Search

Thixotropy is a very important and unique property of soft clay in engineering, which has been drawing more and more attention in recent years. This study investigated the thixotropic strength recovery of representative marine clays in different sites of offshore China. The microstructure changes of clay during thixotropy were observed using scanning electron microscopy, and then related microscopic characteristics were analyzed. Probability entropy, Ep , is proposed as a new indicator based on the statistics of the alteration of diameter and orientation of particles or aggregates. The results show that thixotropy had significant effect on the strength increase for all the offshore Chinese clays that were tested, but their strength regain with time varied between the different sites. Some good correlations were developed between the thixotropy strength ratio and index parameters, particularly for water content, plasticity index, liquidity index, and sensitivity. The microstructural evolution of the clay tested during thixotropy was characterized by the change in both the diameter and the arrangement of particles or aggregates. The probability entropy was proved to quantitatively describe and analyze the microstructural evolution during thixotropy of clay, and its value increases with time. This new indicator could help to provide deeper insight into the thixotropic mechanism of clay. [ABSTRACT FROM AUTHOR]

• A multi-enzyme-mimicking nanozyme-thixotropic anionic hydrogel coating was fabricated. • The coating exhibited antifungal performance and wound healing capacity. • The coating was successfully used for the treatment of fungal keratitis. Fungal keratitis is the primary cause of infectious corneal blindness in China. Currently, early-stage treatment mainly involves the frequent administration of antifungal medications to ensure prolonged corneal contact and maintain effective drug concentration. This approach, however, may lead to harmful side effects and increased antifungal resistance due to the substantial use of antifungal agents. Consequently, the development of advanced antifungal strategies is essential. In the study, we fabricated a multi-enzyme-mimicking nanozyme-thixotropic anionic hydrogel coating (NHC) that incorporated voriconazole and copper-proanthocyanidins (CuPC) nanozyme, by the Schiff base reaction of self-synthesized polyaldehyde oligomer (PAO) with amino functionalized hyaluronic acid (AHA), for the treatment of fungal keratitis. The thixotropic anionic hydrogel significantly boosts the retention time and permeability of voriconazole, allowing a low dose to achieve a high therapeutic concentration. Additionally, the inherent antifungal and peroxidase-like activities of CuPC, coupled with the intrinsic characteristics of anionic hydrogel, further enhance the antifungal efficacy of NHC. Moreover, the NHC assists in corneal wound healing through stimulating cell proliferation by HA derivative as well as scavenging ROS via the catalase-like and superoxide dismutase-like activities of CuPC. The in vitro and in vivo studies have illustrated the safety and effectiveness of NHC, indicating its potential in the treatment of fungal keratitis. [ABSTRACT FROM AUTHOR]

Abstract: This study identified soft–sediment deformation structures (SSDS) of seismic origin from lacustrine sediments in the late Quaternary paleo–dammed lake at Tashkorgan, northeastern Pamir. The observed deformation structures include sand dykes, liquefied diapir and convolute structures, gravity induced SSDS, and thixotropic pillar and tabular structures. We conducted a preliminary study on the morphology, formation and trigger mechanisms of pillar and tabular structures formed by liquefaction of underlying coarse sand and thixotropy of the upper silty clay. The regional tectonic setting and distribution of lacustrine strata indicate that the most probable trigger for the SSDS in lacustrine sediments was seismic activity, with an approximate earthquake magnitude of M>6.0; the potential seismogenic fault is the southern part of the Kongur normal fault extensional system. AMS 14C dating results indicate that the SSDS were formed by seismic events occurring between 26050±100 yrBP and 22710±80 yrBP, implying intense fault activity in this region during the late Pleistocene. This study provides new evidence for understanding tectonic activity and regional geodynamics in western China. [ABSTRACT FROM AUTHOR]

Abstract: This paper focuses on soft-sediment deformation structures (SSDS) in both siliciclastic and carbonate storm deposits of the Cambrian Mantou and Chaomidian formations (Shandong Province, China) in order to understand their deformation mechanisms and possible triggers. Siliciclastic SSDS (e.g., sand volcanoes and pillows) and carbonate SSDS (e.g., sedimentary dykes, grainstone-matrix breccias, deformed cross-beddings, and marlstone-matrix breccias) occur exclusively in hummocky cross-stratified fine sandstone and peloidal grainstone, respectively. The siliciclastic SSDS formed in porous and permeable surface sediment, whereas the carbonate SSDS formed under shallow burial conditions when early marine cementation prevailed. The various deformation structures resulted mainly from differences between siliciclastic and carbonate sediment conditions and resulting deformation mechanisms. Sand volcanoes formed by upward extrusion of over-pressured fluidized sandy sediment, whereas sand pillows resulted from upward injection of lower density muddy sediment into overlying liquefied sandy sediment. Sedimentary dykes and grainstone-matrix limestone breccias formed as a result of differential liquefaction and fluidization of heterogeneously cemented carbonate sediment, whereas deformed cross-beddings and marlstone-matrix limestone breccias developed by the thixotropic liquidization and injection of clayey sediment, and further disruption of thin peloidal layers. Sedimentary facies analysis and analysis of the physical processes indicate that the SSDS were most likely caused by cyclic loading of storm waves. [Copyright &y& Elsevier]