118 research outputs found

    Altered electrochemistry of poly(3,4-ethylenedioxythiophene) after activation of the inserted cobalt ions

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    Cobalt ions were inserted into poly(3,4-ethylenedioxythiophene) by cyclic voltammetry in a 0.1M Co(NO3)2 aqueous solution (PEDOT(Co)). After activation of the inserted cobalt, the PEDOT(aCo) system was investigated by cyclic voltammetry, digital video electrochemistry, spectroelectrogravimetry, and coupled impedance techniques (ac-electrogravimetry) to elucidate the key role of inserted cobalt ions in the altered electrochemistry of PEDOT. The incorporation of Co2+ involves slow transfer of cations for charge compensation during 2+⇄3+ conversion inside the PEDOT. This fact explains the enhanced charge storage showed by PEDOT(aCo) compared with pristine PEDOT at similar potentials. Finally, the stability of PEDOT(aCo) was investigated by cyclic voltammetry measuring at the same time current, mass and motional resistance variation during 100 cycles offering high stability at all times.This work was supported by the Spanish E3TECH-PLUS Research Network RED2022-134552-T (MICINN/AEI, Spain). SEM was carried out in the Microscopy Section of Central Service for Experimental Research (SCSIE) of the University of Valencia. Esteban Guillén acknowledges the support from the Generalitat Valenciana (INVEST/2022/431)

    Ethylene involvement in the regulation of the H\u3csup\u3e+\u3c/sup\u3e-ATPase \u3ci\u3eCsHA1\u3c/i\u3e gene and of the new isolated ferric reductase \u3ci\u3eCsFRO1\u3c/i\u3e and iron transporter \u3ci\u3eCsIRT1\u3c/i\u3e genes in cucumber plants

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    In previous works using ethylene inhibitors and precursors, it has been shown that ethylene participates in the regulation of several Fe-deficiency stress responses by Strategy I plants, such as enhanced ferric reductase activity, rhizosphere acidification, and subapical root hair development. Furthermore, recent evidence suggests that ethylene could regulate the expression of both the ferric reductase and the iron transporter genes of Strategy I plants by affecting the FER (or FER-like) transcription factor. Recently, two H+-ATPase genes have been isolated from cucumber roots, CsHA1 and CsHA2. CsHA1 is up-regulated under Fe deficiency while CsHA2 is constitutively expressed. In this work we have cloned and characterized the sequences of the ferric reductase (CsFRO1) and the iron transporter (CsIRT1) genes from cucumber (Cucumis sativus L. cv Ashley). Expression of CsHA1, CsFRO1, and CsIRT1 is diminished in Fe-deficient roots by treatment with ethylene inhibitors, such as Co (cobalt) or AOA (aminooxyacetic acid). Treatment with ethylene precursors, like ACC (1-aminocyclopropane-1-carboxylic acid) or Ethephon (2-chloroethylphosphonic acid), resulted in increased CsHA1, CsFRO1, and CsIRT1 transcript levels and increased ferric reductase activity during early stages of Fe deficiency. These results suggest that ethylene is involved in the regulation of CsHA1, CsFRO1, and CsIRT1 gene expression

    Ethylene and Phloem Signals Are Involved in the Regulation of Responses to Fe and P Deficiencies in Roots of Strategy I Plants

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    © Copyright © 2019 Lucena, Porras, García, Alcántara, Pérez-Vicente, Zamarreño, Bacaicoa, García-Mina, Smith and Romera. Iron (Fe) and phosphorus (P) are two essential mineral nutrients whose acquisition by plants presents important environmental and economic implications. Both elements are abundant in most soils but scarcely available to plants. To prevent Fe or P deficiency dicot plants initiate morphological and physiological responses in their roots aimed to specifically acquire these elements. The existence of common signals in Fe and P deficiency pathways suggests the signaling factors must act in conjunction with distinct nutrient-specific signals in order to confer tolerance to each deficiency. Previous works have shown the existence of cross talk between responses to Fe and P deficiency, but details of the associated signaling pathways remain unclear. Herein, the impact of foliar application of either P or Fe on P and Fe responses was studied in P- or Fe-deficient plants of Arabidopsis thaliana, including mutants exhibiting altered Fe or P homeostasis. Ferric reductase and acid phosphatase activities in roots were determined as well as the expression of genes related to P and Fe acquisition. The results obtained showed that Fe deficiency induces the expression of P acquisition genes and phosphatase activity, whereas P deficiency induces the expression of Fe acquisition genes and ferric reductase activity, although only transitorily. Importantly, these responses were reversed upon foliar application of either Fe or P on nutrient-starved plants. Taken together, the results reveal interactions between P- and Fe-related phloem signals originating in the shoots that likely interact with hormones in the roots to initiate adaptive mechanisms to tolerate deficiency of each nutrient

    Algorithm for Correcting the Keratometric Error in the Estimation of the Corneal Power in Keratoconus Eyes after Accelerated Corneal Collagen Crosslinking

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    Purpose. To analyze the errors associated to corneal power calculation using the keratometric approach in keratoconus eyes after accelerated corneal collagen crosslinking (CXL) surgery and to obtain a model for the estimation of an adjusted corneal refractive index (nkadj) minimizing such errors. Methods. Potential differences (ΔPc) among keratometric (Pk) and Gaussian corneal power (PGauss c ) were simulated. Three algorithms based on the use of nkadj for the estimation of an adjusted keratometric corneal power (Pkadj) were developed. The agreement between Pk(1.3375) (keratometric power using the keratometric index of 1.3375), PGauss c , and Pkadj was evaluated. The validity of the algorithm developed was investigated in 21 keratoconus eyes undergoing accelerated CXL. Results. Pk(1.3375) overestimated corneal power between 0.3 and 3.2D in theoretical simulations and between 0.8 and 2.9D in the clinical study (ΔPc). Three linear equations were defined for nkadj to be used for different ranges of r1c. In the clinical study, differences between Pkadj and PGauss c did not exceed ±0.8D nk = 1.3375. No statistically significant differences were found between Pkadj and PGauss c (p > 0 05) and Pk(1.3375) and Pkadj (p < 0 001). Conclusions. The use of the keratometric approach in keratoconus eyes after accelerated CXL can lead to significant clinical errors. These errors can be minimized with an adjusted keratometric approach

    Induced Systemic Resistance (ISR) and Fe Deficiency Responses in Dicot Plants

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    Plants develop responses to abiotic stresses, like Fe deficiency. Similarly, plants also develop responses to cope with biotic stresses provoked by biological agents, like pathogens and insects. Some of these responses are limited to the infested damaged organ, but other responses systemically spread far from the infested organ and affect the whole plant. These latter responses include the Systemic Acquired Resistance (SAR) and the Induced Systemic Resistance (ISR). SAR is induced by pathogens and insects while ISR is mediated by beneficial microbes living in the rhizosphere, like bacteria and fungi. These root-associated mutualistic microbes, besides impacting on plant nutrition and growth, can further boost plant defenses, rendering the entire plant more resistant to pathogens and pests. In the last years, it has been found that ISReliciting microbes can induce both physiological and morphological responses to Fe deficiency in dicot plants. These results suggest that the regulation of both ISR and Fe deficiency responses overlap, at least partially. Indeed, several hormones and signaling molecules, like ethylene (ET), auxin, and nitric oxide (NO), and the transcription factor MYB72, emerged as key regulators of both processes. This convergence between ISR and Fe deficiency responses opens the way to the use of ISR-eliciting microbes as Fe biofertilizers as well as biopesticides. This review summarizes the progress in the understanding of the molecular overlap in the regulation of ISR and Fe deficiency responses in dicot plants. Root-associated mutualistic microbes, rhizobacteria and rhizofungi species, known for their ability to induce morphological and/or physiological responses to Fe deficiency in dicot plant species are also reviewed herei

    Monitor de Salud Personal

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    En este artículo se presenta el sistema Monitor de Salud Personal desarrollado en Telefónica I+D, en colaboración con el Departamento deInformática y Automática de la Universidad de Salamanca. Este proyecto se enmarca dentro de las actividades relacionadas con la gestión del Hogar Digital y de los proyectos actualmente en desarrollo en Telefónica I+D en este campo. El objetivo del proyecto global es explorar diversas tecnologíashabilitadoras de inteligencia ambiental con las que el usuario interacciona en elhogar de forma transparente, proporcionando componentes tecnológicos en distintos escenarios: asistencia y bienestar en el hogar, entretenimiento, gestión de la identidad en el hogar, gestión de la ubicación en el hogar. El Monitor de Salud Personal que se describe en este artículo está orientado a satisfacer el objetivo de asistencia y bienestar en el hogar y cuyos objetivos se integran plenamente dentro de la iniciativa europea Ambient Assisted Living JointProgramme (AAL)

    Ethylene and phloem signals are involved in the regulation of responses to Fe and P deficiencies in roots of strategy I plants

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    Iron (Fe) and phosphorus (P) are two essential mineral nutrients whose acquisition by plants presents important environmental and economic implications. Both elements are abundant in most soils but scarcely available to plants. To prevent Fe or P deficiency dicot plants initiate morphological and physiological responses in their roots aimed to specifically acquire these elements. The existence of common signals in Fe and P deficiency pathways suggests the signaling factors must act in conjunction with distinct nutrient-specific signals in order to confer tolerance to each deficiency. Previous works have shown the existence of cross talk between responses to Fe and P deficiency, but details of the associated signaling pathways remain unclear. Herein, the impact of foliar application of either P or Fe on P and Fe responses was studied in P- or Fe-deficient plants of Arabidopsis thaliana, including mutants exhibiting altered Fe or P homeostasis. Ferric reductase and acid phosphatase activities in roots were determined as well as the expression of genes related to P and Fe acquisition. The results obtained showed that Fe deficiency induces the expression of P acquisition genes and phosphatase activity, whereas P deficiency induces the expression of Fe acquisition genes and ferric reductase activity, although only transitorily. Importantly, these responses were reversed upon foliar application of either Fe or P on nutrient-starved plants. Taken together, the results reveal interactions between P- and Fe-related phloem signals originating in the shoots that likely interact with hormones in the roots to initiate adaptive mechanisms to tolerate deficiency of each nutrient

    Efecto de una cepa de Fusarium oxysporum y de diversas levaduras sobre la nutrición férrica de plantas de pepino y tomate

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    Trabajo presentado en el XVI Congreso Nacional de Ciencias Hortícolas, celebrado en Córdoba del 17 al 22 de octubre de 2021,El hierro (Fe) es un micronutriente esencial para las plantas. En suelos calizos se encuentra en su forma oxidada (Fe 3+), presentando baja solubilidad y disponibilidad para las plantas. Bajo deficiencia de Fe, las plantas dicotiledóneas inducen diversas respuestas fisiológicas y morfológicas en sus raíces para facilitar así su captación y paliar los efectos que produce su deficiencia. Existen evidencias de que determinados microorganismos rizosféricos, como los que provocan la Respuesta Sistémica Inducida (ISR), pueden facilitar la nutrición férrica de las plantas. El objetivo de este trabajo ha sido, por una parte, estudiar el efecto de la cepa no patogénica de Fusarium oxysporum (FO12), posiblemente inductora de ISR, sobre el crecimiento y clorosis de plantas de tomate (Solanum lycopersicum Mill.), y sobre la colonización de raíces de pepino (Cucumis sativus L.). Por otra parte, estudiar el efecto de determinadas levaduras (Debaryomyces hansenii, Saccharomyces cerevisiae y Hansenula polymorpha) sobre diversas respuestas a la deficiencia de Fe en plantas de pepino. Los experimentos con tomate se han desarrollado en suelo calizo y los de pepino en cultivo hidropónico. Los resultados obtenidos con FO12 han mostrado su capacidad para colonizar endofiticamente las raíces de pepino y su efecto promotor del crecimiento, la concentración de clorofila y de Fe (en hojas) en plantas de tomate. Las diferentes levaduras utilizadas han causado inducción de la capacidad reductora de Fe 3+, de la acidificación de la rizosfera, y de la proliferación de pelos radicales en la zona subapical de las raíces de pepino. Estos resultados sugieren que, tanto FO12 como las diferentes levaduras utilizadas, tienen potencial como biofertilizantes de Fe.Plan Propio de la Universidad de Córdoba y Ministerio de Ciencia e Innovación

    A Xenogeneic-Free Protocol for Isolation and Expansion of Human Adipose Stem Cells for Clinical Uses

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    Human adipose stem cells (hASCs) play a crucial role in the fields of regenerative medicine and tissue engineering for different reasons: the abundance of adipose tissue, their easy harvesting, the ability to multipotent differentiation and the fact that they do not trigger allogeneic blood response or secrete cytokines that act as immunosuppressants. The vast majority of protocols use animal origin reagents, with the underlying risk of transmitting infections by non-human pathogens. We have designed a protocol to isolate and maintain the properties of hASCs avoiding xenogeneic reagents. These changes not only preserve hASCs morphology, but also increase cell proliferation and maintain their stem cell marker profile. On the other hand, human serum albumin (HSA), Tryple® and human Serum (HS), do not affect hASCs multipotent differentiation ability. The amendments introduced do not trigger modifications in the transcriptional profile of hASCs, alterations in key biochemical pathways or malignization. Thus, we have proven that it is possible to isolate and maintain hASCs avoiding animal reagents and, at the same time, preserving crucial culture parameters during long term culture. Thereby we have revealed a novel and effective tool for the improvement of clinical, cell-based therapies.Peer reviewe
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