1,987 research outputs found

    A Robust 43-GHz VCO in CMOS for OC-768 SONET Applications

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    In this paper, we present a 43-GHz LC-VCO in 0.13-/spl mu/m CMOS for use in SONET OC-768 optical networks. A tuned output buffer is used to provide 1.3 V/sub p-p/ (single-ended) into a 90-fF capacitive load as is required when the VCO is used in typical clock and data recovery (CDR) circuits. Phase noise is -90 dBc/Hz at a 1-MHz offset from the carrier; this meets SONET jitter specifications. The design has a tune range of 4.2%. The VCO, including output buffers, consumes 14 mA from a 1-V supply and occupies 0.06 mm/sup 2/ of die area. Modern CMOS process characteristics and the high center frequency of this design mean that the tank loss is not dominated by the integrated inductor, but rather by the tank capacitance. An area-efficient inductor design that does not require any optimization is used

    Au/ZrO2 catalysts for LT-WGSR: active role of sulfates during gold deposition

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    Two studies examined the effect of acculturation-contact discrepancies on well-being. Specifically, we tested the prediction that well-being will be compromised when cultural minorities' acculturation preferences are not met by the intergroup and intragroup contact in a new society. Study 1 found that for Polish immigrants (n=55) acculturation-contact discrepancies were associated with compromised well-being. Study 2 followed a cohort of international students (n=106) for a period of two academic years. Results suggested that discrepancies in students' acculturation-contact in their first year had harmful consequences for their well-being 1 year later. Overall, the two studies show that discrepancies between acculturation preferences and actual contact have negative implications for the psychological adaptation of acculturating individuals.info:eu-repo/semantics/publishedVersio

    Non-Thermal Plasma Activation of Gold-Based Catalysts for Low-Temperature Water-Gas Shift Catalysis

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    Acknowledgements The UK Catalysis Hub is kindly thanked for resources and support provided via our membership of the UK Catalysis Hub Consortium and funded by EPSRC (Portfolio Grants EP/K014706/2, EP/K014668/1, EP/K014854/1, EP/K014714/1, and EP/I019693/1). Open access data can be found via the University of Manchester research portal. We are grateful to Helen Daly (Queen's University Belfast) for discussion, to Fabio de Rosa (Queen's University Belfast) for the thermodynamic equilibrium calculations (obtained using the Convergence tool of Aspen Plus 8.0) and to Emma Gibson (Harwell Research Complex) for the BET measurements. JJ Delgado is grateful to Ramon y Cajal program and the Ce-NanoSurPhases project grant from MINECO.Peer reviewedPostprintPostprintPublisher PD

    Spectroscopic investigation of Titania-supported gold nanoparticles prepared by a modified deposition/precipitation method for the oxidation of CO

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    The spectroscopic characterization of a material is a fundamental tool for understanding the structure–activity correlation for catalytic purposes. Regarding supported nanoparticles, this perspective has acquired more relevance in recent years and several techniques have been employed. In this work diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), coupled with CO adsorption, was used to investigate a modified deposition/precipitation method (DP-UC) for the preparation of supported gold nanoparticles with very low metal loading (0.1–0.5 wt %). This promising synthetic route involves the use of urea as basic agent and NaBH4 as chemical reductant in contrast to the traditional high-temperature reduction step. The systematic IR spectroscopic study of the Au loading was combined with CO oxidation catalytic tests. The evaluation of the results was also supported by several other techniques, such as X-ray photoelectron spectroscopy, N2 physisorption, and transmission electron microscopy. Particular attention was given to the evaluation of the gold electronic state, surface dispersion, particle size, and the corresponding structure–activity relationship

    Au/TiO2(110) interfacial reconstruction stability from ab initio

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    We determine the stability and properties of interfaces of low-index Au surfaces adhered to TiO2(110), using density functional theory energy density calculations. We consider Au(100) and Au(111) epitaxies on rutile TiO2(110) surface, as observed in experiments. For each epitaxy, we consider several different interfaces: Au(111)//TiO2(110) and Au(100)//TiO2(110), with and without bridging oxygen, Au(111) on 1x2 added-row TiO2(110) reconstruction, and Au(111) on a proposed 1x2 TiO reconstruction. The density functional theory energy density method computes the energy changes on each of the atoms while forming the interface, and evaluates the work of adhesion to determine the equilibrium interfacial structure.Comment: 20 pages, 11 figure

    Clostridium difficile infection in children: epidemiology and risk of recurrence in a low-prevalence country

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    Clostridium difficile infection (CDI) is increasingly found in children worldwide, but limited data are available from children living in southern Europe. A 6-year retrospective study was performed to investigate the epidemiology, clinical features, treatment, and risk of recurrence in Italy. Data of children with community- and hospital-acquired CDI (CA-CDI and HA-CDI, respectively) seen at seven pediatric referral centers in Italy were recorded retrospectively. Annual infection rates/10,000 hospital admissions were calculated. Logistic regression was used to investigate risk factors for recurrence. A total of 177 CDI episodes was reported in 148 children (83 males, median age 55.3 months), with a cumulative infection rate of 2.25/10,000 admissions, with no significant variability over time. The majority of children (60.8 %) had CA-CDI. Children with HA-CDI (39.2 %) had a longer duration of symptoms and hospitalization (p = 0.003) and a more common previous use of antibiotics (p = 0.0001). Metronidazole was used in 70.7 % of cases (87/123) and vancomycin in 29.3 % (36/123), with similar success rates. Recurrence occurred in 16 children (10.8 %), and 3 (2 %) of them presented a further treatment failure. The use of metronidazole was associated with a 5-fold increase in the risk of recurrence [odds ratio (OR) 5.18, 95 % confidence interval (CI) 1.1-23.8, p = 0.03]. Short bowel syndrome was the only underlying condition associated with treatment failure (OR 5.29, 95 % CI 1.17-23.8, p = 0.03). The incidence of pediatric CDI in Italy is low and substantially stable. In this setting, there is a limited risk of recurrence, which mainly concerns children treated with oral metronidazole and those with short bowel syndrome

    Effect of Inflammation on miRNA Expression in Pancreatic Beta Cells and their Exosomes

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    Background and aims. Inflammation is a contributor to the dysfunction of insulin-secreting pancreatic beta-cells in Diabetes Mellitus (DM). Exosomes (EXOs) have emerged as important mediators in cell communication, which carry proteins and RNA species (miRNA, mRNA, tRNAs etc). EXOs have been found under normal physiologic and disease states. Their content can reflect biological events and disease progression. In the present study, we are defining the miRNA profiles of beta cells and EXOs, with and without exposure to inflammatory cytokines. By comparing our data to literary references, it will be possible to identify miRNAs that may reflect beta cell damage and/or death

    Change of initial oral antidiabetic therapy in type 2 diabetic patients

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    Objective To explore the 'real-life' therapy of type 2 diabetes mellitus with oral antidiabetic drugs (OADs). Methods From the PHARMO Record Linkage System comprising linked drug dispensing and clinical laboratory data from approximately 2.5 million individuals in the Netherlands, among others, new users of OADs were identified in the period 1999-2004. New users, aged 30 years and older, without insulin use before cohort entry date and with at least one year follow-up were included. We determined per initial therapy patient characteristics and first therapy change. Results Overall 35,514 patients were included. Metformin and sulfonylureas (SU) were the most frequent initial therapy. Patients on thiazolidinedione (TZD) monotherapy had lower percentages baseline HbA1c ≥ 7% compared to patients on metformin and SU. The proportion of patients still on initial therapy after one year ranged from 46% (TZDs) to around 60% (SU). Among patients starting on monotherapy, add-on (15-20%) and discontinuation (16-25%) of therapy occurred most frequently. In patients starting on combination therapy, a switch occurred in 30% of the patients. Conclusion In more than 40% of the patients a change in initial OAD-therapy is already observed in the first year of therapy. Maintaining patients on initial therapy remains a challenge

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