Dual copper- and photoredox-catalysed reactions

The merger of transition metal catalysis with visible light photoredox catalysis in a cooperative fashion has recently emerged as a versatile way of developing new synthetic methodologies. This review will focus on the relatively new but fast expanding area of dual copper- and photoredox-catalysis, detailing recent developments in the area.     

Purification of monoclonal antibody from tobacco extract using membrane-based bioseparation techniques

Transgenic plants offer a promising system for large-scale production of therapeutic proteins such as monoclonal antibodies (mAbs). This paper describes a membrane-based process suitable for purification of a humanized mAb expressed in tobacco. Most monoclonal antibody purification schemes rely on the use of Protein A as the affinity ligand for antibody capture. The main objective of our work was to develop non-Protein A-based purification methods to avoid some of the problems and limitations associated with this ligand, e.g. cost, immunotoxicity, and antibody aggregation during elution. Ion exchange membrane chromatography (IEMC) was used for primary capture and preliminary purification of the mAb from tobacco juice. Hydrophobic interaction membrane chromatography (HIMC) was then used for high-resolution purification, followed by ultrafiltration for polishing, desalting and buffer exchange. Using this scheme, both high mAb purity (single peak in size exclusion chromatogram, i.e., ca. 100% purity) and high recovery (77% of mAb spiked into the tobacco extract) were achieved. Membrane chromatography is generally considered unsuitable for resolving bound proteins by gradient elution and is therefore commonly used in the bind and elute mode with a single-step change of mobile phase. We show that the gradient elution process in the HIMC step can be optimized to increase the resolution and thereby obtain product of high purity.     

Time resolved resonance fluorescence study of electronically excited iodine atoms, I(5P1/2)

Electronically excited iodine atoms, I(5²P_1/2), have been monitored using time resolved atomic resonance fluorescence. Rate data for quenching by C₃H₈ and CD₄ are presented.     

Determination of therapeutic plasma concentrations of tetrabenazine and an active metabolite by high-performance liquid chromatography

A reversed-phase high-performance liquid chromatographic method for the determination of tetrabenazine and a hydroxy metabolite in plasma is described. Tetrabenazine and the hydroxy metabolite are quantified as their dehydro derivatives using fluorescence detection. This method has been applied to the analysis of plasma samples from patients with Huntington's chorea and has been found to be sensitive, reliable and specific for tetrabenazine and the hydroxy metabolite. The plasma concentrations of tetrabenazine found in patients were lower than could be detected using previously published methods.     

The influence of aliphatic diols on the temperature of maximum density of water

The influence of various aliphatic diols on the temperature of maximum density (TMD) of water has been investigated. 1,2-Propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 2,5-hexanediol were found to yield positive structural contributions to the solute-induced shift in the TMD, i.e., they are structure makers. Contrariwise, data from the literature indicate that 1,2-ethanediol is a structure breaker. Relationships between the structure making/breaking tendencies of the solutes and the relative positions of the two hydroxyl groups are discussed.     

Slab-gel electrophoresis of commercial iodine-125 fibrinogen

The deposition of¹²⁵I in three commercial preparations using polyacrylamide slab gel electrophoresis is studied.     

Harmonic generation process of Gor'kov and Éliashberg

The practicability is discussed of observing one of the electromagnetic phenomena in gapless superconductors predicted by Gor'kov and Éliashberg. The use of realistic boundary conditions shows that the effect should be more difficult to observe than they had indicated.