AIM： To investigate whether continuous veno-venous hemofiltration （CVVH） in different filtration rate to eliminate cytokines would result in different efficiency in acute pancreatitis, whether the saturation time o...AIM： To investigate whether continuous veno-venous hemofiltration （CVVH） in different filtration rate to eliminate cytokines would result in different efficiency in acute pancreatitis, whether the saturation time of filter membrane was related to different filtration rate, and whether the onset time of CWH could influence the survival of acute pancreatitis. METHODS： Thirty-seven patients were classified into four groups randomly. Group 1 underwent low-volume CVVH within 48 h of the onset of abdominal pain （early CVVH, n = 9）. Group 2 received low-volume CVVH after 96 h of the onset of abdominal pain （late CVVH, n= 10）. Group 3 underwent high-volume CVVH within 48 h of the onset of abdominal pain （early CVVH, n = 9）. Group 4 received high-volume CVVH after 96 h of theonset of abdominal pain （late CVVH, n = 9）. CVVH was sustained for at least 72 h. Blood was taken before hemofiltration, and ultrafiltrate was collected at the start of CVVH and every 12 h during CVVH period for the purpose of measuring the concentrations of TNF-α, IL-1β and IL-6. The concentrations of TNF-α, IL-1β and IL-6 were measured by swine-specific ELISA. The Solartron 1 255 B frequency response analyzer （British） was used to observe the resistance of filter membrane. RESULTS： The survival rate had a significant difference （94.44% vs68.42%, P〈0.01） high-volume and low-volume CVVH patients. The survival rate had also a significant difference （88.89% vs 73.68%, P〈0.05） between early and late CVVH patients. The hemodynamic deterioration （MAP, HR, CVP） was less severe in groups 4 and 1 bhan that in group 2, and in group 3 than in group 4. The adsorptive saturation time of filters membranes was 120-180 min if the filtration rate was 1 000-4 000 mL/h. After the first, second and third new hemofilters were changed, serum TNF-α concentrations had a negative correlationwith resistance （r： -0.91, -0.89, and -0.86, respectively in group 1; -0.89, -0.85, and -0.76, respectively in group 2; -0.88, -0.92, and -0.82, respectively in group 3; -0.84, -0.87, and -0.79, respectively in group 4）. The decreasing extent of TNF-α, IL-1β and IL-6 was significantly different between group 3 and group I （TNF-α P〈0.05, IL-1β P〈0.05, IL-6 P〈0.01）, between group 4 and group 2 （TNF-α P〈0.05, IL-1β P〈0.05, IL-6 P〈0.01）, between group 1 and group 2 （TNF-α P〈0.05, IL-1β P〈0.05, IL-6 P〈0.05）, and between group 3 and group 4 （TNF-α P〈0.01, IL-1β P〈0.01, IL-6 P〈0.05）, respectively during CVVH period. The decreasing extent of TNF-α and IL-1β was also significantly different between survival patients and dead patients （TNF-α P〈0.05, IL-1β P〈0.05）. In survival patients, serum concentration of TNF-α and IL-1β decreased more significantly than that in dead patients. CONCLUSION： High-volume and early CWH improve hemodynamic deterioration and survival in acute pancreatitis patients. High-volume CVVH can eliminate cytokines more effidently than low-volume CVVH. The survival rate is related to the decrease extent of TNF-α and IL-1β. The adsorptive saturation time of filter membranes are different under different filtration rate condition. The filter should be changed timely once filter membrane adsorption is saturated.展开更多
AIM： To determine the most cost-effective hemofiltration modality for early management of severe acute pancreatitis （SAP） in China. METHODS： We carried out a search of Pub-Medline and Chinese Biomedical Disk datab...AIM： To determine the most cost-effective hemofiltration modality for early management of severe acute pancreatitis （SAP） in China. METHODS： We carried out a search of Pub-Medline and Chinese Biomedical Disk database. Controlled clinical trials on Chinese population were included in the analysis. The four decision branches that were analyzed were： continuous or long-term veno-venous hemofiltration （CVVH/LVVH）, short-term veno-venous hemofiltration （SVVH）, SVVH plus peritoneal dialysis （PD）, and non-hemofiltration control group. The effectiveness of the technique was determined by survival rate, complications prevention and surgery preservation. The total cost of hospitalization was also assessed. RESULTS： The SVVH only technique was the least costly modality, $5809 （44449 RMB）, and was selected as the baseline treatment modality. SVVH only arm achieved the lowest C/E ratio in terms of overall survival, complications prevention and surgery preservation. In incremental cost-effectiveness analysis, the CWH/ LVVH only and the control arms were inferior to other techniques. Sensitivity analysis showed SVVH only and SVVH plus PD arms overlapped in C/survival ratio. CONCLUSION： The role of early veno-venous hemofiltration as an alternative therapy for SAP remains controversial. However, we propose that early use of short-term high-volume veno-venous hemofiltration would have a beneficial impact on the management of SAP.展开更多
The experimental results of processing the solutions with trace suspended micro particles by a dynamic rotary vane filter press at production site are presented in this paper. Furthermore t...The experimental results of processing the solutions with trace suspended micro particles by a dynamic rotary vane filter press at production site are presented in this paper. Furthermore the effects of the conditions in the productive operation and the method of processing are summarized.展开更多
Aim To analyze the secondary structure and neurotrophic effect of a specific protein in sensory neurons. Methods Comparison of the proteins expressed in the rat spinal sensory neurons and motor neurons was made by t...Aim To analyze the secondary structure and neurotrophic effect of a specific protein in sensory neurons. Methods Comparison of the proteins expressed in the rat spinal sensory neurons and motor neurons was made by two dimensional electrophoresis. One specific protein in sensory neurons was isolated and purified by DEAE Sephacel ion exchange chromatography and high performance liquid chromatography. A primary analysis of its secondary structure by circular dichroism, and its neurotrophic effects were investigated using the model of dorsal root ganglia(DRG) cultured in vitro . Results The molecular weight and isoelectric point of the protein were 33 1 kDa and 5 52, respectively. Its circular dichroism showed that there were 20 8% α helix, 54 8% β sheet, 7 3% turn, and 17 1% random coil in its secondary structure. Biological experiments showed that the protein could promote the neurite outgrowth of DRG. Conclusion A specific protein in spinal sensory tissue with molecular weight of 33 1 kDa has been purified. There is mainly β sheet in the secondary structure of the protein. And the protein has neurotrophic effects in the model of DRG.展开更多
A study on the membrane coalescence demulsification was carried out with four working systems of water/n-butyl alcohol, water/n-octanol, water/30% TBP(in kerosene) and water/kerosene. The membranes made of polytetrafl...A study on the membrane coalescence demulsification was carried out with four working systems of water/n-butyl alcohol, water/n-octanol, water/30% TBP(in kerosene) and water/kerosene. The membranes made of polytetrafluoroethylene (PTFE) with 1.0μm pore size were used. The results indicated that the excellent demulsification efficiency for emulsions with various oil contents was obtained. A conductivity probe was used to study the demulsification mechanism. An electrode probe was designed and used to determine the oil content near the membrane surface. The obtained data showed that the oil content in the permeated stream was much higher than that in the feed emulsion. A physical mechanism to explain the membrane demulsification was put forward.展开更多
In order to recover the SiO_2 contained in the mother liquor in the course ofNaY zeolite synthesis to minimize pollution, the influence of various preparation conditions on thefiltering velocity of gel slurry was stud...In order to recover the SiO_2 contained in the mother liquor in the course ofNaY zeolite synthesis to minimize pollution, the influence of various preparation conditions on thefiltering velocity of gel slurry was studied using the SiO_2/Al_2O_3 gel recovered from the NaYmother liquor in the laboratory. The results of study had shown that at a SiO_2/Al_2O_3 ratio in thefeed equating to 9∶1 the SiO_2 recovery rate and Al_2O_3 utilization rate were high with a fasterflow velocity of the filtrate. The pH value of the system had great impact on the flow velocity offiltrate. Between the two methods for regulating the pH value, the one for formation ofsilica/alumina gel slurry by addition of sulfuric acid prior to adding aluminium sulfate in thesolution could secure a faster filtration velocity. The filtration velocity was decreased in tandemwith increasing SiO_2 concentration in mother liquor, meanwhile an increase in dry filter cakeyield.展开更多
Polyquaternium-6 (PQ6) as the water-soluble polymer was used for complexing the anion forms of tungsten (Ⅵ) before ultrafiltration. Tungsten (Ⅵ)-PQ6 complex was retained by polysulfone hollow fiber ultrafiltration m...Polyquaternium-6 (PQ6) as the water-soluble polymer was used for complexing the anion forms of tungsten (Ⅵ) before ultrafiltration. Tungsten (Ⅵ)-PQ6 complex was retained by polysulfone hollow fiber ultrafiltration membrane in the complexation-ultrafiltration process. Effects of various operating parameters such as polymer metal ratio(PMR), pH and chloride ion concentration on permeate flux (J) and tungsten rejection coefficient (R) were investigated. The integration of four experiments including concentration, decomplexation, diafiltration and reuse of regenerated polymer was carried out. In the process of concentration, J declines slowly and R is about 1 at PMR of 3 and pH of 7. Tungsten concentration in the retentate increases linearly with volume concentration factor. Tungsten is concentrated efficiently with the membrane. The concentrated retentate was used further for the decomplexation. It takes about 6 min to reach the decomplexation equilibrium at chloride ion concentration of 50 mg·L-1 . The decomplexation percentage of tungsten (Ⅵ)-PQ6 complex reaches 56.1%. In the diafiltration process, tungsten (Ⅵ) can be extracted effectively by using 50 mg·L-1 chloride ion solution, and the purification of the regenerated PQ6 is acceptably satisfactory. The regenerated PQ6 was used to bind tungsten (Ⅵ) at various pH values. The binding capacity of the regenerated PQ6 is close to that of fresh PQ6, and the recovery percentage of binding capacity is higher than 90%.展开更多
Generation of polydisperse KCl aerosol with a new salt aerosol generator was investigated, Special attention was paid on particles with diameters between 3 and 10 μm. The main improvement consists of the different ro...Generation of polydisperse KCl aerosol with a new salt aerosol generator was investigated, Special attention was paid on particles with diameters between 3 and 10 μm. The main improvement consists of the different routes of KCl solution droplets. In traditional generators, the solution droplets travel through one cylinder; while in the case analyzed here, after spray atomization, the droplets travel through two cylinders in series. The first cylinder was fed with warm air and the second one with cold air. In such way, the complete evaporation of the water from the droplets can be ensured. The influencing factors of the generated aerosol size distribution were investigated. The data measured show that the concentration of generated aerosol becomes higher both increasing the flow rate of the KCI solution injected in the first cylinder and increasing the concentration in the solution. The temperature of solution influences mainly the generation of smaller KCI particles （0,3-3 μm）. The amount of hot air used in the generation process increases the concentration of larger KC1 particles （〉3 μm） while cold air does not have the same effect. The aerosol generator is able to generate KC1 aerosol stably. This instrument can be used effectively for testing air filters for automotive.展开更多
The mycotoxin, patulin （4-hydroxy-4H-furo [3, 2c] pyran-2 [6H]-one）, is produced by a number of fungi common to fruit and vegetable-based products, most notably apples. Patulin contamination within apple products po...The mycotoxin, patulin （4-hydroxy-4H-furo [3, 2c] pyran-2 [6H]-one）, is produced by a number of fungi common to fruit and vegetable-based products, most notably apples. Patulin contamination within apple products poses a serious health risk to consumers. Studies done on laboratory animals have demonstrated that patulin has a broad spectrum of toxicity, including mutagen city and carcinogenicity. The aim of the experiment was studying influence of selectively acting activated carbon powder--Ercarbon SH （Erbsloh, Germany） which is special produced for lowering HMF （hydroxy methyl furfural）, on reduction of patulin content in clear apple juice. Industrial apple row material with some damaged parts was pressed, juice was pasteurized at 95 ℃ during 2 min. After cooling on 55 ℃, enzymatic treated and clarified juice were filtered by 0.45 [am pore sizes membrane filter, Apple clear juice sample was divided for five parts. The samples of apple juice were diluted to 11.5° Brix and contacted with concentrations of 2, 2.5, 3 and 3.5 g/L activated carbon powder for 30 min. After filtration in the experimental samples, putulin was quantitatively determined by HPLC （high performance liquid chromatography with UV） detector at 276 nm. The research revealed that the best results were achieved by treatment with activated carbon in its powder form at concentration of 2.5 g/L with 30 min contact time.展开更多
基金Supported by the Natural Science Foundation of Shaanxi Province,No. 2002C257
文摘AIM： To investigate whether continuous veno-venous hemofiltration （CVVH） in different filtration rate to eliminate cytokines would result in different efficiency in acute pancreatitis, whether the saturation time of filter membrane was related to different filtration rate, and whether the onset time of CWH could influence the survival of acute pancreatitis. METHODS： Thirty-seven patients were classified into four groups randomly. Group 1 underwent low-volume CVVH within 48 h of the onset of abdominal pain （early CVVH, n = 9）. Group 2 received low-volume CVVH after 96 h of the onset of abdominal pain （late CVVH, n= 10）. Group 3 underwent high-volume CVVH within 48 h of the onset of abdominal pain （early CVVH, n = 9）. Group 4 received high-volume CVVH after 96 h of theonset of abdominal pain （late CVVH, n = 9）. CVVH was sustained for at least 72 h. Blood was taken before hemofiltration, and ultrafiltrate was collected at the start of CVVH and every 12 h during CVVH period for the purpose of measuring the concentrations of TNF-α, IL-1β and IL-6. The concentrations of TNF-α, IL-1β and IL-6 were measured by swine-specific ELISA. The Solartron 1 255 B frequency response analyzer （British） was used to observe the resistance of filter membrane. RESULTS： The survival rate had a significant difference （94.44% vs68.42%, P〈0.01） high-volume and low-volume CVVH patients. The survival rate had also a significant difference （88.89% vs 73.68%, P〈0.05） between early and late CVVH patients. The hemodynamic deterioration （MAP, HR, CVP） was less severe in groups 4 and 1 bhan that in group 2, and in group 3 than in group 4. The adsorptive saturation time of filters membranes was 120-180 min if the filtration rate was 1 000-4 000 mL/h. After the first, second and third new hemofilters were changed, serum TNF-α concentrations had a negative correlationwith resistance （r： -0.91, -0.89, and -0.86, respectively in group 1; -0.89, -0.85, and -0.76, respectively in group 2; -0.88, -0.92, and -0.82, respectively in group 3; -0.84, -0.87, and -0.79, respectively in group 4）. The decreasing extent of TNF-α, IL-1β and IL-6 was significantly different between group 3 and group I （TNF-α P〈0.05, IL-1β P〈0.05, IL-6 P〈0.01）, between group 4 and group 2 （TNF-α P〈0.05, IL-1β P〈0.05, IL-6 P〈0.01）, between group 1 and group 2 （TNF-α P〈0.05, IL-1β P〈0.05, IL-6 P〈0.05）, and between group 3 and group 4 （TNF-α P〈0.01, IL-1β P〈0.01, IL-6 P〈0.05）, respectively during CVVH period. The decreasing extent of TNF-α and IL-1β was also significantly different between survival patients and dead patients （TNF-α P〈0.05, IL-1β P〈0.05）. In survival patients, serum concentration of TNF-α and IL-1β decreased more significantly than that in dead patients. CONCLUSION： High-volume and early CWH improve hemodynamic deterioration and survival in acute pancreatitis patients. High-volume CVVH can eliminate cytokines more effidently than low-volume CVVH. The survival rate is related to the decrease extent of TNF-α and IL-1β. The adsorptive saturation time of filter membranes are different under different filtration rate condition. The filter should be changed timely once filter membrane adsorption is saturated.
基金Supported by The National Natural Science Foundation of China, No.30500684 and Clinical Research Foundation for Residency Granted by the Cooperative Project of West China Hospital and Daiichi Pharmaceutical Co. Ltd., the level Ⅰ
文摘AIM： To determine the most cost-effective hemofiltration modality for early management of severe acute pancreatitis （SAP） in China. METHODS： We carried out a search of Pub-Medline and Chinese Biomedical Disk database. Controlled clinical trials on Chinese population were included in the analysis. The four decision branches that were analyzed were： continuous or long-term veno-venous hemofiltration （CVVH/LVVH）, short-term veno-venous hemofiltration （SVVH）, SVVH plus peritoneal dialysis （PD）, and non-hemofiltration control group. The effectiveness of the technique was determined by survival rate, complications prevention and surgery preservation. The total cost of hospitalization was also assessed. RESULTS： The SVVH only technique was the least costly modality, $5809 （44449 RMB）, and was selected as the baseline treatment modality. SVVH only arm achieved the lowest C/E ratio in terms of overall survival, complications prevention and surgery preservation. In incremental cost-effectiveness analysis, the CWH/ LVVH only and the control arms were inferior to other techniques. Sensitivity analysis showed SVVH only and SVVH plus PD arms overlapped in C/survival ratio. CONCLUSION： The role of early veno-venous hemofiltration as an alternative therapy for SAP remains controversial. However, we propose that early use of short-term high-volume veno-venous hemofiltration would have a beneficial impact on the management of SAP.
文摘The experimental results of processing the solutions with trace suspended micro particles by a dynamic rotary vane filter press at production site are presented in this paper. Furthermore the effects of the conditions in the productive operation and the method of processing are summarized.
文摘Aim To analyze the secondary structure and neurotrophic effect of a specific protein in sensory neurons. Methods Comparison of the proteins expressed in the rat spinal sensory neurons and motor neurons was made by two dimensional electrophoresis. One specific protein in sensory neurons was isolated and purified by DEAE Sephacel ion exchange chromatography and high performance liquid chromatography. A primary analysis of its secondary structure by circular dichroism, and its neurotrophic effects were investigated using the model of dorsal root ganglia(DRG) cultured in vitro . Results The molecular weight and isoelectric point of the protein were 33 1 kDa and 5 52, respectively. Its circular dichroism showed that there were 20 8% α helix, 54 8% β sheet, 7 3% turn, and 17 1% random coil in its secondary structure. Biological experiments showed that the protein could promote the neurite outgrowth of DRG. Conclusion A specific protein in spinal sensory tissue with molecular weight of 33 1 kDa has been purified. There is mainly β sheet in the secondary structure of the protein. And the protein has neurotrophic effects in the model of DRG.
基金Supported by the National Natural Science Foundation of China(No.29976021).
文摘A study on the membrane coalescence demulsification was carried out with four working systems of water/n-butyl alcohol, water/n-octanol, water/30% TBP(in kerosene) and water/kerosene. The membranes made of polytetrafluoroethylene (PTFE) with 1.0μm pore size were used. The results indicated that the excellent demulsification efficiency for emulsions with various oil contents was obtained. A conductivity probe was used to study the demulsification mechanism. An electrode probe was designed and used to determine the oil content near the membrane surface. The obtained data showed that the oil content in the permeated stream was much higher than that in the feed emulsion. A physical mechanism to explain the membrane demulsification was put forward.
文摘In order to recover the SiO_2 contained in the mother liquor in the course ofNaY zeolite synthesis to minimize pollution, the influence of various preparation conditions on thefiltering velocity of gel slurry was studied using the SiO_2/Al_2O_3 gel recovered from the NaYmother liquor in the laboratory. The results of study had shown that at a SiO_2/Al_2O_3 ratio in thefeed equating to 9∶1 the SiO_2 recovery rate and Al_2O_3 utilization rate were high with a fasterflow velocity of the filtrate. The pH value of the system had great impact on the flow velocity offiltrate. Between the two methods for regulating the pH value, the one for formation ofsilica/alumina gel slurry by addition of sulfuric acid prior to adding aluminium sulfate in thesolution could secure a faster filtration velocity. The filtration velocity was decreased in tandemwith increasing SiO_2 concentration in mother liquor, meanwhile an increase in dry filter cakeyield.
基金Supported by the National Natural Science Foundation of China (20976040)Science and Technology Planning Project of Hunan Province of China (2009SK3036)
文摘Polyquaternium-6 (PQ6) as the water-soluble polymer was used for complexing the anion forms of tungsten (Ⅵ) before ultrafiltration. Tungsten (Ⅵ)-PQ6 complex was retained by polysulfone hollow fiber ultrafiltration membrane in the complexation-ultrafiltration process. Effects of various operating parameters such as polymer metal ratio(PMR), pH and chloride ion concentration on permeate flux (J) and tungsten rejection coefficient (R) were investigated. The integration of four experiments including concentration, decomplexation, diafiltration and reuse of regenerated polymer was carried out. In the process of concentration, J declines slowly and R is about 1 at PMR of 3 and pH of 7. Tungsten concentration in the retentate increases linearly with volume concentration factor. Tungsten is concentrated efficiently with the membrane. The concentrated retentate was used further for the decomplexation. It takes about 6 min to reach the decomplexation equilibrium at chloride ion concentration of 50 mg·L-1 . The decomplexation percentage of tungsten (Ⅵ)-PQ6 complex reaches 56.1%. In the diafiltration process, tungsten (Ⅵ) can be extracted effectively by using 50 mg·L-1 chloride ion solution, and the purification of the regenerated PQ6 is acceptably satisfactory. The regenerated PQ6 was used to bind tungsten (Ⅵ) at various pH values. The binding capacity of the regenerated PQ6 is close to that of fresh PQ6, and the recovery percentage of binding capacity is higher than 90%.
基金Project(2010EME006) supported by Open Fund of the Key Laboratory of Environmental Medicine Engineering of Ministry of Education of China Project(51008063) supported by the National Natural Science Foundation of China+1 种基金 Project(3203000601) supported by the Postdoctoral Key Research Program from Southeast University, China Project(2011BAJ03B05) supported by the National Science and Technology Pillar Program during the 12th Five-Year Plan Period of China
文摘Generation of polydisperse KCl aerosol with a new salt aerosol generator was investigated, Special attention was paid on particles with diameters between 3 and 10 μm. The main improvement consists of the different routes of KCl solution droplets. In traditional generators, the solution droplets travel through one cylinder; while in the case analyzed here, after spray atomization, the droplets travel through two cylinders in series. The first cylinder was fed with warm air and the second one with cold air. In such way, the complete evaporation of the water from the droplets can be ensured. The influencing factors of the generated aerosol size distribution were investigated. The data measured show that the concentration of generated aerosol becomes higher both increasing the flow rate of the KCI solution injected in the first cylinder and increasing the concentration in the solution. The temperature of solution influences mainly the generation of smaller KCI particles （0,3-3 μm）. The amount of hot air used in the generation process increases the concentration of larger KC1 particles （〉3 μm） while cold air does not have the same effect. The aerosol generator is able to generate KC1 aerosol stably. This instrument can be used effectively for testing air filters for automotive.
文摘The mycotoxin, patulin （4-hydroxy-4H-furo [3, 2c] pyran-2 [6H]-one）, is produced by a number of fungi common to fruit and vegetable-based products, most notably apples. Patulin contamination within apple products poses a serious health risk to consumers. Studies done on laboratory animals have demonstrated that patulin has a broad spectrum of toxicity, including mutagen city and carcinogenicity. The aim of the experiment was studying influence of selectively acting activated carbon powder--Ercarbon SH （Erbsloh, Germany） which is special produced for lowering HMF （hydroxy methyl furfural）, on reduction of patulin content in clear apple juice. Industrial apple row material with some damaged parts was pressed, juice was pasteurized at 95 ℃ during 2 min. After cooling on 55 ℃, enzymatic treated and clarified juice were filtered by 0.45 [am pore sizes membrane filter, Apple clear juice sample was divided for five parts. The samples of apple juice were diluted to 11.5° Brix and contacted with concentrations of 2, 2.5, 3 and 3.5 g/L activated carbon powder for 30 min. After filtration in the experimental samples, putulin was quantitatively determined by HPLC （high performance liquid chromatography with UV） detector at 276 nm. The research revealed that the best results were achieved by treatment with activated carbon in its powder form at concentration of 2.5 g/L with 30 min contact time.
