4,765 research outputs found

    β-Glucan synthase induction in mushrooms grown on olive mill wastewaters

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    Beta-1-3-Glucan synthase activity and its induction by olive mill wastewaters (OMW) was studied in ten fungal strains (Auricularia auricula-judae, Lentinula edodes, Pleurotus eryngii, Stropharia aeruginosa, Agrocybe aegerita, P. pulmonarius, Armillaria mellea, P. ferulae, P. ostreatus, P. nebrodensis). A microtiter-based enzymatic assay on -1-3-glucan synthase activity was carried out on all mycelia growth both on the control medium and on OMW. Among the fungi assayed, L. edodes -1-3-glucan synthase was highly enhanced in OMW. The main components of OMW, i.e. phenols and lipids, were added separately to the control medium, to highlight the mechanism of L. edodes -1-3-glucan synthase induction. A Southern blot analysis and PCR with degenerated primers were carried out to detect the presence of fks1-like genes in these Basidiomycetes. The sequences obtained from the ten Basidiomycota were remarkably similar to fks1 from Filobasidiella neoformans. Spectrofluorimetric and RT-PCR analyses of -1-3-glucan synthase were performed on the mycelia of L. edodes. In this fungus, a strong stimulation of -1-3-glucan synthase mRNA and protein was recorded in the presence of OMW and phenol

    Very low bias stress in n-type organic single crystal transistors

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    Bias stress effects in n-channel organic field-effect transistors (OFETs) are investigated using PDIF-CN2 single-crystal devices with Cytop gate dielectric, both under vacuum and in ambient. We find that the amount of bias stress is very small as compared to all (p-channel) OFETs reported in the literature. Stressing the PDIF-CN2 devices by applying 80 V to the gate for up to a week results in a decrease of the source drain current of only ~1% under vacuum and ~10% in air. This remarkable stability of the devices leads to characteristic time constants, extracted by fitting the data with a stretched exponential - that are \tau ~ 2\cdot10^9 s in air and \tau ~ 5\cdot10^9 s in vacuum - approximately two orders of magnitude larger than the best values reported previously for p-channel OFETs.Comment: Submitted to Applied Physics Letters; 14 pages, 3 figure

    Facial nerve paralysis in acute otomastoiditis as presenting symptom of FAB M2, T8;21 leukemic relapse. Case report and review of the literature

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    Granulocytic sarcoma (chloroma) is a rare solid, extramedullary tumour composed of immature granulocytes, occurring during granulocytic leukemia. Leukemic involvement of the temporal bone is not uncommon and may present in a variety of ways. Symptomatic facial nerve paralysis is one of these. The authors report a case of facial nerve paralysis as the presenting symptom of leukemic relapse in a 16-year-old white male, affected by acute myelogenous leukemia FAB M2, karyotype 46xy, T8;21

    Effects of crystal morphology on the hot-carrier dynamics in mixed-cation hybrid lead halide perovskites

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    Ultrafast pump-probe spectroscopies have proved to be an important tool for the investigation of charge carriers dynamics in perovskite materials providing crucial information on the dynamics of the excited carriers, and fundamental in the development of new devices with tailored photovoltaic properties. Fast transient absorbance spectroscopy on mixed-cation hybrid lead halide perovskite samples was used to investigate how the dimensions and the morphology of the perovskite crystals embedded in the capping (large crystals) and mesoporous (small crystals) layers affect the hot-carrier dynamics in the first hundreds of femtoseconds as a function of the excitation energy. The comparative study between samples with perovskite deposited on substrates with and without the mesoporous layer has shown how the small crystals preserve the temperature of the carriers for a longer period after the excitation than the large crystals. This study showed how the high sensitivity of the time-resolved spectroscopies in discriminating the transient response due to the different morphology of the crystals embedded in the layers of the same sample can be applied in the general characterization of materials to be used in solar cell devices and large area modules, providing further and valuable information for the optimization and enhancement of stability and efficiency in the power conversion of new perovskite-based devices

    Muscle mass assessment in renal disease: The role of imaging techniques

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    Muscle wasting is a frequent finding in patients with chronic kidney disease (CKD), especially in those with end-stage kidney disease (ESKD) on chronic dialysis. Muscle wasting in CKD is a main feature of malnutrition, and results principally from a vast array of metabolic derangements typical of the syndrome, that converge in determining reduced protein synthesis and accelerated protein catabolism. In this clinical setting, muscle wasting is also frequently associated with disability, frailty, infections, depression, worsened quality of life and increased mortality. On these grounds, the evaluation of nutritional status is crucial for an adequate management of renal patients, and consists of a comprehensive assessment allowing for the identification of malnourished patients and patients at nutritional risk. It is based essentially on the assessment of the extent and trend of body weight loss, as well as of spontaneous dietary intake. Another key component of this evaluation is the determination of body composition, which, depending on the selected method among several ones available, can identify accurately patients with decreased muscle mass. The choice will depend on the availability and ease of application of a specific technique in clinical practice based on local experience, staff resources and good repeatability over time. Surrogate methods, such as anthropometry and bioimpedance analysis (BIA), represent the most readily available techniques. Other methods based on imaging modalities [dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI), and whole body computed tomography (CT)] are considered to be the “gold standard” reference methods for muscle mass evaluation, but their use is mainly confined to research purposes. New imaging modalities, such as segmental CT scan and muscle ultrasound have been proposed in recent years. Particularly, ultrasound is a promising technique in this field, as it is commonly available for bedside evaluation of renal patients in nephrology wards. However, more data are needed before a routine use of ultrasound for muscle mass evaluation can be recommended in clinical practice
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