149 research outputs found

    Quantification of Phenolic Constituents and Antioxidant Activity of Pterodon emarginatus Vogel Seeds

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    In the present study the phenolic (Folin-Dennis) and flavonoid (colorimetric assay) constituents and the antioxidant activity of Pterodon emarginatus seeds were investigated in several samples prepared with different extraction procedures: essential oil (EO) using a Clevenger-type apparatus; hexanic (HF), ethyl acetate (EAF), buthanolic (BF) and methanolic (MF) fractions using Soxhlet extraction, and extracts (1 g/extract) obtained from different methods: reflux 80°C/30 min, ultrasound/30 min, static maceration/48 h and heating plate 100°C/45 min. These extracts were prepared using water or ethanol/water at 30:70 v/v, 50:50 v/v or 70:30 v/v. Antioxidant activity [2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH)] was tested only in the fractions obtained from Soxhlet extraction. The extract obtained from reflux using ethanol/water (70:30, v/v) showed the highest phenolic constituents level. The EAF, BF and MF showed DPPH scavenging activities with IC50=163.22, 18.89 and 10.15 μg/ml, respectively

    Biogeographic history and cryptic diversity of saxicolous Tropiduridae lizards endemic to the semiarid Caatinga

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    Background: Phylogeographic research has advanced in South America, with increasing efforts on taxa from the dry diagonal biomes. However, the diversification of endemic fauna from the semiarid Caatinga biome in northeastern Brazil is still poorly known. Here we targeted saxicolous lizards of the Tropidurus semitaeniatus species group to better understand the evolutionary history of these endemic taxa and the Caatinga. We estimated a time-calibrated phylogeny for the species group based on two mitochondrial and two nuclear genes and jointly estimated the species limits and species tree within the group. We also devoted a denser phylogeographic sampling of the T. semitaeniatus complex to explore migration patterns, and the spatiotemporal diffusion history to verify a possible role of the São Francisco River as a promoter of differentiation in this saxicolous group of lizards. Results: Phylogenetic analysis detected high cryptic genetic diversity, occurrence of unique microendemic lineages associated with older highlands, and a speciation history that took place during the Pliocene-Pleistocene transition. Species delimitation detected five evolutionary entities within the T. semitaeniatus species group, albeit with low support. Thus, additional data are needed for a more accurate definition of species limits and interspecific relationships within this group. Spatiotemporal analyses reconstructed the geographic origin of the T. semitaeniatus species complex to be located north of the present-day course of the São Francisco River, followed by dispersal that expanded its distribution towards the northwest and south. Gene flow estimates showed higher migration rates into the lineages located north of the São Francisco River. Conclusions: The phylogenetic and population structures are intrinsically associated with stable rock surfaces and landscape rearrangements, such as the establishment of drainage basins located to the northern and southern distribution ranges. The T. semitaeniatus complex preserved high genetic diversity during range expansion, possibly as a result of frequent long-distance dispersal events. Our results indicate that both the current course of the São Francisco River and its paleo-courses had an important role in promoting diversification of the Caatinga endemic T. semitaeniatus species group

    Resolving the fine structure in the energy landscapes of repeat proteins

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    Ankyrin (ANK) repeat proteins are coded by tandem occurrences of patterns with around 33 amino acids. They often mediate protein–protein interactions in a diversity of biological systems. These proteins have an elongated non-globular shape and often display complex folding mechanisms. This work investigates the energy landscape of representative proteins of this class made up of 3, 4 and 6 ANK repeats using the energy-landscape visualisation method (ELViM). By combining biased and unbiased coarse-grained molecular dynamics AWSEM simulations that sample conformations along the folding trajectories with the ELViM structure-based phase space, one finds a three-dimensional representation of the globally funnelled energy surface. In this representation, it is possible to delineate distinct folding pathways. We show that ELViMs can project, in a natural way, the intricacies of the highly dimensional energy landscapes encoded by the highly symmetric ankyrin repeat proteins into useful low-dimensional representations. These projections can discriminate between multiplicities of specific parallel folding mechanisms that otherwise can be hidden in oversimplified depictions.M.N.S. was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq; Grant 130147/2020-6). This research was supported by the Center for Theoretical Biological Physics sponsored by the NSF (Grant PHY-2019745). A.B.O. acknowledges the Robert A. Welch Postdoctoral Fellow program. P.G.W. is also supported by the D.R. Bullard-Welch Chair at Rice University (Grant C-0016). V.B.P.L. was supported by CNPq (Grant 310017/2020-3) and FAPESP (Grants 2019/22540-3 and 2018/18668-1). D.U.F. is a CONICET researcher and is supported by Grant PICT2016/1467, UBACYT, and NASA Astrobiology Institute-Enigma (Grant 80NSSC18M0093).Peer ReviewedPostprint (published version

    Eyes with Large Disc Cupping and Normal Intraocular Pressure: Using Optical Coherence Tomography to Discriminate Those With and Without Glaucoma

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    We evaluated the ability of spectral-domain optic coherence tomography (SD-OCT) to differentiate large physiological optic disc cupping (LPC) from glaucomatous cupping in eyes with intraocular pressure (IOP) within the normal range.  We prospectively enrolled patients with glaucoma or presumed LPC. Participants  had optic discs with confirmed or suspected glaucomatous damage (defined as a vertical cup-to-disc ratio≥0.6), and all eyes had known untreated IOP<21 mmHg. For glaucomatous eyes, a reproducible glaucomatous visual field (VF) defect was required. LPC eyes required normal VF and no evidence of progressive glaucomatous neuropathy (follow-up≥30 months). Peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell complex (GCC) thicknesses were obtained using SD-OCT. For all studied parameters of pRNFL and GCC thicknesses, eyes with glaucoma (n=36) had significantly thinner values compared to eyes with LPC (n=71; P<0.05 for all comparisons). In addition, pRNFL parameters had sensitivity of 66.7% and specificity of 83.1%, and GCC parameters had sensitivity of 61.2% and specificity of 81.7%. The combination of the two analyses increased the sensitivity to 80.6%. In conclusion, while evaluating patients with large optic disc cupping and IOP in the statistically normal range, SD-OCT had only limited diagnostic ability to differentiate those with and without glaucoma. Although the diagnostic ability of the pRNFL and the GCC scans were similar, these parameters yielded an increase in sensitivity when combined, suggesting that both parameters could be considered simultaneously in these cases

    The Role of Kinin Receptors in Preventing Neuroinflammation and Its Clinical Severity during Experimental Autoimmune Encephalomyelitis in Mice

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    Background: Multiple sclerosis (MS) is a demyelinating and neuroinflammatory disease of the human central nervous system (CNS). the expression of kinins is increased in MS patients, but the underlying mechanisms by which the kinin receptor regulates MS development have not been elucidated.Methodology/Principal Findings: Experimental autoimmune encephalomyelitis (EAE) was induced in female C57BL/6 mice by immunization with MOG(35-55) peptide emulsified in complete Freund's adjuvant and injected with pertussis toxin on day 0 and day 2. Here, we report that blockade of the B(1)R in the induction phase of EAE markedly suppressed its progression by interfering with the onset of the immune response. Furthermore, B(1)R antagonist suppressed the production/expression of antigen-specific T(H)1 and T(H)17 cytokines and transcription factors, both in the periphery and in the CNS. in the chronic phase of EAE, the blockade of B(1)R consistently impaired the clinical progression of EAE. Conversely, administration of the B(1)R agonist in the acute phase of EAE suppressed disease progression and inhibited the increase in permeability of the blood-brain barrier (BBB) and any further CNS inflammation. of note, blockade of the B(2)R only showed a moderate impact on all of the studied parameters of EAE progression.Conclusions/Significance: Our results strongly suggest that kinin receptors, mainly the B(1)R subtype, play a dual role in EAE progression depending on the phase of treatment through the lymphocytes and glial cell-dependent pathways.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Programa de Apoio aos Nucleos de Excelencia (PRONEX), BrazilFundacaode Apoio a Pesquisa Cientifica Tecnologica do Estado de Santa Catarina (FAPESC), BrazilUniv Fed Santa Catarina, Dept Pharmacol, Ctr Biol Sci, Florianopolis, SC, BrazilUniversidade Federal de São Paulo, Dept Biophys, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biophys, São Paulo, BrazilWeb of Scienc

    Phylogenomics of manakins (Aves: Pipridae) using alternative locus filtering strategies based on informativeness

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    Target capture sequencing effectively generates molecular marker arrays useful for molecular systematics. These extensive data sets are advantageous where previous studies using a few loci have failed to resolve relationships confidently. Moreover, target capture is well-suited to fragmented source DNA, allowing data collection from species that lack fresh tissues. Herein we use target capture to generate data for a phylogeny of the avian family Pipridae (manakins), a group that has been the subject of many behavioral and ecological studies. Most manakin species feature lek mating systems, where males exhibit complex behavioral displays including mechanical and vocal sounds, coordinated movements of multiple males, and high speed movements. We analyzed thousands of ultraconserved element (UCE) loci along with a smaller number of coding exons and their flanking regions from all but one species of Pipridae. We examined three different methods of phylogenetic estimation (concatenation and two multispecies coalescent methods). Phylogenetic inferences using UCE data yielded strongly supported estimates of phylogeny regardless of analytical method. Exon probes had limited capability to capture sequence data and resulted in phylogeny estimates with reduced support and modest topological differences relative to the UCE trees, although these conflicts had limited support. Two genera were paraphyletic among all analyses and data sets, with Antilophia nested within Chiroxiphia and Tyranneutes nested within Neopelma. The Chiroxiphia-Antilophia Glade was an exception to the generally high support we observed; the topology of this Glade differed among analyses, even those based on UCE data. To further explore relationships within this group, we employed two filtering strategies to remove low-information loci. Those analyses resulted in distinct topologies, suggesting that the relationships we identified within Chiroxiphia-Antilophia should be interpreted with caution. Despite the existence of a few continuing uncertainties, our analyses resulted in a robust phylogenetic hypothesis of the family Pipridae that provides a comparative framework for future ecomorphological and behavioral studies.Peer reviewe

    Acetylation of Eugenol on Functionalized Mesoporous Aluminosilicates Synthesized from Amazonian Flint Kaolin

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    The present work was aimed to investigate the catalytic activity of a mesoporous catalyst synthesized from 3-mercaptopropyltrimethoxysilane (MPTS) functionalized Amazonian flint kaolin in the acetylation of eugenol with acetic anhydride. Materials were characterized by thermogravimetry (TGA), N2 adsorption (BET), X-ray dispersive energy spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and acid-base titration. The results presented proved the efficiency of flint kaolin as an alternative source in the preparation of mesoporous materials, since the material exhibited textural properties (specific surface area of 1071 m2 g−1, pore volume of 1.05 cm3 g−1 and pore diameter of 3.85 nm) and structural properties (d100 = 4.35 nm, a0 = 5.06 nm and Wt = 1.21 nm) within the required and characteristic material standards. The catalyst with the total amount of acidic sites of 4.89 mmol H+ g−1 was efficient in converting 99.9% of eugenol (eugenol to acetic anhydride molar ratio of 1:5, 2% catalyst, temperature and reaction time 80 °C and 40 min reaction). In addition, the reused catalyst could be successfully recycled with 92% conversion activity under identical reaction conditions

    Acetylation of Eugenol over 12-Molybdophosphoric Acid Anchored in Mesoporous Silicate Support Synthesized from Flint Kaolin

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    A new prepared catalyst, 12-molybdophosphoric acid (HPMo) anchored to the mesoporous aluminosilicate AlSiM, synthesized from Amazon kaolin, was characterized and used as a heterogeneous acid catalyst for the production of eugenyl acetate by acetylation of eugenol with acetic anhydride. The effect of various reaction parameters, such as catalyst concentration, eugenol/acetic anhydride molar ratio, temperature and reaction time, was studied to optimize the conditions of maximum conversion of eugenol. The kinetics studies showed that in eugenol acetylation, the substrate concentration follows a first order kinetics. The results of activation energy was 19.96 kJ mol−1 for HPMo anchored to AlSiM. The reuse of the catalyst was also studied and there was no loss of catalytic activity after four cycles of use (from 99.9% in the first cycle to 90% in the fifth cycle was confirmed), and an excellent stability of the material was observed. Based on catalytic and kinetic studies, HPMo anchored to AlSiM is considered an excellent catalyst

    Preservação de amostras e extração de DNA de Spodoptera frugiperda.

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    Neste trabalho empregou-se a metodologia de extração de DNA descrita por Rogers e Bendich (1988), com modificações. Dentre estas se inclui aumento na concentração de ?-mercaptoetanol, além do acréscimo de PVP e BSA no tampão de extração das amostras.bitstream/item/89936/1/bol-68.pd

    Nc886 is epigenetically repressed in prostate cancer and acts as a tumor suppressor through the inhibition of cell growth

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    Background: Nc886 is a 102 bp non-coding RNA transcript initially classified as a microRNA precursor (Pre-miR-886), later as a divergent homologue of the vault RNAs (vtRNA 2-1) and more recently as a novel type of RNA (nc886). Although nc886/vtRNA2-1/Pre-miR-886 identity is still controversial, it was shown to be epigenetically controlled, presenting both tumor suppressor and oncogenic function in different cancers. Here, we study for the first time the role of nc886 in prostate cancer. Methods: Nc886 promoter methylation status and its correlation with patient clinical parameters or DNMTs levels were evaluated in TCGA and specific GEO prostate tissue datasets. Nc886 level was measured by RT-qPCR to compare normal/neoplastic prostate cells from radical prostatectomies and cell lines, and to assess nc886 response to demethylating agents. The effect of nc886 recovery in cell proliferation (in vitro and in vivo) and invasion (in vitro) was evaluated using lentiviral transduced DU145 and LNCaP cell lines. The association between the expression of nc886 and selected genes was analyzed in the TCGA-PRAD cohort. Results: Nc886 promoter methylation increases in tumor vs. normal prostate tissue, as well as in metastatic vs. normal prostate tissue. Additionally, nc886 promoter methylation correlates with prostate cancer clinical staging, including biochemical recurrence, Clinical T-value and Gleason score. Nc886 transcript is downregulated in tumor vs. normal tissue -in agreement with its promoter methylation status- and increases upon demethylating treatment. In functional studies, the overexpression of nc886 in the LNCaP and DU145 cell line leads to a decreased in vitro cell proliferation and invasion, as well as a reduced in vivo cell growth in NUDE-mice tumor xenografts. Finally, nc886 expression associates with the prostate cancer cell cycle progression gene signature in TCGA-PRAD. Conclusions: Our data suggest a tumor suppressor role for nc886 in the prostate, whose expression is epigenetically silenced in cancer leading to an increase in cell proliferation and invasion. Nc886 might hold clinical value in prostate cancer due to its association with clinical parameters and with a clinically validated gene signature
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