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Free Edge (free + edge)
Selected AbstractsDermoscopy provides useful information for the management of melanonychia striataDERMATOLOGIC THERAPY, Issue 1 2007Luc Thomas ABSTRACT:, The diagnosis of melanonychia striata is often difficult, and a biopsy of the nail matrix is required in doubtful cases. However, dermoscopic examination of the nail plate offers interesting information in order to better select the cases in which pathologic examination is indicated. In the case of brown longitudinal pigmentation with parallel regular lines, the diagnosis of nail apparatus melanocytic nevus could be made. On the other hand, the presence of a brown pigmentation overlaid by longitudinal lines irregular in their thickness, spacing, color, or parallelism is highly in favor of a melanoma. Gray homogeneous lines are observed in case of lentigo, lentiginoses, ethnic or drug-induced pigmentations, and in post-traumatic pigmentations. Blood spots are characterized by their round-shaped proximal edge and their filamentous distal edge and are highly suggestive of subungual hemorrhages. Dermoscopic examination of the free edge of the nail plate gives information on the lesion location; pigmentation of the dorsum of the nail plate is in favor of a proximal nail matrix lesion, whereas pigmentation the lower part of the nail edge is in favor of a lesion of the distal matrix. [source] Quantitative evaluation of the prosthetic head damage induced by microscopic third-body particles in total hip replacementJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 4 2001Manuela Teresa Raimondi Abstract The increase of the femoral head roughness in artificial hip joints is strongly influenced by the presence of abrasive particulate entrapped between the articulating surfaces. The aim of the present study is to evaluate the dependence of such damage on the geometry of the particles entrapped in the joint, with reference to the UHMWPE/chrome-cobalt coupling. Five chrome-cobalt femoral heads and their coupled UHMWPE acetabular cups, retrieved at revision surgery after a short period of in situ functioning, have been investigated for the occurrence of third-body damage. This was found on all the prosthetic heads, where the peak-to-valley height of the scratches, as derived from profilometry evaluations, ranged from 0.3,1.3 ,m. The observed damage has been divided into four classes, related to the particle motion while being embedded into the polymer. Two kinds of particle morphology have been studied, spherical and prismatic, with size ranging from 5,50 ,m. In order to provide an estimation of the damage induced by such particles, a finite element model of the third-body interaction was set up. The peak-to-valley height of the impression due to the particle indentation on the chrome-cobalt surface is assumed as an index of the induced damage. The calculated values range from 0.1,0.5 ,m for spherical particles of size ranging from 10,40 ,m. In the case of prismatic particles, the peak-to-valley height can reach 1.3 ,m and depends both on the size and width of the particle's free corner, indenting the chrome-cobalt. As an example, a sharp-edged particle of size 30 ,m can induce on the chrome-cobalt an impression with peak-to-valley height of 0.75 ,m, when embedded into the polyethylene with a free edge of 5 ,m facing the metallic surface. Negligible damage is induced, if a free edge of 7.5 ,m is indenting the counterface. Our findings offer new support to the hypothesis that microscopic third-body particles are capable of causing increased roughening of the femoral head and provide a quantitative evaluation of the phenomenon. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 436,448, 2001 [source] Dynamic boundary stabilization of a Reissner,Mindlin plate with Timoshenko beamMATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 11 2004Marié Grobbelaar-Van Dalsen Abstract This paper is concerned with well-posedness results for a mathematical model for the transversal vibrations of a two-dimensional hybrid elastic structure consisting of a rectangular Reissner,Mindlin plate with a Timoshenko beam attached to its free edge. The model incorporates linear dynamic feedback controls along the interface between the plate and the beam. Classical semigroup methods are employed to show the unique solvability of the coupled initial-boundary-value problem. We also show that the energy associated with the system exhibits the property of strong stability. Copyright © 2004 John Wiley & Sons, Ltd. [source] Comparison of open and closed staff-assisted glove donning on the nature of surgical glove cuff contaminationANZ JOURNAL OF SURGERY, Issue 3 2010Christopher Jones Abstract Background:, We have observed that surgical glove cuffs commonly fold over during an operation, exposing the inside of the glove cuff to the sterile field and wound, a potential source of contamination if the inside of the glove cuff has been in contact with the fingers during glove donning. We hypothesize that open staff-assisted gloving results in more inside-glove cuff contamination than a closed staff-assisted technique. Method:, We performed a blinded, randomized study comparing open and closed staff-assisted glove donning. Two surgeons were gloved 20 times after covering their fingers and hands with GlitterBug(TM) powder. The gloves were turned inside out and the distance of GlitterBug(TM) powder from the free edge of the cuff was measured. Results:, Staff-assisted open glove donning was associated with significantly more glove cuff contamination than closed staff-assisted glove donning (P= 0.001). Conclusion:, Given glove cuff ,turn down' intra-operatively, we strongly recommend closed staff-assisted gloving. [source] Periungual lesions in pyoderma gangrenosumCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 5 2009A. Reich Summary Pyoderma gangrenosum (PG) is a progressive cutaneous necrosis of unknown origin. We report a case of PG presenting with periungual lesions. A 57-year-old woman was on treatment with ciclosporin A for PG. During tapering of the ciclosporin A dose, proliferating periungual lesions developed on the third and fourth finger of the left hand, the fourth finger of the right hand, and on the right great toe and the left fifth toe. All lesions appeared within a 4-week period. These abnormalities were ulcerated, involved about one-third of the distal part of the lateral nail folds including the part of nail fold bordering on the free edge of the nails, and were very painful. The skin biopsy was consistent with that seen in PG. Increasing the ciclosporin A dose led to significant improvement in the periungual lesions within the next few weeks and complete resolution within 6 months. [source] Aluminum "Egg-Box" Panel as an Energy Absorber for Pedestrian ProtectionADVANCED ENGINEERING MATERIALS, Issue 7 2010Sravanthi Nowpada Abstract This paper evaluates the quasi-static performance of lightweight aluminum "egg-box" panels which have an improved architecture specifically designed to increase the energy absorption capability. In its entirety, the egg-box panel structure investigated herein is made up of arrays of positive and negative frusta. To understand the collapse mechanism and the factors influencing the energy absorption thereof, compressive tests were conducted under similar test conditions on two single frusta, one constrained in situ and the other separated from the egg-box panel exposing the free,free edges. Their load-displacement histories show characteristics that are similar, with a rise in load to a point where they plateau at a steady state load for the entire collapse time. But the energy absorbed by the in situ constrained frustum is 80% greater than that separated from the egg-box panel with free,free edges. [source] Matched interface and boundary (MIB) method for the vibration analysis of platesINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 9 2009S. N. Yu Abstract This paper proposes a novel approach, the matched interface and boundary (MIB) method, for the vibration analysis of rectangular plates with simply supported, clamped and free edges, and their arbitrary combinations. In previous work, the MIB method was developed for three-dimensional elliptic equations with arbitrarily complex material interfaces and geometric shapes. The present work generalizes the MIB method for eigenvalue problems in structural analysis with complex boundary conditions. The MIB method utilizes both uniform and non-uniform Cartesian grids. Fictitious values are utilized to facilitate the central finite difference schemes throughout the entire computational domain. Boundary conditions are enforced with fictitious values,a common practice used in the previous discrete singular convolution algorithm. An essential idea of the MIB method is to repeatedly use the boundary conditions to achieve arbitrarily high-order accuracy. A new feature in the proposed approach is the implementation of the cross derivatives in the free boundary conditions. The proposed method has a banded matrix. Nine different plates, particularly those with free edges and free corners, are employed to validate the proposed method. The performance of the proposed method is compared with that of other established methods. Convergence and comparison studies indicate that the proposed MIB method works very well for the vibration analysis of plates. In particular, modal bending moments and shear forces predicted by the proposed method vanish at boundaries for free edges. Copyright © 2008 John Wiley & Sons, Ltd. [source] Repair of Flail Leaflet of the Tricuspid Valve by a Simple Cusp Remodeling TechniqueJOURNAL OF CARDIAC SURGERY, Issue 4 2007Xiubin Yang M.D. We try to present an alternative method and midterm results. Methods: Between April 1997 and December 2004, eight patients (5 males, 3 females; mean age 23.9 ± 5.8 years; range: 8 to 57 years) with severe tricuspid regurgitation (congenital lack of chordae in 5 cases and traumatic rupture of chordae in 3 cases) underwent surgical repair at Fu Wai Hospital. Four patients were in NYHA (New York Heart Association) class III, and 4 in class IV. Eight flail anterior leaflets and one flail septal leaflet of the tricuspid valve with massive tricuspid regurgitation were identified by echocardiography and the spaces of the free edges of the flail leaflets ranged from 20 to 30 mm. Tricuspid repair was performed under hypothermic cardiopulmonary bypass. The free edge of the affected cusp segment was sutured in folio, the segment of annulus devoid of leaflet was plicated, and the neo-annulus was fixed with a flexible annuloplasty ring. Results: All patients survived and recovered after the operation. Echocardiography showed good coaptation with no regurgitation of the tricuspid valve in five patients and a mild residual tricuspid regurgitation in three patients. A remarkable decrease in the diameter of the right ventricle was observed, from a mean of 42.6 ± 12.5 mm to a mean of 23.6 ± 5.3mm (p < 0.01). Mean follow up was 50 ± 42.9 months. Six patients were in NYHA class I, and two in class II and III. Except for one patient who had a mild-to-moderate increase in tricuspid regurgitation a year later, all the other patients were doing well. Conclusion: The procedure provided a simple and valuable option for repair of flail leaflet of tricuspid valve caused by congenital lack of chordae or traumatic rupture of chordae. [source] Modeling of Thermal Stresses in Joining Two Layers with Multi- and Graded InterlayersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2006C. H. Hsueh The technique of introducing interlayers has been used extensively to mitigate residual thermal stresses in joining dissimilar materials. Finite-element analyses have often been used to quantify thermal stresses in these layered structures in case-by-case studies. Recently, simple analytical models containing only three unknowns have been developed to derive closed-form solutions for elastic thermal stresses in both multilayer systems and two layers joined by a graded junction. The analytical solutions are exact for locations away from the free edges of the system. Application of these solutions is shown here to provide a systematic study of thermal stresses in Si3N4 and Al2O3 layers joined by various sialon polytypoid-based multi- and graded interlayers. The effects of the thickness, stiffness, and coefficient of thermal expansion of the interlayer on thermal stresses in the system are examined. The differences in thermal stresses resulting from multi- and graded interlayers are shown. [source] Asymptotic Analysis of Free-Edge and Free-Corner Effects in Laminate StructuresPROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2005Christian Mittelstedt Stress fields in the vicinity of free edges and corners of composite laminates exhibit singular characteristics and may lead to premature interlaminar failure modes like delamination fracture. It is of practical interest to investigate the nature of the arising free-edge and free-corner stress singularities - i.e. the singularity orders and modes - closely. The present investigations are performed using the Boundary Finite Element Method (BFEM) which in essence is a fundamental-solution-less boundary element method employing standard finite element formulations. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||||||||