keyword
MENU ▼
Read by QxMD icon Read
search

topographical guidance

keyword
https://www.readbyqxmd.com/read/28841276/tuning-surface-and-topographical-features-to-investigate-competitive-guidance-of-spiral-ganglion-neurons
#1
Braden Lynn Leigh, Kristy Truong, Reid Bartholomew, Mark Ramirez, Marlan R Hansen, C Allan Guymon
Cochlear Implants (CIs) suffer from limited tonal resolution due, in large part, to spatial separation between stimulating electrode arrays and primary neural receptors. In this work, a combination of physical and chemical micro-patterns, formed on acrylate polymers, are used to direct the growth of primary spiral ganglion neurons (SGNs), the inner ear neurons. Utilizing the inherent temporal and spatial control of photopolymerization, physical micro-grooves are fabricated using a photomask in a single step process...
August 25, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28815971/topographical-and-electrical-stimulation-of-neuronal-cells-through-microwrinkled-conducting-polymer-biointerfaces
#2
Alberto Bonisoli, Attilio Marino, Gianni Ciofani, Francesco Greco
The development of smart biointerfaces combining multiple functions is crucial for triggering a variety of cellular responses. In this work, wrinkled organic interfaces based on the conducting polymer poly(3,4-ethylene dioxythiophene) doped with poly(styrene sulfonate) are developed with the aim to simultaneously convey electrical and topographical stimuli to cultured cells. The surface wrinkling of thin films on heat-shrink polymer sheets allows for rapid patterning of self-assembled anisotropic topographies characterized by micro/sub-microscale aligned wrinkles...
August 16, 2017: Macromolecular Bioscience
https://www.readbyqxmd.com/read/28813592/3d-printed-phema-materials-for-topographical-and-biochemical-modulation-of-dorsal-root-ganglion-cell-response
#3
Adina Badea, Joselle M McCracken, Emily G Tillmaand, Mikhail E Kandel, Aaron W Oraham, Molly B Mevis, Stanislav S Rubakhin, Gabriel Popescu, Jonathan V Sweedler, Ralph G Nuzzo
Understanding and controlling the interactions occurring between cells and engineered materials are central challenges toward progress in the development of biomedical devices. In this work, we describe materials for direct ink writing (DIW), an extrusion-based type of 3D printing, that embed a custom synthetic protein (RGD-PDL) within the microfilaments of 3D-hydrogel scaffolds to modify these interactions and differentially direct tissue-level organization of complex cell populations in vitro. The RGD-PDL is synthesized by modifying poly-d-lysine (PDL) to varying extents with peptides containing the integrin-binding motif Arg-Gly-Asp (RGD)...
September 13, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28805664/correlation-and-comparison-of-cortical-and-hippocampal-neural-progenitor-morphology-and-differentiation-through-the-use-of-micro-and-nano-topographies
#4
Sharvari Sathe, Xiang Quan Chan, Jing Jin, Erik Bernitt, Hans-Günther Döbereiner, Evelyn K F Yim
Neuronal morphology and differentiation have been extensively studied on topography. The differentiation potential of neural progenitors has been shown to be influenced by brain region, developmental stage, and time in culture. However, the neurogenecity and morphology of different neural progenitors in response to topography have not been quantitatively compared. In this study, the correlation between the morphology and differentiation of hippocampal and cortical neural progenitor cells was explored. The morphology of differentiated neural progenitors was quantified on an array of topographies...
August 12, 2017: Journal of Functional Biomaterials
https://www.readbyqxmd.com/read/28792499/revisiting-chemoaffinity-theory-chemotactic-implementation-of-topographic-axonal-projection
#5
Honda Naoki
Neural circuits are wired by chemotactic migration of growth cones guided by extracellular guidance cue gradients. How growth cone chemotaxis builds the macroscopic structure of the neural circuit is a fundamental question in neuroscience. I addressed this issue in the case of the ordered axonal projections called topographic maps in the retinotectal system. In the retina and tectum, the erythropoietin-producing hepatocellular (Eph) receptors and their ligands, the ephrins, are expressed in gradients. According to Sperry's chemoaffinity theory, gradients in both the source and target areas enable projecting axons to recognize their proper terminals, but how axons chemotactically decode their destinations is largely unknown...
August 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28758545/a-topographical-map-approach-to-representing-treatment-efficacy-a-focus-on-positive-psychology-interventions
#6
Eugenia I Gorlin, Josephine Lee, Michael W Otto
A recent meta-analysis by Bolier et al. indicated that positive psychology interventions have overall small to moderate effects on well-being, but results were quite heterogeneous across intervention trials. Such meta-analytic research helps condense information on the efficacy of a broad psychosocial intervention by averaging across many effects; however, such global averages may provide limited navigational guidance for selecting among specific interventions. Here, we introduce a novel method for displaying qualitative and quantitative information on the efficacy of interventions using a topographical map approach...
July 31, 2017: Cognitive Behaviour Therapy
https://www.readbyqxmd.com/read/28722651/ephrin-a-epha-specific-co-adaptation-as-a-novel-mechanism-in-topographic-axon-guidance
#7
Felix Fiederling, Markus Weschenfelder, Martin Fritz, Anne von Philipsborn, Martin Bastmeyer, Franco Weth
Genetic hardwiring during brain development provides computational architectures for innate neuronal processing. Thus, the paradigmatic chick retinotectal projection, due to its neighborhood preserving, topographic organization, establishes millions of parallel channels for incremental visual field analysis. Retinal axons receive targeting information from quantitative guidance cue gradients. Surprisingly, novel adaptation assays demonstrate that retinal growth cones robustly adapt towards ephrin-A/EphA forward and reverse signals, which provide the major mapping cues...
July 19, 2017: ELife
https://www.readbyqxmd.com/read/28671108/cell-instructive-high-resolution-micropatterned-polylactic-acid-surfaces
#8
David Barata, Paulo Dias, Paul Wieringa, Clemens van Blitterswijk, Pamela Habibovic
Micro and nanoscale topographical structuring of biomaterial surfaces has been a valuable tool for influencing cell behavior, including cell attachment, proliferation and differentiation. However, most fabrication techniques for surface patterning of implantable biomaterials suffer from a limited resolution, not allowing controlled generation of sub-cellular three-dimensional features. Here, a direct laser lithography technique based on two-photon absorption was used to construct several patterns varying in size between 500 nm and 15 μm...
July 24, 2017: Biofabrication
https://www.readbyqxmd.com/read/28664962/initial-contact-guidance-during-cell-spreading-is-contractility-independent
#9
Adrià Sales, Andrew W Holle, Ralf Kemkemer
A wide variety of cell types exhibit substrate topography-based behavior, also known as contact guidance. However, the precise cellular mechanisms underlying this process are still unknown. In this study, we investigated contact guidance by studying the reaction of human endothelial cells (ECs) to well-defined microgroove topographies, both during and after initial cell spreading. As the cytoskeleton plays a major role in cellular adaptation to topographical features, two methods were used to perturb cytoskeletal structures...
August 2, 2017: Soft Matter
https://www.readbyqxmd.com/read/28653527/insights-into-the-silver-reflection-layer-of-a-vertical-led-for-light-emission-optimization
#10
Mansoor Ali Khan, Hansheng Chen, Jiangtao Qu, Patrick W Trimby, Steven Moody, Yin Yao, Simon P Ringer, Rongkun Zheng
In this work, Ag as a highly reflective mirror layer of gallium nitride (GaN)-based blue vertical light-emitting diodes (VLEDs) has been systematically investigated by correlating scanning electron microscopy/energy dispersive X-ray spectroscopy/transmission Kikuchi diffraction/electron backscatter diffraction, aberration-corrected scanning transmission electron microscopy, and atomic force microscopy techniques. In the context of high-efficiency lighting, three critical aspects have been scrutinized on the nanoscale: (1) chemical diffusion, (2) grain morphology, and (3) surface topography of the Ag layer...
July 19, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28509381/topography-guided-control-of-local-migratory-behaviors-and-protein-expression-of-cancer-cells
#11
Jung-Youn Shin, Hong Nam Kim, Suk Ho Bhang, Jeong-Kee Yoon, Kahp-Yang Suh, Noo Li Jeon, Byung-Soo Kim
In vivo cancer cell migration and invasion are directed by biophysical guidance mechanisms such as pre-existing microtracks and basement membrane extracellular matrices. Here, this paper reports the correlation of the local migratory behavior of cancer cells and the biochemical signal expression using the topography that can guide or inhibit cell behaviors. To this end, the local apparent migration and the protein expression level are investigated with respect to the topographical feature size (flat, nanoline, and microline) and orientation (microline, microconcentric, and microradial) with the collectively migrating (A431) and individually migrating (MDA-MB-231 and U-87-MG) cancer cells...
August 2017: Advanced Healthcare Materials
https://www.readbyqxmd.com/read/28462069/silicon-microgrooves-for-contact-guidance-of-human-aortic-endothelial-cells
#12
Sara Fernández-Castillejo, Pilar Formentín, Úrsula Catalán, Josep Pallarès, Lluís F Marsal, Rosa Solà
Background: Micro- and nanoscale substrates have been fabricated in order to study the influence of the topography on the cellular response. The aim of this work was to prepare different collagen-coated silicon substrates displaying grooves and ridges to mimic the aligned and elongated endothelium found in linear vessels, and to use them as substrates to study cell growth and behaviour. Results: The influence of groove-shaped substrates on cell adhesion, morphology and proliferation were assessed, by comparing them to flat silicon substrates, used as control condition...
2017: Beilstein Journal of Nanotechnology
https://www.readbyqxmd.com/read/28450099/topographical-anatomy-of-the-distal-ulna-attachment-of-the-radioulnar-ligament
#13
Won-Jeong Shin, Jong-Pil Kim, Hun-Mu Yang, Eun-Young Lee, Jai-Hyang Go, Kang Heo
PURPOSE: The deep component of the distal radioulnar ligament provides translational stability and rotational guidance to the forearm. However, controversy exists regarding the importance of this structure as well as the nature of its attachment to the distal ulna. We aimed to evaluate the topographic anatomy of the distal ulna attachment of both the superficial and the deep components of the radioulnar ligament and to assess the relationship between its internal and its external morphometry...
April 25, 2017: Journal of Hand Surgery
https://www.readbyqxmd.com/read/28438183/semaphorin-plexin-signaling-influences-early-ventral-telencephalic-development-and-thalamocortical-axon-guidance
#14
Manuela D Mitsogiannis, Graham E Little, Kevin J Mitchell
BACKGROUND: Sensory processing relies on projections from the thalamus to the neocortex being established during development. Information from different sensory modalities reaching the thalamus is segregated into specialized nuclei, whose neurons then send inputs to cognate cortical areas through topographically defined axonal connections. Developing thalamocortical axons (TCAs) normally approach the cortex by extending through the subpallium; here, axonal navigation is aided by distributed guidance cues and discrete cell populations, such as the corridor neurons and the internal capsule (IC) guidepost cells...
April 24, 2017: Neural Development
https://www.readbyqxmd.com/read/28437614/engineering-highly-interconnected-neuronal-networks-on-nanowire-scaffolds
#15
Vini Gautam, Shagufta Naureen, Naeem Shahid, Qian Gao, Yi Wang, David Nisbet, Chennupati Jagadish, Vincent R Daria
Identifying the specific role of physical guidance cues in the growth of neurons is crucial for understanding the fundamental biology of brain development and for designing scaffolds for tissue engineering. Here, we investigate the structural significance of nanoscale topographies as physical cues for neurite outgrowth and circuit formation by growing neurons on semiconductor nanowires. We monitored neurite growth using optical and scanning electron microscopy and evaluated the spontaneous neuronal network activity using functional calcium imaging...
June 14, 2017: Nano Letters
https://www.readbyqxmd.com/read/28401884/anisotropic-forces-from-spatially-constrained-focal-adhesions-mediate-contact-guidance-directed-cell-migration
#16
Arja Ray, Oscar Lee, Zaw Win, Rachel M Edwards, Patrick W Alford, Deok-Ho Kim, Paolo P Provenzano
Directed migration by contact guidance is a poorly understood yet vital phenomenon, particularly for carcinoma cell invasion on aligned collagen fibres. We demonstrate that for single cells, aligned architectures providing contact guidance cues induce constrained focal adhesion maturation and associated F-actin alignment, consequently orchestrating anisotropic traction stresses that drive cell orientation and directional migration. Consistent with this understanding, relaxing spatial constraints to adhesion maturation either through reduction in substrate alignment density or reduction in adhesion size diminishes the contact guidance response...
April 12, 2017: Nature Communications
https://www.readbyqxmd.com/read/28296389/abrogated-cell-contact-guidance-on-amino-functionalized-microgrooves
#17
Caroline Mörke, Henrike Rebl, Birgit Finke, Manuela Dubs, Peter Nestler, Aissam Airoudj, Vincent Roucoules, Matthias Schnabelrauch, Andreas Körtge, Karine Anselme, Christiane A Helm, J Barbara Nebe
Topographical and chemical features of biomaterial surfaces affect the cell physiology at the interface and are promising tools for the improvement of implants. The dominance of the surface topography on cell behavior is often accentuated. Striated surfaces induce an alignment of cells and their intracellular adhesion-mediated components. Recently, it could be demonstrated that a chemical modification via plasma polymerized allylamine was not only able to boost osteoblast cell adhesion and spreading but also override the cell alignment on stochastically machined titanium...
March 29, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28253620/conjugation-in-escherichia-coli-biofilms-on-poly-dimethylsiloxane-surfaces-with-microtopographic-patterns
#18
Huan Gu, Kristopher W Kolewe, Dacheng Ren
Bacterial biofilms are highly tolerant to antimicrobials and play an important role in the development and spread of antibiotic resistance based on horizontal gene transfer due to close cell-to-cell contact. As an important surface property, topography has been shown to affect bacterial adhesion and biofilm formation. Here, we demonstrate that micrometer-scale surface topographies also affect horizontal gene transfer through conjugation in bacterial biofilms. Specifically, biofilm formation and associated conjugation on poly(dimethylsiloxane) (PDMS) surfaces with 10 μm tall protruding patterns were studied using fluorescently labeled donor and recipient strains of Escherichia coli...
March 13, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28218340/world-health-organization-global-disability-action-plan-the-mongolian-perspective
#19
Fary Khan, Bhasker Amatya, Baljnnyam Avirmed, Yoon Kyoung Yi, Batchimeg Shirmen, Geoff Abbott, Mary P Galea
OBJECTIVE: To provide an update on disability and rehabilitation in Mongolia, and to identify potential barriers and facilitators for implementation of the World Health Organization (WHO) Global Disability Action Plan (GDAP). METHODS: A 4-member rehabilitation team from the Royal Melbourne Hospital conducted an intensive 6-day workshop at the Mongolian National University of Medical Sciences, for local healthcare professionals (n = 77) from medical rehabilitation facilities (urban/rural, public/private) and non-governmental organizations...
February 16, 2017: Journal of Rehabilitation Medicine
https://www.readbyqxmd.com/read/28197551/ephrina5-signaling-is-required-for-the-distinctive-targeting-of-raphe-serotonin-neurons-in-the-forebrain
#20
Teng Teng, Afsaneh Gaillard, Aude Muzerelle, Patricia Gaspar
Serotonin (5-HT) neurotransmission in the brain relies on a widespread axon terminal network originating from the hindbrain raphe nuclei. These projections are topographically organized such that the dorsal (DR), and median raphe (MnR) nuclei have different brain targets. However, the guidance molecules involved in this selective targeting in development are unknown. Here, we show the implication of ephrinA5 signaling in this process. We find that the EphA5 gene is selectively expressed in a subset of 5-HT neurons during embryonic and postnatal development...
January 2017: ENeuro
keyword
keyword
49872
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"