Abrasive flow machining (AFM) is an effective finishing process for complex internal surfaces, particularly cavities, intersecting holes, and micro-channels that are difficult to access using conventional tools. However, when low-viscosity abrasive media is used (here defined, relative to conventional putty-like viscoelastic AFM carriers (with apparent viscosities of 103-105 mPa·s), as a water-based slurry with an apparent viscosity below 300 mPa·s over the operating shear-rate range), unfavorable flow conditions during the initial polishing stage can induce local over-polishing, erosion depressions, stepped patterns, and cavitation pits, resulting in non-uniform surface quality. The relationship between these flow behaviors and polishing defects remains insufficiently understood. To address this issue, this study investigates the AFM process applied to turbine blade film cooling holes through combined experimental and numerical approaches. The observed defects include erosion depressions, stepped surface patterns, and cavitation pits. The effects of abrasive injection pressure, flow velocity, hole geometry, abrasive viscosity, and particle size on defect formation are systematically examined. The results show that the initial abrasive filling level strongly affects defect distribution by altering the evolution of shear fields and void regions within the hole. Experimentally, at high Reynolds numbers (Re > 2 × 104), intensified local shear and cavitation promote defect formation, while a moderate inclination angle (45-60°) and a higher aspect ratio (>8) are favorable for polishing uniformity. Complementary numerical simulations further indicate that smaller abrasive particles (<5 μm) and a moderate abrasive viscosity (~60 mPa·s) are predicted to improve polishing uniformity. This study clarifies the fluid-dynamic origin of polishing defects in film cooling holes and provides process guidance for suppressing local over-polishing, cavitation, and uneven material removal.
A full-thickness macular hole is conventionally regarded as a vitreoretinal-interface disorder of later life caused by anomalous perifoveal posterior vitreous detachment, tangential traction, and failure of foveal tissue compliance. This model explains idiopathic macular holes. Secondary macular holes could occur secondary to trauma, retinal detachment and high myopia, but less is known about the nature of macular holes associated with inherited retinal dystrophies and vitreoretinopathies, in which the fovea, retinal pigment epithelium, basement membranes, or vitreous cortex may be genetically abnormal before traction is applied. We examine evidence on macular holes in inherited retinal disease, with emphasis on genotype, molecular pathology, optical coherence tomography phenotype and surgical strategy. Three mechanistic groups are clinically useful: (i) disorders of basement membrane and vitreoretinal-interface; (ii) disorders characterized by intrinsic neurosensory retinal weakness; and (iii) retinal pigment epithelium-driven outer-retinal disruption. Surgical closure is often possible, particularly when a tractional component is present and outer-retinal structure is preserved. Visual recovery, however, is limited by photoreceptor integrity, retinal pigment epithelium survival, chronicity and the extent of pre-existing degeneration. In select disorders, especially Alport syndrome, standard internal limiting membrane peeling may be impossible or inappropriate, and alternative scaffold techniques such as amniotic membrane graft may be beneficial. Genetic diagnosis helps to inform mechanism, prognosis, operative planning, counselling and eligibility for emerging gene-directed therapies. This framework may help clinicians interpret optical coherence tomography findings and consider disease-specific surgical risks;. however, the evidence base is dominated by case reports and small case series and varies substantially across diagnoses. Accordingly, the proposed classification and management considerations should be viewed as hypothesis-generating and clinically-pragmatic rather than guideline-level recommendations.
With the release of the fourth LIGO-Virgo-KAGRA gravitational-wave catalog (GWTC-4), we are starting to gain a detailed view of the population of merging binary black holes. The formation channels of these black holes is not clearly understood, but different formation mechanisms may lead to subpopulations with different properties visible in gravitational-wave data. Adopting a phenomenological approach, we find GWTC-4.0 data supports the presence of at least three subpopulations, each associated with a different range of black hole mass and with sharp transition boundaries between them. Each subpopulation is characterized by different distributions for either the mass ratios, the black-hole spin magnitudes or both. Subpopulation A with primary mass m_{1}≤27.7_{-3.4}^{+4.1}M_{⊙} (90% credibility), is characterized by a nearly flat mass ratio distribution q=m_{2}/m_{1}, and by small spin magnitudes (χ≤0.5_{-0.1}^{+0.1}). Subpopulation B, with 27.7_{-3.4}^{+4.1}M_{⊙}≤m_{1}≤40.2_{-3.2}^{+4.7}M_{⊙}, has a much sharper preference for mass ratio q≈1. Subpopulation C, with m_{1}≥40.2_{-3.2}^{+4.7}M_{⊙}, has support for large spin magnitudes, and tentative support for mass ratios q≈0.5. We interpret these transitions as evidence for multiple subpopulations, each potentially associated with a different formation pathways. We suggest putative formation scenarios for each subpopulation, and explore chemically homogeneous evolution, population III stars and dynamical formation channels as an explanation for subpopulation B. Our findings for subpopulation C are largely consistent with recent claims of hierarchical mergers but with some curious differences in properties.
This manuscript gives a solution to the black hole information paradox by bringing to the debate a fundamental aspect of information science: the process of measurement by a receiver. Bekenstein and Hawking established the foundations of black hole thermodynamics based on previous works of Brillouin and Szilard on information physics. In this work, we demonstrate that the relation between energy and information established in communication technology by Shannon and Landauer has not been adequately applied to black hole physics. As Landauer states, a computation process is closely akin to a measurement. Our argument is grounded on the physical concepts of measurement, signal-to-noise ratio, energy dissipation during the switching process in computation, and hysteresis loops. We give special attention to the role of noise and energy dissipation in the process of information transmission. We demonstrate that Szilard's work fails to establish a connection between information and entropy in agreement with the works of Landauer and Shannon. We also demonstrate that a quantum state cannot be directly equivalent to a unit of information. The entropy and temperature attributed to black holes are questioned, and a solution to the black hole information paradox is provided. Similarly to what happens with Maxwell's demon, the black hole information paradox is "exorcised" once we account for the process of measurement and information processing.
To evaluate stage-specific morphofunctional relationships in idiopathic macular holes (IMHs) and determine whether stage 2‑specific features could be explained by hole size alone. Retrospective observational study. A total of 105 eyes with IMHs and available 3-month postoperative follow-up data. Eyes were stratified by Gass stage into stage 2 and stage 3 to 4 groups and by International Vitreomacular Traction Study size criteria into small and medium-to-large groups. Associations between preoperative optical coherence tomography (OCT) parameters and best-corrected visual acuity were assessed using interaction, stratified, and multivariable regression analyses. Associations between preoperative morphological parameters and best-corrected visual acuity before surgery and at 1 and 3 months postoperatively. Preoperative interactions with stage were significant for minimum linear diameter, minimum area/foveal avascular zone ratio, and minimum area. Stage 3 to 4 showed consistent morphofunctional associations, whereas stage 2 showed less consistent associations not fully explained by hole size. In multivariable analyses, predictors were more stable in stage 3 to 4 than in stage 2. Size-based classification showed less consistent patterns than stage-based stratification. Stage 2 IMHs showed less consistent morphofunctional relationships than stage 3 to 4, and these differences were not fully explained by measured OCT-based size parameters alone. These findings support stage-aware interpretation of OCT-derived biomarkers and may inform future prognostic studies in IMHs. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
To review the phenomenon of delayed and spontaneous closure of full-thickness macular holes (FTMHs) following apparent primary surgical failure, and to synthesize reported timelines, visual outcomes, and proposed mechanisms. A scoping review was conducted using PubMed and Embase (January 1990-June 2024). Case reports, case series and observational studies were eligible if they described MH that remained open after surgery but subsequently closed spontaneously. Data on baseline characteristics, surgical technique, postoperative features, time to closure and visual outcomes were extracted. Fifteen studies met inclusion criteria, of which 13 provided patient-level data. Across all cases, the mean time to closure was 536 days (median 150, IQR 90-480, range 27-2555), although this distribution was skewed by rare very late closures up to 7 years. Excluding cases closing beyond one year, the mean time to closure was 124 days (median 120, IQR 70-150, range 27-270), indicating that most delayed closures occur within 3-6 months. Visual Acuity (VA) showed a mean improvement of -0.32 logMAR (median -0.35, IQR -0.50 to -0.15, range -1.10 to +0.80). Restricting to cases closing within one year yielded a mean improvement of -0.35 logMAR (median -0.50, IQR -0.65 to -0.20), corresponding to approximately three to four lines of VA gain. Delayed spontaneous closure of FTMHs after apparent primary surgical failure is uncommon but clinically relevant. It has most often been observed within the first 6-12 months and is frequently accompanied by some visual acuity improvement although outcomes vary widely.
Uncontrolled carbon monoxide (CO) release after deep-hole roof pressure-relief blasting remains a safety problem because conventional shallow drainage often fails to match the strata where blast gases are generated and retained. Here, we clarify the permeability-contrast-controlled retention mechanism and propose an integrated blasting-sealing-extraction framework that couples field diagnosis at the A503 working face, dynamic fracture modeling, confined explosion tests, adsorption-diffusion analysis, and industrial validation. The method uses the critical distance between the fracture front and the coal seam to constrain charge length and places extraction boreholes in the roof gas-enrichment zone rather than only in the coal seam. The A503 measurements showed that the sandstone roof permeability (2.1 × 10-13 m2) was about 41 times lower than that of the coal seam (8.7 × 10-12 m2), creating a low-permeability CO retention zone. Numerical simulations gave an effective blasting influence radius of approximately 6.5 m and showed that the control hole extended the connected plastic zone to about 10 m. Field mass-balance data showed that the optimized scheme increased the CO extraction rate from 4.43% to 82.21%, reduced ventilation discharge from 11.96% to 3.91%, and lowered the residual CO fraction from 83.61% to approximately 13.9%. These results show that the mechanism-guided matching of fracture control, sealing, and targeted roof-strata extraction converts postblasting CO control from delayed ventilation dilution to active capture at the enrichment zone.
Analyses of hundreds of collisions find black holes pair up in at least three ways.
Halogen bonding develops when an electrophilic region associated with a covalently bonded halogen interacts attractively with a nucleophilic site on another same or different molecular entity. Here, we show that in many crystals in the Cambridge Structural Database, the intermolecular distances and directional features of F···F close contacts involve σ-hole-like regions on covalently bound fluorine. However, such interactions cannot readily be classified as classical halogen bonds, as the interacting fluorine atoms may lack a positive site (e.g., a positive σ-hole). In this context, we investigated directional F···F interactions involving HF, CH4-nFn (n = 1-4), and C6H6-nFn (n = 1-6) interacting with negative sites in the same or different partner interacting species using computational methods, which exhibit complex geometries reminiscent of σ-hole interactions. However, such interactions between sites of like polarity are more appropriately described as σ-hole-centered anti-electrostatic interaction motifs, driven in part by dispersion, rather than being recognized as conventional σ-hole-centered halogen bonds. This interpretation is supported by molecular electrostatic surface potential and symmetry-adapted perturbation theory analyses.
Two decades after the Human Genome Project, we finally have the ability to read the complete genome of any human and (nearly) any species. These sequences provide the ideal foundation for training predictive models of the genome that will accelerate basic research, enable accurate diagnostics, and guide precision medicine.
Two-dimensional coalescence of holes (regions with thickness less than the surrounding film) in free-standing Smectic A films was studied. Investigations were made on two types of domains: circular holes and holes with a thin sheet of the external film between holes. Direct evidence was found that before start of coalescence a long, thin sheet of external film can exists between holes. This sheet determines the early mechanism of coalescence. It is shown that the existence of the sheet essentially elongates the linear temporal dependence of the size of the bridge connecting the two holes rb(t) ~ t. Later when the thin sheet disappears the crossover to the conventional dependence rb(t) ~ (t)1/2 was observed. Our results can explain numerous data on two-dimensional and quasi-two-dimensional coalescence at the early and later stages of coalescence.
Dural tenting is performed to reduce the risk of postoperative epidural hematoma; although its routine use remains controversial, it continues to be widely practiced. Suture passage through drill holes in the bone flap is conceptually simple but can be technically cumbersome, often requiring precise alignment and repeated attempts. We describe a pull-through technique using a ligature passer to enable controlled and reproducible suture passage. A single-use wire ligature passer (LAPA-HER-CLOSURE) was used to retrieve dural sutures through drill holes in the bone flap. The device was inserted from the outer table toward the inner surface, where a loop mechanism was deployed to capture the suture and withdraw it through the drill hole. This technique replaces blind threading of a flexible suture with controlled retrieval using a rigid device. The technique eliminates blind suture passage and reduces repeated attempts and unnecessary manipulation. It enables stable, reproducible suture passage through drill holes. Owing to its intuitive mechanical design, the technique requires minimal specialized training. Although the impact on overall operative time may be limited, it may reduce the time required for dural tenting, particularly when dural tenting is performed at multiple sites. This pull-through technique using a ligature passer is a simple and practical refinement that facilitates reliable suture passage and simplifies bone flap handling.
The unique combination of outstanding optical quality and attractive spin properties opens new avenues for optical spin control in hybrid organic-inorganic perovskite semiconductors. Using the optically detected magnetic resonance technique, we study the spins of electrons and holes in mixed-cation MA x FA 1 - x PbI 3 single crystals with x = 0.4 and 0.8. Multiple distinct spin subensembles with absolute values of g -factor spanning from 2.9 to 3.5 for electrons and from 0.5 to 1.6 for holes are resolved, revealing diverse localization environments. We measure the longitudinal spin relaxation times, T 1 , reaching 2 ms and remaining in the μ s range even for weakly localized carriers at cryogenic temperatures. The magnetic-field dependence of T 1 is dominated by the random nuclear (Overhauser) fields with strengths of ∼ 0.5  mT for electrons and ∼ 5 - 12  mT for holes. The corresponding correlation times of the hyperfine field are determined by carrier hopping between shallow localization sites. The temperature dependence of T 1 reveals a weak localization potential of the charge carriers and shows a correlation between T 1 and the inhomogeneity of the spin ensemble. These results establish mixed-A-site perovskite single crystals as a promising solid-state platform with long-lived spin states for quantum information applications.
Series of layer-by-layer organic photovoltaics (LOPVs) were constructed with polymer D18 as donor and small molecule L8-BO with self-dissociation characteristics as acceptor. The high hole mobility and good crystallinity semiconductor C8-BTBT was deliberately incorporated into the D18 and L8-BO layers for optimizing the performance of LOPVs. The power conversion efficiency (PCE) of LOPVs can be increased from 19.10% to 20.11% by incorporating 0.5 wt% C8-BTBT in D18 layer and 0.05 wt% C8-BTBT in L8-BO layer. The PCE improvement benefits from the synergistic enhancement of short circuit current density of 27.56 mA cm-2 and fill factor of 80.10%. The incorporation of C8-BTBT in L8-BO layer can provide efficient transport channels for holes generated from L8-BO exciton self-dissociation. Introducing C8-BTBT in D18 layer can facilitate holes transport owing to its high hole mobility relative to that of D18. The interdiffusion between the D18 and L8-BO layers can be enhanced by incorporating highly crystalline C8-BTBT, facilitating exciton dissociation through enlarged donor/acceptor interfaces, as confirmed from neutron reflectivity measurements. This work indicates that incorporating high hole mobility material with good crystallinity into donor and acceptor layers is an effective strategy for achieving high-performance LOPVs.
Traumatic intracerebral hemorrhage (TICH) often coexists with other traumatic intracranial lesions and presents complex pathophysiology, making surgical decision-making challenging. Although craniotomy has long been the standard treatment for space-occupying traumatic hematomas, endoscopic hematoma evacuation has emerged as a minimally invasive alternative. However, evidence supporting its application to TICH remains limited. We report two patients with TICH who underwent endoscopic hematoma evacuation for acute traumatic management. In both cases, neurological deterioration was attributed to the localized mass effect caused by traumatic intracerebral hematomas, and endoscopic evacuation was selected to achieve focal decompression. The procedures were performed through burr holes using a transparent sheath and rigid neuroendoscope. Adequate hematoma removal was achieved without intraoperative or postoperative hemorrhagic complications. Postoperative computed tomography confirmed satisfactory evacuation, and intracranial pressure was well controlled during the acute phase. Although both patients ultimately died from nonneurological causes, no TICH-related neurological deterioration was observed during the postoperative course. Endoscopic hematoma evacuation may represent a technically feasible minimally invasive option for achieving focal decompression in selected patients with TICH. In the present two cases, adequate hematoma removal was achieved without procedure-related complications. However, because both patients ultimately died from severe systemic comorbidities unrelated to the neurosurgical procedure, no conclusions can be drawn regarding the effect of this technique on overall survival or long-term neurological outcomes. Further studies are required to establish appropriate surgical indications and determine their clinical benefit.
The rapid switching of materials when excited by ultrashort pulses of light is central for many optical technologies, and in particular to the developing field of time-varying metamaterials. These out-of-equilibrium interactions are difficult to capture with traditional theoretical models. Here we combine experiments and theory to unravel different regimes of interactions and a response saturation for a 44 fs, near-infrared pump pulse exciting a switchable doped semiconductor indium tin oxide thin film target. We model this process as a change in plasma frequency due to the excitation of hot electrons in a non-parabolic conduction band, which increases their effective mass. Our calculations show that saturation at high pump intensities arises because the pump heavily depopulates electrons from below the Fermi level. Excellent agreement with values extracted from experimental data confirms our model. For lower pump intensities, a two-temperature model is consistent with our data, but at higher intensities, it is apparent that other processes are at work, which we attribute to Auger transitions from the valence band, which introduce complex structure into the response, due to non-equilibrium rearrangement of energy between electrons and holes.
Container aquatic habitats such as tree-holes in temperate forests host diverse mosquito assemblages, yet the ecological functions of their obligate larval predators remain underexplored. We assessed the ecological roles of two widespread predatory mosquito larvae in Korea, Toxorhynchites christophi (Portschinsky) and Lutzia vorax Edwards, which share the same temperate forest container habitats. This study combined a 2-yr field mesocosm experiment (2023-2024) conducted in Gwangneung Forest in the central Korean Peninsula with laboratory analyses of the predatory behavior of the 2 species. Our field experiments revealed that the predation effects of the two species on mosquito larval communities were contrasting: Communities with Lt. vorax showed markedly low mosquito diversity and density, whereas those with Tx. christophi exhibited high diversity and evenness but low dominance. The two predators also showed temporal niche partitioning and different occurrence densities per container. In the laboratory experiment, both species displayed type II functional responses. However, Lt. vorax had a higher attack rate and a shorter handling time than Tx. christophi, yielding a greater theoretical maximum consumption. Only Lt. vorax showed significant preferences in tests using three dominant prey-mosquito species: Aedes koreicus (Edwards), Ae. flavopictus (Yamada), and Tripteroides bambusa (Yamada). Collectively, we propose that Tx. christophi and Lt. vorax each act as key predators that drive mosquito larval communities in opposite directions: Tx. christophi promotes greater diversity and evenness as a keystone predator, occurring at lower densities, whereas Lt. vorax collapses community structure through intense and rapid predation with higher densities per container.
As semiconductor packaging technology evolves from two-dimensional to three-dimensional integration, the through-glass via (TGV) technique, as a core interconnect method in advanced packaging, is emerging as a strong candidate to replace through-silicon vias (TSVs) and plated through-holes (PTHs) in organic substrates. Glass substrates offer excellent electrical insulation, low dielectric loss, tunable thermal expansion coefficients, and the potential for large-scale panel-level manufacturing. However, issues related to TGV hole quality, metallization uniformity, and thermomechanical reliability remain key bottlenecks limiting their large-scale industrialization. This investigation provides a comparative review of non-laser and laser machining for TGVs to address the above problems. First, the technical background and core advantages of TGVs are outlined. Second, this study details non-laser processing methods, including sandblasting erosion, mechanical drilling, the photosensitive glass method, electrochemical discharge machining (ECDM), deep reactive ion etching (DRIE), and others. Third, laser processing methods, covering laser ablation drilling, laser-induced deep etching (LIDE), femtosecond laser-assisted wet etching and others, are given focus. Moreover, this study analyzes typical applications of TGVs in 3D/2.5D packaging, MEMS devices, optoelectronic integration, and others. In addition, the machining processes of non-laser and laser-based TGVs, such as mechanical machining, ECDM, and LIDE, are compared, and key process challenges, technical trade-offs, and reliability failure mechanisms are discussed. Finally, this review looks ahead to future trends, aiming to provide a systematic technical reference for researchers in the TGV field.
Coal mining creates coupled physicochemical stresses, including extreme pH, nutrient depletion, metal enrichment, compaction, and loss of plant-derived carbon, that reduce microbial biomass, simplify interaction networks, and suppress biogeochemical functions. This review synthesizes recent evidence on microbial community restoration in abandoned coal mine lands, with emphasis on community assembly, stress adaptation, functional genes, and the interpretive value of high-throughput sequencing and meta-omics. During natural recovery, microbial propagule dispersal interacts with strong habitat filtering and rhizosphere selection. Pioneer plants and biological soil crusts progressively add carbon and nitrogen, stabilize surfaces, and recruit bacterial, fungal, and phototrophic guilds. Active interventions accelerate these processes by correcting substrate constraints and by inoculating soils, planting holes, seeds, or carriers with locally adapted microorganisms. However, field performance is often limited by competition with resident communities, host mismatch, environmental heterogeneity, and declining inoculant persistence. Restoration assessment should therefore combine taxonomic composition with functional-gene abundance, gene expression, enzyme activity, microbial biomass, and ecosystem-level indicators. Across sites, no single strategy is consistently superior: amendments act rapidly but may require repeated inputs, vegetation-based approaches are slower but potentially self-sustaining, and inoculation is most effective after major physicochemical barriers have been removed. Future research should prioritize replicated field trials, standardized and activity-resolved measurements, locally adapted consortia, and early-stage interventions that influence microbiome composition and function without assuming complete control. These priorities provide a practical basis for precision restoration of mine-affected soils.
Focal osteochondral defects of the knee are difficult to manage, as untreated lesions may progress to early osteoarthritis. The OvertureTi Knee Resurfacing System is designed to treat focal defects while preserving native bone, cartilage, and soft tissue. Focalplasty is indicated in patients with compartmentalized cartilage lesions, preserved ligamentous stability, and meniscal integrity or repairable tears. Appropriate alignment, joint space preservation, and minimal osteophyte formation are required. The procedure began with arthroscopic repair of the medial meniscus root using a transtibial pull-out technique. Following this, an open approach was performed to expose the medial femoral condyle. The chondral defect was sized, and appropriate instrumentation was used to prepare the site. Cartilage scoring and sequential reaming were performed to achieve the desired depth and contour. Trial components were confirmed to fit and position, after which peg holes were drilled and filled with bone cement. Finally, the oblong OvertureTi femoral implant was seated flush with the surrounding cartilage surface, and standard wound closure was completed. At 2 weeks, radiographs confirmed proper implant positioning. Long-term outcomes of the Overture prosthesis are not yet available. However, studies on similar implants, such as the HemiCAP, have reported improved function and survivorship at mid- to long-term follow-up. The Overture prosthesis offers advantages over arthroplasty and biologic resurfacing, including lower cost, off-the-shelf availability, preservation of native tissues, and bone conservation for future arthroplasty. Larger prospective studies are required to determine its long-term clinical efficacy. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.