1,865 research outputs found
Growth and differentiation of human bone marrow osteoprogenitors on novel calcium phosphate cements
No full textMaterials that augment bone cell proliferation and osteogenic activity have important therapeutic implications for bone regeneration and for use in skeletal reconstruction and joint replacement. We have studied the growth and interactions of human bone marrow cells on a variety of new cement composites in vitro. These cement materials are composed of calcium-deficient hydroxyapatites, carbonated apatite and amorphous calcium phosphate. Cell proliferation was significantly reduced and cell differentiation increased in the presence of these cements compared with cells cultured on tissue culture plastic. Alkaline phosphatase, one of the markers of the osteoblast phenotype, was dramatically stimulated by 3 of the 4 cements examined between day 4 and day 10, above levels observed following culture of human osteoblasts on plastic alone. Photomicroscopic examination demonstrated growth and close integration of bone marrow cells and 3 of the composites. Longer term marrow cultures (15 day) on the cements confirmed the stimulation of cell differentiation over proliferation. From these studies, enhanced osteoblastic differentiation was observed on a 70% carbonated apatite, which has a composition similar to bone mineral, whereas, cell toxicity was observed on cells grown on amorphous calcium phosphate. This in vitro culture system demonstrates the use of human bone marrow cells for the potential evaluation of new biomaterials and the development of a novel carbonated apatite that may be of potential use in orthopaedic implant
Effects of novel calcium phosphate cements on human bone marrow fibroblastic cells
No full textThe identification and characterization of biocompatible materials that augment bone cell proliferation and osteogenic activity have important therapeutic implications in skeletal reconstruction and joint replacement. In the present study, we have examined the effects of three biocements, biocement H, calcium-deficient apatite; biocement F, apatite + CaHPO(4); biocement D, carbonated apatite + CaHPO(4) + CaCO(3) and an amorphous calcium phosphate (ACP) proposed as implant fixing materials, on the growth, differentiation, and cell surface interaction of human bone marrow fibroblastic cells. These cells are known to be progenitors of osteoblasts, chondroblasts, adipocytes, myoblasts, and reticulocytes. Alkaline phosphatase enzyme activity, a marker of the osteoblast phenotype, was increased by a factor of two- to sixfold on carbonated apatite, one- to sixfold on apatite and three- to 10-fold on calcium-deficient apatite, over levels observed on plastic. Cell proliferation was significantly reduced. Photomicroscopic examination indicated high biocompatibility with close adhesion of the bone marrow fibroblastic cells to composites D, F, and H. Longer term marrow cultures (15 days) confirmed the stimulation of cell differentiation, as assessed by collagen production, over cell proliferation, of cells grown on carbonated apatite. Enhanced osteoblastic differentiation was observed on a 70% carbonated apatite, which has a composition similar to bone mineral, whereas cell toxicity was observed on cells grown on amorphous calcium phosphate. This in vitro human bone marrow fibroblast culture system provides a simple and effective method for the evaluation of new biomaterials. The development of these novel cements may be of potential use in orthopedic implant
The Reproducibility of Lists of Differentially Expressed Genes in Microarray Studies
No full textReproducibility is a fundamental requirement in scientific experiments and clinical contexts. Recent publications raise concerns about the reliability of microarray technology because of the apparent lack of agreement between lists of differentially expressed genes (DEGs). In this study we demonstrate that (1) such discordance may stem from ranking and selecting DEGs solely by statistical significance (P) derived from widely used simple t-tests; (2) when fold change (FC) is used as the ranking criterion, the lists become much more reproducible, especially when fewer genes are selected; and (3) the instability of short DEG lists based on P cutoffs is an expected mathematical consequence of the high variability of the t-values. We recommend the use of FC ranking plus a non-stringent P cutoff as a baseline practice in order to generate more reproducible DEG lists. The FC criterion enhances reproducibility while the P criterion balances sensitivity and specificity
Le Corbeau et le Renard: 99 versions réinventées: Style d'exercices
No full textThis book represents a fascinating effort. At first I thought it was going to be a collection of various parodies of La Fontaine's FC. It is not that, but rather a creative presentation of some 97 different versions of La Fontaine created by the author. The first two versions are a French translation of the Greek prose of the most original FC text in the Aesopic manuscripts and then La Fontaine's verse. Thereafter the fun begins! The imagination and the execution of this project are both remarkable. Let me offer a sample of five approaches: (1) an acrostic, so that the opening letters of each verse spell "M Jean La Fontaine"; (2) a prose version after the manner of Balzac; (3) a scientific version needing more than a full page; (4) a tourist guide version; and (5) a rhyming version in English. T of C at the end. 136 pages. 5¼" x 8". Printed upon demand.Language note: FrenchNicolas Mille
FC Omniworld
No full textHet maken van een stedenbouwkundig plan voor de locatie Almere Poort in Almere. Hierbij is het programma van de Gemeente, zoals gespecificeerd voor de locatie, overgenomen. De kern van het nieuwe plan is een centrale (groene) as waaraan alle centrumfuncties voor deze wijk worden gerealiseerd. Deze nieuwe as zorgt, door de combinatie van functies met verschillende gebruikstijden, voor een continue drukte op deze centrale as. Aan een van de eindes van de as ligt een verhoogd maaiveld. Dit maaiveld gaat over het spoortalud zodat men het spoor over kan steken zonder tunnel of spoorwegovergang. In dit talud worden diverse functies gehuisvest welke normaal dichte dozen zijn (zoals parkeren, expo ruimten en sportzalen). Deze functies met voornaleijk dichte gevels worden omkleed met kleinschalige functies om continue activiteit bij het verhoogde maaiveld te genereren en om interessante gevelbeelden te hebben (i.p.v. dichte wanden van grootschalige functies). In het verhoogde maaiveld ligt verdiept het nieuwe stadion voor FC Omniworld. Dit stadion wordt zo opgenomen in een natuurlijke en groene omgeving. De dakconstructie bestaat uit houten spanten en een semi-transparant doek om zo goed mogelijk aan te sluiten op het park bovenop het nieuwe maaiveld. Bezoekers komen ook via het park binnen. Op dit niveau kan men rondlopen om versnaperingen te kopen en vervolgens af te dalen naar de tribunes. Het stadion is in de toekomst uit te breiden door nieuwe tribunes te positioneren boven de promenade van het stadion en onder het dak. Hiervoor zijn geen aanpassingen vereist. Tevens is het stadion multifuntioneel te gebruiken door verplaatsbare tribunedelen.Architectur
Plant expression of cocaine hydrolase-Fc fusion protein for treatment of cocaine abuse
No full textBACKGROUND: A recently reported cocaine hydrolase (CocH3) fused with fragment crystallizable (Fc) region of human immunoglobulin G1, denoted as CocH3-Fc, is known as a promising therapeutic candidate for the treatment of cocaine overdose and addiction. A challenge for practical therapeutic use of this enzyme exists in the large-scale protein production and, therefore, it is interesting to identify a low-cost and feasible, sustainable source of CocH3-Fc production.
RESULTS: CocH3-Fc was transiently expressed in plant Nicotiana benthamiana leaves. The plant-expressed protein, denoted as pCocH3-Fc, was as active as that expressed in mammalian cells both in vitro and in vivo. However, compared to the mammalian-cell expressed CocH3-Fc protein, pCocH3-Fc had a shorter biological half-life, probably due to the lack of protein sialylation in plant. Nevertheless, the in vivo half-life was significantly extended upon the PEGylation of pCocH3-Fc. The Fc fusion did not prolong the biological half-life of the plant-expressed enzyme pCocH3-Fc, but increased the yield of the enzyme expression in the plant under the same experimental conditions.
CONCLUSIONS: It is feasible to express pCocH3-Fc in plants. Further studies on the pCocH3-Fc production in plants should focus on the development of vectors with additional genes/promoters for the complete protein sialylation and for a better yield
Stable Foliage Cluster (FC), a Basic Unit of the Crown Structure of Tree Species and Its Application to Modeling of Tree and Forest Structure: Configuration of the FC Model
No full textThe "foliage cluster (FC) model" shows that the size (the amount of leaves, number of yearly shoots and total twig length), turnover time, and branching (i.e., forking) structure of a twig becomes stable in the top of the crown in an oak species by forming a "stable FC" [1]. A stable FC can be treated as a basic component of the crown structure and as an alternative to individual leaf or current-year shoot. The FC model is composed of several equations approximating the branching structure of twigs. Differences in size and branching morphology among twigs are represented by differences in values of the parameters of the equations. We described details of our analyses of data taken from real twigs and applied to the equations implemented in the FC model
Financial analysis of FC SLOVAN Liberec
No full textThesis "Financial analysis of FC Slovan Liberec" focuses especially on reviewing financial position and efficiency of this football club in four year period. The first theoretical part is complemented with practical calculations in the second part. In the second part author focuses on horizontal analysis, vertical analysis and other models of financial analysis
Contributing human and organizational factors to the collapse of the FC Twente stadium roof
No full textIn 2011 the city of Enschede was shocked by the collapse of the roof of an extension for the FC Twente stadium. The structure collapsed during construction and two fatalities and nine injuries were recorded. The cantilevering steel roof structure was covered with corrugated steel sheets and stabilized by bracings. Investigation showed that the structure was already loaded with the finishing structure before it was completed and stabilized. Contributing influencing human and organizational factors to the incident were the tight schedule resulting in a flawed construction sequence. Furthermore, there was too little attention to the way of execution during design, unjustified trust between parties resulting in inadequate coordination, checking and allocation of responsibilities.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Applied Mechanic
Development of a tick-borne encephalitis serodiagnostic ELISA using recombinant Fc-antigen fusion proteins
No full textCurrent diagnostic tests for tick-borne encephalitis virus (TBEV) infections require high-biosafety facilities for antigen preparation and can cross-react with other flaviviruses. There is, therefore, a need to develop safe, inexpensive serodiagnostic tools with high specificity and sensitivity. In this study, a recombinant plasmid that expresses the membrane and envelope (E) proteins of TBEV fused to the Fc domain of rabbit IgG was constructed and expressed in mammalian cells. The E-Fc proteins were secreted as soluble homodimers, which retained reactivity with anti-TBEV and anti-rabbit IgG antibodies. The E-Fc proteins were then used to develop an enzyme-linked immunosorbent assay (ELISA) to detect TBEV antibodies in rodent and human sera. Compared with the neutralization test, the ELISA had over 90% sensitivity and specificity. In addition, the assay showed no cross-reactivity with Japanese encephalitis virus antibodies. These findings suggest that the E-Fc ELISA may be a useful tool for TBEV serodiagnosis. (C) 2014 Elsevier Inc. All rights reserved
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