1,720,967 research outputs found
Isolation, characterisation and biological evaluation of Apple-derived extracellular vesicles
No full textIntroduzione: Le vescicole extracellulari (EVs) sono piccole particelle delimitate da membrana, rilasciate dalle cellule e coinvolte in processi di comunicazione intercellulare. Studi recenti ne hanno ampliato la comprensione, includendo fonti vegetali come le mele (Malus domestica). Questa tesi esplora l'isolamento e la composizione molecolare delle EVs derivate dalla mela (ADEVs), concentrandosi sul loro potenziale per applicazioni biotecnologiche e nella salute umana.
Materiali e Metodi: Le ADEVs, isolate da mele intere, sono state caratterizzate per dimensione, morfologia e marcatori molecolari. Il loro contenuto è stato analizzato tramite studi proteomici, lipidomici e di miRNA, evidenziando variazioni legate ai metodi di coltivazione. Questa tesi analizza inoltre le proprietà funzionali delle ADEVs, in particolare le loro interazioni con le cellule umane in vitro. Gli effetti biologici sulle cellule immunitarie sono stati studiati esaminando il loro ruolo nell'infiammazione e nell'immunomodulazione, con particolare attenzione alla capacità di influenzare la polarizzazione dei macrofagi umani. È stato inoltre esplorato il loro effetto sull'interazione tra macrofagi e cellule staminali mesenchimali (MSCs) durante la differenziazione osteoblastica, valutando il potenziale delle ADEVs nella rigenerazione tissutale. Il potenziale rigenerativo delle ADEVs è stato analizzato anche nei fibroblasti dermici umani (hDFs), studiando le modifiche mediate dalle ADEVs nei segnali infiammatori, nella produzione della matrice extracellulare (ECM) e nello stress ossidativo. Inoltre, sono stati testati gli effetti antimicrobici delle ADEVs su microrganismi della pelle e dell'intestino, per valutare il loro ruolo nel migliorare la salute della pelle tramite la modulazione del microbiota. Infine, la biocompatibilità e la cinetica di rilascio delle ADEVs sono state analizzate utilizzando biomateriali a base di acido ialuronico (HA), per valutare un possibile sistema di somministrazione in applicazioni mediche.
Risultati e Discussione: Le dimensioni e i marcatori molecolari delle ADEVs suggeriscono che esse originino dai corpi multivescicolari. La presenza di enzimi antiossidanti e lipidi bioattivi indica un ruolo nella protezione dallo stress ossidativo. Dal punto di vista funzionale, le ADEVs hanno dimostrato proprietà immunomodulatorie, favorendo la transizione dei macrofagi umani da uno stato pro-infiammatorio a uno antinfiammatorio attraverso l'inibizione della via TLR4/NF-κB. Nel contesto della rigenerazione ossea, le ADEVs hanno mostrato di favorire la differenziazione delle MSCs in osteoblasti tramite effetti mediati dai macrofagi, supportare l'angiogenesi e regolare gli enzimi coinvolti nel rimodellamento osseo. Nelle applicazioni dermiche, le ADEVs hanno ridotto l'infiammazione nei fibroblasti dermici umani abbassando l'attivazione della via NF-κB, ridotto lo stress ossidativo e stabilizzato la matrice extracellulare regolando l'espressione di Col I, Col III e MMPs. Le ADEVs hanno inoltre mostrato attività antimicrobica selettiva, inibendo la crescita di patogeni opportunisti e promuovendo quella di microrganismi benefici per la pelle e l’intestino, suggerendo un potenziale utilizzo come prebiotici per la gestione della salute. Lo studio ha inoltre rivelato che le ADEVs attivano la segnalazione del calcio nei fibroblasti dermici, indicando il coinvolgimento di vie di segnalazione calcio-mediate nella loro bioattività. Infine, le ADEVs si sono dimostrate compatibili con biomateriali a base di HA, in particolare con patch di MeHA, suggerendo un efficace sistema di rilascio.
Conclusioni: Questa tesi evidenzia il potenziale delle ADEVs in applicazioni mediche, nutraceutiche e cosmetiche, con prospettive promettenti nelle terapie rigenerative, antinfiammatorie, antiossidanti e antimicrobiche. I risultati forniscono una base per future ricerche volte a ottimizzare l’uso delle ADEVs per la salute e il benessere.Introduction and Scope: Extracellular vesicles (EVs) are small membrane-bound particles released by cells, playing critical roles in intercellular communication. Recent studies have expanded the understanding of EVs beyond animal models to plant sources, including apples (Malus domestica). This thesis explores the isolation and molecular composition of apple-derived extracellular vesicles (ADEVs), focusing on their potential for application in biotechnology and human health. Materials and Methods: ADEVs isolated from whole apples were characterized for size, morphology and molecular markers. Comprehensive profiling of ADEVs cargo was achieved through proteomic, lipidomic, and miRNA analyses, revealing how their composition varies with apple cultivar and cultivation methods, and how it can affect ADEVs biological effect on mammalian cells.
This thesis also investigates the functional properties of ADEVs, particularly their interactions with human cells in vitro. The biological effects of ADEVs on immune cells were investigated by examining their role in inflammation and immunomodulation, focusing specifically on their ability to influence human macrophage polarization. Further investigation explored ADEVs' influence on the interaction between macrophages and mesenchymal stem cells (MSCs) during osteoblast
differentiation, evaluating whether ADEV-driven immunomodulation has broader implications for tissue regeneration.
The regenerative potential of ADEVs was also examined in human dermal fibroblasts (hDFs), by investigating ADEV-mediated changes in inflammation signalling, ECM production and oxidative stress. In addition, ADEVs’ antimicrobial effects were tested on skin and intestinal microorganisms, providing insights into their potential role in enhancing skin health via microbiota modulation. Finally, ADEV biocompatibility and release kinetics were evaluated using hyaluronic acid (HA) based biomaterials to assess a potential pathway for ADEV delivery in medical applications.
Results and Discussion: ADEVs' size and molecular markers suggest they primarily originate as MVB-derived exosomes. The presence of antioxidant enzymes along with bioactive lipids indicates a role in countering oxidative stress, while miRNA content suggests potential anti-inflammatory effects. Functionally, ADEVs demonstrated immunomodulatory benefits by promoting a shift in human macrophages from a pro-inflammatory to an anti-inflammatory state via inhibition of the
TLR4/NF-κB pathway. In support of bone regeneration, ADEVs were shown to enhance MSC differentiation into osteoblasts through macrophage-mediated effects, support angiogenesis, and regulate bone remodelling enzymes. In dermal applications, ADEVs reduced inflammation in hDFs by downregulating NF-κB signalling, decreased oxidative stress, and stabilized the ECM by modulating the expression of Col I, Col III, and MMPs. ADEVs also displayed selective antimicrobial
activity, inhibiting the growth of opportunistic pathogens while promoting beneficial microorganisms in the skin and gut, suggesting their use as prebiotics for health management. This study further uncovered that ADEVs trigger calcium signalling in hDFs, indicating calcium mediated pathways as part of their bioactivity. Finally, ADEVs were compatible with HyA-based biomaterials, particularly MeHA patches, which could serve as an effective delivery system combining the therapeutic properties of both components. Conclusions: In conclusion, this thesis underscores the potential of ADEVs across medical,
nutraceutical, and cosmetic applications, with promise in regenerative, anti-inflammatory, antioxidant, and antimicrobial therapies. These findings lay a foundation for future research to fully explore and optimize ADEV-based interventions, contributing to innovative solutions for a range of health and wellness challenges
Biotechnology to investigate the microbial community responsible of biogas production from biomass
No full textBiotechnology represents a new point of view on the organic matter and its purposes. The biotechnological approach consists in the exploitation of living organisms or biological systems for specific intents, such as the production of metabolites or the modification and improvement of processes. The organic waste, used for the biogas production, contains complex microbial consortia. In the humid and airless environment, typical of the anaerobic digestion, the organic matter’s degradation is catalysed by those microbes that, by their nature, are already present in the biomasses used in the implant, constituting the core of methane production. For this reason in the past few years, many researches have been accomplished to understand which are the central microbial species and their relationships, with the aim of optimizing the energetic efficiency and reduce costs of the process itself. This contribute presents a panoramic of the current problematics, confronting them and commenting, pagroposing new possible strategies with the aim of furnish guide lines to enhance the biogas production
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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