Internal waves transport material and energy from the upper water column to the deep ocean, disturbing seabed sediments and resulting in phenomena such as seabed erosion and changes in topography. On the northern slop...Internal waves transport material and energy from the upper water column to the deep ocean, disturbing seabed sediments and resulting in phenomena such as seabed erosion and changes in topography. On the northern slope of the South China Sea and in many coastal margins worldwide, the zones with internal wave action closely overlap with areas where natural gas hydrates are present. However, due to significant differences in the spatial and temporal scales, understanding the influence of internal waves on methane releases from deep seabeds is challenging. In this study, in situ observations of seabed microseismicity and internal waves are conducted at water depths of 655 meters and 1450 meters in the Pearl River Canyon of the South China Sea. The microseismicity caused by internal waves and seabed methane releases is identified, and a method to establish the correlation between internal waves and seabed methane releases through the use of microseismic recordings is proposed, aiming to obtain direct observational evidence of internal waves intensifying seabed methane releases. The results show that internal waves and seabed methane releases generate significant microseismic signals, indicating the continuous influence of internal waves on the deep seabed of the northern slope of the South China Sea and revealing active methane release phenomena on the seabed. At both long and short time scales, internal waves increase the frequency of seabed methane releases by 4.2 times and 2.4 times, respectively, while also enhancing the intensity of these releases. These changes are influenced by the alterations in seabed flow velocity, pressure, and temperature that are induced by internal wave activities. This study emphasizes that microseismic signals are effective carriers of information for multiscale geological processes on seabeds and suggests that internal waves exacerbate marine geological hazards and contribute to global climate change by intensifying seabed methane releases.展开更多
Idiopathic pulmonary fibrosis(IPF)is a chronic interstitial lung disease with a high mortality rate and limited therapeutic options.Dysregulated macrophage polarization as a driver of fibroblast activation and epithel...Idiopathic pulmonary fibrosis(IPF)is a chronic interstitial lung disease with a high mortality rate and limited therapeutic options.Dysregulated macrophage polarization as a driver of fibroblast activation and epithelial-mesenchymal transition(EMT)is the key to IPF evolution,but lacks an effective management approach.Herein,we develop a novel inhalable methane nanocapsule(MNC)which is able to spatiotemporally control methane release in the lung to locally remodel fibrogenic microenvironment in IPF.MNC is formulated through self-assembly of biodegradable poly(lactic-co-glycolic acid)-polyethylene glycol(PLGA-PEG)copolymer and a new acid-responsive methane prodrug Fe(BPY)_(2)(CH_(3))_(2) to enhance the efficacy of pulmonary methane delivery by facilitating mucosal penetration and sustained methane release in response to the acidic inflammatory niche.In a bleomycin(BLM)-induced pulmonary fibrosis model,MNC inhalation achieves efficient MNC deposition and sustained methane release in the lung,significantly reducing inflammation progression,ameliorating fibrosis formation,and improving lung function without systemic side effects.Mechanistically,MNC not only rebalances macrophage polarization by inhibiting M2 phenotype overexpression but also downregulates the ratio of MMP9/TIMP-1 to suppress myofibroblast proliferation and EMT,synergistically suspending the fibrotic progression of IPF.The developed inhalable methane nanocapsule offers a promising strategy to remodel pulmonary fibrogenic microenvironment for safe and effective treatment of IPF.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.41831280)。
文摘Internal waves transport material and energy from the upper water column to the deep ocean, disturbing seabed sediments and resulting in phenomena such as seabed erosion and changes in topography. On the northern slope of the South China Sea and in many coastal margins worldwide, the zones with internal wave action closely overlap with areas where natural gas hydrates are present. However, due to significant differences in the spatial and temporal scales, understanding the influence of internal waves on methane releases from deep seabeds is challenging. In this study, in situ observations of seabed microseismicity and internal waves are conducted at water depths of 655 meters and 1450 meters in the Pearl River Canyon of the South China Sea. The microseismicity caused by internal waves and seabed methane releases is identified, and a method to establish the correlation between internal waves and seabed methane releases through the use of microseismic recordings is proposed, aiming to obtain direct observational evidence of internal waves intensifying seabed methane releases. The results show that internal waves and seabed methane releases generate significant microseismic signals, indicating the continuous influence of internal waves on the deep seabed of the northern slope of the South China Sea and revealing active methane release phenomena on the seabed. At both long and short time scales, internal waves increase the frequency of seabed methane releases by 4.2 times and 2.4 times, respectively, while also enhancing the intensity of these releases. These changes are influenced by the alterations in seabed flow velocity, pressure, and temperature that are induced by internal wave activities. This study emphasizes that microseismic signals are effective carriers of information for multiscale geological processes on seabeds and suggests that internal waves exacerbate marine geological hazards and contribute to global climate change by intensifying seabed methane releases.
基金supported by the National Natural Science Foundation of China(82372104,82172078,and U23A20690)Guangdong Basic and Applied Basic Research Foundation(2024A1515030203)+1 种基金Shenzhen Science and Technology Program(RCJC20210706092010008)Guangzhou Science and Technology Bureau Basic Research Program City School Enterprise Joint Funding Project(2025A03J4530)。
文摘Idiopathic pulmonary fibrosis(IPF)is a chronic interstitial lung disease with a high mortality rate and limited therapeutic options.Dysregulated macrophage polarization as a driver of fibroblast activation and epithelial-mesenchymal transition(EMT)is the key to IPF evolution,but lacks an effective management approach.Herein,we develop a novel inhalable methane nanocapsule(MNC)which is able to spatiotemporally control methane release in the lung to locally remodel fibrogenic microenvironment in IPF.MNC is formulated through self-assembly of biodegradable poly(lactic-co-glycolic acid)-polyethylene glycol(PLGA-PEG)copolymer and a new acid-responsive methane prodrug Fe(BPY)_(2)(CH_(3))_(2) to enhance the efficacy of pulmonary methane delivery by facilitating mucosal penetration and sustained methane release in response to the acidic inflammatory niche.In a bleomycin(BLM)-induced pulmonary fibrosis model,MNC inhalation achieves efficient MNC deposition and sustained methane release in the lung,significantly reducing inflammation progression,ameliorating fibrosis formation,and improving lung function without systemic side effects.Mechanistically,MNC not only rebalances macrophage polarization by inhibiting M2 phenotype overexpression but also downregulates the ratio of MMP9/TIMP-1 to suppress myofibroblast proliferation and EMT,synergistically suspending the fibrotic progression of IPF.The developed inhalable methane nanocapsule offers a promising strategy to remodel pulmonary fibrogenic microenvironment for safe and effective treatment of IPF.
