1,720,990 research outputs found
Comparison of Formation of Capsule Among Different Breast Silicone Implants
No full textBackground/Aim: Silicone implants are widely used biomaterials in surgeries owing to their physiological inertness and low toxicity. However, capsular contracture is a severe complication caused by the insertion of breast implants, which can endanger the health of patients. In this study, twelve different silicone breast implants were tested to determine which could lead to a lower incidence of capsular contracture. Materials and Methods: For in vivo experiments, these silicone implants were implanted into 60 rats (i.e., five implants per rat). The implants were explanted eight weeks after the operation. Samples were analyzed and measured by using hematoxylin and eosin staining, Masson’s trichrome staining, and immunofluorescence staining methods. We compared twelve samples for their differences in the thickness of capsular formation, number of inflammatory cells, collagen expression, fibroblast intensity (i.e., Vimentin and α-SMA), and inflammatory cytokines (i.e., IL-8, CD68, MCP-1, and F4/80). Results: Different surface textures of breast implants gave different effects on capsular thickness, collagen formation, fibroblast formation, and potential inflammation. Samples that had smooth textures such as SEBBIN, HANS, and Mentor showed higher collagen formation than other samples. SEBBIN Texture, Motiva Micro, HANS Smooth I, and HANS Micro exhibited higher fibroblast formation (i.e., α-SMA, Vimentin). SEBBIN Smooth and samples in HANS group displayed lower expression of inflammation cytokines (IL-8, CD68, MCP-1, and F4/80). Conclusion: These findings provide preliminary reports on the surface texture effect and support a selection of breast silicone implants in breast reconstruction to avoid the formation of capsular contracture after implantation
Enhanced random skin flap survival by sustained delivery of fibroblast growth factor 2 in rats
No full textBackground Skin flap survival is a major challenge in reconstructive plastic surgery. Here, we examined the effect of sustained delivery of fibroblast growth factor 2 (FGF2) using heparin-conjugated fibrin (HCF) on skin flap survival in rats. Methods Rats with a skin flap received either phosphate-buffered saline/FGF2 or HCF/FGF2 in the recipient bed. For the no-treatment group, a random skin flap was sutured on the back without any treatment. Seven days after surgery, angiogenesis in the skin flap was evaluated by using Visitrak system and conventional healing quality scoring method. The efficacy of HCF/FGF2 in skin flap survival was evaluated by comparing the results from different groups. Results The necrotic area of the skin flap significantly decreased in the HCF/FGF2 group as compared with the other groups. Conclusion The sustained delivery of FGF2 using HCF has a therapeutic potential to improve skin flap survival.N
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
Risk factors for chest wall depression after implant insertion for breast reconstruction: a retrospective quantitative study
No full textBACKGROUND: Implant-based reconstruction represents the most common form of breast reconstruction after mastectomy. Although the complication rate has lowered owing to the current advances, various implant-related complications are still a problem. There have been few reports discussing chest wall deformation following implant insertion. The aim of this study was to quantify chest wall depression (CWD) after breast implant insertion and identify possible risk factors. METHODS: Patients who underwent unilateral direct-to-implant reconstruction were included in the study. We measured the pre- and postoperative antero-posterior length of the chest wall and used a CWD ratio to measure the change in length. Multivariate analysis was performed with factors with P values of <0.2 in univariate analyses to identify factors associated with CWD. RESULTS: A total of 57 patients were included in this study. The pre- and postoperative difference of antero-posterior length was statistically significant using a paired t-test. Average depth of CWD was 4.16 mm (range, −2.16 to 13.82 mm). In multivariate analysis, capsular contracture and age were the independent prognostic factors correlated with CWD. CONCLUSIONS: This study showed the possibility of CWD following implant insertion. Surgeons and specialists should be aware of the possibility and risk factors of CWD following implant insertion to better inform patients
Micro-textured silicone-based implant fabrication using electrospun fibers as a sacrificial template to suppress fibrous capsule formation
No full textConventionally, macro-textured surfaces comprising several hundred micrometer-sized patterns are used to minimize silicone-based breast implant complications, including capsular contracture. However, because of the recent cases of breast implant-associated anaplastic large cell lymphoma from macro-textured implants, there is a strong demand for nano- or micro-textured silicone implants with dimensions smaller than sub-micrometers. Herein, we propose a simple and cost-effective topographical surface modification strategy for silicone-based implants. Several hundred nanometer to sub-micrometer wide groove-type micro-textures were fabricated on a polydimethylsiloxane surface using electrospun polyvinylpyrrolidone fibers as a sacrificial template. The aligned and randomly oriented microtextures were prepared by controlling the electrospun fiber orientation. In vitro experiments demonstrated that the micro-textured polydimethylsiloxane was cytocompatible and suppressed differentiation of fibroblasts into myofibroblasts. Importantly, the aligned micro-texture promoted the polarization of macrophages into the antiinflammatory M2 phenotype. Long-term in vivo studies established that the micro-textures potently suppressed various factors affecting foreign body reactions by downregulating profibrotic cytokine gene expression and reducing the fibroblast and myofibroblast counts, the cells playing important roles in the immune response. Thus, the thickness and collagen density of fibrous capsules were decreased, demonstrating that the micro-textured surface effectively inhibited capsular contracture. Although the aligned micro-textures contributed to the polarization of macrophages to the M2 phenotype both in vitro and in vivo, foreign body reaction by both the aligned and randomly oriented micro-textures are similar.N
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
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