0000000000022939
AUTHOR
Alain Beck
Ultrasonography for evaluation of the carotid artery in head and neck cancer.
The dynamic relationship of lymph node metastases to surrounding vascular structures in the neck is important for preoperative patient assessment. When carotid artery involvement is suspected, this relationship often determines whether or not to operate. In the case of adhesive neck metastases along the internal jugular vein, it becomes possible to predict preoperatively if the integrity of this vein may be preserved. Ultrasonography has the ability to differentiate subtle from gross adherence, or simple compression from vascular invasion. This is done by manually palpating the tumor mass and asking the patient to perform various maneuvers while observing on a monitor the relationship of th…
Ultra-short ion-exchange columns for fast charge variants analysis of therapeutic proteins
Abstract The purpose of this work was to study the potential of recently developed ultra-short column hardware for ion exchange chromatography (IEX). Various prototype and commercial columns having lengths of 5, 10, 15, 20 and 50 mm and packed with non-porous 3 µm particles were systematically compared. Both pH and salt gradient modes of elution were evaluated. Similarly, what has been previously reported for reversed phase liquid chromatography (RPLC) mode, an “on-off” retention mechanism was observed in IEX for therapeutic proteins and their fragments (25–150 kDa range). Because of the non-porous nature of the IEX packing material, the column porosity was relatively low (e = 0.42) and the…