408 research outputs found

    Temperature Dependence of Solar Light Assisted CO2 Reduction on Ni Based Photocatalyst

    Full text link
    Methanation of CO2 by H-2 can be in the future an important reaction to store the surplus of renewable electricity during production peaks. The catalytic thermal CO2 methanation (the Sabatier reaction) can be carried out at temperatures above 250 degrees C using Ni supported on silica-alumina (Ni/SiO2-Al2O3). Recently it has been observed that this exothermic reaction can be promoted by solar light irradiation of Ni/SiO2-Al2O3 at initial near ambient temperatures. In the present work we provide a study of the influence of the initial temperature on the photoassisted Ni/SiO2-Al2O3 methanation of CO2, under conditions in which the dark reaction is not observed. An increase of the photoassisted methanation rate with the initial temperature in the range from ambient to 150 degrees C has been observed. The reaction kinetics for lower initial temperatures exhibited an induction period not observed for reactions performed at higher temperatures. The results are discussed in terms of the operation of plasmon photo activation in which the energy of photons is thermalised in a confined space of the active nanoparticles leading to locally high temperatures and the simultaneous photogeneration of electrons and positive holes.Albero Sancho, J.; GarcĂ­a GĂłmez, H.; Corma CanĂłs, A. (2016). Temperature Dependence of Solar Light Assisted CO2 Reduction on Ni Based Photocatalyst. Topics in Catalysis. 59(8-9):787-791. doi:10.1007/s11244-016-0550-xS787791598-9Hammarstrom L, Hammes-Schiffer S (2009) Artificial photosynthesis and solar fuels. Acc Chem Res 42:1859–1860Schlögl R (2015) The revolution continues: energiewende 2.0. Angew Chem Int Ed 54:4436–4439Herron JA, Kim J, Upadhye AA, Huber GW, Maravelias CT (2015) A general framework for the assessment of solar fuel technologies. Energy Environ Sci 8:126–157Hoekman SK, Broch A, Robbins C, Purcell R (2010) CO2 recycling by reaction with renewably-generated hydrogen. Int J Greenh Gas Control 4:44–50Hoch LB, Wood TE, O’Brien PG, Liao K, Reyes LM, Mims CA, Ozin GA (2014) The rational design of a single-component photocatalyst for gas-phase CO2 reduction using both UV and visible light. Adv Sci 1:1400010–1400013Sastre F, Puga AV, Liu L, Corma A, Garcia H (2014) Complete photocatalytic reduction of CO2 to methane by H2 under solar light irradiation. J Am Chem Soc 136:6798–6801Melsheimer J, Guo W, Ziegler D, Wesemann M, Schlögl R (1991) Methanation of carbon dioxide over Ru/titania at room temperature: explorations for a photoassisted catalytic reaction. Catal Lett 11:157–168O’Brien PG, Sandhel A, Wood TE, Jelle AA, Hoch LB, Perovic DD, Mims CA, Ozin GA (2014) Photomethanation of gaseous CO2 over Ru/silicon nanowire catalysts with visible and near-infrared photons. Adv Sci 1:1400001–1400007Ghuman KK, Wood TE, Hoch LB, Mims CA, Ozin GA, Singh CV (2015) Illuminating CO2 reduction on frustrated Lewis pair surfaces: investigating the role of surface hydroxides and oxygen vacancies on nanocrystalline In2O3−x(OH)y. Phys Chem Chem Phys 17:14623–14635Wei W, Jinlong G (2011) Methanation of carbon dioxide: an overview. Front Chem Sci Eng 5:2–10Scaiano JC, Stamplecoskie K (2013) Can surface plasmon fields provide a new way to photosensitize organic photoreactions? Custom applications. J Phys Chem Lett 4:1177–1187Fasciani C, Alejo CJB, Grenier M, Netto-Ferreira JC, Scaiano JC (2011) High-temperature organic reactions at room temperature using plasmon excitation: decomposition of dicumyl peroxide. Org Lett 13:204–207Leadbeater NE (2010) Microwave heating as a tool for sustainable chemistry. CRC Press, Boca Rato

    Allelic diversity of S‑RNase alleles in diploid potato species

    Get PDF
    S-ribonucleases (S-RNases) control the pistil specificity of the self-incompatibility (SI) response in the genus Solanum and several other members of the Solanaceae. The nucleotide sequences of S-RNases corresponding to a large number of S-alleles or S-haplotypes have been characterised. However, surprisingly few S-RNase sequences are available for potato species. The identification of new S-alleles in diploid potato species is desirable as these stocks are important sources of traits such as biotic and abiotic resistance. S-RNase sequences are reported here from three distinct diploid types of potato: cultivated Solanum tuberosum Group Phureja, S. tuberosum Group Stenotomum, and the wild species Solanum okadae. Partial S-RNase sequences were obtained from pistil RNA by RT-PCR or 3’RACE (Rapid Amplification of cDNA Ends) using a degenerate primer. Full length sequences were obtained for two alleles by 5’RACE. Database searches with these sequences, identified sixteen S-RNases in total, all of which are novel. The sequence analysis revealed all the expected features of functional S-RNases. Phylogenetic analysis with selected published S-RNase and S-like-RNase sequences from the Solanaceae revealed extensive trans-generic evolution of the S-RNases and a clear distinction from S-like-RNases. Pollination tests were used to confirm the self-incompatibility status and cross-compatibility relationships of the S. okadae accessions. All the S. okadae accessions were found to be self-incompatible as expected with crosses amongst them exhibiting both cross-compatibility and semi-compatibility consistent with the S-genotypes determined from the S-RNase sequence data. The progeny analysis of four semi-compatible crosses examined by allele-specific PCR provided further confirmation that these are functional S-RNases

    Diazepam actions in the VTA enhance social dominance and mitochondrial function in the nucleus accumbens by activation of dopamine D1 receptors.

    Get PDF
    Benzodiazepines can ameliorate social disturbances and increase social competition, particularly in high-anxious individuals. However, the neural circuits and mechanisms underlying benzodiazepines' effects in social competition are not understood. Converging evidence points to the mesolimbic system as a potential site of action for at least some benzodiazepine-mediated effects. Furthermore, mitochondrial function in the nucleus accumbens (NAc) has been causally implicated in the link between anxiety and social competitiveness. Here, we show that diazepam facilitates social dominance, ameliorating both the competitive disadvantage and low NAc mitochondrial function displayed by high-anxious rats, and identify the ventral tegmental area (VTA) as a key site of action for direct diazepam effects. We also show that intra-VTA diazepam infusion increases accumbal dopamine and DOPAC, as well as activity of dopamine D1- but not D2-containing cells. In addition, intra-NAc infusion of a D1-, but not D2, receptor agonist facilitates social dominance and mitochondrial respiration. Conversely, intra-VTA diazepam actions on social dominance and NAc mitochondrial respiration are blocked by pharmacological NAc micro-infusion of a mitochondrial complex I inhibitor or an antagonist of D1 receptors. Our data support the view that diazepam disinhibits VTA dopaminergic neurons, leading to the release of dopamine into the NAc where activation of D1-signaling transiently facilitates mitochondrial function, that is, increased respiration and enhanced ATP levels, which ultimately enhances social competitive behavior. Therefore, our findings critically involve the mesolimbic system in the facilitating effects of diazepam on social competition and highlight mitochondrial function as a potential therapeutic target for anxiety-related social dysfunctions

    Control of mechanical pain hypersensitivity in mice through ligand-targeted photoablation of TrkB-positive sensory neurons

    Get PDF
    Mechanical allodynia is a major symptom of neuropathic pain whereby innocuous touch evokes severe pain. Here we identify a population of peripheral sensory neurons expressing TrkB that are both necessary and sufficient for producing pain from light touch after nerve injury in mice. Mice in which TrkB-Cre-expressing neurons are ablated are less sensitive to the lightest touch under basal conditions, and fail to develop mechanical allodynia in a model of neuropathic pain. Moreover, selective optogenetic activation of these neurons after nerve injury evokes marked nociceptive behavior. Using a phototherapeutic approach based upon BDNF, the ligand for TrkB, we perform molecule-guided laser ablation of these neurons and achieve long-term retraction of TrkB-positive neurons from the skin and pronounced reversal of mechanical allodynia across multiple types of neuropathic pain. Thus we identify the peripheral neurons which transmit pain from light touch and uncover a novel pharmacological strategy for its treatment

    Lasers and ancillary treatments for scar management Part 2: Keloid, hypertrophic, pigmented and acne scars

    Get PDF
    The formation of a wide range of excessive scars following various skin injuries is a natural consequence of healing. Scars resulting from surgery or trauma affect approximately 100 million people per annum in the developed world and can have profound physical, aesthetic, psychological and social consequences. Thus, scar treatment is a priority for patient and physician alike. Laser treatment plays an important role in scar management with additional support from ancillary modalities. Subsequent to part 1: Burns scars, part 2 focuses on our strategies and literature review of treatment of keloid, hypertrophic, pigmented and acne scars where lasers are used in conjunction with other measures, and illustrated with case studies
    • 

    corecore