16 research outputs found

    Auditory Resting-State Network Connectivity in Tinnitus: A Functional MRI Study

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    The underlying functional neuroanatomy of tinnitus remains poorly understood. Few studies have focused on functional cerebral connectivity changes in tinnitus patients. The aim of this study was to test if functional MRI “resting-state” connectivity patterns in auditory network differ between tinnitus patients and normal controls. Thirteen chronic tinnitus subjects and fifteen age-matched healthy controls were studied on a 3 tesla MRI. Connectivity was investigated using independent component analysis and an automated component selection approach taking into account the spatial and temporal properties of each component. Connectivity in extra-auditory regions such as brainstem, basal ganglia/NAc, cerebellum, parahippocampal, right prefrontal, parietal, and sensorimotor areas was found to be increased in tinnitus subjects. The right primary auditory cortex, left prefrontal, left fusiform gyrus, and bilateral occipital regions showed a decreased connectivity in tinnitus. These results show that there is a modification of cortical and subcortical functional connectivity in tinnitus encompassing attentional, mnemonic, and emotional networks. Our data corroborate the hypothesized implication of non-auditory regions in tinnitus physiopathology and suggest that various regions of the brain seem involved in the persistent awareness of the phenomenon as well as in the development of the associated distress leading to disabling chronic tinnitus

    Advances in heterometallic ring-opening (co)polymerisation catalysis

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    Truly sustainable plastics require renewable feedstocks coupled with efficient production and end-of-life degradation/recycling processes. Some of the most useful degradable materials are aliphatic polyesters, polycarbonates and polyamides, which are often prepared via ring-opening (co)polymerisation (RO(CO)P) using an organometallic catalyst. While there has been extensive research into ligand development, heterometallic cooperativity offers an equally promising yet underexplored strategy to improve catalyst performance, as heterometallic catalysts often exhibit significant activity and selectivity enhancements compared to their homometallic counterparts. This review describes advances in heterometallic RO(CO)P catalyst design, highlighting the overarching structure-activity trends and reactivity patterns to inform future catalyst design

    Statistical and Sensory Differences Among Special Bottle Refermented Beers of a Same Type

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    Some countries such as Belgium, Germany, and the United Kingdom are notable for the large quantities of special beer they produce and sell worldwide. When these special beers are classified by type, some classes may include as many as eighty labels. Our aim was to propose a method for detecting the organoleptic specificity of beers by physicochemical analysis. We thus selected eigtheen parameters, independent of beer aging, which characterize a product's visual aspect, aroma, taste, and mouthfeel. The results were analyzed statistically to allow an evaluation of process reproducibility and a comparison of mean values. We conclude that despite relatively poor process reproducibility, the four beers studied here present sufficient distinctive features to make them different. This finding was corroborated by sensory analysis

    Cadmium in the food chain near non-ferrous metal production sites.

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    Dietary cadmium (Cd) exposure was estimated for adults living in Cd-contaminated areas close to non-ferrous metal plants and compared with dietary Cd exposure in the general Belgian adult population. To evaluate the contamination levels of locally produced food items, 35 fruit samples, 97 vegetable samples, 98 samples of potatoes and 53 samples of meat, liver and kidney of cattle, which had resided for more than 18 months in the contaminated area, were analyzed for Cd. Mean Cd concentrations in fruit and vegetables were 1.1- to 9-fold higher than in samples from other regions at ambient Cd levels. Mean Cd concentrations in bovine meat, liver and kidney were 2-fold higher compared to samples from animals in other regions of Belgium. The estimated dietary intake was 31.3 and 63.3 microg day(-1) for average and large consumers, respectively, in the contaminated area, compared to 17 and 38.3 microg day(-1), respectively, for the general adult population. Excessive consumption of locally produced food items in areas close to non-ferrous metal plants could result in Cd intake levels exceeding the provisional tolerable weekly intake (PTWI)

    State- and trait-related alterations of motor cortex excitability in tinnitus patients

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    Chronic tinnitus is a brain network disorder with involvement of auditory and non-auditory areas. Repetitive transcranial magnetic stimulation (rTMS) over the temporal cortex has been investigated for the treatment of tinnitus. Several small studies suggest that motor cortex excitability is altered in people with tinnitus. We retrospectively analysed data from 231 patients with chronic tinnitus and 120 healthy controls by pooling data from different studies. Variables of interest were resting motor threshold (RMT), short-interval intra-cortical inhibition (SICI), intra-cortical facilitation (ICF), and cortical silent period (CSP). 118 patients were tested twice - before and after ten rTMS treatment sessions over the left temporal cortex. In tinnitus patients SICI and ICF were increased and CSP was shortened as compared to healthy controls. There was no group difference in RMT. Treatment related amelioration of tinnitus symptoms were correlated with normalisations in SICI. These findings confirm earlier studies of abnormal motor cortex excitability in tinnitus patients. Moreover our longitudinal data suggest that altered SICI may reflect a state parameter, whereas CSP and ICF may rather mirror a trait-like predisposing factor of tinnitus. These findings are new and innovative as they enlarge the knowledge about basic physiologic and neuroplastic processes in tinnitus
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