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https://www.readbyqxmd.com/read/29671050/-trabecular-micro-invasive-glaucoma-surgery-procedures-and-clinical-results
#1
REVIEW
A G M Jünemann, R Rejdak, B Hohberger
The management of glaucoma therapy to reduce intraocular pressure commonly consists of a gradual approach with local monotherapy, combined therapy, laser surgery and finally filtration surgery. The local side effects of glaucoma medications and the lack of adherence and persistence to the medical therapy as well as the complication profile of the established glaucoma surgical techniques justify the introduction of new surgical procedures. Micro-invasive glaucoma surgery (MIGS) is a promising new surgical approach...
April 18, 2018: Der Ophthalmologe: Zeitschrift der Deutschen Ophthalmologischen Gesellschaft
https://www.readbyqxmd.com/read/29666960/consciousness-indexing-and-outcome-prediction-with-resting-state-eeg-in-severe-disorders-of-consciousness
#2
Sabina Stefan, Barbara Schorr, Alex Lopez-Rolon, Iris-Tatjana Kolassa, Jonathan P Shock, Martin Rosenfelder, Suzette Heck, Andreas Bender
We applied the following methods to resting-state EEG data from patients with disorders of consciousness (DOC) for consciousness indexing and outcome prediction: microstates, entropy (i.e. approximate, permutation), power in alpha and delta frequency bands, and connectivity (i.e. weighted symbolic mutual information, symbolic transfer entropy, complex network analysis). Patients with unresponsive wakefulness syndrome (UWS) and patients in a minimally conscious state (MCS) were classified into these two categories by fitting and testing a generalised linear model...
April 17, 2018: Brain Topography
https://www.readbyqxmd.com/read/29649424/the-safety-and-efficacy-of-supraciliary-stenting-following-failed-glaucoma-surgery
#3
Nathan M Kerr, Jing Wang, Lucia Perucho, Keith Barton
PURPOSE: To evaluate the safety and efficacy of supraciliary stenting following failed glaucoma surgery. DESIGN: Interventional case series. METHODS: Setting: Moorfields Eye Hospital, London, United Kingdom. STUDY POPULATION: Twenty eyes from 20 patients with glaucoma refractory to prior glaucoma surgery. INTERVENTION: Ab interno microstent (CyPass Micro-Stent; Alcon, Fort Worth, TX) implantation into the supraciliary space...
April 9, 2018: American Journal of Ophthalmology
https://www.readbyqxmd.com/read/29599462/recurrence-of-task-related-electroencephalographic-activity-during-post-training-quiet-rest-and-sleep
#4
Michael Murphy, Robert Stickgold, Mittie Elaine Parr, Cameron Callahan, Erin J Wamsley
Offline reactivation of task-related neural activity has been demonstrated in animals but is difficult to directly observe in humans. We sought to identify potential electroencephalographic (EEG) markers of offline memory processing in human subjects by identifying a set of characteristic EEG topographies ("microstates") that occurred as subjects learned to navigate a virtual maze. We hypothesized that these task-related microstates would appear during post-task periods of rest and sleep. In agreement with this hypothesis, we found that one task-related microstate was increased in post-training rest and sleep compared to baseline rest, selectively for subjects who actively learned the maze, and not in subjects performing a non-learning control task...
March 29, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29594774/absolute-alchemical-free-energy-calculations-for-ligand-binding-a-beginner-s-guide
#5
Matteo Aldeghi, Joseph P Bluck, Philip C Biggin
Many thermodynamic quantities can be extracted from computer simulations that generate an ensemble of microstates according to the principles of statistical mechanics. Among these quantities is the free energy of binding of a small molecule to a macromolecule, such as a protein. Here, we present an introductory overview of a protocol that allows for the estimation of ligand binding free energies via molecular dynamics simulations. While we focus on the binding of organic molecules to proteins, the approach is in principle transferable to any pair of molecules...
2018: Methods in Molecular Biology
https://www.readbyqxmd.com/read/29548241/mutual-information-identifies-spurious-hurst-phenomena-in-resting-state-eeg-and-fmri-data
#6
Frederic von Wegner, Helmut Laufs, Enzo Tagliazucchi
Long-range memory in time series is often quantified by the Hurst exponent H, a measure of the signal's variance across several time scales. We analyze neurophysiological time series from electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) resting state experiments with two standard Hurst exponent estimators and with the time-lagged mutual information function applied to discretized versions of the signals. A confidence interval for the mutual information function is obtained from surrogate Markov processes with equilibrium distribution and transition matrix identical to the underlying signal...
February 2018: Physical Review. E
https://www.readbyqxmd.com/read/29539393/escape-of-a-small-molecule-from-inside-t4-lysozyme-by-multiple-pathways
#7
Ariane Nunes-Alves, Daniel M Zuckerman, Guilherme Menegon Arantes
The T4 lysozyme L99A mutant is often used as a model system to study small-molecule binding to proteins, but pathways for ligand entry and exit from the buried binding site and the associated protein conformational changes have not been fully resolved. Here, molecular dynamics simulations were employed to model benzene exit from its binding cavity using the weighted ensemble (WE) approach to enhance sampling of low-probability unbinding trajectories. Independent WE simulations revealed four pathways for benzene exit, which correspond to transient tunnels spontaneously formed in previous simulations of apo T4 lysozyme...
March 13, 2018: Biophysical Journal
https://www.readbyqxmd.com/read/29500714/-subconjunctival-minimally-invasive-glaucoma-surgery-methods-and-clinical-results
#8
REVIEW
M Lenzhofer, M Hohensinn, C Strohmaier, H A Reitsamer
Minimally invasive glaucoma surgery (MIGS) has been developed for all drainage pathways in glaucoma treatment. Besides implants overriding the resistance in the trabecular meshwork (iStent®, iStent Inject® [both Glaukos Germany GmbH, Wiesbaden, Germany], Hydrus Microstent® [Ivantis, Irvine, CA, USA]) and draining to the suprachoroidal space (Cypass Micro Stent® [Alcon Laboratories, Inc., Fort Worth, TX, USA], iStent Supra® [Glaukos Germany GmbH]), surgeons can further drain aqueous humor into the subconjunctival space with a transscleral MIGS implant (XEN45® [Allergan Plc...
March 2, 2018: Der Ophthalmologe: Zeitschrift der Deutschen Ophthalmologischen Gesellschaft
https://www.readbyqxmd.com/read/29427849/luminance-polarity-distribution-across-the-symmetry-axis-affects-the-electrophysiological-response-to-symmetry
#9
Damien Wright, Claire Mitchell, Benjamin R Dering, Elena Gheorghiu
Electrophysiological studies of symmetry have found a difference wave termed the Sustained Posterior Negativity (SPN) related to the presence of symmetry. Yet the extent to which the SPN is modulated by luminance-polarity and colour content is unknown. Here we examine how luminance-polarity distribution across the symmetry axis, grouping by luminance polarity, and the number of colours in the stimuli, modulate the SPN. Stimuli were dot patterns arranged either symmetrically or quasi-randomly. There were several arrangements: 'segregated'-symmetric dots were of one polarity and random dots of the other; 'unsegregated'-symmetric dots were of both polarities in equal proportions; 'anti-symmetric'-dots were of opposite polarity across the symmetry axis; 'polarity-grouped anti-symmetric'-as anti-symmetric but with half the pattern of one polarity and the other opposite; multi-colour symmetric patterns made of either two, three and four colours...
February 7, 2018: NeuroImage
https://www.readbyqxmd.com/read/29401159/late-spontaneous-dislocation-of-an-ab-interno-gelatin-microstent
#10
Erin A Boese, Manjool Shah
PURPOSE: To report a case of spontaneous dislocation of a gelatin microstent six months after the initial uncomplicated surgery. PATIENTS AND METHODS: We describe a 73-year-old male with a history of advanced primary open angle glaucoma who had previously undergone an unsuccessful micropulse transcleral cyclophotocoagulation (CPC) of the left eye. He underwent an uncomplicated combined phacoemulsification with an ab interno gelatin microstent, but was noted to have a spontaneous dislocation of the microstent six months post-operatively...
February 2, 2018: Journal of Glaucoma
https://www.readbyqxmd.com/read/29352255/offline-stimulation-of-human-parietal-cortex-differently-affects-resting-eeg-microstates
#11
Pierpaolo Croce, Filippo Zappasodi, Paolo Capotosto
The interference effects of transcranial magnetic stimulation (TMS) on several electroencephalographic (EEG) measures in both temporal and frequency domains have been reported. We tested the hypothesis whether the offline external inhibitory interference, although focal, could result in a global reorganization of the functional brain state, as assessed by EEG microstates. In 16 healthy subjects, we inhibited five parietal areas and used a pseudo stimulation (Sham) at rest. The EEG microstates were extracted before and after each stimulation...
January 19, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29347348/consciousness-as-a-global-property-of-brain-dynamic-activity
#12
D M Mateos, R Wennberg, R Guevara, J L Perez Velazquez
We seek general principles of the structure of the cellular collective activity associated with conscious awareness. Can we obtain evidence for features of the optimal brain organization that allows for adequate processing of stimuli and that may guide the emergence of cognition and consciousness? Analyzing brain recordings in conscious and unconscious states, we followed initially the classic approach in physics when it comes to understanding collective behaviours of systems composed of a myriad of units: the assessment of the number of possible configurations (microstates) that the system can adopt, for which we use a global entropic measure associated with the number of connected brain regions...
December 2017: Physical Review. E
https://www.readbyqxmd.com/read/29330134/a-supplementary-functional-connectivity-microstate-attached-to-the-default-mode-network-in-depression-revealed-by-resting-state-magnetoencephalography
#13
Siqi Zhang, Shui Tian, Mohammad Ridwan Chattun, Hao Tang, Rui Yan, Kun Bi, Zhijian Yao, Qing Lu
Default mode network (DMN) has discernable involvement in the representation of negative, self-referential information in depression. Both increased and decreased resting-state functional connectivity between the anterior and posterior DMN have been observed in depression. These conflicting connectivity differences necessitated further exploration of the resting-state DMN dysfunction in depression. Hence, we investigated the time-varying dynamic interactions within the DMN via functional connectivity microstates in a sub-second level...
April 20, 2018: Progress in Neuro-psychopharmacology & Biological Psychiatry
https://www.readbyqxmd.com/read/29323898/caliber-corrected-markov-modeling-c-2-m-2-correcting-equilibrium-markov-models
#14
Purushottam D Dixit, Ken A Dill
Rate processes are often modeled using Markov State Models (MSMs). Suppose you know a prior MSM and then learn that your prediction of some particular observable rate is wrong. What is the best way to correct the whole MSM? For example, molecular dynamics simulations of protein folding may sample many microstates, possibly giving correct pathways through them while also giving the wrong overall folding rate when compared to experiment. Here, we describe Caliber Corrected Markov Modeling (C2 M2 ), an approach based on the principle of maximum entropy for updating a Markov model by imposing state- and trajectory-based constraints...
February 13, 2018: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/29318353/the-barrel-vascular-reconstruction-device-a-retrospective-observational-multicentric-study
#15
C Kabbasch, A Mpotsaris, V Maus, J C Altenbernd, C Loehr
BACKGROUND AND PURPOSE: The Barrel device is an electrolytically detachable laser cut, closed-cell microstent that is used for neck reconstruction in wide-necked bifurcation and branching aneurysms to support coiling. The key feature is a barrel section that herniates over the aneurysmal ostium. The objective was to evaluate the safety, feasibility and the immediate and mid-term occlusion results of this new device. MATERIAL AND METHODS: The databases of two tertiary care centers were screened for all Barrel-based stent-assisted intracranial coil embolization of wide-necked aneurysms between June 2015 and September 2016...
January 9, 2018: Clinical Neuroradiology
https://www.readbyqxmd.com/read/29258404/xen-gel-implant-a-new-surgical-approach-in-glaucoma
#16
Ankita Chaudhary, Lauriane Salinas, Jacopo Guidotti, André Mermoud, Kaweh Mansouri
Glaucoma is a leading cause of blindness worldwide. Intraocular pressure (IOP) lowering is the only effective treatment strategy. Traditional glaucoma surgeries are generally considered to be unpredictable and associated with a high rate of complications. This has led to the development of a novel XEN Gel Implant, a type of minimally invasive glaucoma surgery (MIGS), lowering the IOP without extensive surgical dissection. Areas covered: A literature search was undertaken on PubMed using the terms XEN glaucoma, gelatin microstent, and MIGS...
January 2018: Expert Review of Medical Devices
https://www.readbyqxmd.com/read/29216191/transcription-factors-coregulators-and-epigenetic-marks-are-linearly-correlated-and-highly-redundant
#17
Tobias Ahsendorf, Franz-Josef Müller, Ved Topkar, Jeremy Gunawardena, Roland Eils
The DNA microstates that regulate transcription include sequence-specific transcription factors (TFs), coregulatory complexes, nucleosomes, histone modifications, DNA methylation, and parts of the three-dimensional architecture of genomes, which could create an enormous combinatorial complexity across the genome. However, many proteins and epigenetic marks are known to colocalize, suggesting that the information content encoded in these marks can be compressed. It has so far proved difficult to understand this compression in a systematic and quantitative manner...
2017: PloS One
https://www.readbyqxmd.com/read/29212344/results-obtained-by-combining-different-estimators-of-eeg-connectivity-become-uninterpretable-if-the-underlying-models-are-incompatible
#18
Thomas Koenig, Pedro A Valdés-Sosa
We comment on a recent article published in Brain Connectivity (Hatz et al., 2016 ) that combined electroencephalography (EEG) microstate analysis with the phase-locking index (PLI) and found that the test-retest reliability of connectivity patterns as obtained by the PLI increased when the data had been previously parcellated into microstates. Although we acknowledge the need to parcellate the continuous data into periods that supposedly correspond to transiently stable patterns of connectivity, we believe that the approach chosen by the authors is seriously mistaken...
January 22, 2018: Brain Connectivity
https://www.readbyqxmd.com/read/29196270/eeg-microstates-as-a-tool-for-studying-the-temporal-dynamics-of-whole-brain-neuronal-networks-a-review
#19
REVIEW
Christoph M Michel, Thomas Koenig
The present review discusses a well-established method for characterizing resting-state activity of the human brain using multichannel electroencephalography (EEG). This method involves the examination of electrical microstates in the brain, which are defined as successive short time periods during which the configuration of the scalp potential field remains semi-stable, suggesting quasi-simultaneity of activity among the nodes of large-scale networks. A few prototypic microstates, which occur in a repetitive sequence across time, can be reliably identified across participants...
December 2, 2017: NeuroImage
https://www.readbyqxmd.com/read/29188992/tracking-the-catalytic-cycle-of-adenylate-kinase-by-ultraviolet-photodissociation-mass-spectrometry
#20
M Rachel Mehaffey, Michael B Cammarata, Jennifer S Brodbelt
The complex interplay of dynamic protein plasticity and specific side-chain interactions with substrate molecules that allows enzymes to catalyze reactions has yet to be fully unraveled. Top-down ultraviolet photodissociation (UVPD) mass spectrometry is used to track snapshots of conformational fluctuations in the phosphotransferase adenylate kinase (AK) throughout its active reaction cycle by characterization of complexes containing AK and each of four different adenosine phosphate ligands. Variations in efficiencies of UVPD backbone cleavages were consistently observed for three α-helices and the adenosine binding regions for AK complexes representing different steps of the catalytic cycle, implying that these stretches of the protein sample various structural microstates as the enzyme undergoes global open-to-closed transitions...
January 2, 2018: Analytical Chemistry
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