Littlewood-Paley spline wavelets: a simple and efficient tool for signal and image processing in industrial applications

In this work, we present the Littlewood-Paley Spline Wavelets that are much more effective that the orthonormal discrete wavelets, although it cannot apply the multiresolution scheme. These wavelets carry the advantages of the splines functions what allows their implementation through simple numeric algorithms. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Methods for the preparation of doxycycline-loaded phb micro- and nano-spheres

Natural and synthetic biodegradable polymers have been investigated for controlled drug release. Poly(3-hydroxybutyrate) can be produced by bacteria and is remarkable for this application due to its excellent biocompatibility and biodegradability. The objective of this work was to study different drug-entrapment and emulsification methods for the obtaining of doxycycline-loaded PHB micro- and nano-spheres. The micro-/nano-particles were prepared by polymer precipitation via dialysis, simple emulsion (O/W) or multiple emulsion (W₁/O/W₂) applying solvent evaporation in the last two cases. This was carried out either by ultrasonication, dripping and/or high speed stirring. Different processing conditions were varied in order to evaluate their influence on morphology, size, and drug entrapment capabilities. The highest drug loading was obtained by single emulsion with high speed stirring. In the case of multiple emulsion, the combination of ultrasound with high speed stirring resulted in the most elevate process yield and drug loading capability.     

Intermediate scales in supersymmetric GUTs: the survival of the fittest

We show that intermediate scales in supersymmetric grand unified theories may exist naturally. Their origin is traced to the violation of the survival principle: in supersymmetry internal symmetries often forbid cubic couplings in the superpotential. This leads to a plethora of light supermultiplets whose masses are generated only by higher dimensional operators and thus suppressed by the cut-off scale. These new states often carry exotic quantum numbers and may be, in some cases, accessible to experiments in the near future.     

Titanium-Mediated Catalytic Hydrogenation of Monocyclic and Polycyclic Arenes

Two electron-reduction of the Ti^IV guanidinate complex (Im^DippN)(^Xyketguan)TiCl₂ gives (η⁶-Im^DippN)(^xyketguan)Ti ( 1^intra ) and (Im^DippN)(^Xyketguan)Ti(η⁶-C₆H₆) ( 1^inter ) (^Xyketguan=[(tBuC=N)C(NXylyl)₂]⁻, Xylyl=2,5-dimethylphenyl) in the absence or presence of benzene, respectively. These complexes have been found to hydrogenate monocyclic and polycyclic arenes under relatively mild conditions (150 psi, 80 °C)—the first example of catalytic, homogeneous arene hydrogenation with TON >1 by a Group IV system.     

1H and DOSY NMR spectroscopy analysis of Ligusticum porteri rhizome extracts

The presence of dimeric phthalides and other constituents in extracts of the vegetal species Ligusticum porteri was established by NMR spectroscopy. In comparative qualitative ¹H NMR analyses of acetone extracts of rhizomes from fresh and dried L. porteri samples, we found that the dimeric phthalides tokinolide B (3), diligustilide (4) and riligustilide (5) were naturally produced by the plant and not post‐harvest products. We also obtained DOSY ¹H NMR data that provided both virtual separation and structural information for the phthalides present in a dry acetone extract of L. porteri. In addition, we developed a protocol for the quantification of dimeric phthalides, which is performed by calculating the relative ratio of the peak area of selected proton signals for some compounds with respect to the known signal of the internal standard, 4‐dimethylaminopyridine. The protocol allows the rapid and direct quantification of dimeric phthalides and others constituents in fresh L. porteri rhizomes. Copyright © 2011 John Wiley & Sons, Ltd.     

Unbounded symmetrizable idempotents

The relationship between closed unbounded idempotents and dense decompositions of a Hilbert space is explored by extending the notion of compatibility between closed subspaces and positive bounded operators.     

Mathematical Modeling of Arborescent Polyisobutylene Production in Batch Reactors

A novel model describes copolymerization of isobutylene and inimer (initiator‐monomer) via living carbocationic polymerization. Six different propagation rate constants and two types of equilibrium reactions are considered. Simplifying assumptions are made to enable implementation in PREDICI, so that the molecular weight distribution (MWD) could be predicted for molecules with different branching levels. Four apparent rate constants were estimated from experimental data with <5 branches per molecule. Model predictions provide a good fit to data, and simulation results show that polymers with high‐branching levels and ≥15 inimer units contribute significantly to the MWD, even though their concentrations are very low.