Through the long development processes of reservoir sedimentation and diagenesis, acidic and alkaline fluids play key roles in controlling deep reservoir development. However, the ways in which deep fluids control and...Through the long development processes of reservoir sedimentation and diagenesis, acidic and alkaline fluids play key roles in controlling deep reservoir development. However, the ways in which deep fluids control and transform the reservoir under complex fault conditions remain unclear. In this study, a 2D model was established based on a typical sub-salt to intra-salt vertical profile in the Qaidam Basin, China. Based on measured data, multiphase flow reaction and solute transport simulation technology were used to analyze fluids flow and migration in the intra-salt and sub-salt reservoirs, determine the mineral dissolution, precipitation, and transformation in the reservoir caused by the deep fluids, and calculate the changes in reservoir porosity. Results show that deep fluid migrates preferentially along dominant channels and triggers a series of fluid–rock chemical reactions. In the first stage, a large amount of anhydrite precipitated in the fault as a result of upward migration of deep saline fluid, resulting in the formation of anhydrite veins and blockage at the base of the fault. In the second stage, organic acids caused minerals dissolution and a vertical channel was opened in previously blocked area, which promoted continuous upward migration of organic acids and the formation of secondary pores. This study clarifies the transformative effects of deep alkaline and acidic fluids on the reservoir. Moreover, the important fluid transport role of faults and their effect on reservoir development were determined.展开更多
This work mainly studies the effect of fluid phase momentum transfer mechanisms on the acidizing results,including the retardation effect of the porous structure and the interaction between the fluid phase,such as vis...This work mainly studies the effect of fluid phase momentum transfer mechanisms on the acidizing results,including the retardation effect of the porous structure and the interaction between the fluid phase,such as viscous dissipation and inertial effect.The results show that the acid fluid momentum transfer is influenced by the complex porous structure and fluid viscous dissipation.Eventually,the Stokes-Darcy equation is recommended to be adopted to describe the fluid phase momentum transfer in the following numerical simulation studies of the carbonate acidizing process.Based on this model,a parametric research is carried out to investigate the impact of acid on rock physical characteristics in the stimulation process.Increasing the acid concentration appears to minimize the quantity of acid consumed for the breakthrough.The acid surface reaction rate has a considerable impact on the pore volume to breakthrough and the optimum acid injection rate.The influence of permeability on the acidizing results basically shows a negative correlation with the injection rate.The difference between the acidizing curves of different permeability gradually becomes insignificant with the decrease in injection rate.The existence of isolated fracture and vug significantly reduces acid consumption for the breakthrough.展开更多
Tea is a widely consumed beverage and has many important physiological properties and potential health benefits. In this study, a novel method based on supercritical fluid chromatography coupled with mass spectrometry...Tea is a widely consumed beverage and has many important physiological properties and potential health benefits. In this study, a novel method based on supercritical fluid chromatography coupled with mass spectrometry (SFC-MS) was developed to simultaneously determine 11 amino acids in different types of tea (green teas, Oolong tea, black tea and Pu-erh tea). The separation conditions for the analysis of the selected amino acids including the column type, temperature and backpressure as well as the type of additive, were carefully optimized. The best separation of the 11 amino acids was obtained by adding water (5%, v/v) and trifluoroacetic acid (0.4%, v/v) to the organic modifier (methanol). Finally, the developed SFC-MS method was fully validated and successfully applied to the determination of these amino acids in six different tea samples. Good linearity (r ≥ 0.993), precision (RSDs≤ 2.99%), accuracy (91.95%-107.09%) as well as good sample stability were observed. The limits of detection ranged from 1.42 to 14.69 ng/mL, while the limits of quantification were between 4.53 and 47.0 ng/mL. The results indicate that the contents of the 11 amino acids in the six different tea samples are greatly influenced by the degree of fermentation. The proposed SFC-MS method shows a great potential for further investigation of tea varieties.展开更多
To explore the relationship between the heat-clearing and detoxicating functions and the bacteriostatic actions of berberine hydrochloride （Ber. H）, chlorogenic acid （Chlo. A）, and baicalin （Bai）, their concentr...To explore the relationship between the heat-clearing and detoxicating functions and the bacteriostatic actions of berberine hydrochloride （Ber. H）, chlorogenic acid （Chlo. A）, and baicalin （Bai）, their concentrations in rabbit body fluid were compared with their minimal inhibitory concentrations （MICs）. Their concentrations in rabbit blood and tissue fluid were determined by reversed-phase high performance liquid chromatography, and their MICs to Escherichia coli were determined by tube dilution method. The results showed that the peak concentrations of Ber. H, Chlo. A, and Bai in rabbit blood were 3.2, 5.03, and 7.63 μg mL^-1, and in rabbit tissue fluid were 0.12, 0.11, and 0.12 μg mL^-1, respectively. Their MICs to E. coli were, respectively, 1.0×10^3, 3.75 × 10^3, and 6.75 ×10^3μg mL^-1, which were far higher than the concentrations in rabbit body fluids. This study indicates that Ber. H, Chlo. A, and Bai have weak bacteriostatic actions and do not reach their effective inhibitory concentrations in rabbit body fluids, and their heat-clearing and detoxicating functions are independent on the bacteriostatic actions.展开更多
The amino acids are necessarily nutritious components, their diffusions in body fluid and blood that be- long to typical non-Newtonian fluid are of virtual importance to control the diffusive process and help clinical...The amino acids are necessarily nutritious components, their diffusions in body fluid and blood that be- long to typical non-Newtonian fluid are of virtual importance to control the diffusive process and help clinical treatment. In this article, a holographic interferometer has been adopted to measure the diffusivity of amino acids in non-Newtonian fluid with the use of real-time holographic interference technique. In order to prove the reliability of the experimental instrument, the diffusivities of sucrose aqueous solution at 298.15K were determined. The meas- ured result displays a satisfactory accuracy of the apparatus used. Furthermore, the diffusion coefficients of glynine, L-serine, L-threonine and L-valine in polyacrylamide (PAM) aqueous solution at 298.15K were measured, respec- tively. The experimental data were fitted by a newly proposed correlation equation based on Li’s predictive model. The calculating results by the present model are at considerably good agreement with experimental values, and the maximum average deviation is only 0.5%.展开更多
A rapid method to determine glutamic acid (Glu) in cerebrospinal fluid (CSF) by capillaryelectrophoresis with high frequency conductivity detection (contactless conductivity detection) wasdescribed. The CSF sample was...A rapid method to determine glutamic acid (Glu) in cerebrospinal fluid (CSF) by capillaryelectrophoresis with high frequency conductivity detection (contactless conductivity detection) wasdescribed. The CSF sample was pretreated with silver cation resin to remove high concentration ofCl- ions in CSF. The separation was achieved in the buffer solution of 10 mmol/L Tris and 8mmol/L boric acid at the separation voltage of 20.0 kV. Glu showed linear response in the range of5.0×10-6 to 6.0×10-3 mol/L, the limit of detection was 1.0×10-6 mol/L. The method was used foranalysis Glu in CSF satisfactorily with a recovery of 97.8-98.8%.展开更多
Fluid coking on micro-spherical particles with acid sites on them could produce more light oils from Tahe AR.The conversion rate could increase by about 20% on the catalyst B compared to that obtained on the catalyst ...Fluid coking on micro-spherical particles with acid sites on them could produce more light oils from Tahe AR.The conversion rate could increase by about 20% on the catalyst B compared to that obtained on the catalyst A and the light oil yield could increase by about 12%.The yield of gasoline and diesel was more than 50% from Tahe AR over the catalyst B.Tests on acidity of the catalyst B by pyridine FT-IR spectrometry showed that the total acid content and the ratio of weak acid number to total acid number were higher than other catalysts.展开更多
Objective To probe into the mechanism on acupuncture treatment for brain injury. Methods Thirty cases of acute craniocerebral injury were divided into two groups according to the sequence of visiting. In the control ...Objective To probe into the mechanism on acupuncture treatment for brain injury. Methods Thirty cases of acute craniocerebral injury were divided into two groups according to the sequence of visiting. In the control （15 cases）, the routine western medicine was applied. In the experimental group （15 cases）, on the basis of routine western medicine, acupuncture was applied on Neiguan （ 内关 PC 6） and Zusanli （足三时 ST 36）. Before the treatment and on the 1^st and 5^th days after the treatment, the contents of aspartic acid （Asp）, glutamic acid （Glu） and 7-amino butyric acid （GABA） were observed successively and the relevant analysis was done. Results There was no significant difference in the concentrations of Asp, Glu and GABA before and on the 1^st day after the treatment between two groups （P〉0.05）. The difference had not been presented between the concentrations on the 1^st day and before the treatment. But, the difference was significant or very significant between the concentrations on the 5^th days and before the treatment （P〈0.05, P 〈 0.01 ）. In the experimental group, the concentration of Asp in the cerebrospinal fluid was lower obviously compared with that in the control （P〈0.05） and the concentration of GABA was higher compared with the control （P 〈 0.01）. Conclusion Acupuncture lowered the contents of Asp and Glu and increased the level of GABA in the cerebrospinal fluid rapidly so that the excitation and inhibition in the nervous system could be rebalanced. It was further indicated that acupuncture worked on the treatment of craniocerebral injury.展开更多
BACKGROUND： Under normal conditions, excitatory amino acids are dynamically balanced with inhibitory amino acids. Excitatory amino acids have been implicated in perinatal brain injury. OBJECTIVE： To investigate diff...BACKGROUND： Under normal conditions, excitatory amino acids are dynamically balanced with inhibitory amino acids. Excitatory amino acids have been implicated in perinatal brain injury. OBJECTIVE： To investigate differences in the levels of the excitatory amino acids glutamic acid and aspartic acid, and the inhibitory amino acid gamma-aminobutyric acid （GABA） in the cerebrospinal fluid （CSF） of children with spastic cerebral palsy or athetotic cerebral palsy. DESIGN, TIME AND SETTING： Case-control exploratory observation of neurotransmitter in patients. The experiment was performed in the Pediatrics Department of the Second Affiliated Hospital of Changsha Medical College, the Cerebral Palsy Center of Xiangtan Affiliated Hospital of South China University and the Pediatrics Department of Xiangya Hospital, between February 2006 and May 2007. PARTICIPANTS： We selected 27 children with cerebral palsy, including 13 with spastic cerebral palsy and 14 with athetotic cerebral palsy. We selected 10 patients who were not affected by any neurological disease as controls. METHODS： Two mL blood-free CSF was harvested between the third and fourth lumbar vertebrae of each patient after anesthesia, and stored at -70℃. One mL CSF was mixed with 10 mg sulfosalicylic acid and placed in ice-bath for 10 minutes, then centrifuged 2 000 g for 10 minutes. The supernatant was collected for amino acid quantitation. MAIN OUTCOME MEASURES： The concentrations of glutamic acid, aspartic acid and GABA in the CSF were determined by high-performance liquid chromatography and fluorometric method. The correlation of glutamic acid, aspartic acid and GABA levels with muscular tension in children with cerebral palsy was analyzed using linear dependence. RESULTS： The concentration of GABA was significantly lower in both spastic cerebral palsy and athetotic cerebral palsy patients than in the control group （P 〈 0.01）. Glutamic acid and aspartic acid were significantly higher in both cerebral palsy groups than in the control group （P 〈 0.05-0.01）. The concentration of GABA was significantly decreased in spastic cerebral palsy patients compared with the athetotic cerebral palsy group （P 〈 0.05）. Muscular tension was positively correlated with the concentration of glutamic acid in spastic cerebral palsy patients （P 〈 0.05） but there was no significant correlation between aspartic acid or GABA and muscular tension （P 〉 0.05）. CONCLUSION： Spastic cerebral palsy and athetotic cerebral palsy patients exhibit an imbalance of excitatory amino acids and inhibitory amino acids in their CSF： an increase in glutamic acid and aspartic acid, and a decrease in GABA. Amino acid levels are different in the CSF in varied types of cerebral palsy.展开更多
To elucidate the correlation between excitatory amino acids (EAA) and spinal cord injury, we investigat-ed the dynamic changes in excitatory amino acids, aspartate (Asp) and glutamate (Gin ) contents in cerebrospinalf...To elucidate the correlation between excitatory amino acids (EAA) and spinal cord injury, we investigat-ed the dynamic changes in excitatory amino acids, aspartate (Asp) and glutamate (Gin ) contents in cerebrospinalfluid (CSF) of 26 patients with acute spinal cord injury by amino acids autoanalyzer. The results showed that con-tent of glutanlate and aspartate was renlarkably elevated in 24 h after trauma and was related to the seventy of injury. The more severe the spinal cord injured, the more remarkable the content of Asp and Gin in CSF increased.The more pronounced the content of EAA in CSF increased, the worse the patient’s prognosis was. Content of EAA in CSF after spinal cord injury may be an indicator to judge injury extent and prognosis. and provide further support for a potential pathophysiological role of EAA in spinal cord injury.展开更多
Investigation of amino acids in hydrothermal systems is of prime importance for the understanding of geochemistry and microbiology of hydrothermal vents and plumes, for carbon and metals global cycles, for metabolism ...Investigation of amino acids in hydrothermal systems is of prime importance for the understanding of geochemistry and microbiology of hydrothermal vents and plumes, for carbon and metals global cycles, for metabolism of some hydrothermal microorganisms and for the origin of life issue. Extensive theoretical and experimental work on amino acids behaviour in hydrothermal fluids has been done, conversely only few data exist on natural samples. Because each hydrothermal vent is unique, the more data we collect the better we will be able to address each of these questions. Usually amino acids in hydrothermal fluids have been measured by HPLC-FLD. The chromatographic separation was at least 26 min and up to 135 min and the required derivatization step may be time consuming, may use harmful chemicals and may be source of contamination. Alternatively, we describe here a method combining quickness (4.5 min), high resolution (10,000), very low LOD (sub-ppb) and without derivatization. Characterisation and separation of 10 relevant proteinogenic underivatized amino acids was achieved by ion-pairing reversed-phase Ultra-high Performance Liquid Chromatography-Electrospray Ionisation-Quadrupole Time of Flight-Mass Spectrometry (UPLC-ESI-QTOF-MS). Excellent linearity in the response was obtained for all amino acids with correlation coefficients > 0.9921. This method was successfully applied to natural hydrothermal fluid samples from ultramafic-hosted vents of the Mid-Atlantic Ridge region. Results are consistent with the only 2 other studies published on ultramafic-hosted vents and complete the few available data.展开更多
The amino acids are necessarily nutritious components, their diffusions in body fluid and blood that belong to typical non-Newtonian fluid are of virtual importance to control the diffusive process and help clini...The amino acids are necessarily nutritious components, their diffusions in body fluid and blood that belong to typical non-Newtonian fluid are of virtual importance to control the diffusive process and help clinical treatment. In this article, a holographic interferometer has been adopted to measure the diffusivity of amino acids in non-Newtonian fluid with the use of real-time holographic interference technique. In order to prove the reliability of the experimental instrument, the diffusivities of sucrose aqueous solution at 298.15K were determined. The meas- ured result displays a satisfactory accuracy of the apparatus used. Furthermore, the diffusion coefficients of glynine, L-serine, L-threonine and L-valine in polyacrylamide （PAM） aqueous solution at 298.15K were measured, respec- tively. The experimental data were fitted by a newly proposed correlation equation based on Li＇s predictive model. The calculating results by the present model are at considerably good agreement with experimental values, and the maximum average deviation is only 0.5%.展开更多
Meningitis is often associated with cerebral compromise which may be responsible for neurological squeal in nearly half of the survivors. Little is known about the mechanisms of Central Nervous System （CNS） involvem...Meningitis is often associated with cerebral compromise which may be responsible for neurological squeal in nearly half of the survivors. Little is known about the mechanisms of Central Nervous System （CNS） involvement in bacterial meningitis. The present study was undertaken to assess the changes in biochemical parameters including glucose, protein, Sialic Acid （SA） and various enzymes like Aspartate Aminotransferase （AST）, Alanine Aminotransferase （ALT）, Creatine Kinase （CK）, Gamma Glutamyltranspeptidase 7 （GGTP） and Lactate Dehydrogenase （LDH） have been determined in the Cerebrospinal Fluid （CSF） of the meningitis patients （n = 26） and compared with control subjects （n = 26）. Total Protein, CK, SA （P 〈 0.02）, AST （P 〈 0.001） and ALT （P 〈 0.0001） of meningitis patients were significantly higher, whereas, glucose （P 〈 0.05） and Gamma Glutamyltranspeptidase （GGT） （P 〈 0.01 and P 〈 0.05, respectively） were significantly lower than those of the controls. This study suggests that loss of integrity of brain-CSF barriers, sialic acid and enzyme profiles may contribute to the severity and neurological complications of meningitis.展开更多
Coating protects substances such as L-ascorbic acid from natural processes like oxidation. In this study, L-ascorbic acid was coated by fluid bed technology. A pH-dependent polymer was used as a coating material in or...Coating protects substances such as L-ascorbic acid from natural processes like oxidation. In this study, L-ascorbic acid was coated by fluid bed technology. A pH-dependent polymer was used as a coating material in order to release L-ascorbic acid (dissolution above pH 5.5) under conditions closest to the skin’s natural condition. Different techniques were used to determine the coating (SEM and size distribution) and to evaluate the percentage of coated L-ascorbic acid and its diffusion through the skin.展开更多
BACKGROUND A case of neuromyelitis optica spectrum disorder(NMOSD)with positive cerebrospinal fluid(CSF)anti-aquaporin-4 antibody(AQP4-IgG)and anti-glial fibrillary acidic protein IgG(GFAP-IgG)at the time of relapse w...BACKGROUND A case of neuromyelitis optica spectrum disorder(NMOSD)with positive cerebrospinal fluid(CSF)anti-aquaporin-4 antibody(AQP4-IgG)and anti-glial fibrillary acidic protein IgG(GFAP-IgG)at the time of relapse was reported.The exact roles of GFAP-IgG in NMOSD are not fully understood and are the subject of ongoing research.This study revealed the possible connection between GFAPIgG and the occurrence or development of diseases.CASE SUMMARY A 19-year-old woman was admitted to the hospital due to a constellation of symptoms,including dizziness,nausea,and vomiting that commenced 1 year prior,reoccurred 2 mo ago,and were accompanied by visual blurring that also began 2 mo ago.Additionally,she presented with slurred speech and ptosis,both of which emerged 1 mo ago.Notably,her symptoms deteriorated 10 d prior to admission,leading to the onset of arm and leg weakness.During hospitalization,magnetic resonance imaging showed high T2-fluid attenuated inversion recovery signals,and slightly high and equal diffusion-weighted imaging signals.The serum antibody of AQP4-IgG tested positive at a dilution of 1:100.CSF antibody testing showed positive results for GFAP-IgG at a dilution of 1:10 and AQP4-IgG at a dilution of 1:32.Based on these findings,the patient was diagnosed with NMOSD.She received intravenous methylprednisolone at a daily dose of 500 mg for 5 d,followed by a tapering-off period.Afterward,the rate of reduction was gradually slowed down and the timely use of immunosuppressants was implemented.CONCLUSION The CFS was slightly GFAP-IgG-positive during the relapse period,which can aid in the diagnosis and treatment of the disease.展开更多
基金supported by the Natural Science Foundation of China(No.41902045,41702249)the Strategic Priority Research Program of the Chinese Academy of Sciences,Grant No.XDA14010401.
文摘Through the long development processes of reservoir sedimentation and diagenesis, acidic and alkaline fluids play key roles in controlling deep reservoir development. However, the ways in which deep fluids control and transform the reservoir under complex fault conditions remain unclear. In this study, a 2D model was established based on a typical sub-salt to intra-salt vertical profile in the Qaidam Basin, China. Based on measured data, multiphase flow reaction and solute transport simulation technology were used to analyze fluids flow and migration in the intra-salt and sub-salt reservoirs, determine the mineral dissolution, precipitation, and transformation in the reservoir caused by the deep fluids, and calculate the changes in reservoir porosity. Results show that deep fluid migrates preferentially along dominant channels and triggers a series of fluid–rock chemical reactions. In the first stage, a large amount of anhydrite precipitated in the fault as a result of upward migration of deep saline fluid, resulting in the formation of anhydrite veins and blockage at the base of the fault. In the second stage, organic acids caused minerals dissolution and a vertical channel was opened in previously blocked area, which promoted continuous upward migration of organic acids and the formation of secondary pores. This study clarifies the transformative effects of deep alkaline and acidic fluids on the reservoir. Moreover, the important fluid transport role of faults and their effect on reservoir development were determined.
基金financial support from the Key Project of the National Natural Science Foundation of China(No.52034010)the China Scholarship Council(201906450038)
文摘This work mainly studies the effect of fluid phase momentum transfer mechanisms on the acidizing results,including the retardation effect of the porous structure and the interaction between the fluid phase,such as viscous dissipation and inertial effect.The results show that the acid fluid momentum transfer is influenced by the complex porous structure and fluid viscous dissipation.Eventually,the Stokes-Darcy equation is recommended to be adopted to describe the fluid phase momentum transfer in the following numerical simulation studies of the carbonate acidizing process.Based on this model,a parametric research is carried out to investigate the impact of acid on rock physical characteristics in the stimulation process.Increasing the acid concentration appears to minimize the quantity of acid consumed for the breakthrough.The acid surface reaction rate has a considerable impact on the pore volume to breakthrough and the optimum acid injection rate.The influence of permeability on the acidizing results basically shows a negative correlation with the injection rate.The difference between the acidizing curves of different permeability gradually becomes insignificant with the decrease in injection rate.The existence of isolated fracture and vug significantly reduces acid consumption for the breakthrough.
基金the financial support from China Postdoctoral Science Foundation(2018M643205)
文摘Tea is a widely consumed beverage and has many important physiological properties and potential health benefits. In this study, a novel method based on supercritical fluid chromatography coupled with mass spectrometry (SFC-MS) was developed to simultaneously determine 11 amino acids in different types of tea (green teas, Oolong tea, black tea and Pu-erh tea). The separation conditions for the analysis of the selected amino acids including the column type, temperature and backpressure as well as the type of additive, were carefully optimized. The best separation of the 11 amino acids was obtained by adding water (5%, v/v) and trifluoroacetic acid (0.4%, v/v) to the organic modifier (methanol). Finally, the developed SFC-MS method was fully validated and successfully applied to the determination of these amino acids in six different tea samples. Good linearity (r ≥ 0.993), precision (RSDs≤ 2.99%), accuracy (91.95%-107.09%) as well as good sample stability were observed. The limits of detection ranged from 1.42 to 14.69 ng/mL, while the limits of quantification were between 4.53 and 47.0 ng/mL. The results indicate that the contents of the 11 amino acids in the six different tea samples are greatly influenced by the degree of fermentation. The proposed SFC-MS method shows a great potential for further investigation of tea varieties.
基金supported by a grant from Beijing Natural Science Foundation, China (6021001)agrant from Learning Innovative Group Programs of Beijing Education Committee, China (5090245)
文摘To explore the relationship between the heat-clearing and detoxicating functions and the bacteriostatic actions of berberine hydrochloride （Ber. H）, chlorogenic acid （Chlo. A）, and baicalin （Bai）, their concentrations in rabbit body fluid were compared with their minimal inhibitory concentrations （MICs）. Their concentrations in rabbit blood and tissue fluid were determined by reversed-phase high performance liquid chromatography, and their MICs to Escherichia coli were determined by tube dilution method. The results showed that the peak concentrations of Ber. H, Chlo. A, and Bai in rabbit blood were 3.2, 5.03, and 7.63 μg mL^-1, and in rabbit tissue fluid were 0.12, 0.11, and 0.12 μg mL^-1, respectively. Their MICs to E. coli were, respectively, 1.0×10^3, 3.75 × 10^3, and 6.75 ×10^3μg mL^-1, which were far higher than the concentrations in rabbit body fluids. This study indicates that Ber. H, Chlo. A, and Bai have weak bacteriostatic actions and do not reach their effective inhibitory concentrations in rabbit body fluids, and their heat-clearing and detoxicating functions are independent on the bacteriostatic actions.
基金Supported by the National Natural Science Foundation of China (No.20476073).
文摘The amino acids are necessarily nutritious components, their diffusions in body fluid and blood that be- long to typical non-Newtonian fluid are of virtual importance to control the diffusive process and help clinical treatment. In this article, a holographic interferometer has been adopted to measure the diffusivity of amino acids in non-Newtonian fluid with the use of real-time holographic interference technique. In order to prove the reliability of the experimental instrument, the diffusivities of sucrose aqueous solution at 298.15K were determined. The meas- ured result displays a satisfactory accuracy of the apparatus used. Furthermore, the diffusion coefficients of glynine, L-serine, L-threonine and L-valine in polyacrylamide (PAM) aqueous solution at 298.15K were measured, respec- tively. The experimental data were fitted by a newly proposed correlation equation based on Li’s predictive model. The calculating results by the present model are at considerably good agreement with experimental values, and the maximum average deviation is only 0.5%.
基金This project was supported by the Guangdong Provincial Foundation of Natural Science(021808)
文摘A rapid method to determine glutamic acid (Glu) in cerebrospinal fluid (CSF) by capillaryelectrophoresis with high frequency conductivity detection (contactless conductivity detection) wasdescribed. The CSF sample was pretreated with silver cation resin to remove high concentration ofCl- ions in CSF. The separation was achieved in the buffer solution of 10 mmol/L Tris and 8mmol/L boric acid at the separation voltage of 20.0 kV. Glu showed linear response in the range of5.0×10-6 to 6.0×10-3 mol/L, the limit of detection was 1.0×10-6 mol/L. The method was used foranalysis Glu in CSF satisfactorily with a recovery of 97.8-98.8%.
文摘Fluid coking on micro-spherical particles with acid sites on them could produce more light oils from Tahe AR.The conversion rate could increase by about 20% on the catalyst B compared to that obtained on the catalyst A and the light oil yield could increase by about 12%.The yield of gasoline and diesel was more than 50% from Tahe AR over the catalyst B.Tests on acidity of the catalyst B by pyridine FT-IR spectrometry showed that the total acid content and the ratio of weak acid number to total acid number were higher than other catalysts.
文摘Objective To probe into the mechanism on acupuncture treatment for brain injury. Methods Thirty cases of acute craniocerebral injury were divided into two groups according to the sequence of visiting. In the control （15 cases）, the routine western medicine was applied. In the experimental group （15 cases）, on the basis of routine western medicine, acupuncture was applied on Neiguan （ 内关 PC 6） and Zusanli （足三时 ST 36）. Before the treatment and on the 1^st and 5^th days after the treatment, the contents of aspartic acid （Asp）, glutamic acid （Glu） and 7-amino butyric acid （GABA） were observed successively and the relevant analysis was done. Results There was no significant difference in the concentrations of Asp, Glu and GABA before and on the 1^st day after the treatment between two groups （P〉0.05）. The difference had not been presented between the concentrations on the 1^st day and before the treatment. But, the difference was significant or very significant between the concentrations on the 5^th days and before the treatment （P〈0.05, P 〈 0.01 ）. In the experimental group, the concentration of Asp in the cerebrospinal fluid was lower obviously compared with that in the control （P〈0.05） and the concentration of GABA was higher compared with the control （P 〈 0.01）. Conclusion Acupuncture lowered the contents of Asp and Glu and increased the level of GABA in the cerebrospinal fluid rapidly so that the excitation and inhibition in the nervous system could be rebalanced. It was further indicated that acupuncture worked on the treatment of craniocerebral injury.
基金a grant from Health Department of Hunan Province,No.B2006-204
文摘BACKGROUND： Under normal conditions, excitatory amino acids are dynamically balanced with inhibitory amino acids. Excitatory amino acids have been implicated in perinatal brain injury. OBJECTIVE： To investigate differences in the levels of the excitatory amino acids glutamic acid and aspartic acid, and the inhibitory amino acid gamma-aminobutyric acid （GABA） in the cerebrospinal fluid （CSF） of children with spastic cerebral palsy or athetotic cerebral palsy. DESIGN, TIME AND SETTING： Case-control exploratory observation of neurotransmitter in patients. The experiment was performed in the Pediatrics Department of the Second Affiliated Hospital of Changsha Medical College, the Cerebral Palsy Center of Xiangtan Affiliated Hospital of South China University and the Pediatrics Department of Xiangya Hospital, between February 2006 and May 2007. PARTICIPANTS： We selected 27 children with cerebral palsy, including 13 with spastic cerebral palsy and 14 with athetotic cerebral palsy. We selected 10 patients who were not affected by any neurological disease as controls. METHODS： Two mL blood-free CSF was harvested between the third and fourth lumbar vertebrae of each patient after anesthesia, and stored at -70℃. One mL CSF was mixed with 10 mg sulfosalicylic acid and placed in ice-bath for 10 minutes, then centrifuged 2 000 g for 10 minutes. The supernatant was collected for amino acid quantitation. MAIN OUTCOME MEASURES： The concentrations of glutamic acid, aspartic acid and GABA in the CSF were determined by high-performance liquid chromatography and fluorometric method. The correlation of glutamic acid, aspartic acid and GABA levels with muscular tension in children with cerebral palsy was analyzed using linear dependence. RESULTS： The concentration of GABA was significantly lower in both spastic cerebral palsy and athetotic cerebral palsy patients than in the control group （P 〈 0.01）. Glutamic acid and aspartic acid were significantly higher in both cerebral palsy groups than in the control group （P 〈 0.05-0.01）. The concentration of GABA was significantly decreased in spastic cerebral palsy patients compared with the athetotic cerebral palsy group （P 〈 0.05）. Muscular tension was positively correlated with the concentration of glutamic acid in spastic cerebral palsy patients （P 〈 0.05） but there was no significant correlation between aspartic acid or GABA and muscular tension （P 〉 0.05）. CONCLUSION： Spastic cerebral palsy and athetotic cerebral palsy patients exhibit an imbalance of excitatory amino acids and inhibitory amino acids in their CSF： an increase in glutamic acid and aspartic acid, and a decrease in GABA. Amino acid levels are different in the CSF in varied types of cerebral palsy.
文摘To elucidate the correlation between excitatory amino acids (EAA) and spinal cord injury, we investigat-ed the dynamic changes in excitatory amino acids, aspartate (Asp) and glutamate (Gin ) contents in cerebrospinalfluid (CSF) of 26 patients with acute spinal cord injury by amino acids autoanalyzer. The results showed that con-tent of glutanlate and aspartate was renlarkably elevated in 24 h after trauma and was related to the seventy of injury. The more severe the spinal cord injured, the more remarkable the content of Asp and Gin in CSF increased.The more pronounced the content of EAA in CSF increased, the worse the patient’s prognosis was. Content of EAA in CSF after spinal cord injury may be an indicator to judge injury extent and prognosis. and provide further support for a potential pathophysiological role of EAA in spinal cord injury.
文摘Investigation of amino acids in hydrothermal systems is of prime importance for the understanding of geochemistry and microbiology of hydrothermal vents and plumes, for carbon and metals global cycles, for metabolism of some hydrothermal microorganisms and for the origin of life issue. Extensive theoretical and experimental work on amino acids behaviour in hydrothermal fluids has been done, conversely only few data exist on natural samples. Because each hydrothermal vent is unique, the more data we collect the better we will be able to address each of these questions. Usually amino acids in hydrothermal fluids have been measured by HPLC-FLD. The chromatographic separation was at least 26 min and up to 135 min and the required derivatization step may be time consuming, may use harmful chemicals and may be source of contamination. Alternatively, we describe here a method combining quickness (4.5 min), high resolution (10,000), very low LOD (sub-ppb) and without derivatization. Characterisation and separation of 10 relevant proteinogenic underivatized amino acids was achieved by ion-pairing reversed-phase Ultra-high Performance Liquid Chromatography-Electrospray Ionisation-Quadrupole Time of Flight-Mass Spectrometry (UPLC-ESI-QTOF-MS). Excellent linearity in the response was obtained for all amino acids with correlation coefficients > 0.9921. This method was successfully applied to natural hydrothermal fluid samples from ultramafic-hosted vents of the Mid-Atlantic Ridge region. Results are consistent with the only 2 other studies published on ultramafic-hosted vents and complete the few available data.
基金the National Natural Science Foundation of China （No.20476073）.
文摘The amino acids are necessarily nutritious components, their diffusions in body fluid and blood that belong to typical non-Newtonian fluid are of virtual importance to control the diffusive process and help clinical treatment. In this article, a holographic interferometer has been adopted to measure the diffusivity of amino acids in non-Newtonian fluid with the use of real-time holographic interference technique. In order to prove the reliability of the experimental instrument, the diffusivities of sucrose aqueous solution at 298.15K were determined. The meas- ured result displays a satisfactory accuracy of the apparatus used. Furthermore, the diffusion coefficients of glynine, L-serine, L-threonine and L-valine in polyacrylamide （PAM） aqueous solution at 298.15K were measured, respec- tively. The experimental data were fitted by a newly proposed correlation equation based on Li＇s predictive model. The calculating results by the present model are at considerably good agreement with experimental values, and the maximum average deviation is only 0.5%.
文摘Meningitis is often associated with cerebral compromise which may be responsible for neurological squeal in nearly half of the survivors. Little is known about the mechanisms of Central Nervous System （CNS） involvement in bacterial meningitis. The present study was undertaken to assess the changes in biochemical parameters including glucose, protein, Sialic Acid （SA） and various enzymes like Aspartate Aminotransferase （AST）, Alanine Aminotransferase （ALT）, Creatine Kinase （CK）, Gamma Glutamyltranspeptidase 7 （GGTP） and Lactate Dehydrogenase （LDH） have been determined in the Cerebrospinal Fluid （CSF） of the meningitis patients （n = 26） and compared with control subjects （n = 26）. Total Protein, CK, SA （P 〈 0.02）, AST （P 〈 0.001） and ALT （P 〈 0.0001） of meningitis patients were significantly higher, whereas, glucose （P 〈 0.05） and Gamma Glutamyltranspeptidase （GGT） （P 〈 0.01 and P 〈 0.05, respectively） were significantly lower than those of the controls. This study suggests that loss of integrity of brain-CSF barriers, sialic acid and enzyme profiles may contribute to the severity and neurological complications of meningitis.
文摘Coating protects substances such as L-ascorbic acid from natural processes like oxidation. In this study, L-ascorbic acid was coated by fluid bed technology. A pH-dependent polymer was used as a coating material in order to release L-ascorbic acid (dissolution above pH 5.5) under conditions closest to the skin’s natural condition. Different techniques were used to determine the coating (SEM and size distribution) and to evaluate the percentage of coated L-ascorbic acid and its diffusion through the skin.
基金Hospital Level Project of Jiaxing First Hospital,No.2022-YB-034.
文摘BACKGROUND A case of neuromyelitis optica spectrum disorder(NMOSD)with positive cerebrospinal fluid(CSF)anti-aquaporin-4 antibody(AQP4-IgG)and anti-glial fibrillary acidic protein IgG(GFAP-IgG)at the time of relapse was reported.The exact roles of GFAP-IgG in NMOSD are not fully understood and are the subject of ongoing research.This study revealed the possible connection between GFAPIgG and the occurrence or development of diseases.CASE SUMMARY A 19-year-old woman was admitted to the hospital due to a constellation of symptoms,including dizziness,nausea,and vomiting that commenced 1 year prior,reoccurred 2 mo ago,and were accompanied by visual blurring that also began 2 mo ago.Additionally,she presented with slurred speech and ptosis,both of which emerged 1 mo ago.Notably,her symptoms deteriorated 10 d prior to admission,leading to the onset of arm and leg weakness.During hospitalization,magnetic resonance imaging showed high T2-fluid attenuated inversion recovery signals,and slightly high and equal diffusion-weighted imaging signals.The serum antibody of AQP4-IgG tested positive at a dilution of 1:100.CSF antibody testing showed positive results for GFAP-IgG at a dilution of 1:10 and AQP4-IgG at a dilution of 1:32.Based on these findings,the patient was diagnosed with NMOSD.She received intravenous methylprednisolone at a daily dose of 500 mg for 5 d,followed by a tapering-off period.Afterward,the rate of reduction was gradually slowed down and the timely use of immunosuppressants was implemented.CONCLUSION The CFS was slightly GFAP-IgG-positive during the relapse period,which can aid in the diagnosis and treatment of the disease.
