Ferroelectric properties of Bi0.5(Na0.8K0.2)0.5TiO3 ceramics

Different processing conditions and the effect of secondary phases on ferroelectric properties of Bi0.5(Na0.8K0.2)0.5TiO3 (BNKT) are studied. Ceramic powders are prepared by solid state reaction and different sintering temperatures (temperatures between 1075 and 1150ºC) are analyzed. Finally, samples are characterized by X-ray diffraction, Raman microspectroscopy, Scanning Electron Microscopy, impedance spectroscopy, and density measurements. Through XRD patterns, the perovskite structure is stabilized; together with small peaks corresponding to a secondary phase associated with K2-xNaxTi6O13 phase. Moreover, the content of the secondary phase, d33 piezoelectric constant and dielectric properties increase with sintering temperature.Fil: Camargo, Javier Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Ramajo, Leandro Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Rubio Marcos, Fernando. Instituto de Ceramica y Vidrio de Madrid; EspañaFil: Castro, Miriam Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Changes in Teacher Training within the TPACK Model Framework: A Systematic Review

The TPACK model represents a high-impact advance in teacher training regarding their technological, pedagogical and content knowledge. This research presents an analysis of several publications in international databases that address the matter of the TPACK model. Accordingly, a review of the scientific literature applying the documentation as a systematization method was performed. The present study analyses 37 contributions, published between 2014 and 2017, indexed in the Web of Science (WOS) and Scopus databases, with TPACK and TPCK as the applied descriptors. Thus, the documentary analysis was based on four different criteria: public, topic, main results, and methodological design. Results show that all the reviewed publications are mainly focused on studies of basic and higher education where case studies, quantitative empirical studies, and mixed studies are predominant. Consequently, regarding the studies analyzed, there is a lack of longitudinal studies showing the teachers’ actions when applying TPACK in their daily practice

'A very pleasant, safe, and effectual medicine’: The Serial Comma in the History of English.

Política de acceso abierto tomada de: https://v2.sherpa.ac.uk/id/publication/4990Estudio ortográfico de la coma serial –también denominada coma de Oxford o coma de Harvard por ser un rasgo característico del estilo de estas dos editoriales– en la historia de la lengua inglesa para indagar en las circunstancias que han motivado su progresivo retroceso en el transcurso del siglo XX. El estudio diacrónico concluye, en primer lugar, que la difusión de la coma serial es un fenómeno acontecido en el siglo XVII, impulsado en primera instancia por los impresores de la época, conscientes de su necesidad en sintagmas de tres o más elementos; y, en segundo lugar, que la estandarización de este signo de puntuación se produciría durante los siglos XVIII y XIX, especialmente en este último, como resultado de la defensa del mismo por parte de los gramáticos de la época y del impulso recibido por publicaciones de prestigio como el Diccionario de Oxford o la Enciclopedia Británica. El estudio variacional revela, por su parte, una mayor tendencia al empleo de la coma serial en los recetarios, quizás por la propia naturaleza de este tipología textual a la hora de listar los remedios para una cura determinada. El estudio sincrónico confirma, en segundo lugar, el cambio de actitud acontenido a comienzos del siglo XX, que provoca en el progresivo abandono de este signo de puntuación, posiblemente como resultado de la transición hacia un estilo de puntuación más abierto y la progresiva simplificación de los usos de la coma en ese mismo siglo

Conventional and Non-Conventional Roles of Non-Muscle Myosin II-Actin in Neuronal Development and Degeneration

Myosins are motor proteins that use chemical energy to produce mechanical forces driving actin cytoskeletal dynamics. In the brain, the conventional non-muscle myosin II (NMII) regulates actin filament cytoskeletal assembly and contractile forces during structural remodeling of axons and dendrites, contributing to morphology, polarization, and migration of neurons during brain development. NMII isoforms also participate in neurotransmission and synaptic plasticity by driving actin cytoskeletal dynamics during synaptic vesicle release and retrieval, and formation, maturation, and remodeling of dendritic spines. NMIIs are expressed differentially in cerebral non-neuronal cells, such as microglia, astrocytes, and endothelial cells, wherein they play key functions in inflammation, myelination, and repair. Besides major efforts to understand the physiological functions and regulatory mechanisms of NMIIs in the nervous system, their contributions to brain pathologies are still largely unclear. Nonetheless, genetic mutations or deregulation of NMII and its regulatory effectors are linked to autism, schizophrenia, intellectual disability, and neurodegeneration, indicating non-conventional roles of NMIIs in cellular mechanisms underlying neurodevelopmental and neurodegenerative disorders. Here, we summarize the emerging biological roles of NMIIs in the brain, and discuss how actomyosin signaling contributes to dysfunction of neurons and glial cells in the context ofneurological disorders. This knowledge is relevant for a deep understanding of NMIIs on the pathogenesis and therapeutics of neuropsychiatric and neurodegenerative diseases

On the Use of the Oxford Comma in Early Modern English Scientific Writing

Punctuation has traditionally been disregarded in the literature due to its suggested arbitrariness and inconsistency in pre-modern English. Some of the factors that have contributed to this neglect are the lack of systematisation and correspondence to modern punctuation and the overlapping functions of punctuation symbols (Lucas 1971, 19; Mitchell 1980, 412; Calle-Martín and Miranda-García 2005, 28). The Renaissance stands out as the transitional period towards the consolidation of the English system of punctuation, the establishment of the printing press contributing to the standardisation of both the inventory of marks of punctuation and the functions attributed to them. The study of historical punctuation has been mainly concerned with Old and Middle English. Even though the early Modern English system of punctuation has also received editorial attention, most of the studies are concerned with literary compositions, while the other text types have been hitherto disregarded, scientific texts in particular. The unexplored condition of punctuation is even more significant in the particular case of early Modern printed texts, despite their active participation in the process of standardisation. Curiously enough, no studies have focused on the use of the Oxford comma in the history of English. The Oxford comma (also known as serial comma) refers to the existence of a pause immediately before the conjunctions and/or in a series of three or more elements in a clause. The present paper assesses the use of the so-called Oxford comma in early Modern English handwritten and printed documents. In the light of this, this paper pursues the following objectives: a) to study the use and distribution of the Oxford comma in the period 1500-1700; and b) to evaluate the distribution of this punctuation mark in the two types of writing, i.e. handwriting and printing.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Response of potential cucurbit rootstocks against Meloidogyne spp

the Cucurbita hybrids, usually used as cucurbit rootstocks, are susceptible to Meloidogyne. Its cultivation increases the nematode population densities at similar levels than ungrafted cucumber or melon crops, and higher 'Ievels than watermelon.Postprint (published version

Low-cost active orthosis for gait assistance of subjects with spinal cord injury

Postprint (published version

Pyrolysis of Polyolefins in a Conical Spouted Bed Reactor: A Way to Obtain Valuable Products

The amount of waste plastic increases every single year, which causes a critical environmental issue. Polyolefins (mainly high‐ and low‐density polyethylene and polypropylene) are the most common types of plastics, accounting for 60 wt% of the plastic waste. Pyrolysis, the thermal degradation in an inert atmosphere, is considered to be one of the most appealing technologies for the recycling of plastic materials. The conical spouted bed reactor is suitable for the pyrolysis of plastic waste due to its ability to avoid agglomeration problems that may be caused by the melted plastic. The pyrolysis process may be carried out at different temperatures and with or without the presence of catalysts in the reaction environment in order to streamline product distribution. The resulting products are hydrocarbons: non‐condensable gases (C1–C4), gasoline fraction, diesel fraction, and waxes. These fractions might be used directly as feed streams for refinery units or as pools to be mixed with other streams from refineries

New insights into enterocin CRL35: mechanism of action and immunity revealed by heterologous expression in Escherichia coli

The role of the class IIa bacteriocin membrane receptor protein remains unclear, and the following two different mechanisms have been proposed: the bacteriocin could interact with the receptor changing it to an open conformation or the receptor might act as an anchor allowing subsequent bacteriocin insertion and membrane disruption. Bacteriocin-producing cells synthesize an immunity protein that forms an inactive bacteriocin–receptor–immunity complex. To better understand the molecular mechanism of enterocin CRL35, the peptide was expressed as the suicidal probe EtpM-enterocin CRL35 in Escherichia coli, a naturally insensitive microorganism since it does not express the receptor. When the bacteriocin is anchored to the periplasmic face of the plasma membrane through the bitopic membrane protein, EtpM, E. coli cells depolarize and die. Moreover, co-expression of the immunity protein prevents the deleterious effect of EtpM-enterocin CRL35. The binding and anchoring of the bacteriocin to the membrane has demonstrated to be a sufficient condition for its membrane insertion. The final step of membrane disruption by EtpM-enterocin CRL35 is independent from the receptor, which means that the mannose PTS might not be involved in the pore structure. In addition, the immunity protein can protect even in the absence of the receptor.Fil: Barraza, Daniela Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Ríos Colombo, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Galván, Adriana Emilce. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Acuña, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Minahk, Carlos Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Bellomio, Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Chalon, Miriam Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentin

Synthesis of TiO2/Nanozeolite Composites for Highly Efficient Photocatalytic Oxidation of Propene in the Gas Phase

In this work, we reported the preparation of composites based on titania (TiO2) and Zeolite Socony Mobil-5 (ZSM-5) nanozeolite, following two approaches (i.e., incorporating the presynthesized zeolite in the synthesis medium of TiO2 and incorporating presynthesized TiO2 in the synthesis medium of ZSM-5). The materials synthesized were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), nitrogen adsorption, X-ray photoelectron spectroscopy (XPS), ultraviolet–visible spectroscopy (UV–vis), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectrometry analysis, and their photocatalytic activities were assessed in the oxidation of propene in the gas phase. It was observed that the synthesis methodology affects the final properties of the composite, which ultimately affected their photocatalytic performance in the studied application. It was found that the Nano-ZSM5/TiO2 composite was the most active among the investigated samples, which was attributed to the intimate contact between the two components of the composite, the preserved properties of the photocatalytic active phase in the final material, and the positive contribution of the nanozeolite by increasing the local concentration of propene.The authors thank Ministerio de Ciencia Innovación y Universidades and FEDER (Project RTI2018-095291-B-I00) and the Generalitat Valenciana (PROMETEOII/2018/076) for financial support. J.F.-C. thanks MINECO for a researcher formation grant (BES-2016-078079). M.N.-G. gratefully acknowledges Generalitat Valenciana and Plan GenT (CDEIGENT/2018/027) for the postdoctoral grant