18 research outputs found
Phase transitions in thermally annealed films of Alq₃
Organic light emitting devices have been so very much improved lately that they are being widely applied for
displays and lighting. Among many improving technologies, annealing processes in different atmospheres affect
greatly their performance, for instance when the active material is the small molecule Alq3. In particular, a significant
increase of the photoluminescence is observed in thin films of this molecule between 150 and 180 °C, before
the physical destruction of the films occurs at higher temperatures. This phenomenon is attributed to a phase transition
towards a novel morphological aggregation of the molecules in the film, which proved to be a much improved
optical material for luminescent applications, and which seems common to other molecules as well
Conspicuity and muscle-invasiveness assessment for bladder cancer using VI-RADS: a multi-reader, contrast-free MRI study to determine optimal b-values for diffusion-weighted imaging
To (1) compare bladder cancer (BC) muscle invasiveness among three b-values using a contrast-free approach based on Vesical Imaging-Reporting and Data System (VI-RADS), to (2) determine if muscle-invasiveness assessment is affected by the reader experience, and to (3) compare BC conspicuity among three b-values, qualitatively and quantitatively
The enhancement of activity rescues the establishment of Mecp2 null neuronal phenotypes
MECP2 mutations cause Rett syndrome (RTT), a severe and progressive neurodevelopmental disorder mainly affecting females. Although RTT patients exhibit delayed onset of symptoms, several evidences demonstrate that MeCP2 deficiency alters early development of the brain. Indeed, during early maturation, Mecp2 null cortical neurons display widespread transcriptional changes, reduced activity, and defective morphology. It has been proposed that during brain development these elements are linked in a feed-forward cycle where neuronal activity drives transcriptional and morphological changes that further increase network maturity. We hypothesized that the enhancement of neuronal activity during early maturation might prevent the onset of RTT-typical molecular and cellular phenotypes. Accordingly, we show that the enhancement of excitability, obtained by adding to neuronal cultures Ampakine CX546, rescues transcription of several genes, neuronal morphology, and responsiveness to stimuli. Greater effects are achieved in response to earlier treatments. In vivo, short and early administration of CX546 to Mecp2 null mice prolongs lifespan, delays the disease progression, and rescues motor abilities and spatial memory, thus confirming the value for RTT of an early restoration of neuronal activity
Neuron-restrictive silencer factor/repressor element 1-silencing transcription factor (NRSF/REST) controls spatial K+ buffering in primary cortical astrocytes
Neuron-restrictive silencer factor/repressor element 1 (RE1)-silencing transcription factor (NRSF/REST) is a transcriptional repressor of a large cluster of neural genes containing RE1 motifs in their promoter region. NRSF/REST is ubiquitously expressed in non-neuronal cells, including astrocytes, while it is down-regulated during neuronal differentiation. While neuronal NRSF/REST homeostatically regulates intrinsic excitability and synaptic transmission, the role of the high NRSF/REST expression levels in the homeostatic functions of astrocytes is poorly understood. Here, we investigated the functional consequences of NRSF/REST deletion in primary cortical astrocytes derived from NRSF/REST conditional knockout mice (KO). We found that NRSF/REST KO astrocyte displayed a markedly reduced activity of inward rectifying K+ channels subtype 4.1 (Kir4.1) underlying spatial K+ buffering that was associated with a decreased expression and activity of the glutamate transporter-1 (GLT-1) responsible for glutamate uptake by astrocytes. The effects of the impaired astrocyte homeostatic functions on neuronal activity were investigated by co-culturing wild-type hippocampal neurons with NRSF/REST KO astrocytes. Interestingly, neurons experienced increased neuronal excitability at high firing rates associated with decrease after hyperpolarization and increased amplitude of excitatory postsynaptic currents. The data indicate that astrocytic NRSF/REST directly participates in neural circuit homeostasis by regulating intrinsic excitability and excitatory transmission and that dysfunctions of NRSF/REST expression in astrocytes may contribute to the pathogenesis of neurological disorders. (Figure presented.
Rapid Detection of Brettanomyces bruxellensis in Wine by Polychromatic Flow Cytometry
Brettanomyces bruxellensis is found in several fermented matrices and produces relevant
alterations to the wine quality. The methods usually used to identify B. bruxellensis contamination are
based on conventional microbiological techniques that require long procedures (15 days), causing
the yeast to spread in the meantime. Recently, a flow cytometry kit for the rapid detection (1–2 h) of
B. bruxellensis in wine has been developed. The feasibility of the method was assessed in a synthetic
medium as well as in wine samples by detecting B. bruxellensis in the presence of other yeast species
(Saccharomyces cerevisiae and Pichia spp.) and at the concentrations that produce natural contami nations (up to 105
cells/mL), as well as at lower concentrations (103–102
cells/mL). Wine samples
naturally contaminated by B. bruxellensis or inoculated with four different strains of B. bruxellensis
species together with Saccharomyces cerevisiae and Pichia spp., were analyzed by flow cytometry. Plate
counts were carried out in parallel to flow cytometry. We provide evidence that flow cytometry
allows the rapid detection of B. bruxellensis in simple and complex mixtures. Therefore, this technique
has great potential for the detection of B. bruxellensis and could allow preventive actions to reduce
wine spoilage
Temporal summation of the nociceptive withdrawal reflex involves deactivation of posterior cingulate cortex
Temporal summation of pain sensation is pivotal both in physiological and pathological nociception. In humans, it develops in parallel with temporal summation of the nociceptive withdrawal reflex (NWR) of the lower limb, an objective representation of the temporal processing of nociceptive signals into the spinal cord
MRI-based clinical-radiomics model predicts tumor response before treatment in locally advanced rectal cancer
Neoadjuvant chemo-radiotherapy (CRT) followed by total mesorectal excision (TME) represents the standard treatment for patients with locally advanced (>= T3 or N+) rectal cancer (LARC). Approximately 15% of patients with LARC shows a complete response after CRT. The use of pre-treatment MRI as predictive biomarker could help to increase the chance of organ preservation by tailoring the neoadjuvant treatment. We present a novel machine learning model combining pre-treatment MRI-based clinical and radiomic features for the early prediction of treatment response in LARC patients. MRI scans (3.0 T, T2-weighted) of 72 patients with LARC were included. Two readers independently segmented each tumor. Radiomic features were extracted from both the "tumor core" (TC) and the "tumor border" (TB). Partial least square (PLS) regression was used as the multivariate, machine learning, algorithm of choice and leave-one-out nested cross-validation was used to optimize hyperparameters of the PLS. The MRI-Based "clinical-radiomic" machine learning model properly predicted the treatment response (AUC=0.793, p=5.6x10(-5)). Importantly, the prediction improved when combining MRI-based clinical features and radiomic features, the latter extracted from both TC and TB. Prospective validation studies in randomized clinical trials are warranted to better define the role of radiomics in the development of rectal cancer precision medicine