56 research outputs found
Dynamics SSI Analyses Considering Anisotropy of the Foundation Gravelly Layer in Hualien, Taiwan
The Hualien Large-Scale Seismic Test program is under way to investigate Soil-Structure Interaction during large earthquakes in the field of Hualien, a high seismic region in Taiwan. In this paper, the ground of the test site, which consists of a sand layer and a hard gravelly layer, was characterized and modeled for accurate dynamic simulation analysis. Especially, the anisotropic behavior of the gravelly layer is modeled and simulation analysis of the forced vibration test is conducted. Consequently, it was revealed that anisotropic behavior of the gravelly layer observed in earthquake observation and forced vibration tests could be expressed by the orthotropic elastic body model
Evaluation of Liquefaction Potential of Gravelly Soil Layer Based on Field Performance Data
In general, gravelly soil layers are considered to be less susceptible to liquefy during earthquakes than sandy soil layers. However, in 1995 Hyogoken-Nambu Earthquake, sand ejection due to liquefaction was observed in Port Island and Rokkco Island, which were man-made islands reclaimed by gravelly soils. In this paper, firstly, site investigation including sampling by freezing technique was conducted in Rokko Island where lots of ejected sand was not observed during the earthquake to know liquefaction strengths of the reclaimed deposits. Secondly, earthquake response analyses were conducted for a site in Rokko Island as well as a site in Port Island to evaluate maximum stress ratios which were generated in the reclaimed deposits during the earthquake. Finally, relationships between maximum shear stress ratios during earthquakes and penetration resistance were investigated for liquefied sites and nonliquefied sites in the man-made islands
Anti-angiogenic effect of siphonaxanthin from green alga, Codium fragile.
Since anti-angiogenic therapy has becoming a promising approach in the prevention of cancer and related diseases, the present study was aimed to examine the anti-angiogenic effect of siphonaxanthin from green alga (Codium fragile) in cell culture model systems and ex vivo approaches using human umbilical vein endothelial cells (HUVECs) and rat aortic ring, respectively. Siphonaxanthin significantly suppressed HUVEC proliferation (p<0.05) at the concentration of 2.5 μM (50% as compared with control) and above, while the effect on chemotaxis was not significant. Siphonaxanthin exhibited strong inhibitory effect on HUVEC tube formation. It suppressed the formation of tube length by 44% at the concentration of 10 μM, while no tube formation was observed at 25 μM, suggesting that it could be due to the suppression of angiogenic mediators. The ex vivo angiogenesis assay exhibited reduced microvessel outgrowth in a dose dependent manner and the reduction was significant at more than 2.5 μM. Our results imply a new insight on the novel function of siphonaxanthin in preventing angiogenesis related diseases
Area of Compaction to Prevent Uplift by Liquefaction
In this study, shaking table tests, upper seepage flow tests and numerical analyses were conducted to determine the condition of improvement by the compaction method, including the extent of area and the density, to prevent uplift of underground pipes by liquefaction. Based on the results of these investigations, a procedure to determine the improvement conditions was proposed
リファキシミンとルビプロストンの併用は脂肪性肝炎ラットの腸管バリア機能を修復し肝線維化を抑制する
Background: Although gut-derived lipopolysaccharide (LPS) affects the progression of non-alcoholic steatohepatitis (NASH) pathogenesis, few studies have focused on this relationship to develop treatments for NASH. Aims: To explore the effects of combination with rifaximin and lubiprostone on NASH liver fibrosis through the modulation of gut barrier function. Methods: To induce steatohepatitis, F344 rats were fed a choline-deficient l -amino acid-defined (CDAA) diet for 12 weeks and received oral administration of rifaximin and/or lubiprostone. Histological, molec- ular, and fecal microbial analyses were performed. Barrier function in Caco-2 cells were assessed by in vitro assays. Results: Combination rifaximin/lubiprostone treatment significantly suppressed macrophage expansion, proinflammatory responses, and liver fibrosis in CDAA-fed rats by blocking hepatic translocation of LPS and activation of toll-like receptor 4 signaling. Rifaximin and lubiprostone improved intestinal perme- ability via restoring tight junction proteins (TJPs) with the intestinal activation of pregnane X receptor and chloride channel-2, respectively. Moreover, this combination increased the abundance of Bacteroides, Lactobacillus, and Faecalibacterium as well as decreased that of Veillonella resulting in an increase of fecal short-chain fatty acids and a decrease of intestinal sialidase activity. Both agents also directly suppressed the LPS-induced barrier dysfunction and depletion of TJPs in Caco-2 cells. Conclusion: The combination of rifaximin and lubiprostone may provide a novel strategy for treating NASH-related fibrosis.博士(医学)・甲第860号・令和5年3月15
Differences in Trocar Positioning within the Vertebral Body Using Two Different Positioning Methods: Effect on Trainee Performance
Purpose. To evaluate the educational effect of the Japanese Society of Interventional Radiology 7th Academic Summer Seminar from a technical perspective. Materials and Methods. Nineteen trainees participated in the seminar. The seminar consisted of vertebroplasty trainings using swine with the single-plane landmark method and with the ISOcenter Puncture (ISOP) method. All trainees were advised by an instructor as they operated the instruments and punctured the vertebra. For each trainee, the accuracy in the final position of the needle tip of the initial puncture in each swine training was evaluated. Results. Error in the final position of the needle tip of ≥5 mm from the target puncture site occurred in the lateral direction in 42% (8/19) of trainees with the landmark method and 5% (1/19) with the ISOP method. No error ≥5 mm occurred in the vertical or anteroposterior directions. In terms of puncture accuracy, error in the lateral direction was significantly lower with the ISOP method than with the landmark method (2.2 ± 1.5 mm versus 5.6 ± 3.2 mm). Conclusion. This seminar was effective training for trocar placement for beginners. The puncture was more accurate with the ISOP method than with the landmark method
VERTECS: 6U CubeSat Mission to Study Star-Formation History by Observation of Visible Extragalactic Background Light
We describe an astronomical 6U CubeSat mission VERTECS (Visible Extragalactic background RadiaTion Exploration by CubeSat). The scientific purpose of VERTECS is to reveal star-formation history of the universe by observation of the extragalactic background light (EBL) in visible wavelengths. Earlier observations by sounding rockets and infrared astronomical satellites have shown that the near-infrared EBL is several times brighter than the integrated light of known galaxies. As candidates for the excess light, first-generation stars in the early universe or low-redshift intra-halo light have been proposed, but it has not been concluded. Since these objects are expected to show different emission spectra in visible wavelengths, precise visible observation is important to reveal the origin of excess light. Since detection sensitivity of the EBL is determined by the product of telescope aperture and field of view, a small wide-field telescope system enables the EBL observation with high sensitivity. In VERTECS mission, we develop a 6U CubeSat equipped with a 3U size telescope optimized for observation of visible EBL. The telescope is composed of lens optics and a CMOS sensor of 3k times 3k array format, which is designed to observe the sky in four photometric bands in 400-800nm. The satellite bus is composed of on-board computer (OBC), electric power system (EPS), communication (COM), attitude determination and control system (ACDS), and thermal structure. Design of OBC and EPS is based on heritage of CubeSats developed at Kyushu Institute of Technology, but deployable solar array wings is added to EPS to supply sufficient power to the VERTECS subsystems. In COM system, S-band is used for command uplink and X-band is used for high-speed downlink of large-size images captured by the telescope. Since the EBL measurement need discrimination of the background light from discrete foreground stars, VERTECS requires 10 arcseconds pointing stability (1 sigma) over 1 minute exposure. In 2022, VERTECS was selected for JAXA-Small Satellite Rush Program (JAXA-SMASH Program), a new program that encourages universities, private companies and JAXA to collaborate to realize small satellite missions utilizing commercial small launch opportunities, and to diversify transportation services in Japan. We have been working on functionality and interface teast using Bread Board Model (BBM), and enviroonmental tests by using the satellite structure thermal model. Launch of the satellite is planned in FY2025. We aim at developing the satellite and obtaining scientific results much more quickly than recent large astronomical-satellite missions
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