Electronic excited states of benzene in interaction with water clusters : influence of structure and size

This work is dedicated to the theoretical investigation of the influence of water clusters' organisation and size on the electronic spectrum of an interacting benzene (Bz) molecule using both TD-DFT and CASPT2 approaches. Two series of geometries, namely $Geo_{IEI}$ and $Geo_{IED}$ were extracted from two Bz-hexagonal ice configurations leading to maximum and minimum ionization energies respectively. An appropriate basis set containing atomic diffuse and polarisation orbitals and describing the Rydberg states of Bz was determined. The TD-DFT approach was carefully benchmarked against CASPT2 results for the smallest systems.Despite some discrepancies, the trends were found to be similar at both levels of theory: the positions and intensities of the main $\pi \rightarrow \pi^{\star}$ transitions were found slightly split due to symmetry breaking. For the smallest systems, our results clearly show the dependence of the electronic transitions on the clusters' structures. Of particular interest, low energy transitions of non negligible oscillator strength from a Bz $\pi$ orbital to a virtual orbital of Rydberg character, also involving atomic diffuse functions and partially expanded on the water cluster, were found for the $Geo_{IED}$ series. The energies of such transitions were determined to be more than 2\,eV below the ionization potential of Bz. When the cluster's size increases, similar transitions were found for all structures, the virtual orbitals becoming mainly developed on the H atoms of the water molecules at the edge of the cluster. Given their nature and energy, such transitions could play a role in the photochemistry of aromatic species in interaction with water clusters or ice, such processes being of astrophysical interest.Comment: 37 pages, 15 figures, 7 table

Multi-scale multireference configuration interaction calculations for large systems using localized orbitals: Partition in zones

A new multireference configuration interaction method using localised orbitals is proposed, in which a molecular system is divided into regions of unequal importance. The advantage of dealing with local orbitals, i.e., the possibility to neglect long range interaction is enhanced. Indeed, while in the zone of the molecule where the important phenomena occur, the interaction cut off may be as small as necessary to get relevant results, in the most part of the system it can be taken rather large, so that results of good quality may be obtained at a lower cost. The method is tested on several systems. In one of them, the definition of the various regions is not based on topological considerations, but on the nature, σ or π, of the localised orbitals, which puts in evidence the generality of the approac

Prevalence of chronic obstructive respiratory diseases amongst fishermen

Background: The objective was to screen and evaluate the prevalence of respiratory diseases and obstructive  ventilatory defects among fishermen in Morocco.  Materials and methods: This observational and cross-sectional epidemiological study involved 924 men  over 20 years old and with at least two years of seniority. It included a questionnaire and a spirometry.  The questionnaire is composed of four sections: sociodemographic and occupational characteristics, toxic  habits, medical history and respiratory clinical symptoms.  Results: The prevalence of symptoms of tracheobronchial irritation was 9.2% for cough, 8.2% for sputum  7.8% for dyspnoea and chest wheezing 8.1%. The frequency of rhinitis was 17.1%, asthma 6.8%, chronic  bronchitis 5.6% and chronic obstructive pulmonary disease (COPD) 4.1% (5.4% for current and former  smokers versus 1.1% for non-smokers). The prevalence was reaching 6.8% among those who smoked  more than 10 pack-years and 17.9% among those who smoked more than 20 pack-years. Among subjects  over 40 years old who had smoked more than 10 pack-years, the prevalence of COPD was 8.1%. The  comorbidities were frequent.  Conclusions: Smoking was very common among fishermen. Symptoms and respiratory diseases remain  underdiagnosed and undertreated. Prevention and early detection must be a priority in this sector.

Cohort Profile: Burden of Obstructive Lung Disease (BOLD) study

The Burden of Obstructive Lung Disease (BOLD) study was established to assess the prevalence of chronic airflow obstruction, a key characteristic of chronic obstructive pulmonary disease, and its risk factors in adults (≥40 years) from general populations across the world. The baseline study was conducted between 2003 and 2016, in 41 sites across Africa, Asia, Europe, North America, the Caribbean and Oceania, and collected high-quality pre- and post-bronchodilator spirometry from 28 828 participants. The follow-up study was conducted between 2019 and 2021, in 18 sites across Africa, Asia, Europe and the Caribbean. At baseline, there were in these sites 12 502 participants with high-quality spirometry. A total of 6452 were followed up, with 5936 completing the study core questionnaire. Of these, 4044 also provided high-quality pre- and post-bronchodilator spirometry. On both occasions, the core questionnaire covered information on respiratory symptoms, doctor diagnoses, health care use, medication use and ealth status, as well as potential risk factors. Information on occupation, environmental exposures and diet was also collected

Size-consistent self-consistent configuration interaction from a complete active space

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