1,721,021 research outputs found
Measuring the Radius of Gyration and Intrinsic Flexibility of Viral Proteins in Buffer Solution Using Small-Angle X‑ray Scattering
Full text linkMeasuring structural features of proteins dispersed in
buffer solution,
in contrast to crystal form, is indispensable in understanding morphological
characteristics of the biomolecule in a native environment. We report
on the structure and apparent viscosity of unfolded α and β
variants of SARS-CoV-2 spike proteins dispersed in buffer solutions.
The radius of gyration of the β variant is found to be larger
than that of the α variant, while the ab initio computation
of one of the possible particle-like bodies is consistent with the
small-angle X-ray scattering (SAXS) profiles resembling a conformation
similar to the three-dimensional structure of the folded state of
the corresponding α and β spike variant. However, a smaller
radius of gyration with respect to the predicted folded state of 2.4
and 2.7 is observed for both α and β variants, respectively.
Our work complements the structural characterization of spike proteins
using cryo-electron microscopy techniques. The measurement/analysis
discussed here might be useful for quick and cost-effective evaluation
of several protein structures, let alone mutated viral proteins, which
is useful for drug discovery/development applications
Sensing Dynamically Evolved Short‐Range Nanomechanical Forces in Fast‐Mutating Single Viral Spike Proteins
Full text linkUnderstanding changes in the mechanical features of a single protein from a mutated virus while establishing its relation to the point mutations is critical in developing new inhibitory routes to tackle the uncontrollable spread of the virus. Addressing this, herein, the chemomechanical features of a single spike protein are quantified from alpha, beta, and gamma variants of SARS‐CoV‐2. Integrated amplitude‐modulation atomic force microscopy is used with dynamic force–distance curve (FDC) spectroscopy, in combination with theoretical models, to quantify Young's modulus, stiffness, adhesion forces, van der Waals forces, and the dissipative energy of single spike proteins. These obtained nanomechanical properties can be correlated with mutations in the individual proteins. Therefore, this work opens new possibilities to understand how the mechanical properties of a single spike protein relate to the viral functions. Additionally, single‐protein nanomechanical experiments enable a variety of applications that, collectively, may build up a new portfolio of understanding protein biochemistry during the evolution of viruses
Modern Myth: South Asian Modern and Contemporary Works on Paper
No full text"Artist biographies from Modern Myth: South Asian Modern and Contemporary Works on Paper. Featured artists in this exhibition included Manjit Bawa, Atul Bhalla, Nikhil Biswas, Sakti Burman, Allan deSouza, Rohini Devasher, Anju Dodiya, Atul Dodiya, Anita Dube, Zarina Hashmi, Krishen Khanna, Surendran Nair, Badri Narayan, Gogi Saroj Pal, Ganesh Pyne, Anandajit Ray, Jamini Roy, Nilima Sheikh, K. G. Subramanyan, and
Muhammad Zeeshan.
Towards Fast 2D Imaging of Gas Flows Using Focal Planar Arrays
No full textMeasurement of gas concentration and temperature distribution at high repetition rates in a plasma chemical reactor is important for the optimization of the reactor performance, for example, by placing more catalysts in the reaction zones. Tunable diode laser absorption spectroscopy combined with focal planar arrays is an effective method used for fast mapping of concentration and temperature in gaseous flows. A custom two dimensional (2D) high temperature gas flow cell has been constructed for the validation of the concept. An interband cascade laser and a focal planar array camera (Infratec ImageIR 5355) is employed for detection; 2D beam expanding optics to image the flow cell. The technique will be further developed for calibration and measurement of temperature and concentration, improvement of the speed etc., towards the realization of fast concentration and temperature measurements in a plasma reactor, targeting key plasma catalytic reactions such as methane valorization involving conversion of greenhouse gases such as methane to useful industrial precursors.</p
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
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