Random marginal and random removal values

We propose two variations of the non-cooperative bargaining model for games in coalitional form, introduced by Hart and Mas-Colell (Econometrica 64:357–380, 1996a). These strategic games implement, in the limit, two new NTU-values: the random marginal and the random removal values. Their main characteristic is that they always select a unique payoff allocation in NTU-games. The random marginal value coincides with the Consistent NTU-value (Maschler and Owen in Int J Game Theory 18:389–407, 1989) for hyperplane games, and with the Shapley value for TU games (Shapley in In: Contributions to the theory of Games II. Princeton University Press, Princeton, pp 307–317, 1953). The random removal value coincides with the solidarity value (Nowak and Radzik in Int J Game Theory 23:43–48, 1994) in TU-games. In large games we show that, in the special class of market games, the random marginal value coincides with the Shapley NTU-value (Shapley in In: La Décision. Editions du CNRS, Paris, 1969), and that the random removal value coincides with the equal split value.      

Cystine as Ligand of Calcium(II) and Magnesium(II) in Two Ionic Media and at Two Different Temperatures (25 and 37 °C)

Cystine plays an important role in human physiology, it is the precursor of cysteine. Cystine is the molecular form preferred by the immunity cellules system, included macrophages. Although slightly soluble, it can be a ligand towards cations because it is a sulfur-containing amino acid. Because of the physiological importance of calcium(II) and magnesium(II), complex formation between these cations and cystine was studied potentiometrically by employing electrochemical cells involving glass electrodes. The investigation was performed at two temperatures (25 and 37) °C and in two ionic media (1.00 and 0.15 mol·dm^?3 NaCl). In both ionic media, the adoption of a constant ionic medium allows extension of the investigation to a large range of reagent concentration. As the formation of weak complexes was foreseen, the low solubility of cystine is an advantage. Experimental data can be explained in any case by assuming the formation of mononuclear complexes in the presence of both calcium(II) and magnesium(II). The relative stability constants were determined.     

CAESAR models for developmental toxicity

Background

The new REACH legislation requires assessment of a large number of chemicals in the European market for several endpoints. Developmental toxicity is one of the most difficult endpoints to assess, on account of the complexity, length and costs of experiments. Following the encouragement of QSAR (in silico) methods provided in the REACH itself, the CAESAR project has developed several models.

Results

Two QSAR models for developmental toxicity have been developed, using different statistical/mathematical methods. Both models performed well. The first makes a classification based on a random forest algorithm, while the second is based on an adaptive fuzzy partition algorithm. The first model has been implemented and inserted into the CAESAR on-line application, which is java-based software that allows everyone to freely use the models.

Conclusions

The CAESAR QSAR models have been developed with the aim to minimize false negatives in order to make them more usable for REACH. The CAESAR on-line application ensures that both industry and regulators can easily access and use the developmental toxicity model (as well as the models for the other four endpoints).

     

Radiation-induced grafting of stimuli-responsive binary monomers: PDMAEMA/PEGMEMA onto PP films

Both poly[2-(dimethylamino) ethyl methacrylate] (PDMAEMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) were radiation grafted onto polypropylene films (PP) using gamma radiation from a ⁶⁰Co source. PP was pre-irradiated by gamma ray for modification following by grafted PDMAEMA and PEGMEMA by a one step method. Grafting was studied as a function of the pre-irradiation dose between 20 and 180 kGy, dose rate of 10.4 kGy/h, and monomer concentration 50% of PDMAEMA/PEGMEMA (1/1) in different solvents (toluene, acetone, and methanol). FTIR-ATR, TGA, and DSC were carried out in the characterization of the graft copolymer obtained. Stimuli-responsive behavior and critical pH point were studied by swelling in water. pH and thermo-responsive films of PE-g-(DMAEMA/PEGMEMA) presented a lower critical solution temperature (LCST) of 50 °C and critical pH point around 8.7.     

A new on-line solid phase extraction high performance liquid chromatography tandem mass spectrometry method to study the sun light photodegradation of mono-chloroanilines in river water

The study investigates the natural photodegradation pathway of mono-chloroanilines in river waters, with the aim to identify the predominant photoproducts formed. At this purpose a new sensitive on-line SPE HPLC–MS/MS method has been developed with LOQ values equal or lower than the legal threshold concentration levels allowed for mono-chloroanilines in waters. The degradation processes of o-, m- and p-chloroaniline have been investigated subjecting their solutions, prepared both in ultrapure and in river water, to sun light irradiation simulated by a solar box system. The SPE HPLC–MS/MS methodology allowed to evaluate the degradation kinetics, to identify the predominant photodegradation products and to propose the chemical structures. Two photoproducts (aniline and 3-aminophenol), for which standards are available, have also been quantified.     

PP films grafted with N-isopropylacrylamide and N-(3-aminopropyl) methacrylamide by γ radiation: synthesis and characterization

Simultaneous grafting of N-isopropylacrylamide (NIPAAm) and N-(3-aminopropyl) methacrylamide hydrochloride (APMA) on polypropylene (PP) was investigated for obtaining interfaces that are stimuli-responsive under physiological conditions. A pre-irradiation method was optimized tuning the γ-irradiation dose, reaction time, temperature, and monomers concentrations. FT-IR ATR and XPS analysis of the grafted copolymers evidenced a greater content in NIPAAm than in APMA; the APMA/NIPAAm ratio increasing with the concentration of APMA in the reaction medium and when the grafting was carried out in 1 M NaNO₃. The grafted films were characterized regarding their thermal properties (DSC and TGA) swelling behavior and contact angle. Immersion of the pre-irradiated films in 1 M NIPAAm/0.5 M APMA aqueous solution rendered PP-g-(1NIPAAm-r-0.5APMA) which exhibited rapid and reversible transitions showing a LCST around the physiological temperature. By contrast, a greater content in APMA enhanced the hydrophilicity and prevented the shrinking of PP-g-(1NIPAAm-r-1APMA).     

Effect of temperature on the photobehavior of Rose Bengal associated with dipalmitoylphosphatidyl choline liposomes

The association and photobehavior of Rose Bengal (RB) in the presence of dipalmitoylphosphatidyl choline (DPPC) small unilamellar liposomes is determined by the temperature. At temperatures above the main phase transition of the bilayer, the incorporation of the dye is ca. 2.5 times more efficient than that taking place when the bilayer is in the gel state. In both temperature ranges, adsorption isotherms show a noticeable anti-cooperativity that can be related to electrostatic repulsion between bound molecules. The photophysics and the photochemistry of the bound dye molecules also depend on the bilayer status. In particular, in the liquid crystalline state the surrounding of the dye is more polar and production of singlet oxygen is less efficient (Φ∼0.1). This reduced singlet oxygen production is partially due to a low triplet yield (Φ_T=0.35) and triplet self-quenching due to a high local RB concentration. In spite of these, tryptophan is efficiently photobleached when RB is associated to liposomes in the liquid crystalline state, probably due to a Type I mechanism favored by its high local concentration in the sensitized surroundings.     

Synthesis and characterization of silicon-doped gallium oxide nanowires for optoelectronic UV applications

Silicon-doped gallium oxide nanowires have been synthesized by thermal methods using either a mixture of gallium oxide and silicon powders or metallic gallium with silicon powder as precursor materials. The growth mechanism has been found to be a vapour–liquid–solid (VLS) or vapour–solid (VS) process, respectively, depending on the precursor used. In the former case, silicon oxide droplets at the end of the nanowires have been observed. Their possible role during the growth of the nanostructures is discussed. Structural and morphological characterization of the doped nanowires has been performed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results show a high crystalline quality and a uniform distribution of silicon along the nanowires. Room temperature cathodoluminescence (CL) in the SEM shows that slight variations in the composed UV–blue emission band appear due to the influence of Si impurities in the oxygen vacancy defect structure.