1,720,995 research outputs found
A new biogenic, struvite-related phosphate, the ammonium-analog of hazenite, (NH4)NaMg2(PO4)2·14H2O Yang Hexiong [email protected]
No full textA new biogenic, struvite-related phosphate, the ammonium analog of hazenite (AAH), ideally (NH4) NaMg2(PO4)2·14H2O, has been found in cultures containing the bacterial strain Virgibacillus sp.NOT1 (GenBank Accession Number: JX417495.1) isolated from an XVII Century document made of parchment. The chemical composition of AAH, determined from the combination of electron microprobe and X-ray structural analyses, is [(NH4)0.78K0.22]NaMg2(PO4)2·14H2O. Single-crystal X-ray diffraction shows that AAH is orthorhombic with space group Pmnb and unit-cell parameters a = 6.9661(6), b = 25.236(3), c = 11.292(1) Å, and V = 1985.0(3) Å3. Compared with hazenite, the substitution of NH4+for K+results in a noticeable increase of the average A-O (A = NH4++K+) bond length and the unit-cell volume for AAH, as also observed for struvite vs. struvite-K. Both infrared and Raman spectra of AAH resemble those of hazenite, as well as struvite. Our study reveals that AAH forms only in cultures with Na-bearing solutions and pH below 10.0. No AAH or hazenite was found in experiments with the K-bearing solutions, suggesting the necessity of a Na-bearing solution for AAH formation
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
A safe microbe-based procedure for a gentle removal of aged animal glues from ancient paper
No full textIn the past, the animal glues were used in paper manufacturing and in restoration of artworks preserved in museums, libraries and archives. By ageing they went through deterioration creating distortions, tensions, cockling and discolouration in paper materials. Consequently, the removal of glue residues becomes an essential step in the restoration of ancient and artwork paper material. Current mechanical and chemical methods display serious drawbacks mainly related to aggressiveness towards material or toxicity for restorers. Bio-based methods for paper cleaning rely on the use of enzymes that require skilled operators, optimal application conditions and high costs, creating difficulties in mastering enzyme use so far. This paper describes a first attempt of biocleaning ancient paper from organic deposits using living bacteria. The non-pathogenic, non-spore-forming and non-cellulolytic original strain Ochrobactrum sp. TNS15E was successfully applied -immobilised in an agar gel-on original paper specimens dating back to the 17th. After 4 h of contact with the bacterial pack, the cellulose fibres underlying glue were disclosed, highlighting the bacterial capacity of removing the glue layer without damaging the paper or leaving undesirable residues. Both colorimetry and SEM analyses proved the results. The procedure is simple, low-cost and safe for the artefact, the restorers and the environment. © 2016
NASH-related Hepatocellular carcinoma: current therapeutic approaches and the emerging role of sodium homeostasis as a novel targeting strategy
No full text: Non-Alcoholic Steatohepatitis (NASH) rates are progressively accelerating due to lifestyle changes, which contribute to increased Hepatocellular carcinoma (HCC) incidence. HCC accounts for 90% of liver cancer cases, which ranks as the sixth prevalent, and the third leading cause of cancer-related deaths globally. NASH-HCC outweighs the decline in viral hepatitis-HCC, leaving a gap in the available therapies. The limited overall survival in the current treatments invokes the necessity of exploring novel therapeutic strategies to improve the poor prognosis of HCC. The pH gradient is a hallmark of cancer and is associated with increased intracellular sodium. Elevating this accumulation of intracellular sodium with sodium ionophores, such as Monensin, leads to selective death of murine HCC cancer cells without affecting the functionality of vital organs and proliferating activity of normal and transformed tissues. This study synthesizes the status of HCC risk and management, its molecular landscape, and sheds light on exploiting the elevated accumulation of intracellular sodium as a novel therapeutic strategy against HCC
Laponite micro-packs for the selective cleaning of multiple coherent deposits on wall paintings: The case study of Casina Farnese on the Palatine Hill (Rome-Italy)
No full textAs a result of the research described in this article a safe, bio-based procedure has been established to treat hard-to-remove coherent deposits composed of gypsum, weddellite, calcium carbonate, apatite, nitrate, and aged proteinaceous matter from the wall paintings of the lower loggia of the Casina Farnese (Palatine Hill, Rome). Following a laboratory screening, three bacterial non-spore-forming strains were selected from our laboratory collection to solubilise calcium sulphate and carbonate (Cellulosimicrobium cellulans TBF11E), to degrade proteins (Stenotrophomonas maltophilia UI3E), to solubilise inorganic compounds and to degrade protein material (Pseudomonas koreensis UT30E). The living bacterial cells were suspended in a Laponite gel, which is highly compatible with the survival of the cells and is also easily applied, and removed from, vertical walls. Compresses containing microorganisms (micro-packs) were used in a series of biocleaning tests carried out in situ, from July 2012 to February 2013, in temperatures ranging from 6ᄚC to 37ᄚC. Each micro-pack contained a single bacterial strain (TBF11E, UI3E or UT30E). The micro-packs containing the different bacteria were applied, individually or in succession, depending on the nature and layers of the deposits to be removed. Contact times of between 24 and 48h were established in accordance with the advice of the restorers. The strain TBF11E removed the inorganic darker layer, UI3E dissolved the brownish layer (probably aged casein) and UT30E removed the mixed deposits. No residues were left after the treatment and the restorers successfully completed the restoration. ᄅ 2014 Elsevier Ltd
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
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