12 research outputs found

    Photophysics of Two-Dimensional Perovskites—Learning from Metal Halide Substitution

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    Whereas their photophysics exhibits an intricate interplay of carriers with the lattice, most reports have so far relied on single compound studies. With the exception of variations of the organic spacer cations, the effect of constituent substitution on the photophysics and the nature of emitting species, in particular, has remained largely under-explored. Here PEA2_2PbBr4_4, PEA2_2PbI4_4, and PEA2_2SnI4_4 are studied through a variety of optical spectroscopy techniques to reveal a complex set of excitonic transitions at low temperature. We attribute the emergence of weak high energy features to a vibronic progression breaking Kasha's rule and highlight that the responsible phonons cannot be accessed through simple Raman spectroscopy. Bright peaks at lower energy are due to two distinct excitons, of which the upper is a convolution of a bright exciton and a localised state, whereas the lower is attributed to shallow defects. Our study offers deeper insights into the photophysics of two-dimensional perovskites through compositional substitution and highlights critical limits to the communities' current understanding of the photophysics of these compounds

    Audiovestibular involvement in systemic sclerosis

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    In order to evaluate the nature and association of audiovestibular disturbances and systemic sclerosis (SSC), 37 unselected SSC patients were studied with a detailed audiological and vestibular examination since November, 1987. Pure-tone audiometry, speech audiometry, impedance audiometry, brainstem response audiometry and vestibular function using electronystagmographic recording were performed. We found a rather frequent audiovestibular involvement (41%). A hearing loss was found in 14 SSC patients; hearing loss was sensorineural in 10 cases and mixed in 4 cases. The latter revealed a finding similar to tympanosclerosis. Four patients showed altered vestibular test values and only one of these had normal hearing. Sensorineural deafness was the more frequent pathological finding and in all cases the site of lesion was cochlear. SSC appears to be directly responsible for audiovestibular damage, since in 12 out of 15 patients with such involvement, no other apparent cause could be revealed. SSC may be included among the autoimmune diseases which may cause audiovestibular disturbance

    Deinococcus radiodurans' SRA-HNH domain containing protein Shp (Dr1533) is involved in faithful genome inheritance maintenance following DNA damage

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    Background: Deinococcus radiodurans R1 (DR) survives conditions of extreme desiccation, irradiation and exposure to genotoxic chemicals, due to efficient DNA breaks repair, also through Mn2+protection of DNA repair enzymes. Methods: Possible annotated domains of the DR1533 locus protein (Shp) were searched by bioinformatic analysis. The gene was cloned and expressed as fusion protein. Band-shift assays of Shp or the SRA and HNH domains were performed on oligonucleotides, genomic DNA from E. coli and DR. shp knock-out mutant was generated by homologous recombination with a kanamycin resistance cassette. Results: DR1533 contains an N-terminal SRA domain and a C-terminal HNH motif (SRA-HNH Protein, Shp). Through its SRA domain, Shp binds double-strand oligonucleotides containing 5mC and 5hmC, but also unmethylated and mismatched cytosines in presence of Mn2+. Shp also binds to Escherichia coli dcm+genomic DNA, and to cytosine unmethylated DR and E. coli dcm 12genomic DNAs, but only in presence of Mn2+. Under these binding conditions, Shp displays DNAse activity through its HNH domain. Shp KO enhanced >100 fold the number of spontaneous mutants, whilst the treatment with DNA double strand break inducing agents enhanced up to 3-log the number of survivors. Conclusions: The SRA-HNH containing protein Shp binds to and cuts 5mC DNA, and unmethylated DNA in a Mn2+dependent manner, and might be involved in faithful genome inheritance maintenance following DNA damage. General significance: Our results provide evidence for a potential role of DR Shp protein for genome integrity maintenance, following DNA double strand breaks induced by genotoxic agents

    Deinococcus radiodurans' SRA-HNH domain containing protein Shp (Dr1533) is involved in faithful genome inheritance maintenance following DNA damage

    No full text
    Background: Deinococcus radiodurans R1 (DR) survives conditions of extreme desiccation, irradiation and exposure to genotoxic chemicals, due to efficient DNA breaks repair, also through Mn2+ protection of DNA repair enzymes. Methods: Possible annotated domains of the DR1533 locus protein (Shp) were searched by bioinformatic analysis. The gene was cloned and expressed as fusion protein. Band-shift assays of Shp or the SRA and HNH domains were performed on oligonucleotides, genomic DNA from E. coif and DR. slip knock-out mutant was generated by homologous recombination with a kanamycin resistance cassette. Results: DR1533 contains an N-terminal SRA domain and a C-terminal HNH motif (SRA-HNH Protein, Shp). Through its SRA domain, Shp binds double-strand oligonucleotides containing 5mC and 5hmC, but also unmethylated and mismatched cytosines in presence of Mn2+. Shp also binds to Escherichia coli dcm(+) genomic DNA, and to cytosine unmethylated DR and E. coli dcm(-) genomic DNAs, but only in presence of Mn2+. Under these binding conditions, Shp displays DNAse activity through its HNH domain. Shp KO enhanced > 100 fold the number of spontaneous mutants, whilst the treatment with DNA double strand break inducing agents enhanced up to 3-log the number of survivors. Conclusions: The SRA-HNH containing protein Shp binds to and cuts 5mC DNA, and unmethylated DNA in a Mn2+ dependent manner, and might be involved in faithful genome inheritance maintenance following DNA damage. General significance: Our results provide evidence for a potential role of DR Shp protein for genome integrity maintenance, following DNA double strand breaks induced by genotoxic agents

    The role of lung ultrasound in diagnosing COVID-19-related multisystemic inflammatory disease: A preliminary experience

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    Background: To date, there are no data regarding the systematic application of Point-of-Care Lung Ultrasound (PoC-LUS) in children with Multisystem Inflammatory Syndrome in Children (MIS-C). The main aim of this study is to show the role of Point-of-Care Lung Ultrasound as an additional aid in the diagnosis of COVID-19-related Multisystem Inflammatory Syndrome in Children (MIS-C). Methods: Between April 2020 and April 2021, patients aged 0-18 years referred to our emergency department for fever, and later hospitalized without a specific diagnosis, underwent PoC-LUS. Ultrasound images of patients with a final diagnosis of MIS-C were retrospectively evaluated. Results: Ten patients were enrolled. All were described to have pleural irregularities and B-lines. In particular: 8/10 children presented with isolated B-lines in at least half of the lung areas of interest; 8/10 presented with multiple B-lines and 3/8 had them in at least 50% of lung areas; 5/10 had a white lung appearance in at least one lung area and 1/5 had them in half of the areas of interest. Pleural effusion was described in 9/10. Conclusions: During the ongoing COVID-19 pandemic, we suggest performing PoC-LUS in febrile patients with high levels of inflammatory indices and clinical suspicion of MIS-C, or without a certain diagnosis; the finding of many B-lines and pleural effusion would support the diagnosis of a systemic inflammatory disease

    The costs of multiple sclerosis: A cross-sectional, multicenter cost-of-illness study in Italy

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    Objectives: To estimate the socio-economic impact of multiple sclerosis (MS) in Italy. Methods: Outpatients with MS were enrolled at 44 centres across Italy. Socio-demographic, clinical and resource utilization data were collected using a validated questionnaire. Each patient completed a weekly diary of expenses due to MS over a three-month period. Direct health care costs and indirect costs (lack of productivity for the patient and for caregivers) were assessed for the whole population and were compared among five groups, categorised by disease severity (EDSS score). An analysis of variance was carried out on socio-demographic variables. Results: For the total population of 566 patients, the mean direct cost over three months was ITL 2,134,000, the mean indirect cost was ITL 7,775,000. Costs were significantly higher for male patients (p < 0.05) and showed a significant increase with increasing age (p < 0.0005), disease duration (p < 0.0005) and disease severity (p < 0.0005). Costs for patients in a progressive phase were significantly higher (p < 0.0005). There were no significant geographical differences among the regions of Italy. Conclusions: This study confirms that MS represents a high economic burden, with indirect costs greatly exceeding direct costs. Unpaid caregivers remain the culturally accepted mode of care for MS patients in Italy and this study illustrates the impact of their loss of earnings. As costs increase with disease progression, these findings suggest that treatment efforts should focus on patients in the early stages of MS, in order to slow down disease progression
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