Search Results (4,273)

Superhydrophobic SiO₂ nanofibers were deposited on copper foam substrates via micro/nano surface modification to improve the pool boiling heat transfer performance of porous copper media. By adopting an electrospinning technique, uniform and robust superhydrophobic SiO₂ nanofibers were firmly deposited on copper foam skeletons, forming interconnected porous structures with intrinsic superhydrophobic characteristics. The fabricated superhydrophobic nanofiber structures greatly reduce bubble nucleation resistance and provide sufficient stable vaporization sites, effectively promoting boiling heat transfer enhancement. Experimental results verify that surface modification with superhydrophobic SiO₂ nanofibers significantly improves the overall boiling performance of copper foam. The sample with a nanofiber loading of 1.8 mg achieves the optimal thermal performance, presenting lower wall superheat, higher critical heat flux, and an improved heat transfer coefficient. CFD simulations were conducted, and the numerical results exhibit good consistency with experimental measurements. Full article

To investigate the elevated-temperature performance of Ultra-High-Performance Concrete (UHPC) and Ultra-High-Performance Geopolymer Concrete (UHPGC), a systematic comparative study was conducted at 800 °C. This study examined the effects of the steel fibre geometry (micro and hooked-end) and dosage (1.5% and 2.0%) on mass loss, crack propagation, residual compressive, flexural, and tensile strengths, and chemical evolution following a 24 h pre-drying protocol to mitigate explosive spalling. The results demonstrate that UHPGC exhibits superior thermal stability and residual mechanical performance compared with UHPC after high-temperature exposure. Among all mixtures, the UHPGC mixture reinforced with 2% micro steel fibres (UHPGC-M2) achieved the highest residual compressive strength (30 ± 0.4 MPa, corresponding to 25% strength retention compared with 21% for the equivalent UHPC mixture), the lowest post-exposure crack width (0.08 mm), and the highest tensile strength retention (17.9%). Micro steel fibres were more effective in controlling crack propagation and preserving peak load capacity, whereas hooked-end fibres contributed more significantly to post-peak ductility. Chemical analysis revealed substantial chemical changes in both systems after exposure to 800 °C. However, UHPGC exhibited lower mass loss (4.8%) and greater residual performance. These findings establish micro steel fibre-reinforced UHPGC as a sustainable and high-performance material for fire-resistant structural applications. Full article

This study investigates the atmospheric corrosion behavior of high-lead bronze alloys within a simulated aggressive environment characterized by high humidity, acidity, chlorides, oxygen, and CO₂. The evolution of surface morphology and corrosion products was systematically monitored using colorimetric analysis and micro-Raman spectroscopy. Results indicate that the initial patina primarily comprised cuprite (Cu₂O) and cassiterite (SnO₂), which are predominantly benign phases. During the early corrosion stage, lead oxidation and carbonation prevailed, generating abundant bright-white cerussite. Subsequently, as copper-driven corrosion became dominant, these white deposits diminished and were progressively replaced by characteristic green “bronze disease”, identified as atacamite (Cu₂(OH)₃Cl). The findings reveal that preferential lead corrosion is likely to induce localized pitting, thereby accelerating degradation of the copper substrate. Consequently, higher lead content may reduce the overall corrosion resistance of bronze artifacts under these specific conditions. These results offer experimental insights into atmospheric corrosion mechanisms and inform the development of evidence-based conservation strategies for bronze cultural heritage. Full article

Water-cooled tungsten targets may remain in contact with stagnant deionized water during accelerator shutdown, creating a beam-off corrosion condition distinct from irradiation-assisted service. Untreated tungsten (W), laser-ablated tungsten (LA-W), and a 500 nm tantalum-coated laser-ablated tungsten surface (Ta-LA-W) were therefore immersed in deionized water for up to 28 days. Laser ablation replaced the machined surface with a hierarchical micro/nanostructure and increased the areal roughness Sa from 0.22 ± 0.01 to 1.75 ± 0.07 μm; after Ta deposition, Sa was 1.62 μm. LA-W exhibited the largest topographic attenuation and the highest dissolved W concentration, reaching 7.915 mg·L⁻¹ at 21 days. Ta-LA-W maintained Sa within the range from 1.60 ± 0.06 to 1.66 ± 0.07 μm and limited dissolved W to 1.118–1.601 mg·L⁻¹. X-ray photoelectron spectroscopy showed increased WOx-related intensity and disappearance of the metallic-W loss feature only for untreated W. The W 4f envelopes of LA-W and Ta-LA-W remained broadly similar before and after immersion, but for different reasons: sustained W dissolution for LA-W and suppression of W oxidation and release by the Ta-containing barrier for Ta-LA-W. The dissolution-based corrosion sequence was LA-W > W > Ta-LA-W. Laser texturing therefore acted as an interfacial-engineering treatment rather than an intrinsically corrosion-resistant modification. Full article

Pitting distress introduces discontinuous surface texture, thereby modifying the friction–adhesion coupling at the rubber–asphalt interface. This study systematically investigates the interfacial friction response of SBS-modified asphalt pavements with three pitting distribution patterns (sparse, medium, and dense) under varying sliding rates, temperatures, and cyclic loading using a custom-developed friction testing apparatus. The results reveal that adhesion-dominated friction is strongly dependent on both texture distribution and operating conditions. With increasing temperature, the dense pattern exhibits the most pronounced adhesion enhancement, with an average friction increase of 55.0%. The sparse pattern shows a continuous decreasing trend in the low-to-medium speed range, but exhibits a strengthening rebound at high speeds, demonstrating the most complex rate sensitivity. Under cyclic loading, among the three pitting patterns tested, the dense pattern exhibits the best friction retention, with an average friction reduction of only 6.2% after 30 cycles, compared to 9.5% for the sparse pattern and 10.8% for the medium pattern. Three-dimensional topography indicates that the medium pattern exhibits a continuous and relatively uniform wavy roughness, while the dense pattern transforms into a high-frequency serrated morphology. However, the wear in both patterns is dominated by homogenized micro-grooves, without the formation of local deep pits or sharp undulations, which favors the maintenance of stable skid resistance under the laboratory cyclic loading conditions tested in this study. Furthermore, a unified regression model with distribution dummy variables and interaction terms (R² = 0.826; cross-validated Q² = 0.646) quantifies the synergistic effect of pitting density and temperature, with the temperature sensitivity increasing six-fold from the sparse to the dense pattern (0.011 to 0.071 N/°C). Full article

Breast cancer is a highly heterogeneous malignancy that remains one of the leading causes of cancer-related mortality among women worldwide. Despite significant advances in breast cancer research and therapy, disease heterogeneity, treatment resistance, and metastatic progression remain major obstacles to effective disease management. Among the molecular regulators involved in breast cancer, microRNAs (miRNAs) have been recognized as critical post-transcriptional regulators of gene expression, functioning as either oncogenes or tumor suppressors. By modulating the expression of target RNAs, miRNAs control key biological processes involved in tumor initiation and progression, including cell proliferation, apoptosis, angiogenesis, epithelial–mesenchymal transition (EMT), invasion, and metastasis. To investigate miRNA function and explore their therapeutic potential, a wide range of approaches have been developed to modulate miRNA expression. These include gain-of-function strategies, like miRNA mimics, miRNA expression vectors, and CRISPR activation (CRISPRa), as well as loss-of-function approaches, including anti-miRNA oligonucleotides (AMOs), miRNA sponges, CRISPR-Cas9-mediated gene knockout, and CRISPR interference (CRISPRi). This review provides a comprehensive overview of the biological roles of miRNAs in breast cancer and discusses current technologies for miRNA modulation, their molecular mechanisms, experimental and therapeutic applications, and associated limitations. In addition, it summarizes recent advances in miRNA delivery systems, including viral vectors, organic nanoparticles, and inorganic nanocarriers, highlighting their potential to improve delivery efficiency, target specificity, and facilitate clinical translation. Finally, the review discusses future perspectives, emphasizing the transition from single-target interventions toward network-level regulation and the integration of miRNA-based strategies into precision oncology to support the development of more effective breast cancer therapies. Full article

Flexible pressure sensors with porous structures are essential for wearable electronics and robotic perception. However, traditional porous flexible sensors suffer from poor stability and long recovery times. To address these challenges, a strategy integrating bionic architectures inspired by the rigid–flexible coupling structure of Bambusa textilis and the micro-protrusion structure of Salvia plebeia R.Br. is proposed. An aluminum sheet serves as the support layer, and the sensing layer is prepared through mold replication, material impregnation, and layer-by-layer assembly, offering a simple and scalable fabrication route. The sensor exhibits a broad effective pressure range of 0–31.5 kPa, with a minimum resolvable force of 0.2 N, and within its operating range (0–23.5 kPa), the relationship between resistance and pressure exhibits a trend that can be fitted to a quadratic term, with a coefficient of determination of 0.9986. It achieves a minimum response time of 350 ms and maintains stable signals under dynamic loading at different frequencies, indicating reliable detection of low-frequency weak pressures. After 5000 loading–unloading cycles, the device shows no obvious performance degradation. When mounted on a robotic foot, the sensor successfully distinguishes land, sponge, sand, and pebbles surfaces, demonstrating its potential for intelligent environmental perception. Full article

With the growing complexity of user-side energy storage applications, multi-source operational data, including active power trajectories, operating state records, valid operating day information, and time-of-use tariff windows, increasingly contain standby periods and atypical conditions, making the true switching strategies of devices difficult to identify. Accordingly, this study aims to extract stable typical operating patterns from multi-source real-world operational data and to establish a hierarchical switching-strategy profile for practical business use. To achieve this objective, this paper proposes a multi-source data-driven switching strategy profiling method based on typical curves and hierarchical clustering using real-world operational data, in which a standby-interference-resistant typical-curve extraction algorithm first reconstructs the core output pattern of each device by adaptively screening effective operating conditions. On this basis, a hierarchical shape–feature profiling framework is constructed: OPTICS is used to determine baseline physical shapes, and temporal anchoring together with execution consistency features is used for fine-grained K-Means subdivision. A case study using 151 user-side energy storage devices from January 2023 to December 2025 shows that the proposed method identifies three macro operating shapes and six micro execution types, revealing differences in duration, timing deviation, and execution quality. The results provide interpretable support for refined operation, performance evaluation, and asset management of distributed user-side energy storage. Full article

Ultrafast laser processing enables the creation of functional surfaces in metals, semiconductors, ceramics, polymers and other materials through spatially controlled nonequilibrium energy deposition. However, the resulting surface functionality cannot be explained solely by laser parameters or geometric features. Femtosecond irradiation induces a sequence of coupled processes, including nanoscale structuring, phase transformation, chemical modification, defect formation, and relaxation, which define the final surface state. This review introduces the Surface-by-Design concept, where functional surfaces are considered as engineered material states formed through controlled laser–matter interaction rather than as predefined patterns. Representative examples including laser-induced periodic surface structures, hierarchical micro/nanotextures, modified oxide layers, and laser-generated functional interfaces are analyzed in relation to wettability, tribological behavior, corrosion resistance, optical response, and other properties. The review further examines how advanced characterization, digital engineering, beam shaping, in situ diagnostics, and data-driven methods contribute to controlling surface evolution. Remaining challenges include reproducibility, scalability, and reliable prediction of functional behavior during service conditions. Future progress in femtosecond laser surface engineering will depend on the ability to control not only the generated morphology but also the evolving structural and physicochemical state of functional interfaces. Full article

Coatings based on polyvinylidene fluoride (PVDF) and poly(dimethylsiloxane) (PDMS)-based polymeric microspheres can be easily fabricated via non-solvent-induced phase separation (NIPS) and electrostatic spraying (ES) techniques. Both techniques are promising strategies for constructing superhydrophobic surfaces on various substrates. However, PVDF and PDMS inherently suffer from severe aggregation, which generates oversized particles and inhomogeneous microstructures. Conventionally, costly and environmentally hazardous dispersants are required to alleviate this issue, severely restricting the industrial scalability and practical application of such coatings. In this work, methyltrimethoxysilane-modified cellulose nanocrystals (Si-CNCs) were introduced as a green multifunctional modifier to tackle these issues. The results revealed that as structural building blocks and dispersants, Si-CNCs inhibited polymer aggregation via electrostatic repulsion and steric hindrance, refined the particle size and formed uniform micro/nano hierarchical structures. Increasing Si-CNC loading further improved polymer dispersion and superhydrophobic performance. Coatings fabricated by ES showed better hydrophobicity than those fabricated by NIPS. ES achieved a water contact angle (WCA) of 160–166° and a sliding angle (SA) near 1° on cotton fabric, while NIPS had a WCA of 153.8–158° and an SA of around 2°. Wood and glass substrates also obtained favorable superhydrophobicity, with WCAs above 150° and SAs below 1°. Furthermore, all modified surfaces exhibited excellent abrasion resistance. This work provides a relatively eco-friendly, environmentally sustainable, scalable and substrate-flexible strategy for fabricating high-performance PVDF/PDMS-based superhydrophobic coatings. Full article

Adult deep neck infection (DNI) is a potentially life-threatening condition associated with significant morbidity and mortality. Contemporary large-scale data characterizing long-term microbial evolution and clinical outcome trends in adult DNI remain limited. This study aimed to investigate temporal changes in bacterial pathogens, treatment strategies, and clinical outcomes of adult DNI across an 18-year period. This is a retrospective multicenter cohort study using the Chang Gung Research Database (CGRD) and a de-identified nationwide database from Taiwan’s largest medical system. Hospitalized adult patients (aged ≥18 years) with DNI from 2006 to 2023 were identified and stratified into two consecutive 9-year epochs (Epoch 1: 2006–2014, n = 5512; Epoch 2: 2015–2023, n = 6551). Demographics, comorbidities, treatment modalities, disease severity, and microbiological profiles were analyzed. Bacterial isolates were evaluated at genus and species levels, with methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) assessed separately. Among 12,063 adult DNI patients (Epoch 1: n = 5512; Epoch 2: n = 6551), antibiotic-only treatment increased (77.3% to 83.2%) and surgical intervention decreased (22.7% to 16.9%). Descending necrotizing mediastinitis decreased markedly (2.7% to 0.7%) and in-hospital mortality declined (7.7% to 6.4%). Poly-microbial infections increased substantially (45.3% to 53.7%). Among facultative anaerobic and aerobic isolates, the Streptococcus anginosus group (SAG) emerged as a clinically important pathogen. Among anaerobes, Prevotella displaced Peptostreptococcus as the dominant genus, with Peptostreptococcus micros (Parvimonas micra) and Prevotella buccae emerging as prominent species. Over 18 years, adult DNI in Taiwan demonstrated significant improvements in clinical outcomes, with marked reductions in mediastinitis and in-hospital mortality. Concurrently, poly-microbial infections increased, and the SAG, Peptostreptococcus micros (Parvimonas micra), Prevotella, and anaerobic organisms emerged as clinically important pathogens, underscoring the need for empiric antibiotic regimens providing broad aerobic and anaerobic coverage. Although microbiological profiles vary geographically, these findings provide a contemporary evidence base to guide empiric antibiotic selection, inform surgical decision-making, and identify high-risk adult patients with DNI. Full article

Ultraviolet (UV) radiation in high-altitude regions critically accelerates asphalt aging by inducing surface oxidation, molecular chain scission, and loss of low-temperature crack resistance. However, systematic comparisons of the macro-rheological and micro-chemical evolution between base asphalt and SBS-modified asphalt under UV aging remain insufficient. In this study, two types of asphalt (virgin and SBS-modified) were subjected to three aging protocols, namely short-term thermal oxidation (RTFOT), long-term thermal oxidation (PAV), and equivalent UV radiation for 13 h, 26 h, and 37 h. Low-temperature rheological properties were evaluated using the bending beam rheometer (BBR), while atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) characterized the microstructural and chemical changes. The results show that long-term thermal oxidation causes the most severe deterioration of low-temperature rheological performance, whereas short-term thermal oxidation and 13 h UV aging exhibit comparable effects. For SBS-modified asphalt, extending UV exposure from 13 h to 37 h leads to progressive stiffening and loss of relaxation capacity at −12 °C and −18 °C. However, the m-value shows a non-monotonic response at −24 °C, indicating that the temperature dependence of UV aging is more complex at extremely low temperature. For base asphalt, aging promotes the formation and subsequent agglomeration of bee-like structures. For SBS-modified asphalt, the sulfoxide index increases monotonically, while the carbonyl index first increases and then decreases. Although 13 h UV aging and RTFOT produce similar macroscopic outcomes, their mechanisms differ fundamentally, where UV aging is hypothesized to act primarily via photon-induced bond scission, whereas thermal oxidation proceeds through radical chain reactions. Full article

MicroRNAs (miRNAs) are key regulators of gene expression that act primarily by binding to target messenger RNAs (mRNAs). However, the biology of miRNAs is more complex than initially thought, with functional complexity extending beyond canonical sequences. A multilayered miRNA regulatory landscape involving isomiR generation, altered 5p/3p strand usage, arm switching, A-to-I RNA editing, and epitranscriptomic RNA modifications operates in eukaryotic cells to regulate miRNA function. Collectively, these mechanisms expand the functional diversity of miRNAs by regulating their biogenesis, stability, strand selection, and target specificity, increasing their functional plasticity and contributing to regulatory heterogeneity found in cells. IsomiRs arise from alternative Drosha/Dicer processing, terminal nucleotide additions, RNA editing, and genetic variation, producing functionally distinct isoforms. Arm switching alters gene regulatory outputs through context-dependent changes in predominant 5p/3p strand usage. In addition, epitranscriptomic RNA modifications, such as m6A and m5C, together with A-to-I RNA editing, represent an additional layer of miRNA regulation. These mechanisms can act directly on miRNAs or their precursors, or indirectly by modifying circRNAs and lncRNAs, thereby altering miRNA availability and function. Together, these processes form a dynamic regulatory network that influences key cancer hallmarks, including cell proliferation, apoptosis, epithelial–mesenchymal transition, metastasis, immune evasion, and therapy resistance. However, the contribution of these non-canonical regulatory layers to tumor-specific miRNA function remains poorly understood. In this review, we explore how isomiR generation, miRNA strand selection, arm switching, and epitranscriptomic regulation expand the functional diversity of miRNAs in gynecologic cancers. Full article

Mineral-scale deposition remains a persistent flow-assurance and asset-integrity constraint in oil and gas production. Calcium carbonate, calcium sulfate, barium sulfate, iron sulfide, and mixed inorganic scale deposits reduce tubing internal diameter. They also impair near-wellbore permeability, block safety-critical valves, reduce heat-transfer efficiency, and intensify under-deposit corrosion. Conventional management relies on prediction, chemical inhibition, squeeze treatments, acid dissolution, chelation, mechanical scraping, milling, jetting, and operational water management. These methods are indispensable, but each has a restricted operating envelope. Key limitations include mineral selectivity, corrosion risk, environmental discharge, intervention cost, debris generation, and poor effectiveness against chemically resistant sulfate scales, particularly BaSO₄. Ultrasound has therefore attracted interest as a non-chemical technology. Acoustic cavitation, microstreaming, pressure oscillation, mechanical vibration, and micro jetting may suppress nucleation, disturb boundary layers, weaken adhesion, and fragment brittle deposits. This review critically evaluates ultrasound-assisted scale prevention and removal, with emphasis on production tubing and oilfield relevance. Existing studies show credible mechanistic plausibility and promising laboratory performance for CaCO₃, CaSO₄/gypsum, KCl, NaCl, and membrane or heat-transfer fouling systems. It also compares performance metrics, field cases, and technology-readiness barriers. The evidence is less mature for long steel tubulars operating under high-pressure, high-temperature, multiphase production conditions. Current evidence positions ultrasound at technology-readiness level (TRL) 3–4 for CaCO₃ and CaSO₄ systems, where laboratory and bench-scale validation is established, and at TRL 2–3 for BaSO₄, where mechanistic plausibility exists but controlled experimental validation remains absent. The technology is not yet at the pilot–production transition for downhole tubing applications, but it is approaching that threshold for surface process equipment. Its most credible near-term role is as an intensifier paired with low-dose chemical inhibitors, where acoustic boundary-layer disruption can reduce the minimum inhibitory concentration threshold of inhibitors, and with mild chelating agents for early-stage BaSO₄ management, where ultrasound-enhanced mass transfer may accelerate chelant penetration into deposit microstructure. Advancing ultrasound from its current TRL toward field qualification requires targeted BaSO₄ scale validation in steel tubing systems, acoustic field mapping under HPHT multiphase conditions, mass-removal metrics, and a structured pilot programme. Full article

Sn-3Ag-0.5Cu-xBi alloys (SAC305-xBi) represent promising lead-free alternatives for low-temperature soldering. Low Bi concentrations can strengthen SAC-based solders through solid-solution strengthening, refining β–Sn grains and transforming needle-like Ag₃Sn phases into equiaxed morphologies. However, excessive Bi alloying may induce precipitation of brittle Bi particles, cause microstructural instability and interfacial degradation, thereby weakening the solder joint performance. As such, the concentration of Bi in the SAC305 alloys should be carefully controlled. In this work, the microstructure and corrosion behavior of Sn-3Ag-0.5Cu-xBi solder alloys (SAC305-xBi, where x = 0, 1, 2 and 4 wt. %) were investigated. Attention has been paid to the influence of low Bi concentration on the microstructure, morphology, and chemical composition of the phases present in the solder alloys before and after corrosion exposure. The alloys were prepared by induction melting of Sn, Ag, Cu and Bi lumps under Ar gas. The microstructure of the SAC305 and SAC305-1Bi alloys represented a hypoeutectic microstructure with dendritic (Sn) grains and the ternary eutectic, consisting of (Sn), Cu₆Sn₅ and Ag₃Sn, located in inter-dendritic regions. In the SAC305-2Bi and SAC305-4Bi alloys, a segregation of (Bi) particles was observed in addition to dendritic (Sn) and ternary eutectic. The (Bi) particles were located at the (Sn)Ag₃Sn interface in the inter-dendritic spaces of the (Sn) solid solution. The corrosion resistance of the as-cast alloys was studied in aqueous NaCl electrolyte (3.5 wt. %) using electrochemical methods. Open circuit potentials of the alloys were found to increase with increasing concentration of Bi. The highest corrosion current was found for the SAC305-1Bi alloy. It was observed that micro-galvanic cells at the Sn-Ag₃Sn interface were the initiating factors of corrosion in the SAC305-1Bi alloy. The corrosion activity of the SAC305-1Bi alloy is related to the high density of fine Ag₃Sn particles. The higher fraction of Ag₃Sn particles provided a dense network of local galvanic interaction sites, leading to the acceleration of the corrosion rate. The presence of discrete Bi precipitates in the SAC305-2Bi and SAC305-4Bi alloys, on the other hand, partially reduced the risk of galvanic corrosion. Since Bi has a higher standard electrode potential compared to Sn, the Bi/Ag₃Sn and Bi/Cu₆Sn₅ couples were less prone to corrosion. The corrosion mechanism of the SAC305-xBi alloys is discussed, and results are compared to previously studied SAC-Bi alloys. Full article