1,721,203 research outputs found
Front Cover: Macromol. Chem. Phys. 6/2014
No full textThe preparation of different styrene-based polymer films containing small amounts of tetraphenylethylene (TPE) and the evaluation of their photoluminescent behavior are reported. TPE molecular rotors show brilliant blue emission in a poor solvent or in a glassy styrene-based polymer matrix, where the intramolecular rotations of its aryls result as being completely arrested, but the fluorescence is weakened to pale green and eventually to a faint signal when good solvents or viscous but not glassy polymer matrices are used. This behavior suggests potential benefits in applications such as polymer traceability. Further details can be found in the article by G. Iasilli, A. Battisti, F. Tantussi, F. Fuso, M. Allegrini, G. Ruggeri, and A. Pucci on page 499
Biosensori, Biochip e Microarray. Principi ed applicazioni nel settore biomedico
No full textUn biosensore è un dispositivo che rivela la presenza di un composto chimico per mezzo di una componente biologica. Tale componente è tipicamente una biomolecola, ma può anche trattarsi di intere cellule, frammenti di tessuti biologici o batteri. La struttura della maggior parte dei biosensori è costituita da tre componenti principali: l’elemento biologico di riconoscimento (anticorpi, enzimi, DNA, RNA, cellule), un substrato (silicio, oro, vetro, polimeri) a cui è legata la biomolecola ed un trasduttore (elettrochimico, elettroottico, piezoelettrico, meccanico) che trasforma l’interazione con l’analita in un segnale più facilmente misurabile e quantificabile. Un biochip non è altro che un biosensore che integra le tecniche costruttive e di registrazione dei dati proprie della microelettronica. I biochip capaci di rilevare contemporaneamente più analiti (tipicamente tra 100 e 50.000) sono definiti microarray. Nel presente articolo sono descritti i principi di selezione ed assemblaggio delle componenti insieme ad una panoramica sui principali campi di applicazione di biosensori, biochip e microarray
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
Climate change and forest insect pests
Full text linkClimate change and the underlying causal factors have been thoroughly described in the scientific literature. Although well understood and documented in general, we are only beginning to understand the effects of climate change on biotic systems, such as insect communities. It seems obvious that insect pest problems should be be more important in a warmer climate; temperature has a strong impact on insect physiology and demography. It must be remembered, however, that insect distribution and abundance are controlled by many factors other than temperature, e.g. host plant, natural enemies. This chapter summarizes empirical evidence for climate change-induced insect pest problems, i.e. changed distribution range and frequency of insect outbreaks. The chapter reviews cases of forest pests for which there is sufficient scientific evidence of climate change-effects on their population dynamics leading to outbreaks, strong enough to be a concern for forest ecology and management
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
Current treatment status of stable angina: medical treatment versus percutaneous coronary intervention versus coronary artery by-pass grafting.
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