3,899 research outputs found

    Nuestra Experiencia en el Estudio con Ultrasonografía en la Cadera Neonatal

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    Se estudian mediante ultrasonografía las caderas de 112 recién nacidos (224 caderas) con signos clínicos de displasia luxante de cadera. Los resultados se comparan con los datos de exploración clínica y estudio radiográ- fico poniendo en evidencia las limitaciones diagnósticas de las maniobras exploratorias clásicas y la radiografía. Concluye que la ultrasonografía es el método más seguro e inocuo para el diagnóstico precoz de la displasia luxante de cadera en el recién nacido.The authors are studied by ultrasonography 112 newborns (224 hips) with clinical signs of congenital dysplasia and dislocation of the hip. The results obtained are compared with clinical findings and radiographic study emphasizing the diagnostic limitations of the clasics maneuvistes of physical examination and radiography. They conclude that the ultrasonography is the most sure method and innocuous to the early diagnosis of the congenital dysplasia and dislocation of the hip at the newborn

    Los Ultrasonidos en la Cadera Neonatal

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    Los autores describen la técnica de Estudio mediante Ecografía de la cadera neonatal, las imágenes normales, los métodos de mediciones y las características de los distintos grados de displasiaThe authors describe the technique of the study by ultrasound examination of neonatal hip, normal images, methods of measurement and characteristics of differents degrees of dysplasi

    “Zombie attack” a new way to teach Chemistry

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    The Higher Education requires new models which allow training people able to adapt and survive in changing environments. It is based on the use of technologies and the adaptation of knowledge to people. It is about an education according to circumstances, which is adapted to context and virtual behaviour of people. One of the main difficulties that lecturers find in the classroom is how to maintain students' attention and interest in their subject, especially when students also think that the subject is not important for their training. In order to motivate these students, innovation in educational techniques and methodologies, such as experiential learning, are progressively being imposed to and/or coordinated with the traditional ones. Escape Room is a very modern concept in education, based on the development of mental skills for the solution of enigmas and problems. It is a tool to develop the cooperative, cognitive, deductive and logical reasoning skills of the students. In this work, an educational gamification experience based on the escape room concept is presented. The students have 1 hour and 30 minutes to carry out this activity. They will have to solve four puzzles and enigmas that will give them the key to open a treasure chest and finally let them escape from the classroom. Logic, ingenuity and teamwork will allow participants to develop not only chemical competence, but also other basic skills. The story that is told throughout the escape room is a zombie attack: the city has been infected (with a virus) and only the occupants of the room where the activity takes place have not been infected. In addition, they can all protect themselves if they are able to open the chest where the antidote is located. The aim of this activity is to enhance the knowledge acquired throughout the semester as well as the development of skills.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Premios Nobel de Economía

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    Con esta sección, la revista Semestre Económico desea entregar a sus lectores un espacio informativo donde se consignen apartes del pensamiento económico y sus aportes a esta disciplina, teniendo en cuenta el momento y los contextos donde cambios estructurales se han dado, para que tales trabajos hayan contribuido al desarrollo de la Economía.Inicialmente, se ha pensado en quienes han trabajado desde la década de los sesenta, cuyos planteamientos se han perfilado a la solución de algunos problemas económicos que generalmente han brillado por su carácter teórico, técnico, de formalización matemática de modelos y, últimamente, por atención a la parte social. Son, en resumidas cuentas, aquellos trabajos que se identifican con los Premios Nobel de Economía

    Effect of Heating on Avian (Cortical and Medullary) Bone Chemistry, Mineralogy and Structural Organization

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    The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.cgd.3c00648.The study of bone changes induced by heating is highly relevant for forensic and archeological analyses as well as for the production of bone-derived materials with novel properties and applications. In the present study, we study in detail how different types of avian bone (cortical, medullary) transform during thermal treatments (up to 800 °C) using different analytical techniques such as thermogravimetry (TGA-DSC), electron microscopy, X-ray diffraction and infrared spectroscopy. We show that bone transformation following thermal treatments is strongly influenced by bone architecture, the composition of the organic matrix, and the integration of the mineral with the organic fractions. For instance, in avian cortical bone, the apatite nanocrystals are integrated within collagen fibrils and coated with phosphorylated proteins. During heating, the collagen losses structural order and denatures (at around 200 °C), losing all structural integrity at 300 °C. In the bone mineral fraction, there is a gradual conversion of phosphate, in poorly crystalline/amorphous environments, into apatite (up to 400 °C). However, it is not until all organics are completely lost at around 600 °C that recrystallization sets in with a rapid increase in the size of apatite crystals. Also, during recrystallization, foreign ions (Mg2+, Na+) are expelled from the apatite lattice to the crystal surface, and the degree of preferential orientation of the apatite crystals increases as larger, well-oriented apatite crystals grow epitaxially at the expense of smaller, randomly oriented crystals. However, the scenario is different for the medullary bone. In this case, with an organic matrix rich in noncollagen proteins and proteoglycans, the recrystallization sets in at much lower temperatures (around 400 °C compared to 600 °C in cortical bone). Thus, the association of mineral and organic components controls recrystallization, particularly in the case of apatite nanocrystals within collagen fibrils in cortical bone. Also, the calcination process creates additional microporosity in both types of bone, increasing the bone mineral surface area and reactivity. The information obtained in this study provides a better understanding of the dynamics of bone transformation during alteration in natural processes (e.g., diagenesis, burning) and how bone mineral characteristics can be modified for specific applications (e.g., bone grafts, waste removal, or chromatography).Junta de Andalucía (P20_00208 and P20_00207)Spanish government (PID2020-116660GB-I00), UCE-PP2016-05Biotechnology Institute (University of Granada

    Structural and morphological evolution of powders nanostructured ceramics: transitional aluminas

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    This work aims with the study of the transformation of boehmite into transitional aluminas. Boehmite was obtained by a sol-gel method from an aluminium hazardous waste. The thermal behaviour of boehmite was followed by thermogravimetry and differential thermal analysis to determine the transformation temperatures.  By calcinations of boehmite at temperatures ranging between 250-1000ºC, transitional aluminas (?, ? , ?-Al2O3)  were synthesized and characterized by XRD, TEM and FTIR. All the transitional aluminas exhibit nanometric crystallite size, ranging from 2.5-15nm. ?-Al2O3 was obtained as a nanostructured material at 500ºC with a cell parameter a=7.923Å. ?-phase stars to appear at 850ºC with a crystallite size of 6nm and cell parameters a=5.672Å and c=24.600Å. For ?-Al2O3 the cell parameters, in Å, were a=11.817, b=2.912, c=5.621 and ?=103.8º. The progressive conversion of the transitional phase ?-Al2O3 into the stable polymorph ?-alumina, takes place gradually and a four-phases region is achieved at 1000ºC, where coexist with other transitional phase such as  ?- and ?-Al2O3

    V centers in MgAl2O4 spinels

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    V centers induced by ionizing irradiation at 80 or 300 K in single-crystal and polycrystalline MgAl2O4 samples have been studied by use of electron paramagnetic resonance and optical absorption. Vt- and Vo2- centers, as a result of hole trapping at tetrahedral and octahedral cation vacancies, respectively, have been found to be responsible for two EPR bands centered at g=2.011 and optical absorption bands involved in the complex absorption spectrum at about 3.4 eV. These centers anneal thermally in a very wide step from 220 to 575 K. © 1991 The American Physical SocietyPeer Reviewe

    Short-term microbial response after laboratory heating and ground mulching adition

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    Fire alters soil organic matter inducing quantitative and qualitative changes that presumably will affect post-fire soil microbial recolonisation. Several studies have evidenced marked soil organic carbon reduction after moderate and high intensity fire, which limit the total recovery of microbial biomass during years. In order to evaluate the role of soil organic matter alteration in short-term microbial colonization process, we perform a preliminary experiment where unaltered soil from Sierra Nevada Natural Park was heated at 300 ºC during 20 minutes in a muffle furnace (H300) to simulate a medium-high intensity fire. After heating, soil samples were inoculated with unaltered fresh soil, rewetted at 55-65% of water holding capacity and incubated during 3 weeks. At the same time, unheated soil samples were incubated under the same conditions as control (UH). In addition, trying to partially alleviate soil organic matter fire-induced alterations effects on microbial colonization, we include an organic amendment treatment (M+). So, part of heated and unheated samples were amended with a mix of ground alfalfa:straw (1:1) and soil microbial abundance and activity were monitored together with soil organic matter changes. Heating process reduces total organic carbon content. After one week of incubation carbon content in heated samples was lower than the control one, in both, amended and un-amended samples. Microbial biomass and respiration were negatively affected by heating. Ground mulching addition increase microbial biomass and respiration but was not enough to reach control values during the whole study. Nevertheless, viable and cultivable fungi and bacteria showed different pattern. After two weeks of incubation both, fungi and bacteria were higher in heated samples. Ground mulching addition appears to stimulate fungal response in both, heated and unheated samples. Preliminary results of this experiment evidence the transcendence of soil organic matter fire-induced changes on microbial colonization process and the importance to determine several microbial parameters to obtain a more faithful conclusion about microbial response. The organic amendment appears to alleviate partially heated-induced damage, highlighting the positive stimulation on fungal abundance in both, heated and unheated samples.Ministerio de Economía y Competitividad CGL2013-47862-C2-1- RMinisterio de Economía y Competitividad CGL2012-38655-C04-0
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