50 research outputs found

    Hepatoprotective effect of Phytosome Curcumin against paracetamol-induced liver toxicity in mice

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    Curcuma longa, which contains curcumin as a major constituent, has been shown many pharmacological effects, but it is limited using in clinical due to low bioavailability. In this study, we developed a phytosome curcumin formulation and evaluated the hepatoprotective effect of phytosome curcumin on paracetamol induced liver damage in mice. Phytosome curcumin (equivalent to curcumin 100 and 200 mg/kg body weight) and curcumin (200 mg/kg body weight) were given by gastrically and toxicity was induced by paracetamol (500 mg/kg) during 7 days. On the final day animals were sacrificed and liver function markers (ALT, AST), hepatic antioxidants (SOD, CAT and GPx) and lipid peroxidation in liver homogenate were estimated. Our data showed that phytosome has stronger hepatoprotective effect compared to curcumin-free. Administration of phytosome curcumin effectively suppressed paracetamol-induced liver injury evidenced by a reduction of lipid peroxidation level, and elevated enzymatic antioxidant activities of superoxide dismutase, catalase, glutathione peroxidase in mice liver tissue. Our study suggests that phytosome curcumin has strong antioxidant activity and potential hepatoprotective effects

    REALIZATION OF BROADBAND AND INDEPENDENT POLARIZATION METAMATERIAL PERFECT ABSORBER BASED ON THE THIRD-ORDER RESONANCE

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    In this report, we studied numerically and experimentally the electromagnetic properties of perfect MAs using ring-shaped structures at microwave frequencies. By creating a magnetic resonance, the ring structure confines electromagnetic energy at the first- and third-order resonances. And then, we leveraged the super-cell structures, which consist of different rings in one unit cell to obtain broadband absorption. The results showed that the absorption band of MA is broaden from 1.3 to 2.17 GHz when the number of rings in the unit cell increases from four to nine-ring

    HORIZONTALLY PLASMON HYBRIDIZATION ON SYMMETRIC-BREAKING METAMATERIALS

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    In this report, we present a study on the fundamental negative-permeability metamaterials, named as the cut-wire-pair structure. The physics of the cut-wire-pair metamaterial is interpreted using the electromagnetic analog of molecular-orbital theory. It is shown that a symmetric-breaking cut-wire-pair metamaterial is horizontally plasmon-hybridized, leading to an additional magnetic resonance beyond the conventional one. The transmission spectra and the induced energy distributions are performed to demonstrate our prediction

    Criblage virtuel sur grille de composés isolés au Vietnam

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    Criblage virtuel sur grille de composés isolés au Vietna

    All-dielectric Metamaterial for Electromagnetically-induced Transparency in Optical Region

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    Metamaterial (MM) is emerging as a promising approach to manipulate electromagnetic waves, spanning from radio frequency to the optical region. In this paper, we employ an effect called electromagnetically-induced transparency (EIT) in all-dielectric MM structures to create a narrow transparent window in opaque broadband of the optical region (580-670 nm). Using dielectric materials instead of metals can mitigate the large non-radiative ohmic loss on the metal surface. The unit-cell of MM consists of Silicon (Si) bars on Silicon dioxide (SiO2_{2}) substrate, in which two bars are directed horizontally and one bar is directed vertically. By changing the relative position and dimension of the Si bars, the EIT effect could be achieved. The optical properties of the proposed MM are investigated numerically using the finite difference method with commercial software Computer Simulation Technology (CST). Then, characteristic parameters of MM exhibiting EIT effect (EIT-MM), including Q-factor, group delay, are calculated to evaluate the applicability of EIT-MM to sensing and light confinement

    Broadband negative permeability using hybridized metamaterials: Characterization, multiple hybridization, and terahertz response

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    There is an increased interest to create artificial magnetic metamaterials that show a negative permeability over a wide frequency range. In this paper, we experimentally and numerically demonstrate a broadband negative permeability using symmetric cut-wire-pair metamaterial structures. This finding is based on the second-order hybridization, which is activated by manipulating the correlation between the coupling within a single cut-wire pair and the coupling between neighboring cut-wire pairs. An effective medium analysis is performed to identify the role of the internal and external interactions in the hybridized metamaterials. An extended second-order hybridization scheme is proposed, which describes the electromagnetic response of more complex systems that exhibit an extremely wide band of negative permeability. In addition, the terahertz response of the cut-wire-pair dimer is further explored by scaling down the dimensions of the structures.status: publishe

    Thermally tunable magnetic metamaterials at THz frequencies

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    We investigate theoretically and numerically the tunability of the magnetic property of metamaterial in the THz region via thermal control. One component of the meta-atom is InSb, playing an important role as an alterable metal. When the temperature of the InSb stack increases from 300 to 350 K, the resonance peak of the transmission spectra shows a shift from 0.6 to 0.85 THz accompanied by a stronger magnetic behavior. The S-parameter retrieval method realizes the tunability of the negative permeability achieved in the above heating range.status: publishe
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