Evaluating the Impedance Field through several transport models: a comparison

J. APPL. PHYS

Ag nanoparticle-based inkjet printed planar transmission lines for RF and microwave applications: considerations on ink composition, nanoparticle size distribution and sintering time

Sintering of Ag Nanoparticle (NP) - based inkjet printed tracks is a crucial process for the next-generation digitally printed electronics. In particular, while the digital printing, as additive technology, is now well settled for what concerns either DC or signal applications both on rigid and on flexible substrates, this technology has not been demonstrated yet in the RF or microwave field, and a few works appear considering vacuum-evaporated films, screen-printed pastes or inkjet printed inks. We studied the effects of both ink composition and thermal profile on the resulting electrical properties, performing real-time resistance acquisition (DC) and post-annealing microwave measurements. We tested ink compositions featuring both different NP size distributions and different phase compositions, including a pure solvent/salt/metal one and a solvent/salt/metal/polymer one, resulting in a peculiar mass distribution and heat diffusion. The composition strongly affects the onset of electrical percolation and the final resistivity; on the contrary, the heating rate can either have an effect on electrical properties or not depending on the composition. The microwave characterization of microstrip lines printed on alumina substrates, performed up to 26.5 GHz, yield attenuations that are comparable with the best results obtained so far with the same technolog

Evaluating GaN Doherty architectures for 4G Picocells, WiMax and microwave backhaul links

This paper evaluates the Doherty power amplifier architecture in terms of linearity, efficiency and design solutions. As case study four different prototypes are presented, one for 4G Picocells at 2.1 GHz, one for WiMax applications at 3.5 GHz and two for point-to-point microwave backhaul radiolinks at 7 GHz. Experimental results together with design guidelines are discussed addressing strengths and weaknesses of the Doherty architectur

Oral chemotherapy: an innovative choice

10nonemixedBergui, L.; SCALDAFERRI, matilde; SCIORSCI, elisa; VALINOTTI, GIULIA; GHIGGIA, ADA; CAVALLO, Federica; FERRERO, Simone; Ghione, P.; CASTELLI, Lorys; TORTA, RiccardoBergui, L.; Scaldaferri, Matilde; Sciorsci, Elisa; Valinotti, Giulia; Ghiggia, Ada; Cavallo, Federica; Ferrero, Simone; Ghione, P.; Castelli, Lorys; Torta, Riccard

Alginate-based hydrogels functionalised at the nanoscale using layer-by-layer assembly for potential cartilage repair

Injuries to articular cartilage are frequently difficult to repair, in part because of the poor regenerative capacity of this tissue. To date, no successful system for complete regeneration of the most challenging cartilage defects has been demonstrated. The aim of this work was to develop functionalised hydrogels at the nanoscale by Layer-by-Layer (LbL) assembly to promote cartilage healing. Hydrogels, based on sodium alginate (NaAlg) and gelatin (G), were prepared by an external gelation method consisting of CaCl2 diffusion and genipin addition for G crosslinking. Successively, hydrogels were coated with G to obtain a positive charge on the surface, then functionalised by LbL assembly to create 16 nanolayers, based on poly(styrene sulfonate)/poly(allyl amine) (PSS/PAH), including a specific peptide sequence (CTATVHL) and transforming growth factors β1 (TGF-β1). Physico-chemical properties were evaluated by XPS, ATR-FTIR and rheological analyses while in vitro cytocompatibility was studied using bovine articular chondrocytes (BAC). XPS spectra showed N1s and S2p peaks, indicating that PAH and PSS have been introduced with success. ATR-FTIR indicated the specific PAH and PSS absorption peaks. Finally, the biomolecule incorporation influenced positively the processes of BAC adhesion and proliferation, and glycosamynoglycan secretion. The functionalised alginate-based hydrogels described here are ideally suited to chondral regeneration in terms of their integrity, stability, and cytocompatibility

Modeling challenges for high-efficiency visible light-emitting diodes

In order to predict through numerical simulation the optical and carrier transport properties of GaN-based light-emitting diodes (LEDs), a genuine quantum approach should be combined with an atomistic description of the electronic structure. However, computational considerations have elicited the empirical inclusion of quantum contributions within conventional semiclassical drift-diffusion approaches. The lack of first-principles validation tools has left these \u201cquantum corrections\u201d largely untested, at least in the context of LED simulation. We discuss here the results obtained comparing state-of-the-art commercial numerical simulators, in order to assess the predictive capabilities of some of the most important quantum-based models complementing the drift-diffusion equations

Influencia del procesamiento del fruto de membrillo (Cydonia Oblonga Miller) en el contenido de polifenoles y actividad antioxidante del mismo.

Los polifenoles son metabolitos secundarios presentes en gran proporción en las frutas, en su mayoría representados por los flavonoides y ácidos fenólicos. El creciente interés por estas sustancias es principalmente debido a su capacidad antioxidante y la asociación entre su consumo y la prevención de algunas enfermedades. Entre las frutas, el membrillo es una importante fuente de componentes que promueven la salud, tales como compuestos fenólicos. Si bien el membrillo no se consume fresco debido a su dureza, amargor y astringencia, es muy apreciado como materia prima para la producción de dulces y jaleas. El objetivo de este trabajo fue evaluar la propiedad antioxidante del fruto de membrillo, su dulce y los productos intermediarios de su elaboración, con el fin de estudiar el efecto del procesado térmico en las características nutricionales del mismo. Se analizaron el fruto (pulpa+piel), la mezcla cruda (pulpa+piel+azúcar) y el dulce regular y el reducido en carbohidratos. Se midió el contenido de polifenoles totales (PT), perfil de polifenoles por HPLC-DAD-MSMS y la actividad antioxidante in vitro por las técnicas DPPH (capacidad de atrapamiento de radicales libres) y FRAP (poder reductor). Todas las muestras analizadas presentaron un alto contenido de polifenoles en un rango de 200-500 mg ac. gálico/100g muestra (futo, mezcla cruda, dulce). Se demostró la actividad antioxidante in vitro por ambos métodos en todas las muestras. Los valores obtenidos variaron entre 400 y 1500 μmol TROLOX/100g muestra (futo, mezcla cruda, dulce). Tanto para la línea regular como la reducido en carbohidratos se mantuvo el contenido de polifenoles desde el fruto al dulce, conteniendo el regular 370 mg de ác. gálico/100 g de dulce y el light 184 mg ác. gálico/100g de dulce. Por otro lado se lograron identificar 16 compuestos polifenólicos, siendo los mayoritarios los ácidos cafeoil-quínicos, seguidos por los derivados del ácido cumárico, catequina y quercetina. La proporción de los distintos compuestos también se mantuvo desde el fruto al dulce, lo que significa que el procesado térmico no afecta cuantitativamente ni cualitativamente el contenido de polifenoles. Con respecto a la capacidad antioxidante determinada por DPPH y FRAP, como era de esperarse al mantenerse el contenido de polifenoles, no hubo tampoco pérdida de la actividad debido al procesamiento del membrillo. Los resultados obtenidos demuestran que el dulce de membrillo realiza un aporte importante de antioxidantes en la dieta, y además que no existe perdida en la calidad nutricional debido al procesado térmico.publishedVersio

Five-year outcomes of chronic total occlusion treatment with a biolimus A9-eluting biodegradable polymer stent versus a sirolimus-eluting permanent polymer stent in the LEADERS all-comers trial

Background: Few data are available on long-term follow-up of drug-eluting stents in the treatment of chronic total occlusion (CTO). The LEADERS CTO sub-study compared the long-term results in CTO and non-CTO lesions of a Biolimus A9™-eluting stent (BES) with a sirolimus-eluting stent (SES). Methods: Among 1,707 patients enrolled in the prospective, multi-center, all-comers LEADERS trial, 81 with CTOs were treated with either a BES (n = 45) or a SES (n = 36). The primary endpoint was the occurrence of major adverse cardiac events (MACE): cardiac death, myocardial infarction (MI) and clinically-indicated target vessel revascularization (TVR). Results: At 5 years, the rate of MACE was numerically higher in the CTO group than in the non-CTO group (29.6% vs. 23.3%; p = 0.173), with a significant increase in the incidence of target lesion revascularization (TLR) (21.0 vs. 12.6; p = 0.033), but no difference in stent thrombosis (ST). Patients with CTO receiving a BES demonstrated a lower incidence of MACE (22.2% vs. 38.9%; p = 0.147) with a significant reduction in TLR compared to patients receiving a SES (11.1% vs. 33.3%, p = 0.0214) with an incidence similar to that observed in the non-CTO group treated with BES (11.6%). Definite ST at 5 years nearly halved in the BES group (4.4% vs. 8.3%, p = 0.478) with no ST in the BES group after the first year (0% vs. 8.3%, p for interaction = 0.009). Conclusions: The use of a BES showed a reduction in MACE, TVR, TLR, and ST over time in the CTO subset with similar outcome as for non-CTO lesions

Pasquale del Pezzo, Duke of Caianello, Neapolitan mathematician

This article is dedicated to a reconstruction of some events and achievements, both personal and scientific, in the life of the Neapolitan mathematician Pasquale del Pezzo, Duke of Caianello

Cardiovascular mortality and exposure to extremely low frequency magnetic fields: a cohort study of Swiss railway workers

<p>Abstract</p> <p>Background</p> <p>Exposure to intermittent magnetic fields of 16 Hz has been shown to reduce heart rate variability, and decreased heart rate variability predicts cardiovascular mortality. We examined mortality from cardiovascular causes in railway workers exposed to varying degrees to intermittent 16.7 Hz magnetic fields.</p> <p>Methods</p> <p>We studied a cohort of 20,141 Swiss railway employees between 1972 and 2002, including highly exposed train drivers (median lifetime exposure 120.5 μT-years), and less or little exposed shunting yard engineers (42.1 μT-years), train attendants (13.3 μT-years) and station masters (5.7 μT-years). During 464,129 person-years of follow up, 5,413 deaths were recorded and 3,594 deaths were attributed to cardio-vascular diseases. We analyzed data using Cox proportional hazards models.</p> <p>Results</p> <p>For all cardiovascular mortality the hazard ratio compared to station masters was 0.99 (95%CI: 0.91, 1.08) in train drivers, 1.13 (95%CI: 0.98, 1.30) in shunting yard engineers, and 1.09 (95%CI: 1.00, 1.19) in train attendants.Corresponding hazard ratios for arrhythmia related deaths were 1.04 (95%CI: 0.68, 1.59), 0.58 (95%CI: 0.24, 1.37) and 1.30 (95%CI: 0.87, 1.93) and for acute myocardial infarction 1.00 (95%CI: 0.73, 1.36), 1.56 (95%CI: 1.04, 2.32), and 1.14 (95%CI: 0.85, 1.53). The hazard ratio for arrhythmia related deaths per 100 μT-years of cumulative exposure was 0.94 (95%CI: 0.71, 1.24) and 0.91 (95%CI: 0.75, 1.11) for acute myocardial infarction.</p> <p>Conclusion</p> <p>This study provides evidence against an association between long-term occupational exposure to intermittent 16.7 Hz magnetic fields and cardiovascular mortality.</p