1,211 research outputs found

    Experimental pre-assessing entanglement in Gaussian states mixing

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    We suggest and demonstrate a method to assess entanglement generation schemes based on mixing of Gaussian states at a beam splitter (BS). Our method is based on the fidelity criterion and represents a tool to analyze the effect of losses and noise before the BS in both symmetric and asymmetric channels with and without thermal effects. More generally, our scheme allows one to pre-assess entanglement resources and to optimize the design of BS-based schemes for the generation of continuous variable entanglement.Comment: 10 pages, 15 figure

    Detection, characterization and sizing of hydrogen induced cracking in pressure vessels using phased array ultrasonic data processing

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    Pressure vessels operating in sour service conditions in refinery environments can be subject to the risk of H₂S cracking resulting from the hydrogen entering into the material. This risk, which is related to the specific working conditions and to the quality of the steel used, shall be properly managed in order to maintain the highest safety at a cost-effective level. Nowadays the typical management strategy is based on a risk based inspection (RBI) evaluation to define the inspection plan used in conjunction with a fitness for service (FFS) approach in defining if the vessel, although presenting dangerous defects such as cracks, can still be considered “fit for purpose” for a given time window based on specific fracture mechanics analysis. These vessels are periodically subject to non-destructive evaluation, typically ultrasonic testing. Phased Array (PA) ultrasonic is the latest technology more and more used for this type of application. This paper presents the design and development of an optimized Phased Array ultrasonic inspection technique for the detection and sizing of hydrogen induced cracking (HIC) type flaws used as reference for comparison. Materials used, containing natural operational defects, were inspected in “as-service” conditions. Samples have then been inspected by means of a “full matrix capture” (FMC) acquisition process followed by “total focusing method” (TFM) data post processing. FCM-TFM data have been further post-processed and then used to create a 3D geometrical reconstruction of the volume inspected. Results obtained show the significant improvement that FMC/TFM has over traditional PA inspection techniques both in terms of sensitivity and resolution for this specific type of defect. Moreover, since the FMC allows for the complete time domain signal to be captured from every element of a linear array probe, the full set of data is available for post-processing. Finally, the possibility to reconstruct the geometry of the component from the scans, including the defects present in its volume, represents the ideal solution for a reliable data transferring process to the engineering function for the subsequent FFS analysi

    Anderson-Fabry disease: a multiorgan disease.

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    Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by a deficiency of the enzyme α-galactosidase A . FD causes glycolipids, such as globotriaosylceramide (Gb3), to accumulate in the vascular endothelium of several organs (fig.2), including the skin, kidneys, nervous system, and heart, thereby triggering inflammation and fibrosis . These processes generally result in organ dysfunction, which is usually the first clinical evidence of FD. Patients with classic FD have various symptoms, eg, acroparesthesias, hypohidrosis, angiokeratomas, corneal opacities, cerebrovascular lesions, cardiac disorders, andrenal dysfunction.However, evolving knowledge about the natural course of disease suggests that it is more appropriate to describe FD as a disease with a wide spectrum of heterogeneously progressive clinical phenotypes. Indeed, most female heterozygotes develop symptoms due to yet undetermined mechanisms and a high percentage of females develops vital organ involvement including the kidneys, heart and/or brain about a decade later than males . Renal failure is a serious complication of this disease. Fabry nephropathy lesions are present and progress in childhood while the disease commonly remains silent by routine clinical measures. Early and timely diagnosis of Fabry nephropathy is crucial since late initiation of enzyme replacement therapy may not halt progressive renal dysfunction. This may be challenging due to difficulties in diagnosis of Fabry disease in children and absence of a sensitive non-invasive biomarker of early Fabry nephropathy. Accurate measurement of glomerular filtration rate and regular assessment for proteinuria and microalbuminuria are useful, though not sensitive enough to detect early lesions in the kidney. The principal clinical manifestationsin Fabry disease consist of artery associated complications (such as cerebral disease and nephropathy), but the pathophysiology of this specific vasculopathy is unclear. Several studies indicate that the specific vascular lesions that are present in Fabry disease occur as a result of vascular dysfunction with major components being endothelial dysfunction, alterations in cerebral perfusion and a pro-thrombotic phenotype. Fabry cardiac involvement has several clinical manifestations (table 10): concentric left ventricular hypertrophy without left ventricular dilation and severe loss of left ventricular systolic function, mitral and aortic valvulopathy, disorders of the atrioventricular conduction or repolarization, and compromised diastolic function. The neurological manifestations of Fabry disease include both peripheral nervous system and CNS involvement, with globotriaosylceramide accumulation found in Schwann cells and dorsal root ganglia together with deposits in CNS neurones. The main involvement of the CNS is attributable to cerebrovasculopathy, with an increased incidence of stroke. The abnormal neuronal accumulation of glycosphingolipid appears to have little clinical effect on the natural history of Fabry disease, with the possible exception of some reported mild cognitive abnormalities. The pathogenesis of Fabry vasculopathy remains poorly understood, but probably relates, in part, to abnormal functional control of the vessels, secondary to endothelial dysfunction as a consequence of α-galactosidase A deficiency. The diagnosis of Fabry disease is made in hemizygous males after the detection of the presence of angiokeratomas (fig 19 A, B), irregularities in sweating, edema, scant body hair, painful sensations, and of cardiovascular, gastrointestinal, renal, ophthalmologic, phlebologic, and respiratory involvement. A deficiency of alpha-gal A in serum, leukocytes, tears, tissue specimens, or cultured skin fibroblasts further supports the diagnosis in male patients. Since heterozygous women show angiokeratomas in only about 30% of cases and may have alpha-gal A levels within normal range, genetic analysis is recommended. The resultant storage of undegraded glycolipids leads to the progressive development of potentially life-threatening manifestations affecting multiple organ systems in the body. The Mainz Severity Score Index (MSSI) (table 12), a scoring system for patients with Fabry disease has been proven to be representative in patients with 'classic' Fabry disease and may be useful for monitoring clinical improvement in patients receiving enzyme replacement therapy. The MSSI of patients with AFD was significantly higher than that of patients with other severe debilitating diseases

    Clinical outcomes of endurant II stent-graft for infrarenal aortic aneurysm repair: Comparison of on-label versus off-label use

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    PURPOSE We aimed to compare the outcomes of the Endurant II (Medtronic) stent-graft used under instructions for use versus off-label in high-risk patients considered unfit for conventional surgery. METHODS Data from patients treated with the Endurant II stent-graft between December 2012 and March 2015 were retrospectively analyzed. Sixty-four patients were included. Patients were assigned to group A if treated under instructions for use (n=34, 53%) and to group B if treated off-label (n=30, 47%). Outcome measures included perioperative mortality and morbidity, survival, freedom from reintervention, endoleak incidence, in-hospital length of stay, and mean stent-graft component used. Mean follow-up was 22.61±12 months (median, 21.06 months; range, 0–43 months). RESULTS One perioperative mortality (1.6%) and one perioperative complication (1.6%) occurred in group B. At two months follow-up, one iliac limb occlusion (1.6%) occurred in group A. No type I/III endoleaks were recorded. A type II endoleak was identified in three cases (4.7%). Overall survival at three years was 89% (97% for group A, 82% for group B; P = 0.428). Reintervention-free survival at three years was 97% for both groups (P = 0.991). A longer in-hospital stay was observed in group B (P = 0.012). CONCLUSION The Endurant II (Medtronic) new generation device was safe in off-label setting at mid-term follow-up. The off-label use of the Endurant II (Medtronic) is justified in patients considered unfit for conventional surgery. Larger studies are required in this subgroup of patients

    Blood cyanide determination in two cases of fatal imtoxication: comparison between headspace gas chromatography and a spectrophotometric method

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    Blood samples of two cases were analyzed preliminarily by a classical spectrophotometric method (VIS) and by an automated headspace gas chromatographic method with nitrogen-phosphorus detector (HS-GC \u2044 NPD). In the former, hydrogen cyanide (HCN) was quantitatively determined by measuring the absorbance of chromophores forming as a result of interaction with chloramine T. In the automated HS-GC \u2044NPD method, blood was placed in a headspace vial, internal standard (acetonitrile) and acetic acid were then added. This resulted in cyanide being liberated as HCN. The spectrophotometric (VIS) and HS-GC\u2044NPD methods were validated on postmortem blood samples fortified with potassium cyanide in the ranges 0.5\u201310 and 0.05\u20135 lg \u2044 mL, respectively. Detection limits were 0.2 lg \u2044mL for VIS and 0.05 lg \u2044mL for HS-GC\u2044NPD. This work shows that results obtained by means of the two procedures were insignificantly different and that they compared favorably. They are suitable for rapid diagnosis of cyanide in postmortem cases

    Early stages of the HFCVD process on multi-vicinal silicon surfaces studied by electron microscopy probes (SEM, TEM)

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    In this paper, we show that silicon dimples are suitable samples to study diamond nucleation on a controlled distribution of defects by SEM FEG and HRTEM observations. Indeed, multi-vicinal surfaces generated by a UHV thermal treatment have been characterised by STM experiments. On these terraces, we observed a strong increase of the nucleation density higher than two orders of magnitude compared to pristine silicon samples. Moreover, a preferential location of diamond nuclei along the steps is reported. This result is explained by the large surface diffusion length of carbon species compared to the terrace's width. Indeed, during the early stages of growth, oriented silicon carbide nano-crystals are observed with the relationship SiC(220)//Si(220)

    Neurological complications of Anderson-Fabry disease

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    Characteristic clinical manifestations of AFD such as acroparesthesias, angiokeratoma, corneal opacity, hypo/ and anhidrosis, gastrointestinal symptoms, renal and cardiac dysfunctions can occur in male and female patients, although heterozygous females with AFD usually seems to be less severely affected. The most prominent CNS manifestations consist of cerebrovascular events such as transient ischaemic attacks (TIAs) and (recurrent) strokes . For the most part, CNS complications in AFD have been attributed to cerebral vasculopathy, including anatomical abnormalities. The natural history of Fabry patients includes transitory cerebral ischaemia and strokes, even in very young persons of both genders. The mechanism is partly due to vascular endothelial accumulation of Gb-3. White matter lesions (WML) on MRI occur. Both males and females can be safely treated with enzyme replacement; and thus screening for Fabry disease of young stroke populations should be considered. There are, however, no hard data of treatment effect on mortality and morbidity. Stroke in Anderson-Fabry disease study of 721 patients with cryptogenic stroke, aged 18-55 years, showed a high prevalence of Fabry disease in this group: 5% (21/432) of men and 3% (7/289) of women. Combining results for both sexes showed that 4% of young patients with stroke of previously unknown cause had Fabry disease, corresponding to about 1-2% of the general population of young stroke patients. Cerebral micro- and macro-vasculopathy have been described in Fabry disease. Neuronal globotriaosylceramide accumulation in selective cortical and brain stem areas including the hippocampus has been reported by autopsy studies in FD, but clinical surrogates as well as the clinical relevance of these findings have not been investigated so far. Another Neurologic hallmarks of Fabry disease (FD) include small fiber neuropathy as well as cerebral micro- and macroangiopathy with premature stroke. Cranial MRI shows progressive white matter lesions (WML) at an early age, increased signal intensity in the pulvinar, and tortuosity and dilatation of the larger vessels. Conventional MRI shows a progressive load of white matter lesions (WMLs) due to cerebral vasculopathy in the course of FD. Another study has been conducted to quantify brain structural changes in clinically affected male and female patients with FD. The peripheral neuropathy in Fabry disease manifests as neuropathic pain, reduced cold and warm sensation and possibly gastrointestinal disturbances. Patients with Fabry disease begin having pain towards the end of the first decade of life or during puberty. Children as young as 6 years of age have complained of pain often associated with febrile illnesses with reduced heat and exercise tolerance. The patients describe the pain as burning that is often associated with deep ache or paresthesiae. Some patients also have joint pain. A high proportion of patients with Fabry disease is at increased risk of developing neuropsychiatric symptoms, such as depression and neuropsychological deficits. Due to both somatic and psychological impairment, health-related quality of life (QoL) is considerably reduced in patients with Fabry disease. Targeted screening for Fabry disease among young individuals with stroke seems to disclose unrecognized cases and may therefore very well be recommended as routine in the future. Furthermore, ischemic stroke is related to inflammation and arterial stiffness [and no study had addressed this relationship in patients with AF disease and cerebrovascular disease, so this topic could represent a possible future research line

    Periodicity and quasi-periodicity effects on vibration band gaps

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    PERIODICITY AND QUASI-PERIODICITY EFFECTS ON VIBRATION BAND GAPS: NUMERICAL INVESTIGATIONS ON ONE-DIMENSIONAL STRUCTURE

    Heterogeneity of Human Mast Cells With Respect to MRGPRX2 Receptor Expression and Function.

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    Mast cells and their mediators play a role in the control of homeostasis and in the pathogenesis of several disorders. The concept of rodent mast cell heterogeneity, initially established in the mid-1960s has been extended in humans. Human mast cells isolated and purified from different anatomic sites can be activated via aggregation of cell surface high affinity IgE receptors (FcεRI) by antigens, superantigens, anti-IgE, and anti-FcεRI. MAS-related G protein-coupled receptor-X2 (MRGPRX2) is expressed at high level in human skin mast cells (MCs) (HSMCs), synovial MCs (HSyMCs), but not in lung MCs (HLMCs). MRGPX2 can be activated by neuropeptide substance P, several opioids, cationic drugs, and 48/80. Substance P (5 × 10-7 M - 5 × 10-6 M) induced histamine and tryptase release from HSMCs and to a lesser extent from HSyMCs, but not from HLMCs and human cardiac MCs (HHMCs). Morphine (10-5 M - 3 × 10-4 M) selectively induced histamine and tryptase release from HSMCs, but not from HLMCs and HHMCs. SP and morphine were incomplete secretagogues because they did not induce the de novo synthesis of arachidonic acid metabolites from human mast cells. In the same experiments anti-IgE (3 μg/ml) induced the release of histamine and tryptase and the de novo synthesis of prostaglandin D2 (PGD2) from HLMCs, HHMCs, HSyMCs, and HSMCs. By contrast, anti-IgE induced the production of leukotriene C4 (LTC4) from HLMCs, HHMCs, HSyMCs, but not from HSMCs. These results are compatible with the heterogeneous expression and function of MRGPRX2 receptor on primary human mast cells isolated from different anatomic sites.This work was supported partly by grants from the Regione Campania CISI-Lab Project, CRèME Project and TIMING Project

    Superantigenic Activation of Human Cardiac Mast Cells.

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    B cell superantigens, also called immunoglobulin superantigens, bind to the variable regions of either the heavy or light chain of immunoglobulins mirroring the lymphocyte-activating properties of classical T cell superantigens. Protein A of Staphylococcus aureus, protein L of Peptostreptococcus magnus, and gp120 of HIV are typical immunoglobulin superantigens. Mast cells are immune cells expressing the high-affinity receptor for IgE (FcεRI) and are strategically located in the human heart, where they play a role in several cardiometabolic diseases. Here, we investigated whether immunoglobulin superantigens induced the activation of human heart mast cells (HHMCs). Protein A induced the de novo synthesis of cysteinyl leukotriene C4 (LTC4) from HHMCs through the interaction with IgE VH3+ bound to FcεRI. Protein L stimulated the production of prostaglandin D2 (PGD2) from HHMCs through the interaction with κ light chains of IgE. HIV glycoprotein gp120 induced the release of preformed (histamine) and de novo synthesized mediators, such as cysteinyl leukotriene C4 (LTC4), angiogenic (VEGF-A), and lymphangiogenic (VEGF-C) factors by interacting with the VH3 region of IgE. Collectively, our data indicate that bacterial and viral immunoglobulin superantigens can interact with different regions of IgE bound to FcεRI to induce the release of proinflammatory, angiogenic, and lymphangiogenic factors from human cardiac mast cells.This work was supported in part by grants from Regione Campania CISI-Lab Project, CRèME Project, and TIMING Project
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