The t#-property for integral domains

Generalizing work of Gilmer and Heinzer, we define a t#-domain to be a domain R in which for any two distinct subsets and of the set of maximal t-ideals of R. We provide characterizations of these domains, and we show that polynomial rings over t#-domains are again t#-domains. Finally, we study overrings of t#-domains.     

Microfluidic sensor based on integrated optical hollow waveguides

A simple integrated optical refractometric sensor based on hollow-core antiresonant reflecting optical waveguides is proposed. The sensor uses the antiresonant reflecting guidance mechanism and permits one to measure the refractive index of a liquid filling the core by simply monitoring the transmitted spectrum. The device has been made with standard silicon technology, and the experimental results confirm numerical simulations performed in one- and two-dimensional geometry. The sensor exhibits a linear response over a wide measurement range (1.3330-1.4450) and a resolution of 9 x 10(-4) and requires a small analyte volume.     

Catalytic activity of myoglobin immobilized on zirconium phosphonates

The adsorption and catalytic activity of myoglobin (Mb) on zirconium phosphonates (a-zirconium benzenephosphonate (alpha-ZrBP), a-zirconium carboxyethanephosphonate (alpha-ZrCEP), and a novel layered zirconium fluoride aminooctyl-N,N-bis(methylphosphonate) (ZrC8)) were investigated. The maximum adsorption was reached after 16 h of contact and was greater on hydrophobic supports such as alpha-ZrBP and ZrC8 compared to hydrophilic supports such as alpha-ZrCEP. The equilibrium adsorption isotherms fitted the Langmuir equation, suggesting the presence of a monolayer of protein molecules on the support surfaces. The catalytic activities of free Mb and of the obtained biocomposites were studied in terms of the oxidation of two aromatic substrates, o-phenylenediamine and 2-methoxyphenol (guaiacol), by hydrogen peroxide. The oxidation catalyzed by immobilized myoglobin followed the Michaelis-Menten kinetics, similar to oxidation by free Mb. The kinetic parameters, kcat and KM, were significantly affected by the adsorption process. Mb/alpha-ZrCEP was the most efficient biocatalyst obtained, probably because of the hydrophilic nature of the support. The effect of immobilization on the stability of Mb toward inactivation by hydrogen peroxide was also investigated, and an increased resistance was found. The biocomposites obtained can be stored at 4 degrees C for months without a significant loss of catalytic activity.     

Functionalised enones as starting materials for the construction of aziridine scaffolds

alpha-Substituted beta-keto esters have been transformed by means of a straightforward procedure into aziridine-1,2-dicarboxylates, which have been efficiently converted into alkenyl aziridine-1,2-dicarboxylates through Wittig olefination reaction. The possibility of aziridine ring elaborations and the presence of an olefin function make these new molecules suitable scaffolds for further derivatisation into potential bioactive targets.     

Mononuclear manganese(III) complexes as building blocks for the design of trinuclear manganese clusters: study of the ligand influence on the magnetic properties of the [Mn3(mu3-O)](7+) core

The synthesis, crystal structure, and magnetic properties of three new manganese(III) clusters are reported, [Mn 3(mu 3-O)(phpzH) 3(MeOH) 3(OAc)] (1), [Mn 3(mu 3-O)(phpzMe) 3(MeOH) 3(OAc)].1.5MeOH (2), and [Mn 3(mu 3-O)(phpzH) 3(MeOH) 4(N 3)].MeOH (3) (H 2phpzH = 3(5)-(2-hydroxyphenyl)-pyrazole and H 2phpzMe = 3(5)-(2-hydroxyphenyl)-5(3)-methylpyrazole). Complexes 1- 3 consist of a triangle of manganese(III) ions with an oxido-center bridge and three ligands, phpzR (2-) (R = H, Me) that form a plane with the metal ions. All the complexes contain the same core with the general formula [Mn 3(mu 3-O)(phpzR) 3] (+). Methanol molecules and additional bridging ligands, that is, acetate (complexes 1 and 2) and azide (complex 3), are at the terminal positions. Temperature dependent magnetic susceptibility studies indicate the presence of predominant antiferromagnetic intramolecular interactions between manganese(III) ions in 1 and 3, while both antiferromagnetic and ferromagnetic intramolecular interactions are operative in 2.     

Multilocus mutation scanning for the analysis of genetic variation within Malassezia (Basidiomycota: Malasseziales)

Members of the genus Malassezia are budding yeasts, characterized by a thick cell wall. Recently, these yeasts have received attention as emerging pathogens. They are common commensals on the skin of animals and can become pathogenic under the influence of various predisposing factors. Central to studying their taxonomy, systematics, and ecology and to diagnosis is the accurate identification of species or operational taxonomic units. To overcome the limitations of current phenotypic and biochemical methods of identification, a PCR-coupled SSCP approach, utilizing sequence variation (0.4-33.5%) in short regions (approximately 250-270 bp) of the first internal transcribed spacer (ITS-1) of nuclear ribosomal DNA and the chitin synthase-2 gene (chs-2), was assessed for the identification and differentiation of different species/genotypes of Malassezia, characterized previously by DNA sequencing. Genomic DNA samples (n = 30) from Malassezia isolates cultured from canine skin scrapings were assessed by SSCP analysis of the two different genetic loci, and unequivocal delineation between genotypes and species was achieved. This SSCP approach is considered to provide a practical tool for the rapid and reliable genetic characterization of Malassezia genotypes/species from dogs and for investigating their population genetics and ecology. It will also provide a powerful tool for studies of Malassezia isolates from other animal species.     

Production of Mesoglycan/PCL Based Composites through Supercritical Impregnation

The development of targeted therapies for wound repair is knowing a growing interest due to the increasing aging of the population and the incidence of chronic pathologies, mainly pressure ulcers. Among molecules recruiting cell populations and promoting the formation of new vital tissue, sodium mesoglycan (MSG) has been proven to be effective in wound healing. In this work, MSG impregnation of polymer matrices has been attempted by a supercritical carbon dioxide-based process. Polymeric matrices are composed of polycaprolactone blends, where water-soluble polymers, polyethylene glycol, polyvinyl pyrrolidone, gelatin, and thermoplastic starch, have been employed to modulate the MSG release, making the devices potentially suitable for topical administrations. Two different techniques have been used to obtain the films: the first one is compression molding, producing compact and continuous structures, and the second one is electrospinning, producing membrane-like designs. A higher amount of MSG can be loaded into the polymeric matrix in the membrane-like structures since, in these films, the impregnation process is faster than in the case of compression molded films, where the carbon dioxide has firstly diffused and then released the active molecule. The type of water-soluble polymer influences the drug release rate: the blend polycaprolactone-gelatin gives a prolonged release potentially suitable for topical administration.     

Isothiourea‐Catalysed Acylative Kinetic Resolution of Aryl–Alkenyl (sp2 vs. sp2) Substituted Secondary Alcohols

The non‐enzymatic acylative kinetic resolution of challenging aryl–alkenyl (sp² vs. sp²) substituted secondary alcohols is described, with effective enantiodiscrimination achieved using the isothiourea organocatalyst HyperBTM (1 mol %) and isobutyric anhydride. The kinetic resolution of a wide range of aryl–alkenyl substituted alcohols has been evaluated, with either electron‐rich or naphthyl aryl substituents in combination with an unsubstituted vinyl substituent providing the highest selectivity (S=2–1980). The use of this protocol for the gram‐scale (2.5 g) kinetic resolution of a model aryl–vinyl (sp² vs. sp²) substituted secondary alcohol is demonstrated, giving access to >1 g of each of the product enantiomers both in 99:1 e.r.     

Hyperpigmentation induced by topical 5-aminolaevulinic acid plus visible light

Photodynamic therapy (PDT) with 5-aminolaevulinic acid (ALA) is an alternative tool for the treatment of superficial non-melanoma skin cancers. Recently ALA-PDT has been employed with encouraging results also for warts, condylomata and psoriasis. In this study the effects of topical ALA plus irradiation with visible light on intact human skin have been evaluated. Five skin areas (A, B, C, D, and E) on the inner upper part of the arms of five healthy volunteers (skin types III and IV) were treated with (A) ALA 20% in base cream without irradiation, (B) only the vehicle (base cream) without ALA, (C, D and E) ALA cream at the concentrations of 5, 10 and 20%, respectively; all treatments were applied with an occlusive dressing. Four hours after ALA or vehicle application areas B, C, D and E were irradiated with a fixed dose of 40 J/cm(2). ALA penetration through the intact skin was evaluated by in vivo fluorescence determination. The effects on healthy skin were evaluated by clinical and chromometric examinations, light microscopy, immunohistochemistry and electron microscopy. RESULTS: (1) in vivo fluorescence demonstrated that ALA is able to penetrate through the intact skin, when applied with occlusive dressing and induces a classical fluorescence peak due to Protoporphyrin IX (PpIX) formation, which is the active photosensitiser. (2) Skin areas receiving ALA plus irradiation showed erythema and swelling just after the irradiative session and hyperpigmentation 48-72 h later. (3) Colourimetric data confirmed significant skin colour changes: values a* (representing the erythematous changes) increased only on the skin areas where ALA+irradiation were applied and during the 48 h after irradiation, thereafter a* began to decrease; values L* (pigmentation) increased during the 2 weeks following treatment. (4) Histopathological, immunohistochemical (S100, HMB-45) and electron microscopic findings showed an absolute increment of the number of melanocytes, which appeared clearly activated. In conclusion the application of ALA cream followed by irradiation is able to induce a pigmentation response in healthy human skin, at least in skin types III and IV. This melanocytic activation could have a potential for the treatment of skin disorders characterised by hypopigmentation.     

Unexpected and expeditious entry into trifluoromethyl aziridines from substituted beta-dicarbonyl compounds

[Reaction: see text]. One-pot aziridinations were obtained starting from substituted 2,2,2-trifluoroethyl beta-dicarbonyl compounds with nosyloxycarbamates in the presence of an excess of CaO as base. The unexpected ring closure reaction takes place at room temperature, leading to the N-protected alpha-trifluoromethyl aziridines with good yields. The reaction pathway seems to be influenced by the choice of the base.