1,721,025 research outputs found
Corrosion mechanisms in copper-based artifacts investigated by secondary ion mass spectrometry
No full textIn the field of ancient metallic objects belonging to the world of Cultural Heritage, copper-based artifacts represent the largest part of them. The pristine appearance of these objects as conceived by the artist or the craftsman is often concealed from our eyes due to the presence of surface corrosion patinas or crusts. This sort of extra layer can sometimes completely modify color and structure of the artwork. Therefore, understanding the formation mechanism of the corrosion layers is of fundamental importance to preserve and protect the good when it is made of copper or copper alloys. Secondary ion mass spectrometry is considered an emerging technique for the investigation of patina and crusts of corroded objects. The surface and in-depth chemistry of such complicated multilayer structures can be efficiently described with high depth (1 nm) and lateral (<50 nm) resolution by using SIMS and ToF-SIMS techniques. In this article, we summarize how information obtained from ion bombardment experiments such as the penetration profiles of reactive species, the stratigraphy of corrosion products, and the identification of emerging and surface-spalling species can improve the knowledge of the corrosion phenomena in copper-based artifacts
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
Study of expression and role of Metabotropic Glutamate Receptors in Human Acute Myeloid Leukemia cell lines and involvement of L1-CAM in migration of mGluR1+ mouse melanoma cell lines
Full text linkmGluRs are a family of G-coupled protein receptors with widespread expression in the central nervous system (CNS), some normal tissues, and in various cancers. The predominant functions of mGluRs in the CNS are modulating presynaptic neurotransmission but in cancers, mGluRs are involved in regulating cell proliferation.
Acute Myeloid Leukemia (AML) is a clonal, malignant disease of hematopoietic tissue and is the most common type of acute leukemia in adults and the elderly. Despite the wide number of drugs available to treat this disease, there are many unmet needs in AML therapy; relapsed or refractory patients or those unable to receive intensive chemotherapy display a poor prognosis.
Skin cancer is described as the abnormal multiplication of skin cells, which is frequently detected in sun-exposed regions. Basal cell carcinoma, squamous cell carcinoma, Merkel cell carcinoma, cutaneous lymphoma, Kaposi sarcoma, and melanoma are the six primary forms. Melanoma is the most severe form of skin cancer and is caused by melanocyte transformation. In the United States, invasive melanoma is expected to account for about 100,000 new cases and over 7,000 fatalities from skin cancer in 2022.
In this study, there are two distinct studies, in one, we evaluated metabotropic glutamate receptors (mGluRs) to assess if one or more of mGluRs may be a putative therapeutic target in AML. We have found a novel, previously unknown role of mGluRs in AML. The second study is to use mGluR1+ mouse melanoma cell lines to determine if the presence of L1-NCAM (CD171), a neural cell adhesion molecule 1 is involved in cell migration as shown previously in glioblastoma cell
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
Monolateral macroorchidism
No full textThe unilateral enlargement of a testis, in the absence of symptoms that point towards an acute scrotum, is a situation that must require careful assessment because the exclusion of a tumour process is the first step to be taken. Tumour or endocrine disorders, such as hypothyroidism and the adrenal genital syndrome, must necessarily enter into differential diagnosis. Unilateral cause of unilateral enlargement of the testis is the benign monolateral macrorchidism. This little known condition can also occur in childhood or early adolescence. Unilateral magnification is not necessarily an indication for surgical exploration if there are no clinical signs, tumour markers and suspect images. The described case of macroorchdism in a 9-year-old child belongs to the benign forms, as a compensatory framework to a gonadal suffering of the contralateral testis
Clinical presentation of PTEN mutations
Full text linkPTEN analysis should be considered in any child presenting with macrocephaly and dermatologic features and/or mental retardation and/or hamartomatous overgrowth involving the skin, the subcutaneous tissue, and the bowel. PHTS leads to an increased risk of developing breast, skin, colorectal, endometrial, and thyroid malignancies, which indicates that cancer surveillance is the cornerstone of management
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