH) and significantly reduced cardiac fibrosis development, confirmed by pathohistological findings and biochemical marker reduction (↓ MMP2, ↓ MMP9). However, further investigations are needed to fully understand the exact cellular mechanisms involved in the CHF attenuation via pyridostigmine. Full article

Electric vehicles face increasing cybersecurity threats that can compromise the integrity of their electric drive systems, especially under Denial-of-Service (DoS) attacks. To precisely regulate torque and speed in electric vehicles, vector-controlled induction motor drives rely on continuous communication between controllers and sensors. This flow could be broken by a DoS attack, which could result in unstable motor operation or complete drive system failure. To address this, we propose a novel ellipsoidal-set-based state feedback controller with integral action, formulated via linear matrix inequalities (LMIs). This controller improves disturbance rejection, maintains system stability under DoS-induced input disruptions, and enhances security by constraining the system response within a bounded invariant set. The proposed tracker has a faster dynamic reaction and better disturbance attenuation capabilities than the traditional H_ꚙ control method. The effectiveness of the proposed controller is validated through a series of diverse testing scenarios. Full article

In DC microgrids, optimizing the hybrid energy storage system (HESS) current control to meet the power requirements of the load is generally a difficult and challenging task. This is because the HESS always operates under various load conditions, which are influenced by measurement disturbances and parameter uncertainties. Therefore, in this paper, we propose the H_∞ state feedback control based on the reference modulation to improve the current tracking errors of the battery (Bat) and supercapacitor (SC) in the HESS for power tracking performance. Without altering the system control signal, the reference modulation technique combines the feedforward channel and output feedback signal directly to modulate the required currents of the Bat and SC derived from the required load power. The H_∞ state feedback control based on the required Bat and SC currents modulated by the reference modulation technique is proposed to improve the current tracking errors under the influence of measurement disturbances and parameter uncertainties without a disturbance observer. The ability of the reference modulation technique to attenuate the disturbance without the use of a disturbance observer is one advantage for improving transient performance. The improvement of the HESS’s power tracking performance in DC microgrids is confirmed by study results presented under the influence of measurement disturbances for nominal parameters and parameter uncertainties. Full article

This study investigates pre-seismic ionospheric anomalies preceding the 2023 Jishishan Ms6.2 earthquake using total electron content (TEC) data derived from BDS geostationary orbit (GEO) satellites. Multi-scale analysis integrating Butterworth filtering and wavelet transforms resolved TEC disturbances into three distinct frequency regimes: (1) high-frequency perturbations (0.56–3.33 mHz) showed localized disturbances (amplitude ≤ 4 TECU, range < 300 km), potentially associated with near-field acoustic waves from crustal stress adjustments; (2) mid-frequency signals (0.28–0.56 mHz) exhibited anisotropic propagation (>1200 km) with azimuth-dependent N-shaped waveforms, consistent with the characteristics of acoustic–gravity waves (AGWs); and (3) low-frequency components (0.18–0.28 mHz) demonstrated phase reversal and power-law amplitude attenuation, suggesting possible lithosphere–atmosphere–ionosphere (LAI) coupling oscillations. The stark contrast between near-field residuals and far-field weak fluctuations highlighted the dominance of large-scale atmospheric gravity waves over localized acoustic disturbances. Geometry-based velocity inversion revealed incoherent high-frequency dynamics (5–30 min) versus anisotropic mid/low-frequency traveling ionospheric disturbance (TID) propagation (30–90 min) at 175–270 m/s, aligning with theoretical AGW behavior. During concurrent G1-class geomagnetic storm activity, spatial attenuation gradients and velocity anisotropy appear primarily consistent with seismogenic sources, providing insights for precursor discrimination and contributing to understanding multi-scale coupling in seismo-ionospheric systems. Full article

Silty clay is extensively distributed in northern China. Numerous seismic events have demonstrated that underground structures embedded in silty clay strata are prone to severe damage during earthquakes. This study employs dynamic cyclic triaxial tests on undisturbed and remolded specimens (50–300 kPa confining pressures) to pioneer the quantification of pressure-amplified structural superiority. The experimental results reveal that: (1) Undisturbed soils exhibit 20–30% higher maximum shear stress (τ_dmax) and shear modulus (G_dmax) than remolded counterparts at 300 kPa, far exceeding the <5% deviation at 50 kPa due to enhanced particle-cementation synergy under pressure. (2) The normalized shear modulus ratio (G_d/G_dmax) exhibits low sensitivity to confining pressure, with G_d/G_dmax–γ_d relationship curves predominantly confined within a narrow band range. A triphasic evolutionary characteristic is manifested in the progressive reduction of G_d/G_dmax with increasing shear strain (γ_d), and quasi-linear attenuation is observed within the shear strain range of 1 × 10⁻⁴ ≤ γ_d ≤ 1 × 10⁻². (3) Remolded and undisturbed specimens demonstrate close correspondence in damping ratio (λ_d) across consolidation pressures. Under identical γ_d conditions, undisturbed specimens consistently exhibit lower λ_d values than remolded counterparts, attributable to enhanced energy dissipation resulting from structural homogenization in remolded soils, with λ_dmax magnitudes ranging between 0.2 and 0.3. The research provides mechanistic insights for seismic design of underground structures in silty clay terrains, particularly regarding disturbance sensitivity under deep burial conditions. Full article

This paper presents a high-order model-based robust control strategy for a dual-motor road wheel actuating system in a steer-by-wire (SbW) architecture. The system consists of a belt-driven and a pinion-driven motor collaboratively actuating the road wheels through mechanically coupled dynamics. To accurately capture the interaction between actuators, structural compliance, and road disturbances, a four-degree-of-freedom (4DOF) lumped-parameter model is developed. Leveraging this high-order dynamic model, a composite control framework is proposed, integrating feedforward model inversion, pole-zero feedback compensation, and a disturbance observer (DOB) to ensure precise trajectory tracking and disturbance rejection. High-fidelity co-simulations in MATLAB/Simulink and Siemens Amesim validate the effectiveness of the proposed control under various steering scenarios, including step and sine-sweep inputs. Compared to conventional low-order control methods, the proposed approach significantly reduces tracking error and demonstrates enhanced robustness and disturbance attenuation. These results highlight the critical role of high-order modeling in the precision control of dual-motor SbW systems and suggest its applicability in real-time, safety-critical vehicle steering applications. Full article

In this paper, a sliding-mode control strategy incorporating prescribed features was systematically designed, resolving the dual challenges of trajectory tracking precision maintenance and disturbance attenuation for an AUV subjected to dynamic model inaccuracies and disturbances. To neutralize the impact of parametric uncertainties and environmental disturbances on the controlled plant, an adaptive finite-time sliding-mode disturbance observer (AFTSMDO), the upper bound of perturbations was not required for the proposed observer. Subsequently, by embedding error transformations and prescribed performance functions, we designed a novel sliding-mode surface. This surface ensured that tracking errors and their derivatives converge to specified regions within predefined temporal bounds, irrespective of initial configurations. This overcomes the longstanding limitations of traditional prescribed performance control methods and contributes to enhancing system performance. Finally, we conducted comparative simulation experiments with existing sliding-mode control methods to prove the practical viability and comparative advantage of the synthesized control methodology. Full article

This work introduces a novel approach to extract beam bridge mode shapes using the residual response between consecutive contact points of vehicles passing through a bridge. A comprehensive investigation is conducted on several critical parameters, including window size, vehicle velocity, road roughness, and beam damping property, as well as the influence of traffic flow. To enhance the mode shape extraction performance using the approximate expression of the contact points’ displacements under noisy disturbance, two new signal denoising methods, CEEMDAN-NSPCA and CEEMDAN-IWT, are proposed based on complete ensemble empirical mode decomposition (CEEMDAN). CEEMDAN-NSPCA integrates CEEMDAN with principal component analysis and a coefficient-based filtering strategy. While CEEMDAN-IWT utilizes an improved wavelet thresholding technique with adaptive threshold selection. The numerical simulations demonstrate that both methods could effectively attenuate high-frequency noise with small amplitudes and retain low-frequency components. Among them, CEEMDAN-IWT exhibits superior denoising performance and greater stability, making it particularly suitable for robust modal identification in noisy environments. Full article

This study addresses the challenge of ride height control in linear motor-based active suspension systems by proposing a control strategy based on linear active disturbance rejection control (LADRC). The effectiveness of the proposed approach is experimentally validated using a high-precision test platform built on the NI cRIO-9014 real-time controller. The platform integrates a permanent magnet synchronous linear motor, a motor driver, acceleration sensors, and a vibration control system to realize closed-loop control of vehicle body height. Experimental results demonstrate that, compared with conventional PID control, LADRC achieves superior performance in height regulation accuracy, dynamic responsiveness, vertical acceleration suppression, and steady-state stability. In step response experiments, LADRC reduces the regulation time by 53.8% (from 1.3 s to 0.6 s) and lowers the steady-state error from 0.502 mm to 0.05 mm. In sinusoidal trajectory tracking tests, the LADRC approach reduces peak and RMS tracking errors by 81.5% and 80.3%, respectively. Moreover, under random road excitation, LADRC effectively attenuates high-frequency body vibrations, with reductions of 29.58% in peak vertical acceleration and 12.23% in RMS acceleration. Full article

Traditional control strategies for vibration suppression primarily focus on reducing settling time. However, this approach may not adequately address situations where the initial peak response of the vibration poses a risk of damage. This paper presents a novel application of active disturbance rejection control (ADRC) for attenuating the first-cycle peak response of free vibration in flexible structures. Inspired by the sudden impact scenario of particle accelerator collimators, a smart beam was designed to investigate the percentage first-cycle peak attenuation (FCPA) achievable by the disturbance estimation-based controller, in comparison with a classical proportional–differential (PD) controller. This study examined the limitations of the controller in mitigating initial deviations caused by real-world factors, such as delay and noise, through experimental methods. Results indicate that the PD controller achieves a maximum attenuation of 18%, while the ADRC achieves 30% attenuation. Improving the collocation configuration of the smart beam further improves the ADRC attenuation to 46.5%. Experimental data was used to fine-tune the system model in a sensitivity analysis to determine the delay within the system. Additionally, a new tuning parameter, α, representing the ratio of the observer bandwidth to controller bandwidth, was introduced to investigate the impact of observer and controller gain choices. System noise was amplified by 20 to 30 times, depending on the α value, although no significant effect on the control of the beam was observed. Full article