172 research outputs found

    Research of rainstorm event disaster hazard assessment method-A case study of "8·12" rainstorm event in Xiaogan City

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    The assessment of disaster-causing hazards for the rainstorm event is a fundamental and key aspect of assessing the risk of rainstorm disasters, which can provide essential technical support for meteorological disaster prevention and mitigation. Using the hourly and daily precipitation data from 7 national meteorological observation stations and 120 regional automatic weather stations in Xiaogan City, as well as geographic information data, etc., a regional rainstorm event disaster-causing hazard that occurred in Xiaogan City on 12 August 2021 was evaluated base on dynamic assessment method of disaster hazard assessment of rainstorm process. By analyzing rainfall characteristic quantity, the disaster-causing factors were identified. Four disaster-causing factors were calculated using the information entropy-weight method, and the rainstorm event intensity index was calculated. The topographic-effected indices and the drainage-effected indices were determined as environmental factors based on analyzing the underlying surface characteristics in the rainstorm area. Then a synthetical index of disaster-prone environment was calculated using equal weighted summation of these indices. The disaster-causing hazard indices of the rainstorm event are composed of the weighted intensity indices of rainfall and the synthetical indices of disaster-prone environment. It was divided into five levels by using the Jenks natural breaks method, and the hazard level zonation chart for the rainstorm event was created using GIS. Finally, the hazard evaluation results were validated by the real rainstorm disaster data from the main affected area. The main results are as follows. (1) The "8.12" rainstorm event was characterized by its suddenness, heavy short-term rainfall, and concentrated precipitation, with 86.1% precipitation concentrated in 6 hours, and maximum precipitation in 6 hours of being up to a 50-year recurrence period, so the disaster-causing factors were selected by mainly considering the short-term precipitation. (2) The highest-level disaster hazard zones are located in most of Xiaonan district, central Yunmeng, north-east Yingcheng City, and southwest Anlu City, while the higher-level disaster hazard zone covers almost all the central part of Xiaogan City. Note that the results depend on the rainstorm intensity, the environment of the terrain, and the river network. (3) The highest- and higher-level hazard zones were areas corresponding to the regions with heavy rainstorm damage, with the actual disaster level reaching the "major" disaster level. The hazard assessment results actually reflected the actual losses in the main affected area

    Dynamic Interactions between TIP60 and p300 Regulate FOXP3 Function through a Structural Switch Defined by a Single Lysine on TIP60

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    SummaryThe human FOXP3 molecule is an oligomeric transcriptional factor able to mediate activities that characterize T regulatory cells, a class of lymphocytes central to the regulation of immune responses. The activity of FOXP3 is regulated at the posttranslational level, in part by two histone acetyltransferases (HATs): TIP60 and p300. TIP60 and p300 work cooperatively to regulate FOXP3 activity. Initially, p300 and TIP60 interactions lead to the activation of TIP60 and facilitate acetylation of K327 of TIP60, which functions as a molecular switch to allow TIP60 to change binding partners. Subsequently, p300 is released from this complex, and TIP60 interacts with and acetylates FOXP3. Maximal induction of FOXP3 activities is observed when both p300 and TIP60 are able to undergo cooperative interactions. Conditional knockout of TIP60 in Treg cells significantly decreases the Treg population in the peripheral immune organs, leading to a scurfy-like fatal autoimmune disease

    Enhanced pre-synaptic glutamate release in deep-dorsal horn contributes to calcium channel alpha-2-delta-1 protein-mediated spinal sensitization and behavioral hypersensitivity

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    Nerve injury-induced expression of the spinal calcium channel alpha-2-delta-1 subunit (Cavα2δ1) has been shown to mediate behavioral hypersensitivity through a yet identified mechanism. We examined if this neuroplasticity modulates behavioral hypersensitivity by regulating spinal glutamatergic neurotransmission in injury-free transgenic mice overexpressing the Cavα2δ1 proteins in neuronal tissues. The transgenic mice exhibited hypersensitivity to mechanical stimulation (allodynia) similar to the spinal nerve ligation injury model. Intrathecally delivered antagonists for N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxyl-5-methylisoxazole-4-propionic acid (AMPA)/kainate receptors, but not for the metabotropic glutamate receptors, caused a dose-dependent allodynia reversal in the transgenic mice without changing the behavioral sensitivity in wild-type mice. This suggests that elevated spinal Cavα2δ1 mediates allodynia through a pathway involving activation of selective glutamate receptors. To determine if this is mediated by enhanced spinal neuronal excitability or pre-synaptic glutamate release in deep-dorsal horn, we examined wide-dynamic-range (WDR) neuron excitability with extracellular recording and glutamate-mediated excitatory postsynaptic currents with whole-cell patch recording in deep-dorsal horn of the Cavα2δ1 transgenic mice. Our data indicated that overexpression of Cavα2δ1 in neuronal tissues led to increased frequency, but not amplitude, of miniature excitatory post synaptic currents mediated mainly by AMPA/kainate receptors at physiological membrane potentials, and also by NMDA receptors upon depolarization, without changing the excitability of WDR neurons to high intensity stimulation. Together, these findings support a mechanism of Cavα2δ1-mediated spinal sensitization in which elevated Cavα2δ1 causes increased pre-synaptic glutamate release that leads to reduced excitation thresholds of post-synaptic dorsal horn neurons to innocuous stimuli. This spinal sensitization mechanism may mediate at least partially the neuropathic pain states derived from increased pre-synaptic Cavα2δ1 expression

    Bar-Coded Pyrosequencing Reveals the Responses of PBDE-Degrading Microbial Communities to Electron Donor Amendments

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    Polybrominated diphenyl ethers (PBDEs) can be reductively degraded by microorganisms under anaerobic conditions. However, little is known about the effect of electron donors on microbial communities involved in PBDEs degradation. Here we employed 454 Titanium pyrosequencing to examine the phylogenetic diversity, composition, structure and dynamics of microbial communities from microcosms under the conditions of different electron donor amendments. The community structures in each of the five alternate electron donor enrichments were significantly shifted in comparison with those of the control microcosm. Commonly existing OTUs between the treatment and control consortia increased from 5 to 17 and more than 50% of OTUs increased around 13.7 to 186 times at least in one of the microcosms after 90-days enrichment. Although the microbial communities at different taxonomic levels were significantly changed by different environmental variable groups in redundancy analysis, significant correlations were observed between the microbial communities and PBDE congener profiles. The lesser-brominated PBDE congeners, tri-BDE congener (BDE-32) and hexa-BDE, were identified as the key factors shaping the microbial community structures at OTU level. Some rare populations, including the known dechlorinating bacterium, Dehalobacter, showed significant positive-correlation with the amounts of PBDE congeners in the consortia. The same results were also observed on some unclassified bacteria. These results suggest that PBDEs-degrading microbial communities can be successfully enriched, and their structures and compositions can be manipulated through adjusting the environmental parameters

    Preparation and Characterization of Covalently Binding of Rat Anti-human IgG Monolayer on Thiol-Modified Gold Surface

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    The 16-mercaptohexadecanoic acid (MHA) film and rat anti-human IgG protein monolayer were fabricated on gold substrates using self-assembled monolayer (SAM) method. The surface properties of the bare gold substrate, the MHA film and the protein monolayer were characterized by contact angle measurements, atomic force microscopy (AFM), grazing incidence X-ray diffraction (GIXRD) method and X-ray photoelectron spectroscopy, respectively. The contact angles of the MHA film and the protein monolayer were 18° and 12°, respectively, all being hydrophilic. AFM images show dissimilar topographic nanostructures between different surfaces, and the thickness of the MHA film and the protein monolayer was estimated to be 1.51 and 5.53 nm, respectively. The GIXRD 2θ degrees of the MHA film and the protein monolayer ranged from 0° to 15°, significantly smaller than that of the bare gold surface, but the MHA film and the protein monolayer displayed very different profiles and distributions of their diffraction peaks. Moreover, the spectra of binding energy measured from these different surfaces could be well fitted with either Au4f, S2p or N1s, respectively. Taken together, these results indicate that MHA film and protein monolayer were successfully formed with homogeneous surfaces, and thus demonstrate that the SAM method is a reliable technique for fabricating protein monolayer

    Probing Specific Interaction Forces Between Human IgG and Rat Anti-Human IgG by Self-Assembled Monolayer and Atomic Force Microscopy

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    Interaction forces between biological molecules such as antigen and antibody play important roles in many biological processes, but probing these forces remains technically challenging. Here, we investigated the specific interaction and unbinding forces between human IgG and rat anti-human IgG using self assembled monolayer (SAM) method for sample preparation and atomic force microscopy (AFM) for interaction force measurement. The specific interaction force between human IgG and rat anti-human IgG was found to be 0.6–1.0 nN, and the force required for unbinding a single pair of human IgG and rat anti-human IgG was calculated to be 144 ± 11 pN. The results are consistent with those reported in the literatures. Therefore, SAM for sample preparation combined with AFM for interaction measurement is a relatively simple, sensitive and reliable technique to probe specific interactions between biological molecules such as antigen and antibody
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