57 research outputs found

    The potential of ryegrass (Lolium perenne L.) to clean up multi-contaminated soils from labile and phytoavailable potentially toxic elements to contribute into a circular economy

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    International audienceAided phytoremediation was studied for 48 weeks with the aim of reducing extractable and phytoavailable toxic elements and producing potential marketable biomass. In this sense, biomass of ryegrass was produced under greenhouse on two contaminated garden soils that have been amended with two successive additions of phosphates. After the first addition of phosphates, seeds of ryegrass were sown and shoots were harvested twice. A second seedling was performed after carefully mixing the roots from the first production (used as compost), soils and phosphates. Forty-eight weeks after starting the experiments, the concentrations of Cd, Pb, Zn, Cu, Fe, and Mn extracted using the rhizosphere-based method were generally lower than those measured before the addition of phosphates and cultivation (except for Pb and Fe in the most contaminated soil). The concentrations of metals in the shoots of ryegrass from the second production were lower than those from the first (except for Al). The best results were obtained with phosphates and were the most relevant in the lowest contaminated soil, demonstrating that the available metal concentrations have to be taken into account in the management of contaminated soils. In view of the concentration of metals defined as carcinogens, mutagens, and reprotoxics (e.g., Cd, Pb) and those capable to be transformed into Lewis acids (e.g., Zn, Fe), the utilization of ryegrass in the revegetation of contaminated soils and in risk management may be a new production of marketable biomass. The development of phytomanagement in combination with this type of biomass coincided with the view that contaminated soils can still represent a valuable resource that should be used sustainably. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature

    New Efficient Eco‐Friendly Supported Catalysts for the Synthesis of Amides with Antioxidant and Anti‐Inflammatory Properties

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    International audienceA new environmentally friendly approach for the synthesis of idrocilamide (1), a marketed myorelaxant and anti-inflammatory agent, is reported herein. The synthetic strategy involves a solvent-free aminolysis reaction catalyzed by zinc-containing species (ZnCl2 , montmorillonite K10 (MK10) impregnated with ZnCl2 or eco-catalysts). The latter have been prepared from the aerial parts of Lolium perenne L. plants grown on contaminated soils from northern France without and with thermal activation at 120 °C and supported on MK10 (Ecocat1 and Ecocat2, respectively). The best aminolysis catalysts in the current study (ZnCl2 and Ecocat2) were selected for additional aminolyses. Compared to ZnCl2 , Ecocat2 had the advantage of being reusable over five test runs and constituted a sustainable catalyst allowing a green route to idrocilamide. Synthesized derivatives 1-4, 6 and 9 were first evaluated for their effect on reactive oxygen species (ROS) generation from macrophages and displayed antioxidant properties by preventing ROS production. Next, the analysis of the effect of molecules 1-4, 6 and 9 on macrophage migration between epithelial cells to human opportunistic fungus Candida albicans indicated that molecules 2-4, 6 and 9 exert anti-inflammatory properties via reducing macrophage migration while the parent idrocilamide (1) did not show any significant effect. This work opens the way for the discovery of new analogues of idrocilamide with improved properties

    Contamination of woody habitat soils around a former lead smelter in the North of France.

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    International audienceThe contamination of the topsoil of 262 woody habitats around a former lead smelter in the North of France was assessed. In this urbanized and industrialized area, these kinds of habitats comprise of hedges, groves, small woods, anthropogenic creations and one large forest. Except for the latter, which is 3km away, these woody habitat soils often present a high anthropization degree (a significant amount of pebbles and stones related to human activities) with a high metal contamination. In the studied woody habitat topsoils, Cd, Pb and Zn concentrations largely exceeded those of agricultural topsoils located in the same environmental context. Therefore, atmospheric emissions from the smelter are not the only cause of the high contamination of the woody habitat soils. This last one is related to the nature and the contamination level of deposit in relation with human activities (rubbles, slag, soils, etc). With regard to the results obtained with chemical extractions, the mobility of Cd, Pb and Zn in these soils is also greater than in agricultural soils. In the forest, pollutant solubility is increased by soil acidic pH. The variability of the physico-chemical parameters and the high metal contamination of the topsoils are the main characteristics of the woody habitats located around the former smelter. Although never taken into account during risk assessment, the disturbance of these environmental components could have important biogeochemical impacts (nutrients and metal cycles). Moreover, any modification of the soils' use could potentially cause mobilization and transfer of the pollutants to the biosphere. Six years after the closure of the smelter, and as social and economic pressures considerably increase in this area, the study of these peculiar ecosystems is necessary to understand and predict the bioavailability, transfer, bioaccumulation and effects of pollutants in food chains

    Impaired phagocytic activity of neutrophils in patients receiving haemodialysis: the critical role of iron overload.

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    The metabolic burst (as measured by the spontaneous and stimulated nitroblue tetrazolium tests), the phagocytosis of heat inactivated bakers' yeast and of Staphylococcus aureus, the killing of Staph aureus, and the myeloperoxidase activity of polymorphonuclear neutrophils were studied in 11 patients receiving maintenance haemodialysis. Of these patients, six were polytransfused and had high serum ferritin concentrations (mean 5940 (SD 2925) micrograms/l; group 1), and five had normal serum ferritin values (mean 171 (116) micrograms/l; group 2). Patients in group 1 had a history of more infectious episodes (0.167 v 0.025 per patient per month) and significantly more genitourinary infections (p = 0.015) than those in group 2. Phagocytosis and myeloperoxidase activity were severely reduced in group 1 but normal in group 2. Percentages of neutrophils ingesting one or more particles together with the index of phagocytosis in patients' serum were inversely correlated with serum ferritin concentrations. Four patients in group 1 were treated with desferrioxamine, and after six to 18 weeks of treatment phagocytosis and myeloperoxidase activity had returned to normal in three of them. These data suggest that in patients receiving haemodialysis iron overload due to multiple transfusions plays an important part in the mechanisms underlying the susceptibility to bacterial infections, mediated at least partially through impaired neutrophil function

    Complications related to subcalvian catheters for hemodialysis: report and review

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    Personal experience with subclavian vein cannulations for hemodialysis are given, and the pertinent literature on the subject is reviewed. Two hundred subclavian dialysis catheters were placed in 148 patients who kept them in place for a total of 2,798 days. Immediate complications were two pneumothoraxes and two hemothoraxes due to subclavian artery puncture. Seventeen cases of bacteremia were related to subclavian catheter infections. In 1 case, a complication of sepsis was a vertebral osteomyelitis. Clinical evidences of subclavian vein thrombosis occurred in 5 cases. Life-threatening complications were met in 2 cases: 1 with pericardial tamponade due to right atrium perforation and 1 with mediastinal hematoma and right hemothorax due to superior vena cava perforation. Review of the literature indicates that pneumothoraxes and/or hemothoraxes occurred in 1.7% of the catheter insertions and that sepsis related to subclavian dialysis catheters occurred in 8.9% of the patients. As systematically investigated subclavian vein thrombosis involved at least 50% of the patients. Our 2 personal cases of life-threatening complications and 14 similar cases of the literature were analyzed: left subclavian catheters were associated with superior vena cava perforation with right hemothorax or mediastinal hematoma, while right subclavian catheters gave atrial perforation with pericardial tamponade. Death occurred in 3 of 16 cases, and emergency surgery was required in 5 of 16 cases. Taking into account all these complications, recommendations are made for the use of subclavian dialysis catheters.Case ReportsJournal Articleinfo:eu-repo/semantics/publishe

    Effets comparés sur l'excrétion urinaire des ions et de l'acide oxalique de charges orales en eaux de compositions minérales différentes

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    The effects on urinary excretion of a 1500 ml daily load of three drinking waters with different ionic contents were studied in six normal subjects. Diuresis was similarly increased by the three waters of an amount equal to the load. Urine output of urea, creatinin, uric acid, phosphate, potassium, magnesium was not significantly modified by the three waters as compared to a control period. Natriuresis was significantly increased following the intake of the water which contained sodium as well as calciuria with the water containing calcium. Urine output of oxalate was increased by the three waters in correlation with the free water content of the load. This effect is probably due to a reduction in passive tubular reabsorption of oxalate since a similar effect was observed with an equivalent water load given by intravenous route. Nevertheless, due to the dilution of urine, the index of urine saturation for calcium oxalate was diminished by the three waters.Comparative StudyEnglish AbstractJournal ArticleSCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

    Infections associated with subclavian dialysis catheters

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    Two hundred subclavian dialysis catheters were placed in 148 patients who kept them in place for a total of 2,798 days. Catheterization time ranged from 1 to 79 days with an average of 14.0 +/- 1.0 days per catheter and 18.9 +/- 1.0 days per patient. Twenty nine catheters were infected, 17 of which were the source of bacteremias due to Staphylococcus epidermidis in 13 cases and to Staphylococcus aureus in 4 cases. The incidence of sepsis was not significantly greater in diabetic patients, in patients with corticotherapy or in patients presenting an underlying systemic disease. On the contrary, the incidence was greater in hospitalized patients (15 bacteremias during 1,948 catheter days) than in ambulatory patients (2 bacteremias during 850 catheters-days) as well as during a period corresponding to a greater number of untrained nurses enrolled in the dialysis team. During this period, 6 sepsies occurred in 19 catheters (other periods: 7 sepsies/116 catheters, p less than 0.01). 6 of 28 nurses had less than 3 months of professional experience (other periods: 1 of 25, p less than 0.01). These data underline the key role of nurse training in the prevention of catheter-related infections.Comparative StudyJournal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe
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