A comparative study to determine the shock absorption ability of two popular mouth guards available on the South African market

It is expected that most mouth guards will provide some level of protection to teeth. In this study a device was developed to measure the relative impact absorption of two different mouth guards (Proform, Type III vacuum-formed and Max, Type IV pressure laminate). Seven of each of the two types of mouth guards were made and each batch was exposed to between six and 10 impact trials.DHE

Apport diagnostique du dosage des chaînes légères libres sériques d'immunoglobulines pour l'exploration des gammapathies monoconales

RésuméLes gammapathies monoclonales sont d\u27occurrence non négligeable (3,2 %) chez les sujets de plus de 50 ans. Pour environ la moitié d\u27entre elles, elles correspondent, lors de leur découverte, à une gammapathie monoclonale de signification indéterminée (ou MGUS en anglais pour monoclonal gammopathy of undetermined significance). Un peu plus du tiers sont des hémopathies lymphoïdes B avérées (myélome multiple, maladie de Waldenström, amylose) qui représentent le stade ultime de progression des MGUS avec une incidence annuelle de 1 %. L\u27exploration biologique immunologique validée à ce jour repose sur une analyse conjointe du sérum et des urines par immunoélectrophorèse/immunofixation qui vise à typer l\u27immunoglobuline monoclonale. Depuis 2001, un nouveau dosage est proposé pour la prise en charge diagnostique de ces patients : la détermination néphélémétrique ou turbidimétrique des chaînes légères libres (CLL) d\u27immunoglobulines kappa et lambda à l\u27aide d\u27anti-sérums spécifiques avec détermination du rapport κ/λ dont le déséquilibre peut être indicateur d\u27un excès de production monoclonale. Cela reste cependant un dosage quantitatif qui ne peut faire la preuve d\u27une anomalie qualitative (monoclonalité). L\u27apport pour le diagnostic et pour le suivi de ce dosage doit tenir compte des propriétés de la réaction antigène/anticorps en milieu liquide (phénomène de zone), du métabolisme rénal des chaînes légères avec ses conséquences en cas d\u27insuffisance rénale et des interférences possibles avec les chaînes légères liées des immunoglobulines intactes. L\u27apport diagnostique du dosage des CLL est patent dans les situations cliniques où l\u27absence de marqueur monoclonal peut être un handicap : myélome à chaîne légère, myélome apparemment non sécrétant, amylose et maladie de dépôt des chaînes d\u27immunoglobulines. Dans les autres situations (myélome à immunoglobuline intacte, MGUS), l\u27apport du dosage des CLL comme marqueur diagnostique ou comme indicateur de pronostic ou de suivi thérapeutique n\u27est pas encore prouvé. Son évaluation nécessitera des études prospectives particulièrement rigoureuses

Tissue Clearing and Deep Imaging of the Kidney Using Confocal and Two-Photon Microscopy

Microscopic and macroscopic evaluation of biological tissues in three dimensions is becoming increasingly popular. This trend is coincident with the emergence of numerous tissue clearing strategies, and advancements in confocal and two-photon microscopy, enabling the study of intact organs and systems down to cellular and sub-cellular resolution. In this chapter, we describe a wholemount immunofluorescence technique for labeling structures in renal tissue. This technique combined with solvent-based tissue clearing and confocal imaging, with or without two-photon excitation, provides greater structural information than traditional sectioning and staining alone. Given the addition of paraffin embedding to our method, this hybrid protocol offers a powerful approach to combine confocal or two-photon findings with histological and further immunofluorescent analysis within the same tissue

Serial optical coherence microscopy for label-free volumetric histopathology

The observation of histopathology using optical microscope is an essential procedure for examination of tissue biopsies or surgically excised specimens in biological and clinical laboratories. However, slide-based microscopic pathology is not suitable for visualizing the large-scale tissue and native 3D organ structure due to its sampling limitation and shallow imaging depth. Here, we demonstrate serial optical coherence microscopy (SOCM) technique that offers label-free, high-throughput, and large-volume imaging of ex vivo mouse organs. A 3D histopathology of whole mouse brain and kidney including blood vessel structure is reconstructed by deep tissue optical imaging in serial sectioning techniques. Our results demonstrate that SOCM has unique advantages as it can visualize both native 3D structures and quantitative regional volume without introduction of any contrast agents

Characterization of Polyphosphoesters by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

FT-ICR mass spectrometry, together with collision-induced dissociation and electron capture dissociation, has been used to characterize the polyphosphoester poly[1,4-bis(hydroxyethyl)terephthalate-alt-ethyloxyphosphate] and its degradation products. Three degradation pathways were elucidated: hydrolysis of the phosphate–[1,4-bis(hydroxyethyl)terephthalate]bonds; hydrolysis of the phosphate–ethoxy bonds; and hydrolysis of the ethyl–terephthalate bonds. The dominant degradation reactions were those that involved the phosphate groups. This work constitutes the first application of mass spectrometry to the characterization of polyphosphoesters and demonstrates the suitability of high mass accuracy FT-ICR mass spectrometry, with CID and ECD, for the structural analysis of polyphosphoesters and their degradation products

Experimental Verification Towards Feed-Forward Ground Motion Mitigation at ATF2

International audienceWithout counter measures, ground motion effects would deteriorate the performance of future linear colliders to an unacceptable level. An envisioned new ground motion mitigation method (based on feed-forward control) has the potential to improve the performance and to reduce the system cost compared to other proposed methods. For the experimental verification of this feed-forward scheme, a dedicated measurement setup has been installed at ATF2 at KEK. In this paper, the progress on this experimental verification is described. An important part of the feed-forward scheme could be already demonstrated, namely the prediction of the orbit jitter due to ground motion measurements

Voxel-wise comparisons of cellular microstructure and diffusion-MRI in mouse hippocampus using 3D Bridging of Optically-clear histology with Neuroimaging Data (3D-BOND)

A key challenge in medical imaging is determining a precise correspondence between image properties and tissue microstructure. This comparison is hindered by disparate scales and resolutions between medical imaging and histology. We present a new technique, 3D Bridging of Optically-clear histology with Neuroimaging Data (3D-BOND), for registering medical images with 3D histology to overcome these limitations. Ex vivo 120 × 120 × 200 μm resolution diffusion-MRI (dMRI) data was acquired at 7 T from adult C57Bl/6 mouse hippocampus. Tissue was then optically cleared using CLARITY and stained with cellular markers and confocal microscopy used to produce high-resolution images of the 3D-tissue microstructure. For each sample, a dense array of hippocampal landmarks was used to drive registration between upsampled dMRI data and the corresponding confocal images. The cell population in each MRI voxel was determined within hippocampal subregions and compared to MRI-derived metrics. 3D-BOND provided robust voxel-wise, cellular correlates of dMRI data. CA1 pyramidal and dentate gyrus granular layers had significantly different mean diffusivity (p > 0.001), which was related to microstructural features. Overall, mean and radial diffusivity correlated with cell and axon density and fractional anisotropy with astrocyte density, while apparent fibre density correlated negatively with axon density. Astrocytes, axons and blood vessels correlated to tensor orientation

Reactor physics methods, models, and applications used to support the conceptual design of the Advanced Neutron Source

This report summarizes the neutronics analysis performed during 1991 and 1992 in support of characterization of the conceptual design of the Advanced Neutron Source (ANS). The methods used in the analysis, parametric studies, and key results supporting the design and safety evaluations of the conceptual design are presented. The analysis approach used during the conceptual design phase followed the same approach used in early ANS evaluations: (1) a strong reliance on Monte Carlo theory for beginning-of-cycle reactor performance calculations and (2) a reliance on few-group diffusion theory for reactor fuel cycle analysis and for evaluation of reactor performance at specific time steps over the fuel cycle. The Monte Carlo analysis was carried out using the MCNP continuous-energy code, and the few- group diffusion theory calculations were performed using the VENTURE and PDQ code systems. The MCNP code was used primarily for its capability to model the reflector components in realistic geometries as well as the inherent circumvention of cross-section processing requirements and use of energy-collapsed cross sections. The MCNP code was used for evaluations of reflector component reactivity effects and of heat loads in these components. The code was also used as a benchmark comparison against the diffusion-theory estimates of key reactor parameters such as region fluxes, control rod worths, reactivity coefficients, and material worths. The VENTURE and PDQ codes were used to provide independent evaluations of burnup effects, power distributions, and small perturbation worths. The performance and safety calculations performed over the subject time period are summarized, and key results are provided. The key results include flux and power distributions over the fuel cycle, silicon production rates, fuel burnup rates, component reactivities, control rod worths, component heat loads, shutdown reactivity margins, reactivity coefficients, and isotope production rates

Prognosis of vasculitis associated myelodysplasia

Systemic and immune manifestations have been reported in patients with MDS. The correlation between immunological abnormalities and prognosis in myelodysplastic syndrome patients remains controversial. Most of the authors agree that the median survival in myelodysplastic syndrome is not related to the presence of systemic and immune manifestations, but only with the existence of a systemic vasculitis