Search Results (415)

This paper presents the novel, smart, commutable, and self-regulated SSF-Roundabout as one of the potential solutions in the environment of smart mobility. The SSF-Roundabout implements traffic counting systems, smart cameras, LED road markers, and Variable Message Signs (VMS) on arms. Based on the instantaneous detection of the traffic demand level, vehicles can be properly channelled or not into right-turn bypass lanes, which the roundabout is equipped with in every arm, to guarantee the requested capacity, Level of Service (LOS), and safety. In total, fifteen very different layout configurations of the SSF-Roundabout are available. Several traffic analyses were performed by using ad hoc traffic engineering closed-form models and case studies based on many origin-destination traffic matrices (M_O/D(t)) and proportions of CAVs in the traffic stream (from 0% to 100%). Simulation results demonstrate the correlation between layout scenarios, traffic intensity, distribution among arms, and composition in terms of CAVs and their impact on entry and total capacity, control delay, and LOS of the SSF-Roundabout. For instance, the right-turn bypass lane activation may produce an entry capacity increase of 48% and a total capacity increase of 50% in the case of 100% of CAVs in traffic streams. Full article

Introduction: It has been recently demonstrated that some cerebral microbleeds (CMBs) are connected to cerebral veins in patients with cerebral small vessel disease (CSVD) including cerebral amyloid angiopathy (CAA). We sought to demonstrate the presence of CMB at 3 Tesla using susceptibility-weighted imaging and speculated that it was more prevalent in persons with Alzheimer’s disease (AD), another amyloid-related disease, than in healthy ageing controls. Material and Methods: We included persons from the publicly available OASIS3-database. Persons were included if they had a structural MRI including a susceptibility-weighted sequence (SWI) and relevant clinical data. Two raters assessed the presence and location of CMBs and CMBs with a venous connection (CMB_ven). Results: A total of 571 persons (AD, n = 140, healthy controls, n = 431) were included. In total, 367 CMBs were detected, encompassing 26/571 persons (4.5%) who had a total of 40/367 (10.9%) CMBs with a CMB_ven, though there was no difference between persons with AD and healthy controls (AD 6.6%, healthy controls 7.4%, p = 0.773). Persons with CMB_ven had a higher total CMB load, were more likely female, displayed an APOE ε2/2 genotype and had antithrombotic treatment more often. Logistic regression revealed a higher number of CMB (OR (95% CI) = 1.351 (1.161–1.688), p < 0.0014) and a lower MoCA score (OR (95% CI) = 0.862 (0.762–0.982), p = 0.018), indicating a statistically significant association with the presence of CMB_ven. Discussion: CMB_ven are not an uncommon finding in persons with AD and healthy ageing controls. Our results highlight the potential venous contribution to CSVD. Histopathological studies will be needed to assess these further. Full article

This paper presents a novel multi-sensor system for enhanced maneuver analysis in Olympic dinghy sailing. In the ILCA class, there is an increasing demand for precise in-field measurement and analysis of physical properties beyond well-established velocity and course metrics. The low-cost setup presented in this study consists of a combination of commercially available sensor systems, such as the AdMos sensor for IMU and GNSS measurement, in combination with custom measurement systems for rudder and mast rotations using fully waterproofed potentiometers. Data streams are synchronized using GNSS time stamping for streamlined analysis. The resulting analysis presents a selection of 12 upwind tacks, with corresponding path overlays, detailed timeseries data, and performance metrics. The system has demonstrated the value of extended data analysis of in situ data with an elite ILCA 7 sailor. The addition of rudder and mast rotations has enabled enhanced analysis of on-water maneuvers for single-handed Olympic dinghies like the ILCA 7, on a level of detail previously reserved for simulated environments. Full article

Background: This systematic review investigates the role of virtual reality (VR)-based multisensory cognitive training in cognitive function, executive function and wayfinding ability among people diagnosed with mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Methods: The review was carried out using PRISMA guidelines. PubMed, Scopus, Embase, and Google Scholar were searched up from inception to February 2025 using terms related to MCI, AD, VR, and cognitive functions. Studies were included if they involved participants with MCI or early AD, used VR-based training, collected baseline data, and reported cognitive outcomes. Results: Nine studies with MCI were included, but no eligible studies focused on AD. Seven out of nine eligible studies in MCI reported significant improvements in global cognitive function (MoCA, CERAD-K, MMSE). Some studies showed improvements in executive function (EXIT-25, TMT-A/B, and SCWT), while others found no significant differences. One study reported improved depression/mental status (GDS, MOSES, QoL-AD). Just one study reported improvement in functional ability (IADL). One study reported enhanced cognition and reduced discomfort (SSQ). VR programs were generally well-tolerated, with no significant adverse events reported. Conclusions: VR shows promise for improving cognitive function in MCI. VR also showed potential benefits in executive function and psychological outcomes like depression and quality of life, though consistency varied. Full article

Background/Objectives: Neuromodulation is under investigation as a possibly effective add-on therapy in Alzheimer’s disease (AD). While transcranial pulse stimulation (TPS) has shown positive short-term effects, long-term effects have not yet been fully explored. This study aims to evaluate the long-term feasibility, safety, and potential cognitive benefits of TPS over one year in patients with Alzheimer’s disease, focusing on domains such as memory, speech, orientation, visuo-construction, and depressive symptoms. Methods: We analyzed preliminary data from the first ten out of thirty-five patients enrolled in a prospective TPS study who completed one year of follow-up and were included in a dedicated long-term database. The protocol consisted of six initial TPS sessions over two weeks, followed by monthly booster sessions delivering 6000 pulses each for twelve months. Patients underwent regular neuropsychological assessments using the Alzheimer Disease Assessment Scale (ADAS), Mini-Mental Status Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Beck Depression Inventory (BDI-II). All adverse events (AEs) were documented and monitored throughout the study. Results: Adverse events occurred in less than 1% of stimulation sessions and mainly included mild focal pain or transient unpleasant sensations, as well as some systemic behavioral or vigilance changes, particularly in patients with underlying medical conditions, with some potentially related to the device’s stimulation as adverse device reactions (ADRs). Cognitive test results showed significant improvement after the initial stimulation cycle (ADAS total improved significantly after the first stimulation cycle (M_pre = 28.44, M_post = 18.56; p = 0.001, d = 0.80, 95% CI (0.36, 1.25)), with stable scores across all domains over one year. Improvements were most notable in memory, speech, and mood. Conclusions: TPS appears to be a generally safe and feasible add-on treatment for AD, although careful patient selection and monitoring are advised. While a considerable number of participants were lost to follow-up for various reasons, adverse events and lack of treatment effect were unlikely primary causes. A multifocal stimulation approach (F-TOP2) is proposed to enhance effects across more cognitive domains. Full article

To address the issues of hydrogen embrittlement, creep, and fatigue that commonly occur in the welds of hydrogen production reactor operating under hydrogen exposure, high temperature and high pressure, this study proposes adding Si and Mo as reinforcing elements to the welding materials to enhance weld performance. Given the varying performance requirements of different weld layers in the stacked weld, a gradient performance optimization method for the stacked weld of hydrogen production reactors based on the response surface methodology (RSM)–genetic algorithm (GA) is proposed. Using tensile strength, the hydrogen embrittlement sensitivity index, fatigue strain strength, creep rate and weld performance evaluation indices, a high-precision regression model for Si and Mo contents and weld performance indices was established through RSM and analysis of variance (ANOVA). A multi-objective optimization mathematical model for gradient improvement of the stacked weld was also established. This model was solved using a GA to obtain the optimal element content combination added to the welding wire and the optimal weld thickness for each weld layer. Finally, submerged arc welding experiments of the stacked weld were conducted according to the optimization results. The results show that the tensile strength of the base layer, filling layer and cover layer of the stacked weld increased by 5.60%, 6.16% and 4.53%, respectively. Hydrogen embrittlement resistance increased by 70.56%, 52.40% and 45.16%, respectively. The fatigue and creep resistance were also improved. The experimental results validate the feasibility and accuracy of the proposed optimization method. Full article

To enhance the mechanical properties of NbMoTaW refractory high-entropy alloys (RHEAs), Si was added at varying concentrations (x = 0, 0.25, and 0.5) via vacuum induction levitation melting (re-melted six times for homogeneity). The microstructure and mechanical properties of NbMoTaWSi_x (x = 0, 0.25, and 0.5) RHEAs were characterized using scanning electron microscopy (SEM), universal testing, microhardness testing, and tribological equipment. Experimental results manifested that Si addition induces the formation of the (Nb,Ta)₅Si₃ phase, and the volume fraction of the silicide phase increases with higher Si content, which significantly improves the alloy’s strength and hardness but deteriorates its plasticity. Enhanced wear resistance with Si addition is attributed to improved hardness and oxidation resistance. Tribological tests confirm that Si₃N₄ counterfaces are optimal for evaluating RHEA wear mechanisms. This work can provide guidance for the fabrication of RHEAs with excellent performance. Full article

Maternal obesity programs the fetus for increased risk of chronic disease development in early life and adulthood. We hypothesized that maternal nutrient excess leads to fetal inflammation and impairs offspring skeletal muscle mitochondrial biogenesis in non-human primates. At least 12 months before pregnancy, female baboons were fed a normal chow (CTR, 12% energy fat) or a maternal nutrient excess (MNE, 45% energy fat, and ad libitum fructose sodas) diet, with the latter to induce obesity. After 165 days of gestation (0.9 G), offspring baboons were delivered by cesarean section, and the soleus muscle was collected (CTR n = 16, MNE n = 5). At conception, MNE mothers presented increased body fat and weighed more than controls. The soleus muscle of MNE fetuses exhibited increased levels of stress signaling associated with inflammation (TLR4, TNFα, NF-kB p65, and p38), concomitant with reduced expression of key regulators of mitochondrial biogenesis, including PGC1α, both at the protein and transcript levels, as well as downregulation of PPARGC1B, PPARA, PPARB, CREB1, NOS3, SIRT1, SIRT3. Decreased transcript levels of NRF1 were observed alongside diminished mitochondrial DNA copy number, mitochondrial fusion elements (MFN1, MFN2), cytochrome C protein levels, and cytochrome C oxidase subunits I and II transcripts (cox1 and cox2). MNE coupled to MO-induced stress signaling in fetal baboon soleus muscle is associated with impaired mitochondrial biogenesis and lower mitochondrial content, resembling the changes observed in metabolic dysfunctions, such as diabetes. The observed fetal alterations may have important implications for postnatal development and metabolism, potentially increasing the risk of early-onset metabolic disorders and other non-communicable diseases. Full article

This article presents a review of the composition optimization progress of nickel-based single crystal (SC) superalloy design in recent years in order to obtain better high-temperature performance for the development of the aviation industry. The influence of alloying elements on the creep resistance, microstructure characteristics, oxidation resistance, castability, density, and cost of superalloys is analyzed and discussed. In order to obtain better high-temperature performance, the content of refractory elements (Ta + Re + W + Mo) and Co was increased gradually. The addition of Ru was added in the fourth-generation nickel-based SC superalloy to stabilize the microstructures and suppress the precipitation of the topologically close-packed (TCP) phase. However, the content of the antioxidant element Cr significantly decreased, while the synergistic effect of Al, Cr, and Ta received more attention. Therefore, synergistic effects should also receive more attention to meet the practical needs of reducing the content of refractory elements to reduce costs and density in future single crystal alloy designs without compromising critical performance. Full article

Nickel matrix composites reinforced with T15 high-speed steel (HSS) were prepared using powder metallurgy techniques. A systematic investigation was conducted into the effect of CeO₂, MoS₂, and graphite additives on the tribological properties of the composites. The results show that when T15 HSS particles are added, nickel grains do not grow as much as they do in pure sintered nickel. It was also observed that the T15 HSS particles were diffusion-bonded to the nickel matrix after sintering. The highest relative density after sintering is obtained for composites containing graphite, but the maximum hardness of 243 HV can be achieved for composites containing 2% of CeO₂, which is about 16% higher than that of the Ni-T15 HSS composite. The wear rate of Ni-T15 HSS composites reduces from 3.4782 × 10⁻⁷ cm³/N∙m to 2.0222 × 10⁻⁷ cm³/N∙m as the content of CeO₂ rises from 0 wt.% to 2 wt.%. The wear mechanisms of composites with MoS₂ or graphite are abrasive wear and adhesive wear. The introduction of CeO₂ enhances the hardness of the investigated composites to the highest degree, leading to a change in the wear mechanism of the composites to slight abrasive wear. The addition of CeO₂ can effectively optimize the tribological properties of Ni-T15 HSS composites. Full article

This study investigates the effects of molybdenum (Mo) additions on the crystallization behavior and soft magnetic properties and of Fe_82-xSi₄B₁₂Nb₁Mo_xCu₁ (x = 0–2) nanocrystalline alloys. Molybdenum enhances glass-forming ability (GFA) and magnetic properties by increasing negative mixing enthalpy ($∆{\mathrm{H}}_{\mathrm{m}\mathrm{i}\mathrm{x}}$), mixing entropy ($∆{\mathrm{S}}_{\mathrm{m}\mathrm{i}\mathrm{x}}$), and atomic size mismatch ($\delta$), which stabilize the amorphous phase. X-ray diffraction (XRD) analysis shows that Mo addition improves amorphous phase stability, further enhancing GFA. The simultaneous addition of Mo and Nb increases mixing entropy, promotes nucleation rates, and creates favorable conditions for optimizing nanocrystallization. Upon annealing, this optimized microstructure demonstrated low coercivity and high permeability. Notably, the Fe₈₀Si₄B₁₂Nb₁Mo₂Cu₁ ribbon, annealed at 470 °C for 10 min, exhibited exceptional soft magnetic properties, with a coercivity of 4.54 A/m, a maximum relative permeability of 48,410, and a saturation magnetization of 175.24 emu/g. High-resolution transmission electron microscopy (TEM) revealed an average crystal size of 18.16 nm. These findings suggest that Fe_82-xSi₄B₁₂Nb₁Mo_xCu₁ (x = 0–2) nanocrystalline alloys are suitable for advanced electromagnetic applications pursuing miniaturization and high efficiency. Full article

Background/Objectives: T1-weighted magnetic resonance imaging (MRI) and the Montreal Cognitive Assessment are standard, efficient, and swift clinical and research tools used when interrogating cognitively impairing (CI) conditions, such as Mild Cognitive Impairment (MCI) and Alzheimer’s disease (AD). However, the associations between gross cognitive impairment (CI) as compared to domain-specific functioning and underlying neuroanatomical correlates have not been investigated among individuals with early-onset Mild Cognitive Impairment (MCI) or Alzheimer’s disease (EOAD), who can benefit greatly from early diagnosis and intervention strategies. Methods: We analyzed T1-weighted MRIs and Montreal Cognitive Assessment (MoCA) scores from the ADNI database in individuals < 65 years old who were either cognitively normal (CN) or had MCI or EOAD. Gray matter volume (GMV) was estimated in voxel-based morphometry (VBM) and ROI-parcellation general linear models examining associations with individual MoCA scores after adjusting for demographic covariates. Results: Results from 120 subjects (44 CN, 62 MCI, and 14 EOAD), identified significant global but also individually distinct domain-specific topographical signatures spanning the temporal, parietal, limbic, occipital, frontal lobes, and cingulate gyri. Conclusions: The results highlight neural correlates of cognitive functioning in a sample of young patients representative of the AD continuum, in addition to studying the structural MRI and functional cognitive difference. Full article

This study investigates the effect of boron carbide (B₄C) ceramic reinforcement on the microstructural, mechanical, electrical, and electrochemical properties of CoCrMo, Ti, and 17-4 PH alloys produced via powder metallurgy for potential biomedical applications. A systematic experimental design was employed, incorporating varying B₄C contents into each matrix through mechanical alloying, cold pressing, and vacuum sintering. The microstructural integrity and dispersion of B₄C were examined using scanning electron microscopy. The performance of the materials was evaluated using several methods, including Vickers hardness, pin-on-disk wear testing, ultrasonic elastic modulus measurements, electrical conductivity, and electrochemical assessments (potentiodynamic polarization and EIS). This study’s findings demonstrated that B₄C significantly enhanced the hardness and wear resistance of all alloys, especially Ti- and CoCrMo-based systems. However, an inverse correlation was observed between B₄C content and corrosion resistance, especially in 17-4 PH matrices. Ti-5B₄C was identified as the most balanced composition, exhibiting high wear resistance, low corrosion rate and elastic modulus values approaching those of human bone. Weibull analysis validated the consistency and reliability of key performance metrics. The results show that adding B₄C can change the properties of biomedical alloys, offering engineering advantages for B₄C-reinforced biomedical implants. Ti-B₄C composites exhibit considerable potential for application in advanced implant technologies. Full article

Background/Objectives: Cognitive impairment and vestibular dysfunction commonly co-occur in older adults and may share overlapping neuroanatomical pathways. Understanding their association may enhance the early identification of cognitive decline using clinically feasible vestibular assessments. This study aimed to examine the relationship between vestibular dysfunction and early cognitive impairment, assess the diagnostic accuracy of vestibular markers, and explore the association of subjective dizziness and balance measures with cognitive performance. Methods: Our cross-sectional study included 90 participants aged ≥60 years, classified into cognitively healthy, mild cognitive impairment (MCI), and early Alzheimer’s disease (AD) groups. Cognitive function was assessed using the MoCA and the MMSE; vestibular function was evaluated via posturography sway and horizontal vHIT gain. Subjective dizziness and balance were measured using the Dizziness Handicap Inventory (DHI), gait speed, and eyes-closed balance time. The data were analyzed using SPSS v24 with ANOVA, Pearson correlations, linear regression, and ROC curve analyses. Results: Significant group differences were found across the cognitive and vestibular scores (MoCA: p = 0.001. Sway: p = 0.001. vHIT: p = 0.001). vHIT gain and posturography sway independently predicted the MoCA and MMSE scores (adjusted R² = 0.68 and 0.65, respectively). The ROC analysis showed a strong diagnostic accuracy for posturography sway (AUC = 0.87) and vHIT gain (AUC = 0.82). Conclusions: Vestibular dysfunction is significantly associated with early cognitive impairment and may serve as a useful clinical marker for cognitive screening in older adults. Full article

This paper introduces a high-efficiency buck converter designed for a wide load range, targeting low-power applications in medical devices, smart homes, wearables, IoT, and technology utilizing WiFi and Bluetooth. To achieve high efficiency across varying loads, the proposed converter employs a low-power adaptive on-time (AOT) controller that ensures output voltage stability and seamless mode transitions. An adaptive comparator (ACP) with variable output impedance is introduced, offering a variable DC gain and bandwidth to be suitable for different load conditions. A negative-level shifter (NLS) circuit, with its swing ranging from −0.5 V to the battery voltage (V_BAT), is proposed to control the smaller power p-MOS transistors. By using an NLS, the chip area, which is mostly occupied by power CMOS transistors, is reduced while the power efficiency is improved, particularly under a heavy load. A status time detector (STD) block which provides control signals to the ACP and NLS for optimized power consumption is added to identify load conditions (heavy, light, ultra-light). By employing a 180 nm CMOS technology, the active chip area occupies about 0.31 mm². With an input voltage range of 2.8–3.3 V, the controller’s current consumption ranges from 1.2 μA to 16 μA, corresponding to the output load current varying from 12 μA to 120 mA. Although the output load can vary, the output voltage is regulated at 1.2 V with a ripple between 3 and 12 mV. The proposed design achieves a peak efficiency of 96.2% under a heavy load with a switching frequency of 1.3 MHz. Full article