Methods for extracting biochemical information from bacterial Raman spectra: focus on a group of structurally similar biomolecules--fatty acids

In this paper we explore the possibilities of Raman spectroscopy in order to deduce information on the fatty acid composition of bacterial cells. Therefore, representative strains of two bacterial taxa were each cultured in different conditions and in parallel analyzed by Raman spectroscopy and gaschromatographic FAME analysis. Raman spectra of pure fatty acids were recorded and used as reference spectra. The culturing conditions for each strain could be easily distinguished by the fatty acid information retrieved from bacterial Raman spectra. Chemometric techniques such as EMSC and PCA allowed to extract information about groups of fatty acids, that was consistent with the results from FAME analysis. Although the information retrieved from Raman spectroscopy is not as refined as that from FAME analysis, the presented methods could be useful to obtain basic information on the fatty acid present in bacteria when performing Raman spectroscopic analysis for fast whole cell profiling, which provides information for different types of cell components (fatty acids, amino acids, primary metabolites, etc.).     

Lanthanum-strontium cuprate: A promising cathodic material for solid oxide fuel cells

Samples of lanthanum-strontium cuprate LaSrCuO_3.61 are synthesized by a solid-phase method at 1473 K, in air. Electron diffraction patterns reveal low-intensity satellites whose position is described in the reciprocal space by the (3 + 2)-dimensional space group I4/mmm(αα0, α-α0)00mg. Using a five-layer cell LaSrCuO_4-δ|YSZ|LaSrCuO_4-δ|YSZ|LaCuO_4-δ prepared by isostatic hot pressing, the ionic component of conductivity of LaSrCuO_4-δ is determined (σ_{1179 K} = 3.8 × 10^?3 S cm^?1), which is commensurate with other mixed conductors based on complex oxides of cobalt and iron.     

Effect of Bimetallic Pd/Pt Clusters on the Sensing Properties of Nanocrystalline SnO<Subscript>2</Subscript> in the Detection of CO

Nanocrystalline tin dioxide modified by Pd and Pt clusters or by bimetallic PdPt nanoparticles was synthesized. Distribution of the modifers on the SnO₂ surface was studied by high-resolution transmission electron microscopy and energy dispersive X-ray microanalysis with element distribution mapping. It was shown that the Pd/Pt ratio in bimetallic particles varies over a broad range and does not depend on the particle diameter. The effect of platinum metals on the reducibility of nanocrystalline SnO₂ by hydrogen was determined. The sensing properties of the resulting materials towards 6.7 ppm CO in air were estimated in situ by electrical conductivity measurements. The sensor response of SnO₂ modified with bimetallic PdPt particles was a superposition of the signals of samples with Pt and Pd clusters.     

Dressings Loaded with Cyclodextrin–Hamamelitannin Complexes Increase Staphylococcus aureus Susceptibility Toward Antibiotics Both in Single as well as in Mixed Biofilm Communities

Bacteria reside within biofilms at the infection site, making them extremely difficult to eradicate with conventional wound care products. Bacteria use quorum sensing (QS) systems to regulate biofilm formation, and QS inhibitors (QSIs) have been proposed as promising antibiofilm agents. Despite this, few antimicrobial therapies that interfere with QS exist. Nontoxic hydroxypropyl‐β‐cyclodextrin‐functionalized cellulose gauzes releasing a burst of the antibiotic vancomycin and the QSI hamamelitannin are developed, followed by a sustained release of both. The gauzes affect QS and biofilm formation of Pseudomonas aeruginosa and Staphylococcus aureus in an in vitro model of chronic wound infection and can be considered as candidates to be used to prevent wound infection as well as treat infected wounds.

     

Neutron emission following muon capture in heavy nuclei

The energy distribution of neutrons following muon capture in heavy nuclei is investigated. It is shown that the experimental high energy tail (E > 10 MeV) of the neutron distribution can be explained by a direct emission process.     

Fragmentation of an infinite ZnO2 square plane into discrete [ZnO2]2- linear units in the oxyselenide Ba2ZnO2Ag2Se2

Analysis of single crystal X-ray diffraction, neutron powder diffraction, electron diffraction and Zn-K-edge EXAFS data show that Ba2ZnO2Ag2Se2 contains unusual isolated [ZnO2]2- moieties resulting from fragmentation of a ZnO2 infinite plane placed under tension.     

Evidence on the influence of fission channels on fission phenomena

Partial fission channel widths can be extracted from fission cross-section analysis only up to a rotation in the space of fission vectors. We propose to obtain a physically significant basis for fission vectors taking into account information from other fission characteristics such as the valley-to-peak ratio of the mass distribution and the number of prompt neutrons emitted per fission event. Fission widths and other channel characteristics are calculated for 0⁺ resonances in low energy neutron induced fission of ²³⁹Pu.     

Probabilities of muon induced nuclear reactions involving charged particle emission

The probabilities for the reactions (μ^?, p), (μ^?, pn), (μ^?, p2n), (μ^?, p3n) and (μ^?, α) were measured by activation experiments on 18 elements from Na to Bi. The results suggest the following systematics : (i) the probability W of each type of reaction depends on the atomic number of the target and can be described by W = aexp( -bV), where V is the Coulomb barrier of the compound nucleus for the ejected charged particle; (ii) the factor b is the same for all (μ^?, pxn) reactions and not very different for (μ^?, α) reactions; (iii) the relative probabilities for (μ^?, pxn) reactions for a given target vary as 1 :6 :4 :4 for x = 0, 1, 2, 3. The experimental results are compared with a theoretical estimate of the reaction probability and with the corresponding 14 MeV neutron induced reactions.     

Der chemische Transport von Nickel mit Indiumjodid

Chemical Transport of Nickel by Indium Iodide At higher temperatures (1273 → 1073 K) the chemical transport of nickel by means of indium iodide going into the zone with lower temperature is caused by the endothermic reaction Ni + InJ₃O,_g = NiJ₂,_g + InJ_,g At lower temperatures (873 → 973 K) this reaction is superimposed by the formation of gas complexes. These exothermic reactions cause transport in the inversed direction.