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Bis(2-phenylpyridine-C,N)(2,2′-bipyridine-N,N′) iridium(III) hexafluorophosphate ([Ir(ppy)2(bpy)][PF6]) is an ionic transition-metal complex (iTMC) of interest for use in light-emitting electrochemical cells (LEECs). Films of [Ir(ppy)2(bpy)][PF6] blended with the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm][PF6]), deposited on different substrates, have been investigated for their morphological features, which are expected to affect the functional properties of the films, e.g., charge carrier transport. In literature, ionic liquids have been included in films of transition-metal complexes (TMCs) to increase the ion mobility and improve the performance of LEECs. A systematic comparison between the morphology of pure [Ir(ppy)2(bpy)][PF6] films and [Ir(ppy)2(bpy)][PF6] films containing [BMIm][PF6] has been carried out on different types of substrate, namely Au-patterned SiO2, indium tin oxide (ITO), and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS)-modified ITO. Although [Ir(ppy)2(bpy)][PF6] forms smooth films on SiO2, ITO, and PEDOT:PSS-modified ITO substrates, addition of [BMIm][PF6] caused formation of vertical, discontinuous aggregates, which are expected to be detrimental to charge transport in LEECs with planar architecture.

A new synthetic method is reported for the N-phosphorylation of pyrroles via intramolecular migration of a phosphonate diester group. The reaction proceeds under mild conditions and produces N-phosphorylated pyrrole derivatives in moderate to good yields.

We aimed to investigate whether simvastatin had any impact on the prevention of adhesion formation after thyroidectomy in a rat model.This study was performed in 66 Wistar albino rats randomized into three experimental groups. A right hemithyroidectomy was carried out in all the rats. Simvastatin was administered locally at a dose of 0.5 mg/kg and 0.8 mg/kg. Control rats received a saline solution only. Changes during the 1st week, 1st month and 3rd month were evaluated. Efficacy of the treatment was assessed by using a scoring system.The severity of adhesions in low-dose simvastatin group was significantly less than the control and high-dose groups during the 1st and 3rd month (p .05). In addition, adhesions were less in the high dose group during the 3rd month, when compared to the control group (p .05). Moreover, fibrosis and fibroblast scores, which represent adhesions, were significantly lower in low-dose and high-dose groups at 3rd month, compared to controls (p .05).We investigated the influence of simvastatin application on post-thyroidectomy adhesion formation in rats. Whether adhesions, causing technical difficulties during neck redo surgery, can be reduced by the use of simvastatin in human, needs to be studied.

In this study; novel aryl, heteroaryl, pyrrolyl and phosphoryl groups containing pyrrolizines were synthesized by the ring annulation reaction of aryl or heteroaryl substituted α-phosphoryl-α,β-unsaturated ketones with pyrrole under mild reaction conditions. This domino reaction involves scandium triflate catalyzed addition of pyrrole to the double bond of α-phosphoryl-α,β-unsaturated ketones, carbonyl group and finally ring annulation sequences. The presented work provided a convenient way for the synthesis of novel bispyrrolic compounds.

A physical model of human Tympanic Membrane (TM), based on PDMS, as an easily accessible test platform for acoustic transducers was designed and fabricated.

Made available in DSpace on 2022-04-28T19:01:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-09-17 Electrolyte-gated (EG) transistors, based on electrolyte gating media, are powerful device structures to modulate the charge carrier density of materials by orders of magnitude, at relatively low operating voltages (sub-2 V). Tungsten trioxide (WO3) is a metal oxide semiconductor well investigated for applications in electrochromism, sensing, photocatalysis, and photoelectrochemistry. In this work, we report on EG transistors making use of mesoporous nanostructured WO3 thin films easily permeated by the electrolyte as the transistor channel and bis(trifluoromethylsulfonyl)imide ([TFSI])-based ionic liquids as the gating media. The WO3 EG transistors operate at ca. 1 V. Using a combination of cyclic voltammetry, X-ray diffraction, and transistor performance characterizations, complemented by spectroscopic (Raman and infrared) investigations, we correlate the metal oxidation state and the charge transport properties of the metal oxide, shedding light on the doping process in electrically biased WO3 nanostructured thin films exposed to electrolytes. Département de Génie Physique Polytechnique Montréal, C.P. 6079, Succ. Centre Ville Departamento de Físico-Química Universidade Estadual Paulista, Rua Professor Degni, 55 CNR-IENI Dipartimento di Scienze Chimiche Università di Padova, Via F. Marzolo 1 Département de Chimie Université de Montréal, C.P. 6128, Succ. Centre Ville Dipartimento di Chimica giacomo Ciamician Università di Bologna, Via Selmi, 2 Departamento de Físico-Química Universidade Estadual Paulista, Rua Professor Degni, 55

Upconverting materials are currently explored in the field of solar energy conversion in order to extend the light harvesting properties of semiconductors to the near-infrared (NIR) region, their absorption being generally limited to the visible region of the solar spectrum. Here, we propose to photosensitize nanostructured films of tungsten oxide (WO3), a semiconductor widely investigated in photoelectrochemistry, photocatalysis and electrochromics, with NaGdF4:Er3+, Yb3+ upconverting nanoparticles (UCNPs). In order to do so, we fabricate nanocomposite films of WO3 and NaGdF4:Er3+, Yb3+ UCNPs (indicated as UCNP/WO3 films). Current–time measurements show that, under irradiation at λ = 980 nm, a relative increase in current of about 3% with respect to the dark current is observed in the UCNP/WO3 films. The UCNP/WO3 mol% ratio and the temperature of the thermal treatment of the nanocomposite films are both critical to simultaneously achieve photosensitization and charge carrier transport in the UCNP/WO3 films.

This paper presents design and fabrication of a MEMS-based thin film piezoelectric transducer to be placed on an eardrum for fully-implantable cochlear implant (FICI) applications. Resonating at a specific frequency within the hearing band, the transducer senses eardrum vibration and generates the required voltage output for the stimulating circuitry. Moreover, high sensitivity of the sensor, 391.9 mV/Pa @900 Hz, decreases the required power for neural stimulation. The transducer provides highest voltage output in the literature (200 mVpp @100 dB SPL) to our knowledge. A multi-frequency piezoelectric sensor, covering the daily acoustic band, is designed based on the test results and validated through FEA. The implemented system provides mechanical filtering, and mimics the natural operation of the cochlea. Herewith, the proposed sensor overcomes the challenges in FICI operations and demonstrates proof-of-concept for next generation FICIs.

This paper presents the first acoustic experimental results of a MEMS based bulk piezoelectric transducer for use in fully implantable cochlear implants (FICI). For this purpose, the transducer was attached onto an acoustically vibrating membrane. Sensing and energy harvesting performances were measured using neural stimulation and rectifier circuits, respectively. The chip has a 150 Hz bandwidth around 1800 Hz resonance frequency that is suitable for mechanical filtering as a sensor. As an energy harvester, bulk piezoelectric transducer generated a rectified power of 16.25μW with 2.47 VDCwith 120 dB-A sound input at 1780 Hz. Among other MEMS acoustic energy harvesters in the literature, reported transducer has the highest power density (1.5 × 10−3W/cm3) to our knowledge.

In this study; novel aryl, heteroaryl, pyrrolyl and phosphoryl groups containing pyrrolizines were synthesized by the ring annulation reaction of aryl or heteroaryl substituted α-phosphoryl-α,β-unsaturated ketones with pyrrole under mild reaction conditions. This domino reaction involves scandium triflate catalyzed addition of pyrrole to the double bond of α-phosphoryl-α,β-unsaturated ketones, carbonyl group and finally ring annulation sequences. The presented work provided a convenient way for the synthesis of novel bispyrrolic compounds.

Novel phosphonate compounds were synthesized via Michael addition of N-heteroaromatic compounds to aryl- and alkyl­-substituted vinylphosphonates using scandium triflate as the catalyst. Intramolecular cyclization reaction of the Michael adducts obtained gives novel (dimethoxyphosphoryl)pyrrolizin-3-ones in high yields as a single diastereomer.

In this work, we explored the capacity of p-conjugated thiopheno-azomethines in the form of thin films for use in organic electronic applications. The charge-carrier transport properties of the p-conjugated thiopheno-azomethines were obtained in field-effect transistor configuration after the characterization of the film forming properties by fluorescence hyperspectral imaging and atomic force microscopy. We observed a semiconducting behavior for the azomethines investigated, being an oligomer thiophene triad, consisting of two azomethine bonds, and its polymer counterpart, consisting of about 15 azomethines bonds. The charge transport properties of an analogous thiophene vinylene triad were also examined for validating the mobility measurements, because such compounds are known to have hole transport properties. The azomethine triad was found to have a hole mobility of 3 � 10 � 5 cm 2 /Vs.

Useful triheteroarylmethanes were prepared by the double Friedel–Crafts reaction of a wide variety of aromatic N -tosyl imines with furan, thiophene, and pyrrole in the presence of Cu(OTf) 2 and Montmorillonite K-10 clay catalysts.

Regioselective addition of pyrrole to methyl 3-aryl-2-cyanoacrylates was achieved, in high yields, with copper(II) triflate as the catalyst in toluene. C-Alkylated pyrroles afforded novel pyrrolizin-3-ones, in good to high yields and high diastereomeric ratio by an intramolecular cyclization reaction under mild reaction conditions.

A series of metal triflate-catalyzed addition reactions of pyrrole to C=C and C=N bonds have been investigated to access pyrrole-based heterocyclic compounds. The addition of pyrrole to different α,β-unsaturated compounds or N-tosyl imines afforded suitable structures for the construction of [5-5] bicyclic systems or porphyrins, respectively. Intramolecular cyclization reactions were applied for the synthesis of pyrrolizine derivatives. In the other reaction mode, intermolecular cyclization reactions gave A4- and trans-A2B2-meso-substituted porphyrins under mild reaction conditions with low scrambling.

The conversion of Knoevenagel products to N-hetaryl-substituted vinylphosphonates is developed.

We report on ambipolar thin film transistors based on solution-deposited films of a pentacene derivative, 2,3-dicyano-6,13-bis-(triisopropylsilylethynyl)pentacene (2,3-CN2-TIPS-Pn). The ambipolar charge transport observed in this material is well balanced; the values of the hole and electron mobility are both about 2 x 10(-3) cm(2)/Vs. The position of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of 2,3-CN2-TIPS-Pn with respect to the work function of the Au charge-injecting electrode and the arrangement of the molecules in the film, as deduced by grazing incidence x-ray diffraction analysis, contributes to explain the charge transport properties of 2,3-CN2-TIPS-Pn films.

Useful triheteroarylmethanes were prepared by the double Friedel–Crafts reaction of a wide variety of aromatic N -tosyl imines with furan, thiophene, and pyrrole in the presence of Cu(OTf) 2 and Montmorillonite K-10 clay catalysts.

Regioselective addition of pyrrole to methyl 3-aryl-2-cyanoacrylates was achieved, in high yields, with copper(II) triflate as the catalyst in toluene. C-Alkylated pyrroles afforded novel pyrrolizin-3-ones, in good to high yields and high diastereomeric ratio by an intramolecular cyclization reaction under mild reaction conditions.

β-Amino alcohols derived from (1R,2S)-norephedrine were synthesized and used as ligands in the catalytic enantioselective diethylzinc addition to benzaldehydes. N-alkylated (1R,2S)-norephedrine-based derivative 3a gave the highest enantioselectivity. The effects of different parameters on the enantioselectivity of the product were investigated. Copyright © 2009 John Wiley & Sons, Ltd.

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This work main focus is the use of Gold thermocompression and gold-tin transient liquid phase bonding to achieve a hermetic wafer-level packaging. Herein, we describe the major advantages and difficulties that characterized these two bonding processes at design and materials levels. We also provide detailed in- and ex- situ studies of morphological and thermal stabilities of the multi-layer stacks utilized to prepare the wafers to be bonded. These investigations also set the ground to optimize the bonding conditions in order to enable high-quality bonding interfaces.