BACKGROUND Characteristics of alterations of serum hepatitis B virus(HBV) RNA in different chronic hepatitis B(CHB) patients still cannot be fully explained. Whether HBV RNA can predict HBeAg seroconversion is still c...BACKGROUND Characteristics of alterations of serum hepatitis B virus(HBV) RNA in different chronic hepatitis B(CHB) patients still cannot be fully explained. Whether HBV RNA can predict HBeAg seroconversion is still controversial.AIM To investigate whether HBV RNA can predict virological response or HBeAg seroconversion during entecavir(ETV) treatment when HBV DNA is undetectable.METHODS The present study evaluated 61 individuals who were diagnosed and treated with long-term ETV monotherapy at the Department of Infectious Diseases of Peking University First Hospital(China) from September 2006 to December 2007.Finally, 30 treatment-naive individuals were included. Serum HBV RNA were extracted from 140 μL serum samples at two time points. Then they were reverse transcribed to cDNA with the HBV-specific primer. The product was quantified by real-time quantitative PCR(RT-PCR) using TAMARA probes. Statistical analyses were performed with IBM SPSS 20.0.RESULTS Level of serum HBV RNA at baseline was 4.15 ± 0.90 log10 copies/mL. HBV RNA levels showed no significant difference between the virological response(VR)and partial VR(PVR) groups at baseline(P = 0.940). Serum HBV RNA significantly decreased among patients who achieved a VR during ETV therapy(P < 0.001). The levels of HBV RNA in both HBeAg-positive patients with seroconversion group and those with no seroconversion increased after 24 wk of treatment. Overall, HBV RNA significantly but mildly correlated to HBsAg(r =0.265, P = 0.041), and HBV RNA was not correlated to HBV DNA(r = 0.242, P =0.062). Furthermore, serum HBV RNA was an independent indicator for predicting HBeAg seroconversion and virological response. HBeAg seroconversion was more likely in CHB patients with HBV RNA levels below4.12 log10 copies/mL before treatment.CONLUSION The level of serum HBV RNA could predict HBeAg seroconversion and PVR during treatment. In the PVR group, the level of serum HBV RNA tends to be increasing.展开更多
The modification mechanism of the water/alcohol cathode interlayer is one of the most complicated problems in the field of organic photovoltaics,which has not been clearly elucidated yet;this greatly restricts the fur...The modification mechanism of the water/alcohol cathode interlayer is one of the most complicated problems in the field of organic photovoltaics,which has not been clearly elucidated yet;this greatly restricts the further enhancement of the PCE for polymer solar cells.Herein,we clarified the different effects of PFN and its derivatives,namely,poly[(9,9-bis(3’-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)](PFN-Br) in modifying fullerene-free PSCs.It is found for the first time that doping on IT-4F by the amino group of PFN leads to the unfavorable charge accumulation,and hence,forms a dense layer of electronegative molecule due to the poor electron transport capacity of the non-fullerene acceptor IT-4F.The electronegative molecular layer can block the electron transfer from the active layer to the interlayer and cause serious charge recombination at the active layer/cathode interface.This mechanism could be verified by the ESR measurement and electron-only devices.By replacing PFN with PFN-Br,the excessive doping effect between the cathode interlayer and IT-4F is eliminated,by which the charge transport and collection can be greatly improved.As a result,a high PCE of 13.5%was achieved in the fullerene-free PSCs.展开更多
Groundwater is a significant component of the hydrological cycle in arid and semi-arid areas. Its evapotranspiration is an important part of the water budget because many plants are groundwater-dependent. To restore t...Groundwater is a significant component of the hydrological cycle in arid and semi-arid areas. Its evapotranspiration is an important part of the water budget because many plants are groundwater-dependent. To restore the degraded ecosystems, the need is pressing to further our understanding of the groundwater evapotranspiration（ET_g） in arid and semi-arid areas. This study employed the White method to estimate ET_g at four sites in the Mu Us Sandy Land in northern China, and the four sites are covered by Salix psammophila（SP site）, Artemisia ordosica（AO site）, Poplar alba（PA site）, and Carex enervis（CE site）, respectively. The depth of groundwater table and the duration of drainage were taken into account in calculating the specific yield（S_y） to improve the accuracy of the ET_g estimats. Our results showed that from late May to early November 2013 the ET_g were 361.87（SP site）, 372.53（AO site）, 597.86（PA site） and 700.76 mm（CE site）, respectively. The estimated ET_g rate was also species-dependent and the descending order of the ET_g rate for the four vegetation was： C. enervis, P. alba, A. ordosica, and S. psammophila. In addition, the depth of groundwater table has an obvious effect on the ET_g rate and the effect varied with the vegetation types. Furthermore, the evapotranspiration for the vegetation solely relying on the water supply from unsaturated layers above the groundwater table was much less than that for the vegetation heavily relying on the water supply from shallow aquifers.展开更多
Objective:To establish a basis for Angelica Sinensis Radix(ASR)as a dietary supplement for colorectal cancer chemoprevention,the effect of co-existent components in supercritical fluid extract(SFE)of ASR on the pharma...Objective:To establish a basis for Angelica Sinensis Radix(ASR)as a dietary supplement for colorectal cancer chemoprevention,the effect of co-existent components in supercritical fluid extract(SFE)of ASR on the pharmacokinetics of Z-ligustilide after oral administration was investigated in vitro and in vivo.Methods:Incubation in gastrointestinal contents and incubation in rat liver tissue homogenates post-mitochondrial supernatant(PMS)experiments were used to study changes in the levels of Z-ligustilide in vitro.Results:Within 4 hours,the level of Z-ligustilide in SFE declined at a slower rate than in its pure form.Clearance of Z-ligustilide after administration in its pure form was significantly slower than that of SFE of ASR(CL,0.96±0.16 mL·min/kg versus 1.24±0.21 mL·min/kg P<0.05;AUC,243.37±16.84 versus 176.69±12.59 mg·min/L).Conclusion:These phenomena may be attributed to the interactions between the co-existent components in SFE of ASR and Z-ligustilide enhancing the stability of Z-ligustilide.These results suggest that the bioavailability of Z-ligustilide in SFE of ASR is improved.However,stabilization of plasma concentration was not sustained,so that the efficacy of active components could not be maintained.Thus,further processing of SFE of ASR is required.展开更多
基金National Key R&D Program of China(2017YFB0310500)National Natural Science Foundation of China(61775226)+1 种基金CAS President’s International Fellowship Initiative(E00YGH21)Operational Programme Research,Development and Education financed by European Structural and Investment Funds and the Czech Ministry of Education,Youth and Sports(SOLID21 CZ.02.1.01/0.0/0.0/16_019/0000760)。
文摘BACKGROUND Characteristics of alterations of serum hepatitis B virus(HBV) RNA in different chronic hepatitis B(CHB) patients still cannot be fully explained. Whether HBV RNA can predict HBeAg seroconversion is still controversial.AIM To investigate whether HBV RNA can predict virological response or HBeAg seroconversion during entecavir(ETV) treatment when HBV DNA is undetectable.METHODS The present study evaluated 61 individuals who were diagnosed and treated with long-term ETV monotherapy at the Department of Infectious Diseases of Peking University First Hospital(China) from September 2006 to December 2007.Finally, 30 treatment-naive individuals were included. Serum HBV RNA were extracted from 140 μL serum samples at two time points. Then they were reverse transcribed to cDNA with the HBV-specific primer. The product was quantified by real-time quantitative PCR(RT-PCR) using TAMARA probes. Statistical analyses were performed with IBM SPSS 20.0.RESULTS Level of serum HBV RNA at baseline was 4.15 ± 0.90 log10 copies/mL. HBV RNA levels showed no significant difference between the virological response(VR)and partial VR(PVR) groups at baseline(P = 0.940). Serum HBV RNA significantly decreased among patients who achieved a VR during ETV therapy(P < 0.001). The levels of HBV RNA in both HBeAg-positive patients with seroconversion group and those with no seroconversion increased after 24 wk of treatment. Overall, HBV RNA significantly but mildly correlated to HBsAg(r =0.265, P = 0.041), and HBV RNA was not correlated to HBV DNA(r = 0.242, P =0.062). Furthermore, serum HBV RNA was an independent indicator for predicting HBeAg seroconversion and virological response. HBeAg seroconversion was more likely in CHB patients with HBV RNA levels below4.12 log10 copies/mL before treatment.CONLUSION The level of serum HBV RNA could predict HBeAg seroconversion and PVR during treatment. In the PVR group, the level of serum HBV RNA tends to be increasing.
基金the financial support from NSFC(21325419,21504095,and 51373181)the Chinese Academy of Science(XDB12030200,KJZD-EW-J01)。
文摘The modification mechanism of the water/alcohol cathode interlayer is one of the most complicated problems in the field of organic photovoltaics,which has not been clearly elucidated yet;this greatly restricts the further enhancement of the PCE for polymer solar cells.Herein,we clarified the different effects of PFN and its derivatives,namely,poly[(9,9-bis(3’-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)](PFN-Br) in modifying fullerene-free PSCs.It is found for the first time that doping on IT-4F by the amino group of PFN leads to the unfavorable charge accumulation,and hence,forms a dense layer of electronegative molecule due to the poor electron transport capacity of the non-fullerene acceptor IT-4F.The electronegative molecular layer can block the electron transfer from the active layer to the interlayer and cause serious charge recombination at the active layer/cathode interface.This mechanism could be verified by the ESR measurement and electron-only devices.By replacing PFN with PFN-Br,the excessive doping effect between the cathode interlayer and IT-4F is eliminated,by which the charge transport and collection can be greatly improved.As a result,a high PCE of 13.5%was achieved in the fullerene-free PSCs.
基金funded by the National Natural Science Foundation of China (41072184, 41472220)the Special Fund for Basic Scientific Research of Central Colleges, Chang’an University (310829162015)
文摘Groundwater is a significant component of the hydrological cycle in arid and semi-arid areas. Its evapotranspiration is an important part of the water budget because many plants are groundwater-dependent. To restore the degraded ecosystems, the need is pressing to further our understanding of the groundwater evapotranspiration（ET_g） in arid and semi-arid areas. This study employed the White method to estimate ET_g at four sites in the Mu Us Sandy Land in northern China, and the four sites are covered by Salix psammophila（SP site）, Artemisia ordosica（AO site）, Poplar alba（PA site）, and Carex enervis（CE site）, respectively. The depth of groundwater table and the duration of drainage were taken into account in calculating the specific yield（S_y） to improve the accuracy of the ET_g estimats. Our results showed that from late May to early November 2013 the ET_g were 361.87（SP site）, 372.53（AO site）, 597.86（PA site） and 700.76 mm（CE site）, respectively. The estimated ET_g rate was also species-dependent and the descending order of the ET_g rate for the four vegetation was： C. enervis, P. alba, A. ordosica, and S. psammophila. In addition, the depth of groundwater table has an obvious effect on the ET_g rate and the effect varied with the vegetation types. Furthermore, the evapotranspiration for the vegetation solely relying on the water supply from unsaturated layers above the groundwater table was much less than that for the vegetation heavily relying on the water supply from shallow aquifers.
基金by the National Natural Science Foundation(No.81073059).
文摘Objective:To establish a basis for Angelica Sinensis Radix(ASR)as a dietary supplement for colorectal cancer chemoprevention,the effect of co-existent components in supercritical fluid extract(SFE)of ASR on the pharmacokinetics of Z-ligustilide after oral administration was investigated in vitro and in vivo.Methods:Incubation in gastrointestinal contents and incubation in rat liver tissue homogenates post-mitochondrial supernatant(PMS)experiments were used to study changes in the levels of Z-ligustilide in vitro.Results:Within 4 hours,the level of Z-ligustilide in SFE declined at a slower rate than in its pure form.Clearance of Z-ligustilide after administration in its pure form was significantly slower than that of SFE of ASR(CL,0.96±0.16 mL·min/kg versus 1.24±0.21 mL·min/kg P<0.05;AUC,243.37±16.84 versus 176.69±12.59 mg·min/L).Conclusion:These phenomena may be attributed to the interactions between the co-existent components in SFE of ASR and Z-ligustilide enhancing the stability of Z-ligustilide.These results suggest that the bioavailability of Z-ligustilide in SFE of ASR is improved.However,stabilization of plasma concentration was not sustained,so that the efficacy of active components could not be maintained.Thus,further processing of SFE of ASR is required.
