1,720,976 research outputs found
The effect of menopause hypoestrogenism on osteogenic differentiation of periodontal ligament cells (PDLC) and stem cells (PDLCs): A systematic review
Full text link(1) Background: Menopause is a physiological condition typified by drastic hormonal changes, and the effects of this transition have long-term significant clinical implications on the general health, including symptoms or physical changes. In menopausal women, the periodontium can be affected directly or through neural mechanism by oestrogen (E2) deficiency. The majority of the biological effects of E2 are modulated via both oestrogen receptor-α (ERα) and oestrogen receptor-β (ERβ). There is evidence that hypoestrogenism has a substantial impact on the aetiology, manifestation and severity of periodontitis, via the regulation of the expression of osteoproges-terin and RANKL in human periodontal ligament cells through ERβ. However, the mechanistic understanding of oestrogen in periodontal status has been partially clarified. The aim of this paper was to synopsize the recent scientific evidence concerning the link between the menopause and periodontitis, through the investigation of physio-pathological impact of the oestrogen deficiency on osteogenic differentiation of PDLSCs and PDLSC, as well as the dynamic change of ERα and ERβ. (2) Methods: Search was conducted for significant studies by exploring electronic PubMed and EMBASE databases, and it was independently performed by two researchers. All studies on the impact of oestrogen level on alveolar bone resorption were searched from 2005 to July 2020. Data selection was in concordance with PRISMA guidelines. (3) Results: Eight studies met the criteria and were included in this systematic review. All studies reported that oestrogen deficiency impairs the osteogenic and osteoblastic differentiation of PDL cells and oestrogen affects the bone formation capacity of cells. Seven studies were conducted on animal samples, divided into two groups: the OVX animals and animals who received the sham operation. (4) Conclusions: There is a multitude of data available showing the influence of menopause on periodontal status. However, the evidence of this line to investigation needs more research and could help explain the physiological linkage between menopause state and periodontal disease
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Oral microbiome and preterm birth: Correlation or coincidence? A narrative review
No full textBACKGROUND: Physiological changes that occur during pregnancy involve, as a natural consequence, also modifications of oral microbiome. However, the addition with microbial imbalance due to pre-existing periodontal infection might impair a pathological alteration in the phylogenetic community structure and composition in the oral cavity, exacerbating an inflammatory status, and becoming a potential risk factor for preterm birth. From the empirical findings about the relationship between periodontal pathogens and systemic diseases, a clear interest focused on the potential impact of some periodontal pathogens on the preterm birth risk has emerged. AIM: Exploration of the potential interdependence existing between dysbiosis of oral microbiome and changes in maternal-fetal barrier in premature rupture of membranes. MATERIALS AND METHODS: In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a Medline search was performed for studies focusing on oral microbioma and its association with pre-term birth, and completed by additional hand searching. Two reviewers independently selected studies and extracted data. The search was restricted to only reports written in English. RESULTS: The electronic search produced 66 items. Six duplicates were found. Among the collected studies, 56 were discarded because they met the exclusion criteria. The articles and reports in our review showed a connection between preterm birth and altered oral microbiome, suggesting a potential key role of Fusobacterium nucleatum, a notable periodontal pathogen involved in several pathological periodontal conditions, in increasing the risk of premature birth. CONCLUSIONS: Since F. nucleatum is frequently associated with preterm birth, it is coherent to hypothesize a potential role for the oral microbiota for preterm birth risk. Further studies should be carried out to determine the changes of the oral microflora in pregnancy and to provide comprehensive knowledge of the diversity of oral bacteria involved in preterm birth
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Exploring the role of Fusobacterium nucleatum in preterm birth: A narrative review
Full text linkIn recent years, substantive attention has been drawn to the relationship between oral microbiome homeostatic equilibrium disruption and systemic health, demonstrating the negative impacts of this reciprocal biological interplay. Increasingly, there is a concern over the potential noxious effect of oral microbiome dysbiosis on obstetric poor outcomes, focusing on preterm birth. This epidemiological observation remains unexplained, although biologically plausible mechanism has been proposed. Intrauterine infection has long been associated with adverse pregnancy, when the elicitation of an immune response is determinant. There is evidence that Fusobacterium nucleatum (FN), a Gram-negative anaerobe ubiquitous in the oral cavity, infects the mouse placenta originating in the decidua basalis. Based on the current data in literature, we performed a review to provide resources for the explanation of the potential impact of microbiome dysbiosis on poor obstetric outcomes, focusing on the role of FN
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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