A field experiment was carried out to examine the soil respiration rate in Abies fabri forests in Gongga Mountain National Nature Reserve using LI-6400-09 portable soil respiration chamber.The results showed that the ...A field experiment was carried out to examine the soil respiration rate in Abies fabri forests in Gongga Mountain National Nature Reserve using LI-6400-09 portable soil respiration chamber.The results showed that the soil respiration rate and soil temperature of mature and middle-aged A.fabri forests were different in each month.The soil CO2 emission rates of the two stands had obvious seasonal variation characteristics,which were arranged: summer > autumn > spring > winter;the monthly average soil CO2 emission rate of the mature aged forest ranged from 0.82 to 5.88 μmol/(s·m^2),with the coefficient of seasonal variation of 50.6%;and the average monthly soil respiration rate of middle-aged forest was in the range of 0.52-3.52 μmol/(s·m^2),with the coefficient of seasonal variation of 48.5%.The seasonal variation of soil CO2 emission rate was positively correlated with the 5 cm soil temperature.And the Q10 values of the soil CO2 emission rates in the mature and middle-aged A.fabri forests were 3.2 and 2.6,respectively,and the sensitivity index of CO2 emission to temperature in the mature A.fabri forest was higher than that in the middle-aged forest.展开更多
Naturally occurred precore(PC,G1896A)and/or basal core promoter(BCP,A1762T/G1764A)mutations are prevalent in chronic HBV-infected patients,especially those under HBeAg-negative status.However,the replicative capacity ...Naturally occurred precore(PC,G1896A)and/or basal core promoter(BCP,A1762T/G1764A)mutations are prevalent in chronic HBV-infected patients,especially those under HBeAg-negative status.However,the replicative capacity of HBV with PC/BCP mutations remains ambiguous.Herein,meta-analysis showed that,only under HBeAg-negative status,the serum HBV DNA load in patients with PC mutation was 7.41-fold higher than those without the mutation.Both PC mutation alone and BCPþPC mutations promoted HBV replication in cell and hydrodynamic injection mouse models.In human hepatocyte chimeric mouse model,BCPþPC mutations led to elevated replicative capacity and intrahepatic core protein accumulation.Mechanistically,preC RNA harboring PC mutation could serve as mRNA to express core and P proteins,and such pgRNA-like function favored the maintenance of cccDNA pool under HBeAg-negative status.Additionally,BCPþPC mutations induced more extensive and severe human hepatocyte damage as well as activated endoplasmic reticulum stress and TNF signaling pathway in livers of chimeric mice.This study indicates that HBeAg-negative patients should be monitored on HBV mutations regularly and are expected to receive early antiviral treatment to prevent disease progression.展开更多
基金Supported by National Key Research and Development Program of China(2017YFC0504903 2016YFC0503305)+1 种基金National Natural Science Foundation of China(41771062)CAS Key Technology Talent Program(CAS201665)
文摘A field experiment was carried out to examine the soil respiration rate in Abies fabri forests in Gongga Mountain National Nature Reserve using LI-6400-09 portable soil respiration chamber.The results showed that the soil respiration rate and soil temperature of mature and middle-aged A.fabri forests were different in each month.The soil CO2 emission rates of the two stands had obvious seasonal variation characteristics,which were arranged: summer > autumn > spring > winter;the monthly average soil CO2 emission rate of the mature aged forest ranged from 0.82 to 5.88 μmol/(s·m^2),with the coefficient of seasonal variation of 50.6%;and the average monthly soil respiration rate of middle-aged forest was in the range of 0.52-3.52 μmol/(s·m^2),with the coefficient of seasonal variation of 48.5%.The seasonal variation of soil CO2 emission rate was positively correlated with the 5 cm soil temperature.And the Q10 values of the soil CO2 emission rates in the mature and middle-aged A.fabri forests were 3.2 and 2.6,respectively,and the sensitivity index of CO2 emission to temperature in the mature A.fabri forest was higher than that in the middle-aged forest.
基金supported by National Key R&D Program of China(2023YFC2306800)National Natural Science Foundation of China(No.82072280 and No.82272315)Beijing Municipal Natural Science Foundation(No.7212063 and No.7222108).
文摘Naturally occurred precore(PC,G1896A)and/or basal core promoter(BCP,A1762T/G1764A)mutations are prevalent in chronic HBV-infected patients,especially those under HBeAg-negative status.However,the replicative capacity of HBV with PC/BCP mutations remains ambiguous.Herein,meta-analysis showed that,only under HBeAg-negative status,the serum HBV DNA load in patients with PC mutation was 7.41-fold higher than those without the mutation.Both PC mutation alone and BCPþPC mutations promoted HBV replication in cell and hydrodynamic injection mouse models.In human hepatocyte chimeric mouse model,BCPþPC mutations led to elevated replicative capacity and intrahepatic core protein accumulation.Mechanistically,preC RNA harboring PC mutation could serve as mRNA to express core and P proteins,and such pgRNA-like function favored the maintenance of cccDNA pool under HBeAg-negative status.Additionally,BCPþPC mutations induced more extensive and severe human hepatocyte damage as well as activated endoplasmic reticulum stress and TNF signaling pathway in livers of chimeric mice.This study indicates that HBeAg-negative patients should be monitored on HBV mutations regularly and are expected to receive early antiviral treatment to prevent disease progression.
