750 research outputs found

    Super-hydrodynamic limit in interacting particle systems

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    This paper is a follow-up of the work initiated in [3], where it has been investigated the hydrodynamic limit of symmetric independent random walkers with birth at the origin and death at the rightmost occupied site. Here we obtain two further results: first we characterize the stationary states on the hydrodynamic time scale and show that they are given by a family of linear macroscopic profiles whose parameters are determined by the current reservoirs and the system mass. Then we prove the existence of a super-hyrdrodynamic time scale, beyond the hydrodynamic one. On this larger time scale the system mass fluctuates and correspondingly the macroscopic profile of the system randomly moves within the family of linear profiles, with the randomness of a Brownian motion.Comment: 22 page

    Titanium alloys (AoN) and their involvement in osseointegration.

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    Background: Osseointegration is essential for a long-term successful and inflammation-free dental implant. Such a result depends on osteoblastic cells growth and differentiation at the tissue-implant interface. The aim of this study was to compare two different AoN titanium layers (GR4 and GR5) to investigate which one had a greater osteoconductive power using human osteoblasts (HOb) culture at two different time-points. Materials and Methods: The expression levels of some bone-related (ALPL, COL1A1, COL3A1, SPP1, RUNX2, and SPARC) were analyzed using real time reverse transcription-polymerase chain reaction (real time RT-PCR). Results: Real-time RT-PCR data showed that after 3 days of treatment with TiA4GR, the genes up-regulated were COL3A1, ALPL, SPP1, and RUNX2. Moreover, no difference in gene expression was noticed 4 days later. On the other hand, the genes that overexpressed after 3 days of treatment with AoN5GR were ALPL, SPP1, and RUNX2. In both cases, the expression of COL1A1 and SPARC was negatively regulated. Conclusion: Our data showed that both titanium surfaces led to osteoblasts recruitment, maturation, and differentiation, thus promoting osseointegration at the tissue-implant interface

    Fibroblast behavior after titanium surfaces exposure.

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    Background: The main requirements for a good material are its ability to promote attraction and adhesion of bone precursor cells and their proliferation and differentiation. Different biocompatible materials are currently employed as scaffold. Among these, titanium is considered a gold standard because of its biocompatibility and good corrosion resistance. Materials and Methods: The aim of this work was to compare two different AoN titanium layers (GR4 and GR5) to investigate which one had a greater osteoconductive power using human fibroblasts (HFb) culture at two different time-points. The expression levels of some adhesion and traction-resistance related genes (COL11A1, COL2A1, COL9A1, DSP, ELN, HAS1, and TFRC) were analyzed using real time reverse transcription-polymerase chain reaction. Results: After 7 days of treatment with TiA 4GR, the only two up-regulated genes were COL2A1 and DSP. After 15 days of treatment, none of genes over expressed. Conclusion: Our preliminary results suggest that neither AoN 4GR nor AoN 5GR are able to promote the production of protein involved in cell\u2013cell and cell\u2013matrix adhesion and in stress-resistance, required for a good outcome in dental implantolog

    Duality relations for the ASEP conditioned on a low current

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    We consider the asymmetric simple exclusion process (ASEP) on a finite lattice with periodic boundary conditions, conditioned to carry an atypically low current. For an infinite discrete set of currents, parametrized by the driving strength sKs_K, K≥1K \geq 1, we prove duality relations which arise from the quantum algebra Uq[gl(2)]U_q[\mathfrak{gl}(2)] symmetry of the generator of the process with reflecting boundary conditions. Using these duality relations we prove on microscopic level a travelling-wave property of the conditioned process for a family of shock-antishock measures for N>KN>K particles: If the initial measure is a member of this family with KK microscopic shocks at positions (x1,…,xK)(x_1,\dots,x_K), then the measure at any time t>0t>0 of the process with driving strength sKs_K is a convex combination of such measures with shocks at positions (y1,…,yK)(y_1,\dots,y_K). which can be expressed in terms of KK-particle transition probabilities of the conditioned ASEP with driving strength sNs_N.Comment: 26 page

    Oral health status among migrants from middle-and low-income countries to europe: A systematic review

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    Introduction. Economic inequality, political instability and globalization have contributed to the constant growth of the migration phenomenon in recent years. In particular, a total of 4.2 million people migrated to Europe during 2019 and most of them settled in Germany, France and Italy. Objectives. The objective of this study was to conduct a systematic review of studies analyzing the oral health condition among migrants from middle-and low-income countries to Europe and assessing the eventual association between their sociodemographic and socioeconomic characteristics and oral health status. Materials and Methods. A systematic review was conducted in PubMed, Cochrane Library, Scopus and Science Direct databases. After titles, abstracts and full-text exami-nation, only 27 articles were selected on the basis of inclusion criteria and consequently included for quality assessments and data extraction. Results. Most of the studies reported a higher prevalence of caries experience, a poorer periodontal health and more difficulties in accessing dentalcare services among migrant groups compared with the non-migrant population. Inequalities were mostly associated with ethnic background, economic condition and social grade. Conclusion. Our review demonstrates the lack of dental health among migrants, underlining that their cultural beliefs and their social and economic living conditions could influence their oral health

    Hyaluronic acid modulates growth, morphology and cytoskeleton in embryonic chick skin fibroblasts

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    The action that hyaluronic acid (HA) exerts on cell proliferation was investigated in embryonic chick skin fibroblasts at different ages (7-14 days) and in different cell-cycle stages evaluated by flow cytometry (cells maintained with and without serum). Proliferation was estimated by 3H- thymidine incorporation and cell counting. The results demonstrated hyaluronic acid inhibits cell multiplication in all different environmental conditions examined. The inhibitory effect of HA is more evident in 14-day than 7-day old fibroblasts. The ability of HA to modulate 3H-thymidine incorporation did not involve a change in the time required for cells entering the S phase of the replicating cycle, but is due to a smaller number of cells entering in this phase. As the relationships between components of the extracellular matrix (ECM) and the cytoskeleton are known, parallel studies were carried out on some cytoskeleton proteins. Furthermore, by modifying the capacity of cells to adhere to the substrate, HA induced alterations in cell shape and in cytoskeleton components involved in these processes. We may hypothesize that HA, binding specific membrane receptors, affects cell adhesion and morphology inducing less receptivity of fibroblasts to mitogenic stimuli by transmembrane interactions with cytoskeleton

    Evaluation of IL6, IL10 and VDR alleles distribution in an Italian large sample of subjects affected by chronic periodontal disease

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    In recent decades, the role played by the immune response to bacteria in the pathogenesis of chronic periodontal disease (PD) has long been studied. Although from the clinical point of view, adequate oral hygiene is essential to ensure a satisfactory response of the host to infections, modulation of the reaction of immune system could be influenced by genetic factors. The aim of the present study was to investigate the distribution of alleles of polymorphisms relevant for chronic periodontitis in a sample of adult subjects affected by chronic PD. The present study was conducted with sample collected in Italian private practice offices from January 2013 to December 2017. The sample included 744 adult patients diagnosed with chronic periodontitis. The inclusion criteria were as follows: age > 18 years, diagnosis of chronic PD. The diagnosis of chronic periodontitis was based on the criteria established by the American Academy of Periodontology. No significant difference in allele distribution among patients from different Italian regions was found. Results, supporting absence of population heterogeneity for the investigated polymorphisms in Italy, suggest similar effect in periodontitis etiology

    Langevin dynamics with a tilted periodic potential

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    We study a Langevin equation for a particle moving in a periodic potential in the presence of viscosity γ\gamma and subject to a further external field α\alpha. For a suitable choice of the parameters α\alpha and γ\gamma the related deterministic dynamics yields heteroclinic orbits. In such a regime, in absence of stochastic noise both confined and unbounded orbits coexist. We prove that, with the inclusion of an arbitrarly small noise only the confined orbits survive in a sub-exponential time scale.Comment: 38 pages, 6 figure
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