25 research outputs found

    Effects of Lithium Slag on the Frost Resistance of Cement-Soil

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    In this study, the effect of lithium slag (LS) on the frost resistance of cement-soil was evaluated. The results of freeze–thaw damage on the surface of the cement-soil, freeze–thaw mass loss, unconfined compression strength, triaxial shear strength, cohesion, and internal friction angle were tested at various freeze–thaw cycles after 90 days of curing when LS was incorporated into the cement-soil at different proportions (0%, 6%, 12%, and 18%). Combining nuclear magnetic resonance (NMR) T2 distribution and scanning electron microscopy (SEM) microscopic images, the mechanism of the effect of LS on the cement-soil was also analyzed. The experiment confirmed that the surface freeze–thaw damage degree and mass loss value of the cement-soil decreased after incorporating different LS contents, and that the unconfined compression strength, triaxial shear strength, cohesion, and internal friction angle also improved significantly compared with the specimens without LS. In this experiment, the optimization level of the cement-soil performance with different LS content was ranked as 12% > 18% > 6% > 0%. According to the NMR and SEM analysis results, the LS content of 12% can optimize the internal pore structure of the cement-soil and strengthen the bond between aggregate particles, hence inhibiting the extension of freeze-swelling cracks induced by freeze–thaw cycles. In conclusion, LS can effectively enhance the frost resistance of cement-soil, and the optimum content in this experiment is 12%

    Investigation on Primary Breakup of High-Pressure Diesel Spray Atomization by Method of Automatic Identifying Droplet Feature Based on Eulerian–Lagrangian Model

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    To investigate primary breakup close to an injector, this paper presents both experimental and numerical research on high-pressure common-rail diesel injection. We propose a new method named SD-ELSA model to realize automatically identifying droplet features for high-pressure diesel spray based on the classic ELSA (Eulerian Lagrangian Spray Atomization) model; this method is suitable for varied injection operation conditions. The SD-ELSA first identifies the liquid bulk due to breakup of the continuous phase in near field, and then converts the Eulerian liquid bulk into Lagrangian particles to complete the calculation of the total spray atomization. The SD-ELSA model adopts two key criteria, i.e., the sphericity (S) and the particle diameter (D); the qualified liquid mass is transformed into Lagrangian particle, realizing the coupling of the Eulerian–Lagrangian model. The SD-ELSA model illustrates the total diesel spray atomization process from the breakup liquid column to the droplets

    LncRNA miR663AHG represses the development of colon cancer in a miR663a-dependent manner

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    Abstract The MIR663AHG gene encodes both miR663AHG and miR663a. While miR663a contributes to the defense of host cells against inflammation and inhibits colon cancer development, the biological function of lncRNA miR663AHG has not been previously reported. In this study, the subcellular localization of lncRNA miR663AHG was determined by RNA-FISH. miR663AHG and miR663a were measured by qRT-PCR. The effects of miR663AHG on the growth and metastasis of colon cancer cells were investigated in vitro and in vivo. CRISPR/Cas9, RNA pulldown, and other biological assays were used to explore the underlying mechanism of miR663AHG. We found that miR663AHG was mainly distributed in the nucleus of Caco2 and HCT116 cells and the cytoplasm of SW480 cells. The expression level of miR663AHG was positively correlated with the level of miR663a (r = 0.179, P = 0.015) and significantly downregulated in colon cancer tissues relative to paired normal tissues from 119 patients (P < 0.008). Colon cancers with low miR663AHG expression were associated with advanced pTNM stage (P = 0.021), lymph metastasis (P = 0.041), and shorter overall survival (hazard ratio = 2.026; P = 0.021). Experimentally, miR663AHG inhibited colon cancer cell proliferation, migration, and invasion. The growth of xenografts from RKO cells overexpressing miR663AHG was slower than that of xenografts from vector control cells in BALB/c nude mice (P = 0.007). Interestingly, either RNA-interfering or resveratrol-inducing expression changes of miR663AHG or miR663a can trigger negative feedback regulation of transcription of the MIR663AHG gene. Mechanistically, miR663AHG could bind to miR663a and its precursor pre-miR663a, and prevent the degradation of miR663a target mRNAs. Disruption of the negative feedback by knockout of the MIR663AHG promoter, exon-1, and pri-miR663A-coding sequence entirely blocked these effects of miR663AHG, which was restored in cells transfected with miR663a expression vector in rescue experiment. In conclusion, miR663AHG functions as a tumor suppressor that inhibits the development of colon cancer through its cis-binding to miR663a/pre-miR663a. The cross talk between miR663AHG and miR663a expression may play dominant roles in maintaining the functions of miR663AHG in colon cancer development

    Spatio-temporal clustering of Mountain-type Zoonotic Visceral Leishmaniasis in China between 2015 and 2019.

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    With several decades of concerted control efforts, visceral leishmaniasis(VL) eradication had almost been achieved in China. However, VL cases continue to be detected in parts of western China recent years. Using data of reported cases, this study aimed to investigate the epidemiology and spatio⁃temporal distribution, of mountain-type zoonotic visceral leishmaniasis (MT-ZVL) in China between the years 2015 and 2019. Epidemiological data pertaining to patients with visceral leishmaniasis (VL) were collected in Gansu, Shaanxi, Sichuan, Shanxi, Henan and Hebei provinces between the years 2015 and 2019. Joinpoint regression analysis was performed to determine changes in the epidemic trend of MT-ZVL within the time period during which data was collected. Spatial autocorrelation of infection was examined using the Global Moran's I statistic wand hotspot analysis was carried out using the Getis-Ord Gi* statistic. Spatio-temporal clustering analysis was conducted using the retrospective space-time permutation flexible spatial scanning statistics. A total of 529 cases of MT-ZVL were detected in the six provinces from which data were collected during the study time period, predominantly in Gansu (55.0%), Shanxi (21.7%), Shaanxi (12.5%) and Sichuan (8.9%) provinces. A decline in VL incidence in China was observed during the study period, whereas an increase in MT-ZVL incidence was observed in the six provinces from which data was obtained (t = 4.87, P < 0.05), with highest incidence in Shanxi province (t = 16.91, P < 0.05). Significant differences in the Moran's I statistic were observed during study time period (P < 0.05), indicating spatial autocorrelation in the spatial distribution of MT-ZVL. Hotspot and spatial autocorrelation analysis revealed clustering of infection cases in the Shaanxi-Shanxi border areas and in east of Shanxi province, where transmission increased rapidly over the study duration, as well as in well know high transmission areas in the south of Gansu province and the north of the Sichuan province. It indicates resurgence of MT-ZVL transmission over the latter three years of the study. Spatial clustering of infection was observed in localized areas, as well as sporadic outbreaks of infection
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