Search Results (2,192)

The sustainability of Arctic ecosystems that are extremely vulnerable is contingent upon the state of cryosoils. Understanding the principles of ecosystem stability in permafrost conditions, particularly under external natural or human-induced influences, necessitates an examination of the thermal and moisture regimes of the seasonally thawed soil layer. The study concentrated on the variability in the soil’s thermophysical properties in Central Siberia’s permafrost zone (the northern part of Krasnoyarsk Region, Taimyr, Russia). In the industrially affected area of interest, we evaluated and contrasted the differences in the thermophysical properties of soils between two opposing types of landscapes. On the one hand, these are soils that are characteristic of the natural landscape of flat shrub tundra, with a well-developed moss–lichen cover. An alternative is the soils in the landscape, which have exhibited significant degradation in the vegetation cover due to both natural and human-induced factors. The heat-insulating properties of background areas are controlled by the layer of moss and shrubs, while its disturbance determines the excessive heating of the soil at depth. In comparison to the background soil characteristics, degradation of on-ground vegetation causes the active layer depth of the soils to double and the temperature gradient to decrease. With respect to depth, we examine the changes in soil temperature and heat flow dynamics (q, W/m²). The ranges of thermal conductivity (λ, W/(m∙K)) were assessed using field-measured temperature profiles and heat flux values in the soil layers. The background soil was discovered to have lower thermal conductivity values, which are typical of organic matter, in comparison to the soil of the transformed landscape. Thermal diffusivity coefficients for soil layers were calculated using long-term temperature monitoring data. It is shown that it is possible to use an adjusted model of the thermal conductivity coefficient to reconstruct the dynamics of moisture content from temperature dynamics data. A satisfactory agreement is shown when the estimated ($W_{calc}$, %) and observed ($W_{exp}$, %) moisture content values in the soil layer are compared. The findings will be employed to regulate the effects on landscapes in order to implement sustainable nature management in the region, thereby preventing the significant degradation of ecosystems and the concomitant risks to human well-being. Full article

Ovarian cancer is a highly lethal malignancy, characterised by late-stage diagnosis, marked inter- and intra-tumoural heterogeneity, and frequent development of chemoresistance. Existing preclinical models, including conventional two-dimensional cultures, three-dimensional spheroids, and organoids, only partially recapitulate the structural and functional complexity of the ovarian tumour microenvironment (TME). Tumour-on-chip (CoC) technology has emerged as a promising alternative, enabling the co-culture of tumour and stromal cells within a microengineered platform that incorporates relevant extracellular matrix components, biochemical gradients, and biomechanical cues under precisely controlled microfluidic conditions. This review provides a comprehensive overview of CoC technology relevant to ovarian cancer research, outlining fabrication strategies, device architectures, and TME-integration approaches. We systematically analyse published ovarian cancer-specific CoC models, revealing a surprisingly limited number of studies and a lack of standardisation across design parameters, materials, and outcome measures. Based on these findings, we identify critical technical and biological considerations to inform the rational design of next-generation CoC platforms, with the aim of improving their reproducibility, translational value, and potential for personalised medicine applications. Full article

Accurate mapping of small water structures and streambeds is essential for hydrological modeling, erosion control, and landscape management. While traditional geodetic methods such as GNSS and total stations provide high precision, they are time-consuming and require specialized equipment. Recent advances in mobile technology, particularly smartphones equipped with LiDAR sensors, offer a potential alternative for rapid and cost-effective field data collection. This study assesses the accuracy of the iPhone 14 Pro’s built-in LiDAR sensor for mapping streambeds and retention structures in challenging terrain. The test site was the Dílský stream in the Oslavany cadastral area, characterized by steep slopes, rocky surfaces, and dense vegetation. The stream channel and water structures were first surveyed using GNSS and a total station and subsequently re-measured with the iPhone. Several scanning workflows were tested to evaluate field applicability. Results show that the iPhone LiDAR sensor can capture landscape features with useful accuracy when supported by reference points spaced every 20 m, achieving a vertical RMSE of 0.16 m. Retention structures were mapped with an average positional error of 7%, with deviations of up to 0.20 m in complex or vegetated areas. The findings highlight the potential of smartphone LiDAR for rapid, small-scale mapping, while acknowledging its limitations in rugged environments. Full article

Older adults are vulnerable to changes in sleep with age. Poor sleep quality is associated with self-reported cognitive changes, which can occur before the onset of objective cognitive decline associated with Mild Cognitive Impairment and Alzheimer’s disease. The objective of this study was to examine associations between self-reported sleep complaints, objective sleep quality, and self-reported cognitive changes and their relations to symptoms of depression and anxiety in a group of community-dwelling older adults. Adults aged ≥ 50 without dementia (n = 45) were recruited and completed 1–2 weeks of rest-activity monitoring using a wrist-worn device, underwent a test of global cognitive functioning (Mini-Mental State Examination; MMSE), and completed questionnaires assessing insomnia (Insomnia Severity Index; ISI), subjective sleep quality (Pittsburgh Sleep Quality Index; PSQI), self-reported cognitive changes (Cognitive Function Instrument; CFI), and symptoms of depression and anxiety (Beck Depression Inventory-II; BDI-II and Generalized Anxiety Disorder 7-item assessment; GAD-7). Pearson partial correlations assessed relations among subjective and objective sleep quality, insomnia ratings, CFI ratings, and global cognition, while controlling for BDI-II and GAD-7 ratings. Exploratory analyses examined the correlation between PSQI component scores and CFI ratings and global cognition. Greater ISI (r = 0.50, p ≤ 0.001) ratings significantly correlated with higher CFI scores. PSQI total ratings and actigraphy-based measures (n = 41) did not significantly correlate with CFI scores. Exploratory PSQI subscale analyses revealed that worse subjective sleep quality (r = 0.31, p = 0.048), shorter sleep duration (r = 0.32, p = 0.04), and greater use of sleep medications (r = 0.31, p = 0.048) correlated with higher CFI scores. Poorer sleep quality due to less time spent asleep, fragmented or disturbed sleep, and requiring medications to sleep, may be associated with greater memory concerns. Alternatively, worries about cognition may deleteriously affect sleep. Subjective measures of sleep quality may be useful to identify older adults at increased risk of cognitive decline. Full article

Introduction: Clear aligner therapy has become a mainstream alternative to fixed orthodontics due to its versatility. However, the variability in thermoforming and the limited validation of digital workflows remain major barriers to reproducibility and predictability. Methods: This study addresses that gap by presenting a proof-of-concept digital workflow for clear aligner manufacturing by integrating additive manufacturing (AM), thermoforming simulation, and finite element analysis (FEA). Dental models were 3D-printed and thermoformed under clinically relevant pressures (400 kPa positive and −90 kPa negative). Results and Discussion: Geometric accuracy was quantified using CloudCompare v2.13.0, showing that positive-pressure thermoforming reduced maximum deviations from 1.06 mm to 0.4 mm, with all deviations exceeding the expanded measurement uncertainty. Thickness simulations of PETG sheets (0.5 and 0.75 mm) showed good agreement with experimental values across seven validation points, with errors <10% and overlapping 95% confidence intervals. Stress analysis indicated that force transmission was localized at the aligner–attachment interface, consistent with expected orthodontic mechanics. Conclusion: By quantifying accuracy and mechanical behavior through numerical and experimental validation, this framework demonstrates how controlled thermoforming and simulation-guided design can enhance aligner consistency, reduce adjustments, and improve treatment predictability. Full article

Purpose: To investigate the efficacy of a novel test for diagnosing colour vision deficiencies using reflexive eye movements measured using an unmodified tablet. Methods: This study followed a cross-sectional design, where thirty-three participants aged between 17 and 65 years were recruited. The participant group comprised 23 controls, 8 deuteranopes, and 2 protanopes. An anomaloscope was employed to determine the colour vision status of these participants. The study methodology involved using an Apple iPad Pro’s built-in eye-tracking capabilities to record eye movements in response to coloured patterns drifting on the screen. Through an automated analysis of these movements, the researchers estimated individuals’ red–green equiluminant point and their equivalent luminance contrast. Results: Estimates of the red–green equiluminant point and the equivalent luminance contrast were used to classify participants’ colour vision status with a sensitivity rate of 90.0% and a specificity rate of 91.30%. Conclusions: The novel colour vision test administered using an unmodified tablet was found to be effective in diagnosing colour vision deficiencies and has the potential to be a practical and cost-effective alternative to traditional methods. Translation Relevance: The test’s objectivity, its straightforward implementation on a standard tablet, and its minimal requirement for patient cooperation, all contribute to the wider accessibility of colour vision diagnosis. This is particularly advantageous for demographics like children who might be challenging to engage, but for whom early detection is of paramount importance. Full article

Within the modernizing energy infrastructure of today, the integration of renewable energy sources and direct current (DC)-powered technologies calls for the re-examination of traditional alternative current (AC) networks. Low-voltage DC (LVDC) grids offer an attractive way forward in reducing conversion losses and simplifying local power management. However, ensuring reliable operation depends on a thorough understanding of DC distortions—phenomena generated by power converters, source instability, and varying loads. Two complementary traceable measurement chains are presented in this article with the purpose of measuring the steady-state DC component and the amplitude and frequency of the distortions around the DC bus with low uncertainties. One chain is optimized for laboratory environments, with high effectiveness in a controlled setup, and the other one is designed as a flexible and easily transportable solution, ensuring efficient and accurate assessments of DC distortions for field applications. In addition to our hardware solutions fully characterized by the uncertainty budget, we present the measurement method used for assessing DC distortions after evaluating the limitations of conventional AC techniques. Both arrangements are set to measure voltages of up to 1000 V, currents of up to 30 A, and frequency components of up to 150–500 kHz, with an uncertainty varying from 0.01% to less than 1%. This level of accuracy in the measurements will allow us to draw reliable conclusions regarding the dynamic behavior of future LVDC grids. Full article

Background/Objectives: Dyslipidemia is becoming a significant economic healthcare burden in low- to middle-income countries (LMICs) due to its role in heightening cardiovascular-related mortality. Statins are the first-line treatment for reducing LDL-C levels, thereby minimizing direct costs associated with cardiovascular disease management, with pitavastatin being of the newest generation of statins. This research work conducted a cost-utility analysis of pitavastatin to determine the economic benefit in Vietnam. Methods: A decision tree model was developed to compare the rate of LDL-C controlled patients over a lifetime horizon among patients treated with pitavastatin, atorvastatin, and rosuvastatin. The primary outcome was the incremental cost-effectiveness ratio (ICER), measured from the healthcare system perspective. Effectiveness was evaluated in terms of quality-adjusted life years (QALYs), using an annual discount rate of 3%. A one-way sensitivity analysis was performed to identify the key input parameters that most influenced the ICER outcomes. Results: Pitavastatin was cost-effective compared to atorvastatin but was dominated by rosuvastatin. Although pitavastatin gained fewer QALYs than atorvastatin, the ICER was 195,403,312 VND/QALY, well below Vietnam’s 2024 willingness-to-pay. Drug cost had the most significant impact on ICERs. Conclusions: Pitavastatin represents an economical short-term alternative to atorvastatin, particularly in resource-constrained settings. Full article

This paper presents a novel mechanically beam-steered antenna system for 10 GHz applications, enabled by multi-material 3D-printing technology. The proposed design eliminates the need for complex electronic circuitry by integrating a mechanically rotatable, 3D-printed hemispherical lens with a conventional rectangular patch antenna. The system comprises three main components: a 10-GHz patch antenna, a precision-fabricated hemispherical dielectric lens produced via stereolithography (SLA), and a structurally robust rotation assembly fabricated using fused deposition modeling (FDM). The mechanical rotation of the lens enables discrete beam-steering from −45° to +45° in 5° steps. Experimental results demonstrate a gain improvement from 6.21 dBi (standalone patch) to 10.47 dBi with the integrated lens, with minimal degradation across steering angles (down to 9.59 dBi). Simulations and measurements show strong agreement, with the complete system achieving 94% accuracy in beam direction. This work confirms the feasibility of integrating additive manufacturing with passive beam-steering structures to deliver a low-cost, scalable, and high-performance alternative to electronically scanned arrays. Moreover, the design is readily adaptable for motorized actuation and closed-loop control via embedded systems, enabling future development of real-time, programmable beam-steering platforms. Full article

Several broad ecological analyses have been conducted, mostly in urban settings in Europe and North America, suggesting that air pollution may be associated with greater severity of SARS-CoV-2 infection. Following the identification of possible measurement and confounding biases, we review published studies using alternative study designs, whose main finding was a crude association between COVID-19 severity and PM_2.5 long-term exposure. These preliminary studies are lacking adequate control for confounders and data for other major pollutants. Their results are inconsistent regarding short-term exposures, and virtually all were from high-income countries, limiting their generalizability. We consider the role of alternative study designs in elucidating further such a potential association, by using individual baseline and health outcome data and epidemiological methods to control for potential confounders. To further investigate the role of air pollution in COVID-19 severity between early 2020 and late 2021, we propose to design retrospectively case–control and case-crossover studies using data from public health and air pollution registries, as these may represent the best compromise between validity, reproducibility, and cost. Public health and air pollution registries may provide adequate data sources in industrialized countries and some middle-income countries, facilitating the study of air pollution and COVID-19. Full article

Background/Objectives: Whole-body vibration (WBV) has been widely studied for its effects on neuromuscular activation, circulation, and balance. This study investigates the effect of wearing frequency of vibrating sneakers (18 Hz) on lower limb muscle activation during walking and squatting in middle-aged Koreans (40–60 years old). The objective is to assess whether WBV footwear enhances muscle engagement in both active and sedentary individuals. Methods: A 16-week randomized controlled trial was conducted with 64 participants divided into exercise (walking 30 min, three times a week) and non-exercise groups. Each group was further divided into wearing and non-wearing vibrating sneaker subgroups. Muscle activation of the quadriceps and gastrocnemius was measured using surface electromyography before and after the intervention. Results: Participants wearing vibrating sneakers showed significantly increased quadriceps and gastrocnemius activation during squatting and walking compared to non-wearers (p < 0.05). The exercise group wearing WBV sneakers exhibited greater improvements in muscle activation than the non-exercise group, indicating that WBV enhances the benefits of regular walking. However, no significant differences were observed in some lower leg muscles, suggesting that WBV effects may vary based on movement type and muscle group. Conclusions: Findings suggest that WBV sneakers (18 Hz) can enhance muscle activation during dynamic movements, potentially offering a low-impact training alternative for improving lower limb strength. These results provide valuable insights for exercise professionals, rehabilitation specialists, and wearable sensor developers, highlighting the potential of WBV footwear in neuromuscular conditioning and injury prevention. Full article

This study investigated the microbiological, physicochemical, textural, and sensory characteristics of ayran and kefir samples produced from milk treated with different doses of UV-C radiation. For this purpose, raw milk was passed through a UV-C column at three different flow rates (15, 30, and 45 mL/min), and irradiated with doses of 72, 36, and 24 J/mL, respectively, corresponding to the flow rate. Samples produced from milk pasteurised by thermal treatment were used as the control group. This research indicated that UV-C treatment effectively reduced the microbial load in milk to a level comparable to that achieved through conventional pasteurisation. A reduction of 2.15 log cfu/mL in total aerobic mesophilic bacteria count was achieved, while total coliform group bacteria counts were decreased to an undetectable level. Samples produced from milk treated with UV-C showed lower pH and higher titration acidity (% lactic acid). Furthermore, the organic acid content was higher in these samples. Lactic acid, the main organic acid, levels in the ayran and kefir samples were measured at their highest as 11,951.51 mg/kg and 12,989.34 mg/kg, respectively, in the UV45 sample with a radiation dose of 24 J/mL. The treatment of UV-C resulted in a minor change in the colour and textural properties of the samples. Nonetheless, this change was not significant enough to influence consumer acceptance. The application of UV-C to raw milk, depending on the radiation level used, can enhance the fermentation process in the production of ayran and kefir. This study showed that the application of UV-C has improved the quality of drinkable fermented milk products. This research has shown that, while reducing nutritional losses caused by thermal processing, microbial safety is obtained at an approximate value similar to pasteurisation. As a result, UV-C application decreases the loss of dietary compounds and provides an alternative method for microbial inactivation. Full article

Purpose: While peak oxygen uptake ($\stackrel{.}{\mathrm{V}}$O_2peak) is the gold standard method for assessing exercise tolerance, there is a tendency for underestimation. Several other cardiopulmonary exercise testing (CPET) variables may provide additive prognostic value beyond $\stackrel{.}{\mathrm{V}}$O_2peak alone. The aim of this study was to examine if alternative CPET indices of exercise tolerance are (a) impaired in people with T2D and (b) independently associated with measures of cardiovascular structure and function measured via echocardiography and cardiac MRI. Methods: Participants with type 2 diabetes (T2D) and healthy controls underwent cardiac magnetic resonance imaging, transthoracic echocardiography, and a CPET. Multiple linear regression was used to determine the relationship between indices of exercise tolerance and markers of cardiovascular structure and function. Results: A total of 84 people with T2D and 36 healthy volunteers were included in the analysis. All CPET outcomes were worse in those with T2D vs. the controls. Three CPET outcomes were associated with markers of cardiovascular structure and function: $\stackrel{.}{\mathrm{V}}$O₂ recovery with mean aortic distensibility (β = 0.218, p = 0.049); heart rate recovery with early filling velocity on transmitral Doppler/early relaxation velocity (β = −0.270, p = 0.024), left ventricular mass/volume ratio (β = −0.248, p = 0.030) and mean aortic distensibility (β = 0.222, p = 0.029); and $\stackrel{.}{\mathrm{V}}$O₂ at the ventilatory threshold with myocardial perfusion reserve (β = 0.273, p = 0.018). Perspective: These lesser-used CPET indices could be used to identify which people with T2D are at elevated risk of progression to symptomatic heart failure. However, larger longitudinal studies are required to confirm these findings and their potential clinical application. Full article

Background: Total hip and knee arthroplasty are common procedures for end-stage osteoarthritis, with rehabilitation playing a central role in functional recovery. Conventional face-to-face programs are often limited by accessibility, costs, and logistical barriers. Digital telerehabilitation has been increasingly investigated as an alternative. This review aims to summarize current evidence on its effectiveness, patient-reported outcomes, satisfaction, and economic impact. Materials and Methods: A narrative review was conducted using Medline, Web of Science, and Scopus up to April 2025. Randomized controlled trials and longitudinal studies evaluating telerehabilitation after total hip or knee arthroplasty were included. Data were extracted on functional performance, pain, autonomy, quality of life, patient satisfaction, and cost-effectiveness. Results: Across multiple RCTs, telerehabilitation produced functional outcomes generally comparable to conventional rehabilitation, with some studies reporting superior short-term improvements. For example, in a retrospective trial, Timed Up and Go improved by −8.0 ± 2.6 s in the digital group versus −4.9 ± 2.5 s with standard care (p < 0.01). Tablet-assisted programs reduced Five Times Sit-to-Stand times to 11.7 s at 6 months compared with 14.7 s in controls (p = 0.05). In hip arthroplasty, digital rehabilitation resulted in higher active flexion (97.4° vs. 89.9°, p = 0.018) and abduction (51.7° vs. 43.8°, p = 0.024). Quality-of-life measures, such as EQ-5D VAS, also showed improvements (82.9 ± 4.3 vs. 68.7 ± 4.6 at 6 months). Some studies reported higher patient satisfaction, for instance, a VR-based RCT found GPE at day 15 of 4.76 ± 0.43 in the intervention group versus 3.96 ± 0.65 in controls (p < 0.001). Conclusions: Telerehabilitation after hip and knee arthroplasty appears to produce short-term functional and patient-reported outcomes comparable to conventional rehabilitation in selected populations. Evidence of superiority is limited and heterogeneous, and long-term effectiveness, equity, and cost-effectiveness remain uncertain. Heterogeneity in protocols and digital literacy barriers highlight the need for standardized guidelines and further independent validation. Full article

Frequent and severe droughts intensify water scarcity in arid and semi-arid regions, creating an urgent need for alternative water resources in agriculture. Treated wastewater (TWW) has emerged as a sustainable option; however, its long-term use may alter soil properties and pose risks if not carefully managed. This study tested the hypothesis that long-term TWW irrigation increases soil salinity, alters fertility, and affects microbial quality, with rainfall partially mitigating these effects. Soil samples (n = 96 at each time point) were collected from two calcareous soils in Jordan, silt loam (Mafraq) and silty clay loam (Ramtha), under four treatments (control and 2, 5, and 10 years of TWW irrigation) at three depths (0–30, 30–60, and 60–90 cm). Sampling was conducted at two intervals, before and after rainfall, to capture the seasonal variation. Soil indicators included the pH, electrical conductivity (EC), sodium (Na⁺), chloride (Cl⁻), calcium (Ca²⁺), magnesium (Mg²⁺), exchangeable sodium percentage (ESP), sodium adsorption ratio (SAR), organic matter (OM), total nitrogen (TN), and microbial parameters (total coliforms (TC), fecal coliforms (FC), and Escherichia coli). Data were analyzed using a linear mixed-effects model with repeated measures, and significant differences were determined using Tukey’s Honest Significant Difference (HSD) test at p < 0.05. The results showed that rainfall reduced Na⁺ by 70%, Cl⁻ by 86%, EC by 73%, the ESP by 28%, and the SAR by 30%. Furthermore, the TC and FC concentrations were diminished by almost 96%. Moderate TWW irrigation (5 years) provided the most balanced outcomes across both sites. This study provides one of the few long-term field-based assessments of TWW irrigation in semi-arid calcareous soils of Jordan, underscoring its value in mitigating water scarcity while emphasizing the need for monitoring to ensure soil sustainability. Full article