1,720,959 research outputs found
Copper based metal organic framework decorated with gold nanoparticles as a new electrochemical sensor material for the detection of L-Cysteine in milk samples
No full textA facile electrochemical sensor based on carbon felt electrode (CFE) modified with gold nanoparticles decorated copper based metal organic framework (AuNPs@Cu-MOF) was achieved for the electrochemical sensing of L-Cysteine (L-Cys). For this purpose, AuNPs@Cu-MOF was synthesized and characterized. The electrochemical behaviors of L-Cys at plain and modified CFEs were investigated via cyclic voltammetry (CV). According CV results, AuNPs@Cu-MOF structure showed a catalytic effect on the oxidation of L-Cys as well as increasing the active electrode surface area by 206% compared to bare CFE. In addition, the pH effect on electrochemical determination of L-Cys at AuNPs@Cu-MOF/CFE was widely examined, and it was determined that the best oxidation peak current of L-Cys was obtained in pH 5 acetate buffer. Moreover, a linear detection range of 30–400 µM for L-Cys with a limit of detection value of 2.21 µM (n = 3) was achieved with the proposed electrochemical sensor. The developed L-Cys sensor was also applied for L-Cys detection in various milk samples and acceptable recovery values were obtained ranging from 100.05 to 108.45%
A polyoxy group branched diazo dye as an alternative material for the fabrication of an electrochemical epinephrine sensor
No full textWOS: 000507580000017In the present study, a novel diazo dye with a polyoxy group (2{2[2(2-methoxyethoxy)ethoxy]ethoxy}-5-[(E)-(4-nitrophenyl)diazenyl]benzaldehyde (AZOTEG)) was used as a modifier to fabricate modified electrochemical platforms for epinephrine detection. For this purpose, a carbon paste electrode (CPE), which was the working electrode, was modified with AZOTEG molecules. An increase in epinephrine oxidation peak current with a negative shift in peak potentials demonstrated the electrocatalytic effect of the AZOTEG/CPE compared to the plain CPE. After the observation of this effect, experimental parameters like AZOTEG amount and pH were optimized. Then, the electrochemical mechanism was investigated by obtaining cyclic voltammograms versus scan rates. Under the optimized conditions, the analytical characteristics were examined and as a result, a wide linear range (0.1-75 mu M) with a limit of detection and a limit of quantification of 0.013 mu M and 0.042 mu M (n = 3) were obtained. After the examination of the interference effect of uric acid, the developed sensor was successfully used for epinephrine detection in adrenaline injection samples
Fabrication of metal–organic framework based electrochemical Leishmania immunosensor
No full textLeishmaniasis is a disease with a high impact on public health in many countries. In this study, an electro-chemical immunosensor for Leishmania major surface protease (Gp63) antibody detection was developed using copper metal organic framework (Cu-(NH2-BDC)-MOF) modified gold screen printed electrode (AuSPE). For this purpose, after modification step of AuSPE with Cu-(NH2-BDC)-MOF, recombinant L.donovani antigen was immobilized on to electrode surface via crosslinker where change in electrochemical signal was monitored with electrochemical impedance spectroscopy technique. After conducting comprehensive optimization studies on experimental parameters of developed Leishmania immunosensor, analytical characteristics were searched. As a result, it was observed that anti-gp63 solution diluted up to the ratio of 1:1500 could be detected with the developed sensor. Meanwhile, relative standard deviation value was found as 4.67% for anti-gp63 diluted in the ratio of 1:80 (n = 3). Accordingly, real sample analysis was also performed by using Leishmania parasite crude antigen and rabbit serum which were positive and negative control samples, respectively. According to the re-sults obtained, it can be concluded that a practical immunosensor that can allow the early diagnosis of leish-maniasis was developed
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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