261 research outputs found

    Chiral anomaly in a (1+1)-dimensional Floquet system under high-frequency electric fields

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    We investigate the chiral anomaly in a Floquet system under a time-periodic electric field in (1+1) dimensions. Using the van~Vleck high-frequency expansion, we analytically calculate the chiral current and the pseudo-scalar condensate for massless/massive fermions and how they are balanced with the topological charge. In the high-frequency limit, we find that finite-mass effects are suppressed and the topological charge is dominated by the chirality production. Our calculations show that the information about the chiral anomaly is stored not in the static Floquet Hamiltonian but in the periodic kick operator. The computational steps are useful as the theoretical foundation for higher-dimensional generalization.Comment: 29 pages; v2: minor changes, to appear in Annals of Physic

    Novel Diagnostic and Therapeutic Approach to Antibody-Mediated Rejections in Heart Transplantation

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    Despite the improvement of immunosuppressive therapy in heart transplantation (HTx), antibody-mediated rejection (AMR) is still a great obstacle to prolong cardiac graft survival. Anti-donor-specific antibodies (DSAs), especially anti-donor human leukocyte antigen (HLA) antibody, lead to heart graft failure resulting in hemodynamic consequence and often in the recipient death. To prevent hyperacute rejection, prospective complement-dependent cytotoxicity test has been performed in every cardiac donor in Japan. But in other solid organ transplantations, flow cytometry crossmatch has been recently recommended to crossmatch to select the recipient in Japan as well as the world. However, flow cytometry is too sensitive to select the recipient, because not all DSAs determined by flow cytometry are cytotoxic to the cardiac graft. On the first complement classical pathway, alloantibodies bind to HLA antigens on cells of the graft and then recruit C1q, which is essential to make membrane attack complex and kill the cell. We review a role of the novel monitoring method of complement pathway regarding C1q in occurrence of AMR and its diagnostic and therapeutic significance in managing AMR in HTx

    Social Awareness from Analysis of Available Time for Automated External Defibrillators in a City

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    Murata T., Fukushima A., Harada T., et al. Social Awareness from Analysis of Available Time for Automated External Defibrillators in a City. 2021 5th IEEE International Conference on Cybernetics, CYBCONF 2021, 45 (2021); https://doi.org/10.1109/CYBCONF51991.2021.9464135.In this paper, we conduct an investigation of available time for automated external defibrillators (AED) in a Japanese city. In Japan, there are about 600,000 AEDs available in cities or towns, but only 4.9% of AEDs are used by bystanders when citizens suffer a sudden cardiac arrest. One reason of such low usage rate comes from their available time. Since many AEDs are installed by business owners, they are not available when their business is closed. We investigate the available time of AEDs in a Japanese city, Takatsuki, Osaka Japan. The number of AEDs that are available 24 hours can be increased by installing new AEDs in 24-hour convenience stores and a koban that is a small police station with policemen

    Ume (Japanese Apricot)-Induced Small Bowel Obstruction with Chronic Radiation Enteritis

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    Stricture formation is recognized as one of the complications of chronic radiation enteritis. Here, we present a case of a 73-year-old woman who presented with small bowel obstruction 16 years after pelvic irradiation for uterine cancer. Computed tomographic (CT) scan of the abdomen demonstrated a 1-cm foreign body in the terminal ileum. Laparotomy revealed a stone of ume (Japanese apricot) stuck in an ileal stricture, leading to complete impaction and perforation. She was successfully treated with ileocecal resection and ileocolic anastomosis without any complication. Pathological study revealed that the low compliance caused by fibrosis of the bowel wall prevented the small ume stone from passing through the irradiated ileum. Our case implies the specific risk of food-induced small bowel obstruction in patients with a history of pelvic irradiation

    FOREVER22: the first bright galaxies with population III stars at redshifts z1020z \simeq 10-20 and comparisons with JWST data

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    We study the formation of the first galaxies in overdense regions modelled by the FORmation and EVolution of galaxies in Extremely overdense Regions motivated by SSA22 (FOREVER22) simulation project. Our simulations successfully reproduce the star formation rates and the MUVMstarM_{\rm UV}-M_{\rm star} relations of candidate galaxies at z1014z \sim 10-14 observed by the James Webb Space Telescope (JWST). We suggest that the observed galaxies are hosted by dark-matter haloes with Mh1010 MM_{\rm h} \gtrsim 10^{10}~{\rm M_{\odot}} and are in short-period starburst phases. On the other hand, even simulated massive galaxies in overdense regions cannot reproduce the intense star formation rates and the large stellar masses of observed candidates at z16z \sim 16. Also, we show that the contribution of population III stars to the UV flux decreases as the stellar mass increases and it is a few percent for galaxies with Mstar107 MM_{\rm star} \sim 10^{7}~{\rm M_{\odot}}. Therefore, a part of the observed flux by JWST could be the light from population III stars. Our simulations suggest that the UV flux can be dominated by population III stars and the UV-slope shows β3\beta \lesssim -3 if future observations would reach galaxies with Mstars105 MM_{\rm stars} \sim 10^{5}~{\rm M_{\odot}} at z20z \sim 20 of which the mass fraction of population III stars can be greater than 10 percent.Comment: 9 pages, 6 figures, accepted for publication in MNRA

    Effect of scan length on densification and crystallographic texture formation of pure chromium fabricated by laser powder bed fusion

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    Processing of pure chromium (Cr) encounters substantial challenges due to its high melting point and intrinsic brittleness. Although laser powder bed fusion processing (LPBF) offers a novel processing approach by reaching the temperature required to melt pure Cr, the high ductile-to-brittle transformation temperature (DBTT) of pure Cr prevents the density of the as-built Cr component from reaching the level of industrial acceptance. This study focuses on raising the quality of the as-built pure Cr components to the industrial level while considering the effect of scan length on densification and crystallographic texture. It was found that short scan length induced by feature size improved the density of as-built specimens while strengthening the texture suggesting uniform heat distribution and lower thermal gradients as a result of short time intervals in scanning tracks and layers. It was discovered that cracking caused by residual stress was detrimental to densification due to the DBTT characteristic of pure Cr, which was localized at high-angle grain boundaries (HAGBs) with high misorientation. The decrease in density and misorientation of HAGBs owing to the increase in grain size and texture strength, respectively, improved the density of as-built Cr up to 97.6% and altered its mechanical properties. Therefore, these findings offer new insight into the LPBF processing of metals with high DBTT characteristics.Gokcekaya O., Ishimoto T., Todo T., et al. Effect of scan length on densification and crystallographic texture formation of pure chromium fabricated by laser powder bed fusion. Crystals, 11, 1, 1. https://doi.org/10.3390/cryst11010009

    Current status of research on sarcopenia in post-treatment cancer survivors in Japan: A narrative review

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    Sarcopenia is prevalent among 11-25% of adult cancer survivors, depending on the cancer type, although the available data on post-treatment survivors in Japan are limited. If cancer patients develop cachexia, they may experience sustained weight loss as a result, ultimately leading to sarcopenia. Conversely, some patients experience post-treatment weight gain, resulting in sarcopenic obesity. Both sarcopenia and obesity elevate the risk of cardiovascular diseases and mortality; therefore, the importance of sarcopenia prevention and management is undeniable. The Guidelines for Exercise for Cancer Survivors recommend continued physical activity. Recent studies have reported the effectiveness of multimodal interventions, combining pharmacological, nutritional, and exercise approaches, necessitating multidisciplinary care for post-treatment sarcopenia. Innovative health interventions using mobile devices have also gained attention. However, studies on sarcopenia in post-treatment cancer survivors, especially those regarding exercise interventions, remain scarce in Japan, primarily due to limited insurance coverage for such post-treatment interventions and workforce challenges. It is clear that some cancer survivors have sarcopenia, which can lead to worse survival and secondary illness. While the benefits of exercise are clear, a comprehensive approach to sarcopenia is a further challenge for the future
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