202 research outputs found
Development of a virtual flood experience system and its suitability as a flood risk communication tool
Preventing late evacuation has been a challenge in Japan's flood management. Our hypothesis is that people often have little idea about how dangerous a flood can be and thus do not understand the importance of early evacuation. To help them realize the possible risk of flooding, we developed the Virtual Flood Experience System (VFES) using virtual reality (VR) technology. This tool is also expected to improve flood risk communication and flood evacuation training. We evaluated the realness of a virtual flood reconstructed by VFES and conducted an evacuation behaviour experiment using VFES. This paper reports an overview of VFES, including the results of the evaluation and experiment conducted in Aga Town, Niigata Prefecture, Japan. The results confirmed that VFES can successfully reconstruct the flood conditions caused by Typhoon No.19 in 2019 and quantitatively record the difference in evacuation behaviour and the time required to select appropriate evacuation behaviour between individuals with knowledge of flood risk and those without, indicating its high potential as an effective risk commutation tool capable of providing virtual flood experiences and assisting behavioural psychology experiments.</p
Antiviral effect of alkaloids-free Ephedra Herb extract on respiratory syncytial virus infection
Respiratory syncytial virus (RSV) is a major cause of respiratory tract infection in children. Despite decades of efforts, no effective therapies are available. We recently reported that extracts of Ephedra Herb and Cinnamon Bark interacted with the G attachment protein of RSV to inhibit infectivity. The present in vitro study aimed to investigate the antiviral effect of ephedrine alkaloids-free Ephedra Herb extract (EFE), which is characterized by free of harmful effects of ephedrine alkaloids in Ephedra Herb, on experimental RSV infection. Infection of RSV into A549 cells simultaneously with EFE resulted the significant reduction of RSV RNA, viral protein, and viral titers after the incubation of the cells. We found that RSV attachment to the cell surface was inhibited both in the presence of EFE and when RSV particles were pre-treated with EFE. We also found that EFE specifically interacted with the central conserved domain of RSV G protein by surface plasmon resonance, demonstrating that specific binding of G protein to the cellular receptor was inhibited by EFE. Another mechanism was found in which a higher concentration of EFE inhibited the viral load immediately after the viral entry into host cells, suggesting the inhibition of viral RNA replication. These results demonstrate that EFE worked against RSV infection through multiple antiviral mechanisms, a unique feature of this crude drug extract
Atomic structures and functional implications of the archaeal RecQ-like helicase Hjm
<p>Abstract</p> <p>Background</p> <p><it>Pyrococcus furiosus </it>Hjm (<it>Pfu</it>Hjm) is a structure-specific DNA helicase that was originally identified by <it>in vitro </it>screening for Holliday junction migration activity. It belongs to helicase superfamily 2, and shares homology with the human DNA polymerase Θ (PolΘ), HEL308, and <it>Drosophila </it>Mus308 proteins, which are involved in DNA repair. Previous biochemical and genetic analyses revealed that <it>Pfu</it>Hjm preferentially binds to fork-related Y-structured DNAs and unwinds their double-stranded regions, suggesting that this helicase is a functional counterpart of the bacterial RecQ helicase, which is essential for genome maintenance. Elucidation of the DNA unwinding and translocation mechanisms by <it>Pfu</it>Hjm will require its three-dimensional structure at atomic resolution.</p> <p>Results</p> <p>We determined the crystal structures of <it>Pfu</it>Hjm, in two apo-states and two nucleotide bound forms, at resolutions of 2.0–2.7 Å. The overall structures and the local conformations around the nucleotide binding sites are almost the same, including the side-chain conformations, irrespective of the nucleotide-binding states. The architecture of Hjm was similar to that of <it>Archaeoglobus fulgidus </it>Hel308 complexed with DNA. An Hjm-DNA complex model, constructed by fitting the five domains of Hjm onto the corresponding Hel308 domains, indicated that the interaction of Hjm with DNA is similar to that of Hel308. Notably, sulphate ions bound to Hjm lie on the putative DNA binding surfaces. Electron microscopic analysis of an Hjm-DNA complex revealed substantial flexibility of the double stranded region of DNA, presumably due to particularly weak protein-DNA interactions. Our present structures allowed reasonable homology model building of the helicase region of human PolΘ, indicating the strong conformational conservation between archaea and eukarya.</p> <p>Conclusion</p> <p>The detailed comparison between our DNA-free <it>Pfu</it>Hjm structure and the structure of Hel308 complexed with DNA suggests similar DNA unwinding and translocation mechanisms, which could be generalized to all of the members in the same family. Structural comparison also implied a minor rearrangement of the five domains during DNA unwinding reaction. The unexpected small contact between the DNA duplex region and the enzyme appears to be advantageous for processive helicase activity.</p
Room-temperature plasticity of a nanosized GaN crystal
GaN wurtzite crystal is commonly regarded as
eminently brittle. However, our research demonstrates that
nanodeconfined GaN compressed along the M direction begins
to exhibit room-temperature plasticity, yielding a dislocation-free
structure despite the occurrence of considerable, irreversible
deformation. Our interest in M-oriented, strained GaN nanoobjects
was sparked by the results of first-principles bandgap
calculations, whereas subsequent nanomechanical tests and
ultrahigh-voltage (1250 kV) transmission electron microscopy
observations confirmed the authenticity of the phenomenon.
Moreover, identical experiments along the C direction produced
only a quasi-brittle response. Precisely how this happens is
demonstrated by molecular dynamics simulations of the deformation of the C- and M-oriented GaN frustum, which mirror our
nanopillar crystals
MLH1-mediated recruitment of FAN1 to chromatin for the induction of apoptosis triggered by O6-methylguanine
O6 -Methylguanines (O6 -meG), which are produced in DNA by the action of alkylating agents, are mutagenic and cytotoxic, and induce apoptosis in a mismatch repair (MMR) protein-dependent manner. To understand the molecular mechanism of O6 -meG-induced apoptosis, we performed functional analyses of FANCD2 and FANCI-associated nuclease 1 (FAN1), which was identified as an interacting partner of MLH1. Immunoprecipitation analyses showed that FAN1 interacted with both MLH1 and MSH2 after treatment with N-methyl-N-nitrosourea (MNU), indicating the formation of a FAN1-MMR complex. In comparison with control cells, FAN1-knockdown cells were more resistant to MNU, and the appearances of a sub-G1 population and caspase-9 activation were suppressed. FAN1 formed nuclear foci in an MLH1-dependent manner after MNU treatment, and some were colocalized with both MLH1 foci and single-stranded DNA (ssDNA) created at damaged sites. Under the same condition, FANCD2 also formed nuclear foci, although it was dispensable for the formation of FAN1 foci and ssDNA. MNU-induced formation of ssDNA was dramatically suppressed in FAN1-knockdown cells. We therefore propose that FAN1 is loaded on chromatin through the interaction with MLH1 and produces ssDNA by its exonuclease activity, which contributes to the activation of the DNA damage response followed by the induction of apoptosis triggered by O6 -meG.福岡歯科大
Assessment of flood damage to agricultural crops under climate change scenarios using MRI-AGCM outputs in the Solo River basin of Indonesia
Understanding the effects of climate change on agricultural crops is an essential part of flood-risk management and adaptation measures. However, the quantitative impact of flood damage on agricultural crops under climate change is still not clearly understood. It is thus crucial to investigate flood damage to agricultural crops under climate change scenarios to understand future crop damage better. In this study, we first explored the relationship between extreme rainfall and damaged paddy area for a historical period, and then focused on the quantitative analysis of flood impact on rice crops under climate change using MRI-AGCM3.2S climate model outputs for the past (1979–2002) and future (2075–2098) climate periods for the Solo River basin in Indonesia. We developed a quantitative damage assessment method by coupling water and energy budget-based rainfall-runoff-inundation model outputs and a flood loss model. Flood damage to rice crops was defined as a function of flood depth and duration, and depth-duration-damage curves were applied to quantify the damage. The results show that flood damage to rice crops will be more severe in the future than in the past, and the findings can be useful in establishing risk reduction and adaptation measures.</p
Significance of measurement of tumor marker in primary breast cancer
We investigated a prognosis in the presence or absence of preoperative marker abnormality for 371 cases with primary breast cancer that we experienced in our department this time. 60 (16%) of 371 cases showed the abnormality of the tumor marker and 25 (41.7%) of 60 patients had a recurrence. The positive rate of the marker was 8.1% in CA 15 3, 6.7% in CEA, 4.1% in NCC ST 439, and each rate of recurrence was 56.7%, 48.0%, 33.3%. Rate of recurrence in the negative cases was 12.7%, 13.9, 15.0% respectively and recognized a significant difference statistically (p <0.001) . Of 11 cases (3.8%) shown CA 15 3 abnormal high level, 3 cases (27.2%) had recurrence when we examined in 0 3 metastases to lymph nodes according to markers. 281 cases (96.2%) was normal range in CA15 3. Only 15 cases (5%) had recurrence. It showed a significant difference statistically (p <0.05) . For the cases shown abnormality of the preoperative CA 15 3, careful serial observations are necessary
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