Gestione energeticamente efficiente di bruciatori a gas metano

Il funzionamento efficiente dal punto di vista energetico di un impianto di processo termico riscaldato ametano dipende in larga misura dalla qualità e dalla costruzione dei bruciatori utilizzati. In base ad esempipratici viene dimostrato in che modo possa essere individuato un aumento inutile del consumo, verificatosi acausa di una errata regolazione del bruciatore o di pressioni oscillanti dei servo mezzi di alimentazione.Tali fenomeni possono essere evitati in maniera efficace e permanente, adottando delle contromisure, in parteanche semplici. Inoltre viene illustrata la diretta dipendenza dell’efficienza energetica dalla dimensione dellasuperficie del tubo radiante

Staphylococcal PknB as the First Prokaryotic Representative of the Proline-Directed Kinases

In eukaryotic cell types, virtually all cellular processes are under control of proline-directed kinases and especially MAP kinases. Serine/threonine kinases in general were originally considered as a eukaryote-specific enzyme family. However, recent studies have revealed that orthologues of eukaryotic serine/threonine kinases exist in bacteria. Moreover, various pathogenic species, such as Yersinia and Mycobacterium, require serine/threonine kinases for successful invasion of human host cells. The substrates targeted by bacterial serine/threonine kinases have remained largely unknown. Here we report that the serine/threonine kinase PknB from the important pathogen Staphylococcus aureus is released into the external milieu, which opens up the possibility that PknB does not only phosphorylate bacterial proteins but also proteins of the human host. To identify possible human targets of purified PknB, we studied in vitro phosphorylation of peptide microarrays and detected 68 possible human targets for phosphorylation. These results show that PknB is a proline-directed kinase with MAP kinase-like enzymatic activity. As the potential cellular targets for PknB are involved in apoptosis, immune responses, transport, and metabolism, PknB secretion may help the bacterium to evade intracellular killing and facilitate its growth. In apparent agreement with this notion, phosphorylation of the host-cell response coordinating transcription factor ATF-2 by PknB was confirmed by mass spectrometry. Taken together, our results identify PknB as the first prokaryotic representative of the proline-directed kinase/MAP kinase family of enzymes