Experimental assessment of CO2-mineral-toxic ion interactions in a simplified freshwater aquifer: Implications for CO2 leakage from deep geological storage

International audienceThe possible intrusion of CO2 into a given freshwater aquifer due to leakage from deep geological storage involves a decrease in pH, which has been directly associated with the remobilization of hazardous trace elements via mineral dissolution and/or via desorption processes. In an effort to evaluate the potential risks to potable water quality, the present study is devoted to experimental investigation of the effects of CO2 intrusion on the mobility of toxic ions in simplified equilibrated aquifers. We demonstrate that remobilization of trace elements by CO2 intrusion is not a universal physicochemical effect. In fact goethite and calcite, two minerals frequently found in aquifers, could successfully prevent the remobilization of adsorbed Cu(II), Cd(II), Se(IV) and As(V) if CO2 is intruded into a drinking water aquifer. Furthermore, a decrease in pH resulting from CO2 intrusion could reactivate the adsorption of Se(IV) and As(V) if goethite and calcite are sufficiently available in underground layers. Our results also suggest that adsorption of cadmium and copper could be promoted by calcite dissolution. These adsorbed ions on calcite are not remobilized when CO2 is intruded into the system, but it intensifies calcite dissolution. On the other hand, arsenite As(III) is significantly adsorbed on goethite, but is partially remobilized by CO2 intrusion

WNT/β-Catenin Signalling and Epithelial Patterning in the Homoscleromorph Sponge Oscarella

Sponges branch basally in the metazoan phylogenetic tree and are thus well positioned to provide insights into the evolution of mechanisms controlling animal development, likely to remain active in adult sponges. Of the four sponge clades, the Homoscleromorpha are of particular interest as they alone show the “true” epithelial organization seen in other metazoan phyla (the Eumetazoa). We have examined the deployment in sponges of Wnt signalling pathway components, since this pathway is an important regulator of many developmental patterning processes. We identified a reduced repertoire of three divergent Wnt ligand genes in the recently-sequenced Amphimedon queenslandica (demosponge) genome and two Wnts from our EST collection from the homoscleromorph Oscarella lobularis, along with well-conserved genes for intracellular pathway components (β-catenin, GSK3β). Remarkably, the two O. lobularis Wnt genes showed complementary expression patterns in relation to the evenly spaced ostia (canal openings) of the exopinacoderm (ectoderm), highly reminiscent of Wnt expression during skin appendage formation in vertebrates. Furthermore, experimental activation of the Wnt/β-catenin pathway using GSK3β inhibitors provoked formation of ectopic ostia, as has been shown for epithelial appendages in Eumetazoa. We thus suggest that deployment of Wnt signalling is a common and perhaps ancient feature of metazoan epithelial patterning and morphogenesis

Improving headspace-solid-phase microextraction of 3-isobutyl-2-methoxypyrazine by experimental design with regard to stable isotope dilution gas chromatography–mass spectrometric analysis of wine

To solve problems of sensitivity, repeatability and multi-step extraction related to 3-isobutyl-2-methoxypyrazine (IBMP) determination in wines, a simple method based on the novel combination of solid-phase microextraction and stable isotope dilution assay is presented. Among the parameters that affect this type of extraction, five of them have been optimised since the other parameters have common values or do not require optimisation (e.g. addition of sodium chloride at saturated concentration) and so were fixed. Vial volume, sample volume/vial volume ratio, pH, adsorption time and temperature have been optimised by means of two experimental designs. After extraction, quantification was performed by stable isotope dilution with gas chromatography-tandem mass spectrometry ([]-IBMP as internal standard). The final procedure allowed quantification far below IBMP’s sensory threshold (1 ng l−1 versus 15 ng l−1) with a 4% standard deviation. This method has been applied to experimental Fer servadou wines. Comparison of IBMP contents confirmed the efficiency of some viticultural and enological techniques on the herbaceous flavour decrease, such as prior fermentation maceration at high temperature (70 °C) and the use of a reflective carpet on viticultural soil

Long-term outcomes of CLIPPERS (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids) in a consecutive series of 12 patients.

BACKGROUND: Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a central nervous system inflammatory disease. OBJECTIVE: To describe the disease course of CLIPPERS. DESIGN: A nationwide study was implemented to collect clinical, magnetic resonance imaging, cerebrospinal fluid, and brain biopsy specimen characteristics of patients with CLIPPERS. SETTING: Academic research. PATIENTS: Twelve patients with CLIPPERS. MAIN OUTCOME MEASURES: The therapeutic management of CLIPPERS was evaluated. RESULTS: Among 12 patients, 42 relapses were analyzed. Relapses lasted a mean duration of 2.5 months, manifested frequent cerebellar ataxia and diplopia, and were associated with a mean Expanded Disability Status Scale (EDSS) score of 4. Besides typical findings of CLIPPERS, magnetic resonance imaging showed brainstem mass effect in 5 patients, extensive myelitis in 3 patients, and closed ring enhancement in 1 patient. Inconstant oligoclonal bands were found on cerebrospinal fluid investigation in 4 patients, with an increased T-cell ratio of CD4 to CD8. Among 7 available brain biopsy specimens, staining was positive for perivascular CD4 T lymphocytes in 5 samples. Thirty-eight of 42 relapses were treated with pulse corticosteroid therapy, which led to improvement, with a mean residual EDSS score of 1.9 (range, 0-7). In 1 patient with untreated relapses, scores on the EDSS progressively increased to a score of 10 at death. Among 5 patients without long-term corticosteroid therapy, the mean annualized relapse rate was 0.5 (range, 0.25-2.8). Among 7 patients taking oral corticosteroids, no relapses occurred in those whose daily dose was 20 mg or higher. No progressive course of CLIPPERS was observed. Four patients with a final EDSS score of 4 or higher had experienced previous severe relapses (EDSS score, ≥5) and brainstem and spinal cord atrophy. CONCLUSIONS: CLIPPERS is a relapsing-remitting disorder without progressive forms. Long-term disability is correlated with the severity of previous relapses. Further studies are needed to confirm that prolonged corticosteroid therapy prevents further relapses.journal article2012 Julimporte

Functional outcomes in symptomatic versus asymptomatic patients undergoing incisional hernia repair: Replacing one problem with another? A prospective cohort study in 1312 patients

Background: Incisional hernias can be associated with pain or discomfort. Surgical repair especially mesh reinforcement, may likewise induce pain. The primary objective was to assess the incidence of pain after hernia repair in patients with and without pre-operative pain or discomfort. The secondary objectives were to determine the preferred mesh type, mesh location and surgical technique in minimizing postoperative pain or discomfort. Materials and methods: A registry-based prospective cohort study was performed, including patients undergoing incisional hernia repair between September 2011 and May 2019. Patients with a minimum follow-up of 3–6 months were included. The incidence of hernia related pain and discomfort was recorded perioperatively. Results: A total of 1312 patients were included. Pre-operatively, 1091 (83%) patients reported pain or discomfort. After hernia repair, 961 (73%) patients did not report pain or discomfort (mean follow-up = 11.1 months). Of the pre-operative asymptomatic patients (n = 221), 44 (20%, moderate or severe pain: n = 14, 32%) reported pain or discomfort after mean follow-up of 10.5 months. Of those patients initially reporting pain or discomfort (n = 1091), 307 (28%, moderate or severe pain: n = 80, 26%) still reported pain or discomfort after a mean follow-up of 11.3 months postoperatively. Conclusion: In symptomatic incisional hernia patients, hernia related complaints may be resolved in the majority of cases undergoing surgical repair. In asymptomatic incisional hernia patients, pain or discomfort may be induced in a considerable number of patients due to surgical repair and one should be aware if this postoperative complication

Modification régio- et chimiosélective de polyols par réduction de dérivés carbonylés par des hydrures de zirconium générés in situ

This work has been focused on the regio- and chemoselective deprotection reaction of carbonylated compounds by zirconium hydrides generated in situ. We first explored the capacity of our system to regioselectively deprotect the primary acetate of carbohydrate derivatives thanks to a catalytic amount of zirconocene and carried out the mecanistic studies needed to explain the reaction. We also explored the effect of the ligands of the zirconocene on the conversion and the selectivity of the reaction and performed the orthogonal deprotection of an acetate in presence of a benzoate. In order to develop a new orthogonal deprotection method, we considered the elaboration of a chemoselective deprotection of methyl carbonates in presence of esters. The methodology was first on model compounds before being used efficiently on more complex carbohydrates. Finally, the efficiency of our system was applied on the regio- and chemoselective deprotection of the peracetylated cytidine in order to synthesize functionnalized compounds useful in organic synthesis.Ces travaux de thèse ont été consacrés à l’étude des propriétés d’hydrures de zirconium générés in situ dans le cadre d’une réaction de déprotection régio- et chimiosélective de composés carbonylés. Nous avons tout d’abord exploré la capacité de notre système à déprotéger régiosélectivement l’acétate primaire de sucres à l’aide d’une quantité catalytique de zirconium et effectué les études mécanistiques nécessaires à la compréhension de la réaction. Par ailleurs, nous avons étudié l’effet des ligands du zirconocène employé sur la conversion et la sélectivité de la réaction et réalisé la déprotection orthogonale d’un acétate en présence d’un groupement benzoate. Afin de développer une nouvelle méthode de déprotection orthogonale nous nous sommes ensuite intéressés à l’élaboration d’une réaction de déprotection chimiosélective de carbonates de méthyle en présence d’esters. Tout d’abord mise au point sur des substrats modèles, elle s’est par la suite avérée efficace sur des sucres plus complexes. Nous avons enfin choisi de sonder l’efficacité de notre système sur la déprotection régio- et chimiosélective de la cytidine peracétylée afin d’atteindre des substrats fonctionnalisés d’intérêt en synthèse organique

Modification régio- et chimiosélective de polyols par réduction de dérivés carbonylés par des hydrures de zirconium générés in situ

This work has been focused on the regio- and chemoselective deprotection reaction of carbonylated compounds by zirconium hydrides generated in situ. We first explored the capacity of our system to regioselectively deprotect the primary acetate of carbohydrate derivatives thanks to a catalytic amount of zirconocene and carried out the mecanistic studies needed to explain the reaction. We also explored the effect of the ligands of the zirconocene on the conversion and the selectivity of the reaction and performed the orthogonal deprotection of an acetate in presence of a benzoate. In order to develop a new orthogonal deprotection method, we considered the elaboration of a chemoselective deprotection of methyl carbonates in presence of esters. The methodology was first on model compounds before being used efficiently on more complex carbohydrates. Finally, the efficiency of our system was applied on the regio- and chemoselective deprotection of the peracetylated cytidine in order to synthesize functionnalized compounds useful in organic synthesis.Ces travaux de thèse ont été consacrés à l’étude des propriétés d’hydrures de zirconium générés in situ dans le cadre d’une réaction de déprotection régio- et chimiosélective de composés carbonylés. Nous avons tout d’abord exploré la capacité de notre système à déprotéger régiosélectivement l’acétate primaire de sucres à l’aide d’une quantité catalytique de zirconium et effectué les études mécanistiques nécessaires à la compréhension de la réaction. Par ailleurs, nous avons étudié l’effet des ligands du zirconocène employé sur la conversion et la sélectivité de la réaction et réalisé la déprotection orthogonale d’un acétate en présence d’un groupement benzoate. Afin de développer une nouvelle méthode de déprotection orthogonale nous nous sommes ensuite intéressés à l’élaboration d’une réaction de déprotection chimiosélective de carbonates de méthyle en présence d’esters. Tout d’abord mise au point sur des substrats modèles, elle s’est par la suite avérée efficace sur des sucres plus complexes. Nous avons enfin choisi de sonder l’efficacité de notre système sur la déprotection régio- et chimiosélective de la cytidine peracétylée afin d’atteindre des substrats fonctionnalisés d’intérêt en synthèse organique

Regio- and chemoselective modification of polyol derivatives by reduction of carbonylated compounds by zirconium hydrides generated in situ

Ces travaux de thèse ont été consacrés à l’étude des propriétés d’hydrures de zirconium générés in situ dans le cadre d’une réaction de déprotection régio- et chimiosélective de composés carbonylés. Nous avons tout d’abord exploré la capacité de notre système à déprotéger régiosélectivement l’acétate primaire de sucres à l’aide d’une quantité catalytique de zirconium et effectué les études mécanistiques nécessaires à la compréhension de la réaction. Par ailleurs, nous avons étudié l’effet des ligands du zirconocène employé sur la conversion et la sélectivité de la réaction et réalisé la déprotection orthogonale d’un acétate en présence d’un groupement benzoate. Afin de développer une nouvelle méthode de déprotection orthogonale nous nous sommes ensuite intéressés à l’élaboration d’une réaction de déprotection chimiosélective de carbonates de méthyle en présence d’esters. Tout d’abord mise au point sur des substrats modèles, elle s’est par la suite avérée efficace sur des sucres plus complexes. Nous avons enfin choisi de sonder l’efficacité de notre système sur la déprotection régio- et chimiosélective de la cytidine peracétylée afin d’atteindre des substrats fonctionnalisés d’intérêt en synthèse organique.This work has been focused on the regio- and chemoselective deprotection reaction of carbonylated compounds by zirconium hydrides generated in situ. We first explored the capacity of our system to regioselectively deprotect the primary acetate of carbohydrate derivatives thanks to a catalytic amount of zirconocene and carried out the mecanistic studies needed to explain the reaction. We also explored the effect of the ligands of the zirconocene on the conversion and the selectivity of the reaction and performed the orthogonal deprotection of an acetate in presence of a benzoate. In order to develop a new orthogonal deprotection method, we considered the elaboration of a chemoselective deprotection of methyl carbonates in presence of esters. The methodology was first on model compounds before being used efficiently on more complex carbohydrates. Finally, the efficiency of our system was applied on the regio- and chemoselective deprotection of the peracetylated cytidine in order to synthesize functionnalized compounds useful in organic synthesis

Influence of nitrogen fertilization on <em>Vitis vinifera</em> cv. Merlot with permanent grass cover. (Nitrogen content, nature and concentration levels of some amino acids of musts and wines)

Since 1995, it has heen running an experiment on the introduction of nitrogen fertilization on permanent grass cover. This has been done in order to determine both the role and the influence of nitrogen on the fermentability of the must. Located south of Saint-Emilion, the plot area studied has a regular, sandy, clayey soil 60 centimeters deep. The cultivar Merlot is grafted on the Riparia Gloire from Montpellier rootstock. Five N- fertilizations were compared : T (0 kg N/ha/year), A (30 kg N/ha/year), 8 (60 kg N/ha/year), C ( 90 kg N/ha/year), and D (45 kg N/ha at springtime and 45 kg N/ha at flowering period). For the different N-fertilizations, the numher of clusters per vine was the same for the two experimental years. The mean cluster weight allowed for evaluating the nitrogen effect on the yield. Nitrogen fertilization on the permanent grass cover in the vineyard depends upon climatic conditions in the spring and, more specifically, upon the rainfall pattern. Varietal vigor can he increased or decreased with the level of nitrogen. However, in all cases studied, late contribution of nitrogen was found to he harmful. In fact, most nitrogen added at springtime was used by the grass cover and the competitiveness of the latter was increased. Only test « C » proved to be adequate to satisfy both vineyard and grass cover needs (this is shown in the study of the pruning wood weight variation compared to the standard « T»). The duration of alcoholic fermentation is quite closely correlated to the content of nitrogen composites in the must and more particularly in amino acids. The global amino acid contents of musts and wines were higher in 1996 than in 1995, but in this last case more numerous kinds of amino acids were present. However, for both years studied, proline represented at least 50 percent of the global amino acids content. A statistical analysis on the five N-fertilizations showed a clear differentiation between the two vintages studied ; that is to say, each vintage was identified by specific amino acid profiles. This « vintage » effect was proved by tasting results