287 research outputs found

    Surface-Modified Bacterial Cellulose with Mercaptosilane as a Multifunctional Platform

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    Cellulose synthesized by bacteria has unique properties such as high water retention capacity, biocompatibility, biodegradability and flexibility. Nevertheless, modification of this biomaterial is required in order to obtain multifunctional materials, which may be applied in several high-value added products, as catalytic and cell culture platforms. The surface of bacterial cellulose (BC) can be modified by several approaches, namely: (i) physical treatment by plasma, (ii) adsorption of molecules onto BC surface, and (iii) chemical modification. In this sense, the aim of this study was to modify the BC surface by silanization reaction at room temperature using a mixture of ethanol and water, using two different protocols. Thus, BC membranes synthesized by Komagataeibacter xylinus were modified by adding the thiol (SH) functional group with (3-mercaptopropyl)trimethoxysilane under mild conditions. The produced materials were analyzed by elemental analysis, ATR-FTIR, TGA and SEM, and the successful modification was proven by elemental analysis and SEM.

    Simple method for fast deprotection of nucleosides by triethylamine-catalyzed methanolysis of acetates in aqueous medium

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    A straightforward methodology for deacetylation of protected ribonucleosides was developed based on triethylamine-catalyzed solvolysis in aqueous methanol. Reactions are completed in a few minutes under microwave irradiation and the free nucleosides are obtained in high yield after simple evaporation of volatiles. Other important features include the involvement of readily available reagents and the compatibility with diverse functional groups, which make this process very attractive for broad application

    New and rare records of teleost fishes from the Cape Verde Islands (eastern-central Atlantic Ocean)

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    As a result of six exploratory surveys and several opportunistic catches in the Cape Verde Islands from a few metres to about 1000 m of depth, a list of 66 species of teleost fishes is given, six of which are first records from the archipelago: Gnathophis mystax (Congridae), Nezumia africana, Nezumia duodecim (Macrouridae), Ectreposebastes imus (Scorpaenidae), Paraliparis sp. (Liparidae) and Lappanella fasciata (Labridae). Additionally, data on six poorly-known species is also given: Myroconger compressus (Myrocongridae), Myrichthys pardalis, Phaenomonas longissima (Ophichthidae), Sphagemacrurus hirundo (Macrouridae), Gadella imberbis and Physiculus cyanostrophus (Moridae). Data includes distribution, habitat, morphometry and reproduction.Six campagnes exploratoires ainsi que quelques captures opportunistes réalisées de quelques mètres jusqu’à environ 1000 m de profondeur aux îles du Cap-Vert ont permis d’établir une liste comprenant 66 espèces de poissons téléostéens. Six espèces sont signalées pour la première fois aux îles du Cap-Vert : Gnathophis mystax (Congridae), Nezumia africana, Nezumia duodecim (Macrouridae), Ectreposebastes imus (Scorpaenidae), Paraliparis sp. (Liparidae) et Lappanella fasciata (Labridae). La présence de six autres espèces mal connues est confirmée pour cet archipel : Myroconger compressus (Myrocongridae), Myrichthys pardalis, Phaenomonas longissima (Ophichthidae), Sphagemacrurus hirundo (Macrouridae), Gadella imberbis et Physiculus cyanostrophus (Moridae). Les données présentées concernent la distribution, l’habitat, la morphométrie et la reproduction.Postprin

    The striped soldier shrimp Plesionika edwardsii (Crustacea:Decapoda:Pandalidae) from the cape Verde Islands

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    This study is part of the PROACTIVA 1-2 (2009-2012) and MARPROF-CV (2010-2014) projects, in the framework of the Canary Islands Government and UE PCT MAC 2007-2013 programmes respectively. Research has mainly focused on the stock assessment of the striped soldier shrimp, Plesionika edwardsii (Brandt, 1851), because it has shown moderate to high levels of fishing yield and abundances compatible with the development of a new sustainable fishery in the Cape Verde Islands. Cruises took place on board the R/V Prof. Ignacio Lozano. Four 15-day surveys have been conducted to date: Cabo Verde 2010-04 (April 2010), Camar˜ao-1 (November 2011), Camar˜ao-2 (Mars 2012) and Camar ˜ao-3 (July 2012). An innovative fishing gear so-called multiple semi-floating shrimp trap (MSFST) was used. Each fishing line was composed by 40-65 traps operating around 2.4 m above the seafloor, using Decapterus macarellus (Carangidae) as unique bait of the traps. Fishing depth was 66-458 m, and efective fishing time was 16-18 h. Each trap was attached to the main bottom line every 15 m, and the maximum attraction of this bait was established to be 100 or 150 m, according to the experience gained from the local fishery for deep-sea lobsters. So density by area was calculated assuming two different areas of attraction of the fishing gear. Initial biomass was estimated from depletion experiments at different abundance stations by applying the Leslie & Davis (1939) method, modified by Ricker (1975). Each fishing operation was classified according to its yield (CPUE in g/trap/night). The potential fishing planar area was estimated between the isobathymetric lines between 90 and 220 m. Total biomasses (Bt) were calculated from areas (km2) and mean minimum/maximum densities (kg/km2). Maximum sustainable yield (MSY) was estimated from Bt using the Beddington and Cooke (1983) model by entering natural mortality (0.6), growth rate (0.53 year�1) and recruitment age (1.32 year), which are the parameters for this target species published for the Canaries. These parameters estimate a biological exploitation rate ( ) of 0.262. Interpolations were applied to estimate MSY for insular stocks representing lesser than 5% of the total fishing grounds for this species in the archipelago. The MSY estimated by depletion were 30.5 tons/year for the stock of S˜ao Vicente, Santa Luzia, Ilheus and S˜ao Nicolau, 10 tons/year for the stock of Santiago, 138.8 tons/year for the stock of Boa Vista and Maio, and 5.6 tons/year for the stock of Sal. The small stocks estimated by interpolation were: 4.5 tons/year for the stock of Santo Ant˜ao, 1.3 tons/year for the stock of Fogo, and 1.8 tons/year for the stock of Brava and Ilheus. In total, 192.5 tons per year was the total MSY for the striped soldier shrimp around the islands of the Cape Verde archipelago, occupying a total area of 1,918 km2 of new fishing grounds at between 90 and 220 m of depth. In comparison with the traditional bottom trap used in the Canary Islands, the innovative fishing gear MSFST were proved to be more selective for pandalid shrimps, minimizing the gear impact on the seafloor as well as the by-catch by reducing the discards. Depletion methods are based on the assumption of a closed system, that is with minimum or zero immigration between neighbouring areas. The straight forward decline of CPUEs obtained during the depletion experiments seems to confirm that P. edwardsii is a low mobility species, making this assumption valid at least during short-time periods. Because of the bathymetry profile of these islands,the depth range is from very close (few nautical miles in Santiago) to far away (10-12 n.m. in Boa Vista) to the coastline. Fishing effort should be controlled on the basis of quotas, number of fishing vessels and a precautionary approach in order to ensure that catching is commensurate with sustainable levels of exploitation. MSY estimates suggest that this new Capeverdean fishery should be carried out by specialized medium-sized fishing vessels. During the last decades a combination of shrimp trawling and industrial trapping activity has threatened over-exploitation in the Mediterranean fisheries targeting on P. edwardsii; currently the shrimp collapse has conducted to the decline of these fisheries. Can the Cape Verde regulatory bodies and all the stakeholders involved learn the lessons this teaches us about this resource management

    By-catch composition of the striped soldier shrimp Plesionika edwardsii (Crustace: Decapoda: Pandalidae) experimental fishery in the Cape Verde Islands

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    This work focuses on the by-catch composition of Plesionika edwardsii experimental fishery in the Cape Verde Islands. Obtaining information on abundance, composition and lifecycle of species involved in this potential fishery is useful, in order to ensure its sustainable development under an ecosystem approach. The first step towards this goal is the description of catches. Four 15-day research surveys were conducted on board the R/V Prof. Ignacio Lozano: April 2010 (S˜ao Vicente and Santa Luzia islands), November 2011 (Santiago island), March 2012 (Boa Vista island,) and July 2012 (Sal and S˜ao Nicolau islands). The working depths were between 66 and 458 m depth. A standardized innovative fishing gear was used, so-called multiple semi-floating shrimp traps. Each fishing line was composed by 40-65 traps operating around 2.4 m above the seafloor, using Decapterus macarellus (Carangidae) as unique bait of the traps. Multiple semi-floating shrimp traps is a passive fishing system that allows catch and release sea significant part of the unwanted catches, as in the case of Chondrichthyes or Anguilliformes, reducing the fishing impact on non-target species. The main by-catch was composed of 53 species belonging to three groups including Chondrichthyes (three families and three species), Crustacea (11 families and 19 species) and Osteichthyes (15 families and 29 species). Plesionika edwardsii, the target species of this fishery, represented 97.8% of the catch in terms of abundance and 40.1% in biomass. By-catch represented 59.9% of total catch in terms of biomass. Osteichthyes (87.5%) were the dominant group and was represented by the following main families; Sparidae (33.9%), Moridae (32.5%), Muraenidae (32.5%), Scorpaenidae (9.9%) and Tetraodontidae (9.8%). Chondrichthyes (11.6%) were composed by Centrophoridae (65.3%) and Triakidae (34.1%). Finally, Crustacea (1.9%) were chiefly composed by Pandalidae (79.1%). However, different families represented by specific species were found to be dominant around each island. Sparidae were the dominant family represented by Pagellus acarne (46.2% of total by-catch) at S˜ao Vicente, and by Dentex macrophthalmus (42.6%) at Boa Vista. Tetraodontidae with Sphoeroides pachygaster (25.9%) and Sparidae with P. acarne (25.1%) were the co-dominant families in the by-catch around Santa Luzia. Muraenidae were the dominant family represented by Gymnothorax polygonius (69.4%) at Sal, and by Muraena helena (63.4%) at S˜ao Nicolau. Finally, Scorpaenidae with Pontinus kuhlii (22.3%) and Moridae with Physiculus cyanostrophus (22.1%) were the co-dominant families of the bycatch around Santiago. Acknowledgements: This study is part of the PROACTIVA 1-2 (2009-2012) and MARPROF-CV (2010-2014) projects, in the framework of the Canary Islands Government and UE PCT MAC 2007- 2013 programmes respectively

    Evaluation of in vitro Antifungal Activity of Xylosma prockia (Turcz.) Turcz. (Salicaceae) Leaves Against Cryptococcus spp.

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    Cryptococcus species are responsible for important systemic mycosis and are estimated to cause millions of new cases annually. The available therapy is limited due to the high toxicity and the increasing rates of yeast resistance to antifungal drugs. Popularly known as “sucará,” Xylosma prockia (Turcz.) Turcz. (Salicaceae) is a native plant from Brazil with little information on its pharmacological potential. In this work, we evaluated in vitro anticryptococcal effects of the leaf ethanolic extract of X. prockia and its fractions against Cryptococcus gattii and Cryptococcus neoformans. We also evaluated phenotypic alterations caused by ethyl acetate fraction (EAF) (chosen according to its biological results). The liquid chromatography–mass spectrometry (LC-MS) analysis of EAF demonstrated the presence of phenolic metabolites that belong to three structurally related groups as majority compounds: caffeoylquinic acid, coumaroyl-glucoside, and caffeoyl-glucoside/deoxyhexosyl-caffeoyl glucoside derivatives. The minimum inhibitory concentration (MIC) values against C. gattii and C. neoformans ranged from 8 to 64 mg/L and from 0.5 to 8 mg/L, for ethanolic extract and EAF, respectively. The EAF triggered an oxidative burst and promoted lipid peroxidation. EAF also induced a reduction of ergosterol content in the pathogen cell membrane. These effects were not associated with alterations in the cell surface charge or in the thermodynamic fingerprint of the molecular interaction between EAF and the yeasts evaluated. Cytotoxic experiments with peripheral blood mononuclear cells (PBMCs) demonstrated that EAF was more selective for yeasts than was PBMCs. The results may provide evidence that X. prockia leaf extract might indeed be a potential source of antifungal agents.Fil: Folly, Mariany L. C.. Universidade Federal de Juiz de Fora; BrasilFil: Ferreira, Gabriella F.. Universidade Federal de Juiz de Fora; BrasilFil: Salvador, Maiara R.. Universidade Federal de Juiz de Fora; BrasilFil: Sathler, Ana A.. Universidade Federal de Juiz de Fora; BrasilFil: da Silva, Guilherme F.. Universidade Federal de Juiz de Fora; BrasilFil: Santos, Joice Castelo Branco. Ceuma University; BrasilFil: Santos, Julliana R. A. dos. Ceuma University; BrasilFil: Nunes Neto, Wallace Ribeiro. Ceuma University; BrasilFil: Rodrigues, João Francisco Silva. Ceuma University; BrasilFil: Fernandes, Elizabeth Soares. Ceuma University; BrasilFil: da Silva, Luís Cláudio Nascimento. Ceuma University; BrasilFil: de Freitas, Gustavo José Cota. Universidade Federal de Minas Gerais; BrasilFil: Denadai, Ângelo M.. Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas; BrasilFil: Rodrigues, Ivanildes V.. Universidade Federal de Juiz de Fora; BrasilFil: Mendonça, Leonardo M.. Universidade Federal de Juiz de Fora; BrasilFil: Monteiro, Andrea Souza. Ceuma University; BrasilFil: Santos, Daniel Assis. Universidade Federal de Minas Gerais; BrasilFil: Cabrera, Gabriela Myriam. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; ArgentinaFil: Siless, Gastón Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; ArgentinaFil: Lang, Karen L.. Universidade Federal de Juiz de Fora; Brasi

    Functional Analysis and Fine Mapping of the 9p22.2 Ovarian Cancer Susceptibility Locus.

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    Genome-wide association studies have identified 40 ovarian cancer risk loci. However, the mechanisms underlying these associations remain elusive. In this study, we conducted a two-pronged approach to identify candidate causal SNPs and assess underlying biological mechanisms at chromosome 9p22.2, the first and most statistically significant associated locus for ovarian cancer susceptibility. Three transcriptional regulatory elements with allele-specific effects and a scaffold/matrix attachment region were characterized and, through physical DNA interactions, BNC2 was established as the most likely target gene. We determined the consensus binding sequence for BNC2 in vitro, verified its enrichment in BNC2 ChIP-seq regions, and validated a set of its downstream target genes. Fine-mapping by dense regional genotyping in over 15,000 ovarian cancer cases and 30,000 controls identified SNPs in the scaffold/matrix attachment region as among the most likely causal variants. This study reveals a comprehensive regulatory landscape at 9p22.2 and proposes a likely mechanism of susceptibility to ovarian cancer. SIGNIFICANCE: Mapping the 9p22.2 ovarian cancer risk locus identifies BNC2 as an ovarian cancer risk gene.See related commentary by Choi and Brown, p. 439

    In vitro influence of photodynamic antimicrobial chemotherapy on staphylococcus aureus by using phenothiazines derivatives associated with laser/LED Light

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    ABSTRACT The aim of this study was to evaluate the effect of photodynamic antimicrobial chemotherapy (PACT) using phenothiazinium dyes -PTZ irradiated with red laser (ʎ660nm) or red-orange LED (ʎ632±2nm) on Staphylococcus aureus in vitro. triplicate tests were performed in 10 groups: control, Laser (L1 + P -and L2 + P -) bacterial suspensions were irradiated only with laser energy 2.4 and 4.8 J/cm 2 respectively, (Led1 + P -and Led2 + P -) irradiated only with LED energy 2.4 and 4.8 J/cm 2 respectively, (L1 + P + and L2 + P + ) irradiated with laser in the presence of 1μg/ml of photosensitizer, (Led1 + P + and Led2 + P + ) irradiated with LED in the presence of 1μg/ml of photosensitizer and finally (L -P + ) only in the presence of PTZ dye. Bactericidal effect of the PACT was assessed by counting colony-forming units. The results showed no significant difference on regards different energy densities on group PACT for both lights. PACT groups (L2 + P + and Led2 + P + ) compared to the Control showed significant reduction of CFUs. LED/Laser groups (L2 + P -and Led2 + P -) compared to control and PTZ groups showed also significant differences as groups LED/Laser (4.8J/cm 2 ) increased the average of CFUs. Although the results of this study have shown a reduction in average number of colonyforming units by the appropriate Laser or LED-dye treatment combination, it this topic requires further investigation

    Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

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    Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets
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