Identification of students' mental models about the milk transformation in yogurt

A review of the scientific literature reveals that there are still few researches on the conceptions of secondary school students about chemical reactions involving microorganisms, especially those related to the mental models that students use in their explanations. This paper describes a study concerning the different mental models related to the milk transformation into yogurt with 83 students from a Spanish secondary school of 8th and 9th grade (13-16 years) developed in the framework of a research that intends to use the elaboration of this product as a context for the teaching and learning of chemical reactions through modeling approaches. In order to identify the mental models of the students, in this paper we consider the milk transformation into yogurt as a process in which its main components are: the entities involved (milk and bacteria), the interaction between them and the result (yogurt). A simplified school model of this process would involve students considering that bacteria use the sugar in milk to transform it into lactic acid through a chemical reaction to obtain the necessary energy. Using this scheme in interaction with the students' answers, the underlying mental models were identified. Although almost half of the students showed great difficulties explaining the process, five models have been identified. Students often consider the milk transformation into yogurt primarily as a physical process of agglutination or change of state. These models are far from a school model of reference in which the bacteria have a fundamental role in the transformation of milk into yogurt by a chemical reaction.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Matemáticas. Volumen II

Diplomatura en Ciències Empresarials. C08: Matemàtique

Reactivity of a trans-[H-Mo≣Mo-H] Unit Towards Alkenes and Alkynes. Bimetallic Migratory Insertion, H-Elimination and Other Reactions

Complex [Mo2(H)2{μ-HC(NDipp)2}2(THF)2], (1·THF), reacts with C2H4 and PhCH[double bond, length as m-dash]CH2 to afford hydrido-hydrocarbyl and bis(hydrocarbyl) derivatives of the Mo[quadruple bond, length as m-dash]Mo bond. Reversible migratory insertion and β-hydrogen elimination, as well as reductive elimination and other reactions, have been uncovered. PhC[triple bond, length as m-dash]CH behaves instead as a Brönsted–Lowry acid towards the strongly basic Mo–H bonds of 1·THF.Ministerio de Economía y Competitividad CTQ2016-75193-PEuropean Research Council 75657

Toward of Safer Phenylbutazone Derivatives by Exploration of Toxicity Mechanism

A drug design for safer phenylbutazone was been explored by reactivity and docking studies involving single electron transfer mechanism, as well as toxicological predictions. Several approaches about its structural properties were performed through quantum chemistry calculations at the B3LYP level of theory, together with the 6-31+G(d,p) basis sets. Molecular orbital and ionization potential were associated to electron donation capacity. The spin densities contribution showed a preferential hydroxylation at the para-positions of phenyl ring when compared to other positions. In addition, on electron abstractions the aromatic hydroxylation has more impact than alkyl hydroxylation. Docking studies indicate that six structures 1, 7, 8 and 13–15 have potential for inhibiting human as well as murine COX-2, due to regions showing similar intermolecular interactions to the observed for the control compounds (indomethacin and refecoxib). Toxicity can be related to aromatic hydroxylation. In accordance to our calculations, the derivatives here proposed are potentially more active as well safer than phenylbutazone and only structures 8 and 13–15 were the most promising. Such results can explain the biological properties of phenylbutazone and support the design of potentially safer candidates.We acknowledge the support provided by the PROPESP/UFPA and CNPq for financial suppor

Design and Identification of Inhibitors for the Spike-ACE2 Target of SARS-CoV-2

settingsOrder Article Reprints Open AccessArticle Design and Identification of Inhibitors for the Spike-ACE2 Target of SARS-CoV-2 by Ruan S. Bastos 1,2,*,Lúcio R. de Lima 1,2,Moysés F. A. Neto 3,Maryam 4,Numan Yousaf 4ORCID,Jorddy N. Cruz 2ORCID,Joaquín M. Campos 5,6ORCID,Njogu M. Kimani 7ORCID,Ryan S. Ramos 2ORCID andCleydson B. R. Santos 1,2,*ORCID 1 Graduate Program in Medicinal Chemistry and Molecular Modeling, Federal University of Pará, Belem 66075-110, PA, Brazil 2 Laboratory of Modeling and Computational Chemistry, Department of Biological and Health Sciences, Federal University of Amapá, Macapa 68903-419, AP, Brazil 3 Laboratory of Molecular Modeling, State University of Feira de Santana, Feira de Santana 44036-900, BA, Brazil 4 Department of Biosciences, COMSATS University Islamabad, Park Road, Islamabad 45550, Pakistan 5 Department of Pharmaceutical and Organic Chemistry, Faculty of Pharmacy, Campus of Cartuja, University of Granada, 18071 Granada, Spain 6 Biosanitary Institute of Granada (ibs.GRANADA), University of Granada, 18071 Granada, Spain 7 Department of Physical Sciences, University of Embu, Embu 6-60100, Kenya * Authors to whom correspondence should be addressed. Int. J. Mol. Sci. 2023, 24(10), 8814; https://doi.org/10.3390/ijms24108814 Received: 12 September 2022 / Revised: 23 November 2022 / Accepted: 28 November 2022 / Published: 16 May 2023 (This article belongs to the Special Issue The Research about Computer-Aided Drug Design) Download Browse Figures Versions Notes Abstract When an epidemic started in the Chinese city of Wuhan in December 2019, coronavirus was identified as the cause. Infection by the virus occurs through the interaction of viral S protein with the hosts’ angiotensin-converting enzyme 2. By leveraging resources such as the DrugBank database and bioinformatics techniques, ligands with potential activity against the SARS-CoV-2 spike protein were designed and identified in this investigation. The FTMap server and the Molegro software were used to determine the active site of the Spike-ACE2 protein’s crystal structure. Virtual screening was performed using a pharmacophore model obtained from antiparasitic drugs, obtaining 2000 molecules from molport®. The ADME/Tox profiles were used to identify the most promising compounds with desirable drug characteristics. The binding affinity investigation was then conducted with selected candidates. A molecular docking study showed five structures with better binding affinity than hydroxychloroquine. Ligand_003 showed a binding affinity of −8.645 kcal·mol−1, which was considered an optimal value for the study. The values presented by ligand_033, ligand_013, ligand_044, and ligand_080 meet the profile of novel drugs. To choose compounds with favorable potential for synthesis, synthetic accessibility studies and similarity analyses were carried out. Molecular dynamics and theoretical IC50 values (ranging from 0.459 to 2.371 µM) demonstrate that these candidates are promising for further tests. Chemical descriptors showed that the candidates had strong molecule stability. Theoretical analyses here show that these molecules have potential as SARS-CoV-2 antivirals and therefore warrant further investigation.Pró-reitoria de Pesquisa e Pós-graduação (PROPESP) from Federal University of Pará (UFPA)

Alkylated Sesamol Derivatives as Potent Antioxidants

Sesamol is a phenolic derivative. Its antioxidant activity is low than that of Trolox and depends on benzodioxole moiety. Thus, a molecular modification strategy through alkylation, inspired by natural and synthetic antioxidants, was studied by molecular modeling at the DFT/B3LYP level of theory by comparing the 6-31+G(d,p) and 6-311++G(2d,2p) basis sets. All proposed derivatives were compared to classical related antioxidants such as Trolox, t-butylated hydroxytoluene (BHT) and t-butylated hydroxyanisole (BHA). According to our results, molecular orbitals, single electron or hydrogen-atom transfers, spin density distributions, and alkyl substitutions at the ortho positions related to phenol moiety were found to be more effective than any other positions. The trimethylated derivative was more potent than Trolox. t-Butylated derivatives were stronger than all other alkylated derivatives and may be new alternative forms of modified antioxidants from natural products with applications in the chemical, pharmaceutical, and food industries.PROPESP/UFPANational Council for Scientific and Technological Development (CNPq

La sostenibilidad en los proyectos de cooperqación al desarrollo humano aplicando las metodologias del backcasting y del desarrollo a escala humana

Existe un amplio acuerdo internacional acerca de que la cooperación para el desarrollo humano se encuentra en una fase de transición. El uso del Marco Lógico como principal herramienta para gestionar el ciclo de proyectos dentro de las políticas establecidas por los programas de cooperación precisa una revisión. En el presente informe se propone un enfoque nuevo del cual surge una herramienta mejorada para el diseño, implementación y evaluación de estos proyectos. La herramienta presentada permite la integración activa y transparente de las condiciones críticas, tanto cualitativas como cuantitativas, capaces de afectar el sistema en análisis. Asegura así la viabilidad práctica de ésta para las agencias de cooperación. La formulación de los objetivos de la intervención deben cumplir con los imperativos del desarrollo sostenible; el equilibrio dinámico entre los sistemas naturales y sociales. A través de la metodología del “Backcasting”, según Holmberg y Jansen, con su marco temporal ampliado y el análisis iterativo de escenarios futuros, se logra retar las tendencias actuales. Permite integrar las hipótesis como factores críticos y de alta incertidumbre en la formulación de las actividades para alcanzar los objetivos establecidos. Además, con la propuesta de reforzar este enfoque, a partir de la inclusión de la herramienta “Matriz de Satisfactores y Necesidades” del economista chileno Max-Neef, elaborada en el ámbito del paradigma de Desarrollo a Escala Humana, se garantiza la sostenibilidad social y cultural de la comunidad a intervenir. El desarrollo de los objetivos según las necesidades reales tal como las perciben las poblaciones beneficiarias, fomenta y exige un aprendizaje ecológico, social, cultural y económico de todos los actores, tanto de las comunidades del norte como del sur. La herramienta presentada, al estar basada en un conjunto de principios de sostenibilidad equilibrado entre la ecología y la sociedad, permite alcanzar los objetivos establecidos. Consigue identificar las interacciones y propiedades de los sistemas ecológicos como sociales, y proporciona con su concepto dinámico nuevas plataformas para futuros cambios dentro del ámbito de la cooperación.Peer Reviewe

Hierarchical Virtual Screening and Binding Free Energy Prediction of Potential Modulators of Aedes Aegypti Odorant-Binding Protein 1

The Aedes aegypti mosquito is the main hematophagous vector responsible for arbovirus transmission in Brazil. The disruption of A. aegypti hematophagy remains one of the most efficient and least toxic methods against these diseases and, therefore, efforts in the research of new chemical entities with repellent activity have advanced due to the elucidation of the functionality of the olfactory receptors and the behavior of mosquitoes. With the growing interest of the pharmaceutical and cosmetic industries in the development of chemical entities with repellent activity, computational studies (e.g., virtual screening and molecular modeling) are a way to prioritize potential modulators with stereoelectronic characteristics (e.g., pharmacophore models) and binding affinity to the AaegOBP1 binding site (e.g., molecular docking) at a lower computational cost. Thus, pharmacophore- and docking-based virtual screening was employed to prioritize compounds from Sigma-Aldrich (R) (n = 126,851) and biogenic databases (n = 8766). In addition, molecular dynamics (MD) was performed to prioritize the most potential potent compounds compared to DEET according to free binding energy calculations. Two compounds showed adequate stereoelectronic requirements (QFIT > 81.53), AaegOBP1 binding site score (Score > 42.0), volatility and non-toxic properties and better binding free energy value (Delta G < -24.13 kcal/mol) compared to DEET ((N,N-diethyl-meta-toluamide)) (Delta G = -24.13 kcal/mol)