Independence of the Total Reflexivity Conditions for Modules

We show that the conditions defining total reflexivity for modules are independent. In particular, we construct a commutative Noetherian local ring R and a reflexive R-module M such that Ext_Rⁱ(M,R)=0 for all i>0, but Ext_Rⁱ(M^*,R)≠0 for all i>0. Presented by Juergen Herzog Mathematics Subject Classification (2000) 13D07.     

Preparation of nodular carbon cryogel from simple and inexpensive polycondensation reaction of commercial modified black wattle tannin

Tannin–formaldehyde cryogels (TFC) were synthesized by sol–gel polycondensation of low molecular weight and highly reactive modified tannin with formaldehyde using HCl as a catalyst. Carbon cryogels (CC) were obtained by the TFC pyrolysis at an inert atmosphere at 800 °C. Pyrolysis caused significant changes in the physical and chemical properties of the material. The pyrolysis induced the decomposition of acid superficial groups and the development of basic ones. Pyrolysis also provoked significant change in the pore volume, forming a great amount of micropores. TFC and CC showed amorphous and turbostratic structures, respectively. Unpurified samples had inorganic impurities in their compositions.     

An iron-catalysed synthesis of amides from nitriles and amines

The cheap, commercially available iron complex, Fe(NO₃)₃·9H₂O, has been used to catalyse the formation of amides by the addition of amines to nitriles.     

Effect of HeNe Laser Irradiation on Extracellular Matrix Deposition and Expression of Cytokines and Chemokines in Paracoccidioidomycotic Lesions

Paracoccidioidomycosis is the most prevalent human mycosis in Latin America. Cutaneous lesions are extremely painful and sensitive, and current treatment with antifungal drugs is lengthy and may cause side effects to patients. In this perspective, the helium-neon (HeNe) laser emerges as a novel therapy form due to its ability to heal wounds without changing cell function. In this work, we evaluate the effects of HeNe laser irradiation on extracellular matrix deposition and expression of cytokines and chemokines in cutaneous lesions caused by experimental infection of Balb/c mice. Our results showed decreased levels of pro-inflammatory interleukin (IL)-17 and tumor necrosis factor-α, and of anti-inflammatory IL-10 cytokines in lesions exposed to HeNe laser irradiation. Chemokines CCL3 and CXCL10 showed decreased levels in laser-treated lesions, but no significant difference was observed in relation to CCL5 expression. We also detected decreased density of fibronectin and laminin in HeNe laser-treated lesions. Data presented herein support the validity of our previous results suggesting positive effects of HeNe laser in accelerating wound healing in this experimental model. We believe that HeNe laser is a new nonharmful strategy that may be used as adjuvant and/or alternative therapy for improving treatment of paracoccidioidomycotic lesions.     

Synthesis of binaphthyl bridged chiral bis-corrole

Chiral bis-corrole 1 and 2 were prepared by reaction of(s)-2,2′-bis(bromomethyl)-1,1′-binaphthyl and 10-(4-hydroxylphenyl)- 5,15-bis(pentafluorophenyl)corrole or 10-(3-hydroxylphenyl)-5,15-bis(pentafluorophenyl)corrole in DMF at 60℃in the presence of anhydrous K_2CO_3 with an isolated yield～8%.Both 1 and 2 exhibit unsymmetrical induced circular dichroism(ICD)in the soret band with positive exciton chirality.     

Peculiarities of luminescent properties of cerium doped YAG transparent nanoceramics

Optical and luminescence properties of transparent nanosized cerium doped Y₃Al₅O₁₂ (YAG:Ce) ceramics have been studied. YAG:Ce nanoceramics were obtained by means of low temperature and high pressure (LTHP) sintering method. Nanoceramic samples were sintered in the 2–8 GPa pressure range, whereas Ce³⁺ concentration was varied in the 0.5–5 at. % range. It is shown that, in contrast to the single crystal, a strong rise of absorption coefficient was detected already at wavelength shorter than 400 nm in all nanoceramic samples studied. Furthermore, in nanoceramic samples unusual UV emission band near 3.1 eV was observed, which is not observed in the YAG:Ce single crystal. High pressure applied during nanoceramics sintering leads to significant changes in their optical and luminescence properties.     

The fundamental form of almost-quaternionic Hermitian manifolds

We prove that if the fundamental 4-form Ω$\Omega$ of an almost-quaternionic Hermitian manifold (M,Q,g)$(M,Q,g)$ of dimension 4n≥8$4n\ge 8$ satisfies the conformal-Killing equation, then (M,Q,g)$(M,Q,g)$ is quaternionic-Kähler.     

Isomorphic homotopy groups of certain regular sets and their images

In this paper we study the relation between the topology of the set R(f) of regular points and the topology of its image f(R(f)), for some special maps acting between two manifolds M and N. The results are oriented towards negative examples for the inverse problem of deciding whether a given closed subset of the source manifold is a critical set.     

The Penrose Transform for Compactly Supported Cohomology

Let the manifold X parametrise a family of compact complex submanifoldsof the complex (or CR) manifold Z. Under mild conditions thePenrose transform typically provides isomorphisms between acohomology group of a holomorphic vector bundle V Z and thekernel of a differential operator between sections of vectorbundles over X. When the spaces in question are homogeneousfor a group G the Penrose transform provides an intertwiningoperator between representations. The paper develops a Penrose transform for compactly supportedcohomology on Z. It provides a number of examples where a compactlysupported cohomology group is shown to be isomorphic to thecokernel of a differential operator between compactly supportedsections of vector bundles over X. It considers also how theSerre duality pairing carries through the transform.     

Catalytic CO oxidation by free Au2-: experiment and theory

Temperature-dependent rf-ion trap mass spectrometry and first-principles simulations reveal the detailed reaction mechanism of the catalytic gas-phase oxidation of CO by free Au(2)(-) ions in the presence of O(2). A metastable intermediate with a mass of Au(2)CO(3)(-) was observed at low temperatures. Two alternative structures corresponding to digold carbonate or peroxyformate are predicted for this intermediate. Both structures are characterized by low activation barriers for the formation of CO(2). These combined experimental and theoretical investigations provide a comprehensive understanding of the kinetics, energetics, and atomic arrangements along the reaction path, thus allowing a formulation of the catalytic cycle for the oxidation reaction.