A New Phenomenon—Amplitude‐Modulated Free Oscillations (Beatings) in Loaded,Highly Oriented Fibers from Semicrystalline Polymers

A new phenomenon in highly oriented semicrystalline polymers has been found—the occurrence of amplitude‐modulated oscillations (or beatings). The beatings appeared for certain external conditions. A preliminary interpretation of the phenomenon is given at the supermolecular level.     

Synthesis and biological evaluation of new N-substituted 4-(arylmethoxy)piperidines as dopamine transporter inhibitors

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Synthesis and solid‐state structures of t‐Bu3Ga–EPh3 Lewis acid–base adducts

Three Lewis acid–base adducts t‐Bu₃Ga–EPh₃ (E = P 1 , As 2 , Sb 3 ) were synthesized by reactions of Ph₃E and t‐Bu₃Ga and characterized by heteronuclear NMR (¹H, ¹³C (³¹P)) and IR spectroscopy, elemental analysis and single crystal X‐ray diffraction. Their structural parameters are discussed and compared to similar t‐Bu₃Ga adducts. The strength of the donor‐acceptor interactions within 1 – 3 was investigated in solution by temperature‐dependent ¹H NMR spectroscopy and by quantum chemical calculations.     

On Laplacian spectra of parametric families of closely connected networks with application to cooperative control

In this paper, we introduce mathematical models for studying a supernetwork that is comprised of closely connected groups of subnetworks. For several related classes of such supernetworks, we explicitly derive an analytical representation of their Laplacian spectra. This work is motivated by an application of spectral graph theory in cooperative control of multi-agent networked systems. Specifically, we apply our graph-theoretic results to establish bounds on the speed of convergence and the communication time-delay for solving the average-consensus problem by a supernetwork of clusters of integrator agents.     

Oxa-spirocycles: synthesis,properties and applications

A general approach to a new generation of spirocyclic molecules – oxa-spirocycles – was developed. The key synthetic step was iodocyclization. More than 150 oxa-spirocyclic compounds were prepared. Incorporation of an oxygen atom into the spirocyclic unit dramatically improved water solubility (by up to 40 times) and lowered lipophilicity. More potent oxa-spirocyclic analogues of antihypertensive drug terazosin were synthesized and studied in vivo.

A general practical approach to a new generation of spirocyclic molecules – oxa-spirocycles – is developed.     

Ionic Complexes of Biotechnological Polyacids with Cationic Surfactants

Summary: Stoichiometric complexes of biotechnological poly(γ-glutamic) acid and poly(β,L -malic) acid with alkyltrimethylammonium surfactants of long alkyl chains could be readily prepared in aqueous medium. They adopt a biphasic layered structures in which the main chain and the side chain alternate with nanometric periodicity. Alkyl side chains show reversible melting that involves generation of mesophases. Complexes degraded by water by different mechanisms depending on the constitution of the main chain; the polymalic complexes underwent surface erosion whereas the polyglutamic ones degraded in bulk. Erythromycin could be homogenously loaded into the paraffinic subphase of the complexes and delivered upon incubation under physiological conditions in parallel to the hydrolysis of the polymer.