Search Results (22,326)

Cellulose-derived gel films are promising matrices for the immobilization and delivery of beneficial microorganisms in sustainable plant protection. This study evaluated the effects of polymer molecular weight and chemical structure on the physicochemical properties and biocontrol performance of hydroxyethyl cellulose (HEC) films of low, medium, and high molecular weight, as well as sodium carboxymethyl cellulose (CMC-Na), loaded with Bacillus subtilis. The films were characterized in terms of morphology, swelling behavior, mechanical properties, microbial viability, and antifungal activity against Fusarium avenaceum and Alternaria solani. Increasing HEC molecular weight produced progressively denser and more homogeneous gel networks, resulting in improved structural integrity, whereas CMC-Na formed dense but less stable networks. Swelling studies at pH 4, 7, and 9 showed high water uptake for all HEC systems, with enhanced structural stability observed in high-molecular-weight films, whereas CMC-Na dissolved rapidly under all conditions. Mechanical testing further confirmed that increasing molecular weight enhanced stiffness and tensile strength but reduced flexibility. Immobilized in gel matrices, B. subtilis remained viable after 12 months of storage and rapidly reactivated after rehydration. All biohybrid films inhibited fungal growth, with stronger formulation-dependent responses against F. avenaceum than against A. solani. In general, polymer molecular weight and structure were identified as key parameters controlling network organization, hydration behavior, mechanical performance, and biological functionality. These findings highlight the potential of cellulose-derived gel matrices as tunable carriers for microbial biocontrol applications. Full article

The dynamical tropopause layer pressure (DTLP) represents a key interface characterizing upper-tropospheric stratification and atmospheric dynamical structure. Its spatial morphology and gradient variations directly influence jet stream distribution as well as the intensity and location of clear-air turbulence (CAT). Over the Tibetan Plateau, complex terrain and pronounced dynamical variability result in a significantly lower tropopause height and enhanced horizontal gradients during winter. Aircraft cruising altitudes frequently approach or intersect the tropopause layer in this region, making accurate and fine-scale characterization of DTLP structures critically important for aviation safety. A deep learning-based DTLP retrieval model (Att-ResUNet_DEM) is developed by integrating terrain constraints and an attention mechanism. Using MERRA-2 reanalysis data as supervisory labels, the model incorporates a squeeze-and-excitation (SE) attention mechanism within a residual encoder–decoder framework, while a digital elevation model (DEM) is introduced as an additional input channel and fused with satellite brightness temperature data to explicitly account for terrain effects. A random forest (RF) model is implemented as a baseline for comparison. Compared with the RF model, the Att-ResUNet_DEM reduces the MAE and RMSE by 13.20% and 9.19%, respectively, while increasing the correlation coefficient to 0.76. Over the primary aviation corridors of the Tibetan Plateau, the Att-ResUNet_DEM model achieves a correlation coefficient(R) of 0.87, with markedly reduced gradient dispersion. A representative CAT case further confirms the model’s ability to capture the overall DTLP morphology and gradient enhancement zones. Overall, by combining a regionalized modeling strategy with terrain constraints, this study systematically improves DTLP retrieval accuracy and gradient consistency over complex terrain, providing a new technical pathway for high-resolution tropopause monitoring and aviation operation support. Full article

In this paper, the effects of 4 wt.% of silicon on the microstructure and mechanical properties of AM50 magnesium alloys fabricated by the casting method are presented. New AM50/Si material and the base AM50 alloy were gravity cast into a metal mould under the same conditions for comparison. Analyses of the alloys’ microstructures were carried out by light microscopy (with differential interface contrast), scanning electron microscopy (with an energy dispersive X-ray spectrometer), as well as X-ray diffraction (XRD). In as-cast conditions, both materials were composed of α-Mg solid solution, α + γ eutectic (where γ is Al₁₂Mg₁₇), Al₈Mn₅ intermetallic phases and discontinuous γ precipitates. The AM50/Si material also consisted of the Mg₂Si phase. This structural constituent appeared in the form of primary crystals with regular polygonal morphology and an α + Mg₂Si eutectic in the form of “Chinese script”. In the microstructure of the AM50/Si material, the Mn₃SiAl₉ ternary phase was also identified. The detailed analyses presented in this paper revealed that the new ternary Mn₃SiAl₉ structural compound caused a reduction in the volume fraction of the Al₈Mn₅ phase but did not completely replace it. These two phases formed competitively. The fabricated material exhibited higher tensile and compression strength as well as yield strength in comparison with the AM50 alloy. Additionally, analyses of the fracture surfaces of the AM50/Si material carried out using scanning electron microscopy (SEM) were presented. Full article

This study investigates the influence of the depth of lattice-array micro-pillar surface microstructures on the cavitation erosion (CE) of nickel-aluminum bronze (NAB) in a saline solution using both experimental and simulation methods. Mass-loss measurements, electrochemical tests, and morphological characterizations (SEM, white-light interferometry, EBSD) were conducted to clarify the erosion, corrosion, and synergistic components. Pressure distribution, vapor volume fraction, and bubble dynamics were revealed by numerical simulation in the cavitation region. Results show that shallow microstructures (0.02 and 0.07 mm depths) significantly reduce the CE by up to 74% compared to the smooth surface. This structure can form a shielding field and suppress the mechanical erosion component. In contrast, deep microstructures (0.18 and 0.22 mm depths) aggravate CE, which is attributed to increased bubble nucleation and localized vapor content, and intensified pressure difference. The pure erosion component dominates the damage, followed by synergistic action, and the pure corrosion component is the least. This trend is independent of the change in the microstructure. These findings extend the knowledge on how to design the microstructure depth to alleviate CE. Full article

Nickel-rich NMC-811 is a benchmark cathode material for high-energy density lithium-ion batteries due to its high specific capacity (>200 mAh g⁻¹) and operating voltage (~3.8 V). However, its strong surface reactivity toward atmospheric species, particularly moisture and CO₂, poses significant challenges during storage and processing, leading to the formation of LiOH- and Li₂CO₃-rich surface layers. Although the effects of humid air have been widely investigated, a direct comparison between high relative humidity and pure CO₂ exposure remains limited. Here, we systematically examine the morphological, structural, chemical, and electrochemical evolution of commercial NMC-811 electrodes after 5 h exposure to 80% relative humidity or CO₂-saturated atmosphere. Moisture treatment induces substantial surface reconstruction, lattice shrinkage, and increased cation disorder, accompanied by extensive hydroxide and carbonate formation. In contrast, CO₂ exposure mainly modifies the outermost surface layer without significant bulk structural changes. Electrochemical testing reveals that CO₂-treated electrodes display higher initial polarization but quickly recover near-pristine performance, whereas humidity-treated electrodes exhibit persistent kinetic limitations, accelerated capacity fading, and earlier end-of-life. Overall, degradation severity follows the trend: pristine < CO₂ < RH 80%, highlighting the dominant role of moisture in irreversible structural deterioration. Full article

The genus Morpheis Hübner, [1820] (Lepidoptera: Cossidae) represents a taxonomically challenging group within Zeuzerinae, characterised by uniform, simply structured genitalia and significant intraspecific variability in external morphology, specifically in wing pattern, body colouration, and size. The taxonomic status and phylogenetic placement of many Morpheis taxa remain uncertain. Our study provides the first comprehensive taxonomic revision of Morpheis, based on detailed morphological analysis, examination of type specimens, assessment of distribution records, and molecular data. As a result, here we provide the first complete taxonomic list with updated diagnoses and distribution maps, based on 1247 specimen records and 191 publicly available observations. We describe the female genitalia of Morpheis for the first time and provide illustrations of imagoes for all currently recognised species, as well as of available type specimens. Additionally, we describe the immature stages and summarise the trophic associations of known Morpheis species. Based on morphological and molecular data, we recognise 11 valid Morpheis species. We applied molecular-based species delimitation methods, which uncovered far more candidate species within the genus than are recognised by traditional taxonomy, suggesting overlooked cryptic diversity that morphology alone cannot detect. We conclude that the integrative approach used here provides a powerful tool, especially valuable for understudied Zeuzerinae groups with high intraspecific variability in traditional characters. Full article

Dental restorative resins available today still have limitations that may affect their durability. This study explores reinforcing a universal microhybrid dental composite resin with organomodified nanoclay at low filler loadings (0, 0.5, 1, 3, and 5 wt%). The morphology, structural features, and light transmittance of the composites were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), attenuated total reflection–Fourier transform infrared (ATR–FTIR), and UV–Vis spectroscopy. The degree of conversion and polymerization shrinkage were measured with ATR–FTIR and a linear variable displacement transducer (LVDT). Water sorption and solubility parameters and flexural properties were assessed gravimetrically and with a dynamometer, respectively. The composites mainly showed exfoliated structures and an improved degree of conversion. Polymerization shrinkage and solubility were lower than those of unmodified dental resin. The highest degree of conversion was observed in composites with 0.5–1 wt% nanoclay. The incorporation of 1 wt% nanoclay resulted in the lowest shrinkage and sorption, along with the highest flexural modulus and strength. Overall, the results suggest that low nanoclay concentrations can improve the physicochemical and mechanical properties of dental composites, highlighting their potential to develop advanced restorative materials that can address current clinical challenges. Full article

Starch synthesis is critical for crop yield and quality and is regulated and coordinated by a series of key enzymes encoded by starch synthesis-related genes (SSRGs). Although this process is well characterized in many crops, the genomic location and expression patterns of SSRGs in wheat remain unclear. Here, we performed a genome-wide analysis and identified 78 SSRGs in wheat, classified into the AGPase, SSS, GBSS, SBE, and DBE subfamilies. SSRGs within each subfamily showed conserved motifs and domain organization. RNA-seq analysis indicated that most SSRGs are expressed during early grain development. We further examined genetic variation in SSRGs across wheat and its progenitors using re-sequencing data. Diploid wheat showed greater genetic differentiation and diversity than tetraploid and hexaploid wheat. Five SSRGs exhibited significant haplotype differences between emmer wheat and common wheat; emmer wheat displayed diverse haplotypes, whereas common wheat showed a single dominant haplotype. Finally, starch characteristics differed between emmer wheat and common wheat in amylose content and thermodynamic properties, while viscosity, crystal structure, and morphology were largely similar. Overall, this study systematically characterizes SSRGs in wheat and provides insights for improving starch quality. Full article

Background: Blood flow restriction (BFR) training induces morphological and neuromuscular adaptations using low-intensity exercise (20–40% 1RM), offering a reduced mechanical load alternative to traditional high-load resistance training. Safe and effective implementation, however, requires a clear understanding of physiological mechanisms, contraindications, and pressure determination methodologies. In this three-part series, we provide a comprehensive review of BFR for athletic populations and provide strength and conditioning coaches with a structured framework for screening, safety, and methodological considerations to support BFR integration in high-performance settings. Methods: A narrative review of the literature examining BFR safety, contraindication screening, adverse event reporting, and occlusion pressure determination was conducted using a PubMed and MEDLINE search. Search terms included combinations of (“blood flow restriction” OR “BFR” OR “occlusion training” OR “KAATSU”) AND (“safety” OR “contraindications” OR “risk stratification”) AND (“arterial occlusion pressure” OR “limb occlusion pressure” OR “occlusion pressure” OR “Doppler” OR “handheld Doppler” OR “pulse oximetry” OR “cuff width” OR “capillary refill time” OR “monitoring”). Studies examining contraindication screening systems, arterial occlusion pressure calculation methods, and real-time monitoring protocols were evaluated. Primary considerations included risk stratification frameworks, pressure determination accuracy, and control parameter validation for ensuring vascular safety during application. Results: Risk stratification systems can effectively identify absolute and relative contraindications requiring medical clearance prior to BFR use. Epidemiological data indicate that adverse events are transient and non-serious, while serious events appear rare when evidence-informed protocols are applied. Doppler-based assessment remains a criterion approach for determining inflation pressure, although validated estimation methods using limb circumference and systolic blood pressure offer a pragmatic and comparable alternative for applied environments. Inflation pressures of 50–80% arterial occlusion, adjusted for cuff width, produce effective and safe stimulus. Real-time monitoring through capillary refill time, pulse strength palpation, and skin coloration can support iterative pressure optimization and help identify excessive restriction pressures. Conclusions: BFR implementation in athletic populations requires systematic screening protocols, individualized inflation pressure determination using validated methods, and real-time monitoring parameters. These foundations provide the essential safety infrastructure required before progressing to specific training applications across resistance, cardiovascular, and other performance and rehabilitation modalities. Full article

During the production, storage, and use of solid rocket motors, the impact generated by unexpected accidents, such as collision or drop, will cause damage to the propellant and affect the safety of the motor. However, the progressive evolution mechanism of mesoscopic damage in NEPE propellant under such impact conditions has not been fully elucidated, and there is still a lack of quantitative method to evaluate the impact-induced damage degree, which restricts the engineering safety assessment of solid rocket motors. To investigate the influence mechanism, the mesoscale damage characteristics of NEPE propellant under drop-weight impact is systematically studied. First, damaged NEPE specimens are obtained by conducting drop-weight experiments with a 10 kg hammer, where the drop height is varied to apply different impact impulses. The internal meso-structure of the propellant is then characterized using micro-CT, yielding detailed imagery of the refined meso-structural features and damage morphologies in the NEPE propellant. To capture the dynamic evolution process of mesoscale damage, a mesoscopic model incorporating AP, Al, HMX particles and voids, is subsequently constructed based on the high-precision mesoscopic morphology characterized by micro-CT. By integrating the deviatoric constitutive model, Gurson plastic damage model, and bilinear cohesive zone model, high-fidelity numerical simulations of the drop-weight impact damage process are performed using the advanced SPH-FEM coupling algorithm. The results indicate that no significant damage occurs when the impact impulse is less than 13.85 N·s. As the impulse increases, phenomena including matrix microcracks, void collapse, particle/matrix interface debonding, and main crack formation appear sequentially. When the impulse exceeds 24.25 N·s, particle fragmentation and transgranular fracture occur, accompanied by plastic flow and frictional heating that induce ignition. Finally, the overall damage degree is fitted by the Boltzmann function, and a function for quantitatively describing the damage degree is obtained, which can provide theoretical support for the impact safety assessment of solid rocket motors. Full article

The circulatory system of cuttlefish (family Sepiidae) has been extensively studied; however, a comprehensive anatomical reconstruction of bobtail squids (family Sepiolidae) remains limited despite their ecological and evolutionary importance within Decapodiformes. This study reconstructs the circulatory architecture of sepiolids through comparative histological analysis and documents microorganisms or parasites associated with renal tissues. Two bobtail squid species, Rossia bipapillata and Sepiolina nipponensis, were examined using serial histological sections, while four cuttlefish species—Sepia lycidas, Sepia esculenta, Sepia japonica, and Sepia tenuipes—were analyzed for comparative purposes. Morphometric parameters, including sex, total length, and mantle length, were recorded prior to histological processing. Branchial hearts and renal appendages were sectioned using serial microtomy (~120 sections per specimen) and stained with hematoxylin and eosin, periodic acid–Schiff, Masson’s trichrome, and Giemsa to visualize vascular continuity and tissue organization. Histological observations confirmed vascular connections between the gills, branchial hearts, the systemic heart, and renal appendages, enabling reconstruction of the sepiolid circulatory pathway. In addition, the light organ characteristic of Sepiolidae was identified as a tissue receiving oxygenated blood within the circulatory network. Renal tissues revealed the presence of parasitic organisms, including Dicyema in cuttlefish and ciliates of the genus Chromidina in bobtail squids. Morphological observations revealed structural diversity in Chromidina, including characteristic spiral anterior features and variation in body form, as well as developmental variation in nuclear number relative to body length in dicyemids. These findings provide new insights into cephalopod circulatory organization, parasite diversity, and host–parasite interactions. Full article

This study reports a straightforward and controllable two-step hydrothermal synthesis of novel Ni₉S₈@NiMoO₄/NF nanospherical catalysts supported on nickel foam (NF), accompanied by a systematic evaluation of their performance in the electrochemical hydrogen evolution reaction (HER). Structural characterization revealed a well-defined Ni₉S₈–NiMoO₄ interfacial region, whose synergistic interaction, combined with the distinctive nanospherical morphology, substantially increased the electrochemically active surface area and the density of reactive sites, thereby optimizing HER kinetics. In alkaline media, the Ni₉S₈@NiMoO₄/NF catalyst demonstrated outstanding electrocatalytic performance, delivering an overpotential of only 64.2 mV at a current density of 20 mA cm⁻². The catalyst also exhibited a high double-layer capacitance of 22.2 mF cm⁻², reflecting a substantial active interfacial area. Long-term durability tests showed negligible performance degradation after 165 h of continuous operation at 10 mA cm⁻², underscoring the catalyst’s robust structural stability and durability. X-ray photoelectron spectroscopy confirmed a uniform distribution of Ni, Mo, and S across the NF framework and revealed optimized chemical states, providing material-level evidence for the enhanced performance. Collectively, this work proposes a viable strategy for designing efficient and stable HER catalysts, contributing to the advancement of green hydrogen production and clean energy technologies. Full article

Background: Sulfated chitosan (ChS) is a chemically modified polysaccharide derived from chitin that mimics heparan sulfate (HS) structures and has emerged as a promising antimicrobial biomaterial. Piscirickettsia salmonis, the etiological agent of Salmonid Rickettsial Septicemia (SRS), represents the main driver of antibiotic use in Chilean aquaculture. Objective: In this study, the in vitro antibacterial activity of ChS against P. salmonis was evaluated. Methods: Elemental characterization by SEM-EDS and FTIR analysis confirmed successful sulfation of the polymer, with a degree of sulfation ranging from 0.92 to 0.95. Additionally, X-ray diffraction (XRD) analysis revealed a reduction in polymer crystallinity, indicating a transition toward a more amorphous structure associated with increased molecular flexibility and functional group accessibility. Results: Antibacterial assays revealed a minimum inhibitory concentration (MIC) of 1500 µg/mL and a minimum bactericidal concentration (MBC ≥ 1500 µg/mL). LIVE/DEAD™ fluorescence imaging showed the formation of bacterial aggregates with increasing size, frequency, and red fluorescence compared to controls over the exposure to ChS, indicating progressive membrane damage. This was supported by a reduction (p < 0.05) in the Green/Red fluorescence ratio of 37–46% between 5 h and 96 h of exposure, corresponding to alteration of the cell membrane. Scanning electron microscopy revealed pronounced morphological alterations by ChS, including surface disruption and loss of cellular integrity. This was more severe compared to commercial chitosan (ChC). Also, ChS reduced (p < 0.05) biofilm formation (>50% at day 6 and 34.8% at day 8). Conclusions: These results demonstrated that ChS disrupts the cell membrane and reduces biofilm formation in P. salmonis, thereby affecting viability. This is the first report of the antibacterial effect of ChS, an HS analogue, against P. salmonis. Full article

The use of hydrogen direct injection (DI) plays a crucial role in decarbonizing internal combustion engine (ICE) technology. However, a suitable characterization of the injection process is required to control the mixture preparation before combustion, especially in the case of late injection timing. CFD modeling represents a useful tool to support experiments in addressing this goal. This study presents a numerical investigation of hydrogen DI using a swirled-type injector, seated in a constant-volume vessel. First, the selected numerical setup is validated against optical measurements of the jet penetration, demonstrating the reliability of the approach. Then, the analysis compares swirling and non-swirling configurations under different nozzle pressure ratios (nPRs) to evaluate the interaction between swirl-induced mixing and under-expanded jet structures. Results show that at lower nPR, swirl significantly alters the momentum distribution, reducing axial penetration. Instead, at higher nPR, where the H2 jets exhibit strong shock structures, the effects of swirl become negligible, with penetration and plume morphology nearly identical to non-swirling conditions. Analysis of the scalar dissipation rate showed the presence of a redistribution of mixing characteristics at low nPR due to swirl, while shock structures dominate at high nPR. This could have a significant impact on combustion and NO_x emissions in ICE operated with late injection strategies, where lower nPR are found. Full article

The global construction industry urgently requires sustainable alternatives to ordinary Portland cement (OPC) to mitigate its immense carbon footprint. Red mud (RM), a highly alkaline bauxite residue, presents tremendous but challenging potential as a supplementary cementitious material. This review systematically bridges the gap between atomic-level interfacial bonding mechanisms and macroscopic engineering performance, highlighting how these properties are significantly dictated by specific RM sources (e.g., Bayer vs. Sintering processes). We first elucidate advanced pretreatment strategies, notably CO₂ mineralization, which synergistically mitigates extreme alkalinity and sequesters carbon. Crucially, the fundamental bonding mechanisms are decoded: beyond physical filling, RM integration induces significant micro-morphological densification via intense aluminosilicate depolymerization—evidenced by the Al[VI] to Al[IV] coordination shift—and the quantitative integration of approximately 40% reactive iron phases into stable Fe-S-H networks. By clearly distinguishing between traditional hydration and clinker-free alkali-activation pathways, we evaluate holistic structural parameters beyond mere 28-day compressive strength (40–67 MPa), explicitly addressing flexural capacity, modulus of elasticity, and volume stability. Environmental assessments confirm exceptional heavy metal immobilization (>95% efficiency, leaching < 0.010 mg/L) and a substantial 50–80% reduction in Global Warming Potential (GWP), provided the environmental burden of alkaline activators is rigorously accounted for. Furthermore, the long-term risk of Alkali–Silica Reaction (ASR) is evaluated as a primary durability concern. Finally, to overcome persistent rheological bottlenecks, this paper highlights transformative future trajectories, particularly data-driven Machine Learning (ML) for complex mix optimization and 3D concrete printing for advanced infrastructure. Ultimately, this review provides a robust theoretical foundation and a pragmatic roadmap for upcycling RM into safe, high-performance, and ultra-low-carbon building materials. Full article