Subliminal and supraliminal processing of reward-related stimuli in anorexia nervosa.

BACKGROUND: Previous studies have highlighted the role of the brain reward and cognitive control systems in the etiology of anorexia nervosa (AN). In an attempt to disentangle the relative contribution of these systems to the disorder, we used functional magnetic resonance imaging (fMRI) to investigate hemodynamic responses to reward-related stimuli presented both subliminally and supraliminally in acutely underweight AN patients and age-matched healthy controls (HC). METHODS: fMRI data were collected from a total of 35 AN patients and 35 HC, while they passively viewed subliminally and supraliminally presented streams of food, positive social, and neutral stimuli. Activation patterns of the group × stimulation condition × stimulus type interaction were interrogated to investigate potential group differences in processing different stimulus types under the two stimulation conditions. Moreover, changes in functional connectivity were investigated using generalized psychophysiological interaction analysis. RESULTS: AN patients showed a generally increased response to supraliminally presented stimuli in the inferior frontal junction (IFJ), but no alterations within the reward system. Increased activation during supraliminal stimulation with food stimuli was observed in the AN group in visual regions including superior occipital gyrus and the fusiform gyrus/parahippocampal gyrus. No group difference was found with respect to the subliminal stimulation condition and functional connectivity. CONCLUSION: Increased IFJ activation in AN during supraliminal stimulation may indicate hyperactive cognitive control, which resonates with clinical presentation of excessive self-control in AN patients. Increased activation to food stimuli in visual regions may be interpreted in light of an attentional food bias in AN.

Combined nitrogen, hexane, and benzene adsorption characterization of pores and surfaces of lyophobic mesoporous silicas.

For lyophobic porous surfaces, structural analysis by vapor adsorption is complicated due to weak adsorbate-adsorbent interactions and limited wetting of the pores (nonzero contact angles). To investigate further, adsorption isotherms of three distinct adsorbates (nitrogen - 77 K, n-hexane and benzene - 298 K) were studied for SBA-15 ordered mesoporous silica where the surface was functionalized with lyophobic perfluoroalkyl groups (C6F13 termini). The results demonstrated a clear advantage of the combined use of the adsorption isotherms of less surface sensitive (nitrogen) and more surface sensitive (hydrocarbons) adsorbates. The adsorption of nitrogen provided basic structural characteristics like surface area, pore volume, and pore size distribution, while the isotherms of benzene and n-hexane were used to characterize wetting (contact angles) and surface energy of the C6F13 surfaces within the pores. For the first time, the statistical film thickness for nitrogen, benzene, and n-hexane are being reported for the adsorption on fluorinated surfaces, thereby providing critical data for the pore size and the contact angle determination of the lyophobic materials.

[Introduction of definite molecular weight heparan sulfate in a protocol of prevention of deep venous thrombosis in prosthetic orthopedic surgery]. / Introduzione del eparan solfato a peso molecolare definito in un protocollo di prevenzione della TVP nella chirurgia ortopedica protesica.

Use of definite molecular weight heparan sulphate in a protocol for the prevention of deep venous thrombosis in the total joint replacement surgery. The authors propose a working protocol for the prevention of deep venous thrombosis in prosthetic orthopaedic surgery. It requires that integration of pharmacological, anaesthesiological, rheological and physiokinesitherapic measures, it has permitted a very good prevention of thromboembolic disease and it is well-tolerated and safe. The protocol requires: peripheral anaesthesia (sub-arachnoidal block), pre and post-operative pharmacological treatment with heparan-sulphate of a fixed molecular weight, haemodilution with maintenance of the haematocrit at no more than 30%, early physiokinesitherapy associated with the use of elastic stockings graduated tension. The fifty patients treated with this protocol were controlled during the pre-operative and post-operative stage and one month later and no thrombo-embolic complications resulted.