Based on daily precipitation data supplied by the Chinese meteorological administration,hourly reanalysis datasets provided by the ECMWF and daily outgoing long wave radiation supplied by the NOAA,the evolution regula...Based on daily precipitation data supplied by the Chinese meteorological administration,hourly reanalysis datasets provided by the ECMWF and daily outgoing long wave radiation supplied by the NOAA,the evolution regularity of continuous heavy precipitation over Southern China(SC)from April to June in 1979-2020 was systematically analyzed.The interaction between specific humidity and circulation field at the background-scale,the intra-seasonal-scale and the synoptic-scale,and its influence on persistent heavy precipitation over the SC during the April-June rainy season were quantitatively diagnosed and analyzed.The results are as follows.Persistent heavy rainfall events(PHREs)over the SC during the April-June rainy season occur frequently from mid-May to mid-and late-June,exhibiting significant intra-seasonal oscillation(10-30-day)features.Vertically integrated moisture flux convergence(VIMFC)can well represent the variation of the PHREs.A multiscale quantitative diagnosis of the VIMFC shows that the pre-summer PHREs over the SC are mainly affected by the background water vapor(greater than 30 days),intraseasonal circulation disturbance(10-30-day)and background circulation(greater than 30 days),and water vapor convergences are the main factor.The SC is under the control of a warm and humid background and a strong intraseasonal cyclonic circulation,with strong convergence and ascending movements and abundant water vapor conditions during the period of the PHREs.Meanwhile,the westward inter-seasonal oscillation of tropical atmosphere keeps the precipitation system over the SC for several consecutive days,eventually leading to the occurrence,development and persistence of heavy precipitation.展开更多
The aim of the study was to investigate the hepatoprotective effects of Folium syringae(FS) extracts against ethanolinduced acute liver injury. Mice and primary hepatocytes were pretreated with FS extracts at differen...The aim of the study was to investigate the hepatoprotective effects of Folium syringae(FS) extracts against ethanolinduced acute liver injury. Mice and primary hepatocytes were pretreated with FS extracts at different dosages before ethanol administration. Transaminases, glutathione S-transferase A1 level and hepatic biochemical indices(malondialdehyde, superoxide dismutase, glutathione and glutathione peroxidase) were determined. Pretreatment with FS extracts significantly inhibited the damage caused by ethanol and the hepatoprotective effects of FS were almost similar to Silymarin that was used to treat alcoholic liver injury. GSTA1 contents in all the FS extract-treated groups were significantly different from those in the ethanol-induced acute liver injury model group(p<0.01), and similar trends were observed in transaminases and hepatic indices level both in vitro and in vivo. The results showed that FS extracts had hepatoprotective effects against ethanol-induced injury. Those effects might be related to the enhancement of antioxidant capacity of liver cells, and FS extracts could reduce the release of liver GSTA1, which contributed to improve liver detoxification.展开更多
基金National Natural Science Foundation of China(42088101)。
文摘Based on daily precipitation data supplied by the Chinese meteorological administration,hourly reanalysis datasets provided by the ECMWF and daily outgoing long wave radiation supplied by the NOAA,the evolution regularity of continuous heavy precipitation over Southern China(SC)from April to June in 1979-2020 was systematically analyzed.The interaction between specific humidity and circulation field at the background-scale,the intra-seasonal-scale and the synoptic-scale,and its influence on persistent heavy precipitation over the SC during the April-June rainy season were quantitatively diagnosed and analyzed.The results are as follows.Persistent heavy rainfall events(PHREs)over the SC during the April-June rainy season occur frequently from mid-May to mid-and late-June,exhibiting significant intra-seasonal oscillation(10-30-day)features.Vertically integrated moisture flux convergence(VIMFC)can well represent the variation of the PHREs.A multiscale quantitative diagnosis of the VIMFC shows that the pre-summer PHREs over the SC are mainly affected by the background water vapor(greater than 30 days),intraseasonal circulation disturbance(10-30-day)and background circulation(greater than 30 days),and water vapor convergences are the main factor.The SC is under the control of a warm and humid background and a strong intraseasonal cyclonic circulation,with strong convergence and ascending movements and abundant water vapor conditions during the period of the PHREs.Meanwhile,the westward inter-seasonal oscillation of tropical atmosphere keeps the precipitation system over the SC for several consecutive days,eventually leading to the occurrence,development and persistence of heavy precipitation.
基金Supported by the National Natural Science Foundation of China(31472241)the Application Technology Research and Development Projects in Heilongjiang Province of China(PC13S03)
文摘The aim of the study was to investigate the hepatoprotective effects of Folium syringae(FS) extracts against ethanolinduced acute liver injury. Mice and primary hepatocytes were pretreated with FS extracts at different dosages before ethanol administration. Transaminases, glutathione S-transferase A1 level and hepatic biochemical indices(malondialdehyde, superoxide dismutase, glutathione and glutathione peroxidase) were determined. Pretreatment with FS extracts significantly inhibited the damage caused by ethanol and the hepatoprotective effects of FS were almost similar to Silymarin that was used to treat alcoholic liver injury. GSTA1 contents in all the FS extract-treated groups were significantly different from those in the ethanol-induced acute liver injury model group(p<0.01), and similar trends were observed in transaminases and hepatic indices level both in vitro and in vivo. The results showed that FS extracts had hepatoprotective effects against ethanol-induced injury. Those effects might be related to the enhancement of antioxidant capacity of liver cells, and FS extracts could reduce the release of liver GSTA1, which contributed to improve liver detoxification.
