DPP IV resistance and insulin releasing activity of a novel di-substituted analogue of glucose-dependent insulinotropic polypeptide, (Ser(2)-Asp(13))GIP

Structure-function studies suggest that preservation of the N-terminus and secondary structure of glucose-dependent insulinotropic polypeptide (GIP) is important for biological activity. Therefore, a novel di-substituted analogue of GIP, (Ser(2)-Asp(13))GIP, containing a negatively charged Asp residue in place of an Ala in position 13, seas synthesised and evaluated for in vitro biological activity. Incubation with dipeptidyl peptidase IV (DPP IV) showed the half-lives of GIP and (Ser(2)-Asp(13))GIP to be 2.3 and >4 h, respectively. Insulin releasing studies in clonal pancreatic BRIN-BD11 cells demonstrated that (Ser(2)-Asp(13))GIP (10(-12) to 10(-7) mol/l) was significantly less potent (60-90%; P

Formation of Novel Di-Nuclear Lanthanide Luminescent Sm(III), Eu(III) and Tb(III) Triple Stranded Helicates from a C2 Symmetrically 2,6-Dicarboxylic Amide based 1,3-Xylene Ligand in CH3CN

The synthesis of the C2-symmetrical ligand 1 consisting of two naphthalene units connected to two pyridine-2,6-dicarboxamide moieties linked by a xylene spacer and the formation of LnIII-based (Ln1/4 Sm, Eu, Tb, and Lu) dimetallic helicates [Ln2 · 13] in MeCN by means of a metal-directed synthesis is described. By analyzing the metal-induced changes in the absorption and the fluorescence of 1, the formation of the helicates, and the presence of a second species [Ln2 · 12] was confirmed by nonlinear- regression analysis. While significant changes were observed in the photophysical properties of 1, the most dramatic changes were observed in the metal-centred lanthanide emissions, upon excitation of the naphthalene antennae. From the changes in the lanthanide emission, we were able to demonstrate that these helicates were formed in high yields (ca. 90% after the addition of 0.6 equiv. of LnIII), with high binding constants, which matched well with that determined from the changes in the absorption spectra. The formation of the LuIII helicate, [ Lu2 · 13 ] , was also investigated for comparison purposes, as we were unable to obtain accurate binding constants from the changes in the fluorescence emission upon formation of [Sm2 · 13], [Eu2 · 13], and [Tb2 · 13].

La ciudad de Rávena y los paisajes de la abstracción en "Deserto Rosso" de Michelangelo Antonioni

La presente investigación trata de poner énfasis en la importancia del paisaje en Deserto Rosso de Michelangelo Antonioni, erigiéndose este como elemento fundamental de la trama argumental del filme. Partiendo de esta premisa, se analiza el significado de dicho paisaje en el contexto socioartístico de los años 60. La interacción del hombre con su entorno parece ser el punto de partida para una reflexión más profunda sobre el devenir humano. Las nuevas conquistas estéticas alcanzadas y el análisis históricoartístico de los precedentes más inmediatos del filme, sitúan a Deserto Rosso como obra cumbre de la neovanguardia posmoderna europea.

Some thoughts on Juan Antonio Ramírez´s iconologic-paranoid method for the study of Dali´s works

In 1990, Juan Antonio Ramírez made known his iconological paranoiac method to the academic world. It is a system devised to study Dalí´s work, born of happy matrimony between the catalonian artist´s critical paranoiac method and the first iconographic school of Warburg and Panofsky. What, at first sight, seemed to be an extravagant methodology with little academic credibility, turned out to be, by going forward in time, an effective research method when analyzing Dali´s initial works. It is no wonder that, at the beginning of XXI century, this hybridization between Dalí´s and Panofsky’s methods, were regarded as a strange and nonsensical idea. Nevertheless, twenty years after, blatant examples have been noted, which endorse the advantages of this new system for “iconographic” study. As usual, this new contribution by Juan Antonio Ramirez to art history methodology is called upon to have a successful future survival, in forthcoming generations. This article, attempts to analyze this method, inquiring into the validity, effectiveness and practical utility.

Poly[[dibromomercury(II)]-di-mu-pyrazine-kappa N-4 : N ']

The crystal structure of [HgBr2(Pyp)(2)](n) (Pyp = pyrazine, C4H4N2) consists of almost linear HgBr2 molecules which are linked by pyrazine molecules to form double strands of a coordination polymer in the [010] direction. The Hg and Br atoms lie on mirror planes.

Toxicity of mono-, di- and tri-chlorophenols to lux marked terrestrial bacteria, Burkholderia species Rasc c2 and Pseudomonas fluorescens

Burkholderia species RASC and Pseudomonas fluorescens were marked with lux genes, encoding for bioluminescence and used to assess the toxicity of mono-, di- and tri-chlorophenols by determining the decline in bioluminescence following exposure to the compounds in aqueous solution. Toxicity was expressed as a 50% effective concentration value (EC50, equating to the concentration of compound which caused a 50% decline in bioluminescence. Comparing the toxicity values of the compounds showed that, in general, increasing the degree of chlorination, increased toxicity. By carrying out forward multiple linear regressions with log10 EC50 values and physio-chemical descriptors, it was shown that molecular parameters describing the hydrogen bonding nature of a chlorophenol provided a better fit than regressions between toxicity data and log10 Kow alone. Utilising these descriptor variables in equations, it was shown that the toxicity of chlorophenols to the lux marked bacteria could be predicted from the compounds physio-chemical characteristics. By correlating lux marked RASC c2 and P. fluorescens EC50 values with toxicity values using Pimephales promelas (fathead minnow), Tetrahymena pyriformis (ciliate) and marine bacterium Vibriofischeri, it was apparent that lux marked RASC c2 correlated well with the freshwater aquatic species (P. promelas and T. pyriformis). This implied that for predictions of toxicity of organic xenobiotic compounds to higher organisms, lux marked RASC c2 could be utilised as a rapid surrogate.