24 research outputs found

    Analysis of immunohistochemical expression of proinflammatory cytokines (IL-1α, IL-6, and TNF-α) in gallbladder mucosa: comparative study in acute and chronic calculous cholecystitis

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    Background: Several studies have shown increased serum levels of proinflammatory cytokines (IL-1α, IL-6, and TNF-α) in patients with cholelithiasis. The local expression of the proteins involved in pathogenesis of the disease is poorly recognised. Materials and methods: The authors examined immunohistochemically (IHC) the expression status of IL-1α, IL-6, and TNF-α in gallbladder mucosa of the patients with cholelithiasis as related to acute (ACC) and chronic (CCC) types of cholecystitis. Proinflammatory cytokines were quantitatively evaluated in gallbladder mucosa (epithelium and lamina propria) in ACC (n = 16) and CCC (n = 55) groups using modern spatial visualisation technique. Results: Quantitative analysis of IHC signals showed no significant differences in IL-1α and IL-6, and immunoexpression in patients with ACC and CCC. A significantly greater IHC expression of TNF-α was detected in CCC as compared with ACC group. In either of the patient groups immunoexpression of IL-1α and of TNF-α was significantly higher than that of IL-6. Immunoexpression of TNF-α was significantly higher than that of IL-1α only in CCC group. A positive correlation was disclosed between IHC expression of IL-1α and body mass index in CCC group. IHC expression of TNF-α correlated positively with expression of CD68 molecule (histiocytic marker), number of leukocytes in blood and higher grading of gallbladder wall in ACC group. Conclusions: A more pronounced IHC expression of TNF-α and IL-1α than IL-6 in both types of cholecystitis may suggest the role of these cytokines in pathogenesis of cholelithiasis. IHC expression of TNF- α shows better correlation with clinical/laboratory data in acute cholecystitis, and its quantitative prevalence over the remaining cytokines points to the role of the TNF-α in maintenance of inflammation in the course of cholelithiasis

    Ceria nanoparticles as promoters of CO2 electroreduction on Ni YSZ An efficient preparation strategy and insights into the catalytic promotion mechanism

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    Since many decades nickel yttria stabilized zirconia cermet Ni YSZ has been the most frequently used fuel electrode material for high temperature solid oxide cells SOCs . However, in recent years there has been considerable effort to improve the Ni YSZ performance through surface engineering. In this work, we report a simple strategy to apply nanosized un doped CeOx and Ni doped NiCeOy ceria particles into porous Ni YSZ cermet electrodes via infiltration from hexane solution. Detailed characterization of the particles in their solution revealed differences in the ease of agglomeration, with NiCeOy nanoparticles being better dispersed and thus forming smaller aggregates. This property is critical for the effectiveness of the solution in filling the pores of Ni YSZ cermet and the consequent ceria deposition. In particular, morphological and microstructural characterization reveals that NiCeOy nanoparticles decorate uniformly the pores of Ni YSZ backbone, deep up to the interface with the electrolyte. More importantly, this can be done with relatively high ceria loading per infiltration co firing step. Electrochemical tests demonstrate that infiltrated Ni YSZ fuel electrodes have improved I V performance in CO2 electrolysis as compared to pristine Ni YSZ. Synchrotron based operando NAP XPS experiments using both soft and tender X rays revealed the formation of an ultrathin Ni Ce3 layer on the electrode surface, which can rationalize the ameliorated CO2 electrolysis performanc

    Corrosion behavior of zirconia in acidulated phosphate fluoride

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    ABSTRACT Objective The corrosion behavior of zirconia in acidulated phosphate fluoride (APF) representing acidic environments and fluoride treatments was studied. Material and Methods Zirconia rods were immersed in 1.23% and 0.123% APF solutions and maintained at 37°C for determined periods of time. Surfaces of all specimens were imaged using digital microscopy and scanning electron microscopy (SEM). Sample mass and dimensions were measured for mass loss determination. Samples were characterized by powder X-ray diffraction (XRD) to detect changes in crystallinity. A biosensor based on electrochemical impedance spectroscopy (EIS) was used to detect ion dissolution of material into the immersion media. Results Digital microscopy revealed diminishing luster of the materials and SEM showed increased superficial corrosion of zirconia submerged in 1.23% APF. Although no structural change was found, the absorption of salts (sodium phosphate) onto the surface of the materials bathed in 0.123% APF was significant. EIS indicated a greater change of impedance for the immersion solutions with increasing bathing time. Conclusion Immersion of zirconia in APF solutions showed deterioration limited to the surface, not extending to the bulk of the material. Inferences on zirconia performance in acidic oral environment can be elucidated from the study
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