66 research outputs found

    Chiral Oligothiophenes with Remarkable Circularly Polarized Luminescence and Electroluminescence in Thin Films

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    We report circular polarized electroluminescence (CPEL) in thin films of self-organized oligothiophenes. Four new 1,4-phenylene and 9H-carbazole-based oligothiophenes were ad hoc designed to ensure efficient spontaneous formation of chiral supramolecular order. They were easily synthetized and their chiroptical properties in thin films were measured. Circularly polarized luminescence (CPL) spectra revealed glum in the order of 10-2 on a wide wavelengths range, originating from their self-organized chiral supramolecular organization. These molecules have reasonable properties as organic semiconductors and for this reason they can constitute the active layer of circularlypolarized organic light-emitting diodes (CP-OLEDs). Thus, we could investigate directly their electroluminescence (EL) and CPEL, without resorting to blends, but rather in a simple multilayer device with basic architecture. This is the first example of a CP-OLED with active layer made only of a small organic compound

    A porphyrin pentamer as a bright emitter for NIR OLEDs

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    The luminescence and electroluminescence of an ethyne-linked zinc(ii) porphyrin pentamer have been investigated, by testing blends in two different conjugated polymer matrices, at a range of concentrations. The best results were obtained for blends with the conjugated polymer PIDT-2TPD, at a porphyrin loading of 1 wt%. This host matrix was selected because the excellent overlap between its emission spectrum and the low-energy region of the absorption spectrum of the porphyrin oligomer leads to efficient energy transfer. Thin films of this blend exhibit intense fluorescence in the near-infrared (NIR), with a peak emission wavelength of 886 nm and a photoluminescent quantum yield (PLQY) of 27% in the solid state. Light-emitting diodes (LEDs) fabricated with this blend as the emissive layer achieve average external quantum efficiencies (EQE) of 2.0% with peak emission at 830 nm and a turn-on voltage of 1.6 V. This performance is remarkable for a singlet NIR-emitter; 93% of the photons are emitted in the NIR (λ > 700 nm), indicating that conjugated porphyrin oligomers are promising emitters for non-toxic NIR OLEDs

    A porphyrin pentamer as a bright emitter for NIR OLEDs

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    The Luminescence and electroluminescence of an ethyne-Linked zinc(II) porphyrin pentamer have been investigated, by testing blends in two different conjugated polymer matrices, at a range of concentrations. The best results were obtained for blends with the conjugated polymer PIDT-2TPD, at a porphyrin loading of 1 wt%. This host matrix was selected because the excellent overlap between its emission spectrum and the low-energy region of the absorption spectrum of the porphyrin oligomer leads to efficient energy transfer. Thin films of this blend exhibit intense fluorescence in the near-infrared (NIR), with a peak emission wavelength of 886 nm and a photoluminescent quantum yield (PLQY) of 27% in the solid state. Light-emitting diodes (LEDs) fabricated with this blend as the emissive layer achieve average external quantum efficiencies (EQE) of 2.0% with peak emission at 830 nm and a turn-on voltage of 1.6 V. This performance is remarkable for a singlet NIR-emitter; 93% of the photons are emitted in the NIR (lambda > 700 nm), indicating that conjugated porphyrin oligomers are promising emitters for non-toxic NIR OLEDs

    AVALIAÇÃO DA ATIVIDADE ANTIMICROBIANA DE METABÓLITOS SECUNDÁRIOS PRODUZIDOS POR ACTINOBACTÉRIAS FRENTE À ISOLADOS CLÍNICOS DE ESCHERICHIA COLI ORIUNDAS DE INFECÇÕES DO TRATO URINÁRIO

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    As infecçÔes do trato urinĂĄrio (ITU) estĂŁo entre as principais doenças infecciosas evidenciadas na prĂĄtica clĂ­nica, sendo o principal agente causador a bactĂ©ria Escherichia coli. A exposição frequente desta bactĂ©ria aos antimicrobianos vem acarretando o desenvolvimento de mecanismos de resistĂȘncia, tornando-se necessĂĄrio a obtenção de novos medicamentos com ação bactericida ou bacteriostĂĄtica. Neste sentido, as actinobactĂ©rias se destacam pelo notĂĄvel potencial na produção de novos compostos antibacterianos. O objetivo deste trabalho foi avaliar a atividade antimicrobiana de metabĂłlitos secundĂĄrios produzidos por actinobactĂ©rias frente Ă  isolados clĂ­nicos de E. coli oriundos de infecçÔes do trato urinĂĄrio. Para tanto, foram empregados 88 isolados de actinobactĂ©rias provenientes da rizosfera de plantas. Como microrganismos teste utilizou-se um isolado de E. coli sensĂ­vel e um resistente a antimicrobianos, bem como uma cepa ATCC 25922 desta espĂ©cie, como controle. Dos 88 isolados de actinobactĂ©rias testados, 9,10% (8) apresentaram atividade antimicrobiana frente aos isolados de E. coli. Destacaram-se os isolados R18(6), CT-149, M1-2, M1-23 de actinobactĂ©rias, pois apresentaram os melhores Ă­ndices de antibiose (IA) respectivamente, sendo que o isolado de actinobactĂ©ria que apresentou o maior Ă­ndice de antibiose aos isolados de E. coli foi o isolado R18(6) com IA= 4,28. Os resultados demostram que os metabĂłlitos secundĂĄrios das actinobactĂ©rias contra espĂ©cies patogĂȘnicas de E. coli, sĂŁo uma fonte viĂĄvel de compostos bioativos para a produção de novos antimicrobianos

    Nanoscale Photoluminescence Manipulation in Monolithic Porous Silicon Oxide Microcavity Coated with Rhodamine-Labeled Polyelectrolyte via Electrostatic Nanoassembling

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    Porous silicon (PSi) is a promising material for future integrated nanophotonics when coupled with guest emitters, still facing challenges in terms of homogenous distribution and nanometric thickness of the emitter coating within the silicon nanostructure. Herein, it is shown that the nanopore surface of a porous silicon oxide (PSiO2) microcavity (MC) can be conformally coated with a uniform nm-thick layer of a cationic light-emitting polyelectrolyte, e.g., poly(allylamine hydrochloride) labeled with Rhodamine B (PAH-RhoB), leveraging the self-tuned electrostatic interaction of the positively-charged PAH-RhoB polymer and negatively-charged PSiO2 surface. It is found that the emission of PAH-RhoB in the PSiO2 MC is enhanced (≈2.5×) and narrowed (≈30×) at the resonant wavelength, compared with that of PAH-RhoB in a non-resonant PSiO2 reference structure. The time-resolved photoluminescence analysis highlights a shortening (≈20%) of the PAH-RhoB emission lifetime in the PSiO2 MC at the resonance versus off-resonance wavelengths, and with respect to the reference structure, thereby proving a significant variation of the radiative decay rate. Remarkably, an experimental Purcell factor Fp = 2.82 is achieved. This is further confirmed by the enhancement of the photoluminescence quantum yield of the PAH-RhoB in the PSiO2 MC with respect to the reference structure. Application of the electrostatic nanoassembling approach to other emitting dyes, nanomaterials, and nanophotonic systems is envisaged

    A film-forming graphene/diketopyrrolopyrrole covalent hybrid with far-red optical features: Evidence of photo-stability

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    A dianiline derivative of a symmetric donor-acceptor-donor diketopyrrolopyrrole-based dye is employed for the two-sided covalent functionalization of liquid exfoliated few layers graphene flakes, through a direct arylation reaction. The resulting nanohybrid features the properties of a polymeric species, being solution-processed into homogeneous thin films, featuring a pronounced red-shift of the main absorption band with respect to the model dye unit and energy levels comparable to those of common diketopyrrolopyrrole-based polymers. A good electrical conductivity and the absence of radical signals generated after intense white light illumination, as probed through electron paramagnetic resonance, suggest a possible future application of this composite ma- terial in the field of photoprotective, antistatic layers with tunable colors

    Perspectives and Emotional Experiences of Patients With Chronic Myeloid Leukemia During ENESTPath Clinical Trial and Treatment-Free Remission: Rationale and Protocol of the Italian Substudy

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    Achievement of deep molecular response following treatment with a tyrosine kinase inhibitor (TKI) allows for treatment-free remission (TFR) in many patients with chronic myeloid leukemia (CML). Successful TFR is defined as the achievement of a sustained molecular response after cessation of ongoing TKI therapy. The phase 3 ENESTPath study was designed to determine the required optimal duration of consolidation treatment with the second-generation TKI, nilotinib 300 mg twice-daily, to remain in successful TFR without relapse after entering TFR for 12 months. The purpose of this Italian ‘patient’s voice CML’ substudy was to evaluate patients’ psycho-emotional characteristics and quality of life through their experiences of stopping treatment with nilotinib and entering TFR. The purpose of the present contribution is to early present the study protocol of an ongoing study to the scientific community, in order to describe the study rationale and to extensively present the study methodology. Patients aged ≄18 years with a confirmed diagnosis of Philadelphia chromosome positive BCR-ABL1+ CML in chronic phase and treated with front-line imatinib for a minimum of 24 months from the enrollment were eligible. Patients consenting to participate the substudy will have quality of life questionnaires and in-depth qualitative interviews conducted. The substudy will include both qualitative and quantitative design aspects to evaluate the psychological outcomes as assessed via patients’ emotional experience during and after stopping nilotinib therapy. Randomization is hypothesized to be a timepoint of higher psychological alert or distress when compared to consolidation and additionally any improvement in health-related quality of life (HRQoL) due to nilotinib treatment is expected across the timepoints (from consolidation, to randomization, and TFR). An association is also expected between dysfunctional coping strategies, such as detachments and certain personality traits, and psychological distress and HRQoL impairments. Better HRQoL outcomes are expected in TFR compared to the end of consolidation. This substudy is designed for in-depth assessment of all potential psycho-emotional variables and aims to determine the need for personalized patient care and counselling, and also guide clinicians to consider the psychological well-being of patients who are considering treatment termination. NCT number: NCT01743989, EudraCT number: 2012-005124-1

    Draft genome sequences of six listeria monocytogenes strains isolated from dairy products from a processing plant in Southern Italy

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    Here we announce the draft genome sequences of 6 Listeria monocytogenes strains from ricotta cheese produced in a dairy processing plant located in southern Italy and potentially involved in a multistate outbreak of listeriosis in the United States

    Chromoblastomycosis after a leech bite complicated by myiasis: a case report

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    Background Chromoblastomycosis is a chronic mycotic infection, most common in the tropics and subtropics, following traumatic fungal implantation. Case presentation A 72 year-old farmer was admitted to Luang Namtha Provincial Hospital, northern Laos, with a growth on the left lower leg which began 1 week after a forefoot leech bite 10 years previously. He presented with a cauliflower-like mass and plaque-like lesions on his lower leg/foot and cellulitis with a purulent tender swelling of his left heel. Twenty-two Chrysomya bezziana larvae were extracted from his heel. PCR of a biopsy of a left lower leg nodule demonstrated Fonsecaea pedrosoi, monophora, or F. nubica. He was successfully treated with long term terbinafin plus itraconazole pulse-therapy and local debridement. Conclusions Chromoblastomycosis is reported for the first time from Laos. It carries the danger of bacterial and myiasis superinfection. Leech bites may facilitate infection.This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

    Chronic Myeloid Leukemia Patient's Voice About the Experience of Treatment-Free Remission Failure: Results From the Italian Sub-Study of ENESTPath Exploring the Emotional Experience of Patients During Different Phases of a Clinical Trial

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    Background: The main objective of this study is to gain further insights on how chronic myeloid leukemia (CML) patients involved in an interventional clinical trial with the purpose of reaching treatment free remission (TFR) phase, perceived and experienced TFR failure. TFR failure was defined for the individual patient as either not being eligible for drug discontinuation or as having relapse in the TFR phase with reintroduction of nilotinib treatment. Methods: Using a qualitative approach, out of 25 patients with CML who experienced TFR failure 14 were interviewed. Patients' views and experiences were explored using in-depth interviews, analyzed using the Interpretative Phenomenological Analysis (IPA). Results: The analysis of the interviews revealed that the experience of the diagnosis seems to have been lived as a traumatic break that has created a dichotomy, like an ambivalence in the ways in which CML patients perceived and experienced the whole disease journey, with contradictory feelings of both positive and negative emotions (e.g., a diagnosis of cancer, that is something distressing and of being afraid of, but also with a treatment and a life expectancies of which being grateful). This ambivalence of feelings was found to give meaning to the way in which patients cognitively and emotionally experienced the different steps of their disease history. Thus, four main issues, corresponding to different steps of the patients' journey, were identified: (1) the moment of the diagnosis, (2) the experience of the illness journey: disease and treatment, (3) the moment of "TFR failure," and (4) the impact of disease, treatment and relapse on the patient's life. Conclusion: This qualitative analysis helps in understanding patients' perspective, both in terms of getting access to the inner subjective experience of having CML and its strict relationship with the involvement in a trial or its cessation. Clinicians should consider that the way in which CML patients feel engaged in a clinical trial, create expectancies about TFR or experience the TFR failure is linked to the process of coping with the diagnosis, which is characterized by ambivalence
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