48 research outputs found

    Contrast medium administration and image acquisition parameters in renal CT angiography: what radiologists need to know

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    Over the last decade, exponential advances in computed tomography (CT) technology have resulted in improved spatial and temporal resolution. Faster image acquisition enabled renal CT angiography to become a viable and effective noninvasive alternative in diagnosing renal vascular pathologies. However, with these advances, new challenges in contrast media administration have emerged. Poor synchronization between scanner and contrast media administration have reduced the consistency in image quality with poor spatial and contrast resolution. Comprehensive understanding of contrast media dynamics is essential in the design and implementation of contrast administration and image acquisition protocols. This review includes an overview of the parameters affecting renal artery opacification and current protocol strategies to achieve optimal image quality during renal CT angiography with iodinated contrast media, with current safety issues highlighted

    Green Infrastructure Design Influences Communities of Urban Soil Bacteria

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    The importance of natural ecosystem processes is often overlooked in urban areas. Green Infrastructure (GI) features have been constructed in urban areas as elements to capture and treat excess urban runoff while providing a range of ancillary benefits, e.g., ecosystem processes mediated by microorganisms that improve air and water quality, in addition to the associations with plant and tree rhizospheres. The objective of this study was to characterize the bacterial community and diversity in engineered soils (Technosols) of five types of GI in New York City; vegetated swales, right of way bioswales (ROWB; including street-side infiltration systems and enhanced tree pits), and an urban forest. The design of ROWB GI features directly connects with the road to manage street runoff, which can increase the Technosol saturation and exposure to urban contaminants washed from the street and carried into the GI feature. This GI design specifically accommodates dramatic pulses of water that influence the bacterial community composition and diversity through the selective pressure of contaminants or by disturbance. The ROWB had the highest biodiversity, but no significant correlation with levels of soil organic matter and microbially-mediated biogeochemical functions. Another important biogeochemical parameter for soil bacterial communities is pH, which influenced the bacterial community composition, consistent with studies in non-urban soils. Bacterial community composition in GI features showed signs of anthropogenic disturbance, including exposure to animal feces and chemical contaminants, such as petroleum products. Results suggest the overall design and management of GI features with a channeled connection with street runoff, such as ROWB, have a comprehensive effect on soil parameters (particularly organic matter) and the bacterial community. One key consideration for future assessments of GI microbial community would be to determine the source of organic matter and elucidate the relationship between vegetation, Technosol, and bacteria in the designed GI features

    Green Infrastructure Design Influences Communities of Urban Soil Bacteria

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    The importance of natural ecosystem processes is often overlooked in urban areas. Green Infrastructure (GI) features have been constructed in urban areas as elements to capture and treat excess urban runoff while providing a range of ancillary benefits, e.g., ecosystem processes mediated by microorganisms that improve air and water quality, in addition to the associations with plant and tree rhizospheres. The objective of this study was to characterize the bacterial community and diversity in engineered soils (Technosols) of five types of GI in New York City; vegetated swales, right of way bioswales (ROWB; including street-side infiltration systems and enhanced tree pits), and an urban forest. The design of ROWB GI features directly connects with the road to manage street runoff, which can increase the Technosol saturation and exposure to urban contaminants washed from the street and carried into the GI feature. This GI design specifically accommodates dramatic pulses of water that influence the bacterial community composition and diversity through the selective pressure of contaminants or by disturbance. The ROWB had the highest biodiversity, but no significant correlation with levels of soil organic matter and microbially-mediated biogeochemical functions. Another important biogeochemical parameter for soil bacterial communities is pH, which influenced the bacterial community composition, consistent with studies in non-urban soils. Bacterial community composition in GI features showed signs of anthropogenic disturbance, including exposure to animal feces and chemical contaminants, such as petroleum products. Results suggest the overall design and management of GI features with a channeled connection with street runoff, such as ROWB, have a comprehensive effect on soil parameters (particularly organic matter) and the bacterial community. One key consideration for future assessments of GI microbial community would be to determine the source of organic matter and elucidate the relationship between vegetation, Technosol, and bacteria in the designed GI features

    THESE Maha DEEB Influence des plantes, des vers de terre et de la matière organique sur la structure de Technosols construits

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    Constructed Technosols are mixtures of technogenic materials used to create a new soil dedicated to growing plants. Constructed Technosols provide an opportunity to recycle and optimally use urban waste, and are an alternative to the use of agricultural soils for producing urban soils.This work is assessing in particular the influence of the OM levels and interactions with earthworms and plants on the physical properties of Constructed Technosols.The materials used to build our Technosols are compost and excavated deep horizons. In a first experiment, we tested the influence of OM rates on hydrostructural properties of Technosols, realizing 6 mixtures of increasing volume proportions of compost (0 to 50%). The shrinkage and retention curves show that the hydrostructural properties of Technosols are similar to those of natural soils. Increasing the amount of organic material is accompanied with a positive effect on micro and macro porosity, as well as on the water available for plants.Secondly, these mixtures were incubated in a growth chamber with or without earthworms (Aporrectodea caliginosa) and with or without plants (Lolium perenne). After 5 month of experiment, we measured hydrostructural properties, aggregation, and distribution of carbon in each fraction. The presence of plants and / or earthworms explains 19% of the variance of hydrostructural properties of the soil, and compost dose affects 14%. The interaction between organisms and compost further explains the variance (40%) than the effects of these individual factors. Compost and plants play a positive role in the available water by acting on both macroporosity and microporosity, while earthworms play a positive role only on the latter. Furthermore, the proportion of aggregates >3 mm is more important in the treatments control and earthworms, while the proportion of aggregates 3 mm est plus importante dans les traitements sans organisme (témoin) et avec des vers de terre, tandis que la proportion d’agrégats < 3 mm est plus importante en présence de plantes, indépendamment de la présence de vers de terre. Les organismes ont un effet plus fort sur la stabilité structurale (77 %) que le compost (4 %). Tous ont un effet positif sur la quantité de Corg dans les différentes fractions d’agrégats. Enfin, la minéralisation du Corg augmente en présence de vers ou de compost, mais diminue en présence de plantes. Nos résultats démontrent l’intérêt de valoriser des matériaux urbains tels que les horizons profonds excavés et le compost de déchets verts pour construire des Technosols. Une synthèse des résultats nous permet de conseiller une teneur volumique en compost comprise entre 20 et 30 % pour obtenir des propriétés structurales intéressantes, sans trop alourdir le coût induit par le compost et maximiser les volumes d’horizons excavés ainsi utilisés. Constatant l’effet positif des vers de terre, des plantes et des interactions plantes-vers de terre sur la porosité, la stabilité structurale et le stockage de carbone, il semble opportun de favoriser la présence des organismes

    Influence des plantes, des vers de terre et de la matière organique sur la structure de technosols construits

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    Constructed Technosols are mixtures of technogenic materials used to create a new soil dedicated to growing plants. Constructed Technosols provide an opportunity to recycle and optimally use urban waste, and are an alternative to the use of agricultural soils for producing urban soils. This work is assessing in particular the influence of the OM levels and interactions with earthworms and plants on the physical properties of Constructed Technosols. The materials used to build our Technosols are compost and excavated deep horizons. In a first experiment, we tested the influence of OM rates on hydrostructural properties of Technosols, realizing 6 Mixtures of increasing volume proportions of compost (0 to 50%). The shrinkage and retention curves show that the hydrostructural properties of Technosols are similar to those of natural soils. Increasing the amount of organic material is accompanied with a positive effect on micro and macro porosity, as well as on the water available for plants.Secondly, these mixtures were incubated in a growth chamber with or without earthworms (Aporrectodea caliginosa) and with or without plants (Lolium perenne). After 5 month of experiment, we measured hydrostructural properties, aggregation, and distribution of carbon in each fraction. The presence of plants and / or earthworms explains 19% of the variance of hydrostructural properties of the soil, and compost dose affects 14%. The interaction between organisms and compost further explains the variance (40%) than the effects of these individual factors. Compost and plants play a positive role in the available water by acting on both macroporosity and microporosity, while earthworms play a positive role only on the latter. Furthermore, the proportion of aggregates >3 mm is more important in the treatments control and earthworms, while the proportion of aggregates 3mm est plus importante dans les traitements sans organisme (témoin) et avec des vers de terre, tandis que la proportion d'agrégats <3mm est plus importante en présence de plantes, indépendamment de la présence de vers de terre. Les organismes ont un effet plus fort sur la stabilité structurale (77%) que le compost (4%). Tous ont un effet positif sur la quantité de Corg dans les différentes fractions d'agrégats. Enfin, la minéralisation du Corg augmente en présence de vers ou de compost, mais diminue en présence de plantes. Nos résultats démontrent l'intérêt de valoriser des matériaux urbains tels que les horizons profonds excavés et le compost de déchets verts pour construire des Technosols. Une synthèse des résultats nous permet de conseiller une teneur volumique en compost comprise entre 20 et 30% pour obtenir des propriétés structurales intéressantes, sans trop alourdir le coût induit par le compost et maximiser les volumes d'horizons excavés ainsi utilisés. Constatant l'effet positif des vers de terre, des plantes et des interactions plantes-vers de terre sur la porosité, la stabilité structurale et le stockage de carbone, il semble opportun de favoriser la présence des organisme

    Influence of plants, earthworms and organic matter on the constructed technosols structure

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    Pour répondre à la demande sociétale et aux contraintes environnementales, la création de Technosols à partir de déchets organiques et minéraux est une alternative à l'importation de sols agricoles fertiles au profit des espaces urbanisés. Si le rôle de la matière organique (MO) et des organismes est reconnu sur la fertilité des sols naturels, il reste peu connu en ce qui concerne les Technosols. Ce travail de thèse s'intéresse en particulier à l'influence du taux de MO et des interactions avec les vers de terre et les plantes sur les propriétés physiques et hydriques des Technosols construits. Les matériaux utilisés pour construire nos Technosols sont le compost de déchets verts et des remblais d'horizons profonds excavés. Dans une première expérience, nous avons testé l'influence du taux de MO sur les propriétés hydrostructurales des Technosols, en réalisant 6 mélanges contenant des proportions volumiques croissantes de compost (de 0 à 50%). Les courbes de retrait et de rétention montrent que les propriétés hydrostructurales des Technosols sont similaires à celles de sols naturels et proches de celles de sols argileux, alors que nos Technosols n'en contiennent qu'une très faible quantité (2%). L'augmentation de la quantité de matière organique s'accompagne d'effets positifs sur la micro et la macro porosité, ainsi que sur l'eau disponible pour les plantes.Dans un deuxième temps, ces différents mélanges ont été incubés en chambre de culture avec ou sans vers de terre (Aporrectodea caliginosa) et avec ou sans plantes (Lolium perenne). Après 5 mois d'expérience, nous avons mesurés les propriétés hydrostructurales, l'agrégation, et la distribution du carbone dans chaque fraction. La présence de plantes et/ou vers explique 19% de la variance des propriétés hydrostructurales du sol, et la dose de compost influe à 14%. L‘interaction entre organismes et compost explique davantage la variance (40%) que les effets de ces facteurs isolés. Le compost et les plantes jouent un rôle positif sur l'eau disponible en agissant à la fois sur la macroporosité et sur la microporosité, alors que les vers jouent un rôle positif uniquement sur cette dernière. Par ailleurs, la proportion d'agrégats >3mm est plus importante dans les traitements sans organisme (témoin) et avec des vers de terre, tandis que la proportion d'agrégats 3 mm is more important in the treatments control and earthworms, while the proportion of aggregates <3mm is greater in the presence of plants, regardless of the presence of earthworms. Organisms have a stronger effect on the structural stability (77%) than compost (4%). All have a positive effect on the amount of Corg in the different fractions of aggregates. Finally, mineralization of Corg increases in the presence of worms or compost, but decreases in the presence of plants. Our results demonstrate the interest of enhancing urban materials such as excavated deep horizons and compost to build Technosols. A summary of the results allows us to recommend a volume content of compost between 20 and 30% for a good structure, without increasing much the cost induced by compost. Noting the positive effect of earthworms, plants and earthworms/plants interactions on porosity, structural stability and carbon storage, it seems appropriate to favor the presence of organism

    The dominant effects of biota on stability, aggregation, and soil organic content distribution of Technosols compared to that of organic matter

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    International audienceThe effect of organic matter on soil structure is largely known. In this work, we show the importance of the biotic effect compared to the abiotic effect, particularly in constructed Technosols (soil engineering)

    ADAMTS13 in pediatric sepsis: a prognostic biomarker with potential therapeutic implications

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    Abstract Background Growing evidence implicates a pro-thrombotic state, caused by ADAMTS13 deficiency, in sepsis-associated organ dysfunction, but pediatric data is limited. Our purpose was to evaluate association of ADAMTS13 with prognosis of pediatric sepsis. Results This was prospective observational study, conducted on 70 children with sepsis and 18 healthy controls. Patients were classified upon Pediatric Intensive Care Unit (PICU) admission into sepsis, severe sepsis, and septic shock groups. Serum ADAMTS13 was measured within 24 h of admission. The primary outcome was all-cause PICU mortality. ADAMTS13 was lower among patients than controls [median and interquartile range (IQR): 1.30 (0.88–3.13ng/mL) vs. 6.00 (5.55–6.50 ng/mL); p < 0.001]. ADAMTS13 was lower in both severe sepsis and septic shock than sepsis [median (IQR): 0.90 (0.80–1.75 ng/mL); 1.0 ng/ml (0.90–1.20); and 2.80 (1.00–3.85ng/mL), p = 0.026 and 0.006 respectively]. ADAMTS13 was lower among non-survivors compared with survivors [median (IQR): 0.9 (0.80–1.18 ng/mL) vs. 2.45 (0.98–3.50 ng/mL); p < 0.001]. ADAMTS13 had area under Receiver Operating Characteristic Curve (AUC) of 0.77 for mortality prediction. Lower ADAMTS13 level was associated with mechanical ventilation; vasoactive medications; acute respiratory distress syndrome; and multiple organ dysfunction syndrome. ADAMTS13 correlated with pediatric Sequential Organ Failure Assessment (pSOFA) score (r s  = -0.46, p < 0.001); vasoactive infusion days ((r s  = -0.48, p < 0.001); and vasoactive-inotropic score on day1 (r s  = -0.43, p < 0.001) and day2 ((r s  = -0.41; p < 0.001). Conclusion In pediatric sepsis, lower ADAMTS13 level is a risk factor for organ dysfunction and mortality, lending theoretical foundations to therapeutic interventions aiming at reversing the pro-thrombotic state in sepsis

    Interactive effects of compost, plants and earthworms on the aggregations of constructed Technosols

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    EA SPE BIOmE AGROSUP SUPDATInternational audienceggregation is an important physical process to study during the early formation of Technosols. It is known to be influenced both by the organic matter content and soil biota. Constructed Technosols represent good models to test the importance of these factors since their composition can be easily manipulated by mixing different proportions of parent materials and introducing soil organisms. In this study, we performed a 5 month mesocosm experiment, using excavated deep horizons of soils (EDH) as mineral material mixed with green waste compost (GWC) at six different proportions (from 0 to 50%) in the presence or absence of plants and/or earthworms. After 21 weeks of incubation, aggregation was characterized by: 1) determining the size fraction and morphology, 2) measuring the distribution of organic carbon (OC) in each fraction and 3) testing the aggregate stability. Results showed that organisms accounted for 50% of soil aggregation variance while GWC was responsible for only 5% of the variance. The percentage of total variance of OC distribution in aggregates explained by organisms, GWC, and the interaction of the two was similar (28%, 22% and 26%, respectively). The effect of GWC on structural stability was negligible (2%) compared to that of organisms (70%). The effect of earthworms combination with plants was complex: plants had a dominant effect on the distribution of the size of aggregates by disrupting earthworm casts, but earthworms had a dominant effect over plants for aggregate stability under fast wetting only when the percentage of compost was low. This study underlines the importance of considering the interaction of the organic matter and soil biota: in this case, increasing compost proportion in a Technosol has significant effects on aggregation only in the presence of plants or earthworms

    Influence de la teneur en matière organique sur les propriétés de rétention d’eau et de retrait des technosols construits

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    National audiencePas de résuméInfluence de la teneur en matière organique Influence de la teneur en matière organique sur les propriétés de rétention d'eau et de retrait des technosols construit
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