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[Purposes] The injection of water and/or CO2 alters the shear characteristics of jointed rock, directly impacting the stability of the sequestered formation. Thus, the influence of water injection and CO2 injection on the shear characteristics of jointed rock mass is explored. [Methods] Shear tests were carried out on flat jointed sandstone under three test conditions: drying, water injection, and CO2 injection. The changes of shear strength with confining pressure, injected fluid type, and injection fluid pressure were investigated. [Findings] The results indicate the following: The shear stress-shear displacement curves for straight jointed sandstone under all three test conditions (dry, CO2 injection, and water injection) exhibit a sliding failure pattern; Water/CO2 injection will weaken the shear strength of straight jointed rock, and the weakening effect of water is stronger than that of CO2; The empirical formula between shear strength and confining pressure, injection fluid type, and fluid injection pressure is proposed. The average error between experimental and theoretical data is 5.69%. [Conclusions] This research work is of great significance for predicting the shear strength of sandstone after water/CO2 injection, optimizing the construction scheme, and improving the construction safety.

Objective During pipe jacking construction, aging sewage pipes within the construction area are prone to rupture, leading to sewage infiltration into the thixotropic slurry along the soil body, thus impacting the performance of the thixotropic slurry to some extent. In order to ensure the construction safety, it is necessary to study the change law of performance indicator after sewage infiltration of the thixotropic slurry. Method Using the No. 1 entrance and exit project of Baohua Street Station on Jinan Rail Transit Line 2 as a case study, combined with the construction conditions of the sewage pipe rupture due to the jacking pipe underpass at the entrance and exit of the station, the change law of the thixotropic slurry performance indicators after sewage infiltration is studied, and the sewage infiltration impact on the drag reduction effect of thixotropic slurry is analyzed by drag reduction test. Result & Conclusion After sewage infiltration, the performance of the thixotropic slurry deteriorates, with a reduction in slurry funnel viscosity and a significant increase in water separation rate and water loss. The positive charges of inorganic salts in the sewage and the negative charges of the slurry soil particles attract each other, causing the slurry Zeta potential dropping from a stable 31.0 mV to below 20.0 mV. Sewage infiltration results in a noticeable increase in the mass fraction of large-size soil particles, and aggregation and precipitation of the slurry, this is the reason for the significant increase in slurry water separation rate. Sewage infiltration also leads to the decrease in the slurry drag reduction effect, with an increase in the friction factor and pipe jacking thrust.

Angiopoietin-like 2 (Angptl2) is reported to be correlated with cardiovascular diseases, but its role in hypertension remains unclear. This study aimed to investigate the role and potential mechanism of Angptl2 in hypertension. Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs) were used to detect the expression of Angptl2. Angiotensin II (Ang II) stimulates vascular smooth muscle cells (VSMCs) to mimic hypertension in vitro. Cell proliferation, migration, and invasion abilities were determined using CCK-8, cell colony formation, wound healing, and transwell assays, respectively. The cell cycle distribution was detected by flow cytometry. The expression of Ki67 was determined by immunofluorescence, and protein expression was measured using western blotting. Angptl2 was found to be elevated in hypertensive rats in vivo and in VSMCs upon Ang II stimulation in vitro. Angptl2 knockdown suppressed cell proliferation, colony formation, cell migration, and invasion as well as the downregulation of Ki67. Additionally, Angptl2 knockdown hindered cell cycle progression and downregulated protein expression of CDK2/4 and cyclin D1, but upregulated p21 expression. Furthermore, Angptl2 knockdown inhibited activation of the NLRP3 inflammasome. Our findings suggest that Angptl2 knockdown suppresses VSMC proliferation, migration, and invasion induced by Ang II. Angptl2 may be a new target for vascular remodeling in hypertension. Key words: angiopoietin-like 2, vascular smooth muscle cell, angiotensin II, proliferation. On rapporte que la proteine Angptl2 (angiopoietin-like 2) est correlee aux maladies cardiovasculaires, mais son role dans l'hypertension reste flou. Cette etudevisea etudier leroleet lemecanismed'action potentiel d'Angptl2 dans l'hypertension. Des rats Wistar-Kyoto (WKY) et des rats hypertendus spontanes (RHS) ont ete utilises pour mesurer l'expression d'Angptl2 Des CMLV ont ete stimulees a l'angiotensine II (Ang II) pour mimer l'hypertension in vitro. Les capacites de proliferation, de migration et d'invasion des cellules ont ete determinees en utilisant respectivement les tests CCK-8, de formation de colonies, de cicatrisation et de migration sur Transwell. La distribution dans le cycle cellulaire a ete detectee par analyse en cytometrie en flux. L'expression de Ki67 a ete determinee par immunofluorescence, et l'expression des proteines a ete mesuree par transfert de Western. Les auteurs ont constate que l'Angptl2 etait elevee chez les rats hypertendus in vivo et dans les CMLV apres stimulation a l'Ang II in vitro. Le knock-out du gene Angptl2 supprimait la proliferation, la formation de colonies, la migration et l'invasion des cellules, ainsi que la regulation a la baisse de Ki67. De plus, le knock-out du gene Angptl2 entravait la progression du cycle cellulaire et diminuait l'expression proteique de CDK2/4 et de la cycline D1, mais regulait a la hausse p21. En outre, le knock-out du gene Angptl2 inhibait l'activation de l'inflammasome NLRP3. Ces resultats suggerent que le knock-down du gene Angptl2 supprime la proliferation, la migration et l'invasion des VSMCs induites par l'Ang II. L'Angptl2 pourrait etre une nouvelle cible pour le remodelage vasculaire dans l'hypertension. [Traduit par la Redaction] Mots-cles: Angiopoietin-like 2, cellule musculaire lisse vasculaire, angiotensine II, proliferation., Introduction Cardiovascular diseases (CVDs) are the leading cause of death and are estimated to contribute to 25% of deaths worldwide by 2030 (Lim et al. 2012). Hypertension is one of [...]

To investigate the effect of stochastic uncertainty on the dynamic behaviors of ship propulsion shafting with misalignment, a stochastic uncertainty model of ship shafting is established based on nonparametric theory and stochastic excitation. Numerical simulation and experimental verification of the dynamic behaviors are carried out using a ship shafting test bench. The results indicate that stochastic uncertainty has a significant effect on the dynamic behaviors of shafting with misalignment. With an increase in stochastic uncertainty, the fractional frequency appears in the spectrum, and the axis trajectory becomes more complex and gradually deviates from the center orbit. Therefore, to ensure the safe navigation of ships, it is necessary to consider the stochastic uncertainty in dynamic research on the misalignment of shafting. [ABSTRACT FROM AUTHOR]

An approach combining the stochastic resonance, the harmonic wavelet packet transforms and the probability density function was proposed to obtain the early fault signal of a rolling bearing. Firstly, an adaptive variable-scale stochastic resonance was employed to detect the frequency range of the rolling bearing's fault signal based on the improved signal-to-noise ratio, and then the harmonic wavelet packet transforms and the probability density function were utilized to extract and identify the fault signal of the rolling bearings from the detected signals. The case studies show that the proposed method can effectively obtain the early fault signals of the outer race, inner race and rolling element in the rolling bearings despite not knowing the frequency band distribution, and that the early fault diagnosis of the rolling bearings can be achieved. [ABSTRACT FROM AUTHOR]