Gas-propelled nanomotors alleviate colitis through the regulation of intestinal immunoenvironment-hematopexis-microbiota circuits

The progression of ulcerative colitis(UC)is associated with immunologic derangement,intestinal hemorrhage,and microbiota imbalance.While traditional medications mainly focus on mitigating inflammation,it remains challenging to address multiple symptoms.Here,a versatile gas-propelled nanomotor was constructed by mild fusion of post-ultrasonic CaO_(2) nanospheres with Cu_(2)O nanoblocks.The resulting CaO_(2)–Cu_(2)O possessed a desirable diameter(291.3 nm)and a uniform size distribution.It could be efficiently internalized by colonic epithelial cells and macrophages,scavenge intracellular reactive oxygen/nitrogen species,and alleviate immune reactions by pro-polarizing macrophages to the anti-inflammatory M2 phenotype.This nanomotor was found to penetrate through the mucus barrier and accumulate in the colitis mucosa due to the driving force of the generated oxygen bubbles.Rectal administration of CaO_(2)–Cu_(2)O could stanch the bleeding,repair the disrupted colonic epithelial layer,and reduce the inflammatory responses through its interaction with the genes relevant to blood coagulation,anti-oxidation,wound healing,and anti-inflammation.Impressively,it restored intestinal microbiota balance by elevating the proportions of beneficial bacteria(e.g.,Odoribacter and Bifidobacterium)and decreasing the abundances of harmful bacteria(e.g.,Prevotellaceae and Helicobacter).Our gas-driven CaO_(2)–Cu_(2)O offers a promising therapeutic platform for robust treatment of UC via the rectal route.

Response surface modeling-based source contribution analysis and VOC emission control policy assessment in a typical ozone-polluted urban Shunde,China

To develop a sound ozone（O_3） pollution control strategy,it is important to well understand and characterize the source contribution due to the complex chemical and physical formation processes of O_3.Using the ＂Shunde＂ city as a pilot summer case study,we apply an innovative response surface modeling（RSM） methodology based on the Community Multi-Scale Air Quality（CMAQ） modeling simulations to identify the O_3 regime and provide dynamic analysis of the precursor contributions to effectively assess the O_3 impacts of volatile organic compound（VOC） control strategy.Our results show that Shunde is a typical VOC-limited urban O_3 polluted city.The ＂Jiangmen＂ city,as the main upper wind area during July 2014,its VOCs and nitrogen oxides（NO_x） emissions make up the largest contribution（9.06%）.On the contrary,the contribution from local（Shunde） emission is lowest（6.35%） among the seven neighbor regions.The local VOCs industrial source emission has the largest contribution comparing to other precursor emission sectors in Shunde.The results of dynamic source contribution analysis further show that the local NO_x control could slightly increase the ground O_3 under low（10.00%） and medium（40.00%）reduction ratios,while it could start to turn positive to decrease ground O_3 under the high NO_x abatement ratio（75.00%）.The real-time assessment of O_3 impacts from VOCs control strategies in Pearl River Delta（PRD） shows that the joint regional VOCs emission control policy will effectively reduce the ground O_3 concentration in Shunde.