Background: Subjects living close to high traffic roads (HTR) are more likely to suffer from air-pollution related morbidity and mortality. The issue has large public health consequences but few studies have described the main socio-demographic characteristics of people exposed to traffic.
Objectives: To characterise a large cohort of residents in Rome according to different measures of traffic exposure, socioeconomic position (SEP), and baseline health status.
Chem Commun (Camb)
September 2010
A facile strategy towards conformationally stable chiral ladder-type oligo-perylene bisimides is established via copper-mediated Ullmann coupling. Absolute configurations are determined with the help of quantum-chemical calculations.
View Article and Find Full Text PDFThe intramolecular and intermolecular charge transport parameters are evaluated quantum chemically for three fluorinated derivatives of perylene bisimide (PBI) semiconductors, two of which feature a twisted PBI core. Charge transfer rates are computed within the Marcus-Levich-Jortner formalism including a single effective mode treated quantum mechanically and are injected in a kinetic Monte Carlo scheme to propagate the charge carrier in the crystal and to estimate charge mobilities at room temperature. The relative order of computed mobilities agrees with the observed trend, and the largest mobility is computed for the planar PBI derivative.
View Article and Find Full Text PDFWe present a computational study encompassing quantum-chemical calculations of the ground and low-lying excited states of 9H-adenine and modeling of vibronic activities associated with the S(0) --> L(b) and S(0) --> n pi* transitions. Minima on the ground and excited states and the saddle point on the n pi* potential energy surface are determined with CASSCF calculations. Vibrational frequencies are computed at the same level of theory on ground and excited states while transition dipole moments and oscillator strengths are estimated, at the optimized geometries, with CASPT2//CASSCF calculations.
View Article and Find Full Text PDFIn this paper, we present the synthesis of S- and N-heterocyclic annelated di(perylene bisimide) with extraordinary doubly bowl-shaped structures. The structures of fused PBI bowls confirmed by single-crystal X-ray structure analysis and temperature-dependent (1)H NMR are realized by the introduction of the steric congestion in nonbay regions and by the concurrent formation of the five-membered heterorings strain in bay regions. On the basis of the geometry obtained from the X-ray analysis, the maximum POAV1 pyramidalization angle is found in N-heterocyclic annelated diPBI 7, as large as 4.
View Article and Find Full Text PDFThe fluorescence spectra of triphenylene (TP) and 2,3,6,7,10,11-hexamethoxy-triphenylene (HMTP) are measured in glass matrices, and the vibronic structure associated with the electronic spectra is simulated with the help of quantum chemically computed molecular parameters. Franck-Condon (FC) and Herzberg-Teller (HT) mechanisms are included. For excited-state calculations, both configuration interaction with single excitations (CIS) and time-dependent density functional theory (TDDFT) are employed.
View Article and Find Full Text PDFThe electrical bistability behavior of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) along with two additional benzoquinone derivatives (TCQ and TCN) and pentacene (PNT) is investigated by computing intra- and intermolecular charge transfer parameters and by comparing the efficiency of bulk charge transport and charge injection at the electrode/organic interface in the presence of neutral and charged molecular species. The bulk charge transport is modeled assuming a charge hopping regime and by computing hopping rates and mobilities. Molecular dynamics simulations are carried out to estimate the effect of thermal disorder on charge transfer integrals.
View Article and Find Full Text PDFThe need to collect data representative of overall urban pollution is all-important in order to monitor the population exposure. High spatial resolution monitoring using diffusive samplers allows studying of the urban pollutant distribution, thus enabling deeper investigation of their generation and diffusion mechanisms. Nevertheless, such a monitoring campaign has a certain cost.
View Article and Find Full Text PDFPolycyclic aromatic hydrocarbons (PAHs) are employed to model the Raman features that are generally associated with sp(2) nanostructures in carbon materials or with disorder and defects in graphitic materials. To this end molecular parameters (geometry changes upon electronic excitation, vibrational normal modes, and displacement parameters) are computed with semiempirical quantum-chemical methods for a series of PAHs ranging from 6 to 384 carbon atoms, and Raman intensities are evaluated according to Albrecht's formalism restricted to the A term. The computed preresonance and resonance Raman intensities are compared with available experimental data for hexa-peri-hexabenzocoronene and for pyrene.
View Article and Find Full Text PDFThe aim of this study was to evaluate how physiological processes of potted Pinus halepensis plants, grown under controlled conditions, were affected by ozone (O3) and/or water stress, integrating the gas exchange and biochemical data with fluorescence OJIP polyphasic transient data. Plants submitted to only water stress (T1) and with ozone (T3) showed a strong decrease in stomatal conductance and gas exchange, coinciding with a reduction of maximum yield of photochemistry (varphipo) and very negative values of leaf water potential. Simultaneously, a great increase of both PSII antenna size, indicated by absorption per reaction centre, and electron transport per reaction centre were found.
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