A Molecular Hybrid for Mitochondria‐Targeted NO Photodelivery

The design, synthesis, spectroscopic and photochemical properties, and biological evaluation of a novel molecular hybrid that is able to deliver nitric oxide (NO) into mitochondria are reported. This molecular conjugate unites a tailored o‐CF₃‐p‐nitroaniline chromophore, for photo‐regulated NO release, and a rhodamine moiety, for mitochondria targeting, in the same molecular skeleton via an alkyl spacer. A combination of steady‐state and time‐resolved spectroscopic and photochemical experiments demonstrate that the two chromogenic units preserve their individual photophysical and photochemical properties in the conjugate quite well. Irradiation with violet light triggers NO release from the nitroaniline moiety and photoionization in the rhodamine center, which also retains considerable fluorescence efficiency. The molecular hybrid preferentially accumulates in the mitochondria of A549 lung adenocarcinoma cells where it induces toxicity at a concentration of 1 μm , exclusively upon irradiation. Comparative experiments, carried out with ad‐hoc‐synthesized model compounds, suggest that the phototoxicity observed at such a low concentration is probably not due to NO itself, but rather to the formation of the highly reactive peroxynitrite that is generated from the reaction of NO with the superoxide anion.     

Information Technology and Financial Performance: The Impact of being an Internet-Dependent Firm on Stock Returns

The choice of a particular technology to implement a firm's business strategy may impact the firm's market performance. This study assesses the impact of being an Internet-dependent firm on a firm's stock valuation. The empirical results indicate that in a booming economy, Internet-dependent firms have lower excess returns than non-Internet firms. These high returns can be explained by the fact that in such an economy, Internet stocks trade at relatively higher prices than non-Internet stocks. Therefore, choosing a particular technology to implement business strategy may have a significant impact a firm's stock performance.     

Characterisation of dragon fruit peel pectin extracted with natural deep eutectic solvent and sequential microwave-ultrasound-assisted approach

In this research, the physicochemical characteristics (proximate and chemical compositions, monosaccharides profiles, chemical structures, antioxidant activities and rheological properties) of dragon fruit peel pectin extracted with the solvent system of choline chloride-glucose-water (5:2:5) and sequential microwave-ultrasound-assisted approach (PC-MUAE), were evaluated, and then compared with those of the commercial pectin and other products from various extraction methods. No remarkable differences in the FTIR spectra of the commercial and extracted samples were observed, leading to the fact that the derived polysaccharides were pectin. The commercial pectin possessed a bright-yellow colour, while extracted pectin was yellow to brownish. Moreover, the facade of the latter under SEM was rough with miniature heterogeneous fragments. PC-MUAE was categorised as high methoxyl pectin with the degree of esterification of 59.76% and as a pseudoplastic substance with neutral pH (6.42), average level of solubility (73.90%), high equivalent weight (680.6 g mol⁻¹), high molecular weight (5.05 × 10⁵ Da), high antioxidant activities (total phenolic content of 8.14 mg of gallic acid equivalent/g pectin and 2,2-Diphenyl-1-picrylhydrazyl free radical scavenging capacity of 2.41 µmol Trolox equivalent/g pectin) and high viscosity at all tested domains of shear rate as compared with those of the commercial product and others from various methods. The anhydrouronic acid content of PC-MUAE was 64.28%, approximately to the minimum level (65%) proposed by FAO and EU. There were arabinose, galactose, glucose, mannose, rhamnose and xylose detected in extracted pectin. Consequently, PC-MUAE has the potential characteristics of high methoxyl pectin for the food industries.     

ARAMIS project: a comprehensive methodology for the identification of reference accident scenarios in process industries

In the frame of the Accidental Risk Assessment Methodology for Industries (ARAMIS) project, this paper aims at presenting the work carried out in the part of the project devoted to the definition of accident scenarios. This topic is a key-point in risk assessment and serves as basis for the whole risk quantification.

The first result of the work is the building of a methodology for the identification of major accident hazards (MIMAH), which is carried out with the development of generic fault and event trees based on a typology of equipment and substances. The term “major accidents” must be understood as the worst accidents likely to occur on the equipment, assuming that no safety systems are installed.

A second methodology, called methodology for the identification of reference accident scenarios (MIRAS) takes into account the influence of safety systems on both the frequencies and possible consequences of accidents. This methodology leads to identify more realistic accident scenarios. The reference accident scenarios are chosen with the help of a tool called “risk matrix”, crossing the frequency and the consequences of accidents.

This paper presents both methodologies and an application on an ethylene oxide storage.     

Comparison of Procedures for Resveratrol Analysis in Beer: Assessment of Stilbenoids Stability through Wort Fermentation and Beer Aging

Three resveratrol extraction procedures were compared in beer. Two‐step pre‐cleaning with toluene and cyclohexane allows 76% trans‐resveratrol recovery by solid‐phase extraction (SPE) before RP‐HPLC‐MS/MS analysis. This procedure proved much more efficient than liquid/liquid extraction, which requires solvents that are too hydrophobic for stilbenoids. SPME‐GC‐MS, where the main limiting factor is non‐reproducibility from fibre to fibre, is an interesting alternative for resveratrol quantification in complex mixtures where pre‐cleaning is too difficult. With the optimized SPE procedure, 5 μg.L^?1 trans‐resveratrol was detected in four commercial beers. However, concentrations of stilbenoids in beer should be higher taking into account the presence of cis‐stilbenoids. During fermentation, trans‐resveratrol was partially regenerated from its glucoside, more stable through beer aging. Adding a stilbenoids‐enriched ethanolic hop extract after fermentation significantly increases the beer stilbenoids potential.     

PEDOT:PSS coating on specialty papers: Process optimization and effects of surface properties on electrical performances

In this study, the effects of different paper substrates on the electrical resistance of conducting polymer films are reported. A novel method of bar coating is used for the fabrication of organic conductive films on various substrates. Solutions to improve the continuity of conductive thin film in order to enhance the electrical properties are demonstrated. In order to compare the capability of these different substrates for a potential use in the organic electronic field, sheet resistance measurements were made. It is emphasized that substrate roughness and surface energy are two fundamental parameters, due to their significant impact on sheet resistance. Two methods to overcome bad paper surface properties are proposed. The first consists in the superimposition of conductive polymer layers and the second in the use of a protective layer.     

Failure characteristics of cladding tubes under RIA conditions

In the frame of actions for improving the safety of its nuclear power plants, Electricité de France needs to build the mechanical criteria ensuring the clad integrity for several operating conditions.This paper presents analytical mechanical models used to derive failure criteria for reactivity insertion accidents (RIA) and interpretation of the CABRI REP-Na experimental tests.Building analytical criteria requires an experimental database. Mechanical tests performed on non-irradiated and irradiated cladding tubes have been provided from French and international programmes (PROMETRA, EPRI, …). These tests consist of tube burst and axial tension, and ring tension. Several strain biaxiality ratios are thus available: pure circumferential tension (from ring tension), pure axial tension (from tube axial tension), and plane strain conditions (from tube burst tests). Several strain rates, temperatures, irradiation conditions are also available.The major feature of our study has been to make it possible that these several thermomechanical conditions be representative of “standard” RIA loading conditions.To this aim, we have derived some biaxiality and strain rate corrections to be applied to the results of experimental tests, in such a way that they could be representative of RIA biaxiality conditions (which are assumed to be strain equibiaxiality), and also representative of RIA strain rate conditions (which are assumed to be 5 s⁻¹).The corrections that we derive are based on the fracture properties of hydrided zirconium alloys (especially in terms of anisotropy), and also on an assumed form of the material constitutive equations.Each test of the “homogenized” database has thus been used to calculate a strain energy density, representative of its fracture (the strain energy density is defined as the integral of the stress times strain rate states, over the duration of the mechanical test). The SED values are plotted against the sample's oxide thickness, and a lower bound limit can be established, with respect to oxide thickness.In order to address the problem of representativeness of the laboratory database, an experimental set-up has been developed that aims at characterizing the failure behavior of cladding tubes under RIA conditions. The developed experimental set-up is based on electromagnetic forming.The development of the test and in particular of the die is delicate but leads to repeatable results with a controlled strain biaxiality ratio higher than those obtained through conventional tests such as ring tests or PSU ring tests. The use of electromagnetic forming process allows testing the specimen with very high strain rates. For the next test series other zircaloy alloys at the reception state and in hydrided conditions will be tested in order to look at hydrides influence on fracture strains.A first finite element simulation of the test was engaged. The simulation and the experimental results are in quite good agreement. In future, the consistency of the previously developed analytical mechanical criterion with the electromagnetic forming experimental results will be verified.     

Atomistic simulation of point defects behavior in ceria

The cerium and oxygen threshold displacement energies and the Frenkel pair recombination in CeO₂ have been investigated with empirical potential molecular dynamics simulations. The oxygen and cerium threshold displacement energies have been evaluated to be 27 and 56 eV, respectively, in agreement with experimental results. The short-range cerium and oxygen Frenkel pair recombination processes are found to be strongly dependent on the local topology and the pathways. The oxygen Frenkel pair recombinations are either spontaneous or thermally activated unlike the standard recombination usually defined in rate equations. The lifetime of Frenkel pair recombination is in general found to be much shorter than the characteristic time for single defect diffusion.