79 research outputs found

    ANALYSIS OF THE ENERGETIC AND EXERGETIC EFFICIENCY OF THE ELECTROHYDRODYNAMIC DRYING PROCESS

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    International audienceDrying is an energy intensive unit operation encountered in many industrial sectors, especially in the food industry. Still over 85% of industrial dryers are convective type. Electrohydrodynamic convective drying (EHD drying) is a novel drying method used to enhance forced convection drying by using electrodes to create an electrostatic field and generate an electric wind. This latter may alter the boundary layer and enhance the heat and mass transfer. In this study, experiments were performed to analyze the drying kinetics during EHD and forced convection (FC) drying experiments. Transient energy and exergy efficiencies expressions were discussed, proposed and computed for each experiment. With airflow of 0.3 m/s in the case of EHD configurations, similar drying rates than FC at 1.0-2.0 m/s can be achieved. Moreover, it leaded to greater energy efficiency (x5) and it was confirmed, using exergy efficiency concept, that EHD better used energy than FC

    Alzheimer's early detection in post-acute COVID-19 syndrome: a systematic review and expert consensus on preclinical assessments.

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    The risk of developing Alzheimer's disease (AD) in older adults increasingly is being discussed in the literature on Post-Acute COVID-19 Syndrome (PACS). Remote digital Assessments for Preclinical AD (RAPAs) are becoming more important in screening for early AD, and should always be available for PACS patients, especially for patients at risk of AD. This systematic review examines the potential for using RAPA to identify impairments in PACS patients, scrutinizes the supporting evidence, and describes the recommendations of experts regarding their use. We conducted a thorough search using the PubMed and Embase databases. Systematic reviews (with or without meta-analysis), narrative reviews, and observational studies that assessed patients with PACS on specific RAPAs were included. The RAPAs that were identified looked for impairments in olfactory, eye-tracking, graphical, speech and language, central auditory, or spatial navigation abilities. The recommendations' final grades were determined by evaluating the strength of the evidence and by having a consensus discussion about the results of the Delphi rounds among an international Delphi consensus panel called IMPACT, sponsored by the French National Research Agency. The consensus panel included 11 international experts from France, Switzerland, and Canada. Based on the available evidence, olfaction is the most long-lasting impairment found in PACS patients. However, while olfaction is the most prevalent impairment, expert consensus statements recommend that AD olfactory screening should not be used on patients with a history of PACS at this point in time. Experts recommend that olfactory screenings can only be recommended once those under study have reported full recovery. This is particularly important for the deployment of the olfactory identification subdimension. The expert assessment that more long-term studies are needed after a period of full recovery, suggests that this consensus statement requires an update in a few years. Based on available evidence, olfaction could be long-lasting in PACS patients. However, according to expert consensus statements, AD olfactory screening is not recommended for patients with a history of PACS until complete recovery has been confirmed in the literature, particularly for the identification sub-dimension. This consensus statement may require an update in a few years

    Design and development of apparatus to provide repeatable surface temperature-time treatments on inoculated food samples

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    The majority of data relating heat treatments to thermal death kinetics has previously been obtained by carrying out in vitro tests on small samples of microorganisms in growth medium or food slurries. However, strong evidence exists that suggests microbial death on heat-treated food surfaces cannot be predicted accurately from such systems. An apparatus was therefore designed to enable microbial death on food surfaces to be quantified. The apparatus uses hot air to provide a ‘dry’ heat treatment to raise the surface of a food sample to a given temperature, up to 100 °C, hold and then cool it. The surface temperature was measured using an infra-red (IR) thermometer and the air heater was controlled to give a specified surface temperature history. Steam was also used to provide a ‘wet’, but less controlled heating cycle

    Basal ganglia dysfunction in OCD: subthalamic neuronal activity correlates with symptoms severity and predicts high-frequency stimulation efficacy

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    Functional and connectivity changes in corticostriatal systems have been reported in the brains of patients with obsessive–compulsive disorder (OCD); however, the relationship between basal ganglia activity and OCD severity has never been adequately established. We recently showed that deep brain stimulation of the subthalamic nucleus (STN), a central basal ganglia nucleus, improves OCD. Here, single-unit subthalamic neuronal activity was analysed in 12 OCD patients, in relation to the severity of obsessions and compulsions and response to STN stimulation, and compared with that obtained in 12 patients with Parkinson's disease (PD). STN neurons in OCD patients had lower discharge frequency than those in PD patients, with a similar proportion of burst-type activity (69 vs 67%). Oscillatory activity was present in 46 and 68% of neurons in OCD and PD patients, respectively, predominantly in the low-frequency band (1–8 Hz). In OCD patients, the bursty and oscillatory subthalamic neuronal activity was mainly located in the associative–limbic part. Both OCD severity and clinical improvement following STN stimulation were related to the STN neuronal activity. In patients with the most severe OCD, STN neurons exhibited bursts with shorter duration and interburst interval, but higher intraburst frequency, and more oscillations in the low-frequency bands. In patients with best clinical outcome with STN stimulation, STN neurons displayed higher mean discharge, burst and intraburst frequencies, and lower interburst interval. These findings are consistent with the hypothesis of a dysfunction in the associative–limbic subdivision of the basal ganglia circuitry in OCD's pathophysiology

    Alzheimers Dement

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    Introduction: The free and cued selective reminding test is used to identify memory deficits in mild cognitive impairment and demented patients. It allows assessing three processes: encoding, storage, and recollection of verbal episodic memory. Methods: We investigated the neural correlates of these three memory processes in a large cohort study. The Memento cohort enrolled 2323 outpatients presenting either with subjective cognitive decline or mild cognitive impairment who underwent cognitive, structural MRI and, for a subset, fluorodeoxyglucose-positron emission tomography evaluations. Results: Encoding was associated with a network including parietal and temporal cortices; storage was mainly associated with entorhinal and parahippocampal regions, bilaterally; retrieval was associated with a widespread network encompassing frontal regions. Discussion: The neural correlates of episodic memory processes can be assessed in large and standardized cohorts of patients at risk for Alzheimer's disease. Their relation to pathophysiological markers of Alzheimer's disease remains to be studied

    Aptitude cognitive à la conduite automobile : retour d’expérience du Centre Leenaards de la Mémoire [Cognitive fitness to drive : feedback at Leenaards Memory Centre]

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    Cognitive impairment can interfere with the fitness to drive. An increase in requests to assess this aspect is observed at Leenaards Memory Centre. Changes in the law could be an explanatory factor. The views formulated in 2019 are mainly unfavorable because all the patients present cognitive disorders, generally attributed to Alzheimer's disease or a related disorder, but never linked with aging only. Moreover, unfavorable views are frequently expressed before the age of 75. Therefore, each patient is unique, and each decision is based neither on the patient's age or his diagnosis, but rather on his cognitive profile. In this article we discuss the reasons for an unfavorable view and discuss them in the context of the tasks of our centre

    Troubles neurocognitifs chez les personnes âgées avec maladie oncologique [Cancer-related cognitive impairment in older adults]

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    Chemotherapy is associated with transient or permanent cognitive dysfunction ranging from subjective complaints to measurable deficits in working memory, attention and language. Given that old age may be related to cognitive decline, the interaction between chemotherapy-induced cognitive impairment and the effects of age is of growing concern in view of our aging population. Chemotherapy-associated cognitive dysfunction may have an additive impact on pre-existing age-related cognitive performance decline, which calls for awareness in its detection, to reduce impact on quality of life and improve management of older patients. We discuss here the « chemobrain », concept, review the existing evidence about pathophysiology, neuroimaging and cognitive phenotype and propose practical tools for routine detection in the outpatient setting

    Cancer-related cognitive impairment in older adults

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    Chemotherapy is associated with transient or permanent cognitive dysfunction ranging from subjective complaints to measurable deficits in working memory, attention and language. Given that old age may be related to cognitive decline, the interaction between chemotherapy-induced cognitive impairment and the effects of age is of growing concern in view of our aging population. Chemotherapy-associated cognitive dysfunction may have an additive impact on pre-existing age-related cognitive performance decline, which calls for awareness in its detection, to reduce impact on quality of life and improve management of older patients. We discuss here the « chemobrain », concept, review the existing evidence about pathophysiology, neuroimaging and cognitive phenotype and propose practical tools for routine detection in the outpatient setting

    Clinical Reasoning: A 69-year-old man with rare complex visual symptoms.

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