330 research outputs found
Effects of wet/dry-cycling and plasma treatments on the properties of flax nonwovens intended for composite reinforcing
Producción CientíficaThis research analyzes the effects of different treatments on flax nonwoven (NW) fabrics which are intended for composite reinforcement. The treatments applied were of two different kinds: a wet/dry cycling which helps to stabilize the cellulosic fibers against humidity changes and plasma treatments with air, argon and ethylene gases considering different conditions and combinations, which produce variation on the chemical surface composition of the NWs. The resulting changes in the chemical surface composition, wetting properties, thermal stability and mechanical properties were determined. Variations in surface morphology could be observed by scanning electron microscopy (SEM). The results of the X-ray photoelectron spectroscopy (XPS) showed significant changes to the surface chemistry for the samples treated with argon or air (with more content on polar groups on the surface) and ethylene plasma (with less content of polar groups). Although only slight differences were found in moisture regain and water retention values (WRV), significant changes were found on the contact angle values, thus revealing hydrophilicity for the air-treated and argon-treated samples and hydrophobicity for the ethylene-treated ones. Moreover, for some of the treatments the mechanical testing revealed an increase of the NW breaking force.Ministerio de Educación y Formación Profesional (grants BIA2014-59399-R and FPU12/05869
Gas dissolution foaming as a novel approach for the production of lightweight biocomposites of PHB/natural fibre fabrics
Producción CientíficaThe aim of this study is to propose and explore a novel approach for the production of cellular lightweight natural fibre, nonwoven, fabric-reinforced biocomposites by means of gas dissolution foaming from composite precursors of polyhydroxybutyrate-based matrix and flax fabric reinforcement. The main challenge is the development of a regular cellular structure in the polymeric matrix to reach a weight reduction while keeping a good fibre-matrix stress transfer and adhesion. The viability of the process is evaluated through the analysis of the cellular structure and morphology of the composites. The effect of matrix modification, nonwoven treatment, expansion temperature, and expansion pressure on the density and cellular structure of the cellular composites is evaluated. It was found that the nonwoven fabric plays a key role in the formation of a uniform cellular morphology, although limiting the maximum expansion ratio of the composites. Cellular composites with a significant reduction of weight (relative densities in the range 0.4–0.5) were successfully obtained.Ministerio de Educación y Formación Profesional (grants FPU12/05869 and EST14/00273)Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (grants BIA2014-59399-R and MAT2015-69234-R)Junta de Castilla y Leon (grant VA011U16
Multímeros de la adiponectina en la diabetes gestacional: relación con parámetros maternos y repercusión en el crecimiento fetal
El tejido adiposo juega un activo papel en la homeostasis metabólica. Sus funciones son mediadas por unos factores secretados por los adipocitos conocidos como adipocitoquinas.
La adiponectina es una adipocitoquina producida en los adultos en el tejido graso y en los fetos en varios tejidos fetales. Presente en la circulación sanguínea en forma de multímeros de diferentes pesos moleculares con diferentes implicaciones funcionales.
Se encuentra inversamente relacionado con los niveles de insulinoresistencia, que se incrementan en la gestación, agravándose en la diabetes gestacional (DMG), entidad asociada a macrosomia fetal, hemos postulado que la cantidad y distribución de sus multímeros adiponectina tanto maternos como fetales, pueden ser uno de los factores implicados en la regulación del crecimiento fetal y la adiposidad neonatal.
Postulamos sobre una correlación de los niveles de adiponectina materna y fetal.
También hemos valorado nuevas fórmulas de estimación de peso ecográficas en tres dimensiones.Adipose tissue plays an active role in metabolic homeostasis. Its functions are mediated by factors secreted by adipocytes known as adipocytokines.
Adiponectin is an adipocytokine produced in the adult fat tissue and fetuses in various fetal tissues. Present in the bloodstream in the form of multimers of different molecular weights with different functional implications.
Is inversely related to levels of insulin resistance, which increased during pregnancy, gestational diabetes to worsen in the (DMG), an entity associated with fetal macrosomia, we postulate that the quantity and distribution of adiponectin multimers both maternal and fetal, can be one of the factors involved in regulating fetal growth and neonatal adiposity.
We postulate a correlation of levels of maternal and fetal adiponectin.
We also evaluated new methods of weight estimation in three-dimensional ultrasound
La cooperació internacional com a eina per al desenvolupament: memòries de Moçambic
La primera part del treball està creada amb la finalitat de fer una investigació generalitzada de lo que denominem Organitzacions No Governamentals per al Desenvolupament. Allí parlo del motiu del seu origen, la seva evolució històrica a través dels seus 35 anys de trajectòria a Catalunya i a la resta de l’Estat espanyol, les seves característiques, les seves finalitats, el seu funcionament i estructuració, la seva amplia heterogeneïtat i, per suposat, la seva base social i de participació ciutadana, que es una de les seves fortaleses i característiques principals.
A més a més, he creat dos apartats addicionals. El primer, dedicat a la Educació per el Desenvolupament, per tal de reflexionar sobre els motius pels quals aquesta matèria encara consta força desconeguda en l’àmbit educatiu i universitari, i com es podria arribar a solucionar aquesta problemàtica. El segon, ens serveix per contextualitzar-nos els problemes economicosocials que han afavorit la actual situació de subdesenvolupament en la major part del continent Africà, i com la cooperació catalana contribueix a remeiar aquesta situació.
La segona part del treball consisteix en una documentació exhaustiva del projecte del qual vaig ser partícip l’estiu del 2018, amb l’objectiu d’extreure’n una reflexió crítica i aprofundir en els principis que aquesta experiència em va inculcar. Apropant, a la vegada, el lector a la meva experiència i motius personals, els quals podrien portar a algú a aventurar-se i a introduir-se en aquest món
Aportacions de la filosofia budista a l'educació occidental
L'educació actual ha deixat de ser rellevant per a les persones contemporànies, aquest tipus d'educació produeix a les noves generacions molts més conflictes i insatisfaccions de les que ens pensem. L'actual sistema educatiu no ofereix cap sentit a les vides dels nostres alumnes per a realment comprendre's a ells mateixos, a un nivell més profund, i com a mestra, em preocupa. Normalment entrenem el cos amb esport, disciplina i bons aliments, però i la ment, i les emocions? El treball de les emocions necessita unes eines, unes actituds, i uns aprenentatges que ajudaran als nostres alumnes, com a futurs membres de la societat, a cultivar la seva pròpia felicitat. La filosofia budista ofereix unes aportacions com ara el control de la ment, uns valors com el respecte, l'autodeterminació, o la empatia, i unes actituds tals com, el perdó, la humilitat i la gratitud, amb les quals podem millorar el nostre sistema educatiu i les nostres escoles, i amb ella, tota la comunitat educativa té moltes possibilitats de millora
Effect of chain extender and water-quenching on the properties of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) foams for its production by extrusion foaming
Bacterial polyesters such as polyhydroxyalkanoates (PHAs) are of great interest for a large number of applications both because of their properties and because they come from renewable resources, despite having a higher cost than commodity polymers. Their foaming—although it presents some difficulties—could be an option to increase their competitiveness. In this work, two strategies have been studied to enhance the poly(3-hydoxybutyrate-co-4-hydroxybutyrate) (P3HB4HB) foamability by extrusion foaming. The effect of the cooling system (water-quenching or air-cooling), chain extender (CE) addition and chemical blowing agent (CBA) amount were evaluated. Density, cellular morphology, mechanical and thermal properties were studied. Optimal density reduction was achieved with use of CE and 3–4 wt.% of CBA masterbatch. The most effective strategy on density reduction was the addition of CE, while the water quenching had only a slight influence on the samples in which CE was not present. CE addition decreased the viscosity and the degradation rate of the polymer, thus leading to lighter foams with larger cells but with equal or even slightly better resistance to compressive and tensile stress, in general termsPostprint (author's final draft
Risk factors and incidence of invasive bacterial infection in severe bronchiolitis: the RICOIB prospective study
Background: Bacterial infection (BI), both community-acquired (CA-BI) and hospital-acquired (HAI), might present as a severe complication in patients with bronchiolitis. This study aimed to describe BI in children with severe bronchiolitis, and to define risk factors for BI. Methods: This was a prospective, descriptive study that included infants admitted to the pediatric intensive care unit (PICU) due to bronchiolitis between 2011 and 2017. The BROSJOD score was calculated to rate the severity of bronchiolitis. Results: Inclusion of 675 patients, with a median age of 47 days (IQR 25-99). 175 (25.9%) patients developed BI, considered HAI in 36 (20.6%). Patients with BI had higher BROSJOD score, PRISM III, and required invasive mechanical ventilation and inotropic support more frequently (p 12 (OR 2.435, 95%CI 1.379-4.297) and bacterial co-infection (OR 2.294 95%CI 1.051-5.008). Concerning HAI, an independent association was shown with mechanical ventilation longer than 7 days (OR 5.139 95%CI 1.802-14.652). Infants with BI had longer PICU and hospital stay (p 12 may alert the presence of CA-BI, especially pneumonia. Patients with BI have higher morbidity and mortality
Pro-atrial natriuretic peptide and proadrenomedullin before cardiac surgery in children. Can we predict the future?
Introduction and objective: Pro-atrial natriuretic peptide (proANP) and pro-adrenomedullin (proADM) levels increase in acute heart failure and sepsis. After cardiac surgery, children may require increased support in the intensive care unit and may develop complications. The aim of this study was to evaluate the utility of proANP and proADM values, determined prior to cardiac surgery, for predicting the need for increased respiratory or inotropic support during the post-operative period. Methods: This was a prospective study in children. Biomarkers were analyzed before surgery using a single blood test. The primary endpoints were the need for greater respiratory and/or inotropic support during the post-operative period. Secondary endpoints were the relationship between these biomarkers and complications after surgery. Results: One hundred thirteen patients were included. ProANP and proADM were higher in children who required greater respiratory and inotropic support, especially proANP; for increased respiratory support, 578.9 vs. 106.6 pmol/L (p = 0.004), and for increased inotropic support, 1938 vs. 110.4 pmol/L (p = 0.002). ProANP had a greater AUC than proADM for predicting increased respiratory support after surgery: 0.791 vs. 0.724. A possible cut-off point for proANP could be ≥ 325 pmol/L (sensitivity = 66.7% and specificity = 88.8%). In the multivariate analysis, the logarithmic transformation of proANP was independently associated with the need for increased respiratory support (OR = 3.575). Patients who presented a poor outcome after cardiac surgery also had higher biomarker values (proADM, p = 0.013; proANP, p = 0.001). Conclusions: Elevated proANP before cardiac surgery may identify which children will need more respiratory and inotropic support during the post-operative period
Amyotrophic lateral sclerosis, gene deregulation in the anterior horn of the spinal cord and frontal cortex area 8: implications in frontotemporal lobar degeneration
Transcriptome arrays identifies 747 genes differentially expressed in the anterior horn of the spinal cord and 2,300 genes differentially expressed in frontal cortex area 8 in a single group of typical sALS cases without frontotemporal dementia compared with age-matched controls. Main up-regulated clusters in the anterior horn are related to inflammation and apoptosis; down-regulated clusters are linked to axoneme structures and protein synthesis. In contrast, up-regulated gene clusters in frontal cortex area 8 involve neurotransmission, synaptic proteins and vesicle trafficking, whereas main down-regulated genes cluster into oligodendrocyte function and myelin-related proteins. RT-qPCR validates the expression of 58 of 66 assessed genes from different clusters. The present results: a. reveal regional differences in de-regulated gene expression between the anterior horn of the spinal cord and frontal cortex area 8 in the same individuals suffering from sALS; b. validate and extend our knowledge about the complexity of the inflammatory response in the anterior horn of the spinal cord; and c. identify for the first time extensive gene up-regulation of neurotransmission and synaptic-related genes, together with significant down-regulation of oligodendrocyte-and myelin-related genes, as important contributors to the pathogenesis of frontal cortex alterations in the sALS/frontotemporal lobar degeneration spectrum complex at stages with no apparent cognitive impairment
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