This study investigates the influences of urban land cover on the extreme rainfall event over the Zhengzhou city in central China on 20 July 2021 using the Weather Research and Forecasting model at a convection-permit...This study investigates the influences of urban land cover on the extreme rainfall event over the Zhengzhou city in central China on 20 July 2021 using the Weather Research and Forecasting model at a convection-permitting scale[1-km resolution in the innermost domain(d3)].Two ensembles of simulation(CTRL,NURB),each consisting of 11 members with a multi-layer urban canopy model and various combinations of physics schemes,were conducted using different land cover scenarios:(i)the real urban land cover,(ii)all cities in d3 being replaced with natural land cover.The results suggest that CTRL reasonably reproduces the spatiotemporal evolution of rainstorms and the 24-h rainfall accumulation over the key region,although the maximum hourly rainfall is underestimated and displaced to the west or southwest by most members.The ensemble mean 24-h rainfall accumulation over the key region of heavy rainfall is reduced by 13%,and the maximum hourly rainfall simulated by each member is reduced by 15–70 mm in CTRL relative to NURB.The reduction in the simulated rainfall by urbanization is closely associated with numerous cities/towns to the south,southeast,and east of Zhengzhou.Their heating effects jointly lead to formation of anomalous upward motions in and above the planetary boundary layer(PBL),which exaggerates the PBL drying effect due to reduced evapotranspiration and also enhances the wind stilling effect due to increased surface friction in urban areas.As a result,the lateral inflows of moisture and high-θe(equivalent potential temperature)air from south and east to Zhengzhou are reduced.展开更多
OBJECTIVE： To observe the impact of total flavo- noids from Ganshanbian （Herba Hyperici Attenuati） on the expression of vascular smooth muscle mem-brane L-type calcium channel alpha1 C subunit （CaL-olC） and ATP-s...OBJECTIVE： To observe the impact of total flavo- noids from Ganshanbian （Herba Hyperici Attenuati） on the expression of vascular smooth muscle mem-brane L-type calcium channel alpha1 C subunit （CaL-olC） and ATP-sensitive K＋ channel （KATp）-Kir6.1 mRNA, and explore the mechanisms of the antiar- rhythmic effect of Ganshanbian （Herba Hyperici At- tenuatl~ total flavonoids. METHODS： The treatment vonoids from Ganshanbian group was fed total fla- （Herba Hyperici Attenua- ti） for 7 days by gavage with 100 mg. kg-~. d 1. The blank control group and model control group were given the same amount of normal saline for 7 do Ar- rhythmias were induced by performing a myocardi- al ischemia-reperfusion and electrocardiogram was observed. Reverse transcription-polymerase chain reaction was used to detect the expression of CaL-a 1Cand KATp-Kir6.1 mRNA in the myocardial cell mem- brane of all groups of rats. RESULTS： Total flavonoids from Ganshanbian （Her- ba Hyperici Attenuat can delay the appearance of myocardial ischemia reperfusion arrhythmias, shorten the duration of myocardial ischemia reper- fusion arrhythmias, reduce heart rate, reduce cell membrane expression of CaL-a1C mRNA and en- hance the expression of K_ATp-Kir6.1 mRNA in myocar- dial ischemia-reperfusion arrhythmic rats. CONCLUSION： Total flavonoids from Ganshanbian （Herba Hyperici Attenuat can alleviate arrhythmias by affecting the expression of L-type calcium chan- nels and ATP-sensitive K_ATP channels.展开更多
基金The National Natural Science Foundation of China(Grant Nos.42030610 and 42075083)the Innovation and Development Project of China Meteorological Administration(CXFZ2022J014)supported this study.
文摘This study investigates the influences of urban land cover on the extreme rainfall event over the Zhengzhou city in central China on 20 July 2021 using the Weather Research and Forecasting model at a convection-permitting scale[1-km resolution in the innermost domain(d3)].Two ensembles of simulation(CTRL,NURB),each consisting of 11 members with a multi-layer urban canopy model and various combinations of physics schemes,were conducted using different land cover scenarios:(i)the real urban land cover,(ii)all cities in d3 being replaced with natural land cover.The results suggest that CTRL reasonably reproduces the spatiotemporal evolution of rainstorms and the 24-h rainfall accumulation over the key region,although the maximum hourly rainfall is underestimated and displaced to the west or southwest by most members.The ensemble mean 24-h rainfall accumulation over the key region of heavy rainfall is reduced by 13%,and the maximum hourly rainfall simulated by each member is reduced by 15–70 mm in CTRL relative to NURB.The reduction in the simulated rainfall by urbanization is closely associated with numerous cities/towns to the south,southeast,and east of Zhengzhou.Their heating effects jointly lead to formation of anomalous upward motions in and above the planetary boundary layer(PBL),which exaggerates the PBL drying effect due to reduced evapotranspiration and also enhances the wind stilling effect due to increased surface friction in urban areas.As a result,the lateral inflows of moisture and high-θe(equivalent potential temperature)air from south and east to Zhengzhou are reduced.
基金Supported by National Natural Science Foundation of China(Proteomics research on the complexes of Ganshanbian(Herba Hyperici Attenuati)and Salvia miltiorrhiza anti-reperfusion arrhythmia based on the iTRAQ technology.No.81173185)Key Project of Natural Science Foundation of Heilongjiang Province(Proteomics research on the complexes of Ganshanbian(Herba Hyperici Attenuati)and Salvia miltiorrhiza anti-reperfusion arrhythmia based on the iTRAQ technology.No.ZD201111)+1 种基金Heilongjiang Province Graduate Students Research Key Project(Proteomics research on the complexes of Ganshanbian(Herba Hyperici Attenuati)and Salvia miltiorrhiza anti-reperfusion arrhythmia based on the iTRAQ technology.No.YJSCX2012-334HLJ)Outstanding Talents Support Program of Heilongjiang University of Chinese Medicine(Proteomics research on the complexes of Ganshanbian(Herba Hyperici Attenuati)and Salvia miltiorrhiza anti-reperfusion arrhythmia based on the iTRAQ technology,2012)
文摘OBJECTIVE： To observe the impact of total flavo- noids from Ganshanbian （Herba Hyperici Attenuati） on the expression of vascular smooth muscle mem-brane L-type calcium channel alpha1 C subunit （CaL-olC） and ATP-sensitive K＋ channel （KATp）-Kir6.1 mRNA, and explore the mechanisms of the antiar- rhythmic effect of Ganshanbian （Herba Hyperici At- tenuatl~ total flavonoids. METHODS： The treatment vonoids from Ganshanbian group was fed total fla- （Herba Hyperici Attenua- ti） for 7 days by gavage with 100 mg. kg-~. d 1. The blank control group and model control group were given the same amount of normal saline for 7 do Ar- rhythmias were induced by performing a myocardi- al ischemia-reperfusion and electrocardiogram was observed. Reverse transcription-polymerase chain reaction was used to detect the expression of CaL-a 1Cand KATp-Kir6.1 mRNA in the myocardial cell mem- brane of all groups of rats. RESULTS： Total flavonoids from Ganshanbian （Her- ba Hyperici Attenuat can delay the appearance of myocardial ischemia reperfusion arrhythmias, shorten the duration of myocardial ischemia reper- fusion arrhythmias, reduce heart rate, reduce cell membrane expression of CaL-a1C mRNA and en- hance the expression of K_ATp-Kir6.1 mRNA in myocar- dial ischemia-reperfusion arrhythmic rats. CONCLUSION： Total flavonoids from Ganshanbian （Herba Hyperici Attenuat can alleviate arrhythmias by affecting the expression of L-type calcium chan- nels and ATP-sensitive K_ATP channels.
