143 research outputs found

    Characterization of CMOS Spiral Inductors

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    In this work "full-wave" simulations of integrated inductors are presented and compared with measurements of fabricated CMOS chips. The good agreement between measurements and simulations demonstrates the accuracy of the tool, which is, hence, a cheaper alternative to experimental characterization. Furthermore, the proposed approach may give precious hints for performance improvements, by making internal device fields and currents available for the VLSI designer and providing compact, most effective, equivalent models

    EH Performance of an Hybrid Energy Harvester for Autonomous Nodes

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    This paper reports the Energy Harvesting (EH) performance of a hybrid energy harvester able to collect energy form different energy sources: thermal, solar and electromagnetic. The main block of the system is the quarter-wavelength patch antenna, operating in the Industrial, Scientific and Medical (ISM) frequency band 2.4-2.5 GHz. The antenna has been designed and optimized to support a Thermo-Electric Generator (TEG) and a Solar Cell on its top. Moreover, a rectifier has been designed to work with the antenna and a DC-DC converter has been used to manage the TEG output voltage

    Low-Noise Ku-Band Receiver Frontend with Switchable SIW Filters for Cubesat Applications

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    This paper proposes a low-noise receiver frontend for nanosatellite and Cubesat platforms. The frontend is composed by a Low-Noise Amplifier (LNA) and two Substrate Integrated Waveguide (SIW) filters, providing a frequency reconfigurability to the system. The two filters operate in the 13 and in the 14 GHz uplink bands, and are selected by means of a pair of solid-state SPDT switches. As a results, 15.5 dB gain with 2.4 dB noise figure for the 13 GHz configuration and 17.8 dB gain with 2.3 dB noise figure for the 14 GHz configuration are obtained. This work is important since demonstrates a low-cost solution for satellite radio apparatuses based on commercial components on a standard PCB

    Simulation and measurement of quasi-optical multipliers

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    Microwave investigation of pinning in Te-and cubic-BN-added MgB2

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    Abstract MgB2 has great potential for many applications, thanks to its relatively high critical temperature and low fabrication cost. Large efforts are done to improve the current carrying capabilities of bulks and tapes in view of different application fields, e.g. with the addition of Te and cubic-BN to MgB2. To elucidate the vortex pinning physics exploiting a different dynamic regime, we present here a microwave study of the pinning properties of spark plasma sintered bulk MgB2 with and without the addition of 0.01 % at. Te or cubic-BN. We show the surface resistance Rs of the MgB2 samples measured with a dielectric-loaded resonator at ~ 16.5 GHz and ~ 26.7 GHz in the 10 K-Tc temperature range at fields up to 1.0 T. Then, the MgB2 Rs is studied with high frequency vortex motion models in order to obtain the pinning constant (Labusch parameter) and the depinning frequency. Finally, the microwave behavior of MgB2 in the mixed state is compared with the recent results obtained on Nb3Sn

    Low-Noise Block Downconverter based on COTS and SIW Filters for Ku-band Cubesat Transponders

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    This paper proposes a Low-Noise Block (LNB) downconverter operating in the Ku-band for Cubesat transponders. The frontend is composed by a Low-Noise Amplifier (LNA) and two switchable Substrate Integrated Waveguide (SIW) filters, providing a frequency reconfigurability to the system. The LNB is completed by a downconversion unit, constituted by a mixer, a PLL frequency synthesizer and an IF amplifier. A first breadboard features an overall gain of 54 dB with a 2.3 dB noise figure. The worst case linearity performance indicates an input-referred 1 dB compression point (P1dB) and a third-order intercept point (IIP3) equal to -27 dBm and -16 dBm respectively. This work is important since demonstrates a low-cost solution for satellite radio apparatuses based on commercial components and standard PCB

    SARS-CoV-2 infection in patients with inflammatory bowel disease: comparison between the first and second pandemic waves

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    In Italy, the incidence of SARS-CoV-2 infection peaked in April and November 2020, defining two pandemic waves of coronavirus disease 2019 (COVID-19). This study compared the characteristics and outcomes of patients with inflammatory bowel disease (IBD) and SARS-CoV-2 infections between pandemic waves.MethodsObservational longitudinal study of IBD patients with SARS-CoV-2 infection. Patients with established diagnoses of IBD and of SARS-CoV-2 infection were consecutively enrolled in two periods: (i) first wave, from 1 March 2020 to 31 May 2020; and (ii) second wave, from 15 September to 15 December 2020.ResultsWe enrolled 937 IBD patients (219 in the first wave, 718 in the second wave). Patients of the first wave were older (mean & PLUSMN; SD: 46.3 & PLUSMN; 16.2 vs. 44.1 & PLUSMN; 15.4 years, p = 0.06), more likely to have ulcerative colitis (58.0% vs. 44.4%, p < 0.001) and comorbidities (48.9% vs. 38.9%; p < 0.01), and more frequently residing in Northern Italy (73.1% vs. 46.0%, p < 0.001) than patients of the second wave. There were no significant differences between pandemic waves in sex (male: 54.3% vs. 53.3%, p = 0.82) or frequency of active IBD (44.3% vs. 39.0%, p = 0.18). The rates of negative outcomes were significantly higher in the first than second wave: pneumonia (27.8% vs. 11.7%, p < 0.001), hospital admission (27.4% vs. 9.7%, p < 0.001), ventilatory support (11.9% vs. 5.4%, p < 0.003) and death (5.5% vs. 1.8%, p < 0.007).ConclusionBetween the first and second SARS-CoV-2 pandemic waves, demographic, clinical and geographical features of IBD patients were different as were the symptoms and outcomes of infection. These differences are likely due to the different epidemiological situations and diagnostic possibilities between the two waves

    A new national survey of centers for cognitive disorders and dementias in Italy

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    IntroductionA new national survey has been carried out by the Italian Centers for Cognitive Disorders and Dementias (CCDDs). The aim of this new national survey is to provide a comprehensive description of the characteristics, organizational aspects of the CCDDs, and experiences during the COVID-19 pandemic.MethodsA list of all national CCDDs was requested from the delegates of each Italian region. The online questionnaire is divided in two main sections: a profile section, containing information on location and accessibility, and a data collection form covering organization, services, treatments, activities, and any service interruptions caused by the COVID-19 outbreak.ResultsIn total, 511 out of 534 (96%) facilities completed the profile section, while 450 out of 534 (84%) CCDDs also completed the data collection form. Almost half of the CCDDs (55.1%) operated for 3 or fewer days a week. About one-third of the facilities had at least two professional figures among neurologists, geriatricians and psychiatrists. In 2020, only a third of facilities were open all the time, but in 2021, two-thirds of the facilities were open.ConclusionThis paper provides an update on the current status of CCDDs in Italy, which still shows considerable heterogeneity. The survey revealed a modest improvement in the functioning of CCDDs, although substantial efforts are still required to ensure the diagnosis and care of patients with dementia

    Vigilância do desenvolvimento neuropsicomotor de crianças de um programa DST/AIDS

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    A terapia anti-retroviral de alta potência (TARV) é uma forma eficaz de prevenção da transmissão do vírus HIV de mãe para filho. No entanto, os estudos ainda investigam os efeitos da exposição intraútero à TARV, dentre eles o atraso no desenvolvimento neuropsicomotor (DNPM). O presente estudo apresenta o relato de um projeto de extensão, cujos objetivos foram verificar o DNPM de crianças de um programa DST/AIDS, orientar as famílias considerando seu contexto socioeconômico e realizar encaminhamentos para serviços de saúde específicos. A vigilância do DNPM foi feita em três etapas: (1) avaliação em ambulatório; (2) avaliação e orientações em domicílio; (3) elaboração de relatórios aos gestores de saúde. Foram utilizados os testes DENVER II e o PEDI, além de um questionário socioeconômico. Participam do programa DST/AIDS 15 crianças, sendo 12 soro-revertidas, 1 soropositiva e 2 indefinidas. Doze crianças foram avaliadas, e os domínios mais comprometidos foram linguagem, pessoal-social e motor fino, respectivamente. Quanto ao nível econômico, 73,3% pertenciam ao nível E, e 58,3% das mães eram analfabetas ou cursaram apenas o primário. Crianças filhas de mães HIV positivo, além de fatores biológicos, geralmente estão expostas a fatores de risco ambientais que contribuem para alterações do DNPM. Desta forma, o acompanhamento por uma equipe de profissionais de saúde, em parceria com a família da criança, torna-se uma importante ferramenta para a identificação e intervenção precoce.Highly active antiretroviral therapy (HAART) is an effective way of preventing mother-to-child transmission of HIV. However, further studies investigate the effects of short and long term exposure to HAART in-utero and its consequence on child neuropsychomotor development (NPMD). The paper presents a report and discussion of results of an extension project whose objectives were to verify the NPMD of children participating of the STD/AIDS program, to orientate families according to their socioeconomic context and make referrals to specific health services. The NPMD surveillance was divided into three parts: (1) ambulatory evaluation; (2) home evaluation and orientations; (3) reporting health managers. DENVER II and PEDI tests were used and also a socioeconomic questionnaire. Fifteen children were on the program of which 12 uninfected, 1 HIV+ and 2 indeterminate. Twelve children were evaluated and the most impaired domain were language, personal-social and fine motor, respectively. Regarding to socioeconomic status, 73,3% were E level and 58,3% of mothers were analphabet or had primary school. Children born of infected mothers, besides the biological risks, usually are exposed to environment/social risks that can affect the NPMD. Thus, monitoring by a team of health professionals, in partnership with the child's family, becomes an important tool for identification and early intervention
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