1,721,003 research outputs found
Regulation of canonical Wnt signalling pathway during cementum regeneration
No full textThis project highlights the important role of cell signalling pathway during tooth regeneration. Biomaterials can be designed to activate relevant cell signals for the purpose of dental repair and tooth regeneration. Based on the results in the present project, strategies directly targeting cell signalling pathway may provide new approaches for periodontal regenerative tissue engineering
The cementogenic differentiation of periodontal ligament cells via the activation of\ud Wnt/β-catenin signalling pathway by Li+ ions released from bioactive scaffolds
No full textLithium (Li) has been widely used as a long-term mood stabilizer in the treatment of bipolar and depressive disorders. Li+ ions are thought to enhance the remyelination of peripheral nerves and also stimulate the proliferation of neural progenitor cells and retinoblastoma cells via activation of the Wnt/β-catenin signalling pathway. Until now there have been no studies reporting the biological effects of released Li+ in bioactive scaffolds on cemetogenesis in periodontal tissue engineering applications. In this study, we incorporated parts of Li+ ions into the mesoporous bioactive glass (MBG) scaffolds and showed that this approach yielded scaffolds with a favourable composition, microstructure and mesopore properties for cell attachment, proliferation, and cementogenic differentiation of human periodontal ligament-derived cells (hPDLCs). We went on to investigate the biological effects of Li+ ions themselves on cell proliferation and cementogenic differentiation. The results showed that 5% Li+ ions incorporated into MBG scaffolds enhanced the proliferation and cementogenic differentiation of hPDLCs on scaffolds, most likely via activation of Wnt/β-catenin signalling pathway. Further study demonstrated that Li+ ions by themselves significantly enhanced the proliferation, differentiation and cementogenic gene expression of PDLCs. Our results indicate that incorporation of Li+ ions into bioactive scaffolds is a viable means of enhancing the Wnt canonical signalling pathway to stimulate cementogenic differentiation of PDLCs
The effect of silicate ions on proliferation, osteogenic differentiation and cell signalling pathways (WNT and SHH) of bone marrow stromal cells
No full textSilicon (Si) is a trace element, which plays an important role in human bone growth. Si has been incorporated into biomaterials for bone regeneration in order to improve their osteogenic potential, both in vitro and in vivo. Little is known, however, as to how Si ions elicit their biological response on bone-forming cells. The aim of this study was to investigate the effect of Si ions on the proliferation, differentiation, bone-related gene expression and cell signalling pathways of bone marrow stromal cells (BMSCs) by comparing the BMSC responses to different concentrations of NaCl and Na2SiO3, while taking into account and excluding the effect of Na ions. Our study showed that Si ions at a concentration of 0.625 mM significantly enhanced the proliferation, mineralization nodule formation, bone-related gene expression (OCN, OPN and ALP) and bone matrix proteins (ALP and OPN) of BMSCs. Furthermore, Si ions at 0.625 mM could counteract the effect of the WNT inhibitor (W.I.) cardamonin on the osteogenic genes expression, (OPN, OCN and ALP), WNT and SHH signalling pathway-related genes in BMSCs. These results suggest that Si ions by themselves play an important role in regulating the proliferation and osteogenic differentiation of BMSCs, with the involvement of WNT and SHH signalling pathways. Our study provides evidence to explain possible molecular mechanisms whereby Si ions released from Si-containing biomaterials can acquire enhanced bioactivity at desired concentration
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
