225 research outputs found

    Ground-state properties of neutron-rich Mg isotopes

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    We analyze recently-measured total reaction cross sections for 24-38Mg isotopes incident on 12C targets at 240 MeV/nucleon by using the folding model and antisymmetrized molecular dynamics(AMD). The folding model well reproduces the measured reaction cross sections, when the projectile densities are evaluated by the deformed Woods-Saxon (def-WS) model with AMD deformation. Matter radii of 24-38Mg are then deduced from the measured reaction cross sections by fine-tuning the parameters of the def-WS model. The deduced matter radii are largely enhanced by nuclear deformation. Fully-microscopic AMD calculations with no free parameter well reproduce the deduced matter radii for 24-36Mg, but still considerably underestimate them for 37,38Mg. The large matter radii suggest that 37,38Mg are candidates for deformed halo nucleus. AMD also reproduces other existing measured ground-state properties (spin-parity, total binding energy, and one-neutron separation energy) of Mg isotopes. Neutron-number (N) dependence of deformation parameter is predicted by AMD. Large deformation is seen from 31Mg with N = 19 to a drip-line nucleus 40Mg with N = 28, indicating that both the N = 20 and 28 magicities disappear. N dependence of neutron skin thickness is also predicted by AMD.Comment: 15 pages, 13 figures, to be published in Phys. Rev.

    ネガティブ カンジョウ タイケン ノ コウゾウカ カイジ ガ シンシン キノウ ニ オヨボス エイキョウ : メタ ニンチ ノ カンテン カラ ノ メカニズム ケントウ

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    The purposes of this study were to examine the effects of structured disclosure to enhance cognitive reappraisal of negative emotional experience on health and working memory in a Japanese sample, and to investigate the effects of the structured disclosure in those who can “keep away from thinking and emotion” (distancing). The participants were 75 undergraduates. They were randomly assigned to structured disclosure (n=25), free disclosure, which was developed by Pennebaker, J. W. (n=25), and control groups (n=25). They were asked to disclose through writing for 20 minutes on 3 days. It is suggested that the structured disclosure may improve physical symptoms, because there was a significant trend in interaction between groups and time periods on physical symptoms, and effect size of the structured group was modest. Though all the participants in the groups revealed significantly improvements in other health measures and score of working memory from pre to 2 week, 1 month, and 3 month follow-up assessment times, no interaction effects were obtained. It is showed that those who could keep away from thinking and emotion while writing (high-distanced) can significantly improve scores of posttraumatic stress reactions and pain of the negative emotional experience than those who could not do so (low-distanced). These results and the mechanism of the disclosure were discussed from the view point of metacognition

    Perfusion MRI for brain tumors

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    Purpose : To compare data on brain tumors derived from intravoxel incoherent motion (IVIM) and arterial spin labeling (ASL) imaging with multiple parameters obtained on dynamic susceptibility contrast (DSC) perfusion MRI and to clarify the characteristics of IVIM and ASL perfusion data from the viewpoint of cerebral blood flow (CBF) analysis. Methods : ASL-CBF and IVIM techniques as well as DSC examination were performed in 24 patients with brain tumors. The IVIM data were analyzed with the two models. The relative blood flow (rBF), relative blood volume (rBV) corrected relative blood volume (crBV), mean transit time (MTT), and leakage coefficient (K2) were obtained from the DSC MRI data. Results : The ASL-CBF had the same tendency as the perfusion parameters derived from the DSC data, but the permeability from the vessels had less of an effect on the ASL-CBF. The diffusion coefficient of the fast component on IVIM contained more information on permeability than the f value. Conclusion : ASL-CBF is more suitable for the evaluation of perfusion in brain tumors than IVIM parameters. ASL-CBF and IVIM techniques should be carefully selected and the biological significance of each parameter should be understood for the correct comprehension of the pathological status of brain tumors

    Medaka: a promising model animal for comparative population genomics

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    <p>Abstract</p> <p>Background</p> <p>Within-species genome diversity has been best studied in humans. The international HapMap project has revealed a tremendous amount of single-nucleotide polymorphisms (SNPs) among humans, many of which show signals of positive selection during human evolution. In most of the cases, however, functional differences between the alleles remain experimentally unverified due to the inherent difficulty of human genetic studies. It would therefore be highly useful to have a vertebrate model with the following characteristics: (1) high within-species genetic diversity, (2) a variety of gene-manipulation protocols already developed, and (3) a completely sequenced genome. Medaka (<it>Oryzias latipes</it>) and its congeneric species, tiny fresh-water teleosts distributed broadly in East and Southeast Asia, meet these criteria.</p> <p>Findings</p> <p>Using <it>Oryzias </it>species from 27 local populations, we conducted a simple screening of nonsynonymous SNPs for 11 genes with apparent orthology between medaka and humans. We found medaka SNPs for which the same sites in human orthologs are known to be highly differentiated among the HapMap populations. Importantly, some of these SNPs show signals of positive selection.</p> <p>Conclusion</p> <p>These results indicate that medaka is a promising model system for comparative population genomics exploring the functional and adaptive significance of allelic differentiations.</p

    レスリング選手の海外合宿時におけるコンディショニングに関する事例的研究

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      Globalization of sports has rapidly advanced, leading to various challenges for conditioning during competitions and camps in other countries. This study conducted a survey to collect basic data about the conditioning of student wrestlers in Japanese and international camps. The subjects were 18 student wrestlers who were scheduled to compete in the All- Japan Student Championship Tournament and participated in both international and Japanese training camps at the Korea National Sport University (Seoul Special City, Republic of Korea, March 2014) and Agatsuma-gun, Gunma prefecture. We conducted a questionnaire-based survey at Japanese and international (Korea) camps. The results showed that body weight was significantly reduced during the last half of the Japanese camp, compared to that in the Korean camp. The dietary survey also showed that much spicy food was served during the camp in Korea, resulting in abnormal bowel movements. The results of our survey showed that it is important to provide prior education about dietary management and the use of supplements during international training camp

    Impact of a learning health system on acute care and medical complications after intracerebral hemorrhage

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    Introduction: Patients with stroke often experience pneumonia during the acute stage after stroke onset. Oral care may be effective in reducing the risk of stroke‐associated pneumonia (SAP). We aimed to determine the changes in oral care, as well as the incidence of SAP, in patients with intracerebral hemorrhage, following implementation of a learning health system in our hospital. Methods: We retrospectively analyzed the data of 1716 patients with intracerebral hemorrhage who were hospitalized at a single stroke center in Japan between January 2012 and December 2018. Data were stratified on the basis of three periods of evolving oral care: period A, during which conventional, empirically driven oral care was provided (n = 725); period B, during which standardized oral care was introduced, with SAP prophylaxis based on known risk factors (n = 469); and period C, during which oral care was risk‐appropriate based on learning health system data (n = 522). Logistic regression analysis was performed to evaluate associations between each of the three treatment approaches and the risk of SAP. Results: Among the included patients, the mean age was 71.3 ± 13.6 years; 52.6% of patients were men. During the course of each period, the frequency of oral care within 24 hours of admission increased (P < .001), as did the adherence rate to oral care ≥3 times per day (P < .001). After adjustment for confounding factors, a change in the risk of SAP was not observed in period B; however, the risk significantly decreased in period C (odds ratio 0.61; 95% confidence interval 0.43‐0.87) compared with period A. These associations were maintained for SAP diagnosed using strict clinical criteria or after exclusion of 174 patients who underwent neurosurgical treatment. Conclusions: Risk‐appropriate care informed by the use of learning health system data could improve care and potentially reduce the risk of SAP in patients with intracerebral hemorrhage in the acute stage
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