1,720,977 research outputs found
Le cancer stem cells nei tumori della regione testa-collo: studio in vitro ed in vivo della linea cellulare HEP2
Full text linkAbstract
Recenti evidenze scientifiche hanno proposto un nuovo modello di tumorigenesi, secondo il quale l’origine di un tumore dipende da un accumulo sequenziale e stocastico di mutazioni all’interno di una popolazione cellulare eterogenea costituente uno specifico tessuto. Benché le cellule tumorali spesso esibiscono un largo numero di mutazioni, solo una piccola sottopopolazione risulta cruciale per lo sviluppo ed il mantenimento del tumore. Studi condotti a tale riguardo hanno evidenziato che il cancro origina e viene mantenuto da cellule che posseggono caratteristiche di staminalità, ossia capacità di auto-rinnovamento e di differenziazione. Questa sottopopolazione di cellule cancerose è stata definita come “cellule staminali tumorali” (o cancer stem cells, CSCs) e ad oggi è ritenuta principale responsabile della progressione neoplastica e possibile causa dell’eterogeneità del tumore.
Le CSCs rappresentano, dunque, un modello utile per studiare i meccanismi alla base dell’oncogenesi, prerequisito fondamentale per perseguire l’obiettivo ultimo di individuazione di nuovi target molecolari specifici per terapie topiche nel trattamento dei tumori HNSCC. In quest‘ottica è risultato interessante affrontare uno studio volto all’identificazione e alla caratterizzazione molecolare e fenotipica delle cellule staminali cancerose nel tumore della regione testa-collo (Head and neck squamous cell carcinoma, HNSCC). Tale ricerca è stata condotta a carico delle Hep-2, una linea cellulare continua e ben differenziata di carcinoma laringeo umano. Mediante uno specifico protocollo di crescita, la coltura cellulare di Hep-2 è stata arricchita in cancer stem cells. Successivamente, il potenziale tumorigenico delle Hep-2 arricchite in CSCs è stato valutato mediante analisi in vivo
The crucial role of protein phosphorylation in cell signaling and its use as targeted therapy (Review)
Full text linkAbstract. Protein phosphorylation is an important cellular regulatory mechanism as many enzymes and receptors are activated/deactivated by phosphorylation and dephosphorylation events, by means of kinases and phosphatases.
In particular, the protein kinases are responsible for cellular transduction signaling and their hyperactivity, malfunction or overexpression can be found in several diseases, mostly tumors. Therefore, it is evident that the use of kinase inhibitors can be valuable for the treatment of cancer. In this review, we discuss the mechanism of action of phosphorylation, with particular attention to the importance of phosphorylation under physiological and pathological conditions. We also discuss the possibility of using kinase inhibitors in the treatment of tumors
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
DENTAL PULP STEM CELLS, DIFFERENTIATING INTO OSTEOBLASTS, BECOME A SOURCE OF THE PRO-APOPTOTIC FACTOR TRAIL: EVALUATION OF AN EXPERIMENTAL MODEL FOR CANCER THERAPY
No full textAppropriate 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
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