1,721,013 research outputs found
EFFETTI DELL'IRISINA SULLA MASSA FUNZIONALE BETA-CELLULARE IN MODELLI MURINI E IN ISOLE PANCREATICHE DI SOGGETTI CON DIABETE MELLITO DI TIPO 2
No full textL’ Irisina è una miochina in grado di mediare il crosstalk tra il muscolo scheletrico e le β-cellule pancreatiche in condizioni fisiologiche, promuovendo la secrezione di insulina e la vitalità delle β-cellule. In questo studio, gli effetti dell'irisina sulla massa funzionale delle β-cellule sono stati valutati in condizioni di diabete, sia in vivo, in topi resi diabetici tramite somministrazione di una dieta ricca di grassi e l’iniezione intraperitoneale di una singola dose di streptozotocina, che ex vivo, nelle isole pancreatiche umane isolate da pazienti con diabete di tipo 2 (DMT2). Inoltre, sono stati studiati i meccanismi molecolari alla base dell'azione dell'irisina. La somministrazione di irisina nei topi diabetici ha migliorato l'omeostasi glicemica, ridotto il peso corporeo e ripristinato la massa funzionale delle β-cellule stimolando la proliferazione delle β-cellule e migliorando la secrezione di insulina stimolata dal glucosio (GSIS). Inoltre, nelle isole pancreatiche isolate da pazienti con DMT2, caratterizzati da difetti funzionali e strutturali, l'irisina ha ripristinato il contenuto di insulina e la GSIS. Da notare che l'irisina è stata in grado di attivare le proteine CREB e AKT nelle cellule INS-1E in condizioni fisiologiche, ma non in condizioni glucotossiche. Al contrario, in tali condizioni, l’irisina ha ripristinato l’incremento dei livelli di calcio indotto dal glucosio in acuto, che risultava essere compresso. In particolare, l'irisina ha ripristinato questa risposta attraverso la mobilizzazione AMPK-dipendente delle riserve di calcio dal reticolo endoplasmatico, contribuendo così al ripristino della secrezione di insulina. Questi risultati suggeriscono come l’irisina possa essere considerata un ormone capace di contrastare il danno delle β-cellule in condizioni dismetaboliche sia in modelli murini che nell’uomo e che quindi possa essere potenzialmente utilizzata per ritardare l'insorgenza e/o la progressione del DMT2.The myokine irisin mediates the crosstalk between skeletal muscle and pancreatic β-cells under physiological conditions, enhancing insulin secretion and β-cell viability. In this study, the effects of irisin on the β-cell functional mass were evaluated both in diabetic mice in vivo and in human pancreatic islets isolated from subjects with type 2 diabetes (T2D) ex vivo. Moreover, the molecular mechanisms underlying irisin action were investigated. Irisin administration improved glycemic homeostasis, reduced body weight, and increased β-cell functional mass by stimulating β-cell proliferation (4.5-fold) and enhancing glucose-stimulated insulin secretion in mice made diabetic by a high-fat diet and a single-dose of streptozotocin. Furthermore, in islets from T2D subjects, characterized by functional and structural defects, irisin restored insulin content and glucose-stimulated insulin secretion. Of note, irisin was able to activate CREB and AKT proteins in INS-1E cells under physiological conditions, but not under glucotoxic conditions. However, while chronic exposure to excess glucose blunted the glucose-evoked increase in cytoplasmic calcium levels, irisin restored this response through the AMPK-dependent mobilization of calcium stores from the endoplasmic reticulum which could mediate insulin secretion. These findings highlight the role of irisin as a hormone that potentially counteracts β-cell failure under dysmetabolic conditions in both rodents and humans and could be used to potentially delay T2D onset and/or progression
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
Machine Learning and Lean Six Sigma to Assess How COVID-19 Has Changed the Patient Management of the Complex Operative Unit of Neurology and Stroke Unit: A Single Center Study
Full text linkBackground: In health, it is important to promote the effectiveness, efficiency and adequacy of the services provided; these concepts become even more important in the era of the COVID-19 pandemic, where efforts to manage the disease have absorbed all hospital resources. The COVID-19 emergency led to a profound restructuring—in a very short time—of the Italian hospital system. Some factors that impose higher costs on hospitals are inappropriate hospitalization and length of stay (LOS). The length of stay (LOS) is a very useful parameter for the management of services within the hospital and is an index evaluated for the management of costs. Methods: This study analyzed how COVID-19 changed the activity of the Complex Operative Unit (COU) of the Neurology and Stroke Unit of the San Giovanni di Dio e Ruggi d’Aragona University Hospital of Salerno (Italy). The methodology used in this study was Lean Six Sigma. Problem solving in Lean Six Sigma is the DMAIC roadmap, characterized by five operational phases. To add even more value to the processing, a single clinical case, represented by stroke patients, was investigated to verify the specific impact of the pandemic. Results: The results obtained show a reduction in LOS for stroke patients and an increase in the value of the diagnosis related group relative weight. Conclusions: This work has shown how, thanks to the implementation of protocols for the management of the COU of the Neurology and Stroke Unit, the work of doctors has improved, and this is evident from the values of the parameters taken into consideration
Is It Possible to Predict the Length of Stay of Patients Undergoing Hip-Replacement Surgery?
Full text linkThe proximal fracture of the femur and hip is the most common reason for hospitalization in orthopedic departments. In Italy, 115,989 hip-replacement surgeries were performed in 2019, showing the economic relevance of studying this type of procedure. This study analyzed the data relating to patients who underwent hip-replacement surgery in the years 2010–2020 at the “San Giovanni di Dio e Ruggi d’Aragona” University Hospital of Salerno. The multiple linear regression (MLR) model and regression and classification algorithms were implemented in order to predict the total length of stay (LOS). Lastly, using a statistical analysis, the impact of COVID-19 was evaluated. The results obtained from the regression analysis showed that the best model was MLR, with an R(2) value of 0.616, compared with XGBoost, Gradient-Boosted Tree, and Random Forest, with R(2) values of 0.552, 0.543, and 0.448, respectively. The t-test showed that the variables that most influenced the LOS, with the exception of pre-operative LOS, were gender, age, anemia, fracture/dislocation, and urinary disorders. Among the classification algorithms, the best result was obtained with Random Forest, with a sensitivity of the longest LOS of over 89%. In terms of the overall accuracy, Random Forest and Gradient-Boosted Tree achieved a value of 71.76% and an error of 28.24%, followed by Decision Tree, with an accuracy of 71.13% and an error of 28.87%, and, finally, Support Vector Machine, with an accuracy of 65.06% and an error of 34.94%. A significant difference in cardiovascular disease, fracture/dislocation, and post-operative LOS variables was shown by the chi-squared test and Mann–Whitney test in the comparison between 2019 (before COVID-19) and 2020 (in full pandemic emergency conditions)
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
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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