1,721,026 research outputs found
Reduction of venous thromboembolic events in COVID-19 patients: Which role for IL-6 antagonists?
No full textNo abstract availabl
Metabolic syndrome and the risk of late onset Alzheimer's disease: An updated review and meta-analysis
No full textAims: This study aims to provide an updated systematic review and meta-analysis on the risk of Alzheimer's disease (AD) in patients with metabolic syndrome (MetS) and to analyze the contribution of each MetS component on AD onset. Data synthesis: The study was performed according to the PRISMA guideline. Data were obtained searching MEDLINE, Scopus, Web of Science, and EMBASE for studies published between January 1, 2010 and July 30, 2020, evaluating the association between MetS and AD risk. A total of 255 articles were retrieved and 6 investigations (4 prospective and 2 retrospective) met the inclusion criteria. Overall, 9.788.021 patients with a mean follow-up of 4.5 years were analyzed. The pooled analysis revealed a slight increased risk of AD in MetS (hazard ratio, HR: 1.10, 95% and confidence interval, CI: 1.05–1.15). Egger's test indicated the absence of publication bias (t = 2.095 and p = 0.104). However, while analysis based on prospective studies failed to show a significant association between MetS and AD (HR: 0.80 and 95% CI: 0.61–1.05), analysis based on retrospective studies demonstrated a significant, slight increased risk (HR:1.11 and 95% CI: 1.08–1.66). With regard to MetS components, the risk was: arterial hypertension, HR: 1.05 (95% CI: 1.04–10.6); hyperglycemia/diabetes, HR: 1.19 (95% CI: 1.18–1.99); low high-density lipoprotein cholesterol (HDL-C), HR: 1.07 (95% CI: 1.06–1.07); hypertriglyceridemia, HR: 1.06 (95% CI: 1.05–1.06); and abdominal obesity, HR: 0.84 (95% CI: 0.74–0.95). Conclusions: We found a significant association between MetS and AD, mainly driven by large retrospective studies. Our data also support the association of single MetS components with AD incidence, while increased waist circumference seems to have a “protective role” probably due to reverse causality
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
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
Dementia and the risk of death in elderly patients with COVID‐19 infection: Systematic review and meta‐analysis
No full textObjectives: The COVID-19 infection represents a global public health emergency worldwide. Several risk factors have been associated with a poor prognosis among COVID-19 patients. We aimed to perform a systemic review and meta-analysis to evaluate the mortality risk in elderly patients with dementia and COVID-19 infection. Methods: Literature search was based on Cochrane Library, Embase, PubMed, and Google Scholar to locate articles published between December 2019 and July 2020, presenting the number of survived versus deceased patients with dementia and COVID-19 infection. Results: A total of 233 articles were retrieved: 158 were excluded for not meeting the inclusion criteria, leaving 75 articles to assess for eligibility. After evaluation of the full-text articles, eight met the inclusion criteria and were thus included into the final analysis (6493 patients – mean age: 69.6 years). Among COVID-19 patients, the prevalence of dementia was higher in non-survivors compared with survivors (17.5% vs. 5.4%, p < 0.001). The pooled analysis performed using a random-effect model showed an increase in the risk of death in COVID-19 patients with dementia (odds ratio: 3.75; 95% confidence interval: 2.54–5.54, p < 0.0001, I2 = 49.5%). The Egger's regression test confirmed that there were not statistically evidences of publication bias (t = 0.059; p = 0.954). Conclusions: Our preliminary results suggest that patients with COVID-19 infection and dementia have a higher mortality risk in the short-term period compared with infected non-demented individuals. Due to their intrinsic frailty, dementia patients may require a more aggressive treatment and prompt isolation to improve their short-term outcome
Methylenetetrahydrofolate reductase C667T polymorphism and susceptibility to late-onset Alzheimer's disease in the Italian population
No full textINTRODUCTION: This study is a meta-analysis of the published studies on the relationship between methylenetetrahydrofolate reductase (MTHFR) C667T polymorphism and the risk of late- onset Alzheimer's disease (LOAD) in Italian cohorts. EVIDENCEACQUISITION: We conducted a search on the electronic databases PubMed/Medline, Web of Science and Scopus. All cohort and case-control studies investigating the association between MTHFR677T polymorphism and LOADin Italian population published any time to May 8, 2020 were included in the analysis. EVIDENCESYNTHESIS: From an initial screening of 136 articles, 4 were included into the systemic review. The pooled analysis based on the co-dominant model revealed that the MTHFR C677T polymorphism was associated with a significant risk of LOAD among Italian cohorts (TC vs. CC: OR=1.20, 95% CI=1.06-1.36, P=0.004, I2=0%). Conversely, the pooled analysis based on the allelic model demonstrated a non-significant relationship between the MTHFR C677T polymorphism and susceptibility to LOADin Italians (OR: 1.25, 95% CI: 0.99-1.59, P=0.060, I2=14.6%). Moreover, Italian subjects with MTHFR 677TT genotype resulted to have a significantly increased susceptibility to LOAD (OR=1.75, 95% CI=1.23-2.50, P=0.002, I2=0%). CONCLUSIONS: The present meta-analysis showed only trend of association between MTHFR C677T polymorphism and LOADin Italian population; however, it also demonstrated an increased susceptibility of LOADin patients having MTHFR 677TT genotype. Further studies are needed to establish whether MTHFRpolymorphisms can be used as non-invasive biomarker for LOAD
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
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