排序方式: 共有15条查询结果,搜索用时 15 毫秒
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Genovaitė Valiulienė Albina Žielienė Birutė Šimkūnaitė Leonas Naruškevičius Loreta Tamašauskaitė Tamašiūnaitė Vidas Pakštas Algis Selskis 《Journal of Solid State Electrochemistry》2010,14(2):203-212
The electrochemical behavior of Bi2S3 coatings in Watts nickel plating electrolyte was investigated using the cyclic voltammetry, electrochemical quartz crystal
microbalance, X-ray diffraction, and energy dispersive X-ray analysis methods. During the bismuth sulfide coating reduction
in Watts background electrolyte in the potential region from −0.4 to −0.6 V, the Bi2S3 and Bi(III) oxygen compounds are reduced to metallic Bi, and the decrease in coating mass is related to the transfer of S2− ions from the electrode surface. When the bismuth sulfide coating is reduced in Watts nickel plating electrolyte, the observed
increase in coating mass in the potential region −0.1 to −0.4 V is conditioned by Ni2+ ions reduction before the bulk deposition of Ni, initiated by Bi2S3. In this potential region, the reduction of Bi(III) oxygen compounds can occur. After the treatment of as-deposited bismuth
sulfide coating in nickel plating electrolyte at E = −0.3 V, the sheet resistance of the layer decreases from 1013 to 500–700 Ω cm. A metal-rich mixed sulfide Ni3Bi2S2–parkerite is obtained when as-deposited bismuth sulfide coating is treated in Watts nickel plating electrolyte at a potential
close to the equilibrium potential of the Ni/Ni2+ system and then annealed at temperatures higher than 120 °C. 相似文献
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Vilija Pautienienė Loreta Tamašauskaitė-Tamašiūnaitė Aloyzas Sudavičius Giedrius Stalnionis Zenonas Jusys 《Journal of Solid State Electrochemistry》2010,14(9):1675-1680
Spontaneous modification of polycrystalline Pt by irreversibly adsorbed bismuth was performed in BiCl3 solution in concentrated hydrochloric acid under open-circuit conditions. After spontaneous modification, followed by extensive
rinsing with water and drying, the surface was characterized using X-ray photoelectron spectroscopy and electrochemistry.
Bi-oxy(chloride), oxide species, and metallic Bi were found at a submonolayer coverage on the Pt surface after spontaneous
modification. The electrochemical response of Bi-modified polycrystalline Pt electrode in sulfuric acid solution exhibits
a complex multi-peak feature, which is resulting in about constant redox charge (Bi species coverage) in the potential region
from 0 to 0.9 V (vs. a standard hydrogen electrode). The spontaneously Bi-modified Pt catalyst in model studies exhibits a
superior activity towards formic acid oxidation at fuel cell anode relevant potentials. The catalytic effect of bismuth oxy-species
is explained in terms of both inhibition of COad formation and oxidation of COad in reaction with Bi-oxy-species. 相似文献
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Saunoriene Loreta Ragulskis Minvydas Cao Jinde Sanjuán Miguel A. F. 《Nonlinear dynamics》2021,104(1):739-751
Nonlinear Dynamics - The Wada index based on the weighted and truncated Shannon entropy is presented in this paper. The proposed Wada index can detect if a given basin boundary is a Wada boundary.... 相似文献
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Rima Tarozaitė Loreta Tamašauskaitė Tamašiūnaitė Vitalija Jasulaitienė 《Journal of Solid State Electrochemistry》2009,13(5):721-731
Platinum–tin complexes were prepared by the reduction of Pt(IV) with Sn(II) in HCl media and studied by light absorption spectrometry,
X-ray photoelectron spectroscopy (XPS), and electron microscopy. The formation of three complexes, H3[Pt(SnCl3)5], H2[Pt(SnCl3)2Cl2], and H2[Pt3(SnCl3)8], depending on HCl and SnCl2 concentrations, has been shown. The glassy carbon (GC) electrode modified in the complexes solutions was found to be an electrocatalyst
for borohydride oxidation in a 1.0-M NaOH solution. Comparison of BH4
− electrooxidation on Pt and on GC modified with platinum–tin complexes has shown that catalytic hydrolysis of BH4
− did not proceed in the latter case in contrast to its oxidation on the Pt electrode, and only direct BH4
− oxidation has been observed in the positive potentials scan. The activity of Pt–Sn complexes for BH4
− oxidation changes with time and eventually decreases due to Sn(II), bound in the complex with Pt(II), oxidation by atmospheric
oxygen. The complexes may be renewed by addition of missing amounts of SnCl2 and HCl. 相似文献
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Generalised Sierpiński carpets are planar sets that generalise the well-known Sierpiński carpet and are defined by means of sequences of patterns. We present necessary and sufficient conditions, under which generalised Sierpiński carpets are connected, with respect to Euclidean topology. 相似文献
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Annalisa Chiavaroli Simonetta Cristina Di Simone Alessandra Acquaviva Maria Loreta Libero Claudia Campana Lucia Recinella Sheila Leone Luigi Brunetti Giustino Orlando Nilofar Irene Vitale Stefania Cesa Gokhan Zengin Luigi Menghini Claudio Ferrante 《Molecules (Basel, Switzerland)》2022,27(19)
Pollen extract represents an innovative approach for the management of the clinical symptoms related to prostatitis and pelvic inflammatory disease (PID). In this context, the aims of the present work were to analyze the phenolic composition of a hydroalcoholic extract of PollenAid Plus soft gel capsules, and to evaluate the extract’s cytotoxic effects, in human prostate cancer PC3 cells and human ovary cancer OVCAR-3 cells. Additionally, protective effects were investigated in isolated prostate and ovary specimens exposed to lipopolysaccharide (LPS). The phytochemical investigation identified catechin, chlorogenic acid, gentisic acid, and 3-hydroxytyrosol as the prominent phenolics. The extract did not exert a relevant cytotoxic effect on PC3 and OVCAR-3 cells. However, the extract showed a dose-dependent inhibition of pro-inflammatory IL-6 and TNF-α gene expression in prostate and ovary specimens, and the extract was effective in preventing the LPS-induced upregulation of CAT and SOD gene expression, which are deeply involved in tissue antioxidant defense systems. Finally, a docking approach suggested the capability of catechin and chlorogenic acid to interact with the TRPV1 receptor, playing a master role in prostate inflammation. Overall, the present findings demonstrated anti-inflammatory and antioxidant effects of this formulation; thus, suggesting its capability in the management of the clinical symptoms related to prostatitis and PID. 相似文献
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Eulogio J. Llorent-Martínez Antonio Ruiz-Medina Gokhan Zengin Gunes Ak Sharmeen Jugreet Mohamad Fawzi Mahomoodally Gizem Emre Giustino Orlando Maria Loreta Libero Nilofar Alessandra Acquaviva Simonetta Cristina Di Simone Luigi Menghini Claudio Ferrante Luigi Brunetti Lucia Recinella Sheila Leone Mohamad Ali Shariati Abdullahi Ibrahim Uba Annalisa Chiavaroli 《Molecules (Basel, Switzerland)》2022,27(24)
In this study, the methanolic and infusion extracts of two species, Thymbra capitata and Thymus sipyleus subsp. rosulans, were tested for their chemical composition and biological abilities (antioxidant, enzyme inhibitory and anti-inflammatory effects). The extracts yielded total phenolic and flavonoid contents in the range of 83.43–127.52 mg GAE/g and 9.41–46.34 mg RE/g, respectively. HPLC analysis revealed rosmarinic acid to be a major component of the studied extracts (15.85–26.43%). The best ABTS radical scavenging ability was observed in the methanol extract of T. capitata with 379.11 mg TE/g, followed by in the methanol extract of T. sipylus (360.93 mg TE/g). In the CUPRAC assay, the highest reducing ability was also found in the methanol extract of T. capitata with 802.22 mg TE/g. The phosphomolybdenum ability ranged from 2.39 to 3.61 mmol TE/g. In terms of tyrosinase inhibitory effects, the tested methanol extracts (83.18–89.66 mg KAE/g) were higher than the tested water extracts (18.74–19.11 mg KAE/g). Regarding the BChE inhibitory effects, the methanol extracts were active on the enzyme while the water extracts showed no inhibitory effect on it. Overall, the methanolic extracts showed better enzyme inhibition compared to the infusion extracts. Molecular docking also showed the selected exhibited potential binding affinities with all enzymes, with a preference for cholinesterases. Additionally, the extracts were effective in attenuating the LPS-induced increase in COX-2 and IL-6 gene expression in isolated colon, thus indicating promising anti-inflammatory effects. The preliminary results of this study suggest that these species are good natural sources of antioxidants and also provide some scope as enzyme inhibitors, most likely due to their bioactive contents such as phenolic acids, and thus can be exploited for different applications related to health promotion and disease prevention. 相似文献
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Vilma Kaškonienė Paulius Kaškonas Audrius Maruška Loreta Kubilienė 《Central European Journal of Chemistry》2014,12(6):736-746
Six samples of propolis were analyzed in the paper: a sample from Brazil, Estonia, China and three samples from different locations of Uruguay. Static headspace technique coupled with gas chromatography-mass spectrometry analysis has been applied for the determination of the characteristic volatile profile with the aim to differentiate the propolis from different regions. Monoterpenes (α- and β-pinenes) were predominant in all samples, except the sample from China. This sample separated itself by the alcohols 3-methyl-3-buten-1-ol and 3-methyl-2-buten-1-ol, (40.33% and 11.57%, respectively) and ester 4-penten-1-yl acetate (9.04%). α-Pinene and β-pinene composed 64.59–77.56% of volatiles in Brazilian and Uruguayan propolis, and 29.43% in Estonian propolis. Brazilian propolis was distinguished by a high amount of β-methyl crotonaldehyde (10.11%), one of Uruguayan samples 3- by limonene (15.58%), and the Estonian sample — by eucalyptol (25.95%). Statistical investigation of the samples was made applying principal component, hierarchical cluster and K-Means cluster analyses. Various data pre-processing techniques were proposed and used to study and obtain the important volatile compounds contributed to the differentiation of the propolis samples from different regions to separate clusters. 相似文献
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Minvydas Ragulskis Loreta Saunoriene Jurate Ragulskiene 《Optics and Lasers in Engineering》2006,44(11):1209-1218
Inverse problem of reconstruction of dynamic displacements from the fringe pattern generated by time average reflection moiré is investigated in this paper. A technique for numerical simulation of time average smoothed reflection moiré fringes is proposed. The smoothing procedure is incorporated into the finite element formulation of the problem. Reconstruction of the field of deflections is illustrated for a centrally clamped disk. Such techniques can be effectively exploited in hybrid numerical–experimental procedures for different objects and grating geometries. 相似文献