Cementless RM Pressfit® Cup. A clinical and radiological study of 91 cases with at least four years follow-up

AbstractCementless metal-back acetabular cups have good long-term results, but some problems have appeared due to the shell's stiffness, modularity and required bearing surfaces. The RM Pressfit® Cup is a single-piece polyethylene cementless acetabular cup that is covered by a thin layer of titanium. This allows for bone integration without limitations related to the stiffness of a metal-back shell. There is very little published information about this new, innovative implant design. The purpose of this study was to evaluate the clinical and radiological results from a continuous series of 91 cups (85 patients) with a follow-up of at least 4years. No patients were lost to follow-up. The Harris Hip Score (HHS) was used to assess the clinical outcome. To assess the radiological outcomes, digital X-rays were used to evaluate the cup position and integration; wear was measured using Livermore's technique. The clinical results were excellent: the mean HHS was 94 and 82% of cases had good or excellent scores. Three of the cups had to be revised because of dislocation brought on by incorrect positioning. X-rays revealed that three implants had shifted during the first 6weeks, but had stabilized afterwards. Bone integration on X-rays was satisfactory in all cases with no signs of osteolysis. The configuration of the bone trabeculae showed that loads between the implant and peri-acetabular cancellous bone were evenly distributed. The wear of the polyethylene cup-ceramic head bearing was 0.07mm/year. The results of this series are consistent with recent published studies with the RM Pressfit® Cup.Level of evidenceIV

Towards Integration of CAx Systems and a Multiple-View Product Modeller in Mechanical Design

This paper deals with the development of an integration framework and its implementation for the connexion of CAx systems and multiple-view product modelling. The integration framework is presented regarding its conceptual level and the implementation level is described currently with the connexion of a functional modeller, a multiple-view product modeller, an optimisation module and a CAD system. The integration between the multiple-view product modeller and CATIA V5 based on the STEP standard is described in detail. Finally, the presented works are discussed and future research developments are suggested.

Piezoelectric and optical setup to measure an electrical field: Application to the longitudinal near-field generated by a tapered coax

We propose a new setup to measure an electrical field in one direction. This setup is made of a piezoelectric sintered lead zinconate titanate film and an optical interferometric probe. We used this setup to investigate how the shape of the extremity of a coaxial cable influences the longitudinal electrical near-field generated by it. For this application, we designed our setup to have a spatial resolution of 100 um in the direction of the electrical field. Simulations and experiments are presented

Impact of Li2.9_{2.9}B0.9_{0.9}S0.1_{0.1}O3.1_{3.1} glass additive on the structure and electrical properties of the LATP-based ceramics

The existing solid electrolytes for lithium ion batteries suffer from low total ionic conductivity, which restricts its usefulness for the lithium-ion battery technology. Among them, the NASICON-based materials, such as Li1.3Al0.3Ti1.7(PO4)3 (LATP) exhibit low total ionic conductivity due to highly resistant grain boundary phase. One of the possible approaches to efficiently enhance their total ionic conductivity is the formation of a composite material. Herein, the Li2.9B0.9S0.1O3.1 glass, called LBSO hereafter, was chosen as an additive material to improve the ionic properties of the ceramic Li1.3Al0.3Ti1.7(PO4)3 base material. The properties of this Li1.3Al0.3Ti1.7(PO4)3-xLi2.9B0.9S0.1O3.1 (0 < x < 0.3) system have been studied by means of high temperature X-ray diffractometry (HTXRD), 7Li, 11B, 27Al and 31P magic angle spinning nuclear magnetic resonance spectroscopy (MAS NMR), thermogravimetry (TG), scanning electron microscopy (SEM), impedance spectroscopy (IS) and density methods. We show here that the introduction of the foreign LBSO phase enhances their electric properties. This study reveals several interesting correlations between the apparent density, the microstructure, the composition, the sintering temperature and the ionic conductivity. Moreover, the electrical properties of the composites will be discussed in the terms of the brick-layer model (BLM). The highest value of {\sigma}tot = 1.5 x 10-4 Scm-1 has been obtained for LATP-0.1LBSO material sintered at 800{\deg}C

Satellites of the largest Kuiper Belt objects

We have searched the four brightest objects in the Kuiper Belt for the presence of satellites using the newly commissioned Keck Observatory Laser Guide Star Adaptive Optics system. Satellites are seen around three of the four objects: Pluto (whose satellite Charon is well-known and whose recently discovered smaller satellites are too faint to be detected), 2003 EL61 (where a second satellite is seen in addition to the previously known satellite), and 2003 UB313 (where a satellite is seen for the first time). The object 2005 FY9, the brightest Kuiper Belt object (KBO) after Pluto, does not have a satellite detectable within 0".4 with a brightness of more than 1% of the primary. The presence of satellites around three of the four brightest KBOs is inconsistent with the fraction of satellites in the Kuiper Belt at large at the 99.2% confidence level, suggesting a different formation mechanism for these largest KBO satellites. The two satellites of 2003 EL61, and the one satellite of 2003 UB313, with fractional brightnesses of 5% and 1.5%, and 2%, of their primaries, respectively, are significantly fainter relative to their primaries than other known KBO satellites, again pointing to possible differences in their origin

Electromagnetic Hydrophone with Tomographic System for Absolute Velocity Field Mapping

The velocity and pressure of an ultrasonic wave can be measured by an electromagnetic hydrophone made of a thin wire and a magnet. The ultrasonic wave vibrates the wire inside a magnetic field, inducing an electrical current. Previous articles reported poor spatial resolution of comparable hydrophones along the axis of the wire. In this study, submillimetric spatial resolution has been achieved by using a tomographic method. Moreover, a physical model is presented for obtaining absolute measurements. A pressure differential of 8% has been found between piezoelectric and electromagnetic hydrophone measurements. These characteristics show this technique as an alternative to standard hydrophones

Properties of LiMnBO3 glasses and nanostructured glass-ceramics

Polycrystalline LiMnBO3 is a promising cathode material for Li-ion batteries. In this work, we investigated the thermal, structural and electrical properties of glassy and nanocrystallized materials having the same chemical composition. The original glass was obtained via a standard meltquenching method. SEM and 7Li solid-state NMR indicate that it contains a mixture of two distinct glassy phases. The results suggest that the electrical conductivity of the glass is dominated by the ionic one. The dc conductivity of initial glass was estimated to be in the order of 10-18 S.cm-1 at room temperature. The thermal nanocrystallization of the glass produces a nanostructured glass-ceramics containing MnBO3 and LiMnBO3 phases. The electric conductivity of this glass-ceramics is increased by 6 orders of magnitude, compared to the starting material at room temperature. Compared to other manganese and borate containing glasses reported in the literature, the conductivity of the nanostructured glass ceramics is higher than that of the previously reported glassy materials. Such improved conductivity stems from the facilitated electronic transport along the grain boundaries

Sonically-enhanced widgets: comments on Brewster and Clarke, ICAD 1997

This paper presents a review of the research surrounding the paper “The Design and Evaluation of a Sonically Enhanced Tool Palette” by Brewster and Clarke from ICAD 1997. A historical perspective is given followed by a discussion of how this work has fed into current developments in the area

3D time series analysis of cell shape using Laplacian approaches

Background: Fundamental cellular processes such as cell movement, division or food uptake critically depend on cells being able to change shape. Fast acquisition of three-dimensional image time series has now become possible, but we lack efficient tools for analysing shape deformations in order to understand the real three-dimensional nature of shape changes. Results: We present a framework for 3D+time cell shape analysis. The main contribution is three-fold: First, we develop a fast, automatic random walker method for cell segmentation. Second, a novel topology fixing method is proposed to fix segmented binary volumes without spherical topology. Third, we show that algorithms used for each individual step of the analysis pipeline (cell segmentation, topology fixing, spherical parameterization, and shape representation) are closely related to the Laplacian operator. The framework is applied to the shape analysis of neutrophil cells. Conclusions: The method we propose for cell segmentation is faster than the traditional random walker method or the level set method, and performs better on 3D time-series of neutrophil cells, which are comparatively noisy as stacks have to be acquired fast enough to account for cell motion. Our method for topology fixing outperforms the tools provided by SPHARM-MAT and SPHARM-PDM in terms of their successful fixing rates. The different tasks in the presented pipeline for 3D+time shape analysis of cells can be solved using Laplacian approaches, opening the possibility of eventually combining individual steps in order to speed up computations