scholarly journals Diffraction/Scattering Tomography on multi-phase crystalline/amorphous materials

2014 ◽  
Vol 70 (a1) ◽  
pp. C139-C139 ◽  
Author(s):  
Michelle Alvarez-Murga ◽  
Pierre Bleuet ◽  
Christophe Lepoittevin ◽  
Nathalie Boudet ◽  
Gaston Gabarino ◽  
...  
Keyword(s):  
Amorphous Materials ◽  
Structural Information ◽  
Local Variation ◽  
X Rays ◽  
Complex Materials ◽  
Diffraction Scattering ◽  
Invasive Approach ◽  
Non Invasive ◽  
Phase Selectivity ◽  
Multi Phase

By suitably combining diffraction/scattering and tomography (DSCT), it is possible to access to selective submicron 2D/3D structural and micro-structural information, which cannot be obtained from separate, independent diffraction and tomography experiments. DSCT is used to discriminate between multi-phase crystalline and amorphous materials, especially when the similarities in densities limit the use of other methods. In addition, this method is sensitive to local variation of the crystalline state, texture, grain size or strains inside the object and can allow simultaneous 3D mappings of such properties. The DSCT phase-selectivity can be easily combined with fluorescence and absorption for added chemical and density resolution allowing multi-modal analyses. As samples can be used in their original state, this method can be applied without cutting or polishing them. Moreover the setup can be adapted with specific sample environments in order to monitor phase and microstructure evolution as a function of an externally controlled parameter with a non-invasive approach. After a first report on in 1998 [1], since 2008 capabilities of DSCT have been demonstrated using x-rays on complex materials as diverse as biological tissue, pigments, Portland cements, Carbon-based materials, Uranium-based nuclear fuel, Ni/Al2O3 catalysts or amorphous systems [2]. More recently, the technique has evolved towards quantitative characterization of the microstructure and stress/strain through either Rietveld or Peak Profile analyses and also pair distribution function techniques (PDF) and their application to nanostructured materials [3]. In this poster contribution, we briefly review the principle and methodology of pencil-beam based x-ray DSCT which is two-fold: (i) selective structural imaging and (ii) extraction of selective scattered patterns of ultra-minor phases.

Diffraction/scattering computed tomography for three-dimensional characterization of multi-phase crystalline and amorphous materials

2012 ◽  
Vol 45 (6) ◽  
pp. 1109-1124 ◽  
Author(s):  
M. Álvarez-Murga ◽  
P. Bleuet ◽  
J.-L. Hodeau
Keyword(s):  
Computed Tomography ◽  
Amorphous Materials ◽  
Materials Science ◽  
Three Dimensional ◽  
Diffraction Scattering ◽  
Amorphous Phases ◽  
The Matrix ◽  
Local Patterns ◽  
Structural Image ◽  
Multi Phase

The three-dimensional characterization method described herein is based on diffraction and scattering techniques combined with tomography and uses the variation of these signals to reconstruct a two-dimensional/three-dimensional structural image. To emphasize the capability of the method in discriminating between different poorly ordered phases, it is named diffraction/scattering computed tomography (DSCT). This combination not only allows structural imaging but also yields an enhancement of the weak signals coming from minor phases, thereby increasing the sensitivity of structural probes. This article reports the suitability of the method for discrimination of polycrystalline and amorphous phases and for extraction of their selective local patterns with a contrast sensitivity of about 0.1% in weight of minor phases relative to the matrix. The required background in tomography is given and then the selectivity of scattering signal, the efficiency of the method, reconstruction artefacts and limitations are addressed. The approach is illustrated through different examples covering a large range of applications based on recent literature, showing the potential of DSCT in crystallography and materials science, particularly when functional and/or precious samples with sub-micrometre features have to be investigated in a nondestructive way.

The atomic scale structure of graphene powder studied by neutron and X-ray diffraction

2015 ◽  
Vol 48 (5) ◽  
pp. 1429-1436 ◽  
Author(s):  
Natalia Woznica ◽  
Lukasz Hawelek ◽  
Henry E. Fischer ◽  
Ivan Bobrinetskiy ◽  
Andrzej Burian
Keyword(s):  
Amorphous Materials ◽  
Structural Information ◽  
Topological Defects ◽  
Md Simulations ◽  
Atomic Scale ◽  
Wide Angle ◽  
X Rays ◽  
X Ray ◽  
Neutron Diffractometer ◽  
Bond Order Potential

The structure of graphene obtained by chemical exfoliation of graphiteviathe oxidation/reduction procedure has been determined using wide-angle scattering of neutrons and X-rays combined with computer simulations based on classical molecular dynamics (MD). A comparison of results obtained from wide-angle neutron scattering (WANS) with the D4 neutron diffractometer dedicated for liquids and amorphous materials (Institute Laue–Langevin in Grenoble) and from wide-angle X-ray scattering (WAXS) with the laboratory Rigaku-Denki D/MAX RAPID II diffractometer has shown that both techniques provide data of a good quality that can be used to derive precise and valuable structural information about graphene. To obtain detailed structural information, the paracrystal formalism has been used along with MD simulations. The MD simulations were performed at 300 K with second-generation reactive empirical bond order potential for atoms lying in the same layer and the Lennard–Jones potential for interlayer interactions. The proposed models consist of three-layered systems, 36 Å in diameter, in which mono-vacancy, di-vacancy and Stone–Thrower–Wales types of defects are introduced. The reported results show that the WANS and WAXS methods together with the MD simulations contribute to a detailed description of the graphene materials, including the presence of topological defects, which is important as their structure at the atomic scale dramatically affects their electrical and mechanical properties.

Structural studies of small amorphous volumes by electron diffraction

1990 ◽  
Vol 48 (4) ◽  
pp. 122-123
Author(s):  
Pierre Moine
Keyword(s):  
Electron Diffraction ◽  
Born Approximation ◽  
Structural Information ◽  
Fundamental Relation ◽  
X Rays ◽  
Structural Studies ◽  
Diffraction Experiment ◽  
Transmission Electron ◽  
Amorphous Structures ◽  
Diffraction Patterns

Qualitatively, amorphous structures can be easily revealed and differentiated from crystalline phases by their Transmission Electron Microscopy (TEM) images and their diffraction patterns (fig.1 and 2) but, for quantitative structural information, electron diffraction pattern intensity analyses are necessary. The parameters describing the structure of an amorphous specimen have been introduced in the context of scattering experiments which have been, so far, the most used techniques to obtain structural information in the form of statistical averages. When only small amorphous volumes (< 1/μm in size or thickness) are available, the much higher scattering of electrons (compared to neutrons or x rays) makes, despite its drawbacks, electron diffraction extremely valuable and often the only feasible technique.In a diffraction experiment, the intensity IN (Q) of a radiation, elastically scattered by N atoms of a sample, is measured and related to the atomic structure, using the fundamental relation (Born approximation) : IN(Q) = |FT[U(r)]|.

scholarly journals Salivary cortisol as a non-invasive approach to assess stress in dystocic dairy calves

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Levente Kovács ◽  
Fruzsina Luca Kézér ◽  
Szilárd Bodó ◽  
Ferenc Ruff ◽  
Rupert Palme ◽  
...  
Keyword(s):  
Birth Weight ◽  
Body Condition ◽  
Salivary Cortisol ◽  
Sampling Period ◽  
Dairy Calves ◽  
Birth Process ◽  
Invasive Approach ◽  
Non Invasive ◽  
Saliva Cortisol ◽  
Cortisol Levels

AbstractThe intensity and the magnitude of saliva cortisol responses were investigated during the first 48 h following birth in newborn dairy calves which underwent normal (eutocic, EUT, n = 88) and difficult (dystocic, DYS, n = 70) calvings. The effects of parity and body condition of the dam, the duration of parturition, the time spent licking the calf, the sex and birth weight of the calf were also analyzed. Neonatal salivary cortisol concentrations were influenced neither by factors related to the dam (parity, body condition) nor the calf (sex, birth weight). The duration of parturition and the time spent licking the calf also had no effect on salivary cortisol levels. Salivary cortisol concentrations increased rapidly after delivery in both groups to reach their peak levels at 45 and 60 min after delivery in EUT and DYS calves, respectively supporting that the birth process means considerable stress for calves and the immediate postnatal period also appears to be stressful for newborn calves. DYS calves exhibited higher salivary cortisol concentrations compared to EUT ones for 0 (P = 0.022), 15 (P = 0.016), 30 (P = 0.007), 45 (P = 0.003), 60 (P = 0.001) and 120 min (P = 0.001), and for 24 h (P = 0.040), respectively. Peak levels of salivary cortisol and the cortisol release into saliva calculated as AUC were higher in DYS than in EUT calves for the 48-h of the sampling period (P = 0.009 and P = 0.003, respectively). The greater magnitude of saliva cortisol levels in DYS calves compared to EUT ones suggest that difficult parturition means severe stress for bovine neonates and salivary cortisol could be an opportunity for non-invasive assessment of stress during the early neonatal period in cattle.

A NOVEL EXTENSIVE EX-VIVO OCT DATABASE FROM MURINE MODELS OF COLORECTAL CANCER

2021 ◽  
Vol 108 (Supplement_3) ◽  
Author(s):  
J Bote ◽  
J F Ortega-Morán ◽  
C L Saratxaga ◽  
B Pagador ◽  
A Picón ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Machine Learning ◽  
Structural Information ◽  
Ex Vivo ◽  
Ground Truth ◽  
Colon Polyps ◽  
Learning Methods ◽  
Non Invasive ◽  
Machine Learning Methods ◽  
In Situ Methods

Abstract INTRODUCTION New non-invasive technologies for improving early diagnosis of colorectal cancer (CRC) are demanded by clinicians. Optical Coherence Tomography (OCT) provides sub-surface structural information and offers diagnosis capabilities of colon polyps, further improved by machine learning methods. Databases of OCT images are necessary to facilitate algorithms development and testing. MATERIALS AND METHODS A database has been acquired from rat colonic samples with a Thorlabs OCT system with 930nm centre wavelength that provides 1.2KHz A-scan rate, 7μm axial resolution in air, 4μm lateral resolution, 1.7mm imaging depth in air, 6mm x 6mm FOV, and 107dB sensitivity. The colon from anaesthetised animals has been excised and samples have been extracted and preserved for ex-vivo analysis with the OCT equipment. RESULTS This database consists of OCT 3D volumes (C-scans) and 2D images (B-scans) of murine samples from: 1) healthy tissue, for ground-truth comparison (18 samples; 66 C-scans; 17,478 B-scans); 2) hyperplastic polyps, obtained from an induced colorectal hyperplastic murine model (47 samples; 153 C-scans; 42,450 B-scans); 3) neoplastic polyps (adenomatous and adenocarcinomatous), obtained from clinically validated Pirc F344/NTac-Apcam1137 rat model (232 samples; 564 C-scans; 158,557 B-scans); and 4) unknown tissue (polyp adjacent, presumably healthy) (98 samples; 157 C-scans; 42,070 B-scans). CONCLUSIONS A novel extensive ex-vivo OCT database of murine CRC model has been obtained and will be openly published for the research community. It can be used for classification/segmentation machine learning methods, for correlation between OCT features and histopathological structures, and for developing new non-invasive in-situ methods of diagnosis of colorectal cancer.

scholarly journals AB0945 CONTRIBUTION OF MICROBIOLOGICAL AND ANATOMOPATHOLOGICAL EXAMINATIONS IN THE DIAGNOSIS OF SPONTANEOUS PYOGENIC SPONDYLODISCITIS IN ADULTS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1771.3-1771
Author(s):  
I. Mahmoud ◽  
M. Moalla ◽  
A. Ben Tekaya ◽  
S. Bouden ◽  
R. Tekaya ◽  
...  
Keyword(s):  
Histopathological Examination ◽  
Klebsiella Oxytoca ◽  
Rare Condition ◽  
Blood Cultures ◽  
X Rays ◽  
Skin Sample ◽  
Bacteriological Study ◽  
Non Invasive ◽  
Pyogenic Spondylodiscitis ◽  
Serious Infection

Background:Pyogenic spondylodiscitis (SPD) is a serious infection of an intervertebral disc and/or adjacent vertebrae, that remains a topical problem in rheumatological practice. Early diagnosis and treatment are the only guarantees of a favorable outcome. Clinicians must strive to isolate the responsible bacteria in order to adapt the treatment, and thus reduce the risk of resistance and complications due to SPD itself, but also to the multiplication of probabilistic treatments.Objectives:Our aim was to study the contribution of the different microbiological and anatomopathological examinations in the diagnosis of pyogenic SPD.Methods:It was a descriptive study in a single rheumatology department. Data were collected retrospectively from observations of patients hospitalized in the past 20 years who have been diagnosed with pyogenic SPD. We excluded cases of tuberculous and brucellar SPD from our study because of their completely different histological and microbiological profiles.Results:Twenty-two cases of pyogenic SPD were collected (14M/ 8F). The mean age of the population was 55.9 years [29,80]. A bacteriological survey including at least one cytobacteriological examination of the urine (CBEU), chest X-rays and blood cultures allowed the identification of the bacteria in 16 cases (73%). The most common site were bacteria was identified was blood culture in 7 cases, skin sample and urine collection in 2 cases each. Disco-vertebral puncture and biopsy (DVPB) was performed in 19 patients when there was no bacteria identification and/or when diagnosis of infectious SPD persisted doubtful. On histopathological examination, were described: an infiltrate and/or inflammatory changes without specificity signs in 7 patients and an appearance of chronic pyogenic SPD very likely in 12 patients. Bacteriological study of DVPB fluid or paravertebral abscesses sample helped to isolate bacteria in 4 patients. DVPB or abscesses puncture were contributing by histological and/or bacteriological examination in 12 patients (63%).Infecting bacteria was identified in 14 patients (64%). Gram-negative bacilli (GNB) and staphylococcus aureus were the most frequent germs (7 cases each) including 2 cases of co-infection. GNBs were represented by: Escherichia Coli and Enterobacter Cloacae in 2 cases each, Proteus Mirabilis, Serratia Marcescens and Klebsiella oxytoca in 1 case each. Clostridium clostridioforme and Lactococcus cremoris were isolated in 1 case each. For patients whose etiological investigation remained negative, SPD diagnosis was retained based on imaging (MRI) guided by anamnestic, clinico-biological and histopathological arguments.Conclusion:SPD is a rare condition that needs to be treated rapidly. Once the diagnosis is suspected, bacteria must be isolated before starting any antibiotic therapy. Simple and non-invasive exams as blood cultures, CBUE and chest rays, should be undertaken first. In fact, these simple exams allowed a germ identification in 73% cases in our study. If doubt persist, DVPB could be contributive to the diagnosis.References:NoneDisclosure of Interests:None declared

scholarly journals The Cat Mandible (II): Manipulation of the Jaw, with a New Prosthesis Proposal, to Avoid Iatrogenic Complications

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 683
Author(s):  
Matilde Lombardero ◽  
Mario López-Lombardero ◽  
Diana Alonso-Peñarando ◽  
María del Mar Yllera
Keyword(s):  
Imaging Techniques ◽  
Recovery Period ◽  
Prosthesis Design ◽  
Patient Specific ◽  
Mandibular Fractures ◽  
Rigid Fixation ◽  
Invasive Approach ◽  
Non Invasive ◽  
Iatrogenic Complications ◽  
Mandibular Body

The cat mandible is relatively small, and its manipulation implies the use of fixing methods and different repair techniques according to its small size to keep its biomechanical functionality intact. Attempts to fix dislocations of the temporomandibular joint should be primarily performed by non-invasive techniques (repositioning the bones and immobilisation), although when this is not possible, a surgical method should be used. Regarding mandibular fractures, these are usually concurrent with other traumatic injuries that, if serious, should be treated first. A non-invasive approach should also first be considered to fix mandibular fractures. When this is impractical, internal rigid fixation methods, such as osteosynthesis plates, should be used. However, it should be taken into account that in the cat mandible, dental roots and the mandibular canal structures occupy most of the volume of the mandibular body, a fact that makes it challenging to apply a plate with fixed screw positions without invading dental roots or neurovascular structures. Therefore, we propose a new prosthesis design that will provide acceptable rigid biomechanical stabilisation, but avoid dental root and neurovascular damage, when fixing simple mandibular body fractures. Future trends will include the use of better diagnostic imaging techniques, a patient-specific prosthesis design and the use of more biocompatible materials to minimise the patient’s recovery period and suffering.

scholarly journals Holistic description of new deep sea megafauna (Cephalopoda: Cirrata) using a minimally invasive approach

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Alexander Ziegler ◽  
Christina Sagorny
Keyword(s):  
Minimally Invasive ◽  
Dna Barcoding ◽  
Deep Sea ◽  
Imaging Techniques ◽  
Structural Complexity ◽  
Micro Computed Tomography ◽  
Invasive Approach ◽  
Non Invasive ◽  
Additional Support ◽  
Holistic Description

Abstract Background In zoology, species descriptions conventionally rely on invasive morphological techniques, frequently leading to damage of the specimens and thus only a partial understanding of their structural complexity. More recently, non-destructive imaging techniques have successfully been used to describe smaller fauna, but this approach has so far not been applied to identify or describe larger animal species. Here, we present a combination of entirely non-invasive as well as minimally invasive methods that permit taxonomic descriptions of large zoological specimens in a more comprehensive manner. Results Using the single available representative of an allegedly novel species of deep-sea cephalopod (Mollusca: Cephalopoda), digital photography, standardized external measurements, high-field magnetic resonance imaging, micro-computed tomography, and DNA barcoding were combined to gather all morphological and molecular characters relevant for a full species description. The results show that this specimen belongs to the cirrate octopod (Octopoda: Cirrata) genus Grimpoteuthis Robson, 1932. Based on the number of suckers, position of web nodules, cirrus length, presence of a radula, and various shell characters, the specimen is designated as the holotype of a new species of dumbo octopus, G. imperator sp. nov. The digital nature of the acquired data permits a seamless online deposition of raw as well as derived morphological and molecular datasets in publicly accessible repositories. Conclusions Using high-resolution, non-invasive imaging systems intended for the analysis of larger biological objects, all external as well as internal morphological character states relevant for the identification of a new megafaunal species were obtained. Potentially harmful effects on this unique deep-sea cephalopod specimen were avoided by scanning the fixed animal without admixture of a contrast agent. Additional support for the taxonomic placement of the new dumbo octopus species was obtained through DNA barcoding, further underlining the importance of combining morphological and molecular datasets for a holistic description of zoological specimens.

Platelet production estimation in thrombocytopenic patient: a non-invasive or invasive approach?

2004 ◽  
Vol 25 (4) ◽  
pp. 422 ◽  
Author(s):  
M. Todorovic-Tirnanic ◽  
V. Obradovic ◽  
N. Suvajdzic ◽  
I. Elezovic ◽  
M. Rolovic ◽  
...  
Keyword(s):  
Invasive Approach ◽  
Platelet Production ◽  
Non Invasive ◽  
Thrombocytopenic Patient

scholarly journals Phenotyping plants: genes, phenes and machines

2012 ◽  
Vol 39 (11) ◽  
pp. 813 ◽  
Author(s):  
Roland Pieruschka ◽  
Hendrik Poorter
Keyword(s):  
Structural Information ◽  
Plant Phenotyping ◽  
Phenotypic Traits ◽  
Special Issue ◽  
Non Invasive ◽  
The Core ◽  
The Relationship ◽  
Non Destructive ◽  
Major Progress ◽  
Meaningful Data

No matter how fascinating the discoveries in the field of molecular biology are, in the end it is the phenotype that matters. In this paper we pay attention to various aspects of plant phenotyping. The challenges to unravel the relationship between genotype and phenotype are discussed, as well as the case where ‘plants do not have a phenotype’. More emphasis has to be placed on automation to match the increased output in the molecular sciences with analysis of relevant traits under laboratory, greenhouse and field conditions. Currently, non-destructive measurements with cameras are becoming widely used to assess plant structural properties, but a wider range of non-invasive approaches and evaluation tools has to be developed to combine physiologically meaningful data with structural information of plants. Another field requiring major progress is the handling and processing of data. A better e-infrastructure will enable easier establishment of links between phenotypic traits and genetic data. In the final part of this paper we briefly introduce the range of contributions that form the core of a special issue of this journal on plant phenotyping.

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