PERÍODO DE INDUÇÃO DE BLENDAS DE BIODIESEL DE DIFERENTES FONTES GRAXAS

O presente trabalho teve como objetivo avaliar o efeito da estabilidade a oxidação do biodiesel de soja pela blendagem com outros biodieseis advindos de diferentes fontes graxas amplamente. Para condução do experimento realizou-se planejamento fatorial ao nível 2³ misturando-se biodieseis de soja em diferentes níveis com biodiesel de milho, pequi e gordura suína, todos estes obtidos via transesterificação homogênea alcalina, para avaliação da estabilidade oxidativa (período de indução). A partir dos resultados obtidos pode-se concluir que a blendagem de biodieseis de diferentes origens proporciona variações nas respostas de estabilidade à oxidação do combustível. Enquanto a adição de ésteres advindos de fonte vegetal garantiu melhora na estabilidade oxidativa, ésteres de gordura suína proporcionaram declínio nas respostas obtidas a partir de sua blendagem com o biodiesel de soja

Total synthesis, isolation, surfactant properties, and biological evaluation of ananatosides and related macrodilactone-containing rhamnolipids

Rhamnolipids are a specific class of microbial surfactants, which hold great biotechnological and therapeutic potential. However, their exploitation at the industrial level is hampered because they are mainly produced by the opportunistic pathogenPseudomonas aeruginosa. The non-human pathogenic bacteriumPantoea ananatisis an alternative producer of rhamnolipid-like metabolites containing glucose instead of rhamnose residues. Herein, we present the isolation, structural characterization, and total synthesis of ananatoside A, a 15-membered macrodilactone-containing glucolipid, and ananatoside B, its open-chain congener, from organic extracts ofP. ananatis. Ananatoside A was synthesized through three alternative pathways involving either an intramolecular glycosylation, a chemical macrolactonization or a direct enzymatic transformation from ananatoside B. A series of diasteroisomerically pure (1→2), (1→3), and (1→4)-macrolactonized rhamnolipids were also synthesized through intramolecular glycosylation and their anomeric configurations as well as ring conformations were solved using molecular modeling in tandem with NMR studies. We show that ananatoside B is a more potent surfactant than its macrolide counterpart. We present evidence that macrolactonization of rhamnolipids enhances their cytotoxic and hemolytic potential, pointing towards a mechanism involving the formation of pores into the lipidic cell membrane. Lastly, we demonstrate that ananatoside A and ananatoside B as well as synthetic macrolactonized rhamnolipids can be perceived by the plant immune system, and that this sensing is more pronounced for a macrolide featuring a rhamnose moiety in its native1C4conformation. Altogether our results suggest that macrolactonization of glycolipids can dramatically interfere with their surfactant properties and biological activity

Patologie non neoplastiche da esposizione lavorativa ad amianto

...L\u2019esposizione occupazionale ad amianto \ue8 stata rilevante in passato in molteplici attivit\ue0 lavorative. Oggi, in Italia, sono generalmente esposti solo alcuni lavoratori (ad es. addetti a decoibentazioni, rimozioni e smaltimenti di materiali contenenti amianto), ma l\u2019attenzione deve essere rivota anche agli ex esposti, in considerazione della latenza - anche di varie decadi - con cui si possono manifestare le patologie da amianto, sia neoplastiche che non. I principali quadri clinici non neoplastici derivati dall\u2019esposizione occupazionale ad amianto sono l\u2019asbestosi (pneumoconiosi caratterizzata da alveolite e fibrosi interstiziale diffusa), l\u2019atelettasia rotonda ed alcune pleuropatie (placche, ispessimenti, versamenti pleurici benigni); viene considerata correlata all\u2019amianto anche l\u2019assai rara fibrosi retroperitoneale. Il procedimento diagnostico richiede un\u2019approfondita anamnesi lavorativa ed extra lavorativa, l\u2019esame clinico del paziente e l\u2019effettuazione di indagini essenzialmente strumentali (prove di funzionalit\ue0 respiratoria complete ed imaging radiologico con Rx torace ed eventualmente HRCT), talora integrati da esami di laboratorio (ad es. ricerca corpuscoli dell\u2019asbesto in varie matrici biologiche) e sempre con attenzione alla diagnosi differenziale rispetto ad altre fibrosi polmonari e pleuropatie. Quasi tutte le patologie non neoplastiche da amianto sono incluse per legge nella Tabella delle Malattie Professionali e per alcune di esse sussiste l\u2019obbligo di denuncia alle Autorit\ue0 competenti, da parte di qualsiasi medico che ne formuli la diagnosi o la sospetti. La loro prevenzione \ue8 basata su specifici provvedimenti legislativi, nonch\ue9 sui principi cardine della Medicina del Lavoro e si avvale di vari interventi di prevenzione primaria, secondaria e terziaria.Occupational exposure to asbestos was relevant in the past in many work settings. Nowadays, in Italy, only a few workers are generally exposed (e.g., those involved in removal and disposal of asbestos containing materials); however, ex-exposed workers should also be considered, taking into account the long latency period (various decades) before appearance of all asbestos diseases. The main non-malignant occupational asbestos diseases are: asbestosis (a pneumoconiosis characterized by alveolitis and diffuse interstitial fibrosis); round atelectasis; pleural abnormalities such as plaques, thickenings, effusions; the very rare retroperitoneal fibrosis can also be asbestos-related. The diagnostic procedures requires a thorough occupational and extra-occupational history collection, physical examination of the patient, complete lung function tests, imaging (chest X-ray sometimes supplemented by HRCT), sometimes with laboratory test (e.g., asbestos body count in biological samples); differential diagnosis should be considered versus other interstitial lung disorders and other pleural changes. Almost every non-malignant asbestos disease is included by law in the List of occupational diseases; it is also mandatory for every physician performing diagnosis, to report almost every diseases to the health and compensation authorities. Prevention of non-malignant asbestos diseases is based upon specific legislation as well as upon the cardinal principles of Occupational Health; the interventions pertain to primary, secondary and tertiary prevention