Geometric phase and o-mode blue shift in a chiral anisotropic medium inside a Fabry-P\'erot cavity

Anomalous spectral shift of transmission peaks is observed in a Fabry--P\'erot cavity filled with a chiral anisotropic medium. The effective refractive index value resides out of the interval between the ordinary and the extraordinary refractive indices. The spectral shift is explained by contribution of a geometric phase. The problem is solved analytically using the approximate Jones matrix method, numerically using the accurate Berreman method and geometrically using the generalized Mauguin--Poincar\'e rolling cone method. The $o$-mode blue shift is measured for a 4-methoxybenzylidene-4'-$n$-butylaniline twisted--nematic layer inside the Fabry--P\'erot cavity. The twist is electrically induced due to the homeoplanar--twisted configuration transition in an ionic-surfactant-doped liquid crystal layer. Experimental evidence confirms the validity of the theoretical model.Comment: the text is available both in English (Timofeev2015en.tex) and in Russian (download: other formats - source - Timofeev2015ru.tex, Timofeev2015rus.pdf

First Supramolecular Sensors for Phosphonate Anions

Fluorescent tripodal anion sensors with a 1,3,5-triethylbenzene core display a turn-on fluorescence response to phosphonate and phosphate anions and may be used as optical sensors. The properties of the receptors and sensors as well as their anion binding behavior were investigated both in solution and in solid state. The turn-on fluorescence response can be leveraged in sensing of phosphate anions and, most importantly, hydrolysis products of the nerve gas sarin, isopropyl methylphosphonate (IMP), and methylphosphonate (MP). The fluorescence signal amplification in the presence of anions allows for application of these molecules in a sensor microarray suitable for high-throughput screening.NSF CHE 0750303, EXP-LA 0731153BGSU (TIE Grant)Chemistr

Simple Molecule-based Fluorescent Sensors For Vapor Detection Of Tnt

1,4-Diarylpentiptycenes (1a-e) were synthesized from 1,4-dichloro- or 1,4-difluoro-2,5-diarylbenzene derivatives by double base-promoted dehydrohalogenation to give corresponding arynes, which in the presence of anthracene undergo cycloaddition providing 1,4-diarylpentiptycenes in moderate overall yields. The resulting 1,4-diarylpentiptycenes show fluorescence modulated by the 1,4-aryl residues. The fluorescence is quenched in the presence of vapors of nitroaromatic compounds suggesting potential application in sensing of explosives

Plasma probe characteristics in low density hydrogen pulsed plasmas

Probe theories are only applicable in the regime where the probe's perturbation of the plasma can be neglected. However, it is not always possible to know, a priori, that a particular probe theory can be successfully applied, especially in low density plasmas. This is especially difficult in the case of transient, low density plasmas. Here, we applied probe diagnostics in combination with a 2D particle-in-cell model, to an experiment with a pulsed low density hydrogen plasma. The calculations took into account the full chamber geometry, including the plasma probe as an electrode in the chamber. It was found that the simulations reproduce the time evolution of the probe IV characteristics with good accuracy. The disagreement between the simulated and probe measured plasma density is attributed to the limited applicability of probe theory to measurements of low density pulsed plasmas. Indeed, in the case studied here, probe measurements would lead to a large overestimate of the plasma density. In contrast, the simulations of the plasma evolution and the probe characteristics do not suffer from such strict applicability limits. These studies show that probe theory cannot be justified through probe measurements

Customs’ control on genetically modified food products across the border of the Eurasian Economic Union

Purpose: The purpose of the article is to determine the role of customs' control and directions of its improvement in the movement of genetically modified foods across the customs' border of the Eurasian Economic Union. In carrying out the study, the authors rely on the methods of theoretical modeling and interpretation of legal concepts and normative legal acts, which allowed to identify theoretical and applied problems of customs control in the conditions of Eurasian integration. Design/Methodology/Approach: The authors define the concepts of genetically modified foods and their turnover, highlight the problems of customs control over the movement of genetically modified foods across the customs border of the Eurasian Economic Union, and propose ways to improve it. Findings: The authors define the concepts of genetically modified foods and their turnover, highlight the problems of customs control over the movement of genetically modified foods across the customs border of the Eurasian Economic Union, and propose ways to improve it. Practical Implications: The results may be implicated into a legal framework of Russian Federation and improve customs' regulation both in Russia and abroad. Originality/Value: The main contribution of this article is the comprehensive analysis of legal and institutional background of genetically modified foods and their cross-border movement in EAEU countries as well as the measures of improving their customs' control.peer-reviewe

Ultrasound Promoted Synthesis of Pyrazolyl / Isoxazolyl Oxadiazoles as Antimicrobials

Azoles are the principal core structures present in natural products and acquired significance due to a wide range of biological properties associated with them. Amongst different azoles, oxadiazole and their derivatives have gained importance as they constitute the structural features of many bioactive compounds. 1,3,4-Oxadiazoles exhibit antibacterial, antifungal, antioxidant, anti-inflammatory, analgesic, anticancer and anticonvulsant properties. In fact, the combination of different heterocyclic units in a molecule may alter the biopotency which can accommodate multiple biological targets. In continuation of our interest in the synthesis of bioactive heterocyclic compounds, we focused our attention to develop some new oxadiazoles under ultrasonication. The work related to these aspects will be presented. © 2020 Author(s).The author G. Yamini is thankful to the University Grants Commission (UGC), New Delhi, for the sanction of UGC-BSR fellowship

Рецензия на статью «Параректальная fusion-биопсия предстательной железы под контролем компьютерной томографии»

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