Thermo-responsive, UV-active poly(phenyl acrylate)-b-poly(diethyl acrylamide) block copolymers

The homopolymerization of phenyl acrylate (PA) was investigated for the first time by nitroxide mediated polymerization (NMP) with the succinimidyl form of the SG1-based unimolecular initiator 2-[N-tert-butyl-2,2-(dimethylpropyl)-aminooxy]propionic acid (BlocBuilder MA). The control of PPA homopolymerization was improved by the use of 15 mol% additional free nitroxide SG1 ([tert-butyl[1-(diethoxyphosphoryl)-2,2-dimethylpropyl]amino]oxidanyl) and dispersities, Mw/Mn, of around 1.2 were achieved. A PPA homopolymer was then successfully chain-extended with diethyl acrylamide (DEAAm) to form a block copolymer of PPA-b-PDEAAm where the PDEAAm segment is thermo-responsive, while the PPA block is potentially UV-active. The thermo-responsive behavior of the block copolymer in 0.5 wt% aqueous solution was studied by UV-Vis spectrometry and dynamic light scattering (DLS), indicating cloud point temperatures of 26–30°C, close to that reported for PDEAAm homopolymers

The emergent role of digital technologies in the context of humanitarian supply chains: a systematic literature review

The role of digital technologies (DTs) in humanitarian supply chains (HSC) has become an increasingly researched topic in the operations literature. While numerous publications have dealt with this convergence, most studies have focused on examining the implementation of individual DTs within the HSC context, leaving relevant literature, to date, dispersed and fragmented. This study, through a systematic literature review of 110 articles on HSC published between 2015 and 2020, provides a unified overview of the current state-of-the-art DTs adopted in HSC operations. The literature review findings substantiate the growing significance of DTs within HSC, identifying their main objectives and application domains, as well as their deployment with respect to the different HSC phases (i.e., Mitigation, Preparedness, Response, and Recovery). Furthermore, the findings also offer insight into how participant organizations might configure a technological portfolio aimed at overcoming operational difficulties in HSC endeavours. This work is novel as it differs from the existing traditional perspective on the role of individual technologies on HSC research by reviewing multiple DTs within the HSC domain

Gephyrin, the enigmatic organizer at GABAergic synapses

GABAA receptors are clustered at synaptic sites to achieve a high density of postsynaptic receptors opposite the input axonal terminals. This allows for an efficient propagation of GABA mediated signals, which mostly result in neuronal inhibition. A key organizer for inhibitory synaptic receptors is the 93 kDa protein gephyrin that forms oligomeric superstructures beneath the synaptic area. Gephyrin has long been known to be directly associated with glycine receptor β subunits that mediate synaptic inhibition in the spinal cord. Recently, synaptic GABAA receptors have also been shown to directly interact with gephyrin and interaction sites have been identified and mapped within the intracellular loops of the GABAA receptor α1, α2, and α3 subunits. Gephyrin-binding to GABAA receptors seems to be at least one order of magnitude weaker than to glycine receptors (GlyRs) and most probably is regulated by phosphorylation. Gephyrin not only has a structural function at synaptic sites, but also plays a crucial role in synaptic dynamics and is a platform for multiple protein-protein interactions, bringing receptors, cytoskeletal proteins and downstream signaling proteins into close spatial proximity

Structure elucidation and characterization of patulin synthase, insights into the formation of a fungal mycotoxin

Patulin synthase (PatE) from Penicillium expansum is a flavin-dependent enzyme that catalyses the last step in the biosynthesis of the mycotoxin patulin. This secondary metabolite is often present in fruit and fruit-derived products, causing postharvest losses. The patE gene was expressed in Aspergillus niger allowing purification and characterization of PatE. This confirmed that PatE is active not only on the proposed patulin precursor ascladiol but also on several aromatic alcohols including 5-hydroxymethylfurfural. By elucidating its crystal structure, details on its catalytic mechanism were revealed. Several aspects of the active site architecture are reminiscent of that of fungal aryl-alcohol oxidases. Yet, PatE is most efficient with ascladiol as substrate confirming its dedicated role in biosynthesis of patulin.</p

Reduced Regional NREM Sleep Slow-Wave Activity Is Associated With Cognitive Impairment in Parkinson Disease

Growing evidence implicates a distinct role of disturbed slow-wave sleep in neurodegenerative diseases. Reduced non-rapid eye movement (NREM) sleep slow-wave activity (SWA), a marker of slow-wave sleep intensity, has been linked with age-related cognitive impairment and Alzheimer disease pathology. However, it remains debated if SWA is associated with cognition in Parkinson disease (PD). Here, we investigated the relationship of regional SWA with cognitive performance in PD. In the present study, 140 non-demented PD patients underwent polysomnography and were administered the Montréal Cognitive Assessment (MoCA) to screen for cognitive impairment. We performed spectral analysis of frontal, central, and occipital sleep electroencephalography (EEG) derivations to measure SWA, and spectral power in other frequency bands, which we compared to cognition using linear mixed models. We found that worse MoCA performance was associated with reduced 1–4 Hz SWA in a region-dependent manner (F2, 687 =11.67, p < 0.001). This effect was driven by reduced regional SWA in the lower delta frequencies, with a strong association of worse MoCA performance with reduced 1–2 Hz SWA (F2, 687 =18.0, p < 0.001). The association of MoCA with 1–2 Hz SWA (and 1–4 Hz SWA) followed an antero-posterior gradient, with strongest, weaker, and absent associations over frontal (rho = 0.33, p < 0.001), central (rho = 0.28, p < 0.001), and occipital derivations, respectively. Our study shows that cognitive impairment in PD is associated with reduced NREM sleep SWA, predominantly in lower delta frequencies (1–2 Hz) and over frontal regions. This finding suggests a potential role of reduced frontal slow-wave sleep intensity in cognitive impairment in PD