One-pot synthesis of hierarchical porous carbons with extended ultramicropores: new prospective materials for supercapacitors

A series of carbon electrodes was synthesized via a modification of the polymerization-condensation reaction, where a 4:1 mass excess of melamine was added in basic media to the resorcinol/formaldehyde classical mixture. Melamine, together with variations of the pyrolysis temperature play a key role to define the chemical and textural properties of these carbons. A high nitrogen content, ranging from 23.2 to 11.3 % was determined. A low degree of crystallinity and disordered internal structure were assessed, while a hierarchical porous structure was stablished for all samples, including an important ultramicroporosity, with pore sizes below 0.7 nm. All electrodes showed a predominant double layer capacitive behaviour in aqueous H2SO4, while a small pseudocapacitive contribution was also evidenced for the three carbons pyrolysed at higher temperatures. These three electrodes show the highest specific capacitance (maximum of 153.6 F g−1), and outstanding cycling over 10,000 cycles. A comprehensive analysis correlating morphological and surface properties and the electrochemical behaviour was carried out. The best performing carbon was selected to construct a symmetrical device for which a specific capacitance of 103 F g−1 was determined, reaching energy and power density values of 1.4 Wh Kg−1 and 111.7 W Kg−1, respectively.Fil: Arias, Analía Natalí. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy. - Universidad Nacional de Jujuy. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy. - Gobierno de la Provincia de Jujuy. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy; ArgentinaFil: Villarroel Rocha, Jhonny. Universidad Nacional de San Luis; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sapag, Manuel Karim. Universidad Nacional de San Luis; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mori, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Planes, Gabriel Angel. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; ArgentinaFil: Flexer, Victoria. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy. - Universidad Nacional de Jujuy. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy. - Gobierno de la Provincia de Jujuy. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy; ArgentinaFil: Tesio, Alvaro Yamil. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy. - Universidad Nacional de Jujuy. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy. - Gobierno de la Provincia de Jujuy. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy; Argentin

Función de biomasa para Acacia caven (Mol.) Mol. distribuida en áreas secas del centro sur de Chile

Acacia caven is a key native species in the dry land region of south-central Chile. It is a species of high social and productive interest to landowners. Therefore, this study proposes a biomass function for A. caven, which involves incorporating predictor variables that are easily obtainable in the field and less complex than those used in already existing functions for the species. Due to the multi-purpose nature of the species and its potential for silvopastoral systems, these functions typify important planning tools to improve the management of this plant resource. To generate the biomass function, the methodology of destructive analysis of components was used on a total of 71 trees. These trees were selected, cut and weighed in the field to generate and test different models. Statistical analysis models were used and root collar diameter, diameter at breast height and total height served as predictor variables, resulting in a good adjustment of the models (R2 adjusted the 0.97 for stem-branches, 0.90 for stems and 0.96 for total biomass), with high correlations between estimated and real values. These functions may be used safely in plant formations of A. caven located in the same distribution area and within the range of the used variables. In the future, however, they require validation with new measurements in other sectors than the area considered to increase geographical representativeness.Acacia caven, es una de las principales especies nativas presentes en el secano interior de la zona central de Chile. Es una especie que tiene un alto interés social y productivo para los propietarios de este recurso. En este sentido, el objetivo de este estudio es proponer una función de biomasa validada para A. caven, y que incorpore variables predictoras de fácil obtención en terreno y de menor complejidad que las consideradas en funciones ya conocidas para la especie. Dadas las características de especie multipropósito y su potencial para su uso en sistemas silvopastorales, estas funciones son importantes herramientas de planificación para mejorar la gestión y manejo de este recurso vegetacional. Para la generación de la función de biomasa, se utilizó una metodología de análisis destructivo por componentes de 71 árboles, los cuales fueron seleccionados, volteados y pesados en terreno, para posteriormente generar y probar diferentes modelos. A través de análisis estadísticos se seleccionaron modelos que utilizan como variables predictoras el diámetro a la altura del cuello, diámetro a la altura del pecho y altura total. Los resultados muestran un buen ajuste de los modelos (R2 ajust. de 0,97 para fuste-ramas, 0,90 para ramillas y 0,96 para biomasa total), lo que indica un alto nivel de correlación entre valores estimados y valores reales. Estas funciones se pueden utilizar con seguridad en formaciones vegetacionales de A. caven que se ubiquen en la misma zona distribucional del recurso y dentro de los rangos de las variables utilizadas, siendo conveniente en el futuro validarlas con nuevas mediciones de sectores distintos al área considerada para estos análisis, aumentando su representatividad geográfica.Fil: Lucero Ignamarca, Alejandro. Universidad de Concepción (Chile)Fil: Muñoz Sáez, Fernando. Universidad de Concepción (Chile)Fil: Cancino Cancino, Jorge. Universidad de Concepción (Chile)Fil: Sotomayor Garreton, Alvaro. Universidad de Concepción (Chile)Fil: Dube, Francis. Universidad de Concepción (Chile)Fil: Villarroel Muñoz, Arnoldo. Universidad de Concepción (Chile)Fil: Sáez Carrillo, Katia. Universidad de Concepción (Chile

Influence of environmental knowledge and awareness on pro-environmental behaviour and decision-making

[Resumen] Los retos ambientales a los que nos enfrentamos requieren un cambio de comportamiento de las sociedades actuales y la educación puede jugar un papel muy importante en la estimulación de dicho cambio. Para diseñar programas educativos que impulsen un cambio de comportamiento hacia uno más pro-ambiental, es necesario analizar los factores que pueden determinar el compor - tamiento ambiental de las personas. Este trabajo pretende avanzar en la descripción de los facto - res que influyen en la conducta y toma de decisiones pro-ambientales a partir de una encuesta a personas en formación de diferentes edades. Los resultados mostraron que la conducta y toma de decisiones ambientales parece estar ligada a factores no necesariamente relacionados con el nivel de conocimiento, como pudiera ser el componente afectivo. Finalmente, se proponen estrategias para estimular la creación de vínculos afectivos con el ambiente y su problemática que contribuyan al desarrollo de una conducta pro-ambiental.[Abstract] The environmental challenges that we are currently facing demand changes in our behaviour. Education can play an important role in promoting these changes through educational programmes that encourage more pro-environmental behaviour. This study examines the factors that influence pro-environmental behaviour by surveying adults-in-training of different ages. The results show that environmental behaviour and decision-making are less affected by level of knowledge than by emotional factors. The article concludes by proposing strategies to promote emotional ties with the environment as a way of encouraging more pro-environmental behaviour

Gure bihotzeko kalmodulina

Calcium is a universal signaling messenger that participates in essential processes such as apoptosis, cell proliferation and muscle contraction. Many of the proteins involved in these processes must interact with a calcium sensor to respond to the changes of concentration of this ion. The best-studied sensor is Calmodulin (CaM). It regulates the activity of hundreds of proteins through its N- and C- lobes, where two EF-hands are located to bind up to four calcium ions. Although the role of CaM in cell signaling is widespread, its mutations are especially recognized through its effects on cardiac function. In fact, disease-causing mutations in any of the three genes that encode the same CaM proteins cause severe cardiac dysfunction, indicating their importance in regulating excitability. Therefore, knowing the mechanisms involved in these diseases can allow a rational approach to clinical manifestations and contribute to the development of therapeutic strategies.; Kaltzioa seinalizazio unibertsaleko mezulari bat da, funtsezko prozesuetan parte hartzen duena, hala nola apoptosian, zelulen proliferazioan eta muskuluen uzkurduran. Prozesu horietan parte hartzen duten proteina askok ioi honen kontzentrazioari erantzuteko kaltzio sentsore batekin, kalmodulinarekin (CaM), elkarreragin behar dute. Horrek ehunka proteinaren aktibitatea erregulatzen du bere N- eta C-lobuluen bidez, non EF-eskuak aurkezten dituen Ca2+-ari lotzeko. Zelulen seinalizazioan CaM-k duen papera hedatuta dagoen arren, haren mutazioek bereziki bihotzari eragiten diote. Izan ere, CaM proteina berdinak kodetzen dituzten hiru geneetako edozeinetan gaixotasunak eragiten dituzten mutazioek bihotz-disfuntzio larriak eragiten dituzte, eta horrek kitzikagarritasunaren erregulazioan duen garrantzia adierazten du. Beraz, esku hartzen duten mekanismoen ezagutzak aukera eman dezake adierazpen klinikoei modu kritikoan heltzeko eta kalmodulinopatietarako estrategia terapeutikoak garatzen laguntzeko

Proteinen tolestura tunel erribosomikoan

Proteins are synthesised as linear polymers and must fold into their native three-dimensional structure to perform various functions in the cell. Understanding protein folding is crucial because protein misfolding is at the origin of several neurodegenerative diseases. Protein folding can start cotranslationally, i.e. when the emerging peptide is still asso-ciated with the ribosome. Indeed, it has been shown that more than one third of the cell’s proteins fold in the limited space of the ribosome tunnel. Increasing evidence suggests that the ribosome plays a critical role in protein folding. The ribosome can facilitate protein compaction, cause the creation of non-visible media in solution or delay the onset of folding. However, the study of cotranslational folding presents serious difficulties, mainly due to the limitations of the different current techniques. Hence, most studies on protein folding are based on proteins in solution, which are carried out by unfolding and refolding the protein, without taking into account the role of the ribosome in this process. In this article, we summarised the techniques developed in recent years for the study of cotranslational protein folding.; Proteinak polimero lineal gisa sintetizatzen dira eta beren jatorrizko egitura tridimentsionalean tolestu behar dira zelulan hainbat funtzio betetzeko. Proteinen tolespena ulertzea funtsezkoa da, tolespen okerrak hainbat gaixotasun neuro-degeneratiboren jatorria direlako. Proteinen tolespena modu koitzultzailean has daiteke, hau da, sortzen ari den peptidoa erribosomari lotuta dagoenean oraindik. Izan ere, zelularen proteinen heren bat baino gehiago erribosomaren tunelaren espazio mugatuan tolesten direla frogatu da, hau da, erribosomaren gainazalarekiko interakzioek modulatuta eta erribosoma-tunelaren beraren mugen pean. Gero eta ebidentzia gehiagok iradokitzen dute erribosomak funtsezko zeregina duela proteinen tolespenean. Erribosomak proteina trinkotzea erraztu dezake, soluzioan ikusten ez diren bitartekoak sortzea eragin dezake edo tolestearen hasiera atzeratu dezake. Hala ere, proteinen koitzulpenezko tolesdura aztertzeak zailtasun handiak ditu, batik bat, egungo teknikek dituzten mugengatik. Hori dela eta, proteinen tolesteari buruzko ikerketa gehienak soluzioan dauden proteinetan oinarritzen dira, proteina tolestuz eta destolestuz egiten direnak, prozesu horretan erribosomak duen rola kontuan hartu gabe. Artikulu honetan, azken urteotan proteinen koitzulpenezko tolestura ikertzeko garatu diren tekniken laburpena egin da

Do calmodulin binding IQ motifs have built-in capping domains?

Most calmodulin (CaM) targets are α-helices. It is not clear if CaM induces the adoption of an α-helix configuration to its targets or if those targets are selected as they spontaneously adopt an α-helical conformation. Other than an α-helix propensity, there is a great variety of CaM targets with little more in common. One exception to this rule is the IQ site that can be recognized in a number of targets, such as those ion channels belonging to the KCNQ family. Although there is negligible sequence similarity between the IQ motif and the docking site on SK2 channels, both adopt a similar three-dimensional disposition. The isolated SK2 target presents a pre-folded core region that becomes fully α-helical upon binding to CaM. The existence of this pre-folded state suggests the occurrence of capping within CaM targets. In this review, we examine the capping properties within the residues flanking this core domain, and relate known IQ motifs and capping.The Government of the Autonomous Community of the Basque Country (IT1165-19 and KK-2020/00110) and the Spanish Ministry of Science and Innovation (RTI2018-097839-B-100 to A.V. and PID2019-105488GB-I00 to A.B., A.L., and O.R.B.) and FEDER funds provided financial support for this work. A.M-M. is supported by predoctoral contracts from the Basque Government administered by University of the Basque Country.Peer reviewe

Kv7 Channels Can Function without Constitutive Calmodulin Tethering

M-channels are voltage-gated potassium channels composed of Kv7.2-7.5 subunits that serve as important regulators of neuronal excitability. Calmodulin binding is required for Kv7 channel function and mutations in Kv7.2 that disrupt calmodulin binding cause Benign Familial Neonatal Convulsions (BFNC), a dominantly inherited human epilepsy. On the basis that Kv7.2 mutants deficient in calmodulin binding are not functional, calmodulin has been defined as an auxiliary subunit of Kv7 channels. However, we have identified a presumably phosphomimetic mutation S511D that permits calmodulin-independent function. Thus, our data reveal that constitutive tethering of calmodulin is not required for Kv7 channel function

Selective Interaction of Syntaxin 1A with KCNQ2: Possible Implications for Specific Modulation of Presynaptic Activity

KCNQ2/KCNQ3 channels are the molecular correlates of the neuronal M-channels, which play a major role in the control of neuronal excitability. Notably, they differ from homomeric KCNQ2 channels in their distribution pattern within neurons, with unique expression of KCNQ2 in axons and nerve terminals. Here, combined reciprocal coimmunoprecipitation and two-electrode voltage clamp analyses in Xenopus oocytes revealed a strong association of syntaxin 1A, a major component of the exocytotic SNARE complex, with KCNQ2 homomeric channels resulting in a ∼2-fold reduction in macroscopic conductance and ∼2-fold slower activation kinetics. Remarkably, the interaction of KCNQ2/Q3 heteromeric channels with syntaxin 1A was significantly weaker and KCNQ3 homomeric channels were practically resistant to syntaxin 1A. Analysis of different KCNQ2 and KCNQ3 chimeras and deletion mutants combined with in-vitro binding analysis pinpointed a crucial C-terminal syntaxin 1A-association domain in KCNQ2. Pull-down and coimmunoprecipitation analyses in hippocampal and cortical synaptosomes demonstrated a physical interaction of brain KCNQ2 with syntaxin 1A, and confocal immunofluorescence microscopy showed high colocalization of KCNQ2 and syntaxin 1A at presynaptic varicosities. The selective interaction of syntaxin 1A with KCNQ2, combined with a numerical simulation of syntaxin 1A's impact in a firing-neuron model, suggest that syntaxin 1A's interaction is targeted at regulating KCNQ2 channels to fine-tune presynaptic transmitter release, without interfering with the function of KCNQ2/3 channels in neuronal firing frequency adaptation

Unraveling Amazon tree community assembly using Maximum Information Entropy: a quantitative analysis of tropical forest ecology

In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain eight times more of local relative abundances than constraints based on directional selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary methods, furthering our understanding of ecological dynamics