細胞外基質遺伝子の過剰発現の抑制を介したトラニラストによるラット糖尿病性腎症モデルの発症・進展阻止

取得学位 : 博士（医学）, 学位授与番号 : 医博甲第1714号 , 学位授与年月日 : 平成17年9月30日, 学位授与大学 : 金沢大

Cool core disturbed: Observational evidence for coexistence of sub-sonic sloshing gas and stripped shock-heated gas around the core of RX J1347.5-1145

RXJ1347.5-1145 (z = 0.451) is one of the most luminous X-ray galaxy clusters, which hosts a prominent cool core and exhibits a signature of a major merger. We present the first direct observational evidence for sub-sonic nature of sloshing motion of the cool core. We find that a residual X-ray image from the Chandra X-ray Observatory after removing the global emission shows a clear dipolar pattern characteristic of gas sloshing, whereas we find no significant residual in the Sunyaev-Zel'dovich effect (SZE) image from the Atacama Large Millimeter/submillimeter Array (ALMA). We estimate the equation of state of perturbations in the gas from the X-ray and SZE residual images. The inferred velocity is 420 +310 -420 km s-1, which is much lower than the adiabatic sound speed of the intracluster medium in the core. We thus conclude that the perturbation is nearly isobaric, and gas sloshing motion is consistent with being in pressure equilibrium. Next, we report evidence for gas stripping of an infalling subcluster, which likely shock-heats gas to high temperature well in excess of 20 keV. Using mass distribution inferred from strong lensing images of the Hubble Space Telescope (HST), we find that the mass peak is located away from the peak position of stripped gas with statistical significance of > 5{\sigma}. Unlike for the gas sloshing, the velocity inferred from the equation of state of the excess hot gas is comparable to the adiabatic sound speed expected for the 20 keV intracluster medium. All of the results support that the southeast substructure is created by a merger. On the other hand, the positional offset between the mass and the gas limits the self-interaction cross section of dark matter to be less than 3.7 h-1 cm2 g-1 (95% CL).Comment: 18 pages, 10 figures, accepted for publication in Ap

Hydraulic model test on channel shifting and yielding woody debris on the fan after sediment disaster in the past

The re-movement of sediment and woody debris in torrents after huge sediment transport in the past could cause new flood and sediment disasters due to heavy rainfall events. However, it is not clear how re-movement of logs effects on bed variations such as bars and river channel divergence. In present study, hydraulic model tests were carried out referring to the magnitude of floods, that was over the plan size, in Tottabetsu River basin in August in 2016. These tests include different magnitudes of flood, suppling logs from bed/side bank erosion, and existence of sabo facilities. The key results were as follows: The presence of logs by bed/side bank erosions influences on the patterns of flows and sediment transport, because deposition of logs affects formation of bars. Difference of the magnitudes of the floods affects the activeness of the interaction between logs and sediment transport. In additions, the locations and slits of the sabo dam need to consider hydraulic conditions and characteristics of woody debris for appropriate control of sediment and woody debris

Tissue oxygenation index reflects changes in forearm blood flow after brief ischemia

Whether the near-infrared spectroscopy (NIRS) technology correctly detects the changes in oxygenation related to ischemia and reperfusion of organs and tissues other than brain remains unclear. The present study examined how different tissue oxygenation parameters derived from NIRS reflect the changes in the forearm blood flow (FBF) according to the brief ischemia and the subsequent reperfusion, and whether values of these parameters move in parallel with the medial and lateral sides of FBF. Thirteen volunteers underwent the prospective observational study. The tissue oxygenation index (TOI), regional saturation of oxygen (rSO2), skin tissue oxygenation (StO2), and FBF values were evaluated in the forearm. Medial rSO2 values at 1 to 3 minutes after the termination of brief ischemia were higher than lateral rSO2 and respective TOI values. FBF and StO2 values quickly increased according to the cessation of brief ischemia, whereas the medial and lateral values did not differ during and after the brief ischemia. TOI and StO2, but not rSO2, reflected changes in FBF of both medial and lateral sides simultaneously in response to the reperfusion after brief ischemia. Themuscle tissue oxygenation during reperfusion favors the use of TOI and StO2, but not rSO2, as the surrogate parameter

Liver steatosis, but not fibrosis, is associated with insulin resistance in nonalcoholic fatty liver disease

金子, 周一金沢大学大学院医学系研究科環境社会医学Background: To address the hypothesis that liver steatosis causes systemic insulin resistance, we sought to determine the liver histological feature that most strongly contributes to insulin resistance in patients with nonalcoholic fatty liver disease (NAFLD). Methods: Liver biopsy specimens were obtained from 131 patients with clinically suspected NAFLD. The stage, grade of nonalcoholic steatohepatitis (NASH), and level of steatosis were scored and analyzed in relation to the homeostasis model assessment of insulin resistance (HOMA-IR) and the metabolic clearance rate (MCR), measured using the glucose clamp method. Results: In the univariate analysis, the degree of hepatic steatosis (r = 0.458, P < 0.001), stage (r = 0.360, P < 0.001), and grade (r = 0.349, P < 0.01) of NASH were significantly correlated with the HOMA-IR. Multiple regression analysis adjusting for age, sex, body mass index, and each histological score showed that steatosis was significantly and independently associated with HOMA-IR (coefficient = 1.42, P < 0.001), but not with the stage (coefficient = 0.33, P = 0.307) or grade (coefficient = 0.67, P = 0.134) of NASH. Similar independent relationships were observed between steatosis and MCR, but the relationship was weaker (coefficient = -0.98, P = 0.076). Conclusions: Steatosis of the liver, but not the stage or the grade of NASH, is associated with insulin resistance in patients with NAFLD. © Springer-Verlag Tokyo 2007

Detection of a bright burst from the repeating FRB 20201124A at 2 GHz

We present a detection of a bright burst from FRB 20201124A, which is one of the most active repeating FRBs, based on S-band observations with the 64-m radio telescope at the Usuda Deep Space Center/JAXA. This is the first FRB observed by using a Japanese facility. Our detection at 2 GHz in February 2022 is the highest frequency for this FRB and the fluence of $>$ 189 Jy ms is one of the brightest bursts from this FRB source. We place an upper limit on the spectral index $\alpha$ = -2.14 from the detection of the S band and non-detection of the X band at the same time. We compare an event rate of the detected burst with ones of the previous research, and suggest that the power-law of the luminosity function might be broken at lower fluence, and the fluences of bright FRBs distribute up to over 2 GHz with the power-law against frequency. In addition, we show the energy density of the burst detected in this work was comparable to the bright population of one-off FRBs. We propose that repeating FRBs can be as bright as one-off FRBs, and only their brightest bursts could be detected so some of repeating FRBs intrinsically might have been classified as one-off FRBs.Comment: 8 pages, 5 figures, accepted for publication in Publications of the Astronomical Society of Japan (PASJ