Volume transmission is a form of intercellular communication that does not require synapses; it is based on the diffusion of neuroactive substances across the brain extracellular space (ECS) and their binding to extrasynaptic high-affinity receptors on neurons or glia. Extracellular diffusion is restricted by the limited volume of the ECS, which is described by the ECS volume fraction α, and th...

Diffusion of intracellular water was measured in perfused cells embedded in basement membrane gel threads. F98 glioma cells, primary astrocytes, and epithelial KB cells were used and were exposed to osmotic stress, immunosuppressiva, the water channel blocker p-chloromercuriobenzenesulfonate (pCMBS), and apoptotic conditions. With diffusion-weighted 1H NMR spectroscopy changes in the intracellu...

Approximately 40% of males with the fragile X premutation develop fragile X-associated tremor/ataxia syndrome after age 50. Although the thalamus and basal ganglia play a crucial role in movement disorders, their involvement in fragile X premutation carriers has not been systematically investigated. The current study characterized structural abnormalities associated with fragile X premutation c...

BACKGROUND AND PURPOSE ADC as a marker of tumor cellularity has been promising for evaluating the response to therapy in patients with glioblastoma but does not successfully stratify patients according to outcomes, especially in the upfront setting. Here we investigate whether restriction spectrum imaging, an advanced diffusion imaging model, performed after an operation but before radiation th...

Diffusion tensor imaging has been widely used to study brain diseases, disorders, development, and aging. However, few studies have explored the effects of aging on diffusion imaging measures with higher b values. Further, the water diffusion in biological tissues appears biexponential, although this also has not been explored with aging. In this study, hybrid diffusion imaging (HYDI) was used ...

Effect of the volume phase transition on the diffusion and concentration of molecular probes was studied in temperature-responsive polymeric hydrogels. Results were compared for two gels, poly(N-isopropylacrylamide), NIPA, and poly(N-isopropylacrylamide-co-acrylic acid), NIPA-AA. These gels undergo discontinuous, reversible volume phase transition as a response to temperature changes; this tran...

Here we present blind source separation (BSS) as a new tool to analyse multi-echo diffusion data. This technique is designed to separate mixed signals and is widely used in audio and image processing. Interestingly, when it is applied to diffusion MRI, we obtain the diffusion signal from each water compartment, what makes BSS optimal for partial volume effects correction. Besides, tissue charac...

This study attempts to understand information diffusion in online social networks by investigating the factors that affect message dissemination. Particularly, we identify contextual factors from both message and user characteristics on Twitter and examine their impact on diffusion volume and speed. We collected 11,346 tweets, which have been retweeted at least once, regarding the three major m...

Results from closed-can radon exhalation experiments must be interpreted bearing the time-dependent radon diffusion theory in mind. A rapid change from the free to final steady-state exhalation rate will take place for all samples that are thin compared with the radon diffusion length. The radon gas accumulating in a closed can corresponds to a free exhalation rate only if the outer volume of a...