Development and On‐Orbit Demonstration of Lithium‐Ion Capacitor‐Based Power System for Small Spacecraft

Lithium‐ion capacitors (LICs) offer higher energy density and specific energy than do traditional electric double‐layer capacitors (EDLCs). In spacecraft power systems where traditional lithium‐ion batteries (LIBs) have been used with shallow depth of discharge (DoD) in order to achieve long‐cycle life, LICs would potentially be an alternative to secondary batteries. Firstly, this chapter presents the quantitative comparison between the LIB‐ and LIC‐based spacecraft power system from the viewpoint of system mass. On the basis of the potential suggested by the comparison, we have been developing the technology demonstration platform named “NESSIE” that contains the LIC pouch cell as one of its major demonstration missions. NESSIE was successfully launched with the main satellite HISAKI on September 2013. This chapter also presents the development of the LIC pouch cell for NESSIE and its experimental (or ground test) and on‐orbit operation data

Single-Switch Differential Power Processing PWM Converter to Enhance Energy Yield of Photovoltaic Panels under Partial Shading

The partial shading on a photovoltaic (PV) panel consisting of multiple substrings poses serious issues of decreased energy yield and occurrence of multiple maximum power points (MPPs). Although various kinds of differential power processing (DPP) converters have been proposed to prevent the partial shading issues, multiple switches and/or magnetic components in proportion to the number of substrings are necessary, hence increasing the circuit complexity and volume. This chapter proposes a novel single-switch DPP PWM converter to achieve simplified circuit. The proposed DPP converter is essentially the combination of a forward/flyback resonant inverter (FFRI) and voltage multiplier (VM). The fundamental operation analysis is performed, and the current sensorless control strategy suitable for the proposed DPP converter is also discussed. A 30-W prototype of the proposed DPP converter was built, and various kinds of experimental verification tests were performed emulating partial shading conditions. With the proposed DPP converter, local MPPs of a partially shaded PV panel were successfully eliminated, and energy yield was significantly enhanced, demonstrating the efficacy and performance of the proposed DPP converter

Diverse reaction behaviors of artificial ubiquinones in mitochondrial respiratory complex I

The ubiquinone (UQ) reduction step catalyzed by NADH-UQ oxidoreductase (mitochondrial respiratory complex I) is key to triggering proton translocation across the inner mitochondrial membrane. Structural studies have identified a long, narrow, UQ-accessing tunnel within the enzyme. We previously demonstrated that synthetic oversized UQs, which are unlikely to transit this narrow tunnel, are catalytically reduced by native complex I embedded in submitochondrial particles but not by the isolated enzyme. To explain this contradiction, we hypothesized that access of oversized UQs to the reaction site is obstructed in the isolated enzyme because their access route is altered following detergent solubilization from the inner mitochondrial membrane. In the present study, we investigated this using two pairs of photoreactive UQs (pUQ(m-1)/pUQ(p-1) and pUQ(m-2)/pUQ(p-2)), with each pair having the same chemical properties except for a similar to 1.0 angstrom difference in side-chain widths. Despite this subtle difference, reduction of the wider pUQs by the isolated complex was significantly slower than of the narrower pUQs, but both were similarly reduced by the native enzyme. In addition, photoaffinity-labeling experiments using the four [I-125]pUQs demonstrated that their side chains predominantly label the ND1 subunit with both enzymes but at different regions around the tunnel. Finally, we show that the suppressive effects of different types of inhibitors on the labeling significantly changed depending on [I-125]pUQs used, indicating that [I-125]pUQs and these inhibitors do not necessarily share a common binding cavity. Altogether, we conclude that the reaction behaviors of pUQs cannot be simply explained by the canonical UQ tunnel model.Peer reviewe

Laparoscopic Hepatectomy for the Patient with Hemophilia A with High Titer Factor VIII Inhibitor

We present the first case of laparoscopic left lateral segmentectomy for hepatocellular carcinoma (HCC) in a patient with hemophilia A, acquired hepatitis C, and high-titer factor VIII inhibitor, which was confirmed by preoperative diagnosis. He underwent laparoscopic left lateral segmentectomy with the administration of recombinant activated factor VII. Surgery could be performed with reduced intraoperative hemorrhage. He experienced postoperative intra-abdominal wall hemorrhage, which was successfully managed with red cell concentrates transfusion and administration of recombinant activated factor VII. Laparoscopic hepatectomy can be applied for hemophilia patients with high titer inhibitors

Prompt Resolution of Hypoglycemia by Hepatic Transarterial Embolization for Malignant Insulinoma with Multiple Liver Metastases

A 45-year-old female who presented with loss of consciousness and a cold sweat was found to have a pancreatic tumor and multiple liver metastases. Laboratory studies showed marked hypoglycemia and inappropriately elevated serum insulin, C-peptide, and serum tumor markers. Fine needle aspiration revealed Grade 3 small-cell type primary pancreatic neuroendocrine carcinoma. Consequently, the diagnosis of malignant insulinoma was made. Transarterial embolization (TAE) for hepatic metastases resulted in the reduction of tumor volume and prompt resolution of hypoglycemic attacks, whereas diazoxide and systemic chemotherapy had been ineffective for controlling blood glucose levels, and octreotide was unavailable due to the allergic effect. This case report highlights the potential usefulness of TAE for malignant insulinomas in the management of hypoglycemia

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

MyD88及び関連タンパク質の分子機構解析

付記する学位プログラム名: 充実した健康長寿社会を築く総合医療開発リーダー育成プログラム京都大学0048新制・課程博士博士(工学)甲第21790号工博第4607号新制||工||1718(附属図書館)京都大学大学院工学研究科分子工学専攻(主査)教授 白川 昌宏, 教授 梶 弘典, 教授 森 泰生学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDGA