135 research outputs found

    Properties of OV Spectral Lines in Ionizing and Recombining Plasmas

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    A collisional-radiative model for Be-like oxygen ions has been constructed for OV plasmaspectroscopy. The model takes into account recombination processes as well as collisional ionization, radiative transitions, and collisional excitation/deexcitation. Two sets of atomic data are used for comparison. We obtain OV line intensities as functions of electron temperature and density. The line intensity ratios of 2s3s 35 - 2s3p \u27Pr=o.r., are measured in LHD plasmas and are consistent with our models. The line intensity ratio of 2s2p 3P - 2p"P and 2s2 tS - 2s2p rP in recombining plasma is an increasing function of temperature and one measured in the LHD plasma indicates electron temperature less than 7eV. The ratios measured in steady-state phase are larger than I and difficult to explain with the current model

    Fundamental Studies on Measurement of Plasma lα,25-Dihydroxycholecalciferol Concentration by Radioreceptor Assay

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    It is well known that 1α,25-dihydroxyvitamin D(lα,25 (OH)2D) plays an important role in the pathophysiology of bone and calcium metabolism. In present paper, we established a relatively convenient assay system, using radioreceptor assay, for lα,25 (OH) 2D. Fundamental studies showed that this assay system had good sensitivity enough to detect 2 pg of lα,25 (OH) 2D per tube, and had good reproducibility. Therefore, it was shown that this assay system could be applied for clinical use. The plasma concentrations of lα,25(OH)2D, measured by this assay system, in healthy young males and females, and in aged females were 55.7±16.1, 44.8±22.1 and 23.5±13.0 pg/ml (mean±s.d.), respectively. Thus, the aged females showed significantly lower (p<0.005) lα,25 (OH)2D levels than the young group. This fact suggests that vitamin D deficient state might exist in aged females

    Classifying breast masses in volumetric whole breast ultrasound data: a 2.5-dimensional approach

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    The aim of this paper is to investigate a 2.5-dimensional approach in classifying masses as benign or malignant in volumetric anisotropic voxel whole breast ultrasound data. In this paper, the term 2.5-dimensional refers to the use of a series of 2-dimensional images. While mammography is very effective in breast cancer screening in general, it is less sensitive in detecting breast cancer in younger women or women with dense breasts. Breast ultrasonography does not have the same limitation and is a valuable adjunct in breast cancer detection. The current study focuses on a new 2.5-dimensional approach in analyzing the volumetric whole breast ultrasound data for mass classification

    A Newly Developed Instrument of Dual Photon Absorptiometry for Bone Mineral Analysis of the Lumbar Vertebra: Study in Control and Aged Females

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    In order to determine the quantitatively bone mass, dual photon absorptiometry instrument using a scintillation camera was newly developed, and its basic performance was described. Furthermore, with this instrument, bone mineral at 3rd lumbar vertebra was measured in 57 women (31 controls: age 29.9±6.4 yrs., and 16 seniles: age 67.7±6.6 yrs.). The aged females, compared with the young control females, showed significantly low the all parameters of bone mineral such as bone mineral content (BMC), bone mineral density and total BMC at 3rd lumbar vertebra. Thus, it was shown that assessment of bone mineral with this instrument provided a useful information in the diagnosis of osteoporosis

    Impaired CD4⁺ T cell response in older adults is associated with reduced immunogenicity and reactogenicity of mRNA COVID-19 vaccination

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    高齢者のT細胞応答は立ち上がりが遅く収束は早い --新型コロナワクチン接種機会を活用した免疫応答の個人差・年齢差の解明--. 京都大学プレスリリース. 2023-01-13.T-Cell Responses in the Elderly Rise Slowly and Contract Quickly --Learning About Individual and Age Differences in Immune Response From COVID-19 Vaccinations--. 京都大学プレスリリース. 2023-01-13.Whether age-associated defects in T cells impact the immunogenicity and reactogenicity of mRNA vaccines remains unclear. Using a vaccinated cohort (n = 216), we demonstrated that older adults (aged ≥65 years) had fewer vaccine-induced spike-specific CD4⁺ T cells including CXCR3⁺ circulating follicular helper T cells and the TH1 subset of helper T cells after the first dose, which correlated with their lower peak IgG levels and fewer systemic adverse effects after the second dose, compared with younger adults. Moreover, spike-specific TH1 cells in older adults expressed higher levels of programmed cell death protein 1, a negative regulator of T cell activation, which was associated with low spike-specific CD8⁺ T cell responses. Thus, an inefficient CD4⁺ T cell response after the first dose may reduce the production of helper T cytokines, even after the second dose, thereby lowering humoral and cellular immunity and reducing systemic reactogenicity. Therefore, enhancing CD4⁺ T cell response following the first dose is key to improving vaccine efficacy in older adults
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