Étude et modélisation d'un convertisseur double pont actif triphasé pour application chargeur de batterie d'un véhicule électrique

Ce mémoire présente une étude détaillée des topologies des convertisseurs en pont double DAB actif monophasés et triphasés. La revue de la littérature et la topologie choisie pour le chargeur de batterie ont été effectuées en tenant compte de la direction du flux de puissance du réseau au véhicule G2V et du véhicule au réseau V2G. Ainsi, les étapes de modélisation pour le DAB monophasé et triphasé connecté au réseau par l’intermédiaire d’un redresseur actif sont décrites. En outre, l’évaluation de l’efficacité du convertisseur DAB a été examinée. Basée sur les équations théoriques du DAB et le modèle de perte des dispositifs à semi-conducteurs de puissance, une analyse complète de l'efficacité du système a été réalisée en tenant compte de divers paramètres de contrôle, tels que les rapports cycliques, la puissance de sortie et les déphasages entre les deux ponts actifs du DAB. Les résultats de la simulation sont présentés pour valider les performances du modèle DAB triphasé pour un transfert de puissance élevé, en prenant en compte du modèle de perte du convertisseur de puissance et du rendement

Atividade moluscicida e larvicida das partes aéreas de Atriplex inflata contra o molusco Galba truncatula, hospedeiro intermediário da Fasciola hepatica

Fasciolose é uma parasitose generalizada que ocorre em animais de fazendas em muitos países em desenvolvimento. Por esta razão, é necessária a busca de novas substâncias contra as doenças parasitárias causadas por vermes. De fato, uma grande variedade de plantas terrestres foi objeto de testes farmacológicos e químicos a fim de descobrir o seu potencial para utilização em terapêutica humana. As atividades moluscicida e larvicida de Atriplex inflata foram testadas contra estágios larvários de Galba truncatula e Fasciola hepatica infectando este caracol na Tunísia. Testes fitoquímicos foram realizados com extratos a fim de estabelecer uma relação significativa com as atividades moluscicida e larvicida. A atividade moluscicida foi avaliada submetendo os caracóis a soluções aquosas. Conforme o caso, hexano, acetato de etilo, metanol e metanol-água (8:2, v-v) foram utilizados como solventes de extração. Como resultado, hexano e extratos de acetato apresentaram atividades potentes de acordo com a Organização Mundial de Saúde, resultando em LC50 = 7,59 mg/L e 6,69 mg/L para extratos de hexano de folhas e frutos, respectivamente. Extratos de acetato de etilo resultaram em LC50 = 5,90 mg/L e 7,32 mg/L para as folhas e frutos sucessivamente. Atividades moluscicidas das substâncias sob a forma de pó foram menos potentes em caracóis, mas ativas de acordo com a Organização Mundial de Saúde. Hexano e extratos de acetato de folhas e frutos apresentaram atividade larvicida potente, com uma taxa de atraso superior a 45,50% (45,50-98,92%). Testes fitoquímicos mostraram que estas atividades podem ser atribuídas à presença de triterpenóides e/ou esteróis.Fasciolosis is a widespread parasitosis of farm live-stock in many developing countries. For this reason, it is necessary to search for new substances against parasitic diseases caused by flukes. Indeed, a wide variety of terrestrial plants have been subjected to chemical and pharmacological screening in order to discover their potential for human medicinal use. The molluscicidal and larvicidal activities of Atriplex inflata were tested on Galba truncatula and Fasciola hepatica larval stages infecting this snail in Tunisia. Phytochemical tests were conducted on extracts in order to establish a meaningful relationship with molluscicidal and larvicidal activities. The molluscicidal activity was evaluated by subjecting snails to sample aqueous solutions. Accordingly, hexane, ethyl acetate, methanol and methanol-water (8:2, v-v) were used as extraction solvents. As a result, hexane and ethyl acetate extracts showed potent activity, according to the World Health Organization, giving LC50 = 7.59 mg/L and 6.69 mg/L for hexane extracts of leaves and fruits, respectively. Ethyl acetate extracts gave LC50 = 5.90 mg/L and 7.32 mg/L for leaves and fruits, successively. Molluscicidal activities of powders were less potent on snails, but active according to the World Health Organization. Hexane and ethyl acetate extracts from leaves and fruits gave potent larvicidal activities with a delay rate exceeding 45.50% (45.50- 98.92%). Phytochemical tests showed that these activities may be attributed to the presence of triterpenoids and/or sterols

MOLLUSCICIDAL AND LARVICIDAL ACTIVITIES OF Atriplex inflata AERIAL PARTS AGAINST THE MOLLUSK Galba truncatula, INTERMEDIATE HOST OF Fasciola hepatica

Fasciolosis is a widespread parasitosis of farm live-stock in many developing countries. For this reason, it is necessary to search for new substances against parasitic diseases caused by flukes. Indeed, a wide variety of terrestrial plants have been subjected to chemical and pharmacological screening in order to discover their potential for human medicinal use. The molluscicidal and larvicidal activities of Atriplex inflata were tested on Galba truncatula and Fasciola hepatica larval stages infecting this snail in Tunisia. Phytochemical tests were conducted on extracts in order to establish a meaningful relationship with molluscicidal and larvicidal activities. The molluscicidal activity was evaluated by subjecting snails to sample aqueous solutions. Accordingly, hexane, ethyl acetate, methanol and methanol-water (8:2, v-v) were used as extraction solvents. As a result, hexane and ethyl acetate extracts showed potent activity, according to the World Health Organization, giving LC50 = 7.59 mg/L and 6.69 mg/L for hexane extracts of leaves and fruits, respectively. Ethyl acetate extracts gave LC50 = 5.90 mg/L and 7.32 mg/L for leaves and fruits, successively. Molluscicidal activities of powders were less potent on snails, but active according to the World Health Organization. Hexane and ethyl acetate extracts from leaves and fruits gave potent larvicidal activities with a delay rate exceeding 45.50% (45.50- 98.92%). Phytochemical tests showed that these activities may be attributed to the presence of triterpenoids and/or sterols

MOLLUSCICIDAL AND LARVICIDAL ACTIVITIES OF Atriplex inflata AERIAL PARTS AGAINST THE MOLLUSK Galba truncatula, INTERMEDIATE HOST OF Fasciola hepatica

Fasciolosis is a widespread parasitosis of farm live-stock in many developing countries. For this reason, it is necessary to search for new substances against parasitic diseases caused by flukes. Indeed, a wide variety of terrestrial plants have been subjected to chemical and pharmacological screening in order to discover their potential for human medicinal use. The molluscicidal and larvicidal activities of Atriplex inflata were tested on Galba truncatula and Fasciola hepatica larval stages infecting this snail in Tunisia. Phytochemical tests were conducted on extracts in order to establish a meaningful relationship with molluscicidal and larvicidal activities. The molluscicidal activity was evaluated by subjecting snails to sample aqueous solutions. Accordingly, hexane, ethyl acetate, methanol and methanol-water (8:2, v-v) were used as extraction solvents. As a result, hexane and ethyl acetate extracts showed potent activity, according to the World Health Organization, giving LC50 = 7.59 mg/L and 6.69 mg/L for hexane extracts of leaves and fruits, respectively. Ethyl acetate extracts gave LC50 = 5.90 mg/L and 7.32 mg/L for leaves and fruits, successively. Molluscicidal activities of powders were less potent on snails, but active according to the World Health Organization. Hexane and ethyl acetate extracts from leaves and fruits gave potent larvicidal activities with a delay rate exceeding 45.50% (45.50- 98.92%). Phytochemical tests showed that these activities may be attributed to the presence of triterpenoids and/or sterols

The inflammatory profile of chronic kidney disease patients

Background: Chronic kidney disease is a worldwide public health issue which is associated with an increased risk of end-stage renal failure and cardiovascular disease. Systemic inflammation exists during chronic renal failure. Recent researches have highlighted the pivotal role of inflammation between renal and cardiovascular disease. The aim of our study is to determine the inflammatory profile of the patient suffering from chronic kidney disease and the influence of hemodialysis on this profile.Methods: We carried out a cross sectional study on 93 patients in the Nephrology Department at Hedi Chaker University Hospital, Sfax, South of Tunisia. Among those patients, 72 patients underwent hemodialysis and 21 patients had chronic kidney disease at stage 3. Clinical data and antecedents were collected. Biological samples were taken after informing the patients and taking their consent. Biological data consisted in lipid profile, albumin rate, hemoglobin rate, uric acid concentration and the usual markers of inflammation noting sedimentation rate, C - reactive protein and orosomucoid.Results: Hemodialysis group of the 72 patients had mean hemodialysis vintage of 54.6 ± 43 months. The inflammatory profile was worse in hemodialysis patients compared to chronic kidney disease patients. Both sedimentation rate, C - reactive protein and orosomucoid were higher in hemodialysis group than in chronic kidney disease group with 71 ± 35.3 mm vs. 42.1 ± 15.5 mm (p < 0.05); 14.6 ± 28.7 mg/l vs. 6.7 ± 8 mg/l (p = 0.02); 1.3 ± 0.7g/l vs. 0.9 ± 0.4 g/l (p = 0.01), respectively.Conclusion: Inflammation increases in dialysis patient. It deserves the nephrologist’s consideration in order to minimize its harmful effects. The monitoring of inflammation markers must be integrated into the nephrologist’s medical practice

Identification of compound heterozygous patients with primary hyperoxaluria type 1: clinical evaluations and in silico investigations

Abstract Background Primary hyperoxaluria type 1 (PH1) is an autosomal recessive inherited disorder of glyoxylate metabolism in which excessive oxalates are formed by the liver and excreted by the kidneys. Calcium oxalate crystallizes in the urine, leading to urolithiasis, nephrocalcinosis, and consequent renal failure if treatment is not initiated promptly. Mutations in the AGXT gene which encodes the hepatic peroxisomal enzyme alanine:glyoxylate aminotransferase are responsible of PH1. In the present work, we aimed to analyze AGXT gene and in silico investigations performed in four patients with PH1 among two non consanguineous families. Methods Exhaustive gene sequencing was performed after PCR amplification of coding exons and introns boundaries. Bioinformatic tools were used to predict the impact of AGXT variants on gene expression as well as on the protein structure and function. Results Direct sequencing of all exons of AGXT gene revealed the emergence of multiple mutations in compound heterozygous state in the two studied families. Two patients were compound heterozygous for the c.731 T > C, c.32C > T, c.1020A > G and c.33_34insC and presented clinically with recurrent urinary tract infection, multiple urolithiasis and nephrocalcinosis under the age of 1 year and a persistent hyperoxaluria at the age of diagnosis. The two other patients presenting a less severe phenotypes were heterozygous for c.731 T > C and homozygous for the c.32C > T and c.1020A > G or compound heterozygous for c.26C > A and c.65A > G variants. Conclusion In Summary, we provided relevance regarding the compound heterozygous mutations in non consanguineous PH1 families with variable severity

Resource utilization and preparedness within the COVID-19 pandemic in Tunisian medical intensive care units: A nationwide retrospective multicentre observational study

Background: The worldwide SARS-CoV-2 pandemic represents the most recent global healthcare crisis. While all healthcare systems suffered facing the immense burden of critically-ill COVID-19 patients, the levels of preparedness and adaptability differed highly between countries. Aim: to describe resource mobilization throughout the COVID-19 waves in Tunisian University Medical Intensive Care Units (MICUs) and to identify discrepancies in preparedness between the provided and required resource. Methods: This is a longitudinal retrospective multicentre observational study conducted between March 2020 and May 2022 analyzing data from eight University MICUs. Data were collected at baseline and at each bed expansion period in relation to the nation’s four COVID-19 waves. Data collected included epidemiological, organizational and management trends and outcomes of COVID-19 and non-COVID-19 admissions. Results: MICU-beds increased from 66 to a maximum of 117 beds. This was possible thanks to equipping pre-existing non-functional MICU beds (n = 20) and creating surge ICU-beds in medical wards (n = 24). MICU nurses increased from 53 to 200 of which 99 non-ICU nurses, by deployment from other departments and temporary recruitment. The nurse-to-MICU-bed ratio increased from 1:1 to around 1·8:1. Only 55% of beds were single rooms, 80% were equipped with ICU ventilators. These MICUs managed to admit a total of 3368 critically-ill patients (15% of hospital admissions). 33·2% of COVID-19-related intra-hospital deaths occurred within the MICUs. Conclusion: Despite a substantial increase in resource mobilization during the COVID-19 pandemic, the current study identified significant persisting discrepancies between supplied and required resource, at least partially explaining the poor overall prognosis of critically-ill COVID-19 patients