Current Limiting and Recovery Characteristics Under Load of Transformer Type SFCL with Rewound Structure Using BSCCO Wire in Model Power System

AbstractWe have proposed new design of a transformer type SFCL with primary and secondary superconducting coils which has rewound structure. For not so large fault current, the proposed SFCL limits the current by the inductive component by the normal transition of the flux shielding coil (secondary), and for larger fault current, it can give the resistive component additively by the normal transition of the primary coil. The recovery characteristics under load condition and repetitive limiting operation were experimentally investigated in a laboratory scale power system. The SFCL limited twice repetitive faults current and recovered quickly under load condition

Modeling SARS-CoV-2 infection and its individual differences with ACE2-expressing human iPS cells

ACE発現ヒトiPS細胞を用いたSARS-CoV-2感染の個人差再現と原因究明. 京都大学プレスリリース. 2021-04-19.Stem cells show gender differences in COVID-19 risk. 京都大学プレスリリース. 2021-04-19.Genetic differences are a primary reason for differences in the susceptibility and severity of COVID-19. As induced pluripotent stem (iPS) cells maintain the genetic information of the donor, they can be used to model individual differences in SARS-CoV-2 infection in vitro. We found that human iPS cells expressing the SARS-CoV-2 receptor angiotensin-converting enzyme 2 (ACE2) (ACE2-iPS cells) can be infected w SARS-CoV-2. In infected ACE2-iPS cells, the expression of SARS-CoV-2 nucleocapsid protein, budding of viral particles, and production of progeny virus, double membrane spherules, and double-membrane vesicles were confirmed. We performed SARS-CoV-2 infection experiments on ACE2-iPS/ embryonic stem (ES) cells from eight individuals. Male iPS/ES cells were more capable of producing the virus compared with female iPS/ES cells. These findings suggest that ACE2-iPS cells can not only reproduce individual differences in SARS-CoV-2 infection in vitro but also are a useful resource to clarify the causes of individual differences in COVID-19 due to genetic differences

Elucidation of the liver pathophysiology of COVID-19 patients using liver-on-a-chips

新型コロナウイルス感染症（COVID-19）研究のための肝臓チップの開発 --肝障害の病態解明と治療薬の評価--. 京都大学プレスリリース. 2023-03-08.Using organ-on-a-chip technology to elucidate the liver pathophysiology of COVID-19 patients. 京都大学プレスリリース. 2023-03-08.SARS-CoV-2 induces severe organ damage not only in the lung but also in the liver, heart, kidney, and intestine. It is known that COVID-19 severity correlates with liver dysfunction, but few studies have investigated the liver pathophysiology in COVID-19 patients. Here, we elucidated liver pathophysiology in COVID-19 patients using organs-on-a-chip technology and clinical analyses. First, we developed liver-on-a-chip (LoC) which recapitulating hepatic functions around the intrahepatic bile duct and blood vessel. We found that hepatic dysfunctions, but not hepatobiliary diseases, were strongly induced by SARS-CoV-2 infection. Next, we evaluated the therapeutic effects of COVID-19 drugs to inhibit viral replication and recover hepatic dysfunctions, and found that the combination of anti-viral and immunosuppressive drugs (Remdesivir and Baricitinib) is effective to treat hepatic dysfunctions caused by SARS-CoV-2 infection. Finally, we analyzed the sera obtained from COVID-19 patients, and revealed that COVID-19 patients, who were positive for serum viral RNA, are likely to become severe and develop hepatic dysfunctions, as compared with COVID-19 patients who were negative for serum viral RNA. We succeeded in modeling the liver pathophysiology of COVID-19 patients using LoC technology and clinical samples

PHOSPHATEMIC INDEX EVALUATES PHOSPHORUS LOAD

Objective: Dietary phosphorus (P) restriction is crucial to treat hyperphosphatemia and reduce cardiovascular disease risk and mortality in patients with chronic kidney disease (CKD) and the wider population. Various methods for dietary P restriction exist, but the bioavailability of P in food should also be considered when making appropriate food choices to maintain patients’ quality of life. Here, we propose the ‘‘Phosphatemic Index’’ (PI) as a novel tool for evaluating dietary P load based on P bioavailability; we also evaluated the effect of continuous intake of different PI foods in mixed meals on serum intact fibroblast growth factor 23 concentration. Design and Methods: A 2-stage crossover study was conducted: Study 1: 20 healthy participants consumed 10 different foods containing 200 mg of P, and the PI was calculated from the area under the curve of a time versus serum P concentration curve; Study 2: 10 healthy participants consumed 4 different test meals (low, medium, or high PI meals or a control) over a 5-day period. Results: Study 1 showed milk and dairy products had high PI values, pork and ham had medium PI values, and soy and tofu had low PI values. In Study 2, ingestion of high PI test meals showed higher fasting serum intact fibroblast growth factor 23 levels and lower serum 1,25-dihydroxyvitamin D levels compared with ingestion of low PI test meals. Conclusion: These findings suggest that the PI can usefully evaluate the dietary P load of various foods and may help to make appropriate food choices for dietary P restriction in CKD patients

SARS-CoV-2 disrupts respiratory vascular barriers by suppressing Claudin-5 expression

臓器チップ技術を用いて新型コロナウイルスが血管へ侵入するメカニズムを解明 --Claudin-5発現抑制による呼吸器の血管内皮バリア破壊--. 京都大学プレスリリース. 2022-09-22.A study using an organ-on-a-chip reveals a mechanism of SARS-CoV-2 invasion into blood vessels --Disruption of vascular endothelial barrier in respiratory organs by decreasing Claudin-5 expression--. 京都大学プレスリリース. 2022-09-27.In the initial process of coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects respiratory epithelial cells and then transfers to other organs the blood vessels. It is believed that SARS-CoV-2 can pass the vascular wall by altering the endothelial barrier using an unknown mechanism. In this study, we investigated the effect of SARS-CoV-2 on the endothelial barrier using an airway-on-a-chip that mimics respiratory organs and found that SARS-CoV-2 produced from infected epithelial cells disrupts the barrier by decreasing Claudin-5 (CLDN5), a tight junction protein, and disrupting vascular endothelial cadherin–mediated adherens junctions. Consistently, the gene and protein expression levels of CLDN5 in the lungs of a patient with COVID-19 were decreased. CLDN5 overexpression or Fluvastatin treatment rescued the SARS-CoV-2–induced respiratory endothelial barrier disruption. We concluded that the down-regulation of CLDN5 expression is a pivotal mechanism for SARS-CoV-2–induced endothelial barrier disruption in respiratory organs and that inducing CLDN5 expression is a therapeutic strategy against COVID-19

Interspecific differences in the recovery of rocky intertidal zonation after the 2011 Great East Japan Earthquake

Both natural and anthropogenic disturbances have significant impacts on populations in terrestrial and marine habitats. Despite evidence that population recovery after large-scale disturbances in terrestrial habitats varies substantially among species depending on species traits and types of disturbance, little is known about interspecific differences in population recovery in marine habitats. In this study, we evaluated the course and status of recovery of the vertical distribution of nine intertidal sessile species over 6 years following the 2011 Great East Japan Earthquake. First, we characterized temporal changes in the vertical position of zonation as the spatial distribution, and total coverage as the local population size after the 2011 earthquake. Then, we evaluated the differences in successional status that explain interspecific differences in zonation recovery speed. Finally, we revealed that temporal changes in the vertical position and abundance after the earthquake differed according to species. The interspecific differences in the speed of recovery of zonation after 2014 were correlated with successional status, with later successional species having a delayed recovery rate. These results indicated that intertidal sessile assemblages continued to change 6 years after the large earthquake, suggesting that evaluations of the impacts of disturbances on assemblages and the course of community recovery require long periods of time