350 research outputs found

    Crystal chemistry and temperature behavior of the natural hydrous borate colemanite, a mineral commodity of boron

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    Colemanite, CaB3O4(OH)3*H2O, is the most common hydrous Ca-borate, as well as a major mineral commodity of boron. In this study, we report a thorough chemical analysis and the low-temperature behavior of a natural sample of colemanite by means of a multi-methodological approach. From the chemical point of view, the investigated sample resulted to be relatively pure, its composition being very close to the ideal one, with only a minor substitution of Sr2+for Ca2+. At about 270.5 K, a displacive phase transition from the centrosymmetric P21/a to the acentric P21 space group occurs. On the basis of in situ single-crystal synchrotron X-ray (down to 104 K) and neutron diffraction (at 20 K) data, the hydrogen-bonding configuration of both the polymorphs and the structural modifications at the atomic scale at varying temperatures are described. The asymmetric distribution of ionic charges along the [010] axis, allowed by the loss of the inversion center, is likely responsible for the reported ferroelectric behavior of colemanite below the phase transition temperature

    Bitter taste receptor polymorphisms and human aging.

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    Several studies have shown that genetic factors account for 25% of the variation in human life span. On the basis of published molecular, genetic and epidemiological data, we hypothesized that genetic polymorphisms of taste receptors, which modulate food preferences but are also expressed in a number of organs and regulate food absorption processing and metabolism, could modulate the aging process. Using a tagging approach, we investigated the possible associations between longevity and the common genetic variation at the three bitter taste receptor gene clusters on chromosomes 5, 7 and 12 in a population of 941 individuals ranging in age from 20 to 106 years from the South of Italy. We found that one polymorphism, rs978739, situated 212 bp upstream of the TAS2R16 gene, shows a statistically significant association (p = 0.001) with longevity. In particular, the frequency of A/A homozygotes increases gradually from 35% in subjects aged 20 to 70 up to 55% in centenarians. These data provide suggestive evidence on the possible correlation between human longevity and taste genetics

    Role of OPRM1, clinical and anthropometric variants in neonatal pain reduction

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    An increased awareness on neonatal pain-associated complications has led to the development of pain scales adequate to assess the level of pain experienced by newborns such as the ABC score. A commonly used analgesic procedure is to administer a 33% oral dextrose solution to newborns prior to the painful intervention. Although this procedure is very successful, not in all subjects it reaches complete efficacy. A possible explanation for the different response to the treatment could be genetic variability. We have investigated the genetic variability of the OPRM1 gene in 1077 newborns in relation to non-pharmacologic pain relief treatment. We observed that the procedure was successful in 966 individuals and there was no association between the genotypes and the analgesic efficacy when comparing individuals that had an ABC score = 0 and ABC score >0. However, considering only the individuals with ABC score>0, we found that the homozygous carriers of the G allele of the missense variant SNP rs1799971 (A118G) showed an interesting association with higher ABC score. We also observed that individuals fed with formula milk were more likely to not respond to the analgesic treatment compared to those that had been breastfed

    The Encapsulation of Citicoline within Solid Lipid Nanoparticles Enhances Its Capability to Counteract the 6-Hydroxydopamine-Induced Cytotoxicity in Human Neuroblastoma SH-SY5Y Cells

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    (1) Backgrond: Considering the positive effects of citicoline (CIT) in the management of some neurodegenerative diseases, the aim of this work was to develop CIT-Loaded Solid Lipid Nanoparticles (CIT-SLNs) for enhancing the therapeutic use of CIT in parkinsonian syndrome; (2) Methods: CIT-SLNs were prepared by the melt homogenization method using the self-emulsifying lipid Gelucire® 50/13 as lipid matrix. Solid-state features on CIT-SLNs were obtained with FT-IR, thermal analysis (DSC) and X-ray powder diffraction (XRPD) studies. (3) Results: CIT-SLNs showed a mean diameter of 201 nm, −2.20 mV as zeta potential and a high percentage of entrapped CIT. DSC and XRPD analyses evidenced a greater amorphous state of CIT in CIT-SLNs. On confocal microscopy, fluorescent SLNs replacing unlabeled CIT-SLNs released the dye selectively in the cytoplasm. Biological evaluation showed that pre-treatment of SH-SY5Y dopaminergic cells with CIT-SLNs (50 µM) before the addition of 40 µM 6-hydroxydopamine (6-OHDA) to mimic Parkinson’s disease’s degenerative pathways counteracts the cytotoxic effects induced by the neurotoxin, increasing cell viability with the consistent maintenance of both nuclear and cell morphology. In contrast, pre-treatment with CIT 50 and 60 µM or plain SLNs for 2 h followed by 6-OHDA (40 µM) did not significantly influence cell viability. (4) Conclusions: These data suggest an enhanced protection exerted by CIT-SLNs with respect to free CIT and prompt further investigation of possible molecular mechanisms that underlie this difference

    Utility of neutrophil-to-lymphocyte ratio to identify long-term survivors among HCC patients treated with sorafenib

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    Sorafenib is the first multikinase inhibitor demonstrating a survival benefit for patients suffering from advanced hepatocellular carcinoma (HCC). However, 1 issue remains open: what is the factor able to predict which patients will be long survivors?In the present study, we harnessed the potential of conditional survival, aiming at estimating the probability that a patient receiving sorafenib survives for more than 3 years.The present multicentric study was conducted on a cohort of 438 HCC patients. The primary end point was conditional overall survival. Kaplan-Meier survival analysis was used to calculate conditional overall survival probabilities at 3 years.The 3-year conditional survival of patients without disease progression highlights that NLR and ECOG are the factors that most accurately predict the probability of long survival. The 3-year conditional survival of patients with disease progression showed a medium effect size for HCV status, alpha-fetoprotein and NLR at all time-points. Macro-vascular portal vein invasion, extra hepatic disease, and BCLC we have a large effect size at 6 months and a medium effect size at 12 and 24 months.Our findings support the use of baseline NLR for the identification of patients with a higher probability of long-survival. NLR should be used as a stratification factor in the forthcoming clinical trials on the drugs for the advanced HCC now in pipeline

    Caratterizzazione di Batteri Vibrio harveyi irradiati con luce UV e raggi X

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    Lo studio dei batteri sottoposti a stimolazioni dovute all'ambiente è di estremo interesse per impli-cazioni strutturali, meccanicistiche ed evolutive. Bat-teri luminescenti evoluti in determinati ambienti han-no sviluppato particolari risposte e il loro comporta-mento può fornire informazioni sulla funzione e sulla produzione dell‟enzima luciferina. Per esaminare l'in-terazione con radiazione UV, in condizioni controlla-te di laboratorio sono stati utilizzati ceppi batterici foto-luminescenti appartenenti alla specie Vibrio har-veyi campionati da una grotta costiera con elevato contenuto di radon che genera radiazioni ionizzanti. La sopravvivenza dei ceppi batterici è stata analizza-ta, alla luce e al buio, a seguito di una varietà di trat-tamenti genotossici tra cui esposizione alle radiazioni UV. I ceppi sono stati irradiati mediante una lampada germicida. I risultati hanno dimostrato che la maggior parte dei ceppi esibiscono un basso tasso di sopravvi-venza dopo l'esposizione ai raggi UV. Tutti i ceppi dopo esposizione a luce visibile e ai raggi UV hanno mostrato una forte capacità di fotoriattivazione. Que-sta capacità era inaspettata, poiché questi batteri sono stati prelevati da un ambiente buio in assenza raggi UV. Questo porta ad ipotizzare che la fotoriattivazio-ne in questi batteri potrebbe essere stata sviluppata dagli stessi per riparare le lesioni del DNA provocate anche da radiazioni diverse dall‟UV (ad esempio, raggi X) e che i batteri luminescenti potrebbero usare la luce da essi emessa per effettuare la fotoriattivazio-ne. L'elevata capacità di fotoriattivazione dei batteri è stata anche confermata dai risultati di deconvoluzio-ne. La deconvoluzione è stata applicata agli spettri di emissione che ha evidenziato la presenza di diversi picchi. La presenza del picco nel visibile è in grado di controllare l'enzima fotoliasi

    Fabrication of a hydrogenated amorphous silicon detector in 3-d geometry and preliminary test on planar prototypes

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    Hydrogenated amorphous silicon (a-Si:H) can be produced by plasma-enhanced chemical vapor deposition (PECVD) of SiH4 (silane) mixed with hydrogen. The resulting material shows outstanding radiation hardness properties and can be deposited on a wide variety of substrates. Devices employing a-Si:H technologies have been used to detect many different kinds of radiation, namely, minimum ionizing particles (MIPs), X-rays, neutrons, and ions, as well as low-energy protons and alphas. However, the detection of MIPs using planar a-Si:H diodes has proven difficult due to their unsatisfactory S/N ratio arising from a combination of high leakage current, high capacitance, and limited charge collection efficiency (50% at best for a 30 µm planar diode). To overcome these limitations, the 3D-SiAm collaboration proposes employing a 3D detector geometry. The use of vertical electrodes allows for a small collection distance to be maintained while preserving a large detector thickness for charge generation. The depletion voltage in this configuration can be kept below 400 V with a consequent reduction in the leakage current. In this paper, following a detailed description of the fabrication process, the results of the tests performed on the planar p-i-n structures made with ion implantation of the dopants and with carrier selective contacts are illustrated

    Testing of planar hydrogenated amorphous silicon sensors with charge selective contacts for the construction of 3D-detectors

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    Hydrogenated Amorphous Silicon (a-Si:H) is a well known material for its intrinsic radiation hardness and is primarily utilized in solar cells as well as for particle detection and dosimetry. Planar p-i-n diode detectors are fabricated entirely by means of intrinsic and doped PECVD of a mixture of Silane (SiH4) and molecular hydrogen. In order to develop 3D detector geometries using a-Si:H, two options for the junction fabrication have been considered: ion implantation and charge selective contacts through atomic layer deposition. In order to test the functionality of the charge selective contact electrodes, planar detectors have been fabricated utilizing this technique. In this paper, we provide a general overview of the 3D fabrication project followed by the results of leakage current measurements and X-ray dosimetric tests performed on planar diodes containing charge selective contacts to investigate the feasibility of the charge selective contact methodology for integration with the proposed 3D detector architectures

    Bimodal Approach for Noise Figures of Merit Evaluation in Quantum-Limited Josephson Traveling Wave Parametric Amplifiers

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    The advent of ultra-low noise microwave amplifiers revolutionized several research fields demanding quantum-limited technologies. Exploiting a theoretical bimodal description of a linear phase-preserving amplifier, in this contribution we analyze some of the intrinsic properties of a model architecture (i.e., an rf-SQUID based Josephson Traveling Wave Parametric Amplifier) in terms of amplification and noise generation for key case study input states (Fock and coherents). Furthermore, we present an analysis of the output signals generated by the parametric amplification mechanism when thermal noise fluctuations feed the device.Comment: 5 pages, 6 figure
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