Modal Phenomena of Surface and Bulk Polaritons in Magnetic- Semiconductor Superlattices

We discuss peculiarities of bulk and surface polaritons propagating in a composite magnetic-semiconductor superlattice influenced by an external static magnetic field. Three particular configurations of magnetization, namely, the Voigt, polar, and Faraday geometries, are considered. In the long-wavelength limit, involving the effective medium theory, the proposed superlattice is described as an anisotropic uniform medium defined by the tensors of effective permittivity and effective permeability. The study is carried out in the frequency band where the characteristic resonant frequencies of underlying constitutive magnetic and semiconductor materials of the superlattice are different but closely spaced. The effects of mode crossing and anti-crossing in dispersion characteristics of both bulk and surface polaritons are revealed and explained with an assistance of the concept of Morse critical points from the catastrophe theory

Gain of electron orbital angular momentum in a direct laser acceleration process

Three-dimensional "particle in cell" simulations show that a quasistatic magnetic field can be generated in a plasma irradiated by a linearly polarized Laguerre-Gauss beam with a nonzero orbital angular momentum (OAM). Perturbative analysis of the electron dynamics in the low intensity limit and detailed numerical analysis predict a laser to electrons OAM transfer. Plasma electrons gain angular velocity thanks to the dephasing process induced by the combined action of the ponderomotive force and the laser induced-radial oscillation Similar to the "direct laser acceleration," where Gaussian laser beams transmit part of its axial momentum to electrons, Laguerre-Gaussian beams transfer a part of their orbital angular momentum to electrons through the dephasing process

Chain-like uranyl-coordination polymer as a bright green light emitter for sensing and sunlight driven photocatalysis

A new uranyl-coordination polymer (UCP) has been solvothermally synthesized employing succinic acid and 1,10-phenanthroline (phen) as ligands. The obtained compound with the formula [(UO2)2(phen)(succ)0.5(OH)(O)4(μ3-O)(H2O)]·H2O (UNSL-1) is classified as 1D chains showing I0O1 connectivity. Also, the asymmetric unit is composed of two hepta-coordinated uranyl centers: U1 is surrounded by five oxygen atoms from succinate, while U2 is surrounded by two nitrogen atoms from phen and three oxygen atoms from succinate ([U1O7] and [U2N2O5]). The secondary-building unit (SBU) is composed of a sharing edge tetrameric cluster linked with a succinate ligand in the [-1 0 1] direction. Besides, the chains are reinforced by π-π stacking interactions between the aromatic rings of the phen molecules to conform a 2D supramolecular arrangement. Moreover, photoluminescence experiments show strong green emission consistent with uranyl crystalline materials. Photophysical characterization was completed via low-temperature measurements (77 K) and recording the decay emission for calculating the lifetime (τobs) value. Regarding its multifunctional properties, a cation-sensing performance was achieved showing selective quenching toward iron ions in aqueous media. Finally, UNSL-1 was tested as an efficient water photocatalyst for dye degradation under simulated sunlight irradiation, exhibiting promising results for organic-pollutant water remediation.Fil: Gomez, Germán Ernesto. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Onna, Diego Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Universidad Nacional de San Martin. Instituto de Nanosistemas; ArgentinaFil: D'vries, R. F.. Universidad del Cauca; ColombiaFil: Barja, Beatriz Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Ellena, Javier Alcides. Universidade de Sao Paulo; BrasilFil: Narda, Griselda Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química; ArgentinaFil: Soler Illia, Galo Juan de Avila Arturo. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Use of social networks as a CSR communication tool

The aim of this paper is to analyse the use of online social networks as a tool for Corporate Social Responsibility (CSR) communication and management. To this end, an analysis was performed of the messages posted by the 20 Spanish companies with the highest market capitalisation and the responses that they received on two of the most popular online social networks, Facebook and Twitter. The results of the analysis of these data show that the tendency has been to use social networks for the one-way communication of aspects of CSR related with the organisation. Therefore, it is necessary to change the way companies communicate their CSR issues by shifting to a two-way communication approach, as has been the case in other kinds of enterprise relations with their stakeholders.The authors received no direct funding for this research

Sex differences in the hepatotropic effects of antiulcer drugs and placenta cryoextract in an experimental rat liver injury model

Background/Aim: Sex-related variances in drug metabolism provide a foundation for refining treatment protocols for prevalent conditions based on the patient's sex. Tailoring treatment strategies based on sex is particularly noteworthy among patients with comorbid illnesses due to the potential for drug interactions and the impact of concurrent diseases on clinical outcomes. Aim of this study was to assess the hepatotropic effects of antiulcer drugs (esomeprazole, clarithromycin and metronidazole - E/C/M) and placenta cryoextract (CEP) within a simulated model of tetrachloromethane (CCl4 )-induced hepatitis combined with underlying ethanol-induced liver cirrhosis (EILC), with a focus on the role of subjects' sex. Methods: Using 112 male and female rats, the research explored the effects of different sex hormone levels. Chronic EILC was induced by administering a 50.0 % CCl4 oil solution (8 mL/kg) twice a week, combined with a 5.0 % ethanol solution, over 45 days. Total protein (TP) levels and alkaline phosphatase (AP) activity were measured spectrophotometrically. Results: The research findings indicate that the onset of EILC and the administration of E/C/M resulted in a significantly greater 10.8 % (p = 0.03) reduction in TP levels among females compared to males, without altering hormonal status. Introducing CEP led to a noteworthy (p < 0.001) rise in TP levels, by 30.8 % in males and 33.9 % in females, in the context of EILC and E/C/M administration, while maintaining hormonal status. Among male rats, the most elevated AP activity was observed with excess testosterone propionate administration (5.0 [5.0; 5.9] mmol/L), while the lowest level was recorded in rats after testectomy, measuring 3.8 [2.5; 4.7] mmol/L, exhibiting a significant 20.8 % decrease (p < 0.05) compared to male rats without hormonal status changes. In female rats, the study revealed that against the backdrop of EILC and E/C/M administration, the highest AP level was seen in ovariectomised females, reaching 5.8 [5.1; 6.2] mmol/L, reflecting a substantial 9.4 % increase compared to rats without hormonal status changes. Conclusions: The administration of CEP under similar experimental conditions led to the recovery of the liver's protein-synthesising function in both male and female rats. When female sex hormones were introduced to sham-operated female rats, a significant 20.8 % greater reduction in AP levels was observed. Additionally, gonadectomy led to a more pronounced decrease in this enzyme's levels in male rats compared to female rats, indicating the cytoprotective properties of female sex hormones

Resonant effects in terahertz generation with laser-induced gas plasmas

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Enhanced Dispersion of TiO2 Nanoparticles in a TiO2/PEDOT:PSS Hybrid Nanocomposite via Plasma-Liquid Interactions

A facile method to synthesize a TiO2/PEDOT:PSS hybrid nanocomposite material in aqueous solution through direct current (DC) plasma processing at atmospheric pressure and room temperature has been demonstrated. The dispersion of the TiO2 nanoparticles is enhanced and TiO2/polymer hybrid nanoparticles with a distinct core shell structure have been obtained. Increased electrical conductivity was observed for the plasma treated TiO2/PEDOT:PSS nanocomposite. The improvement in nanocomposite properties is due to the enhanced dispersion and stability in liquid polymer of microplasma treated TiO2 nanoparticles. Both plasma induced surface charge and nanoparticle surface termination with specific plasma chemical species are proposed to provide an enhanced barrier to nanoparticle agglomeration and promote nanoparticle-polymer binding