818 research outputs found

    Polarization Effect on the Performance of On-Chip Wireless Optical Point-to-Point Links

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    Optical on-chip wireless interconnection is an emerging technology that aims to overcome the communication bottleneck in computing architectures and in which multiple processing units are exploited for data-intensive applications. In this work, we propose an integrated dielectric Vivaldi antenna, which exhibits the same gain performances for both TE and TM input polarizations. Point-to-point on-chip communication links between two Vivaldi antennas are analyzed. Moreover, the effect of wave polarization on the link performances is numerically studied in on-chip multilayer structures in connection with the multilayer characteristic parameters, i.e., cladding layer thickness and refractive index. The numerical results show that, with the same antenna gain, TM polarization is affected by lower propagation losses when suitable cladding layer thickness and refractive index are considered

    Graphene-based absorber exploiting guided mode resonances in one-dimensional gratings

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    A one-dimensional dielectric grating, based on a simple geometry, is proposed and investigated to enhance light absorption in a monolayer graphene exploiting guided mode resonances. Numerical findings reveal that the optimized configuration is able to absorb up to 60% of the impinging light at normal incidence for both TE and TM polarizations resulting in a theoretical enhancement factor of about 26 with respect to the monolayer graphene absorption (about 2.3%). Experimental results confirm this behaviour showing CVD graphene absorbance peaks up to about 40% over narrow bands of few nanometers. The simple and flexible design paves the way for the realization of innovative, scalable and easy-to-fabricate graphene-based optical absorbers

    Graphene-based perfect optical absorbers harnessing guided mode resonances

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    We numerically and experimentally investigate graphene-based optical absorbers that exploit guided mode resonances (GMRs) achieving perfect absorption over a bandwidth of few nanometers (over the visible and near-infrared ranges) with a 40-fold increase of the monolayer graphene absorption. We analyze the influence of the geometrical parameters on the absorption rate and the angular response for oblique incidence. Finally, we experimentally verify the theoretical predictions in a one-dimensional, dielectric grating and placing it near either a metallic or a dielectric mirror

    Extrafine beclomethasone/formoterol in severe COPD patients with history of exacerbations

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    The FORWARD study is a randomised, double-blind trial that compares the efficacy and safety of 48 weeks treatment with extrafine beclomethasone dipropionate/formoterol fumarate (BDP/FOR), 100/6 μg pMDI, 2 inhalations BID, vs. FOR 12 μg pMDI, 1 inhalation BID, in severe COPD patients with a history of exacerbations. Co-primary endpoints were exacerbation rate over 48 weeks and pre-dose morning FEV1 at 12 weeks. The ITT population included 1186 patients (69% males, mean age 64 years) with severe airflow limitation (mean post-bronchodilator FEV1 42% predicted). Salbutamol as rescue therapy, theophylline and tiotropium (if stable regimen prior to screening) were allowed. Compared to FOR, BDP/FOR: (1) reduced the exacerbation rate (rate ratio: 0.72 [95% confidence interval 0.62–0.84], p < 0.001); (2) improved pre-dose morning FEV1 (mean difference: 0.069 L [0.043–0.095] p < 0.001); (3) prolonged the time to first exacerbation; (4) improved the SGRQ total score. The percentage of patients with adverse events was similar (52.1% with BDP/FOR and 49.2% with FOR). Pneumonia incidence was low, slightly higher with BDP/FOR (3.8%) than with FOR (1.8%). No difference for laboratory values, ECG or vital signs. Extrafine BDP/FOR significantly reduces the exacerbation rate and improves lung function of patients with severe COPD and history of exacerbations as compared to FOR alone

    Interaction of glutathione transferase from horse erythrocytes with 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole

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    7-Chloro-4-nitrobenzo-2-oxa-1,3-diazole reacts with two thiol groups of the dimeric horse erythrocyte glutathione transferase at pH 5.0, with strong inactivation reversible on dithiothreitol treatment. The inactivation kinetic follows a biphasic pattern, similar to that caused by other thiol reagents as recently reported. Both S-methylglutathione and 1-chloro-2,4-dinitrobenzene protect the enzyme from inactivation. Analysis of the reactive SH group-containing peptide gives the sequence Ala-Ser-Cys-Leu-Tyr, identical with that of the peptide that contains the reactive cysteine 47 of the human placental transferase. In the presence of glutathione, the enzyme is not inactivated by this reagent, but it catalyzes its conjugation to glutathione. At higher pH values, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole reacts with 2 tyrosines/dimer and lysines, as well as with cysteines. Reaction with lysine seems essentially without effect on activity; whether the reactive tyrosines are important for activity could not be determined using this reagent only. However, 2 tyrosines among the 4 that are nitrated by tetranitro-methane are important for activity

    IDENTIFICATION OF E. COLI O157 IN A BOVINE MILK FARM BY MULTIPLEX REAL-TIME PCR

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    Law provisions about direct sell of raw bovine milk require VTEC O157 monitoring in bovine milk farms (milk and faeces). It has been showed that culture-based methods used for this scope, besides being cumbersome and time-consuming, may be also less sensitive, compared to molecular approaches. In this study, a multiplex Real-Time PCR, able to identify VTEC O157, Salmonella spp and Listeria monocytogenes, has been used to analyse milk, filter, sewage and stool samples from a milk farm, in comparison with standard OIE methods. The performances of the molecular protocol have been preliminary assessed with lyophilized samples from proficiency testing VLA, showing 100% accordance. Results from field samples indicated the absence of the pathogen in milk, and the higher sensitivity of Real-Time PCR with other matrices, suggesting its potential use for fast VTEC O157 identification

    Glucose Metabolism, Thyroid Function, and Prolactin Level in Adolescent Patients With First Episode of Schizophrenia and Affective Disorders

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    Schizophrenia and affective spectrum disorders (ASD) typically begin in adolescence or early adulthood. The pathophysiological mechanisms underlying these disorders are still not fully understood, and recent studies have suggested an involvement of dysfunctions in cardiometabolic and neuroendocrine systems at the onset of both disorders. In this context, we aimed to assess thyroid function, prolactin level, glucose metabolism, and lipid profile in drug naive adolescents, comparing patients with first episode of schizophrenia spectrum disorders (SSD) and patients with ASD. We performed a retrospective chart review from inpatients aged from ten to eighteen years, referred to Child and Adolescent Psychiatric Unit of University of Bari “Aldo Moro” over a period of 4 years, with diagnosis of SSD (n=30) or ASD (n=22), according to Diagnostic and Statistical Manual for Mental Disorders-fifth edition (DSM-5) criteria. Data on serum prolactin, glucose, insulin, total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, triglycerides, thyroid stimulating hormone, free triiodothyronin, and free thyroxin were collected, and the insulin resistance (IR) indexes “HOMA1-IR“ and “HOMA2-IR” were calculated. The multivariable linear regression models, adjusting for potential confounding factors (age, sex, and BMI), showed HOMA1-IR (p=0.001), HOMA2-IR (p=0.002), glucose (p=0.004), insulin (p=0.004) and free thyroxin (p&lt;0.001) values higher in the SSD group than in ASD. No others significant differences were found. Our findings suggest the need for a metabolic and endocrine screening at the onset of SSD and ASD, particularly for indexes of IR, that is a testable and treatable risk factor for cardiometabolic diseases. Further studies are required to better understand the role of endocrinological and metabolic dysfunctions at the onset of severe mental illness also considering influencing factors as age, gender, and BMI

    Vitamin D Deficiency in Autism Spectrum Disorder: A Cross-Sectional Study

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    Vitamin D plays a role in central nervous system (CNS) development. Recent literature focused on Vitamin D status in children and adolescents with autism spectrum disorder (ASD), but with inconsistent results. Our case-control study is aimed at evaluating serum 25-hydroxyl-Vitamin D (25(OH)D) concentration in children with ASD (ASD group, n=54) compared to children affected by other neurological and psychiatric disorders (non-ASD group, n=36). All patients were admitted at the Complex Operative Unit of Child Neuropsychiatry, Polyclinic of Bari, Italy. 25(OH)D was quantified by chemiluminescence immunoassay and level defined as: Deficiency (&lt;20 ng/mL); insufficiency (20-30); normality (30-100); toxicity (&gt;100). Statistical analysis was performed using SPSS20 (significance&lt;0.05). The ASD group showed 25(OH)D a mean level significantly lower than control (p=0.014). Multivariable logistic regression analysis showed an association between ASD and Vitamin D deficiency (p=0.006). The nature of such association is unclear. Vitamin D deficiency may probably act as a risk factor for the development of ASD. Further studies are needed to unravel the role of Vitamin D in ASD etiology and investigate its therapeutic potential
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