Publications by authors named "Matheus P Freitas"

Background: This review is an update of the previous study aiming to identify the available evidence related to physical activity (PA) in the context of the coronavirus disease (COVID-19) pandemic.

Methods: We searched 6 databases (PubMed, Embase, SPORTDiscus, Scopus, Web of Science, and CINAHL) in April 2024. Medical subject headings and keywords related to PA and COVID-19 were combined to conduct the online search, which covered the period from July 2020 to April 2024.

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2-(1,3-Benzoxazol-2(3H)-ylidene)-3-oxo-3-phenylpropanenitrile (1) and methyl-2-(1,3-benzoxazol-2(3H)-ylidene)(cyano)acetate (2) are observed as single isomers by NMR spectroscopy. A theoretical study was carried out to investigate if this is due to the exclusive presence of the most stable diastereoisomer or if the ene moiety undergoes fast rotation, thereby allowing for the observation of an average conformer. Indeed, the pronounced stabilization of the E stereoisomer, attributed to intramolecular hydrogen bonding, makes it the single obtained product.

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Selective fluorination of the pyrrolidine ring in proline motifs has been found to induce significant conformational changes that impact the structure and biological roles of modified peptides and proteins. Vicinal difluorination of fluoroproline, for example, in (3,4)-3,4-difluoroproline, serves to mitigate the inherent conformational bias of the pyrrolidine ring by inducing stereoelectronic effects that attenuate this conformational bias. In this investigation, we present a quantumchemical analysis of the conformational equilibrium and effects that are induced in difluorinated pyrrolidines, with a particular focus on exploring the impact of and anomeric effects on the conformer stabilities of different stereo- and regioisomers.

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Compounds containing the thiophene moiety find several applications in physics and chemistry, such as electrical conduction, which depends on specific conformations to properly exhibiting the desired properties. In turn, chalcogen bonding has found to modulate the conformation of some N-thiophen-2-ylfomamides. Since halogens participate in a kin interaction (halogen bonding) and are abundant in agrochemicals, pharmaceuticals, and materials, we have quantum-chemically explored the interaction between organic halogen and thiophene as a conformational modulator in some model compounds.

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The present study aimed to analyze how these changes, both at the national and state levels, could affect the conditions of the implementation of obesity prevention and control (OCP) actions in primary health care (PHC) in the Rio de Janeiro State from 2014 to 2021. This study was based on policy analysis methods that emphasize the understanding of the implementation contexts, as well as the induction mechanisms and government incentives for the development of actions and integration of two projects that analyzed the OPC actions in PHC in the 92 municipalities of RJS between 2014 and 2018 (PPSUS-RJS) and between 2019 and 2021 (PEO-RJS). The results indicate that, by 2016, it was possible to observe the positive impacts of the structuring of PHC and the federal induction mechanisms in RJS.

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Background: Fluorine plays a significant role in agrochemical science because approximately 25% of herbicides licensed worldwide contain this element. In a pool of previously synthesized benzoxazinones, some compounds contained fluorine and demonstrated inhibitory activities against protoporphyrinogen IX oxidase (PPO). Therefore, three data sets of benzoxazinone derivatives with known inhibitory activity against PPO were employed to build a multivariate image analysis applied to a quantitative structure-activity relationships (MIA-QSAR) model to identify improved analogs with at least one fluorine substituent.

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This study aimed to analyze the physical activity trend of Brazilian schoolchildren and the associations with demographic, socioeconomic, and behavioral variables by using the Brazilian National Survey of School Health (PeNSE) in its four editions - 2009, 2012, 2015, and 2019. Data from students (13-17 years old) participating in the four editions of the PeNSE (n = 392,922) were used. We describe the percentage of active, mean, and percentile values of moderate to vigorous intensity physical activity in minutes/week.

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Background: Mesotrione is a triketone widely used as an inhibitor of the hydroxyphenylpyruvate deoxygenase (HPPD) enzyme. However, new agrochemicals should be developed continuously to tackle the problem of herbicide resistance. Two sets of mesotrione analogs have been synthesized recently and they have demonstrated successful phytotoxicity against weeds.

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Fluorine is often considered the only halogen to effectively engage in hydrogen bonds, while the other halogens, particularly iodine, are not electronegative enough to participate as hydrogen bond acceptors in electrostatic interactions. 2-Fluoroethanol and 2-iodoethanol have been studied herein to test this assumption, since a highly stable gauche conformation can experience the intramolecular hydrogen bond. However, the infrared O  H stretching frequency indicates that the hydroxyl group in 2-fluoroethanol is not engaged in intramolecular hydrogen bond, while the corresponding vibration mode for 2-iodoethanol suggests that not only the O  H is engaged in such interaction, but also that intramolecular hydrogen bond may drive the conformational equilibrium in this molecule.

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Hexachlorocyclohexanes (HCHs) have been widely explored as biological compounds during the last century. However, most of them were banned due to their potential toxicity in humans, animals, and the environment. Revisiting HCHs to explore their biological activity while improving key features is valuable and may lead to a new class of pesticides that utilizes the biological response of HCHs without their toxic characteristics.

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The conformer in 1-X,2-Y-disubstituted ethanes, that is, the staggered orientation in which X and Y are in closer contact, is only favored for relatively small substituents that do not give rise to large X···Y steric repulsion. For more diffuse substituents, weakly attractive orbital interactions between antiperiplanar bonds (i.e.

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The anti-tyrosinase activity of the leaf extract of Schinus terebinthifolius, also known as Brazilian peppertree, was evaluated using multiple in silico approaches, such as molecular homology, molecular docking, MM-GBSA, molecular dynamics, MM-PBSA, QSAR, and skin permeability predictions. With these computational tools, the compounds that downregulate tyrosinase enzyme activity could be evaluated, and more potent molecules could be identified. The results indicated that various compounds, especially luteolin, are accountable for the anti-tyrosinase activity of S.

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A series of aryloxyacetic acid derivatives have demonstrated promising herbicidal performance by inhibition of the hydroxyphenylpyruvate deoxygenase (HPPD) enzyme. We hereby applied quantitative structure-activity relationship (QSAR) and docking strategies to model and chemically understand the bioactivities of these compounds and subsequently propose unprecedented analogues aiming at improving the herbicidal and environmental properties. Bulky halogens at the 2-, 3-, 4-, and 6-positions of an aromatic ring, CF in 4-position, and the 2-NO group in a phenyl ring appear to favor the HPPD inhibition.

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Pyrimidine compounds comprise a class of acetohydroxyacid synthase (AHAS) inhibitors, thus possessing herbicidal activity. Due to the ongoing development of resistance by weeds to current herbicides, the design of new agrochemical candidates is often required. This work reports the proposition of unprecedented pyrimidines as herbicides guided by quantitative structure-activity relationship (QSAR) modeling.

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Benzamide herbicides consist of a class of photosynthetic system II (PSII) inhibitors widely used for weed control. However, the development of resistance by these weeds to the known herbicides requires an ongoing search for new agrochemicals. We report the combination of two congeneric series of (thio)benzamide herbicides into a single data set and subsequent modeling of their herbicidal activities against PSII using MIA-QSAR.

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Conformation has a key role in the mechanism of interaction between small molecules and biological receptors. However, encoding this type of information in molecular descriptors for the construction of robust quantitative structure-activity relationships (QSAR) models is not an easy task and, so far, the dependence of these models on such feature has not been thoroughly investigated. In the present study, the authors explore the effects of conformational information on a 3D-QSAR technique by comparing models built with descriptors that encode fully described tridimensional aspects (structures docked inside a biological target), with descriptors in which this information is suppressed (flat structures) or not fully described (structures with quantum-chemically optimized geometries).

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This work reports studies at the molecular level of a series of modified sulfonylureas to determine the chemophoric sites responsible for their antifungal and herbicidal activities. For forage conservation, high antifungal potency and low phytotoxicity are required. A molecular modeling study based on multivariate image analysis applied to quantitative structure-activity relationship (MIA-QSAR) was performed to model these properties, as well as to guide the design of new agrochemical candidates.

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Chlorinated agrochemicals play a major role in toxicity due especially to the labile C - Cl bond and high lipophilicity of organochlorines. In turn, urea and thiourea herbicides are widely used for weed control. A series of substituted N-benzoyl-N'-pyrimidin-2-yl thioureas has been recently synthesized and tested against Brassica napus L.

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Sulphur, not phosphorus, is the only known third-row element capable of experiencing an electrostatic gauche effect with fluorine. Some six-membered rings containing an endocyclic phosphorus atom and a β-fluorine substituent that can interconvert to axial (gauche relative to phosphorus) and equatorial positions were then analysed. While phosphines do not establish an electrostatic attraction between fluorine and phosphorus, some oxidised forms exhibit surprising stability for the sterically disfavoured axial orientation.

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Voltage-gated calcium (Ca) channels malfunction may lead to Alzheimer's and cardiovascular disorders, thus a critical protein target for drug development and treatment against several diseases. Indeed, dihydropyridines (DHPs) as nifedipine and amlodipine are top-selling pharmaceuticals and, respectively, the 121st and 5th most prescribed drugs in the United States that have been used as successful selective blockers for L-type Ca2+ channels (LCC) and may be helpful model structures to compare with new DHP analogs. In this context, we have performed a structure-based drug design (SBDD) study of several fluorinated DHPs by using homology modeling, molecular docking, quantitative structure activity relationship (QSAR) and molecular dynamics calculations.

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The concept of dipolar repulsion has been widely used to explain several phenomena in organic chemistry, including the conformational preferences of carbonyl compounds. This model, in which atoms and bonds are viewed as point charges and dipole moment vectors, respectively, is however oversimplified. To provide a causal model rooted in quantitative molecular orbital theory, we have analyzed the rotational isomerism of haloacetaldehydes OHC-CHX (X = F, Cl, Br, I), using relativistic density functional theory.

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The solubility of inhalational anaesthetics in the bloodstream is related to the minimum alveolar concentration (MAC), which is an indicator of anaesthetic gas potency. The blood-gas partition coefficient (Kbg) is a measure of how much anaesthetics bind to plasma proteins in the blood compared to air. Just like the octanol-water partition coefficient, the Kbg may be related to the molecular dipole moment (μ), which can be modulated by the molecular conformation.

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Multivariate image analysis applied to quantitative structure-activity relationships (MIA-QSAR) has proved to be a high-performance 2D tool for drug design purposes. Nonetheless, MIA-QSAR strategy does not efficiently incorporate conformational information. Therefore, understanding the implications of including this type of data into the MIA-QSAR model, in terms of predictability and interpretability, seems a crucial task.

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Low red-LED irradiances are an attractive alternative for enhancing microalgae photobioreactors treating digestate due to their potential contribution in decreasing area footprints with low energy consumptions. However, more information is required regarding the influence of digestate load on treatment performance and biomass valorisation when low-intensity red-LEDs are applied. Thus, this study assessed microalgae-based photobioreactors treating food waste digestate under different concentrations (5%, 25%, 50%, and 75%, v/v) at low red-LED irradiance (15 µmol·m·s).

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We have quantum chemically investigated the rotational isomerism of 1,2-dihaloethanes XCH CH X (X = F, Cl, Br, I) at ZORA-BP86-D3(BJ)/QZ4P. Our Kohn-Sham molecular orbital (KS-MO) analyses reveal that hyperconjugative orbital interactions favor the gauche conformation in all cases (X = F-I), not only for X = F as in the current model of this so-called gauche effect. We show that, instead, it is the interplay of hyperconjugation with Pauli repulsion between lone-pair-type orbitals on the halogen substituents that constitutes the causal mechanism for the gauche effect.

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