Simplificações para Redução do Custo Computacional da Pré-ênfase de Voz na Plataforma Arduino

Atualmente, existe um crescente interesse por aplicações em que a interação homem-máquina seja realizada via a voz humana. No entanto, alguns equipamentos, como telefones celulares e eletrodomésticos, possuem limitações de armazenamento e processamento, dificultando a implementação deste tipo de sistema. Neste trabalho, foram utilizadas simplificações em uma das etapas do processo de reconhecimento da fala, as quais foram comparadas e analisadas em relação à implementação tradicional. Diante das mesmas, foi obtida uma redução de até 1/5 do tempo de execução e número de ciclos de clock

Amphipathic design dictates self-assembly, cytotoxicity and cell uptake of arginine-rich surfactant-like peptides

Amphiphilicity is the most critical parameter in the self-assembly of surfactant-like peptides (SLPs), regulating the way by which hydrophobic attraction holds peptides together. Its effects go beyond supramolecular assembly and may also trigger different cell responses of bioactive peptide-based nanostructures. Herein, we investigate the self-assembly and cellular effects of nanostructures based on isomeric SLPs composed by arginine (R) and phenylalanine (F). Two amphipathic designs were studied: a diblock construct F4R4 and its bolaamphiphile analog R2F4R2. A strong sequence-dependent polymorphism emerges with appearance of globules and vesicle-like assemblies, or flat nanotapes and cylindrical micelles. The diblock construct possesses good cell penetrating capabilities and effectiveness to kill SK-MEL-28 melanoma tumor cells, in contrast to reduced intracellular uptake and low cytotoxicity exhibited by the bolaamphiphilic form. Our findings demonstrate that amphipathic design is a relevant variable for self-assembling SLPs to modulate different cellular responses and may assist in optimizing the production of nanostructures based on arginine-enriched sequences in cell penetrating and antimicrobial peptides

In vitro and in vivo anti-malarial activity of limonoids isolated from the residual seed biomass from Carapa guianensis (andiroba) oil production

Background: Carapa guianensis is a cultivable tree used by traditional health practitioners in the Amazon region to treat several diseases and particularly symptoms related to malaria. Abundant residual pressed seed material (RPSM) results as a by-product of carapa or andiroba oil production. The objective of this study was to evaluate the in vitro and in vivo anti-malarial activity and cytotoxicity of limonoids isolated from C. guaianensis RPSM.Methods. 6-acetoxyepoxyazadiradione (1), andirobin (2), 6-acetoxygedunin (3) and 7-deacetoxy-7-oxogedunin (4) (all isolated from RPSM using extraction and chromatography techniques) and 6-hydroxy-deacetylgedunin (5) (prepared from 3) were evaluated using the micro test on the multi-drug-resistant Plasmodium falciparum K1 strain. The efficacy of limonoids 3 and 4 was then evaluated orally and subcutaneously in BALB/c mice infected with chloroquine-sensitive Plasmodium berghei NK65 strain in the 4-day suppressive test.Results: In vitro, limonoids 1-5 exhibited median inhibition concentrations (IC50) of 20.7-5.0 μM, respectively. In general, these limonoids were not toxic to normal cells (MRC-5 human fibroblasts). In vivo, 3 was more active than 4. At oral doses of 50 and 100 mg/kg/day, 3 suppressed parasitaemia versus untreated controls by 40 and 66%, respectively, evidencing a clear dose-response.Conclusion: 6-acetoxygedunin is an abundant natural product present in C. guianensis residual seed materials that exhibits significant in vivo anti-malarial properties. © 2014 Pereira et al.; licensee BioMed Central Ltd.x

Self-assembly and intracellular delivery of DNA by a truncated fragment derived from the Trojan peptide Penetratin

Penetratin is a short Trojan peptide that attracts great interest in biomedical research for its capacity to translocate biological membranes. Herein, we study in detail both self-assembly and intracellular delivery of DNA by the heptamer KIWFQNR, a truncated peptide derived from Penetratin. This shortened sequence possesses a unique design with bolaamphiphilic characteristics that preserves the longest noncationic amino acid portion found in Penetratin. These features convey amphipathicity to assist self-assembly and make it a suitable model for exploring the role of hydrophobic residues for peptide interaction and cell uptake. We show that the fragment forms peptiplexes (i.e., peptide–DNA complexes), and aggregates into long nanofibers with clear β-sheet signature. The supramolecular structure of nanofibers is likely composed of DNA cores surrounded by a peptide shell to which the double helix behaves as a template and induces fibrillization. A nucleation and growth mechanism proceeding through liquid–liquid phase separation of coacervates is proposed for describing the self-assembly of peptiplexes. We also demonstrate that peptiplexes deliver double-stranded 200 bp DNA into HeLa cells, indicating its potential for preparing non-viral vectors for oligonucleotides through noncovalent strategies. Since the main structural features of native Penetratin are conserved in this simpler fragment, our findings also highlight the role of uncharged amino acids for structuration, and thus for the ability of Penetratin to cross cell membranes

Evaluation of Antioxidant Capacity of Solanum sessiliflorum

Cubiu is a vegetable of Solanaceae family, native to the Amazon, which is widely distributed through Brazil, Peru, and Colombia. It is used in food, medicine, and cosmetics by native populations. Research has shown that cubiu extracts have antioxidant activities with great biological relevance. We performed a phytochemical screening to identify the main chemical groups that could confer antioxidant activity to this extract. Several tests and qualitative precipitation specific staining for major classes of secondary metabolites were used. Antioxidant capacity in vitro tests (DPPH and ABTS) were also used to assess the extract’s ability to sequester free radicals of 70% hydroethanolic and aqueous extracts of cubiu flour. Alkaloids, organic acids, phenols, flavonoid glycosides, and coumarins were found in the hydroethanolic extract while the aqueous extract presented anthocyanins, gums, tannins and mucilage, amino groups, and volatile and fixed acids. For in vitro tests, the IC50 value obtained in the DPPH assay was 606.3 ± 3.5 μg/mL while that for the ABTS assay was 290.3 ± 10.7 µg/mL. Although cubiu extracts present chemical compounds directly related to antioxidant activity, our results show that it has a low antioxidant activity. Additional studies will be needed to isolate and characterize specific compounds to further assess antioxidant activity

Modulation of the chelatable Zn pool in the brain by diethyldithiocarbamate is associated with behavioral impairment in adult zebrafish

The study of the effects of diethyldithiocarbamate (DEDTC) in some diseases is in focus for many years. However, DEDTC is a metal chelator that can present neurotoxicity as side effects. Here we investigate the effect of DEDTC on brain Zinc (Zn) content and behavior. To address this issue we used adult zebrafish exposed to different concentrations of DEDTC. The animal’s behavioral parameters were evaluated during the exposure of DEDTC (0.2, 1, 5 mM in home tank water) for 1h. At the end of exposure period, the brain levels of DEDTC were measured. The analysis of reactive Zn content in different regions of the brain and in glutamatergic neurons and radial glial cells were performed using histochemical and immunocytochemical techniques, respectively. We also measured the activity of a Zn-dependent enzyme, δ-aminolevulinate dehydratase (δ-ALA-D). We found that DEDTC exposure at 1 and 5 mM induced seizure-like behavior in the zebrafish and death at 5 mM. DEDTC in the zebrafish brain was detected with exposure of 1 and 5 mM (above 100 mg.kg⁻¹ tissue). The reactive Zn was reduced in glutamatergic neurons after 1 and 5 mM DEDTC exposure in radial glial cells after 0.2 and 5 mM. No changes in brain δ-ALA-D activity were detected. Our results showed that DEDTC exposure can accumulate in the brain, leading to impairments in neural behavior and in the homeostasis of reactive Zn in the brain.Keywords: reactive Zn, diethyldithiocarbamate, δ-aminolevulinate-dehydratase, brain, zebrafish, [delta-aminolevulinate-dehydratase]Keywords: reactive Zn, diethyldithiocarbamate, δ-aminolevulinate-dehydratase, brain, zebrafish, [delta-aminolevulinate-dehydratase

Allelic diversity of S‑RNase alleles in diploid potato species

S-ribonucleases (S-RNases) control the pistil specificity of the self-incompatibility (SI) response in the genus Solanum and several other members of the Solanaceae. The nucleotide sequences of S-RNases corresponding to a large number of S-alleles or S-haplotypes have been characterised. However, surprisingly few S-RNase sequences are available for potato species. The identification of new S-alleles in diploid potato species is desirable as these stocks are important sources of traits such as biotic and abiotic resistance. S-RNase sequences are reported here from three distinct diploid types of potato: cultivated Solanum tuberosum Group Phureja, S. tuberosum Group Stenotomum, and the wild species Solanum okadae. Partial S-RNase sequences were obtained from pistil RNA by RT-PCR or 3’RACE (Rapid Amplification of cDNA Ends) using a degenerate primer. Full length sequences were obtained for two alleles by 5’RACE. Database searches with these sequences, identified sixteen S-RNases in total, all of which are novel. The sequence analysis revealed all the expected features of functional S-RNases. Phylogenetic analysis with selected published S-RNase and S-like-RNase sequences from the Solanaceae revealed extensive trans-generic evolution of the S-RNases and a clear distinction from S-like-RNases. Pollination tests were used to confirm the self-incompatibility status and cross-compatibility relationships of the S. okadae accessions. All the S. okadae accessions were found to be self-incompatible as expected with crosses amongst them exhibiting both cross-compatibility and semi-compatibility consistent with the S-genotypes determined from the S-RNase sequence data. The progeny analysis of four semi-compatible crosses examined by allele-specific PCR provided further confirmation that these are functional S-RNases