28 results match your criteria rims holes

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[Functional and Anatomic Outcomes of Primary and Secondary Internal Limiting Membrane Transplantation in Large and Persistent Macular Holes].

Klin Monbl Augenheilkd 2018 Oct 20;235(10):1159-1164. Epub 2017 Nov 20.

Augenklinik, Stadtspital Triemli, Zürich, Schweiz.

Background: The gold standard therapy for full-thickness macular holes (FTMH) is vitrectomy (PPV) with peeling of the internal limiting membrane (ILM), gas tamponade of the vitreous cavity and postoperative face-down positioning. Nevertheless, eyes with large macular holes (> 400 µm) and surgical failures remain difficult to manage. Recently, ILM transplantation (ILM-TX) techniques were developed with acceptable results, advocating different mechanisms of hole closure: in such a setting, the ILM could serve as a scaffold for neuronal tissue in the pedicle ILM flap technique or the ILM could induce a contraction of the FTMH rims through shrinking of a folded ILM plug. Read More

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October 2018

The collision of a hypervelocity massive projectile with free-standing graphene: Investigation of secondary ion emission and projectile fragmentation.

J Chem Phys 2017 Feb;146(5):054305

Department of Chemistry, Texas A&M University, College Station, Texas 77843-3144, USA.

We present here the study of the individual hypervelocity massive projectiles (440-540 keV, 33-36 km/s Au cluster) impact on 1-layer free-standing graphene. The secondary ions were detected and recorded separately from each individual impact in the transmission direction using a time-of-flight mass spectrometer. We observed C ions emitted from graphene, the projectiles which penetrated the graphene, and the Au fragment ions in mass spectra. Read More

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February 2017

3D nano-structures for laser nano-manipulation.

Beilstein J Nanotechnol 2013 17;4:534-41. Epub 2013 Sep 17.

Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Hawthorn, VIC 3122, Australia ; The Australian National Fabrication Facility - ANFF, Victoria node, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Hawthorn, VIC 3122, Australia.

The resputtering of gold films from nano-holes defined in a sacrificial PMMA mask, which was made by electron beam lithography, was carried out with a dry plasma etching tool in order to form well-like structures with a high aspect ratio (height/width ≈ 3-4) at the rims of the nano-holes. The extraordinary transmission through the patterns of such nano-wells was investigated experimentally and numerically. By doing numerical simulations of 50-nm and 100-nm diameter polystyrene beads in water and air, we show the potential of such patterns for self-induced back-action (SIBA) trapping. Read More

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September 2013

Time-domain characterization of the acoustic damping of a perforated liner with bias flow.

J Acoust Soc Am 2012 Jul;132(1):271-81

Aerospace Engineering Division, College of Engineering, Nanyang Technological University, Singapore 639798, 50 Nanyang Avenue, Singapore.

Combustion instabilities are caused by the interaction of unsteady heat releases and acoustic waves. To mitigate combustion instabilities, perforated liners, typically subjected to a low Mach number bias flow (a cooling flow through perforated holes), are fitted along the bounding walls of a combustor. They dissipate the acoustic waves by generating vorticity at the rims of perforated apertures. Read More

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Single-molecule imaging on living bacterial cell surface by high-speed AFM.

J Mol Biol 2012 Sep 18;422(2):300-9. Epub 2012 May 18.

School of Mathematics and Physics, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.

Advances in microscopy have contributed to many biologic discoveries. Electron microscopic techniques such as cryo-electron tomography are remarkable tools for imaging the interiors of bacterial cells in the near-native state, whereas optical microscopic techniques such as fluorescence imaging are useful for following the dynamics of specific single molecules in living cells. Neither technique, however, can be used to visualize the structural dynamics of a single molecule at high resolution in living cells. Read More

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September 2012

One-point fixation of tripod fractures of zygoma through a lateral brow incision.

Authors:
Kun Hwang

J Craniofac Surg 2010 Jul;21(4):1042-4

Department of Plastic Surgery and Center for Advanced Medical Education by BK21 Project, Inha University College of Medicine, Incheon 400-711, Korea.

The aims of this report were to analyze the cases of lateral brow incision and 1-point fixation and to introduce the criteria for application of this selective approach.Among 70 patients with tripod fractures, 14 patients (20%) underwent 1-point fixation technique through lateral brow incisions. Preoperative and postoperative displacements of the infraorbital rim were radiologically measured. Read More

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Dewetting of ultrathin solid films.

Phys Rev Lett 2009 Nov 4;103(19):195501. Epub 2009 Nov 4.

LPMCN, Université Lyon 1, 43 Boulevard du 11 novembre, 69622 Villeurbane, France.

Ultrathin crytalline solid films are found to dewet with a faceted rim. In the case of heterogeneous dewetting initiated from a linear trench or from periodically arranged holes, the dewetted area expands either with a faceted multilayer rim or in a layer-by-layer fashion. In the case of homogeneous dewetting, holes are accompanied with multilayer rims and the uncoverage increases as a power law of time. Read More

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November 2009

Dewetting of polymer films by ion implantation.

Authors:
Z J Han B K Tay

Eur Phys J E Soft Matter 2009 Mar 27;28(3):273-8. Epub 2009 Jan 27.

Nanoelectronics Lab I, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore.

We report dewetting of thermodynamically stable, thick (approximately 100 nm) polystyrene films by titanium ion implantation. The dynamic dewetting patterns in time evolution are recorded. The dewetting mechanism is determined to be heterogeneous nucleation, where the defects and Ti nanoparticles formed by ion implantation serve as the nuclei. Read More

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Surface trapping of atoms and molecules with dipole rings.

Science 2008 Mar;319(5871):1824-6

Physik-Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.

The trapping of single molecules on surfaces without the formation of strong covalent bonds is a prerequisite for molecular recognition and the exploitation of molecular function. On nanopatterned surfaces, molecules may be selectively trapped and addressed. In a boron nitride nanomesh formed on Rh(111), the pattern consisted of holes 2 nanometers in diameter on a hexagonal superlattice, separated by about 3 nanometers. Read More

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The perceived structural shape of thin (wire-like) objects is different from that of silhouettes.

Perception 2006 ;35(12):1679-92

School of Psychology, Eleanor Rathbone Building, University of Liverpool, Liverpool L69 7ZA, UK.

Observers are faster at judging the position of convex vertices compared to concave vertices. This is believed to be due to an explicit representation of position for visual parts. The best evidence comes from comparing the same contours perceived as either figures or holes, because this is a pure figure ground reversal (Bertamini and Croucher, 2003 Cognition 87 33 - 54; Bertamini and Mosca, 2004 Perception 33 35-48). Read More

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Self-assembly of polystyrene-block-poly(ethylene oxide) copolymers at the air-water interface: is dewetting the genesis of surface aggregate formation?

Langmuir 2006 Sep;22(20):8387-96

Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, BC V8W 3V6 Canada.

Block copolymer self-assembly at the air-water interface is commonly regarded as a two-dimensional counterpart of equilibrium block copolymer self-assembly in solution and in the bulk; however, the present analysis of atomic force microscopy (AFM) and isotherm data at different spreading concentrations suggests a nonequilibrium mechanism for the formation of various polystyrene-b-poly(ethylene oxide) (PS-b-PEO) aggregates (spaghetti, dots, rings, and chainlike aggregates) at the air-water interface starting with an initial dewetting of the copolymer spreading solution from the water surface. We show that different spreading concentrations provide kinetic snapshots of various stages of self-assembly at the air-water interface as a result of different degrees of PS chain entanglements in the spreading solution. Two block copolymers are investigated: MW = 141k (11. Read More

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September 2006

Dynamic contact angle in rim instability of dewetting holes.

J Chem Phys 2006 Feb;124(5):054702

Department of Chemical Engineering, The University of Akron, Akron, Ohio 44325-3906, USA.

The effects of dynamic contact angle (thetad), between a substrate and the melt of a dewetting polymer thin film, on the evolution of rim instabilities of dewetting holes were reported. Various thetad's were achieved by covering SiOx surfaces with different coverage of octadecyltrichlorosilane. On each surface, the morphology of the dewetting holes was examined in detail as the hole grew to a certain size. Read More

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February 2006

Shape relaxations in a fluid supported membrane during hydrolysis by phospholipase A(2).

Biochim Biophys Acta 2005 Aug;1715(1):1-5

MEMPHYS Center for Biomembrane Physics, Physics Department, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.

The behavior of a fluid supported membrane during hydrolysis by phospholipase A(2) is for the first time visualized by time-resolved fluorescence imaging. After a lag phase, hydrolysis proceeds from the boundary of existing holes and via nucleation of new holes. During subsequent hydrolysis, the shape of the membrane boundary is determined both by hydrolysis and by shape relaxations due to the action of line tension. Read More

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Dynamics of ultrathin films in the glassy state.

Langmuir 2005 May;21(11):5069-72

Department of Materials Science and Engineering, SUNY at Stony Brook, Stony Brook, New York 11794, USA.

We report hole growth experiments in free-standing polystyrene (PS) films at temperatures up to 10 degrees C below the bulk glass transition. The data show an unexpected result: the growth rate of nucleated holes increases with increasing molecular weight, up to a limiting value beyond which the rate is approximately constant. Film thicknesses of 45, 80, and 100 nm were studied, using PS molecular weights ranging from 65K to 11. Read More

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Instability, dynamics, and morphology of thin slipping films.

Langmuir 2004 Jan;20(1):244-53

Department of Chemical Engineering, Jadavpur University, Kolkata-700032, India.

Based on the linear stability and nonlinear simulations, we show that the surface instability, dynamics, and morphology of supported thin liquid films are profoundly altered by the presence of slippage on the substrate. A general dispersion equation for flow in slipping thin films is derived and simplified to identify three different regimes of slippage (weak, moderate, and strong) and obtain the length and time scales of instability in them. For illustration, the ubiquitous van der Waals interactions have been employed. Read More

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January 2004

Is removal of internal limiting membrane always necessary during stage 3 idiopathic macular hole surgery?

Retina 2005 Jan;25(1):54-8

Department of Ophthalmology and Visual Sciences, Graduate School of Medicine, Kyoto University,Kyoto, Japan.

Purpose: To determine the indications for internal limiting membrane (ILM) removal in stage 3 idiopathic macular holes (MHs).

Methods: Focal posterior vitreous detachments (PVDs) at MH rims were examined preoperatively by optical coherence tomography and binocular slit-lamp fundus examination in 19 patients retrospectively. All eyes underwent pars plana vitrectomy and creation of a PVD, and some eyes underwent a second surgery to remove the ILM. Read More

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January 2005

Why are Foley catheters so vulnerable to encrustation and blockage by crystalline bacterial biofilm?

Urol Res 2003 Oct 11;31(5):306-11. Epub 2003 Jul 11.

Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3TL, UK.

Many patients undergoing long-term bladder catheterisation experience blockage and encrustation of their catheters. The problem stems from infection by urease producing bacteria, particularly Proteus mirabilis. Bacterial biofilms colonise the catheters, the activity of urease raises the pH and induces the deposition of calcium and magnesium phosphate crystals. Read More

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October 2003

Surface modifications induced by ns and sub-ps excimer laser pulses on titanium implant material.

Biomaterials 2003 Oct;24(23):4197-203

Department of Optics and Quantum Electronics, University of Szeged, Dóm tér 9., Szeged, H-6720, Hungary.

Medical implants used in oral and orthopaedic surgery are mainly produced from titanium. Their biological behaviour, e.g. Read More

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October 2003

[Percutaneous closure of atrial septal defect with the Amplatz device: initial result and mid-term follow-up].

Rev Esp Cardiol 2001 Oct;54(10):1190-6

Servicio de Cardiología Infantil. Hospital La Paz. Madrid, Spain.

Objectives: Percutaneous device occlusion of atrial septal defects (ASD) is, although with some limitations, an alternative to surgical closure. The aim of this study was to evaluate the efficacy and safety of percutaneous ASD closure using the Amplatz device.

Patients And Methods: From October 1999 to March 2000, 25 children underwent transcatheter closure of ASD at a mean +/- SD age of 8. Read More

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October 2001

Influence of cyclodextrin ring substituents on folding-related aggregation of bovine carbonic anhydrase.

Authors:
L Sharma A Sharma

Eur J Biochem 2001 Apr;268(8):2456-63

Science Department, Davenport University, Midland, MI, USA.

A common obstacle to proper renaturation of an unfolded protein is aggregation, an intermolecular side reaction of immense importance in biotechnology and in the pathogenesis of several neurodegenerative diseases. Cyclic sugars known as cyclodextrins have been used as protein-folding aids. The effect of cyclodextrin chemistry on aggregation and refolding of carbonic anhydrase was evaluated in this study. Read More

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Dynamics and Morphology of Holes in Dewetting of Thin Films.

J Colloid Interface Sci 1999 Apr;212(2):483-494

Department of Chemical Engineering, Indian Institute of Technology, Kanpur, 208016, India

The formation and growth of holes in apolar nonslipping Newtonian thin films subjected to long-range Lifshitz-van der Waals forces are investigated based directly on numerical solutions of the thin-film equation. The nonphysical divergences of the hydrodynamic model and of the van der Waals force at the three-phase contact line are removed by inclusion of the short-range Born repulsion. Three distinct regimes of the hole growth after its appearance are identified: (1) a short, unsteady phase in which the dynamic contact angle and velocity change rapidly, followed by (2) a long, quasi-steady phase with slow logarithmic changes, and finally (3) a hindered phase in which rims of the neighboring holes overlap and lead to formation of equilibrium drops. Read More

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Histopathological reactions of the blue shark, Prionace glauca, to postlarvae of Hepatoxylon trichiuri (Cestoda: Trypanorhyncha: Hepatoxylidae) in relationship to scolex morphology.

Folia Parasitol (Praha) 1998 ;45(1):47-52

Department of Biology, University of Massachusetts Dartmouth 02747-2300, USA.

Postlarvae of the cestode Hepatoxylon trichiuri (Holten, 1802) were found attached to the surface of viscera of Prionace glauca (Linnaeus, 1758) taken from Atlantic coastal waters off the south coast of Massachusetts, USA. Gross anatomy of the attachment site shows a quadripartite rim surrounding a deep pit with holes corresponding to the penetration site of each tentacle. Hyperplasia of the liver capsule into outgrowths at the attachment site conform to the attachment of the bothridia. Read More

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Quantitative analysis of macular holes with scanning laser tomography.

Ophthalmology 1997 Dec;104(12):2018-29

Schepens Eye Research Institute, Boston, Massachusetts, USA.

Objective: The purpose of the study is to establish objective, quantitative, and reproducible three-dimensional analysis for macular holes with scanning laser tomography and to correlate measurements with visual acuity.

Design: The authors performed a cross-sectional, nonrandomized study.

Participants: The authors examined 28 full-thickness macular holes of 23 patients aged 61 to 84 years. Read More

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December 1997

Three-dimensional measurements of idiopathic macular holes using a scanning laser tomograph.

Ophthalmology 1995 Oct;102(10):1445-9

Department of Ophthalmology, Beilinson Medical Center, Petah Tiqva, Israel.

Purpose: The diagnosis of macular holes is difficult. Confocal laser tomographic analysis of the retina permits the precise measurements of the macular surface. The authors used this technique to study the macular area of patients with full-thickness macular holes. Read More

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October 1995

Depth from binocular rivalry without spatial disparity.

Authors:
I P Howard

Perception 1995 ;24(1):67-74

Centre for Vision Research, York University, North York, Ontario, Canada.

Some new stereoscopic effects are reported that arise from dichoptic stimuli containing no binocular disparity. In one effect, identical arrays of small black discs are presented to the two eyes and slightly smaller white discs are superimposed on one of each pair of black discs. This creates the impression of a surface with holes in it, through which is seen a surface with fluctuating black and white areas. Read More

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Effect of mechanical trauma on the stapedial footplate after stapedectomy. A scanning electron microscopic study.

ORL J Otorhinolaryngol Relat Spec 1990 ;52(5):286-91

Department of Otolaryngology, III ENT Clinic, Rome, Italy.

The possible occurrence of inner-ear trauma linked to stapedectomy was studied by scanning electron microscopy of the medial (or labyrinthine) side of human stapedial footplates after performing a hole with different instruments. The anatomic variations induced experimentally by the different procedures are presented in detail and discussed. Manual instruments were shown to induce irregularities on the rim of the hole, whilst the utilization of either electric or pneumatic drills produced more regular margins. Read More

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December 1990

Vascularity for healing of meniscus repairs.

Arthroscopy 1987 ;3(1):13-8

Vascularity in the human meniscus is poor beyond 1-2 mm from the meniscosynovial junction, yet 22% of the tears in this series occur with a greater than or equal to 3-mm peripheral white rim. It is possible to suture these tears with the wider peripheral white rims, but healing rates are reduced because it is more difficult to obtain a satisfactory vascular supply. This article describes the history of our efforts at obtaining blood supply for healing of meniscus tears with a peripheral white rim up to 5 mm. Read More

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