97 research outputs found

    Removal of refractory organosulfur compounds via oxidation with hydrogen peroxide on amorphous Ti/SiO2 catalysts

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    Efficient removal of benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (DMDBT) has been successfully achieved via oxidation with hydrogen peroxide in liquid phase using an amorphous silica-loaded titanium oxide catalyst. Both BT and DBT are easily oxidized to the corresponding sulfones, however in the case of DMDBT the steric hindrance of the alkyl groups makes the approach of the S-atom to the catalyst active centre (an isolated Ti(IV) species) difficult and therefore its reactivity is inhibited. The concentration of the organosulfur compound, the H2O2 concentration and the nature of the solvent play a key role in the rate of S-removal.Peer reviewe

    Investigation of the long effective conjugation length in defect-free insulated molecular wires

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    Due to the “insulation” of the π-conjugated backbones, insulated molecular wires (IMWs) are expected to be applied to various optoelectronic applications and nanotechnology.[1] Recently, Kazunori et al have succeeded in the synthesis of a self-threading polythiophene with a polyrotaxane-like 3D architecture (PSTB, see Figure 1), for which an intrawire hole mobility of 0.9 cm2 V−1 s−1 has been measured.[2] Here, we aim to evaluate the extent of π-conjugation along polythiophene backbones sheathed within defect-free “insulating” layers. A comparison between the experimental Raman spectra of the self-threading oligomers (i.e. 2STB-5STB) and the corresponding PSTB polymer indicates that: (i) the ratio of relative intensities of the two most intense Raman bands (I1375/1445) increases with the elongation of the size chain but does not saturate up to the pentamer, and (ii) π-conjugation spreads over 17–18 thiophene units in the polymer. Whether the effective conjugation length of the polymer is better described by using the long oligomer extrapolation approach[3] or periodic DFT calculations of the polymer is discussed in detailed by exploiting the very recent potentialities of state-of-the-art quantum chemical simulations of vibrational properties for crystalline solids.[Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂ­a Tech

    Molecular and electronic structure investigation of encapsulated polytiophenes

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    Insulated molecular wires (IMWs) are expected to be applied to various optoelectronic applications due to their unique photophysical, electronic, and mechanical properties which originate from the absence of -stacking.[1] Kazunori et al have succeeded in the synthesis of a self-threading polythiophene with a polyrotaxane-like 3D architecture (PSTB, see Figure 1a), for which an intrawire hole mobility of 0.9 cm2 V−1 s−1 has been measured.[2] In this study we aim to evaluate for the first time the extension of the -conjugation in encapsulated polythiophenes. A comparison between the experimental Raman spectra of the self-threading PSTB polymer with their correspondent oligomers (i.e. 2STB-5STB) suggests that the effective conjugation length in the polymer is longer than five monomer units. Whether the effective conjugation length of the polymer is better described by using the long oligomer extrapolation approach or periodic DFT calculations of the polymer is discussed in detailed by exploiting the very recent potentialities of state-of-the-art quantum chemical simulations of vibrational properties for crystalline solids.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Marker-based linkage map of Andean common bean (Phaseolus vulgaris L.) and mapping of QTLs underlying popping ability traits

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    Abstract Background Nuña bean is a type of ancient common bean (Phaseolus vulgaris L.) native to the Andean region of South America, whose seeds possess the unusual property of popping. The nutritional features of popped seeds make them a healthy low fat and high protein snack. However, flowering of nuña bean only takes place under short-day photoperiod conditions, which means a difficulty to extend production to areas where such conditions do not prevail. Therefore, breeding programs of adaptation traits will facilitate the diversification of the bean crops and the development of new varieties with enhanced healthy properties. Although the popping trait has been profusely studied in maize (popcorn), little is known about the biology and genetic basis of the popping ability in common bean. To obtain insights into the genetics of popping ability related traits of nuña bean, a comprehensive quantitative trait loci (QTL) analysis was performed to detect single-locus and epistatic QTLs responsible for the phenotypic variance observed in these traits. Results A mapping population of 185 recombinant inbred lines (RILs) derived from a cross between two Andean common bean genotypes was evaluated for three popping related traits, popping dimension index (PDI), expansion coefficient (EC), and percentage of unpopped seeds (PUS), in five different environmental conditions. The genetic map constructed included 193 loci across 12 linkage groups (LGs), covering a genetic distance of 822.1 cM, with an average of 4.3 cM per marker. Individual and multi-environment QTL analyses detected a total of nineteen single-locus QTLs, highlighting among them the co-localized QTLs for the three popping ability traits placed on LGs 3, 5, 6, and 7, which together explained 24.9, 14.5, and 25.3% of the phenotypic variance for PDI, EC, and PUS, respectively. Interestingly, epistatic interactions among QTLs have been detected, which could have a key role in the genetic control of popping. Conclusions The QTLs here reported constitute useful tools for marker assisted selection breeding programs aimed at improving nuña bean cultivars, as well as for extending our knowledge of the genetic determinants and genotype x environment interaction involved in the popping ability traits of this bean crop.The authors thank Quival-Frutos Secos El Nogal (Pontevedra, Spain) for technical support and DiputaciĂłn de Pontevedra for farm facilities. We also thank Rosana Pereira Vianello Brondani from Embrapa Arroz e FeijĂŁo, CNPq (Brasil) for supplying some microsatellite primers. MDLF was supported by a research contract of the Xunta de Galicia. This work has been funded by grants PET2008_0167, EUI2009-04052 and AGL2011-25562 of the Ministerio de Ciencia e InnovaciĂłn and PGIDI03RAG16E of the Xunta de Galicia.Peer Reviewe

    Oxidative processes of desulfurization of liquid

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    Environmental concerns have introduced a need to remove sulfur-containing compounds from light oil. As oxidative desulfurization is conducted under very mild reaction conditions, much attention has recently been devoted to this process. In this contribution, the developments in selective removal of organosulfur compounds present in liquid fuels via oxidative desulfurization, including both chemical oxidation and biodesulfurization, are reviewed. At the end of each section, a brief account of the research directions needed in this field is also included.Ministerio de Educación y Ciencia (España) proyecto ENE2007-07345-C03-01/ALTPeer reviewe

    A parallel solution with GPU technology to predict energy consumption in spatially distributed buildings using evolutionary optimization and artificial neural networks

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    Today all governments talk about climate change and its consequences. One of the ways to tackle this problem is by studying the energy consumption of the buildings around us. The study of energy consumption may give us relevant information to make better decisions, and thus reduce costs and pollution. However, ANNtraining models, in order to achieve those goals, has a high computational cost in terms of time. To solve that problem, this paper presents a GPU-based parallel implementation of NGSA-II to train ANNs whose evaluation has also been implemented in a parallel GPU scheme. Our methodology is designed to predict the energy consumption of a series of public buildings, and thus, to model consumption, save energy and improve the energy efficiency of these buildings without compromising their performance obtaining the prediction in a very short period of time. We compared the sequential implementation of the evolutionary algorithm NSGA-II with our new version developed in parallel and the parallel implementation gets better results in much faster execution time.TIN201564776-C3-1-

    Albino T-DNA tomato mutant reveals a key function of 1-deoxy-D-xylulose-5-phosphate synthase (DXS1) in plant development and survival

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    [EN] Photosynthetic activity is indispensable for plant growth and survival and it depends on the synthesis of plastidial isoprenoids as chlorophylls and carotenoids. In the non-mevalonate pathway (MEP), the 1-deoxy-D-xylulose-5-phosphate synthase 1 (DXS1) enzyme has been postulated to catalyze the ratelimiting step in the formation of plastidial isoprenoids. In tomato, the function of DXS1 has only been studied in fruits, and hence its functional relevance during plant development remains unknown. Here we report the characterization of the wls-2297 tomato mutant, whose severe deficiency in chlorophylls and carotenoids promotes an albino phenotype. Additionally, growth of mutant seedlings was arrested without developing vegetative organs, which resulted in premature lethality. Gene cloning and silencing experiments revealed that the phenotype of wls-2297 mutant was caused by 38.6 kb-deletion promoted by a single T-DNA insertion affecting the DXS1 gene. This was corroborated by in vivo and molecular complementation assays, which allowed the rescue of mutant phenotype. Further characterization of tomato plants overexpressing DXS1 and comparative expression analysis indicate that DXS1 may play other important roles besides to that proposed during fruit carotenoid biosynthesis. Taken together, these results demonstrate that DXS1 is essentially required for the development and survival of tomato plants.This work was supported by research grants from the Spanish Ministry of Economy and Competitiveness and the UE-European Regional Development Fund (AGL2015-64991-C3-1-R, and AGL2015-64991-C3-3-R), and Junta de Andalucia (P12-AGR-1482). PhD fellowship to M.G.-A. was funded by the FPU Programme of the Spanish Ministry of Science and Innovation. The authors thank research facilities provided by the Campus de Excelencia Internacional Agroalimentario (CeiA3).Garcia-Alcazar, M.; Giménez Caminero, ME.; Pineda Chaza, BJ.; Capel, C.; García Sogo, B.; Sånchez Martín-Sauceda, S.; Yuste-Lisbona, FJ.... (2017). Albino T-DNA tomato mutant reveals a key function of 1-deoxy-D-xylulose-5-phosphate synthase (DXS1) in plant development and survival. Scientific Reports. 7:1-12. https://doi.org/10.1038/srep45333112

    The res (restored cell structure by salinity) tomato mutant reveals the role of the DEAD-box RNA helicase SlDEAD39 in plant development and salt response

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    [EN] Increasing evidences highlight the importance of DEAD-box RNA helicases in plant development and stress responses. In a previous study, we characterized the tomato res mutant (restored cell structure by salinity), showing chlorosis and development alterations that reverted under salt-stress conditions. Map-based cloning demonstrates that RES gene encodes SlDEAD39, a chloroplast-targeted DEAD-box RNA helicase. Constitutive expression of SlDEAD39 complements the res mutation, while the silencing lines had a similar phenotype than res mutant, which is also reverted under salinity. Functional analysis of res mutant proved SlDEAD39 is involved in the in vivo processing of the chloroplast, 23S rRNA, at the hidden break-B site, a feature also supported by in vitro binding experiments of the protein. In addition, our results show that other genes coding for chloroplast-targeted DEAD-box proteins are induced by salt-stress, which might explain the rescue of the res mutant phenotype. Interestingly, salinity restored the phenotype of res adult plants by increasing their sugar content and fruit yield. Together, these results propose an unprecedented role of a DEAD-box RNA helicase in regulating plant development and stress response through the proper ribosome and chloroplast functioning, which, in turn, represents a potential target to improve salt tolerance in tomato cropsSecretaria de Estado de Investigacion, Desarrollo e Innovacion, Grant/Award Numbers: AGL2015-64991-C3-1-R, AGL2015-64991-C3-2-R, AGL2015-64991-C3-3-R, AGL2017-88702-C2-1-RCapel, C.; Albaladejo, I.; Egea, I.; Massaretto, IL.; Yuste-Lisbona, FJ.; Pineda Chaza, BJ.; GarcĂ­a Sogo, B.... (2020). The res (restored cell structure by salinity) tomato mutant reveals the role of the DEAD-box RNA helicase SlDEAD39 in plant development and salt response. Plant Cell & Environment. 43(7):1722-1739. https://doi.org/10.1111/pce.13776S1722173943

    π-Dimerization of Heptathienoacene Radical Cations

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    Oligothienoacenes, the fused-ring analog of pi-linked oligothiophenes, belong to the most promising candidates for organic electronic applications. This is in part due to their fully planar structure that avoids conformational disorder and allows for densely packed solid-state structures resulting in high charge carrier mobilities. In recent years, there has been a growing interest in the study of the pi-dimerization of conjugated radical cations with a dual purpose: (i) elucidation of the nature of the charge-transport phenomena in p-doped semiconducting polymers and (ii) development of supramolecular bonding ideas for applications in material science, such as actuators. However, the π-dimerization of planar conjugated radical cations in solution is scarce and usually encountered at low temperatures. In this work, we investigate the exceptional pi-dimerization capability showed by radical cations of a heptathienoacene alpha,beta-substituted with four n-decyl side groups (D4T7‱+) by using a joint experimental and theoretical approach. D4T7 radical cations are found to exhibit an exceptional ability to form pi-dimer dications even at ambient temperature. Our results evidence the presence of two different transitory oxidized species formed during the course of the one-electron oxidation: (i) different conformations of the [D4T7‱+]2 pi-dimer dications and (ii) the intermediate [D4T7]2‱+ pi-dimer radical cations.[5] The nature and structure of these transitory species and ultimate pi-dimer dication are rigorously analyzed with the help of the DFT and TD-DFT calculations. Our study would provide valuable guidance for the further development of pi-dimer based supramolecular architectures.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂ­a Tech
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