Publications by authors named "Sarter M"

Ion-conducting polymer membranes are essential in many separation processes and electrochemical devices, including electrodialysis, redox flow batteries, fuel cells and electrolysers. Controlling ion transport and selectivity in these membranes largely hinges on the manipulation of pore size. Although membrane pore structures can be designed in the dry state, they are redefined upon hydration owing to swelling in electrolyte solutions.

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Protein dynamics play a vital role in biology. Quasi elastic neutron scattering (QENS) is an ideal method to access these dynamics. To isolate protein dynamics, it is important to separate the signal of the buffer and the protein.

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Article Synopsis
  • In nanoscience, liquids exhibit solid-like behaviors at very small scales, such as collective shear waves and elasticity, challenging traditional views where such behaviors are rare.
  • Through experiments on liquid water and glycerol confined in graphene oxide membranes, researchers observed a shift from liquid-like to solid-like properties as confinement increases, specifically in low-frequency dynamics.
  • These findings, supported by molecular dynamics simulations, suggest that tighter confinement slows down liquid relaxation processes, highlighting the potential implications for advancing technologies at the nanoscale.
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Background: Pneumatic tourniquets are frequently employed in extremity surgeries, aiming to enhance intraoperative visibility and minimize blood loss. Although their benefits and drawbacks have been extensively studied in lower limb operations, their impact on upper limb procedures, particularly elbow surgery, remains poorly understood. This study investigates the advantages and risks associated with pneumatic tourniquet used in elbow surgery.

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Introduction: The Bartoníček/Rammelt classification is established for posterior malleolar fractures. It subdivides the fractures into 5 types and outlines treatment recommendations. This study aims to determine the intraobserver and interobserver reliability of the Bartoníček/Rammelt classification and investigates its applicability regarding treatment recommendations.

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In this work, we have carried out a comprehensive characterization of the vibrational spectroscopy of the non-planar molecule thianthrene. The combination of infrared, Raman and inelastic neutron scattering spectroscopies is highly complementary and allows all of the modes to be observed. Periodic density-functional theory calculations have provided unambiguous assignments of the spectra.

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Unlabelled: Turning on cue or stopping at a red light requires attending to such cues to select action sequences, or suppress action, in accordance with learned cue-associated action rules. Cortico-striatal projections are an essential part of the brain's attention-motor interface. Glutamate-sensing microelectrode arrays were used to measure glutamate transients in the dorsomedial striatum (DMS) of male and female rats walking a treadmill and executing cued turns and stops.

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Normal-to-cancer (NTC) transition is known to be closely associated to cell´s biomechanical properties which are dependent on the dynamics of the intracellular medium. This study probes different human cancer cells (breast, prostate and lung), concomitantly to their healthy counterparts, aiming at characterising the dynamical profile of water in distinct cellular locations, for each type of cell, and how it changes between normal and cancer states. An increased plasticity of the cytomatrix is observed upon normal-to-malignant transformation, the lung carcinoma cells displaying the highest flexibility followed by prostate and breast cancers.

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Introduction: Nailing of the proximal humerus is an established method for the treatment of proximal humerus fractures. Choice of the correct length for potentially four proximal locking screws is essential for postoperative outcome. Due to positioning of the patient, intraoperative determination of the correct length of the anteroposterior (AP) screw with the x-ray beam is particularly challenging even for experienced surgeons.

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Protein-ligand interactions are of vital importance for biological functions. The biological function of proteins, such as ligand-binding, is strongly influenced by their dynamics. Quasielastic neutron scattering (QENS) was used to investigate the internal molecular dynamics of streptavidin (STV).

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Sign-tracking (ST) describes the propensity to approach and contact a Pavlovian reward cue. By contrast, goal-trackers (GTs) respond to such a cue by retrieving the reward. These behaviors index the presence of opponent cognitive-motivational traits, with STs exhibiting attentional control deficits, behavior dominated by incentive motivational processes, and vulnerability for addictive drug taking.

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Sign tracking versus goal tracking in rats indicate vulnerability and resistance, respectively, to Pavlovian cue-evoked addictive drug taking and relapse. Here, we tested hypotheses predicting that the opponent cognitive-behavioral styles indexed by sign tracking versus goal tracking include variations in attentional performance which differentially depend on basal forebrain projection systems. Pavlovian Conditioned Approach (PCA) testing was used to identify male and female sign-trackers (STs) and goal-trackers (GTs), as well as rats with an intermediate phenotype (INTs).

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Introduction: Due to aging society, osteoporotic posterior ring fractures of the pelvis are gaining importance. Percutaneous iliosacral screw fixation can reduce pain if conservative therapy is not sufficient. One of the surgical complications is the malposition of the screws in neuroforamen.

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Normal-to-malignant transformation is a poorly understood process associated with cellular biomechanical properties. These are strongly dependent on the dynamical behaviour of water, known to play a fundamental role in normal cellular activity and in the maintenance of the three-dimensional architecture of the tissue and the functional state of biopolymers. In this study, quasi-elastic neutron scattering was used to probe the dynamical behaviour of water in human cancer specimens and their respective surrounding normal tissue from breast and tongue, as an innovative approach for identifying particular features of malignancy.

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Dysfunction and degeneration of CNS cholinergic systems is a significant component of multi-system pathology in Parkinson's disease (PD). We review the basic architecture of human CNS cholinergic systems and the tools available for studying changes in human cholinergic systems. Earlier post-mortem studies implicated abnormalities of basal forebrain corticopetal cholinergic (BFCC) and pedunculopontine-laterodorsal tegmental (PPN-LDT) cholinergic projections in cognitive deficits and gait-balance deficits, respectively.

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Transport of choline via the neuronal high-affinity choline transporter (CHT; ) is essential for cholinergic terminals to synthesize and release acetylcholine (ACh). In humans, we previously demonstrated an association between a common CHT coding substitution (rs1013940; Ile89Val) and reduced attentional control as well as attenuated frontal cortex activation. Here, we used a CRISPR/Cas9 approach to generate mice expressing the I89V substitution and assessed, , CHT-mediated choline transport, and ACh release.

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Theta and gamma rhythms and their cross-frequency coupling play critical roles in perception, attention, learning, and memory. Available data suggest that forebrain acetylcholine (ACh) signaling promotes theta-gamma coupling, although the mechanism has not been identified. Recent evidence suggests that cholinergic signaling is both temporally and spatially constrained, in contrast to the traditional notion of slow, spatially homogeneous, and diffuse neuromodulation.

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Inspired by the modular architecture of natural signaling proteins, ligand binding proteins are equipped with two fluorescent proteins (FPs) in order to obtain Förster resonance energy transfer (FRET)-based biosensors. Here, we investigated a glucose sensor where the donor and acceptor FPs were attached to a glucose binding protein using a variety of different linker sequences. For three resulting sensor constructs the corresponding glucose induced conformational changes were measured by small angle X-ray scattering (SAXS) and compared to recently published single molecule FRET results (Höfig et al.

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Objective: Attentional deficits following degeneration of brain cholinergic systems contribute to gait-balance deficits in Parkinson disease (PD). As a step toward assessing whether α4β2* nicotinic acetylcholine receptor (nAChR) stimulation improves gait-balance function, we assessed target engagement of the α4β2* nAChR partial agonist varenicline.

Methods: Nondemented PD participants with cholinergic deficits were identified with [ F]fluoroethoxybenzovesamicol positron emission tomography (PET).

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Rationale: In addition to the disease-defining motor symptoms, patients with Parkinson's disease (PD) exhibit gait dysfunction, postural instability, and a propensity for falls. These dopamine (DA) replacement-resistant symptoms in part have been attributed to loss of basal forebrain (BF) cholinergic neurons and, in interaction with striatal dopamine (DA) loss, to the resulting disruption of the attentional control of balance and complex movements. Rats with dual cholinergic-DA losses ("DL rats") were previously demonstrated to model PD falls and associated impairments of gait and balance.

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Background: In movement disorders such as Parkinson's disease (PD), cholinergic signaling is disrupted by the loss of basal forebrain cholinergic neurons, as well as aberrant activity in striatal cholinergic interneurons (ChIs). Several lines of evidence suggest that gait imbalance, a key disabling symptom of PD, may be driven by alterations in high-level frontal cortical and cortico-striatal processing more typically associated with cognitive dysfunction.

Methods: Here we describe the corticostriatal circuitry that mediates the cognitive-motor interactions underlying such complex movement control.

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By using a combination of experimental neutron scattering techniques, it is possible to obtain a statistical perspective on red blood cell (RBC) shape in suspensions, and the inter-relationship with protein interactions and dynamics inside the confinement of the cell membrane. In this study, we examined the ultrastructure of RBC and protein-protein interactions of haemoglobin (Hb) in them using ultra-small-angle neutron scattering and small-angle neutron scattering (SANS). In addition, we used the neutron backscattering method to access Hb motion on the ns time scale and Å length scale.

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Older persons and, more severely, persons with Parkinson's disease (PD) exhibit gait dysfunction, postural instability and a propensity for falls. These dopamine (DA) replacement-resistant symptoms are associated with losses of basal forebrain and striatal cholinergic neurons, suggesting that falls reflect disruption of the corticostriatal transfer of movement-related cues and their striatal integration with movement sequencing. To advance a rodent model of the complex movement deficits of Parkinsonian fallers, here we first demonstrated that male and female rats with dual cortical cholinergic and striatal DA losses (DL rats) exhibit cued turning deficits, modeling the turning deficits seen in these patients.

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Recent experimental results have shown that the detection of cues in behavioral attention tasks relies on transient increases of acetylcholine (ACh) release in frontal cortex and cholinergically driven oscillatory activity in the gamma frequency band (Howe et al. Journal of Neuroscience, 2017, 37, 3215). The cue-induced gamma rhythmic activity requires stimulation of M1 muscarinic receptors.

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