Tandem mass spectrometry of π-expanded triphenylamine and N-heterotriangulene scaffolds: Radical cation versus silver(I) adduct.

Triphenylamine (TPA) and N-heterotriangulene (N-HTA) scaffolds with up to three oligophenyl extensions are investigated by electrospray ionization (tandem) mass spectrometry (ESI-[MS/]MS). Due to their low oxidation potentials, all molecules readily form radical cations in the electrospray process. The energy-resolved collision-induced dissociation behaviour of the molecular ions is contrasted to that of the silver(I) adducts.

Bexarotene drives the self-renewing proliferation of adult neural stem cells, promotes neuron-glial fate shift, and regulates late neuronal differentiation.

Treatment with bexarotene, a selective retinoid X receptor (RXR) agonist, significantly improves behavioral dysfunctions in various neurodegenerative animal models. Additionally, it activates neurodevelopmental and plasticity pathways in the brains of adult mice. Our objective was to investigate the impact of RXR activation by bexarotene on adult neural stem cells (aNSC) and their cell lineages.

Sodium Butyrate Protects Against Intestinal Oxidative Damage and Neuroinflammation in the Prefrontal Cortex of Ulcerative Colitis Mice Model.

Inflammatory bowel diseases (IBD) cause increased inflammatory signalling and oxidative damage. IBDs are correlated with an increased incidence of brain-related disorders suggesting that the gut-brain-axis exerts a pivotal role in IBD. Butyrate is one of the main microbial metabolites in the colon, and it can cross the blood-brain barrier, directly affecting the brain.

All-digital training course in neurophysiology: lessons learned from the COVID-19 pandemic.

Background: The social distancing and suspension of on-campus learning, imposed by the COVID-19 pandemic, are likely to influence medical training for months if not years. Thus, there is a need for digital replacement for classroom teaching, especially for hands-on courses, during which social distancing is hardly possible. Here, we investigated students' learning experience with a newly designed digital training course in neurophysiology, with intercalated teaching blocks in either asynchronous (unsupervised online lectures and e-labs) or synchronous (online seminars, supervised by instructors) formats.

Characterization of cell type-specific S100B expression in the mouse olfactory bulb.

S100B is an EF-hand type Ca-binding protein of the S100 family, known to support neurogenesis and to promote the interactions between brain's nervous and immune systems. Here, we characterized the expression of S100B in the mouse olfactory bulb, a neurogenic niche comprising mature and adult-born neurons, astrocytes, oligodendrocytes and microglia. Besides astrocytes, for which S100B is a classical marker, S100B was also expressed in NG2 cells and, surprisingly, in APC-positive myelinating oligodendrocytes but not in mature/adult-born neurons or microglia.

Pre-Planarized Triphenylamine-Based Linear Mixed-Valence Charge-Transfer Systems.

Three linear dimers with two redox-active planarized triphenylamines were synthesized and their structures verified by X-ray crystallography. Their radical cations, which exhibit electron self-exchange between the two redox centers, are of great interest. This process was thoroughly investigated by means of electron paramagnetic resonance spectroscopy, absorption spectroscopy, and (time-dependent) density functional theory calculations.

Effect of Caloric Restriction on the Functional Properties of Aging Microglia.

Throughout the lifespan, microglia, the primary innate immune cells of the brain, fulfill a plethora of homeostatic as well as active immune defense functions, and their aging-induced dysfunctionality is now considered as a key trigger of aging-related brain disorders. Recent evidence suggests that both organism's sex and age critically impact the functional state of microglia but determinants of such state(s) remain unclear. Therefore, we analyzed the sex-specific functional states of microglia in young adult, middle aged and old wild type mice by means of multicolor two-photon imaging, using the microglial Ca signaling and directed process motility as main readouts.

Welfare Assessment and Husbandry Practices of Working Horses in Fiji.

Fiji; working horse; welfare, intervention; husbandry; healthcare.

In vivo characterization of functional states of cortical microglia during peripheral inflammation.

Peripheral inflammation is known to trigger a mirror inflammatory response in the brain, involving brain's innate immune cells - microglia. However, the functional phenotypes, which these cells adopt in the course of peripheral inflammation, remain obscure. In vivo two-photon imaging of microglial Ca signaling as well as process motility reveals two distinct functional states of cortical microglia during a lipopolysaccharide-induced peripheral inflammation: an early "sensor state" characterized by dramatically increased intracellular Ca signaling but ramified morphology and a later "effector state" characterized by slow normalization of intracellular Ca signaling but hypertrophic morphology, substantial IL-1β production in a subset of cells as well as increased velocity of directed process extension and loss of coordination between individual processes.

Mutations in blind cavefish target the light-regulated circadian clock gene, period 2.

Light represents the principal signal driving circadian clock entrainment. However, how light influences the evolution of the clock remains poorly understood. The cavefish Phreatichthys andruzzii represents a fascinating model to explore how evolution under extreme aphotic conditions shapes the circadian clock, since in this species the clock is unresponsive to light.

Overexpression of Na/Mg exchanger SLC41A1 attenuates pro-survival signaling.

The Na/Mg exchanger SLC41A1 (A1), a key component of intracellular Mg homeostasis (IMH), is the major cellular Mg efflux system, and its overexpression decreases [Mg]. IMH plays an important role in the regulation of many cellular processes, including cellular signaling. However, whether the overexpression of A1 and the consequent drop of [Mg] impact on intracellular signaling is unknown.

Glutamate Activates AMPA Receptor Conductance in the Developing Schwann Cells of the Mammalian Peripheral Nerves.

Schwann cells (SCs) are myelinating cells of the PNS. Although SCs are known to express different channels and receptors on their surface, little is known about the activation and function of these proteins. Ionotropic glutamate receptors are thought to play an essential role during development of SC lineage and during peripheral nerve injury, so we sought to study their functional properties.

Inhomogeneous distribution of Alzheimer pathology along the isocortical relief. Are cortical convolutions an Achilles heel of evolution?

Alzheimer's disease (AD) is neuropathologically characterized by neuritic plaques and neurofibrillary tangles. Progression of both plaques and tangles throughout the brain follows a hierarchical distribution which is defined by intrinsic cytoarchitectonic features and extrinsic connectivity patterns. What has less well been studied is how cortical convolutions influence the distribution of AD pathology.

Effect of side-chain asymmetry on the intermolecular structure and order-disorder transition in alkyl-substituted polyfluorenes.

We study relations among the side-chain asymmetry, structure, and order-disorder transition (ODT) in hairy-rod-type poly(9,9-dihexylfluorene) (PF6) with two identical side chains and atactic poly(9-octyl-9-methyl-fluorene) (PF1-8) with two different side chains per repeat. PF6 and PF1-8 organize into alternating side-chain and backbone layers that transform into an isotropic phase at T^{ODT}(PF6) and T_{bi}^{ODT}(PF1-8). We interpret polymers in terms of monodisperse and bidisperse brushes and predict scenarios T^{ODT} View Article and Find Full Text PDF

Polymer-sorted semiconducting carbon nanotube networks for high-performance ambipolar field-effect transistors.

Efficient selection of semiconducting single-walled carbon nanotubes (SWNTs) from as-grown nanotube samples is crucial for their application as printable and flexible semiconductors in field-effect transistors (FETs). In this study, we use atactic poly(9-dodecyl-9-methyl-fluorene) (a-PF-1-12), a polyfluorene derivative with asymmetric side-chains, for the selective dispersion of semiconducting SWNTs with large diameters (>1 nm) from plasma torch-grown SWNTs. Lowering the molecular weight of the dispersing polymer leads to a significant improvement of selectivity.

Carbon nanotube network ambipolar field-effect transistors with 10(8) on/off ratio.

Polymer wrapping is a highly effective method of selecting semiconducting carbon nanotubes and dispersing them in solution. Semi-aligned semiconducting carbon nanotube networks are obtained by blade coating, an effective and scalable process. The field-effect transistor (FET) performance can be tuned by the choice of wrapping polymer, and the polymer concentration modifies the FET transport characteristics, leading to a record on/off ratio of 10(8) .

ERK Signaling Regulates Light-Induced Gene Expression via D-Box Enhancers in a Differential, Wavelength-Dependent Manner.

The day-night and seasonal cycles are dominated by regular changes in the intensity as well as spectral composition of sunlight. In aquatic environments the spectrum of sunlight is also strongly affected by the depth and quality of water. During evolution, organisms have adopted various key strategies in order to adapt to these changes, including the development of clocks and photoreceptor mechanisms.

trans-thionate derivatives of Pt(II) and Pd(II) with water-soluble phosphane PTA and DAPTA ligands: antiproliferative activity against human ovarian cancer cell lines.

A series of PTA and DAPTA platinum(II) and palladium(II) thionate complexes of the type trans-[M(SN)2P2] were prepared from the reaction of cis-[MCl2P2] [M = Pt, Pd; P = PTA (1,3,5-triaza-7-phosphaadamantane), DAPTA (3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane)] with the in situ generated sodium salts of the heterocyclic thiones S-m-methylpyrimidine-2-thione, S-4,6-dimethylpyrimidine-2-thione, S-4,6-dihydroxypyrimidine-2-thione, benzothiazole-2-thione, benzoxazole-2-thione, S-1,3,4,-thiadiazole-2-thione, S-4,5-H-thiazolan-2-thione, and S-pyrimidine-4(1H)-one-2-thione.

Semiconducting single-walled carbon nanotubes on demand by polymer wrapping.

Efficient selection of semiconducting SWCNTs of large diameter range (0.8-1.6 nm) on demand is demonstrated.

Charge photogeneration in donor-acceptor conjugated materials: influence of excess excitation energy and chain length.

We investigate the role of excess excitation energy on the nature of photoexcitations in donor-acceptor π-conjugated materials. We compare the polymer poly(2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[1,2-b;3,4-b']dithiophene)-4,7-benzo[2,1,3]thiadiazole) (PCPDTBT) and a short oligomer with identical constituents at different excitation wavelengths, from the near-infrared up to the ultraviolet spectral region. Ultrafast spectroscopic measurements clearly show an increased polaron pair yield for higher excess energies directly after photoexcitation when compared to the exciton population.

A blind circadian clock in cavefish reveals that opsins mediate peripheral clock photoreception.

The circadian clock is synchronized with the day-night cycle primarily by light. Fish represent fascinating models for deciphering the light input pathway to the vertebrate clock since fish cell clocks are regulated by direct light exposure. Here we have performed a comparative, functional analysis of the circadian clock involving the zebrafish that is normally exposed to the day-night cycle and a cavefish species that has evolved in perpetual darkness.

Fate of neuron-glia synapses during proliferation and differentiation of NG2 cells.

Progenitor cells expressing proteoglycan NG2 (also known as oligodendrocyte precursor cells or polydendrocytes) are widespread in the grey and white matter of the CNS; they comprise 8-9% of the total cell population in adult white matter, and 2-3% of total cells in adult grey matter. NG2 cells have a complex stellate morphology, with highly branched processes that may extend more than 100 μm around the cell body. NG2 cells express a complex set of voltage-gated channels, AMPA/kainate and/or γ-aminobutyric acid (GABA)(A) receptors, and receive glutamatergic and/or GABAergic synaptic input from neurons.

A general method for identifying excess revisit rates: the case of hypertension.

Objective: To provide a description and application of a novel methodology for comparing actual to expected visit rates at the physician level (controlling for patient characteristics) that could be employed in healthcare monitoring and management.

Data Sources/study Setting: Two fiscal years (1997/1998 and 1998/1999) of health utilization data extracted from linked administrative data sets on a population-based cohort of 13,688 patients (aged 25+ with hypertension) involving 157 physicians.

Study Design: We re-analyzed data from a previously published retrospective cohort study to develop and apply a new methodology for identifying higher or lower than expected physician visit rates for hypertension.

Estimating nursing home bed demand: 20-year projection from administrative data and stakeholder input.

We describe methods to project the requirement for nursing home beds in Manitoba until 2020. Three methods were developed: Trend, Recent Use, and Combined. The first two methods yielded widely divergent projections, differing by 3,400 beds.