Antimicrobial activity of new bicyclic lactones with three or four methyl groups obtained both synthetically and biosynthetically

Ten new derivatives of isophorone were obtained through a five-step synthesis. Among the products were several unsaturated, bicyclic lactones with three or four methyl groups. These lactones were used as the substrates for biotransformation mediated by selected fungal strains (Fusarium species, Syncephalastrum racemosum, Cunninghamella japonica, Penicillium species, Absidia species, and Pleurotus ostreatus). Four new hydroxylactones were obtained as a result of biotransformation. Because the unsaturated lactone with four methyl groups was a diastereoisomeric mixture, a structural analysis was conducted. The hydroxylactones were also included in this analysis. Both the unsaturated lactones and hydroxylactones were examined for their antimicrobial activity. It was found that some of these compounds exhibited growth inhibition against pathogenic strains of bacteria (Staphylococcus aureus, Pseudomonas fluorescens), yeasts (Candida albicans) and filamentous fungi (Alternaria sp., Penicillium sp.). All obtained compounds were also subjected to scent analysis.     

Correction to: Ethylethanolammonium 4-nitrobenzoate

Journal of Thermal Analysis and Calorimetry - The temperature dependence of molar heat capacity of Ba1.5Fe2(PO4)3 phosphate was investigated between T = 6 and 670 K with...     

Electrochemical deposition of poly[ethylene-dioxythiophene] (PEDOT) films on ITO electrodes for organic photovoltaic cells: control of morphology,thickness, and electronic properties

In this article, controlled changes on morphology, thickness, and band gap of poly[ethylenedioxythiophene] (PEDOT) polymer films fabricated by electrochemical polymerization (potentiostatically) are analyzed. Electropolymerization of the monomer ethylenedioxythiophene (EDOT) was carried out on indium tin oxide (ITO) electrodes, in different dry organic electrolytic media, such as acetonitrile, acetonitrile–dichloromethane, and toluene–acetonitrile mixtures. It was found that electropolymerization kinetics can be controlled by changing the polarity of the electrolytic media, and kinetics is slower for those with low polarity. This fact combined with an accurate control of EDOT monomer concentration and electropolymerization at E_peak/2 potential, allows to control the morphology and thickness of the electropolymerized PEDOT films (E-PEDOT:ClO₄); toluene/ACN (4:1, v/v) and [EDOT]?=?0.3 mM gave the best films for application in organic photovoltaic (OPV) cells. The performance of the E-PEDOT:ClO₄ films was tested on ITO electrodes as anode buffer layer in OPV cells with the configuration ITO/E-PEDOT:ClO₄/P3HT:PC₆₁BM/Field’s metal, where Field’s metal (cathode) is a eutectic alloy that lets to fabricate OPV devices easily and in a fast and economical way at free vacuum conditions. The performance of these devices was compared with an OPV device constructed with a buffer layer anode, prepared using the classical spin coating of PEDOT:PSS on ITO. Results showed that OPV cells fabricated with E-PEDOT:ClO₄ have a slightly increased PV performance.     

Holistic protocol for callus culture optimization using statistical modelling

Plants endue a key role against illnesses caused by oxidative stress. These attributes are frequently associated with polyphenolic compounds. However, presence and concentration of secondary metabolites are affected by abiotic factors. The in vitro culture techniques can solve these drawbacks. Peppers can be a suitable alternative to obtain polyphenols. Aiming to optimise the callus culture stage from Capsicum baccatum to produce polyphenols, this work evaluated systemically the effects of the explant’s origin (root, hypocotyl and cotyledon), growth hormone type (2,4-dichlorophenoxyacetic acid (2,4-D), benzylaminopurine (BAP) and a combination of 2,4-D/BAP at five-to-one ratio) and concentration (0.023–10.000 mg L^?1) on callus culture efficiency parameters using a multilevel factorial design. The root explant in combination with BAP at 1.138 mg L^?1 ensured the optimal values of the assessed responses; ?callus mass (225.03 mg), antioxidant activity (35.95%), total phenols (11.48 mg of GAE/g DE) and flavonoids (15.92 mg of RU/g DE) production.     

A functional limit theorem for Erdös and Rényi's law of large numbers

Summary We use the theory of large deviations on function spaces to extend Erdös and Rényi's law of large numbers. In particular, we show that with probability 1, the double-indexed set of paths {W _{N, n} } defined by where , {X _i : _i 1} is an iid sequence of random variables, andh(N)=[clogN] is relatively compact; the limit set is given by the set [xI ^*(x)1/c] whereI ^*(x) = ₀ ¹ I(x(t))dt andI is Cramér's rate function.     

Atacamite as a natural pigment in a South American colonial polychrome sculpture from the late XVI century

The image of Our Lady of Copacabana is a gilded polychrome sculpture manufactured in maguey wood at the end of the 16th century. It is a highly devotional image in the Andean region and her sanctuary lays at the shores of the Titicaca Lake in Bolivia. In this study, a green sample taken from the Virgin's veil has been analyzed with the aim to identify the green pigment and the gilding technique. The green pigment layer covered completely the shiny color of the gilded area. First, the cross section of the sample was examined by optical microscopy revealing the presence of green crystals on a white layer; beneath it, a gold leaf on a red bole was observed. Scanning electron microscopy‐energy dispersive spectroscopy analysis allowed the identification and quantification of copper and chloride in the green pigment layer. Analysis by micro‐Raman spectroscopy indicated the presence of atacamite (Cu₃Cl₂(OH)₃) as the green pigment. Although this compound has been identified as a degradation product of copper pigments or of metallic objects containing copper, in this polychrome sculpture, atacamite was used as the green pigment and is identified for the first time as a mineral pigment in a colonial sculpture made in the Viceroyalty of Peru. Copyright © 2012 John Wiley & Sons, Ltd.     

Gravitational wave detectors: New eyes for physics and astronomy

Several interferometric gravitational wave detectors around the world are now starting to achieve better sensitivity to gravitational waves than ever before. We describe the prospects these detectors offer for physics and astronomy and review the rapid progress and the present status of the detectors’ sensitivities. We also report the progress made by the LIGO Scientific Collaboration in analysing the data produced by the LIGO and GEO detectors during the Collaboration’s Science Runs.     

Initial-boundary value problem for the nonlinear string-beam system

This paper deals with a nonlinear string-beam system describing the torsional-vertical oscillations of a suspension bridge. We consider the initial-boundary value problem and study the existence and uniqueness question. We assume time independent right hand sides, but allow quite general nonlinear terms. Using the Faedo-Galerkin method we prove the existence of a unique solution on an arbitrary large time interval.