時間領域有限要素法を用いた津波起源電磁場の数値シミュレーション: 2011年東北地方太平洋沖地震津波への応用

京都大学0048新制・課程博士博士(理学)甲第18085号理博第3963号新制||理||1571(附属図書館)30943京都大学大学院理学研究科地球惑星科学専攻(主査)准教授 藤 浩明, 教授 家森 俊彦, 教授 福田 洋一学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDFA

H4K20 monomethylation inhibition causes loss of genomic integrity in mouse preimplantation embryos

Maintaining genomic integrity in mammalian early embryos, which are deficient in DNA damage repair, is critical for normal preimplantation and subsequent development. Abnormalities in DNA damage repair in preimplantation embryos can cause not only developmental arrest, but also diseases such as congenital disorders and cancers. Histone H4 lysine 20 monomethylation (H4K20me1) is involved in DNA damage repair and regulation of gene expression. However, little is known about the role of H4K20me1 during mouse preimplantation development. In this study, we revealed that H4K20me1 mediated by SETD8 is involved in maintaining genomic integrity. H4K20me1 was present throughout preimplantation development. In addition, reduction in the level of H4K20me1 by inhibition of SETD8 activity or a dominant-negative mutant of histone H4 resulted in developmental arrest at the S/G2 phase and excessive accumulation of DNA double-strand breaks. Together, our results suggest that H4K20me1, a type of epigenetic modification, is associated with the maintenance of genomic integrity and is essential for preimplantation development. A better understanding of the mechanisms involved in maintaining genome integrity during preimplantation development could contribute to advances in reproductive medicine and technology

Tsunami-generated magnetic fields have primary and secondary arrivals like seismic waves

A seafloor geomagnetic observatory in the northwest Pacific has provided very long vector geomagnetic time-series. It was found that the time-series include significant magnetic signals generated by a few giant tsunami events including the 2011 Tohoku Tsunami. Here we report that the tsunami-generated magnetic fields consist of the weak but first arriving field, and the strong but second arriving field&mdash;similar to the P- and S-waves in seismology. The latter field is a result of coupling between horizontal particle motions of the conductive seawater and the vertical component of the background geomagnetic main field, which have been studied well so far. On the other hand, the former field stems from coupling between vertical particle motions and the horizontal component of the geomagnetic main field parallel to tsunami propagation direction. The former field has been paid less attention because horizontal particle motions are dominant in the Earth&rsquo;s oceans. It, however, was shown that not only the latter but also the former field is significant especially around the magnetic equator where the vertical component of the background magnetic field vanishes. This implies that global tsunami early warning using tsunami-generated magnetic fields is possible even in the absence of the background vertical geomagnetic component. &nbsp;</p

Carboxylic acid functionalized spin-crossover iron(II) grids for tunable switching and hybrid electrode fabrication

Two carboxyl-substituted iron(II) grids, one protonated, [Fe4(HL)4](BF4)4·4MeCN·AcOEt (1), and the other deprotonated, [Fe4(L)4]·DMSO·EtOH (2), where H2L = 4-{4,5-bis[6-(3,5-dimethylpyrazol-1-yl)pyrid-2-yl]-1H-imidazol-2-yl}benzoic acid, were synthesized. Single-crystal X-ray structure analyses reveal that both complexes have a tetranuclear [2 × 2] grid structure. 1 formed one-dimensional chains through intermolecular hydrogen bonds between the carboxylic acid units of neighboring grids, while 2 formed two-dimensional layers stabilized by π–π-stacking interactions. 1 showed spin transition between the 3HS-1LS and 1.5HS-2.5LS states around 200 K, while 2 showed spin-crossover between the 4LS and 2LS-2HS states above 300 K. A modified indium–tin oxide (ITO) electrode was fabricated by soaking the ITO in a solution of 1. The resultant electrode showed reversible redox waves attributed to the original redox processes of iron(II)/iron(III)

Successful Endoscopic Closure Using Polyglycolic Acid Sheets with Fibrin Glue for Nonhealing Duodenal Ulcer with Perforation after Proton Beam Therapy of Liver Tumor

We describe the first case of a nonhealing duodenal ulcer with perforation after proton beam therapy (PBT) of a liver tumor that was successfully treated endoscopically using polyglycolic acid (PGA) sheets with fibrin glue. A 69-year-old man received PBT for a liver tumor. Esophagogastroduodenoscopy (EGD) 3 months after PBT revealed a duodenal ulcer. A proton pump inhibitor was administered for 7 weeks, and the ulcer healed. Six months after the EGD, recurrence of the duodenal ulcer with perforation occurred. An emergency open surgery with placement of the omental patch was performed. However, 5 days after the surgery, because the EGD revealed a perforation site in the duodenal ulcer that was not closed, the conservative treatment was continued. Twenty-eight days after the surgery, EGD revealed that the perforation size had increased. Therefore, we conducted endoscopic closure therapy using PGA sheets with fibrin glue. Eleven days after the closure procedure, the EGD showed that the perforation site was filled with granulation tissue and was closed. Forty-nine days after the procedure, EGD revealed that the ulcer had healed. This endoscopic closure treatment was effective for a nonhealing duodenal ulcer with perforation after PBT of a liver tumor

Clinical outcomes of laparoscopic and endoscopic cooperative surgery for gastric gastrointestinal stromal tumor

Background: Laparoscopic and endoscopic cooperative surgery (LECS) is a well-recognized surgical procedure for gastric gastrointestinal stromal tumor (GIST). In this report, we describe the clinical outcomes of LECS procedures for gastric GIST in our institution. Methods: We performed LECS procedures, including classical LECS, inverted LECS, closed LECS, and combination of laparoscopic and endoscopic approaches to neoplasia with non-exposure technique (CLEAN-NET), in 40 gastric intraluminal and intramural type GIST patients, whose tumors were ≤ 50 mm in diameter, between September 2012 and December 2020. The patient background, surgical outcomes, postoperative morbidity and mortality, as well as the tumors' clinicopathological characteristics were analyzed retrospectively. Results: Pathological findings showed that most patients had a low or very low risk of tumor recurrence, while one patient had a high risk according to the modified-Fletcher's classification. The median length of postoperative hospital stay was 7 days. Only one patient had severe postoperative grade III complications according to the Clavien-Dindo (C-D) classification, after closed LECS, but was treated successfully with endoscopic hemostasis for postoperative hemorrhage. The remaining patients treated with LECS did not have severe complications. During the follow-up period (median, 31 months), all patients were disease-free, with no tumor recurrence or metastases. Conclusion: LECS is a safe surgical procedure for gastric intraluminal and intramural type GIST ≤ 50 mm in diameter, with good clinical outcomes