The Weak Metal-Water Bond in Diphenylborylated Organoaquacobaloximes and Rhodoximes Leads to the Formation of an Unusual Dinuclear Rh(III) Complex

The synthesis and characterization of a series of RM(DBPh2)2(H2O) complexes (M = Co and Rh) and the X-ray structure of the dinuclear [n-PrRh(DH)(DBPh2)]2 (1) obtained by recrystallization of n-PrRh(DBPh2)2(H2O) in non coordinating solvent are reported. The crystals of (1) are built up by neutral centrosymmetric dinuclear [n-PrRh(DH)(DBPh2)]2 units and CH2Cl2 crystallization molecules in the ratio 1:1. The Rh ion of one n-PrRh(DH)(DBPh2) unit achieves hexacoordination by coordination of one of the oxime O at-oms of the other unit. The formation of the dimer by recrystallization of n-PrRh(DBPh2)2(H2O) in non coordinating solvent may be ascribed to the concomitant effect of the weak metal-water bond in the monomeric aqua complex, the strong tendency of Rh to achieving hexacoordination in such organo derivatives, and the ease of losing a BPh2 bridge of the diphenylborylated organorhodoximes

The Weak Metal-Water Bond in Diphenylborylated Organoaquacobaloximes and Rhodoximes Leads to the Formation of an Unusual Dinuclear Rh(III) Complex

The synthesis and characterization of a series of RM(DBPh2)2(H2O) complexes (M = Co and Rh) and the X-ray structure of the dinuclear [n-PrRh(DH)(DBPh2)]2 (1) obtained by recrystallization of n-PrRh(DBPh2)2(H2O) in non coordinating solvent are reported. The crystals of (1) are built up by neutral centrosymmetric dinuclear [n-PrRh(DH)(DBPh2)]2 units and CH2Cl2 crystallization molecules in the ratio 1:1. The Rh ion of one n-PrRh(DH)(DBPh2) unit achieves hexacoordination by coordination of one of the oxime O at-oms of the other unit. The formation of the dimer by recrystallization of n-PrRh(DBPh2)2(H2O) in non coordinating solvent may be ascribed to the concomitant effect of the weak metal-water bond in the monomeric aqua complex, the strong tendency of Rh to achieving hexacoordination in such organo derivatives, and the ease of losing a BPh2 bridge of the diphenylborylated organorhodoximes

Evaluation of antioxidant supplementation in must on the development and potential reduction of different compounds involved in atypical ageing of wine using HPLC-HRMS

Atypical aging of white wines (ATA) is an off-flavour characterised by rapid loss of fruity aromas and the development of unpleasant odours. This study aims to evaluate the effectiveness of different oenological adjuvants (4-ethylcatechol, 4-methylcatechol, gentisic acid, hydroxytyrosol, ascorbic acid, glutathione, ellagic acid, gallic acid, galla tannin, ellagic tannin, quebracho, grape tannins) added to musts before fermentation for preventing the possible development of ATA. High resolution mass spectrometry made it possible to quantify and qualify free and conjugated IAA in wine at the end of the fermentation and subsequently 2-aminoacetophenone (AAP) was quantified after the force ageing period (6 days at 40 °C). Ascorbic acid was confirmed as the most appropriate antioxidant adjuvant which can be used for ATA defect prevention. With an almost comparable effect, gallotannin addition prevented AAP production to exceed 1 μg/L. A predicted model (ANCOVA) indicated that over 80% of the variability of potential AAP formation in wines was explained by the amount of precursors, grape variety and antioxidant treatment. Moreover, a suspect screening approach made it possible to study the kinetic formation and the consumption of the reaction metabolites formed during the oxidative degradation of IAA leading to AA

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

A first update on mapping the human genetic architecture of COVID-19

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Constitutive laws for metal friction

In this paper we present a method for modeling both the large plastic deformations and the frictional phenomena. The strategy is based on a discrete elements technology, i.e. a collection of rigid spheres with a suitable cohesive contact formulation is used to model the continuum. Sliding and wear between surfaces are also taken into account using a similar method. The strategy presents interesting characteristics both for forging and deep drawing processes. The formulation is based on extension of general concepts of contact as a unilateral constraint condition. For such purpose constitutive laws have been implemented in the node-to-segment contact formulation within the framework of the penalty method

Modelling of cutting tools-soil interactions - Part I: Contact behaviour

The unknown interaction of the cutting tools with geological settings represents an interesting problem for the excavation machinery industry. To simplify the non-linear aspects involved in the numerical analysis of such phenomena a strategy for an accurate soil modelling has to be defined. A possible approach is the discrete one, by considering the soil as an assembly of rigid spheres. In this work this strategy is adopted. The basic idea is to concentrate at the contact level between the spheres the real mechanical behaviour of the soil. For this purpose suitable contact models have been developed, where specific elasto-plastic laws have been implemented in the node-to-segment contact formulation. The framework for the plastic behaviour consists of a failure criterion, a one- dimensional, rate-independent elasto-plastic flow rule for the normal and the tangential force and a non-linear yield criterion. The final aim of this paper is to develop me- chanical models to study the behaviour of stiff soils and rocks under different loading conditions