A simulated moving bed (SMB), equipped with eight silica-gel columns, was used to separate phosphatidylcholine (PC) from soybean phospholipids. The effects of flow rate in Sections 2 (Q2) and 3 (Q3), switching time, f...A simulated moving bed (SMB), equipped with eight silica-gel columns, was used to separate phosphatidylcholine (PC) from soybean phospholipids. The effects of flow rate in Sections 2 (Q2) and 3 (Q3), switching time, feed flow rate and feed concentration on the operating performance parameters: purity, recovery, productivity and desorbent consumption were studied. Operating conditions leading to more than 90% purity in both outlet streams have been identified, together with those achieving optimal performance. Regions leading to complete separation are observed and explained theoretically. As the mass-transfer effect was not considered, the triangle theory only gives initial guesses for the optimal operating conditions.展开更多
为研究预应力混凝土用钢棒(steel bar for prestressed concrete, PC钢棒)-钢筋混合配筋混凝土柱的抗震性能,设计制作了5根相同尺寸、相同纵筋配筋率、不同PC钢棒替代率的PC钢棒-钢筋混合配筋混凝土柱试件,通过拟静力试验研究了PC钢棒...为研究预应力混凝土用钢棒(steel bar for prestressed concrete, PC钢棒)-钢筋混合配筋混凝土柱的抗震性能,设计制作了5根相同尺寸、相同纵筋配筋率、不同PC钢棒替代率的PC钢棒-钢筋混合配筋混凝土柱试件,通过拟静力试验研究了PC钢棒替代率对试件抗震性能的影响规律。结果表明:随着PC钢棒替代率的提高,试件的裂缝分布高度降低,裂缝数量变少,滞回曲线的饱满程度逐渐降低,耗能能力降低,残余位移角减小,自复位能力增强;当PC钢棒的替代率不大于50%时,各试件的峰值荷载接近;当PC钢棒的替代率大于50%时,试件的峰值荷载随PC钢棒替代率的增大而提高;当加载位移角相同且不大于1.0%时,配置PC钢棒的混凝土柱的残余位移角较为接近,且明显小于未配置PC钢棒的钢筋混凝土柱的残余位移角;当加载位移角相同且大于1%时,柱的残余位移角随着PC钢棒替代率的增高而降低。展开更多
The structural and functional alterations within the PSⅡ membrane from phosphatidylcholine reconstitution and Triton X_100 (TX_100) treatment were studied by using Fourier transform_infrared (FT_IR) spectroscopic tec...The structural and functional alterations within the PSⅡ membrane from phosphatidylcholine reconstitution and Triton X_100 (TX_100) treatment were studied by using Fourier transform_infrared (FT_IR) spectroscopic technique and oxygen electrode. Phosphatidylcholine reconstitution showed no significant effect on the protein secondary structures of PSⅡ membrane but an increase of the rate of PSⅡ_mediated oxygen_evolution. The phosphatidylcholine lipids with different length of acyl chains displayed different capabilities to stimulate oxygen_evolution. In contrast, perturbation of the bilayer lipids by TX_100 resulted in obvious changes of the protein secondary structures within the PSⅡ membrane and in the loss of the PSⅡ_mediated oxygen_evolving activity. The results indicate the importance of membrane integrity in maintaining the stability of the photosynthetic membrane proteins.展开更多
AIM:To analyze phospholipid profiles in intrahepatic bile from patients with primary sclerosing cholangitis(PSC)and secondary sclerosing cholangitis(SSC).METHODS:Intrahepatic bile specimens collected via endoscopic re...AIM:To analyze phospholipid profiles in intrahepatic bile from patients with primary sclerosing cholangitis(PSC)and secondary sclerosing cholangitis(SSC).METHODS:Intrahepatic bile specimens collected via endoscopic retrograde cholangiography from 41 patients were analyzed.Fourteen of these patients were diagnosed with PSC,10 with SSC,11 with choledocholithiasis or no identifiable biliary disease,and 6 with cholangiocellular carcinoma(CCC).Bile acid,cholesterol,protein,and bilirubin contents as well as pancreas lipase activity in bile were determined by biochemical methods.Phosphatidylcholine(PC)and lysophosphatidylcholine(LPC)species were quantified using nanoelectrospray ionization tandem mass spectrometry.RESULTS:Bile from all the examined patient groups showed a remarkably similar PC and LPC species composition,with only minor statistical differences.Total biliary PC concentrations were highest in controls(8030±1843 mol/L)and lowest in patients with CCC(1969±981 mol/L)(P=0.005,controls vs SSC and CCC,respectively,P<0.05).LPC contents in bile were overall low(4.2%±1.8%).Biliary LPC/PC ratios and ratios of biliary PC to bilirubin,PC to cholesterol,PC to protein,and PC to bile acids showed no intergroup differences.CONCLUSION:PC and LPC profiles being similar in patients with or without sclerosing cholangitis,these phospholipids are likely not of major pathogenetic importance in this disease group.展开更多
The improvement of biocompatibility of polyurethanes was investigated.The results demonstrate that the blood compatibility of polyurethanes can be further improved by just simply mixing with the fluorinated phosphatid...The improvement of biocompatibility of polyurethanes was investigated.The results demonstrate that the blood compatibility of polyurethanes can be further improved by just simply mixing with the fluorinated phosphatidylcholine poly(carbonate urethane)s(FPCPCUs).The solution blending was done by mixing poly(ether urethane)(PEU)with FPCPCU in different compositions.An increased blood compatibility of the blend films was observed with the increase of FPCPCU content,and when FPCPCU content reached to 40 wt%(40F...展开更多
Objective: To evaluate effects of docosahexaenoic acid-enriched phosphatidylcholine(DHAPC) on cytokine production induced by lipopolysaccharide(LPS). Methods: The culture supernatants of splenocytes exposed to DHA-PC ...Objective: To evaluate effects of docosahexaenoic acid-enriched phosphatidylcholine(DHAPC) on cytokine production induced by lipopolysaccharide(LPS). Methods: The culture supernatants of splenocytes exposed to DHA-PC along with LPS were harvested to determine the production of Th 1(IFN-kines. Cytokines were m毭 and IL-2) and Th2 [IL-4, IL-5, IL-6 and IL-12/IL-23(p40)] cytoeasured using ELISA. Results: Co-administration of DHAPC with LPS resulted in significantly lower IL-2 expression compared to that observed with administration of only LPS(P<0.01). Treatment with DHA-PC and LPS significantly increased IL-5 expression(P<0.01). Moreover, co-administration of DHA-PC with LPS significantly decreased IL-6 and IL-12/IL-23(p40) expressions compared to that observed with administration of only LPS(P<0.01). Conclusions: Our results suggest that DHA-PC inhibits pro-inflammatory cytokines [IL-2, IL-6 and IL-12/IL-23(p40)] expression on induction of inflammation.展开更多
A rate model, which considers axial dispersion, external mass transfer, intraparticle diffusion and nonlinear isotherms, and ports periodic switching is adopted to simulate the simulated moving bed （SMB） process. Th...A rate model, which considers axial dispersion, external mass transfer, intraparticle diffusion and nonlinear isotherms, and ports periodic switching is adopted to simulate the simulated moving bed （SMB） process. The effects of flow rate in Sections 2 and 3 and switching time on the operating performance parameters： purity, recovery, productivity and dcsorbent consumption are studied. A simulation approach is applied to simulate the operation and performance of the SMB. The model predicts the performance of the transient and cyclic steady state behavior to a reasonably good extent, and provides guidance operation condition of the SMB process.展开更多
Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids we...Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6).展开更多
基金Project (No. 20040335045) supported by the Specialized ResearchFund for the Doctoral Program of Higher Education of China
文摘A simulated moving bed (SMB), equipped with eight silica-gel columns, was used to separate phosphatidylcholine (PC) from soybean phospholipids. The effects of flow rate in Sections 2 (Q2) and 3 (Q3), switching time, feed flow rate and feed concentration on the operating performance parameters: purity, recovery, productivity and desorbent consumption were studied. Operating conditions leading to more than 90% purity in both outlet streams have been identified, together with those achieving optimal performance. Regions leading to complete separation are observed and explained theoretically. As the mass-transfer effect was not considered, the triangle theory only gives initial guesses for the optimal operating conditions.
文摘为研究预应力混凝土用钢棒(steel bar for prestressed concrete, PC钢棒)-钢筋混合配筋混凝土柱的抗震性能,设计制作了5根相同尺寸、相同纵筋配筋率、不同PC钢棒替代率的PC钢棒-钢筋混合配筋混凝土柱试件,通过拟静力试验研究了PC钢棒替代率对试件抗震性能的影响规律。结果表明:随着PC钢棒替代率的提高,试件的裂缝分布高度降低,裂缝数量变少,滞回曲线的饱满程度逐渐降低,耗能能力降低,残余位移角减小,自复位能力增强;当PC钢棒的替代率不大于50%时,各试件的峰值荷载接近;当PC钢棒的替代率大于50%时,试件的峰值荷载随PC钢棒替代率的增大而提高;当加载位移角相同且不大于1.0%时,配置PC钢棒的混凝土柱的残余位移角较为接近,且明显小于未配置PC钢棒的钢筋混凝土柱的残余位移角;当加载位移角相同且大于1%时,柱的残余位移角随着PC钢棒替代率的增高而降低。
文摘The structural and functional alterations within the PSⅡ membrane from phosphatidylcholine reconstitution and Triton X_100 (TX_100) treatment were studied by using Fourier transform_infrared (FT_IR) spectroscopic technique and oxygen electrode. Phosphatidylcholine reconstitution showed no significant effect on the protein secondary structures of PSⅡ membrane but an increase of the rate of PSⅡ_mediated oxygen_evolution. The phosphatidylcholine lipids with different length of acyl chains displayed different capabilities to stimulate oxygen_evolution. In contrast, perturbation of the bilayer lipids by TX_100 resulted in obvious changes of the protein secondary structures within the PSⅡ membrane and in the loss of the PSⅡ_mediated oxygen_evolving activity. The results indicate the importance of membrane integrity in maintaining the stability of the photosynthetic membrane proteins.
基金Supported by A Grant from Deutsche Forschungsgemeinschaft(DFG)
文摘AIM:To analyze phospholipid profiles in intrahepatic bile from patients with primary sclerosing cholangitis(PSC)and secondary sclerosing cholangitis(SSC).METHODS:Intrahepatic bile specimens collected via endoscopic retrograde cholangiography from 41 patients were analyzed.Fourteen of these patients were diagnosed with PSC,10 with SSC,11 with choledocholithiasis or no identifiable biliary disease,and 6 with cholangiocellular carcinoma(CCC).Bile acid,cholesterol,protein,and bilirubin contents as well as pancreas lipase activity in bile were determined by biochemical methods.Phosphatidylcholine(PC)and lysophosphatidylcholine(LPC)species were quantified using nanoelectrospray ionization tandem mass spectrometry.RESULTS:Bile from all the examined patient groups showed a remarkably similar PC and LPC species composition,with only minor statistical differences.Total biliary PC concentrations were highest in controls(8030±1843 mol/L)and lowest in patients with CCC(1969±981 mol/L)(P=0.005,controls vs SSC and CCC,respectively,P<0.05).LPC contents in bile were overall low(4.2%±1.8%).Biliary LPC/PC ratios and ratios of biliary PC to bilirubin,PC to cholesterol,PC to protein,and PC to bile acids showed no intergroup differences.CONCLUSION:PC and LPC profiles being similar in patients with or without sclerosing cholangitis,these phospholipids are likely not of major pathogenetic importance in this disease group.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.50673063 and 50533050)Young Foundation of Sichuan University for Financial Support.This work was also subsidized by the Special Funds for Major State Basic Research Projects of China(No.2003CB615600).
文摘The improvement of biocompatibility of polyurethanes was investigated.The results demonstrate that the blood compatibility of polyurethanes can be further improved by just simply mixing with the fluorinated phosphatidylcholine poly(carbonate urethane)s(FPCPCUs).The solution blending was done by mixing poly(ether urethane)(PEU)with FPCPCU in different compositions.An increased blood compatibility of the blend films was observed with the increase of FPCPCU content,and when FPCPCU content reached to 40 wt%(40F...
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and Future Planning(NRF-2017R1A2B4005915)
文摘Objective: To evaluate effects of docosahexaenoic acid-enriched phosphatidylcholine(DHAPC) on cytokine production induced by lipopolysaccharide(LPS). Methods: The culture supernatants of splenocytes exposed to DHA-PC along with LPS were harvested to determine the production of Th 1(IFN-kines. Cytokines were m毭 and IL-2) and Th2 [IL-4, IL-5, IL-6 and IL-12/IL-23(p40)] cytoeasured using ELISA. Results: Co-administration of DHAPC with LPS resulted in significantly lower IL-2 expression compared to that observed with administration of only LPS(P<0.01). Treatment with DHA-PC and LPS significantly increased IL-5 expression(P<0.01). Moreover, co-administration of DHA-PC with LPS significantly decreased IL-6 and IL-12/IL-23(p40) expressions compared to that observed with administration of only LPS(P<0.01). Conclusions: Our results suggest that DHA-PC inhibits pro-inflammatory cytokines [IL-2, IL-6 and IL-12/IL-23(p40)] expression on induction of inflammation.
基金Supported by the Doctoral Program Foundation of the Institution of Higher Education of China (No.20040335045).
文摘A rate model, which considers axial dispersion, external mass transfer, intraparticle diffusion and nonlinear isotherms, and ports periodic switching is adopted to simulate the simulated moving bed （SMB） process. The effects of flow rate in Sections 2 and 3 and switching time on the operating performance parameters： purity, recovery, productivity and dcsorbent consumption are studied. A simulation approach is applied to simulate the operation and performance of the SMB. The model predicts the performance of the transient and cyclic steady state behavior to a reasonably good extent, and provides guidance operation condition of the SMB process.
文摘Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6).
