49 research outputs found

    Investigation of the long effective conjugation length in defect-free insulated molecular wires

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    Due to the “insulation” of the π-conjugated backbones, insulated molecular wires (IMWs) are expected to be applied to various optoelectronic applications and nanotechnology.[1] Recently, Kazunori et al have succeeded in the synthesis of a self-threading polythiophene with a polyrotaxane-like 3D architecture (PSTB, see Figure 1), for which an intrawire hole mobility of 0.9 cm2 V−1 s−1 has been measured.[2] Here, we aim to evaluate the extent of π-conjugation along polythiophene backbones sheathed within defect-free “insulating” layers. A comparison between the experimental Raman spectra of the self-threading oligomers (i.e. 2STB-5STB) and the corresponding PSTB polymer indicates that: (i) the ratio of relative intensities of the two most intense Raman bands (I1375/1445) increases with the elongation of the size chain but does not saturate up to the pentamer, and (ii) π-conjugation spreads over 17–18 thiophene units in the polymer. Whether the effective conjugation length of the polymer is better described by using the long oligomer extrapolation approach[3] or periodic DFT calculations of the polymer is discussed in detailed by exploiting the very recent potentialities of state-of-the-art quantum chemical simulations of vibrational properties for crystalline solids.[Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂ­a Tech

    Molecular and electronic structure investigation of encapsulated polytiophenes

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    Insulated molecular wires (IMWs) are expected to be applied to various optoelectronic applications due to their unique photophysical, electronic, and mechanical properties which originate from the absence of -stacking.[1] Kazunori et al have succeeded in the synthesis of a self-threading polythiophene with a polyrotaxane-like 3D architecture (PSTB, see Figure 1a), for which an intrawire hole mobility of 0.9 cm2 V−1 s−1 has been measured.[2] In this study we aim to evaluate for the first time the extension of the -conjugation in encapsulated polythiophenes. A comparison between the experimental Raman spectra of the self-threading PSTB polymer with their correspondent oligomers (i.e. 2STB-5STB) suggests that the effective conjugation length in the polymer is longer than five monomer units. Whether the effective conjugation length of the polymer is better described by using the long oligomer extrapolation approach or periodic DFT calculations of the polymer is discussed in detailed by exploiting the very recent potentialities of state-of-the-art quantum chemical simulations of vibrational properties for crystalline solids.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    COVID-19 diagnosis and SARS-CoV-2 viral load in hospitalized patients versus people with Flu-Like Syndrome

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    At the beginning of the pandemic, the Brazilian Public Health System (SUS) did not to test all suspects cases of COVID-19, thus, hospitalized individuals, health professionals, and symptomatic contacts were prioritized. Contrary to the criteria adopted by the government, the municipality of Botucatu chose to test all people who manifested flu-like syndrome. We aimed to investigate whether positive cases for COVID-19 were more frequent in patients seeking diagnosis via SUS or in the group of people seeking diagnosis via Municipal Health Center and whether the viral load was expressed differently in hospitalized patients (HP) compared to mild symptoms (MHC). Results showed that there were no differences in the percentage between the groups. Regarding the viral load, significant differences were found between the samples from HP and MHC (3-10 days of symptoms), with HP presenting a lower viral load. The results provide significant information about the viral load at different time-lapses

    Clinical Learning Environment And Graduating Nursing Students’ Competence: A Multi‐Country Cross‐Sectional Study

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    The purpose of this study was to explore nursing students’ perceptions of their final clinical learning environment and its association with their self‐assessed competence, satisfaction with nursing education and turnover intentions at graduation in six European countries. A multi‐country comparative cross‐sectional study was conducted with nursing students (n = 1,746) from the Czech Republic, Finland, Italy, Portugal, Slovakia and Spain using the Nurse Competence Scale and the Clinical Learning Environment and Supervision scale. Nursing students’ overall perceptions of their final clinical learning environment and supervision were positive in all the countries studied. The correlation between the students’ perceptions of their final clinical learning environment and competence was statistically significant and positive. Satisfaction with the nursing programme and clinical practicum and no consideration of career change were related to positive perceptions of the final clinical learning environment. Highlighting the importance of the supervisory relationship and pedagogical atmosphere, nursing students’ positive perceptions of the final clinical learning environment and supervision contribute to a better level of self‐assessed competence and satisfaction with the nursing programme and clinical practicum, leading to lower turnover intentions.</p

    LIME -- a gas TPC prototype for directional Dark Matter search for the CYGNO experiment

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    The CYGNO experiment aims at the development of a large gaseous TPC with GEM-based amplification and an optical readout by means of PMTs and scientific CMOS cameras for 3D tracking down to O(keV) energies, for the directional detection of rare events such as low mass Dark Matter and solar neutrino interactions. The largest prototype built so far towards the realisation of the CYGNO experiment demonstrator is the 50 L active volume LIME, with 4 PMTs and a single sCMOS imaging a 33×\times33 cm\textsuperscript{2} area for 50 cm drift, that has been installed in underground Laboratori Nazionali del Gran Sasso in February 2022. We will illustrate LIME performances as evaluated overground in Laboratori Nazionali di Frascati by means of radioactive X-ray sources, and in particular the detector stability, energy response and energy resolution. We will discuss the MC simulation developed to reproduce the detector response and show the comparison with actual data. We will furthermore examine the background simulation worked out for LIME underground data taking and illustrate the foreseen expected measurement and results in terms of natural and materials intrinsic radioactivity characterisation and measurement of the LNGS underground natural neutron flux. The results that will be obtained by underground LIME installation will be paramount in the optimisation of the CYGNO demonstrator, since this is foreseen to be composed by multiple modules with the same LIME dimensions and characteristics

    Signal-On Fluorescent Imprinted Nanoparticles for Sensing of Phenols in Aqueous Olive Leaves Extracts

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    The activation of signals in fluorescent nanosensors upon interaction with their targets is highly desirable. To this aim, several molecularly imprinted nanogels have been synthetized for the recognition of tyrosol, hydroxytyrosol and oleuropein in aqueous extracts using the non-covalent approach. Two of them contain fluorescein derivatives as co-monomers, and their fluorescence emission is switched on upon binding of the target phenols. The selection of functional monomers was previously done by analyzing the interactions by nuclear magnetic resonance (NMR) in deuterated dimethylsulfoxide (DMSO-d6) of the monomers with tyrosol and hydroxytyrosol. Polymers were synthetized under high dilution conditions to obtain micro- and nano-particles, as verified by transmission electron microscopy (TEM). 1,4-Divinylbenzene (DVB) was used in the fluorescent polymers in order to enhance the interactions with the aromatic ring of the templates tyrosol and hydroxytyrosol by \u3c0-\u3c0 stacking. The results were fully satisfactory as to rebinding: DVB-crosslinked molecularly imprinted polymers (MIPs) gave over 50 nmol/mg rebinding. The sensitivity of the fluorescent MIPs was excellent, with LODs in the pM range. The sensing polymers were tested on real olive leaves extracts, with very good performance and negligible matrix effects

    Effects of irrigation on yield components and quality of walnut cultivar ‘Chandler’

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    In Italy walnut cultivation is mainly concentrated in Campania region, where traditional and new specialized orchard coexist and international cultivars are utilized for the new plantations. The growth and productivity of the international, high yielding cultivar ‘Chandler’ grown in the dry summer conditions of Naples province has been examined during a two year irrigation trial. Three treatments were applied: an un-irrigated control and two different levels of water supply, corresponding respectively to the restitution of 50 and 100% ET0 by means of a drip irrigation system. Plant growth and nut and kernel weight increased at the highest irrigation volume, while nut fall at ripening was more concentrated in the un-irrigated control. The percentage of defected nuts was higher in condition of limited water availability. The restitution of 50% ET0 assured satisfactory levels of production and saving of irrigation water
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