Search results for "Lag"
showing 10 items of 3124 documents
Soportes tridimensionales biodegradables basados en micropartículas para la regeneración del cartílago articular
2017
Introducción El cartílago es una estructura viscoelástica, hipocelular, aneural, alinfático y avascular. Su función en el organismo consiste en el soporte y distribución de carga, soportando cerca de 10 millones ciclos carga/año. Gracias a sus propiedades biomecánicas, permite un movimiento casi libre de fricción al disminuir el coeficiente de rozamiento. Es por tanto de vital importancia para la correcta congruencia y función articular. Las lesiones cartilaginosas poseen escasa capacidad de regeneración, siendo uno de los condicionantes la naturaleza avascular del tejido. Según el diámetro y profundidad de la lesión, el tejido podrá tratar de suplirla de una manera u otra. Si la lesión no …
Implantation of a polycaprolactone scaffold with subchondral bone anchoring ameliorates nodules formation and other tissue alterations
2015
Purpose: Articular cartilage has limited repair capacity. Two different implant devices for articular cartilage regeneration were tested in vivo in a sheep model to evaluate the effect of subchondral bone anchoring for tissue repair. Methods: The implants were placed with press-fit technique in a cartilage defect after microfracture surgery in the femoral condyle of the knee joint of the sheep and histologic and mechanical evaluation was done 4.5 months later. The first group consisted of a biodegradable polycaprolactone (PCL) scaffold with double porosity. The second test group consisted of a PCL scaffold attached to a poly(L-lactic acid) (PLLA) pin anchored to the subchondral bone. Result…
Type V collagen and protein kinase C η down-regulation in 8701-BC breast cancer cells.
2011
We previously reported that ductal infiltrating carcinomas (d.i.c.) of the human breast display profound modifications of the stromal architecture, associated with anomalous collagen composition. Among the major alterations observed in the interstitial collagen, the relative increase of type V collagen content was detected. When type V collagen was used as an ‘‘in vitro’’ substrate for 8701-BC d.i.c. cells, it appeared able to restrain cell growth, inhibit cell motility and invasion ‘‘in vitro’’, and modify the expression levels of genes coding for apoptosis factors, caspases and stress response proteins. In the present paper we demonstrate that type V collagen induces the down-regulation o…
Tannin analysis of chestnut bark samples (Castanea sativa Mill.) by HPLC-DAD-MS.
2014
In the present investigation, an HPLC-DAD/ESI-MS method for the complete analysis of tannins and other phenolic compounds of different commercial chestnut bark samples was developed. A total of seven compounds (vescalin, castalin, gallic acid, vescalagin, 1-O-galloyl castalagin, castalagin and ellagic acid) were separated and quantified, being 1-O-galloyl castalagin tentatively identified and found for the first time in chestnut bark samples. Thus, this method provided information regarding the composition and quality of chestnut bark samples, which is required since these samples are commercialised due to their biochemical properties as ingredients of food supplements.
Ritratto femminile del IV secolo d.C. nella Catacomba di Villagrazia di Carini. MARE INTERNUM, vol. 4, p. 119-127, ISSN: 2035-0783
2013
Si analizza l'iconografia di uno splendido ritratto femminile di IV sec. che riprende la moda dei ritratti dell'Augusta Elena.
La catacomba di Villagrazia di Carini. Un esempio di architettura funeraria paleocristiana in Sicilia. Ricerche 2000-2008
2009
Si presentano il rilievo topografico e diretto delle gallerie I-XII e la restituzione grafica degli apparati decorativi intercettati analizzati nella loro distribuzione all'interno del cimitero e organizzati per periodi.
Immigrant entrepreneur firm start-up behavior and reasoning : a reflective study of causation, effectuation and bricolage
2013
Entrepreneurship research studies how and why firms come into being, survive and grow (Davidsson, 2004; Gartner, 1985; Schumpeter, 1934). Early literature has proposed a linear model of entrepreneurship which is intentional (Bird, 1988), opportunity discovery (Kirzner, 1997; Shane and Venkataraman, 2000) and goal & strategy oriented (Wiklund & Shepherd, 2005). Being a mainstream in the earlier research, it is labelled as causation model by Sarasvathy (2001). Several scholars such as Baker & Nelson (2005) and Sarasvathy (2001a, b; 2008) questioned the validity of the model and proposed two additional models to the classic model: Effectuation (Sarasvathy, 1998) and Entrepreneurial Bricolage (…
Biocompatible hydrogels based on hyaluronic acid cross-linked with a polyaspartamide derivative as delivery systems for epithelial limbal cells.
2011
The aim of this work was to evaluate the potential use of hydrogels based on hyaluronic acid (HA) chemically cross-linked with α,β-poly(N-2-hydroxyethyl) (2-aminoethylcarbamate)-D,L-aspartamide (PHEA-EDA) as substitutes for the amniotic membrane able to release limbal cells for corneal regeneration. Hydrogels, shaped as films, with three different molar ratios (X) between PHEA-EDA and HA (X = 0.5, 1.0 and 1.5) have been investigated. First, it has been evaluated their swelling ability, hydrolytic resistance in simulated physiological fluid and cell compatibility by using human dermal fibroblasts chosen as a model cell line. Then adhesion studies in comparison with collagen gel, have been pe…
Improved yield and functionality of parathyroid cells separated by using collagenase-digestion with cold pre-incubation.
2001
Preparation of cells from solid organs often induces a functional impairment due to the proteolytic cell damage by the applied digestive enzyme like collagenase, trypsin or dispase. To preserve the tissue and to enhance the yield of cells, Laue et al. reported an islet cell isolation with pre-incubation at 4 C permitting the enzyme to diffuse into the tissue and explicite activity equally throughout the whole particle. The aim of this study was to investigate whether this procedure can be applied to parathyroid glands. Therefore porcine parathyroid glands were dissected into 1 mm3 pieces. Subsequently one group of these pieces was incubated 22 h at 4 C in 2 mg/ml collagenase before activati…
Profilin 1 is required for abscission during late cytokinesis of chondrocytes
2009
Profilins are key factors for dynamic rearrangements of the actin cytoskeleton. However, the functions of profilins in differentiated mammalian cells are uncertain because profilin deficiency is early embryonic lethal for higher eukaryotes. To examine profilin function in chondrocytes, we disrupted the profilin 1 gene in cartilage (Col2pfn1). Homozygous Col2pfn1 mice develop progressive chondrodysplasia caused by disorganization of the growth plate and defective chondrocyte cytokinesis, indicated by the appearance of binucleated cells. Surprisingly, Col2pfn1 chondrocytes assemble and contract actomyosin rings normally during cell division; however, they display defects during late cytokines…