743 research outputs found

    Permeability analysis in bisized porous media: wall effect between particles of different size

    Get PDF
    The permeability of binary packings of glass beads with different size ratio – 13.3, 20, and 26.7, was investigated. In the Kozeny–Carman equation, the dependence of the tortuosity τ on the mixture porosity ε(xD) was described according to τ = 1/εn for different volume fraction of large particles in the mixture, xD. Obtained data on packing permeability shows that the parameter n is a function of the volume fraction and particle size ratio, with values between 0.5 and 0.4. This can be explained by the wall effect resulting from the arrangement of the small particles occurring near the large particle surface. A model taking in account this effect was suggested that can be useful in the characterization of transport phenomena in granular beds as well as in engineering applications.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BPD/18128/2004; Project POCI_EQU_58337/2004

    Methyl 3-amino-6-[4 or 3 or 2-(3-arylureido)phenyl]thieno[3,2-b]pyridine-2-carboxylates: synthesis and molecular modelling studies using VEGFR-2

    Get PDF
    The membrane receptor tyrosine kinases (RTKs), possess both extracellular and intracellular domains and selectively catalyze the phosphorylation of tyrosine hydroxyl groups in response to binding of certain extracellular growth factors. RTK signalling pathways are normally highly regulated, yet their over-activation has been shown to promote the growth, survival, and metastasis of cancer cells, and has been associated with the progression of various human cancers. Recently some thieno[3,2-c]pyridine 1,3-diarylurea derivatives were prepared as VEGFR-2 (vascular endothelium growth factor receptor-2) inhibitors.1 Here we present the synthesis of methyl 3-amino-6-[4 or 3 or 2-(3-arylureido)phenyl]thieno[3,2-b]pyridine-2-carboxylates 2 by reaction of the methyl 3-amino-6-(4 or 3 or 2-aminophenyl)thieno[3,2-b]pyridine-2-carboxylates 1, synthesized earlier by our group,2 with arylisocyanate

    NEW SEISMIC SOURCE ZONE MODEL FOR PORTUGAL AND AZORES

    Get PDF
    The development of seismogenic source models is one of the first steps in seismic hazard assessment. In seismic hazard terminology, seismic source zones (SSZ) are polygons (or volumes) that delineate areas with homogeneous characteristics of seismicity. The importance of using knowledge on geology, seismicity and tectonics in the definition of source zones has been recognized for a long time [1]. However, the definition of SSZ tends to be subjective and controversial. Using SSZ based on broad geology, by spreading the seismicity clusters throughout the areal extent of a zone, provides a way to account for possible long-term non-stationary seismicity behavior [2,3]. This approach effectively increases seismicity rates in regions with no significant historical or instrumental seismicity, while decreasing seismicity rates in regions that display higher rates of seismicity. In contrast, the use of SSZ based on concentrations of seismicity or spatial smoothing results in stationary behavior [4]. In the FP7 Project SHARE (Seismic Hazard Harmonization in Europe), seismic hazard will be assessed with a logic tree approach that allows for three types of branches for seismicity models: a) smoothed seismicity, b) SSZ, c) SSZ and faults. In this context, a large-scale zonation model for use in the smoothed seismicity branch, and a new consensus SSZ model for Portugal and Azores have been developed. The new models were achieved with the participation of regional experts by combining and adapting existing models and incorporating new regional knowledge of the earthquake potential. The main criteria used for delineating the SSZ include distribution of seismicity, broad geological architecture, crustal characteristics (oceanic versus continental, tectonically active versus stable, etc.), historical catalogue completeness, and the characteristics of active or potentially-active faults. This model will be integrated into an Iberian model of SSZ to be used in the Project SHARE seismic hazard assessment

    Bioactivity of Methanolic and Aqueous Extracts of Laurus nobilis L. from Different Origins

    Get PDF
    Laurus nobilis L. (Laureaceae), commonly known as laurel, is a native plant from the Mediterranean region. Most widely used as culinary spice, it is also consumed as infusion to treat some gastrointestinal problems (Dall’Acqua et al., 2009) and has been reported as a rich source of bioactive compounds namely, essential oils and phenolic compounds (Dadalioğlu et al., 2004; Dias et al., 2013). In the present work, methanolic and aqueous extracts of wild and cultivated L. nobilis were studied for their in vitro antitumor (against five different human tumor cell lines) and antimicrobial (antibacterial and antifungal) activities. Furthermore, a two-dimensional principal component analysis (PCA) was used to understand how each extract act differentially towards specific bacterial and fungal species, and also selected human tumor cell lines. Both assayed factors, origin (wild or cultivated) and extract type (methanolic or aqueous) act in a differentiated manner; i.e., the same evaluated parameter gave sometimes statistically significant differences regarding laurel origin, but no effect at all from extract type, or vice versa. Nevertheless, the extract type induced the most marked changes in bioactivity of laurel samples. From the PCA biplot, it became clear that wild samples were more effective to inhibit tumor cell lines growth, especially HeLa, MCF7, NCI-H460 and HCT15. It was also observed that methanolic extracts tended to have higher antimicrobial activity, except for Aspergillus niger, Aspergillus. fumigatus and Penicillium verrucosum. The differences in bioactivity might be related to the higher phenolic compounds content (flavonols, flavones and even, total phenolic compounds) presented by methanolic extracts,. The most interesting finding in this work was the bioactive specificity of each laurel extract, considering its wild or cultivated origin. Moreover, from the PCA biplot obtained is possible to choose the combination extract type/origin with potentially highest effect against determined bacteria, fungi or tumor cell line, depending on the objective of the study.FCT for financial support, CIMO (strategic project PEst-OE/AGR/UI0690/2011), REQIMTE (PEst-C/EQB/LA0006/2011), M.I. Dias (SFRH/BD/84485/2012), R.C. Calhelha (SFRH/BPD/68344/2010) and J.C.M. Barreira (BPD/72802/2010

    COMPILATION OF ACTIVE FAULT DATA IN PORTUGAL FOR USE IN SEISMIC HAZARD ANALYSIS

    Get PDF
    To estimate where future earthquakes are likely to occur, it is essential to combine information about past earthquakes with knowledge about the location and seismogenic properties of active faults. For this reason, robust probabilistic seismic hazard analysis (PSHA) integrates seismicity and active fault data. Existing seismic hazard assessments for Portugal rely exclusively on seismicity data and do not incorporate data on active faults. Project SHARE (Seismic Hazard Harmonization in Europe) is an EC-funded initiative (FP7) that aims to evaluate European seismic hazards using an integrated, standardized approach. In the context of SHARE, we are developing a fully-parameterized active fault database for Portugal that incorporates existing compilations, updated according to the most recent publications. The seismogenic source model derived for SHARE will be the first model for Portugal to include fault data and follow an internationally standardized approach. This model can be used to improve both seismic hazard and risk analyses and will be combined with the Spanish database for use in Iberian- and European-scale assessments

    Starch analysis using hydrodynamic chromatography with a mixed-bed particle column

    Get PDF
    Columns packed with commercial glass beads 5 and 19 lm average size and a mixture of both (0.7 volume fraction of large particles) were used to analyse starch composition by hydrodynamic chromatography (HDC), applying water as mobile phase. To obviate retrogradation, experiments were carried out at column temperatures of 15 and 3 °C and several types of starch were assayed. In what concerns amylopectin and amylose separation, a better resolution and a lower pressure drop were obtained for the mixed binary packing when compared with the packing containing uniform 5 lm glass beads. A more efficient cooling of the mobile phase was also obtained with the mixed packing, which was determinant for improving resolution. For the Hylon VII starch the relative retention times (RRT) were 0.777 and 0.964 for amylopectin and amylose, respectively, while for the Tapioca starch the obtained RRTs were 0.799 and 0.923. Application of unbound glass beads as column packing not only might reduce equipment and running costs in preparative scale separations, but also proved to be useful as a fast and reliable method to monitor the amylose and amylopectin content of starch samples of different sources.FEDERThe authors wish to thank FCT for the grant provided to Dr. Alexander Yelshin (Yelshyn). This work was developed under the framework of the project POCI-EQU-58337/2004, partially funded by FEDER

    Causes, patterns and severity of androgen excess in 487 consecutively recruited pre- and post-pubertal children.

    Get PDF
    OBJECTIVE: Androgen excess in childhood is a common presentation and may signify sinister underlying pathology. Data describing its patterns and severity are scarce, limiting the information available for clinical decision processes. Here, we examined the differential diagnostic value of serum dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), and testosterone (T) in childhood androgen excess. DESIGN: Retrospective review of all children undergoing serum androgen measurement at a single center over 5 years. METHODS: Serum A4 and T were measured by tandem mass spectrometry, DHEAS by immunoassay. Patients with at least one increased androgen underwent phenotyping by clinical notes review. RESULTS: In 487 children with simultaneous DHEAS, A4, and T measurements, we identified 199 with androgen excess (140 pre- and 59 post-pubertal). Premature adrenarche (PA) was the most common pre-pubertal diagnosis (61%), characterized by DHEAS excess in 85%, while A4 and T were only increased in 26% and 9%, respectively. PCOS was diagnosed in 40% of post-pubertal subjects, presenting equally frequent with isolated excess of DHEAS (29%) or T (25%) or increases in both A4 and T (25%). CAH patients (6%) predominantly had A4 excess (86%); T and DHEAS were increased in 50% and 33%, respectively. Concentrations increased above the two-fold upper limit of normal were mostly observed in PA for serum DHEAS (>20fold in the single case of adrenocortical carcinoma), and in CAH for serum androstenedione. CONCLUSIONS: Patterns and severity of childhood androgen excess provides pointers to the underlying diagnosis and can be used to guide further investigations

    A simple boiling-based DNA extraction for RAPD profiling of landfarm soil to provide representative metagenomic content

    Get PDF
    Landfarm soils are employed in industrial and petrochemical residue bioremediation. This process induces selective pressure directed towards microorganisms capable of degrading toxic compounds. Detailed description of taxa in these environments is difficult due to a lack of knowledge of culture conditions required for unknown microorganisms. A metagenomic approach permits identification of organisms without the need for culture. However, a DNA extraction step is first required, which can bias taxonomic representativeness and interfere with cloning steps by extracting interference substances. We developed a simplified DNA extraction procedure coupled with metagenomic DNA amplification in an effort to overcome these limitations. The amplified sequences were used to generate a metagenomic data set and the taxonomic and functional representativeness were evaluated in comparison with a data set built with DNA extracted by conventional methods. The simplified and optimized method of RAPD to access metagenomic information provides better representativeness of the taxonomical and metabolic aspects of the environmental samples.Conselho Nacional de Pesquisa e Desenvolvimento (CNPq) [558272/2009-6]Conselho Nacional de Pesquisa e Desenvolvimento (CNPq)Fundacao de Amparo a Pesquisa do Estado da Bahia (FAPESB)Fundacao de Amparo a Pesquisa do Estado da Bahia (FAPESB

    Epidemiological situation of bovine brucellosis in the State of Bahia, Brazil

    Get PDF
    O trabalho consistiu em estratificar o Estado da Bahia em quatro regiões com características homogêneas (circuitos produtores) para que fossem amostradas aleatoriamente, em cada uma delas, 300 propriedades. Em cada propriedade foram escolhidas, de forma aleatória, 10 a 15 fêmeas bovinas adultas, das quais foi obtida uma amostra de sangue. No total, foram amostrados 10.816 animais, provenientes de 1.413 propriedades. O protocolo de testes utilizado foi o da triagem com o teste do antígeno acidificado tamponado (Rosa Bengala) e a confirmação dos positivos com o teste do 2-mercaptoetanol. O rebanho foi considerado positivo se pelo menos um animal reagiu às duas provas sorológicas. As prevalências de focos e a de fêmeas adultas soropositivas do Estado foram de 4,2% [3,1-5,3%] e 0,66% [0,41-0,93%], respectivamente. Para os circuitos produtores foram: circuito 1, 5,8% [3,6-8,7%] e 0,86% [0,41-1,3%]; circuito 2, 3,1% [1,5-5,6%] e 1,2% [0,25-2,1%]; circuito 3, 6,3% [4,0-9,3%] e 1,7% [0,66-2,7%]; e circuito 4, 0,60% [0,07-2,2%] e 0,07 [0,00-0,21%]. Para a análise de fatores de riscos associados à doença foi aplicado um questionário epidemiológico em cada propriedade visitada. Os fatores de risco (odds ratio, OR) associados à condição de foco foram: compra de reprodutores (OR= 2,27) e presença de áreas alagadiças (OR= 1,76). A vacinação de fêmeas de três até oito meses de idade foi um fator de proteção (OR= 0,53). ____________________________________________________________________________________________________________________ ABSTRACTA study to characterize the epidemiological situation of bovine brucellosis in the State of Bahia was carried out in 2004. The State was divided into four similar production regions, 300 herds were randomly sampled in each region, and 10 to 15 adult bovine females were sampled in each of these herds. A total of 10,816 serum samples from 1,413 herds were collected. The serum samples were screened for antibodies to Brucella spp. by the Rose-Bengal Test (RBT), and all RBT-positive sera were re-tested by the 2-mercaptoethanol test (2-ME) for confirmation. A herd was considered positive if at least one animal was positive on both RBT and 2-ME tests. The prevalence of infected herds and seropositive adult bovine females in Bahia State were: 4.2% [3.1-5.3%] and 0.66% [0.41-0.93%], respectively. In the production regions, prevalence of infected herds and animals were, respectively: region 1, 5.8% [3.6-8.7%] and 0.86% [0.41-1.3%]; region 2, 3.1% [1.5-5.6%] and 1.2% [0.25-2.1%]; region 3, 6.3% [4.0-9.3%] and 1.7% [0.66-2.7%]; and region 4, 0.60% [0.07-2.2%] and 0.07%[0.00-0.2%]. In each herd, an epidemiological questionnaire was applied. The risk factors (odds ratio, OR) associated with the presence of the infection were: purchase of breeding animals (OR = 2.27) and presence of flood areas (OR= 1.76). Vaccination of heifers from three to eight months of age was a protective factor (OR=0.53)
    corecore