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1.
REVISTA EDUCACION ; 46(2), 2022.
Article in Spanish | Web of Science | ID: covidwho-1939482

ABSTRACT

This study compares the social connection strategies offered by the Ecuadorian universities in the COVID-19 setting. The main objective was to tackle the transition from face-to-face activities to virtual ones in order to accomplish a degree of continuity in their activities. The data-gathering was done during the 2020 period;the documental method's criteria analysis was accomplished. For the purpose of completing the study, the inductive-deductive method was used to describe, in a general way, particular conditions present during the investigation. Thus, it can be demonstrated that higher-education institutions achieved the continuity of activities through tele-activity backed by the Information and Communication Technologies (ICTs), concluding in benefits for the society's most vulnerable sectors. Finally, new studies which maintain this investigation as a basis are proposed, as a way to show results over more extensive periods of analysis.

2.
Journal of Molecular Liquids ; 346:10, 2022.
Article in English | Web of Science | ID: covidwho-1757683

ABSTRACT

Modified cyclodextrins (CDs) consist of a distribution of different structures with different number and location of the substituted groups. Among the most important applications of these molecules is their use as an enabling excipient in pharmaceutical formulations to provide the necessary solubility, stability and bioavailability for a drug to be effectively used. The most typical interaction mechanism of small molecular groups with CDs is the formation of host-guest inclusion complexes. The thermodynamic affinity constant between CDs and drugs should not be too strong, since then the biological activity could be negated by the formation of the complex. In the opposite scenario, if the affinity constant is too weak, the complex is barely formed and the amount of CD required in the formulation may become too great. Thus, a balance between the affinity of the CD and the drug is necessary for an optimal formulation. Additionally in the case of modified CDs and specific drug complexes there are further questions concerning the effect that the locations and number of substitutions plays in complexation. In the present work, this question is explored by using sulphobutylether-beta-cyclodextrin and remdesivir, the only antiviral medication currently approved by the United States Food and Drug Administration for treating COVID-19, as a case study. This paper presents results from an orthogonal study using isothermal titration calorimetry measurements and biased molecular dynamics simulations that provide complementary information. Isothermal titration calorimetry delves into the global impact of the species distribution while molecular dynamics simulations deals with specific chemical structures. The goal is to provide useful information to optimize pharmaceutical formulations based on modified CDs, specifically in the case of remdesivir, used to treat SARS-CoV-2 infection, although the main conclusions could be extended to the interaction of other drugs with modified cyclodextrins. (C) 2021 The Authors. Published by Elsevier B.V.

3.
International Journal of Education and Practice ; 9(4):637-655, 2021.
Article in English | Scopus | ID: covidwho-1732552

ABSTRACT

This paper aims to examine the impact of E-learning quality on students' satisfaction and performance before and during the COVID-19 pandemic and the role of gender as a moderating variable. A descriptive and inferential approach was used where a specially designed questionnaire was distributed on a simple random sample of students enrolled in Public Security Training City in Riyadh, Saudi Arabia. Data were gathered from 352 respondents. The multiple regression analysis was used to justify the proposed hypotheses. The study found that E-learning system quality and E-learning service quality positively impacted student satisfaction, which made a significant and positive impact on student performance. Moreover, gender played a moderating role in the relationship between E-learning system quality, E-learning service quality, and student satisfaction. Finally, it was found that the relationship between all variables during COVID-19 was stronger than relationships that existed before the COVID-19 pandemic. © 2021 Conscientia Beam. All Rights Reserved.

4.
Sistema ; 2022(263):29-48, 2022.
Article in Spanish | Scopus | ID: covidwho-1668455

ABSTRACT

Due to the global COVID-19 pandemic, the government of Spain declared the State of Alarm in March 2020. One of its consequences has been the increase in remote working and online teaching-learning processes. Taking homes as unit of analysis, the data given by the Survey on Equipment and Use of Information and Communication Technologies in Households conducted by the Spanish National Institute of Statistics is analysed. Two different analyses were undertaken: A descriptive analysis on the variable possession of a computer and internet broadband (constructed from those offered by the aforementioned survey) and a logistic regression analysis on sociodemographic factors that explain the availability of ICT. The results indicate that the household model is the principal variable to explain the digital gap more accurately than other factors such as economic aspects or educational levels of those responsible for the household. © 2022, Fundacion Sistema. All rights reserved.

5.
J Mol Biol ; 433(10): 166946, 2021 05 14.
Article in English | MEDLINE | ID: covidwho-1386061

ABSTRACT

Coronaviruses are a major infectious disease threat, and include the zoonotic-origin human pathogens SARS-CoV-2, SARS-CoV, and MERS-CoV (SARS-2, SARS-1, and MERS). Entry of coronaviruses into host cells is mediated by the spike (S) protein. In our previous ESR studies, the local membrane ordering effect of the fusion peptide (FP) of various viral glycoproteins including the S of SARS-1 and MERS has been consistently observed. We previously determined that the sequence immediately downstream from the S2' cleavage site is the bona fide SARS-1 FP. In this study, we used sequence alignment to identify the SARS-2 FP, and studied its membrane ordering effect. Although there are only three residue differences, SARS-2 FP induces even greater membrane ordering than SARS-1 FP, possibly due to its greater hydrophobicity. This may be a reason that SARS-2 is better able to infect host cells. In addition, the membrane binding enthalpy for SARS-2 is greater. Both the membrane ordering of SARS-2 and SARS-1 FPs are dependent on Ca2+, but that of SARS-2 shows a greater response to the presence of Ca2+. Both FPs bind two Ca2+ ions as does SARS-1 FP, but the two Ca2+ binding sites of SARS-2 exhibit greater cooperativity. This Ca2+ dependence by the SARS-2 FP is very ion-specific. These results show that Ca2+ is an important regulator that interacts with the SARS-2 FP and thus plays a significant role in SARS-2 viral entry. This could lead to therapeutic solutions that either target the FP-calcium interaction or block the Ca2+ channel.


Subject(s)
Calcium/metabolism , Cell Membrane/metabolism , SARS Virus/metabolism , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Viral Fusion Proteins/metabolism , Amino Acid Sequence , Binding Sites , Calcium/pharmacology , Calorimetry , Cell Membrane/drug effects , Cell Membrane/virology , Hydrogen-Ion Concentration , Hydrophobic and Hydrophilic Interactions , SARS Virus/drug effects , SARS-CoV-2/drug effects , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Thermodynamics , Viral Fusion Proteins/chemistry , Viral Fusion Proteins/genetics , Virus Internalization/drug effects
6.
Curr Res Struct Biol ; 3: 179-186, 2021.
Article in English | MEDLINE | ID: covidwho-1336360

ABSTRACT

Chlorotoxin (ClTx) is a 36-residue disulfide-rich peptide isolated from the venom of the scorpion Leiurus quinquestriatus. This peptide has been shown to selectively bind to brain tumours (gliomas), however, with conflicting reports regarding its direct cellular target. Recently, the vascular endothelial growth factor receptor, neuropilin-1 (NRP1) has emerged as a potential target of the peptide. Here, we sought to characterize the details of the binding of ClTx to the b1-domain of NRP1 (NRP1-b1) using solution state nuclear magnetic resonance (NMR) spectroscopy. The 3D structure of the isotope labelled peptide was solved using multidimensional heteronuclear NMR spectroscopy to produce a well-resolved structural ensemble. The structure points to three putative protein-protein interaction interfaces, two basic patches (R14/K15/K23 and R25/K27/R36) and a hydrophobic patch (F6/T7/T8/H10). The NRP1-b1 binding interface of ClTx was elucidated using 15N chemical shift mapping and included the R25/K27/R36 region of the peptide. The thermodynamics of binding was determined using isothermal titration calorimetry (ITC). In both NMR and ITC measurements, the binding was shown to be competitive with a known NRP1-b1 inhibitor. Finally, combining all of this data we generate a model of the ClTx:NRP1-b1 complex. The data shows that the peptide binds to the same region of NRP1 that is used by the SARS-CoV-2 virus for cell entry, however, via a non-canonical binding mode. Our results provide evidence for a non-standard NRP1 binding motif, while also providing a basis for further engineering of ClTx to generate peptides with improved NRP1 binding for future biomedical applications.

7.
Curr Opin Colloid Interface Sci ; 55: 101479, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1267633

ABSTRACT

We provide here a general view on the interactions of surfactants with viruses, with a particular emphasis on how such interactions can be controlled and employed for inhibiting the infectivity of enveloped viruses, including coronaviruses. The aim is to provide to interested scientists from different fields, including chemistry, physics, biochemistry, and medicine, an overview of the basic properties of surfactants and (corona)viruses, which are relevant to understanding the interactions between the two. Various types of interactions between surfactant and virus are important, and they act on different components of a virus such as the lipid envelope, membrane (envelope) proteins and nucleocapsid proteins. Accordingly, this cannot be a detailed account of all relevant aspects but instead a summary that bridges between the different disciplines. We describe concepts and cover a selection of the relevant literature as an incentive for diving deeper into the relevant material. Our focus is on more recent developments around the COVID-19 pandemic caused by SARS-CoV-2, applications of surfactants against the virus, and on the potential future use of surfactants for pandemic relief. We also cover the most important aspects of the historical development of using surfactants in combatting virus infections. We conclude that surfactants are already playing very important roles in various directions of defence against viruses, either directly, as in disinfection, or as carrier components of drug delivery systems for prophylaxis or treatment. By designing tailor-made surfactants, and consequently, advanced formulations, one can expect more and more effective use of surfactants, either directly as antiviral compounds or as part of more complex formulations.

8.
Prev Med Rep ; 22: 101374, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1193451

ABSTRACT

JUUL is a groundbreaking electronic cigarette (e-cig) and the preeminent vaping product on the market. We present an overview of the rapid and spectacular rise of JUUL and its remarkable fall within the timespan of 2015 - 2020. We highlight JUUL's entering the market in June 2015, becoming the industry leader in mid 2017, and experiencing a litany of setbacks by late 2019 through to early 2020. We address the role played by JUUL in the ongoing epidemic of youth vaping. We also feature competing views on the public health impact of JUUL use (in particular), and e-cig vaping (in general). We further highlight the latest trends in youth vaping and sales records for JUUL and tobacco cigarettes. In view of the ongoing pandemic of COVID-19, we briefly summarize the existing evidence on the relationship between vaping and smoking and the prevalence, disease course, and clinical outcomes of COVID-19.

9.
Front Psychol ; 11: 549653, 2020.
Article in English | MEDLINE | ID: covidwho-854017

ABSTRACT

The sudden global outbreak of COVID-19 in late 2019 has led to thriving online teaching, including the teaching of languages, across the world. As the online teaching of English-as-a-foreign-language (EFL) in Chinese universities is facing new challenges, EFL teachers have been positively exploring new solutions. To understand how EFL teachers were coping with the challenges, we set up this research as part of a larger study to examine EFL teachers' cognitions about online teaching in response to the disruption of normal teaching plans. We did so by taking a qualitative approach through analyzing in-depth interviews with three EFL teachers from a Chinese university. Through thematic analysis we found that teachers had clear cognitions about features, advantages, and constraints of online EFL teaching and that they acquired information and communication technology (ICT) literacy through understanding students' learning needs, online teaching practice, and the necessity of integrating traditional classroom teaching methods into online delivery. We conclude this study with a discussion on its pedagogical implications for similar contexts or colleagues facing similar challenges in other parts of the world.

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