63 research outputs found

    Content of Iodine in Broiler Meat

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    The present study brings current information on providing broilers with the required iodine level by the determination of its content in breast and leg muscles and on the relationship between those concentrations and iodine intake by the human population. The iodine content was assessed by the Sandell-Kolthoff method in 84 samples of broiler breast and leg muscles from seven farms in four districts of the Czech Republic, collected during the period from August to September 2004. Average iodine content in broiler breast and leg muscles was 18.9 ± 6.71 μg I kg-1 and 38.1 ± 19.79 μg I kg-1, respectively, and coefficient of variation was 35.5% and 52.0%, respectively. Iodine concentration in leg muscles was statistically significantly higher (P -1 and 18.3 to 61.2 μg I kg-1 in breast and leg muscles, respectively. The detected variations might have been caused by different iodine saturation of broilers from different herds, manifestation of physiological ability of respective animals to utilize the iodine source, potential effect of goitrogens and environmental conditions. Statistical significance of correlation (P -1 and 38.1 μg kg-1 in breast and leg muscles, respectively, the annual iodine intake is 452 to 911 μg; that represents 0.8 to 1.7% of the requirement per year, which is 150 μg day-1 for an adult person

    Epidermal Growth Factor–PEG Functionalized PAMAM-Pentaethylenehexamine Dendron for Targeted Gene Delivery Produced by Click Chemistry

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    Aim of this study was the site-specific conjugation of an epidermal growth factor (EGF)-polyethylene glycol (PEG) chain by click chemistry onto a poly(amido amine) (PAMAM) dendron, as a key step toward defined multifunctional carriers for targeted gene delivery. For this purpose, at first propargyl amine cored PAMAM dendrons with ester ends were synthesized. The chain terminal ester groups were then modified by oligoamines with different secondary amino densities. The oligoamine-modified PAMAM dendrons were well biocompatible, as demonstrated in cytotoxicity assays. Among the different oligoamine-modified dendrons, PAMAM-pentaethylenehexamine (PEHA) dendron polyplexes displayed the best gene transfer ability. Conjugation of PAMAM-PEHA dendron with PEG spacer was conducted via click reaction, which was performed before amidation with PEHA. The resultant PEG-PAMAM-PEHA copolymer was then coupled with EGF ligand. pDNA transfections in HuH-7 hepatocellular carcinoma cells showed a 10-fold higher efficiency with the polyplexes containing conjugated EGF as compared to the ligand-free ones, demonstrating the concept of ligand targeting. Overall gene transfer efficiencies, however, were moderate, suggesting that additional measures for overcoming subsequent intracellular bottlenecks in delivery have to be taken

    Tree method for quantum vortex dynamics

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    We present a numerical method to compute the evolution of vortex filaments in superfluid helium. The method is based on a tree algorithm which considerably speeds up the calculation of Biot-Savart integrals. We show that the computational cost scales as Nlog{(N) rather than N squared, where NN is the number of discretization points. We test the method and its properties for a variety of vortex configurations, ranging from simple vortex rings to a counterflow vortex tangle, and compare results against the Local Induction Approximation and the exact Biot-Savart law.Comment: 12 pages, 10 figure

    Inferring causal molecular networks: empirical assessment through a community-based effort

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    Inferring molecular networks is a central challenge in computational biology. However, it has remained unclear whether causal, rather than merely correlational, relationships can be effectively inferred in complex biological settings. Here we describe the HPN-DREAM network inference challenge that focused on learning causal influences in signaling networks. We used phosphoprotein data from cancer cell lines as well as in silico data from a nonlinear dynamical model. Using the phosphoprotein data, we scored more than 2,000 networks submitted by challenge participants. The networks spanned 32 biological contexts and were scored in terms of causal validity with respect to unseen interventional data. A number of approaches were effective and incorporating known biology was generally advantageous. Additional sub-challenges considered time-course prediction and visualization. Our results constitute the most comprehensive assessment of causal network inference in a mammalian setting carried out to date and suggest that learning causal relationships may be feasible in complex settings such as disease states. Furthermore, our scoring approach provides a practical way to empirically assess the causal validity of inferred molecular networks

    Inferring causal molecular networks: empirical assessment through a community-based effort

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    It remains unclear whether causal, rather than merely correlational, relationships in molecular networks can be inferred in complex biological settings. Here we describe the HPN-DREAM network inference challenge, which focused on learning causal influences in signaling networks. We used phosphoprotein data from cancer cell lines as well as in silico data from a nonlinear dynamical model. Using the phosphoprotein data, we scored more than 2,000 networks submitted by challenge participants. The networks spanned 32 biological contexts and were scored in terms of causal validity with respect to unseen interventional data. A number of approaches were effective, and incorporating known biology was generally advantageous. Additional sub-challenges considered time-course prediction and visualization. Our results suggest that learning causal relationships may be feasible in complex settings such as disease states. Furthermore, our scoring approach provides a practical way to empirically assess inferred molecular networks in a causal sense

    Health status in an Antarctic top predator: micronuclei frequency and white blood cell differentials in the South Polar Skua

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    Distribution of ceramic particles intermetallic alloy Ti-46Al-5Nb-1W

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    Growing requirements to mechanical and physical properties of materials necessitated search for new suitable structural materials, which would fulfil all the requirements. Intermetallic alloys from the system Ti-Al represent undoubtedly an important area of development of new materials determined for special applications. This paper is focused on the alloy Ti-46Al-5Nb-1W (at. %), on its metallurgical preparation, on influencing its structure by directional crystallisation and on gas contents in the alloy. The alloy was prepared by plasma and vacuum metallurgy. Directional crystallisation took its course by constant rates within the range from 5.56×10-6 m×s-1 to 1.18×10-4 m×s-1. The samples were evaluated from metallographic point of view and they were subjected to gas content analysis. Structure of the alloy consists of lamellar grains, in which lamellas a2 and g alternate. Reaction of molten mass with ceramic mold resulted in formation of ceramic, evenly distributed Al2O3 particles
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