Search Results (1,855)

While standard anti- vascular endothelial growth factor (VEGF) therapy, with or without photodynamic therapy (PDT), is effective for patients with polypoidal choroidal vasculopathy (PCV), not all achieve optimal visual outcomes. This study aimed to compare fortified (double the dose and the volume of the standard one) anti-VEGF combined with PDT versus fortified anti-VEGF monotherapy and to investigate biomolecular profiles and disease relationships among PCV, neovascular age-related macular degeneration (nvAMD), and central serous chorioretinopathy (CSCR). The goal was to identify novel pathways to inform future therapeutic strategies, including hypoxia-inducible factors (HIF)-1α inhibitors. This retrospective cohort study included 23 eyes with indocyanine green-confirmed type C PCV. One eye treated with transpupillary thermotherapy was not included in the following two groups. Patients received either combined therapy (PDT + fortified-dose anti-VEGF; n = 12) or fortified-dose anti-VEGF monotherapy (n = 10). Primary outcomes were changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Secondary outcomes included injection burden and recurrence. Exploratory analyses examined aqueous biomarkers, including VEGF, placental growth factor (PlGF), β-catenin, HIF-1α, and Wnt1 across PCV, CSCR, and nvAMD to identify novel therapeutic targets. Significant (p = 0.003/p = 0.005) median CRT reduction was similar (p = 0.468) between groups (combined/monotherapy: 137.5 µm/106.5 µm). BCVA (median [Q1, Q3]) change in logarithm of the minimum angle of resolution (LogMAR) was not statistically significant (p = 0.279), with 0.25 [0.00, 0.98] in the combined group versus 0.00 [−0.03, 0.28] in the monotherapy group. Treatment burden of anti-VEGFs per person per year was lower with combined therapy (1.16 ± 0.47# PDT + 2.81 ± 0.92# anti-VEGF injections) compared with monotherapy (4.61 ± 1.49# injections). Six eyes demonstrated recurrence at a mean of 15.5 months. Incomplete regression of polyps and branching vascular networks was observed in all eyes. Exploratory biomarker analysis revealed significantly (p < 0.05) higher VEGF and PlGF levels in nvAMD compared with PCV. nvAMD also demonstrated significantly (p < 0.05) higher β-catenin and lower HIF-1α levels relative to PCV and CSCR, while no significant biomarker differences were observed between PCV and CSCR. Combined therapy or monotherapy with fortified anti-VEGFs reduced treatment burden and achieved significant anatomical improvement but did not yield superior functional outcomes, highlighting the therapeutic difficulty of type C PCV. Biomarker profiling revealed shared hypoxia-related mechanisms between PCV and CSCR, with elevated HIF-1α compared to nvAMD indicating a “preliminary” possible role for HIF-1α inhibitors. Differential expression of these biomarkers highlights additional molecular pathways that may inform future targeted interventions. Full article

Background and Objectives: Keratoconus is a bilateral but often asymmetric ectatic corneal disease characterized by progressive thinning, increased curvature, and conical shape of the cornea. Previous studies have reported that the use of swimming goggles in patients with keratoconus can lead to increased intraocular pressure (IOP) and a transient reduction in anterior chamber volume (ACV), potentially affecting anterior segment morphology. This study aimed to evaluate the short-term effects of periorbital pressure induced by swimming goggles on corneal parameters in keratoconic eyes. Materials and Methods: A total of 44 eyes of 44 patients (mean age: 26.1 ± 5.1 years) diagnosed with keratoconus Stage 1–4 according to the Amsler–Krumeich classification were included. Measurements were taken using a Pentacam^® Scheimpflug camera before swimming goggle application and immediately after 20 min of wear. The parameters assessed included keratometry values (K1, K2, Km, Kmax), central and thinnest corneal thickness, corneal volume within the 10 mm zone (CV10), ACV, anterior chamber depth (ACD), iridocorneal angle (ICA), and pupil diameter (PD). Results: No statistically significant changes were observed in keratometric values, central and thinnest corneal thickness, ACV, ACD, ICA, PD, or IOP (all p > 0.05). CV10 showed a small reduction following goggle wear (Δ = −0.18 mm³, corresponding to a 0.3% decrease), which was statistically significant in the unadjusted analysis (p = 0.008) but did not remain significant after correction for multiple comparisons (p for false discovery rate [FDR] = 0.10). Conclusions: Short-term swimming goggle use may induce subtle reductions in CV10 in keratoconic eyes, suggesting a potential biomechanical sensitivity to transient periocular pressure. Although the observed change in CV10 did not retain statistical significance after multiple-comparison correction, it may reflect an early physiological response in structurally compromised corneas. CV measurements could serve as exploratory indicators of mechanical responsiveness in keratoconus, warranting further investigation in larger controlled studies. Full article

Methane emissions from rice paddies account for over 11% of global atmospheric CH₄, making water management practices such as Alternate Wetting and Drying (AWD) critical for climate change mitigation. Remote sensing offers an objective approach to monitoring AWD implementation and improving greenhouse gas estimation accuracy. This study investigates the backscattering mechanisms of L-band SAR for inundation/non-inundation classification in paddy fields using full-polarimetric ALOS-2 PALSAR-2 data. Field surveys and satellite observations were conducted in Ryugasaki (Ibaraki) and Sekikawa (Niigata), Japan, collecting 1360 ground samples during the 2024 growing season. Freeman–Durden decomposition was applied, and relationships with plant height and water level were analyzed. The results indicate that plant height strongly influences backscatter, with backscattering contributions from the surface decreasing beyond 70 cm, reducing classification accuracy. Random forest models can classify inundated and non-inundated fields with up to 88% accuracy when plant height is below 70 cm. However, when using this method, it is necessary to know the plant height. Volume scattering proved robust to incidence angle and observation direction, suggesting its potential for phenological monitoring. These findings highlight the effectiveness of L-band SAR for water management monitoring and the need for integrating crop height estimation and regional adaptation to enhance classification performance. Full article

Three-dimensional computational fluid dynamics (CFD) simulation was performed using the eddy-dissipation concept coupled with detailed hydrogen oxidation kinetics and a reduced two-step methane mechanism for a newly proposed W-shaped radiant tube burner (RTB). The effects of the hydrogen volume fraction (0–100%) and excess air ratio (0%, 10%, 20%) on the flame morphology, temperature distribution, and NO_X emissions are systematically analyzed. The results deliver three main points. First, a flame-shape transformation was identified in which the near-injector flame changes from a triangular attached mode to a splitting mode as the mixture reactivity increases with the transition occurring at a characteristic laminar flame speed window of about 0.33 to 0.36 m/s. Second, NO_X shows non-monotonic behavior with dilution, and 10% excess air can produce higher NO_X than 0% or 20% because OH radical enhancement locally promotes thermal NO pathways despite partial cooling. Third, a multi-parameter coupling strategy was established showing that hydrogen enrichment raises the maximum gas temperature by roughly 100 to 200 K from 0% to 100% H₂, while higher excess air improves axial temperature uniformity and can suppress NO_X if over-dilution is avoided. These findings provide a quantitative operating map for balancing stability, uniform heating, and NO_X–CO trade-offs in hydrogen-enriched industrial RTBs. Full article

The Longmaxi from the Anchang Syncline in northern Guizhou exhibits a high degree of thermal evolution of organic matter and significant variation in gas content. Because the synclinal is narrow, steep, and internally faulted, the mechanisms controlling shale gas preservation and escape remain poorly understood, complicating development planning and engineering design. Research on oil and gas migration and accumulation mechanisms in synclinal structures is therefore essential. To address this issue, three proportionally scaled strata—pure shale, gray shale, and sandy shale—were fabricated, and faults and artificial fractures with different displacements and inclinations were introduced. The simulation system consisted of two glass tanks (No. 1 and No. 2). Each tank had three rows of eight transmitting electrodes on one side, and a row of eight receiving electrodes on the opposite side. Tank 1 remained fixed, while Tank 2 could be hydraulically tilted up to 65° to simulate air and water migration under varying formation inclinations. A gas-water injection device was connected at the base. Gas was first injected slowly into the model. After injecting a measured volume (recorded via the flowmeter), the system was allowed to rest for 24–48 h to ensure uniform gas distribution. Water was then injected to displace the gas. During displacement, Tank 1 remained horizontal, and Tank 2 was inclined at a preset angle. An embedded monitoring program automatically recorded resistivity data from the 48 electrodes, and water-driven gas migration was analyzed through resistivity changes. A gas escape rate parameter (G_d), based on differences in gas saturation, was developed to quantify escape velocity. The simulation results show that gas escape increased with formation inclination. Beyond a critical angle, the escape rate slowed and approached a maximum. Faults and fractures significantly enhanced gas escape. Full article

Forming tools adjustable by tensile elastic deformations offer opportunities for improved process control and reduced wear in high-volume metal forming processes such as ironing. However, the lack of tensile and fatigue data for hardened cold-work tool steels limits their broader adoption. This study investigates the mechanical performance of three tool steels—Vanadis^®4 Extra SuperClean, Vancron^® SuperClean, and Caldie^®—through uniaxial tensile and fatigue testing, supplemented by destructive static and fatigue/wear tests on specimens representative of an adjustable ironing punch. Non-coated specimens exhibited ultimate tensile strengths above 2700 MPa with approximately 2% plastic strain, while coated specimens fractured in a brittle manner between 1600–1900 MPa. Fatigue life at stress ranges between 1450–1750 MPa varied from several thousand to over four million cycles, with crack initiation linked to non-metallic inclusions and precipitates 10–30 μm in size. Finite element simulations accurately linked failure observed in uniaxial tests to the component-level tests, confirming that first principal stress is a reliable predictor for punch failure. All punch specimens withstood 10⁶ cycles at diameter changes up to 140 μm (4‰), with coated punches exhibiting minimal wear and non-coated ones showing localized surface damage. The findings support material and coating selection for adjustable forming tools and highlight opportunities for further optimization. Full article

Sulfate corrosion is a significant durability issue for concrete used in sewage and hydraulic infrastructure. In sulfate-rich environments, the formation of expansive products (e.g., ettringite and thaumasite) leads to a progressive loss of performance. Unlike conventional protection methods, which rely on surface-applied coatings or impregnation, this study examines the use of water-dilutable epoxy resins as an internal, volume-wide admixture dispersed throughout the concrete matrix to provide whole-body protection. The experimental program evaluated the mechanical performance, microstructure, and sulfate ion ingress/penetration dynamics of resin-modified concretes. The results suggest that using the appropriate amount of resin can limit the penetration of aggressive ions and slow the harmful changes associated with sulfate attack while maintaining the material’s overall performance. Overall, these findings suggest that water-based epoxy admixtures are a promising strategy for improving the durability of concrete in sulfate-exposed environments. They also provide guidance for designing more resistant cementitious materials for modern infrastructure applications. Full article

Tibetan sheep, a unique breed indigenous to the Qinghai–Tibet Plateau, exhibit remarkable adaptations to high-altitude hypoxia, and their muscle quality is a key economic determinant. However, the molecular mechanisms by which exercise regulates meat quality in this breed remain poorly understood. This study aimed to systematically investigate the effects of different exercise volumes on the biceps femoris muscle of Tibetan sheep, integrating histological analysis with high-throughput transcriptome sequencing. We compared a low-exercise group with a high-exercise group and found that long-term endurance exercise resulted in phenotypic changes suggestive of a shift toward oxidative muscle fiber characteristics. This adaptation was characterized by significantly reduced muscle fiber diameter and cross-sectional area, alongside a crucial increase in intramuscular fat content, collectively enhancing meat tenderness, flavor, and juiciness. Transcriptomic analysis revealed extensive gene expression reprogramming, identifying 208 mRNAs and 490 lncRNAs that were differentially expressed and primarily associated with muscle fiber transition and energy metabolism. Furthermore, we constructed a putative lncRNA-miRNA-mRNA competing endogenous RNA network based on expression correlations and bioinformatic predictions, highlighting potential key regulatory axes such as LOC105603384/miR-16-z/MYLK3, LOC121820630/miR-381-y/NOX4, and LOC132659150/oar-miR-329a-3p/NF1. These findings provide a new perspective on the molecular basis of exercise-induced muscle adaptation in high-altitude animals and offer a solid theoretical framework for improving meat quality through scientific livestock management. Full article

Here, we present published data on the influence of ambient current on the pumping rate of sponges, and subsequently, we make interpretations based on a fluid-mechanical approach for analyzing the sponge–pump system. Ambient water flow past a benthic filter-feeding sponge can give rise to an increased osculum out-flow rate (pumping rate = filtration rate) of the sponge. The mechanism at play is the change in pressure distribution over the sponge. Thus, if ambient flow leads to an increased positive pressure at the ostia inlets and a negative pressure at the osculum outlet, both contribute to a negative backpressure (suction at osculum), which shifts the system characteristic to intersect the pump characteristic at a higher volume flow rate, and this may imply a reduced energy expenditure of the sponge pump. The magnitude of such negative backpressures is estimated for an isolated, upright cylindrical sponge, and based on this, we re-interpret earlier experimental data. However, it is unknown if ambient currents may help the sponge to process the same volume of water at lower energy cost. Full article

Fly ash–based geopolymers have emerged as a promising alternative to ordinary Portland cement, offering high mechanical strength and reduced environmental footprint. However, they are often limited by significant shrinkage and strength degradation when subjected to elevated temperatures. To enhance their thermomechanical performance and thermal stability, this study investigates the effects of mix proportioning parameters, alkali activator type, and thermal shock on performance deterioration. Compressive strength was evaluated for sodium- and potassium-activated fly ash geopolymer composites as a function of alkaline activator (AA) ratios, both under ambient curing and after exposure to the ISO 834 standard fire curve for 1 and 2 h. Volume change, mass loss, and density variation were analysed to interpret mechanical behaviour and relate it to structural transformations, while XRF, XRD, SEM, and particle size distribution were employed for material characterisation. Results indicate that rapid temperature changes, whether from thermal shock or high fire-heating rates, induced notable additional thermal degradation. Sodium activation achieved the highest compressive strength retention of 145% at one hour of firing, while potassium activation showed superior thermal stability with delayed densification, reaching 154% strength retention at two hours. Furthermore, SiO₂/M₂O ratio exerted the strongest influence on both mechanical and thermomechanical performance. Overall, the findings highlight that the activator type, SiO₂/M₂O ratio, and rapid temperature changes collectively exert strong control over the thermomechanical and thermophysical response of fly ash geopolymers at elevated temperatures. Full article

Thin plates are widely used and can be subjected to combined loads that trigger elasto-plastic buckling. Often, these plates are perforated, which significantly changes their mechanical response. This study investigates six perforation geometries (elliptical, longitudinal hexagonal, transverse hexagonal, longitudinal oblong, transverse oblong, and rectangular) and their influence on the ultimate buckling stress of perforated plates under biaxial compression and lateral pressure. Three plates with a distinct width b and length a ratio (b/a) and five unperforated plate volume and perforation volume ratios (ϕ) are analyzed using finite element analysis in ANSYS^®, combined with Constructal Design, Exhaustive Search, and the Technique for Order Preference by Similarity to an Ideal (TOPSIS). Perforation geometry is shown to be a decisive parameter: elliptical perforations are the most efficient, limiting strength loss in rectangular plates with b/a = 1/3 and ϕ = 0.025 to about 6%, while oblong perforations cause reductions of up to 14%. In square plates (b/a = 1), elliptical perforations preserve more than 98% of the original strength for ϕ ≤ 0.05 and over 90% at ϕ = 0.20. TOPSIS results highlight configurations that balance small reductions in ultimate buckling stress with up to 23% lower maximum deflection, providing practical design guidelines. Full article

Molecular dynamics simulations were conducted at a cooling rate of 1.0 × 10¹¹ K/s to investigate the solidification mechanism of zirconium (Zr) under high pressure. Three distinct pressure-dependent regimes are identified: crystallization into a body-centered cubic (BCC) phase below 27.5 GPa, vitrification between 27.5 and 65 GPa, and crystallization into an A15 phase above 65 GPa. The volume change during crystallization is found to reverse at critical pressures of 5 and 103 GPa, and anomalous behavior is observed at the phase boundaries: at 27.5 and 65 GPa, the volume varies continuously despite a sharp drop in potential energy, whereas at 65 GPa, the volume decreases abruptly while the energy changes smoothly. Structural analysis indicates that evolution in the low-pressure regime is governed by atomic configurations extending to the second-neighbor shell, while at high pressures, nearest-neighbor interactions become dominant. This work clarifies the microstructure–pressure relationship during metallic solidification, providing insights into controlling phase transitions under extreme conditions. Full article

Objectives: The Eight-chop technique is a mechanically based nuclear segmentation method designed to improve surgical efficiency and reduce intraocular tissue stress during phacoemulsification. Early postoperative aqueous flare serves as an objective indicator of surgical invasiveness, whereas corneal endothelial cell density (CECD) loss represents a structural measure of endothelial injury. Although both parameters are clinically important, their relationship has not been systematically investigated in the context of this newer mechanical fragmentation approach. Methods: This prospective observational study included 118 eyes from 70 non-diabetic patients undergoing uncomplicated Eight-chop phacoemulsification. Aqueous flare was measured preoperatively and at postoperative Day 1, Day 7, Week 7, and Week 19 using laser flare photometry. CECD was evaluated preoperatively and at Weeks 7 and 19. Changes over time were analyzed using paired t-tests. Linear mixed-effects models (random intercept = patient ID) were constructed to assess predictors of CECD loss and postoperative intraocular pressure (IOP) reduction. Explanatory variables included Day 1 flare, age, preoperative CECD, nucleus hardness (Emery-Little grade), cumulative dissipated energy (CDE), and irrigation fluid volume. Results: Postoperative flare increased significantly at all time points (all p < 0.001), peaking on Day 7 (16.7 ± 9.21 photon counts/ms). CECD loss was extremely small, averaging 1.38% at Week 7 and 1.46% at Week 19. In mixed-effects models, Day 1 flare was not associated with CECD loss at Week 7 (p = 0.35) or Week 19 (p = 0.85). Significant predictors of CECD loss included Emery-Little grade (p = 0.004 at Week 7; p = 0.025 at Week 19), with borderline contributions from CDE and irrigation volume. IOP decreased significantly at Weeks 7 and 19; however, Day 1 flare did not predict IOP reduction. Conclusions: Eight-chop phacoemulsification produced uniformly low postoperative inflammation and exceptionally small corneal endothelial cell loss. Early postoperative flare did not predict CECD loss, suggesting that the Eight-chop technique provides a highly standardized, low-invasiveness surgical environment. These findings suggest that the Eight-chop technique lowers ultrasound energy requirements and may help reduce corneal endothelial stress relative to standard phacoemulsification. Full article

Solar-driven irrigation, a promising clean technology for agricultural water conservation, is constrained by mismatched photovoltaic (PV) pump outflow and irrigation demand, alongside unstable PV output. While compressed-air energy storage (CAES) shows mitigation potential, existing studies lack systematic explorations of pump water-lifting characteristics and supply capacity under coupled meteorological and air pressure effects, limiting its practical promotion. This study focuses on a solar-coupled compressed-air energy storage regulated sprinkler irrigation system (CAES-SPSI). Integrating experimental and theoretical methods, it establishes dynamic flow models for three DC diaphragm pumps considering combined PV output and outlet back pressure, introduces pressure loss and drop coefficients to construct a nozzle pressure dynamic model via calibration and iteration, and conducts a 1-hectare corn field case study. The results indicate the following: pump flow increases with PV power and decreases with outlet pressure (model deviation < 9.24%); nozzle pressure in pulse spraying shows logarithmic decline; CAES-SPSI operates 10 h/d, with hourly water-lifting capacity of 0.317–1.01 m³/h and daily cumulation of 6.71 m³; and the low-intensity and long-duration mode extends irrigation time, maintaining total volume and optimal soil moisture. This study innovatively incorporates dynamic air pressure potential energy into meteorological-PV coupling analysis, providing a universal method for quantifying pump flow changes, clarifying CAES-SPSI’s water–energy coupling mechanism, and offering a design basis for its agricultural application feasibility. Full article

Objectives: This study aimed to comprehensively evaluate and compare the therapeutic effects of Right Angle Maxillary Protraction Appliance (RAMPA) therapy on nasal airway volume in pediatric patients, specifically differentiated by their baseline radiological paranasal sinus status. The objective was to quantify airway volume changes (absolute and percentage) in clear and opacified sinus groups, investigate the influence of age, sex, and treatment duration on these changes, and elucidate potential differences in the underlying mechanisms of airway expansion between groups. Study Design: A retrospective comparative cohort study design was employed. This study includes a “clear sinus group” of 26 patients (mean age: 6.6 years) with radiologically clear sinuses at baseline and an “opacified sinus group” of 20 patients (mean age: 6.8 years) diagnosed with rhinosinusitis and exhibiting significant sinus opacification on baseline CBCT scans. Upper airway volumetric measurements were performed using CBCT scans acquired pre- (T1) and post-treatment (T2), with data analyzed using Invivo 5 software. Results: RAMPA therapy significantly increased upper airway volume in both cohorts. The clear sinus group showed an approximate 18% mean increase (4886.9 mm³ absolute), while the opacified sinus group demonstrated a remarkably greater 61% mean increase (11,192.8 mm³ absolute). This difference was statistically significant. In the clear sinus group, airway volume gain positively correlated with treatment duration (p = 0.0303). Conversely, no significant correlation was found in the opacified sinus group (p = 0.288), suggesting rapid obstruction relief as a dominant mechanism. Sex did not significantly influence outcomes, and age was not a strong independent predictor of volume change magnitude. Conclusions: RAMPA therapy effectively increases upper airway volume in pediatric patients, with a substantially greater effect in those with baseline sinus opacification due to rapid obstruction resolution complementing skeletal changes. The mechanism of action differs by sinus status, with clear sinus patients showing gradual, duration-dependent skeletal adaptation and opacified sinus patients exhibiting immediate, duration-independent gains primarily from sinus clearance. These findings provide crucial insights for tailored clinical decision-making. Full article