248 research outputs found
Formation of a rotaxane from the end-capping process of a pseudorotaxane. Effects of the solvent
The effects that the solvent exerts on the end-capping process of a pseudorotaxane formed by the[Ru(NH3)5(4,4′-bpy)]2+complex and -cyclodextrin were studied. In this process the 4,4′-bpy ligand acts asrigid axle and the cyclodextrin as ring or macrocycle. The stopper used was the [Fe(CN)5H2O]3-complex.The solvents used were mixtures of ethyleneglycol-water and tert-butyl alcohol-water. Results showed similar,although strange, behavior in both media studied. Thus, a decrease of the observed rate constant was obtainedwhen the concentration of cyclodextrin increases for all the media studied. However, at fixed cyclodextrinconcentrations, an increase of kobswas obtained when small quantities of the cosolvent were added to themedium and, further, a decrease of kobsfor the higher quantities of the organic solvents. This strange behaviorcould be explained by taking into account electrostatic and specific solvent (solvent-solvent and solvent-solute)effects.Ministerio de Educación de España - D.G.I.CYT(CTQ2005-01392/BQU
Gas phase selective hydrogenation of furfural to furfuryl alcohol and 2-methylfuran over Cu-CeO2 coprecipitated catalysts
Furfural is an important chemical derived from lignocellulosic biomass, in particular from C5 sugars like xylose, and it is considered as a platform molecule of great potential for the synthesis of a broad spectrum of chemicals. In this sense, furfuryl alcohol and 2-methylfuran are two important chemicals which can be produced through furfural hydrogenation, either in liquid or vapor phase, although the latter is preferred because it can be carried out at atmospheric pressure. Industrially, a copper chromite catalyst is used, although this catalyst can become very toxic due to the presence of chromium. Therefore, much attention is being paid to the development of chromium-free catalysts, more sustainable and environmentally friendly, as those based on Cu or Ni which are active and selective towards the formation of furfuryl alcohol and 2-methylfuran. Furfuryl alcohol is mainly used for the production of thermostatic resins, intermediate in the manufacture of lysine, vitamin C and dispersing agents. Meanwhile, 2-methyl furan is used in the synthesis of pesticides, or in the pharmaceutical and fragrance industries.
The aim of this work is the synthesis of a series of copper based catalysts, which have been synthesized by coprecipitation of copper and cerium(IV) and subsequent thermal programmed reduction. This method allows increasing the dispersion of Cu particles, while the use of a support like CeO2 can modify the electronic density of the active phase, which can influence the catalytic activity and resistance to deactivation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Economy and Competitiveness Ministry (Project CTQ2012-38204-C03-02), Junta de Andalucía (Project: RNM-1565) and FEDER funds of the European Unio
Incidence, Management Experience and Characteristics of Patients with Giardiasis and Common Variable Immunodeficiency
Common variable immunodeficiency (CVID) is an antibody immunodeficiency with a
wide variety of clinical and immunological manifestations, and whose genetic cause is found in
about 25% of diagnosed cases. Giardia lamblia is one of the main causes of gastrointestinal infections
in CVID. 5-Nitroimidazoles are the most used first-line treatment, but nitroimidazole-refractory
giardiasis is increasing. Nevertheless, only a few cases of refractory giardiasis in CVID have been
reported. This study aimed to determine the incidence of Giardia infection in our CVID cohort, shows
our management experience and describes patients’ phenotypic features. Clinical data collection,
immunological, immunogenetics and microbiology assays were performed, and previous cases
of giardiasis in CVID were reviewed. The incidence of symptomatic giardiasis was 12.9%. The
main immunological features were undetectable or decreased IgA levels and reduced switched
memory B cells. A probable PTEN pathogenic variant was detected in one. Three patients responded
to metronidazole but suffered reinfections, and one was a refractory giardiasis eradicated with
innovative quinacrine plus paromomycin combination. This work could contribute to the decisionmaking
and therapeutic management of future patients with CVID and giardiasis, highlighting the
importance of the early detection and treatment of infections in patients with CVID to ensure a good
quality of life
¿Mensajes publicitarios o nutricionales? Esa es la cuestión
La publicidad es uno de los factores más influyentes en la psicología de la alimentación humana y
dada su capacidad persuasiva puede ser determinante en el consumo de un producto,
particularmente en el caso de los niños, pudiendo generar hábitos y patrones de consumo ligados
a los mensajes publicitarios y dejando de lado la información nutricional del envasado. El
profesorado de educación infantil tiene un papel relevante en la educación alimentaria de los
menores de 3 a 6 años. Este profesorado puede colaborar con dietistas-nutricionistas para diseñar
estrategias de educación nutricional en estas edades. Con la propuesta formativa que se presenta
pretendemos que el alumnado determine el tipo de mensajes que aparecen en el envase, y conocer
la competencia que tienen los futuros educadores para discernir entre mensajes nutricionales y
publicitarios. Para ello se han identificado todos los elementos informativos presentes en un envase
alimentario (texto, gráfico, tablas y datos numéricos) siguiendo la metodología de Girón Gambero,
Blanco López y Lupión Cobos (2014) modificada para clasificarlos como información nutricional,
declaración saludable, declaración nutricional o publicidad según el Reglamento Europeo
1169/2011
Teaching and learning about food hygiene in Primary Education: a systematic revie
A systematic review has been carried out following the PRISMA protocol to characterize the scientific production of food hygiene teaching in Primary Education. Bibliometric indicators and research methodologies used are analyzed. The search was carried out in the Web of Science database. Only 12 articles met all the inclusion criteria. There are few publications on food hygiene at this stage, being qualitative studies, co-authored and mostly belonging to the health sector. There is a need to increase research especially in the educational field and to introduce food hygiene in teacher training.Se ha realizado una revisión sistemática siguiendo el protocolo PRISMA para caracterizar la producción científica de la didáctica de la higiene alimentaria en Educación Primaria. Se analizan indicadores bibliométricos y metodologías de investigación utilizadas. La búsqueda se realizó en la base de datos Web of Science. Solo 12 artículos cumplían con todos los criterios de inclusión. Hay escasas publicaciones sobre higiene alimentaria en la etapa, tratándose de estudios cualitativos, autoría conjunta y en su mayoría pertenecen al sector sanitario. Es necesario aumentar las investigaciones especialmente en el ámbito educativo e introducir la higiene alimentaria en la formación del profesorado
Which type of science is presented in Secondary Education textbooks?
Este trabajo muestra un análisis de los temas que introducen la ciencia en los libros de
Biología y Geología y Física y Química de Educación Secundaria. El objetivo es caracterizar la visión
de la «naturaleza de la ciencia» que estos presentan, comprobar si se diferencia ciencia de pseudociencia
y estudiar la presencia de ciertos conceptos. Para ello se han analizado tanto los contenidos teóricos
como las actividades. El análisis revela que varios libros carecen de un tema introductorio. En los que
sí lo tienen, se observa que suele centrarse en el método científico y presta una atención limitada a la
evolución de la ciencia, los modelos científicos u otros conceptos relevantes. La imagen de ciencia que
se promueve, si bien incluye aspectos positivos, no es aún, por lo general, completamente correcta. Se
aprecia, por tanto, una falta de reflexión sobre qué es la ciencia y cómo se construye.This paper presents a study based on an analysis of introductory lessons to biology and
geology and to physics and chemistry in Secondary Education textbooks. The aims of this study are
to characterize the view on the «nature of science» that is transmitted, to determine whether science is
differentiated from pseudoscience and to detect whether certain concepts appear, by examining both
the theoretical content of the textbooks and the recommended activities. The analysis reveals a lack of
an introductory lesson in some books. Where such lesson is included, the text usually focuses on scientific
method, paying little attention to the evolution of science, scientific models or other significant
concepts. The image of science that is promoted, although it has positive aspects, is often deficient. In
short, there is a lack of reflection on what science is and how it is constructed
Magnetitas utilizadas para la obtención de alcohol furfurílico a partir de furfural mediante transferencia catalítica de hidrógeno
El furfural es considerado como una molécula plataforma debido a su alta reactividad en procesos de hidrogenación, oxidación, alquilación o deshidratación, originando una gran variedad de productos de alto valor añadido. En la presente comunicación se presentan los resultados obtenidos en el proceso de hidrogenación de furfural mediante transferencia catalítica de hidrógeno a partir de la reacción de Meerwein, Ponndorf y Verley, usando magnetitas como catalizador ácido, donde se ha variado la relación molar Fe(II)/Fe(III) empleada para su síntesis.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Spanish teaching students’ attitudes towards teaching science at the pre-school level
Previous researches on early childhood teachers´ attitudes
toward science teaching reveals that they feel anxiety and fear regarding
science classes. Sometimes, teaching students´ experience with science
have a significant influence on their attitude toward science and science
teaching. This prior experience has been frequently joined to remember
abstract concepts, and it determine what they guess about science teaching
in early childhood. In order to assess teacher trainee´s pre-existing attitudes
and beliefs toward science teaching in early years, we used a preschool
teachers’ attitudes and beliefs toward science teaching questionnaire
developed and validated for Maier, Greenfield and Bulotsky-Shearer
(2013). Aspects such as science knowledge or ability to create science related activities, at the beginning, are very poorly valued by future
teachers of early childhood education. The main reason is the poor
knowledge that they have about science in general. We can conclude that it
is important that future teachers of early childhood education should
understand importance to teach science to children.Funding was provided by the group HUM613 of the Universidad de Granad
Educational applications of a pico-processor design
Knowledge of the internal structure and
operating mechanism of microprocessors is a very
important part in for engineers in electronics and
computer science. This knowledge can be deepened with
experiences of processor design, which also meet many
aspects linked to other basic skills. However, due to its
complexity, the design of commercial processors is not
effective from an educational point of view. In this
communication we present a VHDL design experience of a
very simple processor that shows multiple learning posed
to the student
Effect of Coronavirus Disease 2019 in Pulmonary Circulation. The Particular Scenario of Precapillary Pulmonary Hypertension.
The Coronavirus Disease of 2019 (COVID-19) has supposed a global health emergency affecting millions of people, with particular severity in the elderly and patients with previous comorbidities, especially those with cardiovascular disease. Patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) could represent an especially vulnerable population because of the high mortality rates reported for respiratory infections. However, the number of COVID-19 cases reported among PAH and CTEPH patients is surprisingly low. Furthermore, the clinical picture that has been described in these patients is far from the severity that experts would expect. Endothelial dysfunction is a common feature between patients with PAH/CTEPH and COVID-19, leading to ventilation/perfusion mismatch, vasoconstriction, thrombosis and inflammation. In this picture, the angiotensin-converting enzyme 2 plays an essential role, being directly involved in the pathophysiology of both clinical entities. Some of these common characteristics could explain the good adaptation of PAH and CTEPH patients to COVID-19, who could also have obtained a benefit from the disease's specific treatments (anticoagulant and pulmonary vasodilators), probably due to its protective effect on the endothelium. Additionally, these common features could also lead to PAH/CTEPH as a potential sequelae of COVID-19. Throughout this comprehensive review, we describe the similarities and differences between both conditions and the possible pathophysiological and therapeutic-based mechanisms leading to the low incidence and severity of COVID-19 reported in PAH/CTEPH patients to date. Nevertheless, international registries should look carefully into this population for better understanding and management.J.N. is recipient of a predoctoral grant (Jordi Soler Soler) through CIBERCV. E.O. is a recipient of funds from “Programa de Atracción de Talento” (2017-T1/BMD-5185) of Comunidad de Madrid. The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence (SEV-2015-0505). This work was supported by the Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation (COV20/00181) and co-financed by the European Development Regional Fund “A way to achieve Europe”.S
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