2,082 research outputs found

    Thermo-hydraulic analysis of the windowless target system

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    The target system, whose function is to supply an external neutron source to a subcritical core in order to sustain the neutron chain reaction, is the most critical part of an ADS being subject to severe thermo-mechanical loading and material damage due to accelerator protons and fission neutrons. In order to reduce the material damage and to increase the life of the target system a windowless option was chosen in the framework of the European PDS-XADS project as reference configuration for the experimental ADS cooled by lead–bismuth eutectic alloy. This document deals with the results of the thermo-hydraulic analysis performed with STAR-CD and RELAP5 codes to assess the behaviour of the windowless target system during off-normal operating conditions. It also reports a description of modifications properly implemented in the codes for studying this kind of plant. The windowless target system shows a satisfactory thermo-hydraulic behaviour for the analysed accidents, except for the loss of both pumps without proton beam shut-off and for the beam trips lasting more than 1 s.2135–2145Pubblicat

    NPY Levels In Type 1 Diabetic Men of Different Duration.

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    Background: The aim of the present study was to evaluate whether the different duration of type 1 diabetes mellitus influences basal NPY secretion. Design: The NPY concentrations were measured in sixty-eight men with insulin-dependent diabetes mellitus (IDDM) (duration: group 1 (n.21) <5 years (range 2-4 years); group 2 (n.24) >5 years and <10 years (range: 6-9 years); group 3 (n.29) >10 years (range: 11-14 years)) and in age matched normal control subjects (n. 30). Results: The NPY levels were significantly lower in group 3 than in group 2 and 1 and in the control group, in group 2 than in group 1 and in the control group and in group 1 than control group. Conclusion: These results support the view that the duration of diabetes may have a modulatory role in the decreased basal NPY secretion observed in diabetics

    Entropy production and fluctuation theorems for monitored quantum systems under imperfect detection

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    The thermodynamic behavior of Markovian open quantum systems can be described at the level of fluctuations by using continuous monitoring approaches. However, practical applications require assessing imperfect detection schemes, where the definition of main thermodynamic quantities becomes subtle and universal fluctuation relations are unknown. Here we fill this gap by deriving a universal fluctuation relation that links entropy production in ideal and in inefficient monitoring setups. This provides a suitable estimator of dissipation using imperfect detection records that lower bounds the underlying entropy production at the level of single trajectories. We illustrate our findings with a driven-dissipative two-level system following quantum jump trajectories.Comment: 5 + 10 pages, 2 figures. The two first authors contributed equally to this wor

    Electroencephalographic Rhythms in Alzheimer's Disease

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    Physiological brain aging is characterized by synapses loss and neurodegeneration that slowly lead to an age-related decline of cognition. Neural/synaptic redundancy and plastic remodelling of brain networking, also due to mental and physical training, promotes maintenance of brain activity in healthy elderly subjects for everyday life and good social behaviour and intellectual capabilities. However, age is the major risk factor for most common neurodegenerative disorders that impact on cognition, like Alzheimer's disease (AD). Brain electromagnetic activity is a feature of neuronal network function in various brain regions. Modern neurophysiological techniques, such as electroencephalography (EEG) and event-related potentials (ERPs), are useful tools in the investigation of brain cognitive function in normal and pathological aging with an excellent time resolution. These techniques can index normal and abnormal brain aging analysis of corticocortical connectivity and neuronal synchronization of rhythmic oscillations at various frequencies. The present review suggests that discrimination between physiological and pathological brain aging clearly emerges at the group level, with suggested applications also at the level of single individual. The possibility of combining the use of EEG together with biological/neuropsychological markers and structural/functional imaging is promising for a low-cost, non-invasive, and widely available assessment of groups of individuals at-risk

    Cytogenetic and molecular characterization of durum wheat chromosome transfers with 1D-associated gluten protein genes and their pyramiding

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    Gluten quality of bread wheat is known to be mainly associated with high- (HMW-GS) and low-(LMW-GS) molecular weight glutenin subunits encoded by Glu-1 (L arm of group-1 chromosomes) and Glu-3 (S arm of group-1 chromosomes) genes, respectively, with the 1D alleles of such genes having the major impact on bread making properties. Transfer of chromosomal segments containing the Glu-D1 and Gli-D1/Glu-D3 loci was successfully achieved in a number of instances resorting to chromosome engineering. Using this strategy, we isolated two 1A-1D recombinant lines, in which the Gli-D1/Glu-D3 genes and the Glu-D1d allele (HMW-GS "5+10") were separately transferred into the 1AS and 1AL arm, respectively, of recipient durum wheat lines (named PS and PL, respectively). Also, a detailed genetic map of both recombinant chromosome arms was developed. Stable PS + PL double-recombinant lines have been obtained as a result of homologous recombination in the 1A portions shared by the two recombinant chromosomes present in PS x PL hybrids. Preliminary quality tests suggest that the Glu-D3 + Glu-D1d combined presence could determine a slight increase of gluten quality parameters over those associated with Glu-D1d alone

    Differences in CSF Biomarkers Profile of Patients with Parkinson's Disease Treated with MAO-B Inhibitors in Add-On

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    Monoamine oxidase type B inhibitors (iMAO-Bs) are a class of largely-used antiparkinsonian agents that, based on experimental evidence, are supposed to exert different degrees of neuroprotection in Parkinson's disease (PD). However, clinical proofs on this regard are very scarce. Since cerebrospinal fluid (CSF) reflects pathological changes occurring at brain level, we examined the neurodegeneration-related CSF biomarkers profile of PD patients under chronic treatment with different iMAO-Bs to identify biochemical signatures suggestive for differential neurobiological effects.Thirty-five PD patients under chronic treatment with different iMAO-Bs in add-on to levodopa were enrolled and grouped in rasagiline (n = 13), selegiline (n = 9), safinamide (n = 13). Respective standard clinical scores for motor and non-motor disturbances, together with CSF biomarkers of neurodegeneration levels (amyloid- β -42, amyloid- β -40, total and 181-phosphorylated tau, and lactate) were collected and compared among the three iMAO-B groups.No significant clinical differences emerged among the iMAO-B groups. CSF levels of tau proteins and lactate were instead different, resulting higher in patients under selegiline than in those under rasagiline and safinamide.Although preliminary and limited, this study indicates that patients under different iMAO-Bs may present distinct profiles of CSF neurodegeneration-related biomarkers, probably because of the differential neurobiological effects of the drugs. Larger studies are now needed to confirm and extend these initial observations

    Heavy Metals in Soil and Salad in the Proximity of Historical Ferroalloy Emission

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    Emissions of manganese (Mn), lead (Pb), iron (Fe), zinc (Zn), copper (Cu) from ferro-alloy operations has taken place in Valcamonica, a pre-Alp valley in the province of Brescia, Italy, for about a century until 2001. Metal concentrations were measured in the soil of local home gardens and in the cultivated vegetables. Soil analysis was carried out using a portable X-Ray Fluorescence (XRF) spectrometer in both surface soil and at 10 cm depth. A subset of soil samples (n = 23) additionally was analysed using the modified BCR sequential extraction method and ICP-OES for intercalibration with XRF (XRF Mn = 1.33 * total OES Mn – 71.8; R = 0.830, p < 0.0001). Samples of salads (Lactuca sativa and Chichorium spp.) were analyzed with a Total Reflection X-Ray Fluorescence (TXRF) technique. Vegetable and soil metal measurements were performed in 59 home gardens of Valcamonica, and compared with 23 gardens from the Garda Lake reference area. Results indicate significantly higher levels of soil Mn (median 986 ppm vs 416 ppm), Pb (median 46.1 ppm vs 30.2 ppm), Fe (median 19,800 ppm vs 13,100 ppm) in the Valcamonica compared to the reference area. Surface soil levels of all metals were significantly higher in surface soil compared to deeper soil, consistent with atmospheric deposition. Significantly higher levels of metals were shown also in lettuce from Valcamonica for Mn (median 53.6 ppm vs 30.2) and Fe (median 153 vs 118). Metals in Chichorium spp. did not differ between the two areas. Surface soil metal levels declined with increasing distance from the closest ferroalloy plant, consistent with plant emis- sions as the source of elevated soil metal levels. A correlation between Mn concentrations in soil and lettuce was also observed. These data show that historic ferroalloy plant activity, which ended nearly a decade before this study, has contributed to the persistence of increased Mn levels in locally grown vegetables. Further research is needed to assess whether this increase can lead to adverse effects in humans and plants especially for Mn, an essential element that can be toxic in humans when exceeding the homeostatic ranges

    Assessment of antioxidant and drug releasing properties of cellulose fabrics functionalized with polymeric nanoparticles as potential biofunctional garments

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    Drug administration through skin raised a great interest as a not invasive and sustained method to deliver active substances both at topical and systemic levels. Biofunctional textiles are a new class of materials that combine conventional fabrics with advanced drug delivery systems in order to develop a wearable functional biomaterial [1]. The present research aims to functionalize cellulosic fabrics (e.g. cotton and viscose) with curcumin (CUR)-loaded polycaprolactone (PCL) nanoparticles (NPs) in order to assess their potential as biofunctional garments. The NPs were produced by the flash nanoprecipitation technique in a confined impinging jet mixer. Such technology was proven to be a simple and scalable approach to produce polymeric nanoparticles; moreover it was successfully applied to curcumin encapsulation [2]. Nanoparticles were then characterized in terms of size and zeta potential by dynamic light scattering (DLS), while the loading capacity (LC%) and encapsulation efficiency (EE%) were measured by exploiting fluorescence spectroscopy. Cotton and viscose fabrics were functionalized by imbibition with the NPs suspensions and the effectiveness of the treatment was observed under wide-field fluorescence microscopy. The release properties of the nanoparticles suspensions were studied in vitro in a multicompartment rotating cell, while the curcumin release from textile support was tested ex vivo in a Franz diffusion cell using porcine skin as membrane. Furthermore, the antioxidant activity of the NPs and of the functionalized fabrics was measured by electron paramagnetic resonance spectroscopy. Curcumin loaded NPs were successfully prepared with good control of particle size and loading capacity, high stability over several days and encapsulation efficiency higher than 99%. Nanoparticles were successfully attached to the textiles material as evidenced by fluorescent imaging. The prepared materials showed an improved antioxidant activity and the capability of controlling curcumin release both in vivo and ex vivo. The present research shows the possibility of producing biofunctional materials by simple and scalable process and opens a route for a new generation of garments that can benefit people health
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