128 research outputs found

    Read-out using F1-TDC-ADC of the newSFD X plane (and dE/dx counter)

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     The data of the SFD X-plane and dE/dx counter, obtained with a minimal DAQ were analyzed. Several features of the new F1-TDC-ADC device were checked. The optimal threshold settings for the future run are found to be 15 - 20 mV for X-plane, and 20 mV for dE/dx counter

    Depth of interaction measured with LYSO (Ce) scintillator in a new method

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     The importance of the information concerning the depth of interaction (DOI) in a PET device has been stressed by many authors. In this paper, the attenuation of the emitted light in a thin LYSO (Ce) scintillator crystal has been measured for the purpose of obtaining information about DOI from the ratio of the light output measured at both ends of the crystal. A pair of photomultipliers were attached to the two ends of the crystal for this purpose. An array of wave-length shifters(WLS) attached to the crystal from a side was used in order to find the hit point of the incident gamma rays along the crystal. The attenuation constant μ determined in this measurement is μ=0.79 ± 0.0007/cm. This value is experimentally demonstrated to be appropriate for the DOI estimation using the ratio of the amounts of light. The obtainable DOI resolution, when the crystal is read out using WLS and a new kind of position-sensitive photomultipliers in our next prototype, is estimated

    Lack of CTGF*-945C/G Dimorphism in Thai Patients with Systemic Sclerosis

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    An association between connective tissue growth factor (CTGF) gene dimorphism at –945 (CTGF*-945C/G) and systemic sclerosis (SSc) has been reported with inconclusive results. We performed this study to determine whether such an association exists among Thai patients with SSc. DNA samples were taken from 50 Thai SSc patients (diffuse SSc in 39 and limited SSc in 11) and 99 healthy controls for determination of CTGF*-945C/G dimorphism by polymerase chain reaction (PCR) using specific oligonucleotide primers. The associations between the genotype frequencies, clinical manifestations and auto-antibodies were determined as well. When compared with the controls, SSc patients had no significantly higher frequencies of the GG genotype (44.0% vs 39.4%, p = 0.60), G allele (63.0% vs 65.2%, p = 0.80) or G phenotype (82.0% vs 90.9%, p = 1.0). There was no association between the presence of the GG genotype and clinical manifestations (pulmonary fibrosis, sclerodactyly, digital pitting scars, telangiectasia and pulmonary arterial hypertension), or the presence of auto-antibodies (anti-Scl-70, anti-SSA/Ro, and anti-RNP). In conclusion, we found no association between CTGF*-945C/G dimorphism and Thai SSc patients

    Efficient Methods of Blind Deconvolution Based on the Lane-Bates Algorithm: Comprehensive Summary

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     We developed efficient methods of blind deconvolution on the basis of the Lane-Bates algorithm. The methods consist of two kinds of mathematical tools and their modified versions. We give a comprehensive summary of them in this report

    Novel scheme for Lane-Bates\u27 blind deconvolution : Determinant conditions for the zeros of blurs and a simple algorithm for eliminating blurs

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     The Lane-Bates method of blind deconvolution makes it possible to analytically recover the original image without prior knowledge of blurs convolved in a given image. The method utilizes the zeros of the z-transform of the given image. Its implementation, however, requires highly nontrivial analysis of the zeros. We have developed a novel scheme that considerably simplifies the analysis of the zeros. We have developed two versions of the scheme, i.e., determinant conditions (DCs) for the zeros of blurs and a search algorithm (SA) of blur images. The DCs consist of two forms, i.e., a derivative form and a multi-point form. The derivative form is given as a determinant form of conditions on derivatives of the zeros of assumed blurs that can be evaluated by using zeros of the z-transform of the given image. On the other hand, the multi-point form is given as a determinant form of conditions on the zeros of assumed blurs that are evaluated at multiple points in z space. The scheme is particularly powerful when the blurs have multiple structures as we illustrate. The SA is given as a form of simultaneous equations for blur elements of an assumed blur. The method is powerful when we try to find a single blur. This method is robust for compressed gray-scale images. These methods have been experimentally tested with model blurred images and shown to be powerful. In this report we illustrate how they are useful for the Lane-Bates blind deconvolution

    Contacts between the commissural axons and the floor plate cells are mediated by nectins

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    AbstractDuring development of the central nervous system (CNS), commissural axons grow toward the ventral midline. After crossing the floor plate, they abruptly change their trajectory from the circumferential to the longitudinal axis. The contacts between the commissural axons and the floor plate cells are involved in this axonal guidance, but their mechanisms or structures have not fully been understood. In this study, we found that nectin-1 and -3, immunoglobulin-like cell–cell adhesion molecules, asymmetrically localized at the contact sites between the commissural axons and the floor plate cells, respectively. In vitro perturbation of the endogenous trans-interaction between nectin-1 and -3 caused abnormal fasciculation of the commissural axons and impairment of the contacts, and resulted in failure in longitudinal turns of the commissural axons at the contralateral sites of the rat hindbrain. These results indicate that the contacts between the commissural axons and the floor plate cells are mediated by the hetero-trans-interaction between nectin-1 and -3 and involved in regulation of the trajectory of the commissural axons

    Development of High-resolution Fast Gamma-ray Imager for the New-generation PET III

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     The disappearance of the air layer between scintillator crystals due to their sticking seems harmful. To avoid this phenomenon, an insertion of black flock paper is tried and the effect was studied. The result seems positive. But we need to look for a better material which is light tight, thin, solid yet not sticky

    Study on the light insulator between scintillator crystals

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     In our current project, we undertake an R&D of a new type of PED device which can be produced with a much lower cost yet has a better spatial resolution, compared to the currently used devices. In the course of this development, we encountered a difficulty of light cross-talk between the scintillator crystals. Large amount of effort has been paid to find out the best material to be used to reduce this cross-talk without reducing the light output and the spatial resolution. The experimental result shows that a black flock paper has the most promising features
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