Proteomic examination of polyester-polyurethane degradation by Streptomyces sp. PU10: Diverting polyurethane intermediates to secondary metabolite production

Global plastic waste accumulation has become omnipresent in public discourse and the focus of scientific research. Ranking as the sixth most produced polymer globally, polyurethanes (PU) significantly contribute to plastic waste and environmental pollution due to the toxicity of their building blocks, such as diisocyanates. In this study, the effects of PU on soil microbial communities over 18 months were monitored revealing that it had marginal effects on microbial diversity. However, Streptomyces sp. PU10, isolated from this PU-contaminated soil, proved exceptional in the degradation of a soluble polyester-PU (Impranil) across a range of temperatures with over 96% degradation of 10 g/L in 48 h. Proteins involved in PU degradation and metabolic changes occurring in this strain with Impranil as the sole carbon source were further investigated employing quantitative proteomics. The proposed degradation mechanism implicated the action of three enzymes: a polyester-degrading esterase, a urethane bond-degrading amidase and an oxidoreductase. Furthermore, proteome data revealed that PU degradation intermediates were incorporated into Streptomyces sp. PU10 metabolism via the fatty acid degradation pathway and subsequently channelled to polyketide biosynthesis. Most notably, the production of the tri-pyrrole undecylprodigiosin was confirmed paving the way for establishing PU upcycling strategies to bioactive metabolites using Streptomyces strains

Set of Small Molecule Polyurethane (PU) Model Substrates: Ecotoxicity Evaluation and Identification of PU Degrading Biocatalysts

Polyurethanes (PUs) are an exceedingly heterogeneous group of plastic polymers, widely used in a variety of industries from construction to medical implants. In the past decades, we have witnessed the accumulation of PU waste and its detrimental environmental impacts. PUs have been identified as one of the most toxic polymers leaching hazardous compounds derived both from the polymer itself and the additives used in production. Further environmental impact assessment, identification and characterization of substances derived from PU materials and establishing efficient degradation strategies are crucial. Thus, a selection of eight synthetic model compounds which represent partial PU hydrolysis products were synthesized and characterized both in terms of toxicity and suitability to be used as substrates for the identification of novel biocatalysts for PU biodegradation. Overall, the compounds exhibited low in vitro cytotoxicity against a healthy human fibroblast cell line and virtually no toxic effect on the nematode Caenorhabditis elegans up to 500 µg mL−1, and two of the substrates showed moderate aquatic ecotoxicity with EC50 values 53 µg mL−1 and 45 µg mL−1, respectively, on Aliivibrio fischeri. The compounds were successfully applied to study the mechanism of ester and urethane bond cleaving preference of known plastic-degrading enzymes and were used to single out a novel PU-degrading biocatalyst, Amycolatopsis mediterranei ISP5501, among 220 microbial strains. A. mediterranei ISP5501 can also degrade commercially available polyether and polyester PU materials, reducing the average molecular number of the polymer up to 13.5%. This study uncovered a biocatalyst capable of degrading different types of PUs and identified potential enzymes responsible as a key step in developing biotechnological process for PU waste treatment options

Sensorimotor Difficulties Are Associated with the Severity of Autism Spectrum Conditions

Present diagnostic criteria for autism spectrum conditions (ASC) include social communication and interaction difficulties, repetitive behaviour and movement, and atypical sensory responsivity. Few studies have explored the influence of motor coordination and sensory responsivity on severity of ASC symptoms. In the current study, we explore whether sensory responsivity and motor coordination differences can account for the severity of autistic behaviours in children with ASC. 36 children took part: 18 (13 male, 5 female) with ASC (ages 7-16: mean age 9.93 years) and 18 (7 male, 11 female) typically developing (TD) children (ages 6-12; mean age 9.16 years). Both groups completed a battery of assessments that included motor coordination, sensory responsivity, receptive language, non-verbal reasoning and social communication measures Children with ASC also completed the Autism Diagnostic Observation Schedule and Autism Diagnostic Interview – Revised.. Results showed that children with ASC scored significantly lower on receptive language, coordination and sensory responsivity and a sensorimotor subscale, Modulation of Activity (MoA) compared to the TD group. In the ASC group, MoA significantly predicted ASC severity across all ASC measures; receptive language and sensory responsivity significantly predicted parental reported autism measures; and coordination significantly predicted examiner observed reported scores. Additionally, specific associations were found between the somatosensory perceptive modalities and ASC severity. The results show that sensorimotor skills are associated with severity of ASC symptoms; furthering the need to research sensorimotor integration in ASC and also implying that diagnosis of ASC should also include the assessment of both coordination deficit and atypical sensory responsivity

The Role of Sensorimotor Difficulties in Autism Spectrum Conditions

AbstractIn addition to difficulties in social communication, current diagnostic criteria for autism spectrum conditions (ASC) also incorporate sensorimotor difficulties; repetitive motor movements and atypical reactivity to sensory input (APA, 2013). This paper explores whether sensorimotor difficulties are associated with the development and maintenance of symptoms in ASC. Firstly, studies have shown difficulties coordinating sensory input into planning and executing movement effectively in ASC. Secondly, studies have shown associations between sensory reactivity and motor coordination with core ASC symptoms, suggesting these areas each strongly influence the development of social and communication skills. Thirdly, studies have begun to demonstrate that sensorimotor difficulties in ASC could account for reduced social attention early in development, with a cascading effect on later social, communicative and emotional development. These results suggest that sensorimotor difficulties not only contribute to non-social difficulties such as narrow circumscribed interests, but also to the development of social behaviours such as effectively coordinating eye contact with speech and gesture, interpreting others’ behaviour and responding appropriately. Further research is needed to explore the link between sensory and motor difficulties in ASC, and their contribution to the development and maintenance of ASC

Evidence of less severe aortic valve destruction after treatment of experimental staphylococcal endocarditis with vancomycin and dexamethasone

The beneficial effects of therapy combining an antibiotic and dexamethasone have been reported in human studies of meningitis and in experimental studies on septic arthritis, nephritis, and endopthalmitis. Since most patients with staphylococcal endocarditis need a combination of medical and surgical treatment, the purpose of this study was to determine whether the addition of dexamethasone to vancomycin has any beneficial effect regarding the degree of valve tissue damage or the course of experimental aortic valve endocarditis caused by a methicillin-resistant strain of Staphylococcus aureus. Rabbits with catheter-induced aortic valve vegetations were randomly assigned to a control group and to groups receiving dexamethasone (0.5 mg/kg of body weight, intravenously [i.v], twice a day [b.i.d]), vancomycin (30 mg/kg, i.v., b.i.d), or dexamethasone plus vancomycin, for a total of 10 doses (two doses per day for 5 days). The severity of valve tissue damage was significantly less in group receiving vancomycin plus dexamethasone compared with that of the group receiving vancomycin alone (P < 0.001). The severity of tissue damage was inversely correlated with the mean polymorphonuclear leukocyte number in valve tissue. No statistically significant differences were observed between the vancomycin-treated group and the vancomycin- plus-dexamethasone-treated group in survival, blood culture sterilization rate, or reduction of the microbial burden (in CFU per gram) in valvular tissue. In conclusion, treatment with a combination of vancomycin and dexamethasone for 5 days reduces the severity of valve tissue damage in experimental staphylococcal aortic valve endocarditis. These findings could have significant implications in the treatment of staphylococcal endocarditis and deserve further confirmation in clinical trials.Η συγχορήγηση δεξαμεθαζόνης και αντιβιοτικών έχει αποδειχθεί ευεργετική σε κλινικές μελέτες ασθενών με μηνιγγίτιδα και σε πειραματικές μελέτες που αφορούν λοιμώξεις όπως η σηπτική αρθρίτιδα, νεφρίτιδα και ενδοφθαλμίτιδα. Με δεδομένο ότι η θεραπεία της σταφυλοκοκκικής ενδοκαρδίτιδας λόγω της μεγάλης ιστικής καταστροφής, απαιτεί στις περισσότερες περιπτώσεις συνδυασμένη χειρουργική και φαρμακευτική αντιμετώπιση, σκοπός της παρούσης μελέτης ήταν να ελεγχθεί εάν η σύγχρονη χορήγηση δεξαμεθαζόνης και βανκομυκίνης μειώνει την ιστική βλάβη. Για τον σκοπό αυτό χρησιμοποιήθηκε μοντέλο πειραματικής ενδοκαρδίτιδας της αορτικής βαλβίδας σε κονίκλους. Για την πρόκληση της χρησιμοποιήθηκε ανθεκτικό στη μεθικιλλίνη στέλεχος Staphylococcus aureus (MRSA). Τα πειραματόζωα χωρίσθηκαν σε 4 ομάδες: ομάδα μαρτύρων, ομάδα δεξαμεθαζόνης (0.5 mg/kg σωματικού βάρους κάθε 12 ώρες ενδοφλεβίως), ομάδα βανκομυκίνης (30 mg/kg σωματικού βάρους κάθε 12 ώρες ενδοφλεβίως), ομάδα βανκομυκίνης (30 mg/kg σωματικού βάρους κάθε 12 ώρες ενδοφλεβίως) και δεξαμεθαζόνης (0.5 mg/kg σωματικού βάρους κάθε 12 ώρες ενδοφλεβίως). Τα πειραματόζωα των ομάδων θεραπείας έλαβαν 10 δόσεις των φαρμάκων. Η βαρύτητα της καταστροφής του βαλβιδικού ιστού ήταν σημαντικά μεγαλύτερη στην ομάδα που έλαβε μόνο βανκομυκίνη, σε σχέση με την ομάδα που έλαβε βανκομυκίνη και δεξαμεθαζόνη. Η βαρύτητα των βλαβών ήταν αντίστροφος ανάλογη του μέσου αριθμού των πολυμορφοπύρηνων στον ιστό. Όσον αφορά την επιβίωση, την αποστείρωση των αιμοκαλλιεργειών και το ποσό των μικροοργανισμών στον βαλβιδικό ιστό, δεν παρατηρήθηκαν στατιστικά σημαντικές διαφορές μεταξύ της ομάδος που έλαβε βανκομυκίνη και της ομάδος που έλαβε βανκομυκίνη και δεξαμεθαζόνη. Συμπερασματικά, ο συνδυασμός βανκομυκίνης και δεξαμεθαζόνης για 5 ημέρες, μειώνει σημαντικά την ιστική βλάβη της αορτικής βαλβίδας σε πειραματικό μοντέλο MRSA ενδοκαρδίτιδας. Η κλινική σημασία αυτού του ευρήματος πρέπει να επιβεβαιωθεί με κλινικές μελέτες

Ψηφιακό αποθετήριο «Πέργαμος» EΚΠΑ. Κατάλογος Δ.Δ. και Δ.Ε. που αφορούν το αντικείμενο του Π.Μ.Σ. «Στρατηγικές Διαχείρισης Κρίσεων και Καταστροφών»

Η εκπόνηση της εργασίας στηρίζεται στην ενιαία πλατφόρμα ιδρυματικού αποθετηρίου ψηφιακής βιβλιοθήκης του Εθνικού Καποδιστριακού Πανεπιστημίου Αθηνών (ΕΚΠΑ),που ονομάζεται «ΠΕΡΓΑΜΟΣ» και θέτει ως στόχο και φιλοδοξία τον εντοπισμό, και την καταγραφή ψηφιακού υλικού για τη δημιουργία ενός βιβλιογραφικού καταλόγου (βιβλιογραφική παρουσίαση) των Διδακτορικών και Μεταπτυχιακών Διατριβών που είναι κατατεθειμένες στο ψηφιακό αποθετήριο και διαπραγματεύονται το αντικείμενο του ΠΜΣ «Στρατηγικές Διαχείρισης Περιβάλλοντος, Κρίσεων και Καταστροφών» και θα μπορούσε να φανεί χρήσιμο, και αξιόπιστο επιστημονικό εργαλείο σε ερευνητές, στο ευρύ κοινό και κυρίως σε φοιτητές τόσο κατά τη διάρκεια των σπουδών τους, όσο και κατά την εκπόνηση των εργασιών τους. Επιμέρους επίσης στόχοι της Μεταπτυχιακής Διατριβής είναι να αναδείξει και να παρουσιάσει τους στόχους και το σκοπό ίδρυσης του ΠΜΣ «Στρατηγικές Διαχείρισης Περιβάλλοντος, Κρίσεων και Καταστροφών» από το τμήμα Γεωλογίας και Γεωπεριβάλλοντος του ΕΚΠΑ. Να γίνει αναφορά στη λειτουργία των ψηφιακών ιδρυματικών αποθετηρίων, δίνοντας πληροφορίες για τους στόχους, τα πλεονεκτήματα τους, και το ρόλο που καλούνται να διαδραματίσουν στη σύγχρονη ψηφιακή πραγματικότητα, αλλάζοντας τον τρόπο διεξαγωγής της ερευνάς και της επιστημονικής επικοινωνίας. Να γίνει αναφορά για την προστασία των ψηφιακών αποθετηρίων από φυσικές, τεχνολογικές και ανθρωπογενείς καταστροφές Να γίνει αναλυτική περιγραφή για τη λειτουργία, τις δράσεις και τους στόχους του Ψηφιακού ακαδημαϊκού αποθετηρίου «ΠΕΡΓΑΜΟΣ» του ΕΚΠΑ Να γίνει αναφορά στην μεθοδολογία εκπόνησης της εργασίας και στον τρόπο που έγινε η επιλογή του υλικού για τη δημιουργία του βιβλιογραφικού καταλόγου. Και τέλος, να καταγράψουμε και να παραθέσουμε τα αποτελέσματα και τα συμπεράσματα που προέκυψαν από την επιμελή και επιστημονική μελέτη των στατιστικών στοιχείων της έρευνας, καθώς και προτάσεις τόσο για το αποθετήριο «ΠΕΡΓΑΜΟΣ» όσο και για το ΠΜΣ βελτιώνοντας ακόμα περισσότερο την υψηλού και επιστημονικού επιπέδου εκπαίδευση που προσφέρει σε όσους ενδιαφέρονται για ειδικές σπουδές στο αντικείμενο της διαχείρισης ανθρωπογενών, τεχνολογικών, και φυσικών καταστροφών, για τη στελέχωση των κρατικών δομών κα οργανισμών με ειδικά καταρτισμένο επιστημονικό προσωπικό.This Master Thesis is based on the unique platform of a digital library institute of the National University of Athens, called «PERGAMOS», which aims to identify and record digital material for the creation of a bibliographic catalog (bibliographic presentation) of Doctoral and Postgraduate Theses deposited in the digital repository. and negotiate the subject of the Strategic &quot;Strategies for Management of the Environment, Crisis and Disasters&quot;, and could be a useful and reliable scientific tool for researchers, the general public and especially students during their studies and in the preparation of the their thesis. The aim of the Master Thesis is also to highlight and present the objectives and the goal of establishing the Strategic Management of Environment, Crisis and Disaster Strategies (PMS) by the Department of Geology and Geoenvironment of the University of Athens. Refer to the operation of digital institutional repositories, providing information about their goals, their advantages, and the role they are requested to play in modern digital reality, by changing the way of researching and scientific communication. Report on the protection of digital repositories against natural, technological and human -made disasters Τhe functioning, actions and objectives of the Academic Digital Depot «Pergamos» of the University of Athens should be analyzed repository. Reference should be made to the methodology for the preparation of the work and the way that, the material was selected for the creation of the bibliographic catalog. Finally, to record and list the results and conclusions that emerged from the diligent and scientific study of the survey statistics, as well as suggestions for both the «PERGAMOS» repository and the Postgraduate study program to further improve the high and scientific level education offered to those interested in specialized studies in the field of management of human-made, technological, and natural disasters, for the staffing of state structures and organizations with special training scientific staff

Παρασκευή, χαρακτηρισμός και μελέτη της ιοντικής αγωγιμότητας υποκατεστημένων περοβσκιτών της γενικής μορφής LaxA(1-x)FeO3 A=Ba,Sr x=0..1

100 σ.Έγινε παρασκευή των περοβσκιτών με την μέθοδο των άμορφων κιτρικών συμπλόκων, κρυσταλλογραφικός έλεγχος τους για τον καθορισμό της μονοφασικότητας τους, μέτρηση του συντελεστή θερμικής διαστολής, έλεγχος με ηλεκτρονική μικροσκοπία, μέτρηση της ιοντικής τους αγωγιμότητας και τέλος αναγωγή των αποτελεσμάτων σε διαπερατότητα οξυγόνου.The perovskites were synthesized by the amorphous citrate route, there were analyzed by XRD in order to determine if they were single phased. Thermal expansion coefficient analysis took plase, among with SEM. Ionic conductivity of the perovskites was measured and finally those measurements were translated to oxygen permeation.Βασίλειος Δ. Σιαπέρα

Evaluation of Zn- and Fe- rich organic coatings for corrosion protection and condensation performance on waste heat recovery surfaces

The corrosion protection performance of commercial organic coatings over Stainless Steel (304 L) was investigated in highly acidic media. Three coatings were applied by air spraying and subsequently evaluated for their performance against chemical corrosion by concentrated H2SO4, HNO3, and HCl in terms of % mass loss. Open current potential (OCP) and potentiodynamic polarization (PD) measurements were performed. The water condensation properties of the coatings were monitored for their evaluation as potential protective coatings in condensing economizer applications. ZN691 coating exhibited better protection than ANORZINC and TROPIS versus time in contact with 40% of H2SO4, HNO3 and 37% HCl. Electrochemical results confirmed the superior performance of ZN691 over ANORZINC and TROPIS with corrosion rates at 0.017, 0.098 and 0.097 mpy respectively. Condensation experiments for ZN691 showed a water collection rate of 1.487 ml m−2 h−1 at 40 °C and 100% RH. According to the results, the Zn rich epoxy-based coatings are promising for corrosion protection of condensing economizer elements. © 2020 The Author