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Correlação entre potência absoluta alfa induzida por EMT (5HZ) e estimativa do tempo

Tue, 20 Oct 2026 00:00:00 GMT

Título: Correlação entre potência absoluta alfa induzida por EMT (5HZ) e estimativa do tempo Autor(es): Freitas, Ana Cláudia Mota de Primeiro Orientador: Bastos, Victor Hugo do Vale Abstract: Behavioral traits such as inattention and/or hyperactivity, characteristic of the ADHD spectrum, even when present at subclinical levels (traits), have been linked to alterations in frontoparietal neural network functioning and can impact executive functions and time perception. Repetitive Transcranial Magnetic Stimulation (rTMS) is a promising neuromodulation technique, but its effects on time perception and neurophysiological activity in individuals with ADHD traits require further investigation. Objective: To investigate the effects of a single session of 5 Hz rTMS, compared to a Sham (placebo) condition, on performance in a time estimation task and on absolute alpha band power in university students with elevated ADHD traits. Methods: A randomized, crossover, placebo-controlled (Sham) study was conducted with 18 university students (18-29 years old) with elevated ADHD traits (>80th percentile on the ETDAH-AD). Participants received active 5 Hz rTMS and Sham stimulation over F3 and PZ in separate sessions (separated by 7 days). Time estimation task performance (1s, 4s, 7s, 9s intervals) and Electroencephalography (EEG) were assessed before and after each intervention, analyzing Absolute Error (AE), Relative Error (RE), and absolute alpha band power (Total, Alpha-1, Alpha-2) across multiple cortical regions. Results: For AE, rTMS significantly reduced the error in the 4s and 9s intervals (p<0.001). RE was significantly lower (indicating improvement) with active rTMS in the 1s (p=0.0029), 4s (p<0.0001), and 9s (p<0.0001) intervals compared to Sham. In the neurophysiological analysis, 5 Hz rTMS induced significant modulations in the absolute power of Total Alpha, Alpha-1, and Alpha-2 bands, involving increased power in central-parietal-temporal regions and frontal modulation. Conclusion: A single session of 5 Hz rTMS modulates cortical alpha oscillatory activity in a region-specific manner and enhances the precision of time perception in university students with elevated ADHD traits. These findings suggest underlying neurophysiological mechanisms for temporal deficits associated with ADHD traits and reinforce the potential of rTMS as an investigational and targeted intervention tool. Instituição: Universidade Federal do Delta do Parnaíba Tipo: Tese

Efeitos sobre perfil antioxidante e reatividade vascular induzidos por uma manteiga obtidas das sementes de Platonia insignis Mart. em modelo de hipertensão L-NAME em ratas

Mon, 04 Nov 2019 00:00:00 GMT

Título: Efeitos sobre perfil antioxidante e reatividade vascular induzidos por uma manteiga obtidas das sementes de Platonia insignis Mart. em modelo de hipertensão L-NAME em ratas Autor(es): Silva, Maisa Gomes Primeiro Orientador: Arcanjo, Daniel Dias Rufino Abstract: Cardiovascular diseases are one of the leading causes of death worldwide. In this context, the use of natural products has been presented as an important source of bioproducts with potential therapeutic applications. In the search for biologically active compounds of the Clusiaceae family, Platonia insignis Mart., Popularly known as “bacuri”, has shown vasorelaxant, antioxidant and hypotensive effects in vivo, showing its promising application in the development of products for the treatment of cardiovascular diseases involving oxidative stress. Thus, the objective of this work is to investigate the toxicological, antioxidant and vasorelaxing effects of an industrialized butter obtained from Platonia insignis Mart seeds. (MIB), through in vitro and in vivo assays, for potential application in the treatment of hypertension. Cytotoxic activity was initially performed by MTT assay on murine macrophages and sheep blood erythrocytes. In the present study, a reduction in cell viability was observed by assessing concentration-dependent mitochondrial activity with a mean cytotoxic concentration (CC50) of 124.036 μg/ml and a low cytotoxicity was observed in hemolytic activity. Since MIB promoted less than 10% hemolysis at the highest concentration tested (800 μg/ml), the mean hemolytic concentration could not be determined. Subsequently, in vitro antioxidant assays were performed to evaluate the effects of MIB on the formation of reactive thiobarbituric acid (TBARS), nitrite (NO2-) and hydroxyl radical (HO-) species. In all assays, MIB showed equipotent antioxidant activity when compared to the positive control. Subsequently, acute oral toxicological evaluation in vivo was performed using the Fixed Dose Test (OECD Guideline 420, 2000), with modifications. No deaths or changes were observed in the clinical and behavioral parameters evaluated, as well as in serum biochemical parameters, weight and macroscopic evaluation of organs. Ahead, the ex vivo responsiveness of aortic artery preparations to acetylcholine (ACh) and sodium nitroprusside (SPN) after subacute treatment (7 days) with MIB (25, 50 and 100 mg/kg) in rats subjected was evaluated. L-NAME-induced hypertension (50 mg/kg·day for 21 days). Aortic preparations of animals treated with MIB at 25 mg/kg showed higher reactivity to acetylcholine, but did not intensify the vessel response to SNP compared to the hypertensive control group, prompting the need for further trials. In the in vivo antioxidant assays, the effects of MIB (25, 50 and 100 mg/kg) on malondialdehyde (MDA), reduced glutathione (GSH), myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase levels were investigated. (CAT) in erythrocytes or plasma of rats submitted to LNAME-induced hypertension (50 mg/kg · day for 21 days). Test results demonstrate that there was a significant reduction in MDA and MPO levels and a significant increase in GSH and SOD levels of hypertensive animals treated with MIB compared with hypertensive control. All these results underscore the immense therapeutic potential of MIB against hypertensive diseases and related oxidative stress, paving the way for the study of new therapeutic branches in the treatment of hypertensive individuals. Instituição: Universidade Federal do Delta do Parnaíba Tipo: Dissertação

Estudo fitoquímico e atividade biológica de folhas de copernicia prunifera (mill.) h.E. Moore

Fri, 06 Apr 2018 00:00:00 GMT

Título: Estudo fitoquímico e atividade biológica de folhas de copernicia prunifera (mill.) h.E. Moore Autor(es): Pinto, Jocélia do Carmo Primeiro Orientador: Andrade, Ivanilza Moreira de Abstract: Copernícia prunifera (Mill) H. E. Moore is a native palm tree from Brazil hat adds values both for the local economy and countrys economy, Among the various parts of the plant, the epieuticular wax that covers the surface of the leaves is the main raw material used in the manufacture of wax, used in various industrial sectors. Although widely used, there are still few phytochemical and biological studies about the species. The objective of this study was to compare two treatments for the removal of epicuticular wax (EC), ehloroform (CHCI3) and hexane (C6HI2), and characterize phytochemistry and evaluate the biological activity of aqueous, ethanolic and methanolic extracts of leaves and epicuticular wax, both without treatment and treatment of C. prunifera. The samples were collected in the city of Caxingó, Piauí Brazil. For the phytochemical characterization were used qualitative tests (phenols, tannins, saponins, reducing sugar, organic acids, polysaccharides, alkaloids and Fflavonoids) and quantitative (yield and total). For the identification of the main chemical groupings of the samples, the electrochemistry and Fourier transform infrared spectroscopy (FIIR) were made. The evaluation of the antioxidant capacity was determined by the 2,2-azinobis (3-ethyIbenzihiazoline-6-sulfonic) - ABTS + » method. The in vitro extotoxic potential of the epicuticular wax extracts was verified in four tumor lines and the biocompatibility was evaluated by analyzing the hemolytic activity on human erythrocytes, The efficacy of the two treatments was observed using surface electron microscopy (SEM). The crude percentage vield (RPB) of the aqueous extract of the mature leaves epicuticular wax (EAFM) was higher (1.9%) than the aqueous extract f the epicuticular wax of the young leaves EAFJ (1.5%). The leaves treated with chloroform had higher RPB than leaves treated with hexane. The hydrogenation potential (pH) of EC extracts were slightly acidic, 5.7 (EAFI) and 6.0 (EAEM), as well as ethanolic (4.7) and methanolic (5.9) extracts of green leaves treated with chloroform, however all other extracts of the leaves of both treatments presented neutral pH. Condensed tannins, saponins and alkaline reducing sugars and flavonols were detected in leaf extracts and cpicuticular wax. FTIR analysis revealed the presence of bands associated with these metabolites. The total phenolic content of aqueous extracts of wax was lower in EAFJ (56.48 + 21.91 mg EAG / g extract) than EAFM (158.52 + 3927 mg EAG / g extract). The antioxidant activity (AA) was 349 + 4,8 ug and 100.3 4 15.2 ug for EAFJ and EAFM, respectively. The extractions (aqueous, ethanolic and methanolic) of mature leaves treated with chloroform had higher AA when compared to mature leaves treated with hexane. Young leaves treated with hexane showed more efficient Aqueous extracts of epicuticular wax showed cytotoxicity to the glioblastoma line (SF-295), while extracts of wax and leaves treated with hexane showed low toxicity to human erythrocytes. The results obtained show that in addition to the industrial applications, the epicuticular wax and the leaves of C. prunifera present great biological potential. Instituição: Universidade Federal do Delta do Parnaíba Tipo: Dissertação

Predição in sílico da afinidade do nebivolol a proteínas envolvidas na infecção por sars-cov-2, através de um estudo de docagem molecular.

Tue, 23 Mar 2021 00:00:00 GMT

Título: Predição in sílico da afinidade do nebivolol a proteínas envolvidas na infecção por sars-cov-2, através de um estudo de docagem molecular. Autor(es): Silva, Priscila Costa Primeiro Orientador: Medeiros, Jand Venes Rolim Abstract: In December 2019, a new coronavirus (CoV) was determined to be responsible for an outbreak of potentially fatal atypical pneumonia, defined as coronavirus-19 disease (COVID-19), caused by severe acute coronavirus 2 respiratory syndrome (SARS-CoV -2) in Wuhan, China. So far, there are no really effective drugs for such infections, making the development of drug therapies of paramount importance. A faster and more effective option in this regard is the study for the use of drugs that have already been approved for use in humans, known as drug repositioning. In this work, nebivolol hydrochloride (NEB), a third generation drug, beta-adrenoceptor antagonist, selective β1, with vasodilating and antioxidant properties, was used in the treatment of hypertension, acting directly on the renin-angiotensin system (RAS). The aim of this study was to analyze the affinity of nebivolol on the proteins that are involved, from viral entry to replication, through a molecular docking study. For this, the following procedures were carried out: obtaining the three-dimensional structures of proteins in the Protein Data Bank (PDB); survey of data related to the ligand and its three-dimensional structure by Drugbank, optimization of these structures and finally, the study of molecular docking, using computer programs such as AutodockTools, LigPlot and Pymol. The result of molecular docking showed that there was interaction between all complexes formed (ligand / protein), with binding energies equal to -9.48 kcal.mol-1 for protein S in the closed state (6VXX), -7.06 kcal / mol-1 in the open state (6VYB), -7.32 kcal / mol-1 for Mpro (6Y2E), -5.46 kcal / mol- 1 for ADAM-17 (2DDF), -5.45 kcal.mol-1 for cathepsin L (2XU3), - 5.26 kcal.mol-1 for TMPRSS2 (2OQ5), -4.94 kcal.mol-1 for the RBD domain (6LZG), and -4.84 kcal.mol- 1 for ECA2 (1R42). The best energies obtained were with protein S and Mpro, thus indicating that the ligand may be acting both in viral entry and in the replication process. Additional studies should be carried out to elucidate the antiviral role of nebivolol, however this initial virtual approach already points to possible targets and mechanisms used by nebivolol, since compared to some drugs used in the clinic, NEB demonstrated better energy. Therefore, the evaluation of the affinity of this ligand to the targets in question is indispensable for the development of therapeutic strategies against the new coronavirus. Instituição: Universidade Federal do Delta do Parnaíba Tipo: Dissertação