ΣΥΝΘΕΣΗ/ΧΑΡΑΚΤΗΡΙΣΜΟΣ ΚΑΙ ΜΕΛΕΤΗ ΘΕΡΜΙΚΩΝ ΙΔΙΟΤΗΤΩΝ ΠΕΡΙΠΛΟΚΩΝ ΑΡΧΙΤΕΚΤΟΝΙΚΩΝ ΔΟΜΩΝ ΤΥΠΟΥ ΒΟΥΡΤΣΑΣ ΜΕ ΒΑΣΗ ΤΟ ΠΟΛΥΜΕΡΕΣ ΠΟΛΥ-δ-ΒΑΛΕΡΟΛΑΚΤΟΝΗ ΜΕ ΠΟΛΥΜΕΡΙΣΜΟ ROP ΚΑΙ ROMP

Στην παρούσα ερευνητική εργασία, παρασκευάστηκαν μακρομονομερή κυρίως πολυ(δ-βαλερολακτόνης), καθώς επίσης και μακρομονομερή πολυ(Ν-βινυλοπυρρολιδόνης) και πολυ(2-βινυλοπυριδίνης) με ακραία ομάδα νορβορνενίου. Παρασκευάστηκε επίσης διπλό μακρομονομερές πολυ(δ-βαλερολακτόνης) που αντιστοιχεί σε 2 αλυσίδες πολυ(δ-βαλερολακτόνης) ανα μόριο νορβορνενίου. Στη συνέχεια έγινε προσπάθεια πολυμερισμού των συγκεκριμένων μακρομονομερών μέσω πολυμερισμού διάνοιξης με μετάθεση δακτυλίου (ROMP). Ο καταλύτης σε όλες τις περιπτώσεις ήταν καταλύτης Grubbs 3 γενιάς και συντέθηκαν πολυμακρομονομερή ή αλλιώς μακρομοριακές βούρτσες με βασικό κορμό το νορβορνένιο και πλευρικές αλυσίδες τα μακρομονομερή. Έγιναν ακόμη προσπάθειες σύνθεσης κατά συστάδων συμπολυμερικών βουρτσών πολυ(δ-βαλερολακτόνης)-b-πολυ(Ν-βινυλοπυρρολιδόνης). Τα μακρομονομερή και τα πολυμακρομονομερή χαρακτηρίστηκαν μοριακά μέσω Χρωματογραφίας Αποκλεισμού Μεγεθών (GPC) και Φασματοσκοπίας Πυρηνικού Μαγνητικού Συντονισμού (NMR). Τελικά, μελετήθηκαν οι θερμικές ιδιότητες των μακρομονομερών και των πολυμακρομονομερών μέσω Θερμοσταθμικής Ανάλυσης (TGA) και Διαφορικής Θερμιδομετρίας Σάρωσης (DSC).In the present research work, mainly poly(δ-valerolactone) macromonomers, as well as poly(N-vinylpyrrolidone) and poly(2-vinylpyridine) macromonomers with a norbornene end group were prepared. A double poly(δ-valerolactone) macromonomer corresponding to poly(δ-valerolactone) two chains per norbornene molecule was also prepared. Subsequent, Ring Opening Metathesis Polymerization (ROMP), was used to polymerize macromonomers. The catalyst in all cases was a 3rd generation Grubbs catalyst and polymacromonomers or macromolecular brushes were synthesized with norbornene as the main backbone and macromonomers as side chains. Attempts have also been made to synthesize poly(δ-valerolactone)-b-poly(N-vinylpyrrolidone) copolymer brushes. Macromonomers and polymacromonomers were molecularly characterized by Size Exclusion Chromatography (GPC) and Nuclear Magnetic Resonance (NMR) Spectroscopy. Finally, the thermal properties of the macromonomers and polymacromonomers were studied by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC)

Non-Typical Clinical Presentation of COVID-19 Patients in Association with Disease Severity and Length of Hospital Stay

Background: This study aimed to investigate the incidence of non-typical symptoms in ambulatory patients with mild-to-moderate COVID-19 infection and their potential association with disease progression. Materials and methods: Data on the symptomatology of COVID-19 patients presenting to the fast-track emergency department were collected between March 2020 and March 2021. Fever, cough, shortness of breath, and fatigue-weakness were defined as “typical” symptoms, whereas all other symptoms such as nasal congestion, rhinorrhea, gastrointestinal symptoms, etc., were defined as “non-typical”. Results: A total of 570 COVID-19 patients with a mean age of 42.25 years were included, the majority of whom were male (61.3%; N = 349), and were divided according to their symptoms into two groups. The mean length of hospital stay was found to be 9.5 days. A higher proportion of patients without non-typical symptoms were admitted to the hospital (p = 0.001) and the ICU (p = 0.048) as well. No significant differences were observed between non-typical symptoms and outcome (p = 0.685). Patients who did not demonstrate at least one non-typical symptom had an extended length of stay (p = 0.041). No statistically significant differences in length of hospital stay were associated with individual symptoms. Conclusion: With the possible exception of gastrointestinal symptoms, non-typical symptoms of COVID-19 at baseline appear to predispose to a milder disease