1,720,962 research outputs found
Production in Escherichia coli of recombinant COVID-19 spike protein fragments fused to CRM197
No full textDuring 2020, the COVID-19 pandemic affected almost 108 individuals. Quite a number of vaccines against COVID-19 were therefore developed, and a few recently received authorization for emergency use. Overall, these vaccines target specific viral proteins by antibodies whose synthesis is directly elicited or indirectly triggered by nucleic acids coding for the desired targets. Among these targets, the receptor binding domain (RBD) of COVID-19 spike protein (SP) does frequently occur in the repertoire of candidate vaccines. However, the immunogenicity of RBD per se is limited by its low molecular mass, and by a structural rearrangement of full-length SP accompanied by the detachment of RBD. Here we show that the RBD of COVID-19 SP can be conveniently produced in Escherichia coli when fused to a fragment of CRM197, a variant of diphtheria toxin currently used for a number of conjugated vaccines. In particular, we show that the CRM197-RBD chimera solubilized from inclusion bodies can be refolded and purified to a state featuring the 5 native disulphide bonds of the parental proteins, the competence in binding angiotensin-converting enzyme 2, and a satisfactory stability at room temperature. Accordingly, our observations provide compulsory information for the development of a candidate vaccine directed against COVID-19
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Proteomic investigation of the impact of Cannabidiolic acid on Eukaryotic Translation complex in glioblastoma
Full text link2021 - 2022Phytocannabinoids, the major secondary metabolites of cannabis plants, exert a wide range
of biological activities. The present work was focused on investigating the mechanism of
action of cannabidiolic acid (CBDA) in U87MG glioblastoma cell line, exploiting the efficacy
of chemical-proteomics based approaches in identifying target proteins of uncharacterized
drugs. DARTS experiments showed Eukaryotic Initiation Translation Factor 2A (EIF2A) as a
putative target of CBDA. This interaction was further validated by western blot and CETSA,
thus showing a thermal stabilization of Eukaryotic Translation Complex conferred by CBDA.
Moreover, Limited Proteolysis showed that the EIF2A C-terminal portion 460-480 could play
a critical role in the molecular recognition of CBDA by the protein. This result was also
confirmed by Molecular Dynamics (MD) calculations, which revealed that CBDA interacts
with a stretch of residues in the 460-480 portion and in the adjacent C-terminal helix, acting
as a bridge between these regions. Hence, since EIF2A is the initiator factor of translation
process, the impact of CBDA-EIF2A interaction on proteins synthesis was investigated by
p-SILAC and enrichment via click-chemistry. Comparing CBDA and EIF2A-silencing
treatments, a similar remodeling of nascent proteome was detected in the two conditions in
terms of protein expression reduction and biological effect. Particularly, CBDA appeared to
induce an UPR response, triggering as a balancing effect between the ER-stress response
and the attempt to restore cellular homeostasis. Moreover, EIF2A revealed to interact not
only with eukaryotic translation proteins but also with the proteins involved in triggering of
UPR response and the CBDA-induced reorganization of eukaryotic translation machinery.
Interestingly, these proteins seem to be involved in several pathways already highlighted by
nascent proteome investigation.
In order to evaluate the protein-CBDA interaction in a cell model closer to the tumor in vivo,
a 3D cell culture was set up using a classic-sandwich model. Based on the observation that
in 2D- and 3D- cell model U87MG cells grow differently since in 3D they show a natural
shape and more cellular interactions, a global proteome comparative analysis was firstly
carried out. Interestingly, the obtained results highlighted a higher-amount of proteins
involved in invasion cellular processes and cell-ECM interaction expressed by 3D-U87MG,
compared to 2D-cultured cells. These findings prompted us to further study the effects of
CBDA in 2D and 3D cellular models. In 3D cultured cells, CBDA showed a different
cytotoxicity depending on the concentration of FBS in the upper and lower- gels and in the
culture medium as well. DARTS assay performed in this cell system also suggested a direct
correlation between the percentage of FBS used in cell culture conditions and the ability of
CBDA to interact with EIF2A, thus confirming the critical role played by the molecule-FBS
interaction on its availability. Furthermore, comparing the results of DARTS assays
performed on 2D and 3D, a difference of the EIF2A interactome with respect to the entire
translational complex was revealed in the two conditions. In contrast to 2D-cellular model,
EIF2A was highly resistant to proteolysis in untreated 3D cultured cells, but was more
digested after CBDA treatment. This result suggested that EIF2A in 3D-U87MG could be
likely associated with the other protein partners more strongly than in the 2D model. In
closing of this study, it is possible to state that the use of a multi-proteomic approach allowed
us to highlight the potential impact of CBDA on the eukaryotic translation machinery, also
suggesting the importance of investigating the interactome differences that exist between
innovative three-dimensional and conventional cellular models. [edited by Author]XXXV cicl
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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