Insider behavior under different market structures: experimental evidence on trading patterns,manipulation, and profitability

Central European Journal of Operations Research - We conduct laboratory experiments incorporating different market structures and insiders who compete with imperfectly informed traders. The...     

Why not using capillary electrophoresis in drug analysis?

CE and related methods are well-established techniques in the analysis of biomolecules, such as DNA and proteins. Even though CE is a rather good alternative to HPLC for the evaluation of the impurity profile and the enantiomeric purity of a drug, it is rarely applied. This might be due to the reservation of national licensing authorities and the pharmacopoeia commissions for several reasons. In this review containing some experimental data we report on several drug examples which demonstrate the superiority of CE over HPLC in special cases, i.e., in the analysis of antibiotics, amino acids and peptides, and the determination of enantiomeric purity. However, in order to make the CE techniques more suitable for pharmacopoeial purposes the general methods describing separation methods have to be complemented with the adjustment of the electrophoretic conditions being necessary to satisfy the system suitability criteria without fundamentally modifying the methods. Taken together CE should be more often applied in drug quality control.     

Structure of the active site of sulfite dehydrogenase from Starkeya novella

In this paper, we report the results of molybdenum K-edge X-ray absorption studies performed on the oxidized and reduced active sites of the sulfite dehydrogenase from Starkeya novella. Our results provide the first direct structural information on the active site of the oxidized form of this enzyme and confirm the conclusions derived from protein crystallography that the molybdenum coordination is analogous to that of the sulfite oxidases. The molybdenum atom of the oxidized enzyme is bound by two Mo=O ligands at 1.73 A and three thiolate Mo-S ligands at 2.42 A, whereas the reduced enzyme has one oxo at 1.74 A, one long oxygen at 2.19 A (characteristic of Mo-OH2), and three Mo-S ligands at 2.40 A.     

Asymmetric homogeneous hydrogenation of 2,5-disubstituted furans

A homogeneous catalyst system for the asymmetric cis-hydrogenation of 2,5-disubstituted furans leading to 2',3'-dideoxynucleoside analogues is described. Best enantioselectivities (ee values of up to 72%) were obtained with cationic rhodium complexes ligated by diphospholanes of the butiphane family. The selectivity of the hydrogenation was reversed by the addition of a base or a polar protic solvent in certain cases. Ferrocene- and proline-based systems gave significant, but lower, ee values.