Mediating gel formation from structurally controlled poly(electrolytes) through multiple "head-to-body" electrostatic interactions

Tuning the chain-end functionality of a short-chain cationic homopolymer, owing to the nature of the initiator used in the ATRP polymerisation step, can be used to mediate the formation of a gel of this poly(electrolyte) in water. While a neutral end group gives a solution of low viscosity, a highly homogeneous gel is obtained with a phosphonate anionic moiety, as characterized by rheometry and diffusion NMR. This novel type of supramolecular control over poly(electrolytic) gel formation could find potential use in a variety of applications in the field of electroactive materials

Hydrogen Production by Catalytic Supercritical Water Gasification of Black Liquor-Based Wastewater

In this work, the wastewater obtained from the hydrothermal liquefaction of black liquor was treated and valorized for hydrogen production by supercritical water gasification (SCWG). The influence of the main process parameters on the conversion yield was studied. The experiments were conducted at three different temperatures (below and above the critical point of water): 350 °C, 450 °C and 600 °C. The results showed that by increasing the temperature from 350 °C to 600 °C, the total gas yield was highly improved (from 1.9 mol gas/kg of dried feedstock to 13.1 mol gas/kg of dried feedstock). The H2 composition was higher than that of CH4 and CO2 at 600 °C, and the HHV of the obtained gas was 61.2 MJ/kg. The total organic carbon (TOC) removal efficiency was also improved by increasing the temperature, indicating that the SCWG process could be used for both applications: (i) for wastewater treatment; (ii) for producing a high calorific gas. The experiments with the Raney-nickel catalyst were performed in order to study the catalyst’s influence on the conversion yield. The results indicated that the catalyst enhances carbon conversion and gas production from mild to higher temperatures. The maximum total gas yield obtained with this catalyst was 32.4 mol gas/kg of dried feedstock at 600 °C, which is 2.5 times higher than that obtained at the same operating conditions without a catalyst. The H2 yield and the HHV of the obtained gas with the catalyst were 20.98 mol gas/kg dried feedstock and 80.2 MJ/kg, respectively. However, the major contribution of the catalytic SCWG process was the improvement of the total gas yield at mild operating temperatures (450 °C), and the obtained performance was even higher than that obtained at 600 °C without catalyst (17.81 mol gas/kg dried feedstock and 13.1 mol gas/kg dried feedstock, respectively). This is a sustainable approach for treating wastewater at mild temperatures by catalytic SCWG

Post-exercise heart rate recovery and parasympathetic reactivation are comparable between prepubertal boys and well-trained adult male endurance athletes

Purpose: This study tested the hypothesis that prepubertal boys, but not untrained men, would exhibit a similar post-exercise parasympathetic reactivation as well-trained adult male endurance athletes. Methods: Twelve prepubertal boys (12.3 ± 1.6 years), 14 untrained men (21.8 ± 2.2 years) and 16 well-trained adult male endurance athletes (24.5 ± 4.8 years) completed an incremental maximal run field test on a track. Immediately after exercise completion, heart rate recovery (HRR) was assessed in the supine position for 5 min. Heart rate variability was analyzed in the time domain, and log-transformed values of the root mean square of successive differences in heart beats (Ln RMSSD30) were calculated over consecutive 30 s windows. Results: Prepubertal children and well-trained adult endurance athletes showed significantly faster HRR than untrained adults from 30 s post-exercise until the end of recovery (p \u3c 0.05). Ln RMSSD30 was significantly higher in prepubertal children and athletes than untrained adults over the post-exercise time interval 60–150 s (p \u3c 0.05). No significant differences were observed for HRR and Ln RMSSD30 between prepubertal children and athletes. Conclusion: Prepubertal children and well-trained adult endurance athletes exhibited comparable and faster HRR and parasympathetic reactivation than untrained adults following maximal exercise. This indirectly suggests that oxidative profile may be preserved by exercise training during growth and maturation to offset the decline in post-exercise HRR, parasympathetic reactivation and aspects of metabolic health

Synthesis and Characterization of a Series of Ruthenium Tris(β-diketonato) Complexes by an UHV-STM Investigation and Numerical Calculations

International audienceA series of ruthenium tris(beta-diketonate), was investigated using electrochemistry, UV-Vis spectroscopy, 1H and 13C NMR and FAB mass spectroscopy. Several new mononuclear mixed-ligand ruthenium(III) complexes including - dibenzoylmethanate ion (dbm); [Ru(dbm)3] 1 - one or two acetylacetonate ion (2,4-pentanedionate, acac-); [Ru(dbm)2(acac)] 2, [Ru(dbm)(acac)2] 3 - acetonitrile ligand; [Ru(dbm)2(CH3CN)2][CF3SO3] 4 - or functionalized acetylacetonate ion; [Ru(dbm)2(acac-I)] 5 (acac-I = 3-iodo-2,4-pentanedionate ion), [Ru(dbm)2(acac-Br)] 6 (acac-Br = 3-bromo-2,4-pentanedionate ion) were prepared. In addition, X-Ray structures for complexes 1, 2, 3, 4 and 6 were determined. Scanning tunneling microscopy measurement at liquid He temperature and in ultra high vacuum (UHV-STM) of complex 1 on Ag(111) surface was conducted. This indicates that the complex can be successfully evaporated and observed after adsorption on a metallic substrate. Analysis of the STM images, supported by adsorption and STM image calculations demonstrates that the molecules exist in two stable forms when adsorbed on the surface

UHV-STM Investigations and Numerical Calculations of a Ruthenium β-Diketonato Complex with Protected Ethynyl Ligand: [Ru(dbm) 2 (acac-TIPSA)]

International audienceThe quest of molecular electronic devices necessitates addressing model molecular systems as starting points. Among the targeted functions, electron transfer between specific moieties inside a molecule is expected to play a fundamental role for ultimate logical gates. Here we propose a coordination complex exhibiting two inorganic centers (Ru and Si) that constitutes a step towards a more complex architecture. Starting from the complex 1 [Ru(dbm)2(acac-I)] (dbm = dibenzoylmethanate ion, acac-I = 3-iodo-2,4-pentanedionate ion), the complex 2 [Ru(dbm)2(acac-TIPSA)] (acac-TIPSA=3-(triisopropylsilyl)acetylene-2,4-pentanedionate ion) was obtained through Sonogashira cross coupling reaction under classical conditions. This complex 2 was characterized by elemental analysis, IR, 1H NMR, 13C NMR, UV-Vis, cyclic voltammetry, mass spectroscopy as well as X-ray single crystal diffraction. It crystallized with empirical formula of C46H49O6Ru1Si1 in a monoclinic crystal system and space group P21/c with a = 21.077(3) Å, b = 9.5130(7) Å, c = 21.8790(12) Å, beta = 94.125(7)°, V = 4375.5(7) Å3 and Z = 4. Additionally, scanning tunneling microscopy measurements at liquid He temperature and in an ultra-high vacuum (UHV-STM) were conducted on complex 2 on a Ag(111) surface. The STM images, supported by adsorption and STM image calculations, demonstrate that the molecules exist in two stable forms when adsorbed on the metallic surface

Food chemicals disrupt human gut microbiota activity and impact intestinal homeostasis as revealed by in vitro systems

Growing evidence indicates that the human gut microbiota interacts with xenobiotics, including persistent organic pollutants and foodborne chemicals. The toxicological relevance of the gut microbiota-pollutant interplay is of great concern since chemicals may disrupt gut microbiota functions, with a potential impairment of host homeostasis. Herein we report within batch fermentation systems the impact of food contaminants (polycyclic aromatic hydrocarbons, polychlorobiphenyls, brominated flame retardants, dioxins, pesticides and heterocyclic amines) on the human gut microbiota by metatranscriptome and volatolome i.e. "volatile organic compounds" analyses. Inflammatory host cell response caused by microbial metabolites following the pollutants-gut microbiota interaction, was evaluated on intestinal epithelial TC7 cells. Changes in the volatolome pattern analyzed via solid-phase microextraction coupled to gas chromatography-mass spectrometry mainly resulted in an imbalance in sulfur, phenolic and ester compounds. An increase in microbial gene expression related to lipid metabolism processes as well as the plasma membrane, periplasmic space, protein kinase activity and receptor activity was observed following dioxin, brominated flame retardant and heterocyclic amine exposure. Conversely, all food contaminants tested induced a decreased in microbial transcript levels related to ribosome, translation and nucleic acid binding. Finally, we demonstrated that gut microbiota metabolites resulting from pollutant disturbances may promote the establishment of a pro-inflammatory state in the gut, as stated with the release of cytokine IL-8 by intestinal epithelial cells

Dual photochemical bond cleavage for a diarylethene-based phototrigger containing both methanolic and acetic sources

International audienceIn this paper, we present a novel concept for "smarter" photolabile organic compounds combining not one but two caged functions. As proof of principle, this diarylethene-based compound possesses two inhibited chemical groups (OMe and OAc) and its efficient release in different solvents is reported. In low- to medium-polarity media, both MeOH and AcOH are released, with a slight preferential uncaging of AcOH except in 1,4-dioxane, where MeOH is preferentially released. In contrast, DMSO or DMF render AcOH release strongly dominating. DFT calculations of the corresponding photoreactive conformations not only afford strong support to the observed release of MeOH and AcOH but also qualitatively explain the preferential release of acid in terms of dispersive noncovalent interactions. Finally, mechanistic aspects are discussed on the bases of the spectroscopic observations and of the TD-DFT calculations

Do different protein intakes influence body composition and muscle function in obese rats ?

T1: Basic and Experimental SciencePoster Session May 18, 2017IntroductionDuring obesity, impairments in oxidative capacities, lipid infiltration and insulin resistance within skeletal muscle may act in concert to lead to loss of muscle mass and function. Considering the role of dietary proteins in preserving mass and improving muscle function, the aim of the study was to determine the potential preventive effects of increased protein intake on changes in metabolism and function muscle induced by obesity.MethodsMale Wistar rats, aged 9 months, were randomized in 4 groups (n=15) and were fed during 10 weeks either with a standard diet (STD) with normal lipid intake (13.8% of total energy intake (TEI)), or with a high fat diet (HFD) (45% of TEI). For each diet, two levels of protein intakes were tested: 12% of TEI (STD12 and HFD12) and 25% of TEI (STD25 and HFD25). For each animal, body weights and food consumption were quantified weekly. Measurements of body composition and muscle function ality were performed. The data are presented as mean ± standard error and analyzed by two-way ANOVA (diet and protein intake) and a Duncan´s Multiple-Comparison Post-hoc Test. ResultsTotal calories intakes were not different between the groups. The increases in weight and fat mass were significantly greater in the HFD12 group (respectively: +176.2±13.9g and +121.5±7.8g) than in STD groups (STD12: +95.3±20.2g and +62.5±4.3g; STD25: +65.6±15.3g and +53.4±3.6g, P<0.05 vs HFD12. These increases were less important in the HFD25 group (+133.9± 17.2g and +98.2± 6.0g, P=NS vs HFD12). The weights of skeletal muscles taken during sacrifices were not different between groups. At the end of the 10 weeks diet, muscle strength and power values were decreased in all groups. However, the decrease of muscle strength and power tended to be higher in HFD12 group (-0.97± 0.33N and -0.23± 0.07W) than in STD groups (STD12:-0.39± 0.32N and -0.07± 0.10W; STD25: -0.35± 0.31N and -0.07± 0.01W). These variations observed in HFD12 group were more attenuated in HFD25 group (-0.51± 0.18N and -0.17± 0.06W).Conclusion. Differences in the macronutrient composition of diets influence the evolution of body weight and composition more than calorie intake. Moreover, protein enrichment in the diet during lipid overnutrition could attenuate the deleterious consequences of obesity on muscle functio

Dependence of Crystallite Formation and Preferential Backbone Orientations on the Side Chain Pattern in PBDTTPD Polymers

Alkyl substituents appended to the π-conjugated main chain account for the solution-processability and film-forming properties of most π-conjugated polymers for organic electronic device applications, including field-effect transistors (FETs) and bulk-heterojunction (BHJ) solar cells. Beyond film-forming properties, recent work has emphasized the determining role that side-chain substituents play on polymer self-assembly and thin-film nanostructural order, and, in turn, on device performance. However, the factors that determine polymer crystallite orientation in thin-films, implying preferential backbone orientation relative to the device substrate, are a matter of some debate, and these structural changes remain difficult to anticipate. In this report, we show how systematic changes in the side-chain pattern of poly­(benzo­[1,2-<i>b</i>:4,5-<i>b</i>′]­dithiophene–<i>alt</i>–thieno­[3,4-<i>c</i>]­pyrrole-4,6-dione) (PBDTTPD) polymers can (i) influence the propensity of the polymer to order in the π-stacking direction, and (ii) direct the preferential orientation of the polymer crystallites in thin films (e.g., “face-on” vs “edge-on”). Oriented crystallites, specifically crystallites that are well-ordered in the π-stacking direction, are believed to be a key contributor to improved thin-film device performance in both FETs and BHJ solar cells

UHV-STM Investigations and Numerical Calculations of a Ruthenium β-Diketonato Complex with Protected Ethynyl Ligand: [Ru(dbm)₂(acac-TIPSA)]

The quest of molecular electronic devices necessitates addressing model molecular systems as starting points. Among the targeted functions, electron transfer between specific moieties inside a molecule is expected to play a fundamental role for ultimate logical gates. Here we propose a coordination complex exhibiting two inorganic centers (Ru and Si) that constitutes a step toward a more complex architecture. Starting from the complex <b>1</b> [Ru­(dbm)₂(acac-I)] (dbm = dibenzoylmethanate ion, acac-<i>I</i> = 3-iodo-2,4-pentanedionate ion), the complex <b>2</b> [Ru­(dbm)₂(acac-TIPSA)] (acac-TIPSA = 3-(triisopropylsilyl)­acetylene-2,4-pentanedionate ion) was obtained through Sonogashira cross coupling reaction under classical conditions. This complex <b>2</b> was characterized by elemental analysis, IR, ¹H NMR, ¹³C NMR, UV–vis, cyclic voltammetry, mass spectroscopy as well as X-ray single-crystal diffraction. It crystallized with empirical formula of C₄₆H₄₉O₆Ru₁Si₁ in a monoclinic crystal system and space group <i>P</i>2₁/<i>c</i> with <i>a</i> = 21.077(3) Å, <i>b</i> = 9.5130(7) Å, <i>c</i> = 21.8790(12) Å, β = 94.125(7)°, <i>V</i> = 4375.5(7) ų and <i>Z</i> = 4. Additionally, scanning tunneling microscopy measurements at liquid He temperature and in an ultrahigh vacuum (UHV-STM) were conducted on complex <b>2</b> on a Ag(111) surface. The STM images, supported by adsorption and STM image calculations, demonstrate that the molecules exist in two stable forms when adsorbed on the metallic surface