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We study axial heterogeneities in capillary ultrahigh pressure liquid chromatography (UHPLC) columns through kinetic performance and bed morphological analysis. Two columns are used in this work, a 75 μm i.d. × 100 cm column packed with 1.3 μm C18-silica particles and a 75 μm i.d. × 45 cm column packed with 1.9 μm C18-silica particles. The long column is chromatographically characterized and is afterwards sectioned into three segments, each analyzed individually. The column packed with the 1.9 μm particles is subjected to a bed morphological analysis using confocal laser scanning microscopy near the inlet, center, and outlet of the column. Chromatographic and morphological characterizations reveal highest separation efficiency and most homogeneous bed microstructure towards the column outlet. Kinetic performance data for inlet and central packing segments indicate enhanced contributions from wall effects to a transcolumn flow heterogeneity. Bed morphological data reveal systematic changes in geometrical and frictional wall effects along the bed: from inlet to outlet, bed morphologies increasingly reflect packing microstructures associated with concentrated slurries. Variations in separation efficiency and bed morphology can be related to the constant-pressure packing mode; the decrease in packing rate along the bed leaves fewer chances for particle rearrangement and bed consolidation from inlet to outlet. It explains the relatively uniform bed morphology towards the outlet and also the relatively loose wall region near the inlet. Bed microstructural features are discussed in a context of previous observations made in the characterization of capillary UHPLC columns., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Aims: to investigate a possible association of cortisol stress response during early abstention with relapse., Methods: Thirty-six alcohol-dependent males, half of them with a comorbid anxiety disorder, and 15 healthy controls were exposed to a standardized psychosocial stress test. Thirty-one of the patients were assessed for relapse 6 weeks after discharge., Results: The relapsers showed almost no cortisol responses in the stress test. Comorbid anxiety disorder influenced neither stress response nor relapse., Conclusions: During early abstention from alcohol, reduced stress-responsivity of the hypothalamo-pituitary-adrenocortical axis seems to be connected to early relapse.

The goals of this study were to describe demographic variables, drinking history, and the 6-month prevalence of Axis I comorbidity among alcohol-dependent subjects in GERMANY: The variables: amount of alcohol consumption, age at onset of the first alcohol consumed, age at onset of daily alcohol consumption, age at onset of withdrawal symptoms and number of detoxifications were related to the different comorbid disorders and gender. In this study, 556 patients from 25 alcohol treatment centres were enrolled between 1 January 1999 and 30 April 1999. After a minimum of 10 days of sobriety patients who fulfilled ICD-10 and DSM-IV criteria of alcohol dependence were interviewed for data collection using the Mini-DIPS (German version of the Anxiety Disorders Interview Schedule) and a standardized psychosocial interview. The 6-month prevalence of comorbid Axis I disorders was 53.1%. Among the patients with comorbidity, affective and anxiety disorders were most frequent. Comorbid stress disorder was associated with an early start of drinking, an early beginning of withdrawal symptoms, highest number of detoxifications, and the highest amount of alcohol consumed. Female patients with anxiety disorder consumed more alcohol and started earlier than females without this comorbid disorder. The data do not answer the question of the pathogenesis of comorbid disorders and alcoholism, but indicate that stress disorders in alcoholic patients and anxiety disorders in female alcoholics influence the course and severity of alcoholism.