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BACKGROUND: INTEVAL_Spain was a complex workplace intervention to prevent and manage musculoskeletal pain among nursing staff. Process evaluations can be especially useful for complex and multifaceted interventions through identifying the success or failure factors of an intervention to improve the intervention implementation. OBJECTIVES: This study performed a process evaluation of INTEVAL_Spain and aimed to examine whether the intervention was conducted according to the protocol, to investigate the fulfilment of expectations and the satisfaction of workers. METHODS: The intervention was a two-armed cluster randomized controlled trial and lasted 1 year. The process evaluation included quantitative and qualitative methods. Quantitative methods were used to address the indicators of Steckler and Linnan's framework. Data on recruitment was collected through a baseline questionnaire for the intervention and the control group. Reach and dose received were collected through participation sheets, dose delivered and fidelity through internal registries, and fulfilment of expectations and satisfaction were collected with two questions at 12-months follow-up. Qualitative methods were used for a content analysis of discussion groups at the end of the intervention led by an external moderator to explore satisfaction and recommendations. The general communication and activities were discussed, and final recommendations were agreed on. Data were synthesized and results were reported thematically. RESULTS: The study was performed in two Spanish hospitals during 2016-2017 and 257 workers participated. Recruitment was 62 and 51% for the intervention and the control group, respectively. The reach of the activities ranged from 96% for participatory ergonomics to 5% for healthy diet. The number of sessions offered ranged from 60 sessions for Nordic walking to one session for healthy diet. Fidelity of workers ranged from 100% for healthy diet and 79% for participatory ergonomics, to 42 and 39% for Nordic walking and case management, respectively. Lowest fidelity of providers was 75% for case management and 82% for Nordic walking. Fulfilment of expectations and satisfaction ranged from 6.6/10 and 7.6/10, respectively, for case management to 10/10 together for the healthy diet session. Discussion groups revealed several limitations for most of the activities, mainly focused on a lack of communication between the Champion (coordinator) and the workers. CONCLUSIONS: This process evaluation showed that the implementation of INTEVAL_Spain was predominantly carried out as intended. Process indicators differed depending on the activity. Several recommendations to improve the intervention implementation process are proposed. TRIAL REGISTRATION: ISRCTN15780649 .

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The present paper focuses on the characterization of the properties of methanol and water molecules in gas and liquid environments. A force field for methanol-methanol and methanol-water interactions, useful to be applied in Molecular Dynamics (MD) simulations, is proposed. The electrostatic interaction contributions, arising from permanent charge and/or from anisotropic charge distributions originating from permanent electric multipoles (Vel), different in gas and in liquid phases, are combined with the non electrostatic ones (Vnel), defined by means of Improved Lennard-Jones (ILJ) functions [F. Pirani et al., Phys. Chem. Chem. Phys., 2008, 10, 5489-5503]. Interestingly, the relevant parameters of the ILJ functions are not fitted to reproduce the selected properties of the systems but calculated from the molecular polarizability, which is considered the key property to define size (or Pauli) repulsion and dispersion and induction attractions. The constructed force field predicts binding energies and geometries of the methanol-methanol and methanol-water dimers, in good agreement with available data. On the other hand, several bulk and structural properties of liquid methanol, such as densities, vaporization enthalpies, diffusion coefficients, coefficients of cubic thermal expansion, heat capacities at constant pressure and some relevant radial distribution functions, calculated considering 2744 molecules and different conditions of pressure and temperature, have also been found to be in good agreement with experimental data. The study has been completed by calculating the density values at 298 K and 1 bar of some methanol-water mixtures, which have also been found to be in good agreement with experimental data.

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Herein, the synthesis of a new family of squaraines (SQs) and their application in p-type dye-sensitized solar cells (DSSCs) is presented. In particular, two sets of SQs were designed featuring either two or four anchoring carboxylic groups combined with either oxygen or dicyanovinyl central groups. The SQs were characterized by using a joint theoretical, photophysical, and electrochemical approach. Importantly, the presence of different central groups forces a frozen cis (dicyanovinyl group) or a trans (oxygen group) SQ conformation. Based on the latter, the current work enables a direct comparison between cis and trans isomers as well as the impact of a different number of anchors. Considering their electron-accepting and light-harvesting character, they were tested in NiO-based DSSCs. Photocurrent-voltage, incident photon-to-current conversion efficiency (IPCE), and electrochemical impedance spectroscopy measurements were performed. By virtue of their different symmetry, stereochemistry, and number of carboxylic groups, altered adsorption behavior onto NiO electrodes as well as diverse charge injection and charge recombination dynamics were noted under operation conditions. SQs with four linkers in a frozen cis isomerism show the best charge collection properties among the investigated SQs, providing a valuable guideline for the molecular design of future SQs for p-type DSSCs. In addition, we assembled tandem DSSCs featuring SQ/NiO photocathodes and N719/TiO2 photoanodes. The IPCE of the resulting tandem DSSCs implies light harvesting throughout most of the visible part of the solar spectrum owing to the complementary absorption features of SQ and N719.

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The effects of alkoxy chain length in triarylamine based donor-acceptor organic dyes are investigated with respect to the electronic and molecular surface structures on the performance of solar cells and the electron lifetime. The dyes were investigated when adsorbed on TiO2 in a configuration that can be used for dye-sensitized solar cells (DSCs). Specifically, the two dyes D35 and D45 were compared using photoelectron spectroscopy (PES) and density functional theory (DFT) calculations. The differences in solar cell characteristics when longer alkoxy chains are introduced in the dye donor unit are attributed to geometrical changes in dye packing while only minor differences were observed in the electronic structure. A higher dye load was observed for D45 on TiO2. However, D35 based solar cells result in higher photocurrent although the dye load is lower. This is explained by different geometrical structures of the dyes on the surface.

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The photophysical and photochemical properties of alizarin, a fluorescent organic red dye of the family of the anthraquinones, have been theoretically investigated by focusing our attention on its emission properties in relation to an excited-state internal proton transfers from the phenolic hydroxyl group to the carbonyl oxygen. The potential energy curve of the proton transfer in the first excited state has been computed in solvents of different polarity and the emission spectra of both tautomers simulated, including the vibronic effects, using the Franck-Condon approximation. Calculations performed by equilibrating the solvent with the excited-state geometry and electron density using a self-consistent procedure have led to interesting differences with respect to their linear response counterpart. The results obtained point out that, while the emission energy of alizarin is sensitive to solvent polarity, that of the proton-transfer tautomer is computed at similar wavelengths independently of the solvent. Comparison between computed and experimental data has allowed us to rationalize the alizarin double emission measured in non-polar solvents.

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Organohalide lead perovskites have revolutionized the scenario of emerging photovoltaic technologies. The prototype MAPbI3 perovskite (MA = CH3NH3(+)) has dominated the field, despite only harvesting photons above 750 nm (∼1.6 eV). Intensive research efforts are being devoted to find new perovskites with red-shifted absorption onset, along with good charge transport properties. Recently, a new perovskite based on the formamidinium cation ((NH2)2CH(+) = FA) has shown potentially superior properties in terms of band gap and charge transport compared to MAPbI3. The results have been interpreted in terms of the cation size, with the larger FA cation expectedly delivering reduced band-gaps in Pb-based perovskites. To provide a full understanding of the interplay among size, structure, and organic/inorganic interactions in determining the properties of APbI3 perovskites, in view of designing new materials and fully exploiting them for solar cells applications, we report a fully first-principles investigation on APbI3 perovskites with A = Cs(+), MA, and FA. Our results evidence that the tetragonal-to-quasi cubic structural evolution observed when moving from MA to FA is due to the interplay of size effects and enhanced hydrogen bonding between the FA cations and the inorganic matrix altering the covalent/ionic character of Pb-I bonds. Most notably, the observed cation-induced structural variability promotes markedly different electronic and optical properties in the MAPbI3 and FAPbI3 perovskites, mediated by the different spin-orbit coupling, leading to improved charge transport and red-shifted absorption in FAPbI3 and in general in pseudocubic structures. Our theoretical model constitutes the basis for the rationale design of new and more efficient organohalide perovskites for solar cells applications.

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A facile and fast approach, based on microwave-enhanced Sonogashira coupling, has been employed to obtain in good yields both mono- and, for the first time, disubstituted push-pull Zn(II) porphyrinates bearing a variety of ethynylphenyl moieties at the ß-pyrrolic position(s). Furthermore, a comparative experimental, electrochemical, and theoretical investigation has been carried out on these ß-mono- or disubstituted Zn(II) porphyrinates and meso-disubstituted push-pull Zn(II) porphyrinates. We have obtained evidence that, although the HOMO-LUMO energy gap of the meso-substituted push-pull dyes is lower, so that charge transfer along the push-pull system therein is easier, the ß-mono- or disubstituted push-pull porphyrinic dyes show comparable or better efficiencies when acting as sensitizers in DSSCs. This behavior is apparently not attributable to more intense B and Q bands, but rather to more facile charge injection. This is suggested by the DFT electron distribution in a model of a ß-monosubstituted porphyrinic dye interacting with a TiO2 surface and by the positive effect of the ß substitution on the incident photon-to-current conversion efficiency (IPCE) spectra, which show a significant intensity over a broad wavelength range (350-650 nm). In contrast, meso-substitution produces IPCE spectra with two less intense and well-separated peaks. The positive effect exerted by a cyanoacrylic acid group attached to the ethynylphenyl substituent has been analyzed by a photophysical and theoretical approach. This provided supporting evidence of a contribution from charge-transfer transitions to both the B and Q bands, thus producing, through conjugation, excited electrons close to the carboxylic anchoring group. Finally, the straightforward and effective synthetic procedures developed, as well as the efficiencies observed by photoelectrochemical measurements, make the described ß-monosubstituted Zn(II) porphyrinates extremely promising sensitizers for use in DSSCs.

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We report a first principles density functional theory/time-dependent density functional theory (DFT/TDDFT) computational investigation on a prototypical perylene dye anchored to realistic ZnO nanostructures, approaching the size of the ZnO nanowires used in dye-sensitized solar cells devices. DFT calculations were performed on (ZnO)(n) clusters of increasing size, with n up to 222, of 1.3 × 1.5 × 3.4 nm dimensions, and for the related dye-sensitized models. We show that quantum confinement in the ZnO nanostructures substantially affects the dye/semiconductor alignment of energy levels, with smaller ZnO models providing unfavourable electron injection. An increasing broadening of the dye LUMO is found moving to larger substrates, substantially contributing to the interfacial electronic coupling. TDDFT excited state calculations for the investigated dye@(ZnO)(222) system are fully consistent with experimental data, quantitatively reproducing the red-shift and broadening of the visible absorption spectrum observed for the ZnO-anchored dye compared to the dye in solution. TDDFT calculations on the fully interacting system also introduce a contribution to the dye/semiconductor admixture, due to configurational excited state mixing. Our results highlight the importance of quantum confinement in dye-sensitized ZnO interfaces, and provide the fundamental insight lying at the heart of the associated DSC devices.

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Chemistry is central to addressing topics of interest in the cultural heritage field, offering particular insight into the nature and composition of the original materials, the degradation processes that have occurred over the years, and the attendant physical and chemical changes. On the one hand, the chemical characterization of the constituting materials allows researchers to unravel the rich information enclosed in a work of art, providing insight into the manufacturing techniques and revealing aspects of artistic, chronological, historical, and sociocultural significance. On the other hand, despite the recognized contribution of computational chemistry in many branches of materials science, this tool has only recently been applied to cultural heritage, largely because of the inherent complexity of art materials. In this Account, we present a brief overview of the available computational methods, classified on the basis of accuracy level and dimension of the system to be simulated. Among the discussed methodologies, density functional theory (DFT) and time-dependent DFT represent a good compromise between accuracy and computational cost, allowing researchers to model the structural, electronic, and spectroscopic properties of complex extended systems in condensed phase. We then discuss the results of recent research devoted to the computer simulation of prototypical systems in cultural heritage, namely, indigo and Maya Blue, weld and weld lake, and the pigment minium (red lead). These studies provide insight into the basic interactions underlying the materials properties and, in some cases, permit the assignment of the material composition. We discuss properties of interest in the cultural heritage field, ranging from structural geometries and acid-base properties to IR-Raman vibrational spectra and UV-vis absorption-emission spectra (including excited-state deactivation pathways). We particularly highlight how computational chemistry applications in cultural heritage can complement experimental investigations by establishing or rationalizing structure-property relations of the fundamental artwork components. These insights allow researchers to understand the interdependence of such components and eventually the composition of the artwork materials. As a perspective, we aim to extend the simulations to systems of increasing complexity that are similar to the realistic materials encountered in works of art. A challenge is the computational investigation of materials degradation and their associated reactive pathways; here the possible initial components, intermediates, final materials, and various deterioration mechanisms must all be simulated.

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A DFT-TDDFT investigation on the aluminium complexation of apigenin and luteolin has been carried out. We have focused our attention on these hydroxyflavonoids, which are the main components of weld, one of the earliest natural dyestuff used in art. In particular, weld, upon complexation with Al(iii) forms a highly prized lake which has been widely used in medieval manuscripts and easel paintings for its rich yellow colour and transparency. The experimental spectra of apigenin and luteolin upon addition of increasing [Al(3+)] show a general red-shift of the lowest absorption bands of both flavonoids spectra, associated with the presence of two and three isosbestic points for apigenin and luteolin, respectively. The molecular geometries of all the Al-apigenin and -luteolin complexes have been optimized, followed by calculation of the formation Gibbs free energies and UV-vis absorption spectra. The comparison between the computed absorption spectra of the Al-flavonoid complexes and the experimental ones corresponding to various limit [Al(3+)] concentrations has been used to discriminate between the possible complexation modes as well as the stoichiometry ratio. We have thus been able to associate specific Al-apigenin (-luteolin) complexes with the experimental absorption spectra as a function of the [Al(3+)] concentration, thus providing insights into the aluminium complexation of these hydroxyflavonoids and most importantly into the weld lake composition.

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The absorption and emission properties of the two components of the yellow color extracted from weld (Reseda luteola L.), apigenin and luteolin, have been extensively investigated by means of DFT and TDDFT calculations. Our calculations reproduce the absorption spectra of both flavonoids in good agreement with the experimental data and allow us to assign the transitions giving rise to the main spectral features. For apigenin, we have also computed the electronic spectrum of the monodeprotonated species, providing a rationale for the red-shift of the experimental spectrum with increasing pH. The fluorescence emission of both apigenin and luteolin has then been investigated. Excited-state TDDFT geometry optimizations have highlighted an excited-state intramolecular proton transfer (ESIPT) from the 5-hydroxyl to the 4-carbonyl oxygen of the substituted benzopyrone moiety. By computing the potential energy curves at the ground and excited states as a function of an approximate proton transfer coordinate for apigenin, we have been able to trace an ESIPT pathway and thus explain the double emission observed experimentally.

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