53 research outputs found
Multi-objective optimisation of a seasonal solar thermal energy storage system combined with an earth â Air heat exchanger for net zero energy building
peer reviewedNet Zero Energy Building (NZEB) is a high performance building concept that integrates passive design and renewable energy systems. The aim of this paper is to analyze the performance of multi-integrated renewable energy systems for nearly zero energy buildings in the Mediterranean context. Taking into account the particular technical characteristics of net-zero energy buildings, this study focuses on three different systems: 1) an Earth â Air Heat Exchanger (EAHE), 2) an Underground Tank (UNT) and 3) a Solar Thermal Collector. The first step of the methodology was to study the energy efficiency of the combination between EAHE and UNT for heating needs. An experimental facility equipped with monitoring sensors was constructed. For the second step, we propose a numerical study of the energy performance of the UNT coupled with a solar thermal collector and combined with an EAHE in order to improve the coverage rate of heating needs. The results show that the combination of the three systems satisfied all the needs with a rate of 131% for the climatic conditions of Oran, Algeria. On the other hand, the EAHE and UNT systems operating separately covered 49.3% and 41.7%, respectively. Combining three systems simultaneously saves 37.9 ⏠(or 232.8 kWh of energy needs) and reduces by 21.1 tons of CO2 emissions during the heating period
SYNDROME DE LâARTERE POPLITEE PIEGEE : UNE CAUSE RARE DE CLAUDICATION INTERMITTENTE DU SUJET JEUNE
The syndrome of the trapped pop1ity artery appears in the young adult like a limping of the calf and or foot. Anatomical anomalies relating to insertions of the internai Twin muscle primarily. The diagnosis is suspect on Doppler echography, showing positional compression, change of direction of the poplitĂ©e artery, or only the existence of an abnormal fascicule of muscle fibres between artery and poplity vein. Angio IRM can replace the conventional assessment arteriographic. The treatment of extrinsic compression must avoid the constitution of parietal lesions and thromboses if they are installed, the suppression of the anatomical anomaly must be associated a segmentary revascularisation in autogenous venous material. Our patient is a young patient who consulted for an intermittent limping of effort of the right calf. The peripheral pulses were present, just as arterial the Doppler echo and the angio scanner of the hollow poplity showed the insertion of a beam of the internal  twin between the artery and the vein poplity. The arterial Ă©chodoppler and the IRM are according to certain authors the only essential examinations with the positive and differential diagnosis of the syndrome of the trapped pop1ity artery and will make it possible to eliminate from other differential diagnoses: pop1ity athĂ©romating and the early athĂ©rome, disease of Burger or thromboangĂ©ite obliterating, the aneurisms poplities and the cysts adventitiels of the poplity artery. The treatment is always surgical and must be early. It includes/understands the lifting of the trap associated with the need with an arterial gesture of revascularisation. For the authors, the permeability to short and long-term was better for the patients among whom one practised a section of the musculo-tendineux beam being wrong compared to the patient which profited from a gesture of  vascular restoration.Le syndrome de lâartĂšre poplitĂ©e piĂ©gĂ©e se manifeste chez lâadulte jeune comme une claudication du mollet et ou du pied. Les anomalies anatomiques concernant essentiellement les insertions du muscle Jumeau interne. Le diagnostic est suspectĂ© sur lâĂ©chographie doppler, montrant la compression positionnelle, le changement de direction de lâartĂšre poplitĂ©e, ou seulement lâexistence dâun faisceau musculaire anormal entre artĂšre et veine poplitĂ©e. Lâangio IRM peut remplacer le bilan artĂ©riographique conventionnel. Le traitement de la compression extrinsĂšque doit Ă©viter la constitution de lĂ©sions pariĂ©tales et de thromboses si elles sont installĂ©es, la suppression de lâanomalie anatomique doit ĂȘtre associĂ©e Ă une revascularisation segmentaire en matĂ©riel veineux autogĂšne. Notre patient est un malade jeune qui a consultĂ© pour une claudication intermittente dâeffort du mollet droit. Les pouls pĂ©riphĂ©rique Ă©taient prĂ©sents, de mĂȘme que lâĂ©cho doppler artĂ©riel et lâangio scanner du creux poplitĂ© montraient lâinsertion dâun faisceau du jumeau interne entre lâartĂšre et la veine poplitĂ©. LâĂ©chodoppler artĂ©riel et lâIRM sont selon certains auteurs les seuls examens indispensables au diagnostic positif et diffĂ©rentiel du syndrome de lâartĂšre poplitĂ©e piĂ©gĂ©e et vont permettre dâĂ©liminer dâautres diagnostics diffĂ©rentiels : poplitĂ©e athĂ©romateuse et lâathĂ©rome prĂ©coce, maladie de Buerger ou thromboangĂ©ite oblitĂ©rante, les anĂ©vrysmes poplitĂ©s et les kystes adventitiels de lâartĂšre poplitĂ©e. . Le traitement est toujours chirurgical et doit ĂȘtre prĂ©coce. Il comprend la levĂ©e du piĂšge associĂ© au besoin Ă un geste de revascularisation artĂ©riel. Pour les auteurs, la permĂ©abilitĂ© a court et Ă long terme Ă©tait meilleure pour les malades chez qui on a pratiquĂ© une section du faisceau musculo-tendineux aberrant par rapport au patient qui ont bĂ©nĂ©ficiĂ© dâun geste de restauration vasculaire
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Accuracy of citrulline, I-FABP and d-lactate in the diagnosis of acute mesenteric ischemia
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Research data are not shared.Supplementary Information oi available online at: https://www.nature.com/articles/s41598-021-98012-w#Sec14 .Early diagnosis of acute mesenteric ischemia (AMI) remains a clinical challenge, and no biomarker has been consistently validated. We aimed to assess the accuracy of three promising circulating biomarkers for diagnosing AMIâcitrulline, intestinal fatty acid-binding protein (I-FABP), and D-lactate. A cross-sectional diagnostic study enrolled AMI patients admitted to the intestinal stroke center and controls with acute abdominal pain of another origin. We included 129 patientsâ50 AMI and 79 controls. Plasma citrulline concentrations were significantly lower in AMI patients compared to the controls [15.3 ÎŒmol/L (12.0â26.0) vs. 23.3 ÎŒmol/L (18.3â29.8), pâ=â0.001]. However, the area under the receiver operating curves (AUROC) for the diagnosis of AMI by Citrulline was low: 0.68 (95% confidence intervalâ=â0.58â0.78). No statistical difference was found in plasma I-FABP and plasma D-lactate concentrations between the AMI and control groups, with an AUROC of 0.44, and 0.40, respectively. In this large cross-sectional study, citrulline, I-FABP, and D-lactate failed to differentiate patients with AMI from patients with acute abdominal pain of another origin. Further research should focus on the discovery of new biomarkers.Grants from MSD-Avenir and APHP funded the SURVIBIO study; Alexandre Nuzzo received Ph.D. Grants from âFondation de l'Avenirâ and the French Gastroenterology Society (SNFGE)
Delayed clearance of triglyceride-rich lipoproteins in young, healthy obese subjects
Obesity is associated with the metabolic syndrome. The aims were, first, to study the postprandial triglyceride clearance in young, healthy obese subjects and, second, to investigate if fasting triglycerides can predict delayed postprandial triglyceride clearance. Eighteen apparently healthy, obese subjects with no clinical signs of metabolic disturbances participated. Controls were ageâ and sexâmatched, healthy, normal weight subjects. Subclinical markers of metabolic disturbances were assessed by measuring postprandial triglycerides in serum and in chylomicrons by oral fat tolerance test. Postprandial triglyceride clearance for 8âh was assessed indirectly as removal of the lipid from serum during the oral fat tolerance test. Insulin resistance was measured by the homeostasis model assessment of insulin resistance (HOMAâIR). Twelve (66%) of the apparently healthy obese individuals had insulin resistance measured by HOMAâIR. There was a delayed clearance of serum triglycerides and chylomicron triglycerides at 6âh when compared with the control group, while, at 8âh, the differences were only detected for the chylomicron triglyceride clearance. Triglyceride response was significantly greater in the obese subjects. Fasting triglycerides in upper normal level predicted a delayed postprandial triglyceride clearance and insulin resistance. In young, apparently healthy obese subjects early metabolic disturbances including insulin resistance and delayed postprandial triglyceride clearance can be detected. Fasting serum triglyceride in upper normal level predicted delayed postprandial triglyceride clearance and insulin resistance
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