The transformation behavior between iron oxides and oxyhydroxides like magnetite, hematite and goethite is still not entirely understood. Crystallographic similarities allow one to predict topotactic ...relationships between them. The related crystallographic aspects have been explored by means of electron backscatter diffraction (EBSD). Samples from natural aggregates of magnetite, hematite and goethite were collected from iron‐formation rocks that outcrop in the southeast of Brazil, in a region known for large deposits of iron and other ores. EBSD misorientation data indicate a pronounced relationship between these iron phases. The transformation seems to be related to the oxygen framework. The original close‐packed cubic arrangement of O atoms in magnetite changes to a hexagonal close‐packed framework in hematite, i.e. {111} of magnetite is parallel to {0001} of hematite. The matrix in which the magnetite grains are embedded is made of aggregates of hematite and goethite. In the matrix, the coincidence observed in the magnetite grains is not observed. On the other hand, the well known twin boundary relationships already described for these mineral phases can be observed here as an orientation relationship in three‐dimensional misorientation space. The spatial data of axis–angle pairs suggest that the twin boundaries serve as facilitating surfaces for phase transformation in the Fe–O–OH system. The main conclusion of this study is that the transformation occurred in the solid state with the newly transformed goethite inheriting the crystallographic orientations of the former crystals and that this phenomenon is better recognized by combining observations of misorientation relationships. In the matrix, such a relation is not observed and, for that reason, the minerals in the matrix are thought to have been formed by a different process, which might have involved dissolution and precipitation of the phase newly out of solution.
According to this study, it is possible to observe that the transformation between magnetite, hematite and goethite occurs in the solid state, with the newly transformed goethite inheriting the crystallographic orientations of the former crystals, and that this phenomenon is better recognized by combining observations of misorientation relationships.
The correct evaluation of ligand binding free energies by computational methods is still a very challenging active area of research. The most employed methods for these calculations can be roughly ...classified into four groups: (i) the fastest and less accurate methods, such as molecular docking, designed to sample a large number of molecules and rapidly rank them according to the potential binding energy; (ii) the second class of methods use a thermodynamic ensemble, typically generated by molecular dynamics, to analyze the endpoints of the thermodynamic cycle for binding and extract differences, in the so-called ‘end-point’ methods; (iii) the third class of methods is based on the Zwanzig relationship and computes the free energy difference after a chemical change of the system (alchemical methods); and (iv) methods based on biased simulations, such as metadynamics, for example. These methods require increased computational power and as expected, result in increased accuracy for the determination of the strength of binding. Here, we describe an intermediate approach, based on the Monte Carlo Recursion (MCR) method first developed by Harold Scheraga. In this method, the system is sampled at increasing effective temperatures, and the free energy of the system is assessed from a series of terms W(b,T), computed from Monte Carlo (MC) averages at each iteration. We show the application of the MCR for ligand binding with datasets of guest-hosts systems (N = 75) and we observed that a good correlation is obtained between experimental data and the binding energies computed with MCR. We also compared the experimental data with an end-point calculation from equilibrium Monte Carlo calculations that allowed us to conclude that the lower-energy (lower-temperature) terms in the calculation are the most relevant to the estimation of the binding energies, resulting in similar correlations between MCR and MC data and the experimental values. On the other hand, the MCR method provides a reasonable view of the binding energy funnel, with possible connections with the ligand binding kinetics, as well. The codes developed for this analysis are publicly available on GitHub as a part of the LiBELa/MCLiBELa project (https://github.com/alessandronascimento/LiBELa).
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•The Monte Carlo Recursion (MCR) Method was evaluated for protein-ligand binding.•Computed binding energies showed a correlation with experimental data of r = 0.75.•The MCR also distinguished correct binding poses from incorrect ones.•MCR can potentially be used as a refinement method for docking calculations.
ObjectiveThis is a psychometric study aimed at proposing a scale for estimating the consumption of ultraprocessed foods using item response theory.MethodsFood consumption data from a representative ...sample of 2515 adolescent individuals aged 18 and 19 from the third phase of the Ribeirão Preto, Pelotas, and São Luís Brazilian Birth Cohorts Consortium were used. The instrument used was a validated food frequency questionnaire. The selection of ultraprocessed foods items occurred through exploratory factor analysis. Items with factor loadings > 0.30 and commonality > 0.20 were applied in Samejima's graded response model and had unidimensionality (variance = 28.0%) as well as good quality of fit (comparative fit index and Tucker-Lewis index > 0.90 and root mean square error of approximation < 0.08). Kruskal-Wallis and Wilcoxon tests were used to assess latent trait levels in thirds (low, moderate, and high), according to food consumption variables.ResultsThe information provided by the test covers the entire latent trait continuum, reinforcing its ability to estimate ultraprocessed foods consumption. Foods classified as in natura had a decline in consumption as the level of ultraprocessed foods consumption increased. Ultraprocessed foods were directly proportional to the latent trait (P < 0.05). The highest level of latent trait concentrated the highest median of total energy intake (P < 0.05).ConclusionsThe proposed ultraprocessed foods consumption scale presents an estimation of consistency and is a potential brief tool for use in assessing the consumption of this food group.
This study explores the stabilization by niobic acid, of Pt, Ni, Pd, and Au nanoparticles (NPs) for the efficient microheterogeneous catalysis of NaBH
4
hydrolysis for hydrogen production. Niobic ...acid is the most widely studied Nb
2
O
5
polymorph, and it is employed here for the first time for this key reaction relevant to green energy. Structural insights from XRD, Raman, and FTIR spectroscopies, combined with hydrogen production data, reveal the role of niobic acid's Brønsted acidity in its catalytic activity. The supported NPs showed significantly higher efficiency than the non-supported counterparts regarding turnover frequency, average hydrogen production rate, and cost. Among the tested NPs, PtNPs and NiNPs demonstrate the most favorable results. The data imply mechanism changes during the reaction, and the kinetic isotope assay indicates a primary isotope effect. Reusability assays demonstrate consistent yields over five cycles for PtNPs, although catalytic efficiency decreases, likely due to the formation of reaction byproducts.
This study explores the stabilization by niobic acid, of Pt, Ni, Pd, and Au nanoparticles (NPs) for the efficient microheterogeneous catalysis of NaBH
4
hydrolysis for hydrogen production.
The COVID-19 outbreak has rapidly spread on a global scale, affecting the economy and public health systems throughout the world. In recent years, peptide-based therapeutics have been widely studied ...and developed to treat infectious diseases, including viral infections. Herein, the antiviral effects of the lysine linked dimer des-Cys11, Lys12,Lys13-(pBthTX-I)2K ((pBthTX-I)2K)) and derivatives against SARS-CoV-2 are reported. The lead peptide (pBthTX-I)2K and derivatives showed attractive inhibitory activities against SARS-CoV-2 (EC50 = 28–65 µM) and mostly low cytotoxic effect (CC50 > 100 µM). To shed light on the mechanism of action underlying the peptides’ antiviral activity, the Main Protease (Mpro) and Papain-Like protease (PLpro) inhibitory activities of the peptides were assessed. The synthetic peptides showed PLpro inhibition potencies (IC50s = 1.0–3.5 µM) and binding affinities (Kd = 0.9–7 µM) at the low micromolar range but poor inhibitory activity against Mpro (IC50 > 10 µM). The modeled binding mode of a representative peptide of the series indicated that the compound blocked the entry of the PLpro substrate toward the protease catalytic cleft. Our findings indicated that non-toxic dimeric peptides derived from the Bothropstoxin-I have attractive cellular and enzymatic inhibitory activities, thereby suggesting that they are promising prototypes for the discovery and development of new drugs against SARS-CoV-2 infection.
Purpose
To evaluate the effectiveness of photobiomodulation (PBMT) in preventing dysgeusia in breast cancer patients treated with doxorubicin-cyclophosphamide (AC).
Methods
This is a phase II, ...randomized, triple-blind, placebo-controlled clinical trial involving 112 breast cancer patients treated with AC. The patients were divided equally into two groups: a test group treated with 2 J red laser and 3 J infrared laser on 21 points that were symmetrically distributed on the tongue on day 0 of four cycles of AC, and an equal placebo group treated with simulated PBMT to blind the patient, evaluator, and statistician. The clinicopathological and sociodemographic data, results of taste test, and subjective taste analysis, and the QoL, ECOG performance status, body mass index, and other side effects were recorded. The data were analyzed using ANOVA-RM/Bonferroni, Friedman/Dunn, and chi-square/Fisher’s exact tests.
Results
PBMT patients showed less objective and subjective taste loss (
p
<0.05). On the other hand, the placebo group showed a higher ECOG status (
p
=0.037) and more significant weight loss (
p
<0.001) after four cycles of AC. The QoL was significantly higher in the PBMT group (
p
<0.05) at all assessment periods, and PBMT treatment also reduced the incidence of cachexia (
p
=0.020), anorexia (
p
<0.001), diarrhea (
p
=0.040), oral mucositis (
p
=0.020), and vomiting (
p
=0.008).
Conclusion
PBMT reduced the taste loss and improved the overall health status and QoL of patients with breast cancer treated with AC.
Trial registration
Brazilian Clinical Trials Registry (
www.ensaiosclinicos.gov.br
) approval number RBR-9qnm34y, registered on 01/05/2021
Evidence from clinical trial studies suggests that docosahexaenoic acids (DHA) may have greater potential effects on improving cardiovascular risk factors than eicosapentaenoic acid (EPA). However, ...this evidence has not yet been meta-analyzed and quantified. The aim of this study was to evaluate and compare the effect of DHA and EPA monotherapy on cardiovascular risk factors based on paired and network meta-analysis.
Relevant articles published up to January 2022 were systematically retrieved from relevant databases. We included all Randomized Controlled Trials (RCTs) on adults that directly compared the effects of DHA with EPA and RCTs of indirect comparisons (DHA and EPA monotherapy compared to control groups). Data were pooled by pairwise and network meta-analysis and expressed as mean differences (MDs) with 95% CIs. The study protocol was registered with PROSPERO (Registration ID: CRD42022328630).
Network meta-analysis of comparisons of DHA and EPA suggested significant comparable effects only on LDL-C (MD EPA versus DHA = −8.51 mg/L; 95% CI: −16.67; −0.35). However, the Network meta-analysis not show a significant effect for other risk factors. Furthermore, pairwise meta-analysis of direct comparisons of DHA and EPA showed significant difference in their effects on plasma glucose (MD EPA versus DHA = −0.31 mg/L; 95% CI: −0.60, −0.02), Insulin (MD EPA versus DHA = −2.14 mg/L; 95% CI: −3.26, −1.02), but the results were not significant for risk factors.
Our findings suggest that both EPA and DHA act similarly on the markers under study, with slight changes in plasma glucose, insulin, and LDL-C.
•Evidence studies suggests that DHA may have greater potential effects on improving CVD risk factors than EPA.•Network meta-analysis of comparisons of DHA and EPA suggested significant comparable effects only on LDL.•Pairwise meta-analysis of DHA and EPA showed significant difference in their effects on glucose and Insulin.•Findings suggest that both EPA and DHA act similarly on the markers with slight changes in glucose, insulin, and LDL.
Objective: To evaluate the prevalence of malnutrition in children under 60 months of age living in quilombo remnant communities of two municipalities in the state of Maranhao and their associated ...factors. Methods: This is a cross-sectional study conducted with a sample of 372 children in August 2015. Socioeconomic, demographic, maternal and child information were collected. The anthropometry followed the one proposed by the World Health Organization. Height-for-age and weight-for-height rates were calculated using Anthro software version 3.2.2. Poisson regression was performed with a robust variance for the association of malnutrition with the studied variables, using Stata software version 14.0. Results: Child malnutrition was high for height-for-age (15.1%) and weight-for-height (7%). Children whose mothers had a short height (< 1.497 m) were more likely to have height-for-age deficits (p < 0.05). No variables were statistically associated with low weight-for-height. Conclusion: Child malnutrition persists as a public health problem in vulnerable regions, and maternal factors such as low maternal height may explain the short stature of the children. The need for actions to address this nutritional deviation is pointed out. Key words Preschoolers, Child malnutrition, Black people
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