Search Results (351)

Severe steam channeling in heterogeneous heavy oil reservoirs severely restricts thermal recovery efficiency, as conventional conformance control materials cannot simultaneously achieve long-term high-temperature resistance and deep reservoir penetration. This work develops a high-temperature-resistant epoxy-based liquid microsphere system for deep profile control in heavy oil steam flooding. A triple thermal-stabilization strategy is constructed: imide chain extension to enhance backbone rigidity, benzoxazine-phthalonitrile grafting to form dense triazine crosslinked networks, and KH-550-functionalized nano-silica for synergistic reinforcement. FT-IR and ¹H NMR verify the successful incorporation of rigid imide and triazine structures. TGA confirms the optimal formulation exhibits less than 5% mass loss at 350 °C. Multi-segment sand-packed tube tests demonstrate favorable deep migration capacity with inter-stage pressure ratios below 4 across 5000–15,000 × 10⁻³ μm² permeability, and the cured network retains over 95% plugging efficiency after 350 °C steam scouring. Dual-tube heterogeneous flooding delivers 12.05% incremental oil recovery, outperforming rigid inorganic particles. This system provides a high-performance candidate for deep steam channeling mitigation in heavy oil thermal recovery. Full article

This in vitro study evaluated the effects of restorative material type, thickness, curing mode, and post-irradiation time on the degree of conversion (DC) of a dual-cure resin cement. Specimens of VITA Suprinity (VS), VITA Enamic (VE), Lava Ultimate (LU), and Saremco Print Crowntec (SC) were prepared at thicknesses of 1.0 and 1.5 mm. A dual-cure resin cement was placed beneath each specimen and light-cured through the specimen using a VALO X curing light in Standard Power (SP) or Xtra Power (XP) mode (n = 8). DC was measured by FT-IR/ATR spectroscopy at days 1 and 10. The normality and homogeneity of variances were assessed using the Shapiro–Wilk and Levene tests, and data were analyzed using mixed-design repeated-measures ANOVA and Tukey HSD tests (α = 0.05). Material type and thickness significantly affected DC (p < 0.001), whereas curing mode did not (p = 0.110). Post-irradiation time significantly affected DC (p < 0.001), and a significant material–thickness interaction was found (p = 0.043). Within the limitations of this study, DC was affected by material type, thickness, and post-irradiation time, but not by curing mode. Full article

This study evaluated the influence of the manufacturing method and cementation protocol on the fracture load of zirconia molar crowns. A total of 32 full-contour crowns with a wall thickness of 1 mm were fabricated from 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP). Sixteen crowns were produced by 3D printing (LithaCon 3Y 210, Lithoz) and 16 by milling (e.max ZirCAD LT, Ivoclar Vivadent). Within each manufacturing group, eight crowns were adhesively luted with a dual-cure resin cement (Bifix QM, VOCO) and eight were conventionally cemented with a glass ionomer cement (Ketac Cem, Solventum). All crown–die complexes underwent thermomechanical aging (6000 thermal cycles between 5 °C/55 °C; 1.2 × 10⁶ cycles at 50 N) as a correlate of five years of clinical service, followed by axial loading to failure. The statistical analysis was a two-way ANOVA on log10-transformed fracture loads with manufacturing and cement as fixed effects (α = 0.05). All crowns survived thermomechanical loading without failure. Milled zirconia crowns showed significantly higher fracture loads when adhesively luted (7162 ± 1294 N) compared with conventional cementation (4021 ± 1126 N; p < 0.001). In contrast, no significant differences were observed between adhesive (4986 ± 1301 N) and conventional cementation (5581 ± 1618 N) for 3D-printed zirconia crowns. Additively manufactured crowns exhibited greater variability in fracture loads (broader interquartile ranges) than their milled counterparts. Two-way ANOVA detected a significant Manufacturing × Cement interaction (p < 0.001), indicating that the effect of cementation differed by manufacturing route. Adhesive cementation increased fracture load for milled zirconia, whereas no statistically significant cementation effect was detected for 3D-printed zirconia under the present conditions. Given the sample size and the observed variability, the study was powered to detect very large effects but not medium or small ones; therefore, this non-significant difference should not be interpreted as proof of no effect. Full article

The peer-reviewed literature on the use of universal adhesives (UAs) with core build-up composite resins (CBCRs) is limited. UAs may enhance the polymerization of dual-cured composite resins, leading to increased microhardness due to the “touch-cure” effect. This study compared the dentin bond strengths and microhardness of CBCRs bonded with UAs. A total of 480 bovine incisors were randomly allocated into 20 groups (n = 24). Two dual-cured CBCRs, ParaCore (PrCore) and Gradia Core (GrCore), one light-cured CBCR, Clearfil Photo Core (PhotoCore), and Filtek Z250 (Z250) were evaluated. For the dual-cured CBCRs, the UAs from the respective manufacturers were mixed with a dual-cure activator (Act): One Coat 7 Universal (OC7+Act) and G-Premio Bond (GrPB+Act). Three additional UAs were evaluated: Tokuyama Universal Bond II (TUB), Scotchbond Universal Plus Adhesive (SBUP), and Scotchbond Universal Adhesive with Dual Cure Activator (SBU+Act). Shear bond strength was evaluated after 24 h. Additional specimens were prepared for Vickers microhardness (VHN) evaluation, with or without UA application to the bottom surface. Bond strengths ranged from 7.4 ± 4.0 to 37.0 ± 7.5 MPa. GrCore and PrCore showed higher bond strengths with SBU+Act than with their manufacturer-recommended adhesives. Dual-cured CBCRs exhibited lower dentin bond strengths and lower VHN than the light-cured composite resins, and the touch-cure effect was more effective for GrCore and PhotoCore. Full article

Alkali-activated mortars (AAMs) have emerged as sustainable alternatives to conventional hydraulic cement (HC) matrices produced with natural sand. In this context, interest in the valorization of industrial by-products to develop eco-efficient construction materials has gained crucial academic and industrial attention. This study investigates the feasibility of producing AAMs incorporating copper slag (CS) as an artificial fine aggregate (AFA) to partially or completely replace natural sand. Moreover, the binder matrix was formulated using 80% CS and 20% HC as precursors, activated with different alkaline solutions (Na₂SiO₃ + NaOH) at activator-to-precursor mass ratios ranging from 0.15 to 0.35. Concurrently, CS was incorporated as AFA at volumetric replacement levels of 0%, 25%, 50%, 75%, and 100%. The AAMs were evaluated in terms of workability, physical performance (i.e., bulk density, water absorption, and void content), and mechanical performance. The results demonstrate that the workability of the AAMs increased with higher AFA dosages, reaching a maximum improvement of 23.8% compared with the AAM without AFA. The bulk density of the AAMs increased monotonically with increasing AFA content (consistent with the higher density of AFA with respect to natural sand), whereas water absorption and void content decreased progressively. Although all AAMs exhibited significantly lower compressive strengths than M1 at 7 and 28 days, the differences progressively decreased with curing age. At 56 and 90 days, M5 and M6, incorporating 75% and 100% AFA, respectively, achieved mean compressive strengths that were not statistically different from those of M1, indicating that the mixtures with the highest AFA contents maintained later-age mechanical performance within the variability of the conventional reference mortar. The study demonstrates the feasibility of the synergistic utilization of CS as both precursor and AFA in AAMs. This dual-pathway valorization closes materials loops and advances circular economy principles within the construction sector. Full article

This study quantitatively investigates the coupled effects of curing temperature and slurry density on the early-age acoustic maturation of ultra-low-density Hollow Glass Microsphere (HGM)-modified oil well cement systems, addressing the critical challenge of determining reliable sonic logging timing under lightweight cementing conditions. Longitudinal wave velocity evolution was systematically characterized across a broad thermo–density domain, revealing a consistent three-stage acoustic trajectory comprising percolation-driven acceleration, transition-controlled consolidation, and acoustic stabilization. The results demonstrate that curing temperature primarily regulates the kinetic rate of acoustic maturation through hydration activation, whereas slurry density modulates the initial structural configuration, HGM-induced acoustic impedance heterogeneity, and development of effective solid connectivity. A derivative-based dual-criterion approach was proposed to define the optimal sonic logging time based on intrinsic acoustic stabilization behavior rather than conventional empirical strength-based thresholds. Furthermore, a thermo–density coupled semi-empirical model incorporating Arrhenius-type thermal activation and density-dependent structural effects was developed, providing reliable prediction of sonic logging timing with clear physical interpretability. The model captures the nonlinear interaction between thermal activation and structural constraints, revealing that acoustic maturation is accelerated under elevated-temperature and higher-density conditions but substantially delayed under low-temperature and ultra-low-density scenarios. This study establishes a physics-informed temperature–density–acoustic coupling framework that links hydration-controlled structural evolution with sonic logging optimization, providing a rational basis for improving cement bond evaluation reliability and operational efficiency under challenging wellbore conditions. Full article

Persistent HIV-1 reservoirs remain a major barrier to a durable functional cure despite long-term suppressive antiretroviral therapy. Although resting memory CD4⁺ T cells constitute the best-characterized cellular reservoir, tissue microenvironments shape viral persistence and immune clearance. The rectal mucosa represents a specialized tissue niche containing HIV-susceptible target cells, antigen-presenting cells, microbial products, inflammatory cues, and local metabolic signals. Within this setting, myeloid-lineage cells, particularly tissue-resident macrophages and dendritic cells, may contribute to HIV-1 persistence through mechanisms distinct from classical T-cell latency. Here, we review how rectal mucosal macrophages may support HIV-1 persistence through longevity, resistance to apoptosis, metabolic adaptation, epigenetic regulation, and sequestration of virions within virus-containing compartments. We also discuss the dual role of mucosal dendritic cells as sentinels that capture and transfer HIV-1 to CD4⁺ T cells, while considering the limited evidence for inducible proviral persistence in selected anatomical and cellular contexts. Importantly, we further distinguish bona fide reservoir-bearing cells from reservoir-supportive mechanisms, including viral capture, trans-infection, immune suppression, and niche-mediated protection. We also highlight how mucosal dysbiosis, barrier disruption, microbial metabolites, chronic interferon signaling, and immunoregulatory myeloid programs may stabilize HIV-1 persistence in rectal tissues. Integrating intact proviral assays, functional measurements, single-cell profiling, multiplex imaging, and spatial transcriptomics will be critical for defining myeloid-associated persistence and guiding tissue-targeted HIV-1 cure strategies. Full article

This study focuses on loess in the Lanzhou region and employs a self-developed LM-1 ionic cementitious curing agent (mainly sodium silicate) combined with cement for loess improvement. Through mechanical tests, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) analysis, the mechanical properties, microstructure, and mineralogical evolution of composite-improved loess were systematically investigated, with emphasis on revealing the reinforcement mechanism. The results show that combining LM-1 and cement significantly enhances the unconfined compressive strength (UCS) of loess. The optimal proportion of 1.5% LM-1 + 10% cement achieves 7-day and 28-day UCS values of 3.43 MPa and 4.12 MPa, representing increases of 69.0% and 54.7% over 10% cement alone, and outperforming 12% cement-only specimens. This formulation develops a uniform, dense C-S-H gel network with optimized pore structure and reduced microcracks. LM-1 generates hydrated silicate products through alkali-activated reactions, which together with cement hydration C-S-H gel form a dual-gel cementation system, while effectively accelerating cement hydration. This provides a theoretical basis and technical support for balancing cement reduction and performance enhancement in subgrade reinforcement and slope protection in loess regions. Full article

Graphene oxide (GO) has been widely reported to enhance the mechanical performance of cementitious composites. However, the fundamental hydration mechanisms underlying these improvements, such as GO’s role as a nucleation site, remain poorly explored and quantified. This study presents a comprehensive, non-destructive investigation into the time-dependent hydration behaviour of GO-induced cement pastes using time-domain ¹H Nuclear Magnetic Resonance (NMR) spectroscopy, supported by thermogravimetric analysis (TGA), humidity-controlled water-retention tests, and compressive strength tests. Cementitious composites containing 0.035%, 0.065%, and 0.08% GO by weight of cement (bwoc) were monitored from 4 h to 28 days to track the evolution of discrete water phases, including capillary, inter-hydrate, gel pore, and interlayer water. NMR results reveal that GO initially facilitates water redistribution by retaining free water within its layered structure, followed by a delayed but sustained release that promotes continued hydration and a progressive shift toward less mobile pore–water environments at later curing ages. TGA confirms enhanced formation of hydration products in GO-induced cementitious systems, with an optimal dosage of 0.035% bwoc achieving the most sustained hydration and highest compressive strength. Higher GO dosages accelerate early hydration but limit later-stage hydration due to diffusion barriers formed by hydration products. This study provides time-dependent scientific evidence of GO’s dual role as a hydration nucleation agent and water-release regulator, establishing a mechanistic basis for dosage optimization in nano-engineered cementitious composites. Full article

Objectives: This systematic review aimed to qualitatively synthesize the available in vitro evidence on the cytocompatibility and bioactivity of resin-modified calcium silicate ce-ments in contact with human dental stem cells and cells from other sources. Materials and Methods: An electronic search was performed in five databases. In vitro studies evalu-ating the biological properties of resin-modified calcium silicate cements were included. Cytocompatibility outcomes comprised cell viability, cytotoxicity, migration, prolifera-tion, adhesion, and apoptosis. Bioactivity outcomes comprised mineralization potential and the expression of osteo/odontogenic differentiation markers. A qualitative synthesis of the methodology and results of the selected studies was performed, together with an assessment of methodological and reporting quality using a modified CONSORT checklist for in vitro studies on dental materials. Results: Thirteen articles were included in the qualitative synthesis. Overall, the evaluated resin-modified calcium silicate cements showed reduced cytocompatibility compared with control groups, particularly regarding cell viability and migration. However, bioactivity findings were generally favorable, with several materials maintaining mineralization potential and the expression of markers associated with osteo/odontogenic differentiation. Conclusions: Resin-modified calcium silicate cements showed formulation-, concentration-, and time-dependent biological responses. Although some dual-cure materials retained mineralization potential and osteo/odontogenic activity, resin-containing formulations generally exhibited lower cytocompatibility than hydraulic calcium silicate cements. Favorable bioactivity should therefore not be interpreted as evidence of overall biological suitability, particularly when direct interaction with pulp tissue is expected. Clinical Relevance: Resin-modified calcium silicate cements should be used cautiously in vital pulp therapy, especially when direct interaction with pulp cells is expected. Full article

Background: In the field of minimally invasive restorative dentistry, ultrathin (<0.5 mm thickness) ceramic occlusal veneers are increasing being used as alternatives to full-coverage crowns, particularly for mild occlusal wear and not deep caries. However, only limited research attention has been given to how marked reduction in the thickness of a veneer restoration affects its mechanical performance. The purpose of the present in vitro study was to compare the performance of restorations that comprised a 0.3 mm thick zirconia veneer to the case when a lithium disilicate veneer was used, under quasi-static compressive loading. Methods: Forty extracted human molars, without caries, cracks or fractures and with intact coronal structure, were randomly assigned to two groups: lithium disilicate occlusal veneers (n = 20) and zirconia occlusal veneers (n = 20). The teeth were embedded in acrylic resin up to the cementoenamel junction. Digital scans were used to record the original anatomy and guide restoration design. Standardized occlusal preparations were performed using a 0.3 mm reduction protocol and verified with silicone guides to support a biomimetic, tooth-preserving approach. After preparation, the teeth were rescanned, and restorations were designed and fabricated using CAD/CAM technology. Lithium disilicate restorations were milled from Ivoclar Porcelain System [IPS], esthetic maximized [e.max] computer-aided design [CAD] blocks, whereas zirconia restorations were milled from Prettau 3 zirconia discs. Restorations were adhesively cemented with dual-cure resin cement following material-specific surface treatment protocols. Fracture resistance was tested using a universal testing machine under compressive loading until failure. Results: The fracture loads with lithium disilicate and zirconia occlusal veneers were 481.45 ± 68.23 N and 720.93 ± 95.44 N, respectively. Fracture was catastrophic in lithium disilicate occlusal veneers whereas it was not so when zirconia veneer was used. Conclusion: Quasi-static compressive fracture load when a lithium disilicate veneer was used was significantly lower than when a zirconia veneer was used. Full article

Against the backdrop of China’s dual-carbon strategy and the development of green transportation, systematic research on direct pavement carbon absorption and sequestration remains limited. Traditional epoxy resin coatings, owing to their dense structure, poor air permeability, and single functionality, fail to meet the requirements for pavement carbon absorption. To address this issue, an ordered, honeycomb-like, porous epoxy carbon-absorbing coating was prepared using bisphenol A epoxy resin as the matrix and diethylenetriamine as the curing agent through the breath-figure method. The pore-formation mechanism and the process regulation principles of the coating were systematically elucidated. Key preparation parameters (ambient humidity, dispersion concentration, and spray dosage) were regulated, and multiple microscopic characterization methods, including SEM, FTIR, and TG, were adopted to comprehensively explore the influences of preparation parameters on the coating’s microstructure, chemical composition, and thermal stability. Experimental results indicate that under optimized process conditions, a honeycomb-like porous coating with uniform pore size and regular arrangement can be fabricated. The fabrication procedure features simple operation, favorable controllability, and low cost. The breath-figure method was successfully applied to the preparation of a porous epoxy carbon-absorbing coating, achieving controllable regulation of the porous structure and thereby effectively overcoming the limitations imposed by the dense nature of traditional epoxy coatings. Consequently, this work provides new technical concepts and data support for the development and application of low-carbon functional coatings for pavements. Full article

Objective: To report the conservative management of a complex failed apexification in a permanent premolar complicated by severe internal root resorption, irregular apical calcification, and exceptionally thin root canal walls and to evaluate its long-term (56-month) clinical and radiographic outcomes. Methods: A 27-year-old male presented with chronic apical periodontitis in the right mandibular first premolar. A previous apexification attempt had failed, resulting in arrested root development, an apical calcified bridge, and extensive internal root resorption. CBCT imaging revealed a critical root canal wall thickness of less than 1 mm in the middle and coronal thirds. To avoid extraction or invasive surgery, a non-surgical apical barrier technique was performed. Due to the severe structural compromise and high risk of root fracture, mechanical instrumentation was minimized; instead, chemomechanical debridement was optimized using Er:YAG laser-activated irrigation. The apical region was sealed with a bioceramic material (iRoot BP), and the weakened root structure was reinforced intraradicularly with dual-cure flowable resin, followed by progressive occlusal adjustments. Results: At the 3-month follow-up, the patient was completely asymptomatic, and radiographs indicated initial periapical bone healing. The 56-month follow-up demonstrated progressive formation of mineralized tissue, apparent thickening of the root canal walls at root apex, complete resolution of periapical radiolucency, and a stable, functional occlusion. Conclusions: This case demonstrates that teeth with severe structural compromise and internal resorption following failed apexification are not necessarily hopeless. A tailored conservative approach, integrating advanced laser-assisted disinfection, bioceramic apical barriers, internal resin reinforcement, and meticulous occlusal management, can yield highly successful long-term outcomes, ensuring the preservation of the natural dentition. Full article

Deficiency of adenosine deaminase 2 (DADA2) is a monogenic autoinflammatory disorder caused by biallelic loss-of-function mutations in the ADA2 gene (formerly CECR1). First described in 2014, DADA2 has emerged as a paradigm for monogenic vasculitis, bridging the gap between primary immunodeficiencies and systemic vasculitides. The disease is characterized by a remarkably broad clinical spectrum encompassing early-onset lacunar stroke, systemic vasculitis resembling polyarteritis nodosa (PAN), hematologic abnormalities ranging from pure red cell aplasia to pancytopenia, humoral immunodeficiency, and variable lymphoproliferation. ADA2, predominantly secreted by myeloid cells, serves dual functions as a growth factor for endothelial cells and a modulator of extracellular adenosine metabolism. Its deficiency leads to a proinflammatory state driven by macrophage dysregulation, excessive tumor necrosis factor (TNF) production, neutrophil extracellular trap (NET) formation, and endothelial dysfunction. The genotype–phenotype correlation is complex, with certain mutations predisposing to vasculitic versus hematologic-predominant phenotypes. Emerging evidence further links ADA2 deficiency to cellular senescence and inflammaging pathways, suggesting a connection between monogenic vasculitis and aging-related biological mechanisms. Anti-TNF therapy has revolutionized disease management, achieving sustained remission in the majority of vasculitic manifestations. Hematopoietic stem cell transplantation (HSCT) offers a definitive cure for severe hematologic disease, while gene therapy approaches are under active investigation. This review synthesizes current knowledge on the immunopathogenesis, clinical heterogeneity, genotype–phenotype correlations, multi-omics insights, and evolving precision therapeutic strategies for DADA2, positioning it as an instructive model for understanding monogenic immune vasculopathy. Despite this progress, fundamental questions remain—including the relative contribution of ADA2 enzymatic versus growth factor functions to disease pathogenesis, the mechanisms underlying tissue-specific vulnerability, the basis of differential treatment responsiveness, and the identity of genetic and environmental modifiers that determine phenotypic heterogeneity—that define the frontier of current DADA2 research. This review critically evaluates both established knowledge and persistent uncertainties, positioning DADA2 as an instructive model for the study of monogenic immune vasculopathy. Full article

Background/Objectives: Luting agents are used to cement indirect restorations to teeth, and some of their components may induce pulpal reactions. This systematic review aims to evaluate the biocompatibility and effects of contemporary luting cements on the vital pulp. Methods: A comprehensive review of electronic databases PubMed, Cochrane Library, ScienceDirect, Web of Science, Scopus, and ClinicalTrials.gov was conducted for studies published between 2000 and 2026. Search strategies included MeSH terms, Boolean operators, and controlled vocabulary. Eligible studies included in vitro, ex vivo, in vivo, and clinical trials assessing pulpal responses to definitive luting cements in vital teeth or human-relevant pulp cell models. Screening and data extraction were performed independently by two reviewers. Risk of bias was assessed using the RoB 2 tool for clinical studies, QUIN for in vitro studies, SYRCLE for animal studies, and ROBINS-I for non-randomized human in vivo designs. Due to heterogeneity, meta-analysis was not performed, and a narrative synthesis was conducted. Results: From 1514 records, 40 studies met the inclusion criteria. Evidence was heterogeneous across study designs and outcomes. Human in vivo studies showed that short-term pulpal inflammation decreased over time, influenced by the remaining dentin thickness and material type. Clinical studies reported variable postoperative sensitivity. In vitro and ex vivo studies demonstrated material- and protocol-dependent effects on cell viability, oxidative stress, inflammatory markers, monomer release, and intrapulpal temperature rise. Conclusions: Luting cement selection should be case-dependent. Dual-cure, self-adhesive resin cements appear to demonstrate favorable biocompatibility in vital teeth; however, application protocols may influence cytotoxicity. Further clinically relevant studies are needed to support safer and biologically wise material selection. Registration: PROSPERO CRD420251156047. Full article