Chonbuk National University

About: Chonbuk National University is a education organization based out in Jeonju, South Korea. It is known for research contribution in the topics: Apoptosis & Graphene. The organization has 14820 authors who have published 28884 publications receiving 554131 citations.

Green synthesis of silver oxide nanoparticles and its antibacterial activity against dental pathogens

Abstract: In the present study, the use of silver oxide nanoparticles (Ag2O NPs) synthesized using Ficus benghalensis prop root extract (FBPRE) as a reducing and stabilizing agent is reported and evaluated for its antibacterial activity against dental bacterial strains. The effects of pH, extract concentration, metal ion concentration, and contact time were studied to confirm the optimum production of Ag2O NPs. Our results suggest that, by increasing the extract concentration and the time frame, there will be a significant increase in the formation of nanoparticles. The UV–vis adsorption spectra show the absorbance peak in the range of 430 nm, and FTIR spectral peaks indicate that the phytochemicals in the extract are responsible for the formation of the nanoparticles. The HR-TEM image, SAED, and XRD pattern confirmed the morphology (spherical), silver oxide 42.7 nm and silver 51.4 nm, and crystalline nature of the obtained nanoparticles, respectively. The blend of FBPRE and Ag2O NPs showed excellent antibacterial activities against the two-dental bacteria Streptococcus mutans and Lactobacilli sp. The study results suggest that the blend of synthesized Ag2O NPS and FBPRE will be useful in tooth paste as a germicidal agent after extensive investigation with animal models.

Energy dependence and fluctuations of anisotropic flow in Pb-Pb collisions at √sNN = 5.02 and 2.76 TeV

Abstract: Measurements of anisotropic flow coefficients with two- and multi-particle cumulants for inclusive charged particles in Pb-Pb collisions at $ \sqrt{s_{\mathrm{NN}}}=5.02 $ and 2.76 TeV are reported in the pseudorapidity range |η| < 0.8 and transverse momentum 0.2 < p$_{T}$ < 50 GeV/c. The full data sample collected by the ALICE detector in 2015 (2010), corresponding to an integrated luminosity of 12.7 (2.0) μb$^{−1}$ in the centrality range 0-80%, is analysed. Flow coefficients up to the sixth flow harmonic (v$_{6}$) are reported and a detailed comparison among results at the two energies is carried out. The p$_{T}$ dependence of anisotropic flow coefficients and its evolution with respect to centrality and harmonic number n are investigated. An approximate power-law scaling of the form v$_{n}$(p$_{T}$) ∼ p$_{T}^{n}^{/3}$ is observed for all flow harmonics at low p$_{T}$ (0.2 < p$_{T}$ < 3 GeV/c). At the same time, the ratios v$_{n}$/v$_{m}^{n}^{/ }^{m}$ are observed to be essentially independent of p$_{T}$ for most centralities up to about p$_{T}$ = 10 GeV/c. Analysing the differences among higher-order cumulants of elliptic flow (v$_{2}$), which have different sensitivities to flow fluctuations, a measurement of the standardised skewness of the event-by-event v$_{2}$ distribution P(v$_{2}$) is reported and constraints on its higher moments are provided. The Elliptic Power distribution is used to parametrise P(v$_{2}$), extracting its parameters from fits to cumulants. The measurements are compared to different model predictions in order to discriminate among initial-state models and to constrain the temperature dependence of the shear viscosity to entropy-density ratio.

CoNi Bimetallic Nanofibers by Electrospinning: Nickel-Based Soft Magnetic Material with Improved Magnetic Properties

Abstract: Recently, bimetallic nanostructures have received special interest due to their promising chemical and physical properties. In the literature, various complicated processes have been reported for the preparation of several bimetallic materials in a nanoparticulate shape. In this study, nanofibers, rather than nanoparticles, composed of cobalt and nickel are introduced; these nanofibers have been prepared by a facile technique, electrospinning. Typically, calcination of electrospun mats originating from nickel acetate, cobalt acetate, and poly(vinyl alcohol) in argon atmosphere led to complete elimination of the utilized polymer and abnormal decomposition of the metallic acetates to produce CoNi nanofibers. Physiochemical characterization indicated that both Ni and Co are uniformly distributed along the obtained nanofibers in the same profile which indicates that Ni and Co have been combined at the crystalline level. The prepared CoNi nanofibers revealed better magnetic properties compared with those of Co...

Wnt/β-catenin signaling enhances osteoblastogenic differentiation from human periodontal ligament fibroblasts.

Abstract: Wnt/β-catenin signaling has been known to influence bone formation and homeostasis. In this study, we investigated the canonical Wnt signaling regulation of osteogenic differentiation from periodontal ligament (PDL) fibroblasts. Stimulating PDL fibroblasts with lithium chloride (LiCl), a canonical Wnt activator, significantly increased mineralized nodule and alkaline phosphatase (ALP) activity in a time- and dose-dependent manner. LiCl up-regulated protein expression of osteogenic transcription factors, including the runt-related gene 2, Msx2, and Osterix 2, in the PDL fibroblasts. Treatment of these cells with LiCl also increased the mRNA levels of ALP, FosB, and Fra1 in a dose-dependent manner. Blockage of canonical Wnt signaling by treating the cells with DKK1 inhibited Wnt1-stimulated mRNA expression of these osteogenic factors. Furthermore, pretreatment with DKK1 reduced the ALP activity and matrix mineralization stimulated by Wnt1. Collectively, these results suggest that canonical Wnt signaling leads to the differentiation of PDL fibroblasts into osteogenic lineage with the attendant stimulation of osteogenic transcription factors.