588 research outputs found
Simplified and refined methods for seismic vulnerability assessment and retrofitting of an Italian cultural heritage masonry building
In the paper the usability check and the seismic vulnerability appraisement and repairing of a masonry building with cultural and artistic value located in the Municipality of Cento (Ferrara, Italy) after the last Italian seismic events (Emilia-Romagna, 2012 May 20th and 29th), are reported and discussed. After some indications on the mentioned earthquakes are given, the case study has been presented and useful information on both historical news and geometrical properties have been given. So, the usability check of examined building has been done through the identification of damages occurred under earthquake. Later on, seismic vulnerability assessment of the building on the basis of both the simplified LV1 and
the refined LV3 analysis levels given by Italian Guidelines on Cultural Heritage has been performed. The analysis results, compared each other in terms of seismic safety factors, have shown that building has an average vulnerability degree, so to require local repairing and strengthening interventions, which have been herein presented. Finally, the effectiveness of the proposed local interventions has been proved by numerical analysis in the non-linear field
Basic fibroblast growth factor mediates carotid plaque instability through metalloproteinase-2 and –9 expression
OBJECTIVE(S): We hypothesized that basic fibroblast growth factor (bFGF) may exert a role in carotid plaque instability by regulating the expression of matrix metalloproteinases (MMP). METHODS: Plaques obtained from 40 consecutive patients undergoing carotid endarterectomy were preoperatively classified as soft or hard. Serum bFGF was pre- and postoperatively measured. The release of MMP-2 and MMP-9 in the blood serum, and the activity, production and expression in the carotid specimens was analyzed. Specific anti-bFGF inhibition tests were performed in vitro on human umbilical artery smooth muscle cells (HUASMC) to evaluate the role of bFGF in the activity, production and expression of MMP-2 and -9. RESULTS: Twenty-one (53%) patients had a soft carotid plaque and 19 (48%) a hard plaque. Preoperative bFGF serum levels were higher in patients with soft plaques [soft=34 (28-39) pg/mL and hard=20 (17-22) pg/mL-p<0.001] and postoperatively returned to normal values (when compared to 10 healthy volunteers). The serum levels of MMP-2 in patients' with soft plaques were higher than those in patients' with hard plaques [soft=1222 (1190-1252) ng/mL and hard=748 (656-793)ng/mL-p<0.0001]. MMP-9 serum values were 26 (22-29) ng/mL for soft plaques and 18 (15-21) ng/mL for hard plaques (p<0.0001). We found increased activity, production and expression of MMP-2 and -9 in soft plaques compared to hard plaques (p<0.001). In vitro inhibition tests on HUASMC showed the direct influence of bFGF on the activity, production and expression of MMP-2 and -9 (p<0.001). CONCLUSIONS: bFGF seems to exert a key role in carotid plaque instability regulating the activity, production and expression of MMP thus altering the physiologic homeostasis of the carotid plaque
Growth factors and experimental arterial grafts
Background: The production of growth factors from several experimental arterial conduits was determined.
Methods: We implanted 105 experimental arterial grafts that were 1 cm long in the abdominal aorta of Lewis rats (average
weight, 250 g). Five different types of grafts were analyzed: arterial isografts, vein grafts, arterial allografts, and polytetrafluoroethylene
(PTFE) grafts with normal or decreased compliance. Animals were killed humanely 4 weeks after
surgery and the production of platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), transforming
growth factor-b, tumor necrosis factor-a, and interleukin-1 was analyzed.
Results: Myointimal hyperplasia (MH) was evident in vein grafts, arterial allografts, and PTFE grafts, but not in arterial
isografts. Growth factor production was increased for grafts prone to develop MH like vein, PTFE grafts, and arterial
allografts. PDGF and bFGF were increased significantly for PTFE and vein grafts, but not for arterial allografts. The
importance of bFGF and PGDF was confirmed by the capability of antibody to PDGF and to bFGF to reduce the
mitogenic activity of smooth muscle cells, in vivo and in vitro, for PTFE and vein grafts, but not for arterial allografts, in
which a predominant role was played by interleukin-1 and tumor necrosis factor-a.
Conclusions: Agents able to neutralize this increased production of growth factors, either directly or by competition with
their receptors, can prevent MH formation. (J Vasc Surg 2016;64:1444-9.)
Clinical Relevance: Arterial grafts release growth factors, which can lead to myointimal hyperplasia formation and
atherosclerosis progression in the arterial tree. Both phenomena can cause graft occlusion. Inhibition of growth factor release by arterial grafts can improve their clinical effectiveness
Aplicació pràctica i sostenible dels nostres coneixements tecnològics a la societat
En els darrers anys hem viscut canvis importants a la nostra universitat i als estudis que impartim, als diferents àmbits de coneixement. I continuarem fem canvis per adaptar-nos a la realitat social i industrial, present i futura. El “Ser o no Ser” es transformaria en dir, o evolucionem o involucionen, no existeix el punt entremig, per tant, el camí a seguir està molt clar.
Des de el nostre grup de Tecnologies de Fabricació, fa temps que estem treballant amb “l’ambientalització integral” de les diferents assignatures que coordinen. Inicialment, nosaltres em treballat de forma bàsica amb la minimització de l’impacte ambiental dels processos de fabricació i la gestió dels seus residus. Però darrerament em donat un pas més endavant, amb el desenvolupament de projectes relacionats amb la fabricació de sistemes energètics renovables, i amb la promoció i divulgació de les energies netes a la societat.
Per exemple, als darrers projectes hem desenvolupat un estudi sobre l’aprofitament de la energia eòlica provocat pel moviment de les onades, o un estudi del disseny i fabricació de un mini-aerogenerador a una vivenda unifamiliar no aïllada per un consum de potencia mínima.
Per altra banda, el nostre grup i la nostra escola han apadrinat una escola de primària a Castellbisbal, i col•labora amb la comissió de Medi Ambient de la escola per a la promoció de les energies renovables. Mercès a aquest cooperació, des de l’any 2008, aquesta escola participa a la celebració dels European Solar Days y Global Wind Day, amb la realització de diverses activitats al recinte. Aquest any 2009, coordinarem també la participació del Campus de la UPC de Terrassa en aquestes celebracions.
Tots aquests projectes han estat i son possibles per la col•laboració estreta amb els alumnes i el seu treball personal, per la col•laboració amb la industria amb la cessió de material, i pel suport de la UPC amb els recursos i equipament bàsic del que disposem, per poder fer recerca aplicada, promoció i divulgació dels nostres coneixements.Peer Reviewe
Reglamento para la provisión de Escuelas Públicas aprobado por Real decreto de 11 de Diciembre de 1896
Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201
Risk factors for adenocarcinoma in the surgically transposed colon not exposed to the fecal stream. Etiological considerations extrapolated to sporadic colon carcinoma in the general population
The aim of the study was to analyze the clinical characteristics and outcomes of patients with de novo secondary adenocarcinoma arising in the operatively transposed colon not exposed to the fecal stream
Diseño y fabricación de un prototipo a pequeña escala de una turbina de aire, para el aprovechamiento de la energía marina, a bajo coste mediante técnicas de prototipado rápido
Existen diferentes procedimientos para aprovechar la energía de las olas [1]. El procedimiento que cuenta con mayor rendimiento y menor coste de mantenimiento es el de Columna Oscilante de Agua (OWC). El sistema consiste en la generación del movimiento de una turbina con el aire generado por el vaivén de la olas, con el problema añadido de que el flujo de aire es bidireccional. Actualmente la única turbina que puede girar en un solo sentido independientemente del sentido del flujo de aire es la turbina Wells [2]. Existen pocos estudios teóricos publicados sobre este tipo de turbina.
En este artículo se describe la metodología para desarrollar un prototipo de bajo coste (de aproximadamente 150€) de una turbina Wells, a escala, para poder contrastar los resultados obtenidos experimentalmente con los propuestos de forma teórica. Se analizarán de igual forma tanto las ecuaciones propuestas obtenidas de forma teórica como los resultados experimentales.
En el diseño de la turbina se ha partido de unos parámetros fijos: álabes de perfil simétrico NACA 0018, las dimensiones del tubo y el caudal de aire previsto y se han calculado el resto de los parámetros a partir de ecuaciones de aerodinámica [3],[4]. Posteriormente se ha realizado el diseño gráfico con un CAD y se ha fabricado el prototipo mediante sinterizado láser y mecanizado de control numérico. Finalmente se ha montado un motor de corriente continua para determinar la potencia generada en vacío.
Se ha construido el prototipo y se ha determinado la velocidad de giro y la potencia generada en función del caudal de aire circulante por el tubo.Peer Reviewe
Influence of bacterial colonization of the healing screws on peri-implant tissue
Abstract Background/purpose A bacterial adhesion to implant surfaces is a first stage of peri-implant mucositis and peri-implantitis. The aim of this longitudinal study was to examine the quantitative and qualitative biofilm formation on healing screws and the presence of periodontal pathogens in peri-implant crevicular fluid (PCF). In each of the 30 participants, one healing screw was adapted to every single implant. Materials and methods Thirty patients, 18 females and 12 males, were selected. Thirty healing abutments were left in situ for 20, 30 and 90 days. At regular times, the presence/absence of bleeding on probing (BOP) was determined. The specific periodontal pathogens were determined in PCF, by polymerase chain reaction (PCR). After 20, 30 and 90 days, the healing screws were removed and analyzed to establish the total bacterial count by a culture method. Results BOP+ increased significantly after 90 days. Biofilm was detected on all healing abutments and the number of cultivable oral flora showed a significant increase from 20 days to 30 days and to 90 days. At 90 days, the anaerobic counts constituted the bulk of plaque examined and Veillonella spp. were present in higher percentages levels (19.82%) among the Gram-negative bacteria. No significant differences among the experimental groups were detected in the frequencies of detection of each monitored bacteria in PCF. Conclusion The healing screws left in situ for a period of 90 days caused a peri-implant inflammation and the presence of periodontal pathogenic bacteria in the peri-implant sulcus, due to the plaque accumulation on screw surfaces
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