Search Results (857)

The Czech Republic and Poland are struggling with problems related to the development of photovoltaics. Both analyzed countries had periods of dynamic development of this renewable energy source (RES). However, neither the Czech Republic nor Poland have developed mechanisms that would lead to the stable development of photovoltaic installations in the long term. The analyses presented in this article demonstrate the implementation of extreme solutions by these countries, which led either to stagnation in the development of photovoltaics or to an excessive increase in the installed capacity, including RES, which then had to be stopped due to, for example, the failure of the power grids to match the increasing capacity. This article conducted research based on secondary data and using the Foresight method. The aim of this manuscript is to present the conditions related to the development of photovoltaics in the Czech Republic and Poland. This article also points to the barriers limiting the development of this type of RES and the potential of solutions related to, e.g., energy storage, which will allow for maintaining stable development of photovoltaics in the future and will prevent excessive overloading of power grids. The research results indicate that in the context of further development of photovoltaics in the study area, what is important are, e.g., changes in legal regulations and financial incentives that will enable the development of micro-installations within energy communities to a greater extent, including co-financing for energy storage. Other factors were also noted, including interconnection capacity within the energy systems of these countries, as well as externally. Full article

Seismic wave propagation in complex terrains, especially in the presence of air layers, plays a crucial role in accurate subsurface imaging. However, the influence of different boundary conditions on seismic wave propagation characteristics has not been fully explored. This study employs the finite element method (FEM) to simulate and analyze seismic wavefields under different boundary conditions, including perfectly matched layer (PML), Neumann free boundary conditions, and air layer conditions. First, the finite element solution for the 2D frequency-domain acoustic wave equation is introduced, and the correctness of the algorithm is validated using a homogeneous model. Then, both horizontal and undulating terrain interfaces are designed to investigate the kinematic and dynamic characteristics of the wavefields under different boundary conditions. The results show that PML boundaries effectively absorb seismic waves, prevent reflections, and ensure stable wave propagation, making them an ideal choice for simulating open boundaries. In contrast, Neumann boundaries generate significant reflected waves, particularly in undulating terrains, complicating the wavefield characteristics. Introducing an air layer alters the dynamics of the wavefield, leading to energy leakage and multi-path effects, which are more consistent with real-world seismic-geophysical models. Finally, the computational results using the Overthrust model under different boundary conditions further demonstrate that different boundary conditions significantly affect wavefield morphology. It is essential to select appropriate boundary conditions based on the specific simulation requirements, and boundary conditions with an air layer are most consistent with real seismic geological models. This study provides new insights into the role of boundary conditions in seismic numerical simulations and offers theoretical guidance for improving the accuracy of wavefield simulations in realistic geological scenarios. Full article

The development of China’s digital waterways has led to the extensive deployment of cameras along inland waterways. However, the limited processing and utilization of digital resources hinder the ability to provide waterway services. To address this issue, this paper introduces a novel waterway perception approach based on an intelligent navigation marker system. By integrating multiple sensors into navigation markers, the fusion of camera video data and automatic identification system (AIS) data is achieved. The proposed method of an enhanced one-stage object detection algorithm improves detection accuracy for small vessels in complex inland waterway environments, while an object-tracking algorithm ensures the stable monitoring of vessel trajectories. To mitigate AIS data latency, a trajectory prediction algorithm is employed through region-based matching methods for the precise alignment of AIS data with pixel coordinates detected in video feeds. Furthermore, an augmented reality (AR)-based traffic situational awareness framework is developed to dynamically visualize key information. Experimental results demonstrate that the proposed model significantly outperforms mainstream algorithms. It achieves exceptional robustness in detecting small targets and managing complex backgrounds, with data fusion accuracy ranging from 84.29% to 94.32% across multiple tests, thereby substantially enhancing the spatiotemporal alignment between AIS and video data. Full article

This paper introduces a novel miniaturized, four-mode, semi-flexible leaky wave Multiple-Input Multiple-Output (MIMO) antenna specifically designed to advance vehicular communication systems. The proposed antenna addresses key challenges in 5G low- and high-frequency bands, including millimeter-wave communication, by integrating innovative features such as a periodic Spoof Surface Plasmon Polariton Transmission Line (SSPP-TL) and logarithmic-spiral-like semi-circular strip patches parasitically fed via orthogonal ports. These design elements facilitate stable impedance matching and wide impedance bandwidths across operating bands, which is essential for vehicular networks. The hybrid combination of leaky wave and SSPP structures, along with a defected wide-slot ground structure and backside meander lines, enhances radiation characteristics by reducing back and bidirectional radiation. Additionally, a naturalization network incorporating chamfered-edge meander lines minimizes mutual coupling and introduces a fourth radiation mode at 80 GHz. Compact in size (14 × 12 × 0.25 mm³), the antenna achieves high-performance metrics, including S11 < −18.34 dB, dual-polarization, peak directive gains of 11.6 dBi (free space) and 14.6 dBi (on vehicles), isolation > 27 dB, Channel Capacity Loss (CCL) < 3, Envelope Correlation Coefficient (ECC) < 0.001, axial ratio < 2.25, and diversity gain (DG) > 9.85 dB. Extensive testing across various vehicular scenarios confirms the antenna’s robustness for Vehicle-to-Vehicle (V2V), Vehicle-to-Pedestrian (V2P), and Vehicle-to-Infrastructure (V2I) communication. Its exceptional performance ensures seamless connectivity with mobile networks and enhances safety through Specific Absorption Rate (SAR) compliance. This compact, high-performance antenna is a transformative solution for connected and autonomous vehicles, addressing critical challenges in modern automotive communication networks and paving the way for reliable and efficient vehicular communication systems. Full article

Fabry nephropathy is a life-threatening complication of Fabry disease characterized by complex and incompletely understood pathophysiological processes possibly linked to premature aging. We aimed to investigate leukocyte telomere length (LTL), oxidative stress, and kidney damage biomarkers in relation to kidney function. The study included 35 Fabry patients and 35 age and sex-matched control subjects. Based on the estimated slope of the glomerular filtration rate, the patients were divided into two groups. Relative LTL was quantified by qPCR, urinary biomarkers 8-hydroxy-2′-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) by UHPLC-MS/MS, and kidney damage biomarkers by flow cytometry. There was no statistically significant difference in LTL between Fabry patients and controls. However, a significant difference was observed in male patients compared to their matched control subjects (p = 0.013). Oxidative stress biomarkers showed no differences between patients and controls, while significant differences were observed in urinary IGFBP7, EGF, and OPN levels between Fabry patients with stable kidney function and those with progressive nephropathy (FDR = 0.021, 0.002, and 0.013, respectively). Significant differences were also observed in plasma levels of cystatin C, TFF3, and uromodulin between patients with progressive nephropathy and controls (all FDR = 0.039). Along with these biomarkers (FDR = 0.007, 0.017, and 0.010, respectively), NGAL also exhibited a significant difference between the two patient groups (FDR = 0.017). This study indicates accelerated telomere attrition, which may be related to disease burden in males. Furthermore, analyses of urinary oxidative stress markers revealed no notable disparities between the different kidney function groups, indicating their limited utility. However, promising differences were found in some biomarkers of kidney damage in urine and plasma. Full article

Frequent agricultural irrigation events continuously raise the groundwater table on loess platforms, triggering numerous loess landslides and significantly contributing to soil erosion in the Chinese Loess Plateau. The movement of irrigation water within the surficial loess layer is crucial for comprehending the mechanisms of moisture penetration into thick layers. To investigate the infiltration and evaporation processes of irrigation water, a large undisturbed soil column with a 60 cm inner diameter and 100 cm height was extracted from the surficial loess layer. An irrigation simulation event was executed on the undisturbed soil column and the ponding infiltration and subsequent evaporation processes were systematically monitored. A ruler placed above the soil column recorded the ponding height during irrigation. Moisture probes and tensiometers were installed at five depths to monitor the temporal variations in volumetric water content (VWC) and matric suction. Additionally, an evaporation gauge and an automatic weighing balance measured the potential and actual evaporation. The results revealed that the initially high infiltration rate rapidly decreased to a stable value slightly below the saturated hydraulic conductivity (K_s). A fitted Mezencev model successfully replicated the ponding infiltration process with a high correlation coefficient of 0.995. The monitored VWC of the surficial 15 cm-thick loess approached a saturated state upon the advancing of the wetting front, while the matric suction sharply decreased from an initial high value of 65 kPa to nearly 0 kPa. The monitored evaporation process of the soil column was divided into an initial constant rate stage and a subsequent decreasing rate stage. During the constant rate stage, the actual evaporation closely matched or slightly exceeded the potential evaporation rate. In the decreasing rate stage, the actual evaporation rate fell below the potential evaporation rate. The critical VWC ranged from 26% to 28%, with the corresponding matric suction recovering to approximately 25 kPa as the evaporation process transitioned between stages. The complete evaporation process was effectively modeled using a fitted Rose model with a high correlation coefficient (R² = 0.971). These findings provide valuable insights into predicting water infiltration and evaporation capacities in loess layers, thereby enhancing the understanding of water movement within thick loess deposits and the processes driving soil erosion. Full article

Background: People with HIV (PWH) are at increased risk of vascular dysfunction and cardiovascular disease (CVD). SARS-CoV-2 infection has been associated with acute CVD complications. The aim of the study was to as-sess macrovascular function as an early indicator of CVD risk in PWH after mild SARS-CoV-2 infection. Methods: PWH aged 20–60 years, with undetectable viral load (RNA < 20 copies/mL), on stable anti-retroviral therapy (≥6 months) and history of mild COVID-19 (≥30 days) without any CVD manifestations prior to enrollment were recruited. Participants were excluded if they had history of diabetes mellitus, end-stage renal disease, heart or respiratory disease. Participants were matched 1:1 to pre-pandemic PWH. A health survey, surrogate measures of CVD risk, and macrovascular function (brachial artery flow-mediated vasodilation and arterial stiffness assessments via applanation tonometry) were compared between group. Results: A total of 17 PWH and history of COVID-19 (PWH/COV+) were matched with 17 PWH without COVID-19 (PWH/COV−) pre-pandemic. Mean age (45.5 years), sex (76.5% male), body mass index (27.3), and duration of HIV infection (12.2 years) were not different between groups. Both groups had comparable CVD risk factors (total cholesterol, LDL, HDL, systolic and diastolic blood pressure). There were no differences in measures of flow mediated arterial dilatation or arterial stiffness after 30 days of SARS-CoV-2 infection. Conclusions: After recent SARS-CoV-2 infection, PWH did not demonstrate evidence of macrovascular dysfunction and increased CVD risk. Results suggest that CVD risk may not be increased in people with well-controlled HIV who did not manifest CVD complications SARS-CoV-2 infection. Full article

Existing research on truck location prediction focuses on direct trajectory prediction and ignores the link between activity patterns and predictability, whereas the mode of operation is an important factor in the difference between activity trajectories, and analyzing the mode of operation can help to develop the next-location prediction algorithms to improve the efficiency of matching truckloads and to reduce costs. Our empirical study, based on 562,071 truck trip data in China, employs Fuzzy c-means (FCM) for clustering operational patterns in space, intensity, and stability dimensions. K-nearest neighbors (KNN), Back Propagation neural (BP) network, and Long Short-Term Memory (LSTM) predict the next truck locations in different modes. The results indicate that range-of-motion stability significantly influences predictability. Truckers with stable spatial activity exhibit the highest predictability, with 45% nearly achieving 100% predictability. Through cluster analysis of driving characteristics, we found that truck clusters are the most predictable because of their relatively small and low-intensity activities, with the percentage of samples with prediction accuracy above 90% reaching over 80%. This research not only characterizes the freight truck community but also aids algorithm optimization by revealing predictability factors for real-world applications. Full article

Vessels can deactivate their Automatic Identification System (AIS) to operate undetected and potentially engage in illegal activities. To address this, satellite-based radio frequency (RF) data are increasingly being used for identifying such vessels. This study evaluates the matching accuracy among RF and AIS data based on the frequency and distance. RF data were acquired on 22 September, 25 September, and 7 December 2023. According to the frequency range, the dataset was separated into frequency-1 (3.024–3.077 GHz) and frequency-2 (9.3734–9.4249 GHz). Six distance thresholds (2 km, 3 km, 6 km, 8 km, 13 km, and 18 km) were employed for the matching process. The results depicted that the average matching rates were 95%, 92%, and 92% for the RF dataset on 22 September, 25 September, and 7 December, respectively. Additionally, the results revealed that the matching rates decreased with distance, e.g., for the RF dataset on 22 September, the average highest matching rate (47%) was found at a 2 km distance and the minimum matching rate (0.9%) was observed at an 18 km distance. Furthermore, the analysis delineated that frequency-2 consistently exceeded frequency-1, particularly at longer distances, showing a more stable trend in matching accuracy. Full article

In a sustainable energy system, managing the charging demand of electric vehicles (EVs) becomes increasingly critical. Uncontrolled charging behaviors of large-scale EV fleets will exacerbate loads imbalanced in a multi-microgrid (MMG). At the same time, the time cost of users will increase significantly. To improve users’ charging experience and ensure stable operation of the MMG, we propose a new joint scheduling strategy that considers both time cost of users and spatial load balancing among MMGs. The time cost encompasses many factors, such as traveling time, queue waiting time, and charging time. Meanwhile, spatial load balancing seeks to mitigate the impact of large-scale EV charging on MMG loads, promoting a more equitable distribution of power resources across the MMG system. Compared to the Shortest Distance Matching Strategy (SDMS) and the Time Minimum Matching Strategy (TMMS) methods, our approach improves the average peak-to-valley ratio by 9.5% and 10.2%, respectively. Similarly, compared to the Load Balancing Matching Strategy (LBMS) and the Improved Load Balancing Matching Strategy (ILBMS) methods, our approach reduces the average time cost by 31.8% and 25% while maintaining satisfactory spatial load balancing. These results demonstrate that the proposed method achieves good results in handling electric vehicle scheduling problems. Full article

Despite the widespread use of COVID-19 vaccines, there is still a global need to find effective therapeutics to deal with the variants of SARS-CoV-2. Moslae herba (MH) is a herbal medicine credited with antiviral effects. This study aims to investigate the antiviral effects and the underlying mechanism of aqueous extract of Moslae herba (AEMH) for treating SARS-CoV-2. The in vitro anti-SARS-CoV-2 activity of AEMH was evaluated using cell viability and viral load. Component analysis was performed by HPLC-ESI-Q-TOF/MS. The connection between COVID-19 and AEMH was constructed by integrating network pharmacology and transcriptome profiles to seek the core targets. The components with antiviral activities were analyzed by molecular docking and in vitro pharmacological verification. AEMH exerted anti-SARS-CoV-2 effects by inhibiting viral replication and reducing cell death caused by infection (IC₅₀ is 170 μg/mL for omicron strain). A total of 27 components were identified from AEMH. Through matching 119 intersection targets of ‘disease and drug’ with 1082 differentially expressed genes of COVID-19 patients, nine genes were screened. Of the nine, the PNP and TPI1 were identified as core targets as AEMH treatment significantly regulated the mRNA expression level of the two genes on infected cells. Three components, caffeic acid, luteolin, and rosmarinic acid, displayed antiviral activities in verification. Molecular docking also demonstrated they could form stable bonds with the core targets. This study explored the antiviral activity and possible mechanism of AEMH for treating SARS-CoV-2, which could provide basic data and reference for the clinical application of MH. Full article

This paper presents a hybrid dielectric resonator antenna (HDRA) for circularly polarized (CP) radiation at 5 GHz, designed for WLAN applications. The antenna features a single probe feed that excites a combination of a circular ring patch and a cylindrical dielectric resonator (DR) element, achieving stable gain across a wide bandwidth. The parametric analysis and vector E-field distribution of the proposed antenna presents the optimization, and it is evidence of CP radiation, respectively. The hybrid DRA has a reflection loss (RL) bandwidth of 485 MHz, from 4740 to 5225 MHz, and an axial ratio (AR) bandwidth of 150 MHz, ranging from 4950 to 5100 MHz. It achieves a peak gain of 7.03 dBic at 5 GHz, making it suitable for missile tracking, data link communications, and IEEE 802.11n WLAN systems. Measurements of a prototype in an anechoic chamber show a close match with simulation results. Full article

Within the framework of Rastall theory, we investigate the impact of charge on the structural development of different types of spherically symmetric anisotropic stars. To do so, we present modified field equations based upon the Finch–Skea metric potentials expressed in terms of three parameters $(A,B,C)$. These constants are determined using suitable matching conditions and observational data for compact objects which include Her X-1, SAX J 1808.4-3658, PSR J038-0842, LMC X-4 and SMC X-1. The equation of state offered by the $\mathbb{MIT}$ bag model for quark–gluon plasma is used to investigate the inner structure and other characteristics of these compact objects. For a fixed bag constant, $\mathcal{B}=60{\mathrm{MeV}/\mathrm{fm}}^3$, and two sets of the Rastall and charge parameters, $\zeta =0.255,0.259$ and $\tilde{\mathcal{Q}}=0.2,0.7$, respectively, we analyze the consistency of the matter variables in the model and other physical parameters such as energy conditions, stellar mass, compactness, and surface redshift. In addition, we assess the stability of the constructed model through two different approaches. It is found that the obtained model is physically viable and stable. Full article

The JUpiter Icy Moon Explorer (JUICE) mission, launched on 14 April 2023, aims to explore Jupiter and its Galilean moons, with arrival in the Jovian system planned for mid-2031. One of the scientific investigations is the Geodesy and Geophysics of Jupiter and the Galilean Moons (3GM) radio science experiment, designed to study the interior structures of Europa, Callisto, and Ganymede and the atmospheres of Jupiter and the Galilean moons. The 3GM experiment employs a Ka-band Transponder (KaT) to enable two-way coherent range and Doppler measurements used for the gravity experiment and an Ultra Stable Oscillator (USO) for one-way downlink occultation experiments. This paper analyzes KaT data collected at the ESA/ESTRACK ground station in Malargüe, Argentina, during the Near-Earth Commissioning Phase (NECP) in May 2023 and the first in-cruise payload checkout (PC01) in January 2024. The radiometric data were fitted using both NASA’s Mission Analysis, Operations, and Navigation Toolkit Environment (MONTE) and ESA’s General Orbit Determination and Optimization Toolkit (GODOT) software. The comparison of the orbital solutions showed an excellent agreement. In addition, the Doppler and range residuals allowed a preliminary assessment of the quality of the radiometric measurements. During the NECP pass, the radio link data showed a range-rate noise of 0.012 mm/s at 1000 s integration time, while the root mean square of the range residuals sampled at 1 s was 8.4 mm. During the first payload checkout, the signal power at the KaT input closely matched the value expected at Jupiter, due to a specific ground station setup. This provided early indications of the 3GM’s performance during the Jovian phase. In this test, the accuracy of range data at an integration time of 1s, particularly sensitive to the link signal-to-noise ratio, degraded to 13.6 cm, whilst the range-rate accuracy turned out to be better than 0.003 mm/s at 1000 s, thanks to the accurate tropospheric delay calibration system (TDCS) available at the Malargue station (inactive during NECP). Full article

Pregnancy involves significant immunological changes to support fetal development while protecting the mother from infections. A growing body of evidence supports the importance of immune checkpoint pathways, especially at the maternal–fetal interface, although limited information is available about the peripheral expression of these molecules by CD8+ and CD8− NK cell subsets during the trimesters of pregnancy. Understanding the dynamics of these immune cells and their checkpoint pathways is crucial for elucidating their roles in pregnancy maintenance and potential complications. This study aims to investigate the peripheral expression and functional characteristics of CD8+ and CD8− NK cell subsets throughout pregnancy, providing insights into their contributions to maternal and fetal health. A total of 34 healthy women were enrolled from the first, 30 from the second and 40 from the third trimester of pregnancy. At the same time, 35 healthy age-matched non-pregnant women formed the control group. From peripheral blood, mononuclear cells were separated and stored at −80 °C. CD8+ and CD8− NK cell subsets were analyzed from freshly thawed samples, and surface and intracellular staining was performed using flow cytometric analyses. The proportions of CD56+ NK cells in peripheral blood were similar across groups. While CD8− NKdim cells increased significantly in all trimesters compared to non-pregnant controls, CD8+ NKdim cells showed no significant changes. CD8− NKbright cells had higher frequencies throughout pregnancy, whereas CD8+ NKbright cells significantly increased only in the first and second trimesters. The expression levels of immune checkpoint molecules, such as PD-1 and PD-L1, and cytotoxic-activity-related molecules were stable, with notable perforin and granzyme B increases in CD8− NKbright cells throughout pregnancy. Our study shows that peripheral NK cell populations, especially CD8− subsets, are predominant during pregnancy. This shift suggests a crucial role for CD8− NK cells in balancing maternal immune tolerance and surveillance. The stable expression of immune checkpoint molecules indicates that other regulatory mechanisms may be at work. These findings enhance our understanding of peripheral immune dynamics in pregnancy and suggest that targeting CD8− NKbright cell functions could help manage pregnancy-related immune complications. This research elucidates the stable distribution and functional characteristics of peripheral NK cells during pregnancy, with CD8− subsets being more prevalent. The increased activity of CD8− NKbright cells suggests their critical role in maintaining immune surveillance. Our findings provide a basis for future studies to uncover the mechanisms regulating NK cell function in pregnancy, potentially leading to new treatments for immune-related pregnancy complications. Full article