RESUMEN
Countercurrent chromatography (CCC) is an attractive separation method because the analytes are partitioned between two immiscible liquid phases avoiding problems related to solid stationary phase. In recent years, this technique has made great progress in separation power and detection potential. This review describes coupling strategies involving high speed CCC (HSCCC) or centrifugal partition chromatography (CPC). It includes on-line extraction-isolation, hyphenation with mass spectrometry (MS) and nuclear magnetic resonance (NMR) detectors, multidimensional CCC (MDCCC), two-dimensional CCC (2D-CCC), on-line coupling with liquid chromatography (LC), and biological tests, and innovative off-line developments. The basic principles of each method are presented and applications are summarized.
Asunto(s)
Centrifugación/tendencias , Distribución en Contracorriente/tendencias , Animales , Centrifugación/instrumentación , Centrifugación/métodos , Cromoterapia/instrumentación , Cromoterapia/métodos , Cromoterapia/tendencias , Distribución en Contracorriente/instrumentación , Distribución en Contracorriente/métodos , Humanos , Péptidos/análisis , Péptidos/aislamiento & purificación , Extractos Vegetales/análisis , Extractos Vegetales/aislamiento & purificaciónRESUMEN
Attentional bias plays an important role in the development and maintenance of alcohol addiction, and has often been measured with a visual probe task, where reaction times are compared for probes replacing either a substancerelated cue or a neutral cue. Systematic low-level differences between image classes are a potential cause of low internal reliability of the probe task (Ataya et al., 2012). Moreover, it is unclear whether automatic attentional capture by low-level properties such as size and colour in the non-substance related image could reduce attentional bias to the alcohol-related cue. Here, alcohol-related attentional bias was assessed in moderate social drinkers by measuring reaction times to targets that replaced either an alcohol-related or a non-alcohol related (i.e., neutral) picture. All alcohol-related images were greyscale, and the neutral stimulus could be either greyscale (control), in colour (colour), or greyscale and 25% larger in size (25% larger size). We found attentional bias towards the alcohol-related stimuli in the control and 25% larger size conditions, but not in the colour condition. The magnitude of attentional bias was significantly reduced in the colour condition compared to the control and 25% larger size conditions. These findings indicate that salient low-level features in the non-substance related cue, in particular colour, can reduce the effect of alcohol-related content on the allocation of alcohol drinkers attention. Further, the results highlight the need for image pairs in visual probe tasks to be closely matched on basic perceptual dimensions (AU)
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