94 research outputs found

    Influence of irrigation conditions in the germination of plasma treated Nasturtium seeds

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    Plasma treatments had emerged as a useful technique to improve seed germination. In this work we investigate the influence of different irrigation conditions and plasma treatments on the germination of nasturtium seeds. During plasma treatment, seeds experience a progressive weight loss as a function of treatment time that has been associated to water release, a process that is more pronounced after longer plasma treatment times. Seeds treated for short times (<30 s) are able to germinate more efficiently than untreated specimen under hydric stress (drought conditions), while plasma treatments for longer times (up to 300 s) impaired germination independently on irrigation conditions. Characterization analysis of plasma treated seeds by FTIR-ATR, SEM/EDX and XPS showed that plasma treatment affected the chemical state of pericarp while, simultaneously, induced a considerable increase in the seeds water uptake capacity. The decrease in germination efficiency found after plasma treatment for long times, or for short times under optimum irrigation conditions, has been attributed to that the excess of water accumulated in the pericarp hampers the diffusion up to the embryo of other agents like oxygen which are deemed essential for germination.España FEDER y MINECO MINECO (projects MAT2013-40852-R, MAT2016-79866-R, MINECOCSIC 201560E055)España, RECUPERA 2020 y Junta de Andalucía project P12-2265 M

    Enhancement of the fire resistance of concrete-filled steel tubular columns by using high performance steels

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    [EN] In recent years, innovative solutions have been developed with the purpose of increasing both the load-bearing capacity and fire resistance of concrete-filled steel tubular (CFST) columns. One of these solutions are the so-called concrete-filled dual steel tubular (CFDST) columns. In this configuration, the inner steel tube is thermally protected by the outer concrete ring and therefore its degradation is delayed, which may thus help resisting the applied load for a longer period of fire exposure time. An alternative solution that might be interesting to evaluate under fire conditions is to embed an inner steel profile inside the CFST section, such as an HEB profile. In addition to the development of new types of composite sections, the use of high strength steels (HSS) in construction is increasing, owing to their excellent mechanical properties, which may also be used for an enhanced fire resistance. In the same line, stainless steels (SS) are also becoming widely used in construction due to their beneficial characteristics such as corrosion resistance, high ductility or good aesthetics. Besides, the degradation of their strength and stiffness at elevated temperature is slower than for carbon steels, hence SS may withstand higher temperatures without significantly altering their mechanical properties. This paper aims at obtaining strategies for enhancing the fire resistance of concrete-filled steel tubular columns with the use of innovative solutions (CFDST sections or embedded HEB profiles) combining high performance steels such as HSS or SS. Taking advantage of the improved mechanical properties of these steels at elevated temperatures and using the appropriate thickness ratio between the outer and inner tube or embedded steel profile, it may be possible to attain the required fire resistance without the need for external protection. A three-dimensional finite element model is used in this paper for conducting parametric studies with the different section types and material combinations, in order to evaluate the interest of using HSS and SS for improving the fire performance of steel-concrete composite columns.The authors would like to express their sincere gratitude to the Conselleria d'Educació, Investigació, Cultura i Esport of the Valencian Community (Spain) for the help provided through the project GV/2017/026.Espinós Capilla, A.; Ibáñez Usach, C.; Lapuebla-Ferri, A.; Romero, ML. (2019). Enhancement of the fire resistance of concrete-filled steel tubular columns by using high performance steels. Independent Publishing Network. 1470-1481. http://hdl.handle.net/10251/181084S1470148

    Numerical investigation on the thermal behaviour of steel-reinforced CFST columns in fire

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    [EN] In previous research, the authors highlighted the limited fire resistance of slender concrete-filled steel tubular (CFST) columns. A possible solution for enhancing the fire resistance of such columns consists of embedding an open steel profile within the concrete infill of the CFST section, generating the so-called steel-reinforced concrete-filled steel tubular (SR-CFST) section, where the inner steel profile results thermally protected by the surrounding concrete, thus delaying its degradation at elevated temperatures. This strategy may result beneficial in the fire situation as compared to other sectional configurations where the steel parts are directly exposed to the heat source. In this paper, a two-dimensional finite element model will be developed for studying the thermal behaviour of SR-CFST columns and validated by comparing the temperature distribution results with experimental tests available in the literature. The numerical model will be subsequently used to carry out parametric studies, in order to analyse the influence of the different parameters, such as the cross-section shape, outer tube thickness or the inner steel profile sectional dimensions over the thermal response of these composite sections when subjected to fire. Finally, a simplified temperature distribution proposal will be developed, which may help practitioners for a fast evaluation of the cross-sectional temperature field of SR-CFST columns at a given fire resistance period by assigning an equivalent temperature to each component of the composite section (hollow steel tube, concrete encasement and inner steel profile). This simplified temperature proposal may result helpful when evaluating the sectional capacity of SR-CFST columns in fire, by using a single strength and stiffness value for each component of the composite cross-section corresponding to its temperature.The authors would like to express their sincere gratitude for the help provided through the Grant PID2019-105908RB-I00 and for the first author's pre-doctoral contract through the Grant PRE2020-093106 funded by MCIN/AEI/ 10.13039/501100011033 and by "ESF Investing in your future".Medall-Martos, D.; Espinós Capilla, A.; Albero Gabarda, V.; Ibáñez, C.; Romero, ML. (2022). Numerical investigation on the thermal behaviour of steel-reinforced CFST columns in fire. Ernst und Sohn. 429-438. https://doi.org/10.1002/cepa.177442943

    Ancient origin of the CAG expansion causing Huntington disease in a Spanish population

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    25 p. Figuras, tablas, bibliografíaHuntington disease (HD, MIM# 143100) is an autosomal dominant neurodegenerative disorder characterized clinically by progressive motor impairment, cognitive decline, and emotional deterioration. The disease is caused by the abnormal expansion of a CAG trinucleotide repeat in the first exon of the huntingtin gene in chromosome 4p16.3. HD is spread worldwide and it is generally accepted that few mutational events account for the origin of the pathogenic CAG expansion in most populations. We have investigated the genetic history of HD mutation in 83 family probands from the Land of Valencia, Eastern Spain. An analysis of the HD/CCG repeat in informative families suggested that at least two main chromosomes were associated in the Valencian population, one associated with allele 7 (77 mutant chromosomes) and one associated with allele 10 (2 mutant chromosomes). Haplotype A-7-A (H1) was observed in 47 out of 48 phase-known mutant chromosomes, obtained by segregation analysis, through the haplotype analysis of rs1313770-HD/CCGrs82334, as it also was in 120 out of 166 chromosomes constructed by means of the PHASE program. The genetic history and geographical distribution of the main haplotype H1 were both studied by constructing extended haplotypes with flanking STRs D4S106 and D4S3034. We found that we were able to determine the age of the CAG expansion associated with the haplotype H1 as being between 4,700 and 10,000 years ago. Furthermore, we observed a nonhomogenous distribution in the different regions associated with the different extended haplotypes of the ancestral haplotype H1, suggesting that local founder effects have occurred.This work was supported by the Fondo de investigación Sanitaria (FIS grant 01/1159), the Instituto de Salud Carlos III (grant G03/56) for the Spanish Network on Cerebellar Ataxias, and the Generalitat Valenciana (grant GRUPOS03/015).Peer reviewe

    Missense mutations in the SH3TC2 protein causing Charcot-Marie-Tooth disease type 4C affect its localization in the plasma membrane and endocytic pathway

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    [EN] Mutations in SH3TC2 (KIAA1985) cause Charcot-Marie-Tooth disease (CMT) type 4C, a demyelinating inherited neuropathy characterized by early-onset and scoliosis. Here we demonstrate that the SH3TC2 protein is present in several components of the endocytic pathway including early endosomes, late endosomes and clathrin-coated vesicles close to the trans-Golgi network and in the plasma membrane. Myristoylation of SH3TC2 in glycine 2 is necessary but not sufficient for the proper location of the protein in the cell membranes. In addition to myristoylation, correct anchoring also needs the presence of SH3 and TPR domains. Mutations that cause a stop codon and produce premature truncations that remove most of the TPR domains are expressed as the wild-type protein. In contrast, missense mutations in or around the region of the first-TPR domain are absent from early endosomes, reduced in plasma membrane and late endosomes and are variably present in clathrin-coated vesicles. Our findings suggest that the endocytic and membrane trafficking pathway is involved in the pathogenesis of CMT4C disease. We postulate that missense mutations of SH3TC2 could impair communication between the Schwann cell and the axon causing an abnormal myelin formation.This work was supported by the Fondo de Investigacion Sanitaria [grant numbers PI08/90857, PI08/0889, CP08/00053] and the Spanish Ministry Science and Innovation [grant number SAF2006-01047]. V. L. is a recipient of JAE predoctoral fellowship from the Spanish Scientific Research Council (CSIC). M. I. G. has a `Ramon y Cajal' contract funded by the Ministry of Science and Innovation. C. E. has a `Miguel Servet' contract funded by the Fondo de Investigacion Sanitaria. Both CIBERER and CIBERNED are initiatives from the Instituto de Salud Carlos III. We are grateful to patients and their families for their kind collaboration. We thank B. Alarcón for his technical assistance and also anonymous reviewers for their invaluable insight and suggestionsLupo, V.; Galindo, MI.; Martínez-Rubio, D.; Sevilla, T.; Vílchez, JJ.; Palau, F.; Espinós-Armero, CÁ. (2009). Missense mutations in the SH3TC2 protein causing Charcot-Marie-Tooth disease type 4C affect its localization in the plasma membrane and endocytic pathway. Human Molecular Genetics. 18(23):4603-4614. https://doi.org/10.1093/hmg/ddp42746034614182

    Ancient origin of the CAG expansion causing Huntingtons disease in a Spanish population.

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    [EN] Huntington disease (HD) is an autosomal dominant neurodegenerative disorder characterized clinically by progressive motor impairment, cognitive decline, and emotional deterioration. The disease is caused by the abnormal expansion of a CAG trinucleotide repeat in the first exon of the huntingtin gene in chromosome 4p16.3. HD is spread worldwide and it is generally accepted that few mutational events account for the origin of the pathogenic CAG expansion in most populations. We have investigated the genetic history of HD mutation in 83 family probands from the Land of Valencia, in Eastern Spain. An analysis of the HD/CCG repeat in informative families suggested that at least two main chromosomes were associated in the Valencian population, one associated with allele 7 (77 mutant chromosomes) and one associated with allele 10 (two mutant chromosomes). Haplotype A-7-A (H1) was observed in 47 out of 48 phase-known mutant chromosomes, obtained by segregation analysis, through the haplotype analysis of rs1313770-HD/CCG-rs82334, as it also was in 120 out of 166 chromosomes constructed by means of the PHASE program. The genetic history and geographical distribution of the main haplotype H1 were both studied by constructing extended haplotypes with flanking short tandem repeats (STRs) D4S106 and D4S3034. We found that we were able to determine the age of the CAG expansion associated with the haplotype H1 as being between 4,700 and 10,000 years ago. Furthermore, we observed a nonhomogenous distribution in the different regions associated with the different extended haplotypes of the ancestral haplotype H1, suggesting that local founder effects have occurred.We are grateful for the kind collaboration of patients and families. This work was supported by the Fondo de investigación Sanitaria (FIS grant 01/1159), the Instituto de Salud Carlos III (grant G03/56) for the Spanish Network on Cerebellar Ataxias, and the Generalitat Valenciana (grant GRUPOS03/015).García-Planells, J.; Burguera, JA.; Solís, P.; Millán, JM.; Ginestar Peiro, D.; Palau, F.; Espinós-Armero, CÁ. (2005). Ancient origin of the CAG expansion causing Huntingtons disease in a Spanish population. Human Mutation. 25(5):453-459. https://doi.org/10.1002/humu.2016745345925

    Enhancement of visible light-induced surface photo-activity of nanostructured N¿TiO2 thin films modified by ion implantation

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    This work reports the morphological and chemical modifications induced in TiO2 thin films by bombardment with high energy N+ ions at different temperatures and their different photo-activity responses after implantation under visible and UV light illumination. When implanted samples are illuminated with visible light, no dye photo-decolouration takes place despite that light transformed the surfaces from hydrophobic to hydrophilic. In agreement with the Wenzel model of wetting, correlation is found between visible light photo-activity and film morphology. We conclude that the photo-activity response can be separated into shallow and Schottky barrier photo-activity, this latter involving a thicker layer of materialMinisterio de Ciencia e Innovación CONSOLIDER CSD2008-00023 MAT2010-21228 MAT2010-1844

    Mutations in the urocanase gene UROC1 are associated with urocanic aciduria

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    [EN] Urocanase is an enzyme in the histidine pathway encoded by the UROC1 gene. This report describes the first putative mutations, p. L70P and p.R450C, in the coding region of the UROC1 gene in a girl with urocanic aciduria presenting with mental retardation and intermittent ataxia. Computed (in silico) predictions, protein expression studies and enzyme activity assays suggest that none of the mutations can produce a fully functional enzyme. The p. L70P substitution, which probably implies the disruption of an alpha-helix in the N-terminus, would alter its properties and therefore, its function. The p.R450C change would render impossible any interaction between urocanase and its substrate and would loss its enzyme activity. Consequently, these studies suggest that both mutations could alter the correct activity of urocanase, which would explain the clinical and biochemical findings described in this patient.We are grateful to the patient for her kind collaboration. We are indebted to Dr C Marco-Marín for the in silico structural studies. CIBERER is an initiative of the Instituto de Salud Carlos III. This work was supported by grants from the Fondo de Investigación Sanitaria (PI051318 and PI070548).Espinós-Armero, CÁ.; Pineda, M.; Martínez-Rubio, D.; Aída Ormazabal; María Antonia Vilaseca; Leo J. M. Spaapen; Palau, F.... (2009). Mutations in the urocanase gene UROC1 are associated with urocanic aciduria. Journal of Medical Genetics. 46(6):407-411. https://doi.org/10.1136/jmg.2008.06063240741146
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