Lining Layer Research Articles

Synoviocyte detachment: an overlooked yet crucial histological aspect in rheumatoid arthritis

ObjectiveRheumatoid arthritis (RA) is a prevalent autoimmune disorder that leads to chronic joint inflammation, deformity, disability, and systemic complications. This study aimed to analyze the clinical characteristics and synovial pathology of RA patients with synoviocyte detachment, and explore the factors associated with this phenomenon.MethodsThis was a retrospective cohort study included RA patients who underwent synovial biopsy at our center from April to September 2023. Demographic, clinical, laboratory, and synovial histological data were retrospectively collected from medical records at the time of joint synovial biopsy in patients. Microscopic examination of hematoxylin and eosin (HE)-stained synovial tissue sections categorized the samples into synoviocyte detachment and no-synoviocyte detachment groups. Clinical characteristics and synovial pathological changes were compared between the two groups, and the factors associated with synoviocyte detachment were explored through logistic regression analysis.ResultsFifty-five RA patients were enrolled; 45 were females, and the mean age was 53.4 ± 11.8 years. Nine RA patients exhibited synoviocyte detachment. A total of 46 RA patients in the no-synoviocyte detachment group (15 with a normal lining layer and 31 with synovial cell proliferation) were included. Compared with the no-synoviocyte detachment group, the synoviocyte detachment group presented higher RF, ESR, CRP and DAS28-CRP levels (P < 0.05). The synoviocyte detachment group exhibited more prominent neovascularization (P < 0.05). ESR, DAS28-CRP and synovial neovascularization were risk factors associated with synoviocyte detachment in RA patients.ConclusionRA patients with synoviocyte detachment exhibit elevated clinical disease activity, marked by pronounced synovial pathology featuring increased neovascularization and less inflammatory cell infiltration. A significant reduction in lymphocyte count compared with patients with synovial cell proliferation was also observed.

The degenerated glenohumeral joint.

This study aimed to define the histopathology of degenerated humeral head cartilage and synovial inflammation of the glenohumeral joint in patients with omarthrosis (OmA) and cuff tear arthropathy (CTA). Additionally, the potential of immunohistochemical tissue biomarkers in reflecting the degeneration status of humeral head cartilage was evaluated. Specimens of the humeral head and synovial tissue from 12 patients with OmA, seven patients with CTA, and four body donors were processed histologically for examination using different histopathological scores. Osteochondral sections were immunohistochemically stained for collagen type I, collagen type II, collagen neoepitope C1,2C, collagen type X, and osteocalcin, prior to semiquantitative analysis. Matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 levels were analyzed in synovial fluid using enzyme-linked immunosorbent assay (ELISA). Cartilage degeneration of the humeral head was associated with the histological presentation of: 1) pannus overgrowing the cartilage surface; 2) pores in the subchondral bone plate; and 3) chondrocyte clusters in OmA patients. In contrast, hyperplasia of the synovial lining layer was revealed as a significant indicator of inflammatory processes predominantly in CTA. The abundancy of collagen I, collagen II, and the C1,2C neoepitope correlated significantly with the histopathological degeneration of humeral head cartilage. No evidence for differences in MMP levels between OmA and CTA patients was found. This study provides a comprehensive histological characterization of humeral cartilage and synovial tissue within the glenohumeral joint, both in normal and diseased states. It highlights synovitis and pannus formation as histopathological hallmarks of OmA and CTA, indicating their roles as drivers of joint inflammation and cartilage degradation, and as targets for therapeutic strategies such as rotator cuff reconstruction and synovectomy.

Macrophage Membrane-Biomimetic Multi-Layered Nanoparticles Targeting Synovial Angiogenesis for Osteoarthritis Therapy.

Osteoarthritis (OA) is an inflammatory and progressive joint disease characterized by angiogenesis-mediated sustained, chronic, and low-grade synovitis. Anti-angiogenesis is emerging as a strategy for attenuating OA progression, but is often compromised by poor targeted drug delivery and immune clearance. Recent studies have identified macrophages formed a "protective barrier" in the lining layer (LL) of synovium, which blocked the communication of joint cavity and sublining layer (SL) of synovium. Inspired by natural mimicry, macrophage membrane-camouflaged drug delivery is explored to avoid immune clearance. Based on the single cell RNA sequencing, the CD34+ synovial cells are identified as "sentinel cells" for synovium angiogenesis. Consequently, CD34 antibody-modified macrophage membraneis constructed to target new angiogenesis. Hence, a biomimetic multi-layered nanoparticle (NP) is developed that incorporates axitinib-loaded poly(lactic-co-glycolic) acid (PLGA) with CD34 antibody modified macrophage membrane (Atb@NP@Raw@CD34) to specifically deliver axitinib (Atb) to the SL and sustain inhibiting angiogenesis without immune elimination. It is found that the Atb@NP@Raw@CD34 can pass through macrophage "barrier", specifically targeting CD34+ cells, continuously releasing Atb and anti-angiogenesis in OA synovitis. Furthermore, in vivo data demonstrated that Atb@NP@Raw@CD34 can attenuate joint degeneration by inhibiting synovium angiogenesis-mediated synovitis. In conclusion, local injection of Atb@NP@Raw@CD34 presents a promising approach for clinically impeding OA progression.

3D spheroids versus 2D-cultured human adipose stem cells to generate smooth muscle cells in an internal anal sphincter-targeting cryoinjured mouse model

BackgroundThe efficacy of cell implantation via 3D-spheroids to treat basal tone in fecal incontinence remains unclear. To address this, in this study, we aimed to identify cell differentiation and assess the development of a contractile phenotype corresponding to smooth muscle cells (SMCs) following implantation of 3D-spheroid and 2D-cultured human adipose stem cells (hASCs) in an in vivo internal anal sphincter (IAS)-targeted mouse model.MethodsWe developed an IAS-targeted in vivo model via rapid freezing (at − 196 °C) of the dorsal layers of the region of interest (ROI) of the IAS ring posterior quarter, between the submucosal and muscular layers, following submucosal dissection (n = 60 rats). After implantation of tetramethylindocarbocyanine perchlorate (Dil)-stained 3D and 2D-cells into randomly allocated cryoinjured rats, the entire sphincter ring or only the cryoinjured ROI was harvested. Expression of SMC markers, RhoA/ROCKII and its downstream molecules, and fibrosis markers was analyzed. Dil, α-smooth muscle actin (α-SMA), and RhoA signals were used for cell tracking.ResultsIn vitro, 3D-spheroids exhibited higher levels of SMC markers and RhoA/ROCKII-downstream molecules than 2D-hASCs. The IAS-targeted cryoinjured model exhibited substantial loss of SMC layers of the squamous epithelium lining of the anal canal, as well as reduced expression of SMC markers and RhoA-related downstream molecules. In vivo, 3D-spheroid implantation induced SMC markers and contractile molecules weakly at 1 week. At 2 weeks, the mRNA expression of aSma, Sm22a, Smoothelin, RhoA, Mypt1, Mlc20, Cpi17, and Pp1cd increased, whereas that of fibrosis markers reduced significantly in the 3D-spheroid implanted group compared to those in the sham, non-implanted, and 2D-hASC implanted groups. Protein levels of RhoA, p-MYPT1, and p-MLC20 were higher in the 3D-spheroid-implanted group than in the other groups. At 2 weeks, in the implanted groups, the cryoinjured tissues (which exhibited Dil, α-SMA, and RhoA signals) were restored, while they remained defective in the sham and non-implanted groups.ConclusionsThese findings demonstrate that, compared to 2D-cultured hASCs, 3D-spheroids more effectively induce a contractile phenotype that is initially weak but subsequently improves, inducing expression of RhoA/ROCKII-downstream molecules and SMC differentiation associated with IAS basal tone.

Integrated framework of multi−physics mechanism models for gas−powder flow, molten pool evolution and part deformation in high alloy steel additive manufacturing process

Multi−physics numerical models for metal additive manufacturing (MAM) could replace the expensive trial−and−error experiments, reveal the mechanisms of printing process, and provide an effective means of optimizing process parameters and mitigating part defects. However, the existing simulations of MAM process seldom consider the coupling effects between multiple recursive processes. There is an urgent need to overcome the dilemma of limiting MAM process simulation to a localized single sub−process. For directed energy deposition (DED) additive manufacturing process, the integrated simulation framework proposed in this study consists of a gas−powder flow model, a heat and fluid flow model, and a sequentially coupled thermal–mechanical model, which can be used to predict the feedstock feeding process, the evolution of molten pool, and the residual deformations of metal part, respectively. The accurate results of the three recursive sub−processes can be obtained by delivering the validated parameters between models. Corresponding experiments are conducted to verify the accuracy of the integrated framework based on 12CrNi2 alloy powders. The deviation of the predicted focal distance of powder streams is 5.14 %, and the deviations of the predicted molten pool height and width are all less than 8.5 %. The integrated framework could rapidly and accurately predict the residual deformation tendency and the position where the maximum deformation occurs. For single−track and eight−layer line deposition, the deviations of the predicted maximum deformation are all within 0.1 mm. The integrated framework could efficiently provide accurate and comprehensive solutions for optimizing DED process.

Immunoexpression of metallothionein, Ki‐67 and PCNA in dermoid and epidermoid cysts of the oral cavity

AbstractObjectiveTo assess the immunoexpression of metallothionein and cell proliferation markers (Ki‐67 and PCNA) in a series of cases comprising four dermoid cysts and six epidermoid cysts of the oral cavity.Materials and MethodsThe percentages of nuclear and/or cytoplasmic staining in the basal and suprabasal layers of the cysts' epithelial lining were assessed.ResultsThis study included six males and four females, with a mean age of 33.1 years. The floor of the mouth was affected in 40% of the cases. The expression of metallothionein, Ki‐67, and PCNA was observed in all cases examined. For both lesions, the basal layer exhibited higher cytoplasmic and nuclear/cytoplasmic expression of metallothionein. Dermoid cysts exhibited higher expression of Ki‐67 and PCNA compared to epidermoid cysts in both basal and suprabasal layers, with a more pronounced expression in the suprabasal layers.ConclusionsOur results indicate that metallothionein is present in the epithelial lining of both dermoid and epidermoid cysts of the oral cavity. The cell proliferation indices observed in both conditions reflect their benign nature and slow growth.

Programming the deformation of the temperature driven spiral structure in 4D printing

Abstract Achieving shape programming of 4D printed actuators by varying the manufacturing process parameters. In this study, the effect of different path combinations on structural deformation was investigated. By altering the driving layer, passive layer, and grid angle, the spiral deformation direction of the double-layer structure was precisely controlled. Additionally, a finite element analysis model was established to predict the deformation behavior of PLA-based spiral structures. Furthermore, the influence of printing speed, nozzle temperature, line width, layer height, and plate temperature on the spiral curvature of the structure was examined. The results show that increasing printing speed and plate temperature can improve the spiral behavior of the structure, whereas increasing line width, layer height, and nozzle temperature have opposite effects. A multiple linear regression analysis was conducted on the five printing parameters to predict their influence on the spiral curvature of the structure, and a predictive model for the spiral deformation was developed. The structure was partitioned for design purposes, aiming to achieve diverse deformations of the actuator under the same geometric configuration. A loop-shaped actuator was designed to capture objects. The results showed that the path combination determined the spiral direction of the actuator, while the forming parameters effectively controlled the spiral curvature of the actuator.

Advancing laser transmission welding for additive manufacturing: A study of glass fiber reinforced polypropylene parts

Laser transmission welding (LTW) is a well-established technique for joining high-volume thermoplastic parts, such as automotive injection molded parts. For low-volume, prototype, and custom production, additive manufacturing is an emerging technology for producing complex thermoplastic parts. When compared to injection molding, the additive manufacturing process fused filament fabrication (FFF) results in an inhomogeneous structure with entrapped air within the volume. Additionally, the presence of short glass fibers in the polymer matrix leads to higher radiation scattering during the welding process. This paper presents a fundamental study of the weldability of additively manufactured fiber-reinforced parts. The specimens were fabricated using a FFF process with glass fiber-reinforced polypropylene (GF-PP). The study investigates the influence of layer thickness and line width of the FFF process on the optical transmittance. LTW-experiments were conducted using additively manufactured uncolored and black GF-PP samples. Lap shear test specimens were welded with a different energy per unit length. This research presents a process for welding additively manufactured GF-PP parts that can be used with optimized FFF-parameters to produce high-strength and durable prototypes or spare parts for the automotive industry. This research provides valuable insights into the process parameters and considerations required to achieve robust welds in additively manufactured thermoplastic parts, facilitating broader adoption of LTW in additive manufacturing contexts.

Research on the railway multi-source homonymous geographical entity matching algorithm based on dynamic time warping

This study aims to explore an efficient technique for matching multisource homonymous geographical entities in railways to address the identification issues of homonymous geographical entities. Focusing on railway line vector spatial data, this research investigates the matching problem of multisource homonymous geographical entities. Building on statistical feature matching of attribute data, a curve similarity calculation method based on the DTW algorithm is designed to achieve better local elastic matching, overcoming the limitations of the Fréchet algorithm. The empirical study utilizes railway line layer data from two data sources within Beijing’s jurisdiction, fusing 6237 segment lines from source 2 with 105 long lines from source 1. The structural comparison between the two data sources is conducted through statistical methods, applying cosine similarity and the maximum similarity value of TF-IDF for text similarity calculation. Finally, Python is used to implement the DTW algorithm for curve similarity. The experimental results show an average DTW distance of 3.92, a standard deviation of 4.63, and a mode of 0.005. Similarity measurement results indicate that 95.53% of records are within the predetermined threshold, demonstrating the effectiveness and applicability of the method. The findings significantly enhance the accuracy of railway data matching, promoting the informatization of the railway industry, and hold substantial significance for improving railway operational efficiency and system performance.

Comparative electron microscopic visualization of the lung alveolar epithelial glycocalyx with different staining and labeling methods.

The alveolar surface of the lung is lined by an epithelium consisting of type I (AECI) and type II alveolar epithelial cells (AECII). This epithelium is covered by a liquid alveolar lining layer (ALL). Besides intra-alveolar surfactant, ALL also contains the alveolar epithelial glycocalyx on the apical side of AECI and AECII. To better understand the alveolar epithelial glycocalyx, its ultrastructural visualization by transmission electron microscopy is required. The aim of this study was to systematically re-evaluate routine cytochemical methods for visualization of the alveolar epithelial glycocalyx and specifically its glycan components. For this purpose, we used chemical fixation by vascular perfusion with aldehydes as a common routine approach in mice. After fixation, staining is needed for glycocalyx visualization. Cytochemical staining agents such as alcian blue, ruthenium red, and lanthanum nitrate were compared. In addition, SNL (Sambucus nigra lectin) and UEA1 (Ulex europaeus agglutinin I) were used for sialic acid and fucose-specific labeling. Alcian blue showed the strongest staining, with cloud-like structures, whereas ruthenium red appeared as thread-like structures. On the other hand, lanthanum nitrate did not stain the alveolar epithelial glycocalyx. For specific sialic acid and fucose labeling, both lectins presented a specific signal. In conclusion, these methods can be used routinely for assessing ultrastructural changes of the alveolar epithelial glycocalyx in experimental invivo models under different physiological and pathological conditions. In addition, cytochemical staining by tissue massage and post-embedding lectin labeling after vascular perfusion support 3R (reduction, refinement, replacement) principles of animal welfare.

A 3D micro-computed tomography study comparing embryonic skeletal development in layer versus broiler strains of the domestic chicken

Our objective was to analyze the effect of selection for divergent traits in the domestic chicken on embryonic skeletal development, which could affect postnatal bird welfare. Development was compared between the Ross 308 broiler line (fast growth and muscle mass accrual) and Novoponte layers (high laying rate and egg quality). In Study 1 (Initial Conditions), we characterized egg composition prior to incubation and identified the onset of embryonic skeletal mineralization in the 2 strains. In Study 2 (Developmental Dynamics), we used 3D X-ray tomographic imaging (µCT) on incubation days ED11, ED13, ED15 and ED17 to track skeletal maturation trajectories as a pseudo-time series. Results showed that Ross 308 embryos, which are heavier than Novoponte embryos, possess higher levels of yolk nutrients including phosphorus and calcium, but lower eggshell mineral content, than Novoponte embryos. Skeletal mineralization started synchronously in both strains, on ED11. The higher mineral ion content in the larger yolk of Ross 308 eggs compared to Novoponte eggs may partly explain why skeletal mineralization in Ross 308 embryos advances faster: using µCT, we show that the mandible and tibiotarsi in Ross 308 embryos are larger at ED11 and ED13 compared with Novoponte embryos. However, Novoponte embryos catch up from this initial lag in mineralization by ED15. The timing of the Novoponte acceleration coincides with the functional activation of the chorioallantoic membrane in releasing calcium from the inner eggshell. This correlates with a decrease in eggshell thickness from ED11 to ED17 in Novoponte eggs, which was not observed during Ross 308 incubation. To conclude, while some temporal discrepancies exist in early skeletal development between the embryos of Ross 308 and Novoponte strains, overall prenatal skeletal maturation seems to be robustly regulated. Despite selection for antagonist production traits, layer and broiler prehatch skeletal morphology ultimately synchronizes. Practically, since the extent of skeletal maturity equalizes between strains towards the end of incubation, refinements of farming practices, postnatal environment, and diet should be considered for improving domestic fowl welfare.

Co-regulation of gelatin content and Hofmeister effect on 3D-printed high internal phase emulsion gel characteristics for resveratrol delivery

The study investigated the influence of gelatin (GE) content and the Hofmeister effect on the physicochemical, rheological, and printing properties of high internal phase emulsion (HIPE) gels. Incremental GE content introduced more triple helix structures (junction zones) in the continuous phase of HIPE. By soaking in a sodium citrate (Na3Cit)-glycerol-water solution, polymer chain bundling, hydrophobic interactions, and abundant hydrogen bonds between GE and glycerol further increased, achieving a more compact crosslinking density and internal network. The optimized HIPE-GE-Cit3- gel with 1.5 wt% GE displayed improved shape retention, generating smoother and firmer gels with enhanced freezing and heat resistance. Its excellent mechanical strength and viscoelasticity can resist large deformations and maintain reversible structures. HIPE-GE gel with 1.5 wt% GE demonstrated satisfactory printing suitability with clear outlines, favorable visual aesthetics, and minimal dimensional deviation. This post-soaking (Hofmeister effect) also eliminated rough surfaces and visible layered lines, improved mechanical properties and more elastic networks. The printed HIPE-GE1.5-Cit3- gel with higher rigidity and elasticity impeding molecular release, protected encapsulated resveratrol against degradation, especially from heat, and enhanced the release rate in the small intestine, achieving sustained release. This work produced customizable HIPE gels by 3D printing with multiple advantages to develop personalized nutraceutical carriers with high-temperature tolerance.

Influence of Extrusion Parameters on the Mechanical Properties of Slow Crystallizing Carbon Fiber-Reinforced PAEK in Large Format Additive Manufacturing.

Additive Manufacturing (AM) enables the automated production of complex geometries with low waste and lead time, notably through Material Extrusion (MEX). This study explores Large Format Additive Manufacturing (LFAM) with carbon fiber-reinforced polyaryletherketones (PAEK), particularly a slow crystallizing grade by Victrex. The research investigates how extrusion parameters affect the mechanical properties of the printed parts. Key parameters include line width, layer height, layer time, and extrusion temperature, analyzed through a series of controlled experiments. Thermal history during printing, including cooling rates and substrate temperatures, was monitored using thermocouples and infrared cameras. The crystallization behavior of PAEK was replicated in a Differential Scanning Calorimetry (DSC) setup. Mechanical properties were evaluated using three-point bending tests to analyze the impact of thermal conditions at the deposition interface on interlayer bonding and overall part strength. The study suggests aggregated metrics, enthalpy deposition rate and shear rate under the nozzle, that should be maximized to enhance mechanical performance. The findings show that the common practice of setting fixed layer times falls short of ensuring repeatable part quality.

Attaining Tailored Wicking Behavior with Additive Manufacturing.

Additive manufacturing (AM) has opened a new pathway to create customized wicking materials. With lower manufacturing costs and a larger design space than many alternatives for wicking, AM is of particular value in fields such as thermal management and microfluidics. Fluid propagation during wicking in porous media, however, has largely remained limited to Washburnian () behavior, and optimizing these materials for wicking in a variety of use cases presents a challenge. In this work, we present a method of tailoring wicking behavior to an arbitrary target function of propagation distance versus time, achieved through the use of AM to create nonuniform porous materials. Layers of parallel lines, each successive layer rotated 90° from the last, form a gridded structure with a spatially varying unit cell size for which analytical models for the capillary pressure and solid fraction and a semianalytical model for permeability were found. These models were validated with capillary rise experiments for spatially uniform porous materials over a range of solid fractions from 0.4 to 0.9. Leveraging these models and representing a nonuniform porous material as a series of Ohmic fluidic resistors, we created an inverse design algorithm that generates a wicking material with spatially varying parameters to achieve a specified target function for fluid propagation as a function of time. These materials can exhibit atypical wicking behavior, including fluid propagation displaying simple linear and piecewise linear relationships with time rather than the conventional Washburn relationship.

Improvement of 3D printing and subsequent microwave freeze-drying solidification accuracy of pineapple gel-based inks: Infill percentage control and internal models design

The purpose of this study was to improve the 3D printing accuracy of pineapple gel and its subsequent microwave freeze drying (MFD) solidification precision based on infill percentage control (30%, 50%, 70%, and 90%) and internal models design (Hilbert curve, honeycomb, and rectilinear). Through comparing the designed models with the physical dimensions of the printed and dehydrated products, the optimal regulation strategy was obtained. Results showed that the printing deviation of samples decreased initially and then increased with higher infill percentages, with the 70% infill percentage having the lowest deviation. Among all internal models, the rectilinear infill pattern showed the best printing accuracy. Porosity and the shape deformation rate of MFD solidification products initially decreased and then increased with higher infill percentages. The 70% infill percentage products had the lowest shape deformation rate. The honeycomb infill pattern performed best in reducing solidification sample shrinkage and deformation. Additionally, micro-CT scans revealed that the honeycomb infill pattern helped maintain the integrity of each layer's lines of MFD solidification products, closely matching the model's line distribution. In the 50% and 70% infill percentage, honeycomb and rectilinear samples exhibited better crispness. A 70% honeycomb infill pattern was recommended for optimal printing and post-solidification accuracy.

Designing 3D-printed concrete structures with scaled fabrication models

This article proposes using scaled fabrication models to assist the design research of 3D-printed discrete concrete structures where full-scale fabrication tests are costly and time-consuming. A scaled fabrication model (SFM) is a scaled model 3D-printed the same way as in actual construction to reflect its fabrication details and acquire alike layer line textures. The components of a 1:10 SFM can be easily produced by consumer-level desktop 3D printers with minimal modification. SFMs assist the design communication and make possible quick tests of distinct fabrication designs that are hard to assess in digital modeling during the conceptual design phase. A case study of a discrete compression-dominant funicular floor derived from graphic statics is presented to illustrate the contribution of SFM to the design research of force-informed toolpathing where the printing direction of a component is aligned to the principal stress line. The design iterations encompass a sequence of component, partial, and full model SFM printing tests to explore and optimize the fabrication schemes where parallel, non-parallel, and creased slicing methods to create toolpaths are compared and chosen to adapt different discrete components.

Design and simulation analysis of an extrusion structure based on screw extrusion 3D printing

Abstract In response to the problems of 3D printing, such as uneven wire discharge and easy clogging of printing nozzles in FDM (Fused Deposition Modeling) printing technology, this paper develops a screw extrusion 3D printing melting deposition system based on simulation. The simulation results show that the maximum deformation of the screw occurs at the tail end, with a maximum value of 0.04 mm, while the fluid pressure and the pressure on the surface of the screw gradually increase along the direction of extrusion, and the maximum pressure occurs near the nozzle, with a value of 0.13 MPa. The fluid pressure is positively correlated with the screw speed and negatively correlated with the screw pitch. The fitting formula is obtained by numerical simulation of the screw speed and the flow velocity at the nozzle outlet. Using a self-made screw extrusion 3D printing equipment, relevant experiments are conducted to explore the influence of different layer thicknesses and line spacings on the mechanical properties of printed samples, as well as the influence of printing speed on surface quality. It is found that layer thickness has a significant impact on the bending strength of printed samples, with a maximum value of 24.74 MPa and a minimum of 19.21 MPa. The bending strength decreases by 28.79 % from 0.6 mm to 1.0 mm layer thickness. The line spacing has a significant impact on the tensile strength of printed samples, with a maximum value of 27.22 MPa and a minimum of 21.16 MPa. As the printing speed increases, the surface roughness of the printed piece also gradually increases from Ra = 389.28 μm at v = 30 mm/s to Ra = 535.45 μm at v = 70 mm/s, an increase of 37.55 %.

Correlation between Periodontitis and Gastritis Induced by Helicobacter pylori: A Comprehensive Review.

The goal of this comprehensive review was to verify if the prevalence of Helicobacter pylori (Hp) bacteria in patients with dyspepsia is higher in the oral cavity of periodontal or non-periodontal patients. The bibliographic search was conducted on scientific studies published in PubMed, Cochrane Library, SciELO, and BVS. The focus question was: "In patients with dyspepsia and periodontitis, is the prevalence of Hp bacteria in the oral cavity higher than in patients with only dyspepsia or without any disease?" The inclusion criteria were human studies in English, Portuguese, or Spanish languages, published between 2000 and 2022, that included patients over the age of 18 and aimed to evaluate the presence of Hp bacteria in the oral cavity and in the protective mucosal layer of the gastric lining of patients with the diseases (periodontitis and dyspepsia) or without disease; clinical trials, randomized controlled clinical trials, comparative studies, case-control studies, cross-sectional studies, and cohort studies. The methodological quality evaluation of the included articles was performed using the Joanna Briggs Institute tools. The final scores could be of "Low" quality (at least two "no" [red] or ≥ five "unclear" found), "Moderate" quality (one "no" [red] was found or up to four "unclear" criteria were met), or "High" quality (all green [yes] or at maximum two "unclear"). Of 155 potentially eligible articles, 10 were included in this comprehensive review after the application of the eligibility criteria. The selected studies were scrutinized regarding the relationship between Hp colonization in the oral cavity and stomach, its impact on severity and complications of gastric infection, as well as the effect of the presence of oral and gastric Hp on dental and systemic parameters. Hp can colonize periodontal pockets regardless of its presence in the stomach. There was a higher prevalence of oral biofilm in dyspeptic patients with periodontal disease, and worse control of bleeding and low oral hygiene was observed in periodontal compared to non-periodontal patients. For que quality assessment, the scientific studies included presented low to moderate methodological quality. Conclusions: It is possible to conclude that Hp is a bacterium that can colonize dental plaque independently of the stomach and vice versa; however, when both diseases are found, its presence may be more significant. Supra and subgingival dental plaque may be a reservoir of Hp, suggesting that patients with gastric infections are more likely to have Hp in the oral cavity. The results must be carefully analyzed due to the limitations present in this review.

Insights into thermomechanical behavior and design parameters of alumina calciner refractory lining

This study investigated the thermomechanical behavior of an alumina calciner’s lining, a critical component in alumina processing, often susceptible to maintenance issues arising from refractory failure due to erosion and cracking. Based on numerical analyses via the finite element method, the design of a refractory panel was modeled. Furthermore, the influence of geometric parameters and friction level between lining layers on the thermal and mechanical behavior of the system was evaluated. Key findings highlighted how the curvature changed the stress profiles, resulting in particular cracking patterns, where curved panels showed higher stress concentrations at the center of their edges. Empirical validation through in-situ crack pattern observations further validated the model’s predictive capability. Additionally, the study evaluated the influence of friction coefficients on resulting stresses, showing their small effect relative to other factors. Analyses on design parameters indicated that stress levels generally increased with the size-to-thickness ratio, highlighting the trade-off between reducing installation time and ensuring structural integrity in panel design and application. An alternative for enhancing lining performance was explored by selecting the material, where decreasing the insulating thermal conductivity reduced the likelihood of failure of the castable layer. Ultimately, the computational numerical method developed in this study offers a robust framework for exploring various geometries and materials, providing engineers with a versatile tool for optimizing lining designs in various operational scenarios.

Пьезоэлектрический дисковый актюатор кручения с дискретно-спиральными электродами

A mathematical model of a disk (ring) torsion actuator with curvilinear interdigital electrodes – «villi» of a spiral form, which are characterized by a constant value of the orientation angle of an arbitrary section of the villus to the circumferential direction of the disk, has been developed. Bases of electrode-villi interacting with each other through local areas of piezoelectric layer are connected with periodic alternation to central or peripheral concentric circular base electrodes, to outputs of which control voltages are connected. As a result of numerical modeling of the «twisting bimorph» graphs of the dependence of the twist angle and the blocking torque on the ratio of the inner and outer radii and the values of the control voltage at the outputs of the base electrodes of the annular two-layer actuator with symmetrical (relative to the radial line) directions of the spiral orientations of the electrode-villi and, as a result, the spiral polarization lines of the piezoelectric layers working for tension/compression.