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Among disruptions induced by oxidative stress, modifications of proteins, particularly irreversible carbonylation, are associated with the development of several diseases, including cardiovascular diseases, neurodegenerative diseases, and cancer. Carbonylation of proteins can occur directly or indirectly through the adduction of lipid oxidation products. In this study, three classical and easy-to-perform techniques to detect direct or indirect carbonylation of proteins were compared. A model protein apomyoglobin and a complex mixture of rat liver cytosolic proteins were exposed to cumene hydroperoxide oxidation or adduction to the lipid peroxidation product 4-hydroxynonenal in order to test direct or indirect carbonylation, respectively. The technique using a specific anti-4-hydroxynonenal-histidine adduct antibody was effective to detect in vitro modification of model apomyoglobin and cytosolic proteins by 4-hydroxynonenal but not by direct carbonylation which was achieved by techniques using biotin-coupled hydrazide or dinitrophenylhydrazine derivatization of carbonyls. Sequential use of these methods enabled the detection of both direct and indirect carbonyl modification in proteins, although constitutively biotinylated proteins were detected by biotin-hydrazide. Although rather classical and efficient, methods for carbonyl detection on proteins in oxidative stress studies may be biased by some artifactual detections and complicated by proteins multimerizations. The use of more and more specific available antibodies is recommended to complete detection of lipid peroxidation product adducts on proteins.

The recently developed One-Step Poly(amidoamine) (OS-PAMAM) dendrimers stand out for their characteristics as the high drug-load capacity and cell-delivery improvement of therapeutic agents. The OS-PAMAM dendrimers have proven to be useful in the biomedical field as nanocarrier or nanosystems for therapy. In the present research it was encouraging to determine their physicochemical characteristics which were compared with commercial PAMAM generation-6 (G6). The spectroscopic measurement of amides, nanoparticle size (10–30 nm), polydispersity index and zeta potential measurements correlates with the commercial product. The OS-PAMAM has cavities detected by AFM, and the force analysis showed the same adhesion force and different elasticity than PAMAM-G6. The molecular weight (MW) was 10 times lower than the commercial one for both techniques employed, resembling the MW of a PAMAM generation-3 (G3). OS-PAMAM/PAMAM-G6 MS-MS mirror plots demonstrate chemical equivalency amongst herein analyzed dendrimers, with the advantage that OS-PAMAM is produced with a faster and low-cost synthetic protocol, which allows them to be applied for both research and industry in the biomedical field.

International audience; In this work, we studied the impact of magnetic nanoparticles (MNPs) interactions with HeLa cells when they are exposed to high frequency alternating magnetic field (AMF). Specifically, we measured the nanobiomechanical properties of cell interfaces by using Atomic Force Microscopy (AFM). The Magnetite (Fe3O4) MNPs were synthesized by coprecipitation and encapsulated with silica (SiO2): Fe3O4@SiO2 and functionalized with amino groups (-NH2): Fe3O4@SiO2-NH2, by sonochemical processing. HeLa cells were incubated or not with MNPs, then exposed or not to AMF at 37 °C. A biomechanical analysis was then performed through AFM, providing the Young's modulus and stiffness of the cells. The statistical analysis (p < 0.001) showed that AMF application or MNPs interaction modify the biomechanical behavior of the cell interfaces. Interestingly, the most significant difference was found for HeLa cells incubated with Fe3O4@SiO2-NH2 and exposed to AMF, showing that local heat of these MNPs modify elasticity and stiffness.

International audience; Radio-frequency magnetron sputtering was used to produce HfO 2 films doped with Nd, Si and N. The deposition was carried out in two different atmospheres: i) in pure argon plasma to grow Si-HfO 2 :Nd films, and ii) in argon-nitrogen mixed plasma to produce SiN -HfO 2 :Nd films. The effect of annealing temperature on optical and structural properties of the films was investigated. Annealing was performed at T A = 800-1100 °C for t A = 15 min in nitrogen atmosphere. The evolution of film's properties was studied by means of the scanning electronic microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and photo-luminescence (PL) methods. It was observed that the film morphology depends significantly on the deposition atmosphere. For the Si-HfO 2 :Nd films, the presence of the grains with the mean size about 100 nm was detected by the SEM method. The tetragonal HfO 2 and SiO 2 phases have been detected by the XRD method after film annealing at 950 °C. PL spectra of these films are complex and demonstrate several PL bands in the visible (400-750 nm) and infrared (800-1430 nm) spectral ranges. Their contribution depends on the annealing temperature and governs the shape of total PL spectrum. In contrary, the SiN -HfO 2 :Nd films showed unstructured smooth surface as well as featureless PL spectra. Whatever the annealing temperature, they demonstrate broad unstructured PL band with the peak within 440-480 nm. Peculiarities of PL spectra of both types of the films and the mechanism of phase separation are analyzed and discussed.

International audience; The intestinal epithelial barrier (IEB) depends on stable interepithelial protein complexes such as tight junctions (TJ), adherens junctions (AJ), and the actin cytoskeleton. During inflammation, the IEB is compromised due to TJ protein internalization and actin remodeling. An important actin regulator is the actin-related protein 2/3 (Arp2/3) complex, which induces actin branching. Activation of Arp2/3 by nucleation-promoting factors is required for the formation of epithelial monolayers, but little is known about the relevance of Arp2/3 inhibition and endogenous Arp2/3 inhibitory proteins for IEB regulation. We found that the recently identified Arp2/3 inhibitory protein arpin was strongly expressed in intestinal epithelial cells. Arpin expression decreased in response to tumor necrosis factor (TNF)α and interferon (IFN)γ treatment, whereas the expression of gadkin and protein interacting with protein C-kinase α-subunit 1 (PICK1), other Arp2/3 inhibitors, remained unchanged. Of note, arpin coprecipitated with the TJ proteins occludin and claudin-1 and the AJ protein E-cadherin. Arpin depletion altered the architecture of both AJ and TJ, increased actin filament content and actomyosin contractility, and significantly increased epithelial permeability, demonstrating that arpin is indeed required for maintaining IEB integrity. During experimental colitis in mice, arpin expression was also decreased. Analyzing colon tissues from ulcerative colitis patients by Western blot, we found different arpin levels with overall no significant changes. However, in acutely inflamed areas, arpin was significantly reduced compared to non-inflamed areas. Importantly, patients receiving mesalazine had significantly higher arpin levels than untreated patients. As arpin depletion (theoretically meaning more active Arp2/3) increased permeability, we wanted to know whether Arp2/3 inhibition would show the opposite. Indeed, the specific Arp2/3 inhibitor CK666 ameliorated TNFα/IFNγ-induced permeability in established Caco-2 monolayers by preventing TJ disruption. CK666 treatment also attenuated colitis development, colon tissue damage, TJ disruption, and permeability in dextran sulphate sodium (DSS)-treated mice. Our results demonstrate that loss of arpin triggers IEB dysfunction during inflammation and that low arpin levels can be considered a novel hallmark of acute inflammation.

International audience; We quantitatively evaluate the effects of UV-C radiation on bean seeds Oti (Phaseolus vulgaris), their germination and phenolic compounds of seedlings, by means of photoacoustic spectroscopy and scanning electron microscopy. It is shown that (i) The photoacoustic signal produced by the bean seeds exposed to UV-C radiation during 15 min, reduces from 0.24 to 0.10 mV for the wavelengths of 295 and 340 nm, as a result of their degradation. This significant reduction of 58.3% decreases, but keeps over 50% for other spectral UV wavelengths within the interval (270-400 nm). (ii) As the UV-C radiation time increases from 2 to 15 min, the morphological changes at the surface of the bean seeds exhibit micro-holes and detachment of the cotyledon sclereids. (iii) There are no significant statistical differences in the variables of germination, dry weight, and seedling length, for exposure times up to 15 min. (iv). The phenolic acids and flavonoids of the bean seedlings of seeds treated by UV-C for different exposure times (0, 2, 5, 10, and 15 min) display significant statistical differences (P ≤ 0.05) in both roots and foliage. For both the roots and foliage, the highest concentration of phenolic acids is observed at 10 and 15 min, while for root flavonoids, it appears at 5 and 15 min.

The impact of the time at high temperature annealing on the morphology, crystal structure and emission in visible spectral range has been studied in Si rich HfO2:Nd films produced by radio-frequency magnetron sputtering in pure argon plasma. The annealing was carried out at 900 °C for 1, 5, 10, 30 and 60 min in the nitrogen atmosphere. A set of experimental methods have been used, such as: scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and photoluminescence (PL). In the present work the joint analysis of PL and XRD results permits us to estimate the optimal time parameters of annealing at 900 °C the Si-HfO2: Nd films for obtaining the bright emission via 4f electronic levels of the Nd ions embedded in the tetragonal HfO2 phase mainly after long annealing (30- 60 min). The film oxidation for annealing times (60 min) stimulated some crystal phase transformation with the start of formation of the tetragonal SiO2 phase, that is accompanied by the defect generation and decreasing the PL intensity. The discussion of PL and XRD results is presented in detail.

Biofouling causes major problems and economic losses to marine and shipping industries. In the search for new antifouling agents, marine bacteria with biosurfactants production capability can be an excellent option, due to the amphipathic surface-active characteristic that confers antimicrobial and antibiofilm activities. The aim of this study was to evaluate the antifouling activity of biosurfactants producing marine bacteria from the Gulf of California. The cell free culture supernatant (CFCS) of Bacillus niabensis (S-69), Ralstonia sp. (S-74) (isolated from marine sediment) and of B. niabensis (My-30) (bacteria associated to the sponge Mycale ramulosa) were screened for production of biosurfactants (using hemolysis and drop collapse test, oil displacement and emulsifying activity). The toxicity and antifouling activity were evaluated against biofoulers (bacteria forming biofilm and macrofoulers) both in laboratory and field assays. The results indicate that all bacteria were biosurfactant producers, but the higher capability was shown by B. niabensis (My-30) with high emulsifying properties (E24) of 71%. The CFCS showed moderate toxicity but were considered non-toxic against Artemia franciscana at low concentrations. In the antifouling assay, the CFCS of both strains of B. niabensis showed the best results for the reduction of the biofilm formation (up 50%) against all Gram-positive bacteria and most Gram-negative bacteria with low concentrations. In the field assay, the CFCS of B. niabensis (My-30) led to the reduction of 30% of biofouling compared to the control. The results indicate that the biosurfactant produced by B. niabensis (My-30) has promising antifouling activity.

International audience; Nanomechanical properties of cells could be considered as cellular biomarkers. The main method used to access the mechanical properties is based on nanoindentations measurements, performed with an operator manipulated Atomic Force Microscope (AFM) which is time-consuming, and expensive. This is one of the reasons preventing the transfer of AFM technology into clinical laboratories. In this presentation we report a methodology1 which includes an algorithm (transferred to a script, executed on a commercial AFM) able to automatically move the tip onto a single cell and through several cells to record force curves combined with a smart strategy of cell immobilization. Cells are placed into microwells of a microstructured polydimethylsiloxane (PDMS) stamp. Inside a classical 100x100 µm2 AFM field, 80 to 100 cells are immobilized. In an optimal configuration we were able to measure a population of 900 Candida albicans cells both unmodified and caspofungin treated in 4 h, which represents an unprecedented performance2. This strategy can be applied to cell arrays, proteins or glycan arrays. The big amount of data generated is compatible with the analysis by machine learning and will most probably generate unexpected understanding of the biological processes.References (max. 5): 1. Severac C.,, Proa-Coronado S., Formosa-Dague C., Martinez-Rivas A., Dague E. 2020 in Press Automation of Bio-Atomic Force Microscope Measurements on Hundreds of C. albicans CellsJournal of Visualized Experiments e61315 URL: https://www.jove.com/video/61315 doi:10.3791/61315 2. Proa-Coronado S., Severac C., Martinez-Rivas A., Dague E. 2019Beyond the paradigm of nanomechanical measurements on cells using AFM: an automated methodology to rapidly analyze thousands of cells.Nanoscale Horizons, DOI : 10.1039/c9nh00438fAcknowledgment: We want to acknowledge FONCYCYT of CONACYT (Mexico), the ministry of Foreign affairs of France and the Universit ́e Paris 13, though the financial support of the international collaborative ECOS-NORD project named Nano-palpation for diagnosis, No. 263337 (Mexico) and MI5P02 (France). AMR would like to thank the financial support of the SIP project No. 20195489, from IPN. SPC is supported by a PhD fellowship from CONACYT (No. 288029) and IPN through the cotutelle agreement to obtain double PhD certificate (IPN-UPS). ED is a researcher at Centre National de la Recherche Scientifique (CNRS).

International audience; In this research, we to apply photoacoustic spectroscopy and evaluate bread added with turmeric (Curcuma longa Linnaeus) at different concentrations in relation to wheat flour weight (0, 1.25, 2.5, 5 and 10%). The amplitude of the photoacoustic signal was related to measures of antioxidant activity and evaluate the sanitary quality and also, the texture, color and sensory acceptability of the breads. It is shown that: i) The photoacoustic signal produced by bread significantly increases with the turmeric concentration, such that it raises more than 100% for a concentration of 10% at the wavelengths of 428 and 515nm. ii) The Bread antioxidant activity is directly proportional to the level of photoacoustic signal at 515 nm and its value increases from 73.21% to 91.73%, when the concentration increases from 0 to 10%. iii) The sanitary quality of bread added with 2.5 % of turmeric is relatively higher than the ones obtained for other lower concentrations. No fungal colonies were observed in bread mixed with 2.5%, 5% and 10%, after six days of storage. iv) The addition of turmeric powder for bread making can slow down their textural changes (hardness, elasticity, cohesiveness, resilience and chewiness) during storage. v) Bread at 2.5 and 5% of turmeric concentration showed the yellowest color, while the one with a 10% concentration exhibited the most reddish color. Finally, through Principal component analysis it was possible to demonstrate that a concentration of either 5 or 10% of turmeric added to wheat flour could be used to improve its sanitary quality and antioxidant activity.

International audience; In an article published in this journal in February 2020, Stefanescu et al. reviewed recent developments in understanding nucleation and growth of spheroidal graphite in cast iron. The intention of the present comment is not to discuss the merits and limits of this highly documentedpaper in general, but to correct erroneous statements made by the authors in their Section 5.1. One of the approaches reviewed in this section is the work by Theuwissen et al., who suggested that the 2-D poly-nucleation-growth (PNG) mechanism applied by Amini and Abbaschian] to describe the formation of polyhedral graphite plates in Ni–C alloys might also be operational for flake and spheroidal graphite in cast iron melts. This hypothesis has been supported by the analytical calculations of Lacaze et al., and it is this latter work which is severely criticized by Stefanescu et al. in section 5.1 of their paper [1]. In the following, we detail that the supposed numerical incongruities and seemingly shortcomings of the work by Lacaze et al. are not real, but are based on a severe misinterpretation of the analytical model parameters and results.

While first discovered in immunoreceptor signaling, the Syk protein kinase behaves as a tumor and metastasis suppressor in epithelial cells. Its reduced expression in breast and other carcinomas is correlated with decreased survival and increased metastasis risk, but its action mechanism remains largely unknown. Using phosphoproteomics we found that Syk phosphorylated E-cadherin and &alpha, &beta, and p120-catenins on multiple tyrosine residues that concentrate at intercellular junctions. Increased Syk expression and activation enhanced E-cadherin/catenin phosphorylation, promoting their association and complex stability. In human breast cancer cells, Syk stimulated intercellular aggregation, E-cadherin recruitment and retention at adherens junctions, and promoted epithelial integrity, whereas it inhibited cell migration and invasion. Opposite effects were obtained with Syk knockdown or non-phosphorylatable mutant E-cadherin expression. Mechanistically, Syk stimulated the interaction of the E-cadherin/catenin complex with zonula occludens proteins and the actin cytoskeleton. Conditional Syk knockout in the lactating mouse mammary gland perturbed alveologenesis and disrupted E-cadherin localization at adherens junctions, corroborating the observations in cells. Hence, Syk is involved in the maintenance of the epithelial integrity of the mammary gland via the phosphorylation and stabilization of the E-cadherin/catenin adherens junction complex, thereby inhibiting cell migration and malignant tumor invasion.

International audience; The Vapor Phase Impregnation decomposition method (VP-IDM) is presented in this study as an alternative technique to obtain well-dispersed metallic nanoparticles on CNTs, for ammonia (NH 3) gas detection. We have analyzed the effectiveness of this method by using chemiresistive sensors (CHRs) based on multi-walled carbon nanotubes (MWCNTs) decorated with Pt and Pd nanoparticles (NPs). We measured their sensitivity through their electrical resistance variation in the presence of NH 3 gas at concentrations from 10 to 200 ppm. Pt/MWCNTs showed the highest sensitivity of about 120% at 100 ppm and 250 • C. It was revealed that the size, dispersion, temperature and type of metal NPs deposited on the MWCNTs are crucial for the detection of the NH 3 gas by the CHRs.

Biofouling causes major economic losses in the maritime industry. In our site study, the Bay of La Paz (Gulf of California), biofouling on immersed structures is a major problem and is treated mostly with copper-based antifouling paints. Due to the known environmental effect of such treatments, the search for environmentally friendly alternatives in this zone of high biodiversity is a priority to ensure the conservation and protection of species. The aim of this work was to link chemical ecology to marine biotechnology: indeed, the natural defense of macroalgae and sponge was evaluated against biofoulers (biofilm and macrofoulers) from the same geographical zone, and some coatings formulation was done for field assays. Our approach combines in vitro and field bioassays to ensure the selection of the best AF agent prospects. The 1st step consisted of the selection of macroalgae (5 species) and sponges (2 species) with surfaces harboring a low level of colonizers, then extracts were prepared and assayed for toxicity against Artemia, activity towards key marine bacteria involved in biofilm formation in the Bay of La Paz, and the potency to inhibit adhesion of macroorganisms (phenoloxidase assays). The most active and non-toxic extracts were further studied for biofouling activity in the adhesion of the bacteria involved in biofilm formation and through incorporation in marine coatings which were immersed in La Paz Bay during 40 days. In vitro assays demonstrated that extracts of Laurencia gardneri, Sargassum horridum (macroalgae), Haliclona caerulea and Ircinia sp. (sponges) were the most promising. The field test results were of high interest as the best formulation were composed of extracts of H. caerulea and S. horridum and led to a reduction of 32% of biofouling compared with the control.

International audience; Background/objectives Maternal obesity is associated with increased risk of obesity and other symptoms of the metabolic syndrome in the offspring. Nevertheless, the molecular mechanisms and cellular factors underlying this enhanced disease susceptibility remain to be determined. Here, we aimed at identifying changes in plasma lipids in offspring of obese mothers that might underpin, and serve as early biomarkers of, their enhanced metabolic disease risk. Subjects/methods We performed a longitudinal lipidomic profiling in plasma samples from normal weight, overweight, and obese pregnant women and their children that participated in the Prenatal Omega-3 Fatty Acid Supplementation, Growth, and Development trial conducted in Mexico. At recruitment women were aged between 18 and 35 years and in week 18–22 of pregnancy. Blood samples were collected at term delivery by venipuncture from mothers and from the umbilical cord of their newborns and from the same infants at 4 years old under non-fasting conditions. Lipidomic profiling was done using ultra-performance liquid chromatography high-resolution mass spectrometry. Results Analysis of the lipidomic data showed that overweight and obese mothers exhibited a significant reduction in the total abundance of ceramides (Cer) in plasma, mainly of Cer (d18:1/20:0), Cer (d18:1/22:0), Cer (d18:1/23:0), and Cer (d18:1/24:0), compared with mothers of normal body weight. This reduction was confirmed by the direct quantification of these and other ceramide species. Similar quantitative differences in the plasma concentration of Cer (d18:1/22:0), Cer (d18:1/23:0), and Cer (d18:1/24:0), were also found between 4-year-old children of overweight and obese mothers compared with children of mothers of normal body weight. Noteworthy, children exhibited equal daily amounts of energy and food intake independently of the BMI of their mothers. Conclusions Maternal obesity results in long-lasting changes in plasma ceramides in the offspring suggesting that these lipids might be used as early predictors of metabolic disease risk due to maternal obesity.

International audience; Nanomaterials based on Pd nanoparticles supported on Vulcan carbon (XC-72R) were prepared by the organometallic approach in one-pot and mild conditions (3 bar hydrogen and room temperature) using Pd(dba)2 (bis (dibenzylideneacetone) palladium (0)) as metal source and hexadecylamine (HDA) as stabilizer. High-resolution transmission electron microscopy (HR-TEM) evidenced the presence of well-dispersed Pd nanoparticles of ca. 4.5 nm mean size onto the carbon support (Pd/HDA/C). Scanning and transmission electron microscopy with electron energy loss spectroscopy (STEM-EELS) allowed to determine the chemical composition of the nanomaterials. When the Pd/HDA/C nanomaterial was submitted to heating treatment (ht) at 400 °C under air (referred as Pd/HDA/C@air-ht), X-ray photoelectron spectroscopy (XPS) and HR-TEM/STEM-EELS analyses suggested the presence of interactions between PdO and Pd(0) as a result of the formation of Pd@PdO core–shell nanoparticles. The highest oxidation current magnitude during methanol oxidation reaction is ascribed to the heat-treated material, linked with a better electron and mass transfer processes at the electrode interface. This can be attributed to electronic interactions at the core–shell formed, which might promote different redox processes at the electrode interface during CH3OH deprotonation in the alkaline electrolyte.

The potential of Pseudomonas putida KT2440 to act as a plant-growth promoter or as a bior-emediator of toxic compounds can be affected by desiccation. In the present work, the bacterial survival ratio (BSR) in response to air desiccation was evaluated for P. putida KT2440 in the presence of different protectors. The BSR in the presence of nonreducing disaccharides, such as trehalose, was high after 15 days of desiccation stress (occurring at 30C and 50% relative humidity), whereas in the absence of a protector the bacterial counts diminished to nondetectable numbers (ca 2.8 log CFU/mL). The LIVE/DEAD staining method showed that bacteria protected with trehalose maintained increased numbers of green cells after desiccation while cells without protection were all observed to be red. This indicated that nonprotected bacteria had compromised membrane integrity. However, when nonprotected bacteria subjected to 18 days of desiccation stress were rehydrated for a short time with maize root exudates or for 48 h with water (prolonged rehydration), the bacterial counts were as high as that observed for those not subjected to desiccation stress, suggesting that the cells entered the viable but nonculturable (VBNC) state under desiccation and that they returned to a culturable state after those means of rehydration. Interestingly an increase in the green color intensity of cells that returned to a culturable state was observed using LIVE/ DEAD staining method, indicating an improvement in their membrane integrity. Cellular activity in the VBNC state was determined. A GFP-tagged P. putida strain expressing GFP constitutively was subjected to desiccation. After 12 days of desiccation, the GFP-tagged strain lost culturability, but it exhibited active GFP expression, which in turn made the cells green. Furthermore, the expression of 16S rRNA, rpoN (housekeeping), mutL, mutS (encoding proteins from the mismatch repair complex), and oprH (encoding an outer membrane protein) were examined by RT-PCR. All evaluated genes were expressed by both types of cells, culturable and nonculturable, indicating active molecular processes during the VBNC state., This work is supported by: JMR: Apoyo Redes PRODEP 2015-2016 (CA-262 and CA-244); JMR: DITCo2016-3, JMR: DITCo2016-4; VIEP-BUAP-2018 (VQH: COL525704-VIEP2018; ABR: 100524554-VIEP2018, JMR: 100425788-VIEP2018). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Mezcal yeasts were evaluated for their potential as grape-juice fermenters, characterizing their fermentation performance, both in terms of primary and volatile metabolites. Experiments were first carried-out in a semi-synthetic medium and then on grape juice, and population dynamics of the chosen mixed inoculum was assessed in grape juice. Accordingly, we initially tested 24 mezcal yeasts belonging to ten different species, and chose those that were more productive and stress tolerant for the mixed (dual) inoculum, having a final selection of three Saccharomyces cerevisiae strains (plus Fermichamp, a commercial wine strain) and three non-Saccharomyces strains, belonging to Kluyveromyces marxianus, Torulaspora delbrueckii, and Zygosaccharomyces bailii species. For the combination S. cerevisiae/T. delbrueckii (Sc/Td) mixed inoculum, we observed increasing isoamyl alcohol and phenyl ethyl acetate concentrations, as compared with the use of individual Saccharomyces strains, which resulted in a fruitier aroma profile. Alcohol final concentration was in average lower for the Sc/Td inoculum (fermentation power, FP, 13.6) as compared with the individual mezcal Saccharomyces strains (FP 14.3), and it was the highest when Td was co-cultured with the commercial strain (FP 14.6). Overall, our results show the feasibility of using yeasts isolated from mezcal as a novel source of inoculum for wine-type fermentation.

One way of reducing the input of pollutants into the marine environment is to enforce the use of non-toxic antifouling paints in marine protected areas. Thus, the purpose of this study was to detect marine microorganisms that secrete inhibitory substances against bacteria and microalgae to avoid biofouling on manmade structures in La Paz bay, B.C.S., Mexico. The inhibitory potential of 125 bacteria was evaluated against biofilm-forming bacteria. Crude extracts were obtained with methanol and ethyl acetate from 16 bacterial strains that exhibited antagonistic and antibacterial activity in a preliminary screening. Antibacterial and antimicroalgal assays were performed using crude extracts, the minimum inhibitory concentration (MIC) was determined. The highest activity against bacteria and microalgae was found in two strains, Shewanella algae and Staphylococcus sp. The results of this study suggest that extracts of bacteria from the Gulf of California with antimicrobial properties against biofilm-forming bacteria can also prevent the adhesion of microalgae, which may control the development of biofilm formation and, as a consequence, biofouling., Una alternativa para reducir la contaminación en el medio marino es el uso de pinturas anti-incrustantes no tóxicas en áreas marinas protegidas. En el presente estudio se propuso encontrar microorganismos marinos que secreten sustancias capaces de inhibir la adhesión de bacterias y microalgas, de esta manera evitar la bioincrustación en estructuras marinas en la bahía de La Paz, B.C.S., México. Un total de 125 bacterias fueron evaluadas por su capacidad para inhibir el desarrollo de bacterias formadoras de biopelículas. En una selección preliminar de actividad antagónica y antibacteriana, 16 cepas bacterianas mostraron potencial actividad inhibitoria, de las que se obtuvieron los extractos crudos con metanol y acetato de etilo. Se realizaron ensayos antibacterianos y anti-microalgales utilizando los extractos crudos, se determinó la concentración mínima inhibitoria (MIC). Dos cepas mostraron la mayor actividad contra bacterias y microalgas: Shewanella algae y Staphylococcus sp. Los resultados de este estudio sugieren que los extractos de bacterias aisladas en el Golfo de California que poseen propiedades antimicrobianas contra las bacterias formadoras de biofilm y también pueden prevenir la adhesión de microalgas, con lo que se podría controlar el desarrollo de la formación de biopelículas y como consecuencia, el biofouling.

International audience; Nanospinel MgAl2O4 powder was obtained by a sol-gel method at low-temperature processing. It was synthesized using aluminum tri-sec-butoxide and magnesium nitrate hexahydrate as precursors, in an acid medium at 80 A degrees C. Heat treatments of the dried gel were performed from 200 to 1000 A degrees C (a dagger T = 100 A degrees C) and the powders were characterized by SEM, XRD, TG/DTA, FT-IR, and HR-TEM. A mixture of semispherical nanoparticles (< 50 nm) of boehmite and unreacted magnesium nitrate was found after the sol-gel reaction. According to HR-TEM and XRD results, a low-crystalline spinel MgAl2O4 started forming at 300 A degrees C, which is a lower temperature than the reported for the same phase in other works. A mechanism of reaction is proposed to explain the formation of spinel at low temperature. At 800 and 900 A degrees C a spinel mono-phase totally crystalline was observed. At 1000 A degrees C, the spinel MgAl2O4 phase is well defined but a second phase, magnesium oxide, was found to be about 6% of the final composition. The crystal sizes were 2.272 +/- 0.054, 5.222 +/- 0.030, 11.610 +/- 0.064, and 25.140 +/- 0.20 nm for the material heat treated at 700, 800, 900, and 1000 A degrees C, respectively. [GRAPHICS]

International audience; The mechanical response of materials under repeated impact loading is of primary importance to model different types of surface mechanical treatments, such as shot peening. A reverse identification method of stress-strain curves using repeated impact has been developed by Kermouche et al. [Kermouche et al., Mater. Sci. Eng., A 569, 71-77 (2013)] and later improved by Al Baida et al. [Al Baida et al., Mech. Mater. 86, 11-20 (2015)]. This study deals with the experimental validation of this method on three materials: a home-made pure iron, a commercially pure copper, and an industrial aluminum alloy. An approximate method derived from cone indentation theory to check the reverse method reliability. Balls of different sizes have been used to cover a wide enough range of strain. The results are also compared with macroscopic compression and traction tests. The effect of the strain rate on the stress-strain curve is discussed. The conclusion section highlights the rapidity and the ease of use of the reverse identification method.

International audience; 20 activated carbons (ACs) were prepared by activation of four coals of different ranks (bituminous, low-ash bituminous and sub-bituminous coals, and one anthracite) with potassium hydroxide, in order to evaluate their hydrogen storage capacities at -196 degrees C. The effect of surface area and oxygen content on hydrogen storage was examined. Oxygen content was determined by temperature-programmed desorption. The significance of oxygen content on hydrogen storage capacity was evaluated by Analysis of Variance (ANOVA). Apparent surface areas higher than 3000 m(2) g(-1) and hydrogen adsorption as high as 6.8 wt.% were obtained. The best results were obtained with ACs from bituminous coals. No significant effect of oxygen content on hydrogen adsorption was observed. We concluded that surface area controls hydrogen storage capacity at -196 degrees C.

International audience; In order to better understand the fate of the toxic element Ag(I), sorption of Ag(I) was studied from batch experiments, at different pHs (2–8) and at 298K. A pure quartz sand (99.999% SiO2) and “natural” quartz sand (99% SiO2, and traces of Fe, Al, Mn (hydr)oxides, of clays and of pyrite) were used as sorbents. The Ag(I) sorption behavior depends strongly on pH with isotherm shapes characteristic of Langmuir-type relationship for initial Ag concentration [Ag(I)], range between 5.0×10−7 and 1.0×10−3M. Even if the Ag (I) sorption capacity on pure quartz sand is very low compared to the natural quartz sands, its affinity is rather high. From speciation calculations, several sites were proposed: at pHi 4, 6 and 8, the first surface site is assumed to be due to iron (hydr)oxides while the second surface site is attributed to silanols. At pHi 2, sorption of Ag(I) was assumed to be on two surface sites of iron (hydr)oxides and a third surface site on silanol groups. Even if the sand is mainly composed of silica, the trace minerals play an important role in sorption capacity compared to silica. The conditional surface complexation constants of Ag(I) depend on pH. On the other hand, it is shown that the Ag speciation depends strongly on the history of “natural” quartz sand due to initial applied treatment, little rinsing or longer washing. In the presence of low amount of pyrite, strong complexes between Ag(I) and sulfur compounds such as thiosulfates due to oxidative dissolution of pyrite are formed what decreases Ag sorption capability. SEM–EDS analyses highlighted the surface complexation–precipitation of Ag2S and Ag(0) colloids which confirmed the important role of pyrite on Ag(I) speciation.

The G-protein coupled estrogen receptor 1 GPER/GPR30 is a transmembrane seven-helix (7TM) receptor involved in the growth and proliferation of breast cancer. Due to the absence of a crystal structure of GPER/GPR30, in this work, molecular modeling studies have been carried out to build a three-dimensional structure, which was subsequently refined by molecular dynamics (MD) simulations (up to 120 ns). Furthermore, we explored GPER/GPR30’s molecular recognition properties by using reported agonist ligands (G1, estradiol (E2), tamoxifen, and fulvestrant) and the antagonist ligands (G15 and G36) in subsequent docking studies. Our results identified the E2 binding site on GPER/GPR30, as well as other receptor cavities for accepting large volume ligands, through GPER/GPR30 π–π, hydrophobic, and hydrogen bond interactions. Snapshots of the MD trajectory at 14 and 70 ns showed almost identical binding motifs for G1 and G15. It was also observed that C107 interacts with the acetyl oxygen of G1 (at 14 ns) and that at 70 ns the residue E275 interacts with the acetyl group and with the oxygen from the other agonist whereas the isopropyl group of G36 is oriented toward Met141, suggesting that both C107 and E275 could be involved in the protein activation. This contribution suggest that GPER1 has great structural changes which explain its great capacity to accept diverse ligands, and also, the same ligand could be recognized in different binding pose according to GPER structural conformations.

We report the synthesis of micellar phosphatidylcholine-coated superparamagnetic iron oxide nanoparticles as a new long circulation contrast agents for magnetic resonance imaging. Oleic acid-coated Fe3 O4 nanoparticles were first prepared through thermal degradation and then encapsulated into small clusters with a phosphatidylcholine coating to obtain hydrophilic nanomicelles. A thorough characterization confirmed the chemical nature of the coating and the excellent colloidal stability of these nanomicelles in aqueous media. Magnetization and relaxivity properties proved their suitability as magnetic resonance imaging (MRI) contrast agent and in vitro cell viability data showed low toxicity. Vascular lifetime and elimination kinetics in the liver were assessed by blood relaxometry and by in vivo MRI in rats and compared with "control" particles prepared with a polyethylene glycol derivative. These micellar particles had a lifetime in blood of more than 10 h, much longer than the control nanoparticles (≈2 h), which is remarkable considering that the coating molecule is a small biocompatible zwitterionic phospholipid. The protein corona was characterized after incubation with rat serum at different times by high-throughput proteomics, showing a higher proportion of bound apolipoproteins and other dysopsonins for the phosphatidylcholine particles. The antibiofouling properties of this corona and its resistance to the adsorption of proteins corroborate the observed enhanced stability and prolonged systemic circulation. This study is supported by a grant from FP7 Marie Curie, Pulmonary imaging network (PINET), by Fundacio La Maratode TV3 (70/C/2012) and by a grant from the Comunidad de Madrid (S2010/BMD-2326, Inmunothercan-CM) and by Spanish Economy Ministry (MAT2013-47303-P). We thank E. Urones (Centro Nacional de Microscopia de la Universidad Complutense de Madrid) for the transmission electronic microscopy imaging; P. Morales (Instituto de Ciencia de Materiales de la Universidad Autonoma de Madrid) for the thermogravimetric and magnetization analysis and B. Salinas (Fundacion Centro Nacional de Investigaciones Cardiovasculares and CIBER de Enfermedades Respiratorias) for the TEM picture of oleic acid coated Fe3 O4. The authors declare no competing financial interests. Sí

International audience; Several studies have shown that the reserve disaccharide trehalose also protects yeast cells under environmental stress. Besides, it is acknowledged that trehalose improves yeast viability so its synthesis has become paramount in baker’s yeast industry, as well as in wine and beer production. In this work, starving carbon or nitrogen conditions were imposed to Saccharomyces cerevisiae growing in fed-batch cultivations in order to induce biosynthesis and accumulation of trehalose. Our experimental results show that yeast can accumulate trehalose up to 13% of biomass dry weight (0.13 gtrehalose g^−1biomass) under carbon or nitrogen starvation. A compartmentalized and biochemically structured model is proposed in order to mathematically describe these experimental findings. The model predictions were compared with literature results obtained under growth conditions different from those established in our experiments, resulting in a very good agreement and thus indicating that the proposed hypotheses are essentially correct.

The nitrate ion reduction was studied on boron-doped diamond (BDD) electrodes by real-time on-line differential electrochemical mass spectrometry (DEMS) coupled with chronoamperometry in K + , Na + cation-containing electrolyte solutions. It was found, via steady state voltammetry, that the hydrogen evolution reaction (HER) was affected by the presence of K + or Na + . A moderate HER occurs in K + -containing electrolyte solution favoring the reaction between NO 3 − and H 2 species, whereas in Na + -containing electrolyte solutions, the HER kinetics was more important leading to a suppression of molecular nitrogen generation. The use of isotope-labeled nitrogen and DEMS confirmed the influence of alkali cations toward the nitrate ion reduction.

International audience; Erbium and ytterbium doped barium titanate nanopowders were prepared using the hydrothermal method. A barium titanate structure doped with rare earth ions manifested new characteristics and improved the field of application of optical devices such as trichromatic tubes, LCD displays, lamps, and infrared lasers. In this work, BaTiO3:Er3+ and BaTiO3:Yb3+ were prepared using barium chloride [BaCl2], titanium butoxide [C16H36O4Ti], erbium chloride [ErCl3] and ytterbium chloride [YbCl3] as precursors. Anhydrous methanol was employed as a solvent. Metallic potassium was used to promote solubility in the system and increase the pH to 13. This method yielded the formation of a predominantly cubic structure in both Er3+ and Yb3+ doped BaTiO3 powders. Characteristic bondings of BaTiO3 were observed with FT-IR spectroscopy. The predominantly cubic structure was confirmed by X-ray diffraction and micro-Raman analyses. The particle size (∼30 nm) was estimated using the Scherrer equation and X-ray diffraction data. The results were presented and discussed.

Article related to the one available at http://dx.doi.org/10.1016/j.jct.2009.06.014; International audience; Although reliable and consistent volumetric data can be derived from density measurements, the greatest experimental difficulty and largest measurement errors often occur in the very dilute regions of concentration. Such data are of great interest in separation processes where a high degree of purity is required. In this communication, the densities of the (tetrahydrofuran + water) systems have been carefully investigated in dilute regions. A vibrating tube densimeter has been used to perform the measurements. A discussion is made on the reliability of the generated experimental data and the questions raised in the literature.

A number of cecropin-A-melittin hybrid peptides have previously been shown to be potent antibacterial agents [Andreu, D., Ubach, J., Boman, A., Wahlin, B., Wade, D., Merrifield, R. B. & Boman, H. G. (1992) FEBS Lett. 296, 190-1941. In the present report we analyze their action on biological systems using rat liver mitochondria as a test system. We demonstrate that the longest peptide, cecropin-A-( 1 - 8) -melittin(l - 18) permeabilizes the mitochondrial inner membrane allowing the movement of both charged and non-charged solutes. Concentrations used have already been shown to be bactericidal. This effect is also demonstrated under respiring conditions where succinate oxidation is uncoupled. Shorter analogs also permeabilize mitochondria although at ten-fold higher concentrations. Heparin potentiates the peptide effects at low concentrations, while at high concentration it becomes inhibitory. We propose that the cecropin-melittin analogs disrupt the mitochondrial membrane in a detergent-like mode rather than by creating selective channels as had been previously suggested.

International audience; The employment of an acid natural clinoptilolite (AZH-1) in the adsorption and separation of n-paraffins has been evaluated. Natural clinoptilolite, NZ, was the raw material used to prepare the sodiumexchanged clinoptilolite (AZ) starting from which the AZH-1 sample was obtained by acid treatment. The structural stability of the samples after the applied treatments was demonstrated. The nitrogen adsorption experiments indicated that the acid sample has a homogeneous porous distribution and a considerable increase in the micropore volume with respect to NZ and AZ. The employment of the inverse gas chromatography at infinite dilution (IGCID) allowed studying the adsorption and separation of n-paraffin mixtures on AZH-1. It was also confirmed that the diffusion on AZH-1 took place in an unblocked structure through the A channel of ten members with minimal interactions. The IGCID results demonstrated the capacities of the acid Cuban natural zeolite in the adsorption and separation of n-paraffin mixtures.

International audience; The ability of crude olive stones, a residue of the olive-oil industry, for the adsorption of iron presentin the industrial wastewaters was studied. Olive stones were used directly and characterized by mer-curic porosimetry. The equilibrium adsorption capacity was higher when the particles size (from

We have adopted the PC12 cell line as in vitro cell model for studying Dp71 function in neuronal cells. These cells express a cytoplasmic (Dp71f) and a nuclear (Dp71d) isoform of Dp71 as well as various dystrophin-associated proteins (DAPs). In this study, we revealed by confocal microscopy analysis and Western blotting evaluation of cell fractions the presence of different DAPs (beta-dystroglycan, beta-dystrobrevin, epsilon-sarcoglycan and gamma1-syntrophin) in the nucleus of PC12 cells. Furthermore, we established by immunoprecipitation assays that Dp71d and the DAPs form a dystrophin-associated protein complex (DAPC) in the nucleus. Interestingly, depletion of Dp71 by antisense treatment (antisense-Dp71 cells) provoked a drastic reduction of nuclear DAPs, which indicates that Dp71d is critical for DAPs stability within the nucleus. Although Up71, the utrophin gene product homologous to Dp71, exhibited increased expression in the antisense-Dp71 cells, its scarce nuclear levels makes unlikely that could compensate for Dp71 nuclear deficiency.

International audience; Fe-ZSM-5 catalysts were prepared by FeCl3 sublimation (CVD method) and impregnation in aqueous media. To describe the morphology of the iron species, the materials were characterized by XRD, SAXS, and 27Al and 129Xe NMR spectroscopy. In the catalysts prepared by impregnation, XRD detected large hematite particles at the external surface of the zeolite. In contrast, the Fe2O3 phase was not detectable by XRD in the materials prepared by CVD, indicating much smaller species. The 129Xe NMR results show that, in the CVD-prepared materials, the amount of free space inside the zeolite cavities was decreased appreciably by the presence of the Fe oxo species. Furthermore, 129Xe NMR spectroscopy reveals a sharp peak for the CVD-prepared material with Fe (3.8 wt %), indicating that this catalyst exhibits strong adsorption sites that are not detectable in the sample of similar Fe content that was prepared by impregnation. Morphology appears to be strongly affected by the method of preparation of the catalyst. The fractal dimension of the metal phase was associated with the catalytic activity in the selective catalytic reduction (SCR) of NO using ammonia and n-decane as reducing agents.

The gene encoding the repetitive domain located in the N-terminal half of [gamma]-Gliadin from wheat endosperm has been subcloned into a thioredoxin expression system (pET102/D-Topo). It was over-expressed as fusion protein with thioredoxin in Escherichia coli. Thioredoxin was removed by enterokinase cleavage or by acid cleavage at the respective engineered recognition sites. The soluble N-terminal half of [gamma]-Gliadin was purified by affinity and reverse-phase chromatography. While, the enterokinase cleavage leaded to only one species detectable by mass spectroscopy, the acid cleavage resulted in a three different length polypetides, due to the presence of the same number of acid cleavage sites. The secondary structure of the purified protein domain was analysed by circular dichroism, showing an spectral shape common to a Poly(Pro) II conformation. The spectrum is dominated by a large negative peak centred around 201 nm and a broad shoulder centred around 225 nm. Also, the temperature denaturation process was studied. The differences observed in the spectra show two main tendencies, the increment of the shoulder intensity, and the drop of the intensity of the peak around 201. When the sample was cooled down, the change on intensity of the shoulder around 225 was completely reversible and that around the 201 nm peak reached a reversibility of 90%. Such structure and thermal behaviour are characteristic of the repetitive domains of the wheat prolamins.

J. Fernandez (University of Santiago de Compostela, Spain), . Gmehling (University of Oldenburg, Germany), H. Inomata Tohoku University, Japan), J.N. Jaubert (INPL, France), T.W. de oos (Delft University, The Netherlands), J.P. O’Connell (Univerity of Virginia, USA), C. Peters (Delft University, The Netherlands), . Ramjugernath (KwaZulu Natal University, South Africa), F. del io (Universidad Autonoma Metropolitana, Mexico), G. Scalabrin Padova University, Italy), K. Tochigi (Nihon University, Japan)