Obtenção e caracterização de compósitos de benzoxazina/fibra de carbono

Pós-graduação em Engenharia Mecânica - FEG

Exercise and oxidative stress: p,otential effects of antioxidant dietary strategies in sports

Free radicals are produced during aerobic cellular metabolism and have key roles as regulatory mediators in signaling processes. Oxidative stress reflects an imbalance between production of reactive oxygen species and an adequate antioxidant defense. This adverse condition may lead to cellular and tissue damage of components, and is involved in different physiopathological states, including aging, exercise, inflammatory, cardiovascular and neurodegenerative diseases, and cancer. In particular, the relationship between exercise and oxidative stress is extremely complex, depending on the mode, intensity, and duration of exercise. Regular moderate training appears beneficial for oxidative stress and health. Conversely, acute exercise leads to increased oxidative stress, although this same stimulus is necessary to allow an up-regulation in endogenous antioxidant defenses (hormesis). Supporting endogenous defenses with additional oral antioxidant supplementation may represent a suitable noninvasive tool for preventing or reducing oxidative stress during training. However, excess of exogenous antioxidants may have detrimental effects on health and performance. Whole foods, rather than capsules, contain antioxidants in natural ratios and proportions, which may act in synergy to optimize the antioxidant effect. Thus, an adequate intake of vitamins and minerals through a varied and balanced diet remains the best approach to maintain an optimal antioxidant status. Antioxidant supplementation may be warranted in particular conditions, when athletes are exposed to high oxidative stress or fail to meet dietary antioxidant requirements. Aim of this review is to discuss the evidence on the relationship between exercise and oxidative stress, and the potential effects of dietary strategies in athletes. The differences between diet and exogenous supplementation as well as available tools to estimate effectiveness of antioxidant intake are also reported. Finally, we advocate the need to adopt an individualized diet for each athlete performing a specific sport or in a specific period of training, clinically supervised with inclusion of blood analysis and physiological tests, in a comprehensive nutritional assessment. (C) 2015 Elsevier Inc. All rights reserved.

Evaluation of mutagenicity and metabolism-mediated cytotoxicity of the naphthoquinone 5-methoxy-3,4-dehydroxanthomegnin from Paepalanthus latipes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Analysis of mesiodistal angulations of preadjusted brackets

Manufacturers offer various prescriptions of preadjusted brackets for use in the "straight-wire" orthodontic technique. However, the need to incorporate bends in the rectangular wires during orthodontic finishing has led to concerns regarding the type of prescription chosen and the credibility of information provided by the manufacturer. The aim of this study was to compare the slot angulations of Roth prescription preadjusted metallic brackets for the maxillary left central incisor and maxillary left canine. For each tooth type, 10 brackets of three commercial brands (GAC, Forestadent and Morelli) were selected. Two individual metal matrices for brackets and tooth positioning were made for each group of teeth. Captured images were obtained by standardized ortho-radial photography with a digital camera. Images were exported and analyzed with the Image J software package. One-way ANOVA and Tukey statistical analyses were performed at the 5% significance level. For brackets of the maxillary left central incisor, differences in mean angulation were observed between the Morelli and GAC groups (p < 0.01) and between the Forestadent and GAC groups (p < 0.01). For brackets of the maxillary left canine, differences in mean angulation were found between the Morelli and GAC groups (p < 0.01) and between the Morelli and Forestadent groups (p < 0.05). In conclusion, despite their same prescription name, the different brands exhibited significantly different angulation measurements.

Conformational changes of the HsDHODH N-terminal microdomain via DEER spectroscopy

The human enzyme dihydroorotate dehydrogenase (HsDHODH) has been studied for being a target for development of new antineoplasic and antiproliferative drugs. The synthetic peptide N-t(DH) represents the N-terminal microdomain of this enzyme, responsible for anchoring it to the inner mitochondrial membrane. Also, it is known to harbor quinones that are essential for enzyme catalysis. Here we report structural features of the peptide/membrane interactions obtained by using CD and DEER spectroscopic techniques, both in micelles and in lipid vesicles. The data revealed different peptide conformational states in micelles and liposomes, which could suggest that this microdomain acts in specific regions or areas of the mitochondria, which can be related with the control of the quinone access to the HsDHODH active site. This is the first study to report on conformational changes of the HsDHODH N-terminal microdomain through a combination of CD and DEER spectroscopic techniques.

Cálcio e fósforo para juvenis da tilápia-do-nilo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fios ortodônticos superelásticos e sua aplicabilidade na clínica ortodôntica: revisão da literatura

During clinical routine, the orthodontist uses several materials, which include metallic alloys in the form of metallic wires. However, it is necessary that the professional has some knowledge of the properties of those wires. Different types of wires are commercially available: stainless steel wires, chrome-cobalt wires, nickel-titanium wires and beta-titanium wires. Among the nickel-titanium wires, there are three subdivisions: a conventional alloy and two superelastic alloys. The superelasticity, associated to the effect of form memory, is a property used in orthodontics to initiate the dental movement in the first phase of the orthodontic treatment. This property is considered to be biologically compatible with the effective dental movement. These wires are available at the market in different transformation temperatures, and they offer the best adaptation in the groove of the bracket, simplicity and a faster treatment. However, they present little formability, and they don’t accept solder. They are also more onerous than other wires. Moreover, the low rigidity of these wires doesn’t allow them to be used for the retraction of the anterior teeth or closing of spaces. Therefore, the coherent use of superelastic orthodontic wires is recommended, accompanied by a detailed diagnosis and planning, so the result will be an efficient orthodontic correction, accomplished in a shorter period of time.

Determinação de fumosina B1, por CLAE: estudo da estabilidade do derivado fumonisina B1-orto-ftaldialdeído

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Determinação de fumonisina B1 por CLAE: estudo da estabilidade do derivado fumonisina B1-orto-ftaldialdeído

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Novas alternativas terapêuticas para o tratamento da Criptococose: análogos de Resveratrol e microRNAs

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Spatial competition induces the mobilization of morula cells in the colonial ascidian Didemnum perlucidum (Tunicata: Didemnidae)

The effects of spatial competition among colonial marine organisms are often evident in the contact zones between colonies. These effects are especially pronounced when the interaction results in overgrowth or necrosis of one of the competitors. Ascidians, one of the dominant taxonomic groups in subtidal sessile communities, have specialized morula cells that provide a defense against microbial infections. Injuries resulting from interspecific competitive interactions might also act as a stimulus for this defensive mechanism. Therefore, we expected to see the recruitment of morula cells in tissues near competitor contact zones. To test the hypothesis that spatial competition elicits this immune response, we placed colonies of the ascidian Didemnum perlucidum from southeastern Brazil in four different types of competitive situations: (1) overgrowth of the competitor, (2) stand-off interactions, (3) overgrowth by the competitor, and (4) free of competitors. Our results indicate that competitive interactions increase the population of morula cells in contact zones, as more cells were observed in interactions that resulted in the overgrowth of individuals of D. perlucidum, and fewer cells were observed in colonies that were free of competitors. We identified the defensive function of the morula cells by showing the presence of the enzyme phenoloxidase within its vacuoles. Phenoloxidase is a widespread enzyme among animals and plants, and is frequently used in defense by synthesizing toxic quinones from polyphenol substrates. This is the first study to document the presence of morula cells in didemnid ascidians and the mobilization of these cells by spatial competition by heterospecifics, and one of the first studies to identify phenoloxidase activity in morula cells.

Role of common mental and physical disorders in partial disability around the world

Background Mental and physical disorders are associated with total disability, but their effects on days with partial disability (i.e. the ability to perform some, but not full-role, functioning in daily life) are not well understood. Aims To estimate individual (i.e. the consequences for an individual with a disorder) and societal effects (i.e. the avoidable partial disability in the society due to disorders) of mental and physical disorders on days with partial disability around the world. Method Respondents from 26 nationally representative samples (n=61 259, age 18+) were interviewed regarding mental and physical disorders, and day-to-day functioning. The Composite International Diagnostic Interview, version 3.0 (CIDI 3.0) was used to assess mental disorders; partial disability (expressed in full day equivalents) was assessed with the World Health Organization Disability Assessment Schedule in the CIDI 3.0. Results Respondents with disorders reported about 1.58 additional disability days per month compared with respondents without disorders. At the individual level, mental disorders (especially post-traumatic stress disorder, depression and bipolar disorder) yielded a higher number of days with disability than physical disorders. At the societal level, the population attributable risk proportion due to physical and mental disorders was 49% and 15% respectively. Conclusions Mental and physical disorders have a considerable impact on partial disability, at both the individual and at the societal level. Physical disorders yielded higher effects on partial disability than mental disorders.

Bioconversion of Iodoacetophenones by Marine Fungi

Nine marine fungi (Aspergillus sclerotiorum CBMAI 849, Aspergillus sydowii Ce19, Beauveria felina CBMAI 738, Mucor racemosus CBMAI 847, Penicillium citrinum CBMAI 1186, Penicillium miczynskii Ce16, P. miczynskii Gc5, Penicillium oxalicum CBMAI 1185, and Trichoderma sp. Gc1) catalyzed the asymmetric bioconversion of iodoacetophenones 1-3 to corresponding iodophenylethanols 6-8. All the marine fungi produced exclusively (S)-ortho-iodophenylethanol 6 and (S)-meta-iodophenylethanol 7 in accordance to the Prelog rule. B. felina CBMAI 738, P. miczynskii Gc5, P. oxalicum CBMAI 1185, and Trichoderma sp. Gc1 produced (R)-para-iodophenylethanol 8 as product anti-Prelog. The bioconversion of para-iodoacetophenone 3 with whole cells of P. oxalicum CBMAI 1185 showed competitive reduction-oxidation reactions.

End-to-end Distance Distribution in Fluorescent Derivatives of Bradykinin in Interaction with Lipid Vesicles

Cellular membranes have relevant roles in processes related to proteases like human kallikreins and cathepsins. As enzyme and substrate may interact with cell membranes and associated co-factors, it is important to take into account the behavior of peptide substrates in the lipid environment. In this paper we report an study based on energy transfer in two bradykinin derived peptides labeled with the donor-acceptor pair Abz/Eddnp (ortho-aminobenzoic acid/N-[2,4-dinitrophenyl]-ethylenediamine). Time-resolved fluorescence experiments were performed in phosphate buffer and in the presence of large unilamelar vesicles of phospholipids, and of micelles of sodium dodecyl sulphate (SDS). The decay kinetics were analyzed using the program CONTIN to obtain end-to-end distance distribution functions f(r). Despite of the large difference in the number of residues the end-to-end distance of the longer peptide (9 amino acid residues) is only 20 % larger than the values obtained for the shorter peptide (5 amino acid residues). The proline residue, in position 4 of the bradykinin sequence promotes a turn in the longer peptide chain, shortening its end-to-end distance. The surfactant SDS has a strong disorganizing effect, substantially broadening the distance distributions, while temperature increase has mild effects in the flexibility of the chains, causing small increase in the distribution width. The interaction with phospholipid vesicles stabilizes more compact conformations, decreasing end-to-end distances in the peptides. Anisotropy experiments showed that rotational diffusion was not severely affected by the interaction with the vesicles, suggesting a location for the peptides in the surface region of the bilayer, a result consistent with small effect of lipid phase transition on the peptides conformations.

On the search for potential anti-Trypanosoma cruzi drugs: Synthesis and biological evaluation of 2-hydroxy-3-methylamino and 1,2,3-triazolic naphthoquinoidal compounds obtained by click chemistry reactions

Five 2-hydroxy-3-substituted-aminomethyl naphthoquinones, nine 1,2,3-triazolic para-naphthoquinones, five nor-beta-lapachone-based 1,2,3-triazoles, and several other naphthoquinonoid compounds were synthesized and evaluated against the infective bloodstream form of Trypanosoma cruzi, the etiological agent of Chagas disease, continuing our screening program for new trypanocidal compounds. Among all the substances, 16-18, 23, 25-29 and 30-33 were herein described for the first time and fifteen substances were identified as more potent than the standard drug benznidazole, with IC50/24 h values in the range of 10.9-101.5 mu M. Compounds 14 and 19 with Selectivity Index of 18.9 and 6.1 are important structures for further studies. (C) 2012 Elsevier Masson SAS. All rights reserved.