Publications by authors named "Thierry Lebeau"

Lead (Pb) is commonly found in urban soils and can transfer to vegetables. This entails a health risk for consumers of garden crops. The increasing demand of gardening on urban soil linked to the population increase and concentration in urban areas induces an increase in the risk, as people could be forced to cultivate contaminated soils.

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Bioaugmentation of soils can increase the mobilization of metal(loid)s from the soil-bearing phases. However, once desorbed, these metal(loid)s are mostly complexed to the dissolved organic matter (DOM) in the soil solution, which can restrict their availability to plants (roots mainly taking up the free forms) and then the phytoextraction performances. Firstly the main drivers influencing phytoextraction are reminded, then the review focuses on the DOM role.

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Article Synopsis
  • - Bioaugmentation with Pseudomonas putida enhanced the ability of sunflowers to extract copper (Cu) from vineyard soils, increasing Cu concentration in roots by 93% and in shoots by 17%, while also boosting sunflower biomass by 30% to 60%.
  • - The study focused on the mechanisms behind copper transfer from soil to plants, highlighting the role of siderophores, particularly pyoverdine (Pvd), which formed a 1:1 complex with Cu, aiding its mobilization and availability for the sunflowers.
  • - Interestingly, carbonated soils did not enhance the mobilization of trace elements as expected, suggesting that further optimization could involve strategies to enhance the dissociation of the Pvd-C
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Copper (Cu) contamination of soils may alter the functioning and sustainability of vineyard ecosystems. Cultivating Cu-extracting plants in vineyard inter-rows, or phytoextraction, is one possible way currently under consideration in agroecology to reduce Cu contamination of vineyard topsoils. This option is rarely used, mainly because Cu phytoextraction yields are too low to significantly reduce contamination due to the relatively "low" phytoavailability of Cu in the soil (compared to other trace metals) and its preferential accumulation in the roots of most extracting plants.

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The environmental and health impacts caused by phosphogypsum (PG) make it necessary to carefully manage these wastes. Bioaugmentation of a PG-compost mix with Bacillus cereus was associated with Trifolium pratense or Helianthus annuus for the phytoextraction of metal trace elements (MTE). In hydroponics, MTE concentrations in sunflower shoots are higher than in clover; however, as opposed to clover, it regulates their accumulation.

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Bacteria isolated from soils in the vicinity of phosphogypsum (PG) stockpiles were studied for their potential use in bioaugmentation-assisted phytoextraction. Quick, miniaturized biochemical tests were performed in the presence of metal trace elements (MTE), including rare earth elements (Cd, Sr, Ce, La, Nd and Y), corresponding to their bioavailable concentrations in PG. The intention herein was to assess the capacity of bacteria to: i) grow in PG; ii) produce indole acetic acid and ACC deaminase to promote plant growth and reduce stress; and iii) produce siderophores, including pyoverdine, to mobilize MTE.

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The development of more sustainable remediation techniques has been receiving greater attention, as an alternative to soil excavation plan in urban gardens. An phytoextraction experiment with buckwheat ( was performed with a 5mmol kg citric acid (CA) application. Joint experiments under laboratory conditions were conducted using various cultivars of in two soils with a Pb contamination of either geogenic or anthropogenic origin and various chelate concentrations.

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The phosphate industry in Tunisia generates large amounts of phosphogypsum (PG) with more than 10 t per year. Environmental impact of this solid waste was studied. Cd, Ce, La, Nd, Sr and Y were analyzed from soils near PG stockpiles (Sfax and M'dhilla) and sediments from marine discharge (Gabes).

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Siderophores are natural metal chelating agents that strongly control the biogeochemical metal cycles such as Fe in the environment. This article describes a new methodology to detect and quantify at the micromolar concentration the spatial distribution at millimeter scale of siderophores within the root's system. The "universal" CAS assay originally designed for bacterial siderophores detection and later designed for fungus was adapted here for diffusive equilibrium in thin film gel techniques (DET).

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With the aim of improving the phytoextraction rate of cesium (Cs), the effect of Pseudomonas fluorescens ATCC 17400 and its siderophore pyoverdine (PVD) on the uptake of Cs by red clover was studied in soil pots. This work also provides a mechanistic understanding of the Cs-bacteria (or PVD)-illite-plant interactions by using a simplified experimental design, i.e.

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Introduction: We sought to assess the impact of surgical wait time (SWT) to robot-assisted radical prostatectomy (RARP) on final pathological outcome.

Methods: A retrospective review of RARP patient records operated between 2006 and 2015 was conducted. SWT was defined as period from prostate biopsy to surgery.

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Although copper (Cu) is an essential micronutrient for all living organisms, it can be toxic at low concentrations. Its beneficial effects are therefore only observed for a narrow range of concentrations. Anthropogenic activities such as fungicide spraying and mining have resulted in the Cu contamination of environmental compartments (soil, water and sediment) at levels sometimes exceeding the toxicity threshold.

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Urban garden soils are a potential repository of heavy metal pollution, resulting from either anthropogenic or geogenic origin. The efficiency of phytoextraction was compared on two garden soils with the same texture and topsoil Pb concentration (170 mg kg) but not the same origin: one geogenic, the other anthropogenic. Two varieties of Brassica juncea were tested with citric acid (25 mmol kg) or ethylenediaminetetraacetic acid (EDTA, 2.

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Introduction: To evaluate erectile function recovery following robotic-assisted radical prostatectomy (RARP) according to preoperative sexual health inventory for men (SHIM) score stratification.

Materials And Methods: We prospectively collected data on 250 consecutive patients who underwent RARP by a single surgeon between October 2006 and October 2012. Thirty-six patients were excluded because of lack of preoperative SHIM score.

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Objective: To study the relation between uroflow Stop Test and early recovery of potency following robot-assisted radical prostatectomy (RARP). We recently showed that the ability to completely stop urine flow during voiding, measured objectively by uroflowmetry at the time of catheter removal (uroflow Stop Test) can predict early urinary continence recovery following RARP.

Materials And Methods: In this prospective observational cohort, data were collected on 108 patients operated by a single surgeon (AEH).

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Introduction: While RARP (robotic-assisted radical prostatectomy) has become the predominant surgical approach to treat localized prostate cancer, there is little Canadian data on its oncological and functional outcomes. We describe the largest RARP experience in Canada.

Methods: Data from 722 patients who underwent RARP performed by 7 surgeons (AEH performed 288, TH 69, JBL 23, SB 17, HW 15, QT 7, and KCZ 303 patients) were collected prospectively from October 2006 to December 2013.

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Background: The robot-assisted laparoscopic approach for radical prostatectomy (RARP) is being performed increasingly worldwide to treat localized prostate cancer (PCa). The aim of this study was to compare the learning curves of two surgeons with different surgical experiences.

Methods: A prospective collection of peri-operative data was made: age, body mass index, PSA, clinical stage, biopsy Gleason score, operative time (OT), blood loss (BL), pathological stages, final Gleason scores, and complications.

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Long term maintenance of microalgal strains by serial subculturing is often expensive and time-consuming. Alternative methods, such as cryopreservation, present several benefits and thus seem more relevant. Our study aimed at comparing two cryopreservation procedures applied to the marine diatom Haslea ostrearia (Simonsen): (1) a two-step freezing method in liquid media using 5%, 10% and 20% MeOH, Me₂SO or Glycerol, and (2) an immobilization-dehydration method consisting in an algal cell entrapped in 0.

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Background: A robot-assisted laparoscopic approach for radical prostatectomy (RALRP) is being adopted increasingly worldwide for the treatment of localized prostate cancer (CaP). Complications assessment is essential to the objective evaluation of any new procedure. This study aimed to assess the perioperative complications encountered during the implementation of a robot-assisted urologic surgery program.

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Low cost materials (sugar beet pulp, corncob, corncob char, perlite, vermiculite, sand, sediment) have been tested for their ability to quickly sorb copper, glyphosate, diuron and 3,4-dichloroaniline (3,4-DCA) as single or mixed compounds. Tests have been performed in increasingly complex liquid matrices: ultra pure water (UPW), runoff water (RW) and sediment extract medium (SEM). Highest sorption levels in UPW are achieved with corncob char for Cu (93%), glyphosate (74%), diuron (98%) and 3,4-DCA (99%).

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This work intended to study the relationship between diuron herbicide dissipation and the population dynamics of co-cultivated Delftia acidovorans WDL34 (WDL34) and Arthrobacter sp. N4 (N4) for different cell formulations: free cells or immobilization in Ca-alginate beads of one or both strains. GFP-tagged WDL34 and N4 Gram staining allowed analyzing the cell growth and distribution of each strain in both beads and culture medium in the course of the time.

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Pyoverdine (PvdI) is the major siderophore secreted by Pseudomonas aeruginosa PAOI in order to get access to iron. After being loaded with iron in the extracellular medium, PvdI is transported across the bacterial outer membrane by the transporter, FpvAI. We used the spectral properties of PvdI to show that in addition to Fe(3+), this siderophore also chelates, but with lower efficiencies, all the 16 metals used in our screening.

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Bioaugmentation-assisted phytoextraction may enhance the phytoextraction efficiency thanks to larger metal mobilization by microbial metabolites. Green fluorescent protein-tagged cells of Pseudomonas aeruginosa, Pseudomonas fluorescens or Ralstonia metallidurans, able to produce siderophores, were inoculated in an agricultural soil containing Cr (488 mg kg(-1)) and Pb (382 mg kg(-1)) and maize was cultivated. Bacteria were inoculated as free or immobilized cells in Ca-alginate beads, with skim milk in the aim at improving both the bacterial survival and the in situ siderophore production.

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Introduction: Controversy persists about whether men should be screened for prostate cancer. On the other hand, the benefit of colorectal cancer screening has been proven for men starting at age 50. We aimed to examine the rate of exposure to previous screening tests for prostate cancer and colorectal cancer in a cohort of men living in Quebec.

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Bioaugmentation-assisted phytoextraction is a promising method for the cleaning-up of soils contaminated by metals. Bacteria mainly Plant Growth Promoting Rhizobacteria (PGPR) and fungi mainly Arbuscular Mycorrhizal Fungi (AMF) associated with hyperaccumulating or non-hyperaccumulating plants were analyzed on the basis of a bioprocess engineering approach (concentration and amount of metals extracted by plants, translocation and bioconcentration factor, and plant biomass). In average bioaugmentation increased metals accumulated by shoots by a factor of about 2 (metal concentration) and 5 (amount) without any obvious differences between bacteria and fungi.

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