Photoelectron circular dichroism of isopropanolamine

Spectroscopies based on circular polarized light are sensitive to the electronic and structural properties of chiral molecules. Photoelectron circular dichroism (PECD) is a powerful technique that combines the chiral sensitivity of the circular polarized light and the electronic information obtained by photoelectron spectroscopy. An experimental and theoretical PECD study of the outer valence and C 1s core states of 1-amino-2-propanol in the gas phase is presented. The experimental dichroic dispersions in the photoelectron kinetic energy are compared with theoretical calculations employing a multicentric basis set of B-spline functions and a Kohn-Sham Hamiltonian. In order to understand analogies and differences in the dichroism of structural isomers bearing the same functional groups, a comparison with previous PECD study of valence band of 2-amino-1-propanol is carried out

Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

The ubiquitin-like modifier FAT10 stimulates the activity of the deubiquitylating enzyme OTUB1

The deubiquitylation of target proteins is mediated by DUBs such as OTUB1 which plays an important role in the immune response, cell cycle progression and DNA repair. Within these processes OTUB1 reduces the ubiquitylation of target proteins in two distinct ways, either by using its catalytic DUB activity or in a non-catalytic manner by inhibiting the E2 conjugating enzyme. Here, we show that the ubiquitin-like modifier FAT10 is regulating the OTUB1 stability and functionality in different manners. Covalent FAT10ylation of OTUB1 results in its proteasomal degradation whereas a non-covalent interaction stabilizes OTUB1. We provide evidence that OTUB1 directly interacts with FAT10 and the E2 conjugating enzyme USE1. This interaction strongly stimulates the OTUB1 DUB activity towards K48-linked diubiquitin. Furthermore, the non-covalent interaction between FAT10 and OTUB1 not only enhances its isopeptidase activity towards K48-linked ubiquitin moieties but also strengthens its non-catalytic activity in reducing K63 polyubiquitylation of its target protein TRAF3. Additionally, the cellular clearance of overall polyubiquitylation by OTUB1 was strongly stimulated through the presence of FAT10. Addition of FAT10 also led to an increased interaction between OTUB1 and its cognate E2 UbcH5B implying a function of FAT10 in the inhibition of polyubiquitylation. Overall, these data indicate that FAT10 does not only play a role in covalent modification and leading its substrates to proteasomal degradation, but that it also regulates stability and functionality of target proteins by interacting in a non-covalent manner. Thereby FAT10 is able to exert a major influence on ubiquitylation processes.publishe

The Reaction of Sulfur Dioxide Radical Cation with Hydrogen and its Relevance in Solar Geoengineering Models

SO2 has been proposed in solar geoengineering as a precursor of H2SO4 aerosol, a cooling agent active in the stratosphere to contrast climate change. Atmospheric ionization sources can ionize SO2 into excited states of (Formula presented.), which quickly reacts with trace gases in the stratosphere. In this work we explore the reaction of (Formula presented.) with (Formula presented.) excited by tunable synchrotron radiation, leading to (Formula presented.) ((Formula presented.)), where H contributes to O3 depletion and OH formation. Density Functional Theory and Variational Transition State Theory have been used to investigate the dynamics of the title barrierless and exothermic reaction. The present results suggest that solar geoengineering models should test the reactivity of (Formula presented.) with major trace gases in the stratosphere, such as H2 since this is a relevant channel for the OH formation during the nighttime when there is not OH production by sunlight. OH oxides SO2, triggering the chemical reactions leading to H2SO4 aerosol

Transfer of chirality from adsorbed chiral molecules to the substrate highlighted by circular dichroism in angle-resolved valence photoelectron spectroscopy

Studies of self-assembled chiral molecules on achiral metallic surfaces have mostly focused on the determination of the geometry of adsorbates and their electronic structure. The aim of this paper is to provide direct information on the chirality character of the system and on the chirality transfer from molecules to substrate by means of circular dichroism in the angular distribution of valence photoelectrons for the extended domain of the chiral self-assembled molecular structure, formed by alaninol adsorbed on Cu(100). We show, by the dichroic behavior of a mixed molecule-copper valence state, that the presence of molecular chiral domains induces asymmetry in the interaction with the substrate and locally transfers the chiral character to the underlying metal atoms participating in the adsorption process; combined information related to the asymmetry of the initial electronic state, which is expected to be chiral, and the final electronic state, which locally probes the asymmetry of the potential, has been obtained. Identification of chirality in the adsorption footprint sheds new light on the transfer of chirality from a chiral modifier to a symmetric metal surface and represents an important aspect for controlling and tuning the functionality of the molecule-metal interfaces