1,721,076 research outputs found
Designing Dendrimers
No full textIn this book, top-leading scientists in the field report their up-to-date contributions covering a broad range of applications and suggesting future possibilities. The book consists of 16 chapters, which are not grouped into sections, but are somehow logically ordered. The first chapters provide an introductory view - even including perspectives for alternative approaches to the dendrimer realm - mainly centered on synthetic methods/approaches. The following ones are more and more applicative-oriented, exploring electrochemically-based applications, photochemical energy conversion, single-molecule detection, biomedical applications, and future perspectives
The Exploration of Supramolecular Systems and Nanostructures by Photochemical Techniques
No full textThe Exploration of Supramolecular Systems and Nanostructures by Photochemical Techniques provides a comprehensive view of the most commonly used photochemical and photophysical techniques and their applications to the study of supramolecular systems. Optical inputs are extremely powerful in the study of nanostructures since they can be used both to “read” the state of the system and to provide it energy to work
Enlightening structure and properties of dendrimers by fluorescence depolarization
No full textDendrimers containing luminescent components , are particularly interesting since (i) luminescence signals offer a handle to better understand the dendritic structures and superstructures, (ii) cooperation among the photoactive components can allow the dendrimer to perform useful functions such as light harvesting, (iii) changes in the photophysical properties can be exploited for sensing purposes with signal amplification, and (iv) photochemical reactions can change the structure and other properties of dendrimers. Luminescent dendrimers are also suitable for fluorescence anisotropy measurements that can give information on specific properties, such as (a) rotational reorientation times and hydrodynamic properties, (b) individual molecule rotational isomerism, (c) local motions of subunits, (d) mechanisms and rate of delocalization of the excitation energy, and (e) hosting ability
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
Silicon quantum dot optical probes
No full textSystems comprising a nanocrystal and a luminescent chromophore are disclosed herein.
The luminescent chromophore can emit energy having a first wavelength. The luminescent
chromophore is configured to transfer the emitted energy having a first wavelength to the
nanocrystal. The luminescent chromophore can be linked to the nanocrystal via a covalent
bond. Absorption of the energy having first wavelength by the nanocrystal can activate the
nanocrystal and result in an increase in quantum yield. In some embodiments, the
nanocrystal can include silicon, germanium, carbon, or combinations thereof. In some
examples, the luminescent chromophore can be pyrene. The luminescent chromophore and
the silicon containing nanocrystal can be in a ratio of about 1: 1 to 100: 1 in the nanocrystal
system. Methods of making and using the system are also disclosed
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
Electrochemistry of Functional Supramolecular Systems
No full textIncorporation of redox-active units in a dendritic architecture enable us to gain information on: (i) dendrimer structure and superstructure; (ii) self-assembly processes; (iii) degree of electronic interaction and communication between redox units located in different sites; (iv) changes in conformation brought about by electron transfer processes. Electroactive dendrimers are attracting increasing interest in view of their possible application as sensors, catalysts, enzyme mimics, in which a redox centre is buried inside the dendritic nanoenvironment, and, last but not least, multielectron storage devices
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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