288 research outputs found
A biorefinery approach to the biomass of the seaweed Undaria pinnatifida (Harvey Suringar, 1873): obtaining phlorotannins-enriched extracts for wound healing
Brown seaweeds are recognized sources of compounds with a wide range of properties and applications. Within these compounds, phlorotannins are known to possess several bioactivities (e.g., antioxidant, anti-inflammatory, and antimicrobial) with potential to improve wound healing. To obtain phlorotannins enriched extracts from Undaria pinnatifida, a biorefinery was set using lowcost industry-friendly methodologies, such as sequential solid–liquid extraction and liquid–liquid extraction. The obtained extracts were screened for their antioxidant and antimicrobial activity against five common wound pathogens and for their anti-inflammatory potential. The ethanolic wash fraction (wE100) had the highest antioxidant activity (114.61 +- 10.04 mmol mg-1 extract by Diphenyl-1-picrylhydrazyl (DPPH) and 6.56 +-1.13mMeq. Fe II mg-1 extract by and Ferric Reducing Antioxidant Power (FRAP)), acting efficiently against Gram-negative (Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria, and showing a nitric oxide production inhibition over 47% when used at 0.01 ug mL-1. NMR and FTIR chemical characterization suggested that phlorotannins are present. Obtained fraction wE100 proved to be a promising candidate for further inclusion as wound healing agents, while the remaining fractions analyzed are potential sources for other biotechnological applications, giving emphasis to a biorefinery and circular economy framework to add value to this seaweed and the industry.info:eu-repo/semantics/publishedVersio
Jitter, Shimmer and HNR classification within gender, tones and vowels in healthy voices
A statistical analysis of the Jitter, Shimmer and Harmonic to Noise Ratio parameters was applied to classify and compare genders, vowels and tones of healthy voices. Different type of speech records has used for the comparison, namely records with sustained vowels /a/, /i/ and /u/ at High, Low and Neutral tones. A gender comparison has made denoting differences only in Jitter parameter. The parameters determined in recorded vowels /a/, /i/ and /u/ has also compared and the Kruskal Wallis statistical test showed differences for parameters rap, Shim, ShdB, apq3, apq5 and HNR. High, Low and Neutral tones has compared using the same statistical test denoting statistical differences for all Jitter, Shimmer and HNR parameters. A statistical classification of the mean and standard values for these parameters on healthy voices is also presented.info:eu-repo/semantics/publishedVersio
A two-lane mechanism for selective biological ammonium transport
The transport of charged molecules across biological membranes faces the dual problem of accommodating charges in a highly hydrophobic environment while maintaining selective substrate translocation. This has been the subject of a particular controversy for the exchange of ammonium across cellular membranes, an essential process in all domains of life. Ammonium transport is mediated by the ubiquitous Amt/Mep/Rh transporters that includes the human Rhesus factors. Here, using a combination of electrophysiology, yeast functional complementation and extended molecular dynamics simulations, we reveal a unique two-lane pathway for electrogenic NH4+ transport in two archetypal members of the family, the transporters AmtB from Escherichia coli and Rh50 from Nitrosomonas europaea. The pathway underpins a mechanism by which charged H+ and neutral NH3 are carried separately across the membrane after NH4+ deprotonation. This mechanism defines a new principle of achieving transport selectivity against competing ions in a biological transport process
Structural and Luminescence Properties of Silica-Based Hybrids Containing New Silylated-Diketonato Europium(III) Complex
A new betadiketonate ligand displaying a trimethoxysilyl group as grafting function and a diketone moiety as complexing site (TTA-Si = 4,4,4-trifluoro-2-(3-trimethoxysilyl)propyl)-1-3-butanedione (C4H3S)COCH[(CH2)3Si(OCH3)3]COCF3) and its highly luminescent europium(III) complex [Eu(TTA-Si)3] have been synthesized and fully characterized. Luminescent silica-based hybrids have been prepared as well with this new complex grafted on the surface of dense silica nanoparticles (28 (+/-3 nm) or on mesoporous
silica particles. The covalent bonding of Eu(TTA-Si)3 inside the core of uniform silica
nanoparticles (40 (+/- 5 nm) was also achieved. Luminescence properties are discussed in relation to the europium chemical environment involved in each of the three hybrids. The general methodology proposed allowed high grafting ratios and overcame chelate release and tendency to agglomeration, and it could be applied to any silica matrix (in the core or at the surface, nanosized or not, dense or mesoporous) and therefore numerous applications such as luminescent markers and luminophors could be foreseen
Invasive fungal diseases in haematopoietic cell transplant recipients and in patients with acute myeloid leukaemia or myelodysplasia in Brazil
Invasive fungal disease (IFD) shows distinct regional incidence patterns and epidemiological features depending on the geographic region. We conducted a prospective survey in eight centres in Brazil from May 2007 to July 2009. All haematopoietic cell transplant (HCT) recipients and patients with acute myeloid leukaemia (AML) or myelodysplasia (MDS) were followed from admission until 1year (HCT) or end of consolidation therapy (AML/MDS). the 12-month cumulative incidence (CI) of proven or probable IFD was calculated, and curves were compared using the Grey test. Among 237 AML/MDS patients and 700 HCT recipients (378 allogeneic, 322 autologous), the 1-year CI of IFD in AML/MDS, allogeneic HCT and autologous HCT was 18.7%, 11.3% and 1.9% (p<0.001), respectively. Fusariosis (23 episodes), aspergillosis (20 episodes) and candidiasis (11 episodes) were the most frequent IFD. the 1-year CI of aspergillosis and fusariosis in AML/MDS, allogeneic HCT and autologous HCT were 13.4%, 2.3% and 0% (p<0.001), and 5.2%, 3.8% and 0.6% (p0.01), respectively. the 6-week probability of survival was 53%, and was lower in cases of fusariosis (41%). We observed a high burden of IFD and a high incidence and mortality for fusariosis in this first multicentre epidemiological study of IFD in haematological patients in Brazil.Pfizer Inc.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed Rio de Janeiro, Univ Hosp, BR-21941913 Rio de Janeiro, BrazilUniv Fed Minas Gerais, Univ Hosp, Belo Horizonte, MG, BrazilUniv Fed Rio Grande do Sul, Univ Hosp, Porto Alegre, RS, BrazilFed Univ Parana UFPR, Univ Hosp, Curitiba, Parana, BrazilUniv São Paulo, Univ Hosp, Ribeirao Preto, BrazilFed Univ São Paulo UNIFESP, Univ Hosp, São Paulo, BrazilUniv Campinas UNICAMP, Haematol & Haemotherapy Ctr, Campinas, SP, BrazilFed Univ São Paulo UNIFESP, Inst Paediat Oncol, São Paulo, BrazilFed Univ São Paulo UNIFESP, Univ Hosp, São Paulo, BrazilFed Univ São Paulo UNIFESP, Inst Paediat Oncol, São Paulo, BrazilCNPq: 472154/2008-7CNPq: 301025/2008-8Web of Scienc
Unveiling the anticancer potential of the ethanolic extract from Trichoderma asperelloides
The discovery of new therapeutic alternatives for cancer treatment is essential for improving efficacy and specificity, overcoming resistance, and enabling a more personalized approach for each patient. We investigated the antitumor activity of the crude ethanolic extract of the fungus Trichoderma asperelloides (ExtTa) and its interaction with chemotherapeutic drugs. It was observed, by MTT cytotoxicity assay, that ExtTa significantly reduced cell viability in breast adenocarcinoma, glioblastoma, lung carcinoma, melanoma, colorectal carcinoma, and sarcomas cell lines. The highest efficacy and selectivity of ExtTa were found against glioblastoma T98G and colorectal HCT116 cell lines. ExtTa is approximately four times more cytotoxic to those tumor cells than to non-cancer cell lines. A synergistic effect between ExtTa and doxorubicin was found in the treatment of osteosarcoma Saos-2 cells, as well as with 5-fluorouracil in the treatment of HCT116 colorectal carcinoma cells using CompuSyn software. Our data unravel the presence of bioactive compounds with cytotoxic effects against cancer cells present in T. asperelloides ethanolic crude extract, with the potential for developing novel anticancer agents
The diet of the black widow spider Latrodectus mirabilis (Theridiidae) in two cereal crops of central Argentina
The spider Latrodectus mirabilis (Holmberg, 1876) is commonly found in cereals crops of central Argentina. We studied its diet composition at the field and capture rate on leaf-cutting ants based on laboratory experiments. This study comprises the first approach that documents the diet of L. mirabilis in wheat and oat fields of central Argentina. We identified 1,004 prey items collected from its webs during the last phenological stages of both cereal crops. The prey composition was variable but the spiders prey mainly on ants (Formicidae, Hymenoptera), who represented more than 86% of the total. Meanwhile, in the capture rate experiences we registered a high proportion of ants captured by spiders at the beginning of experiences, capturing the half of the ants from total in the first four hours. Summarizing, we reported a polyphagous diet of this spider species in wheat and oat fields. Ants were the most important prey item of this spider, as found in other Latrodectus spiders around the world
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