Measurements of hyperfine structure in Ta II

We report the first extensive measurements of hyperfine structure in Ta II. Spectra of Ta II were recorded by high-resolution Fourier transform spectrometry in the region 10 000-53 000 cm-1(1886-10 000 Å) and the majority of observed lines show significant hyperfine structure. Computer fits to several hundred of these line profiles have yielded values of the magnetic dipole hyperfine interaction constant A for 88 energy levels with an uncertainty of between 0.5 and 10 per cent for the majority of A factors. The A factors range from −0.078 to +0.065 cm−1 for the even levels and from −0.064 to +0.083 cm−1 for the odd levels. For the majority of these A factors no previous measurements are known. Approximate values of the electric quadrupole hyperfine interaction constant B were found for 73 levels. These measurements of A and B factors allow, for the first time, the effects of hyperfine structure in Ta II lines to be correctly accounted for both in abundance analysis and in the resolution of blended lines in astrophysical spectr

A VERSTAILE POLYMERIC COATING FOR MICROARRAYS USING COPPER-MEDIATED CLICK CHEMISTRY

In this thesis we introduce a method to functionalize the surface of glassy materials with alkynes using a polymer that produces a coating by a facile 'dip and rinse' method. The alkyne groups on the tri-dimensional surface can be subsequently linked to azide-containing carbohydrates using Cu-catalyzed azide/alkyne cycloaddition (CuAAC, click chemistry)1,2. The research is aimed at developing a new strategy to generate a polymer coating enabling the attachment of complex sugars via click chemistry by a method that does not require skilled personnel and chemistry laboratories. The proposed approach combines the advantages of high sensitivity and superior signal-to-noise ratio of a Si-SiO2 substrate with the quality of a 3D coating. The Si/SiO2 surface was used as the substrate to take advantage from the superior optical properties of this material. A novel polymer named poly (DMA-PMA-MAPS), obtained from the polymerization of N,N-dimethylacrylamide (DMA), 3-trimethylsilanyl-prop-2-yn methacrylate (PMA) and 3(trimethoxysilyl)-propylmethacrylate (MAPS) was synthesized and characterized. It consists of: 1) a segment of polydimethylacrylamide that interacts with the surface by weak, non covalent interactions such as hydrogen bonding, Van der Waals or hydrophobic forces, 2) a pending silane hydrolysable monomers that promote condensation of the polymer with surface silanols or between contiguous chains and 3) chemically active monomers whose reactivity is selected on the basis of the reactivity of the molecules that have to be immobilized. The polymer reported herein is similar to another polymer developed in 2004 by Pirri et al.3 to form a coating on glass slides by a combination of physi- and chemi-sorption. The novelty of this work consists in the presence of an alkyne functional monomer that replaces the succinimide active ester. By exploiting the presence of a stable coating that allows regio-specific and bio-orthogonal immobilization, a glycan microarray was built and its performance was deeply investigated. First, a qualitative assay (fluorescence analysis) was carried out to obtain a fast screening of the affinity of the interaction of nine glycomimetics with Concanavlin A. Second, thanks to the high-sensitivity of the Si/SiO2 platform used, a study of the influence of the multivalency presentation of glycans during lectin interaction was made. The high-performing substrate used allows a dramatic decrease of glycan surface densities (from 1,96\u20221014 down to 5,07\u20221012 molecules/cm2), offering the possibility to calculate and compare the avidity in different conditions by providing density dependent surface dissociation constants (KD,surf). In a second different application, the new poly(DMA-PMA-MAPS) copolymer coating was used to functionalize microarray slides with orientated antibodies taking advantage from the regio-specific reaction between alkyne on the surface and azido groups on the biomolecule. Inspired by the work of Zeglis et al.4 an enzymatic procedure was devised to obtain site-specific modified antibodies using an unnatural UDP-6-azidogalactose and two commercially available enzymes: \u3b2-(1,4)-galactosidase and \u3b2-(1,4)-galactosyltransferase. As the 6-azidogalactose is sterically less hindered, it is expected to display a higher reactivity in the surface immobilization process. The strategy adopted was, in part, mutated from the procedure reported by Bosco et al.5. To validate the methodology and highlight its advantages, a sandwich microray test for the detection of interleukin-6 (IL-6) was developed. Cytokines, a set of proteins implicated in the onset and development of almost every major life-threatening disease are amongst the most intensively studied biomarkers. They play a prominent role in cancer, neurodegenerative diseases, cardiovascular diseases, sepsis and many other pathologies6. Although enzyme-linked immunosorbent assay (ELISA) is the gold standard for the measurement of a single cytokine concentration, the key to successful identification of biomarkers is the simultaneous detection of multiple cytokines with high sensitivity. IL-6 was chosen as a model of a typical inflammatory biomarker, to demonstrate the senistivity provided by an oriented immobilization of the capturing antibody in a microarray based immunoassay. Our site-specifically modified antibody was compared to both a randomly azido-pegylated antibody and a site-specifically modified antibody derivatized by a commercial Kit (Site-Click Antibody Labelling purchase from Life Technology), which makes use of an unnatural UDP-2-azidogalactose instead of UDP-6-azidogalactose, and of a mutant GalT (Y289L) instead of a commercially available GalT. Furthermore, through the use of the label-free sensing platform IRIS, we have correlated the efficiency of the Ab-antigen interaction given by the fluorescence signal with the mass of antibody immobilized per surface unit (ng/mm2). The fluorescence per mass unit allows to assess the importance the antibody orientation on its capturing ability. In particular its was demonstrated that a higher amount of immobilized probe does not necessary lead to a higher antibody-antigen interaction. (1) H. C. Kolb, M. G. Finn and K. B. Sharpless, Angew. Chem. Int. Ed., 2001, 40, 2004. (2) C. W. Torn\uf8e, C. Christensen and M. Meldal, J. Org. Chem., 2002, 67, 3057. (3) G. Pirri, F. Damin, M. Chiari, E. Bontempi, L. E. Depero, Anal. Chem., 2004, 76, 1352. (4) B. M. Zeglis, C. B. Davis, R. Aggeler, H. C. Kang, A. Chen, B. J. Anew and J. S. Lewis, Bioconjugate Chem., 2013, 24, 1057. (5) M. Bosco, S. Le Gall, C. Rihouey, S. Couve-Bonnaire, M. Bardol, P. Lerouge, X. Pannecoucke, Tethraedron Lett., 2008, 49, 2294. (6) R.P. Huang, B. Burkholder, V.S. Jones, W.D. Jiang, Y.Q. Mao, Q.L. Chen, Z. Shi, Current Proteomics, 2012, 9, 55

Flow boiling heat transfer capabilities of R134a low GWP substitutes inside a 4\ua0mm id horizontal smooth tube: R600a and R152a

R134a was recognized as probably one of the most important refrigerants of the two past decades. Among the proposed alternative fluids, there are certainly isobutane (R600a) and R152a.\ua0This article presents about 200 new heat transfer coefficient and pressure drop data obtained during flow boiling of R152a and R600a inside a smooth copper tube having an internal diameter of 4\ua0mm.\ua0Three saturation temperatures were considered for each refrigerant, from 5\ua0\ub0C to 20\ua0\ub0C. Furthermore, for each temperature studied, the heat flux was varied between 15 and 30\ua0kW\ua0m 122 and the refrigerant mass flux from 100 to 400\ua0kg\ua0m 122\ua0s 121. After presenting the new data, a critical comparison was proposed between the performance of these refrigerants and R134a. Finally, some classic correlations available in the literature have been implemented. The deviations between the calculated and experimental values were reported and commented

Universal hydrophilic coating of thermoplastic polymers currently used in microfluidics

A number of materials used to fabricate disposable microfluidic devices are hydrophobic in nature with water contact angles on their surface ranging from 80 to over 100. This characteristic makes them unsuitable for a number of microfluidic applications. Both the wettability and analyte adsorption parameters are highly dependent on the surface hydrophobicity. In this article, we propose a general method to coat the surface of five materials: polydimethylsiloxane (PDMS), cyclic olefin copolymer (COC), polyethylene terephthalate (PET), polycarbonate (PC), and polytetrafluoroethylene (PTFE). This fast and robust process, which is easily implementable in any laboratory including microfabrication clean room facilities, was devised by combining gas-phase and wet chemical modification processes. Two different coatings that improve the surface hydrophilicity were prepared via the "dip and rinse" approach by immersing the plasma oxidized materials into an aqueous solution of two different poly(dimethylacrylamide) copolymers incorporating a silane moiety and functionalized with either N-acryloyloxysuccinimide (NAS) (poly(DMA-NAS-MAPS) or glycidyl methacrylate (GMA) (poly(DMA-GMA-MAPS). The coating formation was confirmed by contact angle (CA) analysis comparing the variation of CAs of uncoated and coated surfaces subjected to different aging treatments. The antifouling character of the polymer was demonstrated by fluorescence and interferometric detection of proteins adsorbed on the surafce. This method is of great interest in microfluidics due to its broad applicability to a number of materials with varying chemical compositions

A corpus study of verbal multiword expressions in Brazilian Portuguese

Verbal multiword expressions (VMWEs) such as to make ends meet require special attention in NLP and linguistic research, and annotated corpora are valuable resources for studying them. Corpora annotated with VMWEs in several languages, including Brazilian Portuguese, were made freely available in the PARSEME shared task. The goal of this paper is to describe and analyze this corpus in terms of the characteristics of annotated VMWEs in Brazilian Portuguese. First, we summarize and exemplify the criteria used to annotate VMWEs. Then, we analyze their frequency, average length, discontinuities and variability. We further discuss challenging constructions and borderline cases. We believe that this analysis can improve the annotated corpus and its results can be used to develop systems for automatic VMWE identification

Characteristics of cured lard of Cinta Senese pig fed acorn and chestnut

Cured lard is a typical Tuscan dry-cured product, generally obtained from pigs of improved breeds intensively reared. The employment of extensive system in pig rearing could represent a concrete possibility to increase the added value of lard, as well as of the other cured products. Moreover, the general belief of a greater quality of products derived from unimproved pigs, particularly when reared outdoors, has been experimentally supported particularly in Iberian (Carrapiso et al., 2003; Cava et al., 2000) and Corsican pig (Coutron-Gambotti et al., 1998)

Fecal N excretion as an approach to estimate forage intake by sheep and cattle.

This study was carried out to evaluate the reliability of using faecal N as a predictor of organic matter (OM) intake by sheep and cattle fed a natural pasture hay

New "clickable" polymeric coating for glycan microarrays

The interaction of carbohydrates with a variety of biological targets, including antibodies, proteins, viruses and cells are of utmost importance in many aspects of biology. Glycan microarrays are increasingly used to determine the binding specificity of glycan-binding proteins. In this study, a novel slide is reported for the fabrication of glycan arrays that combines the higher sensitivity of a layered Si-SiO2 with a novel approach to form a polymeric coating easily modifiable by subsequent click reaction. The alkyne-containing copolymer, adsorbed from an aqueous solution, produces a coating by a single step procedure and serves as a soft, tridimensional support for the oriented immobilization of carbohydrates via azide/alkyne Cu(I) catalyzed "click" reaction. The equilibrium and kinetics parameters of the interaction of Concanavalin A with eight synthetic glycans were determined using fluorescence microarray and Reflective Phantom Interface (RPI), a recently proposed optical label-free detection approach. The enhancement of fluorescence provided by the Si-SiO2 slides enabled to extend the limit of detection at lower surface densities of lectins, in turn enabling the study of the interaction for a wide range of glycans surface density. Equilibrium dissociation constants of a few nM were extracted for multivalent glycan-lectin binding, mimicking the conditions of biological membranes, whereas hundreds of nM were observed at the lower glycan surface densities