49 research outputs found

    Parameters of oxidative stress in saliva from patients with aggressive and chronic periodontitis

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    Objectives: Free radicals play an important role in the onset and progression of many diseases. The aim ofthis study was to investigate the contribution of oxidative stress in the pathology of aggressive (AgP) andchronic (CP) periodontitis and its relation with the clinical periodontal status.Methods: Eighty subjects were divided into two groups: 20 patients with AgP and 20 patients with CP withtheir 20 corresponding matched controls, based on clinical attachment loss (CAL), probing pocket depth(PPD), and bleeding on probing (BOP). Saliva reactive oxygen species (ROS), lipid peroxidation, and nonenzymaticantioxidant defences were measured by luminol-dependent chemiluminescence assay, asthiobarbituric acid-reactive substances (TBARs) and total radical-trapping antioxidant potential (TRAP),respectively. Pearson?s correlation and multivariate analysis were used to determine the relationshipbetween ROS and TBARs and the clinical parameters.Results: ROS and TBARs were increased in AgP while TRAP was decreased, comparing with CP. In AgP, astrong and positive correlation was observed between ROS and TBARs and they were closely associatedwith CAL and PPD.Discussion: In AgP, but not in CP, oxidative stress is a high contributor to periodontal pathology and it isclosely associated with the clinical periodontal status.Fil: Acquier, Andrea Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: de Couto Pita, Alejandra Karina. Universidad de Buenos Aires. Facultad de Odontología. Cåtedra de Farmacología; ArgentinaFil: Busch, Lucila. Universidad de Buenos Aires. Facultad de Odontología. Cåtedra de Farmacología; ArgentinaFil: Sanchez, Gabriel A.. Universidad de Buenos Aires. Facultad de Odontología. Cåtedra de Biofísica; Argentin

    The Inclusiveness and Emptiness of <i>Gong Qi</i>: A Non-Anglophone Perspective on Ethics from a Sino-Japanese Corporation

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    This article introduces a non-Anglophone concept of gong qi(communal vessel, 慬晹) as a metaphor for ‘corporation’. It contributes an endogenous perspective from a Sino-Japanese organizational context that enriches mainstream business ethics literature, otherwise heavily reliant on Western traditions. We translate the multi-layered meanings of gong qi based on analysis of its ideograms, its references into classical philosophies, and contemporary application in this Japanese multinational corporation in China. Gong qi contributes a perspective that sees a corporation as an inclusive and virtuous social entity, and also addresses the elusive, implicit, and forever evolving nature of organizational life that is rarely noticed. We propose gong qi can be applied in other organizations and wider cultural contexts to show a new way of seeing and understanding business ethics and organization. Rather than considering virtue as a list of definable individual qualities, we suggest that the metaphor of gong qi reveals how virtue can be experienced as indeterminate, yet immanently present, like the substance of emptiness. This, then allows us to see the virtue of immanence, the beauty of implicitness, and hence, the efficacy of gong qi

    Good to be bad : should we be worried by the sharing economy?

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    We develop the notion of a legitimacy tipping point to demonstrate how informal economy practices are being utilized by innovative sharing economy ventures to gain a competitive advantage that is subsequently leveraged to reconfigure formal institutional arrangements. Companies who are able to scale rapidly can afford to contravene regulations, provided they have public support. When they reach a certain size, in terms of investment and customer numbers, regulators are forced into a reactive position where novel business models are legitimized. This raises an important question for regulators and entrepreneurs as to whether subverting business regulation is being viewed as a viable source of competitive advantage by scaling firms

    Development of the Dynamic Compaction Resistance Sintering (DCRS): A new process for powder consolidation combining electric current and dynamic loading

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    International audienceA homemade powder consolidation process combining high heating rates obtained by resistive sintering and dynamic compaction loading has been developed. The Dynamic Compaction Resistance Sintering (DCRS) device is fully automated and allows a complete regulation of the loading and temperature cycles under controlled atmosphere conditions. The general principle is to carry the electric current for sintering by means of copper Hopkinson bars. Thus, in addition to the conventional application of a constant uniaxial loading (5-100 MPa), the Hopkinson bars offer the possibility of multiple dynamic loadings at velocities up to 30 m/s. The DCRS device was tested at temperatures as high as 1850 degrees C and for heating rates up to 1000 degrees C/min. Some of the potentialities of this technique are illustrated through the low-temperature consolidation of copper under repeated dynamic loadings and high-temperature sintering of alumina

    Association between Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis in subgingival plaque and clinical parameters, in Argentine patients with aggressive periodontitis

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    Background: Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) have been associated with aggressive (AgP) and chronic periodontitis. Objective: The aim of this study was to evaluate the levels of Aa and Pg in gingival crevicular fluid (GCF) of patients with AgP and its relation with clinical parameters. Design: Sixteen females and fourteen males with clinical diagnosis of AgP aged 17–23 years and their match's controls, were included in this study. Clinical recording concerning probing pocket depth, clinical attachment level, plaque index and gingival bleeding index were performed at baseline, 30 and 60 days after baseline. After clinical examination GCF samples were analyzed for Aa and Pg with a real-time polymerase chain reaction technique. Patients group was treated with a combined of mechanical and oral antibiotic therapy (doxycycline 100 mg/day, during 21 days). A multivariate analysis was used to determine the relationship between Aa and Pg counts with clinical parameters. Results: GCF from all subjects was positive for Aa and PG. In controls Pg concentration was higher than Aa (Pg: 42,420 ± 3,034 copies/ml; Aa: 66.6 ± 5.4 copies/ml p < 0.001) while in patients both microbes showed the same concentration (Aa: 559,878 ± 39,698 Pg: 572,321 ± 58,752). A significant and positive correlation was observed between counts of Aa and Pg (R square: 0.7965, p < 0.0001). Female showed more counts/ml. Aa might be closely associated with clinical parameters while Pg did not. At 30 and 60 days Aa counts in patients were similar to controls while Pg counts were equal to baseline. However, in spite of Pg presence a clinical improvement was observed in all patients. Conclusions: In our population the presence of Aa may be associated with AgP while Pg may be in GCF as an opportunistic pathogen which might caused disease when the ecological balance was favorable.Fil: SĂĄnchez, Gabriel A.. Universidad de Buenos Aires. Facultad de Odontologia. CĂĄtedra de BiofĂ­sica; ArgentinaFil: Acquier, Andrea Beatriz. Universidad de Buenos Aires. Facultad de OdontologĂ­a. CĂĄtedra de FarmacologĂ­a; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: de Couto, Alejandra. Universidad de Buenos Aires. Facultad de OdontologĂ­a. CĂĄtedra de FarmacologĂ­a; ArgentinaFil: Busch, Lucila. Universidad de Buenos Aires. Facultad de OdontologĂ­a. CĂĄtedra de FarmacologĂ­a; ArgentinaFil: Mendez, Carlos Fernando. Universidad de Buenos Aires. Facultad de OdontologĂ­a. CĂĄtedra de FarmacologĂ­a; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentin

    The DCRS: Dynamic compaction resistance sintering. A flash sintering process with a dynamic loading ability

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    A homemade powder processing device combining Joule heating and dynamic compaction is presented. This device has been tested at temperatures as high as 1850 ∘C with heating rates up to 1000 ∘C/min. A detailed description of this device is given here followed by mechanical response and thermal validation tests. This highlights the reproducibility of the results on both the thermal and mechanical point of view

    Welding Thermal Cycle Impact on the Microstructure and Mechanical Properties of Thermo-Mechanical Control Process Steels

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    Steels obtained by the thermo?mechanical control process (TMCP) possess a higher level of strength than conventional normalized steels due to the fine-grained microstructures generated during TMCP. Such enhancement opens ways to decrease metal construction weight. At the same time, TMCP steels have less thermal stability, in connection with a lot of factors affecting and governing grain growth during the heating of TMCP steels. Herein, the effects of the welding thermal cycle (WTC) on the structure and properties of TMCP steels of ferritic?perlite (S460M) and bainitic (alform 620M) types are systematically investigated. ? 2021 Wiley-VCH GmbH11Nsciescopu

    Towards a reference ontology for digital platforms

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    Digital platforms can be categorized into different types including ‘multi-sided platform’, ‘digital marketplace’, ‘crowdfunding platform’, ‘sharing economy platform’ and ‘on-demand platform’. As there is a lack of knowledge regarding the requirements and design of these digital platform types, we developed a method to design a digital platform reference ontology based on a taxonomy. The taxonomy provides an overview of digital platform properties, with the property values expressing the possible variations between digital platforms depending on their type. For each property value, we can create a digital platform reference ontology module using the five-step approach proposed by Ruy et al. [1] based on the patterns of the Unified Foundational Ontology (UFO). UFO is a high-level ontology that provides us with basic concepts for objects, events, social elements and their types, relations and properties. These digital platform reference ontology modules can be combined as building blocks to compose our reference ontology for expressing the functionality for digital platforms of all types. We believe this reference ontology can be a step towards a better understanding of digital platform functionality, better communication between stakeholders and eventually may facilitate future research and development of digital platforms
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