1,721,439 research outputs found
Immunogenetic analysis of B-cell malignancies and the clinical application of DNA idiotypic vaccines
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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
Nanocomposite-coated porous templates for engineered bone scaffolds: A parametric study of layer-by-layer assembly conditions
Get PDFUsing the layer-by-layer (LbL) assembly technique to deposit mechanically reinforcing coatings onto porous templates is a route for fabricating engineered bone scaffold materials with a combination of high porosity, strength, and stiffness. LbL assembly involves the sequential deposition of nano- to micro-scale multilayer coatings from aqueous solutions. Here, a design of experiments (DOE) approach was used to evaluate LbL assembly of polyethyleneimine (PEI), polyacrylic acid (PAA), and nanoclay coatings onto open-cell polyurethane foam templates. The thickness of the coatings, and the porosity, elastic modulus and collapse stress of coated foam templates were most strongly affected by the pH of PAA solutions, salt concentration, and interactions between these factors. The mechanical properties of coated foams correlated with the thickness of the coatings, but were also ascribed to changes in the coating properties due to the different assembly conditions. A DOE optimization aimed to balance the trade-off between higher mechanical properties but lower porosity of foam templates with increasing coating thickness. Micromechanical modelling predicted that deposition of 116 QLs would achieve mechanical properties of cancellous bone (~0.05 GPa stiffness and ~2 MPa strength) at a suitable porosity of ~70%. When capped with a final layer of PAA and cross-linked via thermal treatment, the PEI/PAA/PEI/nanoclay coatings exhibited good indirect cytotoxicity with mesenchymal stem cells. The ability of LbL assembly to deposit a wide range of functional constituents within multilayer-structured coatings makes the general strategy of templated LbL assembly a powerful route for fabricating engineered tissue scaffolds that can be applied onto various porous template materials to achieve a wide range of properties, pore structures, and multifunctionality
A Randomized Controlled Trial Comparing “Early” Versus “Late” Periosteal Patch Attachment to Knee Chondral Defects in Autologous Chondrocyte Implantation
No full textObjectiveTraditional autologous chondrocyte implantation (ACI) involves arthroscopically harvesting a cartilage biopsy (stage 1), followed by arthrotomy 3-4 weeks later to apply a periosteal patch and implant culture-expanded chondrocytes underneath (stage 2). This study aimed to determine if patch application during stage 1 rather than stage 2 improved clinical outcome.DesignA randomised controlled trial was conducted from 1998-2001. Patients were randomised to receive either traditional ACI (control/late), or ACI with ‘early’ patch during stage 1 (intervention/early). Clinical outcome (Lysholm score) was assessed pre-operatively and annually post-operatively.ResultsSeventy-seven patients were recruited, with 40 patients randomised to the early and 37 to the late patch group. The overall mean pre-operative Lysholm score was 51.8 (range 11-89) and significantly improved by 11.1 points (95%CI 4.8 to 17.4) at mean 12.7 years (range 1.5-23.7) follow-up. Latest mean Lysholm scores for the early and late groups were 68.4 (95%CI 19 to 100) versus 56.7 (95%CI 18 to 98). Adjusted for covariate imbalances, no evidence was found for a difference between the groups (mean difference 8.5, 95%CI -5.2 to 22.2, p=0.22). Twenty-year survival until any reoperation or arthroplasty was 59.6%/82.1% for the early and 56.8%/69.5% for the late group, with no evidence for a difference.ConclusionACI is an effective durable treatment for cartilage defects, with high levels of patient satisfaction and low failure rates. No evidence was found that applying the periosteal patch at the time of chondrocyte harvest improved long term Lysholm scores or survival until any reoperation or arthroplasty
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
Advancing bone tissue engineering one layer at a time: a layer-by-layer assembly approach to 3D bone scaffold materials
No full textThe layer-by-layer (LbL) assembly technique has shown excellent potential in tissue engineering applications. The technique is mainly based on electrostatic attraction and involves the sequential adsorption of oppositely charged electrolyte complexes onto a substrate, resulting in uniform single layers that can be rapidly deposited to form nanolayer films. LbL has attracted significant attention as a coating technique due to it being a convenient and affordable fabrication method capable of achieving a wide range of biomaterial coatings while keeping the main biofunctionality of the substrate materials. One promising application is the use of nanolayer films fabricated by LbL assembly in the development of 3-dimensional (3D) bone scaffolds for bone repair and regeneration. Due to their versatility, nanoscale films offer an exciting opportunity for tailoring surface and bulk property modification of implants for osseous defect therapies. This review article discusses the state of the art of the LbL assembly technique, and the properties and functions of LbL-assembled films for engineered bone scaffold application, combination of multilayers for multifunctional coatings and recent advancements in the application of LbL assembly in bone tissue engineering. The recent decade has seen tremendous advances in the promising developments of LbL film systems and their impact on cell interaction and tissue repair. A deep understanding of the cell behaviour and biomaterial interaction for the further development of new generations of LbL films for tissue engineering are the most important targets for biomaterial research in the field. While there is still much to learn about the biological and physicochemical interactions at the interface of nano-surface coated scaffolds and biological systems, we provide a conceptual review to further progress in the LbL approach to 3D bone scaffold materials and inform the future of LbL development in bone tissue engineering
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