SARS-CoV-2 infection in health workers: analysis from Verona SIEROEPID Study during the pre-vaccination era

Background: To report the baseline phase of the SIEROEPID study on SARS-CoV-2 infection seroprevalence among health workers at the University Hospital of Verona, Italy, between spring and fall 2020; to compare performances of several laboratory tests for SARS-CoV-2 antibody detection. Methods: 5299 voluntary health workers were enrolled from 28 April 2020 to 28 July 2020 to assess immunological response to SARS-CoV-2 infection throughout IgM, IgG and IgA serum levels titration by four laboratory tests. Association of antibody titre with several demographic variables, swab tests and performance tests (sensitivity, specificity, and agreement) were statistically analyzed. Results: The overall seroprevalence was 6%, considering either IgG and IgM, and 4.8% considering IgG. Working in COVID-19 Units was not associated with a statistically significant increase in the number of infected workers. Cohen's kappa of agreement between MaglumiTM and VivaDiagTM was quite good when considering IgG only (Cohen's kappa = 78.1%, 95% CI 74.0-82.0%), but was lower considering IgM (Cohen's kappa = 13.3%, 95% CI 7.8-18.7%). Conclusion: The large sample size with high participation (84.7%), the biobank and the longitudinal design were significant achievements, offering a baseline dataset as the benchmark for risk assessment, health surveillance and management of SARS-CoV-2 infection for the hospital workforce, especially considering the ongoing vaccination campaign. Study results support the national regulator guidelines on using swabs for SARS-CoV-2 screening with health workers and using the serological tests to contribute to the epidemiological assessment of the spread of the virus

Aggregati di complessi anfifilici di Cu(2): effetto sulla complessazione del metallo e sul potenziale redox

Dottorato di ricerca in scienze chimiche. 8. ciclo. Supervisore P. ScriminConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

A hydrolytic reporter of copper(II) availability in artificial liposomes

The dioctadecyl ammonium surfactant 1, functionalized with a p-nitrophenyl ester of picolinic acid, has been synthesized and its hydrolysis in covesicular blends of nonfunctional surfactants dihexadecyldimethylammonium bromide, 3, dioctadecyldimethylammonium bromide, 4, and racemic 1,2-bis(palmitoyloxy)-3-(trimethylammonium)propyl bromide, 5, studied after addition of Cu(II) ions at pH = 5.0 and different temperatures. The cleavage of 1 gives the p-nitrophenoxide surfactant 2, which shows a strong absorption band at 400 nm. Clear biphasic kinetics were observed for all vesicular systems at a temperature below the gel-to-liquid crystal phase transition temperature (T(c)) of the membrane: the first, faster process (almost-equal-to 60% of the ester cleaved) was associated with the Cu(II)-catalyzed hydrolysis of the exovesicular ester; the slower one (the remaining almost-equal-to 40% of the ester cleaved) was associated with the uncatalyzed hydrolysis of the endovesicular ester. Above T(c) only a monoexponential process was observed. Variable temperature experiments allowed one to conclude that the cationic vesicles studied are totally impermeable to Cu(II) ions either below or above their T(c) which controls the rate of the transbilayer movements of the lipids

Comparative Reactivities of Phosphate Ester Cleavages by Metallomicelles

The hydrolytic efficiency of the hydrophilic Cu(II) complex of tetramethylethylenediamine (TMED C-1 . Cu(II)) and the amphiphilic N-n-hexadecyl-N,N',N'-trimethylethylenediamine complex (TMED C-16. Cu(II)) in comicelles with CTANO(3) was studied toward a series of phosphate triesters and diesters that were either neutral (1-7) or cationic and amphiphilic (8-10). While the pseudo-first-order rate constants at [catalyst] = 1 x 10(-3) M are larger (ca. one order of magnitude) for the micellar catalyst, the second-order rate constants are higher for the hydrophilic catalyst. With phosphate triesters, regardless of the structure of the substrate, TMED C1(.) Cu(II)-bound OH- is a better nucleophile than free OH-, while TMED C-16. Cu(II)-bound OH- is poorer. This is explained by electrophilic assistance of the metal center which greatly diminishes in micelles. With phosphate diesters the OH- bound to both TMED C-1 . Cu(II) and TMED C-16. Cu(II) is a better nucleophile than free OH-. Partial neutralization of the negative charge of the substrate may explain this behavior. In all cases the amphiphilic substrates are intrinsically more reactive than the neutral ones. Comparison with an iodosobenzoate-based catalyst shows that this is ineffective with phosphate diesters while it is a better reagent than the metallomicellar one with phosphate triesters. Its higher effectiveness, however, seems to vanish as the substrate becomes less reactive

Self-assembled monolayers of Cu(II) metallosurfactants on GC and HOPG

none4noneG. Ghirlanda;P. Scrimin;A. E. Kaifer;L. A. EchegoyenG., Ghirlanda; Scrimin, PAOLO MARIA; A. E., Kaifer; L. A., Echegoye