Papers by Francesca Mocci
Occupational and Environmental Medicine, 2003
Aims: To investigate the presence of liver lesions and their relation with vinyl chloride monomer... more Aims: To investigate the presence of liver lesions and their relation with vinyl chloride monomer (VCM) exposure or other personal risk factors, in workers involved in the production of VCM and polyvinyl chloride (PVC). Methods: A liver ultrasonography examination was conducted in 757 workers, some of whom had long standing service in the production of VCM and PVC. The study involved: assessment of individual past and present VCM exposure of each worker; collection of past personal health history, lifestyle and personal data; routine liver function tests; and liver ultrasonography. Results: No cases of liver malignancies were detected. Angiomas and liver cysts were found with a frequency of occurrence within the expected range of the general population. The main findings consisted of hepatomegaly (34.7%), steatosis (31.8%), and periportal fibrosis (16.0%). A logistic regression analysis indicated that hepatomegaly and steatosis were associated with obesity and lipid metabolism disturbances and not with VCM exposure. Periportal fibrosis, in addition to constitutional or dietary factors, was shown to be associated with VCM exposure, but only when maximum exposure in the subject's history had been at least 200 ppm as a yearly average; no effects were observed at 50 ppm or below. Conclusions: Workers exposed to 200 ppm VCM for at least one year have a fourfold increased risk of developing periportal liver fibrosis. Liver ultrasonography is a suitable and important diagnostic test for the medical surveillance of vinyl chloride workers.
John Wiley & Sons, Ltd eBooks, Oct 14, 2006
This chapter deals mainly with 17 O NMR spectroscopy of organic derivatives containing oxygen bou... more This chapter deals mainly with 17 O NMR spectroscopy of organic derivatives containing oxygen bound to oxygen. Occasional references are given for multinuclear NMR and theoretical calculations, when necessary for the completeness of the subject. They relate mainly to ...
Journal of Physical Chemistry Letters, Jul 17, 2017
The binary mixtures of the ionic liquid ethylammonium nitrate with acetonitrile have been studied... more The binary mixtures of the ionic liquid ethylammonium nitrate with acetonitrile have been studied by means of Wide and Small Angle X-ray Scattering and via two different computational methods, namely classical molecular dynamics and DFT. Our results show how the local arrangement is directly linked to the long-range structure. Moreover, we found once again a similarity in the physicochemical behaviour of ethylammonium nitrate and water. TOC GRAPHICS Dissolving a co-solvent into an Ionic Liquid (IL) may have a variety of effects depending on the nature of the salt and on the added compound 1-3. Taking Ethylammonium Nitrate (EAN) as a prototype, there is a wide range of literature concerning the effects that mixing has on its structure 4-19. The molecular arrangement of neat EAN is shared with a number of other ILs and consists of a nano-segregation of two domains (polar and apolar) percolating each other 8,20,21. This is the so-called sponge-like structure that is responsible for the Low q Peak (LqP) in the Small Angle X-ray Scattering (SAXS) patterns of these compounds 22,23. Recently it has been reported that the addition of n-alcohols to some ILs leads to an unexpected feature in the extreme low q region of the SAXS pattern, which from now on will be termed "Low q Excess" (LqE) 24,25. Greaves et al. observed that in some EAN-alcohol mixtures, some micellar-like structures could be found 26. A confirmation of this behaviour came from Jiang et al. stating that when the alcohol
C, Oct 2, 2019
The emission properties of carbon dots (CDs) have already found many potential applications, from... more The emission properties of carbon dots (CDs) have already found many potential applications, from bio-imaging and cell labelling, to optical imaging and drug delivery, and are largely investigated in technological fields, such as lighting and photonics. Besides their high efficiency emission, CDs are also virtually nontoxic and can be prepared through many green chemistry routes. Despite these important features, the very origin of their luminescence is still debated. In this paper, we present an overview of sounding data and the main models proposed to explain the emission properties of CDs and their tunability.
Biopolymers, Apr 1, 2003
Molecular dynamics simulations have been employed to probe the sequence-specific binding of sodiu... more Molecular dynamics simulations have been employed to probe the sequence-specific binding of sodium ions to the minor groove of B-DNA of three A. T-rich oligomers having identical compositions but different orders of the base pairs: C(AT)(4)G, CA(4)T(4)G, and CT(4)A(4)G. Recent experimental investigations, either in crystals or in solution, have shown that monovalent cations bind to DNA in a sequence-specific mode, preferentially in the narrow minor groove regions of uninterrupted sequences of four or more adenines (A-tracts), replacing a water molecule of the ordered hydration structure, the hydration spine. Following this evidence, it has been hypothesized that in A-tracts these events may be responsible for structural peculiarities such as a narrow minor groove and a curvature of the helix axis. The present simulations confirm a sequence specificity of the binding of sodium ions: Na(+) intrusions in the first layer of hydration of the minor groove, with long residence times, up to approximately 3 ns, are observed only in the minor groove of A-tracts but not in the alternating sequence. The effects of these intrusions on the structure of DNA depend on the ion coordination: when the ion replaces a water molecule of the spine, the minor groove becomes narrower. Ion intrusions may also disrupt the hydration spine modifying the oligomer structure to a large extent. However, in no case intrusions were observed to locally bend the axis toward the minor groove. The simulations also show that ions may reside for long time periods in the second layer of hydration, particularly in the wider regions of the groove, often leading to an opening of the groove.
Journal of Physical Chemistry C, Feb 19, 2021
The molecular emission model is the most accredited one to explain the emission properties of car... more The molecular emission model is the most accredited one to explain the emission properties of carbon dots (CDs) in a lowtemperature bottom-up synthesis approach. In the case of citric acid and urea, the formation of a citrazinic acid (CZA) single monomer and oligomers is expected to affect the optical properties of the CDs. It is therefore mandatory to elucidate the possible role of weak bonding interactions in determining the UV absorption spectrum of some molecular aggregates of CZA. Although this carboxylic acid is largely exploited in the synthesis of luminescent CDs, a full understanding of its role in determining the final emission spectra of the produced CDs is still very far to be achieved. To this aim, by relying on purely firstprinciples density functional theory calculations combined with experimental optical characterization, we built and checked the stability of some molecular aggregates, which could possibly arise from the formation of oligomers of CZA, mainly dimers, trimers, and some selected tetramers. The computed vibrational fingerprint of the formation of aggregates is confirmed by surface-enhanced Raman spectroscopy. The comparison of experimental data with calculated UV absorption spectra showed a clear impact of the final morphology of the aggregates on the position of the main peaks in the UV spectra, with particular regard to the 340 nm peak associated with n-π* transition.
Magnetic Resonance in Chemistry, Oct 1, 2009
The torsion angle effect on the isotropic shielding of (17)O nucleus in alpha,beta-unsaturated ca... more The torsion angle effect on the isotropic shielding of (17)O nucleus in alpha,beta-unsaturated carbonyl groups is studied by means of density functional theory (DFT) calculations using a polarizable continuum model (PCM) for the solvent, employing the PBE0 functional together with the 6-311G(d,p) basis set for geometry optimization, and the 6-311+G(2d,p) basis set for calculating the NMR shielding with the gauge-including atomic orbitals (GIAO) method.This study adds new information on the sensitivity of the (17)O nucleus to conformational changes, revealing a strong dependence of the (17)O NMR chemical shift on the dihedral angle between the carbonyl and the vinyl moiety in all studied compounds; remarkable differences are observed with the data reported for alpha-diketones.
Journal of Colloid and Interface Science, Mar 1, 2023
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Dec 15, 2022
Materials, Feb 6, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Abstract This chapter deals with the structural analysis of ionic liquid-containing mixtures thro... more Abstract This chapter deals with the structural analysis of ionic liquid-containing mixtures through multiscale computational methods. The chapter is divided into two sections, dealing with a basic introduction to the topic, and a more in-depth presentation of four different computational methods typically used to simulate the structural and dynamical properties of complex liquid systems. Initially, the concept of the structure of a liquid is discussed, providing definitions and some examples. Subsequently, the main features of the experimental technique based on X-ray scattering are presented, which allow accessing structural information of amorphous systems. A short introduction of the laws governing the scattering phenomenon, and how scattered photons can provide information about the structure of a system is also presented. A significant part of this chapter is devoted to introducing four of the most used state-of-the-art computational methods, namely density functional theory “static” optimization, semiempirical molecular dynamics, classical molecular dynamics, and coarse-grained molecular dynamics. The starting point is the quantastic treatment of the system, in which only minimal approximations are used. The reader is then guided toward successive approximations enabling to explore different system sizes and timescales. The intricate system ethylammonium nitrate:acetonitrile 1:9 binary mixture is taken as a case study to show what the four obtained models can return in terms of characterization. The final picture describes how the various methods are fundamentally complementary to each other, meaning that there is nothing as a “best” method.
BULETINUL INSTITUTULUI POLITEHNIC DIN IAȘI. Secția Matematica. Mecanică Teoretică. Fizică
Molecular dynamics (MD) simulations are intensively used to obtain information on the microscopic... more Molecular dynamics (MD) simulations are intensively used to obtain information on the microscopic behavior of a system and to evaluate certain properties which they determine at macroscopic level. But, as well as setting up an experiment in a “wet” laboratory, also setting up a simulation in a virtual enviroment implies many variables that influence the results. Two of the variables are the starting structure of the system and the water model in which it is solvated. The present work aims to identify an optimal combination of this two variables able to reveal best the transition from an extended to a collapsed conformation for poly(n-isopropylacrylamide) (PNIPAM) thermoresponsive polymer.
Molecules
The cobalt complex (I) with cyclopentadienyl and 2-aminothiophenolate ligands was investigated as... more The cobalt complex (I) with cyclopentadienyl and 2-aminothiophenolate ligands was investigated as a homogeneous catalyst for electrochemical CO2 reduction. By comparing its behavior with an analogous complex with the phenylenediamine (II), the effect of sulfur atom as a substituent has been evaluated. As a result, a positive shift of the reduction potential and the reversibility of the corresponding redox process have been observed, also suggesting a higher stability of the compound with sulfur. Under anhydrous conditions, complex I showed a higher current enhancement in the presence of CO2 (9.41) in comparison with II (4.12). Moreover, the presence of only one -NH group in I explained the difference in the observed increases on the catalytic activity toward CO2 due to the presence of water, with current enhancements of 22.73 and 24.40 for I and II, respectively. DFT calculations confirmed the effect of sulfur on the lowering of the energy of the frontier orbitals of I, highlighted ...
ChemInform, Jan 30, 2007
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Journal of Organic Chemistry, Oct 20, 2009
Magnetic Resonance in Chemistry, 2009
A number of diazenedicarboxylates have been studied by multinuclear magnetic resonance (17 O, 15 ... more A number of diazenedicarboxylates have been studied by multinuclear magnetic resonance (17 O, 15 N, 13 C) and compared with analogous fumaric, maleic, and phthalic diesters; the investigation of selected compounds of these classes was complemented by density functional theory (DFT) calculations using a polarizable continuum model (PCM) for the solvent, employing the PBE0 functional together with the 6-311G(d,p) basis set for geometry optimization, and the 6-311+G(2d,p) basis set for calculating the NMR shielding using the gauge-including atomic orbital (GIAO) method. This combined approach provided important information about the preferred conformations in chloroform and their influence on the NMR parameters.
ChemInform, May 24, 2010
ChemInform Abstract Konformationen der Ester (I) werden diskutiert und erklärt.
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Papers by Francesca Mocci