1,721,027 research outputs found
Significato clinico-patologico e valore prognostico dell’analisi citopatologica del lavaggio gastrico in 80 pazienti affetti da adenocarcinoma dello stomaco
Get PDFSebbene la sua incidenza stia diminuendo negli ultimi anni, il cancro dello stomaco rappresenta tuttora il quinto tumore più diffuso al mondo (dopo polmone, seno, prostata e colon-retto) e la terza causa di morte per tumore dopo il cancro del polmone e del fegato.1
Il successo registrato in Giappone nel campo della diagnosi precoce del cancro gastrico (early gastric cancer, EGC) viaggia purtroppo su binari molto differenti rispetto a quelli dei Paesi Occidentali nei quali questo tumore viene spesso riscontrato ancora nei suoi stadi più avanzati.2,3
Tale neoplasia è gravata da una prognosi piuttosto infausta dal momento che il tasso di sopravvivenza globale a 5 anni si aggira intorno al 20%. Infatti, anche dopo una resezione chirurgica curativa, dove il campione operatorio ha margini indenni da infiltrazione neoplastica, circa il 50% dei pazienti muore per recidiva locale di malattia che si manifesta in genere entro 2 anni di follow-up.4-7
Il tasso di sopravvivenza globale a 5 anni è fortemente correlato alla stadiazione determinata al momento della diagnosi.
Sebbene molti parametri patobiologici classificativi e stadiativi siano ben studiati e universalmente riconosciuti riguardo al loro significato clinico e prognostico, esistono ancora molte ombre circa la capacità di prevedere esattamente come tale tumore possa evolvere nella sua storia naturale per un dato e noto stadio tra i vari pazienti affetti.
A tutt’oggi, per esempio, mentre per alcuni tumori sono stati identificati determinati marcatori tumorali sierici (ormoni antigenici) utili allo screening, diagnosi o prognosi degli stessi (in particolare l’alfa-fetoproteina per l’epatocarcinoma, il Ca 19.9 per l’adenocarcinoma pancreatico o il colangiocarcinoma, il CEA per l’identificazione di malattia colo-rettale recidiva o metastatica), per l’adenocarcinoma gastrico nessun marcatore ha raggiunto elevati livelli di sensibilità né di specificità per gli scopi sovra descritti.8-16
Quanto alla citopatologia, negli ultimi anni diversi lavori hanno ormai consolidato il ruolo dell’analisi citopatologia del lavaggio peritoneale: il riscontro di cellule cancerose in questo materiale biologico ha, infatti, una sicura valenza prognostica (in termini negativi) per questo tipo di pazienti.17-19
Nasce quindi dalle considerazioni summenzionate l’intento di questo studio: analizzare il lavaggio gastrico dei pazienti affetto da adenocarcinoma gastrico esaminando la presenza (o l’assenza) delle cellule cancerose in esso esfoliate al fine di cercare di identificare un ulteriore possibile parametro utile alla classificazione, prognosi, terapia e monitoraggio. Di interesse, come si evince dalla letteratura scientifica mondiale, prima del nostro gruppo di ricerca nessuno ha condotto questa linea di studio in quanto, per quanto riguarda il cancro dello stomaco, finora l’analisi citopatologica del lavaggio gastrico è stata eseguita con il solo intento diagnostico
Cisti aracnoidee malformative della fossa posteriore: trattamento chirurgico e risultati a distanza
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
- …
