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Submarine hydrate mining can trigger geological disasters, including submarine landslides and seafloor subsidence due to excess pore pressure and weakened layers, which may potentially lead to the reactivation of faults and increased seismic activity. However, current research encounters challenges in assessing geotechnical issues associated with long-term and large-scale production from well grids located in sloped areas. Limited by the complexity of the hydrate sediment, a multifield coupled numerical model of hydrate slope in the Shenhu area was established. Utilizing the modified Mohr–Coulomb model as the constitutive model for hydrate-bearing sediments to track the dynamic reduction in strength and employing the shear strength method to assess submarine slope stability, a series of depressurization strategies are applied to evaluate the risks associated with submarine landslides and seafloor subsidence. Results show that the hydrate dissociation tends to stagnate after a period of mining. The strength of the hydrate decomposed area is severely reduced, and a volume deficit occurs in this area, causing formation displacement. The peripheral region of the decomposed area is compacted by high stress, resulting in a serious decrease in permeability and porosity, which limits the continued decomposition of hydrates. The large-scale submarine landslides with hydrates decomposition will not appear in this block. However, several meters' seafloor subsidence over a wide range risks engineering safety significantly. The amount of seafloor subsidence in the first 50 days is approximately half of the final settlement. A higher production pressure drop can speed up the recovery rate while resulting in more significant seafloor subsidence and slippage. Therefore, the balance between mining speed and formation stability needs more research work. [ABSTRACT FROM AUTHOR]

High metastatic propensity of osteosarcoma leads to its therapeutic failure and poor prognosis. Although nuclear activation miRNAs (NamiRNAs) are reported to activate gene transcription via targeting enhancer and further promote tumor metastasis, it remains uncertain whether NamiRNAs regulate osteosarcoma metastasis and their exact mechanism. Here, we found that extracellular vesicles of the malignant osteosarcoma cells (143B) remarkably increased the migratory abilities of MNNG cells representing the benign osteosarcoma cells by two folds, which attributed to their high miR‐1246 levels. Specially, miR‐1246 located in nucleus could activate the migration gene expression (such as MMP1) to accelerate MNNG cell migration through elevating the enhancer activities via increasing H3K27ac enrichment. Instead, MMP1 expression was dramatically inhibited after Argonaute 2 (AGO2) knockdown. Notably, in vitro assays demonstrated that AGO2 recognized the hybrids of miR‐1246 and its enhancer DNA via PAZ domains to prevent their degradation from RNase H and these protective roles of AGO2 may favor the gene activation by miR‐1246 in vivo. Collectively, our findings suggest that miR‐1246 could facilitate osteosarcoma metastasis through interacting with enhancer to activate gene expression dependent on AGO2, highlighting the nuclear AGO2 as a guardian for NamiRNA‐targeted gene activation and the potential of miR‐1246 for osteosarcoma metastasis therapy. [ABSTRACT FROM AUTHOR]

Field observations were combined with a coupled hydrodynamic and water quality model to investigate the spatial and temporal variation in Chlorophyll-a (Chl-a) in Jinmeng Bay, China. The relatively high Chl-a values were distributed in the inshore waters, mainly due to the abundant nutrient inflow from the Tanghe River. The model's results indicate that the Chl-a concentration was much higher in seaweed beds surrounded by artificial islands and reefs under the southeasterly wind, largely due to the fact that pollutants are prone to accumulate in coastal areas where flow is attenuated by the presence of natural and artificial marine structures. It was also found that the southwesterly winds suppress the inflow of nutrients from the Tanghe River to the coastal areas, and, therefore, lower the Chl-a levels. River input and wind forcing are the major factors that influence Chl-a concentrations in the anthropogenically influenced bay. This finding provides useful guidance for the prediction and mitigation of green tides in Jinmeng Bay in the future. [ABSTRACT FROM AUTHOR]

With the recent development from grey infrastructures to green infrastructures, artificial reefs become more popular in coastal protection projects. To investigate the responses of beach profile evolution to the presence of an artificial reef, a non-hydrostatic model is established. Both hydrodynamic and morphodynamic evolution for the beach with and without an artificial reef are compared under regular wave conditions. In addition, the protected beach profile evolution by an artificial reef is discussed under irregular wave conditions. Three key parameters in non-hydrostatic simulation are considered for sensitivity analysis, including maximum wave steepness criterium (maxbrsteep), water depth factor (depthscale), and equilibrium sediment concentration factor (sedcal). The numerical results under regular wave conditions indicate that the artificial reef enhances wave attenuation by inducing wave breaking. In addition, the artificial reef reduces local flow velocity and offshore sediment transport by 51%, therefore decrease the total erosion by 53%. Over the artificial reef, wave skewness and asymmetry go through a drastic change. Under irregular wave conditions, short waves contribute to the wave energy mainly and reflection-induced standing wave effects decline considerably. It demonstrates that the artificial reef can protect the beach from regular and irregular waves by reducing erosion and offshore transport of suspended sediments. Moreover, in the wave breaking area, the increase of maximum wave steepness criterium may give arise to the wave height. The morphological evolution is more sensitive to water depth factor than equilibrium sediment concentration factor, because the former is a controlling factor for beach profile characteristics while the latter forms the sandbar varying irregularly in shape. [ABSTRACT FROM AUTHOR]