1,720,992 research outputs found
High neurotoxic risk to ChEs in bluefin tuna (Thunnys thynnus thynnus) revealed by high in vitro sensitivity to organophosphates
No full textVibrational Spectroscopy of Fluorescent Proteins: A Tool to Investigate the Structure of the Chromophore and Its Environment
No full textThe design of fluorescent protein (FP) mutants with tailored properties benefits from the comprehension of chromophore structure, interactions, energy landscapes, and dynamics. Vibrational spectroscopy can often provide detailed information on these characteristics for proteins in their natural aqueous environment, during their (photo)dynamics and without the need of crystallization. Here we will review the experimental and theoretical techniques that have been used to analyze the relations between vibrational spectra and different structural, photophysical, and chemical properties of FPs, in particular the ones able to selectively address the chromophore and its close environment, like (pre)resonance Raman, difference-IR absorption measurements, and their computational simulations. Starting from the preliminary results aimed at identifying vibrational modes in the neutral and anionic GFP chromophore, we will discuss selected experiments that unraveled, often thanks to comparison with theoretical studies, the structure of the chromophore in some FP mutants, the impact of cis–trans isomerization and different protonation states in reversibly photoswitchable proteins, and the structural changes and proton-transfer pathway in the photoexcited state
Low-resolution models for the interaction dynamics of coated gold nanoparticles with β2-microglobulin
Full text linkStructural Transition States Explored With Minimalist Coarse Grained Models: Applications to Calmodulin
No full textNano-scale corrugations in graphene: A density functional theory study of structure, electronic properties and hydrogenation
No full textGraphene rippled at the nanoscale level is gathering attention for advanced applications, especially in the field of nanoelectronics and hydrogen storage. Convexity enhanced reactivity toward H was demonstrated on naturally corrugated graphene grown by Si evaporation on SiC, which makes this system a platform for fundamental studies on the effects of rippling. In this work, we report a density functional theory study on a model system specifically designed to mimic graphene on SiC. We first study the supercell geometry and configuration that better reproduce the corrugated monolayer. The relatively low computational cost of this model system allows a systematic study of the dependence of stability, structure, and electronic properties of graphene subject to different levels of stretching and corrugation. The most representative structure is then progressively hydrogenated, imitating the exposure to atomic hydrogen, and stability, structural and electronic properties are evaluated as a function of hydrogenation. Our results quantitatively reproduce the measured evolution of electronic properties as a function of hydrogenation, offering the possibility of evaluating the coverage by means of STS measurements. The dependence of hydrogen binding energy on coverage extends our previous results on reactivity of corrugated graphene, including the effect of H clustering. This work reports quantitative results directly comparable with experimental measurements performed on epitaxial graphene on SiC and reveals the quantitative interplay between local structure, electronic properties and reactivity to hydrogen, which could be used to design devices for flexible nanoelectronics and for H storage
Nano-sized optical devices for applications in proteomics and biomolecular electronics: engineered green fluorescence proteins
No full textFunctional Nanomaterials is the first and unique compilation of the state-of-the-art review chapters covering all aspects of functional nanomaterials and their applications. Nanotechnology has led to a profound paradigm shift after the developments in recent years and after being classified as one of the most important areas of impending technology by the U.S. government. Novel functional nanomaterials are the basis of newly emerging nanotechnologies for various device applications. This book with 30 chapters reflects the tremendous world-wide interest in functional nanostructured materials. The wide variety of topics covered in this book is interesting for professionals working in the fundamental and applied research. The book covers major classes of nanomaterials such as carbon nanotubes, carbon and polymer nanofibers, nanoparticles, nanocomposites, nanosheets, fullerenes, supramolecular and self-assembled nanostructures, and many other types of nanomaterials. In addition, thi..
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
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