39 research outputs found

    Influencia de la hipotiroxinemia materna durante la gestación sobre el desarrollo psicomotor

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    The maternal thyroid function during early pregnancy plays a fundamental role in foetal brain development as synthesis of thyroid hormone does not begin until the 20th week of gestation. Material and methods Throughout the year 2002, 147 women in their 37th week of pregnancy were enrolled for the study. To evaluate their thyroid function, the serum concentrations of free T4 and of TSH were determined. After birth, the psychomotor development of their children was evaluated with the Mc- Carthy scales. Results The median value of free T4 was 9.37 pmol/l, being the data obtained from more than half of the sampled women below the hypothyroxinaemia threshold. Children born from mothers with T4 levels below percentile 10 showed a significantly lower score on the general cognitive index than those whose mothers had normal free T4 serum concentrations. A positive correlation was found between the values of maternal free T4 and the general cognitive index (r 0.43; p < 0.01). Conclusions The concentrations of maternal free T4 are important, not only during the first months of pregnancy, but all along the process to ensure adequate development of the foetal brain

    Insuficiencia respiratoria neonatal asociada a mutación en el gen de la proteína C del surfactante

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    La insuficiencia respiratoria en el recién nacido a término durante las primeras semanas de vida extrauterina es una situación poco frecuente. Entre sus causas se incluyen las enfermedades difusas del intersticio pulmonar, un grupo heterogéneo de enfermedades, la mayoría idiopáticas, caracterizadas por infiltrados difusos, alteraciones funcionales de tipo restrictivo y afectación del intercambio gaseoso. Una forma de enfermedad pulmonar intersticial que puede afectar a lactantes, niños o adultos jóvenes es la que se asocia al déficit congénito de proteínas B o C del surfactante pulmonar. En estos casos los procesos inflamatorios que evolucionan hacia la fibrosis pulmonar están precedidos por la acumulación de material proteináceo en el alvéolo. Se indagó la presencia de mutaciones en los genes de las proteínas B y C del surfactante en una familia española en la cual dos lactantes presentaron insuficiencia respiratoria progresiva desde el nacimiento, con alteraciones radiológicas y anatomopatológicas compatibles con enfermedad del intersticio pulmonar, y el padre refería historia de problemas respiratorios desde la infancia. Se encontró que los dos hermanos de esta familia afectados por la enfermedad presentaban una expresión anómala del precursor de la proteína C del surfactante y concentraciones muy bajas de proteína madura. Se describe además una mutación nueva en el gen que codifica la proteína C del surfactante y que cosegrega con la enfermedad en esta familia

    Linfangioma de pared torácica. A propósito de un caso

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    Lymphangioma is a benign, congenital type of tumor, derived from lymphatic vessels, and located generally in head and neck. Ultrasonography is the procedure of choice for establishing the diagnosis. The main treatment modality is surgical excision, if it is not mutilating. Intralesional injection OK-432 represents an alternative, safe and effective treatment for lymphangiomas. We present a case of lymphangioma on the thoracic wall, solved after the punction.El linfangioma es una malformación congénita derivada de los vasos linfáticos y localizada generalmente en la cabeza o en el cuello. La ecografía es útil para orientar el diagnóstico. El tratamiento de elección es la cirugía, siempre que no sea mutilante. Existen otras alternativas terapéuticas como la inyección intralesional de agentes esclerosantes como el OK-432 que es seguro y muchas veces eficaz. Presentamos el caso de un linfangioma de pared torácica en un niño cuya resolución aconteció después de la punción-aspiración realizada al diagnóstico

    Use of recombinant human granulocyte-macrophage colony stimulating factor in an infant with reticular dysgenesis

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    We present the case of a 2-month-old infant with reticular dysgenesis who was treated with recombinant granulocyte-macrophage colony stimulating factor with the aim of stimulating granulopoiesis while awaiting bone marrow transplant

    High quality single crystal Ge nano-membranes for opto-electronic integrated circuitry

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    Under the terms of the Creative Commons Attribution (CC BY) license to their work.-- et al.A thin, flat, and single crystal germanium membrane would be an ideal platform on which to mount sensors or integrate photonic and electronic devices, using standard silicon processing technology. We present a fabrication technique compatible with integrated-circuit wafer scale processing to produce membranes of thickness between 60 nm and 800 nm, with large areas of up to 3.5 mm2. We show how the optical properties change with thickness, including appearance of Fabry-Pérot type interference in thin membranes. The membranes have low Q-factors, which allow the platforms to counteract distortion during agitation and movement. Finally, we report on the physical characteristics showing sub-nm roughness and a homogenous strain profile throughout the freestanding layer, making the single crystal Ge membrane an excellent platform for further epitaxial growth or deposition of materials.This work was carried out under the RCUK Basic Technology Programme supported by research Grant Nos. EP/F040784/1, EP/J001074/1, and EP/L007010/1. It also received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement NANOFUNCTION n°257375 alongside funding from TAPHOR (MAT2012–31392) and FP7 Project MERGING (Grant No. 309150). Vibrational property measurements were funded by the ERC under Grant No. 202735, NonContactUltrasonic.Peer Reviewe

    Severe cardiac and abdominal manifestations without lung involvement in a child With COVID-19

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    Coronavirus disease 2019 (COVID-19) has become a worldwide pandemic, affecting humans of all ages. Clinical features of the pediatric population have been published, but there is not yet enough information to make a definitive description. Fever is typical, as it is respiratory symptom. Rarely are the infection and complications severe, and, when they are, it is almost always in a patient with another underlying disease. However, some otherwise healthy children with COVID-19 do suffer critical organ injury, such as acute myocarditis, heart failure and gastrointestinal inflammation. The mechanism of these organ damages remains unclear. An otherwise normally healthy 13-year-old male was admitted to the pediatric intensive care unit with acute abdomen pain, possible myocarditis and a suspected diagnosis of COVID-19. Noteworthy basal findings were ventricular extrasystoles in the electrocardiogram (EKG) and moderate left ventricular systolic dysfunction. Chest X-ray was normal. Blood tests revealed altered levels of inflammation factors (C-reactive protein (CRP), D-dimer, fibrinogen, interleukin 6 (IL-6)), lymphopenia and elevated cardiac enzymes. The first test for polymerase chain reaction (PCR) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was negative. The patient’s condition worsened, and he entered cardiogenic shock (hypotension, tachycardia and oliguria). He was vomiting continuously, which made pain control difficult; imaging of his abdomen was undertaken. There was no response to fluid resuscitation, and so milrinone and epinephrine were administered. Empiric treatment began with azithromycin, foscarnet, carnitine and immunoglobulins. Hydroxychloroquine was given before the results of repeated SARSCoV-2 and serology tests were available. Tocilizumab was administered once COVID-19 had been confirmed and massive inflammation had been observed. Progressively the clinical situation and the levels of the parameters studied improved. The patient was discharged 8 days after admission. Most children with SARS-CoV-2 infection are asymptomatic or present only mild symptoms. However, physicians should be aware of atypical and severe manifestations that may occur in the hyperinflammatory phase of the illness

    Thermal transport in epitaxial Si1-xGex alloy nanowires with varying composition and morphology

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    We report on structural, compositional, and thermal characterization of self-assembled in-plane epitaxial Si1-xGex alloy nanowires grown by molecular beam epitaxy on Si (001) substrates. The thermal properties were studied by means of scanning thermal microscopy, while the microstructural characteristics, the spatial distribution of the elemental composition of the alloy nanowires and the sample surface were investigated by transmission electron microscopy and energy dispersive x-ray microanalysis. We provide new insights regarding the morphology of the in-plane nanostructures, their size-dependent gradient chemical composition, and the formation of a 5 nm thick wetting layer on the Si substrate surface. In addition, we directly probe heat transfer between a heated scanning probe sensor and Si1-xGex alloy nanowires of different morphological characteristics and we quantify their thermal resistance variations. We correlate the variations of the thermal signal to the dependence of the heat spreading with the cross-sectional geometry of the nanowires using finite element method simulations. With this method we determine the thermal conductivity of the nanowires with values in the range of 2-3 Wm-1K-1. These results provide valuable information in growth processes and show the great capability of the scanning thermal microscopy technique in ambient environment for nanoscale thermal studies, otherwise not possible using conventional tech-niques

    Phonons in Slow Motion: Dispersion Relations in Ultra-Thin Si Membranes

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    We report the changes in dispersion relations of hypersonic acoustic phonons in free-standing silicon membranes as thin as \sim 8 nm. We observe a reduction of the phase and group velocities of the fundamental flexural mode by more than one order of magnitude compared to bulk values. The modification of the dispersion relation in nanostructures has important consequences for noise control in nano and micro-electromechanical systems (MEMS/NEMS) as well as opto-mechanical devices.Comment: 5 page
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