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2. IRIS-A New Distributed Research Infrastructure on Applied Superconductivity

Author

Rossi, L, Arpaia, P, Attanasio, C, Avallone, G, Avitabile, F, Balconi, L, Bellingeri, E, Beneduce, E, Benson, T, Bernini, C, Bersani, A, Bianchi, A, Broggi, F, Burioli, S, Campana, P, Cannavó, M, Canonica, L, Cialone, M, Cirillo, C, Mario, C, Domenico, D, Mario Del, F, Marta Della, T, Ernesto De, M, Salvatore De, P, Beniamino Di, G, Antonio, E, Stefania, F, Giuliana, F, Umberto, G, Raffaele, G, Gianfrancesco, G, Angelo, L, Enrico, L, Stefano Maffezzoli, F, Andrea, M, Samuele, M, Daniele, M, Giuseppe, M, Fabio, M, Anna Grazia, M, Riccardo, M, Luigi, P, Danilo, P, Marco, P, Marina, P, Silvia, R, Lucia, S, Aniello, S, Carlo, S, Ettore, S, Andrea, S, Claudio, S, Fabio, S, Massimo, S, Stefano, S, Marco, S, Andrea, T, Riccardo, V, and Alessandro, V, Rossi L, Arpaia P, Attanasio C, Avallone G, Avitabile F, Balconi L, Bellingeri E, Beneduce E, Benson T, Bernini C, Bersani A, Bianchi A, Broggi F, Burioli S, Campana P, Cannavó M, Canonica L, Cialone M, Cirillo C, Mario Cuoco, Domenico D’Agostino, Mario Del Franco, Marta Della Torre, Ernesto De Matteis, Salvatore De Pasquale, Beniamino Di Girolamo, Antonio Esposito, Stefania Farinon, Giuliana Fiorillo, Umberto Gambardella, Raffaele Gargiulo, Gianfrancesco Grauso, Angelo Leo, Enrico Leo, Stefano Maffezzoli Felis, Andrea Malagoli, Samuele Mariotto, Daniele Marré, Giuseppe Maruccio, Fabio Miletto, Anna Grazia Monteduro, Riccardo Musenich, Luigi Parodi, Danilo Pedrini, Marco Prioli, Marina Putti, Silvia Rizzato, Lucia Sabbatini, Aniello Saggese, Carlo Santini, Ettore Sarnelli, Andrea Selce, Claudio Severino, Fabio Severino, Massimo Sorbi, Stefano Sorti, Marco Statera, Andrea Traverso, Riccardo Valente, and Alessandro Vannozzi, Rossi, L, Arpaia, P, Attanasio, C, Avallone, G, Avitabile, F, Balconi, L, Bellingeri, E, Beneduce, E, Benson, T, Bernini, C, Bersani, A, Bianchi, A, Broggi, F, Burioli, S, Campana, P, Cannavó, M, Canonica, L, Cialone, M, Cirillo, C, Mario, C, Domenico, D, Mario Del, F, Marta Della, T, Ernesto De, M, Salvatore De, P, Beniamino Di, G, Antonio, E, Stefania, F, Giuliana, F, Umberto, G, Raffaele, G, Gianfrancesco, G, Angelo, L, Enrico, L, Stefano Maffezzoli, F, Andrea, M, Samuele, M, Daniele, M, Giuseppe, M, Fabio, M, Anna Grazia, M, Riccardo, M, Luigi, P, Danilo, P, Marco, P, Marina, P, Silvia, R, Lucia, S, Aniello, S, Carlo, S, Ettore, S, Andrea, S, Claudio, S, Fabio, S, Massimo, S, Stefano, S, Marco, S, Andrea, T, Riccardo, V, and Alessandro, V, Rossi L, Arpaia P, Attanasio C, Avallone G, Avitabile F, Balconi L, Bellingeri E, Beneduce E, Benson T, Bernini C, Bersani A, Bianchi A, Broggi F, Burioli S, Campana P, Cannavó M, Canonica L, Cialone M, Cirillo C, Mario Cuoco, Domenico D’Agostino, Mario Del Franco, Marta Della Torre, Ernesto De Matteis, Salvatore De Pasquale, Beniamino Di Girolamo, Antonio Esposito, Stefania Farinon, Giuliana Fiorillo, Umberto Gambardella, Raffaele Gargiulo, Gianfrancesco Grauso, Angelo Leo, Enrico Leo, Stefano Maffezzoli Felis, Andrea Malagoli, Samuele Mariotto, Daniele Marré, Giuseppe Maruccio, Fabio Miletto, Anna Grazia Monteduro, Riccardo Musenich, Luigi Parodi, Danilo Pedrini, Marco Prioli, Marina Putti, Silvia Rizzato, Lucia Sabbatini, Aniello Saggese, Carlo Santini, Ettore Sarnelli, Andrea Selce, Claudio Severino, Fabio Severino, Massimo Sorbi, Stefano Sorti, Marco Statera, Andrea Traverso, Riccardo Valente, and and Alessandro Vannozzi

Abstract

In the frame of the Next Generation Europe program, the EU program to boost after-COVID recovery, the Italian Minister of University and Research has funded a project called Innovative Research Infrastructure for applied Superconductivity (IRIS). New laboratories will be built or upgraded in six poles: Milan (hub of the infrastructure), Genoa, Frascati, Naples, Salerno, and Lecce, to carry out basic research on magnetism and superconducting materials, test of wires, tapes, and large current cables, superconducting magnets construction with advanced instrumentation, power tests of magnets, and a special facility for high current-high voltage superconducting lines. The program will be executed over three years and then will operate for at least 10 years. It includes two first demonstrators: one HTS magnet to be operated at 10-20 K and a superconducting line of 1 GW (40 kA-25 kV) about 140 m long. The demonstrators anticipate the main scope of the investment in the IRIS infrastructure: to support the use of superconductivity for improving sustainability by decreasing the energy consumption without compromising performance. This article describes the global IRIS project.

Published
2024

9. Il coordinamento della Prevenzione delle Dipendenza Patologiche in un’Asl territoriale. Ipotizzare un modello organizzativo di lavoro innovativo in equipe multidisciplinari

Author

TRIASSI, MARIA, ORTECA R, GIORDANO V, BERNARDO A, GRANATA A, BUONOMO M, QUARTUCCI F, ARTUSO F, MORETTA S, DIANA V, FORMICOLA M, AVITABILE F, AMBROSINO M, PENNACCHIO F, DE LIGUORI P, TORRE G, NOCERINO A, PASSARO M, PIZZA A, SAVOIA F, PELUSO C, MAUTONE P, BUSIELLO F, PALLADINO R, VOZA N, DI MAJO A, SCHETTINI G, MARTINO D, DE PASCALE T, LONGANELLA W, REA T., Triassi, Maria, Orteca, R, Giordano, V, Bernardo, A, Granata, A, Buonomo, M, Quartucci, F, Artuso, F, Moretta, S, Diana, V, Formicola, M, Avitabile, F, Ambrosino, M, Pennacchio, F, DE LIGUORI, P, Torre, G, Nocerino, A, Passaro, M, Pizza, A, Savoia, F, Peluso, C, Mautone, P, Busiello, F, Palladino, R, Voza, N, DI MAJO, A, Schettini, G, Martino, D, DE PASCALE, T, Longanella, W, and Rea, T.

Published
2011

10. La Neurochirurgia dei tumori cerebrali in Campania: analisi di attività e progetto di management sanitario

Author

TRIASSI, MARIA, SCHONAUER E, ARTUSO F, BUONOMO M, GIORDANO V, BERNARDO A, QUARTUCCI F, SPIRITO G, IANNUZZO MT, MORETTO S, GRANATA A, DIANA MV, FORMICOLA M, DE LUCA L, AVITABILE F, MASCOLO D, NOCERINO A, DE LIGUORI P, PASSARO M, DE MARCO G, SAVOIA F, PELUSO C, BOTTA E, CACACE G, DE LUCA, PIZZA A, FABBROCINI M, MAUTONE P, AMBROSIO F, BUSIELLO F., Triassi, Maria, Schonauer, E, Artuso, F, Buonomo, M, Giordano, V, Bernardo, A, Quartucci, F, Spirito, G, Iannuzzo, Mt, Moretto, S, Granata, A, Diana, Mv, Formicola, M, DE LUCA, L, Avitabile, F, Mascolo, D, Nocerino, A, DE LIGUORI, P, Passaro, M, DE MARCO, G, Savoia, F, Peluso, C, Botta, E, Cacace, G, De, Luca, Pizza, A, Fabbrocini, M, Mautone, P, Ambrosio, F, and Busiello, F.

Published
2010

11. L’assistenza nelle cure domiciliari: dalla comunicazione all’educazione dei caregiver, nel rispetto della normativa e dei livelli professionali specifici

Author

TRIASSI, MARIA, PELUSO C, GIORDANO V, BERNARDO A, BUONOMO M, SPIRITO G, NOCERINO A, ARTUSO F, QUARTUCCI F, MORETTO S, GRANATA A, DIANA MV, FORMICOLA M, MASCOLO D, PASSARO M, AVITABILE F, SAVOIA F, DE MARCO G, DE LUCA L, DE LIGUORI P, PIZZA A, BOTTA E, CACACE G, FABBROCINI M, MAUTONE P, AMBROSIO F, MANNA A, ACAMPORA E, BUSIELLO F., Triassi, Maria, Peluso, C, Giordano, V, Bernardo, A, Buonomo, M, Spirito, G, Nocerino, A, Artuso, F, Quartucci, F, Moretto, S, Granata, A, Diana, Mv, Formicola, M, Mascolo, D, Passaro, M, Avitabile, F, Savoia, F, DE MARCO, G, DE LUCA, L, DE LIGUORI, P, Pizza, A, Botta, E, Cacace, G, Fabbrocini, M, Mautone, P, Ambrosio, F, Manna, A, Acampora, E, and Busiello, F.

Published
2010

12. Il 'governo' del blocco operatorio in ospedale: dalla valutazione della performance alla gestione del rischio

Author

TRIASSI, MARIA, IANNUZZO MT, GIORDANO V, BERNARDO A, BUONOMO M, SPIRITO G, QUARTUCCI F, NOCERINO A, PIZZA A, ARTUSO F, MORETTO S, GRANATA A, DIANA MV, AVITABILE F, FORMICOLA M, MASCOLO D, PASSARO M, SAVOIA F, DE LIGUORI P, PELUSO C, BOTTA E, CACACE G, MAUTONE P, AMBROSIO F, MANNA A, ACAMPORA E, DE LUCA L, GIORDANO G., Triassi, Maria, Iannuzzo, Mt, Giordano, V, Bernardo, A, Buonomo, M, Spirito, G, Quartucci, F, Nocerino, A, Pizza, A, Artuso, F, Moretto, S, Granata, A, Diana, Mv, Avitabile, F, Formicola, M, Mascolo, D, Passaro, M, Savoia, F, DE LIGUORI, P, Peluso, C, Botta, E, Cacace, G, Mautone, P, Ambrosio, F, Manna, A, Acampora, E, DE LUCA, L, and Giordano, G.

Published
2010

13. Organizzazione percorsi assistenziali multilivello in cardiologia. La gestione dell’IMA con st sopra o sottoslivellato, con percorsoi definiti pre ricovero, intraospedalieri e post dimissione: impatto nell’organizzazione e nei fondamenti giuridici del rischio clinico

Author

TRIASSI, MARIA, DEDIVITIIS M, GIORDANO V, BERNARDO A, SPIRITO G, QUARTUCCI F, BUONOMO M, IANNUZZO MT, ARTUSO F, MORETTO S, GRANATA A, DIANA MV, FORMICOLA M, AVITABILE F, DE MARCO G, MASCOLO D, PASSARO M, SAVOIA F, DE LIGUORI P, NOCERINO A, PELUSO C, PIZZA A, BOTTA E, CACACE G, MAUTONE P, AMBROSIO F, BUSIELLO F, DE LUCA L., Triassi, Maria, Dedivitiis, M, Giordano, V, Bernardo, A, Spirito, G, Quartucci, F, Buonomo, M, Iannuzzo, Mt, Artuso, F, Moretto, S, Granata, A, Diana, Mv, Formicola, M, Avitabile, F, DE MARCO, G, Mascolo, D, Passaro, M, Savoia, F, DE LIGUORI, P, Nocerino, A, Peluso, C, Pizza, A, Botta, E, Cacace, G, Mautone, P, Ambrosio, F, Busiello, F, and DE LUCA, L.

Published
2010

14. L’accreditamento istituzionale in nefrologia: leva organizzativa per definire modelli applicativi sperimentali in un UOC di Nefrologia di P.O. di ASL territoriale

Author

NAPPI F, GIORDANO V, BERNARDO A, NOCERINO A, SPIRITO G, FABBROCINI M, DELLA VECCHIA A, CUCCARO P, MOLESE A, DI RESTA M, REA T, MASCOLO D, AVITABILE F, MATARANTE E, BOTTA E, CACACE G, CAPPUCCIO A, DE MARCO G, TRIASSI, MARIA, Nappi, F, Giordano, V, Bernardo, A, Nocerino, A, Spirito, G, Fabbrocini, M, DELLA VECCHIA, A, Cuccaro, P, Molese, A, DI RESTA, M, Rea, T, Mascolo, D, Avitabile, F, Matarante, E, Botta, E, Cacace, G, Cappuccio, A, DE MARCO, G, and Triassi, Maria

Published
2009

15. 'Progetto Pharma - Uni - Hospital'. Integrare le funzioni di una U.O.C. Farmacia ospedaliera secondo logiche di pharmaceutical governance mediante una piattaforma unica di servizi per una tracciabilità del farmaco in un’ottica di rete integrata

Author

FUCILE AM, GIORDANO V, BERNARDO A, NOCERINO A, SPIRITO G, DELLA VECCHIA A, MOLESE A, CUCCARO P, DI RESTA M, MASCOLO D, AVITABILE F, MATARANTE E, BOTTA E, CACACE G, CAPPUCCIO A, DE MARCO G, TRIASSI, MARIA, Fucile, Am, Giordano, V, Bernardo, A, Nocerino, A, Spirito, G, DELLA VECCHIA, A, Molese, A, Cuccaro, P, DI RESTA, M, Mascolo, D, Avitabile, F, Matarante, E, Botta, E, Cacace, G, Cappuccio, A, DE MARCO, G, and Triassi, Maria

Subjects
Progetto Pharma
Published
2009

16. Ipotesi organizzativa di un day service per il trattamento delle varici degli arti inferiori

Author

ABATE LV, GIORDANO V, FABBROCINI M, BERNARDO A, NOCERINO A, SPIRITO G, MOLESE A, DELLA VECCHIA A, REA T, CUCCARO P, BOTTA E, CACACE G, CAPPUCCIO A, DE MARCO G, DI RESTA M, MASCOLO D, AVITABILE F, MATARANTE E, TRIASSI, MARIA, Abate, Lv, Giordano, V, Fabbrocini, M, Bernardo, A, Nocerino, A, Spirito, G, Molese, A, DELLA VECCHIA, A, Rea, T, Cuccaro, P, Botta, E, Cacace, G, Cappuccio, A, DE MARCO, G, DI RESTA, M, Mascolo, D, Avitabile, F, Matarante, E, and Triassi, Maria

Published
2009

17. Dall’appropriatezza organizzativa al recupero dei livelli di efficienza nelle attività integrate di Day Surgery in un IRCCS

Author

DEL GIUDICE M, GIORDANO V, FABBROCINI M, BERNARDO A, NOCERINO A, DELLA VECCHIA A, SPIRITO G, GIORDANO G, MANNA A, CUCCARO P, DI RESTA M, MASCOLO D, AVITABILE F, MATARANTE E, BOTTA E, CACACE G, CAPPUCCIO A, DE MARCO G, TRIASSI, MARIA, DEL GIUDICE, M, Giordano, V, Fabbrocini, M, Bernardo, A, Nocerino, A, DELLA VECCHIA, A, Spirito, G, Giordano, G, Manna, A, Cuccaro, P, DI RESTA, M, Mascolo, D, Avitabile, F, Matarante, E, Botta, E, Cacace, G, Cappuccio, A, DE MARCO, G, and Triassi, Maria

Published
2009

18. L’osservazione breve pediatrica: modalità organizzative, caratteristiche gestionali, finalità tendenti all’appropriatezza clinica nell’ottica della razionalizzazione delle attività aziendali e della corretta allocazione di utente e risorse

Author

D’AVINO P, GIORDANO V, BERNARDO A, NOCERINO A, SPIRITO G, DELLA VECCHIA A, MANNA A, CUCCARO P, DI RESTA M, MASCOLO D, AVITABILE F, MATARANTE E, BOTTA E, CACACE G, CAPPUCCIO A, DE MARCO G, TRIASSI, MARIA, D’Avino, P, Giordano, V, Bernardo, A, Nocerino, A, Spirito, G, DELLA VECCHIA, A, Manna, A, Cuccaro, P, DI RESTA, M, Mascolo, D, Avitabile, F, Matarante, E, Botta, E, Cacace, G, Cappuccio, A, DE MARCO, G, and Triassi, Maria

Published
2009

19. La filiera assistenziale in U.O.M.I: il 'consultorio' fra strutture aziendali e integrazione assistenziale. Impatto sull’organizzazione aziendale e sul tessuto socio sanitario di riferimento

Author

AMBROSIO F, GIORDANO V, SPIRITO G, DELLA VECCHIA A, FABBROCINI M, MANNA A, RICCO CS, BERNARDO A, NOCERINO A, CUCCARO P, GIORDANO G, REA T, DI RESTA M, MASCOLO D, AVITABILE F, MATARANTE E, BOTTA E, CACACE G, CAPPUCCIO A, DE MARCO G, TRIASSI, MARIA, Ambrosio, F, Giordano, V, Spirito, G, DELLA VECCHIA, A, Fabbrocini, M, Manna, A, Ricco, C, Bernardo, A, Nocerino, A, Cuccaro, P, Giordano, G, Rea, T, DI RESTA, M, Mascolo, D, Avitabile, F, Matarante, E, Botta, E, Cacace, G, Cappuccio, A, DE MARCO, G, and Triassi, Maria

Published
2009

20. Modello di gestione di un poliambulatorio specialistico territoriale e progetto di day service per patologie ad alta prevalenza e/o complessità nell’ambito di un poliambulatorio distrettuale

Author

BARLETTA M, GIORDANO V, BERNARDO A, DELLA VECCHIA A, MATARANTE E, AVITABILE F, DE MARCO G, MASCOLO D, NOCERINO A, CUCCARO, PATRIZIA, PAUDICE, ALESSANDRO, TRIASSI, MARIA, Barletta, M, Giordano, V, Bernardo, A, Cuccaro, Patrizia, DELLA VECCHIA, A, Paudice, Alessandro, Matarante, E, Avitabile, F, DE MARCO, G, Mascolo, D, Nocerino, A, and Triassi, Maria

Published
2008

23. SOLUTION STRUCTURE OF MONOMERIC BOVINE SEMINAL

Author

C. ERCOLE, AVITABILE, F., ALFANO, C., SPADACCINI, R., TANCREDI, T., PICONE, D., CRESCENZI, ORLANDO, C., Ercole, Crescenzi, Orlando, Avitabile, F., Alfano, C., Spadaccini, R., Tancredi, T., and Picone, D.

Published
2003

26. Solution structure of monomeric bovine seminal ribonuclease

Author

AVITABILE F, CAROTENUTO, ALFONSO, D'URSI A. M., TANCREDI T., D'ALESSIO G, CRESCENZI, ORLANDO, PICONE, DELIA, Avitabile, F, Crescenzi, Orlando, Carotenuto, Alfonso, D'Ursi, A. M., Tancredi, T., D'Alessio, G, and Picone, Delia

Abstract

Francoforte

Published
2001

27. Vortex pinning properties in Fe-chalcogenides

Author

Leo, A, primary, Grimaldi, G, additional, Guarino, A, additional, Avitabile, F, additional, Nigro, A, additional, Galluzzi, A, additional, Mancusi, D, additional, Polichetti, M, additional, Pace, S, additional, Buchkov, K, additional, Nazarova, E, additional, Kawale, S, additional, Bellingeri, E, additional, and Ferdeghini, C, additional

Published
2015
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31. Study of the surface properties of NCCO electron-doped cuprate

Author

Ivana Vobornik, Francesco Avitabile, Paola Romano, Jun Fujii, Adele Ruosi, A. Guarino, Antonio Vecchione, Giancarlo Panaccione, Angela Nigro, Guarino, A., Romano, P., Fujii, J., Ruosi, A., Avitabile, F., Vobornik, I., Panaccione, G., Vecchione, A., and Nigro, A.

Subjects
Materials science, High-temperature superconductivity, Photoemission spectroscopy, Nanowire, General Physics and Astronomy, 02 engineering and technology, 01 natural sciences, law.invention, Condensed Matter::Materials Science, law, Condensed Matter::Superconductivity, 0103 physical sciences, General Materials Science, Cuprate, Surface layer, Physical and Theoretical Chemistry, Thin film, 010306 general physics, Spectroscopy, Auger electron spectroscopy, business.industry, 021001 nanoscience & nanotechnology, Optoelectronics, 0210 nano-technology, business
Abstract

Whenever one is interested in making high temperature superconductor-based devices, the goodness of the sample surface in terms of structural and electrical properties is a strong issue. In fact, it is well known that the surface of high T-c superconducting samples is not bulk-representative, due to air contamination and to the possible presence of oxygen vacancies. In addition, the quality of the surface layer results to be crucial in surface sensitive measurements as in X-ray photoelectron and Angle-resolved photoemission spectroscopy. Recently, some studies have been dedicated to the realization of devices based on electron-doped cuprates, bilayers and nanowires, showing the actual possibility to realize good quality junctions by using these cuprates. In this work, we report on the fabrication of thin films of the electron-doped Nd2-xCexCuO4 +/- compound and analyze the surface natural barrier of as-grown films by means of point contact spectroscopy measurements. Suitable treatments of samples in an ozone rich atmosphere have been developed in order to improve the surface quality of the films. Auger electron spectroscopy has been used to monitor the effectiveness of these treatments.

Published
2019

32. The swapping of terminal arms in ribonucleases: comparison of the solution structure of monomeric bovine seminal and pancreatic ribonucleases

Author

Francesca Avitabile, Delia Picone, Giuseppe D’Alessio, Teodorico Tancredi, Orlando Crescenzi, Anna Maria D'Ursi, Roberta Spadaccini, Caterina Alfano, Avitabile, F, Alfano, C., Spadaccini, R, Crescenzi, O, D'Ursi, Am, D'Alessio, G, Tancredi, T, Picone, Delia, Alfano, C, Spadaccini, Roberta, Crescenzi, Orlando, and D'Alessio, Giuseppe

Subjects
Models, Molecular, Magnetic Resonance Spectroscopy, Proline, Stereochemistry, RNase P, Protein Conformation, Peptide, Bovine pancreatic ribonuclease, Biochemistry, Protein Structure, Secondary, Diffusion, chemistry.chemical_compound, Hydrolase, Endoribonucleases, Escherichia coli, Animals, Ribonuclease, Protein secondary structure, chemistry.chemical_classification, biology, Temperature, Hydrogen Bonding, Ribonuclease, Pancreatic, Hydrogen-Ion Concentration, Protein Structure, Tertiary, Crystallography, Monomer, chemistry, Heteronuclear molecule, biology.protein, Mutagenesis, Site-Directed, Cattle, Dimerization, Protein Binding
Abstract

Bovine seminal ribonuclease (BS-RNase), the only dimeric protein among the pancreatic-like ribonucleases, is endowed with special structural features and with biological functions beyond enzymatic activity. In solution, the protein exists as an equilibrium mixture of two forms, with or without exchange (or swapping) of the N-terminal arms. After selective reduction and alkylation of the two intrachain disulfide bridges, the dimeric protein can be transformed into a monomeric derivative that has a ribonuclease activity higher than that of the parent dimeric protein but is devoid of the special biological functions. A detailed investigation of the structural features of this protein in solution, in comparison with those of other monomeric ribonucleases, may help unveil the structural details which induce swapping of the N-terminal arms of BS-RNase. The solution structure of the recombinant monomeric form of BS-RNase, as determined by 3D heteronuclear NMR, shows close similarity with that of bovine pancreatic ribonuclease (RNase A) in all regions characterized by regular elements of secondary structure. However, significant differences are present in the flexible regions, which could account for the different behavior of the two proteins. To characterize in detail these regions, we have measured H/D exchange rate constants, temperature coefficients and heteronuclear NOEs of backbone amides for both RNase A and monomeric BS-RNase. The results indicate a large difference in the backbone flexibility of the hinge peptide segment 16-22 of the two proteins, which could provide the molecular basis to explain the ability of BS-RNase subunits to swap their N-terminal arms.

Published
2003

34. Point-Contact Spectroscopy in Bulk Samples of Electron-Doped Cuprate Superconductors.

Author

Nigro A, Guarino A, Leo A, Grimaldi G, Avitabile F, and Romano P

Abstract

Point-contact spectroscopy was performed on bulk samples of electron-doped high temperature superconductor Nd 2-x Ce x CuO 4-δ . The samples were characterized using X-ray diffraction and scanning electron microscopy equipped with a wavelength-dispersive spectrometer and an electron backscatter diffraction detector. Samples with Ce content x = 0.15 showed the absence of spurious phases and randomly oriented grains, most of which had dimensions of approximately 220 µm 2 . The low-bias spectra in the tunneling regime, i.e., high-transparency interface, exhibited a gap feature at about ±5 meV and no zero-bias conductance, despite the random oriented grains investigated within our bulk samples, consistent with most of the literature data on oriented samples. High-bias conductance was also measured in order to obtain information on the properties of the barrier. A V-shape was observed in some cases, instead of the parabolic behavior expected for tunnel junctions.

Published
2023
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35. Transport and Point Contact Measurements on Pr 1-x Ce x Pt 4 Ge 12 Superconducting Polycrystals.

Author

Romano P, Avitabile F, Nigro A, Grimaldi G, Leo A, Shu L, Zhang J, Di Bartolomeo A, and Giubileo F

Abstract

We performed a detailed investigation of the superconducting properties of polycrystalline Pr 1-x Ce x Pt 4 Ge 12 pellets. We report the effect of Ce substitution, for x = 0.07, on magnetic field phase diagram H-T. We demonstrate that the upper critical field is well described by the Ginzburg-Landau model and that the irreversibility field line has a scaling behaviour similar to cuprates. We also show that for magnetic fields lower than 0.4 T, the activation energy follows a power law of the type ? -1/2 , suggesting a collective pinning regime with a quasi-2D character for the Ce-doped compound with x = 0.07. Furthermore, by means of a point contact Andreev reflection spectroscopy setup, we formed metal/superconductor nano-junctions as small as tens of nanometers on the PrPt 4 Ge 12 parent compound (x = 0). Experimental results showed a wide variety of conductance features appearing in the dI/dV vs. V spectra, all explained in terms of a modified Blonder-Tinkham-Klapwijk model considering a superconducting order parameter with nodal directions as well as sign change in the momentum space for the sample with x = 0. The numerical simulations of the conductance spectra also demonstrate that s-wave pairing and anisotropic s-waves are unsuitable for reproducing experimental data obtained at low temperature on the un-doped compound. Interestingly, we show that the polycrystalline nature of the superconducting PrPt 4 Ge 12 sample can favour the formation of an inter-grain Josephson junction in series with the point contact junction in this kind of experiments.

Published
2020
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36. Vortex lattice instability at the nanoscale in a parallel magnetic field.

Author

Grimaldi G, Leo A, Avitabile F, Martucciello N, Galluzzi A, Polichetti M, Pace S, and Nigro A

Abstract

In superconducting materials a dynamical rearrangement of the vortex lattice occurs by forcing vortices at high velocities, until the system can become unstable. This phenomenon is known as vortex lattice instability, in which a sudden transition drives the superconducting system abruptly to the normal state. We present an experimental study on submicron bridges of NbN and NbTiN ultra-thin films with a thickness of few nanometers. The nanoscale effect on vortex lattice instability is investigated not only by the ultra-thin thickness in wide bridges, but also by changing the direction of the external magnetic field applied parallel and perpendicular to the c-axis epitaxial films. Indeed, measurements are performed for both orientations and show the vortex lattice instability, regardless of the superconducting material. Critical currents I c as well as instability currents I* have been compared. However, only in the parallel configuration an unusual 'flying birds' feature appears in the magnetic field dependence of current switching, as a consequence of the ratio I*/I c that is approaching 1. This amazing tendency becomes relevant for practical applications involving nanostructures, since by scaling down sample thickness and rotating the external field towards the in-plane orientation, the ultra-thin film geometry can mimic the bridge narrowing down to the nanoscale.

Published
2019
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37. Role of the hinge peptide and the intersubunit interface in the swapping of N-termini in dimeric bovine seminal RNase.

Author

Ercole C, Avitabile F, Del Vecchio P, Crescenzi O, Tancredi T, and Picone D

Subjects
Allosteric Site, Animals, Cattle, Circular Dichroism, Cross-Linking Reagents, Dimerization, Kinetics, Magnetic Resonance Spectroscopy, Models, Molecular, Protein Denaturation, Protein Folding, Protein Structure, Quaternary, Protein Structure, Tertiary, Ribonuclease, Pancreatic genetics, Structure-Activity Relationship, Thermodynamics, Protein Subunits chemistry, Ribonuclease, Pancreatic chemistry, Ribonuclease, Pancreatic metabolism, Semen enzymology
Abstract

Bovine seminal ribonuclease (BS-RNase) is the only known dimeric enzyme characterized by an equilibrium between two different 3D structures: MxM, with exchange (or swapping) of the N-terminal 1-20 residues, and M=M, without exchange. As a consequence, the hinge region 16-22 has a different tertiary structure in the two forms. In the native protein, the equilibrium ratio between MxM and M=M is about 7 : 3. Kinetic analysis of the swapping process for a recombinant sample shows that it folds mainly in the M=M form, then undergoes interconversion into the MxM form, reaching the same 7 : 3 equilibrium ratio. To investigate the role of the regions that are most affected structurally by the swapping, we expressed variant proteins by replacing two crucial residues with the corresponding ones from RNase A: Pro19, within the hinge peptide, and Leu28, located at the interface between subunits. We compared the structural properties of the monomeric forms of P19A-BS-RNase, L28Q-BS-RNase and P19A/L28Q-BS-RNase variants with those of the parent protein, and investigated the exchange kinetics of the corresponding dimers. The P19A mutation slightly increases the thermal stability of the monomer, but it does not alter the swapping tendency of the dimer. In contrast, the L28Q mutation significantly affects both the dimerization and swapping processes but not the thermal stability of the monomer. Overall, these results suggest that the structural determinants that control the exchange of N-terminal arms in BS-RNase may not be located within the hinge peptide, and point to a crucial role of the interface residues.

Published
2003
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38. The swapping of terminal arms in ribonucleases: comparison of the solution structure of monomeric bovine seminal and pancreatic ribonucleases.

Author

Avitabile F, Alfano C, Spadaccini R, Crescenzi O, D'Ursi AM, D'Alessio G, Tancredi T, and Picone D

Subjects
Animals, Cattle, Diffusion, Dimerization, Escherichia coli metabolism, Hydrogen Bonding, Hydrogen-Ion Concentration, Magnetic Resonance Spectroscopy, Models, Molecular, Mutagenesis, Site-Directed, Proline chemistry, Protein Binding, Protein Conformation, Protein Structure, Secondary, Protein Structure, Tertiary, Ribonuclease, Pancreatic chemistry, Temperature, Endoribonucleases chemistry
Abstract

Bovine seminal ribonuclease (BS-RNase), the only dimeric protein among the pancreatic-like ribonucleases, is endowed with special structural features and with biological functions beyond enzymatic activity. In solution, the protein exists as an equilibrium mixture of two forms, with or without exchange (or swapping) of the N-terminal arms. After selective reduction and alkylation of the two intrachain disulfide bridges, the dimeric protein can be transformed into a monomeric derivative that has a ribonuclease activity higher than that of the parent dimeric protein but is devoid of the special biological functions. A detailed investigation of the structural features of this protein in solution, in comparison with those of other monomeric ribonucleases, may help unveil the structural details which induce swapping of the N-terminal arms of BS-RNase. The solution structure of the recombinant monomeric form of BS-RNase, as determined by 3D heteronuclear NMR, shows close similarity with that of bovine pancreatic ribonuclease (RNase A) in all regions characterized by regular elements of secondary structure. However, significant differences are present in the flexible regions, which could account for the different behavior of the two proteins. To characterize in detail these regions, we have measured H/D exchange rate constants, temperature coefficients and heteronuclear NOEs of backbone amides for both RNase A and monomeric BS-RNase. The results indicate a large difference in the backbone flexibility of the hinge peptide segment 16-22 of the two proteins, which could provide the molecular basis to explain the ability of BS-RNase subunits to swap their N-terminal arms.

Published
2003
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39. 1H and 15N sequential assignment and secondary structure of the monomeric N67D mutant of bovine seminal ribonuclease.

Author

Crescenzi O, Carotenuto A, D'Ursi AM, Tancredi T, D'Alessio G, Avitabile F, and Picone D

Subjects
Amino Acid Substitution, Animals, Cattle, Codon genetics, Endoribonucleases genetics, Male, Protein Structure, Secondary, Protein Structure, Tertiary, Recombinant Fusion Proteins chemistry, Seminal Plasma Proteins genetics, Endoribonucleases chemistry, Mutation, Missense, Nuclear Magnetic Resonance, Biomolecular, Seminal Plasma Proteins chemistry
Published
2001
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40. Stereochemical requirements for receptor recognition of the mu-opioid peptide endomorphin-1.

Author

Paterlini MG, Avitabile F, Ostrowski BG, Ferguson DM, and Portoghese PS

Subjects
Animals, Enkephalin, Ala(2)-MePhe(4)-Gly(5)- chemistry, Guinea Pigs, Ileum drug effects, Magnetic Resonance Spectroscopy, Models, Molecular, Oligopeptides pharmacology, Protein Conformation, Stereoisomerism, Structure-Activity Relationship, Oligopeptides chemistry, Receptors, Opioid, mu chemistry
Abstract

A series of diastereoisomers of endomorphin-1 (EM1, Tyr(1)-Pro(2)-Trp(3)-Phe(4)-NH(2)) have been synthesized and their potency measured using the guinea pig ileum assay. [D-Phe(4)]EM1 possessed 1/10 the potency of EM1, while potencies of [D-Tyr(1)]EM1 and [D-Trp(3)]EM1 were 50- and 100-fold lower, respectively. Drastic loss of activity occurred in the [D-Pro(2)]EM1 peptide. The structural determinants for the inactivity and reduced potency of the diastereoisomers were investigated using NMR spectroscopy and conformational analysis. Simulations of trans-[D-Pro(2)]EM1 using NOE-derived distance constraints afforded well-defined structures in which Tyr and Trp side chains stack against the proline ring. The inactivity of [D-Pro(2)]EM1 was explained by structural comparison with EM1 (, FEBS Lett. 439:13-20). The two peptides showed an opposite orientation of the Trp(3) residue with respect to Tyr(1), thus suggesting a role of Pro(2) as a stereochemical spacer in orienting Trp(3) and Phe(4) toward regions suitable for mu-receptor interaction. The agonist activity of [D-Tyr(1)]EM1 and [D-Trp(3)]EM1 was attributed to their ability to adopt low-energy conformations that mimic those of EM1. The requirements for mu-receptor activation were examined further by comparing EM1 with the mu-peptide [D-Ala(2), MePhe(4), Gly-ol]-enkephalin (DAMGO). Conformations of DAMGO with a Tyr(1)-MePhe(4) phenyl ring separation of approximately 12 A were found to mimic Tyr(1)-Phe(4) of EM1, thus suggesting overlapping binding modes between these two peptides.

Published
2000
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