Testing of x-ray microtomography systems using a traceable geometrical standard

International Nuclear Information System (INIS)

Carmignato, S; Dreossi, D; Mancini, L; Tromba, G; Marinello, F; Savio, E

2009-01-01

X-ray computed microtomography is an interesting imaging technique for many applications, and is also very promising in the field of coordinate metrology at the micro scale. The main advantage with respect to traditional tactile-probing or optical coordinate measurement systems is that x-ray tomography can acquire dimensional and geometrical data for both inner and outer surfaces, without accessibility restrictions. However, there are no accepted test procedures available so far and measurement uncertainty is unknown in many cases, due to complex and numerous error sources. The paper presents the first results of a test procedure implemented for determining the errors of indication for length measurements of x-ray microtomography systems, using a new reference standard featuring a regular array of inner and outer cylindrical shapes. The developed test method allows the determination of specific characteristics of x-ray microtomography systems and can be used for the correction of systematic errors

Geoscience Applications of Synchrotron X-ray Computed Microtomography

Science.gov (United States)

Rivers, M. L.

2009-05-01

Computed microtomography is the extension to micron spatial resolution of the CAT scanning technique developed for medical imaging. Synchrotron sources are ideal for the method, since they provide a monochromatic, parallel beam with high intensity. High energy storage rings such as the Advanced Photon Source at Argonne National Laboratory produce x-rays with high energy, high brilliance, and high coherence. All of these factors combine to produce an extremely powerful imaging tool for earth science research. Techniques that have been developed include: - Absorption and phase contrast computed tomography with spatial resolution approaching one micron - Differential contrast computed tomography, imaging above and below the absorption edge of a particular element - High-pressure tomography, imaging inside a pressure cell at pressures above 10GPa - High speed radiography, with 100 microsecond temporal resolution - Fluorescence tomography, imaging the 3-D distribution of elements present at ppm concentrations. - Radiographic strain measurements during deformation at high confining pressure, combined with precise x- ray diffraction measurements to determine stress. These techniques have been applied to important problems in earth and environmental sciences, including: - The 3-D distribution of aqueous and organic liquids in porous media, with applications in contaminated groundwater and petroleum recovery. - The kinetics of bubble formation in magma chambers, which control explosive volcanism. - Accurate crystal size distributions in volcanic systems, important for understanding the evolution of magma chambers. - The equation-of-state of amorphous materials at high pressure using both direct measurements of volume as a function of pressure and also by measuring the change x-ray absorption coefficient as a function of pressure. - The formation of frost flowers on Arctic sea-ice, which is important in controlling the atmospheric chemistry of mercury. - The distribution of

Analysis of 3D Prints by X-ray Computed Microtomography and Terahertz Pulsed Imaging

DEFF Research Database (Denmark)

Markl, Daniel; Zeitler, J Axel; Rasch, Cecilie

2017-01-01

PURPOSE: A 3D printer was used to realise compartmental dosage forms containing multiple active pharmaceutical ingredient (API) formulations. This work demonstrates the microstructural characterisation of 3D printed solid dosage forms using X-ray computed microtomography (XμCT) and terahertz pulsed...... imaging (TPI). METHODS: Printing was performed with either polyvinyl alcohol (PVA) or polylactic acid (PLA). The structures were examined by XμCT and TPI. Liquid self-nanoemulsifying drug delivery system (SNEDDS) formulations containing saquinavir and halofantrine were incorporated into the 3D printed...... was characterised by XμCT and TPI on the basis of the computer-aided design (CAD) models of the dosage form (compartmentalised PVA structures were 7.5 ± 0.75% larger than designed; n = 3). CONCLUSIONS: The 3D printer can reproduce specific structures very accurately, whereas the 3D prints can deviate from...

Application of X-ray computed micro-tomography to the study of damage and oxidation kinetics of thermostructural composites

Energy Technology Data Exchange (ETDEWEB)

Caty, Olivier, E-mail: caty@lcts.u-bordeaux1.fr [Laboratory of Thermostructural Composites (LCTS), Université de Bordeaux, CNRS, SAFRAN, CEA, 3 Allée La Boétie, 33600 Pessac (France); Ibarroule, Philippe; Herbreteau, Mathieu; Rebillat, Francis [Laboratory of Thermostructural Composites (LCTS), Université de Bordeaux, CNRS, SAFRAN, CEA, 3 Allée La Boétie, 33600 Pessac (France); Maire, Eric [MATEIS Laboratory, INSA Lyon, 7 Avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Vignoles, Gérard L. [Laboratory of Thermostructural Composites (LCTS), Université de Bordeaux, CNRS, SAFRAN, CEA, 3 Allée La Boétie, 33600 Pessac (France)

2014-04-01

Thermostructural composites are three-dimensionally (3D) structured materials. Weakening phenomena (mechanical and chemical) take place inside the material following its 3D structure and are thus hard to describe accurately. X-ray computed micro-tomography (μCT) is a recent solution that allows their experimental investigation. The technique is applied here to the study of failure under tensile loading and to the self healing processes during oxidation. Results are useful data to verify or invalidate hypotheses or estimations made in current models.

X-ray microtomography of porous media at BNL

Energy Technology Data Exchange (ETDEWEB)

Dowd, B. [Brookhaven National Labs., Upton, NY (United States)

1997-02-01

This session is comprised of pertinent information about the historical aspects, current status of research, technical achievements, and future plans in X-ray computed microtomography at Brookhaven National Laboratories. An explanation with specifications and diagrams of X-ray instrumentation is provided. Several high resolution 3-D color images of reservoir rock drill cores and other materials are included.

Analysis of Thermal-Hydraulic Behavior of CMT in the SMART-ITL Facility

Energy Technology Data Exchange (ETDEWEB)

Jeon, Byong Guk; Bae, Hwang; Ryu, Sung-Uk; Ryu, Hyobong; Byun, Sun-Joon; Yi, Sung-Jae; Park, Hyun-Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

SMART, an integral small modular reactor, received a standard design approval in 2012 and now extends its safety features through replacing active safety injection pumps by passive safety injection systems: core makeup tanks (CMT) and safety injection tanks (SIT). SMART-ITL has been built in a full height scale and 1/49 area and power scale. One train of CMT and SIT has been installed and their thermal-hydraulic behaviors have been identified through a series of tests. In this paper, initial condensation characteristics as well as force balance around the CMT will be discussed for a representative test. PSIS are added into SMART for better treatment of accidents with prolonged station blackout. In the SMART-ITL, the CMT and SIT are installed to evaluate their performance and a series of tests have been conducted. In this paper, the thermal-hydraulic behavior of CMT is addressed based on the experimental data, especially focusing on the issues of fierce condensation after opening of the isolation valve and driving force balance around the CMT.

Analysis of Thermal-Hydraulic Behavior of CMT in the SMART-ITL Facility

International Nuclear Information System (INIS)

Jeon, Byong Guk; Bae, Hwang; Ryu, Sung-Uk; Ryu, Hyobong; Byun, Sun-Joon; Yi, Sung-Jae; Park, Hyun-Sik

2015-01-01

SMART, an integral small modular reactor, received a standard design approval in 2012 and now extends its safety features through replacing active safety injection pumps by passive safety injection systems: core makeup tanks (CMT) and safety injection tanks (SIT). SMART-ITL has been built in a full height scale and 1/49 area and power scale. One train of CMT and SIT has been installed and their thermal-hydraulic behaviors have been identified through a series of tests. In this paper, initial condensation characteristics as well as force balance around the CMT will be discussed for a representative test. PSIS are added into SMART for better treatment of accidents with prolonged station blackout. In the SMART-ITL, the CMT and SIT are installed to evaluate their performance and a series of tests have been conducted. In this paper, the thermal-hydraulic behavior of CMT is addressed based on the experimental data, especially focusing on the issues of fierce condensation after opening of the isolation valve and driving force balance around the CMT

A computed microtomography method for understanding epiphyseal growth plate fusion

Science.gov (United States)

Staines, Katherine A.; Madi, Kamel; Javaheri, Behzad; Lee, Peter D.; Pitsillides, Andrew A.

2017-12-01

The epiphyseal growth plate is a developmental region responsible for linear bone growth, in which chondrocytes undertake a tightly regulated series of biological processes. Concomitant with the cessation of growth and sexual maturation, the human growth plate undergoes progressive narrowing, and ultimately disappears. Despite the crucial role of this growth plate fusion ‘bridging’ event, the precise mechanisms by which it is governed are complex and yet to be established. Progress is likely hindered by the current methods for growth plate visualisation; these are invasive and largely rely on histological procedures. Here we describe our non-invasive method utilising synchrotron x-ray computed microtomography for the examination of growth plate bridging, which ultimately leads to its closure coincident with termination of further longitudinal bone growth. We then apply this method to a dataset obtained from a benchtop microcomputed tomography scanner to highlight its potential for wide usage. Furthermore, we conduct finite element modelling at the micron-scale to reveal the effects of growth plate bridging on local tissue mechanics. Employment of these 3D analyses of growth plate bone bridging is likely to advance our understanding of the physiological mechanisms that control growth plate fusion.

Computed microtomography and X-ray fluorescence analysis for comprehensive analysis of structural changes in bone.

Science.gov (United States)

Buzmakov, Alexey; Chukalina, Marina; Nikolaev, Dmitry; Schaefer, Gerald; Gulimova, Victoria; Saveliev, Sergey; Tereschenko, Elena; Seregin, Alexey; Senin, Roman; Prun, Victor; Zolotov, Denis; Asadchikov, Victor

2013-01-01

This paper presents the results of a comprehensive analysis of structural changes in the caudal vertebrae of Turner's thick-toed geckos by computer microtomography and X-ray fluorescence analysis. We present algorithms used for the reconstruction of tomographic images which allow to work with high noise level projections that represent typical conditions dictated by the nature of the samples. Reptiles, due to their ruggedness, small size, belonging to the amniote and a number of other valuable features, are an attractive model object for long-orbital experiments on unmanned spacecraft. Issues of possible changes in their bone tissue under the influence of spaceflight are the subject of discussions between biologists from different laboratories around the world.

Evaluation of acquisition parameters in microtomography through of analysis of carbonatic rocks

Energy Technology Data Exchange (ETDEWEB)

Santos, Thaís M.P.; Machado, Alessandra S.; Araujo, Olga M.O.; Ferreira, Cintia G.; Lopes, Ricardo T., E-mail: thaismpds@poli.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentação Nuclear

2017-07-01

X-ray computed microtomography is a powerful nondestructive technique for 2D and 3D structure analysis. However, parameters used in acquisition promote directs influence in qualitative and quantitative results in characterization of samples, due image resolution. The aim of this study is value the influence of theses parameters in results through of tests changing these parameters in different situations and scanner characterization. Results demonstrate that pixel size and detector matrix are the main parameters that influence in resolution and the necessity use additional filters for image quality. Microtomography was considered an excellent technique for characterization using the best image resolution possible. (author)

Evaluation of acquisition parameters in microtomography through of analysis of carbonatic rocks

International Nuclear Information System (INIS)

Santos, Thaís M.P.; Machado, Alessandra S.; Araujo, Olga M.O.; Ferreira, Cintia G.; Lopes, Ricardo T.

2017-01-01

X-ray computed microtomography is a powerful nondestructive technique for 2D and 3D structure analysis. However, parameters used in acquisition promote directs influence in qualitative and quantitative results in characterization of samples, due image resolution. The aim of this study is value the influence of theses parameters in results through of tests changing these parameters in different situations and scanner characterization. Results demonstrate that pixel size and detector matrix are the main parameters that influence in resolution and the necessity use additional filters for image quality. Microtomography was considered an excellent technique for characterization using the best image resolution possible. (author)

3D spectral imaging with synchrotron Fourier transform infrared spectro-microtomography

Science.gov (United States)

Michael C. Martin; Charlotte Dabat-Blondeau; Miriam Unger; Julia Sedlmair; Dilworth Y. Parkinson; Hans A. Bechtel; Barbara Illman; Jonathan M. Castro; Marco Keiluweit; David Buschke; Brenda Ogle; Michael J. Nasse; Carol J. Hirschmugl

2013-01-01

We report Fourier transform infrared spectro-microtomography, a nondestructive three-dimensional imaging approach that reveals the distribution of distinctive chemical compositions throughout an intact biological or materials sample. The method combines mid-infrared absorption contrast with computed tomographic data acquisition and reconstruction to enhance chemical...

CHANNEL MORPHOLOGY TOOL (CMT): A GIS-BASED AUTOMATED EXTRACTION MODEL FOR CHANNEL GEOMETRY

Energy Technology Data Exchange (ETDEWEB)

JUDI, DAVID [Los Alamos National Laboratory; KALYANAPU, ALFRED [Los Alamos National Laboratory; MCPHERSON, TIMOTHY [Los Alamos National Laboratory; BERSCHEID, ALAN [Los Alamos National Laboratory

2007-01-17

This paper describes an automated Channel Morphology Tool (CMT) developed in ArcGIS 9.1 environment. The CMT creates cross-sections along a stream centerline and uses a digital elevation model (DEM) to create station points with elevations along each of the cross-sections. The generated cross-sections may then be exported into a hydraulic model. Along with the rapid cross-section generation the CMT also eliminates any cross-section overlaps that might occur due to the sinuosity of the channels using the Cross-section Overlap Correction Algorithm (COCoA). The CMT was tested by extracting cross-sections from a 5-m DEM for a 50-km channel length in Houston, Texas. The extracted cross-sections were compared directly with surveyed cross-sections in terms of the cross-section area. Results indicated that the CMT-generated cross-sections satisfactorily matched the surveyed data.

Validation of the CMT Pediatric Scale as an outcome measure of disability

Science.gov (United States)

Burns, Joshua; Ouvrier, Robert; Estilow, Tim; Shy, Rosemary; Laurá, Matilde; Pallant, Julie F.; Lek, Monkol; Muntoni, Francesco; Reilly, Mary M.; Pareyson, Davide; Acsadi, Gyula; Shy, Michael E.; Finkel, Richard S.

2012-01-01

Objective Charcot-Marie-Tooth disease (CMT) is a common heritable peripheral neuropathy. There is no treatment for any form of CMT although clinical trials are increasingly occurring. Patients usually develop symptoms during the first two decades of life but there are no established outcome measures of disease severity or response to treatment. We identified a set of items that represent a range of impairment levels and conducted a series of validation studies to build a patient-centered multi-item rating scale of disability for children with CMT. Methods As part of the Inherited Neuropathies Consortium, patients aged 3–20 years with a variety of CMT types were recruited from the USA, UK, Italy and Australia. Initial development stages involved: definition of the construct, item pool generation, peer review and pilot testing. Based on data from 172 patients, a series of validation studies were conducted, including: item and factor analysis, reliability testing, Rasch modeling and sensitivity analysis. Results Seven areas for measurement were identified (strength, dexterity, sensation, gait, balance, power, endurance), and a psychometrically robust 11-item scale constructed (Charcot-Marie-Tooth disease Pediatric Scale: CMTPedS). Rasch analysis supported the viability of the CMTPedS as a unidimensional measure of disability in children with CMT. It showed good overall model fit, no evidence of misfitting items, no person misfit and it was well targeted for children with CMT. Interpretation The CMTPedS is a well-tolerated outcome measure that can be completed in 25-minutes. It is a reliable, valid and sensitive global measure of disability for children with CMT from the age of 3 years. PMID:22522479

Reservoir core porosity in the Resende formation using 3D high-resolution X-ray computed microtomography

International Nuclear Information System (INIS)

Oliveira, Milena F.S.; Lima, Inaya; Lopes, Ricardo T.; Rocha, Paula Lucia F. da

2009-01-01

The storage capacity and production of oil are influenced, among other things, by rocks and fluids characteristics. Porosity is one of the most important characteristics to be analyzed in oil industry, mainly in oil prospection because it represents the direct capacity of storage fluids in the rocks. By definition, porosity is the ratio of pore volume to the total bulk volume of the formation, expressed in percentage, being able to be absolute or effective. The aim of this study was to calculate porosity by 3D High-Resolution X-ray Computed Microtomography using core plugs from Resende Formation which were collected in Porto Real, Rio de Janeiro State. This formation is characterized by sandstones and fine conglomerates with associated fine siliciclastic sediments, and the paleoenviroment is interpreted as a braided fluvial system. For acquisitions data, it was used a 3D high resolution microtomography system which has a microfocus X-ray tube (spot size < 5μm) and a 12-bit cooled X-ray camera (CCD fiber-optically coupled to a scintillator) operated at 100 kV and 100 μA. Twenty-two samples taken at different depths from two boreholes were analyzed. A total of 961 slices were performed with a resolution of 14.9 μm. The results demonstrated that μ-CT is a reliable and effective technique. Through the images and data it was possible to quantify the porosity and to view the size and shape of porous. (author)

Causes of Charcot-Marie-Tooth Disease (CMT)

Science.gov (United States)

... Marie-Tooth Disease (CMT) Congenital Muscular Dystrophy (CMD) Duchenne Muscular Dystrophy (DMD) Emery-Dreifuss Muscular Dystrophy Endocrine Myopathies Metabolic Diseases of Muscle Mitochondrial Myopathies (MM) Myotonic Dystrophy (DM) Spinal-Bulbar ...

Reliability of the CMT neuropathy score (second version) in Charcot-Marie-Tooth disease.

LENUS (Irish Health Repository)

Murphy, Sinéad M

2011-09-01

The Charcot-Marie-Tooth neuropathy score (CMTNS) is a reliable and valid composite score comprising symptoms, signs, and neurophysiological tests, which has been used in natural history studies of CMT1A and CMT1X and as an outcome measure in treatment trials of CMT1A. Following an international workshop on outcome measures in Charcot-Marie-Tooth disease (CMT), the CMTNS was modified to attempt to reduce floor and ceiling effects and to standardize patient assessment, aiming to improve its sensitivity for detecting change over time and the effect of an intervention. After agreeing on the modifications made to the CMTNS (CMTNS2), three examiners evaluated 16 patients to determine inter-rater reliability; one examiner evaluated 18 patients twice within 8 weeks to determine intra-rater reliability. Three examiners evaluated 63 patients using the CMTNS and the CMTNS2 to determine how the modifications altered scoring. For inter- and intra-rater reliability, intra-class correlation coefficients (ICCs) were ≥0.96 for the CMT symptom score and the CMT examination score. There were small but significant differences in some of the individual components of the CMTNS compared with the CMTNS2, mainly in the components that had been modified the most. A longitudinal study is in progress to determine whether the CMTNS2 is more sensitive than the CMTNS for detecting change over time.

CMT for transport in porous media

Energy Technology Data Exchange (ETDEWEB)

Schwartz, L. [Schlumberger-Doll Research, Ridgefield, CT (United States)

1997-02-01

This session is comprised of an outline of uses for x-ray microtomography in the field of petroleum geology. Calculations, diagrams, and color photomicrographs depict the many applications of synchrotron x-ray microtomograpy in determining transport properties and fluid flow characteristics of reservoir rocks, micro-porosity in carbonates, and aspects of multi-phase transport.

An evaluation of designed passive Core Makeup Tank (CMT) for China pressurized reactor (CPR1000)

International Nuclear Information System (INIS)

Wang, Mingjun; Tian, Wenxi; Qiu, Suizheng; Su, Guanghui; Zhang, Yapei

2013-01-01

Highlights: ► Only PRHRS is not sufficient to maintain reactor safety in case of SGTR accident. ► The Core Makeup Tank (CMT) is designed for CPR1000. ► Joint operation of PRHRS and CMT can keep reactor safety during the SGTR transient. ► CMT is a vital supplement for CPR1000 passive safety system design. - Abstract: Emergency Passive Safety System (EPSS) is an innovative design to improve reliability of nuclear power plants. In this work, the EPSS consists of secondary passive residual heat removal system (PRHRS) and the reactor Core Makeup Tank (CMT) system. The PRHRS, which has been studied in our previous paper, can effectively remove the core residual heat and passively improve the inherent safety by passive methods. The designed CMT, representing the safety improvement for CPR1000, is used to inject cool boron-containing water into the primary system during the loss of coolant accident. In this study, the behaviors of EPSS and transient characteristics of the primary loop system during the Steam Generator Tube Rupture (SGTR) accident are investigated using the nuclear reactor thermal hydraulic code RELAP5/MOD3.4. The results show that the designed CMT can protect the reactor primary loop from boiling and maintain primary loop coolant in single phase state. Both PRHRS and CMT operation ensures reactor safety during the SGTR accident. Results reported in this paper show that the designed CMT is a further safety improvement for CPR1000

New Developments and Geoscience Applications of Synchrotron Computed Microtomography (Invited)

Science.gov (United States)

Rivers, M. L.; Wang, Y.; Newville, M.; Sutton, S. R.; Yu, T.; Lanzirotti, A.

2013-12-01

Computed microtomography is the extension to micron spatial resolution of the CAT scanning technique developed for medical imaging. Synchrotron sources are ideal for the method, since they provide a monochromatic, parallel beam with high intensity. High energy storage rings such as the Advanced Photon Source at Argonne National Laboratory produce x-rays with high energy, high brilliance, and high coherence. All of these factors combine to produce an extremely powerful imaging tool for earth science research. Techniques that have been developed include: - Absorption and phase contrast computed tomography with spatial resolution below one micron. - Differential contrast computed tomography, imaging above and below the absorption edge of a particular element. - High-pressure tomography, imaging inside a pressure cell at pressures above 10GPa. - High speed radiography and tomography, with 100 microsecond temporal resolution. - Fluorescence tomography, imaging the 3-D distribution of elements present at ppm concentrations. - Radiographic strain measurements during deformation at high confining pressure, combined with precise x-ray diffraction measurements to determine stress. These techniques have been applied to important problems in earth and environmental sciences, including: - The 3-D distribution of aqueous and organic liquids in porous media, with applications in contaminated groundwater and petroleum recovery. - The kinetics of bubble formation in magma chambers, which control explosive volcanism. - Studies of the evolution of the early solar system from 3-D textures in meteorites - Accurate crystal size distributions in volcanic systems, important for understanding the evolution of magma chambers. - The equation-of-state of amorphous materials at high pressure using both direct measurements of volume as a function of pressure and also by measuring the change x-ray absorption coefficient as a function of pressure. - The location and chemical speciation of toxic

Gene conversion homogenizes the CMT1A paralogous repeats

Directory of Open Access Journals (Sweden)

Hurles Matthew E

2001-12-01

Full Text Available Abstract Background Non-allelic homologous recombination between paralogous repeats is increasingly being recognized as a major mechanism causing both pathogenic microdeletions and duplications, and structural polymorphism in the human genome. It has recently been shown empirically that gene conversion can homogenize such repeats, resulting in longer stretches of absolute identity that may increase the rate of non-allelic homologous recombination. Results Here, a statistical test to detect gene conversion between pairs of non-coding sequences is presented. It is shown that the 24 kb Charcot-Marie-Tooth type 1A paralogous repeats (CMT1A-REPs exhibit the imprint of gene conversion processes whilst control orthologous sequences do not. In addition, Monte Carlo simulations of the evolutionary divergence of the CMT1A-REPs, incorporating two alternative models for gene conversion, generate repeats that are statistically indistinguishable from the observed repeats. Bounds are placed on the rate of these conversion processes, with central values of 1.3 × 10-4 and 5.1 × 10-5 per generation for the alternative models. Conclusions This evidence presented here suggests that gene conversion may have played an important role in the evolution of the CMT1A-REP paralogous repeats. The rates of these processes are such that it is probable that homogenized CMT1A-REPs are polymorphic within modern populations. Gene conversion processes are similarly likely to play an important role in the evolution of other segmental duplications and may influence the rate of non-allelic homologous recombination between them.

Gas bubble network formation in irradiated beryllium pebbles monitored by X-Ray micro-tomography

Energy Technology Data Exchange (ETDEWEB)

Bolier, E; Ferrero, C. [Forschungszentrum Karlsruhe, Zimer 203, Gebaeude 451, Abteilung HVT-TL (Germany); Moslang, A. [Forschungszentrum Karlsruhe GmbH, FZK, Karlsruhe (Germany); Pieritz, R.A. [CNRS, Lab. de Glaciologie et Geophysique de l' Environnement, 38 - Saint Martin d' Heres (France)

2007-07-01

Full text of publication follows: The efficient and safe operation of helium cooled ceramic breeder blankets requires among others an efficient tritium release during operation at blanket relevant temperatures. In the past out-of-pile thermal desorption studies on low temperature neutron irradiated beryllium have shown that tritium and helium release peaks occur together. This phenomenon can be interpreted in terms of growth and coalescence of helium bubbles and tritium that either is trapped inside the helium bubbles in form of T{sub 2} molecules or in their strain field. With increasing temperature the bubble density and size at grain interfaces increase together with the probability of interconnected porosities and channel formation to the outer surface, leading to simultaneous helium and tritium release peaks in TDS. For a reliable prediction of gas release up to end-of-life conditions at blanket relevant temperatures, knowledge of the dynamics of bubble growth and coalescence as well as the 3D distribution of bubble network formation is indispensable. Such data could also be used to experimentally validate any future model predictions of tritium and helium release rates. A high resolution computer aided micro-tomography (CMT) setup has been developed at the European Synchrotron Radiation Facility which allowed reconstructing 3-D images of beryllium pebbles without damaging them. By postprocessing the data a 3D rendering of inner surfaces and of interconnected channel networks can be obtained, thus allowing the identification of open porosities in neutron irradiated and tempered beryllium pebbles. In our case Beryllium pebbles of 2 mm diameter had been neutron irradiated in the 'Beryllium' experiment at 770 K with 1.24 x 10{sup 25} nxm{sup -2} resulting in 480 appm He and 12 appm Tritium. After annealing at 1500 K CMT was performed on the pebbles with 4.9 and 1.4 {mu}m voxel resolution, respectively, followed by morphological and topological post

Scanning transmission ion micro-tomography (STIM-T) of biological specimens

International Nuclear Information System (INIS)

Schwertner, Michael; Sakellariou, Arthur; Reinert, Tilo; Butz, Tilman

2006-01-01

Computed tomography (CT) was applied to sets of Scanning Transmission Ion Microscopy (STIM) projections recorded at the LIPSION ion beam laboratory (Leipzig) in order to visualize the 3D-mass distribution in several specimens. Examples for a test structure (copper grid) and for biological specimens (cartilage cells, cygospore) are shown. Scanning Transmission Micro-Tomography (STIM-T) at a resolution of 260 nm was demonstrated for the first time. Sub-micron features of the Cu-grid specimen were verified by scanning electron microscopy. The ion energy loss measured during a STIM-T experiment is related to the mass density of the specimen. Typically, biological specimens can be analysed without staining. Only shock freezing and freeze-drying is required to preserve the ultra-structure of the specimen. The radiation damage to the specimen during the experiment can be neglected. This is an advantage compared to other techniques like X-ray micro-tomography. At present, the spatial resolution is limited by beam position fluctuations and specimen vibrations

Evaluation of the influence of acquisition parameters of microtomography in image quality applied by carbonate rocks

Science.gov (United States)

Santos, T. M. P.; Machado, A. S.; Araújo, O. M. O.; Ferreira, C. G.; Lopes, R. T.

2018-03-01

X-ray computed microtomography is a powerful nondestructive technique for 2D and 3D structure analysis. However, parameters used in acquisition promote directs influence in qualitative and quantitative results in characterization of samples, due image resolution. The aim of this study is value the influence of theses parameters in results through of tests changing these parameters in different situations and system characterization. Results demonstrate those pixel size and detector matrixes are the main parameters that influence in resolution and image quality. Microtomography was considered an excellent technique for characterization using the best image resolution possible.

HIGH RESOLUTION MICROTOMOGRAPHY FOR DENSITY AND SPATIAL INFORMATION ABOUT WOOD STRUCTURES.

Energy Technology Data Exchange (ETDEWEB)

ILLMAN,B.

1999-07-22

Microtomography has successfully been used to characterize loss of structural integrity of wood. Tomographic images were generated with the newly developed third generation x-ray computed microtomography (XCMT) instrument at the X27A beamline at the National Synchrotron Light Source (NSLS). The beamline is equipped with high-flux x-ray monochromator based on multilayer optics developed for this application. The sample is mounted on a translation stage with which to center the sample rotation, a rotation stage to perform the rotation during data collection and a motorized goniometer head for small alignment motions. The absorption image is recorded by a single-crystal scintillator, an optical microscope and a cooled CCD array detector. Data reconstruction has provided three-dimensional geometry of the heterogeneous wood matrix in microtomographic images. Wood is a heterogeneous material composed of long lignocellulose vessels. Although wood is a strong natural product, fungi have evolved chemical systems that weaken the strength properties of wood by degrading structural vessels. Tomographic images with a resolution of three microns were obtained nonintrusively to characterize the compromised structural integrity of wood. Computational tools developed by Lindquist et al (1996) applied to characterize the microstructure of the tomographic volumes.

X-ray Computed Microtomography technique applied for cementitious materials: A review.

Science.gov (United States)

da Silva, Ítalo Batista

2018-04-01

The main objective of this article is to present a bibliographical review about the use of the X-ray microtomography method in 3D images processing of cementitious materials microstructure, analyzing the pores microstructure and connectivity network, enabling tthe possibility of building a relationship between permeability and porosity. The use of this technique enables the understanding of physical, chemical and mechanical properties of cementitious materials by publishing good results, considering that the quality and quantity of accessible information were significant and may contribute to the study of cementitious materials development. Copyright © 2018 Elsevier Ltd. All rights reserved.

Using the simplified case mix tool (sCMT) to identify cost in special care dental services to support commissioning.

Science.gov (United States)

Duane, B G; Freeman, R; Richards, D; Crosbie, S; Patel, P; White, S; Humphris, G

2017-03-01

To commission dental services for vulnerable (special care) patient groups effectively, consistently and fairly an evidence base is needed of the costs involved. The simplified Case Mixed Tool (sCMT) can assess treatment mode complexity for these patient groups. To determine if the sCMT can be used to identify costs of service provision. Patients (n=495) attending the Sussex Community NHS Trust Special Care Dental Service for care were assessed using the sCMT. sCMT score and costs (staffing, laboratory fees, etc.) besides patient age, whether a new patient and use of general anaesthetic/intravenous sedation. Statistical analysis (adjusted linear regression modelling) compared sCMT score and costs then sensitivity analyses of the costings to age, being a new patient and sedation use were undertaken. Regression tables were produced to present estimates of service costs. Costs increased with sCMT total scale and single item values in a predictable manner in all analyses except for 'cooperation'. Costs increased with the use of IV sedation; with each rising level of the sCMT, and with complexity in every sCMT category, except cooperation. Costs increased with increase in complexity of treatment mode as measured by sCMT scores. Measures such as the sCMT can provide predictions of the resource allocations required when commissioning special care dental services. Copyright© 2017 Dennis Barber Ltd.

High temperature x-ray micro-tomography

Energy Technology Data Exchange (ETDEWEB)

MacDowell, Alastair A., E-mail: aamacdowell@lbl.gov; Barnard, Harold; Parkinson, Dilworth Y.; Gludovatz, Bernd [Lawrence Berkeley National Lab., Berkeley, CA 94720 (United States); Haboub, Abdel [Lawrence Berkeley National Lab., Berkeley, CA 94720 (United States); current –Lincoln Univ., Jefferson City, Missouri, 65101 (United States); Larson, Natalie; Zok, Frank [University California Santa Barbara, Santa Barbara CA 93106 (United States); Panerai, Francesco; Mansour, Nagi N. [NASA Ames Research Centre, Moffett Field, CA, 94035 (United States); Bale, Hrishikesh [University California Berkeley, Berkeley, CA 94720 (United States); current - Carl Zeiss X-ray Microscopy, 4385 Hopyard Rd #100, Pleasanton, CA 94588 (United States); Acevedo, Claire [Lawrence Berkeley National Lab., Berkeley, CA 94720 (United States); University California San Francisco, San Francisco, CA 94143 (United States); Liu, Dong [University of Bristol, Bristol BS8 1TH (United Kingdom); Ritchie, Robert O. [Lawrence Berkeley National Lab., Berkeley, CA 94720 (United States); University California Berkeley, Berkeley, CA 94720 (United States)

2016-07-27

There is increasing demand for 3D micro-scale time-resolved imaging of samples in realistic - and in many cases extreme environments. The data is used to understand material response, validate and refine computational models which, in turn, can be used to reduce development time for new materials and processes. Here we present the results of high temperature experiments carried out at the x-ray micro-tomography beamline 8.3.2 at the Advanced Light Source. The themes involve material failure and processing at temperatures up to 1750°C. The experimental configurations required to achieve the requisite conditions for imaging are described, with examples of ceramic matrix composites, spacecraft ablative heat shields and nuclear reactor core Gilsocarbon graphite.

Characterization of low density carbon foams by x-ray computed tomography (CT) and ion microtomography (IMF)

International Nuclear Information System (INIS)

Moddeman, W.E.; Kramer, D.P.; Firsich, D.W.; Trainer, P.D.; Yancy, R.N.; Weirup, D.L.; Logan, C.M.; Pontau, A.E.; Antolak, A.J.; Morse, D.H.

1990-01-01

Two NDT techniques were used to characterize low-density, microcellular, carbon foams fabricated from a salt replica process. In this paper the two techniques are x-ray computed tomography (CT) and ion microtomography (IMT); data are presented on carbon foams that contain high-density regions. The data show that densities which differ by 3 ) materials. The data reveal that the carbon foams produced by this replica process have small density variations; the density being ∼30% greater at the outer edges than when compared to the interior of the foam. In addition, the density gradient is found to be rather sharp, that is the density drops-off rapidly from the outer edges to a uniform one in the interior of the foam. This edge build-up in carbon density was explained in terms of polymer concentrating on the foam exterior during drying which immediately followed a polymer infusion processing step. Supporting analytical data from other techniques show the foam material to be >88.8% carbon

New applications of corrosion measurements by titration (CMT)

DEFF Research Database (Denmark)

Bech-Nielsen, Gregers

1998-01-01

. It is shown that when aluminium dissolves in alkali, CMT measurements can also be applied, but in this case requiring titration with alkali. Titration with alkali is also required in a special situation, where corrosion of nickel in an acid solution and subsequent formation of a nickel complex results...

Heterogeneous vesiculation of 2011 El Hierro xeno-pumice revealed by X-ray computed microtomography

Science.gov (United States)

Berg, S. E.; Troll, V. R.; Deegan, F. M.; Burchardt, S.; Krumbholz, M.; Mancini, L.; Polacci, M.; Carracedo, J. C.; Soler, V.; Arzilli, F.; Brun, F.

2016-12-01

During the first week of the 2011 El Hierro submarine eruption, abundant light-coloured pumiceous, high-silica volcanic bombs coated in dark basanite were found floating on the sea. The composition of the light-coloured frothy material (`xeno-pumice') is akin to that of sedimentary rocks from the region, but the textures resemble felsic magmatic pumice, leaving their exact mode of formation unclear. To help decipher their origin, we investigated representative El Hierro xeno-pumice samples using X-ray computed microtomography for their internal vesicle shapes, volumes, and bulk porosity, as well as for the spatial arrangement and size distributions of vesicles in three dimensions (3D). We find a wide range of vesicle morphologies, which are especially variable around small fragments of rock contained in the xeno-pumice samples. Notably, these rock fragments are almost exclusively of sedimentary origin, and we therefore interpret them as relicts an the original sedimentary ocean crust protolith(s). The irregular vesiculation textures observed probably resulted from pulsatory release of volatiles from multiple sources during xeno-pumice formation, most likely by successive release of pore water and mineral water during incremental heating and decompression of the sedimentary protoliths.

X-ray fluorescence microtomography analyzing prostate tissues

International Nuclear Information System (INIS)

Pereira, Gabriela R.; Rocha, Henrique S.; Calza, Cristiane; Lopes, Ricardo T.

2009-01-01

The objective of this work is to determine the elemental distribution map in reference samples and prostate tissue samples using X-Ray Fluorescence Microtomography (XRFCT) in order to verify concentrations of certain elements correlated with characteristics observed by the transmission microtomography. The experiments were performed at the X-Ray Fluorescence Facility of the Brazilian Synchrotron Light Laboratory. A quasi-monochromatic beam produced by a multilayer monochromator was used as an incident beam. The transmission CT images were reconstructed using filtered-back-projection algorithm, and the XRFCT images were reconstructed using filtered-back-projection algorithm with absorption corrections. (author)

A synchrotron radiation microtomography system for the analysis of trabecular bone samples.

Science.gov (United States)

Salomé, M; Peyrin, F; Cloetens, P; Odet, C; Laval-Jeantet, A M; Baruchel, J; Spanne, P

1999-10-01

X-ray computed microtomography is particularly well suited for studying trabecular bone architecture, which requires three-dimensional (3-D) images with high spatial resolution. For this purpose, we describe a three-dimensional computed microtomography (microCT) system using synchrotron radiation, developed at ESRF. Since synchrotron radiation provides a monochromatic and high photon flux x-ray beam, it allows high resolution and a high signal-to-noise ratio imaging. The principle of the system is based on truly three-dimensional parallel tomographic acquisition. It uses a two-dimensional (2-D) CCD-based detector to record 2-D radiographs of the transmitted beam through the sample under different angles of view. The 3-D tomographic reconstruction, performed by an exact 3-D filtered backprojection algorithm, yields 3-D images with cubic voxels. The spatial resolution of the detector was experimentally measured. For the application to bone investigation, the voxel size was set to 6.65 microm, and the experimental spatial resolution was found to be 11 microm. The reconstructed linear attenuation coefficient was calibrated from hydroxyapatite phantoms. Image processing tools are being developed to extract structural parameters quantifying trabecular bone architecture from the 3-D microCT images. First results on human trabecular bone samples are presented.

Imaging biofilm in porous media using X-ray computed microtomography.

Science.gov (United States)

Davit, Y; Iltis, G; Debenest, G; Veran-Tissoires, S; Wildenschild, D; Gerino, M; Quintard, M

2011-04-01

In this study, a new technique for three-dimensional imaging of biofilm within porous media using X-ray computed microtomography is presented. Due to the similarity in X-ray absorption coefficients for the porous media (plastic), biofilm and aqueous phase, an X-ray contrast agent is required to image biofilm within the experimental matrix using X-ray computed tomography. The presented technique utilizes a medical suspension of barium sulphate to differentiate between the aqueous phase and the biofilm. Potassium iodide is added to the suspension to aid in delineation between the biofilm and the experimental porous medium. The iodide readily diffuses into the biofilm while the barium sulphate suspension remains in the aqueous phase. This allows for effective differentiation of the three phases within the experimental systems utilized in this study. The behaviour of the two contrast agents, in particular of the barium sulphate, is addressed by comparing two-dimensional images of biofilm within a pore network obtained by (1) optical visualization and (2) X-ray absorption radiography. We show that the contrast mixture provides contrast between the biofilm, the aqueous-phase and the solid-phase (beads). The imaging method is then applied to two three-dimensional packed-bead columns within which biofilm was grown. Examples of reconstructed images are provided to illustrate the effectiveness of the method. Limitations and applications of the technique are discussed. A key benefit, associated with the presented method, is that it captures a substantial amount of information regarding the topology of the pore-scale transport processes. For example, the quantification of changes in porous media effective parameters, such as dispersion or permeability, induced by biofilm growth, is possible using specific upscaling techniques and numerical analysis. We emphasize that the results presented here serve as a first test of this novel approach; issues with accurate segmentation of

Intensive strength and balance training with the Kinect console (Xbox 360) in a patient with CMT1A.

Science.gov (United States)

Pagliano, Emanuela; Foscan, Maria; Marchi, Alessia; Corlatti, Alice; Aprile, Giorgia; Riva, Daria

2017-08-01

Effective drugs for type 1A Charcot-Marie-Tooth (CMT1A) disease are not available. Various forms of moderate exercise are beneficial, but few data are available on the effectiveness of exercise in CMT1A children. To investigate the feasibility and effectiveness of exercises to improve ankle strength and limb function in a child with CMT1A. Outpatient clinic. Nine-year-old boy with CMT1A. The rehabilitation program consisted of ankle exercises and Kinect videogame-directed physical activities (using an Xbox 360 console/movement sensor) that aimed to improve balance and limb strength. The program was given 3 times a week for 5 weeks. The child was assessed at baseline, after 5 weeks, and 3 and 6 months after. By the end of follow-up, child balance and endurance had improved, but ankle strength did not. The encouraging results for balance and endurance justify further studies on videogame-directed activities in CMT1A children/adolescents.

X-ray computed microtomography as a tool for the comparative morphological characterization of Proceratophrys bigibbosa species

International Nuclear Information System (INIS)

Ahmann, Francielle da Silva; Evseev, Ivan; Paz, Manoela Guimaraes Ferreira da; Lingnau, Rodrigo; Ievsieieva, Ievgeniia; Assis, Joaquim T. de; Alves, Haimon D.L.

2011-01-01

The Proceratophrys bigibbosa species group is characterized by the presence of postocular swellings and absence of hornlike palpebral appendages. A new member of this group was described recently from southern Brazil: Proceratophrys brauni. Its body size is between the smaller Proceratophrys avelinoi and the larger Proceratophrys bigibbosa species, both living in the same region. As the external appearance of these three members of the group is very similar to each other, it is interesting to discover a specific morphological categorization through internal characteristics, such as the cranium's proportions. In this paper, we report the preliminary results for comparative cranium's morphological characterization of Proceratophrys bigibbosa species from Brazil using the X-ray computed Microtomography technique through Skyscan 1174 system. Five samples of each three species, i.e., fifteen samples in total, were scanned. The tomographic slice images were reconstructed by SkyScan software. Then, these 2D images were used to create the cranium's models by 3D DOCTOR software. The main result is that some visible differences in the cranium's proportions of the species were observed. (author)

Optical imaging of oral pathological tissue using optical coherence tomography and synchrotron radiation computed microtomography

Science.gov (United States)

Cânjǎu, Silvana; Todea, Carmen; Sinescu, Cosmin; Negrutiu, Meda L.; Duma, Virgil; Mǎnescu, Adrian; Topalǎ, Florin I.; Podoleanu, Adrian Gh.

2013-06-01

The efforts aimed at early diagnosis of oral cancer should be prioritized towards developing a new screening instrument, based on optical coherence tomography (OCT), to be used directly intraorally, able to perform a fast, real time, 3D and non-invasive diagnosis of oral malignancies. The first step in this direction would be to optimize the OCT image interpretation of oral tissues. Therefore we propose plastination as a tissue preparation method that better preserves three-dimensional structure for study by new optical imaging techniques. The OCT and the synchrotron radiation computed microtomography (micro-CT) were employed for tissue sample analyze. For validating the OCT results we used the gold standard diagnostic procedure for any suspicious lesion - histopathology. This is a preliminary study of comparing features provided by OCT and Micro-CT. In the conditions of the present study, OCT proves to be a highly promising imaging modality. The use of x-ray based topographic imaging of small biological samples has been limited by the low intrinsic x-ray absorption of non-mineralized tissue and the lack of established contrast agents. Plastination can be used to enhance optical imagies of oral soft tissue samples.

Microfocus X-ray sources for 3D microtomography

International Nuclear Information System (INIS)

Flynn, M.J.; Hames, S.M.; Reimann, D.A.; Wilderman, S.J.

1994-01-01

An analytic model for the performance of cone beam microtomography is described. The maximum power of a microfocus X-ray source is assumed to be approximately proportional to the focal spot size. Radiation flux penetrating the specimen is predicted by a semi-empirical relation which is valid for X-ray energies less than 20 keV. Good signal to noise ratio is predicted for bone specimens of 0.1 to 10 mm when scanned at the optimal energy. A flux of about 1x10 10 photons/mm 2 /s is identified for 0.2 mm specimens. Cone beam volumetric microtomography is found to compare favorably with synchrotron based methods. ((orig.))

Ion microtomography using ion time-of-flight

International Nuclear Information System (INIS)

Roberts, M.L.; Heikkinen, D.W.; Proctor, I.D.; Pontau, A.E.; Olona, G.T.; Felter, T.E.; Morse, D.H.; Hess, B.V.

1992-01-01

We have developed and are in the process of testing an ion time-of-flight (TOF) detector system for use in our ion microtomography measurements. Using TOF, ion energy is determined by measurement of the ion's flight time over a certain path length. For ion microtomography, the principle advantage of TOF analysis is that ion count rates of several hundred thousand counts per second can be achieved as compared to a limit of about ten thousand ions per second when using a solid-state silicon surface barrier detector and associated electronics. This greater than 10 fold increase in count rate correspondingly shortens sample analysis time or increases the amount of data that can be collected on a given sample. Details of the system and progress to date are described

X-ray computed microtomography as a tool for the comparative morphological characterization of Proceratophrys bigibbosa species

Energy Technology Data Exchange (ETDEWEB)

Ahmann, Francielle da Silva; Evseev, Ivan; Paz, Manoela Guimaraes Ferreira da; Lingnau, Rodrigo, E-mail: evseev@utfpr.edu.b, E-mail: rodrigolingnau@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Francisco Beltrao, PR (Brazil); Ievsieieva, Ievgeniia; Assis, Joaquim T. de, E-mail: ievsieieva@iprj.uerj.b, E-mail: joaquim@iprj.uerj.b [Universidade do Estado do Rio de Janeiro (IPRJ/UERJ), Nova Friburgo, RJ (Brazil). Inst. Politecnico; Alves, Haimon D.L. [Universidade Federal do Rio de Janeiro (PEN/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Energia Nuclear

2011-07-01

The Proceratophrys bigibbosa species group is characterized by the presence of postocular swellings and absence of hornlike palpebral appendages. A new member of this group was described recently from southern Brazil: Proceratophrys brauni. Its body size is between the smaller Proceratophrys avelinoi and the larger Proceratophrys bigibbosa species, both living in the same region. As the external appearance of these three members of the group is very similar to each other, it is interesting to discover a specific morphological categorization through internal characteristics, such as the cranium's proportions. In this paper, we report the preliminary results for comparative cranium's morphological characterization of Proceratophrys bigibbosa species from Brazil using the X-ray computed Microtomography technique through Skyscan 1174 system. Five samples of each three species, i.e., fifteen samples in total, were scanned. The tomographic slice images were reconstructed by SkyScan software. Then, these 2D images were used to create the cranium's models by 3D DOCTOR software. The main result is that some visible differences in the cranium's proportions of the species were observed. (author)

Microstructural Assessment of Cancellous Bone Using 3D Microtomography

International Nuclear Information System (INIS)

Silva A M H; Alves J M; Da Silva O L; Silva Junior N F; Gazziro M; Pereira J C; Lasso P R O; Vaz C M P; Pereira C A M; Leiva T P; Guarniero R

2011-01-01

Cancellous bones have a porous microstructure and can be modeled as linear elastic solid, heterogeneous and anisotropic. Few studies regarding the morphometric analysis of trabecular bone samples with 3D microtomography have been published so far. The technique has spread worldwide for the characterization of trabecular structures in studies related to bone quality and its relationship with metabolic diseases bone like osteoporosis. In our study cancellous bone samples with cubic and cylindrical geometry were extracted from bovine femur were used to investigate the structural arrangement of bone through high resolution x-ray 3D microtomography (μCT). Four trabecular microstructural parameters (tissue volume, bone volume, bone volume fraction and tissue surface) were measured by 2D (stereological method) and 3D morphometric analysis using the software CTan Analyser supplied by the manufacturer of the microtomograph (SkyScan, model 1172, Belgium). The measurements were done in three main directions (superior-inferior, medial-lateral and anterior-posterior) to investigate the correlation between the 2D and 3D morphometric analysis. The results show a high correlation between the analysis. The x-ray 3D microtomography technique has a great potential for the assessment of bone quality.

High-contrast differentiation resolution 3D imaging of rodent brain by X-ray computed microtomography

Science.gov (United States)

Zikmund, T.; Novotná, M.; Kavková, M.; Tesařová, M.; Kaucká, M.; Szarowská, B.; Adameyko, I.; Hrubá, E.; Buchtová, M.; Dražanová, E.; Starčuk, Z.; Kaiser, J.

2018-02-01

The biomedically focused brain research is largely performed on laboratory mice considering a high homology between the human and mouse genomes. A brain has an intricate and highly complex geometrical structure that is hard to display and analyse using only 2D methods. Applying some fast and efficient methods of brain visualization in 3D will be crucial for the neurobiology in the future. A post-mortem analysis of experimental animals' brains usually involves techniques such as magnetic resonance and computed tomography. These techniques are employed to visualize abnormalities in the brains' morphology or reparation processes. The X-ray computed microtomography (micro CT) plays an important role in the 3D imaging of internal structures of a large variety of soft and hard tissues. This non-destructive technique is applied in biological studies because the lab-based CT devices enable to obtain a several-micrometer resolution. However, this technique is always used along with some visualization methods, which are based on the tissue staining and thus differentiate soft tissues in biological samples. Here, a modified chemical contrasting protocol of tissues for a micro CT usage is introduced as the best tool for ex vivo 3D imaging of a post-mortem mouse brain. This way, the micro CT provides a high spatial resolution of the brain microscopic anatomy together with a high tissue differentiation contrast enabling to identify more anatomical details in the brain. As the micro CT allows a consequent reconstruction of the brain structures into a coherent 3D model, some small morphological changes can be given into context of their mutual spatial relationships.

CMT: a constrained multi-level thresholding approach for ChIP-Seq data analysis.

Directory of Open Access Journals (Sweden)

Iman Rezaeian

Full Text Available Genome-wide profiling of DNA-binding proteins using ChIP-Seq has emerged as an alternative to ChIP-chip methods. ChIP-Seq technology offers many advantages over ChIP-chip arrays, including but not limited to less noise, higher resolution, and more coverage. Several algorithms have been developed to take advantage of these abilities and find enriched regions by analyzing ChIP-Seq data. However, the complexity of analyzing various patterns of ChIP-Seq signals still needs the development of new algorithms. Most current algorithms use various heuristics to detect regions accurately. However, despite how many formulations are available, it is still difficult to accurately determine individual peaks corresponding to each binding event. We developed Constrained Multi-level Thresholding (CMT, an algorithm used to detect enriched regions on ChIP-Seq data. CMT employs a constraint-based module that can target regions within a specific range. We show that CMT has higher accuracy in detecting enriched regions (peaks by objectively assessing its performance relative to other previously proposed peak finders. This is shown by testing three algorithms on the well-known FoxA1 Data set, four transcription factors (with a total of six antibodies for Drosophila melanogaster and the H3K4ac antibody dataset.

X-ray micro-tomography system for small-animal imaging with zoom-in imaging capability

International Nuclear Information System (INIS)

Chun, In Kon; Cho, Myung Hye; Lee, Sang Chul; Cho, Min Hyoung; Lee, Soo Yeol

2004-01-01

Since a micro-tomography system capable of μm-resolution imaging cannot be used for whole-body imaging of a small laboratory animal without sacrificing its spatial resolution, it is desirable for a micro-tomography system to have local imaging capability. In this paper, we introduce an x-ray micro-tomography system capable of high-resolution imaging of a local region inside a small animal. By combining two kinds of projection data, one from a full field-of-view (FOV) scan of the whole body and the other from a limited FOV scan of the region of interest (ROI), we have obtained zoomed-in images of the ROI without any contrast anomalies commonly appearing in conventional local tomography. For experimental verification of the zoom-in imaging capability, we have integrated a micro-tomography system using a micro-focus x-ray source, a 1248 x 1248 flat-panel x-ray detector, and a precision scan mechanism. The mismatches between the two projection data caused by misalignments of the scan mechanism have been estimated with a calibration phantom, and the mismatch effects have been compensated in the image reconstruction procedure. Zoom-in imaging results of bony tissues with a spatial resolution of 10 lp mm -1 suggest that zoom-in micro-tomography can be greatly used for high-resolution imaging of a local region in small-animal studies

Identification of ginseng root using quantitative X-ray microtomography.

Science.gov (United States)

Ye, Linlin; Xue, Yanling; Wang, Yudan; Qi, Juncheng; Xiao, Tiqiao

2017-07-01

The use of X-ray phase-contrast microtomography for the investigation of Chinese medicinal materials is advantageous for its nondestructive, in situ , and three-dimensional quantitative imaging properties. The X-ray phase-contrast microtomography quantitative imaging method was used to investigate the microstructure of ginseng, and the phase-retrieval method is also employed to process the experimental data. Four different ginseng samples were collected and investigated; these were classified according to their species, production area, and sample growth pattern. The quantitative internal characteristic microstructures of ginseng were extracted successfully. The size and position distributions of the calcium oxalate cluster crystals (COCCs), important secondary metabolites that accumulate in ginseng, are revealed by the three-dimensional quantitative imaging method. The volume and amount of the COCCs in different species of the ginseng are obtained by a quantitative analysis of the three-dimensional microstructures, which shows obvious difference among the four species of ginseng. This study is the first to provide evidence of the distribution characteristics of COCCs to identify four types of ginseng, with regard to species authentication and age identification, by X-ray phase-contrast microtomography quantitative imaging. This method is also expected to reveal important relationships between COCCs and the occurrence of the effective medicinal components of ginseng.

Beam hardening correction algorithm in microtomography images

International Nuclear Information System (INIS)

Sales, Erika S.; Lima, Inaya C.B.; Lopes, Ricardo T.; Assis, Joaquim T. de

2009-01-01

Quantification of mineral density of bone samples is directly related to the attenuation coefficient of bone. The X-rays used in microtomography images are polychromatic and have a moderately broad spectrum of energy, which makes the low-energy X-rays passing through a sample to be absorbed, causing a decrease in the attenuation coefficient and possibly artifacts. This decrease in the attenuation coefficient is due to a process called beam hardening. In this work the beam hardening of microtomography images of vertebrae of Wistar rats subjected to a study of hyperthyroidism was corrected by the method of linearization of the projections. It was discretized using a spectrum in energy, also called the spectrum of Herman. The results without correction for beam hardening showed significant differences in bone volume, which could lead to a possible diagnosis of osteoporosis. But the data with correction showed a decrease in bone volume, but this decrease was not significant in a confidence interval of 95%. (author)

Beam hardening correction algorithm in microtomography images

Energy Technology Data Exchange (ETDEWEB)

Sales, Erika S.; Lima, Inaya C.B.; Lopes, Ricardo T., E-mail: esales@con.ufrj.b, E-mail: ricardo@lin.ufrj.b [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Assis, Joaquim T. de, E-mail: joaquim@iprj.uerj.b [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Inst. Politecnico. Dept. de Engenharia Mecanica

2009-07-01

Quantification of mineral density of bone samples is directly related to the attenuation coefficient of bone. The X-rays used in microtomography images are polychromatic and have a moderately broad spectrum of energy, which makes the low-energy X-rays passing through a sample to be absorbed, causing a decrease in the attenuation coefficient and possibly artifacts. This decrease in the attenuation coefficient is due to a process called beam hardening. In this work the beam hardening of microtomography images of vertebrae of Wistar rats subjected to a study of hyperthyroidism was corrected by the method of linearization of the projections. It was discretized using a spectrum in energy, also called the spectrum of Herman. The results without correction for beam hardening showed significant differences in bone volume, which could lead to a possible diagnosis of osteoporosis. But the data with correction showed a decrease in bone volume, but this decrease was not significant in a confidence interval of 95%. (author)

Toward regional corrections of long period CMT inversions using InSAR

Science.gov (United States)

Shakibay Senobari, N.; Funning, G.; Ferreira, A. M.

2017-12-01

One of InSAR's main strengths, with respect to other methods of studying earthquakes, is finding the accurate location of the best point source (or `centroid') for an earthquake. While InSAR data have great advantages for study of shallow earthquakes, the number of earthquakes for which we have InSAR data is low, compared with the number of earthquakes recorded seismically. And though improvements to SAR satellite constellations have enhanced the use of InSAR data during earthquake response, post-event data still have a latency on the order of days. On the other hand, earthquake centroid inversion methods using long period seismic data (e.g. the Global CMT method) are fast but include errors caused by inaccuracies in both the Earth velocity model and in wave propagation assumptions (e.g. Hjörleifsdóttir and Ekström, 2010; Ferreira and Woodhouse, 2006). Here we demonstrate a method that combines the strengths of both methods, calculating regional travel-time corrections for long-period waveforms using accurate centroid locations from InSAR, then applying these to other events that occur in the same region. Our method is based on the observation that synthetic seismograms produced from InSAR source models and locations match the data very well except for some phase shifts (travel time biases) between the two waveforms, likely corresponding to inaccuracies in Earth velocity models (Weston et al., 2014). Our previous work shows that adding such phase shifts to the Green's functions can improve the accuracy of long period seismic CMT inversions by reducing tradeoffs between the moment tensor components and centroid location (e.g. Shakibay Senobari et al., AGU Fall Meeting 2015). Preliminary work on several pairs of neighboring events (e.g. Landers-Hector Mine, the 2000 South Iceland earthquake sequences) shows consistent azimuthal patterns of these phase shifts for nearby events at common stations. These phase shift patterns strongly suggest that it is possible to

Ceramic filters analysis for aluminium melting through microtomography technique

International Nuclear Information System (INIS)

Rocha, Henrique de Souza; Lopes, Ricardo Tadeu; Jesus, Edgar Francisco Oliveira de; Oliveira, Luis Fernando de; Duhm, Rainer; Feiste, Karsten L.; Reichert, Christian; Reimche, Wilfried; Stegemann, Dieter

2000-01-01

In this work a ceramic filters analysis is done through the microtomography for improvement of the aluminium melting process through the filter porosity control. Microtomography were obtained of ceramic filters with pore dimensions of 10, 20 and 30 ppi. The data were calculated by using an reconstruction algorithm for divergent beam implemented in the Nuclear Instrumentation Laboratory of COPPE/UFRJ and analysed through cells and windows separation according to the defined by Ray. For the analyses the Image Pro program were used where the cells have been detached by sphere inserted, adjusting by nine points, in the filter cavities. So, the size of the answer sphere were considered as the cell size. The windows were measured by straight lines secant to the window intersections

Snow particles extracted from X-ray computed microtomography imagery and their single-scattering properties

Science.gov (United States)

Ishimoto, Hiroshi; Adachi, Satoru; Yamaguchi, Satoru; Tanikawa, Tomonori; Aoki, Teruo; Masuda, Kazuhiko

2018-04-01

Sizes and shapes of snow particles were determined from X-ray computed microtomography (micro-CT) images, and their single-scattering properties were calculated at visible and near-infrared wavelengths using a Geometrical Optics Method (GOM). We analyzed seven snow samples including fresh and aged artificial snow and natural snow obtained from field samples. Individual snow particles were numerically extracted, and the shape of each snow particle was defined by applying a rendering method. The size distribution and specific surface area distribution were estimated from the geometrical properties of the snow particles, and an effective particle radius was derived for each snow sample. The GOM calculations at wavelengths of 0.532 and 1.242 μm revealed that the realistic snow particles had similar scattering phase functions as those of previously modeled irregular shaped particles. Furthermore, distinct dendritic particles had a characteristic scattering phase function and asymmetry factor. The single-scattering properties of particles of effective radius reff were compared with the size-averaged single-scattering properties. We found that the particles of reff could be used as representative particles for calculating the average single-scattering properties of the snow. Furthermore, the single-scattering properties of the micro-CT particles were compared to those of particle shape models using our current snow retrieval algorithm. For the single-scattering phase function, the results of the micro-CT particles were consistent with those of a conceptual two-shape model. However, the particle size dependence differed for the single-scattering albedo and asymmetry factor.

A new numerical modelling method for deformation behaviour of metallic porous materials using X-ray computed microtomography

Energy Technology Data Exchange (ETDEWEB)

Doroszko, M., E-mail: m.doroszko@pb.edu.pl; Seweryn, A., E-mail: a.seweryn@pb.edu.pl

2017-03-24

Microtomographic devices have limited imaging accuracy and are often insufficient for proper mapping of small details of real objects (e.g. elements of material mesostructures). This paper describes a new method developed to compensate the effect of X-ray computed microtomography (micro-CT) inaccuracy in numerical modelling of the deformation process of porous sintered 316 L steel. The method involves modification of microtomographic images where the pore shapes are separated. The modification consists of the reconstruction of fissures and small pores omitted by micro-CT scanning due to the limited accuracy of the measuring device. It enables proper modelling of the tensile deformation process of porous materials. In addition, the proposed approach is compared to methods described in the available literature. As a result of numerical calculations, stress and strain distributions were obtained in deformed sintered 316 L steel. Based on the results, macroscopic stress-strain curves were received. Maximum principal stress distributions obtained by the proposed calculation model, indicated specific locations, where the stress reached a critical value, and fracture initiation occurred. These are bridges with small cross sections and notches in the shape of pores. Based on calculation results, the influence of the deformation mechanism of the material porous mesostructures on their properties at the macroscale is described.

A new numerical modelling method for deformation behaviour of metallic porous materials using X-ray computed microtomography

International Nuclear Information System (INIS)

Doroszko, M.; Seweryn, A.

2017-01-01

Microtomographic devices have limited imaging accuracy and are often insufficient for proper mapping of small details of real objects (e.g. elements of material mesostructures). This paper describes a new method developed to compensate the effect of X-ray computed microtomography (micro-CT) inaccuracy in numerical modelling of the deformation process of porous sintered 316 L steel. The method involves modification of microtomographic images where the pore shapes are separated. The modification consists of the reconstruction of fissures and small pores omitted by micro-CT scanning due to the limited accuracy of the measuring device. It enables proper modelling of the tensile deformation process of porous materials. In addition, the proposed approach is compared to methods described in the available literature. As a result of numerical calculations, stress and strain distributions were obtained in deformed sintered 316 L steel. Based on the results, macroscopic stress-strain curves were received. Maximum principal stress distributions obtained by the proposed calculation model, indicated specific locations, where the stress reached a critical value, and fracture initiation occurred. These are bridges with small cross sections and notches in the shape of pores. Based on calculation results, the influence of the deformation mechanism of the material porous mesostructures on their properties at the macroscale is described.

An Analysis of the Symptomatic Domains Most Relevant to Charcot Marie Tooth Neuropathy (CMT) Patients

Science.gov (United States)

2017-06-09

Charcot Marie Tooth Disease (CMT); Hereditary Sensory and Motor Neuropathy; Nerve Compression Syndromes; Tooth Diseases; Congenital Abnormalities; Genetic Diseases, Inborn; Heredodegenerative Disorders, Nervous System

Microtomography evaluation of dental tissue wear surface induced by in vitro simulated chewing cycles on human and composite teeth

Directory of Open Access Journals (Sweden)

Rossella Bedini

2012-01-01

Full Text Available In this study a 3D microtomography display of tooth surfaces after in vitro dental wear tests has been obtained. Natural teeth have been compared with prosthetic teeth, manufactured by three different polyceramic composite materials. The prosthetic dental element samples, similar to molars, have been placed in opposition to human teeth extracted by paradontology diseases. After microtomography analysis, samples have been subjected to in vitro fatigue test cycles by servo-hydraulic mechanical testing machine. After the fatigue test, each sample has been subjected again to microtomography analysis to obtain volumetric value changes and dental wear surface images. Wear surface images were obtained by 3D reconstruction software and volumetric value changes were measured by CT analyser software. The aim of this work has been to show the potential of microtomography technique to display very clear and reliable wear surface images. Microtomography analysis methods to evaluate volumetric value changes have been used to quantify dental tissue and composite material wear.

X-Ray Micro-Tomography Applied to Nasa's Materials Research: Heat Shields, Parachutes and Asteroids

Science.gov (United States)

Panerai, Francesco; Borner, Arnaud; Ferguson, Joseph C.; Mansour, Nagi N.; Stern, Eric C.; Barnard, Harold S.; Macdowell, Alastair A.; Parkinson, Dilworth Y.

2017-01-01

X-ray micro-tomography is used to support the research on materials carried out at NASA Ames Research Center. The technique is applied to a variety of applications, including the ability to characterize heat shield materials for planetary entry, to study the Earth- impacting asteroids, and to improve broadcloths of spacecraft parachutes. From micro-tomography images, relevant morphological and transport properties are determined and validated against experimental data.

X-ray microtomography application in pore space reservoir rock

Energy Technology Data Exchange (ETDEWEB)

Oliveira, M.F.S.; Lima, I. [Nuclear Instrumentation Laboratory, COPPE/UFRJ, P.O. Box 68509, 21.941-972, Rio de Janeiro (Brazil); Borghi, L. [Geology Department, Geosciences Institute, Federal University of Rio de Janeiro, Brazil. (Brazil); Lopes, R.T., E-mail: ricardo@lin.ufrj.br [Nuclear Instrumentation Laboratory, COPPE/UFRJ, P.O. Box 68509, 21.941-972, Rio de Janeiro (Brazil)

2012-07-15

Characterization of porosity in carbonate rocks is important in the oil and gas industry since a major hydrocarbons field is formed by this lithology and they have a complex media porous. In this context, this research presents a study of the pore space in limestones rocks by x-ray microtomography. Total porosity, type of porosity and pore size distribution were evaluated from 3D high resolution images. Results show that carbonate rocks has a complex pore space system with different pores types at the same facies. - Highlights: Black-Right-Pointing-Pointer This study is about porosity parameter in carbonate rocks by 3D X-Ray Microtomography. Black-Right-Pointing-Pointer This study has become useful as data input for modeling reservoir characterization. Black-Right-Pointing-Pointer This technique was able to provide pores, grains and mineralogical differences among the samples.

In situ microradioscopy and microtomography of fatigue-loaded dental two-piece implants

Energy Technology Data Exchange (ETDEWEB)

Wiest, Wolfram; Zabler, Simon, E-mail: simon.zabler@physik.uni-wuerzburg.de [University of Würzburg (Germany); Rack, Alexander [European Synchrotron Radiation Facility (France); Fella, Christian; Balles, Andreas [University of Würzburg (Germany); Nelson, Katja; Schmelzeisen, Rainer [Medical Centre – University of Freiburg (Germany); Hanke, Randolf [University of Würzburg (Germany); Fraunhofer EZRT, Fürth (Germany)

2015-10-09

Results of a novel in situ microradiography and microtomography setup for the study of fatigue processes are presented. This setup is optimized for the requirements of dental implants and use at synchrotron imaging beamlines. Synchrotron real-time radioscopy and in situ microtomography are the only techniques providing direct visible information on a micrometre scale of local deformation in the implant–abutment connection (IAC) during and after cyclic loading. The microgap formation at the IAC has been subject to a number of studies as it has been proposed to be associated with long-term implant success. The next step in this scientific development is to focus on the in situ fatigue procedure of two-component dental implants. Therefore, an apparatus has been developed which is optimized for the in situ fatigue analysis of dental implants. This report demonstrates both the capability of in situ radioscopy and microtomography at the ID19 beamline for the study of cyclic deformation in dental implants. The first results show that it is possible to visualize fatigue loading of dental implants in real-time radioscopy in addition to the in situ fatigue tomography. For the latter, in situ microtomography is applied during the cyclic loading cycles in order to visualize the opening of the IAC microgap. These results concur with previous ex situ studies on similar systems. The setup allows for easily increasing the bending force, to simulate different chewing situations, and is, therefore, a versatile tool for examining the fatigue processes of dental implants and possibly other specimens.

In situ microradioscopy and microtomography of fatigue-loaded dental two-piece implants

International Nuclear Information System (INIS)

Wiest, Wolfram; Zabler, Simon; Rack, Alexander; Fella, Christian; Balles, Andreas; Nelson, Katja; Schmelzeisen, Rainer; Hanke, Randolf

2015-01-01

Results of a novel in situ microradiography and microtomography setup for the study of fatigue processes are presented. This setup is optimized for the requirements of dental implants and use at synchrotron imaging beamlines. Synchrotron real-time radioscopy and in situ microtomography are the only techniques providing direct visible information on a micrometre scale of local deformation in the implant–abutment connection (IAC) during and after cyclic loading. The microgap formation at the IAC has been subject to a number of studies as it has been proposed to be associated with long-term implant success. The next step in this scientific development is to focus on the in situ fatigue procedure of two-component dental implants. Therefore, an apparatus has been developed which is optimized for the in situ fatigue analysis of dental implants. This report demonstrates both the capability of in situ radioscopy and microtomography at the ID19 beamline for the study of cyclic deformation in dental implants. The first results show that it is possible to visualize fatigue loading of dental implants in real-time radioscopy in addition to the in situ fatigue tomography. For the latter, in situ microtomography is applied during the cyclic loading cycles in order to visualize the opening of the IAC microgap. These results concur with previous ex situ studies on similar systems. The setup allows for easily increasing the bending force, to simulate different chewing situations, and is, therefore, a versatile tool for examining the fatigue processes of dental implants and possibly other specimens

Potato dextrose agar antifungal susceptibility testing for yeasts and molds: evaluation of phosphate effect on antifungal activity of CMT-3.

Science.gov (United States)

Liu, Yu; Tortora, George; Ryan, Maria E; Lee, Hsi-Ming; Golub, Lorne M

2002-05-01

The broth macrodilution method (BMM) for antifungal susceptibility testing, approved by the National Committee for Clinical Laboratory Standards (NCCLS), was found to have deficiencies in testing of the antifungal activity of a new type of antifungal agent, a nonantibacterial chemically modified tetracycline (CMT-3). The high content of phosphate in the medium was found to greatly increase the MICs of CMT-3. To avoid the interference of phosphate in the test, a new method using potato dextrose agar (PDA) as a culture medium was developed. Eight strains of fungi, including five American Type Culture Collection strains and three clinical isolates, were used to determine the MICs of amphotericin B and itraconazole with both the BMM and the PDA methods. The MICs of the two antifungal agents determined with the PDA method showed 99% agreement with those determined with the BMM method within 1 log(2) dilution. Similarly, the overall reproducibility of the MICs with the PDA method was above 97%. Three other antifungal agents, fluconazole, ketoconazole, and CMT-3, were also tested in parallel against yeasts and molds with both the BMM and the PDA methods. The MICs of fluconazole and ketoconazole determined with the PDA method showed 100% agreement within 1 log(2) dilution of those obtained with the BMM method. However, the MICs of CMT-3 determined with the BMM method were as high as 128 times those determined with the PDA method. The effect of phosphate on the antifungal activity of CMT-3 was evaluated by adding Na2HPO4 to PDA in the new method. It was found that the MIC of CMT-3 against a Penicillium sp. increased from 0.5 microg/ml (control) to 2.0 microg/ml when the added phosphate was used at a concentration of 0.8 mg/ml, indicating a strong interference of Na2HPO4 with the antifungal activity of CMT-3. Except for fluconazole, all the other antifungal agents demonstrated clear end points among the yeasts and molds tested. Nevertheless, with its high reproducibility

Method for obtaining silver nanoparticle concentrations within a porous medium via synchrotron X-ray computed microtomography.

Science.gov (United States)

Molnar, Ian L; Willson, Clinton S; O'Carroll, Denis M; Rivers, Mark L; Gerhard, Jason I

2014-01-21

Attempts at understanding nanoparticle fate and transport in the subsurface environment are currently hindered by an inability to quantify nanoparticle behavior at the pore scale (within and between pores) within realistic pore networks. This paper is the first to present a method for high resolution quantification of silver nanoparticle (nAg) concentrations within porous media under controlled experimental conditions. This method makes it possible to extract silver nanoparticle concentrations within individual pores in static and quasi-dynamic (i.e., transport) systems. Quantification is achieved by employing absorption-edge synchrotron X-ray computed microtomography (SXCMT) and an extension of the Beer-Lambert law. Three-dimensional maps of X-ray mass linear attenuation are converted to SXCMT-determined nAg concentration and are found to closely match the concentrations determined by ICP analysis. In addition, factors affecting the quality of the SXCMT-determined results are investigated: 1) The acquisition of an additional above-edge data set reduced the standard deviation of SXCMT-determined concentrations; 2) X-ray refraction at the grain/water interface artificially depresses the SXCMT-determined concentrations within 18.1 μm of a grain surface; 3) By treating the approximately 20 × 10(6) voxels within each data set statistically (i.e., averaging), a high level of confidence in the SXCMT-determined mean concentrations can be obtained. This novel method provides the means to examine a wide range of properties related to nanoparticle transport in controlled laboratory porous medium experiments.

Bone quality analysis using X-ray microtomography and microfluorescence

Energy Technology Data Exchange (ETDEWEB)

Sales, E.; Lima, I. [Nuclear Instrumentation Laboratory, PEN/COPPE/UFRJ, PO Box: 68509, 21.941-972, Rio de Janeiro (Brazil); Assis, J.T. de [Polytechnic Institute, DEMEC/UERJ (Brazil); Gomez, W. [Department of Electrical Engineering, Center of the National Polytechnic Institute (Mexico); Pereira, W.C.A. [Biomedical Engineering Program, COPPE/UFRJ, Rio de Janeiro (Brazil); Lopes, R.T., E-mail: ricardo@lin.ufrj.br [Nuclear Instrumentation Laboratory, PEN/COPPE/UFRJ, PO Box: 68509, 21.941-972, Rio de Janeiro (Brazil)

2012-07-15

Bone quality is an evaluation index often applied in order to interpret clinical observations made upon bone health, such as bone mineral density, micro and macro architecture, and mineral content. Conventional inspection techniques do not provide full information on trabecular bone quality. This study shows the high resolution potential and the non-destructive character of X-ray microtomography and microfluorescence upon the application of such techniques for evaluating bone quality. The mineral content assessment was performed by two-dimensional concentration mappings of calcium, zinc, and strontium. The results showed significant changes in bone morphology. - Highlights: Black-Right-Pointing-Pointer This study shows bone microarchitectural evaluation by X-ray microtomography and microfluorescence. Black-Right-Pointing-Pointer For this purpose, lumbar vertebrae of Wistar rats have been used as test subjects. Black-Right-Pointing-Pointer X-ray techniques proved to have an excellent perfomance in quantifying bone mineral content.

Development of quantitative x-ray microtomography

International Nuclear Information System (INIS)

Deckman, H.W.; Dunsmuir, J.A.; D'Amico, K.L.; Ferguson, S.R.; Flannery, B.P.

1990-01-01

The authors have developed several x-ray microtomography systems which function as quantitative three dimensional x-ray microscopes. In this paper the authors describe the evolutionary path followed from making the first high resolution experimental microscopes to later generations which can be routinely used for investigating materials. Developing the instrumentation for reliable quantitative x-ray microscopy using synchrotron and laboratory based x-ray sources has led to other imaging modalities for obtaining temporal and spatial two dimensional information

Particle tracking during Ostwald ripening using time-resolved laboratory X-ray microtomography

Energy Technology Data Exchange (ETDEWEB)

Werz, T., E-mail: thomas.werz@uni-ulm.de [Ulm University, Institute of Micro and Nanomaterials, Albert-Einstein-Allee 47, 89081 (Germany); Baumann, M. [Ulm University, Institute of Micro and Nanomaterials, Albert-Einstein-Allee 47, 89081 (Germany); Wolfram, U. [Ulm University, Institute of Orthopaedic Research and Biomechanics, Helmholtzstrasse 14, 89081 (Germany); Krill, C.E. [Ulm University, Institute of Micro and Nanomaterials, Albert-Einstein-Allee 47, 89081 (Germany)

2014-04-01

Laboratory X-ray microtomography is investigated as a method for obtaining time-resolved images of microstructural coarsening of the semisolid state of Al–5 wt.% Cu samples during Ostwald ripening. Owing to the 3D imaging capability of tomography, this technique uniquely provides access to the growth rates of individual particles, thereby not only allowing a statistical characterization of coarsening—as has long been possible by conventional metallography—but also enabling quantification of the influence of local environment on particle boundary migration. The latter information is crucial to understanding growth kinetics during Ostwald ripening at high volume fractions of the coarsening phase. Automated image processing and segmentation routines were developed to close gaps in the network of particle boundaries and to track individual particles from one annealing step to the next. The particle tracking success rate places an upper bound of only a few percent on the likelihood of segmentation errors for any given particle. The accuracy of particle size trajectories extracted from the time-resolved tomographic reconstructions is correspondingly high. Statistically averaged coarsening data and individual particle growth rates are in excellent agreement with the results of prior experimental studies and with computer simulations of Ostwald ripening. - Highlights: • Ostwald ripening in Al–5 wt.% Cu measured by laboratory X-ray microtomography • Time-resolved measurement of individual particle growth • Automated segmentation routines developed to close gaps in particle boundary network • Particle growth/shrinkage rates deviate from LSW model prediction.

Pseudodominant inheritance pattern in a family with CMT2 caused by GDAP1 mutations

NARCIS (Netherlands)

van Paassen, Barbara W.; Bronk, Marieke; Verhamme, Camiel; van Ruissen, Fred; Baas, Frank; van Spaendonck-Zwarts, Karin Y.; de Visser, Marianne

2017-01-01

We report a family in which an autosomal dominantly inherited Charcot-Marie-Tooth (CMT) disease type 2 was suspected. The affected family members (proband, sister, father, and paternal aunt) showed intrafamilial clinical variability. The proband needed walking aids since adolescence because of

Virtual dissection of Thoropa miliaris tadpole using phase-contrast synchrotron microtomography

Science.gov (United States)

Fidalgo, G.; Colaço, M. V.; Nogueira, L. P.; Braz, D.; Silva, H. R.; Colaço, G.; Barroso, R. C.

2018-05-01

In this work, in-line phase-contrast synchrotron microtomography was used in order to study the external and internal morphology of Thoropa miliaris tadpoles. Whole-specimens of T. miliaris in larval stages of development 28, 37 and 42, collected in the municipality of Mangaratiba (Rio de Janeiro, Brazil) were used for the study. The samples were scanned in microtomography beamline (IMX) at the Brazilian Synchrotron Light Laboratory (LNLS). The phase-contrast technique allowed us to obtain high quality images which made possible the structures segmentation on the rendered volume by the Avizo graphic image editing software. The combination of high quality images and segmentation process provides adequate visualization of different organs and soft (liver, notochord, brain, crystalline, cartilages) and hard (elements of the bone skeleton) tissues.

Application of laboratory microtomography to the study of mineralized tissues

International Nuclear Information System (INIS)

Elliot, J.C.; Davis, G.R.; Anderson, P.; Wong, F.S.L.; Dowker, S.E.P.; Mercer, C.E.

1997-01-01

The principles of microtomography are briefly presented and recent studies of mineralized tissues using laboratory and synchrotron X-ray sources are reviewed. Results are given of investigations undertaken with laboratory systems using either a 1 st generation (single beam of 15 mu m and energy dispersive detector) or a novel 4 th generation system with 2-D detector that can provide 3-D images with vowels of 38x38x38 mu m ''3 of specimens with diameter up to 40 mm. Studies include mineral concentration distributions in cortical bone trabecular structure in a human vertebral body, cracking of bone under compression in situ and root canal obturation and Er: YAG laser application to enamel and dentine. Future applications of microtomography to the study of mineralized tissues and their interaction with biomaterials are discussed.(Author) 31 refs

Synchrotron radiation microtomography of musical instruments: a non-destructive monitoring technique for insect infestations

Directory of Open Access Journals (Sweden)

Beatrice Bentivoglio-Ravasio

2011-08-01

Full Text Available X-ray computed tomography is becoming a common technique for the structural analysis of samples of cultural relevance, providing luthiers, art historians, conservators and restorators with a unique tool for the characterization of musical instruments. Synchrotron-radiation phase-contrast microtomography is an ideal technique for the non-destructive 3D analysis of samples where small lowabsorbing details such as larvae and eggs can be detected. We report results from the first feasibility studies performed at the Elettra synchrotron laboratory, where the 1494 organ by Lorenzo Gusnasco da Pavia has been studied. Together with important information about the structural conditions, the presence of xylophages could be detected and characterized.

SYNCHROTRON X-RAY MICROTOMOGRAPHY, ELECTRON PROBE MICROANALYSIS, AND NMR OF TOLUENE WASTE IN CEMENT

International Nuclear Information System (INIS)

Butler, L.G.

1999-01-01

Synchrotron X-ray microtomography shows vesicular structures for toluene/cement mixtures, prepared with 1.22 to 3.58 wt% toluene. Three-dimensional imaging of the cured samples shows spherical vesicles, with diameters ranging from 20 to 250 microm; a search with EPMA for vesicles in the range of 1-20 microm proved negative. However, the total vesicle volume, as computed from the microtomography images, accounts for less than 10% of initial toluene. Since the cements were cured in sealed bottles, the larger portion of toluene must be dispersed within the cement matrix. Evidence for toluene in the cement matrix comes from 29 Si MAS NMR spectroscopy, which shows a reduction in chain silicates with added toluene. Also, 2 H NMR of d 8 -toluene/cement samples shows high mobility for all, toluene and thus no toluene/cement binding. A model that accounts for all observations follows: For loadings below about 3 wt%, most toluene is dispersed in the cement matrix, with a small fraction of the initial toluene phase separating from the cement paste and forming vesicular structures that are preserved in the cured cement. Furthermore, at loadings above 3 wt%, the abundance of vesicles formed during toluene/cement paste mixing leads to macroscopic phase separation (most toluene floats to the surface of the cement paste)

Microstructural characterization of reservoir rocks by X-ray microtomography

International Nuclear Information System (INIS)

Fernandes, Jaquiel Salvi; Appoloni, Carlos Roberto

2007-01-01

The evaluation of microstructural parameters from reservoir rocks is of great importance for petroleum industries. This work presents measurements of total porosity and pore size distribution of a sandstone sample from Tumblagooda geological formation, extracted from the Kalbari National Park in Australia. X-ray microtomography technique was used for determining porosity and pore size distribution. Other techniques, such as mercury intrusion porosimetry and Archimedes method have also been applied for those determinations but since they are regarded destructive techniques, samples cannot usually be used for further analyses. X-ray microtomography, besides allowing future analyses of a sample already evaluated, also provides tridimensional images of the sample. The experimental configuration included a SkysCan 1172 from CENPES-PETROBRAS, Rio de Janeiro, Brazil. The spatial resolution of this equipment is 2.9 μm. Images have been reconstructed using NRecon software and analysed with the IMAGO software developed by the Laboratory of Porous Materials and Thermophysical Properties of the Department of Mechanical Engineering / Federal University of Santa Catarina, Florianopolis, Brazil

X-ray computed microtomography of three-dimensional microcracks and self-healing in engineered cementitious composites

International Nuclear Information System (INIS)

Fan, Shuai; Li, Mo

2015-01-01

Concrete cracking and deterioration can potentially be addressed by innovative self-healing cementitious materials, which can autogenously regain transport properties and mechanical characteristics after the damage self-healing process. For the development of such materials, it is crucial, but challenging, to precisely characterize the extent and quality of self-healing due to a variety of factors. This study adopted x-ray computed microtomography (μCT) to derive three-dimensional morphological data on microcracks before and after healing in engineered cementitious composite (ECC). Scanning electron microscope and energy dispersive x-ray spectroscopy were also used to morphologically and chemically analyze the healing products. This work showed that the evolution of the microcrack 3D structure due to self-healing in cementitious materials can be directly and quantitatively characterized by μCT. A detailed description of the μCT image analysis method applied to ECC self-healing was presented. The results revealed that the self-healing extent and rate strongly depended on initial surface crack width, with smaller crack width favoring fast and robust self-healing. We also found that the self-healing mechanism in cementitious materials is dependent on crack depth. The region of a crack close to the surface (from 0 to around 50–150 μm below the surface) can be sealed quickly with crystalline precipitates. However, at greater depths the healing process inside the crack takes a significantly longer time to occur, with healing products more likely resulting from continued hydration and pozzolanic reactions. Finally, the μCT method was compared with other self-healing characterization methods, with discussions on its importance in generating new scientific knowledge for the development of robust self-healing cementitious materials. (paper)

Identification of ginseng root using quantitative X-ray microtomography

Directory of Open Access Journals (Sweden)

Linlin Ye

2017-07-01

Conclusion: This study is the first to provide evidence of the distribution characteristics of COCCs to identify four types of ginseng, with regard to species authentication and age identification, by X-ray phase-contrast microtomography quantitative imaging. This method is also expected to reveal important relationships between COCCs and the occurrence of the effective medicinal components of ginseng.

X-ray micro-Tomography at the Advanced Light Source

Science.gov (United States)

The X-ray micro-Tomography Facility at the Advanced Light Source has been in operation since 2004. The source is a superconducting bend magnet of critical energy 10.5KeV; photon energy coverage is 8-45 KeV in monochromatic mode, and a filtered white light option yields useful photons up to 50 KeV. A...

In situ microradioscopy and microtomography of fatigue-loaded dental two-piece implants.

Science.gov (United States)

Wiest, Wolfram; Zabler, Simon; Rack, Alexander; Fella, Christian; Balles, Andreas; Nelson, Katja; Schmelzeisen, Rainer; Hanke, Randolf

2015-11-01

Synchrotron real-time radioscopy and in situ microtomography are the only techniques providing direct visible information on a micrometre scale of local deformation in the implant-abutment connection (IAC) during and after cyclic loading. The microgap formation at the IAC has been subject to a number of studies as it has been proposed to be associated with long-term implant success. The next step in this scientific development is to focus on the in situ fatigue procedure of two-component dental implants. Therefore, an apparatus has been developed which is optimized for the in situ fatigue analysis of dental implants. This report demonstrates both the capability of in situ radioscopy and microtomography at the ID19 beamline for the study of cyclic deformation in dental implants. The first results show that it is possible to visualize fatigue loading of dental implants in real-time radioscopy in addition to the in situ fatigue tomography. For the latter, in situ microtomography is applied during the cyclic loading cycles in order to visualize the opening of the IAC microgap. These results concur with previous ex situ studies on similar systems. The setup allows for easily increasing the bending force, to simulate different chewing situations, and is, therefore, a versatile tool for examining the fatigue processes of dental implants and possibly other specimens.

Performance Tests of Three Flow Distributors Using SMART-ITL with 1-Train CMT

Energy Technology Data Exchange (ETDEWEB)

Bae, Hwang; Ryu, Sung Uk; Shin, Yong-Cheol; Ko, Yung-Joo; Min, Kyoung-Ho; Ryu, Hyo Bong; Park, Jong-Kuk; Bang, Yun-Gon; Chae, Young-Jong; Yi, Sung-Jae; Park, Hyun-Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-10-15

Passive safety systems (PSSs) are key tools to remove the heat from the core or containment. Safety improvements for SMART have been studied since the Standard Design Approval (SDA) for SMART was certificated in 2012. Active safety systems such as safety injection pumps are replaced by a passive system, which is a kind of the gravity injection system with core makeup tanks (CMT) and safety injection tanks (SIT). All tanks for the passive safety systems are located higher than a pressurized reactor vessel, whose injection nozzles are located around the reactor coolant pumps (RCP). An Integral Test Loop for the SMART design (SMART-ITL) has been constructed and its commissioning tests finished in 2012. SMART-ITL is scaled down by the volume scaling methodology. Its height is conserved and its volume scale ratio is 1/49. The SMART-ITL has all fluid systems of SMART together with a break system and instruments. Recently, a test program to validate the performance of SMART Passive Safety System (PSS) was launched. A scaled-down test facility for SMART PSS was additionally installed at the existing SMART-ITL facility and a set of validation tests were performed. In this paper, the performance tests of the flow distributors using SMART-ITL with 1-train CMT will be discussed. A 1-train passive safety system including a CMT and SIT, which is operated only by gravity force, was additionally installed in the SMART-ITL to replace the active safety system for the SMART design. Several performance tests for the flow distributors were carried out to estimate a designed flow rate. 1. The peak flow rate in a hot test does not reach the value in a cold test, and the approaching time to peak is also delayed during the early stage of gravity injection. 2.. It is verified that the flow rate from a gravity injection depends on the differential pressure in the injection pipe line including a friction and form drag, which can be adjusted by controlling the resistance coefficient.

Introduction to computational mass transfer with applications to chemical engineering

CERN Document Server

Yu, Kuo-Tsung

2017-01-01

This book offers an easy-to-understand introduction to the computational mass transfer (CMT) method. On the basis of the contents of the first edition, this new edition is characterized by the following additional materials. It describes the successful application of this method to the simulation of the mass transfer process in a fluidized bed, as well as recent investigations and computing methods for predictions for the multi-component mass transfer process. It also demonstrates the general issues concerning computational methods for simulating the mass transfer of the rising bubble process. This new edition has been reorganized by moving the preparatory materials for Computational Fluid Dynamics (CFD) and Computational Heat Transfer into appendices, additions of new chapters, and including three new appendices on, respectively, generalized representation of the two-equation model for the CMT, derivation of the equilibrium distribution function in the lattice-Boltzmann method, and derivation of the Navier-S...

Jumlah bakteri Staphylococcus aureus dan skor California Mastitis Test (CMT pada susu kambing Peranakan Etawa akibat dipping ekstrak daun Babadotan (Ageratum conyzoides L.

Directory of Open Access Journals (Sweden)

Dwi Priono

2016-04-01

Full Text Available The aim of this research is to determine the effect of teat dipping of Ettawa crossbred goat using babadotan leaves (Ageratum conyzoides Linn. extract on the number of Staphylococcus aureusin milk. The udder inflammation degree also was determined using California Mastitis Test (CMT. The treatments were post milking teat dipping using antiseptic solutions containing 1%, 3%, and 5% of babadotan leaves extract (T1, T2 and T3, respectively. Milk samples were collected at before treatment (H0 and on the day 3, 6 and 9 day of the treatments (H3, H6 and H9, respectively. Commercially antiseptic povidone iodine was used as positive control (K+. Experimental research design was completely randomized design (CRD split plot types, with the different extract concentration as the main plot and the day of treatment as subplot. CMT scores was analyzed using Kruskal-Wallis test. The results showed that babadotan leaves extract 5% had the same effectiveness (p>0,05 with povidone iodine to reduce the number of Staphylococcus aureusin milk. All extract concentrations (1%, 3% and 5% had the same effectiveness (H>c0,05(3 to decrease the CMT scores by postmilking teat dip treatments for 9 days. Keywords:Teat dipping, Ageratum conyzoides (L., Staphylococcus aureus, CMT score

Crack repair welding by CMT brazing using low melting point filler wire for long-term used steam turbine cases of Cr-Mo-V cast steels

Energy Technology Data Exchange (ETDEWEB)

Kadoi, Kota, E-mail: kadoi@hiroshima-u.ac.jp [Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Murakami, Aoi; Shinozaki, Kenji; Yamamoto, Motomichi [Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Matsumura, Hideo [Chugoku Electric Power Co., 3-9-1 Kagamiyama, Higashi-Hiroshima 739-0046 (Japan)

2016-06-01

Surface melting by gas tungsten arc (GTA) welding and overlaying by cold metal transfer (CMT) brazing using low melting point filler wire were investigated to develop a repair process for cracks in worn cast steel of steam turbine cases. Cr-Mo-V cast steel, operated for 188,500 h at 566 °C, was used as the base material. Silver and gold brazing filler wires were used as overlaying materials to decrease the heat input into the base metal and the peak temperature during the welding thermal cycle. Microstructural analysis revealed that the worn cast steel test samples contained ferrite phases with intragranular precipitates of Cr{sub 7}C{sub 3}, Mo{sub 2}C, and CrSi{sub 2} and grain boundary precipitates of Cr{sub 23}C{sub 6} and Mo{sub 2}C. CMT brazing using low melting point filler wire was found to decrease the heat input and peak temperature during the thermal cycle of the process compared with those during GTA surface melting. Thus, the process helped to inhibit the formation of hardened phases such as intermetallics and martensite in the heat affected zone (HAZ). Additionally, in the case of CMT brazing using BAg-8, the change in the hardness of the HAZ was negligible even though other processes such as GTA surface melting cause significant changes. The creep-fatigue properties of weldments produced by CMT brazing with BAg-8 were the highest, and nearly the same as those of the base metal owing to the prevention of hardened phase formation. The number of fracture cycles using GTA surface melting and CMT brazing with BAu-4 was also quite small. Therefore, CMT brazing using low melting point filler wire such as BAg-8 is a promising candidate method for repairing steam turbine cases. However, it is necessary to take alloy segregation during turbine operation into account to design a suitable filler wire for practical use.

Microtomography and pore-scale modeling of two-phase Fluid Distribution

Energy Technology Data Exchange (ETDEWEB)

Silin, D.; Tomutsa, L.; Benson, S.; Patzek, T.

2010-10-19

Synchrotron-based X-ray microtomography (micro CT) at the Advanced Light Source (ALS) line 8.3.2 at the Lawrence Berkeley National Laboratory produces three-dimensional micron-scale-resolution digital images of the pore space of the reservoir rock along with the spacial distribution of the fluids. Pore-scale visualization of carbon dioxide flooding experiments performed at a reservoir pressure demonstrates that the injected gas fills some pores and pore clusters, and entirely bypasses the others. Using 3D digital images of the pore space as input data, the method of maximal inscribed spheres (MIS) predicts two-phase fluid distribution in capillary equilibrium. Verification against the tomography images shows a good agreement between the computed fluid distribution in the pores and the experimental data. The model-predicted capillary pressure curves and tomography-based porosimetry distributions compared favorably with the mercury injection data. Thus, micro CT in combination with modeling based on the MIS is a viable approach to study the pore-scale mechanisms of CO{sub 2} injection into an aquifer, as well as more general multi-phase flows.

A quasi-realtime x-ray microtomography system at the Advanced Photon Source

International Nuclear Information System (INIS)

DeCarlo, F.; Foster, I.; Insley, J.; Kesselman, C.; Lane, P.; Mancini, D.; McNulty, I.; Su, M.; Tieman, B.; Wang, Y.; Laszewski, G. von

1999-01-01

The combination of high-brilliance x-ray sources, fast detector systems, wide-bandwidth networks, and parallel computers can substantially reduce the time required to acquire, reconstruct, and visualize high-resolution three-dimensional tomographic datasets. A quasi-realtime computed x-ray microtomography system has been implemented at the 2-BM beamline at the Advanced Photon Source at Argonne National Laboratory. With this system, a complete tomographic data set can be collected in about 15 minutes. Immediately after each projection is obtained, it is rapidly transferred to the Mathematics and Computing Sciences Division where preprocessing and reconstruction calculations are performed concurrently with the data acquisition by a SGI parallel computer. The reconstruction results, once completed, are transferred to a visualization computer that performs the volume rendering calculations. Rendered images of the reconstructed data are available for viewing back at the beamline experiment station minutes after the data acquisition was complete. The fully pipelined data acquisition and reconstruction system also gives us the option to acquire the tomographic data set in several cycles, initially with coarse then with fine angular steps. At present the projections are acquired with a straight-ray projection imaging scheme using 5-20 keV hard x rays in either phase or amplitude contrast mode at a 1-10 pm resolution. In the future, we expect to increase the resolution of the projections to below 100 nm by using a focused x-ray beam at the 2-ID-B beamline and to reduce the combined acquisition and computation time to the 1 min scale with improvements in the detectors, network links, software pipeline, and computation algorithms

Characterization of ceramic archaeological by high resolution X ray microtomography

International Nuclear Information System (INIS)

Machado, Alessandra C.; Freitas, Renato; Calza, Cristiane F.; Lopes, Ricardo T.; Lima, Inaya; Carvalho, Daniele D.; Gaspar, Maria D.

2013-01-01

Characterization of ceramic fragments is a very important area of research in art and archeometry area because it enables a greater understanding of how ancient civilizations behave and what were their traditions and customs. Petrography and chemical analyses are commonly used, but these techniques are destructive, which is not interesting for this type of sample. Through the exchange of multidisciplinary scientific knowledge and new partnerships, high resolution X-ray microtomography has been introduced in archaeological area as a great possibility of 3D inspection in a non-destructive way. The goal of this work is to investigate the internal microstructures of four samples of archeological ceramic, from the Archaeological Site of Macacu - RJ. The X-ray microtomography were performed in a high resolution setup, and can be used to infer the nature of organic temper even with all plant remains completely burnt out during the firing process and also to ensure the homogeneity of samples envisaged for geochemical analyses, especially with respect to the distribution of chemically diverse fabric compounds. In this way this study intends to contribute to our understanding of the archaeological and historical formations of this region. (author)

Characterization of ceramic archaeological by high resolution X ray microtomography

Energy Technology Data Exchange (ETDEWEB)

Machado, Alessandra C.; Freitas, Renato; Calza, Cristiane F.; Lopes, Ricardo T.; Lima, Inaya, E-mail: alecastro@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Carvalho, Daniele D.; Gaspar, Maria D. [Museu Nacional (MN/UFRJ), RJ (Brazil). Centro de Tecnologia

2013-07-01

Characterization of ceramic fragments is a very important area of research in art and archeometry area because it enables a greater understanding of how ancient civilizations behave and what were their traditions and customs. Petrography and chemical analyses are commonly used, but these techniques are destructive, which is not interesting for this type of sample. Through the exchange of multidisciplinary scientific knowledge and new partnerships, high resolution X-ray microtomography has been introduced in archaeological area as a great possibility of 3D inspection in a non-destructive way. The goal of this work is to investigate the internal microstructures of four samples of archeological ceramic, from the Archaeological Site of Macacu - RJ. The X-ray microtomography were performed in a high resolution setup, and can be used to infer the nature of organic temper even with all plant remains completely burnt out during the firing process and also to ensure the homogeneity of samples envisaged for geochemical analyses, especially with respect to the distribution of chemically diverse fabric compounds. In this way this study intends to contribute to our understanding of the archaeological and historical formations of this region. (author)

Inspection of SiC{sub f}/SiC ceramic matrix composite specimens employed for fatigue experiments via laboratory X-ray computed microtomography

Energy Technology Data Exchange (ETDEWEB)

Quiney, Z.; Bache, M.R.; Jones, J.P. [Swansea Univ. (United Kingdom). Inst. of Structural Materials

2015-07-01

Hi-Nicalon SiC{sub f}/SiC ceramic matrix composite (CMC) specimens have been inspected using laboratory based X-ray computed micro-tomography (μCT) both prior and subsequent to isothermal fatigue assessment. The fatigue specimens were in the form of a dog bone-shaped geometry with a minimum cross-sectional area of 40 mm{sup 2}. Pre-test μCT inspections were conducted to identify the subsurface composite architecture and locate associated features introduced during the manufacturing process (e.g. isolated or conjoined porosity, matrix or interface discontinuities etc.). These μCT scans were subsequently correlated with matching post-test volumes in an attempt to determine the influence of such features upon damage accumulation and the ultimate failure position and cyclic damage mode(s). The relationship between μCT scan resolution and identification of critical features is also discussed. In typical cone-beam X-ray systems, resolution is proportional to the source-to-specimen distance, but for efficiency may also be chosen so as to minimise the number of scans needed to capture the whole area of interest. The investigations are intended to provide input into the future development of an in situ mechanical testing μCT facility using lab-based X-ray systems.

X-ray computed microtomography integrated to petrography for the three-dimensional study of rock porosity; A microtomografia computadorizada de raios x integrada a petrografia no estudo tridimensional de porosidade em rochas

Energy Technology Data Exchange (ETDEWEB)

Reis Neto, Joss Manoel dos; Fiori, Alberto Pio; Lopes, Angela Pacheco; Pinto-Coelho, Cristina Valle; Vasconcellos, Eleonora Maria Gouvea; Silva, Gabriel Fischer da [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Geologia; Marchese, Clarice; Secchi, Rodrigo, E-mail: jmreis@ufpr.br, E-mail: fiori@ufpr.br, E-mail: angelalopes@ufpr.br, E-mail: cristinavpc@ufpr.br, E-mail: eleonora@ufpr.br, E-mail: fischergab@hotmail.com, E-mail: clamarchese@hotmail.com, E-mail: rosecchi@yahoo.com.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Geologia. Lab. de Analise de Minerais e Rochas

2011-09-15

The porosity contained in rocks is object of study by geoscientists due to the various genetic implications of these features. However, what have been motivating the search for new analytical techniques to study pores are the petrophysical analyses. The experimental techniques for porosity analysis, such as mercury or gas injection, allow a quantitative approach, but do not allow the visualization of the porous framework. Petrographic analysis by optical microscopy allows the visualization and quantification of intergranular pores, but it is restricted to the two-dimensional space and quantifications are less representative. Technological advances in X-ray computed microtomography (micro-CT) allowed three-dimensional analysis of pore geometry in microscale, in addition to automated volume measurements. The analyses of marble, quartzite, sandstone and dolomite breccia represented in this work and performed under the Project Falhas/ PETROBRAS/UFPR, show the shape, size, connectivity, tortuosity, pore volume and distribution in these rocks, demonstrating the differences in the rocks' porous frameworks. The integration of micro-CT to petrography allows the identification of mineral phases with attenuation of contrasting X-rays, placing the incidence of porosity in the mineralogical context in three dimensions, in addition to the contribution to the consistency of the method. Although the resolution is limited in the X-ray microtomography that was used (the Skyscan model 1172), which does not reach the smallest pore size of some rocks, the integration of both techniques provides new information, of extreme importance for the research about micro-features related to the pores in rocks, helping in genetic interpretations and significantly contributing for the analyses of reservoirs. (author)

Application of Image And X-Ray Microtomography Technique To Quantify Filler Distribution In Thermoplastic-Natural Rubber Blend Composites

International Nuclear Information System (INIS)

Ahmad, Sahrim; Rasid, Rozaidi; Mouad, A. T.; Aziz Mohamed, A.; Abdullah, Jaafar; Dahlan, M.; Mohamad, Mahathir; Jamro, Rafhayudi; Hamzah Harun, M.; Yazid, Hafizal; Abdullah, W. Saffiey W.

2010-01-01

X-ray microtomography and ImageJ 1.39 u is used as a tool to quantify volume percentage of B 4 C as fillers in thermoplastic-natural rubber blend composites. The use of percentage of area occupied by fillers as obtain from ImageJ from the microtomography sliced images enables the proposed technique to easily obtain the amount volume percentage of B 4 C in the composite non-destructively. Comparison with other technique such as density measurement and chemical analysis proves the proposed technique as one of the promising approach.

Quantitative X-ray microtomography with synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Donath, T. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Materialforschung

2007-07-01

Synchrotron-radiation-based computed microtomography (SR{sub {mu}}CT) is an established method for the examination of volume structures. It allows to measure the x-ray attenuation coefficient of a specimen three-dimensionally with a spatial resolution of about one micrometer. In contrast to conventional x-ray sources (x-ray tubes), the unique properties of synchrotron radiation enable quantitative measurements that do not suffer from beam-hardening artifacts. During this work the capabilities for quantitative SR{sub {mu}}CT measurements have been further improved by enhancements that were made to the SR{sub {mu}}CT apparatus and to the reconstruction chain. For high-resolution SR{sub {mu}}CT an x-ray camera consisting of luminescent screen (x-ray phosphor), lens system, and CCD camera was used. A significant suppression of blur that is caused by reflections inside the luminescent screen could be achieved by application of an absorbing optical coating to the screen surface. It is shown that blur and ring artifacts in the tomographic reconstructions are thereby drastically reduced. Furthermore, a robust and objective method for the determination of the center of rotation in projection data (sinograms) is presented that achieves sub-pixel precision. By implementation of this method into the reconstruction chain, complete automation of the reconstruction process has been achieved. Examples of quantitative SR{sub {mu}}CT studies conducted at the Hamburger Synchrotronstrahlungslabor HASYLAB at the Deutsches Elektronen-Synchrotron DESY are presented and used for the demonstration of the achieved enhancements. (orig.)

Quantitative X-ray microtomography with synchrotron radiation

International Nuclear Information System (INIS)

Donath, T.

2007-01-01

Synchrotron-radiation-based computed microtomography (SR μ CT) is an established method for the examination of volume structures. It allows to measure the x-ray attenuation coefficient of a specimen three-dimensionally with a spatial resolution of about one micrometer. In contrast to conventional x-ray sources (x-ray tubes), the unique properties of synchrotron radiation enable quantitative measurements that do not suffer from beam-hardening artifacts. During this work the capabilities for quantitative SR μ CT measurements have been further improved by enhancements that were made to the SR μ CT apparatus and to the reconstruction chain. For high-resolution SR μ CT an x-ray camera consisting of luminescent screen (x-ray phosphor), lens system, and CCD camera was used. A significant suppression of blur that is caused by reflections inside the luminescent screen could be achieved by application of an absorbing optical coating to the screen surface. It is shown that blur and ring artifacts in the tomographic reconstructions are thereby drastically reduced. Furthermore, a robust and objective method for the determination of the center of rotation in projection data (sinograms) is presented that achieves sub-pixel precision. By implementation of this method into the reconstruction chain, complete automation of the reconstruction process has been achieved. Examples of quantitative SR μ CT studies conducted at the Hamburger Synchrotronstrahlungslabor HASYLAB at the Deutsches Elektronen-Synchrotron DESY are presented and used for the demonstration of the achieved enhancements. (orig.)

Natural and laboratory compaction bands in porous carbonates: a three-dimensional characterization using synchrotron X-ray computed microtomography

Science.gov (United States)

Cilona, A.; Arzilli, F.; Mancini, L.; Emanuele, T.

2014-12-01

Porous carbonates form important reservoirs for water and hydrocarbons. The fluid flow properties of carbonate reservoirs may be affected by post-depositional processes (e.g., mechanical and chemical), which need to be quantified. Field-based studies described bed-parallel compaction bands (CBs) within carbonates with a wide range of porosities. These burial-related structures accommodate volumetric strain by grain rotation, translation, pore collapse and pressure solution. Recently, the same structures have been reproduced for the first time in the laboratory by performing triaxial compaction experiments on porous grainstones. These laboratory studies characterized and compared the microstructures of natural and laboratory CBs, but no analysis of pore connectivity has been performed. In this paper, we use an innovative approach to characterize the pore networks (e.g. porosity, connectivity) of natural and laboratory CBs and compare them with the host rock one. We collected the data using the synchrotron X-ray computed microtomography technique at the SYRMEP beamline of the Elettra-Sincrotrone Trieste Laboratory (Italy). Quantitative analyses of the samples were performed with the Pore3D software library. The porosity was calculated from segmented 3D images of pristine and deformed carbonates. A process of skeletonization was then applied to quantify the number of connected pores within the rock volume. The analysis of the skeleton allowed us to highlight the differences between natural and laboratory CBs, and to investigate how pore connectivity evolves as a function of different deformation pathways. Both pore volume and connectivity are reduced within the CBs respect to the pristine rock and the natural CB has a lower porosity with respect to the laboratory one. The grain contacts in the natural CB are welded, whereas in the laboratory one they have more irregular shapes and grain crushing is the predominant process.

X-ray microtomography application in pore space reservoir rock.

Science.gov (United States)

Oliveira, M F S; Lima, I; Borghi, L; Lopes, R T

2012-07-01

Characterization of porosity in carbonate rocks is important in the oil and gas industry since a major hydrocarbons field is formed by this lithology and they have a complex media porous. In this context, this research presents a study of the pore space in limestones rocks by x-ray microtomography. Total porosity, type of porosity and pore size distribution were evaluated from 3D high resolution images. Results show that carbonate rocks has a complex pore space system with different pores types at the same facies. Copyright © 2011 Elsevier Ltd. All rights reserved.

Strain analysis of trabecular bone using time-resolved X-ray microtomography

Czech Academy of Sciences Publication Activity Database

Jiroušek, Ondřej; Zlámal, Petr; Kytýř, Daniel; Kroupa, M.

2011-01-01

Roč. 633, Suppl. 1 (2011), s. 148-151 ISSN 0168-9002. [International Workshop on Radiation Imaging Detectors /11./. Praha, 28.06.2009-02.07.2009] R&D Projects: GA ČR(CZ) GP103/07/P483 Institutional research plan: CEZ:AV0Z20710524 Keywords : trabecular bone * X-ray microtomography * strain analysis * intrinsic material properties Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.207, year: 2011

Electrochemical and CMT measurements of the anomalous dissolution of nickel in solutions containing oxygen

DEFF Research Database (Denmark)

Bech-Nielsen, Gregers; de Fontenay, Frank; Poulsen, Henning

1997-01-01

In addition to single nickel crystals also nickel samples produced by dc and pr (pulse-reversal) plating were examined. As previously reported the true rate of dissolution of nickel in solutions containing oxygen was found to be as much as three times the electrochemical rate at the corrosion...... potential. When passivation was approached (spontaneously or by anodic polarization) the true rate of dissolution approached the rate of anodic reaction. During cathodic polarization there was still a significant rate of dissolution. The true rate of dissolution was determined by CMT measurements (Corrosion...

X-ray computed microtomography characterizes the wound effect that causes sap flow underestimation by thermal dissipation sensors.

Science.gov (United States)

Marañón-Jiménez, S; Van den Bulcke, J; Piayda, A; Van Acker, J; Cuntz, M; Rebmann, C; Steppe, K

2018-02-01

Insertion of thermal dissipation (TD) sap flow sensors in living tree stems causes damage of the wood tissue, as is the case with other invasive methods. The subsequent wound formation is one of the main causes of underestimation of tree water-use measured by TD sensors. However, the specific alterations in wood anatomy in response to inserted sensors have not yet been characterized, and the linked dysfunctions in xylem conductance and sensor accuracy are still unknown. In this study, we investigate the anatomical mechanisms prompting sap flow underestimation and the dynamic process of wound formation. Successive sets of TD sensors were installed in the early, mid and end stage of the growing season in diffuse- and ring-porous trees, Fagus sylvatica (Linnaeus) and Quercus petraea ((Mattuschka) Lieblein), respectively. The trees were cut in autumn and additional sensors were installed in the cut stem segments as controls without wound formation. The wounded area and volume surrounding each sensor was then visually determined by X-ray computed microtomography (X-ray microCT). This technique allowed the characterization of vessel anatomical transformations such as tyloses formation, their spatial distribution and quantification of reduction in conductive area. MicroCT scans showed considerable formation of tyloses that reduced the conductive area of vessels surrounding the inserted TD probes, thus causing an underestimation in sap flux density (SFD) in both beech and oak. Discolored wood tissue was ellipsoidal, larger in the radial plane, more extensive in beech than in oak, and also for sensors installed for longer times. However, the severity of anatomical transformations did not always follow this pattern. Increased wound size with time, for example, did not result in larger SFD underestimation. This information helps us to better understand the mechanisms involved in wound effects with TD sensors and allows the provision of practical recommendations to reduce

Spectroscopic micro-tomography of metallic-organic composites by means of photon-counting detectors

Czech Academy of Sciences Publication Activity Database

Pichotka, Martin; Jakůbek, Jan; Vavřík, Daniel

2015-01-01

Roč. 10, č. 12 (2015), C12033 ISSN 1748-0221 R&D Projects: GA MŠk(CZ) LO1219 Keywords : micro-tomography * photon-counting detectors * metallic-organic composites Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.310, year: 2015 http://iopscience.iop.org/article/10.1088/1748-0221/10/12/C12033/pdf

Three-dimensional reconstruction of statistically optimal unit cells of polydisperse particulate composites from microtomography

International Nuclear Information System (INIS)

Lee, H.; Brandyberry, M.; Tudor, A.; Matous, K.

2009-01-01

In this paper, we present a systematic approach for characterization and reconstruction of statistically optimal representative unit cells of polydisperse particulate composites. Microtomography is used to gather rich three-dimensional data of a packed glass bead system. First-, second-, and third-order probability functions are used to characterize the morphology of the material, and the parallel augmented simulated annealing algorithm is employed for reconstruction of the statistically equivalent medium. Both the fully resolved probability spectrum and the geometrically exact particle shapes are considered in this study, rendering the optimization problem multidimensional with a highly complex objective function. A ten-phase particulate composite composed of packed glass beads in a cylindrical specimen is investigated, and a unit cell is reconstructed on massively parallel computers. Further, rigorous error analysis of the statistical descriptors (probability functions) is presented and a detailed comparison between statistics of the voxel-derived pack and the representative cell is made.

Quantitative comparison of X-ray fluorescence microtomography setups: Standard and confocal collimator apparatus

Energy Technology Data Exchange (ETDEWEB)

Chukalina, M. [Institute of Microelectronics Technology RAS, 142432, Chernogolovka, Moscow District (Russian Federation)], E-mail: marina@ipmt-hpm.ac.ru; Simionovici, A. [Laboratoire de Geophysique Interne et Tectonophysique, University of Grenoble, BP 53, 38041, Grenoble (France)], E-mail: alexandre.simionovici@ujf-grenoble.fr; Zaitsev, S. [Institute of Microelectronics Technology RAS, 142432, Chernogolovka, Moscow District (Russian Federation)], E-mail: zaitsev@ipmt-hpm.ac.ru; Vanegas, C.J. [Institute of Microelectronics Technology RAS, 142432, Chernogolovka, Moscow District (Russian Federation)], E-mail: vanegas@ipmt-hpm.ac.ru

2007-07-15

Recently, there has been a renewed interest for fluorescence spectroscopy, as provided by modern setups which allow 2D and 3D imaging of elemental distributions. Two directions are currently under development: the SR-based fluorescence tomography in polar scanning geometry, provided by the new generation of X-ray microprobes and the confocal scanning geometry, which can be fielded in both SR and laboratory environments. The new probes bring forth a new age in fluorescence spectrometry: high resolution, high intensity and high sensitivity which allow 3D elemental mapping of volumes. The major task now is the development of these complex tools into fully quantitative probes, reproducible and straightforward for general use. In this work we analyze two X-ray fluorescence microtomography techniques: an apparatus tomography using a confocal collimator for the data collection and a standard first generation Computed Tomography (CT) in the parallel scanning scheme. We calculate the deposited dose (amount of energy deposited and distributed in the sample during the data collection time) and find the conditions for the choice of the tomography scheme.

Mutations in noncoding regions of GJB1 are a major cause of X-linked CMT

Science.gov (United States)

Tomaselli, Pedro J.; Rossor, Alexander M.; Horga, Alejandro; Jaunmuktane, Zane; Carr, Aisling; Saveri, Paola; Piscosquito, Giuseppe; Pareyson, Davide; Laura, Matilde; Blake, Julian C.; Poh, Roy; Polke, James; Houlden, Henry

2017-01-01

Objective: To determine the prevalence and clinical and genetic characteristics of patients with X-linked Charcot-Marie-Tooth disease (CMT) due to mutations in noncoding regions of the gap junction β-1 gene (GJB1). Methods: Mutations were identified by bidirectional Sanger sequence analysis of the 595 bases of the upstream promoter region, and 25 bases of the 3′ untranslated region (UTR) sequence in patients in whom mutations in the coding region had been excluded. Clinical and neurophysiologic data were retrospectively collected. Results: Five mutations were detected in 25 individuals from 10 kindreds representing 11.4% of all cases of CMTX1 diagnosed in our neurogenetics laboratory between 1996 and 2016. Four pathogenic mutations, c.-17G>A, c.-17+1G>T, c.-103C>T, and c.-146-90_146-89insT were detected in the 5′UTR. A novel mutation, c.*15C>T, was detected in the 3′ UTR of GJB1 in 2 unrelated families with CMTX1 and is the first pathogenic mutation in the 3′UTR of any myelin-associated CMT gene. Mutations segregated with the phenotype, were at sites predicted to be pathogenic, and were not present in the normal population. Conclusions: Mutations in noncoding DNA are a major cause of CMTX1 and highlight the importance of mutations in noncoding DNA in human disease. Next-generation sequencing platforms for use in inherited neuropathy should therefore include coverage of these regions. PMID:28283593

Introduction to computational mass transfer with applications to chemical engineering

CERN Document Server

Yu, Kuo-Tsong

2014-01-01

This book presents a new computational methodology called Computational Mass Transfer (CMT). It offers an approach to rigorously simulating the mass, heat and momentum transfer under turbulent flow conditions with the help of two newly published models, namely the C’2—εC’ model and the Reynolds  mass flux model, especially with regard to predictions of concentration, temperature and velocity distributions in chemical and related processes. The book will also allow readers to understand the interfacial phenomena accompanying the mass transfer process and methods for modeling the interfacial effect, such as the influences of Marangoni convection and Rayleigh convection. The CMT methodology is demonstrated by means of its applications to typical separation and chemical reaction processes and equipment, including distillation, absorption, adsorption and chemical reactors. Professor Kuo-Tsong Yu is a Member of the Chinese Academy of Sciences. Dr. Xigang Yuan is a Professor at the School of Chemical Engine...

Estudios de nieblas realizados en el C.M.T. de Madrid y Castilla La Mancha

OpenAIRE

Cano Espadas, Darío; Palacio García, José Ignacio; Téllez Jurado, Beatriz; Martínez Albadalejo, Alejandro

2001-01-01

Ponencia presentada en: V Simposio Nacional de Predicción, celebrado en 2001 en Madrid. Se pretende poner a debate el estado de los estudios sobre nieblas en el C.M.T., especialmente sobre las nieblas en Barajas. Básicamente se han desarrollado dos líneas de trabajo. Por un lado, se ha estudiado el comportamiento de índices de predicción especialmente el índice FOGSI . Este trabajo se aborda desde dos puntos de vista: el índice calculado por el sondeo en el punto de Barajas y el índice ...

Principles and concept 1993 of the systemic cancer multistep therapy (sCMT). Extreme whole-body hyperthermia using the infrared-A technique IRATHERM 2000 - selective thermosensitisation by hyperglycemia - circulatory back-up by adapted hyperoxemia

Energy Technology Data Exchange (ETDEWEB)

Ardenne, M. von [Von Ardenne Inst. of Applied Medical Research, Dresden (Germany)

1994-10-01

The so-called Cancer Multistep Therapy was conceived by the author in 1965. It is a combined modality treatment with 3 process steps: Whole-body hyperthermia, hyperglycemia and hyperoxemia. The original therapy concept was further developed into a systemic Cancer Multistep Therapy (sCMT) of high efficiency and selectivity. An outline follows of this therapy and the actual state of the sCMT concept as per 1993 (new in timing, dosage, technique). Knowledge of the synergetic-additive efficiency of various groups of cytostatics reacting to the effects of the main treatment process steps (WBH+HG+HO) led in 1974 to an extension of the sCMT concept by including chemotherapy. In addition, a radiotherapeutical treatment was included in this concept as cancer cells clearly show a higher sensibility to radiation while under the influence of sCMT. Following the sCMT treatment, the patient remains under observation on an intensive in-patient basis for 24 hours before he or she is discharged for out-patient post-treatment care. The systemic tolerance of sCMT with minimal side-effects has been proven with several 100 patients and results have been published as part of the phase-I study. A first evaluation of the efficacy of sCMT was documented in the same study. (orig.) [Deutsch] 1965 wurde vom Autor die sogenannte Krebs-Mehrschritt-Therapie konzipiert. Es handelt sich hierbei um eine kombinierte Behandlung, bestehend aus Ganzkoerperhyperthermie, Hyperglykaemie und Hyperoxaemie. Die Weiterentwicklung der aelteren Therapiekonzepte bis hin zu einer systemischen Krebs-Mehrschritt-Therapie (sKMT) hoher Effizienz und Selektivitaet wird skizziert und der heutige Stand des sKMT-Konzeptes 1993 dargestellt. Es wurde ein strahlentherapeutischer Schritt in das Konzept aufgenommen, da unter der Wirkung der Hauptschritte eine deutlich erhoehte Strahlensensibilitaet der Krebszellen gegeben ist. Somit besteht das sKMT-Konzept 1993 aus den Hauptschritten Hyperthermie, Hyperglykaemie

The use of microtomography in structural geology: A new methodology to analyse fault faces

Science.gov (United States)

Jacques, Patricia D.; Nummer, Alexis Rosa; Heck, Richard J.; Machado, Rômulo

2014-09-01

This paper describes a new methodology to kinematically analyze faults in microscale dimensions (voxel size = 40 μm), using images obtained by X-ray computed microtomography (μCT). The equipment used is a GE MS8x-130 scanner. It was developed using rocks samples from Santa Catarina State, Brazil, and constructing micro Digital Elevation Models (μDEMs) for the fault surface, for analysing microscale brittle structures including striations, roughness and steps. Shaded relief images were created for the μDEMs, which enabled the generation of profiles to classify the secondary structures associated with the main fault surface. In the case of a sample with mineral growth that covers the fault surface, it is possible to detect the kinematic geometry even with the mineral cover. This technique proved to be useful for determining the sense of movement of faults, especially when it is not possible to determine striations in macro or microscopic analysis. When the sample has mineral deposit on the surface (mineral cover) this technique allows a relative chronology and geometric characterization between the faults with and without covering.

X-ray microtomography scanner using time-delay integration for elimination of ring artefacts in the reconstructed image

International Nuclear Information System (INIS)

Davis, G.R.; London Univ.; Elliott, J.C.; London Univ.

1997-01-01

Most X-ray microtomography scanners work on the same principle as third-generation medical CT scanners, that is, the same point in each projection is measured by the same detector element. This leads to ring artefacts in the reconstructed image if the X-ray sensitivities of the individual detector elements, after any analytical correction, are not all identical. We have developed an X-ray microtomography scanner which uses the time-delay integration method of imaging with a CCD detector to average the characteristics of all the detector elements in each linear projection together. This has the added advantage of allowing specimens which are larger than the detector and X-ray field to be scanned. The device also uses a novel mechanical stage to ''average out'' inhomogeneities in the X-ray field. The results show that ring artefacts in microtomographic images are eliminated using this technique. (orig.)

Erosive Wear of Inconel 625 Alloy Coatings Deposited by CMT Method

Directory of Open Access Journals (Sweden)

Solecka M.

2016-06-01

Full Text Available The article presents the investigation results concerning the determination of the characteristics of erosive wear caused by the impact of Al2O3 solid particles on the surface of Inconel 625 alloy after plastic working and the same material after weld cladding process using the CMT method. Erosion wear tests were performed at two temperatures: 20°C and 650°C. The erosion tests were conducted using the standard ASTM G76. A jet with a specified abrasive waight was directed to the surface of the tested material at an α impingement angle varied in the range of 30-90° at a velocity imparted to the abrasive by the medium, which was compressed air. The eroded surface was examined using a scanning electron microscope (SEM, while the depths of craters caused by the erosion tests were measured with an optical profilometer. The predominant mechanisms of the formation of mass losses during solid particle erosion were microcutting and microfissuring.

X-ray Synchrotron Microtomography of a silicified Jurassic Cheirolepidiaceae (Conifer cone: histology and morphology of Pararaucaria collinsonae sp. nov.

Directory of Open Access Journals (Sweden)

David C. Steart

2014-10-01

Full Text Available We document a new species of ovulate cone (Pararaucaria collinsonae on the basis of silicified fossils from the Late Jurassic Purbeck Limestone Group of southern England (Tithonian Stage: ca. 145 million years. Our description principally relies on the anatomy of the ovuliferous scales, revealed through X-ray synchrotron microtomography (SRXMT performed at the Diamond Light Source (UK. This study represents the first application of SRXMT to macro-scale silicified plant fossils, and demonstrates the significant advantages of this approach, which can resolve cellular structure over lab-based X-ray computed microtomography (XMT. The method enabled us to characterize tissues and precisely demarcate their boundaries, elucidating organ shape, and thus allowing an accurate assessment of affinities. The cones are broadly spherical (ca. 1.3 cm diameter, and are structured around a central axis with helically arranged bract/scale complexes, each of which bares a single ovule. A three-lobed ovuliferous scale and ovules enclosed within pocket-forming tissue, demonstrate an affinity with Cheirolepidiaceae. Details of vascular sclerenchyma bundles, integument structure, and the number and attachment of the ovules indicate greatest similarity to P. patagonica and P. carrii. This fossil develops our understanding of the dominant tree element of the Purbeck Fossil Forest, providing the first evidence for ovulate cheirolepidiaceous cones in Europe. Alongside recent discoveries in North America, this significantly extends the known palaeogeographic range of Pararaucaria, supporting a mid-palaeolatitudinal distribution in both Gondwana and Laurasia during the Late Jurassic. Palaeoclimatic interpretations derived from contemporaneous floras, climate sensitive sediments, and general circulation climate models indicate that Pararaucaria was a constituent of low diversity floras in semi-arid Mediterranean-type environments.

X-ray Synchrotron Microtomography of a silicified Jurassic Cheirolepidiaceae (Conifer) cone: histology and morphology of Pararaucaria collinsonae sp. nov.

Science.gov (United States)

Steart, David C; Spencer, Alan R T; Garwood, Russell J; Hilton, Jason; Munt, Martin C; Needham, John; Kenrick, Paul

2014-01-01

We document a new species of ovulate cone (Pararaucaria collinsonae) on the basis of silicified fossils from the Late Jurassic Purbeck Limestone Group of southern England (Tithonian Stage: ca. 145 million years). Our description principally relies on the anatomy of the ovuliferous scales, revealed through X-ray synchrotron microtomography (SRXMT) performed at the Diamond Light Source (UK). This study represents the first application of SRXMT to macro-scale silicified plant fossils, and demonstrates the significant advantages of this approach, which can resolve cellular structure over lab-based X-ray computed microtomography (XMT). The method enabled us to characterize tissues and precisely demarcate their boundaries, elucidating organ shape, and thus allowing an accurate assessment of affinities. The cones are broadly spherical (ca. 1.3 cm diameter), and are structured around a central axis with helically arranged bract/scale complexes, each of which bares a single ovule. A three-lobed ovuliferous scale and ovules enclosed within pocket-forming tissue, demonstrate an affinity with Cheirolepidiaceae. Details of vascular sclerenchyma bundles, integument structure, and the number and attachment of the ovules indicate greatest similarity to P. patagonica and P. carrii. This fossil develops our understanding of the dominant tree element of the Purbeck Fossil Forest, providing the first evidence for ovulate cheirolepidiaceous cones in Europe. Alongside recent discoveries in North America, this significantly extends the known palaeogeographic range of Pararaucaria, supporting a mid-palaeolatitudinal distribution in both Gondwana and Laurasia during the Late Jurassic. Palaeoclimatic interpretations derived from contemporaneous floras, climate sensitive sediments, and general circulation climate models indicate that Pararaucaria was a constituent of low diversity floras in semi-arid Mediterranean-type environments.

Memory and metamemory performance in Alzheimer's disease and healthy elderly: the Contextual Memory Test (CMT).

Science.gov (United States)

Gil, N; Josman, N

2001-08-01

The purpose of the present study was to examine the ability of the Contextual Memory Test (CMT) to differentiate between elderly people suffering from Alzheimer's disease (AD) in comparison to healthy elderly people. Specifically, the objectives were to compare for differences between and within the groups on components of memory, including immediate and delayed recall as well as recognition. In addition, parameters of metamemory skills, such as general awareness, self-prediction of memory capacity, self-estimation, strategy use and use of contextual information, as well as the correlation between self-awareness and actual performance in both groups, were investigated. The sample consisted of 60 elderly participants, including 30 people diagnosed with AD who were assigned to the research group and 30 people matched for age, gender and educational level who were assigned to the control group. The results provide support for the hypothesis positing differences in memory performance between healthy elderly participants and those suffering from AD, particularly in immediate and delayed recall as well as in recognition. Moreover, findings indicate an improvement in memory performance under the cued condition (contextual), whereas improvement in the AD group proved to be significant only for immediate recall. The findings point to a distinct overestimation of memory ability predicted by both the AD and control groups. Following the memory task, however, the participants accurately estimated the number of items they remembered. In addition, significant correlations between the use of contextual and association strategies and the number of items remembered by both groups were obtained, in immediate as well as in delayed recall. Therefore, these findings support the CMT as a valuable memory and metamemory assessment tool for use with the AD population.

Noninvasive Measurement of Vulnerability to Drought-Induced Embolism by X-Ray Microtomography.

Science.gov (United States)

Choat, Brendan; Badel, Eric; Burlett, Regis; Delzon, Sylvain; Cochard, Herve; Jansen, Steven

2016-01-01

Hydraulic failure induced by xylem embolism is one of the primary mechanisms of plant dieback during drought. However, many of the methods used to evaluate the vulnerability of different species to drought-induced embolism are indirect and invasive, increasing the possibility that measurement artifacts may occur. Here, we utilize x-ray computed microtomography (microCT) to directly visualize embolism formation in the xylem of living, intact plants with contrasting wood anatomy (Quercus robur, Populus tremula × Populus alba, and Pinus pinaster). These observations were compared with widely used centrifuge techniques that require destructive sampling. MicroCT imaging provided detailed spatial information regarding the dimensions and functional status of xylem conduits during dehydration. Vulnerability curves based on microCT observations of intact plants closely matched curves based on the centrifuge technique for species with short vessels (P. tremula × P. alba) or tracheids (P. pinaster). For ring porous Q. robur, the centrifuge technique significantly overestimated vulnerability to embolism, indicating that caution should be used when applying this technique to species with long vessels. These findings confirm that microCT can be used to assess the vulnerability to embolism on intact plants by direct visualization. © 2016 American Society of Plant Biologists. All Rights Reserved.

Influence of thickness of zinc coating on CMT welding-brazing with AlSi5 alloy wire

Science.gov (United States)

Jin, Pengli; Wang, Zhiping; Yang, Sinan; Jia, Peng

2018-03-01

Effect of thickness of zinc coating on Cold Mattel Transfer (CMT) brazing of aluminum and galvanized steel is investigated. The thickness of zinc coating is 10 μm, 30 μm, and 60 μm, respectively. A high-speed camera was used to capture images of welding process of different specimens; the microstructure and composition analyses of the welding seam were examined by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS); the mechanical properties were measured in the form of Nano-indentation experiments. The results showed that arc characteristics and metal transfer behavior were unsteady at the beginning of welding process and that became stable after two cycles of CMT. With the thickness of zinc coating thickening, arc characteristics and metal transfer behaviors were more deteriorated. Compared with 10 μm and 30 μm, clad appearance of 60 μm was straight seam edges and a smooth surface which wetting angle was 60°. Zinc-rich zone at the seam edges was formed by zinc dissolution and motel pool oscillating, and zinc content of 10 μm and 30 μm were 5.8% and 7.75%. Zinc content of 60 μm was 14.61%, and it was a belt between galvanized steel and welding seam. The thickness of intermetallic compounds layer was in the range of 1-8 μm, and it changed with the thickness of zinc coating. The average hardness of the reaction layer of 60 μm is 9.197 GPa.

X-ray microtomography of damage in particle-reinforced metal matrix composites

International Nuclear Information System (INIS)

Mummery, P.M.; Derby, B.; Anderson, P.; Davis, G.; Elliott, J.C.

1993-01-01

The damage which occurs on plastic straining of silicon carbide particle-reinforced aluminium alloys has been characterised using x-ray microtomography. The technique is used to provide density measurements as a function of strain in addition to imaging the internal structure with a resolution of ∼15μm. This allows a much more accurate determination of microstructural damage in terms of void growth than is available from measurements of density using buoyancy methods or from elastic modulus decrease. These data can be combined with acoustic emission measurements during straining to allow damage nucleation and growth contributions to be separated. (orig.)

Duplication in chromosome 17p11.2 in Charcot-Marie-Tooth neuropathy type 1a (CMT 1a). The HMSN Collaborative Research Group

NARCIS (Netherlands)

Raeymaekers, P.; Timmerman, V.; Nelis, E.; de Jonghe, P.; Hoogendijk, J. E.; Baas, F.; Barker, D. F.; Martin, J. J.; de Visser, M.; Bolhuis, P. A.

1991-01-01

Hereditary motor and sensory neuropathy type I (HMSN I) or Charcot-Marie-Tooth disease type 1 (CMT 1) is an autosomal dominant disorder of the peripheral nervous system characterized by progressive weakness and atrophy of distal limb muscles. In the majority of HMSN I families, linkage studies

Investigation of elemental distribution in lung samples by X-ray fluorescence microtomography

International Nuclear Information System (INIS)

Pereira, Gabriela R.; Rocha, Henrique S.; Lopes, Ricardo T.

2007-01-01

X-Ray Fluorescence Microtomography (XRFCT) is a suitable technique to find elemental distributions in heterogeneous samples. While x-ray transmission microtomography provides information about the linear attenuation coefficient distribution, XRFCT allows one to map the most important elements in the sample. The x-ray fluorescence tomography is based on the use of the X-ray fluorescence emitted from the elements contained in a sample so as to give additional information to characterize the object under study. In this work a rat lung and two human lung tissue samples have been investigated in order to verify the efficiency of the system in determination of the internal distribution of detected elements in these kinds of samples and to compare the elemental distribution in the lung tissue of an old human and a fetus. The experiments were performed at the X-Ray Fluorescence beamline (XRF) of the Brazilian Synchrotron Light Source (LNLS), Campinas, Brazil. A white beam was used for the excitation of the elements and the fluorescence photons have been detected by a HPGe detector. All the tomographies have been reconstructed using a filtered-back projection algorithm. It was possible to visualize the distribution of high atomic number elements on both, artificial and tissues samples. It was compared the quantity of Zn, Cu and Fe for the lung human tissue samples and verify that these elements have a higher concentration on the fetus tissue sample than the adult tissue sample. (author)

Nano particle fluidisation in model 2-D and 3-D beds using high speed X-ray imaging and microtomography

International Nuclear Information System (INIS)

Gundogdu, O.; Jenneson, P. M.; Tuzun, U.

2007-01-01

Nanoparticles and nanocomposites have become a major focus of interest in science and technology due to exceptional properties they provide. However, handling and processing of ultra-fine powders is very challenging because they are extremely cohesive. Fluidization is one of techniques available to process powders. It has become increasingly important to understand how these nanoparticles can be handled and processed to benefit from their favourable properties. A high spatial (down to 400 nm) and temporal resolution (down to 1 ms) X-ray imaging apparatus has been designed to study nanoparticles in fluidized beds under different gas flow velocities. The mean volume distribution of the nanoparticle agglomerates was determined with X-ray microtomography. The X-ray microtomography technique provides valuable in situ, non-destructive structural information on the morphological changes that take place during fluidisation of powder samples

Nano particle fluidisation in model 2-D and 3-D beds using high speed X-ray imaging and microtomography

Energy Technology Data Exchange (ETDEWEB)

Gundogdu, O. [University of Surrey, Chemical and Process Engineering, School of Engineering (United Kingdom)], E-mail: o.gundogdu@surrey.ac.uk; Jenneson, P. M. [University of Surrey, Department of Physics, School of Electronics and Physical Sciences (United Kingdom); Tuzun, U. [University of Surrey, Chemical and Process Engineering, School of Engineering (United Kingdom)

2007-04-15

Nanoparticles and nanocomposites have become a major focus of interest in science and technology due to exceptional properties they provide. However, handling and processing of ultra-fine powders is very challenging because they are extremely cohesive. Fluidization is one of techniques available to process powders. It has become increasingly important to understand how these nanoparticles can be handled and processed to benefit from their favourable properties. A high spatial (down to 400 nm) and temporal resolution (down to 1 ms) X-ray imaging apparatus has been designed to study nanoparticles in fluidized beds under different gas flow velocities. The mean volume distribution of the nanoparticle agglomerates was determined with X-ray microtomography. The X-ray microtomography technique provides valuable in situ, non-destructive structural information on the morphological changes that take place during fluidisation of powder samples.

Recent achievements in real-time computational seismology in Taiwan

Science.gov (United States)

Lee, S.; Liang, W.; Huang, B.

2012-12-01

Real-time computational seismology is currently possible to be achieved which needs highly connection between seismic database and high performance computing. We have developed a real-time moment tensor monitoring system (RMT) by using continuous BATS records and moment tensor inversion (CMT) technique. The real-time online earthquake simulation service is also ready to open for researchers and public earthquake science education (ROS). Combine RMT with ROS, the earthquake report based on computational seismology can provide within 5 minutes after an earthquake occurred (RMT obtains point source information ROS completes a 3D simulation real-time now. For more information, welcome to visit real-time computational seismology earthquake report webpage (RCS).

Comparative proteome analysis of three mouse lung adenocarcinoma CMT cell lines with different metastatic potential by two-dimensional gel electrophoresis and mass spectrometry

DEFF Research Database (Denmark)

Zhang, Kelan; Wrzesinski, Krzysztof; Stephen, J Fey

2008-01-01

and characterized in vivo to have different metastatic potential. In this study, the comprehensive protein expression profiles of three of these CMT cell lines at passage 5, 15 and 35 were analyzed by 2-DE separation followed by MS identification. As a result, 82 and 40 unique proteins were found...

TEM Microstructure and Chemical Composition of Transition Zone Between Steel Tube and An Inconel 625 Weld Overlay Coating Produced by CMT Method

Directory of Open Access Journals (Sweden)

Rozmus-Górnikowska M.

2017-06-01

Full Text Available The aim of this work was to investigate the microstructure and chemical composition of the transition zone between 16Mo3 steel and Inconel 625 weld overlay coating produced by the Cold Metal Transfer (CMT method. Investigations were primarily carried out through transmission electron microscopy (TEM on thin foils prepared by FIB (Focus Ion Beam.

Formation mechanism of channel segregation in carbon steels by inclusion flotation: X-ray microtomography characterization and multi-phase flow modeling

International Nuclear Information System (INIS)

Cao, Yan Fei; Chen, Yun; Li, Dian Zhong

2016-01-01

Recent experimental dissections of steel ingots and multi-scale simulations have led to the discovery of a potential driving force for channel segregation: the flotation of oxide-based inclusion (D. Li et al., Nat. Commun. 5:5572 (2014)). Further experimental analysis and numerical modeling are necessary to clarify this mechanism in detail. In this work, the inclusions in a carbon steel ingot that exhibits severe channel segregations were characterized by the 3D X-ray microtomography, which revealed a significant enrichment and growth of inclusions in the channels. Based on above microtomography characterization, a 2D macrosegregation model encompassing the inclusion flotation was established. In the model, the motions of solid inclusions and liquid were described using the multi-phase flow scheme within the Euler-Lagrange framework. The benchmark simulations showed that sufficient inclusion populations with appropriate sizes are capable of altering the local flow patterns and destabilize the mushy zone, initiating the subsequent channel segregation. The continuous interplay between melt convection, inclusion flotation and solidification eventually causes the formation of macroscale channel. The predicted sizes and volume fraction of inclusions that are able to trigger the channel segregation effectively are consistent with the data obtained via microtomography characterization. The macrosegregation model was then applied to predict the channel segregations in an industrial carbon steel ingot. A rather good agreement of A-segregates was achieved between the simulation and the dissected ingot.

Ceramic filters analysis for aluminium melting through microtomography technique; Analise de filtros ceramicos para fundicao de aluminio atraves da tecnica de microtomografia

Energy Technology Data Exchange (ETDEWEB)

Rocha, Henrique de Souza; Lopes, Ricardo Tadeu; Jesus, Edgar Francisco Oliveira de; Oliveira, Luis Fernando de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Instrumentacao Nuclear; Duhm, Rainer; Feiste, Karsten L.; Reichert, Christian; Reimche, Wilfried; Stegemann, Dieter [Universidade de Hannover (Germany). IKPH

2000-07-01

In this work a ceramic filters analysis is done through the microtomography for improvement of the aluminium melting process through the filter porosity control. Microtomography were obtained of ceramic filters with pore dimensions of 10, 20 and 30 ppi. The data were calculated by using an reconstruction algorithm for divergent beam implemented in the Nuclear Instrumentation Laboratory of COPPE/UFRJ and analysed through cells and windows separation according to the defined by Ray. For the analyses the Image Pro program were used where the cells have been detached by sphere inserted, adjusting by nine points, in the filter cavities. So, the size of the answer sphere were considered as the cell size. The windows were measured by straight lines secant to the window intersections.

X-ray cone beam microtomography for quantitative assessment of tracheal and pharyngeal volumes of Rhodnius prolixus

International Nuclear Information System (INIS)

Souza, Izabella Soares de

2017-01-01

In the past decade microcomputerized tomography imaging using synchrotron radiation has become a powerful technique to generate high resolution images of Rhodinus prolixus. Images of soft tissues (protocerebrum and muscles) and dense structures (pharynx, trachea and esophagus) of R. prolixus head have been obtained using synchrotron radiation microtomography in mono and polychromatic configuration, respectively. Advancements in conventional microtomography have increased the achievable resolution and contrast, making this relatively inexpensive and widely available technology potentially useful for studies of insect internal morphology. The main goal of this work was to provide a new set of high quality microtomographic images of R. prolixus achieved by means of a desktop X-ray microtomograph. It allows the three-dimensional visualization of important chitinized structures: pharynx and tracheae. Pharyngeal and tracheal volumes were quantitatively evaluated at different days (1, 4, 10, 15 and 20) after feeding. The results suggest that variation of average volumes could be attributed to insect hormone 20-hydroxy-ecdysone (20-OH-Ec) pulse at 11 days after feeding. Pharyngeal volumes decrease 3.80 times. On the other hand, tracheal volumes increase 1.78 times. Head total volume showed similar trends than trachea. (author)

3D images of paper obtained by phase-contrast X-ray microtomography: image quality and binarisation

International Nuclear Information System (INIS)

Antoine, Christine; Nygaard, Per; Gregersen, O.W.; Holmstad, Rune; Weitkamp, Timm; Rau, Christoph

2002-01-01

A series of paper samples was investigated using high-resolution phase-contrast microtomography at the beamline ID 22 of the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. It was shown that X-ray microtomography is a non-destructive method suitable for high resolution depicting real 3D-paper structures. The method detects highly localised changes in the refractive index of the sample, such as fibre-pore interfaces. The resulting tomograms represented an outlined image of the fibre structure with an image resolution of 1 μm. Analyses were performed in dry state, but in addition some were done in wet state. The raw data obtained were transformed into 3D images. The reconstructed slices were in general of rather good quality, even if both noise and ring-like artifacts were observed. These required special filtering efforts before a segmented binary volume could be obtained for further use of the data. This approach was made up of semi-automatic routines to convert the structure into a binary format. The resulting binary volumes can be used for further characterisation of the 3D-paper structure

Development of sealed sample containers and high resolution micro-tomography

Energy Technology Data Exchange (ETDEWEB)

Uesugi, Kentaro, E-mail: ueken@spring8.or.jp; Takeuchi, Akihisa; Suzuki, Yoshio [Japan synchrotron radiation research institute, JASRI/SPring-8 Kouto 1-1-1, Sayo, Hyogo 679-5198 Japan (Japan); Uesugi, Masayuki [Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Hamada, Hiroshi [NTT Advanced technology Corporation, Atsugi, Kanagawa 243-0124 (Japan)

2016-01-28

A sample container and a high resolution micro-tomography system have been developed at BL47XU at SPring-8. The container is made of a SiN membrane in a shape of truncated pyramid, which makes it possible to exclude oxygen and moisture in the air. The sample rotation stage for tomography is set downward to keep the sample in the container without any glue. The spatial resolution and field of view are 300 nm and 110 μm using a Fresnel zone plate objective with an outermost zone width of 100 nm at 8 keV, respectively. The scan time is about 20 minutes for 1800 projections. A 3-D image of an asteroid particle was successfully obtained without adhesive and contamination.

Soft x-ray scanning microtomography with submicron resolution

International Nuclear Information System (INIS)

McNulty, I.; Haddad, W.S.; Trebes, J.E.; Anderson, E.H.

1994-01-01

Scanning soft x-ray microtomography was used to obtain high-resolution three-dimensional images of a microfabricated test object. Using a special rotation stage mounted on the scanning transmission x-ray microscope at the XIA Beamline at the National Synchrotron Light Source, we recorded nine two-dimensional projections of the 3D test object over an angular range of -50 degrees to +55 degrees. The x-ray wavelength was 3.6 nm and the radiation dose to the object per projection was approximately 2 x 10 6 Gy. The object consisted of two gold patterns supported on transparent silicon nitride membranes, separated by 4.75 Jim, with 100 to 300-nm wide and 65-nm thick features. We reconstructed a volumetric data set of the test object from the two-dimensional projections using an algebraic reconstruction technique algorithm. Features of the test object were resolved to ∼100 nm in transverse and longitudinal extent in three-dimensional images rendered from the volumetric set

Variability in coiling technique in LBK pottery inferred by experiments and pore structure micro-tomography analysis

Czech Academy of Sciences Publication Activity Database

Neumannová, Klára; Petřík, J.; Vostrovská, I.; Dvořák, J.; Zikmund, T.; Kaiser, J.

2017-01-01

Roč. 69, č. 2 (2017), s. 172-186 ISSN 0323-1267 R&D Projects: GA ČR(CZ) GA14-07062S Grant - others:GA MŠk(CZ) LQ1601; GA ČR(CZ) GA17-11711S Program:LQ; GA Institutional support: RVO:67985912 Keywords : forming techniques * micro-tomography * Neolithic * Linear Pottery culture (LBK) Subject RIV: AC - Archeology, Anthropology, Ethnology OBOR OECD: Archaeology

Multiscale tomographic analysis of heterogeneous cast Al-Si-X alloys.

Science.gov (United States)

Asghar, Z; Requena, G; Sket, F

2015-07-01

The three-dimensional microstructure of cast AlSi12Ni and AlSi10Cu5Ni2 alloys is investigated by laboratory X-ray computed tomography, synchrotron X-ray computed microtomography, light optical tomography and synchrotron X-ray computed microtomography with submicrometre resolution. The results obtained with each technique are correlated with the size of the scanned volumes and resolved microstructural features. Laboratory X-ray computed tomography is sufficient to resolve highly absorbing aluminides but eutectic and primary Si remain unrevealed. Synchrotron X-ray computed microtomography at ID15/ESRF gives better spatial resolution and reveals primary Si in addition to aluminides. Synchrotron X-ray computed microtomography at ID19/ESRF reveals all the phases ≥ ∼1 μm in volumes about 80 times smaller than laboratory X-ray computed tomography. The volumes investigated by light optical tomography and submicrometre synchrotron X-ray computed microtomography are much smaller than laboratory X-ray computed tomography but both techniques provide local chemical information on the types of aluminides. The complementary techniques applied enable a full three-dimensional characterization of the microstructure of the alloys at length scales ranging over six orders of magnitude. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

Exploring a carbonate reef reservoir - nuclear magnetic resonance and computed microtomography confronted with narrow channel and fracture porosity

Science.gov (United States)

Fheed, Adam; Krzyżak, Artur; Świerczewska, Anna

2018-04-01

The complexity of hydrocarbon reservoirs, comprising numerous moulds, vugs, fractures and channel porosity, requires a specific set of methods to be used in order to obtain plausible petrophysical information. Both computed microtomography (μCT) and nuclear magnetic resonance (NMR) are nowadays commonly utilized in pore space investigation. The principal aim of this paper is to propose an alternative, quick and easily executable approach, enabling a thorough understanding of the complicated interiors of the carbonate hydrocarbon reservoir rocks. Highly porous and fractured Zechstein bioclastic packstones from the Brońsko Reef, located in West Poland were studied. Having examined 20 thin sections coming from two different well bores, 10 corresponding core samples were subjected to both μCT and NMR experiments. After a preliminary μCT-based image analysis, 9.4 [T] high-field zero echo time (ZTE) imaging, using a very short repetition time (RT) of 2 [μs] was conducted. Taking into consideration the risk of internal gradients' generation, the reliability of ZTE was verified by 0.6 [T] Single Point Imaging (SPI), during which such a phenomenon is much less probable. Both narrow channels and fractures of different apertures appeared to be common within the studied rocks. Their detailed description was therefore undertaken based on an additional tool - the spatially-resolved 0.05 [T] T2 profiling. According to the obtained results, ZTE seems to be especially suitable for studying porous and fractured carbonate rocks, as little disturbance to the signal appears. This can be confirmed by the SPI, indicating the negligible impact of the internal gradients on the registered ZTE images. Both NMR imaging and μCT allowed for locating the most porous intervals including well-developed mouldic porosity, as well as the contrasting impermeable structures, such as the stylolites and anhydrite veins. The 3D low-field profiling, in turn, showed the fracture aperture variations

Determination of the Representative Elementary Volume for the study of sandstones and siltstones by X-Ray microtomography

Directory of Open Access Journals (Sweden)

Jaquiel Salvi Fernandes

2012-08-01

Full Text Available X-Ray computerized microtomography (µ-CT besides providing two-dimensional images (2-D of the transversal sections of the sample, the biggest attraction of the methodology is the rendering of three-dimensional images (3-D, enabling a more real analysis of the porous structure of the rock. However, the reconstruction, visualization and analysis of such 3-D images are limited in computer terms. Thus, it is not always possible to reconstruct the images with the total size of the microtomographed sample. Therefore, this study aims at determining the Representative Elementary Volume (REV in reservoir rocks concerning their porosity. In order to collect microtomographic data from reservoir rocks, a microtomograph Skyscan model 1172 was utilized for the sandstone and siltstone samples scanning. After the analysis of the graphs obtained by REV, it was concluded that the most adequate dimensions for the reconstructed volume in each analyzed sample were approximately 1400 × 1400 × 1400 µm, which are dimensions that can easily be reconstructed, visualized and analyzed.

Evaluation of Microstructural Parameters of Reservoir Rocks of the Guarani Aquifer by Analysis of Images Obtained by X- Ray Microtomography

Science.gov (United States)

Fernandes, J. S.; Lima, F. A.; Vieira, S. F.; Reis, P. J.; Appoloni, C. R.

2015-07-01

Microstructural parameters evaluation of porous materials, such as, rocks reservoir (water, petroleum, gas...), it is of great importance for several knowledge areas. In this context, the X-ray microtomography (μ-CT) has been showing a technical one quite useful for the analysis of such rocks (sandstone, limestone and carbonate), object of great interest of the petroleum and water industries, because it facilitates the characterization of important parameters, among them, porosity, permeability, grains or pore size distribution. The X-ray microtomography is a non-destructive method, that besides already facilitating the reuse of the samples analyzed, it also supplies images 2-D and 3-D of the sample. In this work samples of reservoir rock of the Guarani aquifer will be analyzed, given by the company of perforation of wells artesian Blue Water, in the municipal district of Videira, Santa Catarina, Brazil. The acquisition of the microtomographys data of the reservoir rocks was accomplished in a Skyscan 1172 μ-CT scanner, installed in Applied Nuclear Physics Laboratory (LFNA) in the State University of Londrina (UEL), Paraná, Brazil. In this context, this work presents the microstructural characterization of reservoir rock sample of the Guarani aquifer, analyzed for two space resolutions, 2.8 μm and 4.8 μm, where determined average porosity was 28.5% and 21.9%, respectively. Besides, we also determined the pore size distribution for both resolutions. Two 3-D images were generated of this sample, one for each space resolution, in which it is possible to visualize the internal structure of the same ones.

Evaluation of Microstructural Parameters of Reservoir Rocks of the Guarani Aquifer by Analysis of Images Obtained by X- Ray Microtomography

International Nuclear Information System (INIS)

Fernandes, J S; Lima, F A; Vieira, S F; Reis, P J; Appoloni, C R

2015-01-01

Microstructural parameters evaluation of porous materials, such as, rocks reservoir (water, petroleum, gas...), it is of great importance for several knowledge areas. In this context, the X-ray microtomography (μ-CT) has been showing a technical one quite useful for the analysis of such rocks (sandstone, limestone and carbonate), object of great interest of the petroleum and water industries, because it facilitates the characterization of important parameters, among them, porosity, permeability, grains or pore size distribution. The X-ray microtomography is a non-destructive method, that besides already facilitating the reuse of the samples analyzed, it also supplies images 2-D and 3-D of the sample. In this work samples of reservoir rock of the Guarani aquifer will be analyzed, given by the company of perforation of wells artesian Blue Water, in the municipal district of Videira, Santa Catarina, Brazil. The acquisition of the microtomographys data of the reservoir rocks was accomplished in a Skyscan 1172 μ-CT scanner, installed in Applied Nuclear Physics Laboratory (LFNA) in the State University of Londrina (UEL), Paraná, Brazil. In this context, this work presents the microstructural characterization of reservoir rock sample of the Guarani aquifer, analyzed for two space resolutions, 2.8 μm and 4.8 μm, where determined average porosity was 28.5% and 21.9%, respectively. Besides, we also determined the pore size distribution for both resolutions. Two 3-D images were generated of this sample, one for each space resolution, in which it is possible to visualize the internal structure of the same ones. (paper)

New approach to measure soil particulate organic matter in intact samples using X-ray computed micro-tomography

Science.gov (United States)

Kravchenko, Alexandra; Negassa, Wakene; Guber, Andrey; Schmidt, Sonja

2014-05-01

Particulate soil organic matter (POM) is biologically and chemically active fraction of soil organic matter. It is a source of many agricultural and ecological benefits, among which are POM's contribution to C sequestration. Most of conventional research methods for studying organic matter dynamics involve measurements conducted on pre-processed i.e., ground and sieved soil samples. Unfortunately, grinding and sieving completely destroys soil structure, the component crucial for soil functioning and C protection. Importance of a better understanding of the role of soil structure and of the physical protection that it provides to soil C cannot be overstated; and analysis of quantities, characteristics, and decomposition rates of POM in soil samples with intact structure is among the key elements of gaining such understanding. However, a marked difficulty hindering the progress in such analyses is a lack of tools for identification and quantitative analysis of POM in intact soil samples. Recent advancement in applications of X-ray computed micro-tomography (μ-CT) to soil science has given an opportunity to conduct such analyses. The objective of the current study is to develop a procedure for identification and quantitative characterization of POM within intact soil samples using X-ray μ-CT images and to test performance of the proposed procedure on a set of multiple intact soil macro-aggregates. We used 16 4-6 mm soil aggregates collected at 0-15 cm depth from a Typic Hapludalf soil at multiple field sites with diverse agricultural management history. The aggregates have been scanned at SIMBIOS Centre, Dundee, Scotland at 10 micron resolution. POM was determined from the aggregate images using the developed procedure. The procedure was based on combining image pre-processing steps with discriminant analysis classification. The first component of the procedure consisted of image pre-processing steps based on the range of gray values (GV) along with shape and size

Brute force absorption contrast microtomography

Science.gov (United States)

Davis, Graham R.; Mills, David

2014-09-01

In laboratory X-ray microtomography (XMT) systems, the signal-to-noise ratio (SNR) is typically determined by the X-ray exposure due to the low flux associated with microfocus X-ray tubes. As the exposure time is increased, the SNR improves up to a point where other sources of variability dominate, such as differences in the sensitivities of adjacent X-ray detector elements. Linear time-delay integration (TDI) readout averages out detector sensitivities on the critical horizontal direction and equiangular TDI also averages out the X-ray field. This allows the SNR to be increased further with increasing exposure. This has been used in dentistry to great effect, allowing subtle variations in dentine mineralisation to be visualised in 3 dimensions. It has also been used to detect ink in ancient parchments that are too damaged to physically unroll. If sufficient contrast between the ink and parchment exists, it is possible to virtually unroll the tomographic image of the scroll in order that the text can be read. Following on from this work, a feasibility test was carried out to determine if it might be possible to recover images from decaying film reels. A successful attempt was made to re-create a short film sequence from a rolled length of 16mm film using XMT. However, the "brute force" method of scaling this up to allow an entire film reel to be imaged presents a significant challenge.

Hydroxyethyl methacrylate grafted carboxy methyl tamarind (CMT-g-HEMA) polysaccharide based matrix as a suitable scaffold for skin tissue engineering.

Science.gov (United States)

Choudhury, Priyanka; Kumar, Satish; Singh, Abhishek; Kumar, Ashutosh; Kaur, Navneet; Sanyasi, Sridhar; Chawla, Saurabh; Goswami, Chandan; Goswami, Luna

2018-06-01

Patho-physiologies related to skin are diverse in nature such as burns, skin ulcers, atopic dermatitis, psoriasis etc. which impose severe bio-medical problems and thus enforce requirement of new and healthy skin prepared through tissues engineering methodologies. However, fully functional and biodegradable matrix for attachment, growth, proliferation and differentiation of the relevant cells is not available. In the present study, we introduce a set of hydrogels synthesized by incorporation of a synthetic monomer (Hydroxyethlmethacryate) with a semi-synthetic polymer backbone (carboxy methyl tamarind, CMT) in different mole ratios. We termed these materials as CMT:HEMA based hydrogels and these were characterized by different physico-chemical techniques, namely by X-Ray Diffraction, SEM and Dynamic Light Scattering. Biocompatibility studies with HaCaT, NIH-3T3 and mouse dermal fibroblasts confirm that this material is biocompatible. MTT assay further confirmed that this material does not have any cytotoxic effects. Assays for mitochondrial functionality such as ATP assay and mitochondrial reactive oxygen (ROS) generation also suggest that this material is safe and does not have any cytotoxicity. Hemolytic assay with red blood cells and acute skin irritation test on SD Rats confirmed that this material is suitable for ex-vivo application in future. We suggest that this hydrogel is suitable for in-vivo applications and may have clinical and commercial importance against skin disorders. Copyright © 2018. Published by Elsevier Ltd.

Magnified hard x-ray microtomography: toward tomography with submicron resolution

Science.gov (United States)

Schroer, Christian G.; Benner, Boris; Guenzler, Til F.; Kuhlmann, Marion; Lengeler, Bruno; Rau, Christoph; Weitkamp, Timm; Snigirev, Anatoly A.; Snigireva, Irina

2002-01-01

Parabolic compound refractive lenses (PCRLs) are high quality imaging optics for hard x-rays that can be used as an objective lens in a new type of hard x-ray full field microscope. Using an aluminium PCRL, this new type of microscope has been shown to have a resolution of 350 nm. Further improvement of the resolution down to 50 nm can be expected using beryllium as a lens material. The large depth of field (several mm) of the microscope results in sharp projection images for samples that fit into the field of view of about 300 micrometers. This allows to combine magnified imaging with tomographic techniques. First results of magnified microtomography are shown. Contrast formation in the microscope and the consequences for tomographic reconstruction are discussed. An outlook on further developments is given.

3D synchrotron x-ray microtomography of paint samples

Science.gov (United States)

Ferreira, Ester S. B.; Boon, Jaap J.; van der Horst, Jerre; Scherrer, Nadim C.; Marone, Federica; Stampanoni, Marco

2009-07-01

Synchrotron based X-ray microtomography is a novel way to examine paint samples. The three dimensional distribution of pigment particles, binding media and their deterioration products as well as other features such as voids, are made visible in their original context through a computing environment without the need of physical sectioning. This avoids manipulation related artefacts. Experiments on paint chips (approximately 500 micron wide) were done on the TOMCAT beam line (TOmographic Microscopy and Coherent rAdiology experimenTs) at the Paul Scherrer Institute in Villigen, CH, using an x-ray energy of up to 40 keV. The x-ray absorption images are obtained at a resolution of 350 nm. The 3D dataset was analysed using the commercial 3D imaging software Avizo 5.1. Through this process, virtual sections of the paint sample can be obtained in any orientation. One of the topics currently under research are the ground layers of paintings by Cuno Amiet (1868- 1961), one of the most important Swiss painters of classical modernism, whose early work is currently the focus of research at the Swiss Institute for Art Research (SIK-ISEA). This technique gives access to information such as sample surface morphology, porosity, particle size distribution and even particle identification. In the case of calcium carbonate grounds for example, features like microfossils present in natural chalks, can be reconstructed and their species identified, thus potentially providing information towards the mineral origin. One further elegant feature of this technique is that a target section can be selected within the 3D data set, before exposing it to obtain chemical data. Virtual sections can then be compared with cross sections of the same samples made in the traditional way.

Microstructural characterization of porous materials by X-ray microtomography and gamma ray transmission techniques

International Nuclear Information System (INIS)

Moreira, Anderson Camargo

2006-01-01

This work presents the application of the X-ray microtomography and gamma ray transmission techniques for the microstructure characterization of different kinds of materials. Total porosity, pore size distribution and the two point correlation functions were measured. The two point correlation function, which allows the reconstruction of 3D models, was carried out for two samples. Seven ceramic tablets of Alumina (Al 2 O 3 ), seven tablets of Boron Carbide (B 4 C), three samples of sedimentary rocks and one sample of Titanium foam were analyzed. The experimental set up for the Gamma Ray Transmission technique consisted of: a 2'' x 2'' crystal NaI(Tl) detector, an 241 Am radioactive source (59,53 keV, 100 mCi), an automatic micrometric table for the sample XZ movement and standard gamma spectrometry electronics. Two microtomography systems were used: a Fein Focus system, constituted by an X-ray tube, operated at 160 kV and 0.3 to 1.1 mA, a CCD camera and the movement sample system, and a Skyscan system, model 1072, with a X-ray tube operated at 100 kV and 100μA, and a CCD camera. The ceramic tablets, analyzed by the gamma ray transmission technique presented results for most of the porosities data with smaller confidence intervals and inside the intervals supplied by the tablets manufacturer. The Titanium porous sample was analyzed by the two techniques, its microtomography images achieved a resolution of 17μm, obtained employing the Fein Focus system. For both techniques, this sample showed high porosity, which allows its application for this purpose. The sandstones samples were analyzed by the Skyscan system, achieving resolutions of 19μm, 11μm and 3.8μm for each sample, respectively. The resolutions of 11μm and 3.8μm were the ones that generated better 2D sections for the respective samples and, consequently, more reliable porosities. The 3.8μm resolution was the one that best quantified the pore size distribution data, showing information not shown by

X-ray microtomography in the micromorphologic characterization of soil submitted to different management

International Nuclear Information System (INIS)

Passoni, Sabrina

2013-01-01

The X-ray computed microtomography (CT) represents a non-invasive technique that can be used with success to analyze physical properties by the soil scientists without destroying the structure of the soil. The technique has as advantage over conventional methods the characterization of the soil porous system in three dimensions, which allow morphological property analyses such as connectivity and tortuosity of the pores. However, as the soil is a non-homogeneous and complex system, the CT technique needs specific methodologies for digital image processing, mainly during the segmentation procedure. The objectives of this work were: 1) to develop a methodology for microtomographic digital image processing; 2) to characterize the soil structure by using micromorphology analysis of samples submitted to non-tillage and conventional systems collected in three distinct layers (0-10, 10-20 and 20-30 cm); and 3) to identify possible changes in the porous system of the soil analyzed due to the effect of different management systems. The use of the CT technique and the procedures adopted for microtomographic digital image processing show to be efficient for the micromorphologic characterization of soil porous system. Soil under non-tillage system presented the best results from the agricultural point of view regarding porosity, total number of pores, connectivity and tortuosity in comparison to the conventional tillage. (author)

Imaging the Transport of Silver Nanoparticles Through Soil With Synchrotron X-ray Microtomography

Science.gov (United States)

Molnar, I. L.; Gerhard, J.; O'Carroll, D. M.; Willson, C. S.

2012-12-01

Synchrotron x-ray computed microtomography (SXCMT) offers the ability to examine the spatial distribution of contaminants within the pore space of a porous medium; examples include the distribution of nonaqueous phase liquids (NAPLs) and micro-sized colloids. Recently presented was a method, based upon the application of the Beer-Lambert law and K-edge imaging, for using SXCMT to accurately determine the distribution of silver nanoparticles in a porous medium (Molnar et al., AGU Fall Meeting, H53B-1418, 2011). By capturing a series of SXCMT images of a single sample evolving over time, this technique can study the changing distribution of nanoparticles throughout the pore-network and even within individual pores. While previous work on this method focused on accuracy, precision and its potential applications, this study will provide an in-depth analysis of the results of multiple silver nanoparticle transport experiments imaged using this new technique. SXCMT images were collected at various stages of silver nanoparticle injection into columns packed with well graded and poorly graded quartz sand, iron oxide sand and glass bead porous media. The collected images were used to explore the influences of grain type, size and shape on the transport of silver nanoparticles through soil. The results of this analysis illustrate how SXCMT can collect hitherto unobtainable data which can yield valuable insights into the factors affecting nanoparticle transport through soil.

A High-Speed Target-Free Vision-Based Sensor for Bus Rapid Transit Viaduct Vibration Measurements Using CMT and ORB Algorithms

Directory of Open Access Journals (Sweden)

Qijun Hu

2017-06-01

Full Text Available Bus Rapid Transit (BRT has become an increasing source of concern for public transportation of modern cities. Traditional contact sensing techniques during the process of health monitoring of BRT viaducts cannot overcome the deficiency that the normal free-flow of traffic would be blocked. Advances in computer vision technology provide a new line of thought for solving this problem. In this study, a high-speed target-free vision-based sensor is proposed to measure the vibration of structures without interrupting traffic. An improved keypoints matching algorithm based on consensus-based matching and tracking (CMT object tracking algorithm is adopted and further developed together with oriented brief (ORB keypoints detection algorithm for practicable and effective tracking of objects. Moreover, by synthesizing the existing scaling factor calculation methods, more rational approaches to reducing errors are implemented. The performance of the vision-based sensor is evaluated through a series of laboratory tests. Experimental tests with different target types, frequencies, amplitudes and motion patterns are conducted. The performance of the method is satisfactory, which indicates that the vision sensor can extract accurate structure vibration signals by tracking either artificial or natural targets. Field tests further demonstrate that the vision sensor is both practicable and reliable.

Soft x-ray scanning microtomography with submicrometer resolution

International Nuclear Information System (INIS)

McNulty, I.; Haddad, W.S.; Trebes, J.E.; Anderson, E.H.

1995-01-01

Scanning soft x-ray microtomography was used to obtain high-resolution three-dimensional images of a microfabricated test object. Using a special rotation stage mounted on the scanning transmission x-ray microscope at the X1A beamline at the National Synchrotron Light Source, we recorded nine two-dimensional projections of the 3D test object over an angular range of -50 degree to +55 degree. The x-ray wavelength was 3.6 nm and the radiation dose to the object per projection was approximately 2x10 6 Gy. The object consisted of two gold patterns supported on transparent silicon nitride membranes, separated by 4.75 μm, with 100- to 300-nm-wide and 65-nm-thick features. We reconstructed a volumetric data set of the test object from the two-dimensional projections using an algebraic reconstruction technique algorithm. Features of the test object were resolved to ∼100 nm in transverse and longitudinal extent with low artifact in three-dimensional images rendered from the volumetric set

Corrosion Measurements by Titration, (CMT). Alone or Combined With Electrochemical Measurements(EC). Examples: Corrosion of Zinc, Nickel, Aluminium and Iron

DEFF Research Database (Denmark)

Bech-Nielsen, Gregers

1998-01-01

rate (EC) can be made, at intervals, during a recording of CMT measurements, and by comparison of the two kinds of measurements possible differences can be interpreted in terms of such phenomena as metal disintegration during corrosion (chunk effects), effects of dissolution of low valence metal...... measurements should be recognized: Non-buffer solutions at pH values between 3 and 9 are preferable, an atmosphere free of acid or alkaline components is required, and deposition of corrosion products as hydroxides or carbonates should be excluded....

X-ray micro-tomography for investigations of brain tissues on cellular level

Science.gov (United States)

Khimchenko, Anna; Schulz, Georg; Deyhle, Hans; Thalmann, Peter; Zanette, Irene; Zdora, Marie-Christine; Bikis, Christos; Hipp, Alexander; Hieber, Simone E.; Schweighauser, Gabriel; Hench, Jürgen; Müller, Bert

2016-10-01

X-ray imaging in absorption contrast mode is well established for hard tissue visualization. However, performance for lower density materials is limited due to a reduced contrast. Our aim is three-dimensional (3D) characterization of micro-morphology of human brain tissues down to (sub-)cellular resolution within a laboratory environment. Using the laboratory-based microtomography (μCT) system nanotom m (GE Sensing and Inspection Technologies GmbH, Wunstorf, Germany) and synchrotron radiation at the Diamond-Manchester Imaging Branchline I13-2 (Diamond Light Source, Didcot, UK), we have acquired 3D data with a resolution down to 0.45 μm for visualization of a human cerebellum specimen down to cellular level. We have shown that all selected modalities, namely laboratory-based absorption contrast micro-tomography (LBμCT), synchrotron radiation based in-line single distance phase contrast tomography (SDPR) and synchrotron radiation based single-grating interferometry (GI), can reach cellular resolution for tissue samples with a size in the mm-range. The results are discussed qualitatively in comparison to optical microscopy of haematoxylin and eosin (HE) stained sections. As phase contrast yields to a better data quality for soft tissues and in order to overcome restrictions of limited beamline access for phase contrast measurements, we have equipped the μCT system nanotom m with a double-grating phase contrast set-up. Preliminary experimental results of a knee sample consisting of a bony part and a cartilage demonstrate that phase contrast data exhibits better quality compared to absorption contrast. Currently, the set-up is under adjustment. It is expected that cellular resolution would also be achieved. The questions arise (1) what would be the quality gain of laboratory-based phase contrast in comparison to laboratory-based absorption contrast tomography and (2) could laboratory-based phase contrast data provide comparable results to synchrotron radiation based

Computational upscaling of Drucker-Prager plasticity from micro-CT images of synthetic porous rock

Science.gov (United States)

Liu, Jie; Sarout, Joel; Zhang, Minchao; Dautriat, Jeremie; Veveakis, Emmanouil; Regenauer-Lieb, Klaus

2018-01-01

Quantifying rock physical properties is essential for the mining and petroleum industry. Microtomography provides a new way to quantify the relationship between the microstructure and the mechanical and transport properties of a rock. Studies reporting the use microtomographic images to derive permeability and elastic moduli of rocks are common; only rare studies were devoted to yield and failure parameters using this technique. In this study, we simulate the macroscale plastic properties of a synthetic sandstone sample made of calcite-cemented quartz grains using the microscale information obtained from microtomography. The computations rely on the concept of representative volume elements (RVEs). The mechanical RVE is determined using the upper and lower bounds of finite-element computations for elasticity. We present computational upscaling methods from microphysical processes to extract the plasticity parameters of the RVE and compare results to experimental data. The yield stress, cohesion and internal friction angle of the matrix (solid part) of the rock were obtained with reasonable accuracy. Computations of plasticity of a series of models of different volume-sizes showed almost overlapping stress-strain curves, suggesting that the mechanical RVE determined by elastic computations is also valid for plastic yielding. Furthermore, a series of models were created by self-similarly inflating/deflating the porous models, that is keeping a similar structure while achieving different porosity values. The analysis of these models showed that yield stress, cohesion and internal friction angle linearly decrease with increasing porosity in the porosity range between 8 and 28 per cent. The internal friction angle decreases the most significantly, while cohesion remains stable.

Comparative proteome analysis of three mouse lung adenocarcinoma CMT cell lines with different metastatic potential by two-dimensional gel electrophoresis and mass spectrometry.

Science.gov (United States)

Zhang, Kelan; Wrzesinski, Krzysztof; Stephen, J Fey; Larsen, Peter Mose; Zhang, Xumin; Roepstorff, Peter

2008-12-01

Metastasis is a lethal attribute of a cancer and presents a continuing therapeutic challenge. Metastasis is a highly complex process and more knowledge about the mechanisms behind metastasis is highly desirable. Isogenic CMT cell lines were selected from a spontaneous mouse lung adenocarcinoma and characterized in vivo to have different metastatic potential. In this study, the comprehensive protein expression profiles of three of these CMT cell lines at passage 5, 15 and 35 were analyzed by 2-DE separation followed by MS identification. As a result, 82 and 40 unique proteins were found to be significantly up- or down-regulated between cell lines with different metastatic potential at passages 5 and 15, respectively. These proteins were identified by MS and most of them have previously been reported to be related to cancer development and/or metastasis. Bioinformatics analysis indicated that several of the proteins were involved in proteasome, cell-cycle and cell-communication pathways. Among them, some keratins, 14-3-3 proteins and 26S proteasome proteins were identified and their aberrant expression may be directly or indirectly involved in cancer development and metastasis. In conclusion, our comprehensive 2-DE-based proteomics studies revealed some candidate proteins, protein families and signaling pathways, which might be important in cancer development and metastasis.

Real-time data-intensive computing

Energy Technology Data Exchange (ETDEWEB)

Parkinson, Dilworth Y., E-mail: dyparkinson@lbl.gov; Chen, Xian; Hexemer, Alexander; MacDowell, Alastair A.; Padmore, Howard A.; Shapiro, David; Tamura, Nobumichi [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Beattie, Keith; Krishnan, Harinarayan; Patton, Simon J.; Perciano, Talita; Stromsness, Rune; Tull, Craig E.; Ushizima, Daniela [Computational Research Division, Lawrence Berkeley National Laboratory Berkeley CA 94720 (United States); Correa, Joaquin; Deslippe, Jack R. [National Energy Research Scientific Computing Center, Berkeley, CA 94720 (United States); Dart, Eli; Tierney, Brian L. [Energy Sciences Network, Berkeley, CA 94720 (United States); Daurer, Benedikt J.; Maia, Filipe R. N. C. [Uppsala University, Uppsala (Sweden); and others

2016-07-27

Today users visit synchrotrons as sources of understanding and discovery—not as sources of just light, and not as sources of data. To achieve this, the synchrotron facilities frequently provide not just light but often the entire end station and increasingly, advanced computational facilities that can reduce terabytes of data into a form that can reveal a new key insight. The Advanced Light Source (ALS) has partnered with high performance computing, fast networking, and applied mathematics groups to create a “super-facility”, giving users simultaneous access to the experimental, computational, and algorithmic resources to make this possible. This combination forms an efficient closed loop, where data—despite its high rate and volume—is transferred and processed immediately and automatically on appropriate computing resources, and results are extracted, visualized, and presented to users or to the experimental control system, both to provide immediate insight and to guide decisions about subsequent experiments during beamtime. We will describe our work at the ALS ptychography, scattering, micro-diffraction, and micro-tomography beamlines.

Characterization of highly hydrophobic textiles by means of X-ray microtomography, wettability analysis and drop impact

Science.gov (United States)

Santini, M.; Guilizzoni, M.; Fest-Santini, S.; Lorenzi, M.

2017-11-01

Highly hydrophobic surfaces have been intensively investigated in the last years because their properties may lead to very promising technological spillovers encompassing both everyday use and high-tech fields. Focusing on textiles, hydrophobic fabrics are of major interest for applications ranging from clothes to architecture to environment protection and energy conversion. Gas diffusion media - made by a gas diffusion layer (GDL) and a microporous layer (MPL) - for fuel cells are a good benchmark to develop techniques aimed at characterizing the wetting performances of engineered textiles. An experimental investigation was carried out about carbon-based, PTFE-treated GDLs with and without MPLs. Two samples (woven and woven-non-woven) were analysed before and after coating with a MPL. Their three-dimensional structure was reconstructed and analysed by computer-aided X-ray microtomography (µCT). Static and dynamic wettability analyses were then carried out using a modified axisymmetric drop shape analysis technique. All the surfaces exhibited very high hydrophobicity, three of them near to a super-hydrophobic behavior. Water drop impacts were performed, evidencing different bouncing, sticking and fragmentation outcomes for which critical values of the Weber number were identified. Finally, a µCT scan of a drop on a GDL was performed, confirming the Cassie-Baxter wetting state on such surface.

Optimization of image quality and acquisition time for lab-based X-ray microtomography using an iterative reconstruction algorithm

Science.gov (United States)

Lin, Qingyang; Andrew, Matthew; Thompson, William; Blunt, Martin J.; Bijeljic, Branko

2018-05-01

Non-invasive laboratory-based X-ray microtomography has been widely applied in many industrial and research disciplines. However, the main barrier to the use of laboratory systems compared to a synchrotron beamline is its much longer image acquisition time (hours per scan compared to seconds to minutes at a synchrotron), which results in limited application for dynamic in situ processes. Therefore, the majority of existing laboratory X-ray microtomography is limited to static imaging; relatively fast imaging (tens of minutes per scan) can only be achieved by sacrificing imaging quality, e.g. reducing exposure time or number of projections. To alleviate this barrier, we introduce an optimized implementation of a well-known iterative reconstruction algorithm that allows users to reconstruct tomographic images with reasonable image quality, but requires lower X-ray signal counts and fewer projections than conventional methods. Quantitative analysis and comparison between the iterative and the conventional filtered back-projection reconstruction algorithm was performed using a sandstone rock sample with and without liquid phases in the pore space. Overall, by implementing the iterative reconstruction algorithm, the required image acquisition time for samples such as this, with sparse object structure, can be reduced by a factor of up to 4 without measurable loss of sharpness or signal to noise ratio.

Microstructure parameters evaluation of Botucatu formation sandstone by X-ray microtomography

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Jaquiel S.; Appoloni, Carlos R.; Marques, Leonardo C., E-mail: jaquielfernandes@yahoo.com.b, E-mail: appoloni@uel.b, E-mail: leocarma@yahoo.com.b [Universidade Estadual de Londrina (UEL), PR (Brazil). Dept. de Fisica. Lab. de Fisica Nuclear Aplicada; Fernandes, Celso P., E-mail: celso@lmpt.ufsc.b [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Meios Porosos e Propriedades TermoFisicas (LMPT)

2009-07-01

Microstructural parameters evaluation of reservoir rocks are very important to petroleum industry. This work presents total porosity and pore size distribution measurement of a silicified sandstone sample from the Botucatu formation, collected at municipal district of Faxinal, Parana, Brazil. Porosity and pores size distribution were determined using X-Ray microtomography and imaging techniques. Acquired images had 2.9 mum spatial resolution. 800 2-D images where reconstructed for the microstructure analysis. The determined average porosity was 6.1 +- 2.1 %. 95 % of the porous phase refers to pores with radius ranging from 2.9 to 167.4 mum, presenting the larger frequency (6 %) at 5.9 mum radius. The 3-D volume of the sample was reconstructed and compared with the 3-D model obtained through the autocorrelation functions from the 2-D images analysis. (author)

X-ray micro-tomography investigation of the foaming process in the system of waste glass–silica mud–MnO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Ducman, V., E-mail: vilma.ducman@zag.si [ZAG Ljubljana, Dimičeva 12, 1000 Ljubljana (Slovenia); Korat, L.; Legat, A. [ZAG Ljubljana, Dimičeva 12, 1000 Ljubljana (Slovenia); Mirtič, B. [NTF, Aškerčeva 12, 1000 Ljubljana (Slovenia)

2013-12-15

In case of foamed lightweight aggregates (LWAs), porosity is introduced by the addition of a foaming agent to the glassy matrix, which degasses at an elevated temperature, so that the resulting gases remain trapped inside the glassy structure. The efficiency of action of MnO{sub 2} as a foaming agent in waste glass and waste glass/silica mud systems was studied. Samples were fired at different temperatures and with different dwelling times at a certain temperature, and the development of porosity was investigated by means of X-ray micro-tomography. It was found that, with the prolongation in dwelling times, the number of pores decreased, while, on the other hand, the volume of these pores increased, and that the addition of silica mud increases the foaming temperature and slows down the foaming process. - Highlights: • Preparation of lightweight aggregate from waste glass, silica sludge, and MnO{sub 2} • DTA/TG investigation of MnO{sub 2} • Characterization of pore-forming process by means of X-ray micro-tomography (μcT)

A novel technique for investigation of complete and partial anisotropic wetting on structured surface by X-ray microtomography

Energy Technology Data Exchange (ETDEWEB)

Santini, M., E-mail: maurizio.santini@unibg.it [Department of Engineering and Applied Sciences, University of Bergamo, Bergamo (Italy); Guilizzoni, M. [Department of Energy, Politecnico di Milano, Milano (Italy); Fest-Santini, S. [Department of Engineering, University of Bergamo, Bergamo (Italy); Lorenzi, M. [School of Engineering and Mathematical Sciences, City University London, London (United Kingdom)

2015-02-15

An experimental study about the anisotropic wetting behavior of a surface patterned with parallel grooves is presented as an application example of a novel technique for investigation of complete and partial anisotropic wetting on structured surface by X-ray microtomography. Shape of glycerin droplets on such surface is investigated by X-ray micro computed tomography (microCT) acting as a non-intrusive, full volume 3D microscope with micrometric spatial resolution. The reconstructed drop volumes enable to estimate the exact volumes of the drops, their base contours, and 3D static contact angles, based on true cross-sections of the drop-surface couple. Droplet base contours are compared to approximate geometrical contour shapes proposed in the literature. Contact angles along slices parallel and perpendicular to the grooves direction are compared with each other. The effect of the sessile drop volume on the wetting behavior is discussed. The proposed technique, which is applicable for any structured surface, enables the direct measure of Wenzel ratio based on the microCT scan in the wetted region usually inapproachable by any others. Comparisons with simplified models are presented and congruence of results with respect to the minimum resolution needed is evaluated and commented.

Complex Odontoma: A Case Report with Micro-Computed Tomography Findings

Directory of Open Access Journals (Sweden)

L. A. N. Santos

2016-01-01

Full Text Available Odontomas are the most common benign tumors of odontogenic origin. They are normally diagnosed on routine radiographs, due to the absence of symptoms. Histopathologic evaluation confirms the diagnosis especially in cases of complex odontoma, which may be confused during radiographic examination with an osteoma or other highly calcified bone lesions. The micro-CT is a new technology that enables three-dimensional analysis with better spatial resolution compared with cone beam computed tomography. Another great advantage of this technology is that the sample does not need special preparation or destruction in the sectioned area as in histopathologic evaluation. An odontoma with CBCT and microtomography images is presented in a 26-year-old man. It was first observed on panoramic radiographs and then by CBCT. The lesion and the impacted third molar were surgically excised using a modified Neumann approach. After removal, it was evaluated by histopathology and microtomography to confirm the diagnostic hypothesis. According to the results, micro-CT enabled the assessment of the sample similar to histopathology, without destruction of the sample. With further development, micro-CT could be a powerful diagnostic tool in future research.

X-ray phase-contrast micro-tomography and image analysis of wood microstructure

International Nuclear Information System (INIS)

Mayo, Sheridan; Evans, Robert; Chen, Fiona; Lagerstrom, Ryan

2009-01-01

A number of commercially important properties of wood depend on details of the wood micro- and nano- structure. CSIRO Forest Biosciences have developed SilviScan, an analytical instrument which uses a number of high-speed techniques for analyzing these properties. X-ray micro-tomographic analysis of wood samples provides detailed 3D reconstructions of the wood microstructure which can be used to validate results from SilviScan measurements. A series of wood samples was analysed using laboratory-based phase-contrast x-ray micro-tomography. Image analysis techniques were applied to the 3D data sets to extract significant features and statistical properties of the specimens. These data provide a means of verification of results from the more rapid SilviScan techniques, and will clarify the results of micro-diffraction studies of wood microfibrils.

Microtomography of elastomers for tire manufacture

Science.gov (United States)

Dunsmuir, John H.; Dias, A. J.; Peiffer, D. G.; Kolb, R.; Jones, G.

1999-09-01

X-ray microtomography is used to image the internal structure of carbon black filled isobutylene-p-methylstyrene-p- bromomethylstyrene (PIB-PMS/BrPMS or ExxProTM) curing bladders before and after use-to-failure in the manufacture of automobile tires. Curing bladders operate under extreme conditions with extended mechanical cycling at high temperatures. Manufacturers typically do not run the bladders until failure but rather a pull policy is established which emphasizes the distribution of cyclic lifetimes. We examine the bladder elastomer structure at a resolution of about 10 microns with the objective of reducing the variability in performance. Using both edge crossing and absorption contrast we identify several types of heterogeneity including voids, foreign inclusions, and the distribution of curative agent from which we infer the uniformity of the cure. The results indicate several potential failure mechanisms. The small number of voids and foreign inclusions are mechanical defects that can initiate cracking. More widespread through the polymer matrix are small regions of polymer devoid of curative agent as shown by absorption edge imaging. These regions may be uncured polymer with poor mechanical and thermal properties that may lead to early failure. After several cure cycles the uncured regions are no longer present in the bladder tread area but they remain near the bead. At high cycles an approximately 500 micrometer thick zinc rich cap develops where the bladder contacts the inner tread area of the tire. This zinc rich cap may cause over-curing of the polymer resulting in crack initiation at the surface of the bladder that contacts the tire.

Development of a 3-D x-ray micro-tomography system and its application to trabecular bone/cement interface

International Nuclear Information System (INIS)

Chi, Yong Ki; Cho, Gyuseong

2004-01-01

In recent years, the interface analysis of micro-structure based objects is an important research in osteoporosis, vascular imaging since a 3-D X-ray micro-tomography system was developed. However, the micro-tomographic image shows the white-out appearance in case of imaging of similar density objects with low energy X-ray. Therefore these images must be analyzed about the interface between microstructure based objects for its application to biomechanical study. Many published studies suggested approximately assumed model of interface and predicted mechanical failure by means of Finite Element Method (FEM) but these FEM analysis has not used for modeling the real structure and interface between objects such as roughness, voids and pores of objects. We developed micro-tomography system and suggest the application of micro-tomographic image for predicting mechanical failure at the interface. The micro-tomography system consists of a 5 μm micro-focus X-ray tube, a CMOS-based image sensor and a rotating sample holder controlled by a precision motor. CMOS image sensor has 62x62 mm 2 sensing area and uses optical lenses system for increasing resolution. The sample which was manufactured by implanting cement in a pig hip bone was used and its fracture is considered to be an important cause of loosening of hip joint replacement in orthopedic implants. A Feldkamp's cone-beam reconstruction algorithm on the equispatial detector case was used for bone/cement 3D volume data and the analysis of a trabecular bone/cement interface containing white-out appearance was performed by using multiple criterion segmentation of region and volume. Finally, the segmented data can be used for fracture prediction of FEM by determining node of hexahedron meshing. In this paper, we present development of a 3-D cone beam micro-tomographic system with CMOS image sensor and its application to a complex structure of a trabecular bone and implanted cement for predicting the failure mechanism of

Cosine-Modulated Multitone for Very-High-Speed Digital Subscriber Lines

Directory of Open Access Journals (Sweden)

Lin Lekun

2006-01-01

Full Text Available In this paper, the use of cosine-modulated filter banks (CMFBs for multicarrier modulation in the application of very-high-speed digital subscriber lines (VDSLs is studied. We refer to this modulation technique as cosine-modulated multitone (CMT. CMT has the same transmitter structure as discrete wavelet multitone (DWMT. However, the receiver structure in CMT is different from its DWMT counterpart. DWMT uses linear combiner equalizers, which typically have more than 20 taps per subcarrier. CMT, on the other hand, adopts a receiver structure that uses only two taps per subcarrier for equalization. This paper has the following contributions. (i A modification that reduces the computational complexity of the receiver structure of CMT is proposed. (ii Although traditionally CMFBs are designed to satisfy perfect-reconstruction (PR property, in transmultiplexing applications, the presence of channel destroys the PR property of the filter bank, and thus other criteria of filter design should be adopted. We propose one such method. (iii Through extensive computer simulations, we compare CMT with zipper discrete multitone (z-DMT and filtered multitone (FMT, the two modulation techniques that have been included in the VDSL draft standard. Comparisons are made in terms of computational complexity, transmission latency, achievable bit rate, and resistance to radio ingress noise.

Three dimensional imaging of damage in structural materials using high resolution micro-tomography

Energy Technology Data Exchange (ETDEWEB)

Buffiere, J.-Y. [GEMPPM UMR CNRS 5510, INSA Lyon, 20 Av. A. Einstein, 69621 Villeurbanne Cedex (France)]. E-mail: jean-yves.buffiere@insa-lyon.fr; Proudhon, H. [GEMPPM UMR CNRS 5510, INSA Lyon, 20 Av. A. Einstein, 69621 Villeurbanne Cedex (France); Ferrie, E. [GEMPPM UMR CNRS 5510, INSA Lyon, 20 Av. A. Einstein, 69621 Villeurbanne Cedex (France); Ludwig, W. [GEMPPM UMR CNRS 5510, INSA Lyon, 20 Av. A. Einstein, 69621 Villeurbanne Cedex (France); Maire, E. [GEMPPM UMR CNRS 5510, INSA Lyon, 20 Av. A. Einstein, 69621 Villeurbanne Cedex (France); Cloetens, P. [ESRF Grenoble (France)

2005-08-15

This paper presents recent results showing the ability of high resolution synchrotron X-ray micro-tomography to image damage initiation and development during mechanical loading of structural metallic materials. First, the initiation, growth and coalescence of porosities in the bulk of two metal matrix composites have been imaged at different stages of a tensile test. Quantitative data on damage development has been obtained and related to the nature of the composite matrix. Second, three dimensional images of fatigue crack have been obtained in situ for two different Al alloys submitted to fretting and/or uniaxial in situ fatigue. The analysis of those images shows the strong interaction of the cracks with the local microstructure and provides unique experimental data for modelling the behaviour of such short cracks.

Three dimensional imaging of damage in structural materials using high resolution micro-tomography

International Nuclear Information System (INIS)

Buffiere, J.-Y.; Proudhon, H.; Ferrie, E.; Ludwig, W.; Maire, E.; Cloetens, P.

2005-01-01

This paper presents recent results showing the ability of high resolution synchrotron X-ray micro-tomography to image damage initiation and development during mechanical loading of structural metallic materials. First, the initiation, growth and coalescence of porosities in the bulk of two metal matrix composites have been imaged at different stages of a tensile test. Quantitative data on damage development has been obtained and related to the nature of the composite matrix. Second, three dimensional images of fatigue crack have been obtained in situ for two different Al alloys submitted to fretting and/or uniaxial in situ fatigue. The analysis of those images shows the strong interaction of the cracks with the local microstructure and provides unique experimental data for modelling the behaviour of such short cracks

Microstructure of natural hydrate host sediments

International Nuclear Information System (INIS)

Jones, K.W.; Kerkar, P.B.; Mahajan, D.; Lindquist, W.B.; Feng, H.

2007-01-01

There is worldwide interest in the study of natural gas hydrate because of its potential impact on world energy resources, control on seafloor stability, significance as a drilling hazard and probable impact on climate as a reservoir of a major greenhouse gas. Gas hydrates can (a) be free floating in the sediment matrix (b) contact, but do not cement, existing sediment grains, or (c) actually cement and stiffen the bulk sediment. Seismic surveys, often used to prospect for hydrates over a large area, can provide knowledge of the location of large hydrate concentrations because the hydrates within the sediment pores modify seismic properties. The ability to image a sample at the grain scale and to determine the porosity, permeability and seismic profile is of great interest since these parameters can help in determining the location of hydrates with certainty. We report here on an investigation of the structure of methane hydrate sediments at the grain-size scale using the synchrotron radiation-based computed microtomography (CMT) technique. Work has started on the measurements of the changes occurring as tetrahydrofuran hydrate, a surrogate for methane hydrate, is formed in the sediment

Three Dimensional Structures of Particles Recovered from the Asteroid Itokawa by the Hayabusa Mission and a Role of X-Ray Microtomography in the Preliminary Examination

Science.gov (United States)

Tsuchiyama, A.; Uesugi, M.; Uesugi, K.; Nakano, T.; Nakamura, T.; Noguchi, T.; Noguchi, R.; Matsumoto, T.; Matsuno, J.; Nagano, T.;

Biomedical Imaging and Computational Modeling in Biomechanics

CERN Document Server

Iacoviello, Daniela

2013-01-01

This book collects the state-of-art and new trends in image analysis and biomechanics. It covers a wide field of scientific and cultural topics, ranging from remodeling of bone tissue under the mechanical stimulus up to optimizing the performance of sports equipment, through the patient-specific modeling in orthopedics, microtomography and its application in oral and implant research, computational modeling in the field of hip prostheses, image based model development and analysis of the human knee joint, kinematics of the hip joint, micro-scale analysis of compositional and mechanical properties of dentin, automated techniques for cervical cell image analysis, and iomedical imaging and computational modeling in cardiovascular disease.   The book will be of interest to researchers, Ph.D students, and graduate students with multidisciplinary interests related to image analysis and understanding, medical imaging, biomechanics, simulation and modeling, experimental analysis.

3D microstructural architecture of muscle attachments in extant and fossil vertebrates revealed by synchrotron microtomography.

Directory of Open Access Journals (Sweden)

Sophie Sanchez

Full Text Available BACKGROUND: Firm attachments binding muscles to skeleton are crucial mechanical components of the vertebrate body. These attachments (entheses are complex three-dimensional structures, containing distinctive arrangements of cells and fibre systems embedded in the bone, which can be modified during ontogeny. Until recently it has only been possible to obtain 2D surface and thin section images of entheses, leaving their 3D histology largely unstudied except by extrapolation from 2D data. Entheses are frequently preserved in fossil bones, but sectioning is inappropriate for rare or unique fossil material. METHODOLOGY/PRINCIPAL FINDINGS: Here we present the first non-destructive 3D investigation, by propagation phase contrast synchrotron microtomography (PPC-SRµCT, of enthesis histology in extant and fossil vertebrates. We are able to identify entheses in the humerus of the salamander Desmognathus from the organization of bone-cell lacunae and extrinsic fibres. Statistical analysis of the lacunae differentiates types of attachments, and the orientation of the fibres, reflect the approximate alignment of the muscle. Similar histological structures, including ontogenetically related pattern changes, are perfectly preserved in two 380 million year old fossil vertebrates, the placoderm Compagopiscis croucheri and the sarcopterygian fish Eusthenopteron foordi. CONCLUSIONS/SIGNIFICANCE: We are able to determine the position of entheses in fossil vertebrates, the approximate orientation of the attached muscles, and aspects of their ontogenetic histories, from PPC-SRµCT data. Sub-micron microtomography thus provides a powerful tool for studying the structure, development, evolution and palaeobiology of muscle attachments.

Segmentation of Connective Tissue in Meat from Microtomography Using a Grating Interferometer

DEFF Research Database (Denmark)

Einarsdottir, Hildur; Ersbøll, Bjarne Kjær; Larsen, Rasmus

microtomography provides high resolution, the thin structures of the connective tissues are difficult to segment. This is mainly due to partial object voxels, image noise and artifacts. The segmentation of connective tissue is important for quantitative analysis purposes. Factors such as the surface area......, relative volume and the statistics of the electron density of the connective tissue could prove useful for understanding the structural changes occurring in the meat sample due to heat treatment. In this study a two step segmentation algorithm was implemented in order to segment connective tissue from...... the a priori probability of neighborhood dependencies, and the field can either be isotropic or anisotropic. For the segmentation of connective tissue, the local information of the structure orientation and coherence is extracted to steer the smoothing (anisotropy) of the final segmentation. The results show...

Micro-CTvlab: A web based virtual gallery of biological specimens using X-ray microtomography (micro-CT).

Science.gov (United States)

Keklikoglou, Kleoniki; Faulwetter, Sarah; Chatzinikolaou, Eva; Michalakis, Nikitas; Filiopoulou, Irene; Minadakis, Nikos; Panteri, Emmanouela; Perantinos, George; Gougousis, Alexandros; Arvanitidis, Christos

2016-01-01

During recent years, X-ray microtomography (micro-CT) has seen an increasing use in biological research areas, such as functional morphology, taxonomy, evolutionary biology and developmental research. Micro-CT is a technology which uses X-rays to create sub-micron resolution images of external and internal features of specimens. These images can then be rendered in a three-dimensional space and used for qualitative and quantitative 3D analyses. However, the online exploration and dissemination of micro-CT datasets are rarely made available to the public due to their large size and a lack of dedicated online platforms for the interactive manipulation of 3D data. Here, the development of a virtual micro-CT laboratory (Micro-CT vlab ) is described, which can be used by everyone who is interested in digitisation methods and biological collections and aims at making the micro-CT data exploration of natural history specimens freely available over the internet. The Micro-CT vlab offers to the user virtual image galleries of various taxa which can be displayed and downloaded through a web application. With a few clicks, accurate, detailed and three-dimensional models of species can be studied and virtually dissected without destroying the actual specimen. The data and functions of the Micro-CT vlab can be accessed either on a normal computer or through a dedicated version for mobile devices.

X-ray microtomography study of the spallation response in Ta-W

Science.gov (United States)

McDonald, Samuel; Cotton, Matthew; Millett, Jeremy; Bourne, Neil; Withers, Philip

2013-06-01

The response of metallic materials to high strain-rate (impact) loading is of interest to a number of communities. Traditionally, the largest driver has been the military, in its need to understand armour and resistance to ballistic attack. More recently, industries such as aerospace (foreign object damage, bird strike, etc.), automotive (crash-worthiness) and satellite protection (orbital debris) have all appreciated the necessity of such information. It is therefore important to understand the dynamic tensile or spallation response, and in particular to be able to observe in three-dimensions, and in a non-invasive manner, the physical damage present in the spalled region post-impact. The current study presents plate impact experiments investigating the spallation damage response of recovered targets of the tantalum alloy Ta-2.5%W. Using X-ray microtomography the damage resulting from differing impact conditions (impact velocity/stress, pulse duration) is compared and characterised in 3-D. Combined with free surface velocity measurements, the tensile failure mechanisms during dynamic loading have been identified.

Microstructural characterization of industrial foams by gamma ray transmission and X-ray microtomography

International Nuclear Information System (INIS)

Rodrigues, Luiz Eduardo

2004-01-01

This work presents the total porosity measurements of the aluminum and silicon carbide (SiC) foams samples. For porosity determination the gamma ray transmission and X-ray microtomography with conic beam techniques were used. These methods have more advantage than conventional ones, because they are non destructive and provide more details of the analyzed material porous structure. The aluminum foam samples with 10, 20, 30, 40 and 45 ppi (pores per inch) and SiC ceramic foam samples with 20, 30, 45, 60, 75, 80 and 90 ppi were analysed by gamma transmission. The SiC 60, 75 and 90 ppi samples were also analyzed by X-ray microtomography. For the gamma ray transmission measurements it was used an 241 Am source (59.53 keV), a NaI(Tl) scintillation detector, collimators, a XYZ micrometric table and standard gamma spectrometry electronics connected to a multichannel analyzer, at the LFNA/UEL. For the X-ray microtomographic measurements, the Fein Focus X-ray system of the Nuclear Instrumentation Laboratory of the COPPE, located at the Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, was used. This equipment provide us images with micrometric resolution (53.48 μm) using a conic X-ray beam and bidimensional detection. The microtomographic images were pre-processed and analyzed by the Imago software, developed at Porous Media and Materials Thermophysical Properties Laboratory (LMPT) of the Mechanical Engineering Department, located at Universidade Federal de Santa Catarina, Florianopolis, SC. Employing the The Imago software it was calculated the total porosity, pore size distribution and autocorrelation function C(u) of the binarized microtomographic images of the each sample. The microtomographic 3-D image of each sample was compared with 3-D image reconstructed by the Gaussian truncated method. This method generates a periodic 3-D porous structure by using of the autocorrelation function of one 2-D cross sectional image of the sample. (author)

Analysis of cortical bone porosity using synchrotron radiation microtomography to evaluate the effects of chemotherapy

Science.gov (United States)

Alessio, R.; Nogueira, L. P.; Salata, C.; Mantuano, A.; Almeida, A. P.; Braz, D.; de Almeida, C. E.; Tromba, G.; Barroso, R. C.

2015-11-01

Microporosities play important biologic and mechanical roles on health. One of the side effects caused by some chemotherapy drugs is the induction of amenorrhea, temporary or not, in premenopausal women, with a consequent decrease in estrogen production, which can lead to cortical bone changes. In the present work, the femur diaphysis of rats treated with chemotherapy drugs were evaluated by 3D morphometric parameters using synchrotron radiation microtomography. Control animals were also evaluated for comparison. The 3D tomographic images were obtained at the SYRMEP (SYnchrotron Radiation for MEdical Physics) beamline at the ELETTRA Synchrotron Laboratory in Trieste, Italy. Results showed significant differences in morphometric parameters measured from the 3D images of femur diaphysis of rats.

Computational Studies on the Performance of Flow Distributor in Tank

International Nuclear Information System (INIS)

Shin, Soo Jai; Kim, Young In; Ryu, Seungyeob; Bae, Youngmin

2014-01-01

Core make-up tank (CMT) is full of borated water and provides makeup and boration to the reactor coolant system (RCS) for early stage of loss of coolant accident (LOCA) and non-LOCA. The top and bottom of CMT are connected to the RCS through the pressure balance line (PBL) and the safety injection line (SIL), respectively. Each PBL is normally open to maintain pressure of the CMT at RCS, and this arrangement enables the CMT to inject water to the RCS by gravity when the isolation valves of SIL are open. During CMT injection into the Reactor, the condensation and thermal stratification are observed in CMT and the rapid condensation disturbed the injection operation. The optimal design of the flow distributor is very important to ensure structural integrity of the reactor system and their safe operation during some transient or accident conditions. In the present study, we numerically investigated the performance of flow distributor in tank with different shape factor such as the total number of the holes, the pitch-to-hole diameter ratios (p/d), the diameter of the hole and the area ratios. These data will contribute to the design the flow distributor. In the present study, the model of the flow distributor in tank is simulated using the commercial CFD software, Fluent 13.0 with varying the different shape factor of the flow distributor such as the total number of the holes, the diameter of the holes and the area ratio. As the diameter of the hole is smaller, the velocity difference between holes, which is located at upper position and lower position of the flow distributor, also decreases. For larger area ratio, the velocity of the holes is slower. When the diameter of the hole is large enough for the velocity difference between holes to be large, however, the velocity of the holes is not in inverse proportional to the area ratio

Computational Studies on the Performance of Flow Distributor in Tank

Energy Technology Data Exchange (ETDEWEB)

Shin, Soo Jai; Kim, Young In; Ryu, Seungyeob; Bae, Youngmin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

Core make-up tank (CMT) is full of borated water and provides makeup and boration to the reactor coolant system (RCS) for early stage of loss of coolant accident (LOCA) and non-LOCA. The top and bottom of CMT are connected to the RCS through the pressure balance line (PBL) and the safety injection line (SIL), respectively. Each PBL is normally open to maintain pressure of the CMT at RCS, and this arrangement enables the CMT to inject water to the RCS by gravity when the isolation valves of SIL are open. During CMT injection into the Reactor, the condensation and thermal stratification are observed in CMT and the rapid condensation disturbed the injection operation. The optimal design of the flow distributor is very important to ensure structural integrity of the reactor system and their safe operation during some transient or accident conditions. In the present study, we numerically investigated the performance of flow distributor in tank with different shape factor such as the total number of the holes, the pitch-to-hole diameter ratios (p/d), the diameter of the hole and the area ratios. These data will contribute to the design the flow distributor. In the present study, the model of the flow distributor in tank is simulated using the commercial CFD software, Fluent 13.0 with varying the different shape factor of the flow distributor such as the total number of the holes, the diameter of the holes and the area ratio. As the diameter of the hole is smaller, the velocity difference between holes, which is located at upper position and lower position of the flow distributor, also decreases. For larger area ratio, the velocity of the holes is slower. When the diameter of the hole is large enough for the velocity difference between holes to be large, however, the velocity of the holes is not in inverse proportional to the area ratio.

Recent progress of hard x-ray imaging microscopy and microtomography at BL37XU of SPring-8

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Yoshio, E-mail: yoshio@spring8.or.jp; Takeuchi, Akihisa; Terada, Yasuko; Uesugi, Kentaro [Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Sayo, Hyogo 679-5198 (Japan); Mizutani, Ryuta [Department of Applied Biochemistry, Tokai University, Hiratsuka, Kanagawa 259-1292 (Japan)

2016-01-28

A hard x-ray imaging microscopy and microtomography system is now being developed at the beamline 37XU of SPring-8. In the latest improvement, a spatial resolution of about 50 nm is achieved in two-dimensional imaging at 6 keV x-ray energy using a Fresnel zone plate objective with an outermost zone width of 35 nm. In the tomographic measurement, a spatial resolution of about 100 nm is achieved at 8 keV using an x-ray guide tube condenser optic and a Fresnel zone plate objective with an outermost zone width of 50 nm.

Effect of intramammary infusion of recombinant bovine GM-CSF and IL-8 on CMT score, somatic cell count, and milk mononuclear cell populations in Holstein cows with Staphylococcus aureus subclinical mastitis.

Science.gov (United States)

Kiku, Yoshio; Ozawa, Tomomi; Takahashi, Hideyuki; Kushibiki, Shiro; Inumaru, Shigeki; Shingu, Hiroyuki; Nagasawa, Yuya; Watanabe, Atsushi; Hata, Eiji; Hayashi, Tomohito

2017-09-01

The effect of intramammary infusion of recombinant bovine granulocyte-macrophage colony-stimulating factor (rbGM-CSF) and interleukin-8 (rbIL-8) on mononuclear cell populations in quarters, somatic cell count (SCC) and the California Mastitis Test (CMT) score were investigated. From the selected cows with naturally occurring Staphylococcus aureus subclinical mastitis, one quarter of each cow were selected for the infusions of rbGM-CSF (400 μg/5 mL/quarter, n = 9), rbIL-8 (1 mg/5 mL/quarter, n = 9), and phosphate-buffered saline (5 mL/quarter, n = 7). The CMT score of both cytokines post infusion temporarily increased between days 0 and 1 and significantly decreased between days 7 and 14 compared to the preinfusion level. The SCC on day 14 after infusions of rbGM-CSF tended to be lower than that of the control group. The percentage of CD14+ cells increased on days 1 and 2 post infusion of rbGM-CSF. The percentage of CD4+ and CD8+ cells also increased on days 2 and 3, suggesting that the infusion of rbGM-CSF enhanced cellular immunity in the mammary gland. In contrast, the percentage of CD14+ cells decreased on days 0.25 and 1 post infusion of rbIL-8. No significant changes in the percentages of CD4+ and CD8+ cells in milk after infusion of rbIL-8 were evident during the experimental period, which suggested that rbIL-8 had little effect on the function of T cells in the mammary gland. These results indicated that rbGM-CSF and rbIL-8 decreased the CMT score by a different mechanism and may have a potential as therapeutic agents for subclinical mastitis.

Structural investigation of spherical hollow excipient Mannit Q by X-ray microtomography.

Science.gov (United States)

Kajihara, Ryusuke; Noguchi, Shuji; Iwao, Yasunori; Yasuda, Yuki; Segawa, Megumi; Itai, Shigeru

2015-11-10

The structure of Mannit Q particles, an excipient made by spray-drying a d-mannitol solution, and Mannit Q tablets were investigated by synchrotron X-ray microtomography. The Mannit Q particles had a spherical shape with a hollow core. The shells of the particles consisted of fine needle-shaped crystals, and columnar crystals were present in the hollows. These structural features suggested the following formation mechanism for the hollow particles:during the spray-drying process, the solvent rapidly evaporated from the droplet surface, resulting in the formation of shells made of fine needle-shaped crystals.Solvent remaining inside the shells then evaporated slowly and larger columnar crystals grew as the hollows formed. Although most of the Mannit Q particles were crushed on tableting, some of the particles retained their hollow structures, probably because the columnar crystals inside the hollows functioned as props. This demonstrated that the tablets with porous void spaces may be readily manufactured using Mannit Q. Copyright © 2015 Elsevier B.V. All rights reserved.

Application of x-ray microtomography to environmental fluid flow problems

International Nuclear Information System (INIS)

Wildenschild, D.; Culligan, K.A.; Christensen, B.S.B.

2005-01-01

Many environmental processes are controlled by the micro-scale interaction of water and air with the solid phase (soils, sediments, rock) in pore spaces within the subsurface. The distribution in time and space of fluids in pores ultimately controls subsurface flow and contaminant transport relevant to groundwater resource management, contaminant remediation, and agriculture. Many of these physical processes operative at the pore-scale cannot be directly investigated using conventional hydrologic techniques, however recent developments in synchrotron-based micro-imaging have made it possible to observe and quantify pore-scale processes non-invasively. Micron-scale resolution makes it possible to track fluid flow within individual pores and therefore facilitates previously unattainable measurements. We report on experiments performed at the GSECARS** (Advanced Photon Source) microtomography facility and have measured properties such as porosity, fluid saturation and distribution within the pore space, as well as interfacial characteristics of the fluids involved (air, water, contaminant). Different image processing techniques were applied following mathematical reconstruction to produce accurate measurements of the physical flow properties. These new micron-scale measurements make it possible to test existing and new theory, as well as emerging numerical modeling schemes aimed at the pore scale.

Quantitative analysis of flow processes in a sand using synchrotron-based X-ray microtomography

DEFF Research Database (Denmark)

Wildenschild, Dorthe; Hopmans, J.W.; Rivers, M.L.

2005-01-01

been of a mostly qualitative nature and no experiments have been presented in the existing literature where a truly quantitative approach to investigating the multiphase flow process has been taken, including a thorough image-processing scheme. The tomographic images presented here show, both......Pore-scale multiphase flow experiments were developed to nondestructively visualize water flow in a sample of porous material using X-ray microtomography. The samples were exposed to similar boundary conditions as in a previous investigation, which examined the effect of initial flow rate...... by qualitative comparison and quantitative analysis in the form of a nearest neighbor analysis, that the dynamic effects seen in previous experiments are likely due to the fast and preferential drainage of large pores in the sample. Once a continuous drained path has been established through the sample, further...

X-ray microtomography study of the spallation response in Ta-W

International Nuclear Information System (INIS)

McDonald, S A; Withers, P J; Cotton, M; Millett, J C F; Bourne, N K

2014-01-01

Measurement of the damage field resulting from spallation due to shock induced loading is an important aspect of understanding the mechanisms controlling the dynamic tensile failure process. Furthermore, the ability to observe in three-dimensions, and in a non-invasive manner, the physical damage present in a spalled sample post-impact can provide important data for predictive damage models. In the current study, the influence of peak shock stress and pulse duration on the spallation damage response in the tantalum alloy Ta-2.5% W is presented. Rear surface velocimetry (HetV) measurements from plate impact experiments have been combined with 3-D characterisation and quantification of the resulting damage evolution in the recovered targets using X-ray microtomography. Small differences in spall strength are observed - an increase in the pulse duration results in a decrease in spall strength, while spall strength increases with increase in peak shock stress. The level of damaged induced (void coalescence) is more significant for an increase in pulse duration, with a local damage volume fraction double that of the case for an increase in peak shock stress.

Determination of structural geometric parameters of industrial ceramic foams by gamma rays transmission and X-rays microtomography

International Nuclear Information System (INIS)

Rocha, Wilson Roberto Dejato da

2005-01-01

In this work, the gamma rays transmission and X-rays microtomography techniques are used for the evaluation of the porosity and the pore size distribution of SiC ceramic foams. It was also accomplished the three-dimensional images after the determination of samples geometric parameters. The geometric parameters were obtained by two-dimensional images analyses, generated by a Microfocus system, with a CCD camera, an images intensifier, a X-rays tube and an automatic system for rotation of the sample. The spatial resolution of the images was about 32 μm. In the gamma rays transmission methodology, a Nal(Tl) scintillation detector, an 241 Am (59.53 keV, 100 mCi) radioactive source and an automatic X-Z micrometric table was used. The analyzed samples had pores density of 30, 45, 60, 80 and 100 ppi (pores per inch). The gamma rays transmission technique was accurate to supply the porosity of the samples, which ranged about 90% and was in agreement with the values supplied by manufacturer of the foams. The 30 and 45 ppi samples analyzed by X-rays microtomography showed porosity results that agree with the average porosity supplied by the manufacturer. In other hand, the 60, 80 and 100 ppi samples systematically showed average porosity about 4%, lower than the average of the manufacturer. The pore size distributions found through the software IMAGO show the presence of smaller pores than those nominated by the manufacturer. The 30 ppi samples had voids inside the solid material of the ceramic foams structure. Gaussian truncated method, used in the three-dimensional reconstruction, was not able to take into the account the voids inside the solid matrix. (author)

Structural changes of polymer-coated microgranules and excipients on tableting investigated by microtomography using synchrotron X-ray radiation.

Science.gov (United States)

Kajihara, Ryusuke; Noguchi, Shuji; Iwao, Yasunori; Suzuki, Yoshio; Terada, Yasuko; Uesugi, Kentaro; Itai, Shigeru

2015-03-15

Multiple-unit tablets consisting of polymer-coated microgranules and excipients have a number of advantageous pharmaceutical properties. Polymer-coated microgranules are known to often lose their functionality because of damage to the polymer coating caused by tableting, and the mechanism of polymer coating damage as well as the structural changes of excipients upon tableting had been investigated but without in-situ visualization and quantitative analysis. To elucidate the mechanism of coating damage, the internal structures of multiple-unit tablets were investigated by X-ray computed microtomography using synchrotron X-rays. Cross sectional images of the tablets with sub-micron spatial resolution clearly revealed that void spaces remained around the compressed excipient particles in the tablets containing an excipient composed of cellulose and lactose (Cellactose(®) 80), whereas much smaller void spaces remained in the tablets containing an excipient made of sorbitol (Parteck(®) SI 150). The relationships between the void spaces and the physical properties of the tablets such as hardness and disintegration were investigated. Damage to the polymer coating in tablets was found mainly where polymer-coated microgranules were in direct contact with each other in both types of tablets, which could be attributed to the difference in hardness of excipient particles and the core of the polymer-coated microgranules. Copyright © 2015 Elsevier B.V. All rights reserved.

Influence of pore size distributions on decomposition of maize leaf residue: evidence from X-ray computed micro-tomography

Science.gov (United States)

Negassa, Wakene; Guber, Andrey; Kravchenko, Alexandra; Rivers, Mark

2014-05-01

Soil's potential to sequester carbon (C) depends not only on quality and quantity of organic inputs to soil but also on the residence time of the applied organic inputs within the soil. Soil pore structure is one of the main factors that influence residence time of soil organic matter by controlling gas exchange, soil moisture and microbial activities, thereby soil C sequestration capacity. Previous attempts to investigate the fate of organic inputs added to soil did not allow examining their decomposition in situ; the drawback that can now be remediated by application of X-ray computed micro-tomography (µ-CT). The non-destructive and non-invasive nature of µ-CT gives an opportunity to investigate the effect of soil pore size distributions on decomposition of plant residues at a new quantitative level. The objective of this study is to examine the influence of pore size distributions on the decomposition of plant residue added to soil. Samples with contrasting pore size distributions were created using aggregate fractions of five different sizes (pieces of maize leaves 2.5 mg in size (equivalent to 1.71 mg C g-1 soil) were added to half of the studied samples. Samples with and without maize leaves were incubated for 120 days. CO2 emission from the samples was measured at regular time intervals. In order to ensure that the observed differences are due to differences in pore structure and not due to differences in inherent properties of the studied aggregate fractions, we repeated the whole experiment using soil from the same aggregate size fractions but ground to six replicated samples were used for intact and ground samples of all sizes with and without leaves. Two replications of the intact aggregate fractions of all sizes with leaves were subjected to µ-CT scanning before and after incubation, whereas all the remaining replications of both intact and ground aggregate fractions of <0.05, 0.05-0.1, and 1.0-2.0 mm sizes with leaves were scanned with µ-CT after

Analyzing the compressive behavior of porous Ti6Al4V by X-ray microtomography

Energy Technology Data Exchange (ETDEWEB)

Farias, Iván; Jimenez, Omar; Flores, Martín [Departamento de Ingeniería de Proyectos, Universidad de Guadalajara, Jalisco (Mexico); Olmos, Luís, E-mail: luisra24@gmail.com [Instituto de Investigaciones en Ciencias de la Tierra (INICIT), Universidad Michoacana de San Nicolás de Hidalgo, Michoacán (Mexico); Vergara-Hernández, Héctor Javier; Gárnica, Pedro [Instituto Tecnológico de Morelia, Michoacán (Mexico); Bouvard, Didier [Science et Ingénierie des Matériaux et Procédés (SIMaP), Université Grenoble Alpes (France)

2017-11-15

Samples with 40% vol. of pores and a pore size distribution between 100 and 500 μm were produced by powder metallurgy from Ti6Al4V alloy powders. Sintering was performed at 1300 °C during one hour in an inert Argon atmosphere in a vertical dilatometer. The compressive strength and the porosity of these samples was investigated before and after compression tests through X-ray microtomography. The values of the elastic modulus (8GPa) and yield strength (80MPa) are within the range of those used in bone implants. Porosity leads to greater deformation whereas fracture of compacts occurs perpendicularly to the applied load. It was determined that the origin of the failure is generated by rupture of interparticle necks and, large pores enhance the propagation of cracks. (author)

Analyzing the compressive behavior of porous Ti6Al4V by X-ray microtomography

International Nuclear Information System (INIS)

Farias, Iván; Jimenez, Omar; Flores, Martín; Olmos, Luís; Vergara-Hernández, Héctor Javier; Gárnica, Pedro; Bouvard, Didier

2017-01-01

Samples with 40% vol. of pores and a pore size distribution between 100 and 500 μm were produced by powder metallurgy from Ti6Al4V alloy powders. Sintering was performed at 1300 °C during one hour in an inert Argon atmosphere in a vertical dilatometer. The compressive strength and the porosity of these samples was investigated before and after compression tests through X-ray microtomography. The values of the elastic modulus (8GPa) and yield strength (80MPa) are within the range of those used in bone implants. Porosity leads to greater deformation whereas fracture of compacts occurs perpendicularly to the applied load. It was determined that the origin of the failure is generated by rupture of interparticle necks and, large pores enhance the propagation of cracks. (author)

Effects of manual threshold setting on image analysis results of a sandstone sample structural characterization by X-ray microtomography

International Nuclear Information System (INIS)

Moreira, Anderson C.; Fernandes, Celso P.; Fernandes, Jaquiel S.; Marques, Leonardo C.; Appoloni, Carlos R.; Nagata, Rodrigo

2009-01-01

X-ray microtomography is a nondestructive nuclear technique widely applied for samples structural characterization. This methodology permits the investigation of materials porous phase, without special sample preparation, generating bidimensional images of the irradiated sample. The images are generated by the linear attenuation coefficient mapping of the sample. In order to do a quantitative characterization, the images have to be binarized, separating porous phase from the material matrix. The choice of the correct threshold in the grey level histogram is an important and discerning procedure for the binary images creation. Slight variations of the threshold level led to substantial variations in physical parameters determination, like porosity and pore size distribution values. The aim of this work is to evaluate these variations based on some manual threshold setting. Employing Imago image analysis software, four operators determined the porosity and pore size distribution of a sandstone sample by image analysis. The microtomography measurements were accomplished with the following scan conditions: 60 kV, 165 μA, 1 mm Al filter, 0.45 deg step size and 180.0 deg total rotation angle with and 3.8 μm and 11 μm spatial resolution. The global average porosity values, determined by the operators, range from 27.8 to 32.4 % for 3.8 μm spatial resolution and 12.3 to 28.3 % for 11 μm spatial resolution. Percentage differences among the pore size distributions were also found. For the same pore size range, 5.5 % and 17.1 %, for 3.8 μm and 11 μm spatial resolutions respectively, were noted. (author)

Three dimensional characterization of soil macroporosity by X-ray microtomography

International Nuclear Information System (INIS)

Passoni, Sabrina; Pires, Luiz Fernando; Rosa, Jadir Aparecido

2015-01-01

Analysis of the soil pore system represents an important way of characterizing soil structure. Properties such as the shape and number of pores can be determined through soil pore evaluations. This study presents a three-dimensional (3D) characterization of the shape and number of pores of a sub-tropical soil. To do so, a second generation X-ray microtomography equipped with a plain type detector was employed. A voltage of 120 kV and current of 80 mA was applied to the X-ray tube. The soil samples analyzed were collected at three different depths (0-10, 10-20, and 20-30 cm). The results obtained allowed qualitative (images) and quantitative (3D) analyses of the soil structure, revealing the potential of the microtomographic technique, as well as the study of differences in soil macroporosity at different depths. Macroporosity was 5.14 % in the 0-10 cm layer, 5.10 % in the 10-20 cm layer, and 6.64 % in the 20-30 cm layer. The macroporosity of unclassified pores (UN) was 0.30 % (0-10 and 10-20 cm) and 0.40 % (20-30 cm), while equant pores (EQ) had values of 0.01 % at the three depths under analysis. (author)

Three dimensional characterization of soil macroporosity by X-ray microtomography

Energy Technology Data Exchange (ETDEWEB)

Passoni, Sabrina [Centro de Ensino Superior dos Campos Gerais, Ponta Grossa, PR (Brazil); Pires, Luiz Fernando, E-mail: lfpires@uepg.br [Universidade Estadual de Ponta Grossa (UFPG), Ponta Grossa, PR (Brazil). Departamento de Fisica; Heck, Richard [University of Guelph, School of Environmental Sciences, Guelph, Ontario (Canada); Rosa, Jadir Aparecido [Instituto Agronomico do Parana, Polo Regional de Pesquisa de Ponta Grossa, Ponta Grossa, PR (Brazil)

2015-03-15

Analysis of the soil pore system represents an important way of characterizing soil structure. Properties such as the shape and number of pores can be determined through soil pore evaluations. This study presents a three-dimensional (3D) characterization of the shape and number of pores of a sub-tropical soil. To do so, a second generation X-ray microtomography equipped with a plain type detector was employed. A voltage of 120 kV and current of 80 mA was applied to the X-ray tube. The soil samples analyzed were collected at three different depths (0-10, 10-20, and 20-30 cm). The results obtained allowed qualitative (images) and quantitative (3D) analyses of the soil structure, revealing the potential of the microtomographic technique, as well as the study of differences in soil macroporosity at different depths. Macroporosity was 5.14 % in the 0-10 cm layer, 5.10 % in the 10-20 cm layer, and 6.64 % in the 20-30 cm layer. The macroporosity of unclassified pores (UN) was 0.30 % (0-10 and 10-20 cm) and 0.40 % (20-30 cm), while equant pores (EQ) had values of 0.01 % at the three depths under analysis. (author)

High-contrast x-ray microtomography in dental research

Science.gov (United States)

Davis, Graham; Mills, David

2017-09-01

X-ray microtomography (XMT) is a well-established technique in dental research. The technique has been used extensively to explore the complex morphology of the root canal system, and to qualitatively and quantitatively evaluate root canal instrumentation and filling efficacy in extracted teeth; enabling different techniques to be compared. Densitometric information can be used to identify and map demineralized tissue resulting from tooth decay (caries) and, in extracted teeth, the method can be used to evaluate different methods of excavation. More recently, high contrast XMT is being used to investigate the relationship between external insults to teeth and the pulpal reaction. When such insults occur, fluid may flow through dentinal tubules as a result of cracking or porosity in enamel. Over time, there is an increase in mineralization along the paths of the tubules from the pulp to the damaged region in enamel and this can be visualized using high contrast XMT. The scanner used for this employs time-delay integration to minimize the effects of detector inhomogeneity in order to greatly increase the upper limit on signal-to-noise ratio that can be achieved with long exposure times. When enamel cracks are present in extracted teeth, the presence of these pathways indicates that the cracking occurred prior to extraction. At high contrast, growth lines are occasionally seen in deciduous teeth which may have resulted from periods of maternal illness. Various other anomalies in mineralization resulting from trauma or genetic abnormalities can also be investigated using this technique.

High-frame-rate imaging of biological samples with optoacoustic micro-tomography

Science.gov (United States)

Deán-Ben, X. Luís.; López-Schier, Hernán.; Razansky, Daniel

2018-02-01

Optical microscopy remains a major workhorse in biological discovery despite the fact that light scattering limits its applicability to depths of ˜ 1 mm in scattering tissues. Optoacoustic imaging has been shown to overcome this barrier by resolving optical absorption with microscopic resolution in significantly deeper regions. Yet, the time domain is paramount for the observation of biological dynamics in living systems that exhibit fast motion. Commonly, acquisition of microscopy data involves raster scanning across the imaged volume, which significantly limits temporal resolution in 3D. To overcome these limitations, we have devised a fast optoacoustic micro-tomography (OMT) approach based on simultaneous acquisition of 3D image data with a high-density hemispherical ultrasound array having effective detection bandwidth around 25 MHz. We performed experiments by imaging tissue-mimicking phantoms and zebrafish larvae, demonstrating that OMT can provide nearly cellular resolution and imaging speed of 100 volumetric frames per second. As opposed to other optical microscopy techniques, OMT is a hybrid method that resolves optical absorption contrast acoustically using unfocused light excitation. Thus, no penetration barriers are imposed by light scattering in deep tissues, suggesting it as a powerful approach for multi-scale functional and molecular imaging applications.

Biodegradable magnesium-based implants in bone studied by synchrotron radiation microtomography

Science.gov (United States)

Moosmann, Julian; Zeller-Plumhoff, Berit; Wieland, D. C. Florian; Galli, Silvia; Krüger, Diana; Dose, Thomas; Burmester, Hilmar; Wilde, Fabian; Bech, Martin; Peruzzi, Niccolò; Wiese, Björn; Hipp, Alexander; Beckmann, Felix; Hammel, Jörg; Willumeit-Römer, Regine

2017-09-01

Permanent implants made of titanium or its alloys are the gold standard in many orthopedic and traumatological applications due to their good biocompatibility and mechanical properties. However, a second surgical intervention is required for this kind of implants as they have to be removed in the case of children that are still growing or on patient's demand. Therefore, magnesium-based implants are considered for medical applications as they are degraded under physiological conditions. The major challenge is tailoring the degradation in a manner that is suitable for a biological environment and such that stabilization of the bone is provided for a controlled period. In order to understand failure mechanisms of magnesium-based implants in orthopedic applications and, further, to better understand the osseointegration, screw implants in bone are studied under mechanical load by means of a push-out device installed at the imaging beamline P05 of PETRA III at DESY. Conventional absorption contrast microtomography and phasecontrast techniques are applied in order to monitor the bone-to-implant interface under increasing load conditions. In this proof-of-concept study, first results from an in situ push-out experiment are presented.

X-ray microtomography study of the compaction process of rods under tapping.

Science.gov (United States)

Fu, Yang; Xi, Yan; Cao, Yixin; Wang, Yujie

2012-05-01

We present an x-ray microtomography study of the compaction process of cylindrical rods under tapping. The process is monitored by measuring the evolution of the orientational order parameter, local, and overall packing densities as a function of the tapping number for different tapping intensities. The slow relaxation dynamics of the orientational order parameter can be well fitted with a stretched-exponential law with stretching exponents ranging from 0.9 to 1.6. The corresponding relaxation time versus tapping intensity follows an Arrhenius behavior which is reminiscent of the slow dynamics in thermal glassy systems. We also investigated the boundary effect on the ordering process and found that boundary rods order faster than interior ones. In searching for the underlying mechanism of the slow dynamics, we estimated the initial random velocities of the rods under tapping and found that the ordering process is compatible with a diffusion mechanism. The average coordination number as a function of the tapping number at different tapping intensities has also been measured, which spans a range from 6 to 8.

Granule-by-granule reconstruction of a sandpile from x-ray microtomography data

International Nuclear Information System (INIS)

Seidler, G. T.; Martinez, G.; Seeley, L. H.; Kim, K. H.; Behne, E. A.; Zaranek, S.; Chapman, B. D.; Heald, S. M.; Brewe, D. L.

2000-01-01

Mesoscale disordered materials are ubiquitous in industry and in the environment. Any fundamental understanding of the transport and mechanical properties of such materials must follow from a thorough understanding of their structure. However, in the overwhelming majority of cases, experimental characterization of such materials has been limited to first- and second-order structural correlation functions, i.e., the mean filling fraction and the structural autocorrelation function. We report here the successful combination of synchrotron x-ray microtomography and image processing to determine the full three-dimensional real-space structure of a model disordered material, a granular bed of relatively monodisperse glass spheres. Specifically, we determine the center location and the local connectivity of each granule. This complete knowledge of structure can be used to calculate otherwise inaccessible high-order correlation functions. We analyze nematic order parameters for contact bonds to characterize the geometric anisotropy or fabric induced by the sample boundary conditions. Away from the boundaries we find short-range bond orientational order exhibiting characteristics of the underlying polytetrahedral structure

Fast x-ray fluorescence microtomography of hydrated biological samples.

Directory of Open Access Journals (Sweden)

Enzo Lombi

Full Text Available Metals and metalloids play a key role in plant and other biological systems as some of them are essential to living organisms and all can be toxic at high concentrations. It is therefore important to understand how they are accumulated, complexed and transported within plants. In situ imaging of metal distribution at physiological relevant concentrations in highly hydrated biological systems is technically challenging. In the case of roots, this is mainly due to the possibility of artifacts arising during sample preparation such as cross sectioning. Synchrotron x-ray fluorescence microtomography has been used to obtain virtual cross sections of elemental distributions. However, traditionally this technique requires long data acquisition times. This has prohibited its application to highly hydrated biological samples which suffer both radiation damage and dehydration during extended analysis. However, recent advances in fast detectors coupled with powerful data acquisition approaches and suitable sample preparation methods can circumvent this problem. We demonstrate the heightened potential of this technique by imaging the distribution of nickel and zinc in hydrated plant roots. Although 3D tomography was still impeded by radiation damage, we successfully collected 2D tomograms of hydrated plant roots exposed to environmentally relevant metal concentrations for short periods of time. To our knowledge, this is the first published example of the possibilities offered by a new generation of fast fluorescence detectors to investigate metal and metalloid distribution in radiation-sensitive, biological samples.

In vivo bioprinting for computer- and robotic-assisted medical intervention: preliminary study in mice

Energy Technology Data Exchange (ETDEWEB)

Keriquel, Virginie; Guillemot, Fabien; Arnault, Isabelle; Guillotin, Bertrand; Amedee, Joelle; Fricain, Jean-Christophe; Catros, Sylvain [INSERM, U577, Bordeaux, F-33076 (France) and Universite Victor Segalen Bordeaux 2, UMR-S577 Bordeaux, F-33076 (France); Miraux, Sylvain [Centre de Resonance Magnetique des Systemes Biologiques, UMR 5536 (France)

2010-03-15

We present the first attempt to apply bioprinting technologies in the perspective of computer-assisted medical interventions. A workstation dedicated to high-throughput biological laser printing has been designed. Nano-hydroxyapatite (n-HA) was printed in the mouse calvaria defect model in vivo. Critical size bone defects were performed in OF-1 male mice calvaria with a 4 mm diameter trephine. Prior to laser printing experiments, the absence of inflammation due to laser irradiation onto mice dura mater was shown by means of magnetic resonance imaging. Procedures for in vivo bioprinting and results obtained using decalcified sections and x-ray microtomography are discussed. Although heterogeneous, these preliminary results demonstrate that in vivo bioprinting is possible. Bioprinting may prove to be helpful in the future for medical robotics and computer-assisted medical interventions.

In vivo bioprinting for computer- and robotic-assisted medical intervention: preliminary study in mice

International Nuclear Information System (INIS)

Keriquel, Virginie; Guillemot, Fabien; Arnault, Isabelle; Guillotin, Bertrand; Amedee, Joelle; Fricain, Jean-Christophe; Catros, Sylvain; Miraux, Sylvain

2010-01-01

We present the first attempt to apply bioprinting technologies in the perspective of computer-assisted medical interventions. A workstation dedicated to high-throughput biological laser printing has been designed. Nano-hydroxyapatite (n-HA) was printed in the mouse calvaria defect model in vivo. Critical size bone defects were performed in OF-1 male mice calvaria with a 4 mm diameter trephine. Prior to laser printing experiments, the absence of inflammation due to laser irradiation onto mice dura mater was shown by means of magnetic resonance imaging. Procedures for in vivo bioprinting and results obtained using decalcified sections and x-ray microtomography are discussed. Although heterogeneous, these preliminary results demonstrate that in vivo bioprinting is possible. Bioprinting may prove to be helpful in the future for medical robotics and computer-assisted medical interventions.

About a method for compressing x-ray computed microtomography data

Science.gov (United States)

Mancini, Lucia; Kourousias, George; Billè, Fulvio; De Carlo, Francesco; Fidler, Aleš

2018-04-01

The management of scientific data is of high importance especially for experimental techniques that produce big data volumes. Such a technique is x-ray computed tomography (CT) and its community has introduced advanced data formats which allow for better management of experimental data. Rather than the organization of the data and the associated meta-data, the main topic on this work is data compression and its applicability to experimental data collected from a synchrotron-based CT beamline at the Elettra-Sincrotrone Trieste facility (Italy) and studies images acquired from various types of samples. This study covers parallel beam geometry, but it could be easily extended to a cone-beam one. The reconstruction workflow used is the one currently in operation at the beamline. Contrary to standard image compression studies, this manuscript proposes a systematic framework and workflow for the critical examination of different compression techniques and does so by applying it to experimental data. Beyond the methodology framework, this study presents and examines the use of JPEG-XR in combination with HDF5 and TIFF formats providing insights and strategies on data compression and image quality issues that can be used and implemented at other synchrotron facilities and laboratory systems. In conclusion, projection data compression using JPEG-XR appears as a promising, efficient method to reduce data file size and thus to facilitate data handling and image reconstruction.

Synchrotron radiation X-ray microtomography and histomorphometry for evaluation of chemotherapy effects in trabecular bone structure

International Nuclear Information System (INIS)

Alessio, R; Almeida, A P; Braz, D; Nogueira, L P; Colaço, M V; Barroso, R C; Andrade, C B V; Salata, C; De Almeida, C E; Ferreira-Machado, S C; Tromba, G

2014-01-01

Three-dimensional microtomography has the potential to examine complete bones of small laboratory animals with very high resolution in a non-invasive way. One of the side effects caused by some chemotherapy drugs is the induction of amenorrhea, temporary or not, in premenopausal women, with a consequent decrease in estrogen production, which can lead to bone changes. In the present work, the femur heads of rats treated with chemotherapy drugs were evaluated by 3D histomorphometry using synchrotron radiation microcomputed tomography. Control animals were also evaluated for comparison. The 3D tomographic images were obtained at the SYRMEP (SYnchrotron Radiation for MEdical Physics) beamline at the Elettra Synchrotron Laboratory in Trieste, Italy. Results showed significant differences in morphometric parameters measured from the 3D images of femur heads of rats in both analyzed groups.

Synchrotron radiation X-ray microtomography and histomorphometry for evaluation of chemotherapy effects in trabecular bone structure

Science.gov (United States)

Alessio, R.; Nogueira, L. P.; Almeida, A. P.; Colaço, M. V.; Braz, D.; Andrade, C. B. V.; Salata, C.; Ferreira-Machado, S. C.; de Almeida, C. E.; Tromba, G.; Barroso, R. C.

2014-04-01

Three-dimensional microtomography has the potential to examine complete bones of small laboratory animals with very high resolution in a non-invasive way. One of the side effects caused by some chemotherapy drugs is the induction of amenorrhea, temporary or not, in premenopausal women, with a consequent decrease in estrogen production, which can lead to bone changes. In the present work, the femur heads of rats treated with chemotherapy drugs were evaluated by 3D histomorphometry using synchrotron radiation microcomputed tomography. Control animals were also evaluated for comparison. The 3D tomographic images were obtained at the SYRMEP (SYnchrotron Radiation for MEdical Physics) beamline at the Elettra Synchrotron Laboratory in Trieste, Italy. Results showed significant differences in morphometric parameters measured from the 3D images of femur heads of rats in both analyzed groups.

Use of micro-tomography for validation of method to identify interfacial shear strength from tensile tests of short regenerated cellulose fibre composites

DEFF Research Database (Denmark)

Hajlane, A.; Miettinen, A.; Madsen, Bo

2016-01-01

The interfacial shear strength of short regenerated cellulose fibre/polylactide composites was characterized by means of an industry-friendly adhesion test method. The interfacial shear strength was back-calculated from the experimental tensile stress-strain curves of composites by using a micro......-mechanical model. The parameters characterizing the microstructure of the composites, e.g. fibre length and orientation distributions, used as input in the model were obtained by micro-tomography. The investigation was carried out on composites with untreated and surface treated fibres with various fibre weight...

Search for Fluid Inclusions in a Carbonaceous Chondrite Using a New X-Ray Micro-Tomography Technique Combined with FIB Sampling

Science.gov (United States)

Tsuchiyama, A.; Miyake, A.; Zolensky, M. E.; Uesugi, K.; Nakano, T.; Takeuchi, A.; Suzuki, Y.; Yoshida, K.

2014-01-01

Early solar system aqueous fluids are preserved in some H chondrites as aqueous fluid inclusions in halite (e.g., [1]). Although potential fluid inclusions are also expected in carbonaceous chondrites [2], they have not been surely confirmed. In order to search for these fluid inclusions, we have developped a new X-ray micro-tomography technique combined with FIB sampling and applied this techniqu to a carbanaceous chondrite. Experimental: A polished thin section of Sutter's Mill meteorite (CM) was observed with an optical microscope and FE-SEM (JEOL 7001F) for chosing mineral grains of carbonates (mainly calcite) and sulfides (FeS and ZnS) 20-50 microns in typical size, which may have aqueous fluid inclusions. Then, a "house" similar to a cube with a roof (20-30 microns in size) is sampled from the mineral grain by using FIB (FEI Quanta 200 3DS). Then, the house was atached to a thin W-needle by FIB and imaged by a SR-based imaging microtomography system with a Fresnel zone plate at beamline BL47XU, SPring-8, Japan. One sample was imaged at two X-ray energies, 7 and 8 keV, to identify mineral phases (dual-enegy microtomography: [3]). The size of voxel (pixel in 3D) was 50-80 nm, which gave the effective spatial resolution of approx. 200 nm. A terrestrial quartz sample with an aqueous fluid inclusion with a bubble was also examined as a test sample by the same method. Results and discussion: A fluid inclusion of 5-8 microns in quartz was clearly identified in a CT image. A bubble of approx. 4 microns was also identified as refraction contrast although the X-ray absorption difference between fluid and bubble is small. Volumes of the fluid and bubble were obtained from the 3D CT images. Fourteen grains of calcite, two grains of iron sulfide and one grain of (Zn,Fe)S were examined. Ten calcite, one iron sulfide and one (Zn,Fe)S grains have inclusions >1 micron in size (the maximum: approx. 5 microns). The shapes are spherical or irregular. Tiny inclusions (tiny solid

Magnetic resonance imaging and X-ray microtomography studies of a gel-forming tablet formulation.

Science.gov (United States)

Laity, P R; Mantle, M D; Gladden, L F; Cameron, R E

2010-01-01

The capabilities of two methods for investigating tablet swelling are investigated, based on a study of a model gel-forming system. Results from magnetic resonance imaging (MRI) were compared with results from a novel application of X-ray microtomography (XmicroT) to track the movements of embedded glass microsphere tracers as the model tablets swelled. MRI provided information concerning the movement of hydration fronts into the tablets and the composition of the swollen gel layer, which formed at the tablet surface and progressively thickened with time. Conversely, XmicroT revealed significant axial expansion within the tablet core, at short times and ahead of the hydration fronts, where there was insufficient water to be observed by MRI (estimated to be around 15% by weight for the system used here). Thus, MRI and XmicroT may be regarded as complementary methods for studying the hydration and swelling behaviour of tablets. Copyright 2009 Elsevier B.V. All rights reserved.

Relationship between chemical structure of soil organic matter and intra-aggregate pore structure: evidence from X-ray computed micro-tomography

Science.gov (United States)

Kravchenko, Alexandra; Grandy, Stuart A.

2014-05-01

Understanding chemical structure of soil organic matter (SOM) and factors that affect it are vital for gaining understanding of mechanisms of C sequestration by soil. Physical protection of C by adsorption to mineral particles and physical disconnection between C sources and microbial decomposers is now regarded as the key component of soil C sequestration. Both of the processes are greatly influenced by micro-scale structure and distribution of soil pores. However, because SOM chemical structure is typically studied in disturbed (ground and sieved) soil samples the experimental evidence of the relationships between soil pore structure and chemical structure of SOM are still scarce. Our study takes advantage of the X-ray computed micro-tomography (µ-CT) tools that enable non-destructive analysis of pore structure in intact soil samples. The objective of this study is to examine the relationship between SOM chemical structure and pore-characteristics in intact soil macro-aggregates from two contrasting long-term land uses. The two studied land use treatments are a conventionally tilled corn-soybean-wheat rotation treatment and a native succession vegetation treatment removed from agricultural use >20 years ago. The study is located in southwest Michigan, USA, on sandy-loam Typic Hapludalfs. For this study we used soil macro-aggregates 4-6 mm in size collected at 0-15 cm depth. The aggregate size was selected so as both to enable high resolution of µ-CT and to provide sufficient amount of soil for C measurements. X-ray µ-CT scanning was conducted at APS Argonne at a scanning resolution of 14 µm. Two scanned aggregates (1 per treatment) were used in this preliminary study. Each aggregate was cut into 7 "geo-referenced" sections. Analyses of pore characteristics in each section were conducted using 3DMA and ImageJ image analysis tools. SOM chemistry was analyzed using pyrolysis/gas chromatography-mass spectroscopy. Results demonstrated that the relationships

Synchrotron-Radiation Induced X-Ray Emission (SRIXE)

Energy Technology Data Exchange (ETDEWEB)

Jones, Keith W.

1999-09-01

and increase in scientific use can be maintained for the synchrotron x-ray source. A short summary of the present state of the synchrotron radiation-induced x-ray emission (SRIXE) method is presented here. Basically, SRIXE experiments can include any that depend on the detection. of characteristic x-rays produced by the incident x-ray beam born the synchrotron source as they interact with a sample. Thus, experiments done to measure elemental composition, chemical state, crystal, structure, and other sample parameters can be considered in a discussion of SRIXE. It is also clear that the experimentalist may well wish to use a variety of complementary techniques for study of a given sample. For this reason, discussion of computed microtomography (CMT) and x-ray diffraction is included here. It is hoped that this present discussion will serve as a succinct introduction to the basic ideas of SRIXE for those not working in the field and possibly help to stimulate new types of work by those starting in the field as well as by experienced practitioners of the art. The topics covered include short descriptions of (1) the properties of synchrotron radiation, (2) a description of facilities used for its production, (3) collimated microprobe, (4) focused microprobes, (5) continuum and monoenergetic excitation, (6) detection limits, (7) quantitation, (8) applications of SRIXE, (9) computed microtomography (CMT), and (10)chemical speciation using x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine structure (EXAFS). An effort has been made to cite a wide variety of work from different laboratories to show the vital nature of the field.

Synchrotron-Radiation Induced X-Ray Emission (SRIXE)

International Nuclear Information System (INIS)

Jones, Keith W.

1999-01-01

and increase in scientific use can be maintained for the synchrotron x-ray source. A short summary of the present state of the synchrotron radiation-induced x-ray emission (SRIXE) method is presented here. Basically, SRIXE experiments can include any that depend on the detection. of characteristic x-rays produced by the incident x-ray beam born the synchrotron source as they interact with a sample. Thus, experiments done to measure elemental composition, chemical state, crystal, structure, and other sample parameters can be considered in a discussion of SRIXE. It is also clear that the experimentalist may well wish to use a variety of complementary techniques for study of a given sample. For this reason, discussion of computed microtomography (CMT) and x-ray diffraction is included here. It is hoped that this present discussion will serve as a succinct introduction to the basic ideas of SRIXE for those not working in the field and possibly help to stimulate new types of work by those starting in the field as well as by experienced practitioners of the art. The topics covered include short descriptions of (1) the properties of synchrotron radiation, (2) a description of facilities used for its production, (3) collimated microprobe, (4) focused microprobes, (5) continuum and monoenergetic excitation, (6) detection limits, (7) quantitation, (8) applications of SRIXE, (9) computed microtomography (CMT), and (10)chemical speciation using x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine structure (EXAFS). An effort has been made to cite a wide variety of work from different laboratories to show the vital nature of the field

Assessment of the Structural Integrity of a Prototypical Instrumented IFMIF High Flux Test Module Rig by Fully 3D X-Ray Microtomography

International Nuclear Information System (INIS)

Tiseanu, I.; Craciunescu, T.; Mandache, B.N.; Simon, M.; Heinzel, V.; Stratmanns, E.; Simakov, S.P.; Leichtle, D.

2006-01-01

An inspection procedure to asses the mechanical integrity of IFMIF (International Fusion Materials Irradiation Facility) capsules and rigs during the irradiation campaign is necessary. Due to its penetration ability and contrast mechanism, the X-ray micro-tomography is the only known tool that could meet these requirements. In the High Flux Test Module (HFTM) of IFMIF miniaturized specimens are densely packed in capsules. The capsules which wear electric heaters and thermocouples are housed in rigs. To assure a well defined thermal contact the heater wires have to be attached to the capsules by brazing them into grooves. The examination of the quality of the braze material layer is of crucial interest in order to assure the best heat coupling of the heater wires to the capsule. A high density of the heaters is necessary to maintain the required temperature and, in addition NaK filling of narrow channels is employed for improving the 3D-heat transfer between the irradiation specimens and the capsule wall. Fully 3D tomographic inspections of a prototypical HFTM instrumented capsule, developed and manufactures at FZK, were conducted. In order to identify the optimum irradiation parameters and scanning configuration we carried out a comparative NDT analysis on two micro-tomography facilities, our compact, high magnification installation at NILPRP and two high-end industrial tomography facilities with higher X-ray energy and intensity at HWM. At optimum inspection parameters of a microfocus X-ray source (U=220 kV and I=300 μA) the geometry resolution was about 30-50 microns for characteristic dimension of the sample of 50 mm. Voids of 30 microns diameter and cracks of about 20 microns width can be detected. The absolute error of geometrical measurements should be sufficient for the assessment of the structural integrity of the irradiation capsule and for the geometry description within the thermal-hydraulic modeling. Space resolution could be further improved if one

Founder effect and estimation of the age of the c.892C>T (p.Arg298Cys) mutation in LMNA associated to Charcot-Marie-Tooth subtype CMT2B1 in families from North Western Africa.

Science.gov (United States)

Hamadouche, T; Poitelon, Y; Genin, E; Chaouch, M; Tazir, M; Kassouri, N; Nouioua, S; Chaouch, A; Boccaccio, I; Benhassine, T; De Sandre-Giovannoli, A; Grid, D; Lévy, N; Delague, V

2008-09-01

CMT2B1, an axonal subtype (MIM 605588) of the Charcot-Marie-Tooth disease, is an autosomal recessive motor and sensory neuropathy characterized by progressive muscular and sensory loss in the distal extremities with chronic distal weakness. The genetic defect associated with the disease is, to date, a unique homozygous missense mutation, p.Arg298Cys (c.892C>T), in the LMNA gene. So far, this mutation has only been found in affected individuals originating from a restricted region of North Western Africa (northwest of Algeria and east of Morocco), strongly suggesting a founder effect. In order to address this hypothesis, genotyping of both STRs and intragenic SNPs was performed at the LMNA locus, at chromosome 1q21.2-q21.3, in 42 individuals affected with CMT2B1 from 25 Algerian families. Our results indicate that the affected individuals share a common ancestral haplotype in a region of about 1.0 Mb (1 cM) and that the most recent common ancestor would have lived about 800-900 years ago (95% confidence interval: 550 to 1300 years).

Characterization of test specimens produced in reduced size for X-ray microtomography (µ-CT tests

Directory of Open Access Journals (Sweden)

E. E. BERNARDES

Full Text Available Abstract The need to use reduced sample sizes, in order to attain improved spatial resolution in (µ-CT tests applied in Portland cement composites, makes researchers perform the fractionation of materials to obtain samples with dimensions compatible with the capacity of the scanning equipment, which might cause alterations in the microstructure under analysis. Therefore, a test specimen (TS with dimensions compatible with the scanning capacity of a microtomography system that operates with an X-ray tube and voltage ranging from 20 to 100 kV was proposed. Axial compression strength tests were made and their total porosity was assessed by an apparent density and solid fraction density ratio, which were obtained by means of mercury and helium pycnometry and µ-CT technique, respectively. The adoption of that TS has shown to be viable for providing a sample with a higher level of representation.

High-resolution 3D X-ray microtomography as tool to investigate size distribution of grain phase and pore space in sandstones

Science.gov (United States)

Kahl, Wolf-Achim; Holzheid, Astrid

2013-04-01

The geometry and internal structures of sandstone reservoirs, like grain size, sorting, degree of bioturbation, and the history of the diagenetic alterations determine the quantity, flow rates, and recovery of hydrocarbons present in the pore space. In this respect, processes influencing the deep reservoir quality in sandstones are either of depositional, shallow diagenetic, or deep-burial origin. To assess the effect of compaction and cementation on the pore space during diagenesis, we investigated a set of sandstone samples using high-resolution microtomography (µ-CT). By high-resolution µ-CT, size distributions (in 2D and 3D), surface areas and volume fractions of the grain skeleton and pore space of sandstones and - in addition - of mineral powders have been determined. For this study, we analysed aliquots of sandstones that exhibit either complete, partial or no cemententation of the pore space, and sets of mineral powders (quartz, feldspar, calcite). As the resolution of the µ-CT scans is in the µm-range, the surface areas determined for sandstones and powders do detect the geometric surface of the material (Kahl & Holzheid, 2010). Since there are differing approaches to "size" parameters like e.g., long/short particle axes, area equivalent radius, Feret-diameter (2D), and structural thickness (3D), we decided to illustrate the effect of various size determinations for (a) single grains, (b) grain skeletons, and (c) pore space. Therefor, the computer-aided morphometric analysis of the segmented 3D models of the reconstructed scan images comprises versatile calculation algorithms. For example, size distribution of the pore space of partially cemented sandstones can be used to infer the timing of the formation of the cement in respect to tectonic/diagenetic activities. In the case of a late-stage partial cementation of a Bunter sandstone, both pore space and cement phase show identical size distributions. On the contrary, the anhydrite cement of a

Electromyographic and biomechanical analysis of step negotiation in Charcot Marie Tooth subjects whose level walk is not impaired.

Science.gov (United States)

Lencioni, Tiziana; Piscosquito, Giuseppe; Rabuffetti, Marco; Sipio, Enrica Di; Diverio, Manuela; Moroni, Isabella; Padua, Luca; Pagliano, Emanuela; Schenone, Angelo; Pareyson, Davide; Ferrarin, Maurizio

2018-05-01

Charcot-Marie-Tooth (CMT) is a slowly progressive disease characterized by muscular weakness and wasting with a length-dependent pattern. Mildly affected CMT subjects showed slight alteration of walking compared to healthy subjects (HS). To investigate the biomechanics of step negotiation, a task that requires greater muscle strength and balance control compared to level walking, in CMT subjects without primary locomotor deficits (foot drop and push off deficit) during walking. We collected data (kinematic, kinetic, and surface electromyographic) during walking on level ground and step negotiation, from 98 CMT subjects with mild-to-moderate impairment. Twenty-one CMT subjects (CMT-NLW, normal-like-walkers) were selected for analysis, as they showed values of normalized ROM during swing and produced work at push-off at ankle joint comparable to those of 31 HS. Step negotiation tasks consisted in climbing and descending a two-step stair. Only the first step provided the ground reaction force data. To assess muscle activity, each EMG profile was integrated over 100% of task duration and the activation percentage was computed in four phases that constitute the step negotiation tasks. In both tasks, CMT-NLW showed distal muscle hypoactivation. In addition, during step-ascending CMT-NLW subjects had relevant lower activities of vastus medialis and rectus femoris than HS in weight-acceptance, and, on the opposite, a greater activation as compared to HS in forward-continuance. During step-descending, CMT-NLW showed a reduced activity of tibialis anterior during controlled-lowering phase. Step negotiation revealed adaptive motor strategies related to muscle weakness due to disease in CMT subjects without any clinically apparent locomotor deficit during level walking. In addition, this study provided results useful for tailored rehabilitation of CMT patients. Copyright © 2018 Elsevier B.V. All rights reserved.

High-energy synchrotron radiation x-ray microscopy: Present status and future prospects

International Nuclear Information System (INIS)

Jones, K.W.; Gordon, B.M.; Spanne, P.; Rivers, M.L.; Sutton, S.R.

1991-01-01

High-energy radiation synchrotron x-ray microscopy is used to characterize materials of importance to the chemical and materials sciences and chemical engineering. The x-ray microscope (XRM) forms images of elemental distributions fluorescent x rays or images of mass distributions by measurement of the linear attenuation coefficient of the material. Distributions of sections through materials are obtained non-destructively using the technique of computed microtomography (CMT). The energy range of the x rays used for the XRM ranges from a few keV at the minimum value to more than 100 keV, which is sufficient to excite the K-edge of all naturally occurring elements. The work in progress at the Brookhaven NSLS X26 and X17 XRM is described in order to show the current status of the XRM. While there are many possible approaches to the XRM instrumentation, this instrument gives state-of-the-art performance in most respects and serves as a reasonable example of the present status of the instrumentation in terms of the spatial resolution and minimum detection limits (MDLs) obtainable. The examples of applications cited give an idea of the types of research fields that are currently under investigation. They can be used to illustrate how the field of x-ray microscopy will benefit from the use of bending magnets and insertion devices at the Advanced Photon Source (APS)

Life history of the stem tetrapod Acanthostega revealed by synchrotron microtomography.

Science.gov (United States)

Sanchez, Sophie; Tafforeau, Paul; Clack, Jennifer A; Ahlberg, Per E

2016-09-15

The transition from fish to tetrapod was arguably the most radical series of adaptive shifts in vertebrate evolutionary history. Data are accumulating rapidly for most aspects of these events, but the life histories of the earliest tetrapods remain completely unknown, leaving a major gap in our understanding of these organisms as living animals. Symptomatic of this problem is the unspoken assumption that the largest known Devonian tetrapod fossils represent adult individuals. Here we present the first, to our knowledge, life history data for a Devonian tetrapod, from the Acanthostega mass-death deposit of Stensiö Bjerg, East Greenland. Using propagation phase-contrast synchrotron microtomography (PPC-SRμCT) to visualize the histology of humeri (upper arm bones) and infer their growth histories, we show that even the largest individuals from this deposit are juveniles. A long early juvenile stage with unossified limb bones, during which individuals grew to almost final size, was followed by a slow-growing late juvenile stage with ossified limbs that lasted for at least six years in some individuals. The late onset of limb ossification suggests that the juveniles were exclusively aquatic, and the predominance of juveniles in the sample suggests segregated distributions of juveniles and adults at least at certain times. The absolute size at which limb ossification began differs greatly between individuals, suggesting the possibility of sexual dimorphism, adaptive strategies or competition-related size variation.

Multiscale Shannon's Entropy Modeling of Orientation and Distance in Steel Fiber Micro-Tomography Data.

Science.gov (United States)

Chiverton, John P; Ige, Olubisi; Barnett, Stephanie J; Parry, Tony

2017-11-01

This paper is concerned with the modeling and analysis of the orientation and distance between steel fibers in X-ray micro-tomography data. The advantage of combining both orientation and separation in a model is that it helps provide a detailed understanding of how the steel fibers are arranged, which is easy to compare. The developed models are designed to summarize the randomness of the orientation distribution of the steel fibers both locally and across an entire volume based on multiscale entropy. Theoretical modeling, simulation, and application to real imaging data are shown here. The theoretical modeling of multiscale entropy for orientation includes a proof showing the final form of the multiscale taken over a linear range of scales. A series of image processing operations are also included to overcome interslice connectivity issues to help derive the statistical descriptions of the orientation distributions of the steel fibers. The results demonstrate that multiscale entropy provides unique insights into both simulated and real imaging data of steel fiber reinforced concrete.

Monitoring of stainless-steel slag carbonation using X-ray computed microtomography.

Science.gov (United States)

Boone, Marijn A; Nielsen, Peter; De Kock, Tim; Boone, Matthieu N; Quaghebeur, Mieke; Cnudde, Veerle

2014-01-01

Steel production is one of the largest contributors to industrial CO2 emissions. This industry also generates large amounts of solid byproducts, such as slag and sludge. In this study, fine grained stainless-steel slag (SSS) is valorized to produce compacts with high compressive strength without the use of a hydraulic binder. This carbonation process is investigated on a pore-scale level to identify how the mineral phases in the SSS react with CO2, where carbonates are formed, and what the impact of these changes is on the pore network of the carbonated SSS compact. In addition to conventional research techniques, high-resolution X-ray computed tomography (HRXCT) is applied to visualize and quantify the changes in situ during the carbonation process. The results show that carbonates mainly precipitate at grain contacts and in capillary pores and this precipitation has little effect on the connectivity of the pore space. This paper also demonstrates the use of a custom-designed polymer reaction cell that allows in situ HRXCT analysis of the carbonation process. This shows the distribution and influence of water and CO2 in the pore network on the carbonate precipitation and, thus, the influence on the compressive strength development of the waste material.

Analytical dual-energy microtomography: A new method for obtaining three-dimensional mineral phase images and its application to Hayabusa samples

Science.gov (United States)

Tsuchiyama, A.; Nakano, T.; Uesugi, K.; Uesugi, M.; Takeuchi, A.; Suzuki, Y.; Noguchi, R.; Matsumoto, T.; Matsuno, J.; Nagano, T.; Imai, Y.; Nakamura, T.; Ogami, T.; Noguchi, T.; Abe, M.; Yada, T.; Fujimura, A.

2013-09-01

We developed a novel technique called "analytical dual-energy microtomography" that uses the linear attenuation coefficients (LACs) of minerals at two different X-ray energies to nondestructively obtain three-dimensional (3D) images of mineral distribution in materials such as rock specimens. The two energies are above and below the absorption edge energy of an abundant element, which we call the "index element". The chemical compositions of minerals forming solid solution series can also be measured. The optimal size of a sample is of the order of the inverse of the LAC values at the X-ray energies used. We used synchrotron-based microtomography with an effective spatial resolution of >200 nm to apply this method to small particles (30-180 μm) collected from the surface of asteroid 25143 Itokawa by the Hayabusa mission of the Japan Aerospace Exploration Agency (JAXA). A 3D distribution of the minerals was successively obtained by imaging the samples at X-ray energies of 7 and 8 keV, using Fe as the index element (the K-absorption edge of Fe is 7.11 keV). The optimal sample size in this case is of the order of 50 μm. The chemical compositions of the minerals, including the Fe/Mg ratios of ferromagnesian minerals and the Na/Ca ratios of plagioclase, were measured. This new method is potentially applicable to other small samples such as cosmic dust, lunar regolith, cometary dust (recovered by the Stardust mission of the National Aeronautics and Space Administration [NASA]), and samples from extraterrestrial bodies (those from future sample return missions such as the JAXA Hayabusa2 mission and the NASA OSIRIS-REx mission), although limitations exist for unequilibrated samples. Further, this technique is generally suited for studying materials in multicomponent systems with multiple phases across several research fields.

Determination of SiC ceramic foams microstructure properties by X-rays microtomography

International Nuclear Information System (INIS)

Nagata, Rodrigo; Appoloni, Carlos Roberto; Fernandes, Jaquiel Salvi

2009-01-01

Silicon carbide ceramic foams (SiC) can operate at high temperatures, which allow them to be used as heat exchangers, liquid metal filters, composite of rocket nozzles, etc. For many of these applications it is very important to know the foams' porosity. In this work the porosity of SiC ceramic foams was determined by X-rays microtomography, a powerful non-destructive technique that allows the analysis of the sample's internal structure. The samples have pore densities of 30, 45, 60, 80 and 100 pores per inch (ppi). The spatial resolution obtained was 24.8 μm. The cross sections' reconstruction was performed with a cone beam filtered backprojection algorithm. In the analyses, micropores were observed in the foam's lattice wire of the 30 ppi and 45 ppi samples. Micropores were present in few cross sections of 60 ppi sample too, but it was not found in the 80 ppi and 100 ppi samples. The total porosities obtained were Φ = (88.8 ± 4.3) %, Φ = (85.2 ± 1.4) %, Φ = (82.3 ± 1.8) %, Φ (79.9 ± 1.3) % and Φ = (80.4 ± 1.5) %, for the 30, 45, 60, 80 and 100 ppi samples, respectively. (author)

Qualitative and quantitative analysis of different fluid phase in samples of glass beads by X-ray microtomography

International Nuclear Information System (INIS)

Marques, Leonardo C.; Nagata, Rodrigo; Appoloni, Carlos R.; Moreira, Anderson C.; Fernanades, Celso P.

2011-01-01

The X-ray microtomography has showed to be a useful tool for studies of inner structure of reservoir rocks. Moreover recent works have used this methodology to visualize different fluid phases present in these microstructures. In this paper X-ray microtomography has been applied to visualize three fluid phases, separately or simultaneously, in addition to a solid phase (glass beads). Two glass beads samples were manufactured and scanned, one with 0.8 mm (GB1) and other with 0.6 mm (GB2) diameter, respectively. The three fluid phases used were air, oil and a water-salt-potassium iodine solution. Two Skyscan scanners were used, both a 1172 model, which employs X-ray tube with W anode and cone beam. This laboratory based equipment is able to provide images of until 1 μm spatial resolution. One microtomograph is located at CENPES/PETROBRAS and has a CCD camera of 10 mega pixels resolution. It was used to measure the GB1 sample at 4.84 μm spatial resolution. The other one is located at LAMIR/UFPR and has a CCD camera of 11 mega pixels resolution. It was used to measure the GB2 sample at 4.99 μm spatial resolution. GB1 sample was set up with three fluid phases and presented 38.0 (2.7) % of total porosity before fluid presence and 3.5 % and 19.8 %, as lower and higher average porosity values, respectively, after to be filled with them. GB2 sample was set up with oil and water-salt-potassium iodine solution separated. It presented 36.7 (1.9) % of total porosity when dried, 18.7 (2.0) % when filled with oil and 0 % when filled with the solution. The 2D images clearly show the presence of the solution in addition to the air and solid phases. They also show that the presence of oil phase is less clear than the solution. When all the phases are present together in the sample it is possible to differentiate all of them. Individual 3D images are shown for each phase present in the sample. The 3D image containing all the phases is also shown. (author)

Software tools for quantification of X-ray microtomography at the UGCT

Energy Technology Data Exchange (ETDEWEB)

Vlassenbroeck, J. [Department of Subatomic and Radiation Physics, Ghent University, Proeftuinstraat 86, B-9000 Gent (Belgium)], E-mail: jelle.vlassenbroeck@ugent.be; Dierick, M.; Masschaele, B. [Department of Subatomic and Radiation Physics, Ghent University, Proeftuinstraat 86, B-9000 Gent (Belgium); Cnudde, V. [Department of Geology and Soil Science, Ghent University, Krijgslaan 281/S8, B-9000 Gent (Belgium); Van Hoorebeke, L. [Department of Subatomic and Radiation Physics, Ghent University, Proeftuinstraat 86, B-9000 Gent (Belgium); Jacobs, P. [Department of Geology and Soil Science, Ghent University, Krijgslaan 281/S8, B-9000 Gent (Belgium)

2007-09-21

The technique of X-ray microtomography using X-ray tube radiation offers an interesting tool for the non-destructive investigation of a wide range of materials. A major challenge lies in the analysis and quantification of the resulting data, allowing for a full characterization of the sample under investigation. In this paper, we discuss the software tools for reconstruction and analysis of tomographic data that are being developed at the UGCT. The tomographic reconstruction is performed using Octopus, a high-performance and user-friendly software package. The reconstruction process transforms the raw acquisition data into a stack of 2D cross-sections through the sample, resulting in a 3D data set. A number of artifact and noise reduction algorithms are integrated to reduce ring artifacts, beam hardening artifacts, COR misalignment, detector or stage tilt, pixel non-linearities, etc. These corrections are very important to facilitate the analysis of the 3D data. The analysis of the 3D data focuses primarily on the characterization of pore structures, but will be extended to other applications. A first package for the analysis of pore structures in three dimensions was developed under Matlab. A new package, called Morpho+, is being developed in a C++ environment, with optimizations and extensions of the previously used algorithms. The current status of this project will be discussed. Examples of pore analysis can be found in pharmaceuticals, material science, geology and numerous other fields.

PEMANFAATAN REBUSAN DAUN SIRIH MERAH (Piper crocatum DALAM MENURUNKAN TINGKAT KEJADIAN MASTITIS BERDASARKANN UJI CMT DAN SCC

Directory of Open Access Journals (Sweden)

Razan Harastha Sjuhada

2017-11-01

Full Text Available The red betel leaves (Piper crocatum known as herbal antiseptic that contain many substances like essential oil, flavonoid, saponin, and tannin. The red betel leaves can be use to replace chemical antiseptic and more safe to use for teat dipping for dairy cow. The purpose of this research was to determine the effect of teat dipping with red betel leaves decoction to decrease subclinical mastitis level and somatic cell based on CMT and SCC. The method in this research was experiment with Randomize Block Design with 3 treatments and 5 replications. The data analyzed with Analysis of Variance (ANOVA, if there were significant effects it would be continue by Duncan’s Multiple Range Test (DMRT. The results showed that teat dipping with red betel leaves decoction had a significant different (P<0.05 to decrease mastitis level. Teat dipping with red betel leaves decoction 20% concentration could decrease mastitis level up to 30%. Teat dipping with red betel leaves decoction had a significant difference (P<0.05 to decrease the amount of somatic cell too. Teat dipping with red betel leaves stew 20% concentration could decrease the amount of somatic cell up to 1.98% or 0.12CFU/ml. The conclusion that teat dipping with red betel leaves decoction 20% was the best concentration and gave the best results to decrease mastitis level and somatic cell.

Measurement of spatial refractive index distributions of fusion spliced optical fibers by digital holographic microtomography

Science.gov (United States)

Pan, Feng; Deng, Yating; Ma, Xichao; Xiao, Wen

2017-11-01

Digital holographic microtomography is improved and applied to the measurements of three-dimensional refractive index distributions of fusion spliced optical fibers. Tomographic images are reconstructed from full-angle phase projection images obtained with a setup-rotation approach, in which the laser source, the optical system and the image sensor are arranged on an optical breadboard and synchronously rotated around the fixed object. For retrieving high-quality tomographic images, a numerical method is proposed to compensate the unwanted movements of the object in the lateral, axial and vertical directions during rotation. The compensation is implemented on the two-dimensional phase images instead of the sinogram. The experimental results exhibit distinctly the internal structures of fusion splices between a single-mode fiber and other fibers, including a multi-mode fiber, a panda polarization maintaining fiber, a bow-tie polarization maintaining fiber and a photonic crystal fiber. In particular, the internal structure distortion in the fusion areas can be intuitively observed, such as the expansion of the stress zones of polarization maintaining fibers, the collapse of the air holes of photonic crystal fibers, etc.

X-ray spectrometry and X-ray microtomography techniques for soil and geological samples analysis

International Nuclear Information System (INIS)

Kubala-Kukuś, A.; Banaś, D.; Braziewicz, J.; Dziadowicz, M.; Kopeć, E.; Majewska, U.; Mazurek, M.; Pajek, M.; Sobisz, M.; Stabrawa, I.; Wudarczyk-Moćko, J.; Góźdź, S.

2015-01-01

A particular subject of X-ray fluorescence analysis is its application in studies of the multielemental sample of composition in a wide range of concentrations, samples with different matrices, also inhomogeneous ones and those characterized with different grain size. Typical examples of these kinds of samples are soil or geological samples for which XRF elemental analysis may be difficult due to XRF disturbing effects. In this paper the WDXRF technique was applied in elemental analysis concerning different soil and geological samples (therapeutic mud, floral soil, brown soil, sandy soil, calcium aluminum cement). The sample morphology was analyzed using X-ray microtomography technique. The paper discusses the differences between the composition of samples, the influence of procedures with respect to the preparation of samples as regards their morphology and, finally, a quantitative analysis. The results of the studies were statistically tested (one-way ANOVA and correlation coefficients). For lead concentration determination in samples of sandy soil and cement-like matrix, the WDXRF spectrometer calibration was performed. The elemental analysis of the samples was complemented with knowledge of chemical composition obtained by X-ray powder diffraction.

X-ray spectrometry and X-ray microtomography techniques for soil and geological samples analysis

Energy Technology Data Exchange (ETDEWEB)

Kubala-Kukuś, A.; Banaś, D.; Braziewicz, J. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Dziadowicz, M.; Kopeć, E. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Majewska, U. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Mazurek, M.; Pajek, M.; Sobisz, M.; Stabrawa, I. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Wudarczyk-Moćko, J. [Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Góźdź, S. [Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Institute of Public Health, Jan Kochanowski University, IX Wieków Kielc 19, 25-317 Kielce (Poland)

2015-12-01

A particular subject of X-ray fluorescence analysis is its application in studies of the multielemental sample of composition in a wide range of concentrations, samples with different matrices, also inhomogeneous ones and those characterized with different grain size. Typical examples of these kinds of samples are soil or geological samples for which XRF elemental analysis may be difficult due to XRF disturbing effects. In this paper the WDXRF technique was applied in elemental analysis concerning different soil and geological samples (therapeutic mud, floral soil, brown soil, sandy soil, calcium aluminum cement). The sample morphology was analyzed using X-ray microtomography technique. The paper discusses the differences between the composition of samples, the influence of procedures with respect to the preparation of samples as regards their morphology and, finally, a quantitative analysis. The results of the studies were statistically tested (one-way ANOVA and correlation coefficients). For lead concentration determination in samples of sandy soil and cement-like matrix, the WDXRF spectrometer calibration was performed. The elemental analysis of the samples was complemented with knowledge of chemical composition obtained by X-ray powder diffraction.

Quantitative measurements of localized density variations in cylindrical tablets using X-ray microtomography.

Science.gov (United States)

Busignies, Virginie; Leclerc, Bernard; Porion, Patrice; Evesque, Pierre; Couarraze, Guy; Tchoreloff, Pierre

2006-08-01

Direct compaction is a complex process that results in a density distribution inside the tablets which is often heterogeneous. Therefore, the density variations may affect the compact properties. A quantitative analysis of this phenomenon is still lacking. Recently, X-ray microtomography has been successfully used in pharmaceutical development to study qualitatively the impact of tablet shape and break-line in the density of pharmaceutical tablets. In this study, we evaluate the density profile in microcrystalline cellulose (Vivapur 12) compacts obtained at different mean porosity (ranging from 7.7% to 33.5%) using X-ray tomography technique. First, the validity of the Beer-Lambert law is studied. Then, density calibration is performed and density maps of cylindrical tablets are obtained and visualized using a process with colour-scale calibration plot which is explained. As expected, important heterogeneity in density is observed and quantified. The higher densities in peripheral region were particularly investigated and appraised in regard to the lower densities observed in the middle of the tablet. The results also underlined that in the case of pharmaceutical tablets, it is important to differentiate the mechanical properties representative of the total volume tablet and the mechanical properties that only characterize the tablet surface like the Brinell hardness measurements.

Assessment of passive safety injection systems of ALWRs. Final report of the European Commission 4th framework programme. Project FI4I-CT95-004 (APSI)

Energy Technology Data Exchange (ETDEWEB)

Tuunanen, J. [VTT Energy, Espoo (Finland). Nuclear Energy; Vihavainen, J. [Lappeenranta Univ. of Technology (Finland); D' Auria, F. [Univ. of Pisa (Italy); Kimber, G. [AEA Technology (United Kingdom)

1999-07-01

The European Commission 4th Framework Programme project 'Assessment of Passive Safety Injection Systems of Advanced Light Water Reactors (FI4I-CT95-0004)' involved experiments on the PACTEL test facility and computer simulations of selected experiments. The experiments focused on the performance of Passive Safety Injection Systems (PSIS) of Advanced Light Water Reactors (ALWRs) in Small Break Loss-Of-Coolant Accident (SBLOCA) conditions. The PSIS consisted of a Core Make-up Tank (CMT) and two pipelines. A pressure balancing line (PBL) connected the CMT to one cold leg. The injection line (IL) connected it to the downcomer. The project involved 15 experiments in three series. The experiments provided valuable information about condensation and heat transfer processes in the CMT, thermal stratification of water in the CMT, and natural circulation flow through the PSIS lines. The experiments showed the examined PSIS works efficiently in SBLOCAs although the flow through the PSIS may stop in very small SBLOCAs, when the hot water fills the CMT. The experiments also demonstrated the importance of flow distributor (sparger) in the CMT to limit rapid condensation. The project included validation of three thermal-hydraulic computer codes (APROS, CATHARE and RELAP5). The analyses showed the codes are capable of simulating the overall behaviour of the transients. The codes predicted accurately the core heatup, which occurred when the primary coolant inventory was reduced so much that the core top became free of water. The detailed analyses of the calculation results showed that some models in the codes still need improvements. Especially, further development of models for thermal stratification, condensation and natural circulation flow with small driving forces would be necessary for accurate simulation of phenomena in the PSIS. (orig.)

Assessment of passive safety injection systems of ALWRs. Final report of the European Commission 4th framework programme. Project FI4I-CT95-004 (APSI)

International Nuclear Information System (INIS)

Tuunanen, J.; D'Auria, F.; Kimber, G.

1999-01-01

The European Commission 4th Framework Programme project 'Assessment of Passive Safety Injection Systems of Advanced Light Water Reactors (FI4I-CT95-0004)' involved experiments on the PACTEL test facility and computer simulations of selected experiments. The experiments focused on the performance of Passive Safety Injection Systems (PSIS) of Advanced Light Water Reactors (ALWRs) in Small Break Loss-Of-Coolant Accident (SBLOCA) conditions. The PSIS consisted of a Core Make-up Tank (CMT) and two pipelines. A pressure balancing line (PBL) connected the CMT to one cold leg. The injection line (IL) connected it to the downcomer. The project involved 15 experiments in three series. The experiments provided valuable information about condensation and heat transfer processes in the CMT, thermal stratification of water in the CMT, and natural circulation flow through the PSIS lines. The experiments showed the examined PSIS works efficiently in SBLOCAs although the flow through the PSIS may stop in very small SBLOCAs, when the hot water fills the CMT. The experiments also demonstrated the importance of flow distributor (sparger) in the CMT to limit rapid condensation. The project included validation of three thermal-hydraulic computer codes (APROS, CATHARE and RELAP5). The analyses showed the codes are capable of simulating the overall behaviour of the transients. The codes predicted accurately the core heatup, which occurred when the primary coolant inventory was reduced so much that the core top became free of water. The detailed analyses of the calculation results showed that some models in the codes still need improvements. Especially, further development of models for thermal stratification, condensation and natural circulation flow with small driving forces would be necessary for accurate simulation of phenomena in the PSIS. (orig.)

Evaluation of the effect of varying the workability in concrete pore structure by using X-ray microtomography

Directory of Open Access Journals (Sweden)

E. E. Bernardes

Full Text Available The useful life of concrete is associated with the penetrative ability of aggressive agents on their structures. Structural parameters such as porosity, pore distribution and connectivity have great influence on the properties of mass transport in porous solids. In the present study, the effect of varying the workability of concrete in fresh state, produced through the use of additives, on pore structure and on the mechanical compressive strength of hardened concrete was assessed. The pore structure was analyzed with the aid of X-ray microtomography, and the results obtained were compared to the total pore volume calculated from data derived from helium and mercury pycnometry tests. A good approximation between the porosity values obtained through the two techniques was observed, and it was found that, regardless of concrete consistency, the samples from the surface of the specimens showed a percentage of pores higher than those taken from the more inner layers.

Total porosity of carbonate reservoir rocks by X-ray microtomography in two different spatial resolutions

International Nuclear Information System (INIS)

Nagata, Rodrigo; Appoloni, Carlos R.; Marques, Leonardo C.; Fernandes, Celso P.

2011-01-01

Carbonate reservoir rocks contain more than 50% of world's petroleum. To know carbonate rocks' structural properties is quite important to petroleum extraction. One of their main structural properties is the total porosity, which shows the rock's capacity to stock petroleum. In recent years, the X-ray microtomography had been used to analyze the structural parameters of reservoir rocks. Such nondestructive technique generates images of the samples' internal structure, allowing the evaluation of its properties. The spatial resolution is a measurement parameter that indicates the smallest structure size observable in a sample. It is possible to measure one sample using two or more different spatial resolutions in order to evaluate the samples' pore scale. In this work, two samples of the same sort of carbonate rock were measured, and in each measurement a different spatial resolution (17 μm and 7 μm) was applied. The obtained results showed that with the better resolution it was possible to measure 8% more pores than with the poorer resolution. Such difference provides us with good expectations about such approach to study the pore scale of carbonate rocks. (author)

Synchrotron x-ray microtomography of the interior microstructure of chocolate

Science.gov (United States)

Lügger, Svenja K.; Wilde, Fabian; Dülger, Nihan; Reinke, Lennart M.; Kozhar, Sergii; Beckmann, Felix; Greving, Imke; Vieira, Josélio; Heinrich, Stefan; Palzer, Stefan

2016-10-01

The structure of chocolate, a multicomponent food product, was analyzed using microtomography. Chocolate consists of a semi-solid cocoa butter matrix and a dense network of suspended particles. A detailed analysis of the microstructure is needed to understand mass transport phenomena. Transport of lipids from e.g. a filling or liquid cocoa butter is responsible for major problems in the confectionery industry such as formation of chocolate bloom, which is the formation of visible white spots or a grayish haze on the chocolate surface and leads to consumer rejections and thus large sales losses for the confectionery industry. In this study it was possible to visualize the inner structure of chocolate and clearly distinguish the particles from the continuous phase by taking advantage of the high density contrast of synchrotron radiation. Consequently, particle arrangement and cracks within the sample were made visible. The cracks are several micrometers thick and propagate throughout the entire sample. Images of pure cocoa butter, chocolate without any particles, did not show any cracks and thus confirmed that cracks are a result of embedded particles. They arise during the manufacturing process. Thus, the solidification process, a critical manufacturing step, was simulated with finite element methods in order to understand crack formation during this step. The simulation showed that cracks arise because of significant contraction of cocoa butter, the matrix phase, without any major change of volume of the suspended particles. Tempering of the chocolate mass prior to solidification is another critical step for a good product quality. We found that samples which solidified in an uncontrolled manner are less homogeneous than tempered samples. In summary, our study visualized for the first time the inner microstructure of tempered and untempered cocoa butter as well as chocolate without sample destruction and revealed cracks, which might act as transport pathways.

Plasma, cerebrospinal fluid, and brain distribution of 14C-melatonin in rat: a biochemical and autoradiographic study

International Nuclear Information System (INIS)

Vitte, P.A.; Harthe, C.; Lestage, P.; Claustrat, B.; Bobillier, P.

1988-01-01

The distribution of 14C-Melatonin (14C-MT) after systemic injection was studied in the plasma, cerebrospinal fluid (CSF), and brain of rats. Chromatographic analysis (thin-layer chromatography and high-performance liquid chromatography) indicated that the radioactivity from biological samples taken at various times following the injection of label was mainly associated with 14C-MT. Computer analysis of plasma 14C-MT kinetics showed a three-compartment system with half-lives of 0.21 +/- 0.05, 5.97 +/- 1.11, and 47.52 +/- 8.86 min. The volume of distribution and the clearance were 1,736 +/- 349 ml.kg-1 and 25.1 +/- 1.7 ml.min-1.kg-1 respectively. The entry of 14C-MT into the CSF was rapid and reached a maximum at 5 min. The decay followed a two-compartment system with half-lives of 16.5 +/- 2.9 and 47.3 +/- 8.6 min. The CSF/plasma concentration ratio was 0.38 at the steady state (30 min). At 2 min the level of 14C-MT in the brain was 3.8 higher than in the CSF. Representative autoradiograms revealed an heterogeneous localization of 14C-MT in the grey matter. The highest regional values, as evaluated by the permeability area product technique, were found in cortex, thalamic nuclei, medial geniculate nucleus, anterior pretectal area, paraventricular nucleus of the hypothalamus, choroid plexuses, and bulb-pons. Thirty minutes later 14C-MT was still detected in most of the brain regions analyzed. These results point to a low but rapid penetration of circulating MT into the brain and the CSF. The heterogeneous distribution and the partial retention of 14C-MT in the brain are compatible with the hypothesis of a central action of this hormone mediated via binding sites

Extraction of the 3D local orientation of myocytes in human cardiac tissue using X-ray phase-contrast micro-tomography and multi-scale analysis.

Science.gov (United States)

Varray, François; Mirea, Iulia; Langer, Max; Peyrin, Françoise; Fanton, Laurent; Magnin, Isabelle E

2017-05-01

This paper presents a methodology to access the 3D local myocyte arrangements in fresh human post-mortem heart samples. We investigated the cardiac micro-structure at a high and isotropic resolution of 3.5 µm in three dimensions using X-ray phase micro-tomography at the European Synchrotron Radiation Facility. We then processed the reconstructed volumes to extract the 3D local orientation of the myocytes using a multi-scale approach with no segmentation. We created a simplified 3D model of tissue sample made of simulated myocytes with known size and orientations, to evaluate our orientation extraction method. Afterwards, we applied it to 2D histological cuts and to eight 3D left ventricular (LV) cardiac tissue samples. Then, the variation of the helix angles, from the endocardium to the epicardium, was computed at several spatial resolutions ranging from 3.6 3  mm 3 to 112 3  µm 3 . We measure an increased range of 20° to 30° from the coarsest resolution level to the finest level in the experimental samples. This result is in line with the higher values measured from histology. The displayed tractography demonstrates a rather smooth evolution of the transmural helix angle in six LV samples and a sudden discontinuity of the helix angle in two septum samples. These measurements bring a new vision of the human heart architecture from macro- to micro-scale. Copyright © 2017 Elsevier B.V. All rights reserved.

Porous media investigation before and after hydrochloric acid injection on a pre-salt carbonate coquinas sample.

Science.gov (United States)

Machado, A C; Teles, A P; Pepin, A; Bize-Forest, N; Lima, I; Lopes, R T

2016-04-01

Porous space characterization of carbonate rocks is an important aid in petroleum exploration from carbonate reservoir. In this study, X-ray microtomography technique was applied to evaluate total porosity of a coquina sample extracted from pre-salt reservoir, in Brazil, before and after acid injection. Two image processing program were used in order to assess performance. The results showed that microtomography has potential to compute porosity of coquina samples and provides information about rock porous network. Copyright © 2016 Elsevier Ltd. All rights reserved.

ATLAS software configuration and build tool optimisation

Science.gov (United States)

Rybkin, Grigory; Atlas Collaboration

2014-06-01

ATLAS software code base is over 6 million lines organised in about 2000 packages. It makes use of some 100 external software packages, is developed by more than 400 developers and used by more than 2500 physicists from over 200 universities and laboratories in 6 continents. To meet the challenge of configuration and building of this software, the Configuration Management Tool (CMT) is used. CMT expects each package to describe its build targets, build and environment setup parameters, dependencies on other packages in a text file called requirements, and each project (group of packages) to describe its policies and dependencies on other projects in a text project file. Based on the effective set of configuration parameters read from the requirements files of dependent packages and project files, CMT commands build the packages, generate the environment for their use, or query the packages. The main focus was on build time performance that was optimised within several approaches: reduction of the number of reads of requirements files that are now read once per package by a CMT build command that generates cached requirements files for subsequent CMT build commands; introduction of more fine-grained build parallelism at package task level, i.e., dependent applications and libraries are compiled in parallel; code optimisation of CMT commands used for build; introduction of package level build parallelism, i. e., parallelise the build of independent packages. By default, CMT launches NUMBER-OF-PROCESSORS build commands in parallel. The other focus was on CMT commands optimisation in general that made them approximately 2 times faster. CMT can generate a cached requirements file for the environment setup command, which is especially useful for deployment on distributed file systems like AFS or CERN VMFS. The use of parallelism, caching and code optimisation significantly-by several times-reduced software build time, environment setup time, increased the efficiency of

Passive safety injection experiments and analyses (PAHKO)

International Nuclear Information System (INIS)

Tuunanen, J.

1998-01-01

PAHKO project involved experiments on the PACTEL facility and computer simulations of selected experiments. The experiments focused on the performance of Passive Safety Injection Systems (PSIS) of Advanced Light Water Reactors (ALWRs) in Small Break Loss-Of-Coolant Accident (SBLOCA) conditions. The PSIS consisted of a Core Make-up Tank (CMT) and two pipelines (Pressure Balancing Line, PBL, and Injection Line, IL). The examined PSIS worked efficiently in SBLOCAs although the flow through the PSIS stopped temporarily if the break was very small and the hot water filled the CMT. The experiments demonstrated the importance of the flow distributor in the CMT to limit rapid condensation. The project included validation of three thermal-hydraulic computer codes (APROS, CATHARE and RELAP5). The analyses showed the codes are capable to simulate the overall behaviour of the transients. The detailed analyses of the results showed some models in the codes still need improvements. Especially, further development of models for thermal stratification, condensation and natural circulation flow with small driving forces would be necessary for accurate simulation of the PSIS phenomena. (orig.)

High resolution x-ray CMT: Reconstruction methods

Energy Technology Data Exchange (ETDEWEB)

Brown, J.K.

1997-02-01

This paper qualitatively discusses the primary characteristics of methods for reconstructing tomographic images from a set of projections. These reconstruction methods can be categorized as either {open_quotes}analytic{close_quotes} or {open_quotes}iterative{close_quotes} techniques. Analytic algorithms are derived from the formal inversion of equations describing the imaging process, while iterative algorithms incorporate a model of the imaging process and provide a mechanism to iteratively improve image estimates. Analytic reconstruction algorithms are typically computationally more efficient than iterative methods; however, analytic algorithms are available for a relatively limited set of imaging geometries and situations. Thus, the framework of iterative reconstruction methods is better suited for high accuracy, tomographic reconstruction codes.

Equally sloped X-ray microtomography of living insects with low radiation dose and improved resolution capability

International Nuclear Information System (INIS)

Yao, Shengkun; Fan, Jiadong; Zong, Yunbing; Sun, Zhibin; Zhang, Jianhua; Jiang, Huaidong; He, You; Zhou, Guangzhao; Xiao, Tiqiao; Huang, Qingjie

2016-01-01

Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique over conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ∼1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.

Equally sloped X-ray microtomography of living insects with low radiation dose and improved resolution capability

Science.gov (United States)

Yao, Shengkun; Fan, Jiadong; Zong, Yunbing; He, You; Zhou, Guangzhao; Sun, Zhibin; Zhang, Jianhua; Huang, Qingjie; Xiao, Tiqiao; Jiang, Huaidong

2016-03-01

Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique over conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ˜1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.

Equally sloped X-ray microtomography of living insects with low radiation dose and improved resolution capability

Energy Technology Data Exchange (ETDEWEB)

Yao, Shengkun; Fan, Jiadong; Zong, Yunbing; Sun, Zhibin; Zhang, Jianhua; Jiang, Huaidong, E-mail: hdjiang@sdu.edu.cn [State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); He, You; Zhou, Guangzhao; Xiao, Tiqiao [Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Huang, Qingjie [School of Information Science and Engineering, Shandong University, Jinan 250100 (China)

2016-03-21

Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique over conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ∼1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.

Processing of Bi-2212 and Nb$_3$Sn studied in situ by high energy synchrotron diffraction and micro-tomography

CERN Document Server

Kadar, Julian

Next generation superconducting wires have been studied to obtain more information on the evolution of phase growth, crystallite size and strain state during wire processing. The high energy scattering beam line ID15 at the European Synchrotron Radiation Facility provides a very high flux of high energy photons for very fast in situ X-ray diffraction and micro-tomography studies of Bi-2212/Ag and Nb$_3$S/Cu wire samples. The typical wire processing conditions could be imitated in the X-ray transparent furnace at ID15 for diffraction and tomography studies. Efficient data analysis is mandatory in order to handle the very fast data acquisition rate. For this purpose an Excel-VBA based program was developed that allows a semi-automated fitting and tracking of peaks with pre-set constraints. With this method, more than one thousand diffraction patterns have been analysed to extract d-spacing, peak intensity and peak width values. X ray absorption micro tomograms were recorded simultaneously with the X-ray diffrac...

Application of X-ray microtomography to study the influence of the casting microstructure upon the tensile behaviour of an Al–Si alloy

Energy Technology Data Exchange (ETDEWEB)

Limodin, Nathalie, E-mail: nathalie.limodin@ec-lille.fr [Laboratoire de Mécanique de Lille (LML), CNRS, UMR 8107, Cité Scientifique, 59650 Villeneuve d’Ascq (France); El Bartali, Ahmed, E-mail: ahmed.elbartali@ec-lille.fr [Laboratoire de Mécanique de Lille (LML), CNRS, UMR 8107, Cité Scientifique, 59650 Villeneuve d’Ascq (France); Ecole Centrale de Lille, 59650 Villeneuve d’Ascq (France); Wang, Long, E-mail: long.wang@ec-lille.fr [Laboratoire de Mécanique de Lille (LML), CNRS, UMR 8107, Cité Scientifique, 59650 Villeneuve d’Ascq (France); Ecole Centrale de Lille, 59650 Villeneuve d’Ascq (France); Lachambre, Joël, E-mail: joel.lachambre@insa-lyon.fr [Laboratoire Matériaux, Ingénierie et Sciences (MATEIS), INSA-Lyon, CNRS, UMR 5510, 20 Av. Albert Einstein, 69621 Villeurbanne (France); Buffiere, Jean-Yves, E-mail: jean-yves.buffiere@insa-lyon.fr [Laboratoire Matériaux, Ingénierie et Sciences (MATEIS), INSA-Lyon, CNRS, UMR 5510, 20 Av. Albert Einstein, 69621 Villeurbanne (France); Charkaluk, Eric, E-mail: eric.charkaluk@ec-lille.fr [Laboratoire de Mécanique de Lille (LML), CNRS, UMR 8107, Cité Scientifique, 59650 Villeneuve d’Ascq (France)

2014-04-01

In cast aluminium alloys used in the automotive industry the microstructure inherited from the foundry process has a strong influence on the mechanical properties. In the cylinder heads produced by the Lost Foam Casting process, the microstructure consists of hard intermetallic phases and large gas and microshrinkage pores. To study its influence, full field measurements at the microstructure scale were performed during a tensile test performed in situ under X-ray microtomography. Intermetallics were used as a natural speckle pattern. Feasibility of Digital Volume Correlation on this alloy was proved and the accuracy of the measurement was assessed and discussed in light of the small volume fraction of intermetallics and in comparison with the accuracy of Digital Image Correlation performed on optical images at a finer spatial resolution.

X-Ray Microtomography (μCT as a Useful Tool for Visualization and Interpretation of Shear Strength Test Results

Directory of Open Access Journals (Sweden)

Stefaniuk Damian

2015-02-01

Full Text Available The paper demonstrates the applicability of X-ray microtomography (ìCT to analysis of the results of shear strength examinations of clayey soils. The method of X-ray three-dimensional imaging offers new possibilities in soil testing. The work focuses on a non-destructive method of evaluation of specimen quality used in shear tests and mechanical behavior of soil. The paper presents the results of examination of 4 selected clayey soils. Specimens prepared for the triaxial test have been scanned using ìCT before and after the triaxial compression tests. The shear strength parameters of the soils have been estimated. Changes in soil structure caused by compression and shear failure have been presented as visualizations of the samples tested. This allowed for improved interpretation and evaluation of soil strength parameters and recognition of pre-existing fissures and the exact mode of failure. Basic geometrical parameters have been determined for selected cross-sections of specimens after failure. The test results indicate the utility of the method applied in soil testing.

Separation of nucleation and growth of voids during tensile deformation of a dual phase steel using synchrotron microtomography

Energy Technology Data Exchange (ETDEWEB)

Requena, Guillermo, E-mail: guillermo.requena@tuwien.ac.at [INSA-Lyon, MATEIS CNRS UMR5510, F-69621 Villeurbanne (France); Maire, Eric; Leguen, Claire [INSA-Lyon, MATEIS CNRS UMR5510, F-69621 Villeurbanne (France); Thuillier, Sandrine [LIMATB, Université de Bretagne-Sud, rue de Saint Maudé, BP 92116, 56321 Lorient Cedex (France)

2014-01-01

The damage evolution in a DP980 dual phase steel is followed in situ by synchrotron microtomography during tensile deformation focusing on the effect that the triaxiality, induced by different sample geometries, exerts on damage formation and damage evolution. The growth of existing voids is separated from the voids nucleated between consecutive deformation steps using three-dimensional image analysis. The experimental results are correlated with those obtained by finite element analysis using a Gurson–Tvergaard–Needleman framework with a Chu and Needleman formulation to introduce the effect of nucleation of cavities. A relatively simple way to determine the nucleation parameters is proposed based on the volume of nucleated voids obtained from the tomographies. The evolution of the total volume fraction of cavities obtained from the calculations shows a good agreement with the experiments for the notched samples and reflects the effect of triaxiality on damage. Contrarily to experiments, the calculated accumulated volume fraction of nucleated voids does not reflect the effect of triaxiality suggesting the necessity to implement this parameter in the nucleation model.

Explicit control of image noise and error properties in cone-beam microtomography using dual concentric circular source loci

International Nuclear Information System (INIS)

Davis, Graham

2005-01-01

Cone-beam reconstruction from projections with a circular source locus (relative to the specimen) is commonly used in X-ray microtomography systems. Although this method does not provide an 'exact' reconstruction, since there is insufficient data in the projections, the approximation is considered adequate for many purposes. However, some specimens, with sharp changes in X-ray attenuation in the direction of the rotation axis, are particularly prone to cone-beam-related errors. These errors can be reduced by increasing the source-to-specimen distance, but at the expense of reduced signal-to-noise ratio or increased scanning time. An alternative method, based on heuristic arguments, is to scan the specimen with both short and long source-to-specimen distances and combine high frequency components from the former reconstruction with low frequency ones from the latter. This composite reconstruction has the low noise characteristics of the short source-to-specimen reconstruction and the low cone-beam errors of the long one. This has been tested with simulated data representing a particularly error prone specimen

Analysis of Soil Structure Turnover with Garnet Particles and X-Ray Microtomography.

Directory of Open Access Journals (Sweden)

Steffen Schlüter

Full Text Available Matter turnover in soil is tightly linked to soil structure which governs the heterogeneous distribution of habitats, reaction sites and pathways in soil. Thereby, the temporal dynamics of soil structure alteration is deemed to be important for essential ecosystem functions of soil but very little is known about it. A major reason for this knowledge gap is the lack of methods to study soil structure turnover directly at microscopic scales. Here we devise a conceptual approach and an image processing workflow to study soil structure turnover by labeling some initial state of soil structure with small garnet particles and tracking their fate with X-ray microtomography. The particles adhere to aggregate boundaries at the beginning of the experiment but gradually change their position relative to the nearest pore as structure formation progresses and pores are destructed or newly formed. A new metric based on the contact distances between particles and pores is proposed that allows for a direct quantification of soil structure turnover rates. The methodology is tested for a case study about soil compaction of a silty loam soil during stepwise increase of bulk density (ρ = {1.1, 1.3, 1.5} g/cm3. We demonstrate that the analysis of mean contact distances provides genuinely new insights about changing diffusion pathways that cannot be inferred neither from conventional pore space attributes (porosity, mean pore size, pore connectivity nor from deformation analysis with digital image correlation. This structure labeling approach to quantify soil structure turnover provides a direct analogy to stable isotope labeling for the analysis of matter turnover and can be readily combined with each other.

Analysis of Soil Structure Turnover with Garnet Particles and X-Ray Microtomography.

Science.gov (United States)

Schlüter, Steffen; Vogel, Hans-Jörg

2016-01-01

Matter turnover in soil is tightly linked to soil structure which governs the heterogeneous distribution of habitats, reaction sites and pathways in soil. Thereby, the temporal dynamics of soil structure alteration is deemed to be important for essential ecosystem functions of soil but very little is known about it. A major reason for this knowledge gap is the lack of methods to study soil structure turnover directly at microscopic scales. Here we devise a conceptual approach and an image processing workflow to study soil structure turnover by labeling some initial state of soil structure with small garnet particles and tracking their fate with X-ray microtomography. The particles adhere to aggregate boundaries at the beginning of the experiment but gradually change their position relative to the nearest pore as structure formation progresses and pores are destructed or newly formed. A new metric based on the contact distances between particles and pores is proposed that allows for a direct quantification of soil structure turnover rates. The methodology is tested for a case study about soil compaction of a silty loam soil during stepwise increase of bulk density (ρ = {1.1, 1.3, 1.5} g/cm3). We demonstrate that the analysis of mean contact distances provides genuinely new insights about changing diffusion pathways that cannot be inferred neither from conventional pore space attributes (porosity, mean pore size, pore connectivity) nor from deformation analysis with digital image correlation. This structure labeling approach to quantify soil structure turnover provides a direct analogy to stable isotope labeling for the analysis of matter turnover and can be readily combined with each other.

Beyond filtered backprojection: A reconstruction software package for ion beam microtomography data

Science.gov (United States)

Habchi, C.; Gordillo, N.; Bourret, S.; Barberet, Ph.; Jovet, C.; Moretto, Ph.; Seznec, H.

2013-01-01

A new version of the TomoRebuild data reduction software package is presented, for the reconstruction of scanning transmission ion microscopy tomography (STIMT) and particle induced X-ray emission tomography (PIXET) images. First, we present a state of the art of the reconstruction codes available for ion beam microtomography. The algorithm proposed here brings several advantages. It is a portable, multi-platform code, designed in C++ with well-separated classes for easier use and evolution. Data reduction is separated in different steps and the intermediate results may be checked if necessary. Although no additional graphic library or numerical tool is required to run the program as a command line, a user friendly interface was designed in Java, as an ImageJ plugin. All experimental and reconstruction parameters may be entered either through this plugin or directly in text format files. A simple standard format is proposed for the input of experimental data. Optional graphic applications using the ROOT interface may be used separately to display and fit energy spectra. Regarding the reconstruction process, the filtered backprojection (FBP) algorithm, already present in the previous version of the code, was optimized so that it is about 10 times as fast. In addition, Maximum Likelihood Expectation Maximization (MLEM) and its accelerated version Ordered Subsets Expectation Maximization (OSEM) algorithms were implemented. A detailed user guide in English is available. A reconstruction example of experimental data from a biological sample is given. It shows the capability of the code to reduce noise in the sinograms and to deal with incomplete data, which puts a new perspective on tomography using low number of projections or limited angle.

Fatigue crack propagation: In situ visualization using X-ray microtomography and 3D simulation using the extended finite element method

International Nuclear Information System (INIS)

Ferrie, Emilie; Buffiere, Jean-Yves; Ludwig, Wolfgang; Gravouil, Anthony; Edwards, Lyndon

2006-01-01

The propagation of a semi-elliptical crack in the bulk of an ultrafine-grained Al-Li alloy has been investigated using synchrotron radiation X-ray microtomography. In this material, the studied crack, despite its small dimension, can be considered as 'microstructurally long' and described in the frame of the linear elastic fracture mechanics. The extended finite element method is used to calculate the stress intensity factors along the crack front taking into account the three-dimensional geometry extracted from the tomographic images. For the same nominal value of the stress intensity factor range, crack propagation is faster in the bulk than at the surface. The observed anisotropy is attributed to the variation of the closure stress along the crack front between surface and bulk. The experimentally observed fatigue crack propagation is compared to numerical simulations. Good agreement is found when a linear variation of closure stress along the crack front is taken into account in the '3D crack propagation law' used for the simulation

Implant-Abutment Contact Surfaces and Microgap Measurements of Different Implant Connections Under 3-Dimensional X-Ray Microtomography.

Science.gov (United States)

Scarano, Antonio; Valbonetti, Luca; Degidi, Marco; Pecci, Raffaella; Piattelli, Adriano; de Oliveira, P S; Perrotti, Vittoria

2016-10-01

The presence of a microgap between implant and abutment could produce a bacterial reservoir which could interfere with the long-term health of the periimplant tissues. The aim of this article was to evaluate, by x-ray 3-dimensional microtomography, implant-abutment contact surfaces and microgaps at the implant-abutment interface in different types of implant-abutment connections. A total of 40 implants were used in this in vitro study. Ten implants presented a screw-retained internal hexagon abutment (group I), 10 had a Morse Cone taper internal connection (group II), 10 another type of Morse Cone taper internal connection (group III), and 10 had a screwed trilobed connection (group IV). In both types of Morse Cone internal connections, there was no detectable separation at the implant-abutment in the area of the conical connection, and there was an absolute congruity without any microgaps between abutment and implant. No line was visible separating the implant and the abutment. On the contrary, in the screwed abutment implants, numerous gaps and voids were present. The results of this study support the hypothesis that different types of implant-abutment joints are responsible for the observed differences in bacterial penetration.

CHARCOT-MARIE-TOOTH DISEASE

Directory of Open Access Journals (Sweden)

Lea Leonardis

2003-09-01

Full Text Available Background. Charcot-Marie-Tooth (CMT disease is a common inherited disorder of the peripheral nervous system. In our paper, different types of CMT are described with their typical clinical pictures, electrophysiological signs and molecular genetic studies. CMT is classified as demyelinative and axonal type and distal motor neuronopathy.Conclusions. CMT can be of autosomal dominant, recessive and X-linked inheritance. The most frequent form of CMT is the result of the dominantly inherited duplication of chromosome 17p11.2 and is marked as CMT1A. The same group involves also rare patients with point mutation in the peripheral myelin protein-22 gene. CMT1B is associated with point mutations in protein zero gene. CMT1C is linked to chromosome 16p13.1–12.3. Patients with point mutations in early growth response 2 gene (EGR2 are included in group CMT1D. The disease can be also inhereted X-linked (CMTX with the mutations in connexin-32 gene. In autosomal recessive inherited demyelinating polyneuropathies (CMT4, mutations are found in the myotubularin-related protein-2 (CMT4B, N-myc downstream-regulated gene 1 (CMT4D, EGR2 (CMT4E, and in the periaksin (CMT4F genes. In axonal inherited neuropathy, mutations are found in KIF1beta (CMT2A and in light neurofilament (CMT2E genes, other forms map to different chromosomal loci (CMT2B, CMT2D, CMT2F. Some suggestions for the diagnostic procedures of patients with CMT are given.

A versatile system for the rapid collection, handling and graphics analysis of multidimensional data

International Nuclear Information System (INIS)

O'Brien, P.M.; Moloney, G.; O'Oconnor, A.; Legge, G.J.F.

1991-01-01

The paper discusses the performances of a versatile computerized system developed at the Microanalytical Research Centre of the Melbourne University, for handling multiparameter data that may arise from a variety of experiments - nuclear, accelerator mass spectrometry, microprobe elemental analysis or 3-D microtomography. Some of the most demanding requirements arise in the application of microprobes to quantitative elemental mapping and to microtomography. A system to handle data from such experiments had been under continuous development. It has been reprogramed to run on a DG DS7540 workstation. The whole system of software has been rewritten, greatly expanded and made much more powerful and faster, by use of modern computer technology - a VME bus computer with a real-time operating system and a RISC workstation running UNIX and the X-window environment

X-ray cone beam microtomography for quantitative assessment of tracheal and pharyngeal volumes of Rhodnius prolixus; Utilizacao da microtomografia computadorizada com feixe de raios-X conico para a determinacao quantitativa do volume da traqueia e faringe do Rhodnius prolixus

Energy Technology Data Exchange (ETDEWEB)

Souza, Izabella Soares de

2017-07-01

In the past decade microcomputerized tomography imaging using synchrotron radiation has become a powerful technique to generate high resolution images of Rhodinus prolixus. Images of soft tissues (protocerebrum and muscles) and dense structures (pharynx, trachea and esophagus) of R. prolixus head have been obtained using synchrotron radiation microtomography in mono and polychromatic configuration, respectively. Advancements in conventional microtomography have increased the achievable resolution and contrast, making this relatively inexpensive and widely available technology potentially useful for studies of insect internal morphology. The main goal of this work was to provide a new set of high quality microtomographic images of R. prolixus achieved by means of a desktop X-ray microtomograph. It allows the three-dimensional visualization of important chitinized structures: pharynx and tracheae. Pharyngeal and tracheal volumes were quantitatively evaluated at different days (1, 4, 10, 15 and 20) after feeding. The results suggest that variation of average volumes could be attributed to insect hormone 20-hydroxy-ecdysone (20-OH-Ec) pulse at 11 days after feeding. Pharyngeal volumes decrease 3.80 times. On the other hand, tracheal volumes increase 1.78 times. Head total volume showed similar trends than trachea. (author)

MicroCT parameters for multimaterial elements assessment

Science.gov (United States)

de Araújo, Olga M. O.; Silva Bastos, Jaqueline; Machado, Alessandra S.; dos Santos, Thaís M. P.; Ferreira, Cintia G.; Rosifini Alves Claro, Ana Paula; Lopes, Ricardo T.

2018-03-01

Microtomography is a non-destructive testing technique for quantitative and qualitative analysis. The investigation of multimaterial elements with great difference of density can result in artifacts that degrade image quality depending on combination of additional filter. The aim of this study is the selection of parameters most appropriate for analysis of bone tissue with metallic implant. The results show the simulation with MCNPX code for the distribution of energy without additional filter, with use of aluminum, copper and brass filters and their respective reconstructed images showing the importance of the choice of these parameters in image acquisition process on computed microtomography.

MicroCT parameters for multi material elements assessment

Energy Technology Data Exchange (ETDEWEB)

Araújo, Olga M.O. de; Machado, Alessandra S.; Santos, Thaís M.P. dos; Ferreira, Cintia G.; Lopes, Ricardo T., E-mail: olgaufrjlin@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Bastos, Jaqueline Silva [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), São Paulo, SP (Brazil)

2017-07-01

Microtomography is a non-destructive testing technique for quantitative and qualitative analysis. The investigation of multi material elements with great difference of density can result in artifacts that degrade image quality depending on combination of additional filter. The aim of this study is the selection of parameters most appropriate for analysis of bone tissue with metallic implant. The results show the simulation with MCNPX code for the distribution of energy without additional filter, with use of aluminum, copper and brass filters and their respective reconstructed images showing the importance of the choice of these parameters in image acquisition process on computed microtomography. (author)

MORPHOLOGY OF METHANE HYDRATE HOST SEDIMENTS

International Nuclear Information System (INIS)

JONES, K.W.; FENG, H.; TOMOV, S.; WINTER, W.J.; EATON, M.; MAHAJAN, D.

2004-01-01

Results from simulated experiments in several laboratories show that host sediments influence hydrate formation in accord with known heterogeneity of host sediments at sites of gas hydrate occurrence (1). For example, in Mackenzie Delta, NWT Canada (Mallik 2L-38 well), coarser-grained units (pore-filling model) are found whereas in the Gulf of Mexico, the found hydrate samples do not appear to be lithologically controlled. We have initiated a systematic study of sediments, initially focusing on samples from various depths at a specific site, to establish a correlation with hydrate occurrence (or variations thereof) to establish differences in their microstructure, porosity, and other associated properties. The synchrotron computed microtomography (CMT) set-up at the X-27A tomography beam line at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory was used as a tool to study sediments from Blake Ridge at three sub bottom depths of 0.2, 50, and 667 meters. Results from the tomographic analysis of the deepest sample (667 m) are presented here to illustrate how tomography can be used to obtain new insights into the structures of methane hydrate host sediments. The investigation shows the internal grain/pore space resolution in the microstructure and a 3-D visualization of the connecting pathways obtained following data segmentation into pore space and grains within the sediment sample. The analysis gives the sample porosity, specific surface area, mean particle size, and tortuosity, as well. An earlier report on the experimental program has been given by Mahajan et al. (2)

Porosity and pore size distribution determination of Tumblagooda formation sandstone by X-ray microtomography

International Nuclear Information System (INIS)

Fernandes, Jaquiel S.; Appoloni, Carlos R.; Moreira, Anderson C.

2007-01-01

Microstructural parameters evaluations of reservoir rocks are very important to petroleum industry. This work presents total porosity and pore size distribution measurement of a sandstone sample from the Tumblagooda formation, collected at Kalbarri National Park in Australia. Porosity and pores size distribution were determined using X-Ray microtomography and imaging techniques. For these measurements, it was employed a micro-CT (μ-CT) Skyscan system model 1172 with conical beam, operated with a 1 mm Al filter at 80 kV and 125 μA, respectively, and a 2000 x 1048 pixels CCD camera. The sample was rotated from 0 deg to 180 deg, in step of 0.5 deg. For the considered sample, this equipment provided images with 2.9 μm spatial resolution. Six hundreds 2-D images where reconstructed with the Skyscan NRecon software, which were analyzed with the aid of Imago software, developed at the Laboratory of Porous Media and Thermophysical Properties (LMPT), Department of Mechanical Engineering, Federal University of Santa Catarina, Brazil, in association with the Brazilian software company Engineering Simulation and Scientific Software (ESSS), and Petroleo Brasileiro SA (PETROBRAS) Research and Development Center (CENPES). The determined average porosity was 11.45 ±1.53 %. Ninety five percent of the porous phase refers to pores with radius ranging from 2.9 to 85.2 μm, presenting the larger frequency (7.7 %) at 11.7 μm radius. (author)

Ductile damage in aluminium alloy thin sheets: Correlation between micro-tomography observations and mechanical modeling

International Nuclear Information System (INIS)

Thuillier, S.; Maire, E.; Brunet, M.

2012-01-01

This work deals with the characterization of ductile damage in an aluminium alloy AA6016-T4 by X-ray micro-tomography, as a function of anisotropy and triaxiality. Interrupted tensile tests on notched samples with three different geometries were performed and the void volume fraction was measured for different strain values, up to rupture. It was shown that void volume fraction evolution with the strain is rather similar at 0° and 90° to RD but at 45° to RD it shows a more rapid evolution. Moreover, for the same strain level, a higher void volume fraction was recorded for a higher triaxiality ratio. Whatever the orientation and the stress triaxiality ratio, void volume fraction values range from 5×10 −4 up to 0.04. A numerical model based on Gurson–Tvergaard–Needleman constitutive equations was used to simulate the different tests. Hardening of the material was identified from macroscopic tensile test nucleation material parameters were identified by a direct method from void volume fraction evolution. It can be seen that the influence of triaxiality on void volume fraction is underestimated, though void growth is nicely predicted for the highest triaxiality ratio, for strains below 0.5. The load level was correctly predicted, except for high strain, where coalescence seems necessary to be taken into account.

X-ray microtomography

International Nuclear Information System (INIS)

Dunsmuir, J.H.; Ferguson, S.R.; D'Amico, K.L.; Stokes, J.P.

1991-01-01

In this paper the authors describe the application of a new high-resolution X-ray tomographic microscope to the study of porous media. The microscope was designed to exploit the properties of a synchrotron X-ray source to perform three dimensional tomography on millimeter sized objects with micron resolution and has been used in materials science studies with both synchrotron and conventional and synchrotron sources will be compared. In this work the authors have applied the microscope to measure the three dimensional structure of fused bead packs and berea sandstones with micron resolution and have performed preliminary studies of flow in these media with the microscope operated in a digital subtraction radiography mode. Computer graphics techniques have been applied to the data to visually display the structure of the pore body system. Tomographic imaging after flow experiments should detect the structure of the oil-water interface in the pore network and this work is ongoing

Assessment of the structural integrity of a prototypical instrumented IFMIF high flux test module rig by fully 3D X-ray microtomography

Energy Technology Data Exchange (ETDEWEB)

Tiseanu, Ion [National Institute for Laser, Plasma and Radiation Physics, Plasma Physics and Nuclear Fusion Laboratory NILPRP, P.O. Box MG-36, R-77125 Bucharest-Magurele (Romania)], E-mail: tiseanu@infim.ro; Simon, Martin [Hans Waelischmiller GmbH (HWM), Schiessstattweg 16, D-88677 Markdorf (Germany); Craciunescu, Teddy; Mandache, Bogdan N. [National Institute for Laser, Plasma and Radiation Physics, Plasma Physics and Nuclear Fusion Laboratory NILPRP, P.O. Box MG-36, R-77125 Bucharest-Magurele (Romania); Heinzel, Volker; Stratmanns, Erwin; Simakov, Stanislaw P.; Leichtle, Dieter [Forschungszentrum Karlsruhe (FZK), Institut fuer Reaktorsicherheit IRS, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2007-10-15

An inspection procedure to assess the mechanical integrity of the International Fusion Materials Irradiation Facility (IFMIF) capsules and rigs during the irradiation campaign is necessary. Due to its penetration ability and contrast mechanism, the X-ray microtomography is the only known tool that could meet these requirements. In the high flux test module (HFTM) of IFMIF miniaturized specimens are densely packed in capsules. The capsules, which wear electric heaters and thermocouples, are housed in rigs. To assure a well-defined thermal contact the heater wires have to be attached to the capsules by brazing them into grooves. The examination of the quality of the braze material layer is of crucial interest in order to assure the best heat coupling of the heater wires to the capsule. A high density of the heaters is necessary to maintain the required temperature and, in addition NaK filling of narrow channels is employed for improving the 3D-heat transfer between the irradiation specimens and the capsule wall. Fully 3D tomographic inspections of a prototypical HFTM instrumented capsule, developed and manufactured at FZK, were conducted. In order to identify the optimum irradiation parameters and scanning configuration we carried out a comparative NDT analysis on two microtomography facilities: a compact, high magnification installation at NILPRP and a high-end industrial tomography facility with higher X-ray energy and intensity at HWM. At optimum inspection parameters of a directional microfocus X-ray source (U = 220 kV and I = 300 {mu}A) the geometry resolution was about 30 microns for characteristic dimension of the sample of 50 mm. Voids of 30 microns diameter and cracks of about 20 microns width can be detected. The absolute error of geometrical measurements is sufficient for the assessment of the structural integrity of the irradiation capsule and for the geometry description within the thermal-hydraulic modeling. The space resolution and the overall

Assessment of the structural integrity of a prototypical instrumented IFMIF high flux test module rig by fully 3D X-ray microtomography

International Nuclear Information System (INIS)

Tiseanu, Ion; Simon, Martin; Craciunescu, Teddy; Mandache, Bogdan N.; Heinzel, Volker; Stratmanns, Erwin; Simakov, Stanislaw P.; Leichtle, Dieter

2007-01-01

An inspection procedure to assess the mechanical integrity of the International Fusion Materials Irradiation Facility (IFMIF) capsules and rigs during the irradiation campaign is necessary. Due to its penetration ability and contrast mechanism, the X-ray microtomography is the only known tool that could meet these requirements. In the high flux test module (HFTM) of IFMIF miniaturized specimens are densely packed in capsules. The capsules, which wear electric heaters and thermocouples, are housed in rigs. To assure a well-defined thermal contact the heater wires have to be attached to the capsules by brazing them into grooves. The examination of the quality of the braze material layer is of crucial interest in order to assure the best heat coupling of the heater wires to the capsule. A high density of the heaters is necessary to maintain the required temperature and, in addition NaK filling of narrow channels is employed for improving the 3D-heat transfer between the irradiation specimens and the capsule wall. Fully 3D tomographic inspections of a prototypical HFTM instrumented capsule, developed and manufactured at FZK, were conducted. In order to identify the optimum irradiation parameters and scanning configuration we carried out a comparative NDT analysis on two microtomography facilities: a compact, high magnification installation at NILPRP and a high-end industrial tomography facility with higher X-ray energy and intensity at HWM. At optimum inspection parameters of a directional microfocus X-ray source (U = 220 kV and I = 300 μA) the geometry resolution was about 30 microns for characteristic dimension of the sample of 50 mm. Voids of 30 microns diameter and cracks of about 20 microns width can be detected. The absolute error of geometrical measurements is sufficient for the assessment of the structural integrity of the irradiation capsule and for the geometry description within the thermal-hydraulic modeling. The space resolution and the overall

Microstructural characterization of porous materials by X-ray microtomography and gamma ray transmission techniques; Caracterizacao da microestrutura de materiais porosos por microtomografia de raios X e transmissao de raios gama

Energy Technology Data Exchange (ETDEWEB)

Moreira, Anderson Camargo

2006-07-01

This work presents the application of the X-ray microtomography and gamma ray transmission techniques for the microstructure characterization of different kinds of materials. Total porosity, pore size distribution and the two point correlation functions were measured. The two point correlation function, which allows the reconstruction of 3D models, was carried out for two samples. Seven ceramic tablets of Alumina (Al{sub 2}O{sub 3}), seven tablets of Boron Carbide (B{sub 4}C), three samples of sedimentary rocks and one sample of Titanium foam were analyzed. The experimental set up for the Gamma Ray Transmission technique consisted of: a 2'' x 2'' crystal NaI(Tl) detector, an {sup 241} Am radioactive source (59,53 keV, 100 mCi), an automatic micrometric table for the sample XZ movement and standard gamma spectrometry electronics. Two microtomography systems were used: a Fein Focus system, constituted by an X-ray tube, operated at 160 kV and 0.3 to 1.1 mA, a CCD camera and the movement sample system, and a Skyscan system, model 1072, with a X-ray tube operated at 100 kV and 100{mu}A, and a CCD camera. The ceramic tablets, analyzed by the gamma ray transmission technique presented results for most of the porosities data with smaller confidence intervals and inside the intervals supplied by the tablets manufacturer. The Titanium porous sample was analyzed by the two techniques, its microtomography images achieved a resolution of 17{mu}m, obtained employing the Fein Focus system. For both techniques, this sample showed high porosity, which allows its application for this purpose. The sandstones samples were analyzed by the Skyscan system, achieving resolutions of 19{mu}m, 11{mu}m and 3.8{mu}m for each sample, respectively. The resolutions of 11{mu}m and 3.8{mu}m were the ones that generated better 2D sections for the respective samples and, consequently, more reliable porosities. The 3.8{mu}m resolution was the one that best quantified the pore size

Revision and Microtomography of the Pheidole knowlesi Group, an Endemic Ant Radiation in Fiji (Hymenoptera, Formicidae, Myrmicinae)Myrmicinae).

Science.gov (United States)

Fischer, Georg; Sarnat, Eli M; Economo, Evan P

2016-01-01

The Fijian islands, a remote archipelago in the southwestern Pacific, are home to a number of spectacular endemic radiations of plants and animals. Unlike most Pacific archipelagos, these evolutionary radiations extend to social insects, including ants. One of the most dramatic examples of ant radiation in Fiji has occurred in the hyperdiverse genus Pheidole. Most of the 17 native Fijian Pheidole belong to one of two species groups that descended from a single colonization, yet have evolved dramatically contrasting morphologies: the spinescent P. roosevelti species group, and the more morphologically conservative P. knowlesi species group. Here we revise the knowlesi group, in light of recent phylogenetic results, and enhanced with modern methods of X-ray microtomography. We recognize six species belonging to this group, including two of which we describe as new: Pheidole caldwelli Mann, Pheidole kava sp. n., Pheidole knowlesi Mann, P. ululevu sp. n., P. vatu Mann, and P. wilsoni Mann. Detailed measurements and descriptions, identification keys, and high-resolution images for queens, major and minor workers are provided. In addition, we include highly detailed 3D surface reconstructions for all available castes.

Application of synchrotron radiation phase-contrast microtomography with iodine staining to Rhodnius prolixus head during ecdysis period

Science.gov (United States)

Sena, G.; Nogueira, L. P.; Braz, D.; Colaço, M. V.; Azambuja, P.; Gonzalez, M. S.; Tromba, G.; Mantuano, A.; Costa, F. N.; Barroso, R. C.

2018-05-01

Synchrotron radiation phase-contrast microtomography (SR-PHC-CT) has become an important tool in studies of insects, mainly Rhodinius prolixus, the insect vector of Chagas disease. A previous work has shown that SR-PHC-CT is an excellent technique in studies about the ecdysis process of R.prolixus head. The term ecdysis refers to the set of behaviors by which an insect extracts itself from an old exoskeleton. The exoskeleton formation is indispensable for the evolutionary success of insect species, so failure to complete ecdysis will, in most cases result in death, making this process an excellent target in the search for new insect pest management strategies. Understanding the behavior of the ecdysis process is fundamental for the non-proliferation of Chagas disease. Despite it has been possible to identify the moulting process in the first work, main structures of the R.prolixus head could not be identified. In this work, it was developed a staining protocol which enabled the identification of these important structures using Iodine at SYRMEP beamline of ELETTRA. In the 3D images, it was possible to segment essential structures in the process of ecdysis. These structures have never been presented previously in the moulting period with SR-PHC-CT.

A family with autosomal dominant mutilating neuropathy not linked to either Charcot-Marie-Tooth disease type 2B (CMT2B) or hereditary sensory neuropathy type I (HSN I) loci.

Science.gov (United States)

Bellone, Emilia; Rodolico, Carmelo; Toscano, Antonio; Di Maria, Emilio; Cassandrini, Denise; Pizzuti, Antonio; Pigullo, Simona; Mazzeo, Anna; Macaione, Vincenzo; Girlanda, Paolo; Vita, Giuseppe; Ajmar, Franco; Mandich, Paola

2002-03-01

Sensory loss and ulcero-mutilating features have been observed in hereditary sensory neuropathy type I and in hereditary motor and sensory neuropathy type IIB, also referred as Charcot-Marie-Tooth disease type 2B. To date two loci associated with ulcero-mutilating neuropathy have been described: CMT2B at 3q13-q22 and HSN I at 9q22.1-q22.3. We performed linkage analysis with chromosomal markers representing the hereditary sensory neuropathy type I and Charcot-Marie-Tooth disease type 2B loci on an Italian family with a severe distal sensory loss leading to an ulcero-mutilating peripheral neuropathy. Negative likelihood-of-odds scores excluded any evidence of linkage to both chromosome 3q13 and chromosome 9q22 markers, confirming the genetic heterogeneity of this clinical entity and the presence of a third locus responsible for ulcero-mutilating neuropathies.

Properties of compression moulded new fully biobased thermoset composites with aligned flax fibre textiles

DEFF Research Database (Denmark)

Pohl, Th.; Bierer, M.; Natter, E.

2011-01-01

into composites using an industrial scale compression moulding machine, and their material properties were analysed. The density was calculated by using a computed microtomography system, and tensile tests were carried out. Besides the mechanical properties, the burning and the moisture absorption behaviour have...

In vivo time-resolved microtomography reveals the mechanics of the blowfly flight motor.

Directory of Open Access Journals (Sweden)

Simon M Walker

2014-03-01

Full Text Available Dipteran flies are amongst the smallest and most agile of flying animals. Their wings are driven indirectly by large power muscles, which cause cyclical deformations of the thorax that are amplified through the intricate wing hinge. Asymmetric flight manoeuvres are controlled by 13 pairs of steering muscles acting directly on the wing articulations. Collectively the steering muscles account for <3% of total flight muscle mass, raising the question of how they can modulate the vastly greater output of the power muscles during manoeuvres. Here we present the results of a synchrotron-based study performing micrometre-resolution, time-resolved microtomography on the 145 Hz wingbeat of blowflies. These data represent the first four-dimensional visualizations of an organism's internal movements on sub-millisecond and micrometre scales. This technique allows us to visualize and measure the three-dimensional movements of five of the largest steering muscles, and to place these in the context of the deforming thoracic mechanism that the muscles actuate. Our visualizations show that the steering muscles operate through a diverse range of nonlinear mechanisms, revealing several unexpected features that could not have been identified using any other technique. The tendons of some steering muscles buckle on every wingbeat to accommodate high amplitude movements of the wing hinge. Other steering muscles absorb kinetic energy from an oscillating control linkage, which rotates at low wingbeat amplitude but translates at high wingbeat amplitude. Kinetic energy is distributed differently in these two modes of oscillation, which may play a role in asymmetric power management during flight control. Structural flexibility is known to be important to the aerodynamic efficiency of insect wings, and to the function of their indirect power muscles. We show that it is integral also to the operation of the steering muscles, and so to the functional flexibility of the

In vivo time-resolved microtomography reveals the mechanics of the blowfly flight motor.

Science.gov (United States)

Walker, Simon M; Schwyn, Daniel A; Mokso, Rajmund; Wicklein, Martina; Müller, Tonya; Doube, Michael; Stampanoni, Marco; Krapp, Holger G; Taylor, Graham K

2014-03-01

Dipteran flies are amongst the smallest and most agile of flying animals. Their wings are driven indirectly by large power muscles, which cause cyclical deformations of the thorax that are amplified through the intricate wing hinge. Asymmetric flight manoeuvres are controlled by 13 pairs of steering muscles acting directly on the wing articulations. Collectively the steering muscles account for flight muscle mass, raising the question of how they can modulate the vastly greater output of the power muscles during manoeuvres. Here we present the results of a synchrotron-based study performing micrometre-resolution, time-resolved microtomography on the 145 Hz wingbeat of blowflies. These data represent the first four-dimensional visualizations of an organism's internal movements on sub-millisecond and micrometre scales. This technique allows us to visualize and measure the three-dimensional movements of five of the largest steering muscles, and to place these in the context of the deforming thoracic mechanism that the muscles actuate. Our visualizations show that the steering muscles operate through a diverse range of nonlinear mechanisms, revealing several unexpected features that could not have been identified using any other technique. The tendons of some steering muscles buckle on every wingbeat to accommodate high amplitude movements of the wing hinge. Other steering muscles absorb kinetic energy from an oscillating control linkage, which rotates at low wingbeat amplitude but translates at high wingbeat amplitude. Kinetic energy is distributed differently in these two modes of oscillation, which may play a role in asymmetric power management during flight control. Structural flexibility is known to be important to the aerodynamic efficiency of insect wings, and to the function of their indirect power muscles. We show that it is integral also to the operation of the steering muscles, and so to the functional flexibility of the insect flight motor.

Pore-scale study on flow and heat transfer in 3D reconstructed porous media using micro-tomography images

International Nuclear Information System (INIS)

Liu, Zhenyu; Wu, Huiying

2016-01-01

Highlights: • The complex porous domain has been reconstructed with the micro CT scan images. • Pore-scale numerical model based on LB method has been established. • The correlations for flow and heat transfer were derived from the predictions. • The numerical approach developed in this work is suitable for complex porous media. - Abstract: This paper presents the numerical study on fluid flow and heat transfer in reconstructed porous media at the pore-scale with the double-population thermal lattice Boltzmann (LB) method. The porous geometry was reconstructed using micro-tomography images from micro-CT scanner. The thermal LB model was numerically tested before simulation and a good agreement was achieved by compared with the existing results. The detailed distributions of velocity and temperature in complex pore spaces were obtained from the pore-scale simulation. The correlations for flow and heat transfer in the specific porous media sample were derived based on the numerical results. The numerical method established in this work provides a promising approach to predict pore-scale flow and heat transfer characteristics in reconstructed porous domain with real geometrical effect, which can be extended for the continuum modeling of the transport process in porous media at macro-scale.

The grain size dependency of vesicular particle shapes strongly affects the drag of particles. First results from microtomography investigations of Campi Flegrei fallout deposits

Science.gov (United States)

Mele, Daniela; Dioguardi, Fabio

2018-03-01

Acknowledging the grain size dependency of shape is important in volcanology, in particular when dealing with tephra produced and emplaced during and after explosive volcanic eruptions. A systematic measurement of the tridimensional shape of vesicular pyroclasts of Campi Flegrei fallout deposits (Agnano-Monte Spina, Astroni 6 and Averno 2 eruptions) varying in size from 8.00 to 0.016 mm has been carried out by means of X-Ray Microtomography. Data show that particle shape changes with size, especially for juvenile vesicular clasts, since it is dependent on the distribution and size of vesicles that contour the external clast outline. Two drag laws that include sphericity in the formula were used for estimating the dependency of settling velocity on shape. Results demonstrate that it is not appropriate to assume a size-independent shape for vesicular particles, in contrast with the approach commonly employed when simulating the ash dispersion in the atmosphere.

Organization experience of diagnostic and medicosocial services for patients with Charcot—Marie—Tooth disease in Krasnoyarsk region

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E. V. Glushchenko

2012-01-01

Full Text Available Hereditary neuropathy Charcot-Marie-Tooth (CMT is the most common form of hereditary polyneuropathies. Goal of the study was the development of evidence-based diagnostic and treatment algorithms using patients with CMT (for example, in Krasnoyarsk Territory.Materials and methods: A total of 324 people. (probands and their relatives 1 and 2 lines of kinship. We analyzed 125 (38,5 % clinical cases of CMT, 64/125 (51,2 % clinical cases were include to statistical analysis (probands and their family trees, past the full range of clinical and laboratory findings according to the protocol this study. Age ranged from 6 to 81 years, median age — 30,5 years, including women 24 (37,5 %, median age — 33,5 years; males 40 (62,5 %, median age — 28,5 years. Methods of diagnosis: clinical, genetic, neurophysiological, molecular genetic, assessment of quality of life assessment of anxiety and depression.Results: The family history of CMT noted in 53/57 (93,0 % cases, with a predominance of autosomal dominant type of inheritance —52 (91,2 % cases. As a result of DNA testing duplication of peripheral myelin protein gene (RMR22 on chromosome 17, held 34 survey, this mutation was found in 17 (50,0 % patients. Modified method of computer esthesiometry for CMT diagnosis using domestic diagnostic equipment “Vibrotester-MBN” BT-02-1 has a high sensitivity in the early stages of the disease and can be recommended for more widespread adoption of on par with other subjects of the Russian Federation.

Complex three dimensional modelling of porous media using high performance computing and multi-scale incompressible approach

Science.gov (United States)

Martin, R.; Orgogozo, L.; Noiriel, C. N.; Guibert, R.; Golfier, F.; Debenest, G.; Quintard, M.

2013-05-01

In the context of biofilm growth in porous media, we developed high performance computing tools to study the impact of biofilms on the fluid transport through pores of a solid matrix. Indeed, biofilms are consortia of micro-organisms that are developing in polymeric extracellular substances that are generally located at a fluid-solid interfaces like pore interfaces in a water-saturated porous medium. Several applications of biofilms in porous media are encountered for instance in bio-remediation methods by allowing the dissolution of organic pollutants. Many theoretical studies have been done on the resulting effective properties of these modified media ([1],[2], [3]) but the bio-colonized porous media under consideration are mainly described following simplified theoretical media (stratified media, cubic networks of spheres ...). Therefore, recent experimental advances have provided tomography images of bio-colonized porous media which allow us to observe realistic biofilm micro-structures inside the porous media [4]. To solve closure system of equations related to upscaling procedures in realistic porous media, we solve the velocity field of fluids through pores on complex geometries that are described with a huge number of cells (up to billions). Calculations are made on a realistic 3D sample geometry obtained by X micro-tomography. Cell volumes are coming from a percolation experiment performed to estimate the impact of precipitation processes on the properties of a fluid transport phenomena in porous media [5]. Average permeabilities of the sample are obtained from velocities by using MPI-based high performance computing on up to 1000 processors. Steady state Stokes equations are solved using finite volume approach. Relaxation pre-conditioning is introduced to accelerate the code further. Good weak or strong scaling are reached with results obtained in hours instead of weeks. Factors of accelerations of 20 up to 40 can be reached. Tens of geometries can now be

3-D IMAGING, ANALYSIS AND MODELLING OF POROUS CEREAL PRODUCTS USING X-RAY MICROTOMOGRAPHY

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Gerard Van Dalen

2011-05-01

Full Text Available Efficient design of multi-component food products containing dry and wet components such as biscuits with a moist fruit filling, is of growing interests for food industry. Technology is needed to prevent or reduce water migration from the moist filling to the dry porous cereal material. This can be done by using moisture barrier systems. Knowledge of the microstructure and its relation to water mobility is necessary to develop stable products. This paper describes a study that uses X-ray microtomography (μCT for the characterisation and visualisation of the 3-D structure of crackers with different porosity, coated biscuit shells and soup inclusions. μCT was used for imaging the inner cellular structure of the cereal matrix or to analyse the integrity of moisture barriers applied on the cereal product. 3-D image analysis methods were developed to obtain quantitative information about the cellular matrix which can be used as input for simulation models for moisture migration. The developed 3-D image analysis method maps the open cellular structure onto a network (graph representation in which the nodes correspond to the pores and the vertices to the pore-topore interconnection. The pores (nodes have properties such as volume, surface area and location whereas the vertices have properties such as direct (open connection and indirect (separated by a single lamella area. To check the segmentation and network description a model for pore to pore resistance was used. The obtained results demonstrate the potential of μCT and 3-D image analysis for extracting structural information which can be used in models for the moisture penetration in a cellular bakery product.

Study on core make-up water experiment of AC600 make-up water tank

International Nuclear Information System (INIS)

Ji Fuyun; Li Changlin; Zheng Hua; Liu Shaohua; Xu Xiaolan

1999-01-01

The core makeup tank (CMT) is a principal component of the passive high pressure safety injection systems for AC600 and has a function to inject cold borated water into reactor vessel during abnormal events. The purpose of this experiment is to verify the gravity drain behavior of the CMT and to provide experimental data to verify the computer codes used in the safety analyses. Five experiments with simulative small and medium break conditions are conducted at AC600 core makeup tank performance test facility of Nuclear Power Institute of China (NPIC). The author provides the results of one test. The simulated accident is a small break loss-of-coolant accident

Sleep disorders in Charcot-Marie-Tooth disease type 1.

Science.gov (United States)

Boentert, Matthias; Knop, Katharina; Schuhmacher, Christine; Gess, Burkhard; Okegwo, Angelika; Young, Peter

2014-03-01

Obstructive sleep apnoea (OSA) and restless legs syndrome (RLS) have been reported in Charcot-Marie-Tooth disease (CMT) type 1A and axonal subtypes of CMT, respectively. The aim of this case-control study was to investigate both prevalence and severity of OSA, RLS and periodic limb movements in sleep (PLMS) in adult patients with genetically proven CMT1. 61 patients with CMT1 and 61 insomnic control subjects were matched for age, sex, and Body Mass Index. Neurological disability in patients with CMT was assessed using the Functional Disability Scale (FDS). RLS diagnosis was based on a screening questionnaire and structured clinical interviews. All participants underwent overnight polysomnography. OSA was present in 37.7% of patients with CMT1 and 4.9% of controls (psleep quality. In addition to known risk factors, CMT may predispose to OSA. RLS is highly prevalent not only in axonal subtypes of CMT but also in primarily demyelinating subforms of CMT. PLMS are common in CMT1, but do not significantly impair sleep quality.

Application of microtomography and image analysis to the quantification of fragmentation in ceramics after impact loading

Science.gov (United States)

Forquin, Pascal; Ando, Edward

2017-01-01

Silicon carbide ceramics are widely used in personal body armour and protective solutions. However, during impact, an intense fragmentation develops in the ceramic tile due to high-strain-rate tensile loadings. In this work, microtomography equipment was used to analyse the fragmentation patterns of two silicon carbide grades subjected to edge-on impact (EOI) tests. The EOI experiments were conducted in two configurations. The so-called open configuration relies on the use of an ultra-high-speed camera to visualize the fragmentation process with an interframe time set to 1 µs. The so-called sarcophagus configuration consists in confining the target in a metallic casing to avoid any dispersion of fragments. The target is infiltrated after impact so the final damage pattern is entirely scanned using X-ray tomography and a microfocus source. Thereafter, a three-dimensional (3D) segmentation algorithm was tested and applied in order to separate fragments in 3D allowing a particle size distribution to be obtained. Significant differences between the two specimens of different SiC grades were noted. To explain such experimental results, numerical simulations were conducted considering the Denoual-Forquin-Hild anisotropic damage model. According to the calculations, the difference of crack pattern in EOI tests is related to the population of defects within the two ceramics. This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

Effect of Preparation Depth on the Marginal and Internal Adaptation of Computer-aided Design/Computer-assisted Manufacture Endocrowns.

Science.gov (United States)

Gaintantzopoulou, M D; El-Damanhoury, H M

The aim of the study was to evaluate the effect of preparation depth and intraradicular extension on the marginal and internal adaptation of computer-aided design/computer-assisted manufacture (CAD/CAM) endocrown restorations. Standardized preparations were made in resin endodontic tooth models (Nissin Dental), with an intracoronal preparation depth of 2 mm (group H2), with extra 1- (group H3) or 2-mm (group H4) intraradicular extensions in the root canals (n=12). Vita Enamic polymer-infiltrated ceramic-network material endocrowns were fabricated using the CEREC AC CAD/CAM system and were seated on the prepared teeth. Specimens were evaluated by microtomography. Horizontal and vertical tomographic sections were recorded and reconstructed by using the CTSkan software (TView v1.1, Skyscan).The surface/void volume (S/V) in the region of interest was calculated. Marginal gap (MG), absolute marginal discrepancy (MD), and internal marginal gap were measured at various measuring locations and calculated in microscale (μm). Marginal and internal discrepancy data (μm) were analyzed with nonparametric Kruskal-Wallis analysis of variance by ranks with Dunn's post hoc, whereas S/V data were analyzed by one-way analysis of variance and Bonferroni multiple comparisons (α=0.05). Significant differences were found in MG, MD, and internal gap width values between the groups, with H2 showing the lowest values from all groups. S/V calculations presented significant differences between H2 and the other two groups (H3 and H4) tested, with H2 again showing the lowest values. Increasing the intraradicular extension of endocrown restorations increased the marginal and internal gap of endocrown restorations.

The 4D evolution of porosity during ongoing pressure-solution processes in NaCl using x-ray microtomography

Science.gov (United States)

Macente, Alice; Fusseis, Florian; Butler, Ian; Tudisco, Erika; Hall, Stephen; Andò, Edward

2016-04-01

Pressure-solution creep is a common deformation mechanism in the upper crust. It represents a mass transfer via dissolution-reprecipitation that critically affects the hydraulic properties of rocks. Successful management of safe radioactive storage sites in rock-salt deposits critically depends on an accurate knowledge of the hydro-mechanical behaviour of salt deposits. Despite numerous lab experiments that have been conducted, many aspects of pressure-solution are still poorly understood. There is little knowledge about the spatio-temporal evolution of porosity and permeability during pressure-solution creep. While rates of pressure-solution creep in silicates and carbonates are slow, which makes laboratory investigations of these materials impractical, compaction experiments have demonstrated that NaCl samples deform sufficiently fast to study pressure-solution creep in a lab environment at room temperature and modest loads. We present results from novel experiments that quantify the 4-dimensional (three spatial dimensions plus time) evolution of pressure-solution processes using in-situ x-ray microtomography. Our experiments are performed in custom made x-ray transparent presses. 5 mm diameter NaCl powder samples with a grain size of 250-300 μm are loaded dry into the press and pre-compacted to produce a starting aggregated material. The sample is then flooded with saturated NaCl solution and loaded uniaxially by means of a pneumatic actuator to a constant uniaxial stress. Different sample mixtures were tested, as well as different uniaxial loads. The resulting deformation of the samples is documented in 3-dimensional microtomographic datasets, acquired at regular time intervals. Image analysis allowed characterization of the microstructural evolution of the NaCl grains and the spatio-temporal distribution of porosity during ongoing mechanical and chemical compaction. The microtomography data have also been analysed with 3D Digital Image Correlation (3D-DIC or

Microstructure Evolution and Mechanical Behavior of 2219 Aluminum Alloys Additively Fabricated by the Cold Metal Transfer Process

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Xuewei Fang

2018-05-01

Full Text Available In this research, four different welding arc modes including conventional cold metal transfer (CMT, CMT-Pulse (CMT-P, CMT-Advanced (CMT-ADV, and CMT pulse advanced (CMT-PADV were used to deposit 2219-Al wire. The effects of different arc modes on porosity, pore size distribution, microstructure evolution, and mechanical properties were thoroughly investigated. The statistical analysis of the porosity and its size distribution indicated that the CMT-PADV process gave the smallest pore area percentage and pore aspect ratio, and had almost no larger pores. The results from optical microscopy, scanning electron microscopy, and fractographic morphology proved that uniform and fine equiaxed grains, evenly distributed Al2Cu second phase particles were formed during the CMT-PADV process. Furthermore, the X-ray diffraction test ascertained that the CMT-PADV sample had the smallest lattice parameter and the highest solute Cu content. Besides, the tensile strength could reach 283 MPa, the data scattering was the smallest, and the strength scattering of the sample in the horizontal direction was the shortest. In addition, the strength properties were nearly isotropic, with only 5 MPa difference in the vertical and horizontal directions. The above mentioned results indicated that the mechanical properties of 2219 aluminum alloy was improved using the CMT-PADV arc mode.

Microstructure Evolution and Mechanical Behavior of 2219 Aluminum Alloys Additively Fabricated by the Cold Metal Transfer Process.

Science.gov (United States)

Fang, Xuewei; Zhang, Lijuan; Li, Hui; Li, Chaolong; Huang, Ke; Lu, Bingheng

2018-05-16

In this research, four different welding arc modes including conventional cold metal transfer (CMT), CMT-Pulse (CMT-P), CMT-Advanced (CMT-ADV), and CMT pulse advanced (CMT-PADV) were used to deposit 2219-Al wire. The effects of different arc modes on porosity, pore size distribution, microstructure evolution, and mechanical properties were thoroughly investigated. The statistical analysis of the porosity and its size distribution indicated that the CMT-PADV process gave the smallest pore area percentage and pore aspect ratio, and had almost no larger pores. The results from optical microscopy, scanning electron microscopy, and fractographic morphology proved that uniform and fine equiaxed grains, evenly distributed Al₂Cu second phase particles were formed during the CMT-PADV process. Furthermore, the X-ray diffraction test ascertained that the CMT-PADV sample had the smallest lattice parameter and the highest solute Cu content. Besides, the tensile strength could reach 283 MPa, the data scattering was the smallest, and the strength scattering of the sample in the horizontal direction was the shortest. In addition, the strength properties were nearly isotropic, with only 5 MPa difference in the vertical and horizontal directions. The above mentioned results indicated that the mechanical properties of 2219 aluminum alloy was improved using the CMT-PADV arc mode.

Microstructure Evolution and Mechanical Behavior of 2219 Aluminum Alloys Additively Fabricated by the Cold Metal Transfer Process

Science.gov (United States)

Fang, Xuewei; Li, Hui; Li, Chaolong; Lu, Bingheng

2018-01-01

In this research, four different welding arc modes including conventional cold metal transfer (CMT), CMT-Pulse (CMT-P), CMT-Advanced (CMT-ADV), and CMT pulse advanced (CMT-PADV) were used to deposit 2219-Al wire. The effects of different arc modes on porosity, pore size distribution, microstructure evolution, and mechanical properties were thoroughly investigated. The statistical analysis of the porosity and its size distribution indicated that the CMT-PADV process gave the smallest pore area percentage and pore aspect ratio, and had almost no larger pores. The results from optical microscopy, scanning electron microscopy, and fractographic morphology proved that uniform and fine equiaxed grains, evenly distributed Al2Cu second phase particles were formed during the CMT-PADV process. Furthermore, the X-ray diffraction test ascertained that the CMT-PADV sample had the smallest lattice parameter and the highest solute Cu content. Besides, the tensile strength could reach 283 MPa, the data scattering was the smallest, and the strength scattering of the sample in the horizontal direction was the shortest. In addition, the strength properties were nearly isotropic, with only 5 MPa difference in the vertical and horizontal directions. The above mentioned results indicated that the mechanical properties of 2219 aluminum alloy was improved using the CMT-PADV arc mode. PMID:29772708

Concrete hardened characterization using table scanner and microtomography computed

International Nuclear Information System (INIS)

Wilson, R.E.; Pessoa, J.R.; Assis, J.T. de; Dominguez, D.S.; Dias, L.A.; Santana, M. R.

2016-01-01

This paper proposes the use of image processing technologies to analyze hardened concrete samples obtained from table scanner and micro tomography. Techniques will be used to obtain numerical data on the distribution and geometry of aggregates and pores of the concrete, as well as their relative position. It is expected that the data obtained can produce information on the research of concrete pathologies such as AAR, and the freeze / thaw process. (author)

Microstructural characterization of industrial foams by gamma ray transmission and X-ray microtomography; Caracterizacao microestrutural de espumas industriais por transmissao de raios gama e microtomografia de raios X

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Luiz Eduardo

2004-07-01

This work presents the total porosity measurements of the aluminum and silicon carbide (SiC) foams samples. For porosity determination the gamma ray transmission and X-ray microtomography with conic beam techniques were used. These methods have more advantage than conventional ones, because they are non destructive and provide more details of the analyzed material porous structure. The aluminum foam samples with 10, 20, 30, 40 and 45 ppi (pores per inch) and SiC ceramic foam samples with 20, 30, 45, 60, 75, 80 and 90 ppi were analysed by gamma transmission. The SiC 60, 75 and 90 ppi samples were also analyzed by X-ray microtomography. For the gamma ray transmission measurements it was used an {sup 241} Am source (59.53 keV), a NaI(Tl) scintillation detector, collimators, a XYZ micrometric table and standard gamma spectrometry electronics connected to a multichannel analyzer, at the LFNA/UEL. For the X-ray microtomographic measurements, the Fein Focus X-ray system of the Nuclear Instrumentation Laboratory of the COPPE, located at the Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, was used. This equipment provide us images with micrometric resolution (53.48 {mu}m) using a conic X-ray beam and bidimensional detection. The microtomographic images were pre-processed and analyzed by the Imago software, developed at Porous Media and Materials Thermophysical Properties Laboratory (LMPT) of the Mechanical Engineering Department, located at Universidade Federal de Santa Catarina, Florianopolis, SC. Employing the The Imago software it was calculated the total porosity, pore size distribution and autocorrelation function C(u) of the binarized microtomographic images of the each sample. The microtomographic 3-D image of each sample was compared with 3-D image reconstructed by the Gaussian truncated method. This method generates a periodic 3-D porous structure by using of the autocorrelation function of one 2-D cross sectional image of the sample. (author)

High resolution x-ray microtomography of biological samples: Requirements and strategies for satisfying them

Energy Technology Data Exchange (ETDEWEB)

Loo, B.W. Jr. [Univ. of California, San Francisco, CA (United States)]|[Univ. of California, Davis, CA (United States)]|[Lawrence Berkeley National Lab., CA (United States); Rothman, S.S. [Univ. of California, San Francisco, CA (United States)]|[Lawrence Berkeley National Lab., CA (United States)

1997-02-01

High resolution x-ray microscopy has been made possible in recent years primarily by two new technologies: microfabricated diffractive lenses for soft x-rays with about 30-50 nm resolution, and high brightness synchrotron x-ray sources. X-ray microscopy occupies a special niche in the array of biological microscopic imaging methods. It extends the capabilities of existing techniques mainly in two areas: a previously unachievable combination of sub-visible resolution and multi-micrometer sample size, and new contrast mechanisms. Because of the soft x-ray wavelengths used in biological imaging (about 1-4 nm), XM is intermediate in resolution between visible light and electron microscopies. Similarly, the penetration depth of soft x-rays in biological materials is such that the ideal sample thickness for XM falls in the range of 0.25 - 10 {mu}m, between that of VLM and EM. XM is therefore valuable for imaging of intermediate level ultrastructure, requiring sub-visible resolutions, in intact cells and subcellular organelles, without artifacts produced by thin sectioning. Many of the contrast producing and sample preparation techniques developed for VLM and EM also work well with XM. These include, for example, molecule specific staining by antibodies with heavy metal or fluorescent labels attached, and sectioning of both frozen and plastic embedded tissue. However, there is also a contrast mechanism unique to XM that exists naturally because a number of elemental absorption edges lie in the wavelength range used. In particular, between the oxygen and carbon absorption edges (2.3 and 4.4 nm wavelength), organic molecules absorb photons much more strongly than does water, permitting element-specific imaging of cellular structure in aqueous media, with no artifically introduced contrast agents. For three-dimensional imaging applications requiring the capabilities of XM, an obvious extension of the technique would therefore be computerized x-ray microtomography (XMT).

Structural characterization of titanium porous foams by gamma rays transmission and X ray microtomography

International Nuclear Information System (INIS)

Moreira, Anderson C.; Appoloni, Carlos R.

2007-01-01

The advance in porous media studies and the consequent progresses of their applications in medicine, petroleum industry, metallurgy and others, rises the prominence of the area among scientists. This fact increases the research on different characterization techniques of porous materials. In this work three Titanium foams were analyzed by gamma rays transmission (GRT), and one of these was also analyzed by X-ray microtomography (μ-CT). The GRT experimental set consisted by a 2'' x 2''. NaI(Tl) detector, a 241-Am radioactive source (59,53 keV, 100 mCi) and a standard gamma spectrometry electronic chain. In the μ-CT technique it was used a SKYSCAN 1172 scanner consisting of an X-ray tube (20-100 kV and 0-250 μA), a CCD detector and a proper mechanic system for sample and detector movement. The system may reach ∼0.8 μm image resolution. Images of 815 slices of the sample were generated and analyzed by the IMAGO software. It permitted the determination of geometrical parameters like pore size distribution, total porosity and autocorrelation function. The analysis of data, obtained by both techniques, showed that porous media are homogeneous in the reached resolutions (1 mm to GRT and 5 μm to μ-CT). The average total porosities determined by GRT for each sample were φ 1 =53,47±0,36%, φ 2 =55,95±0,23% and φ 3 =56,80±0,56%, and the determined by μ-CT was φ 1 =53,47±0,36%. The porosity data of the Ti-1 sample shows good agreement from both techniques. The pore size distribution, from μ-CT technique of the Ti-1 sample, showed that 57% of porous phase have porous with radius in 20 to 80 μm range. (author)

COMPARATIVE EFFICIENCY OF SOME INDIRECT DIAGNOSTIC TESTS FOR THE DETECTION OF SUB-CLINICAL MASTITIS IN COWS AND BUFFALOES

Directory of Open Access Journals (Sweden)

M. IQBAL, M. AMJED1, M. A. KHAN, M. S. QURESHI1 AND U. SADIQUE1

2006-04-01

Full Text Available The present study was undertaken to compare five laboratory diagnostic tests for sub-clinical mastitis in cattle and buffaloes and to compute cost, time taken by each test and its ranking for availability, adoptability, interpretability and sensitivity. There were 352 cases with each test type viz. California Mastitis Test (CMT, White Side Test (WST, White Side + Dye (WSTD, Surf Test and Surf + Dye, and 880 cases with each species type (cattle and buffaloes. Result scores (1760 for sub-clinical mastitis in each category of negative, trace, single positive, double positive and triple positive by species, and laboratory tests, were analyzed using nonparametric tests. Chi-square statistics showed that CMT was equally effective at both locations (farm vs. laboratory. Correlation further suggested that the association was highly significant. Moreover, cases in category of negative, trace and single positive strongly differed (P0.05. The study further suggested that CMT was the most sensitive test, followed by WST/WSTD and Surf/Surf + Dye. Although, the five tests showed slight discrepancy in the trace category reaction, a strong relationship of Surf Test to CMT, its low cost, easy availability and readily adoptable qualities should spur the relevant authorities to recommend the use of Surf test as a routine practice in dairy farming and add this test in the curriculum of diploma and degree programmes.

Digital Rock Studies of Tight Porous Media

Energy Technology Data Exchange (ETDEWEB)

Silin, Dmitriy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2012-08-07

This technical report summarizes some recently developed approaches to studies of rock properties at a pore scale. Digital rock approach is complementary to laboratory and field studies. It can be especially helpful in situations where experimental data are uncertain, or are difficult or impossible to obtain. Digitized binary images of the pore geometries of natural rocks obtained by different imaging techniques are the input data. Computer-generated models of natural rocks can be used instead of images in a case where microtomography data are unavailable, or the resolution of the tools is insufficient to adequately characterize the features of interest. Simulations of creeping viscous flow in pores produce estimates of Darcy permeability. Maximal Inscribed Spheres calculations estimate two-phase fluid distribution in capillary equilibrium. A combination of both produce relative permeability curves. Computer-generated rock models were employed to study two-phase properties of fractured rocks, or tight sands with slit-like pores, too narrow to be characterized with micro-tomography. Various scenarios can simulate different fluid displacement mechanisms, from piston-like drainage to liquid dropout at the dew point. A finite differences discretization of Stokes equation is developed to simulate flow in the pore space of natural rocks. The numerical schemes are capable to handle both no-slip and slippage flows. An upscaling procedure estimates the permeability by subsampling a large data set. Capillary equilibrium and capillary pressure curves are efficiently estimated with the method of maximal inscribed spheres both an arbitrary contact angle. The algorithms can handle gigobytes of data on a desktop workstation. Customized QuickHull algorithms model natural rocks. Capillary pressure curves evaluated from computer-generated images mimic those obtained for microtomography data.

Two and three-dimensional morphometric analysis of trabecular bone using X-ray microtomography (μCT)

International Nuclear Information System (INIS)

Silva, Alessandro Marcio Hakme da; Silva, Orivaldo Lopes da; Silva Junior, Nelson Ferreira da; Alves, Jose Marcos

2014-01-01

Introduction: trabecular bones have a porous microstructure and can be modeled as linear elastic solids, heterogeneous and anisotropic. In the literature, few investigations have compared the two- dimensional (2D) and three-dimensional (3D) morphometric analyses of cancellous bone. Methods: In this investigation eighteen cylindrical samples of cancellous bone (10 mm of diameter and 20 mm of height) were obtained from six bovine head femurs, with similar values for the weight and age, of the same race and gender. The samples were harvested and freeze at - 20 °C before carrying out the micro CT analysis. The CT-Analyzer software was used to measure in three directions (superior-inferior, lateral-medial and anterior-posterior) parameters such as trabecular thickness, trabecular separation, trabecular number and the eigenvalues of the fabric tensor (M). Results: the Comparison of 2D and 3D analyses for the parameters: 2D (plate model) trabecular thickness, trabecular separation and trabecular number were statistically different (p = 0) showing that measurements are not similar to the 3D ones. However, 2D (rod model) trabecular thickness and 3D trabecular thickness measurements presented no significant difference (p = 0.26). The eigenvalues show that the bovine trabecular microstructure has a tendency to transversally isotropic symmetry. Discussion: The method proved to be quite interesting for the characterization of the bone structure through 3D measurements of trabecular bone morphometric parameters in the three possible directions of loading. The results show that x-ray microtomography (μCT) is a technique of great potential for characterization and generating bone quality parameters for the diagnosis of bone metabolism diseases. (author)

Two and three-dimensional morphometric analysis of trabecular bone using X-ray microtomography (μCT)

Energy Technology Data Exchange (ETDEWEB)

Silva, Alessandro Marcio Hakme da; Silva, Orivaldo Lopes da; Silva Junior, Nelson Ferreira da, E-mail: alhakme@sc.usp.br [Universidade de Sao Paulo (EESC/FMRP/IQSC/USP), Sao Carlos, SP (Brazil); Alves, Jose Marcos [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia. Departamento de Engenharia Eletrica e Computacao

2014-07-01

Introduction: trabecular bones have a porous microstructure and can be modeled as linear elastic solids, heterogeneous and anisotropic. In the literature, few investigations have compared the two- dimensional (2D) and three-dimensional (3D) morphometric analyses of cancellous bone. Methods: In this investigation eighteen cylindrical samples of cancellous bone (10 mm of diameter and 20 mm of height) were obtained from six bovine head femurs, with similar values for the weight and age, of the same race and gender. The samples were harvested and freeze at - 20 °C before carrying out the micro CT analysis. The CT-Analyzer software was used to measure in three directions (superior-inferior, lateral-medial and anterior-posterior) parameters such as trabecular thickness, trabecular separation, trabecular number and the eigenvalues of the fabric tensor (M). Results: the Comparison of 2D and 3D analyses for the parameters: 2D (plate model) trabecular thickness, trabecular separation and trabecular number were statistically different (p = 0) showing that measurements are not similar to the 3D ones. However, 2D (rod model) trabecular thickness and 3D trabecular thickness measurements presented no significant difference (p = 0.26). The eigenvalues show that the bovine trabecular microstructure has a tendency to transversally isotropic symmetry. Discussion: The method proved to be quite interesting for the characterization of the bone structure through 3D measurements of trabecular bone morphometric parameters in the three possible directions of loading. The results show that x-ray microtomography (μCT) is a technique of great potential for characterization and generating bone quality parameters for the diagnosis of bone metabolism diseases. (author)

A Comparative Study of Additively Manufactured Thin Wall and Block Structure with Al-6.3%Cu Alloy Using Cold Metal Transfer Process

Directory of Open Access Journals (Sweden)

Baoqiang Cong

2017-03-01

Full Text Available In order to build a better understanding of the relationship between depositing mode and porosity, microstructure, and properties in wire + arc additive manufacturing (WAAM 2319-Al components, several Al-6.3%Cu deposits were produced by WAAM technique with cold metal transfer (CMT variants, pulsed CMT (CMT-P and advanced CMT (CMT-ADV. Thin walls and blocks were selected as the depositing paths to make WAAM samples. Porosity, microstructure and micro hardness of these WAAM samples were investigated. Compared with CMT-P and thin wall mode, CMT-ADV and block process can effectively reduce the pores in WAAM aluminum alloy. The microstructure varied with different depositing paths and CMT variants. The micro hardness value of thin wall samples was around 75 HV from the bottom to the middle, and gradually decreased toward the top. Meanwhile, the micro hardness value ranged around 72–77 HV, and varied periodically in block samples. The variation in micro hardness is consistent with standard microstructure characteristics.

[Genetic study of the autosomal recessive form of Charcot-Marie-Tooth in an Algerian family].

Science.gov (United States)

Hamadouche, T; Tazir-Melboucy, M; Benhassine, T

1998-01-01

Charcot-Marie-Tooth disease (CMT) is a hereditary neuropathy characterized by muscular atrophy and progressive sensitive alterations that affect limbs. The CMT is one of the most heterogenous diseases, clinically as well as genetically. At least twelve loci are responsible for the CMT phenotype, four of them for the autosomal recessive form. The aim of our work was to determinate the implication/exclusion of these four loci in an Algerian family by linkage analysis using microsatellites markers. We have tested the four loci on 8q13-21.1 (CMT4A), 11q23 (CMT4B), 5q23-33 (CMT4C) 8q24 (CMTAR). The haplotype reconstruction allowed us to exclude all the loci in this family, suggesting that the locus (gene) responsible for this form of CMT is localized elsewhere in the genome, thus providing an other observation of the great heterogeneity of the CMT, particularly autosomal recessive.

Evaluation of the endodontic apical seal after post insertion by synchrotron radiation microtomography

International Nuclear Information System (INIS)

Contardo, L.; De Luca, M.; Biasotto, M.; Longo, R.; Olivo, A.; Pani, S.; Di Lenarda, R.

2005-01-01

The commonly used methods for evaluating the endodontic apical seal, such as longitudinal and transversal section and diaphanization, show some operative difficulties and intrinsic limitation. This study suggests and describes a new method of analysis using a synchrotron radiation microtomography to analyse the root apex after post insertion, creating a three-dimensional image and analysing sections of the specimen every 5μm. The study was performed at SYRMEP beam line at the Electra Synchrotron in Trieste using monochromatic X-rays of 32KeV. Eleven monoradicular teeth were prepared using NiTi GT Rotary files instruments to an apical size 20 with conicity .06 and divided in four groups: in G1 (n=4) and G2 (n=2), the specimens were endodontically filled with guttapercha and a zinc-oxide sealer, in G3 (n=3) and G4 (n=2) guttapercha and a silicon-based sealer were used. An endodontic post was inserted in specimens of groups 1 and 3 following the manufacturer's instructions. Specimens were analysed using monochromatic X-rays of 32KeV. A CCD detector with pixel dimension pf 5x5μm 2 was used for the acquisition process. Seven hundred and twenty projections were performed over 180 o range using a high-resolution rotator. The projections were reconstructed using standard algorithms for tomographic reconstruction. The apical infiltration was evaluated by verifying if black spots were detectable on the images. The specimens of groups 3 and 4 showed a better apical seal than the ones of groups 1 and 2. Post insertion, when a ZOE-based sealer is used, increases the apical gap even if it does not seem to be clinically relevant and sufficient to be a cause of endodontic failure. The new method for analysis appeared to be effective to detect small defects in endodontic obturation, analysing guttapercha-sealer and sealer-dentin interfaces

Investigation of the Incidence and Diagnosis of Subclinical Mastitis in Early Lactation Period Cows

OpenAIRE

BAŞTANC, Ayhan; KAÇAR, Cihan; ACAR, Duygu B.; ŞAHİN, Mithat

2014-01-01

The aim of this study was to compare the results of the California mastitis test (CMT) and bacteriological culture for detection of subclinical intramammary infections after 10 days postpartum. Samples were collected from 102 cows. The CMT was performed once on each cow. The results of bacteriological culture and the CMT were compared in 344 milk samples. Two hundred fifty samples were CMT (+) and 94 samples were CMT (-); 224 samples were bacteriologic culture (+) and 120 samples were culture...

Detecting and visualizing internal 3D oleoresin in agarwood by means of micro-computed tomography

International Nuclear Information System (INIS)

Khairiah Yazid; Roslan Yahya; Mat Rosol Awang

2012-01-01

Detection and analysis of oleoresin is particularly significant since the commercial value of agarwood is related to the quantity of oleoresins that are present. A modern technique of non-destructive may reach the interior region of the wood. Currently, tomographic image data in particular is most commonly visualized in three dimensions using volume rendering. The aim of this paper is to explore the potential of high resolution non-destructive 3D visualization technique, X-ray micro-computed tomography, as imaging tools to visualize micro-structure oleoresin in agarwood. Investigations involving desktop X-ray micro-tomography system on high grade agarwood sample, performed at the Centre of Tomography in Nuclear Malaysia, demonstrate the applicability of the method. Prior to experiments, a reference test was conducted to stimulate the attenuation of oleoresin in agarwood. Based on the experiment results, micro-CT imaging with voxel size 7.0 μm is capable to of detecting oleoresin and pores in agarwood. This imaging technique, although sophisticated can be used for standard development especially in grading of agarwood for commercial activities. (author)

Genetics of the Charcot-Marie-Tooth disease in the Spanish Gypsy population: the hereditary motor and sensory neuropathy-Russe in depth.

Science.gov (United States)

Sevilla, T; Martínez-Rubio, D; Márquez, C; Paradas, C; Colomer, J; Jaijo, T; Millán, J M; Palau, F; Espinós, C

2013-06-01

Four private mutations responsible for three forms demyelinating of Charcot-Marie-Tooth (CMT) or hereditary motor and sensory neuropathy (HMSN) have been associated with the Gypsy population: the NDRG1 p.R148X in CMT type 4D (CMT4D/HMSN-Lom); p.C737_P738delinsX and p.R1109X mutations in the SH3TC2 gene (CMT4C); and a G>C change in a novel alternative untranslated exon in the HK1 gene causative of CMT4G (CMT4G/HMSN-Russe). Here we address the findings of a genetic study of 29 Gypsy Spanish families with autosomal recessive demyelinating CMT. The most frequent form is CMT4C (57.14%), followed by HMSN-Russe (25%) and HMSN-Lom (17.86%). The relevant frequency of HMSN-Russe has allowed us to investigate in depth the genetics and the associated clinical symptoms of this CMT form. HMSN-Russe probands share the same haplotype confirming that the HK1 g.9712G>C is a founder mutation, which arrived in Spain around the end of the 18th century. The clinical picture of HMSN-Russe is a progressive CMT disorder leading to severe weakness of the lower limbs and prominent distal sensory loss. Motor nerve conduction velocity was in the demyelinating or intermediate range. © 2012 John Wiley & Sons A/S.

Tensile testing of materials at high temperatures above 1700 °C with in situ synchrotron X-ray micro-tomography

International Nuclear Information System (INIS)

Haboub, Abdel; Nasiatka, James R.; MacDowell, Alastair A.; Bale, Hrishikesh A.; Cox, Brian N.; Marshall, David B.; Ritchie, Robert O.

2014-01-01

A compact ultrahigh temperature tensile testing instrument has been designed and fabricated for in situ x-ray micro-tomography using synchrotron radiation at the Advanced Light Source, Lawrence Berkeley National Laboratory. It allows for real time x-ray micro-tomographic imaging of test materials under mechanical load at temperatures up to 2300 °C in controlled environments (vacuum or controlled gas flow). Sample heating is by six infrared halogen lamps with ellipsoidal reflectors arranged in a confocal configuration, which generates an approximately spherical zone of high heat flux approximately 5 mm in diameter. Samples are held between grips connected to a motorized stage that loads the samples in tension or compression with forces up to 2.2 kN. The heating chamber and loading system are water-cooled for thermal stability. The entire instrument is mounted on a rotation stage that allows stepwise recording of radiographs over an angular range of 180°. A thin circumferential (360°) aluminum window in the wall of the heating chamber allows the x-rays to pass through the chamber and the sample over the full angular range. The performance of the instrument has been demonstrated by characterizing the evolution of 3D damage mechanisms in ceramic composite materials under tensile loading at 1750 °C

Capecitabine maintenance therapy in patients with recurrent or metastatic breast cancer

Energy Technology Data Exchange (ETDEWEB)

Si, W. [General Hospital of the Chinese People' s Liberation Army, Department of Medical Oncology, Haidian District, Beijing, China, Department of Medical Oncology, General Hospital of the Chinese People’s Liberation Army, Haidian District, Beijing (China); School of Medicine, Nankai University, Tianjin (China); Zhu, Y.Y.; Li, Y.; Gao, P.; Han, C.; You, J.H.; Linghu, R.X.; Jiao, S.C.; Yang, J.L. [General Hospital of the Chinese People' s Liberation Army, Department of Medical Oncology, Haidian District, Beijing, China, Department of Medical Oncology, General Hospital of the Chinese People’s Liberation Army, Haidian District, Beijing (China)

2013-11-25

Our objective was to investigate the efficacy and safety of capecitabine maintenance therapy (CMT) after capecitabine-based combination chemotherapy in patients with metastatic breast cancer. The clinical data of 139 metastatic breast cancer patients treated from March 2008 to May 2012 with capecitabine-based combination chemotherapy were retrospectively analyzed. When initial disease control was achieved by the combination chemotherapy, we used CMT for 50 patients, while 37 patients were treated with a different (non-CMT) maintenance therapy. We compared time to progression (TTP), objective response rate, disease control rate, clinical benefit rate, and safety of the two groups, and a sub-group analysis was performed according to pathological characteristics. Sixty-four percent of the patients received a median of six cycles of a docetaxel+capecitabine combination chemotherapy regimen (range 1-45); the median TTP (MTTP) for the complete treatment was 9.43 months (95%CI=8.38-10.48 months) for the CMT group and 4.5 months (95%CI=4.22-4.78 months; P=0.004) for the non-CMT group. The MTTPs for the maintenance therapies administered after the initial capecitabine combined chemotherapy were 4.11 months (95%CI=3.34-4.87 months) for the CMT group and 2.0 months (95%CI=1.63-2.38 months) for the non-CMT group. Gastrointestinal side effects, decreased white blood cells and palmar-plantar erythrodysesthesia were the main adverse reactions experienced with the combination chemotherapies, CMT and non-CMT treatments. No significant differences in the incidence of adverse reactions were detected in the CMT and non-CMT patients. After initial disease control was achieved with the capecitabine-based combination chemotherapy, CMT can significantly prolong TTP rates with a favorable safety profile.

Capecitabine maintenance therapy in patients with recurrent or metastatic breast cancer

International Nuclear Information System (INIS)

Si, W.; Zhu, Y.Y.; Li, Y.; Gao, P.; Han, C.; You, J.H.; Linghu, R.X.; Jiao, S.C.; Yang, J.L.

2013-01-01

Our objective was to investigate the efficacy and safety of capecitabine maintenance therapy (CMT) after capecitabine-based combination chemotherapy in patients with metastatic breast cancer. The clinical data of 139 metastatic breast cancer patients treated from March 2008 to May 2012 with capecitabine-based combination chemotherapy were retrospectively analyzed. When initial disease control was achieved by the combination chemotherapy, we used CMT for 50 patients, while 37 patients were treated with a different (non-CMT) maintenance therapy. We compared time to progression (TTP), objective response rate, disease control rate, clinical benefit rate, and safety of the two groups, and a sub-group analysis was performed according to pathological characteristics. Sixty-four percent of the patients received a median of six cycles of a docetaxel+capecitabine combination chemotherapy regimen (range 1-45); the median TTP (MTTP) for the complete treatment was 9.43 months (95%CI=8.38-10.48 months) for the CMT group and 4.5 months (95%CI=4.22-4.78 months; P=0.004) for the non-CMT group. The MTTPs for the maintenance therapies administered after the initial capecitabine combined chemotherapy were 4.11 months (95%CI=3.34-4.87 months) for the CMT group and 2.0 months (95%CI=1.63-2.38 months) for the non-CMT group. Gastrointestinal side effects, decreased white blood cells and palmar-plantar erythrodysesthesia were the main adverse reactions experienced with the combination chemotherapies, CMT and non-CMT treatments. No significant differences in the incidence of adverse reactions were detected in the CMT and non-CMT patients. After initial disease control was achieved with the capecitabine-based combination chemotherapy, CMT can significantly prolong TTP rates with a favorable safety profile

The predictive validity of a situational judgement test, a clinical problem solving test and the core medical training selection methods for performance in specialty training .

Science.gov (United States)

Patterson, Fiona; Lopes, Safiatu; Harding, Stephen; Vaux, Emma; Berkin, Liz; Black, David

2017-02-01

The aim of this study was to follow up a sample of physicians who began core medical training (CMT) in 2009. This paper examines the long-term validity of CMT and GP selection methods in predicting performance in the Membership of Royal College of Physicians (MRCP(UK)) examinations. We performed a longitudinal study, examining the extent to which the GP and CMT selection methods (T1) predict performance in the MRCP(UK) examinations (T2). A total of 2,569 applicants from 2008-09 who completed CMT and GP selection methods were included in the study. Looking at MRCP(UK) part 1, part 2 written and PACES scores, both CMT and GP selection methods show evidence of predictive validity for the outcome variables, and hierarchical regressions show the GP methods add significant value to the CMT selection process. CMT selection methods predict performance in important outcomes and have good evidence of validity; the GP methods may have an additional role alongside the CMT selection methods. © Royal College of Physicians 2017. All rights reserved.

Determination of structural geometric parameters of industrial ceramic foams by gamma rays transmission and X-rays microtomography; Determinacao de parametros geometricos estruturais de espumas ceramicas industriais por transmissao de raios gama e microtomografia de raios X

Energy Technology Data Exchange (ETDEWEB)

Rocha, Wilson Roberto Dejato da

2005-07-01

In this work, the gamma rays transmission and X-rays microtomography techniques are used for the evaluation of the porosity and the pore size distribution of SiC ceramic foams. It was also accomplished the three-dimensional images after the determination of samples geometric parameters. The geometric parameters were obtained by two-dimensional images analyses, generated by a Microfocus system, with a CCD camera, an images intensifier, a X-rays tube and an automatic system for rotation of the sample. The spatial resolution of the images was about 32 {mu}m. In the gamma rays transmission methodology, a Nal(Tl) scintillation detector, an {sup 241}Am (59.53 keV, 100 mCi) radioactive source and an automatic X-Z micrometric table was used. The analyzed samples had pores density of 30, 45, 60, 80 and 100 ppi (pores per inch). The gamma rays transmission technique was accurate to supply the porosity of the samples, which ranged about 90% and was in agreement with the values supplied by manufacturer of the foams. The 30 and 45 ppi samples analyzed by X-rays microtomography showed porosity results that agree with the average porosity supplied by the manufacturer. In other hand, the 60, 80 and 100 ppi samples systematically showed average porosity about 4%, lower than the average of the manufacturer. The pore size distributions found through the software IMAGO show the presence of smaller pores than those nominated by the manufacturer. The 30 ppi samples had voids inside the solid material of the ceramic foams structure. Gaussian truncated method, used in the three-dimensional reconstruction, was not able to take into the account the voids inside the solid matrix. (author)

Application of X-ray Computed Tomography to Cultural Heritage diagnostics

International Nuclear Information System (INIS)

Morigi, M.P.; Casali, F.; Bettuzzi, M.; Brancaccio, R.; D'Errico, V.

2010-01-01

Physical methods of diagnosis are more and more frequently applied in the field of Cultural Heritage either for scientific investigations or for restoration and conservation purposes. X-ray Computed Tomography (CT) is one of the most powerful non-destructive testing techniques for the full-volume inspection of an object, as it is able to give morphological and physical information on the inner structure of the investigated sample. The great variety of size and composition that characterizes archaeological findings and art objects requires the development of tomographic systems specifically designed for Cultural Heritage analysis. In the last few years our research group has developed several acquisition systems for Digital Radiography and X-ray CT. We are able to perform high resolution micro-tomography of small objects (voxel size of few microns) as well as CT of large objects (up to 2 m of size). In this paper we will mainly focus the attention on the results of the investigation recently performed on two Japanese wooden statues with our CT system for large works of art. The CT analysis was carried out on site at the Conservation and Restoration Center ''La Venaria Reale'', where the statues have been restored before their exposition at the Oriental Art Museum in Turin. (orig.)

Oral Health, Temporomandibular Disorder, and Masticatory Performance in Patients with Charcot-Marie-Tooth Type 2

Directory of Open Access Journals (Sweden)

Rejane L. S. Rezende

2013-01-01

Full Text Available Background. The aim of this study was to evaluate the oral health status of temporomandibular disorders (TMD and bruxism, as well as to measure masticatory performance of subjects with Charcot-Marie-Tooth type 2 (CMT2. Methods and Results. The average number of decayed, missing, and filled teeth (DMFT for both groups, control (CG and CMT2, was considered low (CG = 2.46; CMT2 = 1.85, P=0.227. The OHIP-14 score was considered low (CG = 2.86, CMT2 = 5.83, P=0.899. The prevalence of self-reported TMD was 33.3% and 38.9% (P=0.718 in CG and CMT2 respectively and for self-reported bruxism was 4.8% (CG and 22.2% (CMT2, without significant difference between groups (P=0.162. The most common clinical sign of TMD was masseter (CG = 38.1%; CMT2 = 66.7% and temporalis (CG = 19.0%; GCMT2 = 33.3% muscle pain. The geometric mean diameter (GMD was not significantly different between groups (CG = 4369; CMT2 = 4627, P=0.157. Conclusion. We conclude that the CMT2 disease did not negatively have influence either on oral health status in the presence and severity of TMD and bruxism or on masticatory performance.

Assessment of MARS for Direct Contact Condensation in the Core Make-up Tank

International Nuclear Information System (INIS)

Park, Keun Tae; Park, Ik Kyu; Lee, Seung Wook

2013-01-01

In order to improve safety features under loss of coolant accident (LOCA) conditions, in many advanced light water reactors, gravity driven passive safety injection systems (PSISs) replace active pump driven emergency core cooling systems. Among various PSISs, the core make-up tank (CMT) with the pressure balancing line (PBL) and the coolant injection line (IL) represents an effective means of providing core cooling. Because the fluid is always sensing the reactor coolant system (RCS) through the PBL connecting the inlet of the CMT to the pressurizer in the case of CP1300 or to the cold legs in the case of AP600/1000, the CMT can provide cold water at any RCS pressure by gravity force. However, after the initiation of LOCAs, if the injection (or isolation) valve is opened, and the steam from the RCS is jetting into the highly subcooled liquid in the CMT and the enhanced interfacial area results in rapid condensation, which in turn, causes a rapid pressure drop in the CMT. As a result, the CMT pressure becomes less than the RCS pressure, and the injection of the CMT can be delayed until the CMT pressure builds up due to greatly reduced condensation in the CMT by the thermal stratification. In order to identify the parameters having significant effects on the gravity-driven injection and the major condensation modes, Lee and No (1998) conducted the separated effect tests of CMT with a small-scale facility. MARS has been developed as a multi-dimensional thermal-hydraulic (TH) system analysis code for the realistic simulation of two-phase TH transients for pressurized water reactor plants. As the backbones for the MARS code, the RELAP5/MOD3.2 and the COB-RA-TF codes were adopted. Recently, Chun et al. (2013) evaluated performance of the SMART passive safety system for SBLOCA using MARS code. However, it is not clarified that MARS can simulate properly the direct contact condensation in the CMT. Thus, in this study, we assess the analysis capability of the MARS code for

X-ray diffraction microtomography using synchrotron radiation

CERN Document Server

Barroso, R C; Jesus, E F O; Oliveira, L F

2001-01-01

The X-ray diffraction computed tomography technique is based on the interference phenomena of the coherent scatter. For low-momentum transfer, it is most probable that the scattering interaction will be coherent. A selective discrimination of a given element in a scanned specimen can be realized by fixing the Bragg angle which produces an interference peak and then, to carry out the computed tomography in the standard mode. The image reconstructed exalts the presence of this element with respect to other ones in a sample. This work reports the feasibility of a non-destructive synchrotron radiation X-ray diffraction imaging technique. This research was performed at the X-ray Diffraction beam line of the National Synchrotron Light Laboratory (LNLS) in Brazil. The coherent scattering properties of different tissue and bone substitute materials were evaluated. Furthermore, diffraction patterns of some polycrystalline solids were studied due to industrial and environmental human exposure to these metals. The obtai...

3D mapping of water in oolithic limestone at atmospheric and vacuum saturation using X-ray micro-CT differential imaging

Energy Technology Data Exchange (ETDEWEB)

Boone, M.A., E-mail: marijn.boone@ugent.be [Department of Geology and Soil Science—UGCT, Ghent University, Krijgslaan 281 S8, 9000 Ghent (Belgium); Unit Sustainable Materials Management, VITO, Boerentang 200, 2400 Mol (Belgium); De Kock, T.; Bultreys, T. [Department of Geology and Soil Science—UGCT, Ghent University, Krijgslaan 281 S8, 9000 Ghent (Belgium); De Schutter, G. [Magnel Laboratory for Concrete Research, Department of Structural Engineering, Ghent University, Technologiepark-Zwijnaarde 904, 9052 Ghent (Belgium); Vontobel, P. [Spallation Neutron Source Division, Paul Scherrer Institute (PSI), 5232 Villigen (Switzerland); Van Hoorebeke, L. [Department of Physics and Astronomy—UGCT, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); Cnudde, V. [Department of Geology and Soil Science—UGCT, Ghent University, Krijgslaan 281 S8, 9000 Ghent (Belgium)

2014-11-15

Determining the distribution of fluids in porous sedimentary rocks is of great importance in many geological fields. However, this is not straightforward, especially in the case of complex sedimentary rocks like limestone, where a multidisciplinary approach is often needed to capture its broad, multimodal pore size distribution and complex pore geometries. This paper focuses on the porosity and fluid distribution in two varieties of Massangis limestone, a widely used natural building stone from the southeast part of the Paris basin (France). The Massangis limestone shows locally varying post-depositional alterations, resulting in different types of pore networks and very different water distributions within the limestone. Traditional techniques for characterizing the porosity and pore size distribution are compared with state-of-the-art neutron radiography and X-ray computed microtomography to visualize the distribution of water inside the limestone at different imbibition conditions. X-ray computed microtomography images have the great advantage to non-destructively visualize and analyze the pore space inside of a rock, but are often limited to the larger macropores in the rock due to resolution limitations. In this paper, differential imaging is successfully applied to the X-ray computed microtomography images to obtain sub-resolution information about fluid occupancy and to map the fluid distribution in three dimensions inside the scanned limestone samples. The detailed study of the pore space with differential imaging allows understanding the difference in the water uptake behavior of the limestone, a primary factor that affects the weathering of the rock. - Highlights: • The water distribution in a limestone was visualized in 3D with micro-CT. • Differential imaging allowed to map both macro and microporous zones in the rock. • The 3D study of the pore space clarified the difference in water uptake behavior. • Trapped air is visualized in the moldic

Different nerve ultrasound patterns in charcot-marie-tooth types and hereditary neuropathy with liability to pressure palsies.

Science.gov (United States)

Padua, Luca; Coraci, Daniele; Lucchetta, Marta; Paolasso, Ilaria; Pazzaglia, Costanza; Granata, Giuseppe; Cacciavillani, Mario; Luigetti, Marco; Manganelli, Fiore; Pisciotta, Chiara; Piscosquito, Giuseppe; Pareyson, Davide; Briani, Chiara

2018-01-01

Nerve ultrasound in Charcot-Marie-Tooth (CMT) disease has focused mostly on the upper limbs. We performed an evaluation of a large cohort of CMT patients in which we sonographically characterized nerve abnormalities in different disease types, ages, and nerves. Seventy patients affected by different CMT types and hereditary neuropathy with liability to pressure palsies (HNPP) were evaluated, assessing median, ulnar, fibular, tibial, and sural nerves bilaterally. Data were correlated with age. Nerve dimensions were correlated with CMT type, age, and nerve site. Nerves were larger in demyelinating than in axonal neuropathies. Nerve involvement was symmetric. CMT1 patients had larger nerves than did patients with other CMT types. Patients with HNPP showed enlargement at entrapment sites. Our study confirms the general symmetry of ultrasound nerve patterns in CMT. When compared with ultrasound studies of nerves of the upper limbs, evaluation of the lower limbs did not provide additional information. Muscle Nerve 57: E18-E23, 2018. © 2017 Wiley Periodicals, Inc.

Modeling the Pathogenesis of Charcot-Marie-Tooth Disease Type 1A Using Patient-Specific iPSCs

Directory of Open Access Journals (Sweden)

Lei Shi

2018-01-01

Full Text Available Charcot-Marie-Tooth disease type 1A (CMT1A, one of the most frequent inherited peripheral neuropathies, is associated with PMP22 gene duplication. Previous studies of CMT1A mainly relied on rodent models, and it is not yet clear how PMP22 overexpression leads to the phenotype in patients. Here, we generated the human induced pluripotent stem cell (hiPSC lines from two CMT1A patients as an in vitro cell model. We found that, unlike the normal control cells, CMT1A hiPSCs rarely generated Schwann cells through neural crest stem cells (NCSCs. Instead, CMT1A NCSCs produced numerous endoneurial fibroblast-like cells in the Schwann cell differentiation system, and similar results were obtained in a PMP22-overexpressing iPSC model. Therefore, despite the demyelination-remyelination and/or dysmyelination theory for CMT1A pathogenesis, developmental disabilities of Schwann cells may be considered as an underlying cause of CMT1A. Our results may have important implications for the uncovering of the underlying mechanism and the development of a promising therapeutic strategy for CMT1A neuropathy.

KETAHANAN BEBERAPA GENOTIPE JAGUNG (ZEA MAYS INTRODUKSI TERHADAP SERANGAN HAMA

Directory of Open Access Journals (Sweden)

Dewi Rumbia Mustikawati

2014-08-01

Full Text Available The resistance of some_introduced hybrid genotypes maize (Zea mays towards insect pests. Plant resistance to insect pest play an important role in integrated pest management. Fourty hybrid genotypes released by CIMMYT Mexico and two National hybrid varieties (Pioner 13 and Andalas as local control had been tested threir resistance to insect pests. The trial was conducted at Natar Station Experimental, South Lampung from April to July 2002. The objective of the experiment was to obtaine the hybrid genotypes in which have a good tolerint or resistance toward insect pests. Alpha latice design with three replicates were used in this experiment. The varieties were grown in two-row plots of 5 m length at row-to-row spacing of 75 cm and hill-to-hill spacing within rows of 25 cm. 300 kg Urea, 150 kg SP-36 and 100 kg KCI ha_1 was applied to the trial. Insect pests damage were observe d at 16 and 80 days after planting. The results showed that there were 12 genotypes have moderate resistance toward insect pests: CMS 991006, CTM 011004, CMT 011018, CMT 011028, CMT 011030, CMT 011036, CMT 011038, CMT 011044, CMT 011050, CMS 951220 (RE, CMT 011056, CMT 011060 and one genotype was susceptible that was CMS 991018, however the others showed varies resistance traits against insect pest.

Medical Management

Science.gov (United States)

... org Close Charcot-Marie-Tooth Disease (CMT) Medical Management Although there’s no cure for CMT, there are ... individualized physical therapy program. For more on medical management of CMT, see Surgery Sometimes, Bracing Often, Caution ...

X-ray computed microtomography studies of MIM and DPR parts

CSIR Research Space (South Africa)

Muchavi, Noluntu S

2016-10-01

Full Text Available the wider or longer strips into small sections, thus requiring a large number of scans. AcknowledgementsS The contributions of Ntate Sam Papo, Mandy Seerane, Hilda Chikwanda and Pierre Rossouw are duly recognized. This work is funded by the DST and the CSIR... Metal injection moulding (MIM) is a novel process, which combines the advantages of powder metallurgy (PM) and plastic injection moulding. MIM has found widespread applications in the cost-effective production of high-sintered density small parts...

Damage observation in a high-manganese austenitic TWIP steel by synchrotron radiation computed tomography

International Nuclear Information System (INIS)

Lorthios, J.; Nguyen, F.; Gourgues, A.-F.; Morgeneyer, T.F.; Cugy, P.

2010-01-01

Internal damage below the fracture surface of a multiaxial specimen made of twinning-induced plasticity (TWIP) steel was observed by three-dimensional X-ray microtomography as very elongated 'primary' voids. Specific tools for the local damage analysis were developed. A gradient in void volume fraction was measured from the fracture surface down to the bulk of the scanned volume (from ∼0.06% to 90% in area fraction), indicating strongly localized final fracture.

The evolution of CHROMOMETHYLASES and gene body DNA methylation in plants.

Science.gov (United States)

Bewick, Adam J; Niederhuth, Chad E; Ji, Lexiang; Rohr, Nicholas A; Griffin, Patrick T; Leebens-Mack, Jim; Schmitz, Robert J

2017-05-01

The evolution of gene body methylation (gbM), its origins, and its functional consequences are poorly understood. By pairing the largest collection of transcriptomes (>1000) and methylomes (77) across Viridiplantae, we provide novel insights into the evolution of gbM and its relationship to CHROMOMETHYLASE (CMT) proteins. CMTs are evolutionary conserved DNA methyltransferases in Viridiplantae. Duplication events gave rise to what are now referred to as CMT1, 2 and 3. Independent losses of CMT1, 2, and 3 in eudicots, CMT2 and ZMET in monocots and monocots/commelinids, variation in copy number, and non-neutral evolution suggests overlapping or fluid functional evolution of this gene family. DNA methylation within genes is widespread and is found in all major taxonomic groups of Viridiplantae investigated. Genes enriched with methylated CGs (mCG) were also identified in species sister to angiosperms. The proportion of genes and DNA methylation patterns associated with gbM are restricted to angiosperms with a functional CMT3 or ortholog. However, mCG-enriched genes in the gymnosperm Pinus taeda shared some similarities with gbM genes in Amborella trichopoda. Additionally, gymnosperms and ferns share a CMT homolog closely related to CMT2 and 3. Hence, the dependency of gbM on a CMT most likely extends to all angiosperms and possibly gymnosperms and ferns. The resulting gene family phylogeny of CMT transcripts from the most diverse sampling of plants to date redefines our understanding of CMT evolution and its evolutionary consequences on DNA methylation. Future, functional tests of homologous and paralogous CMTs will uncover novel roles and consequences to the epigenome.

Hereditary motor and sensory neuropathies or Charcot-Marie-Tooth diseases: an update.

Science.gov (United States)

Tazir, Meriem; Hamadouche, Tarik; Nouioua, Sonia; Mathis, Stephane; Vallat, Jean-Michel

2014-12-15

Hereditary motor and sensory neuropathies (HMSN) or Charcot-Marie-Tooth (CMT) diseases are the most common degenerative disorders of the peripheral nervous system. However, the frequency of the different subtypes varies within distinct populations. Although more than seventy clinical and genetic forms are known to date, more than 80% of CMT patients in Western countries have genetic abnormalities associated with PMP22, MPZ, MFN2 and GJB1. Given the considerable genetic heterogeneity of CMT, we emphasize the interest of both clinical and pathological specific features such that focused genetic testing could be performed. In this regard, peripheral nerve lesions in GDAP1 mutations (AR CMT1A), such as mitochondrial abnormalities, have been newly demonstrated. Otherwise, while demyelinating autosomal recessive CMT used to be classified as CMT4 (A, B, C …), we propose a simplified classification such as AR CMT1 (A, B, C …), and AR CMT2 for axonal forms. Also, we stress that next generation sequencing techniques, now considered to be the most efficient methods of genetic testing in CMT, will be helpful in molecular diagnosis and research of new genes involved. Finally, while no effective therapy is known to date, ongoing new therapeutic trials such as PXT3003 (a low dose combination of the three already approved drugs baclofen, naltrexone, and D-sorbitol) give hopes for potential curative treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

Improving parent-child interactions for families of children with developmental disabilities.

Science.gov (United States)

Harrold, M; Lutzker, J R; Campbell, R V; Touchette, P E

1992-06-01

Child Management Training (CMT) involves compliance training with a focus on consistent use of antecedents and consequences. Planned Activities Training (PAT) focuses on teaching parents to plan for and engage in activities with their children. A multiple probe design counterbalancing PAT and CMT showed that PAT and CMT were about equally effective in improving mother-child interactions in four families with children with developmental disabilities. Responses to a social validation questionnaire indicated that parents were satisfied with the services received, and that PAT was the slightly preferred treatment. Prior research demonstrated that PAT enhanced the results of CMT. The practical advantages of PAT over CMT are discussed.

Effects of infrared laser on the bone repair assessed by x-ray microtomography (μct) and histomorphometry

Science.gov (United States)

Paolillo, Alessandra Rossi; Paolillo, Fernanda Rossi; da Silva, Alessandro M. Hakme; Reiff, Rodrigo Bezerra de Menezes; Bagnato, Vanderlei Salvador; Alves, José Marcos

2015-06-01

The bone fracture is important public health problems. The lasertherapy is used to accelerate tissue healing. Regarding diagnosis, few methods are validated to follow the evolution of bone microarchitecture. The aim of this study was to evaluate the effects of lasertherapy on bone repair with x-ray microtomography (μCT) and histomorphometry. A transverse rat tibia osteotomy with a Kirchner wire and a 2mm width polymeric spacer beads were used to produce a delayed bone union. Twelve rats were divided into two groups: (i) Control Group: untreated fracture and; (ii) Laser Group: fracture treated with laser. Twelve sessions of treatment (808nm laser, 100mW, 125J/cm2, 50seconds) were performed. The μCT scanner parameters were: 100kV, 100μA, Al+Cu filter and 9.92μm resolution. A volume of interest (VOI) was chosen with 300 sections above and below the central region of the fracture, totaling 601sections with a 5.96mm. The softwares CT-Analyzer, NRecon and Mimics were used for 2D and 3D analysis. A histomorphometry analysis was also performed. The connectivity (Conn) showed significant increase for Laser Group than Control Group (32371+/-20689 vs 17216+/-9467, pcartilaginous (0.19+/-0.05% vs 0.11+/-0.09%) and fibrotic (0.21+/-0.12% vs 0.09+/-0.11%) tissues]. The negative effect was presence of the cartilaginous and fibrotic tissues which may be related to the Kirchner wire and the non-absorption of the polymeric that may have influenced negatively the light distribution through the bone. However, the positive effect was greater bone connectivity, indicating improvement in bone microarchitecture.

Comparative evaluation of the accuracy of linear measurements between cone beam computed tomography and 3D microtomography

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Francesca Mangione

2013-09-01

Full Text Available OBJECTIVE: The aim of this study was to evaluate the influence of artifacts on the accuracy of linear measurements estimated with a common cone beam computed tomography (CBCT system used in dental clinical practice, by comparing it with microCT system as standard reference. MATERIALS AND METHODS: Ten bovine bone cylindrical samples containing one implant each, able to provide both points of reference and image quality degradation, have been scanned by CBCT and microCT systems. Thanks to the software of the two systems, for each cylindrical sample, two diameters taken at different levels, by using implants different points as references, have been measured. Results have been analyzed by ANOVA and a significant statistically difference has been found. RESULTS AND DISCUSSION: Due to the obtained results, in this work it is possible to say that the measurements made with the two different instruments are still not statistically comparable, although in some samples were obtained similar performances and therefore not statistically significant. CONCLUSION: With the improvement of the hardware and software of CBCT systems, in the near future the two instruments will be able to provide similar performances.

The use of Na+ and K+ ion concentrations as potential diagnostic indicators of subclinical mastitis in dairy cows

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Abdul Wahid Haron

2014-11-01

Full Text Available Aim: This study was conducted to evaluate the concentrations of sodium (Na+ and potassium (K+ ions in milk of lactating dairy cows with and without subclinical mastitis as putative indicators for detecting subclinical mastitis in dairy cows. Materials and Methods: Thirty seven lactating dairy cows were screened for the evidence of subclinical mastitis using California mastitis test (CMT. The lactating dairy cows were categorized as CMT-Positive (CMT-P; n=20 and CMT-Negative (CMT-N; n=17 based on whether they were positive or negative for CMT using a standard kit. The CMT-P lactating dairy cows were further sub divided into subclinical 1+ (S1+; n=6, subclinical 2+ (S2+; n=9, and subclinical 3+(S3+; n=5. Direct microscopy somatic cell count (SCC was used to determine the SCC using Wright’s stain. The samples were filtered and diluted at 1:100 dilutions before being measured for the concentrations of Na+ and K+ using atomic absorption spectrophotometer. Results: There was a significant increase (p<0.05 in SCCs and Na+ concentration in the milk of CMT-P dairy cows, with a mean Log10 SCC score of 5.35±0.06 cells/ml and mean Na+ concentration of 232±19.1 mg/dL. However, there was a significant reduction (p<0.05 in the concentration of K+ (123±7.6 mg/dL in the milk samples of the CMT-P cows. There were significant differences (p<0.05 in SCC, Na+ and K+ concentrations between milk samples from the CMT-N dairy cows and CMT-P subgroups; S1+, S2+, and S3+ respectively. Potassium (K+ concentration had a significant strong negative correlation with sodium (Na+ concentration (r=−0.688; p<0.01 and weak positive correlation with SCC (r=−0.436; p<0.01. The sensitivity of using Na+ and K+ concentrations as detection indices for sub-clinical mastitis is 40% and 90%, respectively, while the specificity of each was 100%. Conclusion: This study thus shows that evaluation of Na+ and K+ concentrations from milk samples of dairy cows with sub clinical mastitis

X-ray absorption microtomography (microCT) and small beam diffraction mapping of sea urchin teeth.

Science.gov (United States)

Stock, S R; Barss, J; Dahl, T; Veis, A; Almer, J D

2002-07-01

Two noninvasive X-ray techniques, laboratory X-ray absorption microtomography (microCT) and X-ray diffraction mapping, were used to study teeth of the sea urchin Lytechinus variegatus. MicroCT revealed low attenuation regions at near the tooth's stone part and along the carinar process-central prism boundary; this latter observation appears to be novel. The expected variation of Mg fraction x in the mineral phase (calcite, Ca(1-x)Mg(x)CO(3)) cannot account for all of the linear attenuation coefficient decrease in the two zones: this suggested that soft tissue is localized there. Transmission diffraction mapping (synchrotron X-radiation, 80.8 keV, 0.1 x 0.1mm(2) beam area, 0.1mm translation grid, image plate area detector) simultaneously probed variations in 3-D and showed that the crystal elements of the "T"-shaped tooth were very highly aligned. Diffraction patterns from the keel (adaxial web) and from the abaxial flange (containing primary plates and the stone part) differed markedly. The flange contained two populations of identically oriented crystal elements with lattice parameters corresponding to x=0.13 and x=0.32. The keel produced one set of diffraction spots corresponding to the lower x. The compositions were more or less equivalent to those determined by others for camarodont teeth, and the high Mg phase is expected to be disks of secondary mineral epitaxially related to the underlying primary mineral element. Lattice parameter gradients were not noted in the keel or flange. Taken together, the microCT and diffraction results indicated that there was a band of relatively high protein content, of up to approximately 0.25 volume fraction, in the central part of the flange and paralleling its adaxial and abaxial faces. X-ray microCT and microdiffraction data used in conjunction with protein distribution data will be crucial for understanding the properties of various biocomposites and their mechanical functions.

Fluid flow simulation and permeability computation in deformed porous carbonate grainstones

Science.gov (United States)

Zambrano, Miller; Tondi, Emanuele; Mancini, Lucia; Lanzafame, Gabriele; Trias, F. Xavier; Arzilli, Fabio; Materazzi, Marco; Torrieri, Stefano

2018-05-01

In deformed porous carbonates, the architecture of the pore network may be modified by deformation or diagenetic processes altering the permeability with respect to the pristine rock. The effects of the pore texture and morphology on permeability in porous rocks have been widely investigated due to the importance during the evaluation of geofluid reservoirs. In this study, these effects are assessed by combining synchrotron X-ray computed microtomography (SR micro-CT) and computational fluid dynamics. The studied samples pertain to deformed porous carbonate grainstones highly affected by deformation bands (DBs) exposed in Northwestern Sicily and Abruzzo regions, Italy. The high-resolution SR micro-CT images of the samples, acquired at the SYRMEP beamline of the Elettra - Sincrotrone Trieste laboratory (Italy), were used for simulating a pressure-driven flow by using the lattice-Boltzmann method (LBM). For the experiments, a multiple relaxation time (MRT) model with the D3Q19 scheme was used to avoid viscosity-dependent results of permeability. The permeability was calculated using Darcy's law once steady conditions were reached. After the simulations, the pore-network properties (effective porosity, specific surface area, and geometrical tortuosity) were calculated using 3D images of the velocity fields. These images were segmented considering a velocity threshold value higher than zero. The study showed that DBs may generate significant heterogeneity and anisotropy of the permeability of the evaluated rock samples. Cataclasis and cementation process taking place within the DBs reduce the effective porosity and therefore the permeability. Contrary to this, pressure dissolution and faulting may generate connected channels which contribute to the permeability only parallel to the DB.

A brief review of recent Charcot-Marie-Tooth research and priorities [v1; ref status: indexed, http://f1000r.es/53g

Directory of Open Access Journals (Sweden)

Sean Ekins

2015-02-01

Full Text Available This brief review of current research progress on Charcot-Marie-Tooth (CMT disease is a summary of discussions initiated at the Hereditary Neuropathy Foundation (HNF scientific advisory board meeting on November 7, 2014. It covers recent published and unpublished in vitro and in vivo research. We discuss recent promising preclinical work for CMT1A, the development of new biomarkers, the characterization of different animal models, and the analysis of the frequency of gene mutations in patients with CMT. We also describe how progress in related fields may benefit CMT therapeutic development, including the potential of gene therapy and stem cell research. We also discuss the potential to assess and improve the quality of life of CMT patients. This summary of CMT research identifies some of the gaps which may have an impact on upcoming clinical trials. We provide some priorities for CMT research and areas which HNF can support. The goal of this review is to inform the scientific community about ongoing research and to avoid unnecessary overlap, while also highlighting areas ripe for further investigation. The general collaborative approach we have taken may be useful for other rare neurological diseases.

CMT for materials science

Energy Technology Data Exchange (ETDEWEB)

Kinney, J. [Lawrence Livermore National Lab., CA (United States)

1997-02-01

This session is comprised of two articles by John Kinney describing biomedical and other uses for computerized tomography. In the first article, Kinney describes the use of a three-dimensional x-ray tomographic microscope to image the trabecular bone architecture of the proximal tibias of rats in vivo. Research in this field may help to detect the earliest stages of hypoestrogenemic bone loss and may help to more rapidly test the effectiveness of new clinical treatments for this major public health problem. The second article describes recent advances in X-ray tomography using synchrotron radiation to evaluate microstructures in ceramic matrix composites, bone loss in osteoporosis, and the development of carries lesions in teeth.

Visualizing and measuring flow in shale matrix using in situ synchrotron X-ray microtomography

Science.gov (United States)

Kohli, A. H.; Kiss, A. M.; Kovscek, A. R.; Bargar, J.

2017-12-01

Natural gas production via hydraulic fracturing of shale has proliferated on a global scale, yet recovery factors remain low because production strategies are not based on the physics of flow in shale reservoirs. In particular, the physical mechanisms and time scales of depletion from the matrix into the simulated fracture network are not well understood, limiting the potential to optimize operations and reduce environmental impacts. Studying matrix flow is challenging because shale is heterogeneous and has porosity from the μm- to nm-scale. Characterizing nm-scale flow paths requires electron microscopy but the limited field of view does not capture the connectivity and heterogeneity observed at the mm-scale. Therefore, pore-scale models must link to larger volumes to simulate flow on the reservoir-scale. Upscaled models must honor the physics of flow, but at present there is a gap between cm-scale experiments and μm-scale simulations based on ex situ image data. To address this gap, we developed a synchrotron X-ray microscope with an in situ cell to simultaneously visualize and measure flow. We perform coupled flow and microtomography experiments on mm-scale samples from the Barnett, Eagle Ford and Marcellus reservoirs. We measure permeability at various pressures via the pulse-decay method to quantify effective stress dependence and the relative contributions of advective and diffusive mechanisms. Images at each pressure step document how microfractures, interparticle pores, and organic matter change with effective stress. Linking changes in the pore network to flow measurements motivates a physical model for depletion. To directly visualize flow, we measure imbibition rates using inert, high atomic number gases and image periodically with monochromatic beam. By imaging above/below X-ray adsorption edges, we magnify the signal of gas saturation in μm-scale porosity and nm-scale, sub-voxel features. Comparing vacuumed and saturated states yields image

Anatomical variations in the origins of the celiac axis and the superior mesenteric artery: MDCT angiographic findings and their probable embryological mechanisms

Energy Technology Data Exchange (ETDEWEB)

Wang, Yi; Cheng, Cheng; Wang, Lu; Li, Ran; Chen, Jin-hua; Gong, Shui-gen [Institute of Surgery Research, Daping Hospital, Third Military Medical University, Department of Radiology, Chongqing (China)

2014-08-15

To identify the spectrum and prevalence of anatomical variations in the origin of the celiac axis (CA), the superior mesenteric artery (SMA) and their major branches by using multidetector computed tomographic (MDCT) angiography. A retrospective evaluation was carried out on 1,500 abdominal MDCT angiography images. The aortic origins of the CA, the SMA and their major branch patterns were investigated. Normal aortic origins of CA and SMA were noted in 1,347 (89.8 %) patients. Seven types of CA and SMA origin variants were identified in 153 (10.2 %) patients. The three most common variations were hepatomesenteric trunk (67 patients, 4.47 %), celiomesenteric trunk (CMT) (51 patients, 3.4 %) and splenomesenteric trunk (18 patients, 1.2 %). An evaluation of CMT was classified as long (34 patients, 66.7 %) or short (17 patients, 33.3 %) subtypes, compared with the length of the common trunk. Further CMT classification was based on the origin of the left gastric artery: subtype I, 26 patients (53.1 %); subtype II, 5 patients (10.2 %); subtype III, 15 patients (30.6 %); subtype IV, 3 patients (6.1 %). Dislocation interruption, incomplete interruption and persistence of the longitudinal anastomosis could be the embryological mechanisms of the variant origins of the CA, the SMA and their major branches. (orig.)

Anatomical variations in the origins of the celiac axis and the superior mesenteric artery: MDCT angiographic findings and their probable embryological mechanisms

International Nuclear Information System (INIS)

Wang, Yi; Cheng, Cheng; Wang, Lu; Li, Ran; Chen, Jin-hua; Gong, Shui-gen

2014-01-01

To identify the spectrum and prevalence of anatomical variations in the origin of the celiac axis (CA), the superior mesenteric artery (SMA) and their major branches by using multidetector computed tomographic (MDCT) angiography. A retrospective evaluation was carried out on 1,500 abdominal MDCT angiography images. The aortic origins of the CA, the SMA and their major branch patterns were investigated. Normal aortic origins of CA and SMA were noted in 1,347 (89.8 %) patients. Seven types of CA and SMA origin variants were identified in 153 (10.2 %) patients. The three most common variations were hepatomesenteric trunk (67 patients, 4.47 %), celiomesenteric trunk (CMT) (51 patients, 3.4 %) and splenomesenteric trunk (18 patients, 1.2 %). An evaluation of CMT was classified as long (34 patients, 66.7 %) or short (17 patients, 33.3 %) subtypes, compared with the length of the common trunk. Further CMT classification was based on the origin of the left gastric artery: subtype I, 26 patients (53.1 %); subtype II, 5 patients (10.2 %); subtype III, 15 patients (30.6 %); subtype IV, 3 patients (6.1 %). Dislocation interruption, incomplete interruption and persistence of the longitudinal anastomosis could be the embryological mechanisms of the variant origins of the CA, the SMA and their major branches. (orig.)

A novel technique combining high-resolution synchrotron x-ray microtomography and x-ray diffraction for characterization of micro particulates

International Nuclear Information System (INIS)

Merrifield, David R; Ramachandran, Vasuki; Roberts, Kevin J; Armour, Wesley; Axford, Danny; Basham, Mark; Connolley, Thomas; Evans, Gwyndaf; McAuley, Katherine E; Owen, Robin L; Sandy, James

2011-01-01

The processing of solids, such as crystals, is strongly influenced by the surface properties of the material. In recent years the pharmaceutical industry has shown great interest in identifying, or chemically speciating, the molecular components of crystal faces. Formerly, characterization of the molecular identity of crystal faces was restricted to the study of large single crystals. This would have been primarily for structure determination as part of the drug registration process. Diamond Light Source in Oxfordshire is a new synchrotron facility in the UK, having 18 operational beamlines with 4 more in the construction phase. Beamlines at this medium energy light source enable the study of micron-sized objects in great detail. It is well known that x-ray microtomography (XMT) can be used to investigate the external morphology of a crystal whereas x-ray diffraction (XRD) is used to study the molecular orientation, structure and packing within the crystal. The objective of this research is to assess the feasibility of, and thereby develop a new methodology for, characterizing the molecular identity of a particular face of a crystalline particle at a scale of scrutiny of 20–50 µm by combining these two powerful techniques. This work demonstrates the application of XMT and XRD to investigate respectively the shape and crystalline phase/orientation of relevant test crystals. This research has applications in the pharmaceutical industry in that when the exact molecular nature of a particular face is known, the important physico-pharmaceutical properties stemming from that can be better understood. Some initial data are presented and discussed

Endochondral Growth Defect and Deployment of Transient Chondrocyte Behaviors Underlie Osteoarthritis Onset in a Natural Murine Model

Science.gov (United States)

Staines, K. A.; Madi, K.; Mirczuk, S. M.; Parker, S.; Burleigh, A.; Poulet, B.; Hopkinson, M.; Bodey, A. J.; Fowkes, R. C.; Farquharson, C.; Lee, P. D.

2016-01-01

Objective To explore whether aberrant transient chondrocyte behaviors occur in the joints of STR/Ort mice (which spontaneously develop osteoarthritis [OA]) and whether they are attributable to an endochondral growth defect. Methods Knee joints from STR/Ort mice with advanced OA and age‐matched CBA (control) mice were examined by Affymetrix microarray profiling, multiplex polymerase chain reaction (PCR) analysis, and immunohistochemical labeling of endochondral markers, including sclerostin and MEPE. The endochondral phenotype of STR/Ort mice was analyzed by histologic examination, micro–computed tomography, and ex vivo organ culture. A novel protocol for quantifying bony bridges across the murine epiphysis (growth plate fusion) using synchrotron x‐ray computed microtomography was developed and applied. Results Meta‐analysis of transcription profiles showed significant elevation in functions linked with endochondral ossification in STR/Ort mice (compared to CBA mice; P mice. Our novel synchrotron radiation microtomography method showed increased numbers (P mice compared to age‐matched CBA mice. Conclusion Taken together, our data support the notion of an inherent endochondral defect that is linked to growth dynamics and subject to regulation by the MEPE/sclerostin axis and may represent an underlying mechanism of pathologic ossification in OA. PMID:26605758

Gait and footwear in children and adolescents with Charcot-Marie-Tooth disease: A cross-sectional, case-controlled study.

Science.gov (United States)

Kennedy, Rachel A; McGinley, Jennifer L; Paterson, Kade L; Ryan, Monique M; Carroll, Kate

2018-05-01

Children with Charcot-Marie-Tooth disease (CMT) report problems with gait and footwear. We evaluated differences in spatio-temporal gait variables and gait variability between children with CMT and typically developing (TD) children, and investigated the effect of footwear upon gait. A cross-sectional study of 30 children with CMT and 30 age- and gender-matched TD children aged 4-18 years. Gait was assessed at self-selected speed on an electronic walkway while barefoot and in two types of the child's own footwear; optimal (e.g., athletic-type runners) and suboptimal (e.g., flip-flops). Children with CMT walked more slowly (mean (SD) -13.81 (3.61) cm/s), with shorter steps (-6.28 (1.37) cm), wider base of support (+2.47 (0.66) cm; all p footwear than suboptimal (-7.55 (1.31) cm/s) and barefoot (-7.42 (1.07) cm/sec; both p footwear was more variable compared to barefoot and optimal footwear. Greater base of support variability and reduced balance was moderately correlated for both groups (CMT and TD). Gait is slower with shorter, wider steps and greater base of support variability in children with CMT. Poor balance is associated with greater base of support gait variability. Suboptimal footwear negatively affects gait in all children (CMT and TD), which has clinical implications for children and adolescents with CMT who have weaker feet and ankles, and poor balance. Copyright © 2018 Elsevier B.V. All rights reserved.

Direct and indirect measurement of somatic cell count as indicator of intramammary infection in dairy goats

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Olofsson Ida

2011-03-01

Full Text Available Abstract Background Mastitis is the most important and costly disease in dairy goat production. Subclinical mastitis is common in goats and is mainly caused by contagious bacteria. Several methods to diagnose subclinical mastitis are available. In this study indirect measurement of somatic cell count (SCC by California Mastitis Test (CMT and direct measurement of SCC using a portable deLaval cell counter (DCC are evaluated. Swedish goat farmers would primarily benefit from diagnostic methods that can be used at the farm. The purpose of the study was to evaluate SCC measured by CMT and DCC as possible markers for intramammary infection (IMI in goats without clinical symptoms of mastitis. Moreover to see how well indirect measurement of SCC (CMT corresponded to direct measurement of SCC (DCC. Method Udder half milk samples were collected once from dairy goats (n = 111, in five different farms in Northern and Central Sweden. Only clinically healthy animals were included in the study. All goats were in mid to late lactation at sampling. Milk samples were analyzed for SCC by CMT and DCC at the farm, and for bacterial growth at the laboratory. Results Intramammary infection, defined as growth of udder pathogens, was found in 39 (18% of the milk samples. No growth was found in 180 (81% samples while 3 (1% samples were contaminated. The most frequently isolated bacterial species was coagulase negative staphylococci (CNS (72% of all isolates, followed by Staphylococcus aureus (23% of all isolates. Somatic cell count measured by DCC was strongly (p = 0.000 associated with bacterial growth. There was also a very strong association between CMT and bacterial growth. CMT 1 was associated with freedom of IMI while CMT ≥2 was associated with IMI. Indirect measurement of SCC by CMT was well correlated with SCC measured by DCC. Conclusions According to the results, SCC measured with CMT or DCC can predict udder infection in goats, and CMT can be used as a

Heavy metal staining, a comparative assessment of gadolinium chloride and osmium tetroxide for inner ear labyrinthine contrast enhancement using X-ray microtomography.

Science.gov (United States)

Wong, Christopher C; Curthoys, Ian S; O'Leary, Stephen J; Jones, Allan S

2013-01-01

The use of both gadolinium chloride (GdCl(3)) and osmium tetroxide (OsO(4)) allowed for the visualization of the membranous labyrinth and other intralabyrinthine structures, at different intensities, as compared with the control sample. This initial comparison shows the advantages of GdCl(3) in radiological assessments and OsO(4) in more detailed anatomical studies and pathways of labyrinthine pathogenesis using X-ray microtomography (microCT). To assess an improved OsO(4) staining protocol and compare the staining affinities against GdCl(3). Guinea pig temporal bones were stained with either GdCl(3) (2% w/v) for 7 days or OsO(4) (2% w/v) for 3 days, and scanned in a microCT system. The post-scanned datasets were then assessed in a 3D rendering program. The enhanced soft tissue contrast as presented in the temporal bones stained with either GdCl(3) or OsO(4) allowed for the membranous labyrinth to be visualized throughout the whole specimen. GdCl(3)-stained specimens presented more defined contours of the bone profile in the radiographs, while OsO(4)-stained specimens provided more anatomical detail of individual intralabyrinthine structures, hence allowing spatial relationships to be visualized with ease in a 3D rendering context and 2D axial slice images.

Level of conus medullaris termination in adult population analyzed by kinetic magnetic resonance imaging.

Science.gov (United States)

Liu, An; Yang, Kaixiang; Wang, Daling; Li, Changqing; Ren, Zhiwei; Yan, Shigui; Buser, Zorica; Wang, Jeffrey C

2017-07-01

To investigate the change of conus medullaris termination (CMT) level in neutral, flexion and extension positions and to analyze the effects of age and gender on the CMT level. The midline sagittal T2-weighted kinetic magnetic resonance imaging (kMRI) study of 585 patients was retrospectively reviewed to identify the level of CMT. All patients were in an upright position. A straight line perpendicular to the long axis of the cord was drawn from the tip of the cord and then subtended to the adjacent vertebra or disk space. The CMT level was labeled in relation to the upper, middle and lower segments of adjacent vertebra or disk space and assigned values from 0 to 12 [0 = upper third of T12 (T12U), and 12 = upper third of L3 (L3U)]. All parameters were collected for neutral, flexion and extension positions. The level of CMT had the highest incidence (17.61%) at L1 lower (L1L) in neutral position, 17.44% at L1 upper (L1U) in flexion, and 16.92% at L1 middle (L1M) in extension with no significant differences among three positions (p > 0.05) in weight-bearing status. Moreover, the level of CMT was not correlated with age (p > 0.05). In terms of gender, the level of CMT was lower in women than in men in neutral position, flexion, and extension (p level of CMT in the neutral position was in accordance with previous cadaveric and supine-position MRI studies, and it did not change with flexion and extension. Women had lower CMT level than men, especially in the older population. This information can be very valuable when performing spinal anesthesia and spinal punctures.

Computed tomography on a defective CANDU fuel pencil end cap

International Nuclear Information System (INIS)

Lupton, L.R.

1985-09-01

Five tomographic slices through a defective end cap from a CANDU fuel pencil have been generated using a Co-60 source and a first generation translate-rotate tomography scanner. An anomaly in the density distribution that is believed to have resulted from the defect has been observed. However, with the 0.30 mm spatial resolution used, it has not been possible to state unequivocally whether the change in density is caused by a defect in the weld or a statistical anomaly in the data. It is concluded that a microtomography system, with a spatial resolution in the range of 0.1 mm, could detect the flaw

X inactivation in females with X-linked Charcot-Marie-Tooth disease.

LENUS (Irish Health Repository)

Murphy, Sinéad M

2012-07-01

X-linked Charcot-Marie-Tooth disease (CMT1X) is the second most common inherited neuropathy, caused by mutations in gap junction beta-1 (GJB1). Males have a uniformly moderately severe phenotype while females have a variable phenotype, suggested to be due to X inactivation. We aimed to assess X inactivation pattern in females with CMT1X and correlate this with phenotype using the CMT examination score to determine whether the X inactivation pattern accounted for the variable phenotype in females with CMT1X. We determined X inactivation pattern in 67 females with CMT1X and 24 controls using the androgen receptor assay. We were able to determine which X chromosome carried the GJB1 mutation in 30 females. There was no difference in X inactivation pattern between patients and controls. In addition, there was no correlation between X inactivation pattern in blood and phenotype. A possible explanation for these findings is that the X inactivation pattern in Schwann cells rather than in blood may explain the variable phenotype in females with CMT1X.

A Rare Case of Charcot-Mari-Tooth Disease Type 2S in a 20-year-old Man

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Natalia A. Shnayder

2017-12-01

Full Text Available Charcot-Marie-Tooth disease type 2 (CMT2S is rare form of Charcot-Marie-Tooth disease (CMT that is characterized by a mutation in the IGHMBP2 gene. This gene encodes a helicase superfamily member that binds a specific DNA sequence from the region of the immunoglobulin mu chain switch. Mutation of this gene leads to spinal muscle atrophy with respiratory distress type 1 and CMT2S. This case report presents a 20-year-old male with genetically confirmed CMT2S having clinical respiratory involvement and symmetrically involved lower extremities. DNA sequencing revealed a previously unknown heterozygous mutation in the exone 2 of the IGHMBP2 gene leading to the replacement of the amino acid in the 46 position of the protein (chr11q13.3: 68673587 G>C. These atypical features widen the clinical spectrum of CMT2S. In describing this clinical case, we also improve diagnostic management and try to increase the alertness of various doctors towards neuromuscular diseases, including CMT.

Opioid tolerance in periaqueductal gray neurons isolated from mice chronically treated with morphine.

Science.gov (United States)

Bagley, Elena E; Chieng, Billy C H; Christie, MacDonald J; Connor, Mark

2005-09-01

The midbrain periaqueductal gray (PAG) is a major site of opioid analgesic action, and a significant site of cellular adaptations to chronic morphine treatment (CMT). We examined mu-opioid receptor (MOP) regulation of voltage-gated calcium channel currents (I(Ca)) and G-protein-activated K channel currents (GIRK) in PAG neurons from CMT mice. Mice were injected s.c. with 300 mg kg(-1) of morphine base in a slow release emulsion three times over 5 days, or with emulsion alone (vehicles). This protocol produced significant tolerance to the antinociceptive effects of morphine in a test of thermal nociception. Voltage clamp recordings were made of I(Ca) in acutely isolated PAG neurons and GIRK in PAG slices. The MOP agonist DAMGO (Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol enkephalin) inhibited I(Ca) in neurons from CMT mice (230 nM) with a similar potency to vehicle (150 nM), but with a reduced maximal effectiveness (37% inhibition in vehicle neurons, 27% in CMT neurons). Inhibition of I(Ca) by the GABA(B) agonist baclofen was not altered by CMT. Met-enkephalin-activated GIRK currents recorded in PAG slices were significantly smaller in neurons from CMT mice than vehicles, while GIRK currents activated by baclofen were unaltered. These data demonstrate that CMT-induced antinociceptive tolerance is accompanied by homologous reduction in the effectiveness of MOP agonists to inhibit I(Ca) and activate GIRK. Thus, a reduction in MOP number and/or functional coupling to G proteins accompanies the characteristic cellular adaptations to CMT previously described in PAG neurons.

Autosomal recessive Charcot-Marie-Tooth neuropathy.

Science.gov (United States)

Espinós, Carmen; Calpena, Eduardo; Martínez-Rubio, Dolores; Lupo, Vincenzo

2012-01-01

Charcot-Marie-Tooth (CMT) disease, a hereditary motor and sensory neuropathy that comprises a complex group of more than 50 diseases, is the most common inherited neuropathy. CMT is generally divided into demyelinating forms, axonal forms and intermediate forms. CMT is also characterized by a wide genetic heterogeneity with 29 genes and more than 30 loci involved. The most common pattern of inheritance is autosomal dominant (AD), although autosomal recessive (AR) forms are more frequent in Mediterranean countries. In this chapter we give an overview of the associated genes, mechanisms and epidemiology of AR-CMT forms and their associated phenotypes.

Role of stretch therapy in comprehensive physical habilitation of patients with Charcot–Marie–Tooth hereditary neuropathy

Directory of Open Access Journals (Sweden)

N. A. Shnayder

2015-01-01

Full Text Available Charcot–Marie–Tooth hereditary neuropathy (Charcot–Marie–Tooth disease, CMT is the most common form of hereditary neuropathies, accompanied by sensory disorders, progressive muscle weakness with the formation of disabling contractures of the limbs. Currently, the main treatment program is effective CMT habilitation, which can prevent the development of limb deformities and thereby improve the life quality of the patient. Stretch therapy is one of the most effective methods of prevention and treatment of contractures in patients with CMT. This article provides a brief review of the literature regarding the use of stretching as physical therapy program of CMT habilitation.

Evaluation of Microstructure and Transport Properties of Deteriorated Cementitious Materials from Their X-ray Computed Tomography (CT) Images.

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Promentilla, Michael Angelo B; Cortez, Shermaine M; Papel, Regina Anne Dc; Tablada, Bernadette M; Sugiyama, Takafumi

2016-05-19

Pore structure, tortuosity and permeability are considered key properties of porous materials such as cement pastes to understand their long-term durability performance. Three-dimensional image analysis techniques were used in this study to quantify pore size, effective porosity, tortuosity, and permeability from the X-ray computed tomography (CT) images of deteriorated pastes that were subjected to accelerated leaching test. X-ray microtomography is a noninvasive three-dimensional (3D) imaging technique which has been recently gaining attention for material characterization. Coupled with 3D image analysis, the digitized pore can be extracted and computational simulation can be applied to the pore network to measure relevant microstructure and transport properties. At a spatial resolution of 0.50 μm, the effective porosity (ψ e ) was found to be in the range of 0.04 to 0.33. The characteristic pore size ( d ) using a local thickness algorithm was found to be in the range of 3 to 7 μm. The geometric tortuosity (τ g ) based on a 3D random walk simulation in the percolating pore space was found to be in the range of 2.00 to 7.45. The water permeability values ( K ) using US NIST Permeability Stokes Solver range from an order of magnitudes of 10 -14 to 10 -17 m². Indications suggest that as effective porosity increases, the geometric tortuosity increases and the permeability decreases. Correlation among these microstructure and transport parameters is also presented in this study.

Vapor flux and recrystallization during dry snow metamorphism under a steady temperature gradient as observed by time-lapse micro-tomography

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B. R. Pinzer

2012-10-01

Full Text Available Dry snow metamorphism under an external temperature gradient is the most common type of recrystallization of snow on the ground. The changes in snow microstructure modify the physical properties of snow, and therefore an understanding of this process is essential for many disciplines, from modeling the effects of snow on climate to assessing avalanche risk. We directly imaged the microstructural changes in snow during temperature gradient metamorphism (TGM under a constant gradient of 50 K m⁻¹, using in situ time-lapse X-ray micro-tomography. This novel and non-destructive technique directly reveals the amount of ice that sublimates and is deposited during metamorphism, in addition to the exact locations of these phase changes. We calculated the average time that an ice volume stayed in place before it sublimated and found a characteristic residence time of 2–3 days. This means that most of the ice changes its phase from solid to vapor and back many times in a seasonal snowpack where similar temperature conditions can be found. Consistent with such a short timescale, we observed a mass turnover of up to 60% of the total ice mass per day. The concept of hand-to-hand transport for the water vapor flux describes the observed changes very well. However, we did not find evidence for a macroscopic vapor diffusion enhancement. The picture of {temperature gradient metamorphism} produced by directly observing the changing microstructure sheds light on the micro-physical processes and could help to improve models that predict the physical properties of snow.

Clinical and neurophysiological investigation of a large family with dominant Charcot-Marie-Tooth type 2 disease with pyramidal signs

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Eduardo Luis de Aquino Neves

2011-06-01

Full Text Available Charcot-Marie-Tooth (CMT disease is a hereditary neuropathy of motor and sensory impairment with distal predominance. Atrophy and weakness of lower limbs are the first signs of the disease. It can be classified, with the aid of electromyography and nerve conduction studies, as demyelinating (CMT1 or axonal (CMT2. OBJECTIVE: Clinical and neurophysiological investigation of a large multigenerational family with CMT2 with autosomal dominant mode of transmission. METHOD: Fifty individuals were evaluated and neurophysiological studies performed in 22 patients. RESULTS: Thirty individuals had clinical signs of motor-sensory neuropathy. Babinski sign was present in 14 individuals. Neurophysiological study showed motor-sensory axonal polyneuropathy. CONCLUSION: The clinical and neurophysiological characteristics of this family does not differ from those observed with other forms of CMT, except for the high prevalence of Babinski sign.

Shear behavior of thermoformed woven-textile thermoplastic prepregs: An analysis combining bias-extension test and X-ray microtomography

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Gassoumi, M.; Rolland du Roscoat, S.; Casari, P.; Dumont, P. J. J.; Orgéas, L.; Jacquemin, F.

2017-10-01

Thermoforming allows the manufacture of structural parts for the automotive and aeronautical domains using long fiber thermoplastic prepregs with short cycle times. During this operation, several sheets of molten prepregs are stacked and subjected to large macroscale strains, mainly via in-plane shear, out-of-plane consolidation or dilatation, and bending of the fibrous reinforcement. These deformation modes and the related meso and microstructure evolutions are still poorly understood. However, they can drastically alter the end-use macroscale properties of fabricated parts. To better understand these phenomena, bias extension tests were performed using specimens made of several stacked layers of glass woven fabrics and polyamide matrix. The macroscale shear behavior of these prepregs was investigated at various temperatures. A multiscale analysis of deformed samples was performed using X-ray microtomography images of the deformed specimens acquired at two different spatial resolutions. The low-resolution images were used to analyze the deformation mechanisms and the structural characteristics of prepregs at the macroscale and bundle scales. It was possible to analyze the 3D shapes of deformed samples and, in particular, the spatial variations of their thickness so as to quantify the out-of-plane dilatancy or consolidation phenomena induced by the in-plane shear of prepregs. At a lower scale, the analysis of the high-resolution images showed that these mechanisms were accompanied by the growth of pores and the deformation of fiber bundles. The orientation of the fiber bundles and its through-thickness evolution were measured along the weft and warp directions in the deformed samples, allowing the relevance of geometrical models currently used to analyze bias extension tests to be discussed. Results can be used to enhance the current rheological models for the prediction of thermoforming of thermoplastic prepregs.

Evaluation of diagnostic procedures for subclinical mastitis in meat-producing sheep.

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Clements, Archie C A; Taylor, David J; Fitzpatrick, Julie L

2003-05-01

Samples of foremilk were collected from 261 clinically normal glands of 150 ewes, and tested using the California mastitis test (CMT). Further samples were collected from 195 of these glands for determination of automated somatic cell counts (SCC), and from 60 of these glands for bacteriological assessment. The sensitivity and specificity of CMT for detecting samples with SCC above different threshold levels and for CMT and SCC in determining bacteriological status were evaluated using two-graph receiver operating characteristics (TG-ROC). Milk samples were obtained subsequently from ten CMT positive, and five CMT negative first- and second-lactation ewes. Samples were cultured using a variety of media, incubation temperatures and atmospheric conditions, immediately after collection, and 1 week after storage at 4 degrees C and -21 degrees C. Results suggested that CMT is best used as a diagnostic test for ovine subclinical mastitis (SCM) with a cut-off of 3 (distinct gel formation), and that automated SCC thresholds of > 1200 x 10(3) cells/ml are appropriate, especially where low prevalences are expected (e.g. culture, either at 4 degrees C or -21 degrees C, was detrimental to the isolation of several of these organisms.

Bayesian estimation of test characteristics of real-time PCR, bacteriological culture and California mastitis test for diagnosis of intramammary infections with Staphylococcus aureus in dairy cattle at routine milk recordings.

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Mahmmod, Yasser S; Toft, Nils; Katholm, Jørgen; Grønbæk, Carsten; Klaas, Ilka C

2013-11-01

Danish farmers can order a real-time PCR mastitis diagnostic test on routinely taken cow-level samples from milk recordings. Validation of its performance in comparison to conventional mastitis diagnostics under field conditions is essential for efficient control of intramammary infections (IMI) with Staphylococcus aureus (S. aureus). Therefore, the objective of this study was to estimate the sensitivity (Se) and specificity (Sp) of real-time PCR, bacterial culture (BC) and California mastitis test (CMT) for the diagnosis of the naturally occurring IMI with S. aureus in routinely collected milk samples using latent class analysis (LCA) to avoid the assumption of a perfect reference test. Using systematic random sampling, a total of 609 lactating dairy cows were selected from 6 dairy herds with bulk tank milk PCR cycle threshold (Ct) value ≤39 for S. aureus. At routine milk recordings, automatically obtained cow-level (composite) milk samples were analyzed by PCR and at the same milking, 2436 quarter milk samples were collected aseptically for BC and CMT. Results showed that 140 cows (23%) were positive for S. aureus IMI by BC while 170 cows (28%) were positive by PCR. Estimates of Se and Sp for PCR were higher than test estimates of BC and CMT. SeCMT was higher than SeBC however, SpBC was higher than SpCMT. SePCR was 91%, while SeBC was 53%, and SeCMT was 61%. SpPCR was 99%, while SpBC was 89%, and SpCMT was 65%. In conclusion, PCR has a higher performance than the conventional diagnostic tests (BC and CMT) suggesting its usefulness as a routine test for accurate diagnosis of S. aureus IMI from dairy cows at routine milk recordings. The use of LCA provided estimates of the test characteristics for two currently diagnostic tests (BC, CMT) and a novel technique (real-time PCR) for diagnosing S. aureus IMI under field conditions at routine milk recordings in Denmark. Copyright © 2013 Elsevier B.V. All rights reserved.

Imaging of Nuclear Weapon Trainers

Energy Technology Data Exchange (ETDEWEB)

Schwellenbach, David [National Security Technologies, LLC. (NSTec), Mercury, NV (United States)

2017-12-06

The Configurable Muon Tracker (CMT) is an adaptation of the existing drift tube detector commercially available from Decision Sciences International Corporation (DSIC). NSTec engineered the CMT around commercially available drift tube assemblies to make a detector that is more versatile than previous drift tube assemblies. The CMT became operational in February 2013. Traditionally, cosmic-ray muon trackers rely on near-vertical trajectory muons for imaging. Since there are scenarios where imaging using vertical trajectory muons is not practical, NSTec designed the CMT specifically for quick configurability to track muons from any trajectory. The CMT was originally designed to be changed from vertical imaging mode to horizontal imaging mode in a few hours with access to a crane or other lifting equipment. In FY14, locations for imaging weapon trainers and SNM were identified and it was determined that lifting equipment would not typically be available in experimental areas. The CMT was further modified and a portable lifting system was developed to allow reconfiguration of the CMT without access to lifting equipment at the facility. This system was first deployed at Los Alamos National Laboratory’s W-division, where several trainers were imaged in both horizontal and vertical modes. Real-time images have been compared in both modes showing that imaging can be done in both modes with the expected longer integration time for horizontal mode. Further imaging and post processing of the data is expected to continue into early FY15.

Using Beta-Version mHealth Technology for Team-Based Care Management to Support Stroke Prevention: An Assessment of Utility and Challenges.

Science.gov (United States)

Ramirez, Magaly; Wu, Shinyi; Ryan, Gery; Towfighi, Amytis; Vickrey, Barbara G

2017-05-23

Beta versions of health information technology tools are needed in service delivery models with health care and community partnerships to confirm the key components and to assess the performance of the tools and their impact on users. We developed a care management technology (CMT) for use by community health workers (CHWs) and care managers (CMs) working collaboratively to improve risk factor control among recent stroke survivors. The CMT was expected to enhance the efficiency and effectiveness of the CHW-CM team. The primary objective was to describe the Secondary Stroke Prevention by Uniting Community and Chronic Care Model Teams Early to End Disparities (SUCCEED) CMT and investigate CM and CHW perceptions of the CMT's usefulness and challenges for team-based care management. We conducted qualitative interviews with all users of the beta-version SUCCEED CMT, namely two CMs and three CHWs. They were asked to demonstrate and describe their perceptions of the CMT's ease of use and usefulness for completing predefined key care management activities. They were also probed about their general perceptions of the CMT's information quality, ease of use, usefulness, and impact on CM and CHW roles. Interview transcripts were coded using a priori codes. Coded excerpts were grouped into broader themes and then related in a conceptual model of how the CMT facilitated care management. We also conducted a survey with 14 patients to obtain their perspective on CHW tablet use during CHW-patient interactions. Care managers and community health workers expressed that the CMT helped them keep track of patient interactions and plan their work. It guided CMs in developing and sharing care plans with CHWs. For CHWs, the CMT enabled electronic collection of clinical assessment data, provided decision support, and provided remote access to patients' risk factor values. Long loading times and downtimes due to outages were the most significant challenges encountered. Additional issues

Influence of Manufacturing Methods of Implant-Supported Crowns on External and Internal Marginal Fit: A Micro-CT Analysis.

Science.gov (United States)

Moris, Izabela C M; Monteiro, Silas Borges; Martins, Raíssa; Ribeiro, Ricardo Faria; Gomes, Erica A

2018-01-01

To evaluate the influence of different manufacturing methods of single implant-supported metallic crowns on the internal and external marginal fit through computed microtomography. Forty external hexagon implants were divided into 4 groups ( n = 8), according to the manufacturing method: GC, conventional casting; GI, induction casting; GP, plasma casting; and GCAD, CAD/CAM machining. The crowns were attached to the implants with insertion torque of 30 N·cm. The external (vertical and horizontal) marginal fit and internal fit were assessed through computed microtomography. Internal and external marginal fit data ( μ m) were submitted to a one-way ANOVA and Tukey's test ( α = .05). Qualitative evaluation of the images was conducted by using micro-CT. The statistical analysis revealed no significant difference between the groups for vertical misfit ( P = 0.721). There was no significant difference ( P > 0.05) for the internal and horizontal marginal misfit in the groups GC, GI, and GP, but it was found for the group GCAD ( P ≤ 0.05). Qualitative analysis revealed that most of the samples of cast groups exhibited crowns underextension while the group GCAD showed overextension. The manufacturing method of the crowns influenced the accuracy of marginal fit between the prosthesis and implant. The best results were found for the crowns fabricated through CAD/CAM machining.

Volume digital image correlation to assess displacement field in compression loaded bread crumb under X-ray microtomography

KAUST Repository

Moussawi, Ali

2014-10-01

In this study, we present an original approach to assess structural changes during bread crumb compression using a mechanical testing bench coupled to 3D X-ray microtomography. X-ray images taken at different levels of compression of the bread crumb are processed using image analysis. A subset-based digital volume correlation method is used to achieve the 3D displacement field. Within the limit of the approach, deterministic search strategy is implemented for solving subset displacement in each deformed image with regards to the undeformed one. The predicted displacement field in the transverse directions shows differences that depend on local cell arrangement as confirmed by finite element analysis. The displacement component in the loading direction is affected by the magnitude of imposed displacement and shows more regular change. Large displacement levels in the compression direction are in good agreement with the imposed experimental displacement. The results presented here are promising in a sense of possible identification of local foam properties. New insights are expected to achieve better understanding of structural heterogeneities in the overall perception of the product. Industrial relevance: Texture evaluation of cereal product is an important aspect for testing consumer acceptability of new designed products. Mechanical evaluation of backed products is a systemic route for determining texture of cereal based product. From the industrial viewpoint, mechanical evaluation allows saving both time and cost compared to panel evaluation. We demonstrate that better understanding of structural changes during texture evaluation can be achieved in addition to texture evaluation. Sensing structural changes during bread crumb compression is achievable by combining novel imaging technique and processing based on image analysis. We present thus an efficient way to predict displacements during compression of freshly baked product. This method can be used in different

Hand weakness in Charcot-Marie-Tooth disease 1X.

LENUS (Irish Health Repository)

Arthur-Farraj, P J

2012-07-01

There have been suggestions from previous studies that patients with Charcot-Marie-Tooth disease (CMT) have weaker dominant hand muscles. Since all studies to date have included a heterogeneous group of CMT patients we decided to analyse hand strength in 43 patients with CMT1X. We recorded handedness and the MRC scores for the first dorsal interosseous and abductor pollicis brevis muscles, median and ulnar nerve compound motor action potentials and conduction velocities in dominant and non-dominant hands. Twenty-two CMT1X patients (51%) had a weaker dominant hand; none had a stronger dominant hand. Mean MRC scores were significantly higher for first dorsal interosseous and abductor pollicis brevis in non-dominant hands compared to dominant hands. Median nerve compound motor action potentials were significantly reduced in dominant compared to non-dominant hands. We conclude that the dominant hand is weaker than the non-dominant hand in patients with CMT1X.

Postural instability in Charcot-Marie-Tooth 1A disease.

Science.gov (United States)

Tozza, Stefano; Aceto, Maria Gabriella; Pisciotta, Chiara; Bruzzese, Dario; Iodice, Rosa; Santoro, Lucio; Manganelli, Fiore

2016-09-01

The aim of this study was to evaluate the influence of somatosensory impairment, distal muscle weakness and foot deformities on the balance in 21 CMT1A patients using a baropodometric platform. Stabilometric analysis by measuring sway area and velocity of a centre of pressure (CoP) both at open and closed eyes were used to assess postural imbalance. Static analysis, by measuring the load and the plantar surface of forefoot, midfoot and hindfoot was used to define the footprint shape and to assess as a whole foot deformities. Stabilometric and static results were compared with those of a control group. In CMT1A patients, stabilometric findings were correlated with static parameters, Achilles' tendon retraction, distal muscle strength and CMT examination score (CMTES). CMT1A patients compared to controls had lower plantar surface and load on midfoot, and higher load on a forefoot. CMT1A patients had a greater postural instability, since they had a higher CoP velocity, both at open and closed eyes. Moreover, the CoP velocity correlated inversely with the strength of ankle dorsi-flexion muscles and directly with CMTES as whole and with the item "motor symptoms legs". Postural imbalance was not correlated with sensory impairment and foot deformities as expressed by static analysis and Achilles' tendon retraction. In this study we demonstrated an altered balance in CMT1A patients during upright standing. The imbalance in our CMT patients seems to be related to the weakness of ankle dorsi-flexor muscles rather than sensory impairment or foot deformities. These results could be due to a mildly affected CMT1A population, evaluated in an early stage of the disease. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison of cow-side diagnostic tests for subclinical mastitis of dairy cows in Musanze district, Rwanda.

Science.gov (United States)

Iraguha, Blaise; Hamudikuwanda, Humphrey; Mushonga, Borden; Kandiwa, Erick; Mpatswenumugabo, Jean P

2017-06-21

Four subclinical mastitis diagnostic tests (the UdderCheck® test [a lactate dehydrogenasebased test], the California Mastitis Test [CMT], the Draminski® test [a conductivity-based test] and the PortaSCC® test [a portable somatic cell count-based test]) were compared in a study comprising crossbreed dairy cows (n = 30) during September and October 2015. Sensitivity and specificity of the CMT, Draminski® and UdderCheck® tests were compared with the PortaSCC® as reference. The CMT, Draminski® and UdderCheck® test results were compared with the results of the PortaSCC® test using kappa statistics. Duplicate quarter milk samples (n = 120) were concurrently subjected to the four tests. Sensitivity and specificity were 88.46% and 86.17% (CMT), 78.5% and 81.4% (Draminski®) and 64.00% and 78.95% (UdderCheck®). The CMT showed substantial agreement (k = 0.66), the Draminski® test showed moderate agreement (k = 0.48) and the UdderCheck® test showed fair agreement (k = 0.37) with the PortaSCC® test and positive likelihood ratios were 6.40, 4.15 and 3.04, respectively. The cow-level subclinical mastitis prevalence was 70%, 60%, 60% and 56.7% for PortaSCC®, CMT, Draminski® and UdderCheck® tests, respectively. At udder quarter level, subclinical mastitis prevalence was 20%, 21.67% and 20.83% for PortaSCC®, CMT and UdderCheck®, respectively. A correlation (P < 0.05) and moderate strength of association were found between the four tests used. The study showed that compared to the PortaSCC® test, the CMT was the most preferable option, followed by the Draminski® test, while the UdderCheck® test was the least preferable option for subclinical mastitis screening.

Comparison of cow-side diagnostic tests for subclinical mastitis of dairy cows in Musanze district, Rwanda

Directory of Open Access Journals (Sweden)

Blaise Iraguha

2017-06-01

Full Text Available Four subclinical mastitis diagnostic tests (the UdderCheck® test [a lactate dehydrogenasebased test], the California Mastitis Test [CMT], the Draminski® test [a conductivity-based test] and the PortaSCC® test [a portable somatic cell count-based test] were compared in a study comprising crossbreed dairy cows (n = 30 during September and October 2015. Sensitivity and specificity of the CMT, Draminski® and UdderCheck® tests were compared with the PortaSCC® as reference. The CMT, Draminski® and UdderCheck® test results were compared with the results of the PortaSCC® test using kappa statistics. Duplicate quarter milk samples (n = 120 were concurrently subjected to the four tests. Sensitivity and specificity were 88.46% and 86.17% (CMT, 78.5% and 81.4% (Draminski® and 64.00% and 78.95% (UdderCheck®. The CMT showed substantial agreement (k = 0.66, the Draminski® test showed moderate agreement (k = 0.48 and the UdderCheck® test showed fair agreement (k = 0.37 with the PortaSCC® test and positive likelihood ratios were 6.40, 4.15 and 3.04, respectively. The cow-level subclinical mastitis prevalence was 70%, 60%, 60% and 56.7% for PortaSCC®, CMT, Draminski® and UdderCheck® tests, respectively. At udder quarter level, subclinical mastitis prevalence was 20%, 21.67% and 20.83% for PortaSCC®, CMT and UdderCheck®, respectively. A correlation (P < 0.05 and moderate strength of association were found between the four tests used. The study showed that compared to the PortaSCC® test, the CMT was the most preferable option, followed by the Draminski® test, while the UdderCheck® test was the least preferable option for subclinical mastitis screening.

Assessing the environmental performance of construction materials testing using EMS: An Australian study.

Science.gov (United States)

Dejkovski, Nick

2016-10-01

This paper reports the audit findings of the waste management practices at 30 construction materials testing (CMT) laboratories (constituting 4.6% of total accredited CMT laboratories at the time of the audit) that operate in four Australian jurisdictions and assesses the organisation's Environmental Management System (EMS) for indicators of progress towards sustainable development (SD). In Australia, waste indicators are 'priority indicators' of environmental performance yet the quality and availability of waste data is poor. National construction and demolition waste (CDW) data estimates are not fully disaggregated and the contribution of CMT waste (classified as CDW) to the national total CDW landfill burden is difficult to quantify. The environmental and human impacts of anthropogenic release of hazardous substances contained in CMT waste into the ecosphere can be measured by construing waste indicators from the EMS. An analytical framework for evaluating the EMS is developed to elucidate CMT waste indicators and assess these indicators against the principle of proportionality. Assessing against this principle allows for: objective evaluations of whether the environmental measures prescribed in the EMS are 'proportionate' to the 'desired' (subjective) level of protection chosen by decision-makers; and benchmarking CMT waste indicators against aspirational CDW targets set by each Australian jurisdiction included in the audit. Construed together, the EMS derived waste indicators and benchmark data provide a composite indicator of environmental performance and progress towards SD. The key audit findings indicate: CMT laboratories have a 'poor' environmental performance (and overall progress towards SD) when EMS waste data are converted into indicator scores and assessed against the principle of proportionality; CMT waste recycling targets are lower when benchmarked against jurisdictional CDW waste recovery targets; and no significant difference in the average

Evaluation of an automated milk leukocyte differential test and the California Mastitis Test for detecting intramammary infection in early- and late-lactation quarters and cows.

Science.gov (United States)

Godden, S M; Royster, E; Timmerman, J; Rapnicki, P; Green, H

2017-08-01

Study objectives were to (1) describe the diagnostic test characteristics of an automated milk leukocyte differential (MLD) test and the California Mastitis Test (CMT) to identify intramammary infection (IMI) in early- (EL) and late-lactation (LL) quarters and cows when using 3 different approaches to define IMI from milk culture, and (2) describe the repeatability of MLD test results at both the quarter and cow level. Eighty-six EL and 90 LL Holstein cows were sampled from 3 Midwest herds. Quarter milk samples were collected for a cow-side CMT test, milk culture, and MLD testing. Quarter IMI status was defined by 3 methods: culture of a single milk sample, culture of duplicate samples with parallel interpretation, and culture of duplicate samples with serial interpretation. The MLD testing was completed in duplicate within 8 h of sample collection; MLD results (positive/negative) were reported at each possible threshold setting (1-18 for EL; 1-12 for LL) and CMT results (positive/negative) were reported at each possible cut-points (trace, ≥1, ≥2, or 3). We created 2 × 2 tables to compare MLD and CMT results to milk culture, at both the quarter and cow level, when using each of 3 different definitions of IMI as the referent test. Paired MLD test results were compared with evaluate repeatability. The MLD test showed excellent repeatability. The choice of definition of IMI from milk culture had minor effects on estimates of MLD and CMT test characteristics. For EL samples, when interpreting MLD and CMT results at the quarter level, and regardless of the referent test used, both tests had low sensitivity (MLD = 11.7-39.1%; CMT = 0-52.2%) but good to very good specificity (MLD = 82.1-95.2%; CMT = 68.1-100%), depending on the cut-point used. Sensitivity improved slightly if diagnosis was interpreted at the cow level (MLD = 25.6-56.4%; CMT = 0-72.2%), though specificity generally declined (MLD = 61.8-100%; CMT = 25.0-100%) depending on the cut-point used. For LL

Accessing developmental information of fossil hominin teeth using new synchrotron microtomography-based visualization techniques of dental surfaces and interfaces.

Directory of Open Access Journals (Sweden)

Adeline Le Cabec

Full Text Available Quantification of dental long-period growth lines (Retzius lines in enamel and Andresen lines in dentine and matching of stress patterns (internal accentuated lines and hypoplasias are used in determining crown formation time and age at death in juvenile fossil hominins. They yield the chronology employed for inferences of life history. Synchrotron virtual histology has been demonstrated as a non-destructive alternative to conventional invasive approaches. Nevertheless, fossil teeth are sometimes poorly preserved or physically inaccessible, preventing observation of the external expression of incremental lines (perikymata and periradicular bands. Here we present a new approach combining synchrotron virtual histology and high quality three-dimensional rendering of dental surfaces and internal interfaces. We illustrate this approach with seventeen permanent fossil hominin teeth. The outer enamel surface and enamel-dentine junction (EDJ were segmented by capturing the phase contrast fringes at the structural interfaces. Three-dimensional models were rendered with Phong's algorithm, and a combination of directional colored lights to enhance surface topography and the pattern of subtle variations in tissue density. The process reveals perikymata and linear enamel hypoplasias on the entire crown surface, including unerupted teeth. Using this method, highly detailed stress patterns at the EDJ allow precise matching of teeth within an individual's dentition when virtual histology is not sufficient. We highlight that taphonomical altered enamel can in particular cases yield artificial subdivisions of perikymata when imaged using X-ray microtomography with insufficient resolution. This may complicate assessments of developmental time, although this can be circumvented by a careful analysis of external and internal structures in parallel. We further present new crown formation times for two unerupted canines from South African Australopiths, which were

Accessing developmental information of fossil hominin teeth using new synchrotron microtomography-based visualization techniques of dental surfaces and interfaces.

Science.gov (United States)

Le Cabec, Adeline; Tang, Nancy; Tafforeau, Paul

2015-01-01

Quantification of dental long-period growth lines (Retzius lines in enamel and Andresen lines in dentine) and matching of stress patterns (internal accentuated lines and hypoplasias) are used in determining crown formation time and age at death in juvenile fossil hominins. They yield the chronology employed for inferences of life history. Synchrotron virtual histology has been demonstrated as a non-destructive alternative to conventional invasive approaches. Nevertheless, fossil teeth are sometimes poorly preserved or physically inaccessible, preventing observation of the external expression of incremental lines (perikymata and periradicular bands). Here we present a new approach combining synchrotron virtual histology and high quality three-dimensional rendering of dental surfaces and internal interfaces. We illustrate this approach with seventeen permanent fossil hominin teeth. The outer enamel surface and enamel-dentine junction (EDJ) were segmented by capturing the phase contrast fringes at the structural interfaces. Three-dimensional models were rendered with Phong's algorithm, and a combination of directional colored lights to enhance surface topography and the pattern of subtle variations in tissue density. The process reveals perikymata and linear enamel hypoplasias on the entire crown surface, including unerupted teeth. Using this method, highly detailed stress patterns at the EDJ allow precise matching of teeth within an individual's dentition when virtual histology is not sufficient. We highlight that taphonomical altered enamel can in particular cases yield artificial subdivisions of perikymata when imaged using X-ray microtomography with insufficient resolution. This may complicate assessments of developmental time, although this can be circumvented by a careful analysis of external and internal structures in parallel. We further present new crown formation times for two unerupted canines from South African Australopiths, which were found to form over

Study on the influence of several factors on the quality of SR-XFMT image

International Nuclear Information System (INIS)

Deng Biao; Yu Xiaohan; Xu Hongjie

2007-01-01

Synchrotron Radiation based X-ray Fluorescent Microtomography (SR-XFMT) is a novel non-destructive technique, which has the ability to reconstruct elemental distributions within a specimen with nondestructive methods. The paper studied the influence of several factors, such as the sampling interval and projections, image reconstruction algorithm and fluorescence signals, on the quality of SR-XFMT image by computer simulation. Some useful conclusions on the quality of SR-XFMT image can be drawn. (authors)

In-situ, real time micro-CT imaging of pore scale processes, the next frontier for laboratory based micro-CT scanning

OpenAIRE

Boone, Marijn; Bultreys, Tom; Masschaele, Bert; Van Loo, Denis; Van Hoorebeke, Luc; Cnudde, Veerle

2016-01-01

Over the past decade, laboratory based X-ray computed micro-tomography (micro-CT) has given unique insights in the internal structure of complex reservoir rocks, improving the understanding of pore scale processes and providing crucial information for pore scale modelling. Especially in-situ imaging using X-ray optimized Hassler type cells has enabled the direct visualization of fluid distributions at the pore scale under reservoir conditions. While sub-micrometre spatial resolutions are achi...

Morphological Characterisation of Unstained and Intact Tissue Micro-architecture by X-ray Computed Micro- and Nano-Tomography

Science.gov (United States)

Walton, Lucy A.; Bradley, Robert S.; Withers, Philip J.; Newton, Victoria L.; Watson, Rachel E. B.; Austin, Clare; Sherratt, Michael J.

2015-05-01

Characterisation and quantification of tissue structures is limited by sectioning-induced artefacts and by the difficulties of visualising and segmenting 3D volumes. Here we demonstrate that, even in the absence of X-ray contrast agents, X-ray computed microtomography (microCT) and nanotomography (nanoCT) can circumvent these problems by rapidly resolving compositionally discrete 3D tissue regions (such as the collagen-rich adventitia and elastin-rich lamellae in intact rat arteries) which in turn can be segmented due to their different X-ray opacities and morphologies. We then establish, using X-ray tomograms of both unpressurised and pressurised arteries that intra-luminal pressure not only increases lumen cross-sectional area and straightens medial elastic lamellae but also induces profound remodelling of the adventitial layer. Finally we apply microCT to another human organ (skin) to visualise the cell-rich epidermis and extracellular matrix-rich dermis and to show that conventional histological and immunohistochemical staining protocols are compatible with prior X-ray exposure. As a consequence we suggest that microCT could be combined with optical microscopy to characterise the 3D structure and composition of archival paraffin embedded biological materials and of mechanically stressed dynamic tissues such as the heart, lungs and tendons.

Sponge budding is a spatiotemporal morphological patterning process: Insights from synchrotron radiation-based x-ray microtomography into the asexual reproduction of Tethya wilhelma

Directory of Open Access Journals (Sweden)

Nickel Michael

2009-09-01

Full Text Available Abstract Background Primary agametic-asexual reproduction mechanisms such as budding and fission are present in all non-bilaterian and many bilaterian animal taxa and are likely to be metazoan ground pattern characters. Cnidarians display highly organized and regulated budding processes. In contrast, budding in poriferans was thought to be less specific and related to the general ability of this group to reorganize their tissues. Here we test the hypothesis of morphological pattern formation during sponge budding. Results We investigated the budding process in Tethya wilhelma (Demospongiae by applying 3D morphometrics to high resolution synchrotron radiation-based x-ray microtomography (SR-μCT image data. We followed the morphogenesis of characteristic body structures and identified distinct morphological states which indeed reveal characteristic spatiotemporal morphological patterns in sponge bud development. We discovered the distribution of skeletal elements, canal system and sponge tissue to be based on a sequential series of distinct morphological states. Based on morphometric data we defined four typical bud stages. Once they have reached the final stage buds are released as fully functional juvenile sponges which are morphologically and functionally equivalent to adult specimens. Conclusion Our results demonstrate that budding in demosponges is considerably more highly organized and regulated than previously assumed. Morphological pattern formation in asexual reproduction with underlying genetic regulation seems to have evolved early in metazoans and was likely part of the developmental program of the last common ancestor of all Metazoa (LCAM.

Sponge budding is a spatiotemporal morphological patterning process: Insights from synchrotron radiation-based x-ray microtomography into the asexual reproduction of Tethya wilhelma.

Science.gov (United States)

Hammel, Jörg U; Herzen, Julia; Beckmann, Felix; Nickel, Michael

2009-09-08

Primary agametic-asexual reproduction mechanisms such as budding and fission are present in all non-bilaterian and many bilaterian animal taxa and are likely to be metazoan ground pattern characters. Cnidarians display highly organized and regulated budding processes. In contrast, budding in poriferans was thought to be less specific and related to the general ability of this group to reorganize their tissues. Here we test the hypothesis of morphological pattern formation during sponge budding. We investigated the budding process in Tethya wilhelma (Demospongiae) by applying 3D morphometrics to high resolution synchrotron radiation-based x-ray microtomography (SR-muCT) image data. We followed the morphogenesis of characteristic body structures and identified distinct morphological states which indeed reveal characteristic spatiotemporal morphological patterns in sponge bud development. We discovered the distribution of skeletal elements, canal system and sponge tissue to be based on a sequential series of distinct morphological states. Based on morphometric data we defined four typical bud stages. Once they have reached the final stage buds are released as fully functional juvenile sponges which are morphologically and functionally equivalent to adult specimens. Our results demonstrate that budding in demosponges is considerably more highly organized and regulated than previously assumed. Morphological pattern formation in asexual reproduction with underlying genetic regulation seems to have evolved early in metazoans and was likely part of the developmental program of the last common ancestor of all Metazoa (LCAM).

The Effect of Chemically Modified Tetracycline-3 on the Progression of Dental Caries in Rats.

Science.gov (United States)

Xu, Jun; Miao, Congcong; Tian, Zhenchuan; Li, Jinlu; Zhang, Chunmei; Yang, Dongmei

2018-02-07

Matrix metalloproteinases (MMPs) exist in human saliva and dentin and play an important role in the degradation of organic matrix in teeth. Chemically modified tetracycline-3 (CMT-3) is an inhibitor of MMPs. CMT-3 has been used experimentally to treat caries since 1999, but no distinction between dental caries prevalence and dentin caries prevalence has been described. A total of 65 Sprague-Dawley rats were randomly divided into three groups. The positive control group (25 rats) was inoculated with Streptococcus mutans (ATCC700610) and fed the cariogenic feed of improved Keyes Diet 2000. The CMT-3 group (25 rats) was also inoculated with S. mutans and fed the cariogenic feed of improved Keyes Diet 2000; the surfaces of rats' molars were daily treated with 0.02% CMT-3. The negative control group (15 rats) was only fed the standard rodent chow. At the end of the 10th week, the dental caries prevalence and dentin caries prevalence of each group were calculated, and the regions of caries were assessed. No caries was found in the negative control group. The dental caries prevalence of the CMT-3 and the positive control group was 75.0 and 83.3%, respectively (p > 0.05, Table 2). The dentin caries prevalence of the CMT-3 and the positive control group was 33.3 and 70.8%, respectively (p caries in the CMT-3 group was significantly lower than that in the positive control group (p caries, but could lower the prevalence and slow down the progression of dentin caries. © 2018 S. Karger AG, Basel.

Incidental Anatomic Finding of Celiacomesenteric Trunk Associated with 'Nutcracker Phenomenon,' or Compression of the Left Renal Vein.

Science.gov (United States)

Peterson, Joshua; Hage, Anthony N; Diljak, Stephan; Long, Benjamin D; Marcusa, Daniel P; Stribley, John M; Brzezinski, David W; Eliason, Jonathan

2017-12-15

BACKGROUND Celiacomesenteric trunk (CMT) is a very rare anatomic finding in which the celiac artery and the superior mesenteric artery (SMA) originate from the abdominal aorta through a common trunk. Clinical associations with CMT include arterial aneurysm, thrombosis, and celiac artery compression. However, an association between CMT and abdominal venous congestion caused by left renal vein compression, or 'nutcracker phenomenon,' has not been previously reported. CASE REPORT A 91-year-old woman, who died from a cerebrovascular accident (CVA), underwent a cadaveric examination at our medical school. On examination of the abdomen, there was an incidental finding of CMT. The arterial and venous diameters were measured, and vascular histopathology was undertaken. The vascular anatomy was consistent with CMT type 1-b. Nutcracker phenomenon (NCP) (left renal vein compression) was seen anatomically as dilatation and engorgement of the left renal vein, relative to the right renal vein (10.77±0.13 mm vs. 4.49±0.56 mm, respectively), and dilatation and engorgement of the left ovarian vein, relative to the right ovarian vein (4.37±0.15 mm vs. 1.06±0.09 mm, respectively) with left ovarian varicocele. The aortoceliac angle (ACA) and the aortomesenteric angle (AMA) approached zero degrees. CONCLUSIONS We have described a rare anatomic finding of CMT that created an acute AMA and NCP. Awareness of this rare association between CMT and NCP by clinicians, vascular surgeons, and radiologists may be of value in the future evaluation and surgical management of patients who present clinically with 'nutcracker syndrome.'

Quantitative fluorescence-polymerase chain reaction assay for the detection of the duplication of the Charcot Marie Tooth disease type 1A critical region.

Science.gov (United States)

De Toffol, Simona; Bellone, Emilia; Dulcetti, Francesca; Ruggeri, Anna Maria; Maggio, Pietro Paolo; Pulimeno, Maria Rosaria; Mandich, Paola; Maggi, Federico; Simoni, Giuseppe; Grati, Francesca Romana

2010-04-01

Charcot Marie Tooth (CMT) syndrome is the most common hereditary peripheral neuropathy, with an incidence of about 1 in 2500. The subtype 1A (CMT1A) is caused by a tandem duplication of a 1.5-Mb region encompassing the PMP22 gene. Conventional short tandem repeat (STR) analysis can reveal this imbalance if a triallelic pattern, defining with certainty the presence of duplication, is present. In case of duplication with a biallelic pattern, it can only indicate a semiquantitative dosage of the fluorescence intensity ratio of the two fragments. In this study we developed a quantitative fluorescence-PCR using seven highly informative STRs within the CMT1A critical region that successfully disclosed or excluded the presence of the pathogenic imbalance in a cohort of 60 samples including 40 DNAs from samples with the CMT1A duplication previously characterized with two different molecular approaches, and 20 diagnostic samples from 10 members of a five-generation pedigree segregating CMT1A, 8 unrelated cases and 2 prenatal samples. The application of the quantitative fluorescence-PCR using STRs located in the critical region could be a reliable method to evaluate the presence of the PMP22 duplication for the diagnosis and classification of hereditary neuropathies in asymptomatic subjects with a family history of inherited neuropathy, in prenatal samples in cases with one affected parent, and in unrelated patients with a sporadic demyelinating neuropathy with clinical features resembling CMT (i.e., pes cavus with hammer toes) or with conduction velocities in the range of CMT1A.

Soldadura robotizada com tecnologia CMT

OpenAIRE

Silva, Flávio

2015-01-01

A soldadura é um processo fundamental na indústria, permitindo união de diferentes componentes. Cada vez mais existe uma preocupação com a segurança e controlo de qualidade dos automóveis. Um dos parâmetros a penetração da soldadura é essencial para manter a integridade estrutural dos componentes soldados, para tal foram analisados alguns processos aplicados na indústria automóvel. Aprofundando os conhecimentos de soldadura expondo o seu desenvolvimento ao longo dos anos e caracterizando em p...

Charcot-Marie-Tooth disease.

LENUS (Irish Health Repository)

Reilly, Mary M

2011-03-01

Charcot-Marie-Tooth (CMT) disease is the commonest inherited neuromuscular disorder affecting at least 1 in 2,500. Over the last two decades, there have been rapid advances in understanding the molecular basis for many forms of CMT with more than 30 causative genes now described. This has made obtaining an accurate genetic diagnosis possible but at times challenging for clinicians. This review aims to provide a simple, pragmatic approach to diagnosing CMT from a clinician\\'s perspective.

Preliminary results of a randomized trial of mitomycin C as an adjunct to radical radiotherapy in the treatment of locally advanced squamous cell carcinoma of the cervix

International Nuclear Information System (INIS)

Roberts, Kenneth B.; Urdaneta, Nelson; Vera, Raul; Vera, Andres; Gutierrez, Enrique; Rockwell, Sara; Sartorelli, Alan C.; Fischer, Diana B.; Fischer, James J.

1996-01-01

Purpose/Objective: To determine the efficacy of Mitomycin C (MC) in combination with radiotherapy (RT) for the treatment of carcinoma of the cervix Materials and Methods: A Phase III randomized study of MC + RT (CMT) vs. RT was initiated in 1990 to test whether or not a bioreductive alkylating agent would improve the cure of squamous cell carcinoma of the cervix (CCa), a tumor for which hypoxia is known to be a strong prognostic factor. As of March 1996, 157 patients have been enrolled. After excluding 8 patients (pts) for protocol violations (3 in CMT group and 5 in RT group), the 110 analyzable pts having at least two years of partial follow-up were used for the preliminary analysis reported here. Intravenous MC, 15 mg/M 2 , was given on the 1st and 6th week of treatment. Before randomization between CMT and RT, patients were stratified by standardized radiotherapy prescriptions of both brachytherapy and external beam RT dose, as dictated by tumor stage. Results: The 58 pts in the CMT group and 52 pts in the RT group have a mean follow-up of 27.1 months, and a comparable distribution by age and stage (mean age 48.3 years; stage IB 2%, IIA 14%, IIB 47%, IIIA 1%, IIIB 34%, IVA 3%). The three year actuarial survival rates for CMT and RT were 77% and 58%, respectively (p=0.15). Three months following completion of therapy, complete response (CR) was achieved in 51 pts (88%) of the CMT group and in 47 pts (90%) of the RT group (p=NS). Of those with CR, the three year actuarial local recurrence free survivals for CMT and RT were 84% and 68%, respectively (p=0.12). There were no treatment-related deaths. Mild hematologic toxicity was seen only in the CMT group, with 4 pts having a nadir WBC <1.5 (but none below 1.0) and with 1 pt having a nadir platelet count below 25K. Grade 3 skin toxicity was seen in 3 pts receiving CMT and 1 pt receiving RT alone. Grade 3 cystitis was seen in one RT pt. Grade 3 and 4 GI toxicities were seen in two RT pts. No excess in non

Study of thermal performance of capillary micro tubes integrated into the building sandwich element made of high performance concrete

DEFF Research Database (Denmark)

Mikeska, Tomas; Svendsen, Svend

2013-01-01

The thermal performance of radiant heating and cooling systems (RHCS) composed of capillary micro tubes (CMT) integrated into the inner plate of sandwich elements made of high performance concrete (HPC) was investigated in the article. Temperature distribution in HPC elements around integrated CM...... and cooling purposes of future low energy buildings. The investigations were conceived as a low temperature concept, where the difference between the temperature of circulating fluid and air in the room was kept in range of 1–4 °C.......The thermal performance of radiant heating and cooling systems (RHCS) composed of capillary micro tubes (CMT) integrated into the inner plate of sandwich elements made of high performance concrete (HPC) was investigated in the article. Temperature distribution in HPC elements around integrated CMT...... HPC layer covering the CMT. This paper shows that CMT integrated into the thin plate of sandwich element made of HPC can supply the energy needed for heating (cooling) and at the same time create the comfortable and healthy environment for the occupants. This solution is very suitable for heating...

Crystallography of Magnetite Plaquettes and their Significance as Asymmetric Catalysts for the Synthesis of Chiral Organics in Carbonaceous Chondrites

Science.gov (United States)

Chan, Q. H. S.; Zolensky, M. E.

2015-01-01

We have previously observed the magnetite plaquettes in carbonaceous chondrites using scanning electron microscope (SEM) imaging, examined the crystal orientation of the polished surfaces of magnetite plaquettes in CI Orgueil using electron backscattered diffraction (EBSD) analysis, and concluded that these magnetite plaquettes are likely naturally asymmetric materials. In this study, we expanded our EBSD observation to other magnetite plaquettes in Orgueil, and further examined the internal structure of these remarkable crystals with the use of X-ray computed microtomography.

Identification of strain fields in pure Al and hybrid Ni/Al metal foams using X-ray micro-tomography under loading

International Nuclear Information System (INIS)

Fíla, T.; Jiroušek, O.; Jung, A.; Kumpová, I.

2016-01-01

Hybrid foams are materials formed by a core from a standard open cell metal foam that is during the process of electrodeposition coated by a thin layer of different nanocrystalline metals. The material properties of the base metal foam are in this way modified resulting in higher plateau stress and, more importantly, by introduction of strain-rate dependence to its deformation response. In this paper, we used time-lapse X-ray micro-tomography for the mechanical characterization of Ni/Al hybrid foams (aluminium open cell foams with nickel coating layer). To fully understand the effects of the coating layer on the material's effective properties, we compared the compressive response of the base uncoated foam to the response of the material with coating thickness of 50 and 75 μm. Digital volume correlation (DVC) was applied to obtain volumetric strain fields of the deforming micro-structure up to the densification region of the deforming cellular structure. The analysis was performed as a compressive mechanical test with simultaneous observation using X-ray radiography and tomography. A custom design experimental device was used for compression of the foam specimens in several deformation states directly in the X-ray setup. Planar X-ray images were taken during the loading phases and a X-ray tomography was performed at the end of each loading phase (up to engineering strain 22%). The samples were irradiated using micro-focus reflection type X-ray tube and images were taken using a large area flat panel detector. Tomography reconstructions were used for an identification of a strain distribution in the foam using digital volumetric correlation. A comparison of the deformation response of the coated and the uncoated foam in uniaxial quasi-static compression is summarized in the paper.

A novel mouse model carrying a human cytoplasmic dynein mutation shows motor behavior deficits consistent with Charcot-Marie-Tooth type 2O disease.

Science.gov (United States)

Sabblah, Thywill T; Nandini, Swaran; Ledray, Aaron P; Pasos, Julio; Calderon, Jami L Conley; Love, Rachal; King, Linda E; King, Stephen J

2018-01-29

Charcot-Marie-Tooth disease (CMT) is a peripheral neuromuscular disorder in which axonal degeneration causes progressive loss of motor and sensory nerve function. The loss of motor nerve function leads to distal muscle weakness and atrophy, resulting in gait problems and difficulties with walking, running, and balance. A mutation in the cytoplasmic dynein heavy chain (DHC) gene was discovered to cause an autosomal dominant form of the disease designated Charcot-Marie-Tooth type 2 O disease (CMT2O) in 2011. The mutation is a single amino acid change of histidine into arginine at amino acid 306 (H306R) in DHC. In order to understand the onset and progression of CMT2, we generated a knock-in mouse carrying the corresponding CMT2O mutation (H304R/+). We examined H304R/+ mouse cohorts in a 12-month longitudinal study of grip strength, tail suspension, and rotarod assays. H304R/+ mice displayed distal muscle weakness and loss of motor coordination phenotypes consistent with those of individuals with CMT2. Analysis of the gastrocnemius of H304R/+ male mice showed prominent defects in neuromuscular junction (NMJ) morphology including reduced size, branching, and complexity. Based on these results, the H304R/+ mouse will be an important model for uncovering functions of dynein in complex organisms, especially related to CMT onset and progression.

Copy Number Variations in a Population-Based Study of Charcot-Marie-Tooth Disease

Directory of Open Access Journals (Sweden)

Helle Høyer

2015-01-01

Full Text Available Copy number variations (CNVs are important in relation to diversity and evolution but can sometimes cause disease. The most common genetic cause of the inherited peripheral neuropathy Charcot-Marie-Tooth disease is the PMP22 duplication; otherwise, CNVs have been considered rare. We investigated CNVs in a population-based sample of Charcot-Marie-Tooth (CMT families. The 81 CMT families had previously been screened for the PMP22 duplication and point mutations in 51 peripheral neuropathy genes, and a genetic cause was identified in 37 CMT families (46%. Index patients from the 44 CMT families with an unknown genetic diagnosis were analysed by whole-genome array comparative genomic hybridization to investigate the entire genome for larger CNVs and multiplex ligation-dependent probe amplification to detect smaller intragenomic CNVs in MFN2 and MPZ. One patient had the pathogenic PMP22 duplication not detected by previous methods. Three patients had potentially pathogenic CNVs in the CNTNAP2, LAMA2, or SEMA5A, that is, genes related to neuromuscular or neurodevelopmental disease. Genotype and phenotype correlation indicated likely pathogenicity for the LAMA2 CNV, whereas the CNTNAP2 and SEMA5A CNVs remained potentially pathogenic. Except the PMP22 duplication, disease causing CNVs are rare but may cause CMT in about 1% (95% CI 0–7% of the Norwegian CMT families.

Meta-analysis of congenitally missing teeth in the permanent dentition: Prevalence, variations across ethnicities, regions and time.

Science.gov (United States)

Rakhshan, Vahid; Rakhshan, Hamid

2015-09-01

Congenitally missing teeth (CMT) are of concern to many fields of dentistry. Only a few reviews have been published in this regard. The aim was to analyze the literature on CMT in the permanent dentition, excluding the third molars, and to identify potential links with ethnicity, geographical regions, and time. A total of 118 reports on CMT were collected by two authors by interrogating databases. Sample homogeneity, publication bias, publication year (in Caucasian and Mongoloid samples, and in general), ethnicities, and geography of CMT prevalence were statistically analyzed using a Q-test, Egger regression, linear regression, a Spearman coefficient, Kruskal-Wallis, a Dunn post-hoc (α = 0.05), and a Mann-Whitney U test (α = 0.0125, α = 0.0071). The mean CMT prevalence was 6.53% ± 3.33%. There were significant geographic differences in CMT rates (P = 0.0001, Kruskal-Wallis) and between ethnicities (P = 0.0002, Kruskal-Wallis). According to the Mann-Whitney U test (α = 0.0071), eastern Asians (P = 0.0008) and Europeans (marginally significant, P = 0.0128) showed an elevated prevalence, while Western Asians (P = 0.0001) and Americans (marginally significant, P = 0.0292) had lower prevalence rates. Compared with other ethnicities, Mongoloids showed higher prevalence (P = 0.0009) while Asian Caucasians showed lower rates (P = 0.0005, Mann-Whitney U, α = 0.0125). The year of publication was not significantly correlated with any of the subsamples studied (P > 0.3, linear regression). Clinicians should be vigilant in the assessment of CMT in Mongoloids. No increase of this condition was detected during the last century. Copyright © 2015 CEO. Published by Elsevier Masson SAS. All rights reserved.

[Experience in molecular diagnostic in hereditary neuropathies in a pediatric tertiary hospital].

Science.gov (United States)

Fernández-Ramos, Joaquín A; López-Laso, Eduardo; Camino-León, Rafael; Gascón-Jiménez, Francisco J; Jiménez-González, M Dolores

2015-12-01

Charcot-Marie-Tooth (CMT) is the most common hereditary sensory motor neuropathy. Advances in molecular diagnosis have increased the diagnostic possibilities of these patients. Retrospective study of 36 pediatric patients diagnosed with CMT in a tertiary center in 2003-2015. We found 16 patients were diagnosed by a duplication in PMP22; two cases were diagnosed of hereditary neuropathy with liability to pressure palsies, one with a point mutation in PMP22; a male with a mild demyelinating phenotype, without family history, was diagnosed with GJB1 mutation; in a patient with a peripheral hypotonia at birth and axonal pattern in EMG by mutation in MFN2; a gypsy patient, with consanguineous family, CMT4D, was identified by a mutation in the gene NDRG1; a patient with multiplex congenital arthrogryposis and vocal cord paralysis, whose mother had a scapular-peroneal syndrome, had a congenital spinal muscular atrophy with mild distal axonal neuropathy by mutation in gene TRPV4; three girls, from a gypsy consanguineous family, with axonal CMT with neuromyotonic discharges were diagnosed by a mutation in the gene HINT1; twelve patients haven't molecular diagnosis currently. CMT1A predominated in our series (44%), as previous studies. We emphasize the description of a patient with a mutation in TRPV4 recently described as a cause of CMT2C and three cases, of gypsy consanguineous family, with the same mutation in HINT1 gene, recently described as a cause of axonal neuropathy with neuromyotonia, autosomal recessive (AR-CMT2). The proportion of patients without molecular diagnosis is similar to main European series.

Melatonin Treatment Reduces Oxidative Damage and Normalizes Plasma Pro-Inflammatory Cytokines in Patients Suffering from Charcot-Marie-Tooth Neuropathy: A Pilot Study in Three Children.

Science.gov (United States)

Chahbouni, Mariam; López, María Del Señor; Molina-Carballo, Antonio; de Haro, Tomás; Muñoz-Hoyos, Antonio; Fernández-Ortiz, Marisol; Guerra-Librero, Ana; Acuña-Castroviejo, Darío

2017-10-14

Charcot-Marie-Tooth neuropathy (CMT) is a motor and sensory neuropathy comprising a heterogeneous group of inherited diseases. The CMT1A phenotype is predominant in the 70% of CMT patients, with nerve conduction velocity reduction and hypertrophic demyelination. These patients have elevated oxidative stress and chronic inflammation. Currently, there is no effective cure for CMT; herein, we investigated whether melatonin treatment may reduce the inflammatory and oxidative damage in CMT1A patients. Three patients, aged 8-10 years, were treated with melatonin (60 mg at 21:00 h plus 10 mg at 09:00 h), and plasma levels of lipid peroxidation (LPO), nitrites (NOx), IL-1β, IL-2, IL-6, TNF-α, INF-γ, oxidized to reduced glutathione (GSSG/GSH) ratio, and the activities of superoxide dismutase (SOD), glutathione-S transferase (GST), glutathione peroxidase (GPx), and reductase (GRd), were determined in erythrocytes at 3 and 6 months of treatment. Healthy age- and sex-matched subjects were used as controls. The results showed increased activities of SOD, GST, GPx, and GRd in CMT1A patients, which were reduced at 3 and 6 months of treatment. The GSSG/GSH ratio significantly increased in the patients, returning to control values after melatonin treatment. The inflammatory process was confirmed by the elevation of all proinflammatory cytokines measured, which were also normalized by melatonin. LPO and NOx, which also were elevated in the patients, were normalized by melatonin. The results document beneficial effects of the use of melatonin in CMT1A patients to reduce the hyperoxidative and inflammatory condition, which may correlate with a reduction of the degenerative process.

Dynamics of bubble-bubble interaction in sheared low-viscosity magma imaged by X-ray computed micro-tomography

Science.gov (United States)

Helo, C.; Flaws, A.; Hess, K.-U.; Franz, A.; Clague, D. A.; Dingwell, D. B.

2012-04-01

X-ray computed tomography of vesicles in basaltic pyroclastic glass fragments has been used to investigate the syn-eruptive shear environment and resulting bubble-bubble interaction during mild pyroclastic eruptions in a mid-ocean ridge environment. We have imaged vesicles present in two different types of pyroclastic fragments produced by mildly explosive activity on Axial Seamount, limu o Pele, that is, thin glass films often described as bubble walls, and tube scoria fragments. Rapid quenching of the glass has prevented extensive bubble relaxation preserving the syn-eruptive geometry of the bubbles in these fragments. Isolated, ellipsoid-shaped vesicles in low-vesicular limu o Pele indicate deformation in a simple shear environment. Under these shear conditions higher vesiculated parts of the erupting magma show strong bubble-bubble interactions partially leading to coalscence and formation of tubular vesicles. These tubular vesicles can reach significant lengths, exceeding the dimensions of the small glass fragments (2 mm). Their unreformed radius can be more then one order of magnitude larger than that of the isolated vesicles in the limu o Pele fragments. We can distinguish two principle modes of interaction based on the relative orientation of the bubbles. Interaction along the sidewalls of two bubbles, and tip-to-tip interaction. At interdistances of less than a few tens of micrometre, interaction of the sidewalls results in deformation of the bubbles to more irregular shapes, with depressions caused by close, small bubbles or in some cases bubbles being partially mantled around tubular bubbles. This often leads to a more close packing of bubbles. At distances of less than a few microns, the melt films between the bubbles destabilize leading to coalescence. This mechanism appears to involve a bulging of the larger bubble into the smaller, followed by melt film rapture and coalescence. The complete digestion of one bubble by the other is the slow rate

Ocorrência de mastite bovina em fazendas produtoras de leite B no estado de São Paulo Occurrence of bovine mastitis in grade B milk farms in the state of São Paulo

Directory of Open Access Journals (Sweden)

L.F. Laranja

1994-12-01

Full Text Available Durante o período compreendido entre os meses de Março/1991 e Fevereiro /1992 foi realizado um experimento com o objetivo de avaliar a prevalência da mastite bovina em 07 fazendas produtoras de leite tipo B de diferentes regiões do estado de São Paulo. Foram analisadas 1683 vacas que deram origem a 7695 resultados do CMT e das quais foram coletadas 983 amostras de leite para realização do exame microbiológico. A análise do CMT indicou 47,0% de vacas com CMT negativo, 15,1% CMT + e 37,5% CMT ++/+ + + . Os escores do CMT foram distribuidos segundo o número de lactação (1ª lactação, 2ª lactação e 3ª ou + lactações e segundo o estágio de lactação (1-30 dias de lactação, 31-90 dias, 91-250 dias e > 250 dias. A análise dos dados demonstrou que houve um efeito significativo (p From March/1991 to February/1992 1,683 cows from seven grade "B" milk producing dairy farms were used in a study on the prevalence of bovine mastitis. GMT tests (7,695 were 47.0% negative; 15.1% " +" and 37.5% "++/+ + +". CMT scores were grouped by number of lactation (1st, 2nd, 3rd or more and by stage of lactation (1-30 days in milk; 31-90 days; 91-250 and > 250 days. Both stage of lactation and number of lactation had significant effect on % of cows CMT "++/+ + + ". Microbiological results from 983 milk samples were 50.97% positive. From the positive samples were isolated Staphylococcus sp (44.6%, Corynebacteríum sp (15.0%, Streptococcus sp (8.2%, Yeast/Fungi (5.4%. Bacillus sp (4.4%, E. coli (3.2% and Klebsiella sp (0.2%. Considering both pure and mixed culture isolation, Staphylococcus sp represents 55.6%, Corynebacteríum sp, 18.6% and Streptococcus sp, 15.0%.

Synchrotron x-ray studies of the keel of the short-spined sea urchin lytechinus variegatus: absorption microtomography (microCT) and small beam diffraction mapping

International Nuclear Information System (INIS)

Stock, S.R.; Barss, J.; Dahl, T.; Veis, A.; Almer, J.D.; De Carlo, F.

2003-01-01

In sea urchin teeth, the keel plays an important structural role, and this paper reports results of microstructural characterization of the keel of Lytechinus variegatus using two noninvasive synchrotron x-ray techniques: x-ray absorption microtomography (microCT) and x-ray diffraction mapping. MicroCT with 14 keV x-rays mapped the spatial distribution of mineral at the 1.3 microm level in a millimeter-sized fragment of a mature portion of the keel. Two rows of low absorption channels (i.e., primary channels) slightly less than 10 microm in diameter were found running linearly from the flange to the base of the keel and parallel to its sides. The primary channels paralleled the oral edge of the keel, and the microCT slices revealed a planar secondary channel leading from each primary channel to the side of the keel. The primary and secondary channels were more or less coplanar and may correspond to the soft tissue between plates of the carinar process. Transmission x-ray diffraction with 80.8 keV x-rays and a 0.1 mm beam mapped the distribution of calcite crystal orientations and the composition Ca(1-x)Mg(x)CO(3) of the calcite. Unlike the variable Mg concentration and highly curved prisms found in the keel of Paracentrotus lividus, a constant Mg content (x = 0.13) and relatively little prism curvature was found in the keel of Lytechinus variegatus.

Numerical studies on the performance of a flow distributor in tank

Energy Technology Data Exchange (ETDEWEB)

Shin, Soo Jai, E-mail: shinsoojai@kaeri.re.kr; Kim, Young In; Ryu, Seungyeob; Bae, Youngmin; Kim, Keung Koo [Korea Atomic Energy Research Institute, Daedeok-daero 989-111, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

2015-03-10

Flow distributors are generally observed in several nuclear power plants. During core make-up tank (CMT) injection into the reactor, the condensation and thermal stratification are observed in the CMT, and rapid condensation disturbs the injection operation. To reduce the condensation phenomena in the tank, CMT was equipped with a flow distributor. The optimal design of the flow distributor is very important to ensure the structural integrity the CMT and its safe operation during certain transient or accident conditions. In the present study, we numerically investigated the performance of a flow distributor in tank with different shape factors such as the total number of holes, pitch-to-hole diameter ratios, diameter of the hole, and the area ratios. These data will contribute to a design of the flow distributor.

Numerical studies on the performance of a flow distributor in tank

International Nuclear Information System (INIS)

Shin, Soo Jai; Kim, Young In; Ryu, Seungyeob; Bae, Youngmin; Kim, Keung Koo

2015-01-01

Flow distributors are generally observed in several nuclear power plants. During core make-up tank (CMT) injection into the reactor, the condensation and thermal stratification are observed in the CMT, and rapid condensation disturbs the injection operation. To reduce the condensation phenomena in the tank, CMT was equipped with a flow distributor. The optimal design of the flow distributor is very important to ensure the structural integrity the CMT and its safe operation during certain transient or accident conditions. In the present study, we numerically investigated the performance of a flow distributor in tank with different shape factors such as the total number of holes, pitch-to-hole diameter ratios, diameter of the hole, and the area ratios. These data will contribute to a design of the flow distributor

Three-dimensional x-ray microtomography for medical and biological applications

International Nuclear Information System (INIS)

Morton, E.J.; Webb, S.; Clarke, L.J.; Shelton, C.G.

1990-01-01

To obtain microtomographic images apparatus has been developed consisting of a microfocal x-ray source, a computer-controlled stage for rotating the object, a 2D multi-wire gas proportional x-ray counter and a microcomputer to control image acquisition. Projection data were generated by rotating the object to discrete orientations around a single axis until of the order of 100 2D projection images of the object were collected. The projection images were transferred to a VAX 11/750 computer for 3D reconstruction using a convolution and back-projection algorithm in cone-beam geometry. Reconstructed data, comprising cubic voxels, may be displayed as sets of sequential transaxial, sagittal and coronal planes through the object, or perspective displays of individual orthogonal sections formed with either intersecting planes or with these planes projected on the surfaces of a box-like structure. The technique provides for investigation of small-scale structures in biological specimens and some images of dead insects are shown. (author)

Influence of Manufacturing Methods of Implant-Supported Crowns on External and Internal Marginal Fit: A Micro-CT Analysis

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Izabela C. M. Moris

2018-01-01

Full Text Available Aim. To evaluate the influence of different manufacturing methods of single implant-supported metallic crowns on the internal and external marginal fit through computed microtomography. Methods. Forty external hexagon implants were divided into 4 groups (n=8, according to the manufacturing method: GC, conventional casting; GI, induction casting; GP, plasma casting; and GCAD, CAD/CAM machining. The crowns were attached to the implants with insertion torque of 30 N·cm. The external (vertical and horizontal marginal fit and internal fit were assessed through computed microtomography. Internal and external marginal fit data (μm were submitted to a one-way ANOVA and Tukey’s test (α=.05. Qualitative evaluation of the images was conducted by using micro-CT. Results. The statistical analysis revealed no significant difference between the groups for vertical misfit (P=0.721. There was no significant difference (P>0.05 for the internal and horizontal marginal misfit in the groups GC, GI, and GP, but it was found for the group GCAD (P≤0.05. Qualitative analysis revealed that most of the samples of cast groups exhibited crowns underextension while the group GCAD showed overextension. Conclusions. The manufacturing method of the crowns influenced the accuracy of marginal fit between the prosthesis and implant. The best results were found for the crowns fabricated through CAD/CAM machining.

Genetics Home Reference: Charcot-Marie-Tooth disease

Science.gov (United States)

... CMT1 or CMT4. CMTX5 is also known as Rosenberg-Chutorian syndrome. Some researchers believe that this condition ... Dejerine Sottas Disease National Organization for Rare Disorders: Rosenberg-Chutorian Syndrome National Organization for Rare Disorders: Roussy- ...

Incidental Anatomic Finding of Celiacomesenteric Trunk Associated with ‘Nutcracker Phenomenon,’ or Compression of the Left Renal Vein

Science.gov (United States)

Peterson, Joshua; Hage, Anthony N.; Diljak, Stephan; Long, Benjamin D.; Marcusa, Daniel P.; Brzezinski, David W.; Eliason, Jonathan

2017-01-01

Patient: Female, 91 Final Diagnosis: Nutcracker syndrome • celiacomesenteric trunk Symptoms: Dyspepsia • dysphagia Medication: — Clinical Procedure: — Specialty: Surgery Objective: Congenital defects/diseases Background: Celiacomesenteric trunk (CMT) is a very rare anatomic finding in which the celiac artery and the superior mesenteric artery (SMA) originate from the abdominal aorta through a common trunk. Clinical associations with CMT include arterial aneurysm, thrombosis, and celiac artery compression. However, an association between CMT and abdominal venous congestion caused by left renal vein compression, or ‘nutcracker phenomenon,’ has not been previously reported. Case Report: A 91-year-old woman, who died from a cerebrovascular accident (CVA), underwent a cadaveric examination at our medical school. On examination of the abdomen, there was an incidental finding of CMT. The arterial and venous diameters were measured, and vascular histopathology was undertaken. The vascular anatomy was consistent with CMT type 1-b. Nutcracker phenomenon (NCP) (left renal vein compression) was seen anatomically as dilatation and engorgement of the left renal vein, relative to the right renal vein (10.77±0.13 mm vs. 4.49±0.56 mm, respectively), and dilatation and engorgement of the left ovarian vein, relative to the right ovarian vein (4.37±0.15 mm vs. 1.06±0.09 mm, respectively) with left ovarian varicocele. The aortoceliac angle (ACA) and the aortomesenteric angle (AMA) approached zero degrees. Conclusions: We have described a rare anatomic finding of CMT that created an acute AMA and NCP. Awareness of this rare association between CMT and NCP by clinicians, vascular surgeons, and radiologists may be of value in the future evaluation and surgical management of patients who present clinically with ‘nutcracker syndrome.’ PMID:29242494

Bayesian tomographic reconstruction of microsystems

International Nuclear Information System (INIS)

Salem, Sofia Fekih; Vabre, Alexandre; Mohammad-Djafari, Ali

2007-01-01

The microtomography by X ray transmission plays an increasingly dominating role in the study and the understanding of microsystems. Within this framework, an experimental setup of high resolution X ray microtomography was developed at CEA-List to quantify the physical parameters related to the fluids flow in microsystems. Several difficulties rise from the nature of experimental data collected on this setup: enhanced error measurements due to various physical phenomena occurring during the image formation (diffusion, beam hardening), and specificities of the setup (limited angle, partial view of the object, weak contrast).To reconstruct the object we must solve an inverse problem. This inverse problem is known to be ill-posed. It therefore needs to be regularized by introducing prior information. The main prior information we account for is that the object is composed of a finite known number of different materials distributed in compact regions. This a priori information is introduced via a Gauss-Markov field for the contrast distributions with a hidden Potts-Markov field for the class materials in the Bayesian estimation framework. The computations are done by using an appropriate Markov Chain Monte Carlo (MCMC) technique.In this paper, we present first the basic steps of the proposed algorithms. Then we focus on one of the main steps in any iterative reconstruction method which is the computation of forward and adjoint operators (projection and backprojection). A fast implementation of these two operators is crucial for the real application of the method. We give some details on the fast computation of these steps and show some preliminary results of simulations

Novel mutations in the PRX and the MTMR2 genes are responsible for unusual Charcot-Marie-Tooth disease phenotypes.

Science.gov (United States)

Nouioua, Sonia; Hamadouche, Tarik; Funalot, Benoit; Bernard, Rafaëlle; Bellatache, Nora; Bouderba, Radia; Grid, Djamel; Assami, Salima; Benhassine, Traki; Levy, Nicolas; Vallat, Jean-Michel; Tazir, Meriem

2011-08-01

Autosomal recessive Charcot-Marie-Tooth diseases, relatively common in Algeria due to high prevalence of consanguineous marriages, are clinically and genetically heterogeneous. We report on two consanguineous families with demyelinating autosomal recessive Charcot-Marie-Tooth disease (CMT4) associated with novel homozygous mutations in the MTMR2 gene, c.331dupA (p.Arg111LysfsX24) and PRX gene, c.1090C>T (p.Arg364X) respectively, and peculiar clinical phenotypes. The three patients with MTMR2 mutations (CMT4B1 family) had a typical phenotype of severe early onset motor and sensory neuropathy with typical focally folded myelin on nerve biopsy. Associated clinical features included vocal cord paresis, prominent chest deformities and claw hands. Contrasting with the classical presentation of CMT4F (early-onset Dejerine-Sottas phenotype), the four patients with PRX mutations (CMT4F family) had essentially a late age of onset and a protracted and relatively benign evolution, although they presented marked spine deformities. These observations broaden the spectrum of clinical phenotypes associated with these two CMT4 forms. Copyright © 2011 Elsevier B.V. All rights reserved.

Influence of sampling interval and number of projections on the quality of SR-XFMT reconstruction

International Nuclear Information System (INIS)

Deng Biao; Yu Xiaohan; Xu Hongjie

2007-01-01

Synchrotron Radiation based X-ray Fluorescent Microtomography (SR-XFMT) is a nondestructive technique for detecting elemental composition and distribution inside a specimen with high spatial resolution and sensitivity. In this paper, computer simulation of SR-XFMT experiment is performed. The influence of the sampling interval and the number of projections on the quality of SR-XFMT image reconstruction is analyzed. It is found that the sampling interval has greater effect on the quality of reconstruction than the number of projections. (authors)

Coexistent Charcot-Marie-Tooth type 1A and type 2 diabetes mellitus neuropathies in a Chinese family

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A-ping Sun

2015-01-01

Full Text Available Charcot-Marie-Tooth disease type 1A (CMT1A is caused by duplication of the peripheral myelin protein 22 (PMP22 gene on chromosome 17. It is the most common inherited demyelinating neuropathy. Type 2 diabetes mellitus is a common metabolic disorder that frequently causes predominantly sensory neuropathy. In this study, we report the occurrence of CMT1A in a Chinese family affected by type 2 diabetes mellitus. In this family, seven individuals had duplication of the PMP22 gene, although only four had clinical features of polyneuropathy. All CMT1A patients with a clinical phenotype also presented with type 2 diabetes mellitus. The other three individuals had no signs of CMT1A or type 2 diabetes mellitus. We believe that there may be a genetic link between these two diseases.

The implementation and evaluation of cognitive milieu therapy for dual diagnosis inpatients: A pragmatic clinical trial

DEFF Research Database (Denmark)

Lykke, Jørn; Oestrich, I.; Austin, Stephen

2010-01-01

milieu therapy (CMT) among a group of dual diagnosis inpatients. CMT is an integrated treatment for both mental illness and substance abuse based on cognitive behavioral principles and carried out within a supportive inpatient environment. A convenience sample of dual diagnosis inpatients (N = 136......) was assessed pre- and post-intervention from an inpatient setting where CMT was the mode of treatment. Psychopathology was measured using the Brief Psychiatric Rating Scale and substance abuse measured with the DrugCheck scale, breath/urine samples, and the Severity of Dependence Scale. Functioning...

Charcot-Marie-Tooth disease: The development of a diagnostic platform using next generation sequencing

DEFF Research Database (Denmark)

Christensen, Rikke; Væth, Signe; Thorsen, Kasper

, Sanger sequencing of 4 genes have led to a diagnosis in approximately 30% of the patients. Aims: 1) Development of a targeted NGS platform containing 63 genes that currently are found to be associated with CMT. 2) Analysis of the increased diagnostic yield using this platform to analyze 200 CMT samples...... previously analyzed using Sanger sequencing without identification of a disease causing mutation. Materials and Methods: Libraries for 200 patient samples obtained for CMT diagnostics were prepared using Illumina Truseq and target enrichment using SeqCap EZ Choise Library (Nimblegen). The libraries were...

From Cantor To Christaller?

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Morris E Scott

2015-12-01

Full Text Available It is possible that Georg Cantor and Walter Christaller may have been aware of one another during their careers, however, there is no indication the two collaborated. Also, there is no documentation that Christaller’s central place theory (CPT contains any tenets derived from Cantor’s middle third set (CMT. Regardless, CMT and CPT are linked by their constructions as nested hierarchies and the geometry of hexagons. The end points and intervals of CMT may be incorporated, respectively, as anchor points and radii for the hexagonal tessellations of central place theory.

Modeling of the Tension and Compression Behavior of Sintered 316L Using Micro Computed Tomography

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Doroszko Michał

2015-06-01

Full Text Available This paper describes the method of numerical modeling of the tension and compression behavior of sintered 316L. In order to take into account the shape of the mesostructures of materials in the numerical modeling, X-ray microtomography was used. Based on the micro-CT images, three-dimensional geometrical models mapped shapes of the porosity were generated. To the numerical calculations was used finite element method. Based on the received stress and strain fields was described the mechanism of deformation of the materials until fracture. The influence of material discontinuities at the mesoscopic scale on macromechanical properties of the porous materials was investigated.

Dual energy x-ray microtomography for development and inspection of advanced aerospace materials

International Nuclear Information System (INIS)

Alvarez, R.E.; Cao, Q.

1990-01-01

A key step in development of advanced composite materials is to characterize their internal structure and composition in a quantitative manner. In this paper, the authors describe a technique and an instrument that allows the measurements of the interior volume of the material. It has several key advantages over conventional computed tomography. The technique quantitatively measures the mass density and effective atomic number throughout the volume. Further, these measurements are made with microscopic (20 micrometer or better) spatial resolution. The technique is based on ARACOR's Tomoscope computed tomography instrument and on dual energy computed tomography. The authors describe the theory of the technique and show experimental measurements of metal matrix composite materials

Three-dimensional structure of brain tissue at submicrometer resolution

Energy Technology Data Exchange (ETDEWEB)

Saiga, Rino; Mizutani, Ryuta, E-mail: ryuta@tokai-u.jp [Department of Applied Biochemistry, Tokai University, Hiratsuka, Kanagawa 259-1292 (Japan); Inomoto, Chie; Takekoshi, Susumu; Nakamura, Naoya; Tsuboi, Akio; Osawa, Motoki [Tokai University School of Medicine, Isehara, Kanagawa 259-1193 (Japan); Arai, Makoto; Oshima, Kenichi; Itokawa, Masanari [Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8506 (Japan); Uesugi, Kentaro; Takeuchi, Akihisa; Terada, Yasuko; Suzuki, Yoshio [Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Sayo, Hyogo 679-5198 (Japan)

2016-01-28

Biological objects are composed of submicrometer structures such as cells and organelles that are essential for their functions. Here, we report on three-dimensional X-ray visualization of cells and organelles at resolutions up to 100 nm by imaging microtomography (micro-CT) equipped with Fresnel zone plate optics. Human cerebral tissue, fruit fly cephalic ganglia, and Escherichia coli bacteria labeled with high atomic-number elements were embedded in epoxy resin and subjected to X-ray microtomography at the BL37XU and BL47XU beamlines of the SPring-8 synchrotron radiation facility. The obtained results indicated that soft tissue structures can be visualized with the imaging microtomography.

Numerical Simulation of Permeability Change in Wellbore Cement Fractures after Geomechanical Stress and Geochemical Reactions Using X-ray Computed Tomography Imaging.

Science.gov (United States)

Kabilan, Senthil; Jung, Hun Bok; Kuprat, Andrew P; Beck, Anthon N; Varga, Tamas; Fernandez, Carlos A; Um, Wooyong

2016-06-21

X-ray microtomography (XMT) imaging combined with three-dimensional (3D) computational fluid dynamics (CFD) modeling technique was used to study the effect of geochemical and geomechanical processes on fracture permeability in composite Portland cement-basalt caprock core samples. The effect of fluid density and viscosity and two different pressure gradient conditions on fracture permeability was numerically studied by using fluids with varying density and viscosity and simulating two different pressure gradient conditions. After the application of geomechanical stress but before CO2-reaction, CFD revealed fluid flow increase, which resulted in increased fracture permeability. After CO2-reaction, XMT images displayed preferential precipitation of calcium carbonate within the fractures in the cement matrix and less precipitation in fractures located at the cement-basalt interface. CFD estimated changes in flow profile and differences in absolute values of flow velocity due to different pressure gradients. CFD was able to highlight the profound effect of fluid viscosity on velocity profile and fracture permeability. This study demonstrates the applicability of XMT imaging and CFD as powerful tools for characterizing the hydraulic properties of fractures in a number of applications like geologic carbon sequestration and storage, hydraulic fracturing for shale gas production, and enhanced geothermal systems.

Comparative Study Showing The Application Of Three Dimensional Oct And Ffa Correlation After Combined Bevacizumab/Laser And Triamcinolone/Laser In The Management Of Diabetic Macular Edema

International Nuclear Information System (INIS)

Helal, N.; Afahmoud, A.F.; Eliwa, T.F.; Omar, O.A.A.

2012-01-01

Purpose: to compare combined therapy by intravitreal triamicinolone acetonide and laser versus intravitreal bevacizumab and laser by three dimensional OCT in the management of diabetic macular edema regarding, the efficacy, duration of action, side effects, and complications of both regimens. Patients and methods: 40 eyes of 32 patients with type II diabetes mellitus, with clinically significant macular edema were enrolled into the study. They were divided equally into two groups, the first group was treated with intravitreal triamicinolone acetonide (4 mg/0.1 ml) followed 6 weeks later by focal Laser and the other group was treated by intravitreal bevacizumab (1.25 mg) followed 4 weeks later by focal Laser. Complete ophthalmological examination including BCVA, OCT and FFA were done preoperative and postoperative at 1, 3, 6, and 9 months. Results: the IVTA/Laser group showed an earlier improvement of BCVA by one line at the 3 month visit (p value 0.025 <0.05), compared to the IVA/Laser group that showed this change to be statistically significant at the 6 month visit (p value 0.048) with a one line improvement in BCVA. Regarding CMT and decrease of CMT than IVA/Laser although in both groups the improvement was transient, and relapses in both parameters occurred. There was a high incidence of cataract and steroid induced glaucoma in susceptible subjects in the IVTA/laser group than the IVA/Laser group. IVA/Laser may have a detrimental effect on FAZ integrity, and progression of the stage of diabetic retinopathy. Regarding mean change in CMT the IVTA/Laser has a stronger effect in reducing CMT, which is statistically significant at three months (p value <0.05). On the other hand IVA/Laser group, statistically significant change in mean CMT was at 1 month. Mean change in CMT between the 2 groups was not statistically significant throughout the study, although IVTA/Laser had a more powerful effect on the metric reduction of CMT, this difference was transient in both

Sensibilidade e especificidade do "California Mastitis Test" como recurso diagnóstico da mastite subclínica em relação à contagem de células somáticas

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Brito José Renaldi Feitosa

1997-01-01

Full Text Available O "California Mastitis Test" (CMT estima o conteúdo de células somáticas no leite e é interpretado subjetivamente, estabelecendo-se escores que, na maioria dos casos, variam de 1 a 5. O escore 1 indica uma reação completamente negativa e os de 2-5 indicam graus crescentes de resposta inflamatória do úbere, sendo normalmente considerados como indicativos de mastite subclínica. Dependendo da interpretação dos escores, o CMT pode produzir resultados falso-positivos ou falso-negativos. Esse trabalho teve o objetivo de avaliar a sensibilidade e a especificidade do CMT em relação à contagem de células somáticas (CCS. Foram utilizadas 3.012 amostras de leite provenientes de 760 vacas Holandesas ou mestiças Holandês-Zebu, pertencentes a 15 rebanhos. Todas as amostras foram submetidas ao CMT e processadas para CCS em equipamento Fossomatic 90. Os valores médios de CCS (x 1.000 células/ml obtidos para os escores de CMT foram 1 (79,9, 2 (333,5, 3 (670,3, 4 (1.354,0 e 5 (4.455,6. Três opções de interpretação (doente/não-doente para o CMT foram testadas, em relação aos valores de CCS, iniciando com 100.000 células/ml: (a 1 versus 2, 3, 4, e 5; (b 1 e 2 versus 3, 4 e 5; (c 1, 2, 3 versus 4 e 5. As sensibilidades do CMT em identificar corretamente quartos mamários acima de 200.000 células/ml foram 79%, 61% e 34%, para as opções a, b e c, respectivamente. Para identificar corretamente contagens acima de 500.000 células/ml, as sensibilidades do CMT, para as opções a, b e c, foram, respectivamente: 93%, 82% e 54%. A sensibilidade do CMT em identificar quartos mamários com mastite subclínica foi adequada (acima de 80% quando a interpretação do teste foi mais rigorosa (opções a e b. A interpretação da reação 3 como negativa (opção c só alcançou sensibilidade de 80% para contagens entre 1.200.000 e 1.400.000 células/ml. As especificidades do CMT, para CCS de 200.000 e 500.000 foram, respectivamente, 90% e 80% (op

Effects of high-intensity interval versus continuous moderate-intensity aerobic exercise on apoptosis, oxidative stress and metabolism of the infarcted myocardium in a rat model.

Science.gov (United States)

Lu, Kai; Wang, Li; Wang, Changying; Yang, Yuan; Hu, Dayi; Ding, Rongjing

2015-08-01

The optimal aerobic exercise training (AET) protocol for patients following myocardial infarction (MI) has remained under debate. The present study therefore aimed to compare the effects of continuous moderate-intensity training (CMT) and high-intensity interval training (HIT) on cardiac functional recovery, and to investigate the potential associated mechanisms in a post-MI rat model. Female Sprague Dawley rats (8-10 weeks old) undergoing MI or sham surgery were subsequently submitted to CMT or HIT, or kept sedentary for eight weeks. Prior to and following AET, echocardiographic parameters and exercise capacity of the rats were measured. Western blotting was used to evaluate the levels of apoptosis and associated signaling pathway protein expression. The concentrations of biomarkers of oxidative stress were also determined by ELISA assay. Messenger (m)RNA levels and activity of the key enzymes for glycolysis and fatty acid oxidation, as well as the rate of adenosine triphosphate (ATP) synthesis, were also measured. Compared with the MI group, exercise capacity and cardiac function were significantly improved following AET, particularly following HIT. Left ventricular ejection fraction and fraction shortening were further improved in the MI-HIT group in comparison to that of the MI-CMT group. The two forms of AET almost equally attenuated apoptosis of the post-infarction myocardium. CMT and HIT also alleviated oxidative stress by decreasing the concentration of malondialdehyde and increasing the concentration of superoxide dismutase and glutathione peroxidase (GPx). In particular, HIT induced a greater increase in the concentration of GPx than that of CMT. AET, and HIT in particular, significantly increased the levels of mRNA and the maximal activity of phosphofructokinase-1 and carnitine palmitoyl transferase-1, as well as the maximal ratio of ATP synthesis. In addition, compared with the MI group, the expression of signaling proteins PI3K, Akt, p38mapk and AMPK

Visualization and quantification of capillary drainage in the pore space of laminated sandstone by a porous plate method using differential imaging X-ray microtomography

Science.gov (United States)

Lin, Qingyang; Bijeljic, Branko; Rieke, Holger; Blunt, Martin J.

2017-08-01

The experimental determination of capillary pressure drainage curves at the pore scale is of vital importance for the mapping of reservoir fluid distribution. To fully characterize capillary drainage in a complex pore space, we design a differential imaging-based porous plate (DIPP) method using X-ray microtomography. For an exemplar mm-scale laminated sandstone microcore with a porous plate, we quantify the displacement from resolvable macropores and subresolution micropores. Nitrogen (N2) was injected as the nonwetting phase at a constant pressure while the porous plate prevented its escape. The measured porosity and capillary pressure at the imaged saturations agree well with helium measurements and experiments on larger core samples, while providing a pore-scale explanation of the fluid distribution. We observed that the majority of the brine was displaced by N2 in macropores at low capillary pressures, followed by a further brine displacement in micropores when capillary pressure increases. Furthermore, we were able to discern that brine predominantly remained within the subresolution micropores, such as regions of fine lamination. The capillary pressure curve for pressures ranging from 0 to 1151 kPa is provided from the image analysis compares well with the conventional porous plate method for a cm-scale core but was conducted over a period of 10 days rather than up to few months with the conventional porous plate method. Overall, we demonstrate the capability of our method to provide quantitative information on two-phase saturation in heterogeneous core samples for a wide range of capillary pressures even at scales smaller than the micro-CT resolution.

N-myc downstream-regulated gene 1 is mutated in hereditary motor and sensory neuropathy-Lom

NARCIS (Netherlands)

Kalaydjieva, L.; Gresham, D.; Gooding, R.; Heather, L.; Baas, F.; de Jonge, R.; Blechschmidt, K.; Angelicheva, D.; Chandler, D.; Worsley, P.; Rosenthal, A.; King, R. H.; Thomas, P. K.

2000-01-01

Hereditary motor and sensory neuropathies, to which Charcot-Marie-Tooth (CMT) disease belongs, are a common cause of disability in adulthood. Growing awareness that axonal loss, rather than demyelination per se, is responsible for the neurological deficit in demyelinating CMT disease has focused

Survey of core medical trainees in the United Kingdom 2013 - inconsistencies in training experience and competing with service demands.

Science.gov (United States)

Tasker, Fiona; Newbery, Nina; Burr, Bill; Goddard, Andrew F

2014-04-01

There is currently considerable concern about the attractiveness of hospital medicine as a career and experiences in core medical training (CMT) are a key determinant of whether trainees continue in the medical specialties. Little is understood about the quality and impact of the current CMT programme and this survey was designed to assess this. Three key themes emerged. Firstly, the demands of providing service have led to considerable loss of training opportunities, particularly in outpatients and formal teaching sessions. Trainees spend a lot of this service time doing menial tasks and over 90% report that service takes up 80-100% of their time. Secondly, clinical and educational supervision is variable, with trainees sometimes getting little consultant feedback on their clinical performance. Finally, 44% of trainees report that CMT has not prepared them to be a medical registrar and many trainees are put off acute medical specialties by their experiences in CMT.

Letter and Colour Matching Tasks: Parametric Measures of Developmental Working Memory Capacity

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Tamara L. Powell

2014-01-01

Full Text Available We investigated the mediating role of interference in developmental assessments of working memory (WM capacity across childhood, adolescence, and young adulthood. One hundred and forty-two participants completed two versions of visuospatial (colour matching task, CMT and verbal (letter matching task, LMT WM tasks, which systematically varied cognitive load in a high and low interference condition. Results showed similar developmental trajectories across high interference contexts (CMT- and LMT-Complex and divergent developmental growth patterns across low interference contexts (CMT- and LMT-Simple. Performance on tasks requiring greater cognitive control was in closer agreement with developmental predictions relative to simple recall guided tasks that rely solely on the storage components of WM. These findings suggest that developmental WM capacity, as measured by the CMT and LMT paradigms, can be better quantified using high interference contexts, in both content domains, and demonstrate steady increases in WM through to mid-adolescence.

Charcot-Marie-Tooth disease in Denmark

DEFF Research Database (Denmark)

Vaeth, Signe; Vaeth, Michael; Andersen, Henning

2017-01-01

OBJECTIVES: Charcot-Marie-Tooth disease (CMT) is the most common inherited disorder of the peripheral nervous system, yet no studies have compared the mortality in patients with CMT with that of the general population, and prevalence estimates vary considerably. We performed a nationwide register....... The prevalence was estimated by 31 December 2012, and the incidence rate was calculated based on data from 1988 to 2012. We calculated a standardised mortality ratio (SMR) and an absolute excess mortality rate (AER) stratified according to age categories and disease duration. RESULTS: A total of 1534 patients...... a significantly higher SMR in cases below 50 years of age, and in cases with disease duration of more than 10 years. CONCLUSIONS: We found a reduced life expectancy among patients diagnosed with CMT. To our knowledge, this is the first study of CMT to use nationwide register-based data, and the first to report...

Anatomical variations in the origins of the celiac axis and the superior mesenteric artery: MDCT angiographic findings and their probable embryological mechanisms.

Science.gov (United States)

Wang, Yi; Cheng, Cheng; Wang, Lu; Li, Ran; Chen, Jin-hua; Gong, Shui-gen

2014-08-01

To identify the spectrum and prevalence of anatomical variations in the origin of the celiac axis (CA), the superior mesenteric artery (SMA) and their major branches by using multidetector computed tomographic (MDCT) angiography. A retrospective evaluation was carried out on 1,500 abdominal MDCT angiography images. The aortic origins of the CA, the SMA and their major branch patterns were investigated. Normal aortic origins of CA and SMA were noted in 1,347 (89.8%) patients. Seven types of CA and SMA origin variants were identified in 153 (10.2%) patients. The three most common variations were hepatomesenteric trunk (67 patients, 4.47%), celiomesenteric trunk (CMT) (51 patients, 3.4%) and splenomesenteric trunk (18 patients, 1.2%). An evaluation of CMT was classified as long (34 patients, 66.7%) or short (17 patients, 33.3%) subtypes, compared with the length of the common trunk. Further CMT classification was based on the origin of the left gastric artery: subtype I, 26 patients (53.1%); subtype II, 5 patients (10.2%); subtype III, 15 patients (30.6%); subtype IV, 3 patients (6.1%). Dislocation interruption, incomplete interruption and persistence of the longitudinal anastomosis could be the embryological mechanisms of the variant origins of the CA, the SMA and their major branches. • Aortic origins of CA, SMA and their major branches were investigated. • Celiomesenteric trunk includes several different subtypes and configurations. • Probable embryological mechanisms of origin variants in these observed arteries were discussed. • Origin variants in these observed arteries have wide-ranging health implications.

Mild functional differences of dynamin 2 mutations associated to centronuclear myopathy and Charcot-Marie Tooth peripheral neuropathy.

Directory of Open Access Journals (Sweden)

Olga S Koutsopoulos

Full Text Available The large GTPase dynamin 2 is a key player in membrane and cytoskeletal dynamics mutated in centronuclear myopathy (CNM and Charcot-Marie Tooth (CMT neuropathy, two discrete dominant neuromuscular disorders affecting skeletal muscle and peripheral nerves respectively. The molecular basis for the tissue-specific phenotypes observed and the physiopathological mechanisms linked to dynamin 2 mutations are not well established. In this study, we have analyzed the impact of CNM and CMT implicated dynamin 2 mutants using ectopic expression of four CNM and two CMT mutations, and patient fibroblasts harboring two dynamin 2 CNM mutations in established cellular processes of dynamin 2 action. Wild type and CMT mutants were seen in association with microtubules whereas CNM mutants lacked microtubules association and did not disrupt interphase microtubules dynamics. Most dynamin 2 mutants partially decreased clathrin-mediated endocytosis when ectopically expressed in cultured cells; however, experiments in patient fibroblasts suggested that endocytosis is overall not defective. Furthermore, CNM mutants were seen in association with enlarged clathrin stained structures whereas the CMT mutant constructs were associated with clathrin structures that appeared clustered, similar to the structures observed in Dnm1 and Dnm2 double knock-out cells. Other roles of dynamin 2 including its interaction with BIN1 (amphiphysin 2, and its function in Golgi maintenance and centrosome cohesion were not significantly altered. Taken together, these mild functional defects are suggestive of differences between CMT and CNM disease-causing dynamin 2 mutants and suggest that a slight impairment in clathrin-mediated pathways may accumulate over time to foster the respective human diseases.

Effects of coordination and manipulation therapy for patients with Parkinson disease.

Science.gov (United States)

Zhao, Mingming; Hu, Caiyou; Wu, Zhixin; Chen, Yu; Li, Zhengming; Zhang, Mingsheng

2017-09-01

To determine the effects of a new exercise training regimen, i.e. coordination and manipulation therapy (CMT), on motor, balance, and cardiac functions in patients with Parkinson disease (PD). We divided 36 PD patients into the CMT (n = 22) and control (n = 14) groups. The patients in the CMT group performed dry-land swimming (imitation of the breaststroke) and paraspinal muscle stretching for 30 min/workday for 1 year. The control subjects did not exercise regularly. The same medication regimen was maintained in both groups during the study. Clinical characteristics, Unified Parkinson's Disease Rating Scale (UPDRS) scores, Berg balance scale (BBS) scores, mechanical balance measurements, timed up and go (TUG) test, and left ventricular ejection fraction (LVEF) were compared at 0 (baseline), 6, and 12 months. Biochemical test results were compared at 0 and 12 months. The primary outcome was motor ability. The secondary outcome was cardiac function. In the CMT group, UPDRS scores significantly improved, TUG test time and step number significantly decreased, BBS scores significantly increased, and most mechanical balance measurements significantly improved after 1 year of regular exercise therapy (all p < 0.05). In the control group, UPDRS scores significantly deteriorated, TUG test time and step number significantly increased, BBS scores significantly decreased, and most mechanical balance measurements significantly worsened after 1 year (all P < 0.05). LVEF improved in the CMT group only (P = 0.01). This preliminary study suggests that CMT effectively improved mobility disorder, balance, and cardiac function in PD patients over a 1-year period.

Big Data and High-Performance Computing in Global Seismology

Science.gov (United States)

Bozdag, Ebru; Lefebvre, Matthieu; Lei, Wenjie; Peter, Daniel; Smith, James; Komatitsch, Dimitri; Tromp, Jeroen

2014-05-01

Much of our knowledge of Earth's interior is based on seismic observations and measurements. Adjoint methods provide an efficient way of incorporating 3D full wave propagation in iterative seismic inversions to enhance tomographic images and thus our understanding of processes taking place inside the Earth. Our aim is to take adjoint tomography, which has been successfully applied to regional and continental scale problems, further to image the entire planet. This is one of the extreme imaging challenges in seismology, mainly due to the intense computational requirements and vast amount of high-quality seismic data that can potentially be assimilated. We have started low-resolution inversions (T > 30 s and T > 60 s for body and surface waves, respectively) with a limited data set (253 carefully selected earthquakes and seismic data from permanent and temporary networks) on Oak Ridge National Laboratory's Cray XK7 "Titan" system. Recent improvements in our 3D global wave propagation solvers, such as a GPU version of the SPECFEM3D_GLOBE package, will enable us perform higher-resolution (T > 9 s) and longer duration (~180 m) simulations to take the advantage of high-frequency body waves and major-arc surface waves, thereby improving imbalanced ray coverage as a result of the uneven global distribution of sources and receivers. Our ultimate goal is to use all earthquakes in the global CMT catalogue within the magnitude range of our interest and data from all available seismic networks. To take the full advantage of computational resources, we need a solid framework to manage big data sets during numerical simulations, pre-processing (i.e., data requests and quality checks, processing data, window selection, etc.) and post-processing (i.e., pre-conditioning and smoothing kernels, etc.). We address the bottlenecks in our global seismic workflow, which are mainly coming from heavy I/O traffic during simulations and the pre- and post-processing stages, by defining new data

Surgical management of idiopathic torticollis secondary to a fibrotic band

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Christopher David Jones

2012-09-01

Full Text Available Congenital muscular torticollis (CMT is the third commonest congenital deformity, commonly presenting in the first week of life. Due to contracture and shortening of the sternocleidomastoid muscle, the head is tilted towards the affected side; however there may also be a varying degree of rotation towards the contralateral side. Most infants with CMT can be managed non-surgically, however if this is unsuccessful surgery may be necessary, with many different techniques described. In this case report, we describe a 17-year old woman with persistent left sided CMT despite botulinum toxin paralysis that was successfully treated with surgery.

Condensation during gravity driven ECC: Experiments with PACTEL

Energy Technology Data Exchange (ETDEWEB)

Munther, R.; Kalli, H. [Lappeenranta Univ. of Technology (Finland); Kouhia, J. [Technical Research Centre of Finland, Lappeenranta (Finland)

1995-09-01

This paper provides the results of the second series of gravity driven emergency core cooling (ECC) experiments with PACTEL (Parallel Channel Test Loop). The simulated accident was a small break loss-of-coolant accident (SBLOCA) with a break in a cold leg. The ECC flow was provided from a core makeup tank (CMT) located at a higher elevation than the main part of the primary system. The CMT was pressurized with pipings from the pressurizer and a cold leg. The tests indicated that steam condensation in the CMT can prevent ECC and lead to core uncovery.

Dynamics of multiple nuclei in Ashbya gossypii hyphae depend on the control of cytoplasmic microtubules length by Bik1, Kip2, Kip3, and not on a capture/shrinkage mechanism.

Science.gov (United States)

Grava, Sandrine; Philippsen, Peter

2010-11-01

Ashbya gossypii has a budding yeast-like genome but grows exclusively as multinucleated hyphae. In contrast to budding yeast where positioning of nuclei at the bud neck is a major function of cytoplasmic microtubules (cMTs), A. gossypii nuclei are constantly in motion and positioning is not an issue. To investigate the role of cMTs in nuclear oscillation and bypassing, we constructed mutants potentially affecting cMT lengths. Hyphae lacking the plus (+)end marker Bik1 or the kinesin Kip2 cannot polymerize long cMTs and lose wild-type nuclear movements. Interestingly, hyphae lacking the kinesin Kip3 display longer cMTs concomitant with increased nuclear oscillation and bypassing. Polymerization and depolymerization rates of cMTs are 3 times higher in A. gossypii than in budding yeast and cMT catastrophes are rare. Growing cMTs slide along the hyphal cortex and exert pulling forces on nuclei. Surprisingly, a capture/shrinkage mechanism seems to be absent in A. gossypii. cMTs reaching a hyphal tip do not shrink, and cMT +ends accumulate in hyphal tips. Thus, differences in cMT dynamics and length control between budding yeast and A. gossypii are key elements in the adaptation of the cMT cytoskeleton to much longer cells and much higher degrees of nuclear mobilities.

Loss of the E3 ubiquitin ligase LRSAM1 sensitizes peripheral axons to degeneration in a mouse model of Charcot-Marie-Tooth disease

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Laurent P. Bogdanik

2013-05-01

Charcot-Marie-Tooth disease (CMT is a clinically and genetically heterogeneous condition characterized by peripheral axon degeneration with subsequent motor and sensory deficits. Several CMT gene products function in endosomal sorting and trafficking to the lysosome, suggesting that defects in this cellular pathway might present a common pathogenic mechanism for these conditions. LRSAM1 is an E3 ubiquitin ligase that is implicated in this process, and mutations in LRSAM1 have recently been shown to cause CMT. We have generated mouse mutations in Lrsam1 to create an animal model of this form of CMT (CMT2P. Mouse Lrsam1 is abundantly expressed in the motor and sensory neurons of the peripheral nervous system. Both homozygous and heterozygous mice have largely normal neuromuscular performance and only a very mild neuropathy phenotype with age. However, Lrsam1 mutant mice are more sensitive to challenge with acrylamide, a neurotoxic agent that causes axon degeneration, indicating that the axons in the mutant mice are indeed compromised. In transfected cells, LRSAM1 primarily localizes in a perinuclear compartment immediately beyond the Golgi and shows little colocalization with components of the endosome to lysosome trafficking pathway, suggesting that other cellular mechanisms also merit consideration.

Loss of the E3 ubiquitin ligase LRSAM1 sensitizes peripheral axons to degeneration in a mouse model of Charcot-Marie-Tooth disease.

Science.gov (United States)

Bogdanik, Laurent P; Sleigh, James N; Tian, Cong; Samuels, Mark E; Bedard, Karen; Seburn, Kevin L; Burgess, Robert W

2013-05-01

Charcot-Marie-Tooth disease (CMT) is a clinically and genetically heterogeneous condition characterized by peripheral axon degeneration with subsequent motor and sensory deficits. Several CMT gene products function in endosomal sorting and trafficking to the lysosome, suggesting that defects in this cellular pathway might present a common pathogenic mechanism for these conditions. LRSAM1 is an E3 ubiquitin ligase that is implicated in this process, and mutations in LRSAM1 have recently been shown to cause CMT. We have generated mouse mutations in Lrsam1 to create an animal model of this form of CMT (CMT2P). Mouse Lrsam1 is abundantly expressed in the motor and sensory neurons of the peripheral nervous system. Both homozygous and heterozygous mice have largely normal neuromuscular performance and only a very mild neuropathy phenotype with age. However, Lrsam1 mutant mice are more sensitive to challenge with acrylamide, a neurotoxic agent that causes axon degeneration, indicating that the axons in the mutant mice are indeed compromised. In transfected cells, LRSAM1 primarily localizes in a perinuclear compartment immediately beyond the Golgi and shows little colocalization with components of the endosome to lysosome trafficking pathway, suggesting that other cellular mechanisms also merit consideration.

Silver Nanoparticle Transport Through Soil: Illuminating the Pore-Scale Processes

Science.gov (United States)

Molnar, I. L.; Willson, C. S.; Gerhard, J.; O'Carroll, D. M.

2015-12-01

For nanoparticle transport through soil, the pore-scale (i.e., tens to hundreds of grains and pores) is a crucial intermediate scale which links nanoparticle-surface interactions with field-scale transport behaviour. However, very little information exists on how nanoparticles behave within real three-dimensional pore spaces. As a result, pore-scale processes are poorly characterized for nanoparticle systems and, subsequently, continuum-scale transport models struggle to describe commonly observed 'anomalous' behaviour such as extended tailing. This knowledge gap is due to two primary factors: an inability to experimentally observe nanoparticles within real pore spaces, and the computationally expensive models required to simulate nanoparticle movement. However, due to recent advances in Synchrotron X-Ray Computed Microtomography (SXCMT), it is now possible to quantify in-situ pore-scale nanoparticle concentrations during transport through real 3-dimensional porous media [1]. Employing this SXCMT quantification method to examine real nanoparticle/soil transport experiments has yielded new insights into the pore-scale processes governing nanoparticle transport. By coupling SXCMT nanoparticle quantification method with Computational Fluid Dynamics (CFD) simulations we are able to construct a better picture of how nanoparticles flow through real pore spaces. This talk presents SXCMT/CFD analyses of three silver nanoparticle transport experiments. Silver nanoparticles were flushed through three different sands to characterize the influence of grain distribution and retention rates on pore-scale flow and transport processes. These CFD/SXCMT analyses illuminate how processes such as temporary hydraulic retention govern nanoparticle transport. In addition, the observed distributions of pore water velocities and nanoparticle mass flow rates challenge the standard conceptual model of nanoparticle transport, suggesting that pore-scale processes require explicit consideration

Improving core medical training--innovative and feasible ideas to better training.

Science.gov (United States)

Tasker, Fiona; Dacombe, Peter; Goddard, Andrew F; Burr, Bill

2014-12-01

A recent survey of UK core medical training (CMT) training conducted jointly by the Royal College of Physicians (RCP) and Joint Royal College of Physicians Training Board (JRCPTB) identified that trainees perceived major problems with their training. Service work dominated and compromised training opportunities, and of great concern, almost half the respondents felt that they had not been adequately prepared to take on the role of medical registrar. Importantly, the survey not only gathered CMT trainees' views of their current training, it also asked them for their 'innovative and feasible ways to improve CMT'. This article draws together some of these excellent ideas on how the quality of training and the experience of trainees could be improved. It presents a vision for how CMT trainees, consultant supervisors, training programme directors, clinical directors and managers can work together to implement relevant, feasible and affordable ways to improve training for doctors and deliver the best possible care for patients. © 2014 Royal College of Physicians.

Diagnosis of Charcot-Marie-Tooth Disease

Directory of Open Access Journals (Sweden)

Isabel Banchs

2009-01-01

Full Text Available Charcot-Marie-Tooth (CMT disease or hereditary motor and sensory neuropathy (HMSN is a genetically heterogeneous group of conditions that affect the peripheral nervous system. The disease is characterized by degeneration or abnormal development of peripheral nerves and exhibits a range of patterns of genetic transmission. In the majority of cases, CMT first appears in infancy, and its manifestations include clumsiness of gait, predominantly distal muscular atrophy of the limbs, and deformity of the feet in the form of foot drop. It can be classified according to the pattern of transmission (autosomal dominant, autosomal recessive, or X linked, according to electrophysiological findings (demyelinating or axonal, or according to the causative mutant gene. The classification of CMT is complex and undergoes constant revision as new genes and mutations are discovered. In this paper, we review the most efficient diagnostic algorithms for the molecular diagnosis of CMT, which are based on clinical and electrophysiological data.

Use of domestic detergents in the California mastitis test for high somatic cell counts in milk.

Science.gov (United States)

Leach, K A; Green, M J; Breen, J E; Huxley, J N; Macaulay, R; Newton, H T; Bradley, A J

2008-11-08

The California mastitis test (CMT) is used on farms to identify subclinical mastitis by an indirect estimation of the somatic cell count (SCC) in milk. Four commercially available detergents were compared with a bespoke cmt fluid for their ability to detect milk samples with a scc above 200,000 cells/ml; differences between the interpretation of the results of the tests by eight operators were also investigated. The sensitivity and specificity of the test were affected by the type of detergent, and by the operators' interpretations. When used by the most sensitive operator, suitably diluted Fairy Liquid performed almost identically to cmt fluid in identifying milk samples with more than 200,000 cells/ml. The average sensitivities achieved by the eight operators for detecting this threshold were 82 per cent for Fairy Liquid and 84 per cent for cmt fluid, and the specificities were 93 and 91 per cent respectively. The other detergents contained less anionic surfactants and were less sensitive but similarly specific.

Gclust Server: 139399 [Gclust Server

Lifescience Database Archive (English)

Full Text Available 139399 CME_CMT585C Cluster Sequences - 186 putative protein 1 1.00e-99 14.29 0.0 0.0 0.0 0.0 0.0 Show 13939...9 Cluster ID 139399 Sequence ID CME_CMT585C Link to cluster sequences Cluster Sequen

PMP22 related neuropathies: Charcot-Marie-Tooth disease type 1A and Hereditary Neuropathy with liability to Pressure Palsies

NARCIS (Netherlands)

van Paassen, Barbara W.; van der Kooi, Anneke J.; van Spaendonck-Zwarts, Karin Y.; Verhamme, Camiel; Baas, Frank; de Visser, Marianne

2014-01-01

PMP22 related neuropathies comprise (1) PMP22 duplications leading to Charcot-Marie-Tooth disease type 1A (CMT1A), (2) PMP22 deletions, leading to Hereditary Neuropathy with liability to Pressure Palsies (HNPP), and (3) PMP22 point mutations, causing both phenotypes. Overall prevalence of CMT is

Implementation of a Quality Improvement Initiative: Improved Congenital Muscular Torticollis Outcomes in a Large Hospital Setting.

Science.gov (United States)

Strenk, Mariann L; Kiger, Michelle; Hawke, Jesse L; Mischnick, Amy; Quatman-Yates, Catherine

2017-06-01

The American Physical Therapy Association (APTA) published a guideline for congenital muscular torticollis (CMT) in 2013. Our division adopted the guideline as the institutional practice standard and engaged in a quality improvement (QI) initiative to increase the percentage of patients who achieved resolution of CMT within 6 months of evaluation. The aims of this report are to describe the QI activities conducted to improve patient outcomes and discuss the results and implications for other institutions and patient populations. This was a quality improvement study. In alignment with the Chronic Care Model and Model of Improvement, an aim and operationally defined key outcome and process measures were established. Interventions were tested using Plan-Do-Study-Act cycles. A CMT registry was established to store and manage data extracted from the electronic record over the course of testing. Statistical process control charts were used to monitor progress over time. The QI initiative resulted in an increase in the percentage of patients who achieved full resolution of CMT within a 6-month episode of care from 42% to 61% over an 18-month period. Themes that emerged as key drivers of improvement included: (1) timely, optimal access to care, (2) effective audit and clinician feedback, and (3) accurate, timely documentation. The initiative took place at a single institution with a supportive culture and strong QI resources, which may limit direct translation of interventions and findings to other institutions and patient populations. Improvement science methodologies provided the tools and structure to improve division-wide workflow and increase consistency in the implementation of the APTA CMT guideline. In doing so, significant CMT population outcome improvements were achieved. © 2017 American Physical Therapy Association

A method for three-dimensional analysis of the root canal system, before and after mechanical instrumentation, using X-ray Micro-computed tomography

DEFF Research Database (Denmark)

Markvart, Merete; Bjørndal, Lars; Larsen, Per

. Extracted molar teeth were embedded in resin and kept moisturized. Each root canal was instrumented with NiTi instruments to #40. The teeth were scanned before and after instrumentation, using a microCT40 micro-tomography (SCANCO Medical AG, Bassersdorf, Switzerland). The reconstructed slices were imported......Clinical studies have shown a connection between the reduction of micro-organisms in the root canal and the degree of apical enlargement. The aim of this study was to create a non-invasive 3D model for monitoring the apical enlargement in molar teeth before and after mechanical instrumentation...

CMT for biomedical and other applications

Energy Technology Data Exchange (ETDEWEB)

Spanne, P. [ESRF, Grenoble (France)

1997-02-01

This session includes two presentations describing applications for x-ray tomography using synchrotron radiation for biomedical uses and fluid flow modeling, and outlines advantages for using monoenergetic x-rays. Contrast mechanisms are briefly described and several graphs of absorbed doses and scattering of x-rays are included. Also presented are schematic diagrams of computerized tomographic instrumentation with camera head. A brief description of goals for a real time tomographic system and expected improvements to the system are described. Color photomicrographs of the Berea Sandstone and human bone are provided, as well as a 3-D microtomographic reconstruction of a human vertebra sample.

Evaluation of Cow Milk Electrical Conductivity Measurements

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Constantin Gavan

2017-11-01

Full Text Available The efficiency of subclinical mastitis diagnosis using an electrical conductivity (EC meter was evaluated in the dairy farm of Agricultural Research and Development Station ( ARDS Simnic Craiova. The results were compared with those obtained by using the California Mastitis Test (CMT and the Somatic Cell Count (SCC.The milk quarter samples ( 1176 from Holstein Friesian cows were analyzed between September and December 2015. The EC evaluation with  the EC meter  ,showed a high proportion of results differing from SCC and CMT results. The CMT still shows to be the most accessible and efficient test in comparison to the EC meter tested.

Charcot-Marie-Tooth disease: frequency of genetic subtypes and guidelines for genetic testing.

LENUS (Irish Health Repository)

Murphy, Sinead M

2012-07-01

Charcot-Marie-Tooth disease (CMT) is a clinically and genetically heterogeneous group of diseases with approximately 45 different causative genes described. The aims of this study were to determine the frequency of different genes in a large cohort of patients with CMT and devise guidelines for genetic testing in practice.

Recent advances in quantitative analysis of fluid interfaces in multiphase fluid flow measured by synchrotron-based x-ray microtomography

Science.gov (United States)

Schlueter, S.; Sheppard, A.; Wildenschild, D.

2013-12-01

Imaging of fluid interfaces in three-dimensional porous media via x-ray microtomography is an efficient means to test thermodynamically derived predictions on the relationship between capillary pressure, fluid saturation and specific interfacial area (Pc-Sw-Anw) in partially saturated porous media. Various experimental studies exist to date that validate the uniqueness of the Pc-Sw-Anw relationship under static conditions and with current technological progress direct imaging of moving interfaces under dynamic conditions is also becoming available. Image acquisition and subsequent image processing currently involves many steps each prone to operator bias, like merging different scans of the same sample obtained at different beam energies into a single image or the generation of isosurfaces from the segmented multiphase image on which the interface properties are usually calculated. We demonstrate that with recent advancements in (i) image enhancement methods, (ii) multiphase segmentation methods and (iii) methods of structural analysis we can considerably decrease the time and cost of image acquisition and the uncertainty associated with the measurement of interfacial properties. In particular, we highlight three notorious problems in multiphase image processing and provide efficient solutions for each: (i) Due to noise, partial volume effects, and imbalanced volume fractions, automated histogram-based threshold detection methods frequently fail. However, these impairments can be mitigated with modern denoising methods, special treatment of gray value edges and adaptive histogram equilization, such that most of the standard methods for threshold detection (Otsu, fuzzy c-means, minimum error, maximum entropy) coincide at the same set of values. (ii) Partial volume effects due to blur may produce apparent water films around solid surfaces that alter the specific fluid-fluid interfacial area (Anw) considerably. In a synthetic test image some local segmentation methods

Crystal structure of the extracellular domain of human myelin protein zero

Energy Technology Data Exchange (ETDEWEB)

Liu, Zhigang; Wang, Yong; Yedidi, Ravikiran S.; Brunzelle, Joseph S.; Kovari, Iulia A.; Sohi, Jasloveleen; Kamholz, John; Kovari, Ladislau C. (WSU-MED); (NWU)

2012-03-27

Charcot-Marie-Tooth disease (CMT), a hereditary motor and sensory neuropathy, is the most common genetic neuropathy with an incidence of 1 in 2600. Several forms of CMT have been identified arising from different genomic abnormalities such as CMT1 including CMT1A, CMT1B, and CMTX. CMT1 with associated peripheral nervous system (PNS) demyelination, the most frequent diagnosis, demonstrates slowed nerve conduction velocities and segmental demyelination upon nerve biopsy. One of its subtypes, CMT1A, presents a 1.5-Mb duplication in the p11-p12 region of the human chromosome 17 which encodes peripheral myelin protein 22 (PMP22). CMT1B, a less common form, arises from the mutations in the myelin protein zero (MPZ) gene on chromosome 1, region q22-q23, which encodes the major structural component of the peripheral myelin. A rare type of CMT1 has been found recently and is caused by point mutations in early growth response gene 2 (EGR2), encoding a zinc finger transcription factor in Schwann cells. In addition, CMTX, an X-linked form of CMT, arises from a mutation in the connexin-32 gene. Myelin protein zero, associated with CMT1B, is a transmembrane protein of 219 amino acid residues. Human MPZ consists of three domains: 125 residues constitute the glycosylated immunoglobulin-like extracellular domain; 27 residues span the membrane; and 67 residues comprise the highly basic intracellular domain. MPZ makes up approximately 50% of the protein content of myelin, and is expressed predominantly in Schwann cells, the myelinating cell of the PNS. Myelin protein zero, a homophilic adhesion molecule, is a member of the immunoglobulin super-family and is essential for normal myelin structure and function. In addition, MPZ knockout mice displayed abnormal myelin that severely affects the myelination pathway, and overexpression of MPZ causes congenital hypomyelination of peripheral nerves. Myelin protein zero mutations account for {approx}5% of patients with CMT. To date, over 125

Productivity analysis to overcome the limited availability of production time in SME FBS

Science.gov (United States)

Nurhasanah, N.; Jingga; Aribowo, B.; Gayatri, AM; Mardhika, DA; Tanjung, WN; Suri, QA; Safitri, R.; Supriyanto, A.

2017-12-01

Good industrial development should pay attention to the human factor as the main driver. Condition of work procedures, work area, and environment can affect the production result because if not optimal, the production will run slowly. If the work system is less than optimal, the productivity will do so, the operator will work uncomfortably and be easy to undergo work fatigue, even it can cause work accidents. Thus, the optimal and ergonomic arrangement of the the overall work system mechanism and work environment design is required for workers to work well, regularly, safely and comfortably with the aim of improving work productivity. This research measures the performance in textile SME (Small and Medium Enterprise) located in Sukabumi which is SME FBS which produces children’s clothing. This performance measurement is aimed at improving the competitiveness of the textile IKM so that it has the equal competitiveness with other SMEs or with textile industries that already have their name in market. Based on the method of hour standard time and TOC calculation at 2 FBS CMT (Cut-Make-Trim) in Sukabumi, which are the CMT Margaluyu Village and CMT Purabaya Village, the result is that the standard time of shirt work on CMT Margaluyu Village is less than that of CMT Desa Purabaya. It can be seen that more effective in SME FBS production is by process method.

HDAC6 Inhibitors Rescued the Defective Axonal Mitochondrial Movement in Motor Neurons Derived from the Induced Pluripotent Stem Cells of Peripheral Neuropathy Patients with HSPB1 Mutation

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Ji-Yon Kim

2016-01-01

Full Text Available The Charcot-Marie-Tooth disease 2F (CMT2F and distal hereditary motor neuropathy 2B (dHMN2B are caused by autosomal dominantly inherited mutations of the heat shock 27 kDa protein 1 (HSPB1 gene and there are no specific therapies available yet. Here, we assessed the potential therapeutic effect of HDAC6 inhibitors on peripheral neuropathy with HSPB1 mutation using in vitro model of motor neurons derived from induced pluripotent stem cells (iPSCs of CMT2F and dHMN2B patients. The absolute velocity of mitochondrial movements and the percentage of moving mitochondria in axons were lower both in CMT2F-motor neurons and in dHMN2B-motor neurons than those in controls, and the severity of the defective mitochondrial movement was different between the two disease models. CMT2F-motor neurons and dHMN2B-motor neurons also showed reduced α-tubulin acetylation compared with controls. The newly developed HDAC6 inhibitors, CHEMICAL X4 and CHEMICAL X9, increased acetylation of α-tubulin and reversed axonal movement defects of mitochondria in CMT2F-motor neurons and dHMN2B-motor neurons. Our results suggest that the neurons derived from patient-specific iPSCs can be used in drug screening including HDAC6 inhibitors targeting peripheral neuropathy.

Microbiological evaluation of milk samples positive to California Mastitis Test in dairy buffalo cows (Buballus bubalis

Directory of Open Access Journals (Sweden)

D.J. Sturion

2010-02-01

Full Text Available In order to observe the microbiological status of CMT positive samples, 734 apparently health mammary quarters from buffalo cows were submitted to physical evaluation, strip cup test and CMT. After milk samples inoculation in 10% ovine blood agar base media and in MacConkey agar and incubation under aerobic condition for 72 hours at 37oC, identification was proceeded. According to CMT, 227 quarters (30,93% were positive, among them 73 (32,16% presented 1+ reaction, 53 (23,35% were 2+ and 101 (44,49% were 3+. Microbiological exams of such samples were positive in 147 (64,76% out of 227 CMT positive samples and among the remaining 72 (31,72% were negative and 8 (3,52 were contaminated. In the 147 microbiological positive samples 204 bacteria were found in pure or associated growth and the most frequent agents were: Corynebacterium sp (59,25%; Staphylococcus sp (17,65% among which 86,11% were coagulase negative and 13,89% were coagulase positive; and Micrococcus sp (6,37%. The results revealed that, excluding the eight contaminated samples, 147 (67,12% quarters out of 219 CMT positive could be considered as bacteria-carrier and that even in a smaller percentage false-positive results can cause problems in a sanitary program for mastitis control in dairy buffalo cows.

Cold metal transfer spot plug welding of AA6061-T6-to-galvanized steel for automotive applications

International Nuclear Information System (INIS)

Cao, R.; Huang, Q.; Chen, J.H.; Wang, Pei-Chung

2014-01-01

Highlights: • Two Al-to-galvanized steel spot plug welding joints were studied by CMT method. • The optimum process variables for the two joints were gotten by orthogonal test. • Connection mechanism of the two joints were discussed. -- Abstract: In this study, cold metal transfer (CMT) spot plug joining of 1 mm thick Al AA6061-T6 to 1 mm thick galvanized steel (i.e., Q235) was studied. Welding variables were optimized for a plug weld in the center of a 25 mm overlap region with aluminum 4043 wire and 100% argon shielding gas. Microstructures and elemental distributions were characterized by scanning electron microscopy with energy dispersive X-ray spectrometer. Mechanical testing of CMT spot plug welded joints was conducted. It was found that it is feasible to join Al AA6061T6-to-galvanized steel by CMT spot plug welding method. The process variables for two joints with Al AA6061T6-to-galvanized mild steel and galvanized mild steel-to-Al AA6061T6 are optimized. The strength of CMT spot welded Al AA6061T6-to-galvanized mild steel is determined primarily by the strength and area of the brazed interface. While, the strength of the galvanized mild steel-to-Al AA6061T6 joint is mainly dependent upon the area of the weld metal

Quantitative measurement of duplicated DNA as a diagnostic test for Charcot-Marie-Tooth disease type 1a

NARCIS (Netherlands)

Hensels, G. W.; Janssen, E. A.; Hoogendijk, J. E.; Valentijn, L. J.; Baas, F.; Bolhuis, P. A.

1993-01-01

Charcot-Marie-Tooth disease type 1 (CMT1) is a hereditary motor and sensory neuropathy. The autosomal dominant subtype is often linked with a large duplication on chromosome 17p11.2. The gene encoding the peripheral myelin protein PMP 22 (the critical gene in this subtype of CMT1) is located within

2D and 3D imaging resolution trade-offs in quantifying pore throats for prediction of permeability

Energy Technology Data Exchange (ETDEWEB)

Beckingham, Lauren E.; Peters, Catherine A.; Um, Wooyong; Jones, Keith W.; Lindquist, W.Brent

2013-09-03

Although the impact of subsurface geochemical reactions on porosity is relatively well understood, changes in permeability remain difficult to estimate. In this work, pore-network modeling was used to predict permeability based on pore- and pore-throat size distributions determined from analysis of 2D scanning electron microscopy (SEM) images of thin sections and 3D X-ray computed microtomography (CMT) data. The analyzed specimens were a Viking sandstone sample from the Alberta sedimentary basin and an experimental column of reacted Hanford sediments. For the column, a decrease in permeability due to mineral precipitation was estimated, but the permeability estimates were dependent on imaging technique and resolution. X-ray CT imaging has the advantage of reconstructing a 3D pore network while 2D SEM imaging can easily analyze sub-grain and intragranular variations in mineralogy. Pore network models informed by analyses of 2D and 3D images at comparable resolutions produced permeability esti- mates with relatively good agreement. Large discrepancies in predicted permeabilities resulted from small variations in image resolution. Images with resolutions 0.4 to 4 lm predicted permeabilities differ- ing by orders of magnitude. While lower-resolution scans can analyze larger specimens, small pore throats may be missed due to resolution limitations, which in turn overestimates permeability in a pore-network model in which pore-to-pore conductances are statistically assigned. Conversely, high-res- olution scans are capable of capturing small pore throats, but if they are not actually flow-conducting predicted permeabilities will be below expected values. In addition, permeability is underestimated due to misinterpreting surface-roughness features as small pore throats. Comparison of permeability pre- dictions with expected and measured permeability values showed that the largest discrepancies resulted from the highest resolution images and the best predictions of

Environmental interaction, additive and non-additive genetic variability is involved in the expression of tissue and whole-plant heat tolerance in upland cotton (Gossypium hirsutum. L

Directory of Open Access Journals (Sweden)

Hafeez-ur-Rahman

2006-01-01

Full Text Available Heat tolerance is measured at tissue level by cellular membrane thermostability (CMT and at the whole plant level by the heat tolerance index (HTI. Eight upland cotton cultivars and 15 crosses were used to determine the type and extent of genetic variability associated with the expression of these traits between and within environments. Heat stress and non-stress conditions were used as the CMT environments and years for HTI. The wide variation in heterotic expression and combining ability effects observed for CMT and HTI suggest multigenic inheritance of these traits. Significant genetic variability across environments was evident but the traits were not highly heritable because of substantial environmental interaction. The available genetic variability included both additive and non-additive components, but the proportion of additive genetic variability was high for HTI. The parental cultivars CRIS-19 and CIM-448 were good donor parents for high CMT under heat-stressed conditions, and MNH-552 and N-Karishma under non-stressed conditions. Cultivar FH-634 was a good donor parent for HTI. The results show two types of general combining ability (GCA inheritance among high CMT parents: positive GCA inheritance expressed by CRIS-19 in the presence of heat stress and MNH-552 and N-Karishma in the absence of heat stress; and negative GCA inheritance expressed by FH-900 in the presence of heat stress. It was also evident that genes controlling high CMT in cultivar CRIS-19 were different from those present in the MNH-552, N-Karishma and FH-900 cultivars. Similarly, among high HTI parents, FH-634 showed positive and CIM-443 negative GCA inheritance. No significant relationship due to genetic causes existed between tissue and whole plant heat tolerance, diminishing the likelihood of simultaneous improvement and selection of the two traits.

[Review of the recent literature on hereditary neuropathies].

Science.gov (United States)

Birouk, N

2014-12-01

The recent literature included interesting reports on the pathogenic mechanisms of hereditary neuropathies. The axonal traffic and its abnormalities in some forms of Charcot-Marie-Tooth (CMT) disease were particularly reviewed by Bucci et al. Many genes related to CMT disease code for proteins that are involved directly or not in intracellular traffic. KIF1B controls vesicle motility on microtubules. MTMR2, MTMR13 and FIG4 regulate the metabolism of phosphoinositide at the level of endosomes. The HSPs are involved in the proteasomal degradation. GDAP1 and MFN2 regulate the mitochondrial fission and fusion respectively and the mitochondial transport within the axon. Pareyson et al. reported a review on peripheral neuropathies in mitochondrial disorders. They used the term of "mitochondrial CMT" for the forms of CMT with abnormal mitochondrial dynamic or structure. Among the new entities, we can draw the attention to a proximal form of hereditary motor and sensory neuropathy with autosomal dominant inheritance, which is characterized by motor deficit with cramps and fasciculations predominating in proximal muscles. Distal sensory deficit can be present. The gene TFG on chromosome 3 has been recently identified to be responsible for this form. Another rare form of axonal autosomal recessive neuropathy due to HNT1 gene mutation is characterized by the presence of hands myotonia that appears later than neuropathy but constitute an interesting clinical hallmark to orientate the diagnosis of this form. In terms of differential diagnosis, CMT4J due to FIG4 mutation can present with a rapidly progressive and asymmetric weakness that resembles CIDP. Bouhy et al. made an interesting review on the therapeutic trials, animal models and the future therapeutic strategies to be developed in CMT disease. Copyright © 2014. Published by Elsevier Masson SAS.

Role of strategic human resource management in crisis management in Australian greenfield hospital sites: a crisis management theory perspective.

Science.gov (United States)

Kendrick, Madeleine Iris; Bartram, Timothy; Cavanagh, Jillian; Burgess, John

2017-11-20

Objective This study examined strategic human resource management (SHRM) activities in two case hospitals relative to their approach to greenfield site success. Methods A comparative case study analysis approach was used, with documents sourced from public, open-access sites. The theoretical framework of crisis management theory's (CMT) proactive management and open communication channels was used to examine the documents, which were annual reports addressing both hospitals' first year of performance, union publications and transcripts of relevant parliamentary inquiries. Results The hospital that effectively used CMT in its first 12 months was demonstratively more 'successful' than the hospital that reported to not have effectively used CMT. 'Success' in this project was articulated as the hospital's ability to consolidate operations, without ongoing negative media attention, after 12 months. Conclusion This study provided an identification of how the use of CMT in a hospital's greenfield stage can increase the hospital's chances of 'success'. What is known about the topic? Journal and media articles illustrated a gap in greenfield human resource management (HRM) regarding successful consolidation, especially the healthcare context. Although manufacturing firms are addressed in academic literature in a greenfield context, there is a lack of knowledge concerning successful greenfield HRM in a healthcare context. What does this paper add? This study is among the first to identify the role of CMT in successful greenfield site establishment by identifying its presence in management activities. What are the implications for practitioners? The findings of this study suggest a potential link between the implementation of CMT and greenfield site success. This could allow future greenfield healthcare sites to operate with less cost and risk. The lack of stakeholder participation in the present study limits the applicability of its findings. However, archival document

RELAP5 analysis of PACTEL injection tests

International Nuclear Information System (INIS)

Kimber, G.R.; Lillington, J.N.

2000-01-01

A characteristic feature of advanced reactor designs is their reliance on passive safety systems. It is important to assess both the operation of such systems and the ability of systems codes, such as RELAP5, to model them. In Finland VTT Energy, together with Lappeenranta University of Technology, is using the PACTEL facility for the investigation of passive core cooling systems. In particular, a core make-up tank (CMT) has been installed in the rig to operate in a similar manner to those in many Advanced PWR designs. Three small break tests, GDE-24, GDE-34 and GDE-43 in the PACTEL facility were chosen for modelling with RELAP5. The objective of GDE-24 was to investigate CMT behaviour and in particular the effects of condensation in the CMT. The second test, GDE-34, was similar except that it had a smaller CMT and at the start of the test the water in the CMT and connecting pipework was at an elevated temperature. Test GDE-43 focused on conditions when the driving force for flow through the passive system injection system (PSIS) slowly disappears. Analysis of all tests reported here was carried out with RELAP5/MOD 3.2.1.2. The paper summarises the conclusions of all the tests. A critical part of the study revolved around modelling of the CMT. A model was developed to allow its detailed behaviour to be investigated more easily. This enabled recommendations for improving the condensation modelling in RELAP5 to be made. Apart from the wall condensation modelling issue, the implication of the work is that RELAP5/MOD 3.2.1.2 (a comparatively recent version of the code) is broadly adequate for these applications. (author)

Planetesimal core formation with partial silicate melting using in-situ high P, high T, deformation x-ray microtomography

Science.gov (United States)

Anzures, B. A.; Watson, H. C.; Yu, T.; Wang, Y.

2017-12-01

Differentiation is a defining moment in formation of terrestrial planets and asteroids. Smaller planetesimals likely didn't reach high enough temperatures for widescale melting. However, we infer that core formation must have occurred within a few million years from Hf-W dating. In lieu of a global magma ocean, planetesimals likely formed through inefficient percolation. Here, we used in-situ high temperature, high pressure, x-ray microtomography to track the 3-D evolution of the sample at mantle conditions as it underwent shear deformation. Lattice-Boltzmann simulations for permeability were used to characterize the efficiency of melt percolation. Mixtures of KLB1 peridotite plus 6.0 to 12.0 vol% FeS were pre-sintered to achieve an initial equilibrium microstructure, and then imaged through several consecutive cycles of heating and deformation. The maximum calculated melt segregation velocity was found to be 0.37 cm/yr for 6 vol.% FeS and 0.61 cm/year for 12 vol.% FeS, both below the minimum velocity of 3.3 cm/year required for a 100km planetesimal to fully differentiate within 3 million years. However, permeability is also a function of grain size and thus the samples having smaller grains than predicted for small planetesimals could have contributed to low permeability and also low migration velocity. The two-phase (sulfide melt and silicate melt) flow at higher melt fractions (6 vol.% and 12 vol.% FeS) was an extension of a similar study1 containing only sulfide melt at lower melt fraction (4.5 vol.% FeS). Contrary to the previous study, deformation did result in increased permeability until the sample was sheared by twisting the opposing Drickamer anvils by 360 degrees. Also, the presence of silicate melt caused the FeS melt to coalesce into less connected pathways as the experiment with 6 vol.% FeS was found to be less permeable than the one with 4.5 vol.% FeS but without any partial melt. The preliminary data from this study suggests that impacts as well as

Background Traffic-Based Retransmission Algorithm for Multimedia Streaming Transfer over Concurrent Multipaths

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Yuanlong Cao

2012-01-01

Full Text Available The content-rich multimedia streaming will be the most attractive services in the next-generation networks. With function of distribute data across multipath end-to-end paths based on SCTP's multihoming feature, concurrent multipath transfer SCTP (CMT-SCTP has been regarded as the most promising technology for the efficient multimedia streaming transmission. However, the current researches on CMT-SCTP mainly focus on the algorithms related to the data delivery performance while they seldom consider the background traffic factors. Actually, background traffic of realistic network environments has an important impact on the performance of CMT-SCTP. In this paper, we firstly investigate the effect of background traffic on the performance of CMT-SCTP based on a close realistic simulation topology with reasonable background traffic in NS2, and then based on the localness nature of background flow, a further improved retransmission algorithm, named RTX_CSI, is proposed to reach more benefits in terms of average throughput and achieve high users' experience of quality for multimedia streaming services.

Numerical Simulation of Fluid Mixing in Upper Annular Space of SMART during Early Stage of non-LOCA

Energy Technology Data Exchange (ETDEWEB)

Bae, Youngmin; Kim, Young-In; Kim, Keung Koo [KAERI, Daejeon (Korea, Republic of)

2015-05-15

KAERI (Korea Atomic Energy Research Institute) is developing a passive safety injection system (PSIS) to supply cold borated water into a reactor coolant system (RCS) without any operator actions or AC power under the occurrence of postulated design basis accidents. The PSIS consists of four independent trains, each of which is furnished with a gravity drained core makeup tank (CMT) and a safety injection tank (SIT). The CMT is designed to provide makeup and boration functions to the RCS during the early stage of a loss of coolant accident (LOCA) and a non-LOCA. In this paper, we investigate numerically the fluid mixing characteristics in the upper annular space of SMART, especially when single-phase natural circulation is formed between the CMT and RCS following a non-LOCA such as a main steam line break. In this paper, the fluid mixing characteristics in the upper annular space of SMART are investigated numerically when single-phase natural circulation is formed between the RCS and CMT during the early stage of a non-LOCA.

Numerical Simulation of Fluid Mixing in Upper Annular Space of SMART during Early Stage of non-LOCA

International Nuclear Information System (INIS)

Bae, Youngmin; Kim, Young-In; Kim, Keung Koo

2015-01-01

KAERI (Korea Atomic Energy Research Institute) is developing a passive safety injection system (PSIS) to supply cold borated water into a reactor coolant system (RCS) without any operator actions or AC power under the occurrence of postulated design basis accidents. The PSIS consists of four independent trains, each of which is furnished with a gravity drained core makeup tank (CMT) and a safety injection tank (SIT). The CMT is designed to provide makeup and boration functions to the RCS during the early stage of a loss of coolant accident (LOCA) and a non-LOCA. In this paper, we investigate numerically the fluid mixing characteristics in the upper annular space of SMART, especially when single-phase natural circulation is formed between the CMT and RCS following a non-LOCA such as a main steam line break. In this paper, the fluid mixing characteristics in the upper annular space of SMART are investigated numerically when single-phase natural circulation is formed between the RCS and CMT during the early stage of a non-LOCA

Fibrinogen and ceruloplasmin in plasma and milk from dairy cows with subclinical and clinical mastitis.

Science.gov (United States)

Tabrizi, A Davasaz; Batavani, R A; Rezaei, S Asri; Ahmadi, M

2008-02-15

The potential using of Acute Phase Proteins (APPs) in the assessment of mammary gland health was studied by examining the levels of Fibrinogen (Fb) and Ceruloplasmin (Cp) in plasma and milk from dairy cows with different grades of mastitis. Plasma samples were taken from jugular vein and milk samples were collected from quarters of cows with subclinical and clinical mastitis, as well as healthy controls. California Mastitis Test (CMT) were performed on each udder quarter of cows for detection of CMT2+ and CMT3+ quarters. CMT (0) and culture negative cases were considered healthy cows. Clinical mastitis, was graded as mild (clots in milk) or moderate (clots in milk and visible signs of inflammation in the mammary gland/s). The concentrations of Fb in the plasma of the cows with subclinical and clinical mastitis were higher than in the plasma of the healthy cows (p0.05), but differences between clinical and healthy groups were significant (pmastitis were higher than in the milk of the healthy cows (pmastitis in dairy cows.

Induction chemotherapy combined with three-dimensional conformal radiation therapy for locally advanced non-small cell lung cancer

International Nuclear Information System (INIS)

Zheng Aiqing; Yu Jinming; Zhao Xianguang; Wang Xuetao; Wei Guangsheng

2005-01-01

Objective: To evaluate the effect and complication of induction chemotherapy combined with three-dimensional conformal radiation therapy (3DCRT) for locally advanced non small cell lung cancer (NSCLC). Methods: Ninety-two such patients were randomized into radiation therapy alone group(RT-, 50 patients) and induction chemotherapy combined radiotherapy group (CMT-, 42 patients). The induction chemotherapy consisted of 2-4 cycles of platinum-based regimen. Results: The overall median survival time was 15 months with 12 months in the RT group and 18 months in the CMT group (P=0.014) respectively. The 1-year overall survival rates were 48.6% and 71.2% in RT and CMT group, respectively (P=0.004). The 2-year survival rates were 20.8% and 37.6% in RT and CMT group, respectively (P=0.041). Treatment was well tolerated and the toxicities were similar in either group. Conclusion: The addition of induction chemotherapy to 3DCRT takes a survival advantage over 3DCRT alone for Stage III NSCLC without increasing toxicities. (authors)

California mastitis test in the diagnostic of subclinical mastitis

Directory of Open Access Journals (Sweden)

Adna Crisléia Rodrigues Monção de Lima

2013-12-01

Full Text Available Milk production in Brazil is undoubtedly one of the most important Brazilian agroindustrial complex. Moves large sums of money, the dairy industry employs millions of the people, having potential to provide the domestic and foreign markets. Besides surpassing year by year the index production. The quality of milk is increasingly demanded by consumers and there are bonus programs for milk with low somatic cell counts, which reveal, indirectely, the udder sanity. Mastitis, the udder inflamation, is the main factor that substantially compromises the milk quality. Several methods can diagnose the incidence of subclinical mastitis in dairy herds. One these methods, the California Mastitis Test (CMT has as advantages being practical, low cost and the results are immediately available. The CMT method consists of adding the anionic neutral detergent to a milk sample in order to disrupt milk somatic cell membranes and release nucleic material. The viscousity formed by this reaction allows estimating the number of somatic cells (immunity cells presents in the milk. According to the degree of gelatinization obtained in this reaction, the interpretation of the scores varies from zero, no viscosity, to three crosses, highly viscous. This study was aimed to evaluate the CMT of eight dairy herds of different farms in Sao Paulo state, described by the letters A to H. The scores 1, 2 and 3 were considered positive for subclinical mastitis, while 0 was negative. The results were determined in relative frequency (%. It is evident that the herd D is the most affected by subclinical mastitis, because of the greater number of CMT positive (60%. This may be due to the mismanagement and poor conditions of milking. The properties C, F and G require greater attention, as the result of CMT could corroborate the presence of pathogenic microorganisms and infected cows can quickly transmit the infection to the healthy ones. Note that the farms A, B and H are the ones with

Visual acuity loss associated with excessive “dry macula” in exudative age-related macular degeneration

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Takahashi H

2018-02-01

Full Text Available Hidenori Takahashi,1–3 Yuji Inoue,1,2 Xue Tan,2,3 Satoru Inoda,1 Shinichi Sakamoto,1 Yusuke Arai,1 Yasuo Yanagi,4–6 Yujiro Fujino,2,3 Hidetoshi Kawashima1 1Department of Ophthalmology, Jichi Medical University, Shimotsuke, 2Department of Ophthalmology, The University of Tokyo, Bunkyo, 3Department of Ophthalmology, Japan Community Health Care Organization Tokyo Shinjuku Medical Center, Shinjuku, Japan; 4Medical Retina, Singapore National Eye Centre, 5Medical Retina, Singapore Eye Research Institute, 6Eye-ACP, Duke NUS Medical School, National University of Singapore, Singapore Purpose: To investigate the correlation between visual acuity and central macular thickness (CMT and choroidal thickness (CCT in patients with wet age-related macular degeneration (AMD. Methods: In this retrospective analysis, 14 eyes that received >10 ranibizumab injections (based on pro re nata [PRN] regimen and maintained initial visual acuity gain were analyzed. The following 5 parameters were measured at the foveal center: CMT (distance from the inner limiting membrane [ILM] to Bruch’s membrane; central retinal thickness (CRT; distance from the ILM to the inner limit of the retinal pigment epithelium or subretinal fluid [SRF]; SRF thickness (SRFT; pigment epithelium detachment thickness (PEDT; and CCT. The correlation between the logarithm of the minimum angle of resolution (logMAR best-corrected visual acuity (BCVA and the 5 parameters was examined with generalized estimating equations. Results: CMT, CRT, and CCT were negatively correlated with logMAR BCVA (P=0.031, 0.023, and 0.036, respectively when only CMT values less than the thickness that maximized visual acuity for each eye were used for the analysis. Each 100-µm reduction in CMT, CRT, or CCT improved logMAR BCVA by -0.1, -0.08, or -0.07, respectively. SRFT and PEDT were not correlated with BCVA. The median CMT that maximized the visual acuity was 230 µm. Conclusion: Dry macula with CMT <230 µm was

Meta-analysis and systematic review of factors biasing the observed prevalence of congenitally missing teeth in permanent dentition excluding third molars.

Science.gov (United States)

Rakhshan, Vahid

2013-10-01

No meta-analyses or systematic reviews have been conducted to evaluate numerous potential biasing factors contributing to the controversial results on congenitally missing teeth (CMT). We aimed to perform a rather comprehensive meta-analysis and systematic review on this subject. A thorough search was performed during September 2012 until April 2013 to find the available literature regarding CMT prevalence. Besides qualitatively discussing the literature, the meta-sample homogeneity, publication bias, and the effects of sample type, sample size, minimum and maximum ages of included subjects, gender imbalances, and scientific credit of the publishing journals on the reported CMT prevalence were statistically analyzed using Q-test, Egger regression, Spearman coefficient, Kruskal-Wallis, Welch t test (α=0.05), and Mann-Whitney U test (α=0.016, α=0.007). A total of 111 reports were collected. Metadata were heterogeneous (P=0.000). There was not a significant publication bias (Egger Regression P=0.073). Prevalence rates differed in different types of populations (Kruskal-Wallis P=0.001). Studies on orthodontic patients might report slightly (about 1%) higher prevalence (P=0.009, corrected α=0.016). Non-orthodontic dental patients showed a significant 2% decline [P=0.007 (Mann-Whitney U)]. Enrolling more males in researches might significantly reduce the observed prevalence (Spearman ρ=-0.407, P=0.001). Studies with higher minimums of subjects' age showed always slightly less CMT prevalence. This reached about -1.6% around the ages 10 to 13 and was significant for ages 10 to 12 (Welch t test Ptest P>0.2). Studies' sample sizes were correlated negatively with CMT prevalence (ρ=-0.250, P=0.009). It was not verified whether higher CMT rates have better chances of being published (ρ=0.132, P=0.177). CMT definition should be unified. Samples should be sex-balanced. Enrolling both orthodontic and dental patients in similar proportions might be preferable over sampling

ALS5/SPG11/ KIAA1840 mutations cause autosomal recessive axonal Charcot–Marie–Tooth disease

Science.gov (United States)

Montecchiani, Celeste; Pedace, Lucia; Lo Giudice, Temistocle; Casella, Antonella; Mearini, Marzia; Gaudiello, Fabrizio; Pedroso, José L.; Terracciano, Chiara; Caltagirone, Carlo; Massa, Roberto; St George-Hyslop, Peter H.; Barsottini, Orlando G. P.; Kawarai, Toshitaka

2016-01-01

Abstract Charcot–Marie–Tooth disease is a group of hereditary peripheral neuropathies that share clinical characteristics of progressive distal muscle weakness and atrophy, foot deformities, distal sensory loss, as well as diminished tendon reflexes. Hundreds of causative DNA changes have been found, but much of the genetic basis of the disease is still unexplained. Mutations in the ALS5/SPG11/ KIAA1840 gene are a frequent cause of autosomal recessive hereditary spastic paraplegia with thin corpus callosum and peripheral axonal neuropathy, and account for ∼40% of autosomal recessive juvenile amyotrophic lateral sclerosis. The overlap of axonal Charcot–Marie–Tooth disease with both diseases, as well as the common autosomal recessive inheritance pattern of thin corpus callosum and axonal Charcot–Marie–Tooth disease in three related patients, prompted us to analyse the ALS5/SPG11/ KIAA1840 gene in affected individuals with autosomal recessive axonal Charcot–Marie–Tooth disease. We investigated 28 unrelated families with autosomal recessive axonal Charcot–Marie–Tooth disease defined by clinical, electrophysiological, as well as pathological evaluation. Besides, we screened for all the known genes related to axonal autosomal recessive Charcot–Marie-Tooth disease (CMT2A2/HMSN2A2/ MFN2 , CMT2B1/ LMNA , CMT2B2/ MED25 , CMT2B5/ NEFL , ARCMT2F/dHMN2B/ HSPB1 , CMT2K/ GDAP1 , CMT2P/ LRSAM1 , CMT2R/ TRIM2 , CMT2S/ IGHMBP2 , CMT2T/ HSJ1 , CMTRID/ COX6A1 , ARAN-NM/ HINT and GAN/ GAN ), for the genes related to autosomal recessive hereditary spastic paraplegia with thin corpus callosum and axonal peripheral neuropathy (SPG7/ PGN , SPG15/ ZFYVE26, SPG21/ ACP33 , SPG35/ FA2H , SPG46/ GBA2 , SPG55/ C12orf65 and SPG56/ CYP2U1 ), as well as for the causative gene of peripheral neuropathy with or without agenesis of the corpus callosum ( SLC12A6 ) . Mitochondrial disorders related to Charcot–Marie–Tooth disease type 2 were also excluded by sequencing POLG and

ALS5/SPG11/KIAA1840 mutations cause autosomal recessive axonal Charcot-Marie-Tooth disease.

Science.gov (United States)

Montecchiani, Celeste; Pedace, Lucia; Lo Giudice, Temistocle; Casella, Antonella; Mearini, Marzia; Gaudiello, Fabrizio; Pedroso, José L; Terracciano, Chiara; Caltagirone, Carlo; Massa, Roberto; St George-Hyslop, Peter H; Barsottini, Orlando G P; Kawarai, Toshitaka; Orlacchio, Antonio

2016-01-01

Charcot-Marie-Tooth disease is a group of hereditary peripheral neuropathies that share clinical characteristics of progressive distal muscle weakness and atrophy, foot deformities, distal sensory loss, as well as diminished tendon reflexes. Hundreds of causative DNA changes have been found, but much of the genetic basis of the disease is still unexplained. Mutations in the ALS5/SPG11/KIAA1840 gene are a frequent cause of autosomal recessive hereditary spastic paraplegia with thin corpus callosum and peripheral axonal neuropathy, and account for ∼ 40% of autosomal recessive juvenile amyotrophic lateral sclerosis. The overlap of axonal Charcot-Marie-Tooth disease with both diseases, as well as the common autosomal recessive inheritance pattern of thin corpus callosum and axonal Charcot-Marie-Tooth disease in three related patients, prompted us to analyse the ALS5/SPG11/KIAA1840 gene in affected individuals with autosomal recessive axonal Charcot-Marie-Tooth disease. We investigated 28 unrelated families with autosomal recessive axonal Charcot-Marie-Tooth disease defined by clinical, electrophysiological, as well as pathological evaluation. Besides, we screened for all the known genes related to axonal autosomal recessive Charcot-Marie-Tooth disease (CMT2A2/HMSN2A2/MFN2, CMT2B1/LMNA, CMT2B2/MED25, CMT2B5/NEFL, ARCMT2F/dHMN2B/HSPB1, CMT2K/GDAP1, CMT2P/LRSAM1, CMT2R/TRIM2, CMT2S/IGHMBP2, CMT2T/HSJ1, CMTRID/COX6A1, ARAN-NM/HINT and GAN/GAN), for the genes related to autosomal recessive hereditary spastic paraplegia with thin corpus callosum and axonal peripheral neuropathy (SPG7/PGN, SPG15/ZFYVE26, SPG21/ACP33, SPG35/FA2H, SPG46/GBA2, SPG55/C12orf65 and SPG56/CYP2U1), as well as for the causative gene of peripheral neuropathy with or without agenesis of the corpus callosum (SLC12A6). Mitochondrial disorders related to Charcot-Marie-Tooth disease type 2 were also excluded by sequencing POLG and TYMP genes. An additional locus for autosomal recessive Charcot

On the Theory of Coupled Modes in Optical Cavity-Waveguide Structures

DEFF Research Database (Denmark)

Kristensen, Philip Trøst; de Lasson, Jakob Rosenkrantz; Heuck, Mikkel

2017-01-01

Light propagation in systems of optical cavities coupled to waveguides can be conveniently described by a general rate equation model known as (temporal) coupled mode theory (CMT). We present an alternative derivation of the CMT for optical cavitywaveguide structures, which explicitly relies...... in the coupled systems. Practical application of the theory is illustrated using example calculations in one and two dimensions....

EVALUATION OF THE CORRELATION BETWEEN THE INFECTION STATUS OF UDDER AND THE MICROBIOLOGICAL MILK QUALITY IN SOME EXTENSIVE GOAT HERDS OF SARDINIA - PRELIMINARY RESULTS

Directory of Open Access Journals (Sweden)

M. Mulas

2011-01-01

Full Text Available Sub clinical mastitis may cause more losses than clinical mastitis. Farmers can take advantage of employing several tools, California Mastitis Test (CMT and Somatic Cell Count (SCC among the others, to determine the presence of a sub clinical mastitis in their herds. The aim of the present study was to evaluate the microbiological quality of milk produced in some extensive goat herds in Sardinia through a clinical check to determine the infection status of the udder, CMT, SCC and microbiological milk tests. CMT has been confirmed to be a useful, practical and economical tool to detect sub clinical mastitis in goats. Farmers should be encouraged to use this as a first step in order to avoid prospective losses in their herds.

PuMA: the Porous Microstructure Analysis software

Science.gov (United States)

Ferguson, Joseph C.; Panerai, Francesco; Borner, Arnaud; Mansour, Nagi N.

2018-01-01

The Porous Microstructure Analysis (PuMA) software has been developed in order to compute effective material properties and perform material response simulations on digitized microstructures of porous media. PuMA is able to import digital three-dimensional images obtained from X-ray microtomography or to generate artificial microstructures. PuMA also provides a module for interactive 3D visualizations. Version 2.1 includes modules to compute porosity, volume fractions, and surface area. Two finite difference Laplace solvers have been implemented to compute the continuum tortuosity factor, effective thermal conductivity, and effective electrical conductivity. A random method has been developed to compute tortuosity factors from the continuum to rarefied regimes. Representative elementary volume analysis can be performed on each property. The software also includes a time-dependent, particle-based model for the oxidation of fibrous materials. PuMA was developed for Linux operating systems and is available as a NASA software under a US & Foreign release.

Real-time analysis, visualization, and steering of microtomography experiments at photon sources

International Nuclear Information System (INIS)

Laszeski, G. von; Insley, J.A.; Foster, I.; Bresnahan, J.; Kesselman, C.; Su, M.; Thiebaux, M.; Rivers, M.L.; Wang, S.; Tieman, B.; McNulty, I.

2000-01-01

A new generation of specialized scientific instruments called synchrotron light sources allow the imaging of materials at very fine scales. However, in contrast to a traditional microscope, interactive use has not previously been possible because of the large amounts of data generated and the considerable computation required translating this data into a useful image. The authors describe a new software architecture that uses high-speed networks and supercomputers to enable quasi-real-time and hence interactive analysis of synchrotron light source data. This architecture uses technologies provided by the Globus computational grid toolkit to allow dynamic creation of a reconstruction pipeline that transfers data from a synchrotron source beamline to a preprocessing station, next to a parallel reconstruction system, and then to multiple visualization stations. Collaborative analysis tools allow multiple users to control data visualization. As a result, local and remote scientists can see and discuss preliminary results just minutes after data collection starts. The implications for more efficient use of this scarce resource and for more effective science appear tremendous

Oral Chinese Herbal Medicine for Treatment of Dilated Cardiomyopathy: A Systematic Review and Meta-Analysis

Directory of Open Access Journals (Sweden)

Yu-Shuo Zhu

2016-01-01

Full Text Available Dilated cardiomyopathy (DCM is one of the main causes of heart failure and could increase death, hospitalization, and rehospitalization rate. The effect of conventional medicine treatment (CMT is limited; meanwhile, the combination of CMT and Oral Chinese Herbal Medicine (OCHM represents exciting adjunctive therapies. In this study, we ascertained the therapeutic effect of OCHM in combination with CMT for dilated cardiomyopathy by using meta-analysis methods for controlled clinical trials. We searched studies from five databases and extracted data from these studies. We also assessed the methodological quality of the included studies. We evaluated the following outcome measures to estimate the prognosis in patients with DCM: left ventricular ejection fraction (LVEF, left ventricular end-diastolic dimension (LVEDD, stroke volume (SV, brain natriuretic peptide (BNP, 6-minute walk test (6MWT, and overall efficacy. The result showed that OCHM combined with CMT for the improvement of therapeutic effect in DCM patients. However, the evidence remains weak due to the small sample size, high clinical heterogeneity, and poor methodological quality of the included trials. Further, large sample size and well-designed trials are needed.

Congenital vertical talus in four generations of the same family

International Nuclear Information System (INIS)

Levinsohn, E. Mark; Shrimpton, Antony E.; Cady, Robert B.; Packard, David S.; Hootnick, David R.

2004-01-01

This paper presents four generations of a family with radiographically demonstrated congenital vertical talus (CVT) in whom a HOXD10 gene mutation was identified. Some members of the family with this mutation exhibited cavo-varus foot deformity consistent with a Charcot-Marie-Tooth (CMT)-like disorder. Physical examination was performed on nearly all of the affected and unaffected family members. DNA was extracted from blood obtained from 14 subjects who showed radiographic and clinical features of CVT (two of whom also had CMT), from two subjects with features of CMT but not CVT, and from 20 related family members who were clinically normal. Radiographs show the appearance of uncorrected CVT in infancy, in childhood, and in adulthood. DNA analysis revealed a mutation in a HOXD10gene located on chromosome 2 in all of the affected but none of the unaffected family members. There is an autosomal-dominant-inherited mutation with complete penetrance which is found in all members of a pedigree with CVT, some of whom exhibit a CMT-like foot disorder. Radiologic findings vary depending on the severity of involvement, treatment provided and age of the patient. (orig.)

Congenital vertical talus in four generations of the same family

Energy Technology Data Exchange (ETDEWEB)

Levinsohn, E. Mark [Crouse Hospital, Department of Medical Imaging, Syracuse (United States); Shrimpton, Antony E. [SUNY Upstate Medical University, Department of Clinical Pathology, Syracuse (United States); Cady, Robert B. [SUNY Upstate Medical University, Department of Pediatrics, Syracuse (United States); Packard, David S. [SUNY Upstate Medical University, Department of Cell and Developmental Biology, Syracuse (United States); Hootnick, David R. [SUNY Upstate Medical University, Department of Pediatrics, Syracuse (United States); SUNY Upstate Medical University, Department of Cell and Developmental Biology, Syracuse (United States); SUNY Upstate Medical University, Department of Orthopedic Surgery, Syracuse (United States)

2004-11-01

This paper presents four generations of a family with radiographically demonstrated congenital vertical talus (CVT) in whom a HOXD10 gene mutation was identified. Some members of the family with this mutation exhibited cavo-varus foot deformity consistent with a Charcot-Marie-Tooth (CMT)-like disorder. Physical examination was performed on nearly all of the affected and unaffected family members. DNA was extracted from blood obtained from 14 subjects who showed radiographic and clinical features of CVT (two of whom also had CMT), from two subjects with features of CMT but not CVT, and from 20 related family members who were clinically normal. Radiographs show the appearance of uncorrected CVT in infancy, in childhood, and in adulthood. DNA analysis revealed a mutation in a HOXD10gene located on chromosome 2 in all of the affected but none of the unaffected family members. There is an autosomal-dominant-inherited mutation with complete penetrance which is found in all members of a pedigree with CVT, some of whom exhibit a CMT-like foot disorder. Radiologic findings vary depending on the severity of involvement, treatment provided and age of the patient. (orig.)

Laryngeal neuropathy of Charcot-Marie-Tooth disease: further observations and novel mutations associated with vocal fold paresis.

Science.gov (United States)

Benson, Brian; Sulica, Lucian; Guss, Joel; Blitzer, Andrew

2010-02-01

To describe and define laryngeal neuropathy in Charcot-Marie-Tooth (CMT) disease. Retrospective record review from a university laryngology practice. Four adult CMT patients presented with laryngeal symptoms. Three patients exhibited bilateral vocal fold palsy, in each case with more severe hypomobility on the left. One case exhibited an isolated left vocal fold palsy. All patients complained of hoarseness and stridor, three had dyspnea, two patients had dysphagia, and one had obstructive sleep apnea (OSA). One patient has required airway surgery to date. Genetic testing revealed known sequence alterations in one case and sequence alterations previously not associated with laryngeal dysfunction in two cases. One case was familial and two were sporadic; information is not available in a fourth. The clinical course of the cases suggests slowly progressive neuropathy that appears to be nerve length dependent. The lack of severe respiratory distress despite dense bilateral paresis is consistent with existing reports and with the reported low rate of tracheostomy in adults with laryngeal manifestations of CMT. Genetic testing does not currently inform expectations or management of laryngeal disease. Dyspnea, dysphagia, and OSA symptoms in patients with CMT require careful laryngologic evaluation.

Inflammation-related microRNA expression level in the bovine milk is affected by mastitis.

Science.gov (United States)

Lai, Yu-Chang; Fujikawa, Takuro; Maemura, Tadashi; Ando, Takaaki; Kitahara, Go; Endo, Yasuyuki; Yamato, Osamu; Koiwa, Masateru; Kubota, Chikara; Miura, Naoki

2017-01-01

MicroRNA (miRNA) in tissue and liquid samples have been shown to be associated with many diseases including inflammation. We aimed to identify inflammation-related miRNA expression level in the bovine mastitis milk. Expression level of inflammation-related miRNA in milk from mastitis-affected and normal cows was analyzed using qPCR. We found that expression level of miR-21, miR-146a, miR-155, miR-222, and miR-383 was significantly upregulated in California mastitis test positive (CMT+) milk. We further analyzed these miRNA using a chip-based QuantStudio Digital PCR System. The digital PCR results correlated with those of qPCR, demonstrating upregulation of miR-21, miR-146a, miR-155, miR-222, and miR-383 in CMT+ milk. In conclusion, we identified miRNA that are upregulated in CMT+ milk. These miRNA exhibited sensitivity and specificity greater than 80% for differentiating between CMT+ milk and normal milk. Our findings suggest that inflammation-related miRNA expression level in the bovine milk was affected by mastitis, and miRNA in milk have potential for use as biomarkers of bovine mastitis.

Prevalence of bovine subclinical mastitis and isolation of its major causes in Bishoftu Town, Ethiopia.

Science.gov (United States)

Birhanu, Misrak; Leta, Samson; Mamo, Gezahegne; Tesfaye, Shimelis

2017-12-21

A cross-sectional study was conducted from November 2015 to March 2016 to estimate the prevalence, to assess the risk factors and to isolate the major etiological agent of subclinical mastitis in Bishoftu town. The study was conducted on 262 cross breed lactating cows selected from 12 intensively managed dairy farms. California mastitis test (CMT) and bacteriological culture methods were used as diagnostic tools. From 262 cows examined, 105 (40.1%) and from 1048 quarters examined, 170 (16.1%) were positive for sub-clinical mastitis using CMT. All CMT positive samples were cultured for etiological agent identification. From 170 samples cultured, 153 were positive for known subclinical mastitis pathogens. The dominant bacteria isolated were Staphylococcus species from these Staphylococcus aureus (44.9%) was the major one followed by Streptococcus spp. (25.3%) and other gram negative enteric bacteria, Escherichia coli (8.8%). Age, body condition score, milk yield, and number of parity were considered as potential risk factors; among these, age and number of parity have statistically significance association with the occurrence of subclinical mastitis (P < 0.05) both in the CMT and the bacteriological tests.

Effect of selenodiglutathione on the metabolism of canine mammary tumor cells

International Nuclear Information System (INIS)

Fico-Santoro, M.; Lebowitz, A.; Milner, J.A.

1986-01-01

Selenodiglutathione (SDG) has been shown to be an effective inhibitor of tumor growth. The present studies were designed to evaluate altered metabolism in canine mammary tumor cells (CMT-13) exposed to various concentrations of SDG. Addition of SDG at 0.025 μg Se/ml did not inhibit growth of CMT-13 cells after 24 h of incubation. At this concentration of SDG, approximately 25% of 75 Se- 35 S-SDG was retained in these tumor cells after 24 h of incubation. The nuclear fraction contained 96% of the 75 Se and 35 S radioactivity. The ratio of 75 Se to 35 S was 1 to 4.5 in the whole cell and in the nuclear fraction. SDG increased glutathione peroxidase activity by 40% compared to CMT-13 cells not exposed to SDG. Glutathione reductase activity was decreased by 63% by the addition of SDG. In addition, supplemental SDG resulted in a 55% decrease in GSH content but did not alter GSSG concentrations. After 4d of incubation, SDG at 0.1 and 0.5 μg Se/ml caused a 43 and 58% inhibition of growth of CMT-13 cells. Addition of GSH (100μM) partially prevented, 68% and 54%, the growth inhibition caused by SDG at concentrations of 0.1 and 0.5 μg Se per ml respectively during the 4d incubation period. Preincubation of CMT-13 cells with GSH for 48 h before addition of SDG (0.5 μg Se/ml) completely prevented the growth inhibition caused by this seleno-compound

Acute optic neuropathy associated with a novel MFN2 mutation.

Science.gov (United States)

Leonardi, Luca; Marcotulli, Christian; Storti, Eugenia; Tessa, Alessandra; Serrao, Mariano; Parisi, Vincenzo; Santorelli, F M; Pierelli, Francesco; Casali, Carlo

2015-07-01

Mutations in the mitofusin 2 (MFN2) gene cause CMT2A the most common form of autosomal dominant axonal Charcot-Marie-Tooth (CMT). In addition, mutations in MFN2 have been shown to be responsible for Hereditary Motor Sensory Neuropathy type VI (HSMN VI), a rare early-onset axonal CMT associated with optic neuropathy. Most reports of HMSN VI presented with a sub-acute form of optic neuropathy. Herein, we report a CMT2A patient, who developed very rapidly progressing severe optic neuropathy. A 40-year-old Caucasian man was evaluated for gait disturbance and lower limbs weakness, slowly progressed over the last 2 years. Due to clinical data and family history, a diagnosis of CMT2 was made. The novel heterozygous c.775C > T (p.Arg259Cys) mutation in MFN2 was detected in the patient and his clinical affected mother. Interestingly, the patient developed a severe sudden bilateral visual deterioration few years early, with clinical and instrumental picture suggestive of acute bilateral optic neuropathy. Our report expands the spectrum of MFN2-related manifestation because it indicates that visual symptoms of HMSN VI may enter in the differential with acquired or hereditary acute optic neuropathies, and that severe optic neuropathy is not invariably an early manifestation of the disease but may occur as disease progressed. This report could have an impact on clinicians who evaluate patients with otherwise unexplainable bilateral acute-onset optic neuropathy, especially if associated with a motor and sensory axonal neuropathy.

PMP22 related neuropathies: Charcot-Marie-Tooth disease type 1A and Hereditary Neuropathy with liability to Pressure Palsies.

Science.gov (United States)

van Paassen, Barbara W; van der Kooi, Anneke J; van Spaendonck-Zwarts, Karin Y; Verhamme, Camiel; Baas, Frank; de Visser, Marianne

2014-03-19

PMP22 related neuropathies comprise (1) PMP22 duplications leading to Charcot-Marie-Tooth disease type 1A (CMT1A), (2) PMP22 deletions, leading to Hereditary Neuropathy with liability to Pressure Palsies (HNPP), and (3) PMP22 point mutations, causing both phenotypes. Overall prevalence of CMT is usually reported as 1:2,500, epidemiological studies show that 20-64% of CMT patients carry the PMP22 duplication. The prevalence of HNPP is not well known. CMT1A usually presents in the first two decades with difficulty walking or running. Distal symmetrical muscle weakness and wasting and sensory loss is present, legs more frequently and more severely affected than arms. HNPP typically leads to episodic, painless, recurrent, focal motor and sensory peripheral neuropathy, preceded by minor compression on the affected nerve. Electrophysiological evaluation is needed to determine whether the polyneuropathy is demyelinating. Sonography of the nerves can be useful. Diagnosis is confirmed by finding respectively a PMP22 duplication, deletion or point mutation. Differential diagnosis includes other inherited neuropathies, and acquired polyneuropathies. The mode of inheritance is autosomal dominant and de novo mutations occur. Offspring of patients have a chance of 50% to inherit the mutation from their affected parent. Prenatal testing is possible; requests for prenatal testing are not common. Treatment is currently symptomatic and may include management by a rehabilitation physician, physiotherapist, occupational therapist and orthopaedic surgeon. Adult CMT1A patients show slow clinical progression of disease, which seems to reflect a process of normal ageing. Life expectancy is normal.

Subclinical mastitis effects in some dairy herds in the Upper Chicamocha River (Boyacá Department

Directory of Open Access Journals (Sweden)

Andrey Pinzón Trujillo

2009-06-01

Full Text Available The purpose of this work was to carry out a study about the effects of subclinical mastitis in cows of 34 dairy farms in the Upper Chicamocha region (Boyacá department.The farms are registered in the livestock farmers association of Boyacá (FABEGAN. This study was done with the aim to know about the infection status of cows and establish which are the principal etiologic agents associated with the disease and its relation with the milking routine. To this aim, applied comparison even tests for the productive variables to relate with the California Mastitis Test (CMT and the microbiological characterization, a blocks design under factorial 2 x 4 array to analyze the existence of significant differences between the mastitis grades, the sample season and its interaction, and blocks design under factorial 2 x 4 array to analyze the existence of significant differences among the mastitis subclinical grades, the sampling season and its interaction. 6616 quarters were submitted to the California Mastitis Test (CMT in two times and different season. The results did not show any significant differences between the two times of sampling. The positive samples according with CMT (CMT-2 and CMT-3 were submitted to microbiological tests where, in the most of the cases of mastitis, the presence of Streptococcus agalactiae and Staphylococcus aureus was detected. They are the main etiologic agents in the disease. The results indicate the close relation between the milking routine and mastitis. The deficient practices in the milking process are the cause of dissemination and prevalence of mastitis in farms.

Long-term changes in subfoveal choroidal thickness and central macula thickness after Nd:YAG laser capsulotomy.

Science.gov (United States)

Yilmaz, Tolga; Yilmaz, Ahu

2017-08-01

To evaluate changes in central macula thickness (CMT), subfoveal choroid thickness (SCT), and intraocular pressure (IOP) before and after neodymium:yttrium-aluminum-garnet (Nd:YAG) laser capsulotomy. 42 eyes of 42 patients who underwent Nd:YAG laser capsulotomy were included in this prospective study. CMT, SCT, and IOP were evaluated preoperatively and at postoperative week 1 and postoperative months 1, 3, 6, and 12. CMT was 238.1 ± 27.6 μm (mean ± SD) preoperatively, then 239.7 ± 29.8, 241.3 ± 28.7, 242.7 ± 27.2, 238.8 ± 23.7, and 238.3 ± 21.7 μm at postoperative week 1 and months 1, 3, 6, and 12, respectively. SCT was 263.3 ± 21.6 μm preoperatively, and 265.5 ± 24.8, 266.2 ± 25.7, 267.1 ± 26.3, 269.1 ± 24.2, and 269.9 ± 21.4 μm at postoperative week 1 and months 1, 3, 6, and 12, respectively. There were no significant differences between preoperative and postoperative results for CMT, SCT, or IOP (all p > 0.05). Although there were slight changes in choroid thickness in the long term, treatment of posterior capsule opacification with a low-energy Nd:YAG laser is a safe procedure that increases visual acuity without creating a significant increase in IOP, CMT, and SCT.

Hierarchical Role Ontology-based Assessment of Trainee’s Conceptual Knowledge

Directory of Open Access Journals (Sweden)

V. V. Belous

2014-01-01

Full Text Available We believe that this knowledge base of training system structure is based on the subject semantic network (SSN containing concepts of subject domain and relations between them. The SSN is represented as a direct graph, with tops corresponding to concepts, and arcs corresponding to relations. We consider a technique for trainee’s conceptual knowledge assessment using the cognitive maps of trainees (CMT, each of which formalizes his ideas of some SSN fragment and theoretically coincides with this fragment. Assessment of trainee’s achievement of this SSN fragment comes to comparison of SSN subgraph, corresponding to this fragment, with the direct graph, which is defined by the corresponding CMT.A number of important subject domains possess the property that concepts in them have the attribute called ‘role’, and roles of concepts can be linearly sorted. The direct graph SSN, corresponding to such ontology can be presented in a tiered form.The work concerns the assessment of trainee’s conceptual knowledge in the subject domains of this class. The work represents the SSN and CMT models used, describes the offered methods to create CMT, as well metrics for trainee’s achievement of the conceptual knowledge based on his CMT.The main results of work are the following: the model of the semantic network corresponding to hierarchical role ontology, and also a model of a trainee’s cognitive map of are offered, methods for creating the trainee’s cognitive maps are developed, metrics of trainee’s achievement of conceptual knowledge are suggested.

Letter and Colour Matching Tasks: Parametric Measures of Developmental Working Memory Capacity

OpenAIRE

Powell, Tamara L.; Arsalidou, Marie; Vogan, Vanessa M.; Taylor, Margot J.

2014-01-01

We investigated the mediating role of interference in developmental assessments of working memory (WM) capacity across childhood, adolescence, and young adulthood. One hundred and forty-two participants completed two versions of visuospatial (colour matching task, CMT) and verbal (letter matching task, LMT) WM tasks, which systematically varied cognitive load in a high and low interference condition. Results showed similar developmental trajectories across high interference contexts (CMT- and...

SYNCHROTRON X-RAY ABSORPTION-EDGE COMPUTED MICROTOMOGRAPHY IMAGING OF THALLIUM COMPARTMENTALIZATION IN IBERIS INTERMEDIA

Science.gov (United States)

Thallium (TI) is an extremely toxic metal which, due to its similarities to K, is readily taken up by plants. Thallium is efficiently hyperaccumulated in Iberis intermedia as TI(I). Distribution and compartmentalization of TI in I. intermedia is highes...

LHCb: A CMake-based build and configuration framework

CERN Multimedia

Clemencic, M; Mato, P

2011-01-01

The LHCb experiment has been using the CMT build and configuration tool for its software since the first versions, mainly because of its multi-platform build support and its powerful configuration management functionality. Still, CMT has some limitations in terms of build performance and the increased complexity added to the tool to cope with new use cases added latterly. Therefore, we have been looking for a viable alternative to it and we have investigated the possibility of adopting the CMake tool, which does a very good job for building and is getting very popular in the HEP community. The result of this study is a CMake-based framework which provides most of the special configuration features available natively only in CMT, with the advantages of better performances, flexibility and portability.

A CMake-based build and configuration framework

CERN Multimedia

CERN. Geneva

2012-01-01

The LHCb experiment has been using the CMT build and configuration tool for its software since the first versions, mainly because of its multi-platform build support and its powerful configuration management functionality. Still, CMT has some limitations in terms of build performance and the increased complexity added to the tool to cope with new use cases added latterly. Therefore, we have been looking for a viable alternative to it and we have investigated the possibility of adopting the CMake tool, which does a very good job for building and is getting very popular in the HEP community. The result of this study is a CMake-based framework which provides most of the special configuration features available natively only in CMT, with the advantages of better performances, flexibility and portability.

National Nanotechnology Laboratory (LNNano) open facilities for scientific community: new methods for polymeric materials characterization

International Nuclear Information System (INIS)

Silva, Cristiane A.; Santos, Ramon H.Z. dos; Bernardes, Juliana S.; Gouveia, Rubia F.

2015-01-01

National Nanotechnology Laboratory (LNNano) at the National Center for Energy and Materials (CNPEM) presents open facilities for scientific public in some areas. In this work will be discussed the facilities for mainly the polymeric community, as well as new methods for the characterization. Low density polyethylene (LDPE) surfaces were characterized by X-ray microtomography and X-ray photoelectron spectroscopy (XPS). The results obtained by microtomography have shown that these surfaces present different contrasts when compared with the bulk. These differences are correlated with the formation of an oxidized layer at the polymer surface, which consequently have a greater X-ray attenuation. This hypothesis is confirmed by XPS, which shows LDPE surface layers are richer in carbonyl, carboxyl and vinyl groups than the bulk. This work presents that microtomography can be used as a new method for detection and characterization of polymer surface oxidation. (author)

National Nanotechnology Laboratory (LNNano) open facilities for scientific community: new methods for polymeric materials characterization; Instalacoes abertas a comunidade cientifica no Laboratorio Nacional de Nanotecnologia (LNNano): novos metodos de caracterizacao de materiais polimericos

Energy Technology Data Exchange (ETDEWEB)

Silva, Cristiane A.; Santos, Ramon H.Z. dos; Bernardes, Juliana S.; Gouveia, Rubia F., E-mail: rubia.gouveia@lnnano.cnpem.br [Centro Nacional de Pesquisa em Energia e Materiais (LNNano/CNPEM), Campinas, SP (Brazil). Laboratorio Nacional de Nanotecnologia

2015-07-01

National Nanotechnology Laboratory (LNNano) at the National Center for Energy and Materials (CNPEM) presents open facilities for scientific public in some areas. In this work will be discussed the facilities for mainly the polymeric community, as well as new methods for the characterization. Low density polyethylene (LDPE) surfaces were characterized by X-ray microtomography and X-ray photoelectron spectroscopy (XPS). The results obtained by microtomography have shown that these surfaces present different contrasts when compared with the bulk. These differences are correlated with the formation of an oxidized layer at the polymer surface, which consequently have a greater X-ray attenuation. This hypothesis is confirmed by XPS, which shows LDPE surface layers are richer in carbonyl, carboxyl and vinyl groups than the bulk. This work presents that microtomography can be used as a new method for detection and characterization of polymer surface oxidation. (author)

Synchrotron radiation microtomography of Taylor bubbles in capillary two-phase flow

Energy Technology Data Exchange (ETDEWEB)

Boden, Stephan [Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Fluid Dynamics, P.O. Box 510119, Dresden (Germany); Santos Rolo, Tomy dos; Baumbach, Tilo [Karlsruhe Institute of Technology (KIT), Institute for Photon Science and Synchrotron Radiation (IPS), Eggenstein-Leopoldshafen (Germany); Hampel, Uwe [Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Fluid Dynamics, P.O. Box 510119, Dresden (Germany); Technische Universitaet Dresden (TUD), AREVA Endowed Chair of Imaging Techniques in Energy and Process Engineering, Dresden (Germany)

2014-07-15

We report on a study to measure the three-dimensional shape of Taylor bubbles in capillaries using synchrotron radiation in conjunction with ultrafast radiographic imaging. Moving Taylor bubbles in 2-mm round and square capillaries were radiographically scanned with an ultrahigh frame rate of up to 36,000 fps and 5.6-μm pixel separation. Consecutive images were properly processed to yield 2D transmission radiographs of high contrast-to-noise ratio. Application of 3D tomographic image reconstruction disclosed the 3D bubble shape. The results provide a reference data base for development of sophisticated interface resolving CFD computations. (orig.)

Synchrotron radiation microtomography of Taylor bubbles in capillary two-phase flow

Science.gov (United States)

Boden, Stephan; dos Santos Rolo, Tomy; Baumbach, Tilo; Hampel, Uwe

2014-07-01

We report on a study to measure the three-dimensional shape of Taylor bubbles in capillaries using synchrotron radiation in conjunction with ultrafast radiographic imaging. Moving Taylor bubbles in 2-mm round and square capillaries were radiographically scanned with an ultrahigh frame rate of up to 36,000 fps and 5.6-µm pixel separation. Consecutive images were properly processed to yield 2D transmission radiographs of high contrast-to-noise ratio. Application of 3D tomographic image reconstruction disclosed the 3D bubble shape. The results provide a reference data base for development of sophisticated interface resolving CFD computations.

Synchrotron radiation microtomography of Taylor bubbles in capillary two-phase flow

International Nuclear Information System (INIS)

Boden, Stephan; Santos Rolo, Tomy dos; Baumbach, Tilo; Hampel, Uwe

2014-01-01

We report on a study to measure the three-dimensional shape of Taylor bubbles in capillaries using synchrotron radiation in conjunction with ultrafast radiographic imaging. Moving Taylor bubbles in 2-mm round and square capillaries were radiographically scanned with an ultrahigh frame rate of up to 36,000 fps and 5.6-μm pixel separation. Consecutive images were properly processed to yield 2D transmission radiographs of high contrast-to-noise ratio. Application of 3D tomographic image reconstruction disclosed the 3D bubble shape. The results provide a reference data base for development of sophisticated interface resolving CFD computations. (orig.)

Feasibility study of short-term effects of chiropractic manipulation on older adults with impaired balance

Science.gov (United States)

Hawk, Cheryl; Pfefer, Mark T.; Strunk, Richard; Ramcharan, Michael; Uhl, Nathan

2007-01-01

Abstract Objective The purpose of this study was to collect preliminary information on the effects of chiropractic spinal manipulation on reducing risk of falls in older adults with impaired balance, as assessed by the Berg Balance Scale (BBS). This information is necessary to develop a line of investigation into the role of chiropractic care on reduction of fall risk in this population. Methods Randomized, 2-group pretest/posttest design feasibility study with a target sample size of 10 (5 per group), conducted within the outpatient health center of a chiropractic college. Inclusion criteria were as follows: aged 60 years or older, able to stand on one leg <5 seconds, and able to attend all sessions. Patients were assigned to chiropractic care (CMT) or supervised exercise (EX) and scheduled for 2 visits per week for 8 weeks. Results A total of 26 people responded to recruitment; and 11 were enrolled: 6 in the CMT and 5 in the EX group. Two patients dropped out at the baseline visit when they were assigned to the EX group. One CMT patient dropped out in the seventh week because of a fall at home resulting in a leg fracture. All remaining patients were compliant with treatment protocols. Five of 6 CMT patients and 4 of 5 EX patients had baseline BBS scores <45, indicating increased risk of falls. At visit 16, 2 CMT and 1 of the 3 remaining EX patients had BBS scores <45. One mild and transient adverse event was noted. Conclusion Further investigation of the possible role of chiropractic care in reducing fall risk in this population appears feasible. PMID:19674706

Genotype/phenotype correlations in AARS-related neuropathy in a cohort of patients from the United Kingdom and Ireland.

Science.gov (United States)

Bansagi, Boglarka; Antoniadi, Thalia; Burton-Jones, Sarah; Murphy, Sinead M; McHugh, John; Alexander, Michael; Wells, Richard; Davies, Joanna; Hilton-Jones, David; Lochmüller, Hanns; Chinnery, Patrick; Horvath, Rita

2015-08-01

Charcot-Marie-Tooth disease (CMT) is the most common inherited neuropathy with heterogeneous clinical presentation and genetic background. The axonal form (CMT2) is characterised by decreased action potentials indicating primary axonal damage. The underlying pathology involves axonal degeneration which is supposed to be related to axonal protein dysfunction caused by various gene mutations. The overlapping clinical manifestation of CMT2 with distal hereditary motor neuropathy (dHMN) and intermediate CMT causes further diagnostic difficulties. Aminoacyl-tRNA synthetases have been implicated in the pathomechanism of CMT2. They have an essential role in protein translation by attaching amino acids to their cognate tRNAs. To date six families have been reported worldwide with dominant missense alanyl-tRNA synthetase (AARS) mutations leading to clinically heterogeneous axonal neuropathies. The pathomechanism of some variants could be explained by impaired amino acylation activity while other variants implicating an editing defect need to be further investigated. Here, we report a cohort of six additional families originating from the United Kingdom and Ireland with dominant AARS-related neuropathies. The phenotypic manifestation was distal lower limb predominant sensorimotor neuropathy but upper limb impairment with split hand deformity occasionally associated. Nerve conduction studies revealed significant demyelination accompanying the axonal lesion in motor and sensory nerves. Five families have the c.986G>A, p.(Arg329His) variant, further supporting that this is a recurrent loss of function variant. The sixth family, of Irish origin, had a novel missense variant, c.2063A>G, p.(Glu688Gly). We discuss our findings and the associated phenotypic heterogeneity in these families, which expands the clinical spectrum of AARS-related neuropathies.

Charcot Marie Tooth 2B Peripheral Sensory Neuropathy: How Rab7 Mutations Impact NGF Signaling?

Directory of Open Access Journals (Sweden)

Harry Liu

2017-02-01

Full Text Available Charcot-Marie-Tooth 2B peripheral sensory neuropathy (CMT2B is a debilitating autosomal dominant hereditary sensory neuropathy. Patients with this disease lose pain sensation and frequently need amputation. Axonal dysfunction and degeneration of peripheral sensory neurons is a major clinical manifestation of CMT2B. However, the cellular and molecular pathogenic mechanisms remain undefined. CMT2B is caused by missense point mutations (L129F, K157N, N161T/I, V162M in Rab7 GTPase. Strong evidence suggests that the Rab7 mutation(s enhances the cellular levels of activated Rab7 proteins, thus resulting in increased lysosomal activity and autophagy. As a consequence, trafficking and signaling of neurotrophic factors such as nerve growth factor (NGF in the long axons of peripheral sensory neurons are particularly vulnerable to premature degradation. A “gain of toxicity” model has, thus, been proposed based on these observations. However, studies of fly photo-sensory neurons indicate that the Rab7 mutation(s causes a “loss of function”, resulting in haploinsufficiency. In the review, we summarize experimental evidence for both hypotheses. We argue that better models (rodent animals and human neurons of CMT2B are needed to precisely define the disease mechanisms.

Charcot Marie Tooth 2B Peripheral Sensory Neuropathy: How Rab7 Mutations Impact NGF Signaling?

Science.gov (United States)

Liu, Harry; Wu, Chengbiao

2017-02-04

Charcot-Marie-Tooth 2B peripheral sensory neuropathy (CMT2B) is a debilitating autosomal dominant hereditary sensory neuropathy. Patients with this disease lose pain sensation and frequently need amputation. Axonal dysfunction and degeneration of peripheral sensory neurons is a major clinical manifestation of CMT2B. However, the cellular and molecular pathogenic mechanisms remain undefined. CMT2B is caused by missense point mutations (L129F, K157N, N161T/I, V162M) in Rab7 GTPase. Strong evidence suggests that the Rab7 mutation(s) enhances the cellular levels of activated Rab7 proteins, thus resulting in increased lysosomal activity and autophagy. As a consequence, trafficking and signaling of neurotrophic factors such as nerve growth factor (NGF) in the long axons of peripheral sensory neurons are particularly vulnerable to premature degradation. A "gain of toxicity" model has, thus, been proposed based on these observations. However, studies of fly photo-sensory neurons indicate that the Rab7 mutation(s) causes a "loss of function", resulting in haploinsufficiency. In the review, we summarize experimental evidence for both hypotheses. We argue that better models (rodent animals and human neurons) of CMT2B are needed to precisely define the disease mechanisms.

Mutation Spectrum in the Large GTPase Dynamin 2, and Genotype–Phenotype Correlation in Autosomal Dominant Centronuclear Myopathy

Science.gov (United States)

Böhm, Johann; Biancalana, Valérie; DeChene, Elizabeth T.; Bitoun, Marc; Pierson, Christopher R.; Schaefer, Elise; Karasoy, Hatice; Dempsey, Melissa A.; Klein, Fabrice; Dondaine, Nicolas; Kretz, Christine; Haumesser, Nicolas; Poirson, Claire; Toussaint, Anne; Greenleaf, Rebecca S.; Barger, Melissa A.; Mahoney, Lane J.; Kang, Peter B.; Zanoteli, Edmar; Vissing, John; Witting, Nanna; Echaniz-Laguna, Andoni; Wallgren-Pettersson, Carina; Dowling, James; Merlini, Luciano; Oldfors, Anders; Ousager, Lilian Bomme; Melki, Judith; Krause, Amanda; Jern, Christina; Oliveira, Acary S. B.; Petit, Florence; Jacquette, Aurélia; Chaussenot, Annabelle; Mowat, David; Leheup, Bruno; Cristofano, Michele; Aldea, Juan José Poza; Michel, Fabrice; Furby, Alain; Llona, Jose E. Barcena; Van Coster, Rudy; Bertini, Enrico; Urtizberea, Jon Andoni; Drouin-Garraud, Valérie; Béroud, Christophe; Prudhon, Bernard; Bedford, Melanie; Mathews, Katherine; Erby, Lori A. H.; Smith, Stephen A.; Roggenbuck, Jennifer; Crowe, Carol A.; Spitale, Allison Brennan; Johal, Sheila C.; Amato, Anthony A.; Demmer, Laurie A.; Jonas, Jessica; Darras, Basil T.; Bird, Thomas D.; Laurino, Mercy; Welt, Selman I.; Trotter, Cynthia; Guicheney, Pascale; Das, Soma; Mandel, Jean-Louis; Beggs, Alan H.; Laporte, Jocelyn

2012-01-01

Centronuclear myopathy (CNM) is a genetically heterogeneous disorder associated with general skeletal muscle weakness, type I fiber predominance and atrophy, and abnormally centralized nuclei. Autosomal dominant CNM is due to mutations in the large GTPase dynamin 2 (DNM2), a mechanochemical enzyme regulating cytoskeleton and membrane trafficking in cells. To date, 40 families with CNM-related DNM2 mutations have been described, and here we report 60 additional families encompassing a broad genotypic and phenotypic spectrum. In total, 18 different mutations are reported in 100 families and our cohort harbors nine known and four new mutations, including the first splice-site mutation. Genotype–phenotype correlation hypotheses are drawn from the published and new data, and allow an efficient screening strategy for molecular diagnosis. In addition to CNM, dissimilar DNM2 mutations are associated with Charcot–Marie–Tooth (CMT) peripheral neuropathy (CMTD1B and CMT2M), suggesting a tissue-specific impact of the mutations. In this study, we discuss the possible clinical overlap of CNM and CMT, and the biological significance of the respective mutations based on the known functions of dynamin 2 and its protein structure. Defects in membrane trafficking due to DNM2 mutations potentially represent a common pathological mechanism in CNM and CMT. PMID:22396310

PREVALÊNCIA E ETIOLOGIA DA MASTITE BOVINA NO MUNICÍPIO DE TERESINA, PIAUÍ ETIOLOGY AND PREVALENCE BOVINE MASTITIS IN THE TEREZINA CITY, PI

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Nicodemus Alves de Macedo

2007-07-01

Full Text Available Estudou-se a prevalência e a etiologia da mastite em rebanhos leiteiros pertencentes à bacia leiteira do mu¬nicípio de Teresina, Piauí. Analisaram-se 852 amostras de leite, provenientes de vacas em período médio de lactação pertencentes a oito propriedades produtoras de leite tipo C. Verificou-se que 41,10% das amostras foram reagentes à prova de CMT nos mais variados graus (+, ++ e +++. Desse total, 252 (72,83% foram positivas ao exame bac¬teriológico, sendo o gênero Staphylococcus o mais preva¬lente (74,60%. PALAVRAS-CHAVES: CMT, epidemiologia, leite, Piauí (PI, Staphylococcus. The aim of present study was to verify the etiology and prevalence of bovine mastitis in the Terezina, city. A total of 852 quarters from cows during avery lactating pe¬riod raised on 8 dairy farms in Terezina, Piauí, were exa¬mined. Out of 346 (41.10% positive cows by CMT (+, ++ e +++. A total of 252 (72.83% were confirmed though bacteriological methods. From the agents isolated in pure or mixed cultures, the Staphylococcus was most frequen¬tly observed (74.60%. KEY-WORDS: CMT, epidemiology, milk, Piauí, Staphylococcus.

Synthesis and characterization of PEPO grafted carboxymethyl guar and carboxymethyl tamarind as new thermo-associating polymers.

Science.gov (United States)

Gupta, Nivika R; Torris A T, Arun; Wadgaonkar, Prakash P; Rajamohanan, P R; Ducouret, Guylaine; Hourdet, Dominique; Creton, Costantino; Badiger, Manohar V

2015-03-06

New thermo associating polymers were designed and synthesized by grafting amino terminated poly(ethylene oxide-co-propylene oxide) (PEPO) onto carboxymethyl guar (CMG) and carboxymethyl tamarind (CMT). The grafting was performed by coupling reaction between NH2 groups of PEPO and COOH groups of CMG and CMT using water-soluble EDC/NHS as coupling agents. The grafting efficiency and the temperature of thermo-association, T(assoc) in the copolymer were studied by NMR spectroscopy. The graft copolymers, CMG-g-PEPO and CMT-g-PEPO exhibited interesting thermo-associating behavior which was evidenced by the detailed rheological and fluorescence measurements. The visco-elastic properties (storage modulus, G'; loss modulus, G") of the copolymer solutions were investigated using oscillatory shear experiments. The influence of salt and surfactant on the T(assoc) was also studied by rheology, where the phenomenon of "Salting out" and "Salting in" was observed for salt and surfactant, respectively, which can give an easy access to tunable properties of these copolymers. These thermo-associating polymers with biodegradable nature of CMG and CMT can have potential applications as smart injectables in controlled release technology and as thickeners in cosmetics and pharmaceutical formulations. Copyright © 2014 Elsevier Ltd. All rights reserved.

BIOCHEMICAL AND HISTOLOGICAL EFFECTS OF TETRACYCLINES ON SPONTANEOUS OSTEOARTHRITIS IN GUINEA PIGS

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Edin De Bri

2011-05-01

Full Text Available Matrix metalloproteinases (MMPs are mediators in connective tissue destruction in a variety of pathologic processes. Recently discovered chemically modified tetracyclines have been found to be effective inhibitors of MMP mediated connective tissue degradation in both rheumatoid arthritis (RA and osteoarthritis (OA. The Hartley guinea pig model has been described with a high incidence of spontaneous OA-like changes in the knee joint. Therefore we have studied the effect of two tetracyclines, doxycycline (Dox and chemically modified tetracycline-7 (CMT-7 which have both previously been shown as potent MMP inhibitors. We found that prophylactic orally given CMT-7 decreases OA changes in the knee joints both in vitro and in vivo in the guinea pig OA model. OA changes were most severe in the central compartment of the medial condyle in the control group. Cartilage fibrillation and destruction, in addition to subchondral bone sclerosis and cyst formation were all less in the CMT-7 treated group compared with controls. Collagen, hyaluronan and proteoglycan content in cartilage was higher in the CMT-7 treated group compared with controls. In contrast, OA changes were not decreased in the Dox group. These results show that tetracyclines, but not all tetracyclines, can reduce the severity of OA in the guinea pig model of spontaneous OA.

Changes in Macular Retinal Layers and Peripapillary Nerve Fiber Layer Thickness after 577-nm Pattern Scanning Laser in Patients with Diabetic Retinopathy.

Science.gov (United States)

Shin, Ji Soo; Lee, Young Hoon

2017-12-01

The aim of this study was to evaluate the changes in thickness of each macular retinal layer, the peripapillary retinal nerve fiber layer (RNFL), and central macular thickness (CMT) after 577-nm pattern scanning laser (PASCAL) photocoagulation in patients with diabetic retinopathy. This retrospective study included 33 eyes with diabetic retinopathy that underwent 577-nm PASCAL photocoagulation. Each retinal layer thickness, peripapillary RNFL thickness, and CMT were measured by spectral-domain optical coherence tomography before 577-nm PASCAL photocoagulation, as well as at 1, 6, and 12 months after 577-nm PASCAL photocoagulation. Computerized intraretinal segmentation of optical coherence tomography was performed to identify the thickness of each retinal layer. The average thickness of the RNFL, ganglion cell layer, inner plexiform layer, inner nuclear layer, inner retinal layer, and CMT at each follow-up increased significantly from baseline (p 0.05). Each macular retinal layer and CMT had a tendency to increase for one year after 577-nm PASCAL photocoagulation, whereas the average thickness of retinal pigment epithelium decreased at one-year follow-up compared to the baseline. Although an increase in peripapillary RNFL thickness was observed one month after 577-nm PASCAL photocoagulation, there were no significant changes at the one-year follow-up compared to the baseline. © 2017 The Korean Ophthalmological Society

Neoplasias endocrinas múltiples. desde el laboratorio al paciente

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Dr. G. Nelson Wohllk

2013-09-01

Full Text Available Las neoplasias endocrinas múltiples (NEM tipo 1 y 2 son enfermedades genéticas heredadas en forma autosómica dominante. Las principales manifestaciones clínicas en NEM1 incluyen tumores paratiroideos, hipofisiarios y gastroenteropancreáticos. El test genético se puede realizar en los pacientes y potenciales portadores de mutaciones en el gen menin, pero la correlación genotipo-fenotipo es menos directa en comparación a NEM2. En la NEM2 el cáncer medular de tíroides (CMT es común a los tres subtipos: NEM2A (feocromocitoma e hiperparatiroidismo, NEM2B (feocromocitoma y neuromas mucosos y CMT familiar. A aquellos pacientes con mutación RET se les debe recomendar la realización de tiroidectomía profiláctica en la niñez, de acuerdo a la categoría de riesgo ATA. Algunos casos de CMT aparentemente esporádicos son actualmente NEM2 después de la realización del estudio genético para proto-oncogen RET, por lo tanto se recomienda la aplicación rutinaria de este estudio a todos los pacientes con CMT aparentemente esporádico.

Analysis of the AP600 core makeup tank experiments using the NOTRUMP code

International Nuclear Information System (INIS)

Cunningham, J.C.; Haberstroh, R.C.; Hochreiter, L.E.; Jaroszewicz, J.

1995-01-01

The AP600 design utilizes passive methods to perform core and containment cooling functions for a postulated loss of coolant. The core makeup tank (CMT) is an important feature of the AP600 passive safety system. The NOTRUMP code has been compared to the 300-series core makeup tank experiments. It has been observed that the code will capture the correct thermal-hydraulic behavior observed in the experiments. The correlations used for wall film condensation and convective heat transfer to the heated CMT liquid appear to be appropriate for these applications. The code will predict the rapid condensation and mixing thermal-hydraulic behavior observed in the 300-series tests. The NOTRUMP predictions can be noding-dependent since the condensation is extremely dependent on the amount of cold CMT liquid that mixes with the incoming steam flow

An oral Na(V)1.8 blocker improves motor function in mice completely deficient of myelin protein P-0

DEFF Research Database (Denmark)

Rosberg, Mette R.; Alvarez Herrero, Susana; Krarup, Christian

2016-01-01

Mice deficient of myelin protein P0 are established models of demyelinating Charcot-Marie-Tooth (CMT) disease. Dysmyelination in these mice is associated with an ectopic expression of the sensory neuron specific sodium channel isoform NaV1.8 on motor axons. We reported that in P0+/−, a model of CMT......1B, the membrane dysfunction could be acutely improved by a novel oral NaV1.8 blocker referred to as Compound 31 (C31, Bioorg. Med. Chem. Lett. 2010, 20, 6812; AbbVie Inc.). The aim of this study was to investigate the extent to which C31 treatment could also improve the motor axon function in P0......-of-concept that treatment with oral subtype-selective NaV1.8 blockers could be used to improve the motor function in severe forms of demyelinating CMT....

Motivation, working memory, and decision making: a cognitive-motivational theory of personality vulnerability to alcoholism.

Science.gov (United States)

Finn, Peter R

2002-09-01

This article presents a cognitive-motivational theory (CMT) of the mechanisms associated with three basic dimensions of personality vulnerability to alcoholism, impulsivity/novelty seeking, harm avoidance, and excitement seeking. CMT describes the interrelationships between activity in basic motivational systems and attentional, decision-making and working memory processes as the mechanisms associated with variation in each personality trait. Impulsivity/novelty seeking reflects activity in both appetitive and inhibitory motivational systems, greater attention to reward cues, and increased emotional reactivity to reward and frustration. Harm avoidance reflects individual differences in fearfulness and activity in specific inhibitory systems. Excitement seeking reflects the need to engage in appetitive behaviors in less predictable environments to experience positive affect. CMT also describes the impact of working memory and the specific motivational processes underlying each trait dimension on the dynamics of decision making from the perspective of decision field theory.

The evolution of CHROMOMETHYLASES and gene body DNA methylation in plants

OpenAIRE

Leebens-Mack, Jim; Griffin, Patrick; Rohr, Nicholas; Niederhuth, Chad; Ji, Lexiang; Bewick, Adam; Schmitz, Robert

2017-01-01

Background The evolution of gene body methylation (gbM), its origins, and its functional consequences are poorly understood. By pairing the largest collection of transcriptomes (>1000) and methylomes (77) across Viridiplantae, we provide novel insights into the evolution of gbM and its relationship to CHROMOMETHYLASE (CMT) proteins. Results CMTs are evolutionary conserved DNA methyltransferases in Viridiplantae. Duplication events gave rise to what are now referred to as CMT1, 2 and 3. Indepe...

Performance of Multithreaded Chip Multiprocessors And Implications for Operating System Design

OpenAIRE

Fedorova, Alexandra; Seltzer, Margo I.; Small, Christopher A.; Nussbaum, Daniel

2005-01-01

An operating system’s design is often influenced by the architecture of the target hardware. While uniprocessor and multiprocessor architectures are well understood, such is not the case for multithreaded chip multiprocessors (CMT) – a new generation of processors designed to improve performance of memory-intensive applications. The first systems equipped with CMT processors are just becoming available, so it is critical that we now understand how to obtain the best performance from such syst...

Loss of the E3 ubiquitin ligase LRSAM1 sensitizes peripheral axons to degeneration in a mouse model of Charcot-Marie-Tooth disease

OpenAIRE

Bogdanik, Laurent P.; Sleigh, James N.; Tian, Cong; Samuels, Mark E.; Bedard, Karen; Seburn, Kevin L.; Burgess, Robert W.

2013-01-01

SUMMARY Charcot-Marie-Tooth disease (CMT) is a clinically and genetically heterogeneous condition characterized by peripheral axon degeneration with subsequent motor and sensory deficits. Several CMT gene products function in endosomal sorting and trafficking to the lysosome, suggesting that defects in this cellular pathway might present a common pathogenic mechanism for these conditions. LRSAM1 is an E3 ubiquitin ligase that is implicated in this process, and mutations in LRSAM1 have rece...

Radio frequency regenerative oscillations in monolithic high-Q/V heterostructured photonic crystal cavities

International Nuclear Information System (INIS)

Yang, Jinghui; Gu, Tingyi; Zheng, Jiangjun; Wei Wong, Chee; Yu, Mingbin; Lo, Guo-Qiang; Kwong, Dim-Lee

2014-01-01

We report temporal and spectral domain observation of regenerative oscillation in monolithic silicon heterostructured photonic crystals cavities with high quality factor to mode volume ratios (Q/V). The results are interpreted by nonlinear coupled mode theory (CMT) tracking the dynamics of photon, free carrier population, and temperature variations. We experimentally demonstrate effective tuning of the radio frequency tones by laser-cavity detuning and laser power levels, confirmed by the CMT simulations with sensitive input parameters

X-ray computed microtomography analysis of the influence of different agricultural treatments on the topsoil porosity of a Grey Brown Luvisol from Ontario

Science.gov (United States)

Taina, I. A.; Heck, R. J.; Scaiff, N. T.

2009-05-01

One of the most important applications of X-ray computed tomography (CT) for the study of soil is the characterization of the shape and spatial distribution of pores. Analysis of 3D X-ray CT image data, related to different pore categories, can provide insight to soil structural changes, which have implications in water infiltration and soil aeration, resulting from agricultural practices. The aim of this study was to evaluate changes in the spatial characteristics of voids, due to tillage practices, in the Ap horizon of an Orthic Grey- Brown Luvisol (located at the Elora Research Station of the University of Guelph). Undisturbed oriented soil samples were collected from ten plots representing different tillage treatments: spring moldboard plow, spring moldboard plow, cultivate and pack, fall moldboard plow, cultivate and pack, spring tandem disc, no cultivator, fall offset disc, fall offset disc, cultivate and pack, fall chisel plow, cultivate and pack, zero zone till (soys twin rows), zero tillage (long term), and zero tillage (corn residue removed in row, soys twin rows). Since the utilization of standardized classes, in the quantification of similar features, proved to be necessary in order to obtain comparable results, categories of pores, separated according to their size, circularity and orientation were considered in the interpretation of data. Total volume of pores and volume percentage of each class were calculated, revealing substantial differences among the analyzed soil samples.

Strain-dependent evolution of garnets in a high pressure ductile shear zone using Synchroton x-ray microtomography

Science.gov (United States)

Macente, Alice; Fusseis, Florian; Menegon, Luca; John, Timm

2016-04-01

Synkinematic reaction microfabrics carry important information on the kinetics, timing and rheology of tectonometamorphic processes. Despite being routinely interpreted in metamorphic and structural studies, reaction and deformation microfabrics are usually described in two dimensions. We applied Synchrotron-based x-ray microtomography to document the evolution of a pristine olivine gabbro into a deformed omphacite-garnet eclogite in 3D. In the investigated samples, which cover a strain gradient into a shear zone from the Western Gneiss Region (Norway) previously described by John et al., (2009), we focused on the spatial transformation of garnet coronas into elongated clusters of garnets. Our microtomographic data allowed us to quantify changes to the garnet volume, their shapes and their spatial arrangement. We combined microtomographic observations with light microscope- and backscatter electron images as well as electron microprobe- (EMPA) and electron backscatter diffraction (EBSD) analyses to correlate mineral composition and orientation data with the x-ray absorption signal of the same mineral grains. This allowed us to extrapolate our interpretation of the metamorphic microfabric evolution to the third dimension, effectively yielding a 4-dimensional dataset. We found that: - The x-ray absorption contrast between individual mineral phases in our microtomographic data is sufficient to allow the same petrographic observations than in light- and electron microscopy, but extended to 3D. - Amongst the major constituents of the synkinematic reactions, garnet is the only phase that can be segmented confidently from the microtomographic data. - With increasing deformation, the garnet volume increases from about 9% to 25%. - Garnet coronas in the gabbros never completely encapsulate olivine grains. This may indicate that the reaction progressed preferentially in some directions, but also leaves pathways for element transport to and from the olivines that are

Biological activity determination of I-BSP, a potent MMP 2 inhibitor, and its 123I tracer synthesis

International Nuclear Information System (INIS)

Oltenfreiter, R.; Staelens, L.; Slegers, G.; Lejeune, A.; Frankenne, F.; Dierckx, R.A.

2002-01-01

Aim: Matrix metalloproteinases (MMPs) are a family of at least 18 secreted and membrane-bound zinc endopeptidases. Collectively they function in the degradation of extracellular matrix proteins and play an important role in both normal and pathological tissue remodelling. Increased MMP activity is detected in a wide range of cancers and seems to be correlated to their invasive and metastatic potential. MMPs thus seem an attractive target for both diagnostic (SPECT tracer) and therapeutic purposes. Therefore, we synthesised a 123 I-labelled MMP 2 inhibitor and evaluated it in vitro. Materials and methods: The 123 I-labelled compound was synthesised by a Cu-assisted nucleophilic non-isotopic exchange starting from Br-BSP. After reaction, the mixture was purified by HPLC. IC 50 values were obtained by in vitro enzyme assays. A 1:1 mix between non-radiolabelled inhibitor (concentration range: 300 nM - 0.05 nM) and enzymes (MMP2, cMT1-MMP, cMT3-MMP) was incubated for 15 minutes at 37 0 C. The fluorescent substrate (Mca-Pro-Leu-Gly-Leu-Dap(Dnp)-Ala-Arg-NH2) was added and the increase of fluorescence versus time, due to the hydrolysis of substrate, was measured (GEMINI-XS, λ exc = 328 nm and λ em = 393nm). Initial velocities were calculated for different concentrations of inhibitor and the IC 50 values were then determined. Results: Radiochemical yield was 30% ±3%. Radiochemical purity was >95%. IC 50 values for inhibition of MMP2, cMT3-MMP and cMT1-MMP were 0.5 nM, 7.1 nM and 16.9 nM respectively. Conclusion: 123 I-BSP was synthesised with 30% ±3% yield. After HPLC the radiochemical purity was >95%. In vitro enzyme assays of I-BSP showed an inhibition of MMP2, cMT3-MMP and cMT1-MMP in the low nM range (0.5 nM, 7.1 nM and 16.9 nM respectively). In vivo studies (biodistribution, metabolizing) in mice will be performed in the near future

Fixture-abutment connection surface and micro-gap measurements by 3D micro-tomographic technique analysis

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Deborah Meleo

2012-01-01

Full Text Available X-ray micro-tomography (micro-CT is a miniaturized form of conventional computed axial tomography (CAT able to investigate small radio-opaque objects at a-few-microns high resolution, in a nondestructive, non-invasive, and tri-dimensional way. Compared to traditional optical and electron microscopy techniques, which provide two-dimensional images, this innovative investigation technology enables a sample tri-dimensional analysis without cutting, coating or exposing the object to any particular chemical treatment. X-ray micro-tomography matches ideal 3D microscopy features: the possibility of investigating an object in natural conditions and without any preparation or alteration; non-invasive, non-destructive, and sufficiently magnified 3D reconstruction; reliable measurement of numeric data of the internal structure (morphology, structure and ultra-structure. Hence, this technique has multi-fold applications in a wide range of fields, not only in medical and odontostomatologic areas, but also in biomedical engineering, materials science, biology, electronics, geology, archaeology, oil industry, and semi-conductors industry. This study shows possible applications of micro-CT in dental implantology to analyze 3D micro-features of dental implant to abutment interface. Indeed, implant-abutment misfit is known to increase mechanical stress on connection structures and surrounding bone tissue. This condition may cause not only screw preload loss or screw fracture, but also biological issues in peri-implant tissues.

Immediate effects of using ankle-foot orthoses in the kinematics of gait and in the balance reactions in Charcot-Marie-Tooth disease

OpenAIRE

Pereira, Rouse Barbosa; Felício, Lílian Ramiro; Ferreira, Arthur de Sá; Menezes, Sara Lúcia de; Freitas, Marcos Raimundo Gomes de; Orsini, Marco

2014-01-01

The Charcot-Marie-Tooth (CMT) disease is a peripheral hereditary neuropathy with progressive distal muscle atrophy and weakness, mainly in lower limbs, that evolves limiting the gait and balance. The objective of the study was to analyse the immediate effects of using Ankle-Foot Orthosis (AFO) in the gait's kinematics and balance in patients with CMT. Nine individuals were evaluated by Tinetti scales and Dynamic Gait Index (DGI) and gait's kinematics parameters through the motion capturing sy...

Productive performance and efficiency of utilization of the diet components in dairy cows fed castor meal treated with calcium oxide

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Juliana Variz Cobianchi

2012-10-01

Full Text Available The effect of replacing of 0; 0.33; 0.67 and 1.0 (kg/kg of soybean meal (SBM by undecorticated castor seed meal treated with calcium oxide (CMT - 60 g/kg was evaluated on performance and efficiency of nutrient utilization in dairy cows. Sixteen Holstein and crossbred cows were distributed in four 4 × 4 latin squares. Animals received concentrated feed at a ratio of 1 kg for 3 kg of milk produced, in the natural matter. The diets had the same amount of nitrogen (150.4 g crude protein/kg DM, containing 325.6 g of concentrated feed/kg DM. There was no effect on the serum concentration of transaminase and the animals showed no clinical symptoms of intoxication by ricin. The intake of DM, crude protein (CP and non-fibrous carbohydrates (NFC reduced from 0.67 replacement of SBM by CMT. The intake of neutral detergent fibers corrected for ash and protein (NDFap increased from 0.33 replacement of SBM with CMT. Although the digestibility of dietary components decreased from 0.33 replacement, the intake of digestible components only reduced from 0.67 replacement. Because of the reduction of digestible energy, the synthesis of microbial CP and the utilization efficiency of rumen-degradable protein for the synthesis of microbial CP reduced with full replacement of SBM by CMT. Milk yield, milk composition, daily variation of body weight and the efficiency of utilization of the nutrients for the synthesis of N in milk reduced from 0.67 replacement of SBM by CMT. Castor seed meal treated with calcium oxide can replace up to 0.33 of SBM (50 g/kg DM diet DM in the diet of dairy cows with an average milk production of 20 kg/day.

Phacoemulsification with intravitreal bevacizumab injection in diabetic patients with macular edema and cataract.

Science.gov (United States)

Akinci, Arsen; Batman, Cosar; Ozkilic, Ersel; Altinsoy, Ali

2009-01-01

The purpose of this study was to evaluate the results of phacoemulsification with intravitreal bevacizumab injection in patients with diabetic clinically significant macular edema and cataract. The records of 31 patients with diabetic clinically significant macular edema and cataract, which would interfere with macular laser photocoagulation, who have undergone phacoemulsification with intravitreal injection of 1.25 mg bevacizumab were retrospectively evaluated. All patients had undergone focal or modified grid laser photocoagulation 1 month after the surgery. All patients were evaluated by spectral optical coherence tomography/optical coherence tomography SLO before and 1 and 3 months after the surgery beyond complete ophthalmologic examination. The best-corrected visual acuity (BCVA) levels and central macular thickness (CMT) recorded at the first and third months after the surgery were compared with the initial values. Paired samples t test was used for statistical analysis. The mean initial BCVA was 0.10 +/- 0.04 (range, 0.05-0.2). The mean BCVA at the first and third months after the surgery were 0.47 +/- 0.16 (standard deviation) (range, 0.2-0.5) and 0.51 +/- 0.12 (standard deviation) (range, 0.3-0.6), respectively. The BCVA level recorded at the first and third months after the surgery were significantly higher than the initial BCVA (P = 0.004). The mean initial CMT was 387.5 +/- 109.5 microm. The mean CMT at the first and third months after the surgery were 292.7 +/- 57.2 and 275.5 +/- 40.3. The CMT recorded at the first and third months after the surgery were significantly lower than the initial CMT (P < 0.001, P < 0.001). Phacoemulsification with intravitreal injection of bevacizumab provides improvement in clinically significant macular edema with a gain in BCVA in patients with diabetes with clinically significant macular edema and cataract.