990 resultados para Bridged Compounds -- administration


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There is an increasing demand to develop biosensor monitoring devices capable of biomarker profiling for predicting animal adulteration and detecting multiple chemical contaminants or toxins in food produce. Surface plasmon resonance (SPR) biosensors are label free detection systems that monitor the binding of specific biomolecular recognition elements with binding partners. Essential to this technology are the production of biochips where a selected binding partner, antibody, biomarker protein or low molecular weight contaminant, is immobilised. A micro-fluidic immobilisation device allowing the covalent attachment of up to 16 binding partners in a linear array on a single surface has been developed for compatibility with a prototype multiplex SPR analyser.<br/><br/>The immobilisation unit and multiplex SPR analyser were respectively evaluated in their ability to be fit-for-purpose for binding partner attachment and detection of high and low molecular weight molecules. The multiplexing capability of the dual technology was assessed using phycotoxin concentration analysis as a model system. The parent compounds of four toxin groups were immobilised within a single chip format and calibration curves were achieved. The chip design and SPR technology allowed the compartmentalisation of the binding interactions for each toxin group offering the added benefit of being able to distinguish between toxin families and perform concentration analysis. This model is particularly contemporary with the current drive to replace biological methods for phycotoxin screening.<br/>

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Triply-bridged disilver complexes [Ag-2(mu(2)-dppa-P,P')(3)(anion)(2)] form selectively and are stabilised by many aromatic interactions.

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The disilylated compound 1,4-bis(trimethylsilyl)-2,3,5,6-tetrakis((dimethylamino)methyl)benzene, (Me(3)Si)(2)C2N4, 4, can be electrophilically palladated selectively at the C-Si bonds to afford the neutral 1,4-bis(palladium) complex [(AcOPd)(2)(C2N4)], from which the dicationic [(LPd)(2)(C2N4)](2+) (L = MeCN) organometallic species are accessible. The monosilylated species (Me(3)Si)(H)C2N4, 5, can be used for the preparation of the dicationic heterodinuclear platinum(II)-palladium(II) species [(LPd)(LPt)(C2N4)](2+) (L = MeCN) via a sequence of transmetalation of the organolithium derivative of 5 with [PtCl2(SEt(2))(2)], followed by a C-Si bond palladation reaction.

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The bovine spongiform encephalopathy (BSE) outbreak in the United Kingdom is regarded as one of the worst public policy crises the British government has experienced during the postwar era. In material terms, it has led to the slaughter of 3.3 million cattle and estimated economic losses of £3.7 billion. In administrative terms, the crisis brought about the dissolution of the Ministry of Agriculture, Fisheries and Food. This article examines the istitutional context in which decisions about the scientific evidence on BSE were made. The authors argue that a centralized system in which government agencies control science for government is inherently vulnerable to alliances of experts and interest groups that undermine the credible assessment of public health and safety risks. Specific societal conditions may encourage risk-opportunistic behavior among policy makers that is conducive to delays and inaction until such time as the evidence of a health risk becomes overwhelming.

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The novel ligand 4'-diferrocenylallcyne-2,2':6',2 ''-terpyridine (7; Fc-C C-Fc-tpy; tpy = terpyridyl; Fc = ferrocenyl) and its Ru2+ complexes 8-10 have been synthesized and characterized by single-crystal X-ray diffraction, cyclic voltammetry, and UV-vis and luminescence spectroscopy. Electrochemical data and UV absorption and emission spectra indicate that the insertion of an ethynyl group causes delocalization of electrons in the extended pi* orbitals. Cyclic voltammetric measurements of 7 show two successive reversible one-electron-oxidation processes with half-wave potentials of 0.53 and 0.78 V. The small variations of the E-1/2 values for the Fe2+/Fe3+ redox couples after the coordination of the Ru2+ ion suggest a weak interaction between the Ru2+ and Fe2+ centers. After insertion of an ethynyl group, UV-vis absorption spectra show a red shift of the absorption peak of the (1)[(d(pi)(Fe))(6)]-&gt;(1)[(d(pi)(Fe))(5)(pi*(Ru)(tpy))(1)] MMLCT of the Ru2+ complexes. The Ru2+ complex 8 exhibits the strongest luminescence intensity (lambda(em)(max) 712 nm, Phi(em) = 2.63 x 10(-4), tau = 323 ns) relative to analogous ferrocene-based terpyridine Ru(II) complexes in H2O/CH3CN (4/1 v/v) solution.

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The impacts of psychoactive drugs on timing have usefully informed theories of timing and its substrates.

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The possible adverse effects on health of diet-derived advanced glycation endproducts (AGES) and advanced lipoxidation endproducts (ALES) is of current interest. This study had the objective of determining the effects of the addition of AGE/ALE inhibitors and different types of sugar and cooking oil on N-epsilon-(carboxymethyl)lysine (CML) and N-epsilon-(carboxyethyl)lysine (CEL) formation in model foods (sponge cakes). The cake baked using glucose produced the highest level of CML (2.07 +/- 0.24 mmol/mol lysine), whereas the cake baked using fructose produced the highest concentration of CEL (25.1 +/- 0.15 mmol/mol lysine). There were no significant differences between CML concentrations formed in the cakes prepared using different types of cooking oil, but significant differences (P

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Azobenzene dyes derived from various anilines and aminothiaheterocycles ate-coupled with commercially important N,N-diethyl-m-toluidine (T series) and iv,N-diethyl-m-acetylaminoaniline (A series) are positively solvatochromic. The visible spectra of 16 pairs of derivatives have been measured in up to 22 solvents, and the transition energies related to Kamlet-Taft solvent polarity parameters. In general, A-series dyes are more bathochromic than their T-series counterparts in nonpolar solvents, consistent with colour chemistry tradition, However, in more dipolar solvents the more bathochromic T-series representatives unexpectedly become more bathochromic than their A-series partners. The relative solvatochromic shifts of the A and T series are related to their respective dipole moments, These in turn are distinguished by the effect of the anilide carbonyl group dipole moment, which is antiparallel to, and thus reduces, the dipole moment of the chromogen.