Synthesis of a brassinosteroid analogue from vespertiline

In the last years, several research groups have been working on the synthesis of new steroidal plant hormones called brassinosteroids (BS), which promote plant growth and better crops. Many synthetic targets and applications of these compounds and their analogues have been described in the literature. From Solanum species of the Distrito Federal, we isolated the steroidal alkaloid solasodine, which was then converted into our starting material, vespertiline. By functionalization of rings A and B, we have synthesized a new analogue of BS, with a 2alpha,3alpha-dihydroxy-6-one structure, typical of the naturally occurring BS castasterone, the immediate biosynthetic precursor of brassinolide

Chitosan/mangiferin particles for Cr(VI) reduction and removal

AbstractIn this work, chitosan/mangiferin particles (CMP) were prepared by spray-drying technique and characterized by SEM, DLS, FTIR, HPLC–UV and adsorption studies to investigate a possible application as a preventive material in cases of human and animal contamination with Cr(VI). CMP presented sizes ranging from nano to micrometers. Chitosan and mangiferin (MA) presence in the powder was confirmed by FTIR and MA quantification (136μg/mg) was performed using a calibration curve prepared by HPLC–UV. Adsorption capacity of Cr(VI) onto CMP was compared with chitosan and investigated in a batch system by considering the effects of various parameters like contact time, initial concentration of adsorbent and pH. Cr(VI) removal is pH dependent and it was found to be maximum at pH 5.0. The results showed that CMP has a potential application as a preventive material in cases of human or animal contamination with Cr(VI)

Bacteriologic investigation of the effects of sodium hypochlorite and chlorhexidine during the endodontic treatment of teeth with apical periodontitis

SIQUEIRA JR. et al. Bacteriologic investigation of the effects of sodium hypochlorite and chlorhexidine during the endodontic treatment of teeth with apical periodontitis. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod., v. 104, n. 1, p. 122-130, 2007.Objective. This clinical study was undertaken to compare the effectiveness of 2.5% sodium hypochlorite (NaOCl) and 0.12% chlorhexidine digluconate as irrigants in reducing the cultivable bacterial populations in infected root canals of teeth with apical periodontitis. Study design. According to stringent inclusion/exclusion criteria, 32 teeth with primary intraradicular infections and chronic apical periodontitis were selected and followed in the study. Bacterial samples were taken at the baseline (S1) and after chemomechanical preparation using either NaOCl (n 16) or chlorhexidine (n 16) as irrigants (S2). Cultivable bacteria recovered from infected root canals at the 2 stages were counted. Isolates from S2 samples were identified by means of 16S rRNA gene sequencing analysis. Results. At S1, all canals were positive for bacteria, and the median number of bacteria per canal was 7.32 105 for the NaOCl group and 8.5 105 for the chlorhexidine group. At S2, the median number of bacteria in canals irrigated with NaOCl and chlorhexidine was 2.35 103 and 2 102, respectively. Six of 16 (37.5%) canals from the NaOCl group and 8 of 16 (50%) canals from the chlorhexidine group yielded negative cultures. Chemomechanical preparation using either solution substantially reduced the number of cultivable bacteria in the canals. No significant difference was observed between the NaOCl and chlorhexidine groups with regard to the number of cases yielding negative cultures (P .72) or quantitative bacterial reduction (P .609). The groups irrigated with NaOCl or chlorhexidine showed a mean number of 1.3 and 1.9 cultivable species per canal, respectively. The great majority of isolates in S2 were from gram-positive bacteria, with streptococci as the most prevalent taxa. Conclusions. The present findings revealed no significant difference when comparing the antibacterial effects of 2.5% NaOCl and 0.12% chlorhexidine used as irrigants during the treatment of infected canal

A "masculinização" da produção de leite.

O fortalecimento de organizações sociais que possibilitaram fazer da produção de leite uma atividade destinada ao mercado provocou profundas mudanças na divisão sexual do trabalho. A análise sociológica das trocas intradomiciliares nos estabelecimentos rurais familiares mostra que tradições culturais, diferenças de poder entre os gêneros e contextos sociais que ampliam diferenças de acesso aos mercados entre homens e mulheres são as bases sociais e culturais de uma hierarquia estruturada segundo sexo e geração, no qual as mulheres, especialmente as mais jovens, ocupam posições de grande desvantagem. Com o fortalecimento de cooperativas, a produção de leite passou a ocupar um lugar de destaque no provimento de recursos da família, mas o domínio da atividade foi deslocado para o controle masculino. Esse foi um dos resultados não esperados da forma como as organizações conduziram o processo de modernização da produção e de reestruturação dos mercados, que reforçaram ainda mais o domínio masculino sobre a produção familiar e um aumento das desigualdades de gênero no acesso aos recursos

Intragenic antimicrobial peptides (IAPs) from human proteins with potent antimicrobial and anti-inflammatory activity

Following the treads of our previous works on the unveiling of bioactive peptides encrypted in plant proteins from diverse species, the present manuscript reports the occurrence of four proof-of-concept intragenic antimicrobial peptides in human proteins, named Hs IAPs. These IAPs were prospected using the software Kamal, synthesized by solid phase chemistry, and had their interactions with model phospholipid vesicles investigated by differential scanning calorimetry and circular dichroism. Their antimicrobial activity against bacteria, yeasts and filamentous fungi was determined, along with their cytotoxicity towards erythrocytes. Our data demonstrates that Hs IAPs are capable to bind model membranes while attaining α-helical structure, and to inhibit the growth of microorganisms at concentrations as low as 1μM. Hs02, a novel sixteen residue long internal peptide (KWAVRIIRKFIKGFISNH2) derived from the unconventional myosin 1h protein, was further investigated in its capacity to inhibit lipopolysaccharide-induced release of TNF-α in murine macrophages. Hs02 presented potent anti-inflammatory activity, inhibiting the release of TNF-α in LPSprimed cells at the lowest assayed concentration, 0.1 μM. A three-dimensional solution structure of Hs02 bound to DPC micelles was determined by Nuclear Magnetic Resonance. Our work exemplifies how the human genome can be mined for molecules with biotechnological potential in human health and demonstrates that IAPs are actual alternatives to antimicrobial peptides as pharmaceutical agents or in their many other putative applications

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Host-defense peptides AC12, DK16 and RC11 with immunomodulatory activity isolated from Hypsiboas raniceps skin secretion

Inflammation is a natural defense mechanism of the immune system; however, when unregulated, it can lead to chronic illness. Glucocorticoids are the most commonly used agents to effectively treat inflammatory conditions, including autoimmune diseases, however these substances can trigger a number of side effects. Thus, viable alternatives to the use of these drugs would be advantageous. In this study, we have analyzed the anti-inflammatory profile of three synthetic peptides first identified in skin secretion of the tree frog Hypsiboas raniceps. Structural characterization was performed using NMR spectroscopy and Mass Spectrometry, and the peptides were tested in vitro in RAW 264.7 cells and in vivo in Balb/c mice for their functional properties. The samples did not show a significant antimicrobial profile. NMR spectroscopy indicated that AC12 (ACFLTRLGTYVC) has a disulfide bond between C2 and C11 and a β-sheet-turn-β-sheet conformation in aqueous solution. This peptide showed no cytotoxic effect in mammalian cells and it was the most effective in reducing anti-inflammatory markers, such as NO, TNF-α and IL-12. Peptide DK16 (DKERPICSNTFRGRKC) demonstrated anti-inflammatory properties in vitro, while RC11 (RCFRRRGKLTC) significantly altered the cell viability in RAW 264.7 but was shown to be safe in Balb/c erythrocytes. Our results indicate that, of the three peptides studied, AC12 is the most efficient in reducing anti-inflammatory markers, and it could be a potential agent for the treatment of inflammatory diseases.publishe

CONTROLE DE ORIENTAÇÃO E VELOCIDADE DE CADEIRA DE RODAS POR VISÃO COMPUTACIONAL

This work proposes a computer vision system for wheelchair control based on facial coordinates and head position estimation. This work comprises the design of a low-cost motorized wheelchair, which aims to promote independence and quality of life for people who have motor difficulties to manipulate a joystick. The tests performed on the built prototype resulted in an accuracy of 87.78%, an precision of 90.00% and a sensitivity of 87.70%. Tests performed in the motorized wheelchair resulted in an average accuracy of 94.69%, average precision of 91.04% and average sensitivity of 89.38%.Este trabalho propõe um sistema de visão computacional para controle de cadeira de rodas com base em coordenadas faciais e estimativa da posição da cabeça. Este trabalho compõe o projeto de uma cadeira de rodas motorizada de baixo custo, que tem como objetivo promover independência e qualidade de vida a pessoas que possuem dificuldades motoras para manipular um joystick. Os testes realizados no protótipo construído resultaram em uma acurácia de 87,78%, a precisão de 90,00% e uma sensibilidade de 87,70%. Os testes realizados na cadeira de rodas motorizada resultaram em uma acurácia média de 94,69%, precisão média de 91,04% e sensibilidade média de 89,38%

Enhancing Network Slicing Architectures with Machine Learning, Security, Sustainability and Experimental Networks Integration

Network Slicing (NS) is an essential technique extensively used in 5G networks computing strategies, mobile edge computing, mobile cloud computing, and verticals like the Internet of Vehicles and industrial IoT, among others. NS is foreseen as one of the leading enablers for 6G futuristic and highly demanding applications since it allows the optimization and customization of scarce and disputed resources among dynamic, demanding clients with highly distinct application requirements. Various standardization organizations, like 3GPP's proposal for new generation networks and state-of-the-art 5G/6G research projects, are proposing new NS architectures. However, new NS architectures have to deal with an extensive range of requirements that inherently result in having NS architecture proposals typically fulfilling the needs of specific sets of domains with commonalities. The Slicing Future Internet Infrastructures (SFI2) architecture proposal explores the gap resulting from the diversity of NS architectures target domains by proposing a new NS reference architecture with a defined focus on integrating experimental networks and enhancing the NS architecture with Machine Learning (ML) native optimizations, energy-efficient slicing, and slicing-tailored security functionalities. The SFI2 architectural main contribution includes the utilization of the slice-as-a-service paradigm for end-to-end orchestration of resources across multi-domains and multi-technology experimental networks. In addition, the SFI2 reference architecture instantiations will enhance the multi-domain and multi-technology integrated experimental network deployment with native ML optimization, energy-efficient aware slicing, and slicing-tailored security functionalities for the practical domain.Comment: 10 pages, 11 figure