Objective:To observe influence of up‐regulated expression of myocardial heat shock protein (HSP) 70 in‐duced by heat stress on myocardial calcium‐activated potassium channel (KCa ) 3.1 expression in rabbits with atrial fibrillation (AF) caused by rapid atrial pacing (RAP) .Methods :A total of 24 New Zealand white rabbits were ran‐domly divided into sham operation group (n=8 ,only implant electrode without pacing ) ,pacing group (n=8 ,right atrium (RA) received RAP at 600 times/min for 6h) and heat stress pacing group (heat stress group ,n=8 ,received heat stress preconditioning ,then the same RAP as pacing group ) .Results:Compared with sham operation group and pacing group ,there were significant up‐regulation of HSP70 mRNA and protein expression in different sites of heart [HSP70 protein ,left atrium (LA):(39.00 ± 3.21) vs .(39.75 ± 2.82) vs .(69.75 ± 3.45) ,RA: (38.38 ± 2.92) vs .(39.50 ± 3.89) vs .(69.00 ± 2.93) ,left atrial appendage (LAA):(37.75 ± 3.28) vs .(39.00 ± 3.89) vs . (68.63 ± 3.23) ,right atrial appendage (RAA): (37.00 ± 3.85) vs .(38.38 ± 3.74) vs .(68.75 ± 2.82)] in heat stress group , P<0. 01 all ,but there were no significant difference between pacing group and sham operation group , P>0.05 ;compared with pacing group with down‐regulation of KCa3.1 mRNA and protein expressions ,there were significant up‐regulation of KCa3.1 mRNA and protein expressions in different sites of heart [KCa3.1 protein ,LA:(21.25 ± 1.67) vs .(24.00 ± 2.62) ,RA :(21.13 ± 1.96) vs .(23.75 ± 1.83) ,LAA :(21.00 ± 2.07) vs .(23.75 ± 1.67) ,RAA:(20.88 ± 2.03) vs .(23.50 ± 2.45)] in heat stress group ,P<0.05 all ,and there were no significant difference between heat stress group and sham operation group , P>0. 05. Conclusion:Heat stress may induce up‐regulated expression of myocardial HSP 70 of myocardium ,and HSP 70 may inhibit down‐regulation of KCa 3. 1 mR‐NA and protein expressions in rabbits with atrial fibrillation.

Fire safety is crucial for the regular operation of large public hospitals.This paper elaborates on the funda-mental guidelines for fire safety management in large hospitals.Under the framework of collaborative governance theory,it also analyzes and points out that the standardization of peoples behavior in hospitals and the integrity of fire safety facilities are the pri-mary factors influencing the efficacy of fire safety management.Subsequently,based on management practices,it suggests focu-sing on"five synergies"in enforcing primary responsibility for fire safety,namely,the implementation of fire safety main respon-sibilities in synergy,the regular inspection and rectification of fire hazards in synergy,the training and evaluation of basic fire safety skills in synergy,the lifecycle management of fire safety facilities in synergy,and the building of a fire safety management team in synergy.This approach aims to maximize overall fire safety effectiveness and comprehensively enhance the level of fire safety management in hospitals.Finally,the paper discusses and calls for further enhancements in the management of fire safety in large public hospitals.