328 research outputs found

    Pseudolus, un doppio gioco onomastico. Alcune considerazioni sul lessico dell’inganno in Plauto

    Get PDF
    The word dolus recurs very often in this play: this appears to support Pascucci’s view on the name Pseudolus as a nomen agentis, in which -olus did not evolve into -ulus for the very sake of a word play with dolus

    Polyamine–Drug Conjugates: Do They Boost Drug Activity?

    Get PDF
    Over the past two decades, the strategy of conjugating polyamine tails with bioactive molecules such as anticancer and antimicrobial agents, as well as antioxidant and neuroprotective scaffolds, has been widely exploited to enhance their pharmacological profile. Polyamine transport is elevated in many pathological conditions, suggesting that the polyamine portion could improve cellular and subcellular uptake of the conjugate via the polyamine transporter system. In this review, we have presented a glimpse on the polyamine conjugate scenario, classified by therapeutic area, of the last decade with the aim of highlighting achievements and fostering future developments

    Optical properties of polystyrene-ZnO nanocomposite scattering layer to improve light extraction in organic light-emitting diode

    Get PDF
    In this work, experimental measurements on polystyrene-ZnO nanocomposite scattering films and on organic light-emitting device with and without the scattering layers are presented. The results are also compared with Henyey-Greenstein radiative-transfer model to narrow down the parameters that can be important in the identification of more suitable scattering layers. As a result, an increase of efficiency of about 30% has been obtained that it can be translated in 60% of outcoupled light in respect to the total generated amount

    Mutations in the quinolone resistance-determining regions of gyrA and parC in Enterobacteriaceae isolates from Brazil

    Get PDF
    Mutations in the quinolone resistance-determining regions (QRDR) in chromosomal gyrA and parC genes and fluoroquinolone susceptibility profiles were investigated in quinolone-resistant Enterobacteriaceae isolated from community and hospitalized patientsin the Brazilian Southeast region. A total of 112 nalidixic acid-resistant enterobacterial isolates collected from 2000 to 2005 were investigated for mutations in the topoisomerases genes gyrA and parC by amplifying and sequencing the QRDR regions. Susceptibility to fluoroquinolones was tested by the agar dilution method. Amongst the 112 enterobacterial isolates, 81 (72.3%) were resistant to ciprofloxacin and 5 (4.5%) showed reduced susceptibility. Twenty-six (23.2%) were susceptible to ciprofloxacin. Several alterations were detected in gyrA and parC genes. Escherichia coli isolates (47.7%) showed double mutations in the gyrA gene and a single one in the parC gene. Two unusual aminoacid substitutions are reported, an Asp87-Asn in a Citrobacter freundii isolate with reduced susceptibility to fluoroquinolones and a Glu84-Ala in one E. coli isolate.Only a parC gene mutation was found in fluoroquinolone-susceptible Enterobacter aerogenes. None of the isolates susceptible to ciprofloxacin presented mutations in topoisomerase genes. This comprehensive analysis of QRDRs in gyrA and parC genes, covering commonly isolated Enterobacteriaceae in Brazil is the largest reported up to now

    Synthesis of highly regioregular poly[3-(4-alkoxyphenyl)-thiophene]s by oxidative catalysis using copper complexes

    Get PDF
    A novel, easy, and cost-effective synthetic procedure is reported for the production of very highly regioregular poly[3-(4-alkoxyphenyl)thiophene]s by means of oxidative coupling. Four copper complexes were synthesized and used as catalysts to obtain polymers with higher regioregularity compared to the previous oxidative coupling methodologies reported in the literature and similar to that obtained by McCullough and Rieke methods in the synthesis of poly-3-alkylthiophenes. The regioregularity of the synthesized polymers was investigated by UV-Visible characterization on polymer thin films and 1H NMR analysis. The remarkable potentialities of these polymers have emerged from field-effect transistor mobility measurements operated on devices with bottom-contact configuration and hexamethyldisilazane-treated SiO 2 gate dielectric, showing a well-defined p-type field-effect response and maximum mobility values in air higher than 10-4 cm 2 V-1 s-1. © 2013 Wiley Periodicals, Inc

    analysis of hmds self assembled monolayer effect on trap density in pc70bm n type thin film transistors through admittance studies

    Get PDF
    Abstract In this work, n-type organic thin film transistors (OTFTs) were fabricated in the bottom-gate bottom-contact configuration, depositing a fullerene-derived semiconductor (PC 70 BM) by drop-casting technique on SiO 2 substrates treated with a self-assembled monolayer, namely the HMDS. The influence of the deposition temperature of the HMDS on the device performance was investigated, using three different temperatures. The relationship between the properties of the resulting semiconductor films and the electrical characteristics of the transistors was evaluated through admittance measurements. The frequency response of the devices vs. the bias was interpreted applying an electrical equivalent circuit to model the properties of the semiconductor and of the transistor conductive channel. The proposed model shows the critical role played by the quality of the insulator-semiconductor interface on the traps density in the semiconductor, and therefore on the increase of the mobility and on the reduction of the threshold voltage of the transistors

    Photonic crystal electrode to be used in organic LED structures

    Get PDF
    In this work we report the possibility to obtain a high refractive index grid anode directly on the substrate surface by fabricating a relatively large-area photonic crystal (PC) structure using the combinations of electron beam lithography (EBL) and focused ion beam (FIB) techniques. The performance of the realized photonic crystal (PC) structure were enhanced by milling the ITO layer until the glass substrate and by removing the further refractive index jump between the PC and the substrate. The good properties of highly conductive poly(3,4 ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), ensured a continuous path for the current and a high refractive index jump for the PC structure by filling the holes in the PC structure

    Analysis of the muscarinic receptor subtype mediating inhibition of the neurogenic contractions in rabbit isolated vas deferens by a series of polymethylene tetra-amines

    Get PDF
    1. The pharmacological characteristics of the presynaptic muscarinic receptor subtype, which mediates inhibition of the neurogenic contractions in the prostatic portion of rabbit vas deferens, have been investigated by using a series of polymethylene tetra-amines, which were selected for their ability to differentiate among muscarinic receptor subtypes. 2. It was found that all tetra-amines antagonized McN-A-343-induced inhibition in electrically stimulated rabbit vas deferens in a competitive manner and with affinity values (pA2) ranging between 6.27 ± 0.09 (spirotramine) and 8.51 ± 0.02 (AM170). 3. Competition radioligand binding studies, using native muscarinic receptors from rat tissues (M1, cortex; M2, heart; M3, submaxillary gland) or from NG 108-15 cells (M4) and human cloned muscarinic M1-M4 receptors expressed in CHO-K1 cells, were undertaken with the same tetraamines employed in functional assays. All antagonists indicated a one-site fit. 4. The affinity estimates (pKi) of tetra-amines calculated in binding assays using native receptors were similar to those obtained using cloned receptors. Among these compounds some displayed selectivity between muscarinic receptor subtypes, indicating that they may be valuable tools in receptor characterization. Spirotramine was selective for M1 receptors versus all other subtypes (pKi native: M1, 7.32 ± 0.10; M2, 6.50 ± 0.11; M3, 6.02 ± 0.13; M4, 6.28 ± 0.16; pKi cloned: M1, 7.69 ± 0.08; M2, 6.22 ± 0.14; M3, 6.11 ± 0.16; 6.35 ± 0.11) whereas CC8 is highly selective for M2 receptors versus the other subtypes (pKi native: M1 7.50 ± 0.04; M2, 9.01 ± 0.12; M3, 6.70 ± 0.08; M4, 7.56 ± 0.04; pKi cloned: M1, 7.90 ± 0.20; M2, 9.04 ± 0.08; M3, 6.40 ± 0.07; M4, 7.40 ± 0.04). Furthermore, particularly relevant for this investigation were tetra-amines dipitramine and AM172 for their ability to significantly differentiate M1 and M4 receptors. 5. The apparent affinity values (pA2) obtained for tetra-amines in functional studies using the prostatic portion of rabbit vas deferens correlated most closely with the values (pKi) obtained at either native or human recombinant muscarinic M4 receptors. This supports the view that the muscarinic receptor mediating inhibition of neurogenic contractions of rabbit vas deferens may not belong to the M1 type but rather appears to be of the M4 subtype

    pc70bm n type thin film transistors influence of hmds deposition temperature on the devices properties

    Get PDF
    This study investigates the influence of the deposition temperature of hexamethyldisilazane (HMDS) on the performances of organic thin film transistors (OTFTs) using the [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM) as semiconductor. N-type OTFTs have been fabricated using this fullerene derivative, deposited from solution by drop casting technique on HMDS self-assembled monolayer (SAM) deposited at three different temperatures, 7 °C, 25 °C and 60 °C, in order to evaluate the influence of these deposition conditions on the morphology of PC70BM films and on the electrical responses of fullerene derivative-based OTFTs. The effect of the treatments of the surfaces was observed through contact angle measurements. AFM imaging of the deposited material has been used to analyse its structure and morphology. The transistors performances have been evaluated through I vs. V static characterization and parameters extraction. Contact angle vs. HMDS deposition temperature shows the minimum value at 60 °C, instead here field effect mobility presents a maximum. It has been observed that the lower hydrophobicity of the surface of the SAM induces the formation of more homogeneous surface of the PC70BM film, resulting in an increase of the OTFTs performances
    • …
    corecore