29 research outputs found

    Analysis of HIV-1 drug resistant mutations by line probe assay and direct sequencing in a cohort of therapy naive HIV-1 infected Italian patients

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    BACKGROUND: The routine determination of drug resistance in newly HIV-1 infected individuals documents a potential increase in the transmission of drug-resistant variants. Plasma samples from twenty seven therapy naive HIV-1 infected Italian patients were analyzed by the line probe assay (LIPA) and the TruGene HIV-1 assay for the detection of mutations conferring resistance to HIV-1. RESULTS: Both tests disclosed amino-acid substitutions associated with resistance in a variable number of patients. In particular, two mutations (K70R and V118I), detectable by LIPA and by sequencing analysis respectively, revealed resistance to NRTIs in two plasma samples. At least three mutations conferring resistance to NNRTIs, not detectable by commercial LIPA, able to reveal mutations associated only with nucleoside reverse transcriptase analogues, were disclosed by viral sequence analysis. Moreover, most samples showed mutations correlated with resistance to protease inhibitors. Remarkably, a key mutation, like V82A (found as a mixture), and some "indeterminate" results (9 samples), due the absence of signal on the lines corresponding to a specific probe, was revealed only by LIPA, while a variable number of secondary mutations was detectable only by TruGene HIV-1 assay. CONCLUSION: Even if further studies are necessary to establish the impact of different tests on the evaluation of drug-resistant strains transmission, LIPA might be useful in a wide population analysis, where bulk results are needed in a short time, while sequencing analysis, able to detect mutations conferring resistance to both NRTIs and NNRTIs, might be considered a more complete assay, albeit more expensive and more technically complex

    Dual-source vacuum deposition of pure and mixed halide 2D perovskites: thin film characterization and processing guidelines

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    The dual-source vacuum deposition of 2D perovskite films of the type PEA2PbX4, (PEA = phenethylammonium and X = I−, Br−, or a combination of both) is presented. Low-temperature deposited 2D perovskite films showed high crystallinity with the expected trend of bandgap as a function of halide type and concentration. Importantly, we observed an unavoidable halide cross-contamination among different deposition runs, as well as a strong dependence of the material quality on the type of halide precursors used. These findings should be taken into account in the development of vacuum processing for low-dimensional mixed halide perovskites

    Vacuum Deposited Triple-Cation Mixed-Halide Perovskite Solar Cells

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    Hybrid lead halide perovskites are promising materials for future photovoltaics applications. Their spectral response can be readily tuned by controlling the halide composition, while their stability is strongly dependent on the film morphology and on the type of organic cation used. Mixed cation and mixed halide systems have led to the most efficient and stable perovskite solar cells reported, so far they are prepared exclusively by solution-processing. This might be due to the technical difficulties associated with the vacuum deposition from multiple thermal sources, requiring a high level of control over the deposition rate of each precursor during the film formation. In this report, thermal vacuum deposition with multiple sources (3 and 4) is used to prepare for the first time, multications/anions perovskite compounds. These thin-film absorbers are implemented into fully vacuum deposited solar cells using doped organic semiconductors. A maximum power conversion efficiency of 16% is obtained, with promising device stability. The importance of the control over the film morphology is highlighted, which differs substantially when these compounds are vacuum processed. Avenues to improve the morphology and hence the performance of fully vacuum processed multications/anions perovskite solar cells are proposed

    Vacuum-Deposited 2D/3D Perovskite Heterojunctions

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    Low-dimensional (quasi-) 2D perovskites are being extensively studied in order to enhance the stability and the open-circuit voltage of perovskite solar cells. Up to now, thin 2D perovskite layers on the surface and/or at the grain boundaries of 3D perovskites have been deposited solely by solution processing, leading to unavoidable intermixing between the two phases. In this work, we report the fabrication of 2D/3D/2D perovskite heterostructures by dual-source vacuum deposition, with the aim of studying the interaction between the 3D and 2D phases as well as the charge transport properties of 2D perovskites in neat 2D/3D interfaces. Unlike what is normally observed in solution-processed 3D/2D systems, we found a reduced charge transport with no direct evidence of surface passivation, in spite of larger open-circuit voltage. This is likely due to a nonfavorable orientation of the 2D perovskite with respect to methylammonium lead iodide and to the formation of 2D phases with very low dimensionality (pure 2D)

    Red Light-Emitting Electrochemical Cells Employing Pyridazine-Bridged Cationic Diiridium Complexes

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    A rigid dinuclear Ir(III) complex showing high photoluminescence quantum yield in pure films was successfully used to fabricate light-emitting electrochemical cells with and without ionic liquid additives. The devices showed nearly instantaneous electroluminescence after biasing and maximum quantum yield approaching 1%. The lifetime of the devices was found to be limited to approximately 20 hours, which we correlated with the irreversible oxidation of the complex as seen from electrochemical measurements. This work validates the use of highly luminescent dinuclear iridium complexes in light-emitting electrochemical cells. Future studies will pursue materials with more efficient photoluminescence as well as improved electrochemical stability

    Providing a nurse-led complex nursing INtervention FOcused on quality of life assessment on advanced cancer patients: The INFO-QoL pilot trial.

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    PURPOSE Unmet needs for advanced-disease cancer patients are fatigue, pain, and emotional support. Little information is available about the feasibility of interventions focused on patient-reported outcome measurement developed according to the Medical Research Council (MRC) Framework in advanced-disease cancer patients. We aimed to pilot a nurse-led complex intervention focused on QoL assessment in advanced-disease cancer patients. METHODS The INFO-QoL study was based on an exploratory, nonequivalent comparison group, pre-test-post-test design. Study sites received either the INFO-QoL intervention or usual care. Adult advanced-disease cancer patients admitted to hospice inpatient units that gave their informed consent were included in the study. Subjects were 187 patients and their families and 19 healthcare professionals. We evaluated feasibility, acceptability, and patients' outcomes using the Integrated Palliative Care Outcome Scale. RESULTS Nineteen healthcare professionals were included. The mean competence score increased significantly over time (p < 0.001) and the mean usefulness score was high 8.63 (±1.36). In the post-test phase, 54 patients were allocated to the experimental unit and 36 in the comparison unit. Compared to the comparison unit, in the experimental unit anxiety (R2 = 0.07; 95% CI = -0.06; 0.19), family anxiety (R2 = 0.22; 95% CI = -0.03; 0.41), depression (R2 = 0.31; 95% CI = -0.05; 0.56) and sharing feelings (R2 = 0.09; 95% CI = -0.05; 0.23), were improved between pre-test and post-test phase. CONCLUSIONS The INFO-QoL was feasible and potentially improved psychological outcomes. Despite the high attrition rate, the INFO-QoL improved the quality and safety culture for patients in palliative care settings

    Italian Guidelines in diagnosis and treatment of alopecia areata

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    Alopecia areata (AA) is an organ-specific autoimmune disorder that targets anagen phase hair follicles. The course is unpredictable and current available treatments have variable efficacy. Nowadays, there is relatively little evidence on treatment of AA from well-designed clinical trials. Moreover, none of the treatments or devices commonly used to treat AA are specifically approved by the Food and Drug Administration. The Italian Study Group for Cutaneous Annexial Disease of the Italian Society of dermatology proposes these Italian guidelines for diagnosis and treatment of Alopecia Areata deeming useful for the daily management of the disease. This article summarizes evidence-based treatment associated with expert-based recommendations
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