Photo-Inactivation of Staphylococcus aureus by Diaryl-Porphyrins

Photodynamic Antimicrobial Chemotherapy (PACT) has received great attention in recent years since it is an effective and promising modality for the treatment of human oral and skin infections with the advantage of bypassing pathogens' resistance to antimicrobials. Moreover, PACT applications demonstrated a certain activity in the inhibition and eradication of biofilms, overcoming the well-known tolerance of sessile communities to antimicrobial agents. In this study, 13 diaryl-porphyrins (mono-, di-cationic, and non-ionic) P1-P13 were investigated for their potential as photosensitizer anti-Staphylococcus aureus. The efficacy of the diaryl-porphyrins was evaluated through photo-inactivation tests. Crystal-violet staining combined with viable count techniques were aimed at assaying their anti-biofilm activity. Among the tested compounds, the neutral photosensitizer P4 was better than the cationic ones, irrespective of their corresponding binding rates. In particular, P4 was active in inhibiting the biofilm formation and in impairing the viability of the adherent and planktonic populations of a 24 h old biofilm. The inhibitory activity was also efficient against a methicillin resistant S. aureus strain. In conclusion, the diaryl-porphyrin family represents a reservoir of promising compounds for photodynamic applications against the pathogen S. aureus and in preventing the formation of biofilms that cause many infections to become chronic

Structure of the TPR Domain of AIP: Lack of Client Protein Interaction with the C-Terminal alpha-7 Helix of the TPR Domain of AIP Is Sufficient for Pituitary Adenoma Predisposition

PMCID: PMC3534021This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

The Immunophilin-Like Protein XAP2 Is a Negative Regulator of Estrogen Signaling through Interaction with Estrogen Receptor α

XAP2 (also known as aryl hydrocarbon receptor interacting protein, AIP) is originally identified as a negative regulator of the hepatitis B virus X-associated protein. Recent studies have expanded the range of XAP2 client proteins to include the nuclear receptor family of transcription factors. In this study, we show that XAP2 is recruited to the promoter of ERα regulated genes like the breast cancer marker gene pS2 or GREB1 and negatively regulate the expression of these genes in MCF-7 cells. Interestingly, we show that XAP2 downregulates the E2-dependent transcriptional activation in an estrogen receptor (ER) isoform-specific manner: XAP2 inhibits ERα but not ERβ-mediated transcription. Thus, knockdown of intracellular XAP2 levels leads to increased ERα activity. XAP2 proteins, carrying mutations in their primary structures, loose the ability of interacting with ERα and can no longer regulate ER target gene transcription. Taken together, this study shows that XAP2 exerts a negative effect on ERα transcriptional activity and may thus prevent ERα-dependent events

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

The 2018 GaN power electronics roadmap

Gallium nitride (GaN) is a compound semiconductor that has tremendous potential to facilitate economic growth in a semiconductor industry that is silicon-based and currently faced with diminishing returns of performance versus cost of investment. At a material level, its high electric field strength and electron mobility have already shown tremendous potential for high frequency communications and photonic applications. Advances in growth on commercially viable large area substrates are now at the point where power conversion applications of GaN are at the cusp of commercialisation. The future for building on the work described here in ways driven by specific challenges emerging from entirely new markets and applications is very exciting. This collection of GaN technology developments is therefore not itself a road map but a valuable collection of global state-of-the-art GaN research that will inform the next phase of the technology as market driven requirements evolve. First generation production devices are igniting large new markets and applications that can only be achieved using the advantages of higher speed, low specific resistivity and low saturation switching transistors. Major investments are being made by industrial companies in a wide variety of markets exploring the use of the technology in new circuit topologies, packaging solutions and system architectures that are required to achieve and optimise the system advantages offered by GaN transistors. It is this momentum that will drive priorities for the next stages of device research gathered here

Tecnologia dell'Architettura e Design nell'ateneo fiorentino: trent'anni di attività

The research work that led to the publication of the text is illustrated and the events of the conference in which the text was presented are reported.Su invito del Direttore del Dipartimento TAED si illustra il lavoro di ricerca che ha portato alla pubblicazione del testo e si riportano gli eventi del convegno nel quale il testo è stato presentato

Textile design. Elementi di base

La necessità di tenere sempre presenti gli elementi fondamentali della ricerca e della proget- tazione tessile e non solo, la consapevolezza di un crescente interesse verso i temi delle super- fici e della progettazione planare, sono i due principali motivi che hanno fatto nascere il testo. Il design tessile con le sue regole restrittive e, contemporaneamente, con le sue infinite varia- zioni, può essere interpretato semplicemente come una palestra o come una metafora pro- gettuale. Il testo è stato organizzato in modo da esprimere un avvicinamento progressivo più che dalla teoria alla pratica dall’astrazione alla concretezza. L’apparato iconografico, molte immagini del quale sono scatti dell’autrice, si presenta per certi versi come una lettura parallela che può suggerire percorsi di analisi o percorsi creativi

Dalla filiera alimentare al textile design

L’attenzione del design alla riduzione e al reimpiego degli scarti e dei prodotti secondari di lavorazione inerenti alla filiera alimentare, è in continua crescita. Prima della rivoluzione industriale la produzione agroalimentare e quella tessile ave- vano diversi elementi di contatto che sono andati quasi del tutto perduti soprattutto con l’avvento delle fibre artificiali. In Italia e in Europa la lana autoctona, come prodotto secondario della lavorazione del latte e della carne, ha perso quasi completa- mente il proprio valore commerciale. Si riportano alcune esperienze e valutazioni su come le lane possono dare origine a pro- cessi di design sistemico e a prodotti sostenibili rappresentando i caratteri identitari dei territori di provenienza

Interviste

Restituzione delle interviste a Adolfo Natalini e Alessandro Chimenti autori del Centro commerciale Coop di Gavinana a Firenze e del Centro commerciali I Gigli a Campi Bisenzio e a Mario Botta autore del Centro commerciale Canova a Firenze. Le tre opere sono analizzate all'interno del volume