184 research outputs found

    Multi-scale Simulation of Subsequent Tsunami Waves in Japan Excited by Air Pressure Waves Due to the 2022 Tonga Volcanic Eruption

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    The 2022 Hunga Tonga-Hunga Ha’apai eruption generated tsunamis that propagated across the Pacific Ocean. Along the coast of Japan, nearshore amplification led to amplitudes of nearly 1 m at some locations, with varying peak tsunami occurrence times. The leading tsunami wave can generally be reproduced by Lamb waves, which are a type of air-pressure wave generated by an eruption. However, subsequent tsunamis that occurred several hours after the leading wave tended to be larger for unknown reasons. This study performs multi-scale numerical simulations to investigate subsequent tsunami waves in the vicinity of Japan induced by air pressure waves caused by the eruption. The atmospheric pressure field was created using a dispersion relation of atmospheric gravity wave and tuned by physical parameters based on observational records. The tsunami simulations used the adaptive mesh refinement method, incorporating detailed bathymetry and topography to solve the tsunami at various spatial scales. The simulations effectively reproduced the tsunami waveforms observed at numerous coastal locations, and results indicate that the factors contributing to the maximum tsunami amplitude differ by region. In particular, bay resonance plays a major role in determining the maximum amplitude at many sites along the east coast of Japan. However, large tsunami amplification at some west coast locations was not replicated, probably because it was caused by amplification during oceanic wave propagation rather than meteorological factors. These findings enhance our understanding of meteotsunami complexity and help distinguish tsunami amplification factors

    Colon cancer form a colonic graft

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    Neoplasm of a colonic graft after esophageal reconstruction is rare. We treated a colon cancer patient who developed malignancy in a colonic graft after esophagectomy and reconstruction through a retrosternal route. A male had undergone esophagectomy in his 50s due to a benign esophago-bronchial fistula. His dysphagia became exacerbated 20 years later, and further examinations showed a circumferential tumor on the esophago-colonic anastomosis. He underwent resection of the colonic graft adenocarcinoma with median sternotomy after neoadjuvant chemotherapy. Gastric tube reconstruction was performed through a retrosternal route. This report should be informative in terms of making decisions from an initial reconstruction to follow-up and choosing a therapeutic strategy for colonic graft cancer in the future

    Efficacy and safety of temporary biliary stent for prevention of post-ERCP cholangitis after endoscopic common bile duct stone removal: a retrospective study

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     Although post-endoscopic retrograde cholangiopancreatography (ERCP) cholangitis (PEC) is not as severe as post-ERCP pancreatitis, this complication should not be disregarded. The aim of the present study was to evaluate the efficacy of a temporary biliary stent for prevention of PEC. Between April 2011 and May 2017, 190 patients underwent complete stone removal in a first session of ERCP at our hospital. Using propensity score matching, 72 pairs were enrolled in this study. After common bile duct (CBD) stone removal, the endoscopists decided to insert a temporary biliary stent if necessary. The incident rate of PEC was significantly lower in the stent group than the no-stent group (1% vs. 11%, p = 0.03). The length of hospital stay was also significantly shorter in the stent group than the no-stent group (5 days vs. 7 days, p < 0.01). In the stent group, one case had stent migration into the bile duct and two cases had a mooring stent at the papilla after 1 month. Multivariate analysis identified the pancreatic guide wire technique as a risk factor for PEC. We demonstrated that a temporary biliary stent reduced the incidence of PEC significantly and the outcome of its placement contributed to shortening the hospital stay. Furthermore, the placement of a temporary biliary stent caused fewer adverse effects than expected. Mooring stents were noted in three cases, which were confirmed by plain abdominal X-ray, but the patients had no symptoms. In two cases, the stent remained in the orifice of the papilla, and in one case it migrated into the CBD. All three stents were retrieved by elective endoscopic procedures. In conclusion, a temporary biliary stent can reduce the incidence of PEC and shorten the length of hospital stay without severe adverse outcomes

    Inhibition of microRNA-33b in humanized mice ameliorates nonalcoholic steatohepatitis

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    マイクロRNA-33bの阻害は非アルコール性脂肪肝炎を改善する --核酸医薬による治療応用へ--. 京都大学プレスリリース. 2023-06-13.Nonalcoholic steatohepatitis (NASH) can lead to cirrhosis and hepatocellular carcinoma in their advanced stages; however, there are currently no approved therapies. Here, we show that microRNA (miR)-33b in hepatocytes is critical for the development of NASH. miR-33b is located in the intron of sterol regulatory element–binding transcription factor 1 and is abundantly expressed in humans, but absent in rodents. miR-33b knock-in (KI) mice, which have a miR-33b sequence in the same intron of sterol regulatory element–binding transcription factor 1 as humans and express miR-33b similar to humans, exhibit NASH under high-fat diet feeding. This condition is ameliorated by hepatocyte-specific miR-33b deficiency but unaffected by macrophage-specific miR-33b deficiency. Anti-miR-33b oligonucleotide improves the phenotype of NASH in miR-33b KI mice fed a Gubra Amylin NASH diet, which induces miR-33b and worsens NASH more than a high-fat diet. Anti-miR-33b treatment reduces hepatic free cholesterol and triglyceride accumulation through up-regulation of the lipid metabolism–related target genes. Furthermore, it decreases the expression of fibrosis marker genes in cultured hepatic stellate cells. Thus, inhibition of miR-33b using nucleic acid medicine is a promising treatment for NASH

    Effect of oral intake of royal jelly on endothelium function in hemodialysis patients: study protocol for multicenter, double-blind, randomized control trial

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    Background: Hemodialysis (HD) is a common renal replacement therapy for patients with renal failure. Cardiovascular and cerebrovascular diseases are known to shorten survival periods and worsen the quality of life of HD patients. Atherosclerosis is a major cause of vascular diseases, and various factors such as abnormality of lipid metabolism and increased macrophage activity, oxidative stress, and endothelial dysfunction are associated with its pathogenesis and progression. Further, endothelial stem cells (ESCs) have been reported to play important roles in endothelial functions. Royal jelly (RJ) affects atherosclerosis- and endothelial function-related factors. The main aim of this trial is to investigate whether oral intake of RJ can maintain endothelial function in HD patients. In addition, the effects of RJ intake on atherosclerosis, ESC count, inflammation, and oxidative stress will be analyzed.Methods: This will be a multicenter, prospective, double-blind, randomized controlled trial. We will enroll 270 participants at Nagasaki Jin Hospital, Shinzato Clinic Urakami, and Maeda Clinic, Japan. The participants will be randomized into RJ and placebo groups. The trial will be conducted according to the principles of the Declaration of Helsinki, and all participants will be required to provide written informed consent. The RJ group will be treated with 3600 mg/day of RJ for 24 months, and the placebo group will be treated with starch for 24 months. The primary endpoint will be the change in flow-mediated dilation (FMD), a parameter of endothelium function, from the time before treatment initiation to 24 months after treatment initiation. The secondary and other endpoints will be changes in FMD; ESC count; serum levels of vascular endothelial cell growth factor, macrophage colony-stimulating factor, 8-hydroxydeoxyguanosine, and malondialdehyde; the incidence of cardiovascular diseases, cerebrovascular diseases, and stenosis of blood access; and safety.Discussion: This trial will clarify whether oral intake of RJ can maintain endothelial function and suppress the progression of atherosclerosis in HD patients. In addition, it will clarify the effects of RJ on ESCs, oxidative stress, and angiogenic activity in blood samples.Trial registration: The Japan Registry of Clinical Trials jRCTs071200031. Registered on 7 December 2020

    microRNA-33 maintains adaptive thermogenesis via enhanced sympathetic nerve activity

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    褐色脂肪細胞の燃焼を促す新たなメカニズムを解明 --体の熱産生にマイクロRNA-33が関与--. 京都大学プレスリリース. 2021-02-17.Adaptive thermogenesis is essential for survival, and therefore is tightly regulated by a central neural circuit. Here, we show that microRNA (miR)-33 in the brain is indispensable for adaptive thermogenesis. Cold stress increases miR-33 levels in the hypothalamus and miR-33−/− mice are unable to maintain body temperature in cold environments due to reduced sympathetic nerve activity and impaired brown adipose tissue (BAT) thermogenesis. Analysis of miR-33f/f dopamine-β-hydroxylase (DBH)-Cre mice indicates the importance of miR-33 in Dbh-positive cells. Mechanistically, miR-33 deficiency upregulates gamma-aminobutyric acid (GABA)A receptor subunit genes such as Gabrb2 and Gabra4. Knock-down of these genes in Dbh-positive neurons rescues the impaired cold-induced thermogenesis in miR-33f/f DBH-Cre mice. Conversely, increased gene dosage of miR-33 in mice enhances thermogenesis. Thus, miR-33 in the brain contributes to maintenance of BAT thermogenesis and whole-body metabolism via enhanced sympathetic nerve tone through suppressing GABAergic inhibitory neurotransmission. This miR-33-mediated neural mechanism may serve as a physiological adaptive defense mechanism for several stresses including cold stress

    MiR-33a is a therapeutic target in SPG4-related hereditary spastic paraplegia human neurons

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    Recent reports, including ours, have indicated that microRNA (miR)-33 located within the intron of sterol regulatory element binding protein (SREBP) 2 controls cholesterol homeostasis and can be a potential therapeutic target for the treatment of atherosclerosis. Here, we show that SPAST, which encodes a microtubule-severing protein called SPASTIN, was a novel target gene of miR-33 in human. Actually, the miR-33 binding site in the SPAST 3′-UTR is conserved not in mice but in mid to large mammals, and it is impossible to clarify the role of miR-33 on SPAST in mice. We demonstrated that inhibition of miR-33a, a major form of miR-33 in human neurons, via locked nucleic acid (LNA)-anti-miR ameliorated the pathological phenotype in hereditary spastic paraplegia (HSP)-SPG4 patient induced pluripotent stem cell (iPSC)-derived cortical neurons. Thus, miR-33a can be a potential therapeutic target for the treatment of HSP-SPG4

    The Weakness of the Internet Mail System and a Proposal of N ew Mail Transfer Agent

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    This paper presents a framework of implementing Mail Transfer Agent(MTA) for Small office/Home office and aims at the improvement of the security of e-mail server. We simplify the setting file of our MTA to reduce setting errors, because difficult settings cause setting errors and occur security holes. This MTA has limits relaying function of mails in order to prohibit SPAM mail relay. And we limit a size of received mail for the counter measures of mail bomb. Experimental results indicate that, this MTA has high security. And the MTA was evaluated that the settings of the MTA are very easy, and that this MTA is convenient in spite of the minimum functions

    A Proposal of the Presentation Support System Using Autonomous Agent

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    This paper describes the design of the presentation support system using autonomous agents. The user of this system can reduce the work to make the slides of presentation with the autonomous agents, so,the user gets the visual expression effects which are easily incorporated into the presentation. The results of implementation indicate that which this support system, making slides using autonomous agent took about only 30 minutes for a 15-minutes-presentation

    Kansei Evaluation in Agent Rearing Game

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    In this paper, We have studied the Kansei evaluation of the agent rearing game. The agent rearing game is a game by which the characters who are the agents are brouht up. The Kansei evaluation is an evaluation by Kansei engineering like the sensibility and feelings, etc. to treat technological1y. In this research, We produced the agent rearing game. We propose the method of the interesting the game using the technique of Kansei engineering for the evaluation
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