For the flow field in a d50 mm hydrocyclone, numerical studies based on computational fluid dynamics (CFD) simulation and experimental studies based on particle image velocimetry (PIV) measurement were carried out res...For the flow field in a d50 mm hydrocyclone, numerical studies based on computational fluid dynamics (CFD) simulation and experimental studies based on particle image velocimetry (PIV) measurement were carried out respectively. The results of two methods show that air core generally forms after 0.7 s, the similar characteristics of air core can be observed. Vortexes and axial velocity distributions obtained by numerical and experimental methods are also in good agreement. Studies of different parameters based on CFD simulation show that tangential velocity distribution inside the hydrocyclone can be regarded as a combined vortex. Axial and tangential velocities increase as the feed rate increases. The enlargement of cone angle and overflow outlet diameter can speed up the overflow discharge rate. The change of underflow outlet diameter has no significant effect on axial and tangential velocities.展开更多
BACKGROUND Fusobacterium nucleatum(F.nucleatum)has long been known to cause opportunistic infections and has recently been implicated in colorectal cancer(CRC),which has attracted broad attention.However,the mechanism...BACKGROUND Fusobacterium nucleatum(F.nucleatum)has long been known to cause opportunistic infections and has recently been implicated in colorectal cancer(CRC),which has attracted broad attention.However,the mechanism by which it is involved in CRC development is not fully understood.AIM To explore its potential causative role in CRC development,we evaluated the colon pathology,mucosa barrier,colon microbiota and host transcriptome profile after F.nucleatum infection in an azoxymethane/dextran sulfate sodium salt(AOM/DSS)mouse model.METHODS Three groups of mice were compared to reveal the differences,i.e.,the control,AOM/DSS-induced CRC and AOM/DSS-FUSO infection groups.RESULTS Both the AOM/DSS and AOM/DSS-FUSO groups exhibited a significantly reduced body weight and increased tumor numbers than the control group,and AOM/DSS mice with F.nucleatum infection showed the highest tumor formation ratio among the three groups.Moreover,the colon pathology was the most serious in the AOM/DSS-FUSO group.We found that the structure of the colon microbiota changed considerably after F.nucleatum infection;striking differences in mucosal microbial population patterns were observed between the AOM/DSS-FUSO and AOM/DSS groups,and inflammation-inducing bacteria were enriched in the mucosal microbiota in the AOM/DSS-FUSO group.By comparing intestinal transcriptomics data from AOM vs AOM/DSSFUSO mice,we showed that transcriptional activity was strongly affected by dysbiosis of the gut microbiota.The most microbiota-sensitive genes were oncogenes in the intestine,and the cyclic adenosine monophosphate signaling pathway,neuroactive ligand–receptor interaction,PPAR signaling pathway,retinol metabolism,mineral absorption and drug metabolism were highly enriched in the AOM/DSS-FUSO group.Additionally,we showed that microbial dysbiosis driven by F.nucleatum infection enriched eight taxa belonging to Proteobacteria,which correlates with increased expression of oncogenic genes.CONCLUSION Our study demonstrated that F.nucleatum infection altered the colon mucosal microbiota by enriching pathogens related to the development of CRC,providing new insights into the role of F.nucleatum in the oncogenic microbial environment of the colon.展开更多
基金Projects(50974033,51104035)supported by the National Natural Science Foundation of China
文摘For the flow field in a d50 mm hydrocyclone, numerical studies based on computational fluid dynamics (CFD) simulation and experimental studies based on particle image velocimetry (PIV) measurement were carried out respectively. The results of two methods show that air core generally forms after 0.7 s, the similar characteristics of air core can be observed. Vortexes and axial velocity distributions obtained by numerical and experimental methods are also in good agreement. Studies of different parameters based on CFD simulation show that tangential velocity distribution inside the hydrocyclone can be regarded as a combined vortex. Axial and tangential velocities increase as the feed rate increases. The enlargement of cone angle and overflow outlet diameter can speed up the overflow discharge rate. The change of underflow outlet diameter has no significant effect on axial and tangential velocities.
基金Supported by National Natural Science Foundation of China,No. 32070116Open Project Program of CAS Key Laboratory of Pathogenic Microbiology and Immunology,No. CASPMI202102
文摘BACKGROUND Fusobacterium nucleatum(F.nucleatum)has long been known to cause opportunistic infections and has recently been implicated in colorectal cancer(CRC),which has attracted broad attention.However,the mechanism by which it is involved in CRC development is not fully understood.AIM To explore its potential causative role in CRC development,we evaluated the colon pathology,mucosa barrier,colon microbiota and host transcriptome profile after F.nucleatum infection in an azoxymethane/dextran sulfate sodium salt(AOM/DSS)mouse model.METHODS Three groups of mice were compared to reveal the differences,i.e.,the control,AOM/DSS-induced CRC and AOM/DSS-FUSO infection groups.RESULTS Both the AOM/DSS and AOM/DSS-FUSO groups exhibited a significantly reduced body weight and increased tumor numbers than the control group,and AOM/DSS mice with F.nucleatum infection showed the highest tumor formation ratio among the three groups.Moreover,the colon pathology was the most serious in the AOM/DSS-FUSO group.We found that the structure of the colon microbiota changed considerably after F.nucleatum infection;striking differences in mucosal microbial population patterns were observed between the AOM/DSS-FUSO and AOM/DSS groups,and inflammation-inducing bacteria were enriched in the mucosal microbiota in the AOM/DSS-FUSO group.By comparing intestinal transcriptomics data from AOM vs AOM/DSSFUSO mice,we showed that transcriptional activity was strongly affected by dysbiosis of the gut microbiota.The most microbiota-sensitive genes were oncogenes in the intestine,and the cyclic adenosine monophosphate signaling pathway,neuroactive ligand–receptor interaction,PPAR signaling pathway,retinol metabolism,mineral absorption and drug metabolism were highly enriched in the AOM/DSS-FUSO group.Additionally,we showed that microbial dysbiosis driven by F.nucleatum infection enriched eight taxa belonging to Proteobacteria,which correlates with increased expression of oncogenic genes.CONCLUSION Our study demonstrated that F.nucleatum infection altered the colon mucosal microbiota by enriching pathogens related to the development of CRC,providing new insights into the role of F.nucleatum in the oncogenic microbial environment of the colon.
