Effect of an oral branched chain amino acid-enriched snack in cirrhotic patients with sleep disturbance.

Aim:  Sleep is closely related to physical and mental health. Sleep disturbance is reported in patients without encephalopathy. We examined the relationship among cirrhotic symptoms, laboratory data and sleep disturbances. Next, we examined the influence of a branched chain amino acid (BCAA) supplement on sleep disturbance in cirrhotic patients. Methods:  We investigated a total of 21 patients at Nagasaki University Hospital from January to June 2009. We constructed questionnaire items for the evaluation of cirrhotic symptoms. The items, as major symptoms of cirrhotic patients, were as follows: hand tremor, appetite loss, muscle cramp of foot, fatigue, decreased strength, anxiety, abdominal fullness, abdominal pain and a feeling of low energy. We used the Epworth Sleepiness Scale (ESS) for the evaluation of daytime hypersomnolence. Energy supplementation with a BCAA snack was performed as a late evening snack (LES). All patients were assessed at the time of entry into the study, and at 4 and 8 weeks. Results:  It was found that BCAA snack, taken p.o. as an LES, improved the ESS for cirrhotic patients without encephalopathy. This beneficial result was recognized in the short term, 4 weeks after beginning of treatment. This study demonstrated the utility of BCAA supplementation for cirrhotic patients with sleep disturbance. However, the cirrhotic symptom-related score was positively relation with the Child-Pugh score at the time of patient entry, and we were unable to identify the item that related to ESS. Conclusion:  A BCAA snack is a useful drug for cirrhotic patients who do not have any overt encephalopathy, but who suffered from sleep disturbance

Search for astrophysical electron antineutrinos in Super-Kamiokande with 0.01wt% gadolinium-loaded water

We report the first search result for the flux of astrophysical electron antineutrinos for energies O(10) MeV in the gadolinium-loaded Super-Kamiokande (SK) detector. In June 2020, gadolinium was introduced to the ultra-pure water of the SK detector in order to detect neutrons more efficiently. In this new experimental phase, SK-Gd, we can search for electron antineutrinos via inverse beta decay with efficient background rejection and higher signal efficiency thanks to the high efficiency of the neutron tagging technique. In this paper, we report the result for the initial stage of SK-Gd with a $22.5\times552$ $\rm kton\cdot day$ exposure at 0.01% Gd mass concentration. No significant excess over the expected background in the observed events is found for the neutrino energies below 31.3 MeV. Thus, the flux upper limits are placed at the 90% confidence level. The limits and sensitivities are already comparable with the previous SK result with pure-water ($22.5 \times 2970 \rm kton\cdot day$) owing to the enhanced neutron tagging

Search for Cosmic-ray Boosted Sub-GeV Dark Matter using Recoil Protons at Super-Kamiokande

We report a search for cosmic-ray boosted dark matter with protons using the 0.37 megaton$\times$years data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross-section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross-section between $10^{-33}\text{ cm}^{-2}$ and $10^{-27}\text{ cm}^{-2}$ for dark matter mass from 10 MeV/$c^2$ to 1 GeV/$c^2$.Comment: With 1-page appendi

Measurement of the cosmogenic neutron yield in Super-Kamiokande with gadolinium loaded water

Cosmic-ray muons that enter the Super-Kamiokande detector cause hadronic showers due to spallation in water, producing neutrons and radioactive isotopes. Those are a major background source for studies of MeV-scale neutrinos and searches for rare events. Since 2020, gadolinium was introduced in the ultra-pure water in the Super-Kamiokande detector to improve the detection efficiency of neutrons. In this study, the cosmogenic neutron yield was measured using data acquired during the period after the gadolinium loading. The yield was found to be $(2.76 \pm 0.02\,\mathrm{(stat.) \pm 0.19\,\mathrm{(syst.)}}) \times 10^{-4}\,\mu^{-1} \mathrm{g^{-1} cm^{2}}$ at 259 GeV of average muon energy at the Super-Kamiokande detector.Comment: 10 pages, 10 figures, 3 table