1,721,141 research outputs found
The scientific instruments in the museum of the Politecnico di Torino
Full text linkThe paper wants to illustrate scientific instruments in the collections of the Museum of Politecnico di Torino, distributed in various departments in respect of both historical consistency and didactic use.In particular the attention is focused on scientific instruments for electric and electrotechnical measurements
Pancreatic solid pseudopapillary neoplasm: key pathologic and genetic features
Full text linkCONTEXT.—:
Solid pseudopapillary neoplasm of the pancreas is a low-grade malignant tumor generally associated with a good prognosis. Solid pseudopapillary neoplasms show peculiar morphologic features, but sometimes the differential diagnosis with other pancreatic neoplasms (ie, pancreatic neuroendocrine tumors) can be a challenging task, especially in cytologic or biopsy specimens. In these cases immunohistochemistry is a useful tool, but the diagnostic utility of several proposed immunohistochemical markers is questionable. In recent years, despite several attempts to characterize the pathogenetic, molecular, and prognostic features of solid pseudopapillary neoplasms, they still remain unclear.
OBJECTIVE.—:
To give the reader a comprehensive update on this entity.
DATA SOURCES.—:
The PubMed database (US National Library of Medicine) was searched using the following string: pseudopapillary tumor [AND/OR] neoplasm [AND/OR] pancreas. All articles written in English were included. In addition, because a heterogeneous terminology has been used in the past to define solid pseudopapillary neoplasms, the reference lists of each paper selected in the PubMed database were also reviewed.
CONCLUSIONS.—:
This review gives a comprehensive update on the pathologic, clinical, and molecular features of SPNs, particularly addressing issues and challenges related to diagnosis. In addition, we have tried to correlate the molecular alterations with the morphologic and clinical features
Endocrine and neuroendocrine cytopathology
No full textCytology is an easily accessible, cost-effective and safe procedure for the initial evaluation of most endocrine/neuroendocrine lesions. Both fine-needle aspiration cytology and exfoliative cytology have shown good sensitivity and specificity in detecting endocrine/neuroendocrine benign proliferations and malignancies. Thanks to its utility for early diagnosis, cytology has contributed to the decline in mortality of endocrine/neuroendocrine neoplasms. The endocrine system comprises different endocrine organs, such as the thyroid, adrenal glands, paraganglia, parathyroid, pancreas, hypothalamus, pituitary gland, ovaries and testes, which can give rise to non-neoplastic, benign and malignant proliferations. In addition, several neuroendocrine cells do not form specific endocrine organs, but are widely present along other systems, notably in the lungs and in the gastrointestinal tract. The general diagnostic approach to proliferations originating from neuroendocrine cells is similar to that of endocrine organs. In this review we concentrate on the cytological features of neuroendocrine proliferations, with particular emphasis on their most common sites of origin, i.e. the thyroid, pancreas, lungs and skin. We also discuss ancillary approaches applied to cytological material to improve the diagnosis
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
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