Orbital Character Effects in the Photon Energy and Polarization Dependence of Pure C60 Photoemission.

Recent direct experimental observation of multiple highly dispersive C60 valence bands has allowed for a detailed analysis of the unusual photoemission traits of these features through photon energy- and polarization-dependent measurements. Previously obscured dispersions and strong photoemission traits are now revealed by specific light polarizations. The observed intensity effects prove the locking in place of the C60 molecules at low temperatures and the existence of an orientational order imposed by the substrate chosen. Most importantly, photon energy- and polarization-dependent effects are shown to be intimately linked with the orbital character of the C60 band manifolds which allow for a more precise determination of the orbital character within the third highest occupied molecular orbital (HOMO-2). Our observations and analysis provide important considerations for the connection between molecular and crystalline C60 electronic structure, past and future band structure studies, and for increasingly popular C60 electronic device applications, especially those making use of heterostructures.

Microencapsulation of Rhizobium leguminosarum bv. trifolii with guar gum: Preliminary approach using spray drying.

Rhizobium leguminosarum bv trifolii strains TA1 and CC275e have been widely used as effective nitrogen fixing strains for white clover in New Zealand, but rhizobia survival on seeds is usually poor due to different stress conditions. The aim of this study was to select one of those commercial strains grown in a solid carrier (core) and study the influence of the core:polymer ratio in a microencapsulation process by spray drying using guar gum as coating material. First, strains TA1 and CC275e grown on peat and diatomaceous earth were exposed to temperature and desiccation stress. Both strains were stable at 40 °C and completely died after five minutes at 80 °C, while CC275e was more stable than TA1 at 60 °C. TA1 and CC275e slightly decreased viability after six hours drying with either carriers, with no differences between strains. A central composite design was used to develop the microencapsulation process. Independent variables were: inlet temperature (130 °C) and feed flow rate (5 mL/min). Microparticles presented rhizobia loading in 107 CFU/g and mean particle size between 10 and 30 µm. Optimized process reached 50% yield and 107 CFU/g loading. Rhizobia viability dropped two logarithmic units during the microencapsulation/drying process, possibly due to the negative effects of dehydration and high outlet temperature (≈70 °C), suggesting the need to continue optimizing the process by improving the thermal profile in the drying chamber.

Poliarteritis nodosa cutánea / CUTANEOUS POLYARTERITIS NODOSA

La poliarteritis nodosa es una vasculitis de los vasos de mediano calibre que puede afectar solamente la piel o tener compromiso sistémico. Los signos cutáneos más frecuentes son livedo reticularis, nódulos y ulceras dolorosas. Se presenta un paciente masculino de 40 años de edad que consultó por nódulos eritematovioláceos dolorosos en miembros de un mes de evolución. Se realizó biopsia sugestiva de poliarteristis nodosa, se detectó serología para VIH positiva, cavitaciones pulmonares en TAC de tórax y lavado broncoalveolar con baciloscopía positiva para tuberculosis (TBC). Se inicia tratamiento antifímico y antiretroviral con mejoría de la clínica respiratoria y resolución a los 2 meses de las lesiones en piel

Polyarteritis nodosa is a vasculitis of medium sized vessels that can affect only skin or have systemic involvement. The most frequent cutaneous signs are livedo reticularis, nodules and painful ulcers. We present a 40 year-old male patient who consulted for painful erythematouspelvic nodules in a month of evolution. A biopsy suggestive of polyarteritis nodosa was detected, positive HIV serology, pulmonary cavitations in chest CT and bronchoalveolar lavage with tuberculosis-positive smear microscopy (TB). Antimicrobial and antiretroviral treatment with respiratory clinic improvement and resolution at 2 months of skin lesions are started

Molecular Arrangement and Charge Transfer in C60/Graphene Heterostructures.

Charge transfer at the interface between dissimilar materials is at the heart of electronics and photovoltaics. Here we study the molecular orientation, electronic structure, and local charge transfer at the interface region of C60 deposited on graphene, with and without supporting substrates such as hexagonal boron nitride. We employ ab initio density functional theory with van der Waals interactions and experimentally characterize interface devices using high-resolution transmission electron microscopy and electronic transport. Charge transfer between C60 and the graphene is found to be sensitive to the nature of the underlying supporting substrate and to the crystallinity and local orientation of the C60. Even at room temperature, C60 molecules interfaced to graphene are orientationally locked into position. High electron and hole mobilities are preserved in graphene with crystalline C60 overlayers, which has ramifications for organic high-mobility field-effect devices.

Topological valley transport at bilayer graphene domain walls.

Electron valley, a degree of freedom that is analogous to spin, can lead to novel topological phases in bilayer graphene. A tunable bandgap can be induced in bilayer graphene by an external electric field, and such gapped bilayer graphene is predicted to be a topological insulating phase protected by no-valley mixing symmetry, featuring quantum valley Hall effects and chiral edge states. Observation of such chiral edge states, however, is challenging because inter-valley scattering is induced by atomic-scale defects at real bilayer graphene edges. Recent theoretical work has shown that domain walls between AB- and BA-stacked bilayer graphene can support protected chiral edge states of quantum valley Hall insulators. Here we report an experimental observation of ballistic (that is, with no scattering of electrons) conducting channels at bilayer graphene domain walls. We employ near-field infrared nanometre-scale microscopy (nanoscopy) to image in situ bilayer graphene layer-stacking domain walls on device substrates, and we fabricate dual-gated field effect transistors based on the domain walls. Unlike single-domain bilayer graphene, which shows gapped insulating behaviour under a vertical electrical field, bilayer graphene domain walls feature one-dimensional valley-polarized conducting channels with a ballistic length of about 400 nanometres at 4 kelvin. Such topologically protected one-dimensional chiral states at bilayer graphene domain walls open up opportunities for exploring unique topological phases and valley physics in graphene.

C60/collapsed carbon nanotube hybrids: a variant of peapods.

We examine a variant of so-called carbon nanotube peapods by packing C60 molecules inside the open edge ducts of collapsed carbon nanotubes. C60 insertion is accomplished through a facile single-step solution-based process. Theoretical modeling is used to evaluate favorable low-energy structural configurations. Overfilling of the collapsed tubes allows infiltration of C60 over the full cross-section of the tubes and consequent partial or complete reinflation, yielding few-wall, large diameter cylindrical nanotubes packed with crystalline C60 solid cores.

Comprensión y Producción Textual Narrativa en Estudiantes de Educación Primaria / Narrative Textual Comprehension and Production in Primary School Students / Compreensão e Produção Textual Narrativa em Estudantes de Educação Primária

Por medio de un enfoque mixto, se caracterizó la comprensión y producción textual narrativa en estudiantes de educación primaria (primero y segundo grado), así como aspectos psicosociales (valor social de la lectura y hábito lector) y contextuales (interacciones cognitivas y afectivas docente-niños) en docentes de educación primaria de tres instituciones educativas. Se encontró que los estudiantes tuvieron un desempeño medio alto en producción textual y comprensión literal, y bajo en comprensión inferencial. Además, se observó que la mayoría de las docentes son lectoras ocasionales, emplean interacciones cognitivas unidireccionales, ofrecen un mediano apoyo emocional a sus estudiantes y valoran la lectura como una herramienta instrumental y lúdica.

Using a mixed approach, the study described textual comprehension and production of narrative texts in primary school students (first and second grades), as well as psychosocial (social value of reading and reading habits) and contextual (cognitive and affective interactions between teacher and children) aspects in elementary school teachers in three educational institutions. Findings show that students had a medium to high performance in textual production and literal comprehension, and a low performance in inferential comprehension. Furthermore, it was observed that most teachers are occasional readers, use unidirectional cognitive interactions, offer average emotional support to their students, and value reading as an instrumental and recreational tool.

Por meio de um enfoque misto, caracterizaram-se a compreensão e a produção textual narrativa em estudantes de educação primária (primeira e segunda séries), bem como aspectos psicossociais (valor social da leitura e hábito leitor) e contextuais (interações cognitivas e afetivas docente-criança) em docentes de educação primária de três instituições educativas. Constatou-se que os estudantes tiveram um desempenho médio alto em produção textual e compreensão literal, e baixo em compreensão inferencial. Além disso, observou-se que a maioria das docentes são leitoras ocasionais, empregam interações cognitivas unidirecionais, oferecem um apoio emocional médio a seus estudantes e valorizam a leitura como ferramenta instrumental e lúdica.

Comprensión y producción textual narrativa en preescolares / Text narrative comprehension and production in pre-kindergarten

Este estudio buscó identificar y describir las habilidades de comprensión y producción textual narrativa de 158 estudiantes de transición de estrato 1 y 2 de colegios públicos de la ciudad de Barranquilla (Colombia). Para evaluar esta capacidad se les pidió a los niños que narraran un texto que se les había leído anteriormente. Las muestras de lenguaje se analizaron utilizando el software SALT y posteriormente se utilizó el software SPSS para realizar los análisis descriptivos. Se consideró la estructura organizativa microestructura, macroestructura y superestructura desde el nivel de comprensión literal e inferencial. Se encontró que la mayoría de los niños tienen un desarrollo narrativo acorde con su edad, sin embargo, la elaboración inferencial fue escasa, lo que posiblemente afectó la comprensión de la historia por parte de los mismos.

This study aimed to identify and describe the skills of textual narrative comprehension and production in pre-kindergarten students belonging to 1st and 2nd social strata of public schools of the city of Barranquilla (Colombia). To evaluate this capability, the children were asked to narrate a text that had been narrated to them; the language samples were analyzed using the software SALT. The organizational structure of microstructure, macrostructure and superstructure was considered from the level of literal and inferential comprehension, finding that most children have a narrative development according to their age, however the inferential elaboration was low, what possibly affected the understanding of story by children.

Psicooncología pediátrica / Pediatric Psycho-Oncology

La psicooncología pediátrica, entre otras, estudia por qué el cáncer, además de ser una enfermedad crónica que amenaza la vida de quien la padece, es una enfermedad que simboliza el sufrimiento de la persona enferma y su familia. El tratamiento del cáncer infantil implica un régimen médico exigente en el que los niños y sus familias se enfrentan a múltiples factores estresantes, que provocan cambios considerables en las actividades diarias; por ejemplo, alteración de los roles familiares y sociales, temor a la adhesión al tratamiento y una constante amenaza de muerte. El presente trabajo tiene como objetivo mostrar, por medio de una revisión teórica, el papel de la psicooncología pediátrica y el progreso de sus herramientas de intervención psicológica. Se revisan las diferentes aportaciones sobre la comprensión de la enfermedad, las reacciones físicas, psicológicas y sociales del niño enfermo, la familia y el personal sanitario. Además, se proponen los recursos necesarios para la reducción del malestar físico y psicológico del niño y su familia durante la enfermedad.

Pediatric oncology study why cáncer, in addition to being a chronic disease that threatens the patient's life, is a disease that symbolizes the suffering of the sick person and his family. The treatment of childhood cáncer involves a demanding medical regimen in which children and their families face with multiple stressors, which cause significant changes in the everyday activities, disruption of family and social roles, the fear of treatment adherence, and a constant threat of death. The present work aims to show through a theoretical review, the role of the pediatric psychooncology, and the progress of its psychological intervention. Different contributions to the understanding of the disease, physical, psychological and social reactions of the sick child, the family and the medical staff have been reviewed. Resources needed for the reduction of the physical and psychological discomfort of the child and his family during the disease are also showed.

Inferencias sobre un texto narrativo en contextos de interacción en la educación inicial / Inferences over a narrative text in contexts of interaction in early childhood education

La investigación que da lugar al presente artículo se enmarca en la Psicología Educativa de corte cultural. Explora las relaciones entre las características de las interacciones establecidas para propiciar la interpretación de un texto narrativo y las inferencias que los niños hacen sobre él. Un total de 44 niños repartidos en cuatro grupos de preescolar participó en el estudio. El diseño es de tipo descriptivo-exploratorio, con dos clases de análisis: cualitativo -análisis del discurso- y cuantitativo -análisis de redes sociales-, para procesar los datos. Se encontró que los niños cuyas maestras propician más interacciones cognitivas de alta demanda, proponiendo el análisis de los aspectos implícitos en el texto, logran mayor elaboración inferencial, mientras que los niños cuyas docentes proponen menos interacciones con discusiones principalmente sobre información explícita en el texto, hacen pocas inferencias y con nivel de menor elaboración.

This research explores the relationship between the characteristics of interactions established to favor the narrative text interpretation and the inferences that children make on it. This is marked in the educative, cognitive and cultural psychologist. In this research participated four groups of kinder garden with a total of forty four children. This was a descriptive and explorative design. Was realized a discursive analysis and a social nets analysis to process information. It was find that children which teachers favor more interactions and better interactions raised a textual analyses got a high inferencial elaboration, and children which teachers proposed low interaction raised discussions about explicit information in the text, realized a few inferences and with a low level of elaboration.

La interacción en el aula: una vía para posibilitar la comprensión inferencial de textos narrativos en niños de preescolar / Interaction in the classroom: one way to facilitate the understanding inference of narrative texts in children of preschooler

La investigación explora las relaciones entre las características de las interacciones establecidas para propiciar la interpretación de un texto narrativo y las inferencias que los niños hacen sobre él. Ésta se enmarca en la psicología educativa, cognitiva y cultural. 4 grupos de preescolar participaron en el estudio con un total de 48 niños. El diseño fue descriptivo exploratorio. Se hizo un análisis cualitativo - análisis del discurso - y uno cuantitativo - análisis de redes sociales - para procesar los datos. Se encontró que los niños cuya maestra propiciaba más interacciones alrededor del texto buscando una comprensión como transacción texto -lector, lograron mayor elaboración inferencial y los niños cuyas docentes propusieron interacciones en las que planteaban discusiones sobre información explícita en el texto, realizaron pocas inferencias y de menor complejidad.

This research explores the relationship between the characteristics of interactions established to favor the narrative text interpretation and the inferences that children make on it. This is marked in the educative, cognitive and cultural psychologist. In this research participated four groups of kinder garden with a total of forty eight children. This was a descriptive and explorative design. Was realized a discursive analysis and a social nets analysis to process information. It was find that children which teacher favor more interactions and better interactions raised a textual analyses got a high inferencial elaboration, and children which teachers proposed low interaction raised discussions about explicit information in the text, realized a few inferences and with a low level of elaboration.

Exploración de la comprensión inferencial de textos narrativos en niños de preescolar / An approach to the inferential comprehension of narrative texts in preschool children

Se realizó un estudio exploratorio que buscó tipificar las inferencias que elaboran los niños de transición, en Ibagué, sobre un texto narrativo a partir de una tarea de comprensión textual. La investigación se enmarca en la psicología evolutiva, cognitiva y cultural. Participaron seis grupos de transición y un total de 96 niños. A las docentes participantes se les propuso, en su grupo de transición, la lectura de un mismo cuento y trabajarlo durante tres sesiones en la misma semana para posibilitar la comprensión por parte de los niños. Para evaluar el funcionamiento inferencial que hacían los niños del texto, se utilizó un cuestionario y el análisis de contenido para procesar los datos. Se encontró que el tipo de inferencia que más realizan los niños es la referencial; le sigue con frecuencia media la instrumental, la predictiva y la de reacción emocional; las de menor frecuencia fueron la temática y la de antecedente causal. Sin embargo, se encontró que la comprensión inferencial es pobre en los niños de la muestra.

This paper presents an exploratory study conducted in Ibagué, and whose main purpose was to determine the inferences that pre-schoolers made about a specific narrative text. It was based on recent findings of developmental, cognitive and cultural psychology, and gathered data from 96 preschool children in six groups. The teachers participated reading the same short story for three sessions in one week, in order to enhance the students’ comprehension. A questionnaire was used to assess the inferential function around the narrative text, as well as a content analysis to process the data. The results showed that the main kind of inferences that children made was the referential, followed by the instrumental and predictive inferences and the inferences about emotional reactions; the least frequent were the thematic inferences and those about a causal antecedent. However, the findings showed that inferential comprehension is very poor in the preschool children of the sample.