52 research outputs found

    Carbon materials from conventional/unconventional technologies for electrochemical energy storage devices

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    In the last years our society has shown a growing interest on the development of both new sources of clean energy and advanced devices able to store it. In this context supercapacitors (SCs) and hybrid systems have emerged to cover the power and energy demands. Most of these electrochemical devices use carbon materials as electrodes being the activated carbons (ACs) the most commonly ones. Nonetheless graphene (G) has emerged as a promising electrode either by itself or combined with ACs in composites. This work investigates the use of a low added value coal-derived liquid (anthracene oil, AO) for the production of pitch-like carbon precursors to synthesize suitable active electrode materials (ACs, G, AC/G) in SCs and hybrid systems. In addition to the well-known oxidative thermal polymerization of AO, a new alternative based on the use of microwave heating is presented as a promising clean route to obtain such carbon precursors resulting in energy saving, shortening time and specific nonthermal effects. The characteristics of the carbon materials obtained from both conventional/ unconventional technologies are compared mainly in terms of their specific surface area, surface chemistry and electrical conductivity which would allow the design of energy storage devices with an improved electrochemical performance

    Magnetic nanoparticles penetration and transport in planta

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    Resumen del póster presentado en la 9th International Conference on the Scientific and Clinical Applications of Magnetic Carriers, celebrada en Minneapolis (Estados Unidos) del 22 al 26 de mayo de 2012.Magnetic nanoparticles are very suitable for a broad range of applications, like those involving synthesis and use of ferrofluids for bio-applications in general. In medicine the aim is to use them in diagnosis as well as in therapy. The ongoing research and results obtained up to now in these fields open a wide range of possibilities for using magnetic nanoparticles in other disciplines, for example in general plant research and agronomy. To study the use of nanoparticles in agriculture the first stage is to work out the penetration and transport into living plants and plant cells. We present here an overview of the research carried out within the scope of an interdisciplinary collaboration, on how inorganic nanoparticles interact with plant cells and tissues.

    Differential Expression of Fungal Genes Determines the Lifestyle of Plectosphaerella Strains During Arabidopsis thaliana Colonization

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    16 Päg.The fungal genus Plectosphaerella comprises species and strains with different lifestyles on plants, such as P. cucumerina, which has served as model for the characterization of Arabidopsis thaliana basal and nonhost resistance to necrotrophic fungi. We have sequenced, annotated, and compared the genomes and transcriptomes of three Plectosphaerella strains with different lifestyles on A. thaliana, namely, PcBMM, a natural pathogen of wild-type plants (Col-0), Pc2127, a nonpathogenic strain on Col-0 but pathogenic on the immunocompromised cyp79B2 cyp79B3 mutant, and P0831, which was isolated from a natural population of A. thaliana and is shown here to be nonpathogenic and to grow epiphytically on Col-0 and cyp79B2 cyp79B3 plants. The genomes of these Plectosphaerella strains are very similar and do not differ in the number of genes with pathogenesis-related functions, with the exception of secreted carbohydrate-active enzymes (CAZymes), which are up to five times more abundant in the pathogenic strain PcBMM. Analysis of the fungal transcriptomes in inoculated Col-0 and cyp79B2 cyp79B3 plants at initial colonization stages confirm the key role of secreted CAZymes in the necrotrophic interaction, since PcBMM expresses more genes encoding secreted CAZymes than Pc2127 and P0831. We also show that P0831 epiphytic growth on A. thaliana involves the transcription of specific repertoires of fungal genes, which might be necessary for epiphytic growth adaptation. Overall, these results suggest that in-planta expression of specific sets of fungal genes at early stages of colonization determine the diverse lifestyles and pathogenicity of Plectosphaerella strains.This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) grant BIO2015-64077-R and the Spanish Research Agency (AEI) grant RTI2018-096975-B-I00 to A. Molina and by the “Severo Ochoa Programme for Centers of Excellence in R&D” grant SEV-2016-0672 (2017-2021) to the CBGP (UPM-INIA). In the frame of SEV-2016-0672 program, H. Mélida was supported with a postdoctoral contract. A. Muñoz-Barrios was financially supported by the Universidad Politécnica de Madrid (UPM) Ph.D. students PIF program, I. del Hierro was a FPU fellow (Spanish Ministry of Education, Culture and Sports grant FPU16/07118), V. Fernández-Calleja was supported by the Consejería de Educacíon e Investigacíon of Comunidad de Madrid YEI program for postdoctoral researchers (PEJD-2016/BIO-3327), and the work was further supported through a Comunidad de Madrid YEI program for laboratory technicians grant (PEJ16/BIO/TL-1570).Peer reviewe

    Tissue culture of ornamental cacti

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    Functional ultrastructure of the plant nucleolus

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    Microspore-derived embryogenesis in Capsicum annuum: subcellular rearrangements through development

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    14 páginas, 7 figuras -- PAGS nros. 709-722Background information. In vitro-cultured microspores, after an appropriate stress treatment, can switch towards an embryogenic pathway. This process, known as microspore embryogenesis, is an important tool in plant breeding. Basic studies on this process in economically interesting crops, especially in recalcitrant plants, are very limited and the sequence of events is poorly understood. In situ studies are very convenient for an appropriate dissection of microspore embryogenesis, a process in which a mixture of different cell populations (induced and non-induced) develop asynchronically. Results. In the present study, the occurrence of defined subcellular rearrangements has been investigated during early microspore embryogenesis in pepper, an horticultural crop of agronomic interest, in relation to proliferation and differentiation events. Haploid plants of Capsicum annuum L. (var. Yolo Wonder B) have been regenerated from in vitro anther cultures by a heat treatment at 35°C for 8 days. Morphogenesis of microspore-derived embryos has been analysed, at both light and electron microscopy levels, using low-temperature-processed, well-preserved specimens. The comparison with the normal gametophytic development revealed changes in cell organization after embryogenesis induction, and permitted the characterization of the time sequence of a set of structural events, not previously defined in pepper, related to the activation of proliferative activity and differentiation. These changes mainly affected the plastids, the vacuolar compartment, the cell wall and the nucleus. Further differentiation processes mimicked that of the zygotic development. Conclusions. The reported changes can be considered as markers of the microspore embryogenesis. They have increased the understanding of the mechanisms controlling the switch and progression of the microspore embryogenesis, which could help to improve its efficiency and to direct strategies, especially in agronomically interesting cropsThis work was supported by grants from the Spanish MCyT (BOS2002-03572) and Comunidad de Madrid (CM 07G/0026/2003Peer reviewe

    The Methylation-Acetylation Method: An Ultrastructural Cytochemistry for Nucleic Acids Compatible with Immunogold Studies

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    Methylation-acetylation (MA) is an easy and reproducible ultrastructural cytochemical method which gives preferential contrast to nucleic acid containing structures. When performed en bloc before Lowicryl embedding it does not affect the main antigenic and chemical properties of the sample and is compatible with a large variety of modern immunogold methods permitting a better assignment of the labeling to the well-defined nuclear structures. DNA, RNA, and nuclear proteins, with different chemical nature, nuclear localization, and amount, can be immunolocalized on MA-treated samples. Ultrastructural in situ hybridization and other approaches for studying the functional regions of chromatin, the terminal deoxynucleotidyl transferase and the bromodeoxyuridine methods, are also compatible with the MA procedure. It can be also performed on ultrathin cryosections and Lowicryl sections. A much better visualization of the nuclear structures is obtained, enhancing the distinction between the nucleolar granular and dense fibrillar components. Moreover, the combination of the MA procedure with EDTA regressive staining gives preferential contrast to the RNA-rich structures. It is proposed as a useful approach which can be regularly used for in situ studies of the functional organization of the nucleus in both plant and animal cells.This work was supported by project DGICYT PB92-0079-C03-01.Peer reviewe
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