Polycarbosilane containing beryllium(BPCS) precursors was prepared by the reaction of polycarbosilane(PCS) with beryllium acetylacetone(Be(acac)2).The analysis of structures and components of BPCS demonstrates that th...Polycarbosilane containing beryllium(BPCS) precursors was prepared by the reaction of polycarbosilane(PCS) with beryllium acetylacetone(Be(acac)2).The analysis of structures and components of BPCS demonstrates that their main structures are basically the same as PCS.Ceramization of BPCS precursors shows that BPCS precursors are organic below 600 °C and inorganic at 800 °C.At 1400 °C,BPCS precursors convert into silicon carbide ceramics.The ceramization of different beryllium content precursors were studied,which show that beryllium plays an important role in the inhibition of crystalline grain growth of β-SiC at high temperature and it can adjust the dielectric constant of silicon carbide ceramics.展开更多
AIM To investigate the influence of interferon-free antivirus therapy on lipid profiles in chronic hepatitis C virus genotype 1b(HCV1b) infection.METHODS Interferon-free antiviral agents were used to treat 276 patient...AIM To investigate the influence of interferon-free antivirus therapy on lipid profiles in chronic hepatitis C virus genotype 1b(HCV1b) infection.METHODS Interferon-free antiviral agents were used to treat 276 patients with chronic HCV1 b infection, and changes in serum lipids of those who achieved sustained virologic response(SVR) were examined. The treatment regimen included 24 wk of daclatasvir plus asunaprevir(DCV + ASV) or 12 wk of sofosbuvir plus ledipasvir(SOF + LDV). SVR was achieved in 121(85.8%) of 141 patients treated with DCV + ASV and 132(97.8%) of 135 patients treated with SOF + LDV. In the two patient groups(DCV + ASV-SVR and SOF + LDV-SVR), serum total cholesterol(TC), low-density lipoprotein cholesterol(LDL-C), high-density lipoprotein cholesterol(HDL-C), and triglycerides were measured at baseline during treatment and at 4 and 12 wk after treatment. Then, longitudinal changes in lipid profiles were analyzed.RESULTS Serum levels of TC, LDL-C, and HDL-C were significantly increased throughout the observation period in both the DCV + ASV-SVR and SOF + LDV-SVR groups. During antivirus treatment, the increases in TC and LDL-C were significantly greater in the SOF + LDVSVR group than in the DCV + ASV-SVR group(P < 0.001). At 4 and 12 wk after the therapy, serum levels of TC and LDL-C were similar between the two groups and were significantly greater than those at baseline. Approximately 75%-80% of the increase in TC was derived from an increased LDL-C. In multiple regression analysis, the difference in therapy protocol(DCA + ASV or SOF + LDV) was an independent predictor that was significantly associated with the increase in TC and LDL-C at 4 wk of therapy.CONCLUSION Serum cholesterol significantly increased during SOF + LDV treatment. After treatment, HCV elimination was associated with a similar increase in cholesterol regardless of the therapy protocol.展开更多
Objective:To evaluate the predictive performance of‘Diprifusor’TCI(target-controlled infusion)system for its betterapplication in clinical anesthesia.Methods:The predictive performance of a‘Diprifusor’TCI system w...Objective:To evaluate the predictive performance of‘Diprifusor’TCI(target-controlled infusion)system for its betterapplication in clinical anesthesia.Methods:The predictive performance of a‘Diprifusor’TCI system was investigated in 27Chinese patients(16 males and 11 females)during upper abdominal surgery under total intravenous anesthesia(TIVA)withpropofol/fentanyl.Measnred arterial propofol concentrations were compared with the values predicted by the TCI infusion system.Performance was determined by the median performance error(MDPE),the median absolute performance error(MDAPE),thedivergence(the percentage change of the absolute PE with time),and the wobble(the median absolute deviation of each PE fromthe MDPE).Results:The median(range)values of 14.9%(-21.6%~42.9%)for MDPE,23.3%(6.9%~62.5%)for MDAPE,-1.9%h^(-1)(-32.7%~23.0% h^(-1))for divergence,and 18.9%(4.2%~59.6%)for wobble were obtained from 227 samples from all patients.For the studied population,the PE did not increase with time but with increasing target propofol concentration,particularly fol-lowing induction.Conclusions:The control of depth of anaesthesia was good in all patients undergoing upper abdominal surgicaloperation and the predictive performance of the‘Diprifusor’target controlled mthsion system was considered acceptable forclinical purposes.But the relatively bigger wobble showed that the pharmacokinetic model is not so suitable and requires im-provement.展开更多
AIM: To describe the risk profile of patients in hospita with hepatitis C virus (HCV) infection in Poland. METHOD: Using a structured questionnaire, all patients with confirmed HCV infection were interviewed about...AIM: To describe the risk profile of patients in hospita with hepatitis C virus (HCV) infection in Poland. METHOD: Using a structured questionnaire, all patients with confirmed HCV infection were interviewed about the risk factors. RESULTS: Among the 250 patients studied, transfusion before 1993 was the primary risk factor in 26%, intravenous drug use setting in 9% and occupational exposure in health-care in 9%. Women were more likely to have a history of occupational exposure or transfusion before 1993 and less likely to undergo minor surgery. Known nosocomial risk factors (transfusion before 1993, dialysis) were responsible for 27% of infections, probable nosocomial factors (transfusions after 1992, minor surgery) for 14% and further 9% were occupationally acquired infections. CONCLUSION: A careful history investigation can identify a known or probable risk factor for HCV acquisition in 59% of patients with HCV infection. Preventive activities in Poland should focus on infection control measures in health-care setting.展开更多
Linked polymer solution (LPS) is defined as the solution of linked polymer coils (LPCs) dispersed in water, composed of low concentration partially hydrolyzed polyacrylamide (HPAM) and aluminum citrate (crosslinker). ...Linked polymer solution (LPS) is defined as the solution of linked polymer coils (LPCs) dispersed in water, composed of low concentration partially hydrolyzed polyacrylamide (HPAM) and aluminum citrate (crosslinker). In the work, the conformational changes of LPCs under different conditions were investigated by the methods of membrane filtering under low pressure, dynamic light scattering and core flooding experiments. The results showed that in some conditions the LPCs could be compressed mechanically to 1/158.5 of their original volume because of relatively lower HPAM cross-linking. The hydration property of LPCs was similar to that of normal polymer coils. The deformation of LPCs was more restricted than that of ordinary polymer coils under the flow shear stress or the shift of hydration equilibrium caused in the variation of the electrolyte concentration which is responsible for the effective plugging in the throats of porous media when LPCs are used for deep diverting.展开更多
Drilling fluid additives has a major impact on rheology behavior and other performances of the drilling fluid.The key to low temperature drilling fluids is choosing antifreeze and polymer agent which have a strong abi...Drilling fluid additives has a major impact on rheology behavior and other performances of the drilling fluid.The key to low temperature drilling fluids is choosing antifreeze and polymer agent which have a strong ability in resisting low temperature.On the basis of determining glycol as antifreeze agent,the low-temperature-performance and capacities of anti-collapse of regular validity mud agents have been studied,the mechanism of anti-caving of the partially hydrolyzed polyacrylamide(PHPA),polypropylene potassium(KPA) and PAC-141 polymer additives have been also analyzed.A pilot study of compatibility between ethylene glycol and the polymers has educed that the polymers,ethylene glycol and inorganic salt are compatible,and they can significantly reduce the freezing point of drilling fluid.Anti-collapse ability of the drilling mud is the results of synergistic action among the agents.展开更多
基金Project(51074193)supported by the National Natural Science Foundation of ChinaProjects(2011AA7024034,2011AA7053016)supported by the National High Technology Research and Development Program of ChinaProject(LK0903)supported by State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University,China
文摘Polycarbosilane containing beryllium(BPCS) precursors was prepared by the reaction of polycarbosilane(PCS) with beryllium acetylacetone(Be(acac)2).The analysis of structures and components of BPCS demonstrates that their main structures are basically the same as PCS.Ceramization of BPCS precursors shows that BPCS precursors are organic below 600 °C and inorganic at 800 °C.At 1400 °C,BPCS precursors convert into silicon carbide ceramics.The ceramization of different beryllium content precursors were studied,which show that beryllium plays an important role in the inhibition of crystalline grain growth of β-SiC at high temperature and it can adjust the dielectric constant of silicon carbide ceramics.
文摘AIM To investigate the influence of interferon-free antivirus therapy on lipid profiles in chronic hepatitis C virus genotype 1b(HCV1b) infection.METHODS Interferon-free antiviral agents were used to treat 276 patients with chronic HCV1 b infection, and changes in serum lipids of those who achieved sustained virologic response(SVR) were examined. The treatment regimen included 24 wk of daclatasvir plus asunaprevir(DCV + ASV) or 12 wk of sofosbuvir plus ledipasvir(SOF + LDV). SVR was achieved in 121(85.8%) of 141 patients treated with DCV + ASV and 132(97.8%) of 135 patients treated with SOF + LDV. In the two patient groups(DCV + ASV-SVR and SOF + LDV-SVR), serum total cholesterol(TC), low-density lipoprotein cholesterol(LDL-C), high-density lipoprotein cholesterol(HDL-C), and triglycerides were measured at baseline during treatment and at 4 and 12 wk after treatment. Then, longitudinal changes in lipid profiles were analyzed.RESULTS Serum levels of TC, LDL-C, and HDL-C were significantly increased throughout the observation period in both the DCV + ASV-SVR and SOF + LDV-SVR groups. During antivirus treatment, the increases in TC and LDL-C were significantly greater in the SOF + LDVSVR group than in the DCV + ASV-SVR group(P < 0.001). At 4 and 12 wk after the therapy, serum levels of TC and LDL-C were similar between the two groups and were significantly greater than those at baseline. Approximately 75%-80% of the increase in TC was derived from an increased LDL-C. In multiple regression analysis, the difference in therapy protocol(DCA + ASV or SOF + LDV) was an independent predictor that was significantly associated with the increase in TC and LDL-C at 4 wk of therapy.CONCLUSION Serum cholesterol significantly increased during SOF + LDV treatment. After treatment, HCV elimination was associated with a similar increase in cholesterol regardless of the therapy protocol.
文摘Objective:To evaluate the predictive performance of‘Diprifusor’TCI(target-controlled infusion)system for its betterapplication in clinical anesthesia.Methods:The predictive performance of a‘Diprifusor’TCI system was investigated in 27Chinese patients(16 males and 11 females)during upper abdominal surgery under total intravenous anesthesia(TIVA)withpropofol/fentanyl.Measnred arterial propofol concentrations were compared with the values predicted by the TCI infusion system.Performance was determined by the median performance error(MDPE),the median absolute performance error(MDAPE),thedivergence(the percentage change of the absolute PE with time),and the wobble(the median absolute deviation of each PE fromthe MDPE).Results:The median(range)values of 14.9%(-21.6%~42.9%)for MDPE,23.3%(6.9%~62.5%)for MDAPE,-1.9%h^(-1)(-32.7%~23.0% h^(-1))for divergence,and 18.9%(4.2%~59.6%)for wobble were obtained from 227 samples from all patients.For the studied population,the PE did not increase with time but with increasing target propofol concentration,particularly fol-lowing induction.Conclusions:The control of depth of anaesthesia was good in all patients undergoing upper abdominal surgicaloperation and the predictive performance of the‘Diprifusor’target controlled mthsion system was considered acceptable forclinical purposes.But the relatively bigger wobble showed that the pharmacokinetic model is not so suitable and requires im-provement.
基金Supported by the grant from the Medical University of Bialystok,Poland,No.3-56876L
文摘AIM: To describe the risk profile of patients in hospita with hepatitis C virus (HCV) infection in Poland. METHOD: Using a structured questionnaire, all patients with confirmed HCV infection were interviewed about the risk factors. RESULTS: Among the 250 patients studied, transfusion before 1993 was the primary risk factor in 26%, intravenous drug use setting in 9% and occupational exposure in health-care in 9%. Women were more likely to have a history of occupational exposure or transfusion before 1993 and less likely to undergo minor surgery. Known nosocomial risk factors (transfusion before 1993, dialysis) were responsible for 27% of infections, probable nosocomial factors (transfusions after 1992, minor surgery) for 14% and further 9% were occupationally acquired infections. CONCLUSION: A careful history investigation can identify a known or probable risk factor for HCV acquisition in 59% of patients with HCV infection. Preventive activities in Poland should focus on infection control measures in health-care setting.
基金Supported by Open Foundation of State Key Laboratoy of Heavy Oil Processing(No. 200013)
文摘Linked polymer solution (LPS) is defined as the solution of linked polymer coils (LPCs) dispersed in water, composed of low concentration partially hydrolyzed polyacrylamide (HPAM) and aluminum citrate (crosslinker). In the work, the conformational changes of LPCs under different conditions were investigated by the methods of membrane filtering under low pressure, dynamic light scattering and core flooding experiments. The results showed that in some conditions the LPCs could be compressed mechanically to 1/158.5 of their original volume because of relatively lower HPAM cross-linking. The hydration property of LPCs was similar to that of normal polymer coils. The deformation of LPCs was more restricted than that of ordinary polymer coils under the flow shear stress or the shift of hydration equilibrium caused in the variation of the electrolyte concentration which is responsible for the effective plugging in the throats of porous media when LPCs are used for deep diverting.
文摘Drilling fluid additives has a major impact on rheology behavior and other performances of the drilling fluid.The key to low temperature drilling fluids is choosing antifreeze and polymer agent which have a strong ability in resisting low temperature.On the basis of determining glycol as antifreeze agent,the low-temperature-performance and capacities of anti-collapse of regular validity mud agents have been studied,the mechanism of anti-caving of the partially hydrolyzed polyacrylamide(PHPA),polypropylene potassium(KPA) and PAC-141 polymer additives have been also analyzed.A pilot study of compatibility between ethylene glycol and the polymers has educed that the polymers,ethylene glycol and inorganic salt are compatible,and they can significantly reduce the freezing point of drilling fluid.Anti-collapse ability of the drilling mud is the results of synergistic action among the agents.