291 research outputs found

    Carbon-atom wires produced by nanosecond pulsed laser deposition in a background gas

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    Wires of sp-hybridized carbon atoms are attracting interest for both fundamental aspects of carbon science and for their appealing functional properties. The synthesis by physical vapor deposition has been reported to provide sp-rich carbon films but still needs to be further developed and understood in detail. Here the synthesis of carbon-atom wires (CAWs) has been achieved by nanosecond pulsed laser deposition (PLD) expoliting the strong out-of-equilibrium conditions occurring when the ablation plasma is confined in a background gas. Surface Enhnaced Raman scattering (SERS) spectra of deposited films indicates that CAWs are mixed with a mainly sp2sp^2 amorphous carbon in a spsp2sp-sp^2 hybrid material. Optimal conditions for the deposition of sp-carbon phase have been investigated by changing deposition parameters thus suggesting basic mechanisms of carbon wires formation. Our proof-of-concept may open new perspectives for the targeted fabrication of CAWs and spsp2sp-sp^2 structures.Comment: 15 pages 4 figure

    Flexible distributed Bragg reflectors as optical outcouplers for OLEDs based on a polymeric anode

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    Top-emitting OLEDs (TOLEDs) represent a promising technology for the development of next-generation flexible and rollable displays, thanks to their improved light outcoupling and their compatibility with opaque substrates. Metal thin films are the most used electrodes for the manufacturing of TOLEDs, but they show poor resistance to mechanical deformation, which compromises the long-term durability of flexible devices. This paper reports the exploitation of a dielectric mirror (DBR) based on seven pairs of TiO2 and SiO2 combined with a polymeric electrode as an alternative to the bottom metal electrode in flexible TOLEDs. The DBR showed a maximum reflectivity of 99.9% at about 550 nm, and a stop-band width of about 200 nm. The reflectivity remained unchanged after bending and treatment with water and solvents. Green TOLED devices were fabricated on top of DBRs, and demonstrated good stability in terms of electro-optical and colorimetric characteristics, according to varying viewing angles. These results demonstrate that the combination of the flexible DBR with the polymeric anode is an interesting strategy for improving the durability of flexible TOLEDs for display applications, implemented on different kinds of free-standing ultra-thin substrates

    New meson spectroscopy with open charm and beauty

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    All the available experimental information on open charm and beauty mesons is used to classify the observed states in heavy quark doublets. The masses of some of the still unobserved states are predicted, in particular in the beauty sector. Adopting an effective Lagrangian approach based on the heavy quark and chiral symmetry, individual decay rates and ratios of branching fractions are computed, with results useful to assign the quantum numbers to recently observed charmed states which still need to be properly classified. Implications and predictions for the corresponding beauty mesons are provided. The experimental results are already copious, and are expected to grow up thanks to the experiments at the LHC and to the future high-luminosity flavour and ppˉp-\bar p facilities.Comment: RevTex, 15 pages, 1 figure. Corrected Equations (8) and (9

    Light-emitting textiles: Device architectures, working principles, and applications

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    E-textiles represent an emerging technology aiming toward the development of fabric with augmented functionalities, enabling the integration of displays, sensors, and other electronic components into textiles. Healthcare, protective clothing, fashion, and sports are a few examples application areas of e-textiles. Light-emitting textiles can have different applications: Sensing, fashion, visual communication, light therapy, etc. Light emission can be integrated with textiles in different ways: Fabricating light-emitting fibers and planar light-emitting textiles or employing side-emitting polymer optical fibers (POFs) coupled with light-emitting diodes (LEDs). Different kinds of technology have been investigated: Alternating current electroluminescent devices (ACELs), inorganic and organic LEDs, and light-emitting electrochemical cells (LECs). The different device working principles and architectures are discussed in this review, highlighting the most relevant aspects and the possible approaches for their integration with textiles. Regarding POFs, the methodology to obtain side emissions and the critical aspects for their integration into textiles are discussed in this review. The main applications of light-emitting fabrics are illustrated, demonstrating that LEDs, alone or coupled with POFs, represent the most robust technology. On the other hand, OLEDs (Organic LEDs) are very promising for the future of light-emitting fabrics, but some issues still need to be addressed

    Electronic transport, ionic activation energy and trapping phenomena in a polymer-hybrid halide perovskite composite

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    The exploitation of methylammonium lead iodide perovskite-polymer composites is a promising strategy for the preparation of photoactive thin layers for solar cells. The preparation of these composites is a simple fabrication method with improved moisture stability when compared to that of pristine perovskite films. To deepen the understanding of the charge transport properties of these films, we investigated charge carrier mobility, traps, and ion migration. For this purpose, we applied a combinatory measurement approach that proves how such composites can still retain an ambipolar charge transport nature and the same mobility values of the related perovskite. Furthermore, thermally stimulated current measurements revealed that the polymer influenced the creation of additional defects during film formation without affecting charge mobility. Finally, impedance spectroscopy measurements suggested the addition of starch may hinder ion migration, which would require larger activation energies to move ions in composite films. These results pave the way for new strategies of polymer-assisted perovskite film development

    Growth hormone secretagogues exert differential effects on skeletal muscle calcium homeostasis in male rats depending on the peptidyl/non-peptidyl structure

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    TheorexigenicandanaboliceffectsinducedbyghrelinandthesyntheticGHsecretagogues(GHSs) are thought to positively contribute to therapeutic approaches and the adjunct treatment of a number of diseases associated with muscle wasting such as cachexia and sarcopenia. However, manyquestionsaboutthepotentialutilityandsafetyofGHSsinboththerapyandskeletalmuscle functionremainunanswered.Byusingfura-2cytofluorimetrictechnique,wedeterminedtheacute effectsofghrelin,aswellasofpeptidylandnonpeptidylsyntheticGHSsoncalciumhomeostasis, a critical biomarker of muscle function, in isolated tendon-to-tendon male rat skeletal muscle fibers.ThesyntheticnonpeptidylGHSs,butnotpeptidylghrelinandhexarelin,wereabletosignificantlyincreaserestingcytosoliccalcium[Ca2]i.ThenonpeptidylGHS-induced[Ca2] iincrease was independent of GHS-receptor 1a but was antagonized by both thapsigargin/caffeine and cyclosporineA,indicatingtheinvolvementofthesarcoplasmicreticulumandmitochondria.EvaluationoftheeffectsofapseudopeptidylGHSandanonpeptidylantagonistoftheGHS-receptor 1a together with a drug-modeling study suggest the conclusion that the lipophilic nonpeptidyl structureofthetestedcompoundsisthekeychemicalfeaturecrucialfortheGHS-inducedcalcium alterationsintheskeletalmuscle.Thus,syntheticGHSscanhavedifferenteffectsonskeletalmuscle fibersdependingontheirmolecularstructures.Thecalciumhomeostasisdysregulationspecifically induced by the nonpeptidyl GHSs used in this study could potentially counteract the beneficial effects associated with these drugs in the treatment of muscle wasting of cachexia- or other age-related disorders

    Successful private–public funding of paediatric medicines research: lessons from the EU programme to fund research into off-patent medicines

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    The European Paediatric Regulation mandated the European Commission to fund research on off-patent medicines with demonstrated therapeutic interest for children. Responding to this mandate, five FP7 project calls were launched and 20 projects were granted. This paper aims to detail the funded projects and their preliminary results. Publicly available sources have been consulted and a descriptive analysis has been performed. Twenty Research Consortia including 246 partners in 29 European and non-European countries were created (involving 129 universities or public funded research organisations, 51 private companies with 40 SMEs, 7 patient associations). The funded projects investigate 24 medicines, covering 10 therapeutic areas in all paediatric age groups. In response to the Paediatric Regulation and to apply for a Paediatric Use Marketing Authorisation, 15 Paediatric Investigation Plans have been granted by the EMAPaediatric Committee, including 71 studies of whom 29 paediatric clinical trials, leading to a total of 7,300 children to be recruited in more than 380 investigational centres. Conclusion: Notwithstanding the EU contribution for each study is lower than similar publicly funded projects, and also considering the complexity of paediatric research, these projects are performing high-quality research and are progressing towards the increase of new paediatric medicines on the market. Private–public partnerships have been effectively implemented, providing a good example for future collaborative actions. Since these projects cover a limited number of offpatent drugs and many unmet therapeutic needs in paediatrics remain, it is crucial foreseeing new similar initiatives in forthcoming European funding programmes

    Fabrication of high quality plan-view TEM specimens using the focused ion beam

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    We describe a technique using a focused ion beam instrument to fabricate high quality plan-view specimens for transmission electron microscopy studies. The technique is simple, site-specific and is capable of fabricating multiple large, >100 μm2 electron transparent windows within epitaxially-grown thin films. A film of La0.67Sr0.33MnO3 is used to demonstrate the technique and its structural and functional properties are surveyed by high resolution imaging, electron spectroscopy, atomic force microscopy and Lorentz electron microscopy. The window is demonstrated to have good thickness uniformity and a low defect density that does not impair the film’s Curie temperature. The technique will enable the study of in–plane structural and functional properties of a variety of epitaxial thin film systems

    DNA methylation profiling reveals common signatures of tumorigenesis and defines epigenetic prognostic subtypes of canine Diffuse Large B-cell Lymphoma

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    Epigenetic deregulation is a hallmark of cancer characterized by frequent acquisition of new DNA methylation in CpG islands. To gain insight into the methylation changes of canine DLBCL, we investigated the DNA methylome in primary DLBCLs in comparison with control lymph nodes by genome-wide CpG microarray. We identified 1,194 target loci showing different methylation levels in tumors compared with controls. The hypermethylated CpG loci included promoter, 5'-UTRs, upstream and exonic regions. Interestingly, targets of polycomb repressive complex in stem cells were mostly affected suggesting that DLBCL shares a stem cell-like epigenetic pattern. Functional analysis highlighted biological processes strongly related to embryonic development, tissue morphogenesis and cellular differentiation, including HOX, BMP and WNT. In addition, the analysis of epigenetic patterns and genome-wide methylation variability identified cDLBCL subgroups. Some of these epigenetic subtypes showed a concordance with the clinical outcome supporting the hypothesis that the accumulation of aberrant epigenetic changes results in a more aggressive behavior of the tumor. Collectively, our results suggest an important role of DNA methylation in DLBCL where aberrancies in transcription factors were frequently observed, suggesting an involvement during tumorigenesis. These findings warrant further investigation to improve cDLBCL prognostic classification and provide new insights on tumor aggressiveness
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