AIM：To evaluate the potential role of hyperreflective foci（HF） as a prognostic indicator of visual outcome in patients with macular edema（ME） due to retinal vein occlusion（RVO）.METHODS：We retrospectively revie...AIM：To evaluate the potential role of hyperreflective foci（HF） as a prognostic indicator of visual outcome in patients with macular edema（ME） due to retinal vein occlusion（RVO）.METHODS：We retrospectively reviewed 50 eyes of 50 patients with ME due to ischemic central retinal vein occlusion（CRVO）,non-ischemic CRVO and branch retinal vein occlusion（BRVO） who were treated with anti-vascular endothelial growth factor（anti-VEGF） at Beijing Tongren Eye Center from January 2013 to July 2016.All patients underwent best-corrected visual acuity（BCVA）,spectral domain optical coherence tomography（SD-OCT） at baseline and follow-up.Such factors were evaluated and compared among three groups as baseline and final BCVA,central retinal thickness（CRT）,external limiting membrane（ELM） status and the numbers of HF in different position.Multiple linear regression analysis was employed to analyze the relationship between baseline HF and final BCVA.Changes of HF before and after treatment were evaluated too.RESULTS：Among three groups,HF could be located in each retinal layers,as well as in vitreous cavity.The mean HF in outer retinal layer（ORL） at baseline was 5.29±8.48 in ischemic CRVO with intact ELM,1.93±2.76 in non-ischemic CRVO,and 1.75±2.05 in BRVO.With disrupted ELM,the mean HF in ORL increased.There was statistically difference of HF in ORL between intact and disrupted ELM.The numbers of HF in ORL were associated with poor visual outcome among three groups.However,HF in inner retinal layer（IRL） and vitreous cavity were not associated with poor visual outcome.Meanwhile,the baseline HF in ORL and vitreous cavity reduced significantly in nonischemic CRVO and BRVO after anti-VEGF treatment.CONCLUSION：The numbers of HF in ORL are prognostic factors associated with the final BCVA in patients with ME due to RVO after anti-VEGF treatment.展开更多
AIM: To evaluate the effects of lentivirus-mediated pigment epithelium-derived factor (PEDF) gene transfer performed in treatment of rats with established choroidal neovascularization (CNV), and investigates the mecha...AIM: To evaluate the effects of lentivirus-mediated pigment epithelium-derived factor (PEDF) gene transfer performed in treatment of rats with established choroidal neovascularization (CNV), and investigates the mechanism by which PEDF inhibits CNV in rats. METHODS: Brown Norway (BN) rats (n=204) were induced by exposure to a laser, and then randomly assigned to 3 groups: no treatment; treatments with intravitreal injection of lentivirus-PEDF-green fluorescent protein (GFP) or lentivirus-control GFP (free fluorescent protein). Following induction and treatment, the CNV tissue was assessed for form, size and vessel leakage by fluorescein fundus angiography (FFA), optical coherence tomography (OCT), histopathology, and examination of choroidal flat mounts. VEGF, Flk-1, and PEDF expression were evaluated by real-time polymerase chain reaction (PCR) and Western blot. RESULTS: A stable laser-induced rat model of CNV was successfully established, and used to demonstrate lentivirus-mediated REDO gene transfer by intravitreal injection. Expression of green fluorescence labelled PEDF was observed in the retina up to 28d after injection. An intravitreal injection of lentivirus-PEDF-GFP at 7d led to a significant reduction in the size, thickness and area of CNV showed by FFA, OCT and choroidal flat mounts. PEDF was up-regulated while VEGF and Flk-1 were down-regulated in the lentivirus-PEDF-GFP group. The differences in VEGF and Flk-1 expression in the control and lentivirus-PEDF groups at 7, 14, 21 and 28d after laser induction were all statistically significant. CONCLUSION: Lentivirus-mediated PEDF gene transfer is effective for use in treatment of laser-induced CNV, and PEDF exerts its therapeutic effects by inhibiting expression of VEGF and Flk-1.展开更多
The link between crude oil price and stock returns of the Group of Seven(G7)countries(Canada,France,Germany,Italy,Japan,the United Kingdom,and the United States)was analyzed in this study using monthly data from Janua...The link between crude oil price and stock returns of the Group of Seven(G7)countries(Canada,France,Germany,Italy,Japan,the United Kingdom,and the United States)was analyzed in this study using monthly data from January 1999 to March 2020.We adopt a similar approach to Kilian(Am Econ Rev 99(3):1053–1069,2009)and construct a structural vector autoregression framework to decompose crude oil price shocks into oil supply shock,oil aggregate demand shock,and oil-specific demand shock.We then explore the distinct effects of different kinds of oil price shocks from various sources.Based on the decomposed oil price shocks,we apply the connectedness approach and QQ regression to find time-varying co-movements and tail dependence between oil price shocks and G7 stock returns.There is no general correlation between the decomposed oil prices and stock returns in these countries.The effects of oil price shocks on stock returns across different stock market conditions appear to be heterogeneous.Oil supply shock appears to be a net transmitter of spillover effects for all G7 countries within the sample period.展开更多
Soil infiltration capability is the hot spot topic of soil erosion studies and soil physical and chemical properties have great influence on it. A new infiltration method point- source infiltration method was used to ...Soil infiltration capability is the hot spot topic of soil erosion studies and soil physical and chemical properties have great influence on it. A new infiltration method point- source infiltration method was used to precisely evaluate the infiltration capability in different purple soil land- use types. And correlation analysis on soil physical and chemical properties and soil infiltration capability of different land- use types was performed. Results showed that:( i) there is a large difference among soil physical and chemical properties in different land- use types,soil water content,non- capillary porosity,capillary porosity,content of > 0. 25 mm aggregates and organic matter content in the top soil are greater than those in the subsoil;( ii) soil infiltration capability showed differences among different land- use types. Land use showed great effects,in general,the order of decrease on initial infiltration rate and average infiltration rate was: woodland slope > slope farmland >grassland,the order of decrease on steady infiltration rate was: slope farmland > woodland > grassland and the time reaching stable state was:slope farmland > woodland > grassland;( iii) correlation analysis showed that there was a significantly positive correlation between initial infiltration rate and wet sieve MWD value and structural damage rate,and it had a significantly negative correlation with capillary porosity;( iv)steady infiltration rate and non- capillary porosity showed the significantly positive correlation,and it had a significantly negative correlation with the soil bulk density;( v) the average infiltration rate and non- capillary porosity and structural damage rate showed a positive correlation and the correlation coefficient was large and there was a negative correlation between average infiltration rate and soil bulk density and capillary porosity,and the absolute value of correlation coefficient was relatively large. The results of this study can provide the theoretical basis for soil infiltration study in purple soil area.展开更多
文摘AIM：To evaluate the potential role of hyperreflective foci（HF） as a prognostic indicator of visual outcome in patients with macular edema（ME） due to retinal vein occlusion（RVO）.METHODS：We retrospectively reviewed 50 eyes of 50 patients with ME due to ischemic central retinal vein occlusion（CRVO）,non-ischemic CRVO and branch retinal vein occlusion（BRVO） who were treated with anti-vascular endothelial growth factor（anti-VEGF） at Beijing Tongren Eye Center from January 2013 to July 2016.All patients underwent best-corrected visual acuity（BCVA）,spectral domain optical coherence tomography（SD-OCT） at baseline and follow-up.Such factors were evaluated and compared among three groups as baseline and final BCVA,central retinal thickness（CRT）,external limiting membrane（ELM） status and the numbers of HF in different position.Multiple linear regression analysis was employed to analyze the relationship between baseline HF and final BCVA.Changes of HF before and after treatment were evaluated too.RESULTS：Among three groups,HF could be located in each retinal layers,as well as in vitreous cavity.The mean HF in outer retinal layer（ORL） at baseline was 5.29±8.48 in ischemic CRVO with intact ELM,1.93±2.76 in non-ischemic CRVO,and 1.75±2.05 in BRVO.With disrupted ELM,the mean HF in ORL increased.There was statistically difference of HF in ORL between intact and disrupted ELM.The numbers of HF in ORL were associated with poor visual outcome among three groups.However,HF in inner retinal layer（IRL） and vitreous cavity were not associated with poor visual outcome.Meanwhile,the baseline HF in ORL and vitreous cavity reduced significantly in nonischemic CRVO and BRVO after anti-VEGF treatment.CONCLUSION：The numbers of HF in ORL are prognostic factors associated with the final BCVA in patients with ME due to RVO after anti-VEGF treatment.
基金Supported by the National Natural Science Foundation of China(No.81070735)
文摘AIM: To evaluate the effects of lentivirus-mediated pigment epithelium-derived factor (PEDF) gene transfer performed in treatment of rats with established choroidal neovascularization (CNV), and investigates the mechanism by which PEDF inhibits CNV in rats. METHODS: Brown Norway (BN) rats (n=204) were induced by exposure to a laser, and then randomly assigned to 3 groups: no treatment; treatments with intravitreal injection of lentivirus-PEDF-green fluorescent protein (GFP) or lentivirus-control GFP (free fluorescent protein). Following induction and treatment, the CNV tissue was assessed for form, size and vessel leakage by fluorescein fundus angiography (FFA), optical coherence tomography (OCT), histopathology, and examination of choroidal flat mounts. VEGF, Flk-1, and PEDF expression were evaluated by real-time polymerase chain reaction (PCR) and Western blot. RESULTS: A stable laser-induced rat model of CNV was successfully established, and used to demonstrate lentivirus-mediated REDO gene transfer by intravitreal injection. Expression of green fluorescence labelled PEDF was observed in the retina up to 28d after injection. An intravitreal injection of lentivirus-PEDF-GFP at 7d led to a significant reduction in the size, thickness and area of CNV showed by FFA, OCT and choroidal flat mounts. PEDF was up-regulated while VEGF and Flk-1 were down-regulated in the lentivirus-PEDF-GFP group. The differences in VEGF and Flk-1 expression in the control and lentivirus-PEDF groups at 7, 14, 21 and 28d after laser induction were all statistically significant. CONCLUSION: Lentivirus-mediated PEDF gene transfer is effective for use in treatment of laser-induced CNV, and PEDF exerts its therapeutic effects by inhibiting expression of VEGF and Flk-1.
基金This work is supported by the National Natural Science Foundation of PRC(71971098).
文摘The link between crude oil price and stock returns of the Group of Seven(G7)countries(Canada,France,Germany,Italy,Japan,the United Kingdom,and the United States)was analyzed in this study using monthly data from January 1999 to March 2020.We adopt a similar approach to Kilian(Am Econ Rev 99(3):1053–1069,2009)and construct a structural vector autoregression framework to decompose crude oil price shocks into oil supply shock,oil aggregate demand shock,and oil-specific demand shock.We then explore the distinct effects of different kinds of oil price shocks from various sources.Based on the decomposed oil price shocks,we apply the connectedness approach and QQ regression to find time-varying co-movements and tail dependence between oil price shocks and G7 stock returns.There is no general correlation between the decomposed oil prices and stock returns in these countries.The effects of oil price shocks on stock returns across different stock market conditions appear to be heterogeneous.Oil supply shock appears to be a net transmitter of spillover effects for all G7 countries within the sample period.
基金Supported by National Science and Technology Support Program(2011BAD31B03)Fundamental Research Funds for Central Universities(XDJK2011C013)
文摘Soil infiltration capability is the hot spot topic of soil erosion studies and soil physical and chemical properties have great influence on it. A new infiltration method point- source infiltration method was used to precisely evaluate the infiltration capability in different purple soil land- use types. And correlation analysis on soil physical and chemical properties and soil infiltration capability of different land- use types was performed. Results showed that:( i) there is a large difference among soil physical and chemical properties in different land- use types,soil water content,non- capillary porosity,capillary porosity,content of > 0. 25 mm aggregates and organic matter content in the top soil are greater than those in the subsoil;( ii) soil infiltration capability showed differences among different land- use types. Land use showed great effects,in general,the order of decrease on initial infiltration rate and average infiltration rate was: woodland slope > slope farmland >grassland,the order of decrease on steady infiltration rate was: slope farmland > woodland > grassland and the time reaching stable state was:slope farmland > woodland > grassland;( iii) correlation analysis showed that there was a significantly positive correlation between initial infiltration rate and wet sieve MWD value and structural damage rate,and it had a significantly negative correlation with capillary porosity;( iv)steady infiltration rate and non- capillary porosity showed the significantly positive correlation,and it had a significantly negative correlation with the soil bulk density;( v) the average infiltration rate and non- capillary porosity and structural damage rate showed a positive correlation and the correlation coefficient was large and there was a negative correlation between average infiltration rate and soil bulk density and capillary porosity,and the absolute value of correlation coefficient was relatively large. The results of this study can provide the theoretical basis for soil infiltration study in purple soil area.
