1,721,159 research outputs found
Solid phase radioimmunoassay for detection of circulating food protein antigens in human serum
No full textA two site solid phase radioimmunoassay for detection of common food antigens is described. Bovine serum albumin, β-lactoglobulin and ovalbumin can be detected in normal human serum at levels ranging from 0.1 to >1000 ng/ml; sensitivity is not impaired by the presence of low levels of antibodies. Thirty min to 3 h after oral intake of milk, β-lactoglobulin could be detected in the sera of 3 normal individuals, at a concentration of 0.1-3 ng/ml. This assay should prove useful in assessing the importance of macromolecular absorption in food allergy and in other gastrointestinal diseases. © 1980
Power-Efficient UHF Rectification for Long-Distance Wireless Power Transfer in Sensor Nodes
Full text linkIn the last decade, the development and the implementation of smart and ubiquitous sensors in various fields of interest has opened several issues about the life cycle of these devices and the disposal or replacement of their batteries. One potential solution can be found in wireless power transfer and in radio-frequency (RF) Energy Harvesting, which enables devices to be powered up to several meters from a RF source. This study proposes the optimization of an UHF rectifier operating at 868 MHz, and investigates the effects of the main parasitic elements of its implementation, like printed circuit board (PCB) metal traces and the package of lumped elements. Furthermore, an optimization method for matching network design, composed of two specific harmonic balance simulations, is described: in the first one, ideal matching network components are used in order to improve simulation time; in the second, S-parameters provided by manufacturers are used. Finally, a PCB prototype is characterized, producing 4.56 μ W of rectified power, with 36.3% RF-to-DC conversion efficiency and 278 mV in optimum load conditions, with a -19 dBm harmonic input signal at 868 MHz. An estimate of output power over distance is reported in order to evaluate the maximum operative distance of potential commercial devices, like micro-power management integrated circuits
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
Mouse rosette forming cells and surface immunoglobulins in human lymphoid cells
No full textPeripheral blood lymphocytes from normal subjects were studied for mouse rosette-forming cells (MRFC) and their relationship to surface immunoglobulins (SIg). The majority of MRFC expressed both SIgM and SIgD, although some dissociation between population showing SIgM+/MRFC- and SIgM-/MRFC+ could be seen. A similar pattern of association was found in human derived cultured cells of B lineage, but no simple correlation and the number of SIgM+ cells could be established. Increased percentages of MRFC were detected in two foetal livers but greater dissociation of MRFC and SIgM was shown. This heterogeneity of MRFC may be explained by a selective expression of this surface marker in the early stages of B lymphocyte differentiation
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