Search Results (1,488)

Recent deep exploration in the northern Sichuan Basin has advanced our understanding of Lower Cambrian Canglangpu Formation carbonate reservoirs. However, the characteristics, genesis, and distribution of the reservoir, as well as future exploration targets, remain unclear. Specifically, core and thin-section analyses indicate that these reservoirs are notably tight, with virtually no visible macroporosity and low permeability (0.01–1 mD). However, helium porosity measurements reveal values of 2–5%, suggesting significant storage potential. An integrated approach utilizing optical and scanning electron microscopy (SEM), high-pressure mercury injection capillary pressure (MICP), nuclear magnetic resonance (NMR), and micro-computed tomography (micro-CT) was employed to characterize the pore systems. Quantitative thin-section analysis reveals visible areal porosity markedly lower than helium porosity, indicating predominance of micropores; mercury intrusion and NMR demonstrate that intragranular and intergranular micropores constitute most pore volume, although effectively connected throat sizes remain below 1 µm. Comparative stratigraphic evaluations show that porosity is more developed in the dolomite-rich upper and middle intervals of the depositional cycles, whereas the lower intervals are less porous. Early subaerial exposure promoted dolomitization and dissolution, which facilitated pore development. However, the influence of sediment mixing led to a reduction in porosity. And deep burial subjected the rocks to intense compaction and cementation, destroying most of the primary pore space. Consequently, reservoir quality is ultimately governed by the interplay between the original depositional environment and the later diagenetic history, with paleotopographic highs identified as the most promising exploration targets. These findings establish a predictive framework for reservoir quality in tight carbonate rocks, which holds significant implications for analogous plays worldwide. Full article

Background: This study compared two xenogeneic bone graft materials, A-Oss (bovine-derived) and The Graft (porcine-derived), using a rabbit calvarial defect model and a canine mandibular dehiscence-type defect model. Methods: Healing was evaluated at 6 and 12 weeks in rabbits and at 24 weeks in mongrel dogs. Micro-computed tomography quantified mineralized tissue fill (defect closure) in rabbits and, in dogs, the compartments classified as new bone and residual graft, together with vertical and horizontal volumetric maintenance. Hematoxylin and eosin (H&E) sections provided complementary qualitative observations. Results: In rabbits, defect closure did not differ between materials at 6 weeks (67.1 ± 12.7% vs. 70.2 ± 15.1%, p = 0.090) or 12 weeks (78.6 ± 5.9% vs. 72.3 ± 0.9%, p = 0.124). In dogs, new bone was similar between groups (43.5 ± 3.2% vs. 45.9 ± 1.1%, p = 0.208), whereas residual graft showed a numerical trend toward higher values with A-Oss (20.2 ± 3.5% vs. 13.3 ± 4.5%, p = 0.069). Vertical volume maintenance also trended higher with A-Oss (91.1 ± 1.6% vs. 87.8 ± 1.3%, p = 0.056), while horizontal maintenance was comparable (94.5 ± 1.8% vs. 91.4 ± 2.8%, p = 0.241). Histology in both models showed graft particles within the defect/augmented regions with surrounding eosinophilic matrix and intervening tissue spaces. Conclusions: Overall, both materials produced similar healing profiles across models, with small between-material differences most apparent in the canine dehiscence setting. Full article

Chronic d-galactose (d-gal) treatment is a model to induce accelerated aging-like phenotypes in rodents. However, the sex differences in behavioral and musculoskeletal manifestations of this model are not well understood. Heme oxygenase-1 (HO-1) is a cytoprotective protein that may have anti-aging properties. The goal of this study was to better understand the sex differences in the behavioral and musculoskeletal effects of chronic d-gal treatment in C57BL/6J mice, as well as the role of HO-1 induction or inhibition. Eight-week-old male and female mice received daily saline or d-gal injections (500 mg/kg, s.c.) for 12 weeks. After this time, mice in the d-gal group were randomized into three groups (n = 6/group/sex): d-gal, d-gal + cobalt protoporphyrin (CoPP) (5 mg/kg, s.c. weekly), and d-gal + zinc deutroporphyrin bisglycol (ZnBG) (42 mg/kg, i.p. triweekly) for a period of 4 weeks. Open-field, novel-object recognition, Barnes maze, grip strength, micro-computed tomography (µ-CT), histology, and protein analysis were performed. Chronic d-gal treatment resulted in a sexual dimorphic response, with female mice being more prone to develop deficits in both short- and long-term spatial memory as well as in non-spatial memory. Male mice exhibited deficits only in long-term spatial memory when treated chronically with d-gal. Inhibition of HO-1 was protective in both females and males. Chronic d-gal treatment did not accelerate the development of osteoporosis or sarcopenia in either males or females. Our results demonstrate a sexual dimorphic response to the chronic effects of d-gal treatment on aging, with greater effects in females than in males, which is dependent on HO-1. Full article

While cochlear implants allow restoration of sound perception in individuals with severe to profound hearing loss, there remains significant variability in patient outcomes. A potential factor that may account for this unexplained variability is the formation of fibrosis within the cochlea after implantation. This study investigated the therapeutic potential of pirfenidone (PFD) in preventing cochlear implant-induced fibrosis and compared outcomes with dexamethasone (DEX) treated animals. The utility of PFD was determined in cultures of fibrocytes isolated from the inner ear of guinea pigs. Specifically, PFD-treatment significantly reduced p38 MAPK signalling, fibrocyte cell proliferation, migration and collagen III deposition in response to pro-fibrotic stimuli. In a guinea pig model, local hydrogel-mediated delivery of PFD to the round window at the time of implant surgery significantly reduced the amount of tissue reaction measured by micro-computed tomography at two months post-implantation (p = 0.0297). Specifically, a 40% decrease in implant-induced tissue reaction was observed in PFD-treated animals compared to vehicle-treated controls. Notably, no evidence of ototoxicity was observed following PFD-treatment. In contrast, a 36% decrease in the amount of tissue reaction was measured in the DEX-treated control group (p = 0.0436). Overall, these data demonstrate that PFD shows significant therapeutic potential in reducing cochlear implant-induced fibrosis. Full article

This study presents a comprehensive characterization of Argopecten purpuratus (AP) shells—a marine-derived natural bioceramic composed predominantly of calcium carbonate (CaCO₃)—to evaluate their potential as biomaterials for regenerative medicine. Structural and compositional analyses were performed using micro-computed tomography (MicroCT), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). These techniques confirmed a high CaCO₃ content (>96 wt%) and revealed distinct microstructural features: the outer surface showed irregular grooves and rough textures, while the inner surface exhibited smoother, foliated morphologies with mixed calcite and aragonite phases. To assess biocompatibility, human gingival mesenchymal stem cells (hGMSCs) were cultured on both shell surfaces. Viability and adhesion were evaluated via MTS assays and fluorescence microscopy at time points ranging from 30 min to four weeks. Both surfaces supported robust early metabolic activity and long-term proliferation, with cells covering the entire surface area after four weeks. Morphometric analysis indicated time-dependent changes in cell shape, transitioning from rounded to elongated morphologies, with minor differences linked to surface topography. The integration of structural, compositional, and biological data demonstrates that AP shells provide a cytocompatible and sustainable natural material platform capable of supporting cell adhesion and proliferation. Their inherent micro- and nanoscale surface features may facilitate protein adsorption and cell–material interactions. These findings highlight the importance of correlating microstructural material properties with cellular responses and support the future exploration of marine-derived bioceramics for regenerative medicine applications. Full article

Background/Objectives: Osteoarthritis is a chronic joint disorder involving the progressive breakdown of articular cartilage, which leads to joint pain and impaired mobility. The present study investigated the effects of curcuminoids phospholipid (CP) on osteoarthritis progression, assessed its cartilage-protective effects, and elucidated the underlying mechanisms. Methods: Male Sprague–Dawley rats were randomly allocated to six experimental groups. One group received an intra-articular saline injection as the normal control (NC), while the remaining five groups were injected with monosodium iodoacetate (MIA) and consisted of an MIA control group (MC), a positive control group treated with celecoxib (PC, 3 mg/kg), and three groups treated with CP (31.25, 62.5, or 125 mg/kg). Results: Compared with the MC group, CP administration significantly improved pain-related behavior, as assessed by weight-bearing measurements. Micro-computed tomography and histological analyses demonstrated that CP administration mitigated subchondral bone erosion and preserved cartilage integrity. Additionally, the CP treatment significantly reduced markers associated with cartilage degradation, including matrix metalloproteinases and cartilage oligomeric matrix proteins; downregulated the expression of matrix-degrading enzymes; and restored aggrecan expression. Serum levels of inflammatory mediators, including nitric oxide; prostaglandin E₂; C-reactive protein; and pro-inflammatory cytokines, including interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β, were reduced following CP administration. Furthermore, CP decreased the activation of nuclear factor kappa B (NF-κB) signaling. Conclusions: These findings suggest that CP may be a promising functional agent for osteoarthritis, demonstrating beneficial effects on pain-related outcomes and cartilage integrity, potentially mediated by its anti-inflammatory activity. Full article

Hydrogen embrittlement is known to adversely affect the mechanical properties of low-carbon steels used for pipelines and pressure vessels, leading to accelerated crack growth and lowered fracture toughness. To overcome the limitations of surface-based analysis, this study employs X-ray micro-computed tomography (µ-CT) to provide a comprehensive 3D evaluation of the crack evolution. This approach is used to assess hydrogen-assisted crack growth in P355NH compact tension samples from previous fracture mechanical tests and enables a precise quantification of the internal crack path and the crack tip opening angle (CTOA) across the entire specimen thickness as well as the local damage morphology. By integrating these spatial parameters, a deeper understanding of the impact of hydrogen on local fracture mechanisms is achieved, revealing insights that have remained hidden in previous two-dimensional microscopy observations. For instance, µ-CT results clearly demonstrate that the hydrogen-assisted crack propagation is associated with increased void formation and secondary cracking in vicinity of the crack tip. However, it is proposed that the results are superimposed with continuous hydrogen desorption, which implies a need for in situ charging during mechanical loading and an analysis of the hydrogen concentration profile. Both will be the scope of further studies. Full article

Background/Objectives: Atraumatic electrode array insertion should be targeted in cochlear implantation. Robotic insertion is used in many centers worldwide. Our objective was to evaluate manual electrode placement and robot-assisted placement using RobOtol^® on human temporal bones (TBs), in terms of endocochlear trauma and completion of insertion. Methods: Sixteen TBs originating from eight bodies were implanted with Medel-FLEX24 electrodes through the round window. The right TB was implanted manually, while the left TB of the same body was implanted using RobOtol^® for electrode insertion. Results were analyzed through micro-computed tomography imaging. No statistical analysis was used, given the small sample size; a descriptive interpretation of micro-CT scans was rather preferred. Results: In the “manual group”, there were two cases (25%) of insertion trauma: elevation of basilar membrane at basal turn (Eshraghi-stage-1). In the “robotic group”, there were two cases (25%) of insertion trauma: one case of elevation of basilar membrane at the middle turn (Eshraghi-stage-1) and one case of dislocation of all electrodes in scala vestibuli (Eshraghi-stage-3). There were six cases (75%) of incomplete insertion in the “manual group” and four cases (50%) of incomplete insertion in the “robotic group”. Conclusions: Both techniques of electrode placement yielded fairly similar results, in terms of endocochlear trauma and completion of insertion. New larger-scale cadaveric and clinical studies are needed to determine the possible benefit of robot-assisted electrode insertion in cochlear implantation. Full article

Silica-based bioceramics are promising bone substitutes with tunable degradation and mechanical properties. We aimed to assess bone response in critical-size calvarial defects in rats, empty or filled with 3D-printed sphene ceramic (CaTiSiO₅) scaffolds produced using direct ink writing from preceramic polymers and reactive fillers. Scaffold characterization was performed using scanning electron microscopy, X-ray diffraction, porosity analysis, and compressive strength testing. Bilateral cylindrical 5 mm calvarial defects were created in 20 rats: one was randomly filled with sphene scaffold, while the contralateral remained empty. Ten animals were killed at 4 weeks, the rest at 8 weeks. Specimens were collected for micro-X-ray computed tomography (micro-CT) analysis, followed by undecalcified histology. The scaffolds exhibited porous structure with complete sphene phase purity and compressive strength of 17.91 MPa (SD 4.6). In vivo, no adverse event was noted during healing. Overall bone regeneration—as measured by BV/TV—was comparable between groups: Bone volume/total volume (BV/TV) increased over time in the empty and sphene groups, reaching ~40%, with no significant differences between groups or time points. BV/TV was significantly higher in the external regions of the defects compared to the internal areas in both groups at the two time points. The sphene group showed a significantly greater volume of new bone extending beyond the original cortical boundary at both 4 and 8 weeks (p = 0.013). In the sphene group histology revealed partial bone ingrowth within the scaffold, while bone in the control group was limited to defect edges. After 8 weeks, new bone adjacent to the cortical surface was thicker in the sphene group (p < 0.05). These initial findings are consistent with prior preclinical studies, supporting the biocompatibility and osteoconductive nature of sphene ceramic scaffolds. Full article

Optical coherence tomography (OCT) is a key biological sensing and imaging tool widely used in biomedical detection, and its images are often degraded by multiplicative speckle noises—especially when micro-electro-mechanical system (MEMS) mirrors are employed in endoscopic OCT imaging, which reduces visual quality and affects the accuracy of subsequent analysis. Traditional denoising algorithms and supervised deep learning approaches have shown some effectiveness, but they are limited by their reliance on paired noisy–clean data and their insufficient modeling of global structural dependencies. To address these issues, this paper proposes a frequency-domain enhanced UNet based on the Neighbor2Neighbor (N2N) framework (FEN2N). The proposed FEN2N integrates wavelet-guided spectral pooling modules (WSPMs) and frequency-domain enhanced receptive field blocks (FE-RFBs). In this work, OCT images are obtained in a self-constructed MEMS-OCT system. Then the FEN2N is applied to the OCT image dataset. Results show that FEN2N achieves a more than 2.3 dB PSNR improvement over the N2N baseline, while the incorporation of FE-RFB contributes to a 0.02 improvement in SSIM. In addition, FEN2N outperforms several state-of-the-art methods, effectively suppressing speckle noise while preserving fine structural details that are important for clinical diagnosis. Full article

Background: Post-traumatic osteoarthritis (PTOA) lacks effective disease-modifying therapies that preserve joint structure while promoting tissue repair. This study aimed to evaluate the therapeutic efficacy and underlying mechanism of Biluo Qianyuan Formula (BLQYF), a standardized herbal formulation derived from clinical practice, as a potential disease-modifying alternative to celecoxib in a murine model of PTOA. Methods: A murine PTOA model was established and treated with BLQYF at different doses, with celecoxib serving as a pharmacological comparator. Safety was assessed by hepatic and renal toxicity analyses. Therapeutic effects were evaluated using micro-computed tomography (micro-CT) and histological staining. Network-based integrative analyses were conducted to identify key regulatory targets, followed by experimental validation in fibroblast-like synoviocytes. Results: BLQYF was well tolerated under the experimental conditions, with no detectable hepatic or renal toxicity at therapeutic doses. Micro-CT and histological analyses demonstrated that BLQYF dose-dependently mitigated subchondral bone deterioration, enhanced cartilage regeneration, and restored collagen deposition. At higher doses, BLQYF showed therapeutic efficacy comparable to celecoxib, with superior outcomes regarding cartilage reparation. Mechanistically, integrative analyses identified fibronectin 1 (FN1) as a central regulatory hub. Validation experiments confirmed that BLQYF suppressed FN1, MMP3, and TGF-β expression in fibroblast-like synoviocytes, thereby attenuating inflammation and extracellular matrix degradation. Conclusions: These findings support BLQYF as a promising disease-modifying therapeutic candidate for PTOA and highlight the fibroblast–FN1 axis as a novel pharmacological target for intervention. Full article

This study examines the carbonation behavior and CO₂ storage potential of a Ca-rich alkali-activated binder produced entirely from industrial residues-ladle furnace slag (LFS), coal ash (CA), and cement kiln dust (CKD). The system was designed as a one-part alkali-activated material (AAM), with CKD acting as an internal activator, and subjected to ambient curing, water curing, and accelerated CO₂ curing at ambient pressure. Phase evolution, microstructural development, and pore-structure characteristics were investigated using X-ray diffraction, FTIR spectroscopy, DSC–TG analysis, scanning electron microscopy, and X-ray micro-computed tomography, together with measurements of density, water absorption, and compressive strength. Loss-on-ignition measurements combined with chemical analysis were further used to quantify CO₂ uptake and evaluate the degree of carbonation of the binder system. CO₂ curing fundamentally altered the reaction pathway of the binder, shifting it from hydration-dominated to carbonation-controlled phase evolution, leading to the decomposition of calcium-bearing hydrates and complete carbonation of non-hydraulic γ-belite with the formation of vaterite, aragonite, and calcite. These transformations induced pronounced microstructural densification, reflected in a near-doubling of compressive strength (>48 MPa), increased apparent density, reduced water absorption, and simplified pore-network topology. A preliminary carbon footprint assessment indicates that the production of 1 m³ of the developed LFS–CA–CKD concrete generates about 14.36 kg CO₂-eq, while the carbonation process enables significant CO₂ sequestration, resulting in a net negative carbon balance. The results demonstrate that controlled carbonation is an effective post-treatment strategy for waste-derived alkali-activated binders, enabling simultaneous performance enhancement and permanent CO₂ sequestration. Full article

Background/Objectives: Root canal procedures on multi-rooted teeth, including first molars, depend on experience, tactile perception, and anatomical knowledge to avoid perforation in the furcation region. Studies using various methodologies and populations have reported discrepant findings on pulpal floor thickness. No study using micro-computed tomography (Micro-CT), the gold standard, has been conducted on a Black South African sample to evaluate pulpal floor thickness. Methods: In this cross-sectional, descriptive, quantitative study, Micro-CT scans of 91 maxillary and 77 mandibular first molars were reconstructed in 3D and oriented according to a reference plane along the cemento-enamel junction using Avizo software. Measurements were taken from the midpoint of the pulpal chamber floor to the perpendicular point on the furcation. In maxillary molars, an additional measurement between the mesiobuccal and distobuccal roots was taken. The effects of arch, side, age, and sex were assessed. Results: Neither sex, arch, nor side had a significant influence on the pulpal floor thickness. The central mandibular and maxillary pulpal floor thicknesses increased significantly with aging, while the effect on the buccal maxillary pulpal floor thickness was not significant. The mean central mandibular and maxillary pulpal floor thicknesses were 2.66 and 2.83 mm, respectively, while the buccal maxillary pulpal floor thickness was significantly smaller at 2.37 mm. Conclusions: More accurate and repeatable findings compared to the literature could be attributed to the use of Micro-CT, which provides higher resolution images, and to Avizo, which enables precise localization of 3D points. Variations from the literature might also be explained by differences in the age and geographical origin of the samples. Full article

Objectives: To determine the most favourable Micro-Implant (MI) insertion site along the mandibular buccal shelf (MBS), using Cone Beam Computed Tomography (CBCT). Methods: This retrospective study assessed CBCT scans from 90 Portuguese patients (32 males and 58 females, aged 14 to 40 years). Paired MBS sites were determined. Comparative and correlation analyses were performed at p < 0.05. Results: A significant increase in MBS width was observed from the mesial to the distal direction (p < 0.001). Conversely, both the MBS steepness and cortical bone thickness significantly decreased from mesial to distal (p < 0.001). Significant negative correlation was also found between age and cortical bone thickness adjacent to the distobuccal cusp and distal tangent of both mandibular second molars (r ≤ −0.373, p ≤ 0.007). Furthermore, significant asymmetric differences were identified between the right and left MBS steepness as well as in the paired cortical bone thickness at the mesiobuccal cusp, buccal groove, and distobuccal cusp of the mandibular second molar (p ≤ 0.016). Conclusions: The results indicate that although there are sufficient MBS width and cortical bone thickness, vestibular to the mandibular second molar for MI insertion, the sites towards the distal root of the mandibular second molar are more favourable when considering MBS steepness. These findings are consistent for both sexes and apply to young and old individuals. Full article

This paper investigates the fatigue and residual strength behavior of recycled carbon fiber reinforced plastics (rCFRPs) with different fiber architectures in an epoxy resin matrix: a unidirectional (UD) rCFRP and a non-crimp fabric (NCF) composite. Due to the research gap in fatigue testing of recycled carbon fiber-reinforced plastics with quasi-continuous fiber reinforcement, their fatigue properties are investigated in this article. The objective of the present study is to contribute to the broader goal of integrating recycled carbon fibers as quasi-continuous fiber reinforcement in structural applications by understanding their failure behavior. To determine suitable stress levels for fatigue testing, quasi-static tensile tests are conducted first. Subsequently, fatigue tests are performed with a stress ratio of 0.1. Damage evolution is documented by a continuous recording of the stiffness degradation. For the unidirectional material, an S-N_f curve is created based on three stress levels. The curve can be described with a logarithmic equation. Fatigue testing of the NCF laminate is performed at a single stress level. Subsequent residual strength tests using standard specimens show no clear correlation between the number of load cycles of pre-cycling and residual strength, but indicate a sudden-death behavior for both composites. For further investigation of the damage behavior, in situ residual strength tests are carried out using a combination of acoustic emission analysis and micro-computed tomography (µCT) imaging. This investigation is intended to illustrate crack initiation and propagation three-dimensionally after pre-cycling and during residual strength tests. The results demonstrate a significant influence of the microstructure on the failure behavior. Full article