Insights into the cause of the Oroville dam spillway failure, 2017, California.

Earth internal seepage erosion in weathered bedrock under infrequently used hydraulic structures is often overlooked, which causes some solid particles to break away from the solid skeleton, degrading the earth's strength, and even causing unanticipated hydraulic engineering failures. The flood on the Oroville dam spillway in California in 2017 was caused by disturbed water flow due to a crack in the spillway chute caused by internal erosion in poorly weathered bedrock. The abnormal water flow of the spillway in the early stage and subsequent investigation revealed that the main reason for the accident was the insufficient weathered bedrock under the spillway chute. In this study, we formulated a coupled hydro-mechanical mechanism for internal erosion in weathered bedrock during the early stages. Using this model, we conducted an internal erosion numerical simulation at early stage, and the results showed that the physical characteristics of the weathered bedrock were degraded. Our results show the coupling analysis of quantitative computation during the early stage of internal erosion in weathered bedrock, which can provide an early warning method for the occurrence of internal erosion to avoid hydraulic disasters.

Similar Material Proportioning Tests and Mechanical Properties Based on Orthogonal Design.

Shaking table tests serve as an effective method to simulate landslides triggered by seismic activities. These laboratory experiments necessitate the use of materials that mimic those encountered in real-world scenarios. For this investigation, materials analogous to field conditions for the shaking table tests were formulated using quartz sand, barite powder, iron powder, gypsum, rosin, and alcohol. Within the model test compositions, iron powder, barite powder, and quartz sand acted as aggregates; gypsum functioned as an additive, and a solution of rosin and alcohol was employed as a binder. Employing the orthogonal design method, the physical and mechanical parameters of these analogous materials were ascertained through double-sided shear tests, as well as uniaxial compression and splitting tests. Subsequent analyses included extreme difference and regression assessments targeting the determinants influencing the physical and mechanical characteristics of these materials. The ultimate goal was to determine the optimal mixing ratios for the model test materials. The findings revealed that the physical and mechanical properties of analogous materials at varying ratios span a broad spectrum, fulfilling the criteria for distinct rock model experiments. A thorough examination of the factors impacting the physical and mechanical properties of these materials was undertaken, elucidating their respective influences. Based on the relative significance of each determinant on the mechanical attributes of the analogous materials, dominant factors were identified for a multiple regression analysis, from which the regression equations corresponding to the test ratios were derived.

Experimental study on the reasonable proportions of rock-like materials for water-induced strength degradation in rock slope model test.

Water-induced strength deterioration of rock mass is a crucial factor for rock slope instability. To better show the degradation process of rock slope water-rock interaction, we used bentonite as a water-sensitive regulator to build a new rock-like material that matches the features of water-induced strength degradation based on the cement-gypsum bonded materials. Twenty-five schemes of the material mixture proportion were designed using the orthogonal design method considering four factors with five variable levels, and a variety of experiments were conducted to obtain physico-mechanical parameters. In addition, one group of rock-like material proportion was selected and applied to the large-scale physical model test. The experiment results reveal that: (1) The failure mode of this rock-like material is highly similar to that of natural rock masses, and the physico-mechanical parameters vary over a wide range; (2) The bentonite content has a significant influence on the density, elastic modulus, and tensile strength of rock-like materials; (3) It is feasible to obtain the regression equation based on the linear regression analysis to determine the proportion of rock-like material; (4) Through application, the new rock-like material can effectively simulate or reveal the startup mechanism and instability characteristics of rock slopes under water-induced degradation. These studies can serve as a guide for the fabrication of rock-like material in the other model tests.

The comprehensive risk assessment of the Tangjiashan landslide dam incident, China.

Risk assessment for landslide dams is very important to avoid unanticipated landslide failure and calamity. Recognition of the risk of landslide dams associated with changing influencing factors is to identify the risk grade and provide early warning of oncoming failure, while quantitative risk analysis of landslide dams due to many influencing factors changing in spatiotemporal domain is currently lacking. We applied the model to analyze the risk level of the Tangjiashan landslide dam caused by the Wenchuan Ms 8.0 earthquake. The risk evaluation, obtained according to the analysis of the influencing factors located in the risk assessment grade criteria, clearly shows that the risk reaches a higher level at that moment. Our analysis shows that the risk level of landslide dams can be quantitatively analyzed with our assessment method. Our results suggest that the risk assessment system can be an effective measure to dynamically predict the risk level and provide a sufficient early warning of the oncoming hazard by analyzing the variables of influencing factors at different times.

A case report of acute suppurative thyroiditis caused by Clostridium perfringens.

A 42-year-old woman inadvertently discovered a neck mass, which caused pain. Initially, she was treated with antibiotics at a local clinic; however, this treatment did not alleviate the symptoms. She visited the authors' outpatient clinic for further treatment and underwent thyroid ultrasonography, which revealed a mixed echo nodule. On day 4 after admission, surgery was performed to remove the diseased thyroid tissue and levofloxacin (0.4 g/day) was infused. Bacterial culture confirmed infection with Clostridium perfringens. Subsequently, the treatment was switched to ceftriaxone sodium (2 g/day) according to the results of the drug sensitivity test. Following treatment, the patient recovered fully and was discharged. She was then followed up with after discharge. Ultrasonography, laboratory testing and clinical manifestations did not indicate obvious abnormalities.

A time function-based prediction model of mining subsidence: application to the Barapukuria coal mine, Bangla.

Coal mining may lead to ground subsidence in a long term and is widely distributed, which can cause environmental damage and other disasters. Predicting the dynamic process of ground subsidence in real time is very important for offering theoretical or technical guidance to deal with the consequences of mining. In this study, we developed a prediction method for dynamic ground subsidence using a time function model that considers two stages of surface subsidence and reflects the law of surface subsidence in goaf. We applied the model to the Barapukuria mine, and our simulation shows that the prediction results are in good agreement with the monitoring data. Our results suggest that the dynamic development of the ground subsidence basin may be an effective measure to assess the loss of ground and provide early warning of oncoming hazards.

Evaluation of the characterization of acoustic emission of brittle rocks from the experiment to numerical simulation.

Acoustic emission (AE) characterization is an effective technique to indirectly capture the failure process of quasi brittle rock. In previous studies, both experiments and numerical simulations were adopted to investigate the AE characteristics of rocks. However, as the most popular numerical model, the moment tensor model (MTM) cannot be constrained by the experimental result because there is a gap between MTM and experiments in principle, signal processing and energy analysis. In this paper, we developed a particle-velocity-based model (PVBM) that enabled direct monitoring and analysis of the particle velocity in the numerical model and had good robustness. The PVBM imitated the actual experiment and could fill in gaps between the experiment and MTM. AE experiments of marine shale under uniaxial compression were carried out, and the results were simulated by MTM. In general, the variation trend of the experimental result could be presented by MTM. Nevertheless, the magnitudes of AE parameters by MTM presented notable differences of more than several orders of magnitude compared with those by the experiment. We sequentially used PVBM as a proxy to analyse these discrepancies and systematically evaluate the AE characterization of rocks from the experiment to numerical simulation, considering the influence of wave reflection, energy geometrical diffusion, viscous attenuation, particle size and progressive deterioration of rock material. The combination of MTM and PVBM could reasonably and accurately acquire AE characteristics of the actual AE experiment of rocks by making full use of their respective advantages.

Activation of farnesoid X receptor downregulates monocyte chemoattractant protein-1 in murine macrophage.

Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily, which plays important roles in bile acids/lipid homeostasis and inflammation. Monocyte chemoattractant protein-1 (MCP-1) contributes to macrophage infiltration into body tissues during inflammation. Here we investigated whether FXR can regulate MCP-1 expression in murine macrophage. FXR activation down regulate MCP-1 mRNA and protein levels in ANA-1 and Raw264.7 cells. Luciferase reporter assay, Gel shift and Chromatin immunoprecipitation assays have revealed that the activated FXR bind to the FXR element located in -738 bp âˆ¼  -723 bp in MCP-1 promoter. These results suggested that FXR may serve as a novel target for regulating MCP-1 levels for the inflammation related diseases therapies.

Farnesoid X receptor up-regulates expression of lipid transfer inhibitor protein in liver cells and mice.

Apolipoprotein F is a component protein mainly secreted by liver and resides on several lipoprotein classes. It can inhibit lipids transfer between different lipoproteins. FXR is a member of the nuclear receptor superfamily which is also highly expressed in the liver. It modulates bile acids synthesis and lipids metabolism by transcriptional regulation. We aimed to determine whether apoF can be regulated by FXR. The FXR agonist Chenodeoxycholic acid (CDCA) and GW4064 both can activate the expression of apoF in liver cell lines and in C57/BL6 mouse liver. This is dependent on the binding of FXR to the FXR element ER1 (-2904 to -2892 bp) in the apoF gene promoter. Taken together, we have identified apoF as likely another target gene of FXR.

[Infection of recombinant adenovirus Ad5F35-IL-12 in different kinds of human mononuclear macrophages].

Objective To investigate the efficiencies of transfection and expression of human recombinant adenovirus Ad5F35-IL-12 in the different kinds of human mononuclear macrophages. Methods The human recombinant adenovirus Ad5F35-IL-12 was used to infect human peripheral blood monocytes, pleural fluid macrophages as well as THP-1, U937 monocyte cell lines and their phorbol myristate acetate (PMA)-induced macrophages. 48 h later, green fluorescence was observed under the fluorescence microscope to detect the transfection efficiency. The expressions of IL-12 double-subunits (p35, p40) mRNA were tested by RT-PCR and the level of IL-12p70 protein in the cell culture supernatant was detected with ELISA. Results The human recombinant adenovirus Ad5F35-IL-12 successfully infected the human peripheral blood monocytes, pleural fluid macrophages, THP-1 monocytes, U937 monocytes, and THP-1 and U937 macrophages induced with PMA. All above infected mononuclear macrophages effectively secreted IL-12p70 protein, and they were listed from high to low of IL-12p70 protein level as pleural fluid macrophages, U937 and THP-1 macrophages induced with PMA, U937 monocytes, human peripheral blood monocytes and THP-1 monocytes. Conclusion The human recombinant adenovirus Ad5F35-IL-12 could infect different kinds of mononuclear macrophages, and IL-12 p70 protein could be successfully expressed in cell supernatants.

[Prokaryotic expression and purification of a tandem repeat of ovarian cancer antigen CA125 and preparation of its antiserum].

AIM: To establish a prokaryotic expression system of the tandem repeat of CA125 (CA125R), express and purify the recombinant CA125R protein, prepare its antiserum. METHODS: The full gene sequence of one tandem repeat of CA125 was synthesized and cloned into pET-32a(+) to construct a prokaryotic expression vector of the CA125R protein (pET-CA125R). The pET-CA125R was transformed into E.coli BL21 (DE3) and the soluble expression conditions were optimized; the pure recombinant CA125R protein was prepared by affinity Ni-NTA chromatography and identified by Western blotting. A rabbit was immunized with the pure recombinant CA125R protein to prepare its antiserum. RESULTS: The prokaryotic expression vector of CA125R was successfully constructed. The optimal soluble induction expression conditions were 0.5 mmol/L isopropyl ß-D-1-thiogalactopyranoside (IPTG) at 15DegreesCelsius for 6 h. Western blotting confirmed the pure CA125R recombinant protein of high purity. The prepared antiserum specifically recognized recombinant CA125R protein and natural CA125 glycoprotein. CONCLUSION: We successfully established the efficient prokaryotic expression system of the CA125R, and prepared the recombinant CA125R protein of high purity and its antiserum.