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The CO2 methanation catalyzed by supported metals has been widely investigated. In spite of its apparent simplicity, there are still open questions regarding its mechanism, with apparently contradictory proposals that rely mainly on infrared (IR) spectra of functioning catalysts. Here we review the various mechanistic proposals for the reaction. Special focus is made on the following questions: (a) what is the actual physical evidence of adsorbed species present on the catalysts?, (b) how can reaction intermediates be distinguished from spectators?, (c) what is the identity of the active site(s) for the reaction, and (d) could multiple reaction routes occur simultaneously on the catalysts? Kinetic models of the reaction and a survey of the apparent contradictions in the interpretation of IR spectra characterizing functioning catalysts are also presented.

7 Figuras, 2 Tablas, Mesoporous carbons containing up to 3.6 at.% N and 4.4 at.% O and exhibiting graphitic character have been prepared from Ni(II) and Fe(II) phthalocyanines by direct pyrolysis or by HTC + pyrolysis, and subsequently applied as supercapacitor materials. No mesoporous templates or doping post-treatments were used, and the catalytic effect of Ni(II) and Fe(II), naturally present in the precursor molecules, allowed obtaining graphitic carbons at temperatures ≤ 900 °C. Metals were encapsulated in the core of onion–like structures with no contact with the electrolyte, so that electrodes were prevented from degradation during device operation. The materials exhibited high rate capabilities up to 1 V s−1, higher interfacial capacitances than a wide variety of materials possessing higher surface areas, and high capacitance retentions up to 99% at 5 A g−1 current density throughout 10 000 charge–discharge cycles. The electrochemical performances of the phthalocyanine-derived carbons are due to their graphitic character and to the pseudocapacitance contribution of the surface groups through Faradaic reactions. This work opens a new way to obtain carbon materials from a great family of metal phthalocyanines, since the central metal and the radicals of the latter can be varied to tune the carbon properties for specific applications., The IJL research team gratefully acknowledges the Dr. Marta Sevilla’s departement for its scientific support, and the financial support of the CPER 2007-2013 “Structuration du Pôle de Compétitivité Fibres Grand’Est” (Competitiveness Fibre Cluster), through local (Conseil Général des Vosges), regional (Région Lorraine), national (DRRT and FNADT) and European (FEDER) funds. Dr. A. Sanchez-Sanchez acknowledges the CNRS for financing her post-Doctoral contract.

5-Hydroxymethylfurfural (HMF) is a biobased platform chemical that can be valorized into a spectrum of valuable products. In this report, supported Ir, Ir–Co, Ir–Ni, and Ir–Ru catalysts were investigated for this purpose. Only hydrogenation of HMF to 2,5-bis-(hydroxymethyl)furan (BHMF) occurred over all catalysts. The effect of the second metal (Co, Ni, and Ru) on Ir/SiO2 was reflected by the kinetic constants being in the order Ir–Ni/SiO2 > Ir–Co/SiO2 > Ir–Ru/SiO2. The oxophilic nature of the secondary metal improved the catalytic performance of the bimetallic catalysts compared to the monometallic iridium catalyst (Ir/SiO2). Addition of HCOOH and H2SO4 as cocatalysts is a strategy to reach one-pot conversion of HMF to 2,5-di-methylfuran (DMF). Over-hydrogenolysis products such as 2,5-dimethyltetrahydrofuran were formed when only H2SO4 was added, giving higher activity compared to addition of HCOOH. Simultaneous presence of acids gave the highest HMF conversion, promoting esterification to 5-formyloxymethyl furfural and allowing the one-pot transformation of HMF to DMF. Thermodynamic analysis of HMF transformations revealed that both hydrogenation and dehydration steps are feasible.

The binding of C-4-halogenated 1-(4-X-2,5-dimethoxyphenyl)-2-aminopropane (DOX) serotonin agonist psychedelics at all three 5-HT2 receptor subtypes is up to two orders of magnitude stronger for X = Cl, Br, or I (but not F) than when C-4 bears a hydrogen atom and more than expected from their hydrophobicities. Our docking and molecular dynamics simulations agree with the fact that increasing the polarizability of halogens results in halogen-oxygen distances to specific backbone C═O groups, and C-X···O angles, in ranges expected for halogen bonds (XBs), which could contribute to the high affinities observed. Good linear correlations are found for each receptor type, indicating that the binding pocket-ligand affinity is enhanced as the XB interaction becomes stronger (i.e., I ≈ Br > Cl > F). It is also striking to note how the linear equations unveil that the receptor's response on the strength of the XB interaction is quite similar among 5-HT2A and 5-HT2C, whereas the 5-HT2B's sensitivity is less. The calculated dipole polarizabilities in the binding pocket of the receptors reflect the experimental affinity values, indicating that less-polarizable and harder binding sites are more prone to XB formation.

Membrane processes, whose low energy and operating costs make them competitive for gas separation compared to other conventional methods such as pressure swing adsorption, cryogenic distillation or amine absorption, allows high-purity gas to be obtained in a sustainable and continuous manner. Similarly, resin-derived carbon membranes with molecular sieving properties have improved the selectivity and permeability of conventional dense membranes, as well as having high chemical and thermal resistance. In this review, an overview of the preparation of phenolic resin-based carbon membranes and their performance in gas separation is presented, particularly in processes involving permanent gases such as hydrogen purification, air separation, natural gas/biogas sweetening or carbon dioxide capture. Moreover, bioresources already proven for the synthesis of “greener” phenolic resins and the separation performance of some carbon membranes based on bioresource-derived phenolic resins are also reported and discussed in this work. This review will summarise the development and gas separation performance of phenolic resin-based carbon membranes and will provide a clear future direction in “green” carbon membranes research.

Unlike conventional subtractive methods, 3D printing allows rapid prototyping and customization on demand. However, as a process recently applied to carbon-based materials, 3D printing faces many challenges, including the precise tailoring of the printed material and the control of its porosity, as well as obtaining directly printed (pure) carbon. The present review focuses on the latest advances in carbonaceous materials in 3D printing to address these challenges. A brief introduction to additive manufacturing processes is given, followed by a summary and many recent examples of manufacturing processes, structural characteristics, and applications of various carbon-based composites and carbonaceous materials. Finally, viewpoints and prospects for this emerging field are presented.

The ideal construction and tissue substitute with adjusted characteristics and functionalities for the regeneration of bone defects are still under investigation. Current approaches have focused on the use of various biocompatible materials that have been synthesized with carbon-based materials with physicochemical characteristics that contribute to the differentiation of specific stem cell lineages. This work reports on the potential of poly-e-caprolactone (PCL) membranes loaded with β-glycerol phosphate (β-GP) functionalized multiwall carbon nanotubes (f-MWCNTs) to induce differentiation of human dental pulp stem cells (HDPSCs) into osteoblasts. The HDPSCs were seeded on unmodified PCL + f-MWCNTs and β-GP decorated PCL + f-MWCNTs membranes, and then, physicochemical, mechanically and biologically characterized. It was observed an increase in the mechanical properties of PCL by MWCNTs addition rendering a more hydrophilic membrane those containing β-GP. Live/Dead and MTT cytotoxicity tests showed a higher number of living cells in PCL + f-MWCNTs + β-GP membranes, whereas von Kossa showed calcium deposits. After Wistar rat implantation, new bone formation was found around the critical size calvaria defects indicating that these membranes have the ability to enhance the osteodifferentiation of HDPSCs by increasing mineralization.

Senescent cells (SNCs) degenerate the fibrous cap that normally prevents atherogenic plaque rupture, a leading cause of myocardial infarction and stroke. Here we explore the underlying mechanism using pharmacological or transgenic approaches to clear SNCs in the Ldlr–/– mouse model of atherosclerosis. SNC clearance reinforced fully deteriorated fibrous caps in highly advanced lesions, as evidenced by restored vascular smooth muscle cell (VSMC) numbers, elastin content and overall cap thickness. We found that SNCs inhibit VSMC promigratory phenotype switching in the first interfiber space of the arterial wall directly beneath the atherosclerotic plaque, thereby limiting lesion entry of medial VSMCs for fibrous cap assembly or reinforcement. SNCs do so by antagonizing insulin-like growth factor (IGF)-1 through the secretion of IGF-binding protein-3. These data indicate that the intermittent use of senolytic agents or IGF-binding protein-3 inhibition in combination with lipid-lowering drugs may provide therapeutic benefit in atherosclerosis. In a mouse model of atherosclerosis, Childs and colleagues show that senescent cells inhibit the promigratory phenotype switching of vascular smooth muscle cells by secreting IGFBP3 and that senolysis promotes the repair of fibrous caps in advanced lesions.

Over the past few years, cellulose nanocrystals (CNCs), also known as nanocrystalline cellulose (NCCs), have received significant attention owing to their diverse spectrum of applications. CNCs are...

Introduction: Giomers are composed of PRG fillers which in turn contain some ions, in addition to fluoride, which are beneficial to enamel so, it could be used for remineralization. Glass ionomer also contains fluoride and has been a commonly used material for many years. Objective: to analyze information about its chemical composition, physical properties, chemical properties and application of S-PRG technology in comparison with glass ionomer. Methodology: articles were searched in PubMed, Science Direct, Springer and EBSCO. Terms such as S-PRG OR GIOMER, S-PRG AND prevention, glass ionomer AND pediatric dentistry were used. Results: S-PRG has a pre-reactive glass ionomer layer containing reactive ions that acts in contact with water and saliva, thus releasing ions that promote remineralization, bacterial control, etc. It has lower setting shrinkage compared to some ionomers and allows remineralization around the restoration and can be used as a restorative material for primary and permanent teeth. Glass ionomer has an acid-base reaction. By bonding glass ionomer filler to resins, it improves their properties, is successful in the presence of secondary caries and is well accepted as a restorative material after selective removal of carious tissue. Conclusion: Both materials have fluoride releasing and recharging capabilities as well as restorative properties. However, giomer has better esthetic advantages. Further studies are required because giomers are relatively new.

To eat or not to eat Melanocortin receptor 4 (MC4R) plays a role in regulating food intake: Its activation by a stimulating hormone inhibits appetite, whereas binding to a natural antagonist promotes appetite. Complementing a recent structure of MC4R in an inactive conformation, Israeli et al. present the structure bound to setmelanotide, a weight-control drug, and its G protein–signaling partner (see the Perspective by Farooqi). This work reveals the mechanism of MC4R activation and explains why setmelanotide acts as a potent agonist, whereas a structurally similar compound, SHU9119, is an inhibitor. The structure also provides insight into the contribution of mutations in MCR4 to weight-regulation disorders. Science , abf7958, this issue p. 808 ; see also abi8942, p. 792

The present work examined the oxidation and crosslinking of the anti-bacterial enzyme lysozyme (Lyso), which is present in multiple biological fluids, and released from the cytoplasmic granules of macrophages and neutrophils at sites of infection and inflammation. It is therefore widely exposed to oxidants including peroxyl radicals (ROO•). We hypothesized that exposure to ROO• would generate specific modifications and inter- and intra-protein crosslinks via radical-radical reactions. Lyso was incubated with AAPH (2,2′-azobis(2-methylpropionamidine) dihydrochloride) as a ROO• source. Enzymatic activity was assessed, while oxidative modifications were detected and quantified using electrophoresis and liquid chromatography (UPLC) with fluorescence or mass detection (MS). Computational models of AAPH-Lyso interactions were developed. Exposure of Lyso to AAPH (10 and 100 mM for 3 h, and 20 mM for 1 h), at 37 °C, decreased enzymatic activity. 20 mM AAPH showed the highest efficiency of Lyso inactivation (1.78 mol of Lyso inactivated per ROO•). Conversion of Met to its sulfoxide, and to a lesser extent, Tyr oxidation to 3,4-dihydroxyphenylalanine and diTyr, were detected by UPLC-MS. Extensive transformation of Trp, involving short chain reactions, to kynurenine, oxindole, hydroxytryptophan, hydroperoxides or di-alcohols, and N-formyl-kynurenine was detected, with Trp62, Trp63 and Trp108 the most affected residues. Interactions of AAPH inside the negatively-charged catalytic pocket of Lyso, with Trp108, Asp52, and Glu35, suggest that Trp108 oxidation mediates, at least partly, Lyso inactivation. Crosslinks between Tyr20-Tyr23 (intra-molecular), and Trp62-Tyr23 (inter-molecular), were detected with both proximity (Tyr20-Tyr23), and chain flexibility (Trp62) appearing to favor the formation of covalent crosslinks.

A serie of supported bimetallic MoRe carbides were prepared with different Mo/Re molar ratio by using a mixture H2+ C2H4 at 700 °C and compared to the respective monometallic carbides in the guaiacol conversion at 350 °C, 5.0 MPa. Catalysts were characterized by N2-physisorption, CO-chemisorption, temperature programmed reduction/desorption of NH3 (TPR and TPD-NH3 respectively) and XPS. The results have shown an enrichment of Re at the surface occur suggesting that Re carbide recovered Mo carbide particles and, thus improving Re dispersion. This was traduced by an enhancement of the initial rate of conversion of the bimetallic catalyst. A synergistic effect between Mo and Re carbide was reported from XPS results and led to the activation of the demethylation of guaiacol to catechol.

Two micro-mesoporous carbons (MMCs): a disordered mesoporous carbon (DMC) and an ordered mesoporous carbon (OMC), synthesized by an easy, low-cost, and green method are proposed as efficient hydrocarbon sieves for the separation of C6 isomers: n-hexane (nHEX), 2-methylpenthane (2 MP) and 2,2-dimethylbutane (22DMB). Their textural characterization reveals a highly interconnected pore network within the DMC, while a reverse hierarchy of ordered mesopores only accessible through narrow micropores is found in the OMC. The pore texture strongly affects their adsorption performance by kinetic and molecular sieving effects; the narrow constrictions in the OMC allow adsorption of nHEX and partially 2 MP but not 22DMB, whereas the highly connected pore network of DMC allows adsorption of the three isomers. Multi-component adsorption isotherms calculated from the single-component experimental results by ideal adsorbed solution theory (IAST) demonstrates that the OMC material has a remarkably high selectivity for the adsorption of nHEX and nHEX + 2 MP from binary and ternary mixtures, respectively. To the best of the authors’ knowledge, such behavior has never been reported so far for carbon materials. Hence, this study shows that tannin-derived MMCs have great potential to be used as an eco-friendly and low-cost alternative for the selective separation of di-branched C6 isomers. Jimena Castro-Gutiérrez gratefully acknowledges CONACYT-SENER for the scholarship awarded (601021/438978) to support her PhD studies, resulting in the work presented herein. This study was partly funded by the French PIA project "Lorraine Université d’Excellence”, reference ANR-15-IDEX-04-LUE, and TALiSMAN project, funded by FEDER (2019-000214). Joaquín Silvestre-Albero would like to acknowledge the financial support from MINECO (PID2019-108453GB-C21) and H2020 (MSCA-RISE-2016/NanoMed Project).

Oxygen concentration (02) in antral ovarian follicles is below that found in most tissues, which is important for adequate granulosa cell function. The VEGF system is linked to angiogenesis and responds to changing 02 by stimulating neovascularization when levels are low. However, in the avascular granulosa cell layer of the follicle, VEGF action is directed to stimulating cell viability and steroidogenesis. The aim of this study was to examine the effect of 02 concentration on granulosa cell expression of the VEGF-system components. Bovine granulosa cells were isolated from medium-sized follicles (4–7 mm in diameter), placed in McCoy 5a medium supplemented with 10 ng/mL of insulin, 1 ng/mL of IGF-I, and 1 ng/mL of FSH, and cultured in four well plates (500 thousand cells per well), on three separate occasions. Culture plates were placed in gas-impermeable jars with a gas mixture containing either 2%, or 5% of O2, or under atmospheric air condition inside an incubator (20% of 02). Media was replaced at 48 h of culture and cells from the plate in each oxygen concentration were pooled for RNA extraction after 96 h. The number of mRNA copies for the VEGF-system components - including ligands (VEGF120, VEGF120b, VEGF165 and VEGF165b), enzymes (cyclin-dependent like kinases-1, CLK1 and serine–arginine protein kinase 1, SRPK1), splicing factors (serine–arginine-rich splicing factors, SRSF1 and SRSF6), and the membrane-bound (VEGFR1, VEGFR2) and soluble forms of the receptors (sVEGFR1 and sVEGFR2) were quantified by qPCR. Granulosa cells cultured with low 02 (2%) had a higher expression of VEGF ligands (P 0.05). Nonetheless, mRNA copies for the soluble receptors, sVEGFR1 and sVEGFR2, linearly increased (P

The toxic potential of Chattonella is associated with a high production of reactive oxygen species (ROS). Chattonella species can tolerate high irradiance levels but seems not to be efficient in the induction of nonphotochemical chl a fluorescence (NPQ) under light stress conditions. Therefore, we postulated that high ROS production of this microalgal group is related to the lack of effective photoprotection mechanisms. We compared the NPQ induction, xanthophyll cycle interconversion (XC), and the production of the ion superoxide (O2 - ) in Chattonella marina var. antiqua, Chattonella sp., and C. marina acclimated to 43 (LL) and 300 µmol photons · m2 · s-1 (HL). We also evaluated the photosynthetic characteristics of the three strains. Photosynthesis saturated at relative high irradiances (above 500 µmol photons · m2 · s-1 ) in LL and HL Chattonella strains. For the first time, we documented the conversion of diadinoxanthin into diatoxanthin in microalgae that have violaxanthin as the major XC carotenoid. The slow NPQ induction indicated that qE (fast component of NPQ) was not present, and this process was related to the interconversion of XC pigments. However, the quenching efficiency (QE) of deepoxidated xanthophylls was low in the three Chattonella strains. The strain with the lowest QE produced the highest amount of a O2 - . Therefore, ROS production in Chattonella seems to be related to a low expression of XC-related thermal PSII dissipation.

Mesoporous carbonaceous materials were functionalized with iron or copper by a mechanochemical approach. The structural and textural properties of these catalysts were characterized by N2 physisorp...

International audience; Hydrogen adsorption on activated carbons (ACs) is a promising alternative to compression and liquefaction for storing hydrogen. Herein, we have studied hydrogen adsorption on six commercial ACs (CACs) with surface areas ranging from 996 to 2216 m 2 g-1 , in a temperature range of 77 to 273 K and pressures up to 15 MPa. Excess hydrogen adsorption capacities of 2.3 to 5.8 wt. % were obtained at 77 K and 4 MPa. We demonstrated that, contrary to what is normally done, hydrogen capacity is more accurately predicted by the surface area determined by the NLDFT method applied to N 2 and CO 2 adsorption data, than by the BET area. The modified Dubinin-Astakhov (MDA) equation was used to fit the experimental adsorption data, and the relationship between the MDA parameters (n max , V a , α and β) and the textural properties of the CACs was brought for the first time. We concluded that the n max and V a parameters are related to the BET area while the α and β parameters are related to average micropore size and total pore volume, respectively. α and β were used to evaluate the enthalpy and entropy of adsorption and we show that these parameters can be used to assess the best carbon for hydrogen storage or compression.

8 figures, 1 table.-- Supplementary information available.-- © 2021. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/, Biochar derived from the pyrolysis of pine tannin is a green and available by-product of oil manufacturing that presents interesting features after having been activated by KOH at 650 °C. Different weight ratios of KOH to biochar were used and the resulting activated carbons (ACs) presented highly developed specific surface areas of up to 2190 m2 g−1, well-connected porosity and high oxygen content, leading to enhanced electrochemical performance when used as electrochemical capacitor electrodes in a 1 M H2SO4 aqueous electrolyte. Galvanostatic charge/discharge experiments evidenced that the best material achieved a maximum electrode capacitance of up to 232 F g−1 (at 0.5 A g−1) with a capacitance retention of 70% at 10 A g−1 using commercial mass loadings (i.e., approx. 10 mg cm−2). In addition, long cycling stability with a residual capacitance of 92 to 94% after 10,000 cycles at 5 A g−1 was achieved. These results prove that ACs derived from pine tannin biochars have great potential for their commercial use as electrochemical energy storage devices., This study was partly supported by the French PIA project “Lorraine Université d’Excellence”, reference ANR-15-IDEX-04-LUE and the TALiSMAN project funded by ERDF. O. Pinto thanks ANID - Subdirección de Capital Humano/Doctorado, # 2019/21190633. P.S. Poon and C. Segura thank ANID-PIA/APOYO CCTE AFB170007 project. J. Matos acknowledges the funds from the Chilean projects ANID-FONDEF ID19I10003; ANID-FONDECYT 1190591; and Millennium Science Initiative Program-NCN17-040. J. Matos also thanks the Technological Development UNIT (UDT) from the University of Concepción (Chile), for supplying the tannin-derived chars. The authors finally thank Philippe Gadonneix for his technical assistance in laboratory measurements at Université de Lorraine.

8 figures, 4 tables. supplementary information avilable.-- © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0, The main aim of the present study is to provide a comprehensive assessment of the effects of process activation conditions on the textural properties of the resulting activated carbons, which were produced from wheat straw-derived biochar through chemical activation (with K2CO3 at different pressures and mass impregnation ratios) and physical activation (with CO2 at different temperatures and pressures). For chemically activated biochars, it was found that specific surface area and pore size distribution were both only positively affected by increasing the carbonate loading. However, physically activated biochars produced at the highest pressure and lowest temperature (1.0 MPa and 700 °C) had the highest surface areas and widest pore size distributions. The materials with the most appropriate textural properties were then tested as catalysts for steam and dry reforming of the aqueous phase of pyrolysis oil. The best catalytic performance (a total gas yield of 74% and a selectivity toward H2 of almost 40%) was observed for a physically activated biochar. This good performance was ascribed to the high availability of K0 on the catalyst surface, which could effectively promote the reactions involved in the upgrading process., This project received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 721991. The authors also acknowledge the funding from the Aragón Government (Ref. T22_20R), co-funded by FEDER 2014-2020 “Construyendo Europa desde Aragón”. This study was partly supported by the French PIA project “Lorraine Université d’Excellence”, reference ANR-15-IDEX-04-LUE, PROMOTEE project and TALiSMAN project, funded by FEDER (2019-000214).

12 figures.-- Supplementary material available.-- © 2021. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/, A surfactant-water-assisted mechanochemical mesostructuration method is used to produce model carbon materials with a disordered or ordered mesoporous structure (DMCs or OMCs, respectively) from a sustainable precursor, mimosa tannin. These model materials, differing only in their mesoporous structure, allow assessing the importance of the connectivity of the micro-mesopore network on the electrochemical performance of the resultant supercapacitors (SCs). Connectivity is studied through the scanning of hysteresis loops from nitrogen adsorption-desorption isotherms and, contrary to what it is suggested in the literature, order is not always beneficial for the performance of SCs. A thorough review of the open literature and comparison with our electrodes led us to conclude that CO2-activated DMCs and OMCs are among the best materials reported so far, as they exhibit excellent SC behavior, high-rate capability, and long-term stability in aqueous and organic electrolytes. It is showed that ordered mesopores improve the diffusion of the small-size ions of the aqueous electrolyte and hence favor a better performance at high charging rates, resulting in a 12% higher capacitance retention at 80 A g−1 when compared to that obtained with the disordered materials. However, the more interconnected porosity of the disordered materials allows better diffusion of large-size ions, thus improving the electrochemical performance in the organic electrolyte by 15% at 40 A g−1., Jimena Castro-Gutiérrez gratefully acknowledges CONACYT-SENER (601021/438978) for the assigned scholarship to support her PhD studies, resulting in the work presented herein. This study was partly supported by the French PIA project “Lorraine Université d’Excellence” funded by ANR, reference ANR-15-IDEX-04-LUE, and the TALiSMAN project, funded by FEDER (2019–000214). Marta Sevilla thanks funding by the Spanish MINECO/FEDER (CTQ2015-63552-R).

Catalyzed reactions of organic substrates that operate continuously by extrusion techniques are rare. In this study, we developed a mechanochemical bromination of unactivated naphthalene (1) with 1, 3-dibromo-5, 5- dimethylhydantoin (DBDMH) catalyzed by zeolites in a ball mill. The use of DBDMH enabled the atom economy of the reaction to be superior compared to the other brominating agents evaluated. Among the zeolites tested, a FAU-type zeolite demonstrated high catalytic activity and recyclability. The success of the bromination route on a small scale enabled the development of a continuous catalyzed bromination of 1 by twin- screw extrusion.

13 figures.-- Supplementary information available.-- © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/, The effect of heteroatoms on hydrogen adsorption properties of activated and hybrid carbon materials is critically described. For that purpose, olive stones were activated chemically with KOH, and subsequently washed or not, and oxidised with ozone or not. Olive stones were also activated physically with CO2. A series of activated carbons prepared by chemical activation of sucrose was also investigated for comparison. As a result, many activated carbons with different pore-size distributions, surface areas, average micropore widths, oxygen contents and amounts of mineral matter could be compared. All were thoroughly characterised by adsorption of N2, CO2 and H2O, elemental analysis, XPS, thermogravimetry, and adsorption of H2 at different pressures. Many correlations between textural parameters, composition and adsorption properties could be evidenced, and were critically discussed. We show that the hydrogen uptake at 77 K is controlled by the following parameters, listed by decreasing order of importance: specific surface area, average micropore size, surface chemistry and shape of the pore size distribution. At room temperature (i.e., at 298 K), the adsorbed hydrogen uptake was in the range of 0.19–0.42 wt %; the presence of large amounts of alkali metals can further improve the hydrogen adsorption properties, but surface chemistry still has a major influence, especially through the acidic surface functions., This study was funded by the Agence National de la Recherche (ANR) from France supporting the project “Lorraine Université d’Excellence”, reference ANR-15-IDEX-04-LUE. We gratefully acknowledge the financial support of CHEERS and TALiSMAN projects, funded by FEDER.

6 Figures, 1 Table.-- © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/, The competitiveness of European coal tar distillation plants could be improved by the revaluation of coal-derived liquids and rejects such as phenolic oils, which currently lack high-end applications. In this study, carbon gels were successfully prepared for the first time from phenolic oil by base-catalysed sol-gel polymerisation, by taking advantage of all the major components of phenolic oil rather than the pure, single-component phenolic precursors that are normally used in sol-gel routes. To increase the feasibility of industrial applications, the organic gels were dried under subcritical conditions and the resultant xerogels were submitted to carbonisation and chemical activation in a one-step process, using different KOH to organic gel mass ratios. The resultant ACs were applied as supercapacitor electrodes and attained higher electrochemical performances than carbon gels previously obtained from classic precursors: high capacitance retention up to 74.9% at 12 A g−1, energy and power densities up to 7.37 W h kg−1 and 5.70 kW h kg−1, respectively, high cycling stabilities up to 94.8% after 10,000 charge-discharge cycles, high rate capability of 66% under 1 V s−1 scan rate, and fast frequency response of 0.45 s., The IJL research team gratefully acknowledges the financial support of PROMOTEE 2016-2020, “Functional Porous Carbon Materials Derived from Coal Tar for Energy and Environmental Applications”, through the funds of the European Commission and the Research Fund for Coal & Steel. Dr. A. Sanchez-Sanchez acknowledges the CNRS for financing her post-Doctoral contract.

Background: Alzheimer’s disease (AD) and progressive supranuclear palsy (PSP) are examples of neurodegenerative diseases, characterized by abnormal tau inclusions, that are called tauopathies. AD is characterized by highly insoluble paired helical filaments (PHFs) composed of tau with abnormal post-translational modifications. PSP is a neurodegenerative disease with pathological and clinical heterogeneity. There are six tau isoforms expressed in the adult human brain, with repeated microtubule-binding domains of three (3R) or four (4R) repeats. In AD, the 4R:3R ratio is 1:1. In PSP, the 4R isoform predominates. The lesions in PSP brains contain phosphorylated tau aggregates in both neurons and glial cells. Objective: Our objective was to evaluate and compare the processing of pathological tau in PSP and AD. Methods: Double and triple immunofluorescent labeling with antibodies to specific post-translational tau modifications (phosphorylation, truncation, and conformational changes) and thiazin red (TR) staining were carried out and analyzed by confocal microscopy. Results: Our results showed that PSP was characterized by phosphorylated tau in neurofibrillary tangles (NFTs) and glial cells. Tau truncated at either Glu391 or Asp421 was not observed. Extracellular NFTs (eNFTs) and glial cells in PSP exhibited a strong affinity for TR in the absence of intact or phosphorylated tau. Conclusion: Phosphorylated tau was as abundant in PSP as in AD. The development of eNFTs from both glial cells and neuronal bodies suggests that truncated tau species, different from those observed in AD, could be present in PSP. Additional studies on truncated tau within PSP lesions could improve our understanding of the pathological processing of tau and help identify a discriminatory biomarker for AD and PSP.

Methylthionine Chloride (MTC), commonly known as methylene blue, is a substance widely used in medical and clinical industry as indicator, various diseases treatment and diagnostic. When MTC is discarded out of the organism, it becomes a residue which ends in wastewater treatment plants and it is not treated or removed properly because it has a synthetic origin, providing it with stability and chemical structure difficult to break. In the present work, MTC was treated through advanced oxidation processes (AOPs) photolysis and heterogeneous photocatalysis, in three pH magnitudes (3.5, 7.2 and 9.5), and comparing when 1 mMol of H2O2/L of sample was added or not at the beginning of the experiment. MTC degradation reached 62.9 and 54.14%, for photolysis and photocatalysis respectively, both in acid pH conditions and adding H2O2 to the sample. Kinetic constants (K) were calculated, showing acid pH as more effective; likewise, half life time decreases under these conditions. With Student-t statistic test, K from both processes were compared, resulting acidic and basic pH significantly different, but not neutral.

A series of BiVO4/TiO2 nanocomposites with high surface area have been synthesized by a sol–gel method combined with supercritical drying. BiVO4/TiO2 samples with different BiVO4 loadings were synthesized in order to study the effect of this variable on the structuration and development of BiVO4/TiO2 heterojunctions. Bare BiVO4/TiO2 composites are practically inactive for the photoproduction of hydrogen from ethanol under simulated solar light but their photoactivity notably improves after platinum (Pt) deposition. The photocatalytic activity of the Pt–BiVO4/TiO2 composites was determined by the BiVO4/TiO2 ratio that modifies the interfacial charge transfer efficiency between BiVO4 and TiO2 and also by the Pt loading that controls the dispersion and contact of the Pt particles with the composites. In particular, the composite with 0.5 wt% of Pt attained the optimal H2 evolution rate, which is more than 100 times higher than that of the pristine BiVO4/TiO2 composite. The photoactivity of the Pt–BiVO4/TiO2 composites was explained according to the Z-scheme mechanism in which the electrons from the CB of TiO2 reduced H+ to form H2 through the Pt particles preferentially deposited on it.

A gas sensor based on force spun ZnO nanotubes was successfully developed by using a simple and cost-effective approach, as confirmed by SEM, EDS, TGA-DTG and XRD characterization techniques. In order to optimize the sensing performance of the device in terms of sensing response kinetics and stability, the sensor response behavior against ethanol vapor was investigated under dark and UV light. Different reported studies have demonstrated that the resistance of ZnO gas sensors towards ethanol decreases when it is exposed to UV light. In this work, the UV light illumination of the sensor at 370 nm, allowed effectively to activate the detection of ethanol at the ppm level at room-temperature, in contrast to dark conditions. Unexpectedly, it was observed that the resistance behavior of the prepared ZnO sensor was reversed under continuous UV irradiation. The sensing mechanism behind this change is being also discussed.

Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 11180121 1180982 FONDEQUIP EQM 160070 PIA CCTE AFB 170007 Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) 21170881 ANID - Millennium Science Initiative Program NCN17_040 University of Chile in the framework of U-Inicia UI 013/2018

We present a Pt/ZrO2 catalyst that can operate in the harsh conditions of methane oxidation without being deactivated by SO2. XPS analysis of 1%Pt/ZrO2 catalyst revealed the presence of stable Pt2+–Pt4+ and Pt2+–Zr4+ bifunctional catalytic sites of dipolar nature at the Pt–ZrO2 interface. These sites increase the probability of CH4 polarization, increasing the strength of their collision with the catalyst surface, lowering the C–H bond energy and facilitating the abstraction of the first hydrogen in adsorbed CH4. The resistance of the catalyst to deactivation by sulfur poisoning is explained considering the stronger interaction of SO2 with Pt2+–Zr4+ dipolar sites, presenting a higher dipolar electric potential than Pt2+–Pt4+, on which CH4 adsorption and oxidation occur.

Introduction: Great success has been reported with the use of broad-spectrum antibiotics in the treatment of complex bacterial diseases, yet new and recurring bacterial infections continue to pose significant challenges to global health care. Objective: To review the literature on the antimicrobial and antibiotic activity of zinc oxide, gold, silver, and chitosan nanoparticles. Methodology: In this article, important literature on the antimicrobial and antibiotic activity of endodontic nanoparticles is reviewed through a comprehensive search in the PubMed, Web of Science and Google Scholar databases. Results: Zinc oxide nanoparticles do not offer significant improvements when compared to conventional or non-nanometric materials, gold nanoparticles lack clinical applications and their effectiveness is lower than silver nanoparticles. The best options are silver and chitosan nanoparticles due to their low required concentrations and results. Conclusion: Silver and chitosan nanoparticles are the best options for use in endodontic treatment because they demonstrate better antimicrobial and antibiotic film results. Research with AgNP's provides us with its usefulness in the application of sealing cements and intraconduct medicines, while chitosan nanoparticles offer advantages in healing.

The effect of the reduction temperature (300 °C, 400 °C, 500 °C and 600 °C) in cobalt SiO2 core-shell catalysts for chemoselective hydrogenation of cinnamaldehyde is reported. The Co-CoO@SiO2 catalysts structures were synthesized starting from a calcined Co3O4@SiO2 nanostructure obtained using a solvothermal method for the core (Co3O4) and a modified Stober method for the porous shell (SiO2) submitted to different reduction temperatures. The initial Co3O4@SiO2 structure and the derived Co-CoO@SiO2 catalysts were characterized by AAS, TG/DTG, TPR, TEM, XRD, XPS and SBET. The increase in the metallic Co content along with the reduction temperature increased the total conversion of cinnamaldehyde in the liquid-phase hydrogenation reaction. The highest selectivity towards the unsaturated alcohol over Co-CoO@SiO2-500 °C catalyst was attributed to an optimum Co/CoO surface ratio. A large chemical and mechanical stability of the Co-CoO@SiO2 structure was evidenced after five consecutive reaction cycles, revealing the beneficial effect of the core-shell architecture towards cobalt leaching in liquid-phase reactions.

Se realizó la síntesis de zeolita LTA a partir de arcillas de Ecuador, empleando el método de fusión alcalina, y posterior cristalización hidrotérmica a 90 °C. Las arcillas fueron calcinadas con NaOH variando el tiempo y temperatura de calcinación. La composición de la mezcla de síntesis y condiciones del tratamiento hidrotérmico se mantuvieron en todas las síntesis realizadas. La arcilla fue utilizada como fuente de silicio y aluminio, ajustando la composición de la mezcla con NaOH y H2O. Los sólidos fueron sometidas a una caracterización mediante Difracción de Rayos X (DRX), FRX, determinación de área específica y capacidad de adsorción de CO2 de las arcillas de partida y de las zeolitas sintetizadas. Fue posible obtener zeolita A, empleando iguales condiciones de síntesis para las tres arcillas estudiadas. El estudio de la evolución de la cristalización con el tiempo, indicó 2 h como un tiempo adecuado para obtener la zeolita. El área específica y la capacidad de adsorción de las zeolitas obtenidas a partir de las arcillas, se incrementa notablemente en comparación a las arcillas originales, sin embargo, la composición química no cambia apreciablemente.

In the present work, the preparation and use of new supported transition metal carbides as catalyst for the conversion of guaiacol was investigated. Several metals (Mo, Re, Ru, Ni, Fe, and Cu) were impregnated over activated carbon and carburized under a mixture of H2/C2H4 at 700 °C. Catalysts were characterized by XRD, N2 physisorption, XPS, CO chemisorption, and TPR-MS. Evidence for carbide formation was obtained in the case of Mo, Re, Ni and Ru, based primarily on CO formation during the TPR-MS analysis. It was found that carbides were mainly active for primary guaiacol conversion to phenol and catechol through demethoxylation and demethylation. Completely deoxygenated products such as benzene and cyclohexane were also formed. The highest selectivity in benzene was obtained for the Re-TPR catalyst while Ni-TPR was the most hydrogenative one.

International audience; Tannins are polyphenolic molecules of great industrial interest, not only for themselves but also as bio-based precursors for multiple carbonaceous materials with extremely diverse structures, textures and potential applications. In recent years, extensive work has been devoted to these new, predominantly porous carbons, and to their properties. It was therefore time to collect the main results in this invited review, whose objective is to show how a single, inexpensive, non-toxic and commercially available renewable resource can lead to such a wide range of different carbons. Cellular carbons, ordered or disordered mesoporous carbons, carbon gels and vitreous carbons, among others, are presented herein through their textures, morphologies and applications. We show that some of these tannin-derived materials are truly model materials, in the sense of excellent control of their structure. Therefore, they could be successfully used to verify the applicability of certain laws of physics to these carbons, or to observe their limits, for the first time. We end this article with a quick overview of the studies still underway in this area.

This contribution describes the modification in the structure and activity of Cu/ZnO catalyst in the methanol synthesis reaction induced by the co-modification with a low amount of Al and Ga (Al+Ga=3% atom). To elucidate the effect of the co modification, the catalysts were characterized by means of variety of techniques (XRD, N2 physisorption, FTIR, TGA, TEM, TPR and N2O chemisorption) and tested in the methanol synthesis reaction carried out in a flow reactor at 250 °C and total pressure of 3 MPa using syngas. The combined characterization and activity tests demonstrated that the co-doping with Al and Ga affects the structure and activity of Cu/ZnO catalysts in a different manner depending on the Al/Ga ratio used. The best catalyst co-loaded with Ga and Al in equal amount shows an improvement in the activity for methanol synthesis respect to the activity obtained on catalysts individually loaded with Al and Ga. The difference in the activity of the samples co-loaded with Al and Ga normalized by N2O chemisorption point to a different participation of the copper surfaces in combination with the defect sites of ZnO depending on the Al and Ga loading., The present investigation was performed within the research program CTQ2016-76505-C3-1 supported by the Spanish Ministry of Science, Innovation and Universities. Elena Millán would like to acknowledge the FPI programme from Spanish Ministry of Science, Innovation and Universities for the research grant.