7,213 research outputs found

    Characterization of phytoplankton by pigment analysis and the detection of toxic cyanobacteria in reservoirs with aquaculture production

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    Made available in DSpace on 2018-12-11T17:19:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01The intensified use of water bodies and reservoirs for aquaculture production has increased the need for monitoring and early warning of toxins from cyanobacteria. To minimize effects from toxins, simple and fast analytical monitoring methods are crucial. Here, the content of pigments and microcystins in 14 different strains of cyanobacteria cultured under different growth conditions was investigated to determine the influence of light and nutrient starvation on pigment/ chlorophyll a (chl a) ratios. The obtained pigment/chl a ratios were applied in the software CHEMTAX to calculate the biomass of toxic cyanobacteria, as well as other phytoplankton groups. CHEMTAX ratios from the laboratory cultures were applied to water samples collected during 4 sampling periods at 6 fish farms in different reservoirs in São Paulo State, Brazil. Cyanobacteria generally dominated in all reservoirs in all sampling periods and constituted on average 44 to 66% of the average phytoplankton biomass. The concentrations of microcystins were significantly correlated with the chl a concentrations of cyanobacteria and showed that the pigment method can be used to detect microcystin-producing cyanobacteria in these Brazilian reservoirs. When the concentration of cyanobacteria in the reservoirs was above 4 μg chl a l-1, microcystins were always detected. Our results show that pigment analysis can be used to provide fast and reliable results for the early warning, the presence and potential risk of toxic cyanobacteria in freshwater reservoirs used for aqua culture.Environment and Toxicology DHISão Paulo State Agribusiness Agency TechnologySection of Microbial Ecology and Biotechnology Department of Plant and Environmental Sciences University of CopenhagenFicology Department Botanical InstituteUNESP Campus Botucatu Institute of Biosciences Parasitology DepartmentUNESP Campus Botucatu Institute of Biosciences Parasitology Departmen

    Treatment of perinfarction recurrent ventricular fibrillation by percutaneous pharmacological block of left stellate ganglion

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    A patient suffering from an acute myocardial infarction presented on the seventh and eighth days of hospitalization recurrent episodes of ventricular fibrillation refractory to antiarrhythmic treatment. The life-threatening ventricular fibrillation was suppressed by percutaneous pharmacological block of the left stellate ganglion

    Net-phase flow NMR for compact applications

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    The net phase of the NMR signal is proposed as a robust mechanism for the encoding of fluid flow velocity into phase, showing local bijectivity. While magnitude-based or imaging-based methods suffer from loss of signal, by increasing the flow rate, the present method enables us to maintain the high SNR even for the case of fast flow. In addition, it is shown that a well-engineered flow channel is also necessary, which is not the case for traditional cylindrical flow channels. In this contribution, we report on implementing this approach in a low-cost NMR-based flowmeter for use in a low field (1 T) setting, for example, for monitoring reaction flow industrial processes

    Bioinvasion in a Brazilian Bay: Filling Gaps in the Knowledge of Southwestern Atlantic Biota

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    Biological invasions are a major cause of global species change. Nevertheless, knowledge about the distribution and ecology of introduced species is regionally biased, and many gaps in knowledge exist for most developing countries.To study the zoobenthos on the hard substratum of the Ilha Grande Bay, a survey was conducted on both natural and artificial substrata at three depths and seven sites. The species recorded were classified as native, cryptogenic or introduced. Multivariate analyses were conducted to assess the prevalence of introduced species in these communities and to compare the distribution of species on natural and artificial substrata of this bay to identify possible discrepancies in habitat use. Of the 61 species, 25 were cryptogenic, 10 were introduced and 26 were native. Similar numbers of introduced species were found on both natural and artificial substrata, though the community composition was significantly different between them. We also compared the species composition of the Ilha Grande Bay survey to other inventories taken around the world. The highest similarities were found between the Ilha Grande Bay inventory and the Atlantic coastal region (Tampa Bay, USA and the Gulf of Mexico), American Samoa and Pearl Harbor (USA) inventories.This study presents the first published comprehensive list of hard substratum sessile marine invertebrate species in a Brazilian bay. The high percentage of cryptogenic species reveals gaps in both zoological records and information on introduced species for the Brazilian coast. The introduced species successfully colonized different sites in the Ilha Grande Bay, including both natural and artificial substrata. In addition, we find that artificial structures may not be good surrogates for natural rocky shores and may represent an ecological threat. Comparisons with other inventories suggest a history of broad-scale invasion, though more evidence is needed to support this conclusion

    Characterization of functional single jersey knitted fabrics using non-conventional yarns for sportswear

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    Eight functional single jersey plain knitted fabrics have been developed in order to assess a quantitative analysis of various comfort-related properties in terms of thermal control, air and water vapor permeability, wickability, coefficient of kinetic friction and antimicrobial efficiency, using eight different commercially available functional yarns: Polyester Craque and viscose Craque conventional yarns as controls; Finecool and Coolmax polyester yarns for moisture management and quick drying; Holofiber polyester yarns containing an optical responsive material that the producer claims to improve body oxygenation; Airclo polyester hollow yarns for efficient control of body temperature; and, finally, polyester Trevira and viscose Seacell for antimicrobial activity. According to the results, Coolmax for moisture management, Airclo for thermal control and Seacell for antimicrobial activity present the best performances as technical textiles for sportswear for the respective specific functional property.The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Jefferson M Souza acknowledges CAPES Foundation, Ministry of Education of Brazil (Proc. n 8976/13-9). Andrea Zille acknowledges FCT funding from Programa Compromisso para a Ciência 2008, Portugal, FEDER funding from the Programa Operacional Factores de Competitividade-COMPETE and national funds through FCT – Foundation for Science and Technology within the scope of the projects POCI-01-0145-FEDER-007136 and UID/CTM/00264

    Characterization of a natural surfactant from an essential oil from neem (Azadirachta indica A. Juss) for textile industry applications

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    Surfactants are multipurpose active compounds and are ubiquitously present in detergents. Detergent demand spiked due to the current COVID-19 pandemic, further alerting to the need to replace petrochemical synthetic surfactants with natural and renewable surfactants to mitigate further environmental damage. The neem tree (Azadirachta indica A. Juss) is a fast-growing tree that provides a multitude of commodities, namely neem oil. Neem oil possesses insecticidal and medicinal activity. This work reports the extraction and characterization of a surfactant from neem oil (SNO), displaying a yield of approximately 100%. SNO exhibited suitable detergent characteristics with a high potential to be used as a cleansing agent for textile applications, such as high pH value (10.1), suitable foaming of 1.5 cm and a critical micelle concentration of nearly 0.12 g mL−1. In addition, SNO showed a moderate bactericidal activity against Escherichia coli and bacteriostatic activity against Staphylococcus aureus, both common nosocomial pathogens. Therefore, SNO has a good potential to be used in medical textile applications due to its detergent and bactericidal properties. Finally, an economical overview of the SNO production process was assessed, underscoring its viability.This work was supported by the Brazilian Coordenac¸~ao de Aperfei¸oamento de Pessoal de N ıvel Superior and by the Portuguese Fundac¸~ao para Cieˆncia e a Tecnologia, Fundo Europeu de Desenvolvimento Regional and Programa Operacional Competitividade e Internacionalizac¸~ao in the frame of the Portugal 2020 program for the project PLASMAMED PTDC/CTM-TEX/28295/2017

    Prefrontal cortex and behavioral disorders: Theoretical framework and neuropsychological evaluation

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    Los trastornos del córtex prefrontal (CPF) permiten explicar la sintomatología de importantes cuadros neurológicos y psiquiátricos, tales como las secuelas de traumatismos encéfalo-craneanos y las esquizofrenias. Sin embargo, y a pesar de la gran importancia de sus funciones, su estudio se ha visto dificultado por razones teóricas, experimentales y clínicas. Recientemente han surgido dos nuevos modelos que intentan explicar los mecanismos a la base del funcionamiento del CPF. Presentamos una revisión de las principales manifestaciones clínicas ante su disfunción, los modelos explicativos postulados tradicionalmente, además de las dos propuestas recientes de Koechlin y Mesulam, para finalizar con una revisión de los instrumentos más utilizados en el ámbito clínico para la evaluación de las funciones propias de esta región, denominadas funciones ejecutivas y de autorregulación del comportamiento Dysfunction of prefrontal cortex explains the symptoms of many neurological and psychiatric disorders, such as the consequences of cerebral trauma and schizophrenia. Although the importance of frontal lobe functions in complex cognition has long been recognized, systematic research efforts to specify the nature, organization and roles of these functions have been difficult for theoretical, experimental and clinical reasons. Recently, two new theoretical frameworks have been proposed to explain the role of prefrontal cortex. In this paper, we present a revision of the main clinical manifestations secondary to prefrontal dysfunction, the frameworks proposed by Mesulam and Koechlin to explain the role of prefrontal cortex in behavior and the principal instruments available to evaluate executive and strategic self-regulation function

    Knowledge-Based Design of Long-Chain Arylpiperazine Derivatives Targeting Multiple Serotonin Receptors as Potential Candidates for Treatment of Autism Spectrum Disorder.

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    Autism spectrum disorder (ASD) includes a group of neurodevelopmental disorders characterized by core symptoms such as impaired social interaction and communication, repetitive and stereotyped behaviors, and restricted interests. To date, there are no effective treatments for these core symptoms. Several studies have shown that the brain serotonin (5-HT) neurotransmission system is altered in both ASD patients and animal models of the disease. Multiple pieces of evidence suggest that targeting 5-HT receptors may treat the core symptoms of ASD and associated intellectual disabilities. In fact, stimulation of the 5-HT1A receptor reduces repetitive and restricted behaviors; blockade of the 5-HT2A receptor reduces both learning deficits and repetitive behavior, and activation of the 5-HT7 receptor improves cognitive performances and reduces repetitive behavior. On such a basis, we have designed novel arylpiperazine derivatives pursuing unprecedently reported activity profiles: dual 5-HT7/5-HT1A receptor agonist properties and mixed 5-HT7 agonist/5-HT1A agonist/5-HT2A antagonist properties. Seventeen new compounds were synthesized and tested in radioligand binding assay at the target receptors. We have identified the dual 5-HT1AR/5-HT7R agonists 8c and 29 and the mixed 5-HT1AR agonist/5-HT7R agonist/5-HT2AR antagonist 20b. These compounds are metabolically stable in vitro and have suitable central nervous system druglike properties

    Disentangling the Ultrafast Nonlinear Optical Behavior of Plasmonic Resonances Near the Interband Transition

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    The photoexcitation of plasmonic nanostructures with ultrashort laser pulses allows for elucidating the mechanisms underlying the ultrafast nonlinear optical response of such systems, gaining insight into the fundamental processes triggered by light absorption at the nanoscale. To date, the complex temporal and spectral features of the photoinduced response are not fully understood, especially when the photon energies are close to the interband transitions of the metallic medium. Herein, the effects of photoexcitation of plasmonic nanostructures are studied by resorting to a combinaion of broadband transient absorption spectroscopy and semiclassical nonlinear simulations of the energy relaxation processes following illumination. The proposed approach enables an in-depth disentanglement of all the contributions to the ultrafast transient optical response of supported gold nanocrystals. From these methods, the apparent transient blue shift of the localized plasmon resonance observed in the pump-probe signals is rationalized as an interplay between different and spectrally dispersed permittivity modulations, instead of a simple negative permittivity change, as it could be concluded based on the Fröhlich condition. The results provide a comprehensive understanding of the thermo-modulational nonlinearities of plasmonic nanostructures exhibiting resonances close to the interband transition threshold

    Treatment priorities in oncology: do we want to live longer or better?

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    OBJECTIVES: Despite the progress achieved in the fight against cancer over the past several years, assessing the needs, goals and preferences of patients with cancer is of the utmost importance for the delivery of health care. We sought to assess priorities regarding quantity versus quality of life among Brazilian patients, comparing them with individuals without cancer. METHODS: Using a questionnaire presenting four hypothetical cancer cases, we interviewed cancer patients, oncology health-care professionals and laypersons, most of whom had administrative functions in our hospital. RESULTS: A total of 214 individuals participated: 101 patients, 44 health-care professionals and 69 laypersons. The mean ages in the three groups were 56, 34 and 31 years old, respectively (
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