186 research outputs found
The role of DGK1 and DGK2 in Membrane Contact Sites and Stress Tolerance
All eukaryotic cells present regions where the membranes of two different organelles are very close (10-30 nm) without fusion, mediated by tether proteins. These regions are known as Membrane Contact Sites (MCS). Contact sites between the endoplasmic reticulum and plasma membrane (ER-PM CS) play important roles in communication, lipid and Ca2+ homeostasis.
Upon stress perception, phospholipase C (PLC) is activated at the plasma membrane producing diacylglycerol (DAG) and inositol phosphates from the hydrolysis of PIP(4,5)P2 or PI4P. DAG has an amphipathic structure with a hydrophobic region and a small polar head. In normal conditions DAG has a low concentration, 1% of total polar lipids (Gaude et al., 2007). Accumulation of DAG produces a negative curvature stress due to its small polar head that destabilizes the PM (Campomanes et al., 2019; Putta et al., 2016). Thus, DAG concentration must be finely controlled. DAG is phosphorylated by diacylglycerol kinases (DGKs) producing phosphatidic acid (PA). Both, DAG and PA, are important molecules involved in signalling (Arisz et al., 2009). The Arabidopsis thaliana genome contains seven genes encoding DGKs. While most of them are cytosolic (DGK3-DGK7), DGK1 and DGK2 possess a transmembrane domain that anchor them to the ER.
Using different approaches we show that DGK1 (AT5G07920) and DGK2 (AT5G63770) form a complex with Synaptotagmin1 (SYT1, At2g20990), a protein tether located at ER-PM CS (Pérez-Sancho et al., 2015). SYT1 is able to bind preferentially DAG (Ruiz-Lopez et al., 2021), which support the idea of being working together with DGK1 and DGK2. DGK1 and DGK2 transcripts increase after cold treatment and a dgk2 mutant shows reduced root growth under low temperature and a low freezing tolerance. Our studies suggest that DGK1 and DGK2 act in concert with SYT1 to regulate the production of PA at ER-PM CS and highlight the importance of these proteins in stress tolerance.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Unravelling glioblastoma heterogeneity by means of single-cell RNA sequencing.
Glioblastoma (GBM) is the most invasive and deadliest brain cancer in adults. Its inherent heterogeneity has been
designated as the main cause of treatment failure. Thus, a deeper understanding of the diversity that shapes GBM
pathobiology is of utmost importance. Single-cell RNA sequencing (scRNA-seq) technologies have begun to
uncover the hidden composition of complex tumor ecosystems. Herein, a semi-systematic search of reference
literature databases provided all existing publications using scRNA-seq for the investigation of human GBM. We
compared and discussed findings from these works to build a more robust and unified knowledge base. All aspects
ranging from inter-patient heterogeneity to intra-tumoral organization, cancer stem cell diversity, clonal
mosaicism, and the tumor microenvironment (TME) are comprehensively covered in this report. Tumor
composition not only differs across patients but also involves a great extent of heterogeneity within itself. Spatial
and cellular heterogeneity can reveal tumor evolution dynamics. In addition, the discovery of distinct cell
phenotypes might lead to the development of targeted treatment approaches. In conclusion, scRNA-seq expands
our knowledge of GBM heterogeneity and helps to unravel putative therapeutic targets.post-print4967 K
Interacción sedimentaria del polvo sahariano, y los flujos biogénicos y litogénicos en la cuenca oceánica de Canarias
Saharan dust events are currently the predominant source of lithogenic particles in the Canary Basin. In order to quantify this input and its relationship with the biogenic fluxes, a sediment trap was deployed in a free-drifting system at 150 m depth, 50 km off the north coast of Gran Canaria (Canary Islands). The mineralogy of the lithogenic particles included illite, calcite, hematite quartz, barite and kaolinite. The biogenic matter was composed of chitin, transparent exopolymer particles, and carbonates from foraminifera and gastropod shells. The average Saharan dust flux over the ocean surface was approximately 5±4 mg m–2 day-1. The lithogenic, carbonate and chitin fluxes were 0.8±0.6, 6.0±7.4 and 154±386 mg m–2 day-1, respectively. A fairly strong Saharan dust event during sampling was observed in the trap, with a delay of three days in the peaks of lithogenic and biogenic fluxes. The theoretical settling velocity of the lithogenic particles associated with Saharan dust events at 150 m depth was vStokes=275 m day-1, and the experimental settling was about 50 m day-1. The associated sinking behaviour of particulate organic carbon and biogenic and lithogenic fluxes observed in this study may contribute to a more realistic prediction of these fluxes in carbon biological pump models.En la actualidad los eventos de polvo Sahariano son la fuente principal de partículas litogénicas en la cuenca oceánica de Canarias. Con el objetivo de cuantificar su entrada y la interacción con los flujos biogénicos, se instaló una trampa de sedimento a la deriva, a 150 m de profundidad, 50 km al norte de la costa de Gran Canaria (Islas Canarias). Las partículas litogénicas detectadas fueron de illita, calcita, hematites, cuarzo, barita y caolinita. El material biogénico estaba compuesto por quitina, partículas de exopolímeros transparentes (TEP) y carbonatos procedentes de foraminíferos y conchas de gasterópodos. La media del flujo de polvo sahariano sobre la superficie oceánica fue aproximadamente 5±4 mg m-2 dia-1. Las medias de flujos litogénico, carbonato y quitina respectivamente fueron 0.8±0.6 mg m-2 dia–1, 6.0±7.4 mg m–2 dia-1 y 154±386 mg m-2 dia-1. Durante el muestreo se registró un intenso evento de polvo sahariano seguido, a los tres días, de picos en los flujos litogénicos y biogénicos en la trampa de sedimento a 150 m de profundidad. La velocidad teórica de sedimentación de las partículas litogénicas asociadas a los eventos de polvo sahariano a 150 m de profundidad calculada fue de vStokes=275 m dia-1, siendo la velocidad de sedimentación experimental obtenida tras el análisis de los flujos fue de 50 m dia-1. El comportamiento de los procesos de sedimentación asociados al POC, el flujo biogénico y el flujo litogénico observados en este estudio podría contribuir a modelos más realistas de la bomba biológica de carbono en los océanos
Trapping para-quinone methide intermediates with ferrocene: Synthesis and preliminary biological evaluation of new phenol-ferrocene conjugates
The reaction of para-hydroxybenzyl alcohols with ferrocene in the presence of a catalytic amount of InCl3 provided ferrocenyl phenol derivatives, an interesting class of organometallic compounds with potential applications in medicinal chemistry. This transformation exhibited a reasonable substrate scope delivering the desired products in synthetically useful yields. Evidence of involvement of a para-quinone methide intermediate in this coupling process was also provided. Preliminary biological evaluation demonstrated that some of the ferrocene derivatives available by this methodology exhibit significant cytotoxicity against several cancer cell lines with IC50 values within the range of 1.07–4.89 μM
Anticonvulsant and Antioxidant Effects of Tilia americana
Tilia genus is commonly used around the world for its central nervous system properties; it is prepared as tea and used as tranquilizing, anticonvulsant, and analgesic. In this study, anticonvulsant activity of the Tilia americana var. mexicana inflorescences and leaves was investigated by evaluating organic and aqueous extracts (100, 300, and 600 mg/kg, i.p.) and some flavonoids in the pentylenetetrazole-induced seizures in mice. Moreover, antioxidant effect of these extracts and flavonoids was examined in an in vitro study by using spectrophotometric technique. Significant activity was observed in the methanol extract from inflorescences. An HPLC analysis of the methanol extract from inflorescences and leaves of Tilia allowed demonstrating the respective presence of some partial responsible flavonoid constituents: quercetin (20.09 ± 1.20 μg/mg and 3.39 ± 0.10 μg/mg), rutin (3.52 ± 0.21 μg/mg and 8.94 ± 0.45 μg/mg), and isoquercitrin (1.74 ± 0.01 μg/mg and 1.24 ± 0.13 μg/mg). In addition, significant but different antioxidant properties were obtained among the flavonoids and the extracts investigated. Our results provide evidence of the anticonvulsant activity of Tilia reinforcing its utility for central nervous system diseases whose mechanism of action might involve partial antioxidant effects due to the presence of flavonoids
Función orientadora del docente y su incidencia en el desarrollo de las competencias en los estudiantes de educación básica de los centros escolares públicos en los departamentos de San Vicente y La Paz, durante el año 2018
Esta investigación trato sobre la función orientadora del docente y su incidencia en el desarrollo de las competencias de los estudiantes de Educación Básica, en los Centros Escolares Públicos, en los departamentos de San Vicente y La Paz, dicha investigación fue de gran relevancia, ya que permitió identificar la orientación que brindan los docentes en el proceso de enseñanza aprendizaje, dicho subtema se derivó de la elaboración del siguiente tema general: Factores socio educativos que inciden en el sistema educativo a nivel nacional en la continuidad de la formación académica de los estudiantes en Educación Básica, Media y Superior
Pore size analysis from retention of neutral solutes through nanofiltration membranes. The contribution of concentration–polarization
Producción CientíficaPore size distribution is one of the most important characteristics of a membrane. This can be obtained from the
fitting of pore radius calculated fromretention versus flux measurements for a set of solute solutions. In thiswork
a set of non-charged similar molecules is chosen as solutes to minimize other interactions apart of those related
to size. The hydrodynamic model will be used to characterize the behavior of the membrane to uncharged
solutes, assuming that membrane pores are straight and cylindrical.
As is known, the phenomenon of concentration polarization must be taken into account because true retention is
not experimentally accessible by concentration measurements. Frequently, the film layer model is applied for the
dependence of concentration with experimental conditions; but the application of this model requires prior
knowledge of the mass transfer coefficientwhich is evaluated by different dimensionless correlations (Sherwood
correlation). Here we show a review of different alternatives in doing it and analyze their consequences when
computing the pore size distribution.
Experimental data were obtained from dead-end filtration experiments of a set of four ethylene glycol solutions
with a nanofiltration membrane. Obtained results show the importance of the mass transfer model in the pore
size value obtained.Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA302U13
Decolorization and detoxification of synthetic dyes by mexican strains of trametes sp
Laccases have attracted a great deal of interest because of their remarkable ability for the degradation of synthetic dyes present in wastewaters. New laccase producing sources with robust operational and functional properties are being continuously explored. In this work, the potential for the decolorization and detoxification of synthetic dyes was evaluated in two Mexican strains of the genus Trametes. The decolorization capacity of Trametes maxima LE130 and Trametes sp. LA1 was tested in solid and liquid media. The phytotoxicity of the degradation products was determined using Raphanus sativus and Pisum sativum seeds. In solid media, both strains showed a higher decolorization capacity (p ≤ 0.05) than Phanerochaete chrysosporium ATCC 24725, which is known to be very efficient in lignin and dye-degradation. They produced laccase as the main ligninolytic enzyme; T. maxima LE130 secreted a single isoform of 43.9 kDa, while Trametes sp. LA1 produced three isoforms of 67.3, 58.6 and 52.7 kDa, respectively. Trametes sp. LA1 culture fluids were capable of decolorizing and detoxifying chemically diverse dyes (anthraquinonic dye Remazol Brilliant Blue R, azoic Reactive Black 5 and triphenylmethane Crystal Violet) without the addition of redox mediators. Therefore, this could be considered as a new laccase source which could be potentially competitive in the bioremediation of dye-containing wastewaters.Fil: Levin, Laura Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Hernández Luna, Carlos E.. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Niño Medina, Guillermo. Universidad Autonoma de Nuevo Leon.; MéxicoFil: García Rodríguez, Juan Pablo. Universidad Autonoma de Nuevo Leon.; MéxicoFil: López Sadin, Iosvany. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Méndez Zamora, Gerardo. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Gutiérrez Soto, Guadalupe. Universidad Autonoma de Nuevo Leon.; Méxic
Alteraciones emocionales en pacientes entre los 50 a 70 años de edad cronológica, diagnosticados con diabetes mellitus tipo 2 y sus cuidadores de policlínica de atención integral de Santa Ana, en el periodo comprendido de febrero a diciembre de 2017
Cada año más y más personas viven con esta condición que puede generar complicaciones a lo largo de la vida. Estas complicaciones son las principales causas de muerte en la mayoría de los países, esto debido a la falta de conciencia sobre el impacto psicológico, social y económico que conlleva la enfermedad, la falta de conocimiento podría ser una causa que se toma para la obstaculización de la prevención efectiva de la diabetes. La Diabetes Mellitus tipo 2 es el tipo de diabetes más común en El Salvador, esta enfermedad ha aumentado de manera alarmante, afectando todos los aspectos de la vida de la persona diagnosticada. Este cambio en el estilo de vida se caracteriza por desaprender y aprender hábitos de la vida diaria que permitan llevar una rutina lo más equilibrada posible; para ello, se debe asumir la enfermedad, aceptando el diagnóstico, reestructurando el concepto de enfermedad que se posee, manteniendo una actitud positiva, aprendiendo sobre la enfermedad y adoptar hábitos de vida saludable
Desempeño que requiere la formación inicial docente en el ámbito de la investigación
Tesis (Profesor de Educación Física para la Enseñanza Básica, Licenciado en Educación)En la presente investigación, han sido recopilados, revisados, expuestos y
analizados una serie de documentos de diversos orígenes y fuentes, de origen nacional
e internacional, de autorías individuales y grupales, relacionados con el ámbito de la
investigación y la importancia que se otorga a esta en el mundo de la educación en
general y el ámbito formativo de docentes.
Dichos documentos serán utilizados como marco teórico, con el fin de establecer
las falencias y fortalezas existentes en el actual proceso de formación docente y en el
proceso de Seminario de Grado de 4º año de la carrera de Educación Física de la
Universidad Andrés Bello (UNAB) en lo que respecta a la investigación e indagación
científica, además de establecer los diversos desempeños que requiere la formación
inicial docente (FID) en el ámbito investigativo.
Por otro lado, en base a los documentos revisados durante la investigación y las
conclusiones obtenidas al respecto, se espera establecer un diagnóstico que pueda ser
de utilidad para la Universidad Andrés Bello a la hora de plantearse cambios en
innovaciones en la malla curricular de la carrera de Educación Física que en ella se
imparte
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