Field effect transistor with integrated microfluidic channel as pH sensor

International audienceThis paper presents an original design of chemical sensors with an integrated microfluidic channel. Targeted applications are pH-meters devices. The integration of the microfluidic channel allows decreasing the volume required for each measurement. The sensing part of the device consists of a field effect transistor (FET) with a suspended gate directly performed above the fluidic channel. Chemicals under test are driven through the sensing area between the electrical channel of the FET and the suspended gate. By this way products that flow in the microfluidic channel directly module the concentration of charges inside the transistor's gap and thus induce changes in the transfer characteristic. This paper describes the fabrication process and the technological choices for materials. Electrical tests, performed in air and in liquid, have shown a good behavior of the transistor, linked to a good mechanical sustain of the fluidic channel. The system is able to detect transition between air and liquid media. Moreover, it has shown a high sensitivity (about 300 mV/pH) to pH measurements

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Microsystème et capteur intégrés en technologie couches minces basse température

Le sujet de thèse porte sur la réalisation d un microsystème intégrant un capteur à effet Hall et son électronique de traitement à basse température (<600C) sur substrat de verre. La première partie de ce travail a consisté à concevoir l électronique de traitement. Dans un premier temps, un modèle semi empirique de la technologie couches minces basse température a été développé permettant de prévoir le comportement en fréquence des TFTs en silicium polycristallin. Dans un deuxième temps, une série de simulations nous a permis de dimensionner plusieurs amplificateurs différentiels et d estimer leur comportement en fréquence. Enfin les premières réalisations et caractérisations de ces amplificateurs différentiels ont pu avoir lieu. Les premiers résultats obtenus nous ont permis de valider à la fois le modèle développé et la possibilité de réaliser des dispositifs électroniques complexes en technologie couches minces à basse température. La dernière étape a consisté à réaliser et caractériser le microsystème complet intégré sur un même substrat de verre.This study deals with the achievement of a microsystem integrating a Hall effect sensor and its processing electronic at low temperature (<600C) on a glass substrate. The first step of this work consisted in designing the processing electronic. First, a semi-empirical model of thin films technology at low temperature has been developed to predict the frequency behaviour of polycrystalline silicon TFTs. In a second step, simulations allowed us to design several differential amplifiers and estimate their frequency behaviour. Finally, the first achievements and characterizations of these differential amplifiers have been done. The first results allow us to validate the model developed and the feasibility of fabricating complex electronic devices with thin films technology at low temperature. The last step consisted in achieving and characterizing the complete chip on the same glass substrate.RENNES1-BU Sciences Philo (352382102) / SudocSudocFranceF

Structure générique de détection de charges électriques utilisant un transistor à grille suspendue

National audienc

ETUDE ET CARACTERISATION D'UN METABOLITE PRODUIT PAR UN ASPERGILLUS FUMIGATUS D'ORIGINE MARINE

NANTES-BU Médecine pharmacie (441092101) / SudocSudocFranceF

Système microfluidique dédié à la mesure de pH

National audienc

Polysilicon TFT magnet sensors

International audienc