Raman spectroscopy of CaM2+Ge2O6 (M2+ = Mg,Mn, Fe,Co, Ni,Zn) clinopyroxenes

The Raman spectra of Ge‐clinopyroxenes CaM²⁺Ge₂O₆ (M²⁺ = Mg, Mn, Fe, Co, Ni, Zn), general formula M2M1T₂O₆, are reported for the first time. Their spectral features are discussed in comparison with corresponding Si‐pyroxenes. The vibrational wavenumbers of germanates may be roughly obtained by a scale factor of about ~0.8 by those of the corresponding silicates, due to the Ge‐Si mass difference. The main peaks in the germanate Raman spectra at ~850 and ~540 cm⁻¹ may be related to Ge‐O tetrahedral stretching and chain bending, respectively; minor peaks between 200 and 400 cm⁻¹ are ascribed to bending and stretching of the non‐tetrahedral cations. Within Ge‐pyroxenes, possible correlations between crystallographic parameters and the vibrational wavenumbers are investigated. The main stretching mode at ~850 cm⁻¹ shows wavenumber changes with M²⁺ substitutions, but no simple correlation can be found with M²⁺ cation mass or size. On the other hand, the chain bending wavenumber linearly decreases with increasing ionic radius of the M²⁺ cation: the expansion of the M1 polyhedron reduces the chain kinking angle and the Ge‐Ge distances correspondingly increase. Copyright © 2015 John Wiley & Sons, Ltd.     

Alpha-aldehyde terminally functional methacrylic polymers from living radical polymerization: application in protein conjugation "pegylation"

Application of proteins and peptides as human therapeutics is expanding rapidly as drug discovery becomes more prevalent. Conjugation of polymers to proteins can circumvent many problems and pegylation of proteins is now emerging as acceptable practice. This paper describes the synthesis of alpha-aldehyde-terminated poly(methoxyPEG)methacrylates from Cu(I) mediated living radical polymerization (Mn = 11 000, 22 000 and 32 000; PDi < 1.15), and their efficient conjugation to lysozyme, as a model protein. This offers an attractive and flexible alternative to linear poly(ethylene glycol) opening up the possibility of using the full power of living radical polymerization.     

On the Effects of UV‐C and pH on the Mechanical Behavior,Molecular Conformation and Cell Viability of Collagen‐Based Scaffold for Vascular Tissue Engineering

Collagen‐based vascular substitutes represent in VTE a valid alternative for the replacement of diseased small‐calibre blood vessels. In this study, collagen gel‐based scaffolds were crosslinked combining modulation of pH and UV‐C radiation. The effects on the mechanical properties, on the molecular structure and on cell viability and morphology were investigated. The mechanical response increased as a function of pH or UV‐C dose and strongly depended on the test speed. Collagen molecular conformation resulted only slightly modified. While cell adhesion was not significantly altered, cell proliferation partially decreased in function of pH and UV‐C. These findings suggest that UV‐C treated collagen gels can represent an adequate substrate for VTE applications.

     

Regularity of the category of Kelley spaces

We show that the cartesian closed category of compactly generated Hausdorff spaces is regular, but is neither exact, nor locally cartesian closed. In fact we find a coequalizer of an equivalence relation which is not stable under pullback.     

Vertical structure and turbulent properties of wind field observed at a coastal complex site

Summary Six experimental campaigns have been performed at the site of La Spezia Gulf (Northern Italy) from 1974 to 1977 jointly by three Italian research groups. Previous papers analysed various aspects of the collected data. The present paper deals with three topics not covered by preceding analyses. In studying the pibal data set, the statistics of wind field from ground level to free atmosphere has been studied; then an empirical expression, relating sea breeze flow to geostrophic circulation, is proposed; finally, examining no-lift balloon trajectories, turbulent properties, such as diffusion coefficients, turbulence intensities and so on, have been evaluated. The effects of the different surfaces, sea and land, on the turbulent parameters have been evidentiated.

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Riassunto Una serie di sei campagne sperimentali è stata effettuata nel sito del Golfo di La Spezia dal 1974 al 1977 da un gruppo di ricerca congiunto (ENEL/CRTN di Milano, CNR/ICG di Torino e Istituto di Fisica Generale dell'Università di Torino). Alcuni lavori pubblicati in precedenza riportano i risultati di varie analisi effettuate sui dati raccolti. Il lavoro attuale, che si riferisce ad argomenti non studiati in dettaglio in precedenza, si è indirizzato allo studio dei seguenti argomenti: analisi statistica del campo del vento dal suolo al livello dell'atmosfera libera; proposta di una relazione empirica in grado di dare il profilo verticale della velocità del vento, durante le condizioni diurne di brezza di mare, dal suolo alla quota di vento geostrofico; stima delle proprietà turbolente dei primi strati atmosferici, in relazione alla loro capacità di dispersione di eventuali inquinanti.

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Резюме было проведено шесть серий экспериментов в заливе Специя (Северная Италя) в период с 1974 по 1977 г.г. совместно тремя итальянскими исследовательскими группами. В предыдуших работах анализировались различные аспекты собранных данных. В этой работе рассматриваются три вопроса, которые не затрагивались в предыдущих статьях. Исследуется статистика поля ветров от поверхности земли до свободной атмосферы. Затем предлагается эмпирическое выражение, связывающее поток морского бриза с геострофической циркуляцией. В заключение, определяются турбулентные свойства, такие как коэффициенты диффузии, интенсивности турбулентности и др. Анализируется влияние различных поверхностей (море и Земля) на турбулентные параметры.

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This work was partially supported by ?Progetto Finalizzato del C.N.R.: Promozione della Qualità dell'Ambiente? and by a research contract by ENEL/CRTN, Milano.     

First results on diffraction dissociation of neutrons at the ISR

Neutron diffraction dissociation has been measured at the ISR in proton-neutron interactions at 37 GeV c.m. energy. The data were taken with the Split Field Magnet detector, during a short deuteron storage test run with colliding p-d beams. Differential mass and momentum transfer distributions are reported; the value of the total cross-section shows a weak s-dependence when compared to lower energy data.     

Shearlet Smoothness Spaces

The shearlet representation has gained increasingly more prominence in recent years as a flexible and efficient mathematical framework for the analysis of anisotropic phenomena. This is achieved by combining traditional multiscale analysis with a superior ability to handle directional information. In this paper, we introduce a class of shearlet smoothness spaces which is derived from the theory of decomposition spaces recently developed by L. Borup and M. Nielsen. The introduction of these spaces is motivated by recent results in image processing showing the advantage of using smoothness spaces associated with directional multiscale representations for the design and performance analysis of improved image restoration algorithms. In particular, we examine the relationship of the shearlet smoothness spaces with respect to Besov spaces, curvelet-type decomposition spaces and shearlet coorbit spaces. With respect to the theory of shearlet coorbit space, the construction of shearlet smoothness spaces presented in this paper does not require the use of a group structure.     

Site-directed conjugation of "clicked" glycopolymers to form glycoprotein mimics: binding to mammalian lectin and induction of immunological function

Synthesis of well-defined neoglycopolymer-protein biohybrid materials and a preliminary study focused on their ability of binding mammalian lectins and inducing immunological function is reported. Crucial intermediates for their preparation are well-defined maleimide-terminated neoglycopolymers (M(n) = 8-30 kDa; M(w)/M(n) = 1.20-1.28) presenting multiple copies of mannose epitope units, obtained by combination of transition-metal-mediated living radical polymerization (TMM LRP) and Huisgen [2+3] cycloaddition. Bovine serum albumin (BSA) was employed as single thiol-containing model protein, and the resulting bioconjugates were purified following two independent protocols and characterized by circular dichroism (CD) spectroscopy, SDS PAGE, and SEC HPLC. The versatility of the synthetic strategy presented in this work was demonstrated by preparing a small library of conjugating glycopolymers that only differ from each other for their relative epitope density were prepared by coclicking of appropriate mixtures of mannopyranoside and galactopyranoside azides to the same polyalkyne scaffold intermediate. Surface plasmon resonance binding studies carried out using recombinant rat mannose-binding lectin (MBL) showed clear and dose-dependent MBL binding to glycopolymer-conjugated BSA. In addition, enzyme-linked immunosorbent assay (ELISA) revealed that the neoglycopolymer-protein materials described in this work possess significantly enhanced capacity to activate complement via the lectin pathway when compared with native unmodified BSA.