Photodegradation of atrazine and ametryn with visible light using water soluble porphyrins as sensitizers

Abstract The photodegradation of the herbicides atrazine and ametryn with visible light in aerated neutral aqueous solutions and 5, 10, 15, 20-tetrakis (2,6-dichloro-3-sulfophenyl) porphyrin or 5, 10, 15, 20-tetrakis (4-sulfophenyl) porphyrin as sensitizers are reported for the first time. Our findings show that the degradation percentage reached 30% for atrazine and 63% for ametryn. The final photoproducts were characterized as dealkylated s-triazines. Photolysis of the pesticides in the presence of a singlet oxygen quencher showed only a minor contribution of this type of mechanism, while a bimolecular quenching reaction between the triplet state of the sensitizer and the pesticides is excluded by flash photolysis studies. It is proposed that the mechanism may involve the formation of a superoxide radical anion from the triplet state of the sensitizer and molecular oxygen, followed by a radical decomposition pathway

Plantes envahissantes pour les milieux naturels de Nouvelle-Calédonie

Menaces pour la biodiversité, contraintes pour les agriculteurs et les activités humaines, les plantes envahissantes constituent un problème de plus en plus évoqué à travers le monde. Partant de ce constat, l'APICAN (Agence pour la Prévention et l'Indemnisation des Calamités Agricoles ou Naturelles) et ses partenaires ont soutenu l'élaboration de ce guide dans le but de faire connaitre, du plus grand nombre, les problématiques liées aux plantes envahissantes, les moyens de les identifier et les techniques à mettre en oeuvre pour les contrôler. Il s'adresse aux services techniques des communes et des réserves naturelles terrestres, aux exploitants agricoles, aux professionnels des espaces verts mais aussi aux citoyens sensibilisés à la protection de l'environnement. Ce guide décrit 81 espèces végétales envahissantes principales des milieux naturels de Nouvelle-Calédonie (Grande Terre et îles Loyauté). Le texte donne la description, la biologie, la répartition et les moyens de contrôler chaque espèce. Des photographies accompagnent chaque fiche pour faciliter l'identification des plantes

Nosocomial influenza in south-western Swiss hospitals during two seasonal epidemics: an observational study.

In Switzerland each year, influenza leads to between 112,000 and 275,000 medical consultations. Data on nosocomial influenza infection are limited. To describe nosocomial cases of seasonal influenza in south-western Switzerland. This study was conducted during two seasonal influenza epidemics from 2016 to 2018 in 27 acute care public hospitals in south-western Switzerland. During these two time-periods, every patient hospitalized for >72 h who was positively screened by reverse transcription-polymerase chain reaction or antigen detection for influenza was included in the survey. Characteristics of patients included age, sex, and comorbidities. Included patients were followed up until discharge or death. Complications and administration of antineuraminidases and/or antibiotics were registered. The median influenza vaccine coverage of healthcare workers was 40%. In all, 836 patients were included (98% with type A influenza virus in 2016-2017; 77% with type B virus in 2017-2018). Most patients (81%) had an unknown vaccine status. Overall, the incidence of nosocomial influenza was 0.5 per 100 admissions (0.35 per 1000 patient-days). The most frequent comorbidities were diabetes (20%), chronic respiratory diseases (19%), and malnutrition (17%). Fever (77%) and cough (66%) were the most frequent symptoms. Seventy-one percent of patients received antineuraminidases, 28% received antibiotics. Infectious complications such as pneumonia were reported in 9%. Overall, the all-cause mortality was 6%. The occurrence of nosocomial influenza underlines the importance of vaccinating patients and healthcare workers, rapidly recognizing community- or hospital-acquired cases, and applying adequate additional measures to prevent dissemination, including the timely administration of antineuraminidases to avoid antibiotic use (and misuse)