27 research outputs found

    A Compact Two-Wavelength Time-Domain NIRS System Based on SiPM and Pulsed Diode Lasers

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    This paper presents a complete, compact, and low power consumption instrument designed for time-domain near-infrared spectroscopy. It employs two custom-designed pulsed diode lasers (operating at 830 and 670 nm, with average optical power higher than 2 mW at 40 MHz repetition frequency), a single-photon detection module (based on a 1 mm2 active area silicon photomultiplier), and a custom time-to-digital converter with 10 ps time resolution. The system experimental characterization shows an instrument response function narrower than 300 ps (full-width at half maximum), with measurement stability better than ±1% over several hours of operation. The instrument, which is housed into a compact aluminum case (size 200 à 160 à 50 mm3), is specifically tailored for portability and ease of operation, hence fostering the diffusion of time-domain diffuse optics techniques. Thanks to a total power consumption lower than 10 W, this system is suitable for battery operation, thus enabling on-field measurements

    Predicting Long-Term Mortality in TAVI Patients Using Machine Learning Techniques

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    Background: Whereas transcatheter aortic valve implantation (TAVI) has become the gold standard for aortic valve stenosis treatment in high-risk patients, it has recently been extended to include intermediate risk patients. However, the mortality rate at 5 years is still elevated. The aim of the present study was to develop a novel machine learning (ML) approach able to identify the best predictors of 5-year mortality after TAVI among several clinical and echocardiographic variables, which may improve the long-term prognosis. Methods: We retrospectively enrolled 471 patients undergoing TAVI. More than 80 pre-TAVI variables were collected and analyzed through different feature selection processes, which allowed for the identification of several variables with the highest predictive value of mortality. Different ML models were compared. Results: Multilayer perceptron resulted in the best performance in predicting mortality at 5 years after TAVI, with an area under the curve, positive predictive value, and sensitivity of 0.79, 0.73, and 0.71, respectively. Conclusions: We presented an ML approach for the assessment of risk factors for long-term mortality after TAVI to improve clinical prognosis. Fourteen potential predictors were identified with the organic mitral regurgitation (myxomatous or calcific degeneration of the leaflets and/or annulus) which showed the highest impact on 5 years mortality

    Performance Assessment of the LIAISON\uae SARS-CoV-2 Antigen Assay On Nasopharyngeal Swabs

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    The SARS-CoV-2 pandemic is ongoing worldwide, causing prolonged pressure on molecular diagnostics. Viral antigen (Ag) assays have several advantages, ranging from lower cost to shorter turnaround time to detection. Given the rare occurrence of low-load viremia, antigen assays for SARS-CoV-2 have focused on nasopharyngeal swab and saliva as biological matrices, but their effectiveness must be validated. We assayed here the performances of the novel quantitative Liaison\uae SARS-CoV-2 Ag assay on 119 nasopharyngeal swabs and obtained results were compared with Hologic Panther and Abbott m2000 RT-qPCR. The Ag assay demonstrated a good correlation with viral load, shorter turnaround time, and favorable economics. The best performance was obtained in the acute phase of disease

    Construção estética das pessoas trans em Manaus/AM: Uma revisão sistemática

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    Introdução: Os corpos trans percorrem roteiros de transformação para a afirmação identitária    de seus gêneros, sendo a estética destes o produto dos valores simbólicos julgados, individual    e coletivamente, apropriados por e para essas pessoas. Objetivo: Analisar a literatura existente sobre os circuitos estéticos trans em Manaus, Amazonas. Metodologia: Trata-se de uma revisão sistemática com meta-síntese, baseada no modelo PRISMA, nas bases bibliográficas Google acadêmico, LILACS e BIREME. Resultados: Dentre os 355 resultados encontrados, foram analisadas 10 produções acadêmicas após o processo de triagem. Conclusões: As obras trazem violência, prostituição e enfrentamentos sociopolíticos em transversalidade aos roteiros de transformação estética das pessoas trans manauaras, privilegiando menções às trans femininas em relação aos outros gêneros trans. A história oral e as redes comunitárias estabelecidas são as principais bases de transformação destas pessoas, estando os meios oficiais em segundo plano dentro desses circuitos. &nbsp

    Pilot Study: Long-Term Shedding of {SARS}-{CoV}-2 in Urine: A Threat for Dispersal in Wastewater

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    Only 4 months after the beginning of SARS-CoV-2 epidemic, the world is facing a global pandemic due to a complex and insidious virus that today constantly poses new challenges. In this study, we highlight a persistent shedding of SARS-CoV-2 RNA into the urine, even in patients with a negative nasopharyngeal swab and in patients considered recovered. What does it mean? Besides the fact that the kidney is a probable site of viral replication, the prolonged viral excretion is a matter of great concern for our drainage system contamination

    Adaptive proximal scaphoid implant (APSI): a systematic review of the literature

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    : Scapholunate advanced collapse collapse (SLAC) is a challenging topic for hand surgeons. The adaptative proximal scaphoid implant (APSI) (Bioprofile-Tornier) is a pyrocarbon ovoid shaped interpositional implant, that allows adaptive mobility during motion. The aim of this systematic review is to analyze the clinical and radiological outcomes of APSI implants and possible complications. We performed a literature search combining the following key-words: "APSI", "Scaphoid's proximal pole", "implant", "scaphoid avascular necrosis", "SLAC", "SNAC", "pyrocarbon", "prosthesis", and "spacer" with no limitations for year of publication. We selected seven studies considered relevant to our systematic review. All studies described an improvement in the grip strength and the flexion extension arch compared to pre-operative values. The percentage of patients who reported progression of osteoarthritis (OA) with APSI was 17.3%, and implant's mobilization has a rate 5.1% (8/156). In conclusion the APSI implant is a reliable alternative for the treatment of SNAC wrist and SLAC wrist

    Monolithic time-to-digital converter chips for time-correlated single-photon counting and fluorescence lifetime measurements

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    We present a low-power Time-to-Digital Converter (TDC) chip, fabricated in a standard cost-effective 0.35 μm CMOS technology, which provides 160 ns dynamic range, 10 ps timing resolution and Differential Non-Linearity better than 0.01 LSB rms. This chip is the core of a compact TDC module equipped with an USB 2.0 interface for user-friendly control and data-acquisition. The TDC module is suitable for a wide variety of applications such as Fluorescence Lifetime Imaging (FLIM), time-resolved spectroscopy, Diffuse Optical Spectroscopy (DOS), Optical Time-Domain Reflectometry (OTDR), quantum optics, etc. In particular, we show the application of our TDC module to fluorescence lifetime measurements

    Bicyclic γ-amino acids as inhibitors of γ-aminobutyrate aminotransferase

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    The γ-aminobutyrate (GABA)-degradative enzyme GABA aminotransferase (GABA-AT) is regarded as an attractive target to control GABA levels in the central nervous system: this has important implications in the treatment of several neurological disorders and drug dependencies. We have investigated the ability of newly synthesized compounds to act as GABA-AT inhibitors. These compounds have a unique bicyclic structure: the carbocyclic ring bears the GABA skeleton, while the fused 3-Br-isoxazoline ring contains an electrophilic warhead susceptible of nucleophilic attack by an active site residue of the target enzyme. Out of the four compounds tested, only the one named (+)-3 was found to significantly inhibit mammalian GABA-AT in vitro. Docking studies, performed on the available structures of GABA-AT, support the experimental findings: out of the four tested compounds, only (+)-3 suitably orients the electrophilic 3-Br-isoxazoline warhead towards the active site nucleophilic residue Lys329, thereby explaining the irreversible inhibition of GABA-AT observed experimentally

    Previous Humoral Immunity to the Endemic Seasonal Alphacoronaviruses NL63 and 229E Is Associated with Worse Clinical Outcome in COVID-19 and Suggests Original Antigenic Sin

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    Antibody-dependent enhancement (ADE) of severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) infection has been hypothesized. However, to date, there has been no in vitro or in vivo evidence supporting this. Cross-reactivity exists between SARS CoV-2 and other Coronaviridae for both cellular and humoral immunity. We show here that IgG against nucleocapsid protein of alphacoronavirus NL63 and 229E correlate with the World Health Organization’s (WHO) clinical severity score ≥ 5 (incidence rate ratios was 1.87 and 1.80, respectively, and 1.94 for the combination). These laboratory findings suggest possible ADE of SARS CoV-2 infection by previous alphacoronavirus immunity
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