Gravitational excitons from extra dimensions

Inhomogeneous multidimensional cosmological models with a higher dimensional space-time manifold are investigated under dimensional reduction. In the Einstein conformal frame, small excitations of the scale factors of the internal spaces near minima of an effective potential have a form of massive scalar fields in the external space-time. Parameters of models which ensure minima of the effective potentials are obtained for particular cases and masses of gravitational excitons are estimated.Comment: Revised version --- 12 references added, Introduction enlarged, 20 pages, LaTeX, to appear in Phys.Rev.D56 (15.11.97

Deep neural network model for highly accurate prediction of BODIPYs absorption.

A possibility to accurately predict the absorption maximum wavelength of BODIPYs was investigated. We found that previously reported models had a low accuracy (40–57 nm) to predict BODIPYs due to the limited dataset sizes and/or number of BODIPYs (few hundreds). New models developed in this study were based on data of 6000-plus fluorescent dyes (including 4000-plus BODIPYs) and the deep neural network architecture. The high prediction accuracy (five-fold cross-validation room mean squared error (RMSE) of 18.4 nm) was obtained using a consensus model, which was more accurate than individual models. This model provided the excellent accuracy (RMSE of 8 nm) for molecules previously synthesized in our laboratory as well as for prospective validation of three new BODIPYs. We found that solvent properties did not significantly influence the model accuracy since only few BODIPYs exhibited solvatochromism. The analysis of large prediction errors suggested that compounds able to have intermolecular interactions with solvent or salts were likely to be incorrectly predicted. The consensus model is freely available at https://ochem.eu/article/134921 and can help the other researchers to accelerate design of new dyes with desired properties

Effect of polar protic solvents on the photophysical properties of bis(BODIPY) dyes

In this paper, detailed comparative analysis of the spectral properties of bis(BODIPY) dyes in various organic solvents: saturated aromatic hydrocarbons, homologous series of alcohols (CnOH, n = 2–4, 8, 10) and mixture of ethanol-glycerol with different viscosity was carried out. In bis(BODIPY) dimeric molecules, the BODIPY chromophore domains are linked by a methylene spacer at the 2,2-, 2,3-, or 3,3-positions (1, 2, and 3 respectively). The absorption spectra of the bis(BODIPY)s exhibit exciton splitting of band maxima. We showed that bis(BODIPY)s are sensitive to the polarity and acidity of media due to its structural features. The mechanism of fluorescence quenching of 1–3 in the series of alcohols are explained in detail. It has been established that the fluorescence quenching efficiency of dimeric dyes in alcohols is determined by both universal and specific interactions. The fluorescence quantum yield of bis(BODIPY)s is minimal in ethanol and increases in the alcohols homologous series due to a reduction in medium polarity and the stability of the bis(BODIPY)(Solv)2 supramolecular structures. In viscous ethanol-glycerol mixtures, fluorescence of 1–3 increases because of the limitation of the dye molecules conformational mobility. The results of the study allow us to predict the possibility of practical application of 1–3 as alcohols fluorescent sensors in various media

Meso-substituted-BODIPY based fluorescent biomarker: Spectral characteristics, photostability and possibilities for practical application

© 2020 Elsevier B.V. A fluorescent biomarker based on the boron(III) complex with meso-4-methoxycarbonylbutyl-substituted 3,3′,5,5′-tetramethyl-2,2′-dipyrromethene (BODIPY) was synthesized. The BODIPY exhibits a large extinction coefficient (lgε ∼4.82–5.00) at 496–501 nm and high fluorescence quantum yield (∼77–100 %) in the blue-green region of the spectrum (509–518 nm). The maximal fluorescence quantum yield (φ) is observed in non-polar media (∼100 %) while φ slightly decreases to ∼90 % in alcohols (with the exception of octanol-1) and to ∼77 % in electron-donating dimethyl sulfoxide (DMSO). The BODIPY fluorophore demonstrates high photostability with the half-life of 41.4 and 91 h in toluene and cyclohexane, respectively. The proposed luminophore preferentially stains gram-positive bacteria and can be used for differential staining of gram-positive and gram-negative bacteria in mixed cultures. BODIPY also accumulates in the cytoplasm of the mammalian cells giving polar micro-speckled staining pattern which is more intensive in the tumor cells when compared to the fibroblasts. The pronounced affinity of BODIPY to mitochondria of eukaryotic cells could be used for specific staining of these organelles

The algorithm of particles method in the scattering medium

Abstract: Features of a numerical algorithm for solving the kinetic equation for electrons in a scattering medium and a self-consistent electromagnetic field are considered. An algorithm for simulating scattering in the approximation of multiple collisions at a time step is presented. The calculations confirming the effectiveness of the method are performed.Note: Research direction:Mathematical modelling in actual problems of science and technic

On the particles method in the scattering medium

Abstract: The Cauchy problem for the kinetic and electrodynamic equations describing the propagation of the electron beam in an inhomogeneous scattering medium with discontinuous characteristics and the generation of a self-consistent electromagnetic field are considered. Approaches to the interpretation of the generalized solution substantiating the application of the particle method for the numerical solution of the kinetic equation are represented.Note: Research direction:Mathematical modelling in actual problems of science and technic

Design, Spectral Characteristics, and Possibilities for Practical Application of BODIPY FL-Labeled Monoterpenoid

This article describes the design and biological properties of a BODIPY FL-labeled monoterpenoid BF2-meso-(4-((1″R)-6″,6″-dimethylbicyclo[3.1.1]hept-2″-ene-2″)yl-methoxycarbonylpropyl)-3,3′,5,5′-tetramethyl-2,2′-dipyrromethene conjugate (BODIPYmyrt). The fluorophore was characterized using X-ray, NMR, MS, and UV/vis spectroscopy. The conjugate exhibits a high quantum yield (to ∼100%) in the region 515-518 nm. BODIPYmyrt effectively penetrates the membranes of the bacterial and fungal cells and therefore can be used to examine the features of a broad spectrum of Gram-positive and Gram-negative bacteria and pathogenic fungi as well. Moreover, BODIPYmyrt exhibits a moderate tropism to the subcellular structures in mammalian cells (e.g., mitochondria), thereby providing an attractive scaffold for fluorophores to examine these particular organelles

Neoliberalism and knowledge interests in boundaryless careers discourse

Decades of critical research have established that economic and political ideologies permeate and shape thought, text and action, and academic knowledge production is no exception. This article examines how ideologies might permeate academic texts, by assessing the reach and influence of neoliberalism in research on boundaryless careers. Specifically, it asks: did the emergence and growth of scholarship on boundaryless careers support, challenge, or merely run parallel to the rising dominance of neoliberal ideology? It was found that a diversity of knowledge interests, including managerial, agentic, curatorial and critical interests underlie the production of research on boundaryless careers. However, all four of these knowledge interests are complicit in discursively constructing and aligning the notion of boundaryless careers with neoliberalism in two specific ways. Implications for scholarship on careers and work are discussed