76 research outputs found

    Remote sensing of cirrus clouds and aerosols by a sun photometer in Tunisia

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    International audienceSome ground based measurements of solar radiation by using a sun photometer, have been conducted in Tunisia during the period of November 2000–February 2002. Five key measurement sites were selected: Three Sites (Tunis, Sousse, Gabes) are located on the Mediterranean coast and Two sites (Gafsa, Tozeur) on the boarder of Sahara. Over a total of 149 measurement days, 21 days are identified as clear sky, 114 days as Cirrus clouds and 14 days as aerosols. Aerosols and Cirrus clouds Optical Thickness (AOT) are derived from photometric measurements at 532 nm wavelength. Spatial and temporal variabilities of AOT are presented and discussed in this paper. Cirrus clouds were frequently observed at Gafsa and Tozeur where saharan aerosol events are expected to be more frequent than cirrus clouds. The mediterranean sea and saharan aerosols are suspected to have the main role in cirrus clouds formation, by providing water vapor and high concentrations of cloud condensation and ice forming nuclei

    Optoelectronic comb generation and cross-injection locking of photonic integrated circuit for millimetre-wave generation

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    We demonstrate how a monolithically integrated heterodyne source was used for a 33.6 GHz signal generation using an optical solution by a combination of cross-optical injection locking inside the chip and electrical injection locking at the RF signal 7th sub-harmonic

    Combined immune checkpoint inhibitor therapy with nivolumab and ipilimumab causing acute-onset type 1 diabetes mellitus following a single administration: two case reports.

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    The use of immune checkpoint inhibitor (ICI) therapy is becoming a standard of care for several cancers. Monoclonal antibodies targeting cytotoxic T-lymphocyte antigen-4 (CTLA-4) and programmed cell death protein 1 (PD-1) or its ligand (PD-L1) cause a broad spectrum of autoimmune adverse events. ICI-induced type 1 diabetes mellitus (T1DM) is extremely rare (< 1%) but potentially life-threatening. It appears to be more common with PD-1 blockade (or combination immunotherapy) than with anti-CTLA-4 therapy, often during the first three to six months of therapy. We report an acute onset T1DM with severe inaugural diabetic ketoacidosis (DKA) and remarkably elevated Glutamic Acid Decarboxylase antibody (GADA) titres following a single administration of combined ICI therapy with nivolumab (anti-PD-1) and ipilimumab (anti-CTLA-4) in two adult patients with advanced metastatic melanoma. In these cases, the time to diabetes onset was remarkably short (two and five weeks), and one presented with fulminous T1DM in a previous long-standing type 2 diabetes mellitus. Oncological patients treated with combination therapy of anti-PD-1 and anti-CTLA-4 can develop a particular pattern of T1DM, with very rapid onset within a few weeks after starting ICI therapy, even in the presence of an existing type 2 diabetes. ICI-induced T1DM is a medical emergency in presence of severe inaugural DKA and requires a collaboration between specialists and primary care physicians, as well as patient education, for early diagnosis and supportive care

    Demonstration of Photonic Integrated RAU for Millimetre-wave Gigabit Wireless Transmission

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    This work reports the performance of a wireless transmission link based on a radio access unit (RAU) implemented in photonic integrated circuit (PIC) form. The PIC contains a high speed photodiode for direct optical to RF conversion, monolithically integrated with a semiconductor laser, used as an optical local oscillator for up-conversion of the incoming 16-QAM-OFDM signal through heterodyning. Wireless transmission was demonstrated with a spectral efficiency as high as 3 bits/s/Hz at 60 GHz carrier and with 1.2 Gb/s transmission rate. Moreover, the RAU based on a broad bandwidth photodiode integrated with a tuneable laser allowed for a compact unit that could operate at carrier frequencies up to 100 GHz

    Triage et valorisation des déchets solides à la décharge publique de la ville de Mohammedia

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    This work is part of the evaluation of solid waste in landfills in Morocco. It can first show, the importance of triage and valorization and help develop other opportunities in the various sectors of solid waste. The latter is relevant in overcoming the constraints identified and exploiting the opportunities      identified. The results obtained during the triage conducted showed that the dump of Mohammedia is a source of raw material (plastic, glass, paper ...). The study showed an estimated quantity  T/day between 10 and 16 tones of plastic to value, 10 to 6 tons of  paper... The activity of plastic recycling mainly responds to the demand and supply products with an annual deposit within a range from 30000 to 40000 tones (1). The circuit recovery and recycling of solid waste the plastic glassware ... knows a problem of organization and precarious working conditions of scavengers in particular:   hygiene and sanitation and health risk.Ce travail entre dans le cadre de la valorisation des déchets solides triés dans des décharges publiques au Maroc. Il peut d’une part montrer l’importance de triage et valorisation et d’autre part aider  au développement des débouchés des différentes filières de récupération des déchets. Ce dernier présente les actions pertinentes à même de dépasser les contraintes relevées et d’exploiter les opportunités identifiées. Les principaux résultats obtenu durant le triage réalisé a montré que la décharge publique de Mohammedia constitue une source de matière première (plastiques, verreries, papiers cartonnées….). L’étude réalisée a montré qu’on estime une quantité en T/ jour variant entre 10  et 16 tonnes de plastiques à valoriser, 10 à 6 tonnes de papiers,… L’activité de recyclage du plastique répond principalement à l’offre et la demande des produits dont le gisement annuel se situe dans une fourchette de 30 000 à 40 000 tonnes (1). Le circuit de récupération et de valorisation des déchets tel que le plastique la verrerie… connaît un véritable problème d’organisation et de précarité des conditions de travail en particulier des récupérateurs : manquement aux règles de base d’hygiène et de salubrité, risque pour la santé, etc

    Pharmacovigilance - Vaccins à ARNm contre le Covid-19 : le point sur les effets indésirables [Pharmacovigilance - mRNA COVID-19 vaccines : current state of knowledge on their adverse effects]

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    The COVID-19 pandemic has stimulated the rapid development and large-scale use of technologically innovative vaccines, such as the mRNA vaccines Spikevax (Moderna) and Comirnaty (Pfizer-BioNTech). This unprecedented deployment has challenged pharmacovigilance, requiring combined skills in safety monitoring, prompt data analysis and continuous dissemination of knowledge. Main recognised adverse events of these vaccines are moderate and transient, linked to their significant reactogenicity. Active post-marketing surveillance has identified rare adverse events such as myopericarditis and a variety of skin reactions. A number of potential rare adverse events are being evaluated and could be retained at the individual level, but do not question the overall safety of these vaccines

    Systematic comparison with autoimmune liver disease identifies specific histological features of immune checkpoint inhibitor-related adverse events.

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    Immune checkpoint inhibitors (ICIs) have become a mainstay of cancer treatment. Their immune-boosting quality has one major drawback, their proclivity to induce a broad array of immune-related adverse events (irAEs) affecting, among others, the liver and sharing some similarities with classic autoimmune liver diseases (AILD).We aimed to compare clinical, laboratory and histological features of patients with liver-related irAEs and AILD. We systematically compared liver irAEs with AILD, namely autoimmune hepatitis (AIH) and primary biliary cholangitis, regarding their clinical, laboratory, and histological features. Twenty-seven patients with liver irAEs (ICI group) and 14 patients with AILD were identified. We observed three distinct ICI-induced histological liver injury patterns: hepatitic (52%), cholangitic (19%), and mixed (29%). When comparing the ICI and AILD groups, centrilobular injury as well as granuloma formation were more prevalent in the former (p=0.067 and 0.002, respectively). CD4+/CD8+ T cell ratios were heterogeneous between the two groups, without statistically significant difference but with a trend toward increased CD8+ T cells among hepatitic irAEs as compared with AIH. Pattern of liver function test alteration was predictive for the type of irAEs but did not correlate with histological severity. Liver irAEs have broad clinical, laboratory and histological presentations. Histological features of irAEs and AILD are distinct, likely underpinning their different immunological mechanisms
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