1,721,035 research outputs found
Dual action of a tyrosinase-mesoporous silica nanoparticle complex for synergistic tissue adhesion
No full textBridging biological tissues for immediate adhesion and long-term sustainability was accomplished using a combination of mesoporous silica nanoparticles (MSNs) and tyrosinase. Tyrosinase-loaded MSNs provided rapid physical adsorption, while tyrosinase within MSNs induced enzymatic chemical bond gluing of tissues. This synergistic strategy has robust potential in tissue adhesives for clinical settings.11Nsciescopu
Stem-piped light activates phytochrome B to trigger light responses in arabidopsis thaliana roots
No full textThe roles of photoreceptors and their associated signalingmechanisms have been extensively studied in plant photomorphogenesis with amajor focus on the photoresponses of the shoot system. Accumulating evidence indicates that light also influences root growth and development through the light-induced release of signaling molecules that travel from the shoot to the root.We explored whether aboveground light directly influences the root system of Arabidopsis thaliana. Light was efficiently conducted through the stems to the roots, where photoactivated phytochrome B (phyB) triggered expression of ELONGATED HYPOCOTYL 5 (HY5) and accumulation of HY5 protein, a transcription factor that promotes root growth in response to light. Stimulation of HY5 in response to illumination of only the shoot was reduced when root tissues carried a loss-of-functionmutation in PHYB, and HY5 mutant roots exhibited alterations in root growth and gravitropism in response to shoot illumination. These findings demonstrate that the underground roots directly sense stem-piped light to monitor the aboveground light environment during plant environmental adaptation. © 2016 The Authors some rights reserved11sciescopu
Mitochondria-Targeting Ceria Nanoparticles as Antioxidants for Alzheimeŕs Disease
No full textMitochondrial oxidative stress is a key pathologic factor in neurodegenerative diseases, including Alzheimeŕs disease. Abnormal generation of reactive oxygen species (ROS), resulting from mitochondrial dysfunction, can lead to neuronal cell death. Ceria (CeO2) nanoparticles are known to function as strong and recyclable ROS scavengers by shuttling between Ce3+ and Ce4+ oxidation states. Consequently, targeting ceria nanoparticles selectively to mitochondria might be a promising therapeutic approach for neurodegenerative diseases. Here, we report the design and synthesis of triphenylphosphonium-conjugated ceria nanoparticles that localize to mitochondria and suppress neuronal death in a 5XFAD transgenic Alzheimeŕs disease mouse model. The triphenylphosphonium-conjugated ceria nanoparticles mitigate reactive gliosis and morphological mitochondria damage observed in these mice. Altogether, our data indicate that the triphenylphosphonium-conjugated ceria nanoparticles are a potential therapeutic candidate for mitochondrial oxidative stress in Alzheimeŕs disease. © 2016 American Chemical Society159621sciescopu
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
Magnetically separable carbon nanocomposite catalysts for efficient nitroarene reduction and Suzuki reactions
No full textNovel magnetically recyclable carbon nanocomposites were synthesized to support various nanocatalysts using a simple, economical and scalable method. The designed nanocomposites, which are composed of porous carbon and Fe 3O4 nanocrystals, can be used as an expandable platform to load versatile nanoparticle catalysts such as Pd and Pt. These nanocomposites with high surface area and permeable porous structure can contain abundant and accessible small-sized catalyst nanoparticles. These characteristics led to efficient catalytic reactions and enhanced catalytic activity, which were verified in selective reduction of nitroarenes and Suzuki cross-coupling reactions. The nanocomposite catalysts provided excellent catalytic activities to yield the desired products in short reaction time and mild reaction conditions. The catalysts could be easily separated from the reaction mixture by a magnet, and recycled five consecutive cycles in reduction of nitrobenzene and Suzuki cross-coupling of bromobenzene without losing significant activities. © 2014 Elsevier B.V.135321sciescopu
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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