137 research outputs found
Dilatancy Behavior in Constant Strain Rate Consolidation Test
. Although the constant strain rate consolidation (CSRC) test appears to be one of the most promising types of rapid consolidation test, the time dependency in stress-strain response such as the secondary compression has not been sufficiently clarified yet in CSRC test. Subjected to remolded young clay, this paper shows that a lot of time dependent behavior in the standard consolidation (SC) and CSRC tests is represented systematically by a simple assumption concerning the time dependency of dilatancy. In the SC test, at the first stage of each loading step little dilatancy takes place and dilatancy begins to occur several minutes after step loading. At the latter of each loading step, dilatancy occurs proportionally with the logarithm of elapsed time, which is observed as the secondary compression. In CSRC test, some time period after the stress state has entered the normally consolidated region, dilatancy tends to occur rapidly with the increase in stress ratio. Since most of dilatancy has taken place at the earlier stage of consolidation, little dilatancy occurs at the latter stage of CSRC process. This tendency makes the specimen stiffer with the passage of time, and makes the vertical pressure and pore pressure increase substantially at the last stage of CSRC process. Consideration to such behavior may be effective to correctly interpret the result of CSRC test
Dynamic and Static Combination Analysis Method of Slope Stability Analysis during Earthquake
The results of laboratory model tests for simulating the slope failure due to vibration, including unreinforced slope and the slope reinforced by using geotextile, show that the slope failure occurs when a cumulative plastic displacement exceeds a certain critical value. To overcome the defects of conventional stability analysis, which evaluates the slope characteristics only by its strength parameters, a numerical procedure considering the stiffness and deformation of materials and geosynthetics is proposed to evaluate the seismic slope stability. In the proposed procedure, the failure of slope is defined when the cumulative plastic displacement calculated by a dynamic response analysis using actual seismic wave exceeds the critical value of displacement estimated by a static stability analysis considering seismic coefficient. The proposed procedure is applied to the laboratory model tests and an actual failure of slope in earthquake. The case study shows the possibility that the proposed procedure gives the realistic evaluation of seismic slope stability
On-line microdevice for stress proteomics
The handing of the cells or tissues is essential for proteomics research or drug screening, where labor is not avoidable. The steps of cell wash, protein extraction, protein denaturing are complicated procedures in conventional method using centrifugation and pipetting in the laboratory. This is the bottle-neck for proteome research. To solve these problems, we propose to utilize the nanotechnology, which will improve the proteomics methodology. Utilizing the nanotechnology, we developed a novel microseparation system, where centrifugation and pipetting are needless. This system has a nanostructured microdevice, by which the cell handling, protein extraction, and antibody assay can be performed. Since cell transfer is needless, all cells are corrected without any loss during the cell-pretreatment procedures, which allowed high reproducibility and enabled the detection of low amount of protein expression. Utilizing the microdevice, we analyzed the stress induced proteins. We further succeeded the screening of food that was useful for immunity and found that an extraction from seaweed promoted the apoptosis of T-lymphoblastic cells. Here, we present an on-line microdevice for stress proteomics
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In vitro modeling to determine mutation specificity of EGFR tyrosine kinase inhibitors against clinically relevant EGFR mutants in non-small-cell lung cancer
EGFR mutated lung cancer accounts for a significant subgroup of non-small-cell lung cancer (NSCLC). Over the last decade, multiple EGFR tyrosine kinase inhibitors (EGFR-TKIs) have been developed to target mutated EGFR. However, there is little information regarding mutation specific potency of EGFR-TKIs against various types of EGFR mutations. The purpose of this study is to establish an in vitro model to determine the “therapeutic window” of EGFR-TKIs against various types of EGFR mutations, including EGFR exon 20 insertion mutations. The potency of 1st (erlotinib), 2nd (afatinib) and 3rd (osimertinib and rociletinib) generation EGFR-TKIs was compared in vitro for human lung cancer cell lines and Ba/F3 cells, which exogenously express mutated or wild type EGFR. An in vitro model of mutation specificity was created by calculating the ratio of IC50 values between mutated and wild type EGFR. The in vitro model identified a wide therapeutic window of afatinib for exon 19 deletions and L858R and of osimertinib and rociletinib for T790M positive mutations. The results obtained with our models matched well with previously reported preclinical and clinical data. Interestingly, for EGFR exon 20 insertion mutations, most of which are known to be resistant to 1st and 2nd generation EGFR-TKIS, osimertinib was potent and presented a wide therapeutic window. To our knowledge, this is the first report that has identified the therapeutic window of osimertinib for EGFR exon 20 insertion mutations. In conclusion, this model will provide a preclinical rationale for proper selection of EGFR-TKIs against clinically-relevant EGFR mutations
The Japanese space gravitational wave antenna; DECIGO
DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future
Japanese space gravitational wave antenna. DECIGO is expected to open a new window of
observation for gravitational wave astronomy especially between 0.1 Hz and 10 Hz, revealing
various mysteries of the universe such as dark energy, formation mechanism of supermassive
black holes, and inflation of the universe. The pre-conceptual design of DECIGO consists of
three drag-free spacecraft, whose relative displacements are measured by a differential Fabry–
Perot Michelson interferometer. We plan to launch two missions, DECIGO pathfinder and pre-
DECIGO first and finally DECIGO in 2024
DECIGO pathfinder
DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) which is a future space gravitational wave antenna. DECIGO is expected to provide us fruitful insights into the universe, in particular about dark energy, a formation mechanism of supermassive black holes, and the inflation of the universe. Since DECIGO will be an extremely large mission which will formed by three drag-free spacecraft with 1000m separation, it is significant to gain the technical feasibility of DECIGO before its planned launch in 2024. Thus, we are planning to launch two milestone missions: DPF and pre-DECIGO. The conceptual design and current status of the first milestone mission, DPF, are reviewed in this article
Identification of cis-acting promoter sequences required for expression of the glycerol-3-phosphate acyltransferase 1 gene in mice
Glycerol-3-phosphate acyltransferase 1 (GPAT1) is a rate limiting enzyme in de novo glycerophospholipid synthesis. The murine GPAT1 promoter sequence (the “classical” sequence) was reported previously. However, the organization of this DNA sequence does not fully match the mouse genome sequences on NCBI/GenBank. Here we have identified net cis-acting promoter sequences for the mouse GPAT1 gene: promoter 1a which includes part of the classical sequence and the downstream promoter 1b. Promoter 1a facilitates transcription of two alternative GPAT1 transcript variants, GPAT1-V1 and V2, while promoter 1b produces a third transcript variant, GPAT1-V3. Upstream stimulating factor-1 (USF-1) controlled both promoters whereas sterol regulatory element-binding protein-1 (SREBP-1) exclusively regulated promoter 1a activity in vitro. Feeding increased GPAT1-V1 and V2, but not V3 mRNA levels in mouse liver. The obese condition of db/db mice did not alter the hepatic expression levels of any of the three GPAT1 variants. Feeding enhanced hepatic mRNA levels, intranuclear protein levels and promoter 1a-binding levels of SREBP-1, but not of USF-1. Thus, promoter 1a was exclusively activated by routine feeding in vivo. Our results indicate differential roles of the two promoters in the regulation of hepatic GPAT1 gene expression in mice
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