Consistent Posttest Calculations for LOCA Scenarios in LOBI Integral Facility

Integral test facilities (ITFs) are one of the main tools for the validation of best estimate thermalhydraulic system codes. The experimental data are also of great value when compared to the experiment-scaled conditions in a full NPP. The LOBI was a single plus a triple-loop (simulated by one loop) test facility electrically heated to simulate a 1300 MWe PWR. The scaling factor was 712 for the core power, volume, and mass flow. Primary and secondary sides contained all main active elements. Tests were performed for the characterization of phenomenologies relevant to large and small break LOCAs and special transients in PWRs. The paper presents the results of three posttest calculations of LOBI experiments. The selected experiments are BL-30, BL-44, and A1-84. They are LOCA scenarios of different break sizes and with different availability of safety injection components. The goal of the analysis is to improve the knowledge of the phenomena occurred in the facility in order to use it in further studies related to qualifying nodalizations of actual plants or to establish accuracy data bases for uncertainty methodologies. An example of procedure of implementing changes in a common nodalization valid for simulating tests occurred in a specific ITF is presented along with its confirmation based on posttests results

Concerning synthesis of new biobased polycarbonates with curcumin in replacement of bisphenol a and recycled diphenyl carbonate as example of circular economy

Curcumin (CM) is a natural polyphenol well-known for its antioxidant and pharmaceutical properties, that can represent a renewable alternative to bisphenol A (BPA) for the synthesis of biobased polycarbonates (PC). In the presented strategy, preparation of the CM-based PC was coupled with chemical recycling of the fossil-based BPA polycarbonate (BPA-PC) conducting a two-steps trans-polymerization that replaces BPA monomer with CM or its tetrahydrogenated colorless product (THCM). In the first step of synthetic strategy, depolymerization of commercial BPA-PC was carried out with phenol as nucleophile, according to our previous procedure based on zinc derivatives and ionic liquids as catalysts, thus producing quantitatively diphenyl carbonate (DPC) e BPA. In the second step, DPC underwent a melt transesterification with CM or THCM monomers affording the corresponding bio-based polycarbonates, CM-PC and THCM-PC, respectively. THCM was prepared by reducing natural bis-phenol with cyclohexene as a hydrogen donor and characterized by 1H-NMR and MS techniques. Polymerization reactions were monitored by infrared spectroscopy and average molecular weights and dispersity of the two biobased polymers THCM-PC and CM-PC were determined by means of gel permeation chromatography (GPC). Optical properties of the prepared polymers were also measured

Microwave-assisted solvothermal synthesis of fe3o4/ceo2 nanocomposites and their catalytic activity in the imine formation from benzyl alcohol and aniline

Fe3O4/CeO2 nanocomposites were synthetized by coating magnetite seeds of different morphologies (hexagonal, spheroidal, quasi-spherical) with ceria, in ethylene glycol as solvothermal solvent. The synthesis was performed in the presence of microwave irradiation aiming to overcome the common disadvantages proper of the classic solvothermal/hydrothermal procedure. The obtained nanocomposites were calcined at the optimum temperature of 550 °C. The structure of the new nanomaterials was carefully investigated by IR, XRD, SEM, EDS and TEM analyses. The nanocomposites resulted to be constituted by CeO2 nanoparticles distributed onto Fe3O4 seeds, that kept their pristine morphology. The new materials were used as catalysts for imine synthesis from benzyl alcohol and aniline. The highest imine conversion rate was obtained with Fe3O4/CeO2, which was synthesized from Fe3O4 nanoparticles (hexagonal) obtained by microwave hydrothermal procedure in the absence of any organic additive (polyvinylpyrrolidone, trisodium citrate dihydrate or oleic acid). The catalyst could be easily removed from the reaction mixture with the help of an external magnet, and it was recycled for at least five runs with increasing catalytic activit

Microwave-assisted solvothermal synthesis of fe3o4/ceo2 nanocomposites and their catalytic activity in the imine formation from benzyl alcohol and aniline

Fe3O4/CeO2 nanocomposites were synthetized by coating magnetite seeds of different morphologies (hexagonal, spheroidal, quasi-spherical) with ceria, in ethylene glycol as solvothermal solvent. The synthesis was performed in the presence of microwave irradiation aiming to overcome the common disadvantages proper of the classic solvothermal/hydrothermal procedure. The obtained nanocomposites were calcined at the optimum temperature of 550 °C. The structure of the new nanomaterials was carefully investigated by IR, XRD, SEM, EDS and TEM analyses. The nanocomposites resulted to be constituted by CeO2 nanoparticles distributed onto Fe3O4 seeds, that kept their pristine morphology. The new materials were used as catalysts for imine synthesis from benzyl alcohol and aniline. The highest imine conversion rate was obtained with Fe3O4/CeO2, which was synthesized from Fe3O4 nanoparticles (hexagonal) obtained by microwave hydrothermal procedure in the absence of any organic additive (polyvinylpyrrolidone, trisodium citrate dihydrate or oleic acid). The catalyst could be easily removed from the reaction mixture with the help of an external magnet, and it was recycled for at least five runs with increasing catalytic activity

Overexpression of CD157 contributes to epithelial ovarian cancer progression by promoting mesenchymal differentiation

Epithelial ovarian carcinoma (EOC) is an aggressive tumor often diagnosed at an advanced stage, when there is little or no prospect of cure. Despite advances in surgical and chemotherapeutic strategies, only marginal improvements in patient outcome have been obtained. Hence, unraveling the biological mechanisms underpinning EOC progression is critical for improving patients’ survival. Recently, we reported that CD157 (an ectoenzyme regulating leukocyte diapedesis) is expressed in EOC and that high expression of the molecule is negatively correlated with the disease outcome in patients. Here, we demonstrate that forced overexpression of CD157 in OVCAR-3, TOV-21G, A2780 and OV-90 ovarian cancer cell lines promotes morphological and phenotypic changes characterized by disruption of intercellular junctions, downregulation of epithelial markers and upregulation of mesenchymal ones. These changes in cell shape and phenotype bring to reduced sensitivity to anoikis, increased anchorage-independent growth, cell motility and mesothelial invasion. Conversely, knockdown of CD157 in OV-90 and OC314 cells reverts the mesenchymal phenotype and reduces the cells’ migratory potential. Transcriptome profiling analysis highlighted 378 significantly differentially expressed genes, representing the signature of CD157-overexpressing OVCAR-3 and OV-90 cells. The modulation of selected genes translates into alteration of protein expression that give cells a highly malignant phenotype. The overall picture deduced from the analysis of the modulated transcripts is that high expression of CD157 strengthens a number of biological processes favoring tumor progression (including development and cell motility), and weakens several biological processes hindering tumor progression (such as apoptosis, cell death and response to stress). Together, these findings implicate CD157 in the progression of EOC to metastatic disease and suggest that CD157 may represent a valuable therapeutic target

ACTA OTORHINOLARYNGOLOGICA ITALICA

L’obiettivo di questo studio era quello di confrontare la Videofluoroscopia (VFS), la valutazione endoscopica a fibre ottiche della deglutizione (FEES) e la scintigrafia oro-faringo-esofagea (OPES) per quanto riguarda la caduta pre-deglutitoria, il ristagno post-deglutitorio e l’aspirazione, al fine di valutare l’attendibilità di questi test nel rilevare la disfagia orofaringea. Sessanta pazienti, affetti da disfagia di varia origine, sono stati arruolati nello studio e sottoposti a VFS, FEES e OPES utilizzando un bolo liquido e uno semi-solido. Abbiamo usato la VFS come esame di riferimento. La FEES e la OPES hanno entrambe mostrato una buona sensibilità, con valori complessivi elevati (rispettivamente ≥ 80% e ≥ 90%). Il confronto tra FEES e VFS relativamente alla caduta pre-deglutitoria ha evidenziato una buona specificità (84,4% per i semi-solidi e 86,7% per i liquidi). Nel caso di ristagni post-deglutitori, il confronto tra FEES e VFS ha rivelato una buona validità complessiva (75% per i semi-solidi), con specificità e sensibilità ben equilibrate per i semi-solidi. Il confronto tra OPES e VFS ha dimostrato buona sensibilità (88,6%) e validità complessiva (76,7%) per i liquidi. Il confronto dei dati ottenuti tra FEES e VFS, relativamente all’ aspirazione, ha evidenziato una bassa validità complessiva (≤ 65%). D’altra parte, la OPES ha mostrato una validità complessiva apprezzabile (71,7%). VFS, FEES e OPES sono in grado di rilevare la disfagia oro-faringea. La FEES ha fornito risultati significativi nella valutazione dei ristagni post-deglutitori

Gating a single-molecule transistor with individual atoms

Transistors, regardless of their size, rely on electrical gates to control the conductance between source and drain contacts. In atomic-scale transistors, this conductance is sensitive to single electrons hopping via individual orbitals1, 2. Single-electron transport in molecular transistors has been previously studied using top-down approaches to gating, such as lithography and break junctions1, 3, 4, 5, 6, 7, 8, 9, 10, 11. But atomically precise control of the gate—which is crucial to transistor action at the smallest size scales—is not possible with these approaches. Here, we used individual charged atoms, manipulated by a scanning tunnelling microscope12, to create the electrical gates for a single-molecule transistor. This degree of control allowed us to tune the molecule into the regime of sequential single-electron tunnelling, albeit with a conductance gap more than one order of magnitude larger than observed previously8, 11, 13, 14. This unexpected behaviour arises from the existence of two different orientational conformations of the molecule, depending on its charge state. Our results show that strong coupling between these charge and conformational degrees of freedom leads to new behaviour beyond the established picture of single-electron transport in atomic-scale transistors

Qual è l’effetto della radioterapia sulla funzionalità deglutitoria nei pazienti con tumore del rinofaringe e orofaringe? Risultati a breve termine di uno studio prospettico

In questo lavoro vengono riportati i risultati a breve termine di uno studio prospettico, finalizzato alla valutazione strumentale della funzionalità deglutitoria in pazienti affetti da tumore del rinofaringe e orofaringe sottoposti a trattamento radio o radiochemioterapico con tecnica ad intensità modulata (IMRT). L’ IMRT è stata finalizzata, oltre che al miglioramento della conformazione della dose radiante al volume tumorale, alla riduzione della stessa alle strutture responsabili della deglutizione (SWOARs). I criteri dello studio hanno previsto in tutti i pazienti la valutazione strumentale della deglutizione con Videofluoroscopia (VFS), Fibroscopia Endoscopica della deglutizione (FEES) e Scintigrafia Orofaringea (OPES) prima dell’inizio del trattamento e ad 1 mese dal termine dello stesso. Ogni esame è stato eseguito rispettivamente in seguito all’assunzione di un bolo liquido (L) e semiliquido (SL) e per ognuno sono stati calcolati i seguenti valori strumentali: presenza o meno di caduta pre-deglutitoria, presenza o meno di aspirazione, tempo di transito faringeo (PTT) ed indice di ritenzione ipofaringeo (HPRI). Dal Gennaio 2012 al Giugno 2013, un totale di 20 pazienti ha terminato il trattamento ed ha eseguito la valutazione strumentale a 1 mese dal termine della radioterapia. Il confronto tra i valori dell’HPRI prima e dopo il trattamento radiante ha mostrato un peggioramento significativo sia alla FEES-L (p = 0,021) e SL (p = 0,02) che alla VFS-L (p = 0,008) che SL (p = 0,005). Inoltre è stata riscontrata una significativa correlazione tra i valori dell’HPRI basale ed a 1 mese alla FEES-L e SL (p = 0,005) così come alla VFS-L e SL (p 0,2). Solo in pochi pazienti è stata riscontrata la comparsa di caduta pre-deglutitoria ( 1 paziente con tumore della base linguale alla FEES-L e SL) e la presenza di aspirazione (1 paziente con tumore del rinofaringe alla OPES-L e FEES-SL). Nel complesso i risultati iniziali del nostro studio mostrano che l’ IMRT, finalizzata al risparmio delle SWOARs, determina soltanto un significativo incremento della ritenzione di bolo a livello del distretto ipofaringeo. Un follow-up più lungo sarà necessario per valutare se tale incremento sia associato o meno ad un maggior rischio di sviluppare fenomeni di aspirazione tardivi