Search Results (2,142)

Lithium-ion batteries are pivotal components in battery electric vehicles, significantly influencing vehicle design and performance. This study investigates the interactions between cell properties and battery pack characteristics through statistical correlation analysis of datasets derived from industry-leading benchmarking platforms. Findings indicate that energy densities are comparable across cell formats at the pack level. While NMC and NCA chemistries outperform LFP in energy density at both cell and pack levels, LFP’s favorable cell-to-pack factors mitigate these differences. Analysis of cell properties suggests that increases in cell-level volumetric and gravimetric energy density result in proportionally smaller gains at the pack level due to the growing proportion of required passive components. The impact of cell chemistry and format on the z-dimension of a battery pack is analyzed in order to identify dependencies and influences between nominal cell properties and the geometry of the battery pack. The analysis suggests no significant influence of the used cell chemistry on the vertical dimension of a battery pack. The consideration of cell formats shows a dependency between the battery pack z-dimension and cell geometry, with prismatic cells reaching the highest pack heights and cylindrical cells being observed in packs of smaller vertical dimensions. The study also investigates the emerging sodium-ion battery technology and assesses pack-level energy densities derived from cell-level properties. The insights of this study contribute to the understanding of cell-to-pack relationships, guiding R&D toward improved energy storage solutions for electric vehicles. Full article

Daphne odora is an evergreen shrub belonging to the Thymelaeaceae family that is widely cultivated as an ornamental garden plant. Its roots, leaves, and flowers have traditionally been used in Chinese medicine to treat pain, skin diseases, and rheumatism. While previous phytochemical studies have reported the presence of phenols, coumarins, biflavonoids, lignans, and daphnane diterpenoids in D. odora, its flowers remain largely unexplored. In the present study, the first comprehensive investigation of daphnane diterpenoids contained in the flower buds and blooming flowers of D. odora was conducted using ultra-high-performance liquid chromatography coupled with Q-Exactive-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Exactive-Orbitrap MS). A total of 30 daphnane diterpenoids were identified, including 12 previously unreported compounds, through detailed analysis of their retention times and MS/MS fragmentation patterns. Comparative profiling revealed that flower buds contained a higher abundance and greater diversity of daphnane diterpenoids than flowers. Furthermore, LC–MS-guided isolation enabled the purification of a novel compound, daphneodorin I (16), and its structure was elucidated through extensive physicochemical and spectroscopic analyses. Compound 16 represents the first daphnane diterpenoid with a Z-configured phenolic acyl moiety isolated from plants of the Thymelaeaceae family. Full article

Upon transferal from plastic to Matrigel, melanoma cells demonstrate growth in three dimensions and form de novo vascular networks—known as vasculogenic mimicry—that are characteristic of the stemness phenotype of aggressive tumors. It has been reported that during malignant transformation, stress, or differentiation, the long-range inter-chromosomal interactions between numerous developmental genes and nucleoli are changed. The aim of this work was to study the potential mechanisms behind the development of the vasculogenic mimicry phenotype in melanoma cells and whether the formation of these 3D structures is connected with the reorganization of inter-chromosomal contacts of rDNA clusters. Here, we show that after 15 h of growth on Matrigel, and following the formation of the vasculogenic mimicry phenotype, dramatic changes occur in Mel Z cells in rDNA contacts with different genomic regions that possess mainly developmental genes. Approximately 400 genes that retained stable contacts with nucleoli were co-expressed with different lincRNAs and were highly associated with H3K27me3 marks and simultaneously regulated by different transcription factors. These genes are involved in development and cell adhesion and may control the basic stage of differentiation. The genes that acquired or increased contacts with rDNA clusters during growth on Matrigel are associated with cell morphogenesis, cell junctions, and the cytoskeleton. Here, we present the first evidence that nucleoli may be involved in both the activation and repression of particular groups of developmental rDNA-contacting genes in melanoma cells forming the vasculogenic mimicry phenotype. We conclude that the inter-chromosomal interactions between developmental genes and rDNA clusters are dynamic, and that nucleoli play an important role in the development of vasculogenic mimicry and stemness phenotypes in aggressive tumor genes. Full article

This study explores the behavior of phantom dark energy within the framework of Weyl-type $f(Q,T)$ gravity, considering a spatially flat FLRW universe under observational constraints. The field equations are analytically solved for a dust-like fluid source. To determine the present values of the model parameters, we utilize observational data from the Hubble parameter measurements via cosmic chronometers (CC) and the apparent magnitude data from the Pantheon compilation of Type Ia supernovae (SNe Ia). With these obtained parameter values, we analyze the model’s physical characteristics by evaluating the effective and dark energy equation of state parameters ${\omega }_{eff}$ and ${\omega }_{de}$, the deceleration parameter $q\left(z\right)$, and energy conditions. Additionally, we conduct the $O_m$ diagnostic test for the model. We estimate the transition redshift $z_t\le 0.5342, 0.6334$ and the present age of the universe $t_0=13.46, 13.49$ Gyrs with $H_0=67.4\pm 3.6, 68.8\pm 1.9$ Km/s/Mpc, ${\mathsf{\Omega }}_{m0}={0.41}_{-0.24}^{+0.13}, {0.299}_{-0.077}^{+0.042}$, and ${\omega }_{eff}=-0.6447,-0.696$, ${\omega }_{de}=-1.0347,-1.0284$. We find a transit phase accelerating and physically acceptable phantom dark energy model of the universe. Full article

Because allopregnanolone and derivatives represent biologically active molecules, in this letter, we present the synthesis of a new bioconjugate steroid pyridinium salt derived from allopregnanolone in three steps. The key steps involve the formation of the hydrazone intermediate, followed by condensation with bromoacetyl bromide and subsequent coupling with pyridine to generate the pyridinium bromide salt. The new bioconjugate steroid pyridinium salt, 4, was fully characterized by proton and carbon nuclear magnetic resonance (¹H and ¹³C NMR) spectroscopy, mass spectrometry (MS), and Fourier transform infrared spectroscopy (FTIR). ¹H-NMR analysis revealed the presence of a dynamic rotameric mixture in a 7:3 ratio of Z/E amide conformers, which were identified by a 2D NOESY experiment. Full article

The saturable absorption of 2D Bi₂Te₃ layers is studied by using the Z-scan technique employing infrared 400 fs laser pulses. Optimization of the nonlinearities has been carried out by measuring the third-order nonlinear susceptibilities as a function of the film thickness. A thorough optimization of the thin film annealing conditions has been performed and is presented. For each thickness, the annealing parameters have been separately investigated. Scanning electron microscopy, X-ray diffraction, and UV-Vis spectrophotometry studies have also been performed on the as-deposited and crystallized 2D layers. Full article

Localization of Unmanned Aerial Vehicles (UAVs) in spaces with a limited availability of Global Navigation Satellite System signals presents a challenge, and one possible solution is the usage of Ultra-Wideband (UWB) transceivers as an aid in the localization process. This paper examines the influence of placing the UWB anchors on the UAVs’ localization accuracy in indoor spaces. Different testing scenarios, with variations in the number of anchors and their relative position towards the UAV, were created. Results show that the anchor placement plays an important role and is a significant factor in achieving accurate positioning of UAVs. The error for different testing configurations was shown through the RMSE for each axis, backed up by the standard deviation. The increase in the number of UWB anchors with the combined use of an additional laser ranging sensor for altitude measurement provided the best result. The RMSE was less than 18 cm in each axis of a 3D coordinate system with the standard deviation of up to 4.41 cm. For the testing scenarios that included the usage of a laser altimeter, the RMSE for the z-axis dropped below 1 cm, with the standard deviation of under 0.3 cm. Full article

The aim of this study was to analyze the factors that may influence serum osteocalcin levels in children with osteogenesis imperfecta treated with intravenous sodium pamidronate and to define the role of osteocalcin assessment. The study included 61 patients diagnosed with osteogenesis imperfecta type 1 or 3, aged 2 to 18, hospitalized for intravenous sodium pamidronate administration. A retrospective analysis of medical records was conducted, collecting information on age, sex, body weight, height, the number of long bone fractures throughout life, serum levels of osteocalcin, creatinine, alkaline phosphatase, 25(OH)D₃, and DXA BMD z-scores for the L1–L4 spine segment. The concentration of osteocalcin is higher in patients with osteogenesis imperfecta than the reference ranges for sex and age. Patients diagnosed with type 3 have significantly lower osteocalcin levels compared to patients with type 1. Also, increasing the age-standardized pamidronate cycle rate significantly reduced osteocalcin concentration. The strongest predictor of osteocalcin concentration among the factors studied is the type of osteogenesis imperfecta. L1–L4 BMD value and fracture frequency were unrelated to osteocalcin concentration. Osteocalcin is an important marker of bone formation that should be measured at the beginning of treatment, as its concentration decreases after successive doses of bisphosphonates. Full article

To address the challenges of signal recognition and prediction in intelligent sliding sleeve downlink communication systems, this paper proposes a dual-model framework based on Long Short-Term Memory (LSTM) networks. The system comprises a classifier for identifying pressure wave edge types and a generator for predicting pressure waveforms. High-quality training data are generated by simulating pressure wave propagation caused by throttle valve modulations. A sliding window strategy and Z-score normalization are applied to enhance temporal modeling. The classifier achieves a high accuracy in identifying rising and falling edges under noise-free conditions. The generator, trained on down-sampled waveform segments, accurately reconstructs pressure dynamics using a dual-input strategy based on historical segments and hypothetical labels. A residual-based decision mechanism is employed to complete the full sequence label prediction. To evaluate robustness, noise intensities of 30 dB and 40 dB are introduced. The proposed system maintains high performance under both conditions, achieving label prediction accuracies of 100%. Error metrics such as MAE and RMSE remain within acceptable bounds, even in noisy environments. The results demonstrate that the proposed LSTM-based method has been validated on simulated data, showing its potential to approximate performance in real-world conditions. It provides a promising solution for cable-free measurement-while-drilling (MWD) and remote control of intelligent sliding sleeves in complex downhole environments. Full article

Addressing global energy and environmental issues calls for the development of effective photocatalysts capable of enabling solar-driven water splitting, a key route toward sustainable hydrogen generation. In this work, we conducted a detailed density functional theory (DFT) study on three bilayer van der Waals (vdW) heterojunctions, Ga₂SSe/GaP, Ga₂SSe/PtSSe, and Ga₂SSe/SnSSe, each explored in four distinct stacking configurations, with Ga₂SSe serving as the base monolayer. We assessed their structural stability, electronic properties, and optical responses to determine their suitability for photocatalytic water splitting. The analysis showed that Ga₂SSe/GaP and Ga₂SSe/SnSSe exhibit type-II band alignment, while Ga₂SSe/PtSSe displays a type-I alignment. Electrostatic potential profiles and Bader charge calculations identified SeGa₂S/SSnSe and SeGa₂S/SeSnS as direct Z-scheme systems, offering efficient charge carrier separation and robust redox potential. For effective water splitting, the band edges must straddle the water redox potentials. Our results indicate that configurations A and B in Ga₂SSe/GaP, along with C and D in Ga₂SSe/SnSSe, fulfill this requirement. These four configurations also exhibit strong absorption in both the visible and ultraviolet spectral ranges. Notably, configurations C and D of Ga₂SSe/SnSSe achieve high solar-to-hydrogen (STH) efficiencies, reaching 38.44% and 21.75%, respectively. Overall, our findings suggest that these direct Z-scheme heterostructures are promising candidates for water splitting photocatalysis. Full article

Lumbar disc herniation is one of the primary causes of lower back pain, and its incidence has significantly increased with the development of industrialization. To assist in rehabilitation therapy, this paper proposes a flexible exoskeleton for active lumbar rehabilitation based on a 4-SPU/SP biomimetic parallel mechanism. By analyzing the anatomical structure and movement mechanisms of the lumbar spine, a four degree of freedom parallel mechanism was designed to mimic the three-axis rotation of the lumbar spine around the coronal, sagittal, and vertical axes, as well as movement along the z-axis. Using a 3D motion capture system, data on the range of motion of the lumbar spine was obtained to guide the structural design of the exoskeleton. Using the vector chain method, the display equations for the drive joints of the mechanism were derived, and forward and inverse kinematic models were established and simulated to verify their accuracy. The dynamic characteristics of the biomimetic parallel mechanism were analyzed and simulated to provide a theoretical basis for the design of the exoskeleton control system. A prototype was fabricated and tested to evaluate its maximum range of motion and workspace. Experimental results showed that after wearing the exoskeleton, the lumbar spine’s range of motion could still reach over 83.5% of the state without the exoskeleton, and its workspace could meet the lumbar spine movement requirements for daily life, verifying the rationality and feasibility of the proposed 4-SPU/SP biomimetic parallel mechanism design. Full article

This study aimed to evaluate whether clear corneal incisions (CCIs) created with the FEMTO LDV Z8 femtosecond laser during cataract surgery are non-inferior to manual CCIs in terms of surgically induced astigmatism (SIA) and higher-order aberrations (HOAs). A total of 78 cataract patients were randomly assigned to two groups: 38 eyes underwent femtosecond laser-assisted cataract surgery (FLACS), and 40 eyes underwent conventional manual cataract surgery (CCS). Preoperative and six-week postoperative SIA, HOAs, and all topographic and refractive data were analysed for both groups. FLACS-generated CCIs demonstrated equivalence to manual CCIs. The mean SIA was 0.44 ± 0.27 dioptres (D) in the FLACS group and 0.58 ± 0.46 D in the CCS group (p = 0.18), with lower variability in the FLACS group. The root mean square (RMS) corneal HOA at six weeks was 0.69 ± 0.17 µm in the FLACS group and 0.80 ± 0.56 µm in the CCS group (p > 0.05). These results confirm the efficacy, reproducibility, and safety of FLACS. Although not statistically significant, FLACS induced numerically lower SIA values and less variability than manual CCIs. Both groups were comparable in terms of HOAs, though higher mean values and variability were observed in the CCS group. Full article

Global agricultural intensification has exacerbated soil compaction and nitrogen (N) inefficiency, thereby threatening sustainable crop production. Sub-soiling, a tillage technique that fractures subsurface layers while preserving surface structure, offers potential solutions by modifying soil physical properties and enhancing microbial-mediated N cycling. This study investigated the effects of subsoiling depth (0, 20, and 40 cm) on soil microbial communities and N transformations in a semi-arid maize system in China. The results demonstrated that subsoiling to a depth of 40 cm (D2) significantly enhanced the retention of nitrate-N and ammonium-N, which correlated with improved soil porosity and microbial activity. High-throughput 16S rDNA sequencing revealed subsoiling depth-driven reorganization of microbial communities, with D2 increasing the abundance of Proteobacteria (+11%) and ammonia-oxidizing archaea (Nitrososphaeraceae, +19.9%) while suppressing denitrifiers (nosZ gene: −41.4%). Co-occurrence networks indicated greater complexity in microbial interactions under subsoiling, driven by altered aeration and carbon redistribution. Functional gene analysis highlighted a shift from denitrification to nitrification-mineralization coupling, with D2 boosting maize yield by 9.8%. These findings elucidate how subsoiling depth modulates microbiome assembly to enhance N retention, providing a mechanistic basis for optimizing tillage practices in semi-arid agroecosystems. Full article

In repeated-measures meta-analyses, raw data are often unavailable, preventing the calculation of the correlation coefficient r between pre- and post-intervention values. As a workaround, many researchers adopt a heuristic approximation of r = 0.7. However, this value lacks rigorous mathematical justification and may introduce bias into variance estimates of pre/post-differences. We employed Monte Carlo simulations (n = 500,000 per scenario) in Fisher z-space to examine the distribution of the standard deviation of pre-/post-differences (σ_D) under varying assumptions of r and its uncertainty (σ_r). Scenarios included r = 0.5, 0.6, 0.707, 0.75, and 0.8, each tested across three levels of variance (σ_r = 0.05, 0.1, and 0.15). The approximation of r = 0.75 resulted in a balanced estimate of σ_D, corresponding to a “midway” variance attenuation due to paired data. This value more accurately offsets the deficit caused by assuming a correlation, compared to the traditional value of 0.7. While the r = 0.7 heuristic remains widely used, our results support the use of r = 0.75 as a more mathematically neutral and empirically defensible alternative in repeated-measures meta-analyses lacking raw data. Full article

A self-diplexing, full-mode, substrate-integrated waveguide (SIW) rectangular cavity-backed antenna based on an inverted Z-shaped radiating slot with filtering characteristics is investigated in this work. The proposed design allows for individual control through the loading of four different slots, namely, a combination of horizontal and diagonal slots, called inverted Z-shaped slots. The two diagonal slots make 45° angles between them, and this flexible rotation gives the design flexibility regarding control of the bands. By combining these slots into a modified inverted Z-shaped slot, a SIW rectangular cavity is configured and energized with two separate 50 Ω microstrip feed lines to resonate at two different frequencies—11.63 GHz and 13.27 GHz—and TE₂₁₀ and TE₂₂₀ modes are obtained for X- and Ku-band wireless purposes. In an experimental analysis, reflection coefficients of S₁₁ < −10 dB were noted for both operating frequencies of 7.4% (11.23–12.09 GHz) and 3.0% (13.15–13.55 GHz), respectively. The average gain of the proposed antenna design in the two different operating conditions is 6.14 and 6.16 dBi, respectively. In addition, the proposed self-diplexing antenna attained high isolation, greater than 28 dB between both operating channels, and showed overall measured efficiency of 87.32%. Moreover, it features a single-layer structure, operates in dual bands, provides broadside linear polarization, and exhibits filtering capabilities. Full article