Search Results (12,361)

This study investigates the effects of laser power and scanning rate on the surface morphology, relative density, microhardness and microstructure of pure tungsten fabricated by laser powder bed fusion (LPBF). Increasing the laser power or decreasing the scanning rate effectively suppresses spheroidisation and enhances densification, achieving a maximum relative density of ~98%. However, excessive laser power intensifies Marangoni convection, leading to surface protrusions that reduce density. Microstructural analysis reveals that the laser-scanned surface is dominated by fine columnar grains (390–480 HV), whereas the side surface comprises coarser columnar grains with lower hardness (~390 HV). Electron backscatter diffraction analysis confirms that the side surface contains a high proportion of grains exceeding 100 μm and reveals a significant peak (~41.8%) at ~3.5° for low-angle grain boundaries, indicating substantial internal stress and microstrain. Pole figures show a weak preferred orientation (maximum texture intensity of 3.161). Phase analysis shows no significant phase transformation after LPBF, while internal stress and microstrain increase notably. Full article

The development of efficient, low-cost hydrodeoxygenation (HDO) catalysts is essential for converting renewable lipids into sustainable aviation fuels. Here, we report a series of sulfided bimetallic NiFe/γ-Al₂O₃ catalysts and systematically investigate the promotional role of Fe in the HDO of methyl decanoate, a model lipid compound. Using complementary characterization together with fixed-bed reactor kinetic measurements, we elucidate the influence of the Ni/Fe ratio on catalyst structure, sulfidation behavior, electronic properties, and reaction pathway. Fe incorporation promotes Ni sulfidation and induces electron transfer from Fe to Ni, as directly evidenced by a red shift in the CO stretching frequency (from 2094 cm⁻¹ for Ni-only to 2090 cm⁻¹ for NiFe), indicating increased electron density on Ni sites and enhanced π-backdonation. Among the catalysts tested, N5F5 (Ni/Fe mass ratio = 1:1) exhibits the highest Ni sulfidation degree, the highest turnover frequency (32.1 h⁻¹), and the lowest apparent activation energy (E_a ≈ 92 kJ/mol). At 360 °C, it achieves 52.9% methyl decanoate conversion, far exceeding that of monometallic Ni and Fe catalysts. Product selectivity analysis reveals that sulfided Ni sites predominantly promote the decarboxylation/decarbonylation (DCOx) pathway, whereas Fe sites contribute only marginally to direct deoxygenation (DDO). This work provides the first direct spectroscopic evidence for Fe-to-Ni electron transfer in sulfided NiFe catalysts and establishes a clear structure-performance correlation, offering a rational design strategy for low-cost, high-performance HDO catalysts for lipid upgrading. Full article

In order to investigate possible ionospheric anomalies before a magnitude 7.6 earthquake (EQ) in the Japanese Noto Peninsula on 1 January 2024, we used oblique ionosonde data sounding at Wakkanai and Yamagawa with an assumed one-hop reflection point (ORP) only 169 km away from the EQ epicenter, which was not covered by vertical ionosonde observation. The NmF2 at ORP was analyzed. We found a long-lasting negative anomaly from the preceding day to the EQ occurrence, which was 3.37 standard deviations below the previous 30-day mean. We also found a positive anomaly 2 days before the EQ. In addition, we observed a new type of NmF2 anomaly around midday, which has not yet been reported in the literature. The midday NmF2 was anomalous for 10, 8 days, and a few hours before the EQ, implying possible pre-seismic modifications of the mesospheric meridional neutral wind. On the other hand, we also found NmF2 anomalies 3 and 4 days before a major aftershock on 9 January, revealing that the lithosphere–atmosphere–ionosphere coupling (LAIC) remained active, as seismic activity continued some days after the EQ mainshock. Since both positive and negative anomalies were observed before the EQ, pre-seismic atmospheric gravity wave (AGW) activity is the main agent driving LAIC processes. The present study not only reports pre-seismic anomalies before the 2024 Noto Peninsula EQ but also demonstrates the utility of oblique ionosondes on the ionospheric monitoring over Japan, especially for pre-seismic studies. Full article

We report the study of Cur@HKUST-1 composites, obtained through one-pot infiltration of HKUST-1 with curcumin (Cur) as a guest-sensitizing molecule. Cur features a HOMO energy above the valence band (VB) of HKUST-1, enabling modulation of the electronic structure of the host framework by introducing additional energy states within the bandgap. Structural characterization, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), confirmed successful guest incorporation and preservation of HKUST-1 crystallinity. An initial Cur amount of 50% (relative to the BTC linker) was added to the synthetic mixture, and differential UV-vis analysis has shown an infiltration efficiency of 28.0%, corresponding to an infiltration degree of 14% in the Cur@HKUST-1 composite, highlighting a challenging loading process, primarily due to the size and conformations of the Cur structure. Textural analysis revealed a reduction in surface area and pore volume, consistent with a high degree of guest infiltration. Optical properties evaluated by diffuse reflectance UV-vis spectroscopy revealed new absorption bands and a notable decrease of 1.83 eV in the bandgap energy from 3.68 eV (HKUST-1) to 1.85 eV (Cur@HKUST-1) due to guest molecule infiltration. Density functional theory (DFT) calculations supported the experimental findings, showing that guest HOMOs promoted the formation of a new valence band (VB), while the original VB remains lower in energy. Density-of-states analysis confirmed that the new VB originates from 2p orbitals belonging to the guest, while the conduction band remains predominantly Cu-based from the HKUST-1 framework. Photoelectrochemical characterization revealed that the guest-modified material exhibits an enhanced photocurrent response compared to HKUST-1. Cur@HKUST-1 displayed higher stability and stronger photocurrent density, attributed to its narrower bandgap and increased charge carrier density. These results demonstrate the potential of rational guest selection to engineer band structure and improve the light-harvesting performance of MOFs in solar-driven applications. Full article

Hydrolysis of cellulose to produce ethanol has become an effective way to utilize biological resources, but its large-scale industrial application has been limited. In this study, a one-pot catalytic conversion process for transforming cellulose into ethanol was developed. Meanwhile, multifunctional Mo/Pt/WO_x/Al₂O₃ catalysts were prepared by loading nano-alumina (Nano-Al₂O₃) via a stepwise impregnation method. The influence of catalysts with varying metal ratios on the types of products generated during the cellulose hydrolysis process to ethanol was examined. The catalyst with 0.1% Mo, 2% Pt, and 7.5% W loadings showed the best selectivity. With an ethanol yield of 45.3% after heating at 5 MPa H₂ and 518 K for 2 h. Nano-Al₂O₃ can provide suitable active sites. The addition of W⁵⁺ and Mo⁰ increased the surface oxygen vacancy density and enhanced the hydrodeoxidation and metal anchoring capacity of the catalyst. The solid solution structure facilitates electron transfer from W and Mo atoms to Pt atoms, forming electron-rich Pt^δ- species, promoting the hydrolysis of cellulose and the formation of ethanol. Full article

The concentration of electric fields at the end region of stator bars in large generators can readily induce corona discharge. Under long-term operation, corona discharge may cause drift in the surface conductivity and nonlinear coefficient of anti-corona materials, thereby weakening their capability to homogenize the tangential electric field. In severe cases, this can lead to charring failure of the anti-corona material. To improve the electrical-parameter stability and surface morphological resistance to corona aging of silicon carbide (SiC)-based anti-corona materials under long-term corona exposure, epoxy-resin-based anti-corona materials were investigated in this study. Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) were first employed to analyze the effects of corona aging on the microstructure and chemical structure of the anti-corona layer, thereby revealing its failure mechanism. Subsequently, the evolution of surface conductivity, nonlinear coefficient, and surface morphology of bisphenol A epoxy resin (EP)- and hydrogenated bisphenol A epoxy resin (H-EP)-based anti-corona materials during 120 h of corona aging was comparatively investigated. On this basis, different mass fractions of organically modified montmorillonite (OMMT) were introduced into the H-EP-based anti-corona material for synergistic modification. The OMMT used in this study had a particle size of approximately 5 μm and an interlayer spacing of 2.6 nm, and its lamellar morphology and dispersion state in the epoxy matrix were characterized by cross-sectional SEM. Meanwhile, the trap-regulation mechanism of the OMMT-modified anti-corona materials was analyzed using isothermal surface potential decay (ISPD). The results show that erosion of the epoxy resin matrix by corona discharge is the primary cause of internal conductive-pathway disruption and anti-corona layer failure. Compared with the EP-based material, the H-EP-based material exhibited better conductivity and nonlinear stability during aging, although a certain degree of drift still occurred. The incorporation of an appropriate amount of OMMT further improved the corona resistance of the material. Among the investigated samples, the material containing 1 wt% OMMT showed the best performance, with its conductivity stabilized within the range of 10^−13–10⁻¹¹ S, the lowest variation rate of 104.76%, a relatively stable nonlinear coefficient, and slight surface damage. The ISPD results indicate that the interfaces introduced by OMMT increase the deep-trap density and suppress carrier migration, thereby stabilizing the conductive network. Overall, the synergistic effect of the H-EP matrix and 1 wt% OMMT can effectively enhance the corona resistance of SiC-based anti-corona materials. Full article

CoCrFeNi/WC-Nb high-entropy alloy (HEA) composite coating was prepared on the surface of Q235 steel by LC (laser cladding) technology, and the effects of WC and in situ NbC reinforcement on the coating were studied. The phase composition, phase characteristics, microhardness, and wear resistance of the cladding coatings were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), friction and wear tester, and X-ray photoelectron spectroscopy (XPS), and the corrosion resistance was tested by a three-electrode electrochemical workstation. The results show that the CoCrFeNi/WC-Nb HEA coating consists of FCC, WC, NbC, and Laves phases, and the reinforcing phase causes grain refinement and lattice distortion. The microhardness reached (418.29 ± 16.72) HV, which was about 2.64-times higher than that of the CoCrFeNi HEA coating. The wear rate decreased to (1.150 ± 0.11) × 10⁻⁴ mm³N⁻¹m⁻¹, which was about 0.25 times that of the CoCrFeNi HEA coating, and the wear of the coating changed from abrasive wear to adhesive wear. The corrosion current density and corrosion voltage of the CoCrFeNi/WC-Nb HEA coating are (3.3820 ± 0.2103) × 10⁻⁶ A/cm² and −(0.7650 ± 0.0850) V, respectively. Full article

Background/Objectives: Cancer survivors admitted to inpatient rehabilitation suffer from a complex burden of interrelated physical and psychological symptoms. While mean-level improvements during rehabilitation are well-documented, it remains unknown whether rehabilitation modifies the underlying structure of symptom interconnections—the symptom network—beyond reducing individual symptom scores. This study aimed to characterize symptom network structure at admission and discharge of a 21-day inpatient cancer rehabilitation program based on cancer-related physical symptoms and psychosocial functioning, formally compare network topology across timepoints, identify structurally central treatment targets, and assess the transdiagnostic generalizability of findings. Methods: Secondary analysis of routinely collected, electronic patient-reported outcome (PRO) data from 5066 cancer survivors (mean age 60.3 years, SD 12.2; 64.2% female; most frequent diagnoses: breast cancer = 36.9%, hematological malignancies = 10.4%; prostate cancer = 8.5%) admitted to a single-center inpatient rehabilitation program was performed between January 2017 and November 2022. The EORTC QLQ-C30 and the Hospital Anxiety and Depression Scale (HADS) questionnaires were utilized. Bayesian Gaussian Graphical Models were estimated at admission (T0) and discharge (T1) across 17 symptom and functioning domains using Bayesian Model Averaging (15,000 iterations). Edge-level change was quantified via posterior distributions of pairwise differences with 95% Highest Density Intervals. Node-level changes were assessed using Bayesian paired t-tests. Centrality was quantified by Expected Influence and Bridge Expected Influence. Results: Patients showed clinically meaningful improvements across all 17 domains during rehabilitation (all Bayes Factors >10; posterior probability of direction >99.9%). The largest standardized effects were observed for emotional functioning (Cohen’s d = 0.76), global health status (d = 0.69), and fatigue (d = 0.53). These improvements were clinically meaningful for a substantial proportion of patients: 62% improved by at least the minimal important difference in fatigue and 58% in emotional functioning, and the proportion of patients with probable anxiety fell from 15% to 6% and probable depression from 10% to 4%. Emotional functioning and anxiety were the most central domains in the symptom network—most strongly connected to the rest of patients’ symptom burden—at both admission and discharge. Despite the clinical improvements, the overall architecture of symptom interconnections changed little (83% of connections were unchanged). This indicates that the severity of symptoms was mitigated while the structure linking them together remained largely intact. The one connection that strengthened was that between impaired social functioning and financial difficulties (Δ = −0.112). Structural findings were consistent across ten cancer types (leave-one-out r > 0.80 in seven of ten). Conclusions: Over the course of inpatient cancer rehabilitation, patients showed large improvements against a background of largely stable symptom network architecture. Emotional functioning and anxiety occupy structurally central positions at both admission and discharge, identifying them as candidate domains warranting further investigation for network-informed rehabilitation. These findings provide a novel structural perspective on oncological rehabilitation and a framework for developing more targeted intervention strategies. Full article

This study presents a comparative evaluation of geopolymer foams incorporating either commercially available shape-stabilized phase change materials (PCMs) or laboratory-developed diatomite–paraffin PCM granules with controlled particle size fractions ranging from <1.6 mm to >2.5 mm. All PCM variants were incorporated at a constant dosage of 7.5 wt.% to isolate the influence of PCM type on the properties of the resulting composites. The commercial materials comprised PX-4, PX15, and PX20 (Rubitherm Technologies GmbH), whereas the laboratory-developed PCM consisted of paraffin immobilized within a porous diatomite matrix to produce granular shape-stabilized composites. The experimental program included the determination of bulk density, total porosity, pore size distribution, thermal conductivity (λ), thermal resistance (R), specific heat capacity (Cp), and compressive strength. The pore structure was characterized by mercury intrusion porosimetry (MIP), while the morphology and dispersion of PCM particles within the geopolymer matrix were investigated using scanning electron microscopy (SEM). All mixtures were produced using the same alkali-activated matrix and identical curing conditions, with the PCM content maintained at 7.5 wt.%. The results demonstrated that the type of PCM significantly affected the microstructure and thermophysical performance of the geopolymer foams. The laboratory-developed diatomite–paraffin PCM provided the most favorable thermal insulation performance, exhibiting the lowest thermal conductivity (0.095 W/m·K) together with the highest thermal resistance (0.278 m²·K/W). In contrast, the commercial PX15 and PX20 materials exhibited the highest specific heat capacities (1.740 and 1.778 kJ/kg·K, respectively), indicating superior thermal energy storage capability. In addition, the estimated production cost of the laboratory-developed PCM (2.5–4.0 EUR/kg) was substantially lower than that of the commercial PX materials (approximately 20 EUR/kg), highlighting its potential as a cost-effective alternative for sustainable, energy-efficient building materials. These findings demonstrate that both commercial and laboratory-developed PCM systems can effectively enhance the functionality of geopolymer foams, although they provide different balances between thermal insulation, heat storage capacity, and production cost. Full article

The efficient capture of carbon dioxide (CO₂) using polymer, supported ionic liquids (ILs) remains challenging due to limited understanding of atomic-scale interaction mechanisms. Here, a polystyrene (PS) oligomer supported by an amidinium chloride-based IL is proposed as a CO₂-absorbing material. Density functional theory (DFT) calculations were employed to investigate the structural, electronic, and intermolecular interaction energy characteristics of the PS oligomer, amidinium chloride ILs, CO₂, and their binary and ternary complexes. Molecular electrostatic potential maps (MEPs), reduced density gradient (RDG) plots with non-covalent interaction (NCI) snapshots, quantum theory of atoms in molecules critical point (CP) analysis, and electron localization function (ELF) analysis reveal pronounced hydrogen bonding and dispersion interactions between PS and IL that modulate the electronic environment of the IL anion, which is the primary CO₂ binding site. Interaction energy calculations show that the ternary PS–IL–CO₂ complex exhibits a significantly enhanced binding energy compared to the isolated IL–CO₂ complex, providing quantitative evidence for the cooperative role of the PS support. The results indicate enhanced CO₂ binding in the presence of PS supported by ILs, driven by cooperative electrostatic and dispersion interactions. These findings provide molecular-level insights into CO₂ capture mechanisms in polymer–IL hybrid systems. Full article

NAD⁺ depletion is a defining feature of the aging cell, driven by a progressive decline in nicotinamide phosphoribosyltransferase (NAMPT) activity, the rate-limiting enzyme of the NAD⁺ salvage pathway. Pyrroloquinoline quinone (PQQ), a plant-derived redox-active quinone cofactor, elevates intracellular NAD⁺ by a mechanism that remains incompletely understood. We employed an integrated in silico approach combining molecular docking, density functional theory (DFT), and 100 ns molecular dynamics (MD) simulation to evaluate whether PQQ directly targets NAMPT. Docking against the NAMPT crystal structure (PDB: 7ENQ) yielded a binding free energy of −9.4 kcal/mol, with PQQ positioned in the allosteric activation site and forming hydrogen bonds at His191, Asp219, and Val242 together with π–π stacking at Tyr188, extending a known synthetic activator pharmacophore to a dietary ligand class. MM-GBSA analysis yielded binding free energy = −31.2 kcal/mol, confirming dominant electrostatic and van der Waals stabilization. In silico alanine mutagenesis of Tyr188 and Val242 reduced binding affinity to −7.2 and −7.0 kcal/mol respectively, with complete loss of allosteric-site contacts, validating the proposed mechanism computationally. DFT analysis revealed a HOMO–LUMO gap of 3.20 eV and electrophilicity index ω = 8.91 eV, consistent with non-covalent binding to nucleophilic residues. MD simulation confirmed retention of PQQ within the allosteric site over 100 ns. These data provide a structural and electronic framework for the NAD⁺-boosting activity of PQQ and a rationale for experimental validation. Full article

Polypropylene (PP) waste, including microplastic debris, motivates molecular-scale studies of the intrinsic factors governing thermal degradation. In this work, the bond dissociation energies (BDEs) of C–C and C–H bonds were systematically evaluated in a finite isotactic polypropylene oligomer containing fifteen propylene repeat units, (–C₃H₆–)₁₅, using Density Functional Theory at the M06-2X/LANL2DZ level. Thermochemical corrections were evaluated at 873.15 K, a temperature relevant to pyrolysis studies. Within the selected oligomer model, C–C bonds exhibited lower BDE values (82.28–87.41 kcal·mol⁻¹) than C–H bonds (90.18–104.93 kcal·mol⁻¹), indicating a thermochemical preference for backbone scission. The lowest calculated BDE values were associated with specific tertiary carbon environments, including sites C24 and C28. A mixed-effects model identified bond type and carbon type as the principal factors associated with BDE variation, while principal component analysis summarized the covariation among the electronic and thermodynamic descriptors. These results provide a molecular-scale description of intrinsic scission tendencies within the selected PP oligomer and establish a basis for subsequent kinetic, catalytic, and experimental studies. Full article

Membranous nephropathy (MN) is a leading cause of nephrotic syndrome (NS). The remission rate of MN remains limited, and effective strategies for refractory MN are not established. We present the case of a 49-year-old Japanese woman with severe NS caused by MN. Kidney biopsy revealed glomerular basement membrane thickening with granular deposition of immunoglobulin G (IgG) and complement component 3. IgG subclass analysis showed predominant IgG1 deposition, with weak IgG2 and IgG3 deposition. Phospholipase A2 receptor (PLA2R) deposition was equivocal in the first kidney biopsy and negative in the second. Serum anti-PLA2R antibody was not detected. Electron microscopy revealed subepithelial, subendothelial, and mesangial electron-dense deposits. Detailed screening revealed no significant abnormalities other than appendiceal findings, suggesting secondary MN associated with appendiceal infection. Although combined therapy with prednisolone, cyclosporine, rituximab, and low-density lipoprotein apheresis was administered during the first 6 months, remission of MN was not achieved. During dialysis, initiated because of kidney failure, long-term multidisciplinary management, including control of appendiceal infection and inflammation and initiation of angiotensin II receptor blocker therapy, ultimately led to remission of MN and discontinuation of dialysis. Overall, even refractory MN requiring dialysis may have a reversible clinical course with careful conservative management and long-term follow-up. Full article

Melt-spun Fe_70−xPd₃₀Ga_x ribbons (x = 1 and 3 at.% Ga) were heat-treated at 1223 K for 1 h and 2 h and characterized by X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, magnetometry, and magnetoelastic measurements. Increasing Ga content decreases thermodynamic equilibrium temperature from 292.0 K (1 at.% Ga) to 283.5 K (3 at.% Ga) in as-prepared ribbons. Extended heat treatment then shifts it to 288.0 K and 264.5 K, respectively, and promotes Fe-rich precipitation. Fine precipitates at 1 h preserve a large transformable matrix fraction and introduce microstructural heterogeneity that governs variant mobility and domain-wall pinning; prolonged annealing triggers coalescence, depleting the matrix and reducing both the transformation heat and the magnetoelastic response. Kissinger analysis yields apparent activation energies of 338 kJmol⁻¹ (1 at.% Ga) and 228 kJmol⁻¹ (3 at.% Ga), confirming that higher Ga content lowers the transformation energy barrier. The magnetostrictive response depends on annealing: 1 h-annealed samples exhibit field-induced variant reorientation and saturation magnetostriction of ~60 ppm at 200 K, whereas 2 h-annealed samples approach volume-conserving behavior. Coercivity scales with precipitate density, with Ga3-2h showing anomalously soft magnetic behavior following coalescence. Thermally induced precipitation thus emerges as a route to simultaneously control microstructure, transformation kinetics, magnetoelastic response, and magnetic behavior in ferromagnetic shape memory alloys. Full article

Nucleic acids exhibit structured electromagnetic features shaped by classical electronegativity (EN) patterns. Mapping Pauling EN values across DNA and RNA reveals a largely invariant, high-EN phosphodiester backbone that provides a consistent electrostatic scaffold, while nucleobases introduce sequence-specific electron density shifts that generate tunable recognition fields. Together, these features create a dual-system framework in which a stable electrostatic background supports sequence-dependent informational cues. Within this environment, short-timescale vibronic interactions may arise from patterned vibrational and electronic behavior, producing modest “quantum overlay” effects compatible with known decoherence constraints. These structured, anisotropic electrostatic features may help explain differences in stability between DNA and RNA, the functional outcomes of nucleoside modifications such as N¹-methylpseudouridine (m¹Ψ), and the sensitivity of translational fidelity to small architectural perturbations. The framework yields experimentally testable predictions involving vibrational relaxation, dipole reorientation, and charge-transfer behavior, offering a classical-to-quantum interpretive bridge that may inform the design of next-generation therapeutic mRNAs. Full article