Search Results (2,258)

With strategic mineral exploration extending to deep and complex geological settings, traditional methods increasingly struggle to dissect metallogenic systems and locate ore bodies precisely. This synthesis of current progress in muon imaging (a technology leveraging cosmic ray muons’ high penetration) aims to address these exploration challenges. Muon imaging operates by exploiting the energy attenuation of cosmic ray muons when penetrating earth media. It records muon transmission trajectories via high-precision detector arrays and constructs detailed subsurface density distribution images through advanced 3D inversion algorithms, enabling non-invasive detection of deep ore bodies. This review is organized into four thematic sections: (1) technical principles of muon imaging; (2) practical applications and advantages in ore exploration; (3) current challenges in deployment; (4) optimization strategies and future prospects. In practical applications, muon imaging has demonstrated unique advantages: it penetrates thick overburden and high-resistance rock masses to delineate blind ore bodies, with simultaneous gains in exploration efficiency and cost reduction. Optimized data acquisition and processing further allow it to capture dynamic changes in rock mass structure over hours to days, supporting proactive mine safety management. However, challenges remain, including complex muon event analysis, long data acquisition cycles, and limited distinguishability for low-density-contrast formations. It discusses solutions via multi-source geophysical data integration, optimized acquisition strategies, detector performance improvements, and intelligent data processing algorithms to enhance practicality and reliability. Future advancements in muon imaging are expected to drive breakthroughs in ultra-deep ore-forming system exploration, positioning it as a key force in innovating strategic mineral resource exploration technologies. Full article

The layered composite roof of a coal mine roadway exhibits heterogeneity, with pronounced variations in layer thickness and strength. Fully grouted rock bolts installed in such layered roofs usually penetrate two or more strata and bond with them to form an integrated anchorage system. Roof failure typically initiates in the shallow strata and progressively propagates to deeper layers; thus, the mechanical properties of the rock at the free surface critically influence the overall stability of the layered roof and the load-transfer behavior of the bolts. In this study, a layered rock mass model was developed using three-dimensional particle flow code (PFC3D), and a triaxial loading scheme with a single free surface was applied to investigate the effects of free-surface rock properties, support parameters, and confining pressure on the load-bearing performance of the layered rock mass. The main findings are as follows: (1) Without support, the ultimate bearing capacity of a hard-rock-free-surface specimen is about 1.2 times that of a soft-rock-free-surface specimen. Applying support strengths of 0.2 MPa and 0.4 MPa enhanced the bearing capacity by 29–38% and 46–75%, respectively. (2) The evolution of axial stress in the bolts reflects the migration of the load-bearing core of the anchored body. Enhancing support strength improves the stress state of bolts and effectively mitigates the effects of high-stress conditions. (3) Under loading, soft rock layers exhibit greater deformation than hard layers. A hard-rock free surface effectively resists extrusion deformation from deeper soft rocks and provides higher bearing capacity. Shallow free-surface failure is significantly suppressed in anchored bodies, and “compression arch” zones are formed within multiple layers due to bolt support. Full article

We quantitatively analyzed the effects of physical properties of metallic pipe materials on the thermal performance of firestop systems. Fire-resistance tests under realistic fire conditions were conducted for 120 min using five types of metallic pipes—carbon steel, stainless steel, cast iron, copper, and aluminum—under identical firestop material conditions. The temperature distribution at key locations within the slab and average rate of temperature increase over specific time intervals were compared. Materials with higher thermal conductivity and lower wall thickness exhibited faster thermal response characteristics. High-temperature behavior was most pronounced at the pipe surface, where copper and aluminum pipes reached temperatures approximately equal to 200 °C and 190 °C, respectively. During the initial 30 min, the average rates of temperature increase were the highest for aluminum (2.9 °C/min), followed by copper (2.2 °C/min), although the rate of heat transfer gradually decreased subsequently. A correlation analysis between the composite index of thermal conductivity and cross-sectional area, revealed a strong correlation at the pipe’s surface, with a coefficient of determination greater than 0.85. The thermal properties and cross-sectional characteristics of metallic pipes can directly affect the thermal behaviors of firestop systems. The results may serve as a basis for material-informed structural design and performance evaluation criteria. Full article

Photoinitiators (PIs) are pivotal in enabling energy-efficient, spatiotemporally controlled photopolymerization for coatings. To address application-specific demands of coatings, diverse systems of Norrish-Type I (e.g., oxime esters, acylphosphine oxides) and Type II (e.g., onium salts, ketones) PIs have been engineered through systematic molecular design strategies. A comprehensive review necessitates highlighting recent achievements in designing PIs by various molecular engineering approaches. The π-conjugation extension, push–pull structures, and auxochrome incorporation boost strong and long-wavelength absorption; unimolecular PI systems with hydrogen-donor modifications improve reactivity and reduce oxygen inhibition; photobleaching via cleavable bonds and blocking conjugation enables colorless coating and deep-penetration curing; polymerizable macromolecular designs enhance migration resistance; organosilicon-functionalized structures optimize monomer compatibility. These strategies bridge molecular innovations with advanced applications in biomedical and deep-cured coatings. Full article

Pharmacotherapy in the geriatric population is one of the greatest challenges in modern medicine. Elderly patients, characterized by multimorbidity and the resulting polypharmacy, are significantly more exposed to adverse drug reactions (ADRs), which often lead to hospitalization and a decline in quality of life. Understanding the reasons for this difference requires an analysis of the physiological changes that occur during the aging process at the molecular level. This article presents a perspective on the molecular aspects of geriatric pharmacotherapy, focusing on the fundamental mechanisms that are modified with age. The analysis covers changes in pharmacokinetics, including the role and regulation of cytochrome P450 (CYP) enzymes, whose activity, especially in phase I reactions, is significantly reduced. The age-dependent dysfunction of drug transporters from the ABC (ATP-binding cassette) and SLC (solute carrier) families in key organs such as the intestines, liver and kidneys is discussed, which affects the absorption, distribution and elimination of xenobiotic compounds, including drugs. The article also provides a comprehensive analysis of the blood–brain barrier (BBB), describing changes in neurovascular integrity, including the dysfunction of tight junctions and a decrease in the activity of P-glycoprotein, sometimes referred to as multidrug resistance protein (MDR). This increases the susceptibility of the central nervous system to the penetration and action of drugs. In the realm of pharmacodynamics, changes in the density and sensitivity of key receptors (serotonergic, dopaminergic, adrenergic) are described based on neuroimaging data, explaining the molecular basis for increased sensitivity to certain drug classes, such as anticholinergics. The paper also explores new research perspectives, such as the role of the gut microbiome in modulating pharmacokinetics by influencing gene expression and the importance of pharmacoepigenetics, which dynamically regulates drug response throughout life via changes in DNA methylation and histone modifications. The clinical implications of these molecular changes are also discussed, emphasizing the potential of personalized medicine, including pharmacogenomics, in optimizing therapy and minimizing the risk of adverse reactions. Such an integrated approach, incorporating data from multiple fields (genomics, epigenomics, microbiomics) combined with a comprehensive geriatric assessment, appears to be the future of safe and effective pharmacotherapy in the aging population. Full article

In the context of sustainable development, improving the durability of engineering materials and the service life of engineering projects is an important path to address engineering sustainability and low-carbon development. This study addresses the durability issues of steel fiber-reinforced cementitious materials (SFRCMs) under the combined action of stray current and chloride ions in metro engineering. Through simulated stray current-accelerated corrosion tests, combined with compressive strength tests and X-ray computed tomography (X-CT) analysis, the effects of steel fiber volume content (0.5%, 1.0%, 1.5%) and electrification duration (0–72 h) on the mechanical properties and corrosion mechanisms were systematically investigated. The results indicate that steel fiber content significantly influences corrosion rate and strength degradation. Specimens with 1.5% fiber content exhibited the highest initial compressive strength (58.43 MPa), but suffered a severe strength loss rate of 37.67% after 72 h of electrification. In contrast, specimens with 1.0% fiber content demonstrated balanced performance, achieving both high initial strength and superior corrosion resistance (19.66% strength loss after 72 h). X-CT analysis revealed that corrosion products initially filled pores during early stages but later induced microcracks in the matrix. Higher fiber content specimens exhibited increased large-pore ratios due to fiber agglomeration, accelerating chloride ion penetration. Furthermore, digital volume correlation (DVC) analysis demonstrated that steel fibers effectively dispersed loads and reduced stress concentration. However, post-corrosion fiber volume loss weakened their crack resistance capacity, highlighting the critical role of fiber integrity in structural durability. Full article

This study develops a machine learning potential (MLP) based on the Moment Tensor Potential (MTP) method for the TaN-Ce system. This potential is employed to investigate the interfacial structure and wetting behavior between liquid Ce and solid TaN. Molecular dynamics (MDs) simulations reveal that liquid Ce exhibits significant wetting on the TaN surface at high temperatures. The interfacial region undergoes pre-melting and component interdiffusion, forming an amorphous transition layer. Nitrogen atoms display high diffusivity, leading to surface mass loss, while tantalum atoms demonstrate excellent thermal stability and penetration resistance. These findings provide theoretical support for the design of interfacial materials and corrosion control in high-temperature metallurgy. Full article

Asymmetric nanomotors are a class of self-propelled nanoparticles that exhibit asymmetries in shape, composition, or surface properties. Their unique asymmetry, combined with nanoscale dimensions, endows them with significant potential in environmental and biomedical fields. For instance, glutathione (GSH) induced chemotactic nanomotors can respond to the overexpressed glutathione gradient in the tumor microenvironment to achieve autonomous chemotactic movement, thereby enhancing deep tumor penetration and drug delivery for efficient induction of ferroptosis in cancer cells. Moreover, self-assembled spearhead-like silica nanomotors reduce fluidic resistance owing to their streamlined architecture, enabling ultra-efficient catalytic degradation of lipid substrates via high loading of lipase. This review focuses on three core areas of asymmetric nanomotors: scalable fabrication (covering synthetic methods such as template-assisted synthesis, physical vapor deposition, and Pickering emulsion self-assembly), propulsion mechanisms (chemical/photo/biocatalytic, ultrasound propelled, and multimodal driving), and functional applications (environmental remediation, targeted biomedicine, and microelectronic repair). Representative nanomotors were reviewed through the framework of structure–activity relationship. By systematically analyzing the intrinsic correlations between structural asymmetry, energy conversion efficiency, and ultimate functional efficacy, this framework provides critical guidance for understanding and designing high-performance asymmetric nanomotors. Despite notable progress, the prevailing challenges primarily reside in the biocompatibility limitations of metallic catalysts, insufficient navigation stability within dynamic physiological environments, and the inherent trade-off between propulsion efficiency and biocompatibility. Future efforts will address these issues through interdisciplinary synthesis strategies. Full article

Cancer, a leading global cause of death responsible for nearly 10 million deaths annually, demands innovative therapeutic strategies. Intrinsic cytotoxicity and biocompatibility of zinc oxide nanoparticles (ZnO-NPs) have rendered them promising nanoplatforms in oncology. We herein systematically review their applications for targeted cancer chemotherapy, with a focus on physicochemical properties, drug delivery mechanisms, and interactions with the tumor microenvironment (TME). We searched PubMed, SCOPUS, and Web of Science from inception through December 2024 for peer-reviewed preclinical studies on cancer models. Results were qualitatively synthesized. Quality was assessed with the SYRCLE risk of bias tool. Among 20 eligible studies, ZnO-NPs were frequently functionalized with ligands to enhance tumor targeting and minimize systemic toxicity. Chemotherapeutic agents (doxorubicin, 5-fluorouracil, docetaxel, cisplatin, gemcitabine, and tirapazamine) were loaded into ZnO-based carriers, with improved anticancer efficacy compared to free drug formulations, particularly in multidrug-resistant cell lines and in vivo murine xenografts. The mildly acidic TME was exploited for pH-responsive drug release, premature leakage reduction, and improvement of intratumoral accumulation. Enhanced therapeutic outcomes were attributed to reactive oxygen species generation, zinc ion-mediated cytotoxicity, mitochondrial dysfunction, and efflux pump inhibition. Deep tumor penetration, apoptosis induction, and tumor growth suppression were also reported, with minimal toxicity to healthy tissues. ZnO-NPs might constitute a versatile and promising strategy for targeted cancer chemotherapy, offering synergistic anticancer effects and improved safety profiles. Future studies emphasizing long-term toxicity, immune responses, and scalable production could lead to clinical translation of ZnO-based nanomedicine in oncology. Full article

Steel fiber reinforced concrete in marine environments often suffers from stress corrosion coupling. Under mechanical loading, the formation of penetrating cracks in the matrix increases susceptibility to seawater penetration and interfacial degradation. Using molecular dynamics simulations, this study investigated the effects of calcium-to-silicon (Ca/Si) ratios on the interfacial bonding and transport properties of a γ-FeOOH/CSH system. The results show that higher Ca/Si ratios strengthen ionic bonding between CSH and γ-FeOOH, thereby improving interfacial adhesion. Additionally, increased Ca/Si ratios significantly slow the transport of water molecules and ions (Na⁺, Cl⁻, SO₄²⁻) within γ-FeOOH/CSH nanopores. It was observed that Cl⁻ and SO₄²⁻ exhibited pronounced filtration effects at Ca/Si = 2.0. These findings suggest that optimizing the Ca/Si ratio in concrete can simultaneously enhance interfacial strength and reduce permeability. This provides an effective strategy for improving the marine erosion resistance of steel fiber reinforced concrete structures. Full article

Background/Purpose: To compare the microbiologic and histopathologic features of Acanthamoeba isolates recovered from patients with Acanthamoeba keratitis (AK) who underwent a therapeutic penetrating keratoplasty (TPK), optical penetrating keratoplasty (OPK), or deep anterior lamellar keratoplasty (DALK) after Rose Bengal Photodynamic Antimicrobial Therapy (RB-PDAT). Methods: Surgical specimens were stained with hematoxylin, eosin, and Periodic Acid-Schiff stains as per institutional protocol at the University of Miami, Bascom Palmer Eye Institute. Analysis of Acanthamoeba cyst depth, number of cysts, and average corneal thickness was established by light microscopy. Results: Seventeen patients with AK underwent surgical intervention and RB-PDAT. Eight patients underwent a TPK and nine patients underwent an OPK/DALK. In the TPK group, average cyst depth was 42.0 ± 52.5 μm from Descemet’s layer and mean corneal button thickness was 661.7 ± 106.5 μm. Comparatively, in the OPK/DALK group, average cyst depth from Descemet’s layer was 261.7 ± 222.7 μm with a mean corneal button thickness of 474.2 ± 126.6 μm. Conclusions: Acanthamoeba cysts were found to penetrate deeper within the cornea amongst patients that underwent an emergent TPK compared to patients that underwent an elective OPK/DALK. This may suggest an association between Acanthamoeba cyst depth and infection severity and provides valuable clinical insights towards understanding factors such as infection recurrence and resistance to treatment. Full article

T-bar penetrometers have been widely used to measure strength parameters of marine clay in laboratory and in situ tests. However, using the deep resistance factor derived from full-flow conditions to evaluate the undrained shear strength of shallow clay layers may lead to significant underestimation. Furthermore, the deep resistance factor is inherently influenced by the strain-softening behavior of clay rather than maintaining the constant value (typically 10.5) as conventionally assumed in practice. To address this issue, large-deformation finite element (LDFE) simulations incorporating an advanced exponential strain-softening constitutive model were performed to replicate the full T-bar penetration process—from shallow embedment to deeper depths below the mudline. A series of parametric studies were conducted to examine the influence of key parameters on the resistance factor and the associated failure mechanisms during penetration. Based on numerical results, empirical formulas were derived to predict critical penetration depths for both trapped cavity formation and full-flow mechanism initiation. For penetration depths shallower than the full-flow depth, an expression for the softening correction factor was developed to calibrate the shallow resistance factor. Finally, combined with global optimization algorithms, a computer-aided back-analysis procedure was established to estimate strain-softening parameters using resistance-penetration curves from initial penetration tests in marine clay. The reliability of the back-analysis procedure was validated through extensive comparisons with a series of numerical simulation results. This procedure can be applied to the interpretation of T-bar in situ test results in soft marine clay, enabling the evaluation of its strain-softening behavior. Full article

Corrosion failure of oil well tubing in the ocean can lead to significant economic losses. Surface treatment is often used to enhance the corrosion resistance of tubing, while corrosion acceleration will occur in a certain environment. This work combined onset failure analysis and corrosion simulation measurements to understand the failure procedure and corrosion mechanism of nickel plating materials in calcium chloride water-type weak corrosion environment. The microscopic analysis results of the failed part show CO₂ corrosion products co-deposit with SRB bacterial sulfide products and Ca compounds. The damage of nickel plating is accompanied by S-containing products, which was confirmed by simulated immersion experiments at 50 °C, 0.28 MPa CO₂ partial pressure, and a speed of 3 m/s. The aggressive solution penetrates through the micro-damage pores, followed by the degradation of the Ni plating layer into NiS, leading to the localized loss of protection and triggering under-deposit corrosion. Concurrently, the SRB’s anaerobic environment generates CO₂ corrosion byproducts and SRB-derived FeS. Full article

Fine particulate matter (PM2.5) is an environmental factor that triggers gastrointestinal diseases. However, the effects of PM2.5 on intestinal function are not fully understood. This study established an environmental exposure cell model to explore PM2.5-induced intestinal permeability alteration and its mechanisms. Intestinal barrier permeability was evaluated via trans-epithelial electrical resistance (TEER) measurement and FITC–dextran paracellular penetration analysis, followed by detection of intercellular junction protein β-catenin and its coding gene CTNNB1. Expression of inflammatory cytokines (TNF-α, IL-6) and phosphorylation of PI3K and AKT were assessed using quantitative real-time polymerase chain reaction and Western blot, respectively. Reactive oxygen species (ROS) and malondialdehyde were measured using commercial kits to observe cellular oxidative stress. The results showed that PM2.5 impaired the intestinal barrier, as indicated by reduced TEER, increased FITC–dextran penetration, down-regulated expression of β-catenin and CTNNB1. Additionally, compared with the control, inflammatory cytokines and oxidative stress markers were significantly elevated after PM2.5 exposure. The ratio of p-PI3K/PI3K and p-AKT/AKT was also up-regulated in PM2.5-exposed Caco-2 cells. Pretreatment with PI3K inhibitor LY294002 and ROS scavenger NAC modulated β-catenin expression, reduced inflammation/ROS, and alleviated the hyperpermeability of Caco-2 cells. Thus, our results reveal that PM2.5 induces PI3K/AKT-mediated inflammation and ROS generation in Caco-2 cells, leading to intestinal barrier impairment. Full article

Preformed porous media (PPM) technology has emerged as a transformative approach to enhance heat and mass transfer in vacuum freeze-drying (VFD) of agricultural and food products. This review systematically analyzes recent advances in PPM research, with particular focus on spray freeze-drying (SFD) as the dominant technique for precision pore architecture control. Empirical studies confirm PPM’s efficacy: drying time reductions of 20–50% versus conventional VFD while improving product quality (e.g., 15% higher ginsenoside retention in ginseng, 90% enzyme activity preservation). Key innovations include gradient porous structures and multi-technology coupling strategies that fundamentally alter transfer mechanisms through: resistance mitigation via interconnected macropores (50–500 μm, 40–90% porosity), pseudo-convection effects enabling 30% faster vapor removal, and radiation enhancement boosting absorption by 40–60% and penetration depth 2–3 times. While inherent VFD limitations (e.g., low thermal conductivity) persist, we identify PPM-specific bottlenecks: precision regulation of pore structures (<5% size deviation), scalable fabrication of gradient architectures, synergy mechanisms in multi-field coupling (e.g., microwave-PPM interactions). The most promising advancements include 3D-printed gradient pores for customized transfer paths, intelligent monitoring-feedback systems, and multiscale modeling bridging pore-scale physics to macroscale kinetics. This review provides both a critical assessment of current progress and a forward-looking perspective to guide future research and industrial adoption of PPM-enhanced VFD. Full article