New phosphorylated derivatives of carboxymethylcellulose with osteogenic activity

New phosphorylated derivatives of carboxymethylcellulose (CMC) and amidic CMC were realized using trisodium trimetaphosphate (STMP) as the phosphating agent. The new polysaccharides were characterized by infrared spectroscopy and elemental analysis. The characterized polysaccharides were then crosslinked and their rheological and swelling properties determined. The presence of phosphate groups made the three‐dimensional structures more compact and harder than the corresponding non‐phosphated hydrogels. Evaluation of the bioactivity of phosphorylated hydrogels toward osteoblast‐like cells (MG63) showed a significant increase in the osteocalcin production. Copyright © 2008 John Wiley & Sons, Ltd.     

Microwave‐Promoted Ullmann Condensation of 2‐Aminopyridines with 2‐Chlorobenzoic Acids

A new efficient synthetic method of microwave‐promoted Ullmann condensation of 2‐aminopyridines with 2‐chlorobenzoic acids to yield various substituted 11H‐pyrido[2,1‐b]quinazolin‐11‐ones in dry media is presented. Results were compared with those obtained following the classical heating.     

Stereoselective cyanation of β-bromo-β-fluorostyrenes using potassium cyanide and promoted by (CH3CN)4Cu+ BF4−

A general method for the synthesis of α-fluorocinnamonitrile based on the stereoselective reaction between β-bromo-β-fluorostyrene and potassium cyanide, promoted by (CH₃CN)₄Cu⁺ BF₄^? in 1-methyl-2-pyrrolidinone (NMP), is described.     

Wasserung

Ohne Zusammenfassung     

Structure sets of triples of manifolds

The structure set of a given manifold fits into a surgery exact sequence, which is the main tool for classification of manifolds. In the present paper, we describe relations between various structure sets and groups of obstructions which naturally arise for triples of manifolds. The main results are given by commutative braids and diagrams of exact sequences. __________ Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 11, No. 4, pp. 153–172, 2005.     

A strongly convergent hybrid proximal method in Banach spaces

This paper is devoted to the study of strong convergence in inexact proximal like methods for finding zeroes of maximal monotone operators in Banach spaces. Convergence properties of proximal point methods in Banach spaces can be summarized as follows: if the operator have zeroes then the sequence of iterates is bounded and all its weak accumulation points are solutions. Whether or not the whole sequence converges weakly to a solution and which is the relation of the weak limit with the initial iterate are key questions. We present a hybrid proximal Bregman projection method, allowing for inexact solutions of the proximal subproblems, that guarantees strong convergence of the sequence to the closest solution, in the sense of the Bregman distance, to the initial iterate.     

Existence of optimal stationary policies in average reward Markov decision processes with a recurrent state

We consider discrete-timeaverage reward Markov decision processes with denumerable state space andbounded reward function. Under structural restrictions on the model the existence of an optimal stationary policy is proved; both the lim inf and lim sup average criteria are considered. In contrast to the usual approach our results donot rely on the average regard optimality equation. Rather, the arguments are based on well-known facts fromRenewal Theory.This research was supported in part by the Consejo Nacional de Ciencia y Tecnologia (CONACYT) under Grants PCEXCNA 040640 and 050156, and by SEMAC under Grant 89-1/00ifn$.     

Stationary critical points of the heat flow in the plane

In previous papers [MS 1, 2], we considered stationary critical points of solutions of the initial-boundary value problems for the heat equation on bounded domains in ℝ^N,N ≧ 2. In [MS 1], we showed that a solutionu has a stationary critical pointO if and only ifu satisfies a certain balance law with respect toO for any time. Furthermore, we proved necessary and sufficient conditions relating the symmetry of the domain to the initial datau ₀; in this way, we gave a characterization of the ball in ℝ^N([MS 1]) and of centrosymmetric domains ([MS 2]). In the present paper, we consider a rotationA _dby an angle 2π/d,d ≧ 2 for planar domains and give some necessary and some sufficient conditions onu ₀ which relate to domains invariant underA _d. We also establish some conjectures. This research was partially supported by a Grant-in-Aid for Scientific Research (C) (# 10640175) and (B) (# 12440042) of the Japan Society for the Promotion of Science. The first author was supported also by the Italian MURST.     

Electrostatic effect of specifically adsorbed electroinactive ions upon electrode processes: Part III. Further considerations on perbromate electroreduction in the presence of halide and pseudohalide ions

The effect of specifically adsorbed halides and pseudohalides upon the kinetics of BrO₄^? electroreduction, already investigated by the authors and Cozzi [7] and, more recently, by de Levie and Nemes [8], is further examined. The inadequacy of a simple diffuse-layer correction for the kinetics of BrO₄^? electroreduction and the “direct” effect of the charge density q_i at the inner Helmholtz plane (q_i-effect) upon such kinetics are stressed. An alternative method for estimating the q_i-effect, based on the use of corrected Tafel plots at constant q_i, is proposed.