Air blasts induced by rock-ice avalanches are common natural phenomena known for their far-field destructive impact.In this study,remote sensing images,eyewitness videos and numerical modelling were comprehensively ap...Air blasts induced by rock-ice avalanches are common natural phenomena known for their far-field destructive impact.In this study,remote sensing images,eyewitness videos and numerical modelling were comprehensively applied to analyze the initiation and propagation of the 2021 Chamoli avalancheinduced air blast.Our findings indicate that air blasts are observed from the avalanche source area to the Rishiganga valley,but nearly disappear in the Dhauliganga valley.The most intense air blast is concentrated on the left side of Ronti Gad valley,with maximum velocity and pressure estimated at over 70 m/s and 20 kPa,respectively.Such high pressure results in widespread tree breakage in the area.Based on the analysis of the Chamoli event,we further discussed the potential contribution of the avalanche flow regime,avalanche dynamics and geomorphology to the destructive potential of air blasts.Rapidly moved sliding mass can impart the air blast a high initial momentum,and this process will be exaggerated when the avalanche impacts valley walls at bends.However,when the rock-ice avalanche transforms into a debris-enriched flash flood,free water within the flowing mass can displace air,inhibiting the generation of air blasts.Our work offers new insights into the generation and propagation of rock-ice avalanche-induced air blasts,underscoring the importance of including this type of hazard during avalanche risk assessment in high-altitude glacial regions.展开更多
Crohn’s Disease (CD) is a chronic recurrent inflammatory bowel disease with unknown etiology, most common in the terminal ileum and adjacent colon. In the past 30 years, the global prevalence of CD has continued to r...Crohn’s Disease (CD) is a chronic recurrent inflammatory bowel disease with unknown etiology, most common in the terminal ileum and adjacent colon. In the past 30 years, the global prevalence of CD has continued to rise. Although the etiology is unknown, studies have shown that it is closely related to geographical environment, microfold cell damage, intestinal flora changes, epithelial barrier damage, immune dysfunction and low. The main clinical manifestations of CD are abdominal pain, chronic diarrhea, fatigue, fever and weight loss. At present, 5-aminosalicylic acid, antibiotics, glucocorticoids, immunosuppressants and biological agents are mainly used for treatment, but the drug effect is limited and the effect is not good. Recent studies have shown that Mesenchymal Stem Cells (MSC) can down-regulate immune response and promote tissue healing, which has certain safety and effectiveness in the treatment of moderate and severe CD, and has broad application prospects, but also has certain limitations. This paper summarizes the application and efficacy of related therapies in CD, providing a reference for clinicians.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.U2244227,42277126 and 41977215).
文摘Air blasts induced by rock-ice avalanches are common natural phenomena known for their far-field destructive impact.In this study,remote sensing images,eyewitness videos and numerical modelling were comprehensively applied to analyze the initiation and propagation of the 2021 Chamoli avalancheinduced air blast.Our findings indicate that air blasts are observed from the avalanche source area to the Rishiganga valley,but nearly disappear in the Dhauliganga valley.The most intense air blast is concentrated on the left side of Ronti Gad valley,with maximum velocity and pressure estimated at over 70 m/s and 20 kPa,respectively.Such high pressure results in widespread tree breakage in the area.Based on the analysis of the Chamoli event,we further discussed the potential contribution of the avalanche flow regime,avalanche dynamics and geomorphology to the destructive potential of air blasts.Rapidly moved sliding mass can impart the air blast a high initial momentum,and this process will be exaggerated when the avalanche impacts valley walls at bends.However,when the rock-ice avalanche transforms into a debris-enriched flash flood,free water within the flowing mass can displace air,inhibiting the generation of air blasts.Our work offers new insights into the generation and propagation of rock-ice avalanche-induced air blasts,underscoring the importance of including this type of hazard during avalanche risk assessment in high-altitude glacial regions.
文摘Crohn’s Disease (CD) is a chronic recurrent inflammatory bowel disease with unknown etiology, most common in the terminal ileum and adjacent colon. In the past 30 years, the global prevalence of CD has continued to rise. Although the etiology is unknown, studies have shown that it is closely related to geographical environment, microfold cell damage, intestinal flora changes, epithelial barrier damage, immune dysfunction and low. The main clinical manifestations of CD are abdominal pain, chronic diarrhea, fatigue, fever and weight loss. At present, 5-aminosalicylic acid, antibiotics, glucocorticoids, immunosuppressants and biological agents are mainly used for treatment, but the drug effect is limited and the effect is not good. Recent studies have shown that Mesenchymal Stem Cells (MSC) can down-regulate immune response and promote tissue healing, which has certain safety and effectiveness in the treatment of moderate and severe CD, and has broad application prospects, but also has certain limitations. This paper summarizes the application and efficacy of related therapies in CD, providing a reference for clinicians.
