Application of RF correction in thin-layer chromatography by means of two reference RF values

Results of the inter-laboratory experiment described in this paper show that the GALANOS AND KAPOULAS equation can be applied satisfactorily to correct RF values obtained on thin-layer chromatograms in a polar multi-component solvent. Addition of Kieselguhr to the silica gel gives RFc values different from the RFc values found on silica gel alone, the deviation being independent of the amount of Kieselguhr added

Supplementary Material for: Clinical Evaluation of an Image-Guided Cochlear Implant Programming Strategy

<p>The cochlear implant (CI) has been labeled the most successful neural prosthesis. Despite this success, a significant number of CI recipients experience poor speech understanding, and, even among the best performers, restoration to normal auditory fidelity is rare. While significant research efforts have been devoted to improving stimulation strategies, few developments have led to significant hearing improvement over the past two decades. We have recently introduced image processing techniques that open a new direction for advancement in this field by making it possible, for the first time, to determine the position of implanted CI electrodes relative to the nerves they stimulate using computed tomography images. In this article, we present results of an image-guided, patient-customized approach to stimulation that utilizes the electrode position information our image processing techniques provide. This approach allows us to identify electrodes that cause overlapping stimulation patterns and to deactivate them from a patient's map. This individualized mapping strategy yields significant improvement in speech understanding in both quiet and noise as well as improved spectral resolution in the 68 adult CI recipients studied to date. Our results indicate that image guidance can improve hearing outcomes for many existing CI recipients without requiring additional surgery or the use of ‘experimental' stimulation strategies, hardware or software.</p

Early Magnetic Resonance Imaging and Cognitive Markers of Hereditary Cerebral Amyloid Angiopathy

BACKGROUND AND PURPOSE: Early markers for cerebral amyloid angiopathy (CAA) are largely unknown. We aimed to identify which MRI (performed at 7 tesla and 3 tesla) and cognitive markers are an early sign in (pre-)symptomatic subjects with Hereditary Cerebral Hemorrhage With Amyloidosis-Dutch type (HCHWA-D). METHODS: Twenty-seven DNA-proven Dutch type mutation carriers (15 symptomatic and 12 pre-symptomatic) (mean age of 45.9) and 33 controls (mean age of 45.6) were included. 7T and 3T MRI was performed, CAA and small vessel disease type MRI markers were estimated, and cognitive performance was assessed. Univariate general linear modeling analysis was used to assess the association between MRI markers and cognitive performance on the one hand, and on the other mutation status, adjusted for age, sex and education. RESULTS: In symptomatic patients, all established CAA MRI markers (microbleeds, intracerebral hemorrhages, subarachnoid hemorrhages, superficial siderosis, microinfarcts, volume of white matter hyperintensities (WMHs) and dilated perivascular spaces in centrum semiovale) were increased compared to controls (p<0.05). In pre-symptomatic subjects, the prevalence of microinfarcts and median volume of WMHs were increased in comparison to controls (p<0.05). Symptomatic patients performed worse on all cognitive domains, whereas pre-symptomatic subjects did not show differences in comparison with controls (p<0.05). CONCLUSIONS: WMHs and microinfarcts are more prevalent among pre-symptomatic subjects and precede cognitive and neuropsychiatric symptoms and intracerebral hemorrhages