1,721,065 research outputs found
Supporting experimental data for "Z-average and Polydispersity Index of Dynamic Light Scattering" by Bazzoni et al.
No full textData (auto-correlation functions used for preparing Figure 5-8) accompanying manuscript "Z-average and Polydispersity Index of Dynamic Light Scattering" by Bazzoni et al.
1. “Figure 5_ACFs.zip” Large sets of autocorrelation functions (ASCII format) recorded to demonstrate heteroscedastic and angle-dependent uncertainties. Each file may list the basic parameters, instrument’s estimation of Z-average (not evaluated and not used by us), the auto-correlation function, and a low temporal-resolution trace of the scattering intensity. Figure 5 is based on the analyses of subsets of this data set.
2. “Figure 6 & 7_ACFs.zip” Large sets of autocorrelation functions (ASCII format) recorded to demonstrate the impact of uncertainty on precision, and the impact of duration and photon counting rate on the signal-to noise ratio. Each file may list the basic parameters, instrument’s estimation of Z-average (not evaluated and not used by us), the auto-correlation function, and a low temporal-resolution trace of the scattering intensity. Figure 6 and 7 are based on the analyses of subsets of this data set.
3. “Figure 8_ACFs.zip” Large sets of autocorrelation functions (ASCII format) recorded to demonstrate the positive impact of data averaging on precisions. Each file may list the basic parameters, instrument’s estimation of Z-average (not evaluated and not used by us), the auto-correlation function, and a low temporal-resolution trace of the scattering intensity. Figure 8 is based on the analyses of subsets of this data set
Increased uptake of silica nanoparticles in inflamed macrophages but not upon co-exposure to micron-sized particles
No full textSilica nanoparticles (NPs) are widely used in various industrial and biomedical applications. Little is known about the cellular uptake of co-exposed silica particles, as can be expected in our daily life. In addition, an inflamed microenvironment might affect a NP’s uptake and a cell’s physiological response. Herein, prestimulated mouse J774A.1 macrophages with bacterial lipopolysaccharide were post-exposed to micron- and nanosized silica particles, either alone or together, i.e., simultaneously or sequentially, for different time points. The results indicated a morphological change and increased expression of tumor necrosis factor alpha in lipopolysaccharide prestimulated cells, suggesting a M1-polarization phenotype. Confocal laser scanning microscopy revealed the intracellular accumulation and uptake of both particle types for all exposure conditions. A flow cytometry analysis showed an increased particle uptake in lipopolysaccharide prestimulated macrophages. However, no differences were observed in particle uptakes between single- and co-exposure conditions. We did not observe any colocalization between the two silica (SiO2) particles. However, there was a positive colocalization between lysosomes and nanosized silica but only a few colocalized events with micro-sized silica particles. This suggests differential intracellular localizations of silica particles in macrophages and a possible activation of distinct endocytic pathways. The results demonstrate that the cellular uptake of NPs is modulated in inflamed macrophages but not in the presence of micron-sized particles
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
Hydrodynamic Radius of Polymer-Coated Nanoparticles Measured by Taylor Dispersion: A Mathematical Model
No full textModel-Independent Statistical Averages of the Hydrodynamic Radius via Dynamic Light Scattering
No full textI present new, robust, and measurable nonparametric statistical averages that summarize major features of the distribution of the hydrodynamic radius. I explain how these descriptive statistical averages—the mean, standard deviation, and skewness of the intensity-weighted distribution—are obtained. Next, I demonstrate that—unlike the well-known and widely used Z-average and polydispersity index—these statistical averages bear a direct and physically meaningful interpretability. At the same time, these statistical averages are straightforward to obtain from experimental correlograms, and therefore, they merit a place in characterizing particle systems via DLS
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