Facile one-pot preparation of 2-arylpropionic and arylacetic acids from cyanohydrins by treatment with aqueous HI

A novel one-pot two-step procedure has been developed to synthesize highly substituted 2-arylpropionic and arylacetic acids, by treatment with aqueous HI, from cyanohydrins. The hydrogenolytic reduction of α-hydroxy-2-arylpropionic acids was the key step of the process and the optimization of the reaction conditions led to identify aqueous HI as an appropriate and selective reagent for the reductive deoxygenation of cyanohydrins. The synthetic route described a general and efficient strategy for the preparation of large libraries of phenylacetic and phenylpropionic acids derivatives.     

Formation of hybrid nano-crystals in organic–inorganic films from a basic sol

Organic–inorganic films containing hybrid nanocrystals have been prepared by sol–gel processing in controlled conditions. We have systematically changed the temperature and the aging time of a precursor sol containing an organically modified alkoxide bearing an epoxy group, 3-glycidoxypropyltrimethoxysilane, to obtain a controlled crystallization of hybrid layered structures in hybrid films. The precursor sol has been aged at different temperatures, from 5 to 60 °C, and for 1, 2 or 3 days; the films have been deposited from the aged sol and immediately after characterized by X-ray diffraction, Fourier transform infrared spectroscopy and Raman spectroscopy. We have observed that the formation of the hybrid crystals can be obtained only when at least 50% of the epoxies are opened and a larger silica condensation is achieved. These conditions are reached after aging at 60 °C for 1 day, or at longer aging times when the sol is aged at lower temperatures. Transmission electron microscopy and optical polarized images have confirmed the formation of the hybrid crystals.     

Quadrupole and octupole electron-phonon coupling in acoustoelectric effects

We propose an experiment to determine the quadrupole and octupole electron-phonon coupling in germanium and silicon. The experiment consists in measuring the electroacoustic absorption and/or the acoustoelectric field in uniaxially stressed n-type crystals. From theoretical values, quadrupole coupling should be well-measurable.     

Nanoparticles in mesoporous films,a happy marriage for materials science

Mesoporous ordered materials, whose porosity is within the 2–50-nm range, are an ideal host for functional nanoparticles. Mesoporous thin films, in particular, offer a large variety of options for the fabrication of advanced materials and devices based on the host-guest combination of matrix nanoparticles. Nanocomposite mesoporous films embedding metal, oxide, and semiconductor nanoparticles have been prepared using as matrix oxides, mixed oxides, and organic-inorganic hybrids. The organization of the pores is an important peculiar property of mesoporous ordered films and allows producing nanocomposites whose nanoparticles follow a very specific array within the material. The main synthesis methods to obtain mesostructured films containing nanoparticles, together with their applications, are briefly introduced in the present review.     

A modulation invariant Carleson embedding theorem outside local <Emphasis Type="Italic">L</Emphasis><Subscript>2</Subscript>

Yen Do and Christoph Thiele developed a theory of Carleson embeddings in outer L_p spaces for the wave packet transform

$${F_\phi }(f)(u,t,\eta ) = \int {f(x){e^{i\eta (u - x)}}\phi \left( {\frac{{u - x}}{t}} \right)} \frac{{dx}}{t},(u,t,\eta ) \in R \times (0,\infty ) \times R$$

of functions f ∈ L_p(R) in the range 2 ≤ p ≤ ∞, referred to as local L². In this article, we formulate a suitable extension of this theory to exponents 1 < p < 2, answering a question posed by Do and Thiele. The proof of our main embedding theorem involves a refined multi-frequency Calderón-Zygmund decomposition in the vein of work by Di Plinio and Thiele and by Nazarov, Oberlin, and Thiele. We apply our embedding theorem to recover the full known range of L^p estimates for the bilinear Hilbert transforms without reducing to discrete model sums or appealing to generalized restricted weak-type interpolation.

     

A sharp estimate for the Hilbert transform along finite order lacunary sets of directions

We prove, in ZFC, that there is an infinite strictly descending chain of classes of theories in Keisler’s order. Thus Keisler’s order is infinite and not a well order. Moreover, this chain occurs within the simple unstable theories, considered model-theoretically tame. Keisler’s order is a central notion of the model theory of the 60s and 70s which compares first-order theories, and implicitly ultrafilters, according to saturation of ultrapowers. Prior to this paper, it was long thought to have finitely many classes, linearly ordered. The model-theoretic complexity we find is witnessed by a very natural class of theories, the n-free k-hypergraphs studied by Hrushovski. This complexity reflects the difficulty of amalgamation and appears orthogonal to forking.     

Removal of tetramethyl ammonium hydroxide from synthetic liquid wastes of electronic industry through micellar enhanced ultrafiltration

In this paper, the separation of tetramethyl ammonium hydroxide (TMAH) from synthetic liquid wastes of electronic industry is carried out by using a micellar enhanced ultrafiltration (MEUF) process. This treatment represents the first step of an integrated process, aimed at the recovery of TMAH and surfactant and water reuse. The laboratory tests are carried out with an ultrafiltration module using initial solutions having a concentration of pollutant equal to 2?g/L and by adding sodium dodecyl sulfate as a surfactant, at a concentration in the range 4–10?mM/L, that is, under and above its critical micellar concentration (CMC). The experiments have been carried out at a fixed temperature of 25°C. The obtained results showed that very good percentage removals of TMAH are achieved (99%), especially when the surfactant was above the CMC.     

Production and Characterization of F(Ab’)<Subscript>2</Subscript> Fragments Obtained by Enzymatic Digestion from Murine Anti-MRSA PBP2a Monoclonal Antibodies

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a worldwide health problem. In a previous study, a murine monoclonal antibody (mMAB), capable of binding to PBP2a within MRSA strains, was generated. F(ab’)₂ antibody fragments are widely described in the literature as immunochemical tools and reagents for diagnostics and therapeutics, particularly because of their low immunogenicity and rapid pharmacokinetics. In this study, F(ab’)₂ fragments from mMAB were generated by enzymatic digestion, using pepsin. They were purified by affinity chromatography using protein A and concentrated by a MWCO 50 kDa filtration unit. The results indicate that it is possible to obtain F(ab’)₂ fragments by pepsin digestion. ELISA, western blotting, and fluorescence microscopy data demonstrated that F(ab’)₂ affinity for PBP2a is not lost even after the enzymatic digestion process. As expected, in the pharmacokinetics tests, F(ab’)₂ presented a faster elimination (between 12 and 18 h) compared to IgG. These F(ab’)₂ fragments could be used in future immunodiagnostic applications, including in vitro or in situ radiolabeling and in the treatment of infections caused by this important pathogen.     

Preparation of coating films doped with gold metal particles from methyltriethoxysilane-tetraethoxysilane solutions

Silica coating films of 0.5–0.7 m in thickness doped with gold metal particles were prepared by heating gel coating films obtained from solutions of acid-catalyzed methyltriethoxysilane (MTES) and tetraethoxysilane (TEOS) mixture containing chlorauric acid tetrahydrate. Transparent coating films with deep blue, red, and purple colors were obtained. Changes in size and shape of the gold particles with the MTES content were observed. Lower MTES contents gave bigger and non-spherical particles, while higher MTES contents produced smaller and more spherical particles with a more uniform size distribution. The effect of heat-treatment temeprature on the shape, size, and size distribution of the metallic gold particles was also studied.On leave from Dipartimento di Ingegneria Meccanica, Sezione Materiali, Universita di Padova, Via Marzolo, 9-35131 Padova, Italy.