Synthesis,characterization and X-ray crystal structure of the trigonal-planar copper(I) complex [Cu(MIBI)3] (MIBI = 2-methoxyisobutylisocyanide)

The synthesis, spectroscopic and chromatographic characterization, and X-ray crystal structure of the complex tris(2-methoxyisobutylisocyano) copper(I) tetrafluoroborate, [Cu(MIBI)₃][BF₄], is reported. The Cu atom lies on threefold axis and is bonded to three 2-methoxyisobutylisocyano ligands in a perfect trigonal-planar coordination. The calculated and experimental powder-diffraction spectra of this complex are also reported.     

New Values of the Required Hydrophilic-Lipophilic Balance for Oil in Water Emulsions of Solid Fatty Acids and Alcohols Obtained from Solubility Parameter and Dielectric Constant Values

The goals of this articles are to find a correlation between the required HLB values and the solubility parameters of oils; find a more precise correlation between the required HLB values and the dielectric constant, than the one obtained by other authors; and to determine the required HLB values for o/w emulsions of solid fatty acids and alcohols from the values of the solubility parameters and dielectric constants, that could be more trustful than the ones obtained by the methodology proposed by Griffin. It was obtained lineal relation between required HLB and solubility parameter (r = 0.995). Also it was observed lineal relations between required HLB and dielectric constants or logarithm of the dielectric constant more precise than the one obtained by other authors.     

Mastering chiral substituted 2-oxopiperazines

Stereoselective routes for the preparation of chiral 2-oxopiperazines, important structures widely found in naturally occurring substances and pharmaceutically relevant compounds, are studied.     

Fitting of the voltage–Li+ insertion curve of LiFePO4

Fitting of the voltage vs. insertion curves of the LiFePO₄ electrode was based on theoretical expressions describing the Li⁺ diffusive process in a solid medium. The noninteracting gas model for the chemical potential of ions distributed in a solid matrix was taken into account, and the diffusion coefficient and the energy activation for the diffusion process were accordingly calculated. The polarization curves at various discharge stages were theoretically obtained, and a good agreement was found with the experimental data at all discharge rates. A mathematical relation describing the trend of the diffusion resistance vs. insertion degree was also developed.     

On a Generalization of Equilogical Spaces

We use the theory of triposes to prove that every (non-degenerate) locale H is the set of truth values of a complete and co-complete quasi-topos into which the category of topological spaces embeds and the topos of sheaves over H reflectively embeds.     

Valorization of Okara by Enzymatic Production of Anti-Fungal Compounds for Plant Protection

Okara is a soybean transformation agri-food by-product, the massive production of which currently poses severe disposal issues. However, its composition is rich in seed storage proteins, which, once extracted, can represent an interesting source of bioactive peptides. Antimicrobial and antifungal proteins and peptides have been described in plant seeds; thus, okara is a valuable source of compounds, exploitable for integrated pest management. The aim of this work is to describe a rapid and economic procedure to isolate proteins from okara, and to produce an enzymatic proteolyzed product, active against fungal plant pathogens. The procedure allowed the isolation and recovery of about 30% of okara total proteins. Several proteolytic enzymes were screened to identify the proper procedure to produce antifungal compounds. Antifungal activity of the protein digested for 24 h with pancreatin against Fusarium and R. solani mycelial growth and Pseudomonas spp was assessed. A dose-response inhibitory activity was established against fungi belonging to the Fusarium genus. The exploitation of okara to produce antifungal bioactive peptides has the potential to turn this by-product into a paradigmatic example of circular economy, since a field-derived food waste is transformed into a source of valuable compounds to be used in field crops protection.     

On the structure of Borel stable abelian subalgebras in infinitesimal symmetric spaces

Let ${\mathfrak{g}=\mathfrak{g}^{\bar 0}\oplus \mathfrak{g}^{\bar 1}}$ be a ${\mathbb{Z}_2}$ -graded Lie algebra. We study the posets of abelian subalgebras of ${\mathfrak{g}^{\bar 1}}$ which are stable w.r.t. a Borel subalgebra of ${\mathfrak{g}^{\bar 0}}$ . In particular, we find a natural parametrization of maximal elements and dimension formulas for them. We recover as special cases several results of Kostant, Panyushev, and Suter.     

Alcune proprietà di una classe di procedimenti iterativi approssimati connessi con trasformazioni più generali delle contrazioni,in uno spazio metrico

Summary In this paper, we study a class of iterative processes of the type y_n+1 =T_ny_n, which approximate the iterative processes x_n+1 =Tx_n, where T and T_n are more general operators than contractions in a metric space.

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Entrata in Redazione il 27 marzo 1969.

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Istituto Matematico ?U. Dini?, Università degli Studi di Firenze, Viale Morgagni 67/a Firenze. Lavoro eseguito in relazione al Contratto N^o 115.3050.0.5189 del Comitato per la Matematica del C.N.R. nel corso dell'anno accademico 1968–69.