Background: Non-missile traumatic brain injury (nmTBI) without macroscopically detectable lesions often results in cognitive impairments that negatively affect daily life.. Aim: To identify abnormal white matter projections in patients with nmTBI with cognitive impairments using diffusion tensor magnetic resonance imaging (DTI).. Methods: DTI scans of healthy controls were compared with those of 23 patients with nmTBI who manifested cognitive impairments but no obvious neuroradiological lesions. DTI was comprised of fractional anisotropy analysis, which included voxel-based analysis and confirmatory study using regions of interest (ROI) techniques, and magnetic resonance tractography of the corpus callosum and fornix.. Results: A decline in fractional anisotropy around the genu, stem and splenium of the corpus callosum was shown by voxel-based analysis. Fractional anisotropy values of the genu (0.47), stem (0.48), and splenium of the corpus callosum (0.52), and the column of the fornix (0.51) ...
TY - JOUR. T1 - Augmenting the anisotropic network model with torsional potentials improves PATH performance, enabling detailed comparison with experimental rate data. AU - Chandrasekaran,Srinivas Niranj. AU - Carter,Charles W.. PY - 2017/5/1. Y1 - 2017/5/1. N2 - PATH algorithms for identifying conformational transition states provide computational parameters-time to the transition state, conformational free energy differences, and transition state activation energies-for comparison to experimental data and can be carried out sufficiently rapidly to use in the "high throughput" mode.These advantages are especially useful for interpreting results from combinatorial mutagenesis experiments. This report updates the previously published algorithm with enhancements that improve correlations between PATH convergence parameters derived from virtual variant structures generated by RosettaBackrub and previously published kinetic data for a complete, four-way combinatorial mutagenesis of a conformational ...
Background: Diffusion-tensor fractional anisotropy (FA) is an index of neural-fiber damage in patients following stroke. To better characterize FA, tract-based spatial statistics (TBSS) is frequently
A reduction of uniaxial compressive strength (UCS) by the presence of water has been ascertained in many sedimentary rocks and even some metamorphic rocks experimentally. This paper reports and discusses the influence of water content and anisotropy on the strength and deformability of two meta-sedimentary rocks by triaxial compressive tests. Before conducting the triaxial tests, the physical properties of meta-siltstone and meta-sandstone specimens have been carefully examined. The water contents of both tested rocks are very low, for instance, 0.17% for meta-siltstone and 0.10% for meta-sandstone. The porosities of the tested rocks are analyzed by the technique of mercury intrusion porosimetry (MIP). It shows that the meta-sedimentary rocks have very low porosity, 0.18% for meta-siltstone and 0.53% for meta-sandstone on average. The thin section analysis reveals that the meta-siltstone contains more hydrophilic substances such as clay minerals than the meta-sandstone, and both two ...
From the diffusion tensor imaging, diffusion anisotropy measures such as the fractional anisotropy (FA), can be computed. Moreover, the principal direction of the diffusion tensor can be used to infer the white matter connectivity of the brain (i.e. tractography; trying to see which part of the brain is connected to which other part). Fractional anisotropy (FA) is a scalar value between zero and one that describes the degree of anisotropy of a diffusion process. A value of zero means that diffusion is isotropic, i.e. it is unrestricted (or equally restricted) in all directions. A value of one means that diffusion occurs only along one axis and is fully restricted along all other directions. FA is a measure often used in diffusion imaging where it is thought to reflect fiber density, axonal diameter, and myelination in white matter. The FA is an extension of the concept of eccentricity of conic sections in 3 dimensions, normalized to the unit range. FA values of the gray matter, especially in the ...
We report on the synthesis, microstructure and mass transport properties of a colloidal hydrogel self-assembled from a mixture of colloidal silica and nontronite clay plates at different particle concentrations. The gel-structure had uniaxial long-range anisotropy caused by alignment of the clay particles in
Ketamine abuse has been shown to have a deleterious impact on brain function. However, the precise mechanisms of ketamine dependence-induced pathological change remain poorly understood. Although there is evidence for white matter changes in drug abuse, the presence of white matter abnormalities in chronic ketamine users has not been studied. White matter volumes were measured using in vivo diffusion tensor magnetic resonance imaging data in 41 ketamine-dependent subjects and 44 drug-free healthy volunteers. White matter changes associated with chronic ketamine use were found in bilateral frontal and left temporoparietal cortices. There was also evidence that frontal white matter fractional anisotropy correlated with the severity of drug use (as measured by estimated total ketamine consumption). We provide direct evidence for dose-dependent abnormalities of white matter in bilateral frontal and left temporoparietal regions following chronic ketamine use. The findings suggest a microstructural ...
Traumatic brain injury (TBI) is a serious public health problem. Even injuries classified as mild, the most common, can result in persistent neurobehavioural impairment. Diffuse axonal injury is a common finding after TBI, and is presumed to contribute to outcomes, but may not always be apparent using standard neuroimaging. Diffusion tensor imaging (DTI) is a more recent method of assessing axonal integrity in vivo. The primary objective of the current investigation was to characterize white matter integrity utilizing DTI across the spectrum of chronic TBI of all severities. A secondary objective was to examine the relationship between white matter integrity and cognition. Twenty mild, 17 moderate to severe TBI and 18 controls underwent DTI and neuropsychological testing. Fractional anisotropy, axial diffusivity and radial diffusivity were calculated from the DTI data. Fractional anisotropy was the primary measure of white matter integrity. Region of interest analysis included anterior and ...
The article discusses the proposal for a "Charter of Digital Fundamental Rights of the European Union," whose central element is a binding effect of its fundamental rights not only to state authorities, but also to powerful private internet companies, which have a potential similar to that of the state to infringe on fundamental rights in the digital era. The article outlines the traditional German approach to fundamental rights and its underlying distinction between state and society, which makes it difficult for German scholars to handle a so-called horizontal effect of fundamental rights. Finally, the article discusses the main objections to such a horizontal effect and shows some practical problems it has the potential to cause in German and European constitutional law. ...
Results-The FA laterality index for the cerebral peduncle-regions of interest was a poor predictor of 3-month outcome (R2=0.044; P=0.137), whereas the slope over the FA laterality index of the nearest-5-slices showed a relatively weak but significant prediction (R2=0.11; P=0.022) with the affected side having lower FA values. Initial upper extremity Fugl-Meyer (R2=0.69; P,0.001) and the weighted CST lesion load (R2=0.71; P,0.001) were strong predictors of 3-month outcome. In multivariate analyses, controlling for initial upper extremity Fugl-Meyer, weighted CST lesion load, and days-of-therapy, neither the FA laterality index of the cerebral peduncle nor the slope over the FA laterality index of the nearest-5-slices significantly contributed to the prediction of 86% of the variance in the upper extremity Fugl-Meyer at 3 months. ...
To achieve a deeper understanding of the brain, scientists, and clinicians use electroencephalography (EEG) and magnetoencephalography (MEG) inverse methods to reconstruct sources in the cortical sheet of the human brain. The influence of structural and electrical anisotropy in both the skull and th …
We used diffusion tensor imaging (DTI) to study 2 patients with traumatic brain injury. The first patient recovered reliable expressive language after 19 years in a minimally conscious state (MCS); the second had remained in MCS for 6 years. Comparison of white matter integrity in the patients and 20 normal subjects using histograms of apparent diffusion constants and diffusion anisotropy identified widespread altered diffusivity and decreased anisotropy in the damaged white matter. These findings remained unchanged over an 18-month interval between 2 studies in the first patient. In addition, in this patient, we identified large, bilateral regions of posterior white matter with significantly increased anisotropy that reduced over 18 months. In contrast, notable increases in anisotropy within the midline cerebellar white matter in the second study correlated with marked clinical improvements in motor functions. This finding was further correlated with an increase in resting metabolism measured ...
An anisotropically conductive adhesive composition (10) for use in electrically connecting at least one conductive area (14) on one substrate (12) with at least one conductive area (20) on a second substrate (18) is disclosed. The composition (10) is comprised of a mixture of conductive particles and a nonconductive adhesive binder (26). The conductive particles are dispersed throughout the binder in a plurality of noncontiguous conductive units (24) such that, upon applying a layer (30) of the composition (10) over both the conductive and insulating areas (14, 16) on one substrate (12) and positioning in a conducting relationship and adhering said at least one conductive area (20) on the second substrate (18) with said at least one conductive area (14) on the first substrate (12), the units (24) establish electrical connection between the adhered conductive areas (14, 20) on the two substrates (12, 18). The units (24) are sufficiently spaced apart, however, to preclude electrical conductivity
We present evolution equations for a family of paths that results from anisotropically weighting curve energies in non-linear statistics of manifold valued data. This situation arises when performing inference on data that have non-trivial covariance and are anisotropic distributed. The family can be interpreted as most probable paths for a driving semi-martingale that through stochastic development is mapped to the manifold. We discuss how the paths are projections of geodesics for a sub-Riemannian metric on the frame bundle of the manifold, and how the curvature of the underlying connection appears in the sub-Riemannian Hamilton-Jacobi equations. Evolution equations for both metric and cometric formulations of the sub-Riemannian metric are derived. We furthermore show how rank-deficient metrics can be mixed with an underlying Riemannian metric, and we relate the paths to geodesics and polynomials in Riemannian geometry. Examples from the family of paths are visualized on embedded surfaces, and we
Distributed anisotropic diffusion provides a wrapper program around ITKs anisotropic diffusion filters that allows an input image to be spread across
Distributed anisotropic diffusion provides a wrapper program around ITKs anisotropic diffusion filters that allows an input image to be spread across
We apply the full-wave electromagnetic theory to study electromagnetic scattering by a small cylindrical particle with radial anisotropy for normally incident light with transverse magnetic (TM) polarization. The scattering coefficients are derived, when the radial anisotropies in both the permittivity and permeability tensors are taken into account. It is shown that the surface and volume plasmon resonances can be identified by the sign of dεt/dq, in which εt is the permittivity element in a direction tangential to the local r-axis, and q is the size parameter. The near field distributions for surface and volume modes are illustrated by finite element method. It is found that small changes of anisotropy can affect the scattering efficiencies significantly. Moreover, the quadrupole and octupole resonant peaks may be much higher and sharper than those of dipole resonance in the scattering efficiency spectra ...
The influence of scattering anisotropy on polarized light transport in microsphere solutions was studied experimentally an with Monte Carlo programs. Anisotropy is an important parameter in the depolarization of light traveling through a scattering media.. © Optical Society of America. PDF Article ...
swarm, towards the hydrodynamical modeling of ebullated bed reactors Soutenance de thèse Clément Toupoint. Jeudi 29 novembre - Amphithéâtre Nougaro. Abstract : The origin of this PhD. thesis lies in the study of Ebullated Bed Reactors (EBRs). These chemical reactors are very active research topics in chemical processes, notably thanks to their many usages in heavy oil processing. Many complex phenomena take place within EBRs, and make their design and optimization difficult. In fluid mechanics, a lot of physical mechanisms present in EBRs are active fields of study (three-phase flow, fluid-body interaction...). Hence, in the present work, a study of mechanisms participating in the hydrodynamics of an EBR with cylindrical catalysts is performed.. In a first part, the impact of the catalyst anisotropy on its fall is investigated. In order to gain insight on the effect of the body anisotropy on its fall dynamics, we investigate experimentally the free fall of a solid cylinder in a fluid at ...
Y. Shimotsuma, M. Nakabayasi, K. Miura, K. Hirao, and P. G. Kazansky, "Optical anisotropy of self-assembled nanostructure in glass," in Advanced Photonics Congress, OSA Technical Digest (online) (Optical Society of America, 2012), paper BW1D.1 ...
Immune responses to exercise generally consist of induced lymphocyte populations (mainly T-cells, B-cells and natural killer cells) in the blood under exercise and immune suppression during regeneration (29). The inflicted damages of the CNS structures lead to dysregulations of the inflammatory balance in favour of a pro-inflammatory state that may be targeted and modulated via exercise (12). MS research has more and more focused on the role of cytokines and neurotrophic factors linking the beneficial effects of exercise found in elder adults and animal studies also with MS pathogenesis. Data from cross-sectional studies in pwMS show positive associations between the levels of cardiorespiratory fitness and measures of grey matter atrophy and white matter integrity: in 21 pwMS (EDSS 1.0-6.0) high levels of cardiorespiratory fitness were positively correlated with grey matter volume and higher focal fractional anisotropy values (33).However, training interventions studies in pwMS show mixed ...
OBJECTIVE: To demonstrate the sensitivity of a recently developed whole-brain magnetic resonance spectroscopic imaging (MRSI) sequence to cerebral pathology and disability in amyotrophic lateral sclerosis (ALS), and compare with measures derived from diffusion tensor imaging. METHODS: Whole-brain MRSI and diffusion tensor imaging were undertaken in 13 patients and 14 age-similar healthy controls. Mean N-acetylaspartate (NAA), fractional anisotropy, and mean diffusivity were extracted from the corticospinal tract, compared between groups, and then in relation to disability in the patient group. RESULTS: Significant reductions in NAA were found along the course of the corticospinal tracts on whole-brain MRSI. There were also significant changes in fractional anisotropy (decreased) and mean diffusivity (increased) in the patient group, but only NAA showed a significant relationship with disability (r = 0.65, p = 0.01). CONCLUSION: Whole-brain MRSI has potential as a quantifiable neuroimaging marker of
Elastic Network Models (ENM) have been successful in reproducing fluctuations for proteins of native conformations. ENM is a coarse-grained method for modeling protein dynamics, meaning in generally in ENM each residue is represented by one bead in its Alpha Carbon position. These beads are then connected by elastic springs if the distance between two beads fall under a cutoff value (usually within the range of 7 to 15 angstroms). For more details please read here. PyANM is developed as a cross-platform Pymol Plugin to allow its users to build and visualize Anisotropic Network Models, a member of the ENM family. This plugin allows its users to draw arrows or make movies based on calculated mode motions, to draw all springs used to build the ANM within the protein, to color the protein based on its Mean Square Fluctuations (MSF) calculated from ANM and to export data from ANM for future processing. PyANM also allows its users to change the colors and scales (sizes) for movies or arrows generated ...
Diffusion MRI (dMRI) can be used to examine white matter structures in the living human brain. A common approach to dMRI analysis involves calculating a sc
Host: Core B, Dr. Ivet Bahar. Place: Victoria Building, Room 228. Date and Time: Wednesday, Oct. 5, 2016, 3:00 - 4:40 pm. 3:00 - 3:10 pm General Business for CDAR 3:10 - 4:20 pm Core B Monthly Report Update Presenters: Dr. Hongchun Li (Postdoctoral Associate, Bahar lab) gave an update on his work describing γ-secretase as an attractive target for treatment of Alzheimers disease and presented potential figures for a manuscript. G-secretase is a membrane protein and its function is related to many diseases. Recently, its 3-dimensional intact structure was determined, and we studied the intact structure with anisotropic network model (ANM) and molecular dynamics (MD) simulations. Our ANM model showed interesting motions related with modulator binding in a cavity, and our MD simulations found that the cavity is druggable. We also provided atomistic details of potential modulators in the cavity.. Title of presentation: "Dynamic Modulation of Binding Affinity as a Mechanism to Regulate Interferon ...
Critical white matter structures in the brains of babies who are born so prematurely that they weigh less than 1,500 grams develop more robustly when their mothers breast-feed them, compared with preemie peers who are fed formula.
High-resolution, 3D reconstructions of the ONH were generated for four clinically confirmed normal and two clinically confirmed glaucomatous human donor eyes from six donors. Eyes were immersion fixed at 10 mmHg and reconstructed using a custom automated microtome-based system that serially images the embedded tissue block face at 1.5 µm resolution in the fluorescent domain after each 1.5 µm section is cut. The images are then aligned and stacked into a digital 3D ONH reconstruction with 1.5x1.5x1.5 µm voxel resolution. The lamina cribrosa (LC) architecture was delineated and segmented and the laminar microarchitecture was sampled on a discrete grid to compute the connective tissue volume fraction (CTVF), the degree of anisotropy and the predominant laminar beam orientation within each sampling volume. CTVF, LC beam orientation, and LC beam anisotropy were mapped for each eye and compared.. ...
Anisotropy at the nanoscale is a critical factor in the mechanical, optical, electronic, and magnetic properties of nanoparticles. Indeed, many unusual properties of colloidal materials arise due to heterogeneous spatial confinement of electrons, plasmons and electric fields around the particles. As the field of nanoparticle synthesis and application matures, there is an increasing need for the design of novel and more complex nanosized objects. In particular, the incorporation of multiple functionalities, the directionality of such functions, and the incorporation of lower or higher dimensional order have great relevance and interest for biomolecule detection, diagnosis and therapeutic medical applications ...
We have analyzed the effect of microstructural changes on the initiation and growth of shear bands. These have been studied by developing an adaptive mesh refinement technique to decipher adiabatic shear bands in two-dimensional problems, formulating a three-dimensional finite-deformation theory for dipolar thermoviscoplastic materials and using it to examine the initiation and growth of shear bands in plane strain thermomechanical deformations of dipolar materials, employing an internal variable theory of Brown, Kim and Anand to study the shear band problem, investigating the possibility of phase transformations during the development of adiabatic shear bands in a steel specimen, ascertaining the speed of propagation of a shear band in a steel tube, assessing the effect of frictional forces between the loading device and the cylinder ends, and, analyzing the development of a shear band in a FCC single crystal. Principal results obtained during these investigations are summarized in the
We review results of recent combined theoretical and experimental studies of Ti1−xAlxN, an archetypical alloy system material for hard-coating applications. Theoretical simulations of lattice parameters, mixing enthalpies, and elastic properties are presented. Calculated phase diagrams at ambient pressure, as well as at pressure of 10 GPa, show a wide miscibility gap and broad region of compositions and temperatures where the spinodal decomposition takes place. The strong dependence of the elastic properties and sound wave anisotropy on the Al-content offers detailed understanding of the spinodal decomposition and age hardening in Ti1−xAlxN alloy films and multilayers. TiAlN/TiN multilayers can further improve the hardness and thermal stability compared to TiAlN since they offer means to influence the kinetics of the favorable spinodal decomposition and suppress the detrimental transformation to w-AlN. Here, we show that a 100 degree improvement in terms of w-AlN suppression can be achieved, which
Early stages of vertebrate embryogenesis are characterized by a remarkable series of shape changes. The resulting morphological complexity is driven by molecular, cellular, and tissue-scale biophysical alterations. Operating at the cellular level, extracellular matrix (ECM) networks facilitate cell motility. At the tissue level, ECM networks provide material properties required to accommodate the large-scale deformations and forces that shape amniote embryos. In other words, the primordial biomaterial from which reptilian, avian, and mammalian embryos are molded is a dynamic composite comprised of cells and ECM. Despite its central importance during early morphogenesis we know little about the intrinsic micrometer-scale surface properties of primordial ECM networks. Here we computed, using avian embryos, five textural properties of fluorescently tagged ECM networks - (a) inertia, (b) correlation, (c) uniformity, (d) homogeneity, and (e) entropy. We analyzed fibronectin and fibrillin-2 as ...
Author(s): Griesel, A; Mcclean, JL; Gille, ST; Sprintall, J; Eden, C | Abstract: Lagrangian isopycnal diffusivities quantify the along-isopycnal mixing of any tracer with mean gradients along isopycnal surfaces. They are studied in the Southern Ocean of the 1/10° Parallel Ocean Program (POP) model using more than 50 000 float trajectories. Concurrent Eulerian isopycnal diffusivities are estimated directly from the eddy fluxes and mean tracer gradients. Consistency, spatial variation, and relation to mean jets are evaluated. The diffusivities are calculated in bins large enough to reduce contributions from the rotational components that do not lead to net tracer mixing. Because the mean jets are nonzonal and nonparallel, meridional dispersion includes standing eddies and is significantly different from cross-stream dispersion. With the subtraction of the local Eulerianmean, the full Lagrangian diffusivity tensor can be estimated. Along-stream diffusivities are about 6 times larger than cross-stream
Figure S4. 6-hydroxyindole transition bandshapes, 1La and 1Lb, calculated from eqns. (6) and (7), using limiting anisotropy values derived from the fluorescence excitation anisotropy measurement at 77 K, given in Fig. 4b: fa(λ), dashed line and fb(λ), solid line ...
Abstract , References , Additional Information Abstract: In a previous paper [7] it was shown that for waves propagating in certain linear anisotropic mechanical systems there exist universal connections between the phase speeds of harmonic plane waves. Here the results are shown to hold in a wider context ...
GOCEs highly sensitive gradiometer instrument has been switched on and is producing data. Forming the heart of GOCE, the gradiometer is specifically designed to measure Earths gravity field with unprecedented accuracy.. "We are very pleased with what we have seen from the gradiometer from the moment it was switched on. All accelerometer sensor heads are working in very good health and provide meaningful data," GOCE Project Manager Danilo Muzi said.. The gradiometer consists of three pairs of identical ultra-sensitive accelerometers, each mounted to point in orthogonal directions to allow the simultaneous measurement of the spatial variations of the gravity field.. With the switching on of the gradiometer, all systems on the satellite have now been activated. The satellites sophisticated electric ion propulsion system was switched on last week and continues to operate normally. In order to get the maximum performance from the gradiometer, GOCE was designed to provide a highly stable and ...
The material structure in Maxwells equations is determined by the relative permittivity ε(x) and the relative permeability μ(x). However, ε is not only a function of position. In general, it also depends on frequency (material dispersion) and on the electric field E itself (nonlinearity). It may also depend on the orientation of the field (anisotropy). Material dispersion, in turn, is generally associated with absorption loss in the material, or possibly gain. All of these effects can be simulated in Meep, with certain restrictions. Similarly for the relative permeability μ(x), for which dispersion, nonlinearity, and anisotropy are all supported as well. In this section, we describe the form of the equations and material properties that Meep can simulate. The actual interface with which you specify these properties is described in the Meep reference. ...
Diffusion, Tissue, Magnetic, Water, Work, Brain, Anisotropy, Displacement, Magnetic Field, Magnetic Resonance, Scales, Rat, Measure, Motion, Time, Pulse, Pathologies, Distance, Human, Diffusion Mri
The magnetic susceptibility along the c axis (xc) and in the basal plane (xb) has been measured on a single crystal of Gd in the reduced temperature range 410-4t1.310-2. Uniaxial anisotropy is observed. Magnetic dipole-dipole ...
Cell, Chromatography, Electronic, Ligands, Parent, Reagents, Absorption, Anisotropy, Charge, Diffusion, Dmso, Fluorescence, Homo, Nature, Relaxation, Scales, Time, Transfer, Transient
The wide range of tests for determining the composition of samples, as well as their thermal, rheological and thermomechanical properties.
Background The tectorial membrane (TM) in the mammalian cochlea displays anisotropy, where mechanical or structural properties differ along varying directions. The anisotropy arises from the presence of collagen fibrils organized in fibers of ∼1 µm diameter that run radially across the TM. Mechanical coupling between the TM and the sensory epithelia is required for normal hearing. However, the lack of a suitable technique to measure mechanical anisotropy at the microscale level has hindered understanding of the TMs precise role. Methodology/Principal Findings Here we report values of the three elastic moduli that characterize the anisotropic mechanical properties of the TM. Our novel technique combined Atomic Force Microscopy (AFM), modeling, and optical tracking of microspheres to determine the elastic moduli. We found that the TMs large mechanical anisotropy results in a marked transmission of deformations along the direction that maximizes sensory cell excitation, whereas in the perpendicular
TY - JOUR. T1 - The usefulness of fractional anisotropy maps in localization of lacunar infarctions in striatum, internal capsule and thalamus. AU - Jeong, Hyun Kyung. AU - Lee, Seung Koo. AU - Kim, Dong Ik. AU - Heo, Ji Hoe. PY - 2005/4/1. Y1 - 2005/4/1. N2 - We aimed in this study to assess the clinical usefulness of fractional anisotropy (FA) maps in the evaluation of lacunar infarctions in striatum, internal capsule and thalamus. We retrospectively reviewed 28 patients (18 men, 10 women; mean age 63 years) who had acute lacunar infarction in striatum, internal capsule and thalamus on diffusion weighted MR imaging (DWI). Fractional anisotropy (FA) maps were generated in addition to conventional T2 weighted images (T2WI) and trace maps of DWI. Two radiologists reviewed the location of infarcts in combination with and without FA maps. Exact location of infarction was determined by FA maps, i.e. on the white band of internal capsule or outside the internal capsule. Accuracy and inter-observer ...
Six men performed ankle plantar flexion exercises with eccentric contraction. The fractional anisotropy (FA), λ1, λ2, λ3, mean diffusivity (MD), and T2 values in the triceps surae muscles were measured by magnetic resonance diffusion tensor and spin-echo imaging. Passive torque of plantar flexors, maximal voluntary isometric plantar flexion torques (MVIP), and Achilles tendon stiffness during MVIP were measured by combined ultrasonography and dynamometry. Plasma creatine kinase and muscle soreness were also assessed. These parameters were measured before and 1-8 days postexercise. ...
The analysis of DTI images showed that injured nerves have lower FA values as compared to the naïve nerves. It suggests that in area distally to coaptation site of injured nerves water diffuses in various directions indicating low structural integrity whereas most of the water inside of the naïve nerve diffuses in the same direction. FA has increased or did not change in the proximal and transection segment of injured nerve across groups from 2 to 5 weeks post-surgery. In the distal segment, FA value has increased by a noticeable margin in IGF-1 group and to a lesser degree, in FK506 treated group. This correlated strongly with changes in GAP43 expression, neurofilament M and myelin expressions in the distal nerve fragment ...
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UNLABELLED: Antisocial personality disorder (ASPD) and psychopathy involve significant interpersonal and behavioural impairments. However, little is known about their underlying neurobiology and in particular, abnormalities in white matter (WM) microstructure. A preliminary diffusion tensor magnetic resonance imaging (DT-MRI) study of adult psychopaths employing tractography revealed abnormalities in the right uncinate fasciculus (UF) (Craig et al., 2009), indicating fronto-limbic disconnectivity. However, it is not clear whether WM abnormalities are restricted to this tract or are or more widespread, including other tracts which are involved in connectivity with the frontal lobe. We performed whole brain voxel-based analyses on WM fractional anisotropy (FA) and mean diffusivity (MD) maps acquired with DT-MRI to compare 15 adults with ASPD and healthy age, handedness and IQ-matched controls. Also, within ASPD subjects we related differences in FA and MD to measures of psychopathy. Significant WM FA
UNLABELLED: Antisocial personality disorder (ASPD) and psychopathy involve significant interpersonal and behavioural impairments. However, little is known about their underlying neurobiology and in particular, abnormalities in white matter (WM) microstructure. A preliminary diffusion tensor magnetic resonance imaging (DT-MRI) study of adult psychopaths employing tractography revealed abnormalities in the right uncinate fasciculus (UF) (Craig et al., 2009), indicating fronto-limbic disconnectivity. However, it is not clear whether WM abnormalities are restricted to this tract or are or more widespread, including other tracts which are involved in connectivity with the frontal lobe. We performed whole brain voxel-based analyses on WM fractional anisotropy (FA) and mean diffusivity (MD) maps acquired with DT-MRI to compare 15 adults with ASPD and healthy age, handedness and IQ-matched controls. Also, within ASPD subjects we related differences in FA and MD to measures of psychopathy. Significant WM FA
The purpose of the present study was to detail the childhood developmental course of different white matter (WM) characteristics. In a longitudinal diffusion tensor imaging (DTI) study of 159 healthy children between 4 and 11 years scanned twice, we used tract-based spatial statistics as well as delineation of 15 major WM tracts to characterize the regional pattern of change in fractional anisotropy (FA), mean (MD), radial (RD) and axial diffusivity (AD). We tested whether there were decelerations of change with increasing age globally and tract-wise, and also illustrated change along medial-to-lateral, posterior-to-anterior and inferior-to-superior gradients. We found a significant linear increase in global FA, and decrease in MD and RD over time. For mean AD, a weak decrease was observed. The developmental changes in specific WM tracts showed regional differences. Eight WM tracts showed non-linear development patterns for one or several DTI metrics, with a deceleration in change with age. Sex ...
An ovine model can cast great insight in translational neuroscientific research due to its large brain volume and distinct regional neuroanatomical structures. The present study examined the applicability of brain functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to sheep using a clinical MR scanner (3 tesla) with a head coil. The blood-oxygenation-level-dependent (BOLD) fMRI was performed on anesthetized sheep during the block-based presentation of external tactile and visual stimuli using gradient echo-planar-imaging (EPI) sequence. The individual as well as group-based data processing subsequently showed activation in the eloquent sensorimotor and visual areas. DTI was acquired using 26 differential magnetic gradient directions to derive directional fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values from the brain. White matter tractography was also applied to reveal the macrostructure of the corticospinal tracts and optic radiations. Utilization
We describe the use of the fast Fourier transform (FFT) in the measurement of anisotropy in electrospun scaffolds of gelatin as a function of the starting conditions. In electrospinning, fiber alignment and overall scaffold anisotropy can be manipulated by controlling the motion of the collecting mandrel with respect to the source electrospinning solution. By using FFT to assign relative alignment values to an electrospun matrix it is possible to systematically evaluate how different processing variables impact the structure and material properties of a scaffold. Gelatin was suspended at varying concentrations (80, 100, 130, 150 mg/ml) and electrospun from 2,2,2 trifluoroethanol onto rotating mandrels (200-7000 RPM). At each starting concentration, fiber diameter remained constant over a wide range of mandrel RPM. Scaffold anisotropy developed as a function of fiber diameter and mandrel RPM. The induction of varying degrees of anisotropy imparted distinctive material properties to the electrospun