1,149 research outputs found
Antibacterial Activity on Orthopedic Clinical Isolates and Cytotoxicity of the Antimicrobial Peptide Dadapin-1
No full textIn orthopedic surgery, biomaterial-associated infections represent a complication of serious concern. Most promising strategies to prevent these infections currently rely on the use of anti-infective biomaterials. Desirably, in anti-infective biomaterials, the antibacterial properties should be achieved by doping, grafting, or coating the material surfaces with molecules that are alternative to conventional antibiotics and exhibit a potent and highly specific activity against bacteria, without altering the biocompatibility. Antimicrobial peptides (AMPs) are among the most interesting candidate molecules for this biomaterial functionalization. Here, the potential expressed by the recently discovered peptide Dadapin-1 was explored by assaying its MIC, MBIC and MBC on clinical strains of relevant bacterial species isolated from orthopedic infections and by assessing its cytotoxicity on the human osteoblast-like MG63 cells. When appropriately tested in diluted Mueller Hinton Broth II (MHB II), Dadapin-1 exhibited significant antibacterial properties. MIC values were in the range of 3.1–6.2 µM for the gram-positive bacteria Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus warneri, and 12.4–24.9 µM for the gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Interestingly, the peptide was found non-cytotoxic, with an IC50 exceeding the highest concentration tested of 179 µM. Overall, Dadapin-1 expresses considerable potential for future application in the production of anti-infective biomaterials
Giulia Veronica Varisco
No full textThe headword explains the biography and the contribution of the author Giulia Varisco to the children's literatur
Searching for Virulence Factors among Staphylococcus lugdunensis Isolates from Orthopedic Infections: Correlation of β-hemolysin, hemolysin III, and slush Genes with Hemolytic Activity and Synergistic Hemolytic Activity
No full textStaphylococcus lugdunensis is an emerging high-virulent pathogen. Here, the presence and expression of virulence genes (icaA, fbl, vwbl, fbpA, slush A, B and C, and genes of the putative beta-hemolysin and hemolysin III) and the ability to induce synergistic hemolytic activity and hemolysis after 24, 48 and 72 h were investigated in a collection of twenty-two S. lugdunensis clinical isolates. The collection of isolates, mainly from implant orthopedic infections, had previously been grouped by ribotyping/dendrogram analysis and studied for biofilm matrices, biomasses and antibiotic resistances. Two isolates, constituting a unique small ribogroup sharing the same cluster, exhibited an amplicon size of the slush operon (S. lugdunensis synergistic hemolysin) which was shorter than the expected 977 bp. This outcome can predict the genetic lineage of the S. lugdunensis strains. One isolate (cra1342) presented two deletions: one of 90 bp in slush A and the other of 91 bp in slush B. Another isolate (N860314) showed a single 193 bp deletion, which encompassed part of the slush B terminal sequence and most of slush C. The isolate N860314 was devoid of hemolytic activity after 24 h, and the first consideration was that the deleted region deals with the coding of the active enzymatic site of the slush hemolysin. On the other hand, cra1342 and N860314 isolates with different slush deletions and with hemolytic activity after 24 and 48 h, respectively, could have replaced the hemolytic phenotype through other processes
Ytterbium Disilicate/Monosilicate Multilayer Environmental Barrier Coatings: Influence of Atmospheric Plasma Spray Parameters on Composition and Microstructure
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Ytterbium Disilicate/Monosilicate Multilayer Environmental Barrier Coatings: Influence of Atmospheric Plasma Spray Parameters on Composition and Microstructure
by Giulia Di Iorio,Laura Paglia *ORCID,Giulia PedrizzettiORCID,Virgilio GenovaORCID,Francesco MarraORCID,Cecilia BartuliORCID andGiovanni PulciORCID
INSTM Reference Laboratory for Materials and Surface Engineering, Sapienza University of Rome, Eudossiana 18, 00184 Rome, Italy
*
Author to whom correspondence should be addressed.
Coatings 2023, 13(9), 1602; https://doi.org/10.3390/coatings13091602
Original submission received: 10 August 2023 / Revised: 31 August 2023 / Accepted: 11 September 2023 / Published: 13 September 2023
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Abstract
SiC/SiC ceramic matrix composites (SiCf/SiC CMCs) are regarded as the new materials for the hot-section components of aircraft gas turbine engines, since they have one-third of the density of metallic superalloys, a higher temperature capability, good mechanical strength, and excellent thermal shock resistance. However, high-temperature water-vapor-rich combustion gases can induce severe surface recession phenomena in SiC/SiC leading to component failure. For this reason, it is necessary to design protective coatings, i.e., environmental barrier coatings (EBCs), able to protect the SiC/SiC surface in combustion environments. In the present work, ytterbium monosilicate (Yb2SiO5), stable when exposed to water vapor at high temperatures, and ytterbium disilicate (Yb2Si2O7), characterized by a thermal expansion coefficient closer to that of the substrate, were selected for a multilayer EBC system. EBCs were processed using the atmospheric plasma spray (APS) technique. A set of deposition parameters were tested, varying the power of the torch, and the composition and microstructure of the deposited coatings were studied in terms of porosity, crack density, and post-deposition phase retention by performing SEM, EDS, and XRD analysis. The results allow for the definition of the influence of deposition parameters on the final properties of multilayer EBC coatings
Correction to: Safety and Psychological Outcomes of Tandem t:Slim X2 Insulin Pump with Control-IQ Technology in Children, Adolescents, and Young Adults with Type 1 Diabetes: A Systematic Review
No full textThe second author name was incorrectly published as Giula Maria Smylie. The correct name is Giulia Marie Smylie. The original article has been corrected
Scrivere senza anestesia. La chiarezza di Giulia Niccolai
No full textIl saggio colloca storicamente la narratrice e poetessa Giulia Niccolai nel canone del Novecento letterario italiano discutendone poetica e cifre stilistiche. L'ampia analisi proposta tocca tutte le opere dell'autrice evidenziandone i legami intertestuali, anche tra poesia e narrativa, e i progressivi sviluppi in un arco cronologico esteso, tra anni Sessanta e primi anni Duemila. Lo studio coglie anche l'importanza dei riferimenti alle arti visive, in particolare alla fotografia, che Giulia Niccolai ha praticato in prima persona negli anni della Neoavanguardia, e alla pittura americana.The essay places the narrator and poet Giulia Niccolai in the canonical twentieth century Italian literary discussing her poetics and stylistic figures. The wide analysis proposed touches all the works of the author highlighting the intertextual links, also between poetry and narrative, and the progressive developments in an extended chronological period, between the Sixties and early Twenties. The study also captures the importance of references to the visual arts, especially photography, which Giulia Niccolai has practiced in the years of the Neo-avant-garde, and to American painting
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L'afrofuturismo tra Stati Uniti e Italia. Dalla memoria storica ai viaggi intergalattici per re-immaginare futuri postumani
No full textIn this article the author explores the cultural movement called Afrofuturism, tracing its origins, features, simbology, and its historical and political meanings. Starting from the (supposed) discoursive gap between African and African American people on one side and technology and science fiction on the other, this paradigm addresses themes related to the intersection of African Diaspora and African cultures with technology and science fiction, with the aim to recover the history of slavery and racism through the projections into alternative space-time contexts. In particular, the author explores the feminist afrofuturism perspective in order to examine the specific oppression and cultural production of African and African American women. In doing so, the author analyzes the development of afrofuturism in Italy, focusing on the work of the singer and beatmaker Karima 2G
BDC-Decomposition for global influence analysis
No full textIn biochemical networks, the steady-state input-output influence is the sign of the output steady-state variation due to a persistent positive input perturbation; if the sign does not depend on the value of the strictly positive system parameters, the influence is structural. As recently shown for small perturbations, when the linearized system approximation is valid, steady-state input-output influences can be structurally assessed, for biochemical networks with m unknown parameters, by means of a vertex algorithm with complexity 2m. This letter shows that the structural input-output influence of a biochemical network is a global property, which does not require any small-perturbation assumption. It also shows that, using a new algorithm, the complexity can be reduced down to 2m-n , where n is the system order, thus drastically reducing the computation time. Finally, when the uncertain parameters belong to known intervals, non-conservative bounds are given for the steady-state ratio between output and input, allowing for sensitivity analysis.Accepted Author ManuscriptTeam Tamas Keviczk
Luoghi di danza
No full textWriter, journalist, theater and film critic, Marco Ramperti is one of the few that deals with dance in the Italian press of the fascist period. For the newspaper «La Stampa», between 1926 and 1928, he edits the column Luoghi di danza (dance venues), dedicated to ballroom and modern dances. The article investigates the performative nature of Ramperti’s writing, dominated by “staging” devices of the subject matter, as well as by an intrusive presence of the body, first of all that of the author. What emerges is an unprecedented image of the dance in the Twenties, at the same time catalysing the most alienating - and Pirandellian - aspects of modernity, but also a place where genuinely experiencing themselves and the others
Von der Sorge und Sorglosigkeit : zu Gemeinsamkeiten von Pflege und Tourismus
No full textDieser Beitrag zum Denkanstoß 17 „Zukunft der Pflege“ ergänzt die Beiträge des Denkanstoßes um weitere Aspekte, die nicht in dem Heft berücksichtigt werden konnten. Harald Pechlaner, Giulia Isetti und Michael de Rachewitz erläutern in ihrem Beitrag die Gemeinsamkeiten zwischen den Konzepten von Gastfreundschaft und Pflege (cura)
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