Search results for "Oxide"
showing 10 items of 6424 documents
Nitric oxide and glutathione impact the expression of iron uptake- and iron transport-related genes as well as the content of metals in A. thaliana p…
2012
International audience; Mounting evidence indicate that nitric oxide (NO) acts as a signaling molecule mediating iron deficiency responses through the upregulation of the expression of iron uptake-related genes. Accordingly, NO donors such as nitrosoglutathione (GSNO) were reported to improve the fitness of plants grown under iron deficiency. Here, we showed that glutathione, a by-product of GSNO, triggered the upregulation of the expression of iron uptake- and transport-related gene and an increase of iron concentration in Arabidopsis thaliana seedlings facing iron deficiency. Furthermore, we provided evidence that under iron deficiency, NO released by GSNO did not improve the root iron co…
Carbon emission along a eutrophication gradient in temperate riverine wetlands: effect of primary productivity and plant community composition
2016
International audience; 1. Eutrophication increases primary productivity and favours the predominance of floating vegetation in wetlands. Carbon (C) fluxes in wetlands are strongly driven by primary productivity and can differ by vegetation type. However, to the best of our knowledge, the role of eutrophication in C fluxes has rarely been assessed. 2. Consequently, we aimed to measure the seasonal variation in carbon dioxide (CO2) and methane (CH4) fluxes at six aquatic sites in four temperate wetlands, ranging along a gradient of sediment total phosphorus content, and determine whether C fluxes correlate with above-ground net primary productivity (ANPP) and plant community composition alon…
Nitric oxide contributes to cadmium toxicity in Arabidopsis by promoting cadmium accumulation in roots and by up-regulating genes related to iron upt…
2009
Abstract Nitric oxide (NO) functions as a cell-signaling molecule in plants. In particular, a role for NO in the regulation of iron homeostasis and in the plant response to toxic metals has been proposed. Here, we investigated the synthesis and the role of NO in plants exposed to cadmium (Cd2+), a nonessential and toxic metal. We demonstrate that Cd2+ induces NO synthesis in roots and leaves of Arabidopsis (Arabidopsis thaliana) seedlings. This production, which is sensitive to NO synthase inhibitors, does not involve nitrate reductase and AtNOA1 but requires IRT1, encoding a major plasma membrane transporter for iron but also Cd2+. By analyzing the incidence of NO scavenging or inhibition …
Colorimetic biosensing dispositive based on reagentless hybrid biocomposite: Application to hydrogen peroxide determination
2016
Abstract An efficient approach to enhance the performance of colorimetric biosensors has been developed. The biosensor is based on the co-immobilization of the reagent 3,3′,5,5′-teramethylbencidine (TMB) and the enzyme horseradish peroxidase (HRP) in a PDMS-TEOS-SiO2NPs support. The HRP, in presence of H2O2, catalyzes the oxidation of TMB, producing a blue color. The generated biosensor, doped with the substrate (TMB) and the enzyme (HRP) (entrapped or adsorbed), has been used to determine H2O2 in real samples. Firstly, the immobilization of TMB and HRP in the composite has been studied in order to find the best suitable configuration. The kinetic parameters Vmax (maximum reaction rate) and…
Corrosion in alkanolamine used for acid gas removal: From natural gas processing to CO2 capture
2010
The aim of this paper is to review some of the parameters influencing the corrosivity of alkanolamine solvents used for natural gas purification or for CO2 capture. In the light of literature data and of new experimental results, the influences of temperature and of acid gas loading are discussed. These two parameters appear to have a strong impact on corrosion rates of carbon steel, with extrapolated corrosion rates of several tens of mm/year for the highest temperature and acid gas loading condition.
Life Cycle Energy Consumption and Carbon Dioxide Emissions of Agricultural Residue Feedstock for Bioenergy
2021
The depletion of fossil fuels and climate change concerns are drivers for the development and expansion of bioenergy. Promoting biomass is vital to move civilization toward a low-carbon economy. To meet European Union targets, it is required to increase the use of agricultural residues (including straw) for power generation. Using agricultural residues without accounting for their energy consumed and carbon dioxide emissions distorts the energy and environmental balance, and their analysis is the purpose of this study. In this paper, a life cycle analysis method is applied. The allocation of carbon dioxide emissions and energy inputs in the crop production by allocating between a product (g…
Bleaching efficacy of at home 16% carbamide peroxide. A long-term clinical follow-up study.
2019
OBJECTIVE To assess the whitening efficacy of a 16% carbamide peroxidase (CP) gel after 42 months of clinical follow-up. MATERIALS AND METHODS A retrospective clinical study was carried out involving 95 participants. CP 16% was applied for 90 minutes a day for 4 weeks using individualized trays. Tooth color was assessed using spectrophotometry at baseline, 1 week after the end of treatment, and every 6 months until completing 42 months of follow-up. Color parameters were compared using analysis of variance for repeated measures. The analysis by teeth groups was performed using two-way ANOVA. RESULTS The mean baseline L* was 81.7 ± 5.2 versus 83.6 ± 8.8 after 42 months (P<.01). L* showed a d…
Al-SiC Metal Matrix Composite production through Friction Stir Extrusion of aluminum chips
2017
Abstract The production of most mechanical component requires machining operation, thus usually implying the cut material to be wasted as scrap. Traditional recycling techniques are not able to efficiently recycle metal chips because of some critical aspects that characterize such kind of scraps (shape, oxide layers, contaminating residues, etc). Friction Stir Extrusion is an innovative solid state direct-recycling technique for metal machining chips. During the process, a rotating tool is plunged into a hollows matrix to compact, stir and finally, back extrudes the chips to be recycled in a full dense rod. This process results to be particularly relevant since no preliminary treatment of t…
Analysis of Possibility of Yeast Production Increase at Maintained Carbon Dioxide Emission Level
2016
Abstract Main parameters polluting of technological wastewater (dregs from decantation and thicken of the wort) from yeast industry are: nitrogen, potassium and COD. Such wastewater are utilized mostly on agricultural fields. Unfortunately, these fields can only accept a limited amount of wastes. The basic parameter limiting there the amount of wastewater is nitrogen. When capacity of the production is large sewages are often pretreated at an evaporator station. However, due to the fairly high running costs of the evaporator station currently such a solution is applied only to a small amount of wastes (just to meet legal requirements). Replacement of the earth gas with a biomass being suppl…
Evaluation of Glyphosate Ecotoxicity and Biodegradability in the Municipal Wastewaters
2018
Glyphosate (G) is a broad-spectrum systemic organophosphate herbicide being widely used to control weeds in agricultural fields and urban areas. Its safety for both human health and aquatic biomes is a subject of wide debate. This study was aimed at evaluating the removal efficiency and ecotoxicity of G based herbicide (GBH) Klinik® (Nufarm, Austria) added to the raw municipal wastewater (WW) in a lab-scale model column system. The effect of oxide ceramics as a filtering medium (treatment „B”), as well as activated sludge and nutrients (treatment „C”) was compared with the control columns, which contained only WW (treatment „A”). After 72h treatment of WW spiked with 100 mg/L G, the lowest …