The focus of this study is to examine the level of awareness, as well as the impacts of environmental information provision, regarding plastic bag consumption in Greece, taking into consideration the effects of plastic pollution in the marine environment within the framework of the environmental levy. This study was conducted through the use of two structured questionnaires as web-based surveys. The aim of both questionnaires was to explore citizen attitudes towards the marine environment in addition to their preferences with regard to the implementation of a program aimed at marine conservation and the reduction of plastic bag use.
View Article and Find Full Text PDFThe structural evolution of neutral and anionic iridium-doped boron (B) clusters, IrB with n = 10-20, has been studied by the Crystal structure AnaLYsis by Particle Swarm Optimization (CALYPSO) method and density functional theory (DFT) calculations. The IrB cluster with a quasi-plane structure and high stability is uncovered. Molecular orbital (MO) and adaptive natural density partitioning (AdNDP) analyses indicate that the high stability of the IrB cluster is attributed to the strong covalent interactions between the 5d orbitals of the Ir atom and the 2p orbitals of the surrounding B atoms.
View Article and Find Full Text PDFWe have implemented a scheme for classical molecular dynamics simulations of collision-induced absorption. The program has been applied to a gas mixture of argon (Ar) and krypton (Kr). The simulations are compared with accurate quantum dynamical calculations.
View Article and Find Full Text PDFBeryllium-doped boron clusters display essential similarities to borophene (boron sheet) with a molecular structure characterized by remarkable properties, such as anisotropy, metallicity and high conductivity. Here we have determined low-energy structures of BeB (n = 10-20) clusters by utilizing CALYPSO searching program and DFT optimization. The results indicated that most ground states of clusters prefer plane or quasi-plane structures by doped Be atom.
View Article and Find Full Text PDFThe main effort in this study is focused on devising a numerical model procedure capable of providing reliable values of collisionally induced microscopic properties of importance in processes of light radiation interactions with molecular media. Special attention is devoted to the anisotropic polarizability of the weakly bound H-H compounds, although broader applicability of the routines proposed is anticipated as well. To this end, Cartesian components of the collision-induced anisotropic polarizability, Δα , are obtained for the L- (linear, 0°), S- (45°), and T-shape (90°) configurations of the supermolecular systems.
View Article and Find Full Text PDFWe investigated the interaction (hyper)polarizability of neon-dihydrogen pairs by performing high-level ab initio calculations with atom/molecule-specific, purpose-oriented Gaussian basis sets. We obtained interaction-induced electric properties at the SCF, MP2, and CCSD levels of theory. At the CCSD level, for the T-shaped configuration, around the respective potential minimum of 6.
View Article and Find Full Text PDFDirhenium halide dianions received considerable attention in past decades due to the unusual metal-metal quadruple bond. The systematic structural evolution of dirhenium halide clusters has not been sufficiently studied and hence is not well-understood. In this work, we report an in-depth investigation on the structures and electronic properties of doubly charged dirhenium halide clusters ReX (X = F, Cl, Br, I).
View Article and Find Full Text PDFTransition-metal (TM)-doped boron clusters have received considerable attention in recent years, in part, because of their remarkable size-dependent structural and electronic properties. However, the structures of medium-sized boron clusters doped with TM atoms are still not well-known because of the much increased complexity of the potential surface as well as the rapid increase in the number of low-energy isomers, which are the challenges in cluster structural searches. Here, by means of an unbiased structure search, we systematically investigated the structural evolution of medium-sized tantalum-doped boron clusters, TaB (n = 10-20).
View Article and Find Full Text PDFPhys Chem Chem Phys
September 2016
The effect of Mg doping on the growth behavior and the electronic properties of aluminum clusters has been investigated theoretically using the CALYPSO (Crystal structure AnaLYsis by Particle Swarm Optimization) method in combination with density functional theory calculations. Compared to pure aluminum clusters, the structure of Mg-doped clusters shows the charming transformation with increasing atomic number. The photoelectron spectra (PES) of the global minima of anionic Al and AlMg (n = 3-20) clusters have been calculated based on the time-dependent density functional theory (TD-DFT) method.
View Article and Find Full Text PDFJ Chem Phys
July 2016
A comprehensive study is presented of many aspects of the depolarized anisotropic collision induced (CI) component of light scattered by weakly bound compounds composed of a dihydrogen molecule and a rare gas (Rg) atom, H2-Rg. The work continues a series of earlier projects marking the revival of interest in linear light scattering following the development of new highly advanced tools of quantum chemistry and other theoretical, computational, and experimental means of spectral analyses. Sophisticated ab initio computing procedures are applied in order to obtain the anisotropic polarizability component's dependence on the H2-Rg geometry.
View Article and Find Full Text PDFTwo new diastereomeric lignan amides (4 and 5) serving as dimeric caffeic acid-l-DOPA hybrids were synthesized. The synthesis involved the FeCl3-mediated phenol oxidative coupling of methyl caffeate to afford trans-diester 1a as a mixture of enantiomers, protection of the catechol units, regioselective saponification, coupling with a suitably protected l-DOPA derivative, separation of the two diastereomers thus obtained by flash column chromatography and finally global chemoselective deprotection of the catechol units. The effect of hybrids 4 and 5 and related compounds on the proliferation of two breast cancer cell lines with different metastatic potential and estrogen receptor status (MDA-MB-231 and MCF-7) and of one epithelial lung cancer cell line, namely A-549, was evaluated for concentrations ranging from 1 to 256μM and periods of treatment of 24, 48 and 72h.
View Article and Find Full Text PDFWe performed an unbiased structure search for low-lying energetic minima of neutral and charged palladium Pdn(Q) (n = 2-20, Q = 0, + 1 and -1) clusters using CALYPSO method in combination with density functional theory (DFT) calculations. The main candidates for the lowest energy neutral, cationic and anionic clusters are identified, and several new candidate structures for the cationic and anionic ground states are obtained. It is found that the ground state structures of small palladium clusters are more sensitive to the charge states.
View Article and Find Full Text PDFSelective alkylation of the antipsoriatic drug dithranol (DTR) at C-10 with tert-butyl bromoacetate, followed by acid-mediated deprotection, produced the corresponding carboxylic acid 4 which was coupled with selectively protected polyamines (PAs), such as putrescine (PUT), spermidine (SPD) and spermine (SPM), dopamine and aliphatic amines and substituted benzylamines producing a series of DTR-PA hybrids, after acid-mediated deprotection, as well as simple amides. The compounds were tested as antioxidants and inhibitors of lipoxygenase (LOX). The amides 4,4'-dimethoxybenzhydrylamide 13 (86% and 95%), 2,4-dimethoxybenzylamide 12 (87% and 81%) and dodecylamide 9 (98% and 74%), and the hybrid DTR-SPM (7) (93% and 87%), showed the highest antioxidant activity in the DPPH and AAPH assays, whereas the most potent inhibitors of LOX were amide 13 (IC50=7 μM), the benzylamide 10 (IC50=7.
View Article and Find Full Text PDFWe have performed unbiased searches for the global minimum structures of neutral and charged sulfur clusters Sn(Q) (n = 3-20, Q = 0, ±1) relying on the CALYPSO structure searching method combined with density functional theory geometric optimization. Very accurate ab initio calculations are used to determine relative stabilities and energy ranking among competing low-lying isomers of the neutral and charged sulfur clusters obtained from the structure search. The harmonic vibrational analysis is also undertaken to assure that the optimized geometries are the true minima.
View Article and Find Full Text PDFThe report presents results of theoretical and numerical analysis of the electrical properties related to the isotropic part of the polarizability induced by interactions within compounds built up of a hydrogen H2 molecule and a set of noble gas atoms, Rg, ranging from the least massive helium up to the heaviest xenon perturber. The Cartesian components of the collisional polarizabilities of the H2-Rg systems are found by means of the quantum chemistry methods and their dependence on the intermolecular distance is determined. On the basis of these data, the spherical, symmetry adapted components of the trace polarizability are derived in order to provide data sets that are convenient for evaluating collisional spectral profiles of the isotropic polarized part of light scattered by the H2-Rg mixtures.
View Article and Find Full Text PDFThis article reports new results of theoretical and numerical studies of spectral features of the collision-induced hyper-Rayleigh light scattered in dihydrogen-noble gas (H2-Rg) mixtures. The most massive and polarizable scattering supermolecules with Rg = Kr and Xe have been added to the previously considered systems in order to gain a more complete insight into the evolution of the spectral properties. The symmetry adapted components of the first collisional hyperpolarizabilities are obtained by means of the quantum chemistry numerical routines supplemented with appropriate theoretical methods.
View Article and Find Full Text PDFAcitretin analogs, incorporating changes in the lipophilic part, were efficiently synthesized from commercially available aromatic aldehydes or methyl ketones using the Wittig or Horner-Wadsworth-Emmons reaction. Their antiproliferative activity was evaluated against human breast MCF-7 epithelial cells. Analogs 3, 4, 8 and 11 exhibited strong, dose-dependent, antiproliferative activity on the tested cell line.
View Article and Find Full Text PDFTurner's syndrome is characterized by an ovarian failure which occurs in most cases before puberty and leads to infertility. In less than 10% of women with Turner syndrome, puberty may occur and spontaneous pregnancies is possible but with a high risk of fetal loss, chromosomal and congenital abnormalities. We present the case of a 33-year-old woman with a mosaic Turner's syndrome karyotype 45,X/47,XXX who conceived spontaneously and had two successful pregnancies.
View Article and Find Full Text PDFWe report an extensive high-level ab initio theoretical investigation of the interaction electric properties of the weakly bound complexes of water with rare gases, H(2)O...
View Article and Find Full Text PDFGynecol Endocrinol
May 2010
Objective: We measured first trimester plasma leptin concentrations in 37 women who subsequently developed pre-eclampsia and 53 normotensive controls to determine the interrelation between leptin and body mass index (BMI) in both groups. We further investigated the association between the risks for pre-eclampsia with maternal leptin levels.
Methods: Bloods samples were collected at 13 weeks.
J Matern Fetal Neonatal Med
October 2009
Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine (Phe) metabolism resulting from deficiency of phenylalanine hydroxylase (PAH). Most forms of PKU are caused by mutations in the PAH gene. Untreated PKU is associated with an abnormal phenotype, which includes growth failure, seizures, global developmental delay and severe intellectual impairment.
View Article and Find Full Text PDFThe collision-induced hyper-Rayleigh (CIHR) spectra of the gaseous H(2)-Ar mixture are discussed in the binary regime on the basis of our ab initio computed H(2)-Ar collision-induced (CI) first dipole hyperpolarizability tensor Deltabeta(R). A method for the computation of the spherical, rotationally adapted components Deltabeta(lambdaL) ((s,K))(R) of Deltabeta(R) needed for spectroscopic line shape analysis is proposed. Both the vector and the septor parts of the H(2)-Ar CIHR spectrum are evaluated at room (T=295 K) temperature.
View Article and Find Full Text PDFAn extensive conventional ab initio and density functional theory investigation reveals that HXeI is a polar molecule with large multipole moments and highly anisotropic (hyper)polarizability. At the CCSD(T) level of theory our best values for the mean (hyper)polarizability are alphae(2)a(0) (2)E(h) (-1)=101.46, betae(3)a(0) (3)E(h) (-2)=-850.
View Article and Find Full Text PDFWe present a systematic study of the static electric hyperpolarizability of Ga(2)As(2). The authors rely on finite-field high-level ab initio calculations with carefully optimized basis sets. Their best values for the mean and the anisotropy of the dipole polarizability are alpha=158.
View Article and Find Full Text PDFHeavy menstrual bleeding (HMB) occurs in a considerable percentage of the general population and is one of the main causes due to which a patient is referred to health services. Despite the efforts for pharmaceutical interventions, the symptom usually persists, therefore operative techniques are needed to control the bleeding. Today, apart from the choice of hysterectomy, other less aggressive techniques have been invented.
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