Background The present study aimed to investigate the detailed mode and specific sites for their binding as well as the functional relevance of this binding in the phenotypic proliferation of vascular smooth muscle ce...Background The present study aimed to investigate the detailed mode and specific sites for their binding as well as the functional relevance of this binding in the phenotypic proliferation of vascular smooth muscle cells(SMCs). Methods CREG knocked-down SMCs were employed to evaluate the biological activity of wtCREG and mCREG.Expressions of SMC differentiation markers SM myosin heavy chain(SM-MHC),SM-actin,heavy caldesmon and myocardin were determined by Western blotting using specific antibodies. Cellular growth of SMCs was assessed by bromide dewuridine (BrdU) incorporation and cell cycle analysis on fluorescence-activated cell sorting(FACS).A solid-phase binding assay was used to study the binding of CREG to extracellular domains of M6P/IGF2R.The cellular co-localization of the two recombinant CREGs with M6P/IGF2R was detected on SMC surface by immunoprecipitation and immunofluorescence analysis.Results The molecular weight of wtCREG was around 30 kD while that of the mCREG was～25 kD.Treatment of wtCREG with PNGase F reduced its molecular weight from～30 kD to～25 kD,whereas PNGase F treatment had no effect on the molecular weight of mCREG.Both wtCREG and mCREG proteins enhanced SMC differentiation,inhibited BrdU incorporation,and arrested cell cycle progression when added to the culture medium.In CREG knocked-down SMCs,the amount of CREG detected by immunoblotting in M6P/IGF2R immunoprecipitates was significantly reduced when compared to normal cells.Both recombinant CREGs co-immunoprecipitated with M6P/IGF2R, although slightly reduced amount of the mutant CREG was detected in M6P/IGF2R immunoprecipitates.Immunostaining revealed that His-tagged CREGs co-localized with IGF2R on the cell surface in a glycosylation-independent manner.In vitro binding assay showed that CREGs bound to M6P/ IGF2R extracellular domains 7-10 and 11-13 in a glycosylation -dependent and -independent manner,respectively.Further blocking experiments using soluble M6P/IGF2R fragments and M6P/IGF2R neutralizing antibody indicated that the biological activities of recombinant CREGs in SMC growth and the up-regulation of SMC differentiation markers were all abolished by treatment with the M6P/IGF2R neutralizing antibody. However,although the growth inhibitory effect of wtCREG was nearly abolished by D7-10 or D11-13,the effect of mCREG was only reversed by Dll-13,indicating that the binding to domains 11-13 is required for CREG to modulate the proliferation of SMCs.Conclusions These data suggest that solubleCREG proteins can exert their biological function via binding to the extracellular domains 7-10 and 11-13 of cell surface M6P/IGF2R in both a glycosylation-dependent and -independent manner.展开更多
BACKGROUND Previous studies have suggested that the costimulatory molecule 4-1BB plays pivotal roles in regulating immunity during chronic viral infection.However,up to now,there are few studies about 4-1BB in chronic...BACKGROUND Previous studies have suggested that the costimulatory molecule 4-1BB plays pivotal roles in regulating immunity during chronic viral infection.However,up to now,there are few studies about 4-1BB in chronic hepatitis B(CHB).AIM To clarify this issue,we report our comprehensive study results on the expression levels of 4-1BB in patients with CHB.METHODS From September 2018 to June 2019,a total of 64 patients with CHB were recruited from the Department of Hepatology,The First Hospital of Jilin University.Peripheral blood samples were collected from 52 treatment-naïve and 12 entecavir-treated patients with CHB as well as 37 healthy donors(including 24 healthy adults and 13 healthy children).The levels of soluble 4-1BB(s4-1BB)in plasma were measured by ELISA.4-1BB mRNA expression in peripheral blood mononuclear cells was detected by real-time quantitative PCR.RESULTS The s4-1BB levels in the plasma of patients with CHB were significantly higher than those in healthy adults(94.390±7.393 ng/mL vs 8.875±0.914 ng/mL,P<0.001).In addition,the s4-1BB level in plasma was significantly increased in patients with a higher viral load and a disease flare up.However,there were no significant differences between treatment-naïve and entecavir-treated patients.Interestingly,among treatment-naïve patients with CHB,the levels of s4-1BB in plasma had a significant positive correlation with hepatitis B surface antigen,hepatitis B virus DNA,hepatitis B e antigen,and triglyceride levels(r=0.748,P<0.001;r=0.406,P=0.004;r=0.356,P=0.019 and r=-0.469,P=0.007,respectively).The 4-1BB mRNA expression was higher in the peripheral blood mononuclear cells of patients with CHB than in the peripheral blood mononuclear cells of healthy adults,but the difference was not statistically significant.CONCLUSION These results suggest that the levels of s4-1BB may be associated with pathogenesis of hepatitis B virus and therefore may be a promising biomarker for disease progression.展开更多
Aggregate amyloid beta protein1-42 (Aβ1-42) can typically be found in the early stage of Alzheimer’s disease (AD). Aβ1-42 self-assembles and is highly toxic to neurons. Thus, recognizing aggregated Aβ1-42 is very ...Aggregate amyloid beta protein1-42 (Aβ1-42) can typically be found in the early stage of Alzheimer’s disease (AD). Aβ1-42 self-assembles and is highly toxic to neurons. Thus, recognizing aggregated Aβ1-42 is very important for elucidation of Aβ1-42 structure and for the diagnosis of AD. In this study, the specificity of the 79-3 monoclonal antibody against soluble aggre- gate Aβ1-42 was measured by sandwich Enzyme-Linked Immuno Sorbent Assay (ELISA). Eight monoclonal antibodies against both soluble aggregates and amorphous aggregates were used as primary antibodies. Soluble aggregates and amorphous aggregates were used as antigen. As secondary antibody, HRP was labeled with the 79-3 monoclonal antibody. The reactivity of the 79-3 monoclonal antibody against soluble aggregates was confirmed in all combinations, but little reactivity against amorphous aggregates was found. Furthermore, we performed the above sandwich ELISA using the 37-11 antibody, which is reactive against large oval aggregates (LOA) that occur in micro aggregates, instead of the 79-3 antibody. The 77-3 antibody is 1 of the 8 monoclonal antibodies against soluble aggregates;amorphous aggregates also reacted with the 37-11 antibody. These results indicated that soluble aggregates are specifically recognized by a combination of different antibodies. The combined use of these antibodies can be applied to the diagnosis of AD and to defining the structure of the Aβ1-42.展开更多
（S）-（＋）-2,2-dimethylcyclopropane carbox amide is a key intermediate of Cilastatin, an inhibitor of dehydropeptidase-I. Its corresponding solid-liquid equilibrium data will provide essential support for industrial...（S）-（＋）-2,2-dimethylcyclopropane carbox amide is a key intermediate of Cilastatin, an inhibitor of dehydropeptidase-I. Its corresponding solid-liquid equilibrium data will provide essential support for industrial design and further theoretical studies. The solubilities of （S）-（＋）-2,2-dimethylcyclopropane carbox amide in toluene, dichloromethane, trichloromethane, ethyl acetate, ethanol and pure water at different temperature were measured using the synthetic method by a laser monitoring observation technique. The solubility data were correlated with the modified Apelblat equation.The calculated values were good in agreement with the experimental values.展开更多
(S)-(+)-2,2-dimethylcyclopropane carbox amide is a key intermediate of Cilastatin, an inhibitor of de- hydropeptidase-I. Its corresponding solid-liquid equilibrium data will provide essential support for industrial de...(S)-(+)-2,2-dimethylcyclopropane carbox amide is a key intermediate of Cilastatin, an inhibitor of de- hydropeptidase-I. Its corresponding solid-liquid equilibrium data will provide essential support for industrial design and further theoretical studies. The solubilities of (S)-(+)-2,2-dimethylcyclopropane carbox amide in toluene, di- chloromethane, trichloromethane, ethyl acetate, ethanol and pure water at different temperature were measured us- ing the synthetic method by a laser monitoring observation technique. The solubility data were correlated with the modified Apelblat equation. The calculated values were good in agreement with the experimental values.展开更多
Solubilities of 2,4-dichlorobenzaldehyde in five single organic solvents,namely,n-propanol,n-butanol.cyclohexane,chloroform and dichloromethane as well as in two mixed solvents,namely,cyclohexane-acetone and cyclohexa...Solubilities of 2,4-dichlorobenzaldehyde in five single organic solvents,namely,n-propanol,n-butanol.cyclohexane,chloroform and dichloromethane as well as in two mixed solvents,namely,cyclohexane-acetone and cyclohexane n-butanol,have been measured.These data are correlated withWilson,NRTL and UNIQUAC activity coefficient models and can be used for the process design inthe purification of 2,4-dichlorobenzaldehyde.展开更多
Nonaqueous amine-based system is an attractive solution to overcome high-energy-intensive CO_(2) capture process using the conventional aqueous amines.Advanced nonaqueous absorbent of 2-(butylamino)ethanol(BAE)with 2-...Nonaqueous amine-based system is an attractive solution to overcome high-energy-intensive CO_(2) capture process using the conventional aqueous amines.Advanced nonaqueous absorbent of 2-(butylamino)ethanol(BAE)with 2-butoxyethanol(2-BE)has been recently proposed for low-energyconsumption CO_(2) capture.In this work,Henry’s law constants of CO_(2) in the BAE/2-BE blend were obtained by N_(2)O/CO_(2) analogy,and correlated in the temperature range of(283–333)K.Vapor-liquid equilibrium(VLE)data for the BAE+CO_(2)+2-BE system at 65.4%(mass)BAE were also determined in a stirred equilibrium cell at temperatures of(313–393)K and CO_(2) partial pressures up to 275 kPa.A single apparent equilibrium constant KCO_(2);app was proposed for this system and correlated as a function of temperature,carbonated degree of amine and CO_(2) loading.Solubility data were well represented by the modified Kent-Eisenberg model with an average absolute relative deviation(AARD)of 13%.展开更多
A series of novel 2-（1-substituted-1,11-undecylidene）-5-arylimino-△^3-1,3,4-thiadiazolines （4） were synthesized and their structure was characterized by ^1H NMR, ^13C NMR and elemental analysis. Their solubility ...A series of novel 2-（1-substituted-1,11-undecylidene）-5-arylimino-△^3-1,3,4-thiadiazolines （4） were synthesized and their structure was characterized by ^1H NMR, ^13C NMR and elemental analysis. Their solubility in both polar and non-polar solvents is significantly improved owing to the introduction of ethyl or methylthio group at cyclododecyl ring as compared with parent compounds [1, 2-（1,11-undecylidene）-5-arylimino-△^3-1,3,4-thiadiazolines]. However, their fungicidal activity against Rhizoctonia solani is less than that of parent compounds. X-ray diffraction analysis of a representative compound （4d） showed that the conformation of 12-membered ring is still [3333], in which the ethyl group present at the side-exo position and the thiadiazoline ring at the comer carbon. The thiadiazoline plane is perpendicular to the cyclododecyl one.展开更多
Two kinds of Nd 1+ x Ba 2- x Cu 3O 7- δ , the sintered samples and zone melted samples, were treated in pure Ar at 950 ℃. The substitution of Nd ions for Ba ions in the Nd 1+ x Ba 2- ...Two kinds of Nd 1+ x Ba 2- x Cu 3O 7- δ , the sintered samples and zone melted samples, were treated in pure Ar at 950 ℃. The substitution of Nd ions for Ba ions in the Nd 1+ x Ba 2- x Cu 3O 7- δ before and after the heat treatment was investigated by XRD. In order to know the effects of heat treatment, the T c and J c of samples with and without the heat treatment in Ar were comparatively studied. The results show that the substitution of Nd for Ba decreases, whereas T c and J c increase after the treatment. The Nd 1+ x Ba 2- x Cu 3O 7- δ samples were oxygenated in pure oxygen at 300 ℃ . Based on the XRD spectra it was found that the samples with x <0.4 can transform from tetragonal phase into orthorhombic phase after the oxygenation, whereas in the sample with x >0.4 no phase transition occurs even after a long time oxygenation.展开更多
Enhancing the dispersion and dissolution of substrate particles in substrate water suspension is a feasible way to improve steroid bioconversion. The aim of the present study is to investigate the effects of applying ...Enhancing the dispersion and dissolution of substrate particles in substrate water suspension is a feasible way to improve steroid bioconversion. The aim of the present study is to investigate the effects of applying surfactant to microbial conversion system on the dispersion, solubilization and in turn bioconversion of steroid substrate. The model system is hydroxylation of substrate 19α- 17α-epoxy- 4-pregnene- 3.2It-dine by microbial enzymes from Rhizopus nigricanl. The results show that the presence of substrate leads to an increase in critical micelle concentration （ CMC） of surfactant PSE compared with the normal CMC of PSE in aqueous solution. The grinding time during substrate suspension preparation affects the substrate aqueous solubility differently with the varied surfactant concentrations while barely making any difference in substrate solubility in the absence of surfactant. The properly prolonged grinding time can make up for the loss in substrate solubility arising from the reduction in surfactant concentration. The surfactant complexes composed of surfactants PSE and MGE at appropriate ratios are screened out with orthodoxy experiment method. the interaction between PSE and MGE exerts the most prominent effects on substrate bioconversion, and the surfactant complexes show more beneficial effects on steroid bioconversion than the surfactant PSE used alone.展开更多
Raising cattle in feedlots is becoming more common in Argentina, but there is little information available about the effects of this practice on soil phosphorus (P) dynamics. In this study, concentrations of water and...Raising cattle in feedlots is becoming more common in Argentina, but there is little information available about the effects of this practice on soil phosphorus (P) dynamics. In this study, concentrations of water and Bray -1 extractable soil P were quantified in a feedlot (upper and lower slope positions in the feedlot pen), runoff area and pasture during 2006 - 2008. The feedlot showed higher P concentrations in all P forms, soluble reactive P, soluble nonreactive, total soluble P, and Bray-P1 when compared to runoff area and pasture. Most of the total soluble P was soluble reactive P from the soil in the feedlot and the runoff area, while soluble nonreactive P predominated in the pasture. Concentrations of total soluble P were elevated in the feedlot at the soil surface, ranging on average from 158.71 to 245.86 mg?P?kg?1, and had a rapid decrease within the first 20 cm and remained relatively low, about 25.53 - 27.33 mg?P?kg?1. The evidence that total soluble P concentration in the feedlot was significantly (p < 0.05) higher than that registered in the pasture at 20 - 40 and 40 - 60 cm soil depth suggests a potential transfer of P through the soil from the surface. Although the feedlot had a moderate increase of 23.05 to 24.55 mg?P?kg?1 from the background concentration, it may represent a long-term source of increased nutrient loading to groundwater. Soil extractable Bray-1 P in the top 0 - 2.5 cm fluctuated from 659.26 to 45.36 mg?P?kg?1 in the feedlot and pasture, respectively. The relationship between soil P extracted by test and TSP was linear, and correlation coefficient was r2 = 0.95.展开更多
4,6-α-Glucanotransferase(4,6-α-GT)converts starch into product with increasedα(1-6)glycosidic bonds ratio,and this product is a new type of soluble dietary fiber with property of escaping small intestine digestion....4,6-α-Glucanotransferase(4,6-α-GT)converts starch into product with increasedα(1-6)glycosidic bonds ratio,and this product is a new type of soluble dietary fiber with property of escaping small intestine digestion.4,6-α-GT gained interest recently because of their potential use in enzymatic synthesis of soluble dietary fiber.In this study,a putative GtfB sequence from Limosilactobacillus fermentum NCC 3057 was identified.This sequence was truncated and expressed in Escherichia coli to obtain the protein L.fermentum NCC 3057 GtfBΔN.GtfBΔN showed optimal activity at 35℃and pH 6.0,and it converted amylose V to isomalto-/maltopolysaccharide(IMMP)with low molecular mass(3.1 kDa).This IMMP product contains 72%α(1-6)glycosidic bonds,and it showed 64%indigestible content in vitro digestion experiment.These results indicate that the product of L.fermentum NCC 3057 GtfBΔN is a soluble dietary fiber.Finally the X-ray crystal structure of GtfBΔN(2.4Å)was resolved.Based on the GtfBΔN structure,we offer an insight about that three loops of domain C may be related to the molecular mass of IMMP product.展开更多
A new soluble polymer on 2-[(2 E)-1-methyl-2-buten-1-yl]aniline and its copolymers with aniline basis have been synthesized in various molar ratios. For all samples, the electrical conductivity, morphology, solubility...A new soluble polymer on 2-[(2 E)-1-methyl-2-buten-1-yl]aniline and its copolymers with aniline basis have been synthesized in various molar ratios. For all samples, the electrical conductivity, morphology, solubility, electrochemical properties, as well as spectral and molecular mass characteristics have been studied, and a comparative analysis with polyaniline has been carried out. The substituent introduced into the aniline aromatic ring significantly improves the solubility in typical organic solvents of a high molecular weight product. The morphology of the test compounds depends on the co-monomer ratio. As the content of the substituted aniline in the initial mixture increases, the morphology of the polymer changes from the inherent polyaniline fibrous microstructure to the globular one with irregular substituted polyaniline shapes and sizes. Electrochemical study of the samples revealed that the higher the oxidation potential, the wider the band gap(ranging from 2.00 to 2.15). The electrical conductivity decreases in proportion to the increase in the substituted aniline concentration of the initial co-monomer mixture and amounts to 12.5–35.7 × 10~6 nSm.展开更多
文摘Background The present study aimed to investigate the detailed mode and specific sites for their binding as well as the functional relevance of this binding in the phenotypic proliferation of vascular smooth muscle cells(SMCs). Methods CREG knocked-down SMCs were employed to evaluate the biological activity of wtCREG and mCREG.Expressions of SMC differentiation markers SM myosin heavy chain(SM-MHC),SM-actin,heavy caldesmon and myocardin were determined by Western blotting using specific antibodies. Cellular growth of SMCs was assessed by bromide dewuridine (BrdU) incorporation and cell cycle analysis on fluorescence-activated cell sorting(FACS).A solid-phase binding assay was used to study the binding of CREG to extracellular domains of M6P/IGF2R.The cellular co-localization of the two recombinant CREGs with M6P/IGF2R was detected on SMC surface by immunoprecipitation and immunofluorescence analysis.Results The molecular weight of wtCREG was around 30 kD while that of the mCREG was～25 kD.Treatment of wtCREG with PNGase F reduced its molecular weight from～30 kD to～25 kD,whereas PNGase F treatment had no effect on the molecular weight of mCREG.Both wtCREG and mCREG proteins enhanced SMC differentiation,inhibited BrdU incorporation,and arrested cell cycle progression when added to the culture medium.In CREG knocked-down SMCs,the amount of CREG detected by immunoblotting in M6P/IGF2R immunoprecipitates was significantly reduced when compared to normal cells.Both recombinant CREGs co-immunoprecipitated with M6P/IGF2R, although slightly reduced amount of the mutant CREG was detected in M6P/IGF2R immunoprecipitates.Immunostaining revealed that His-tagged CREGs co-localized with IGF2R on the cell surface in a glycosylation-independent manner.In vitro binding assay showed that CREGs bound to M6P/ IGF2R extracellular domains 7-10 and 11-13 in a glycosylation -dependent and -independent manner,respectively.Further blocking experiments using soluble M6P/IGF2R fragments and M6P/IGF2R neutralizing antibody indicated that the biological activities of recombinant CREGs in SMC growth and the up-regulation of SMC differentiation markers were all abolished by treatment with the M6P/IGF2R neutralizing antibody. However,although the growth inhibitory effect of wtCREG was nearly abolished by D7-10 or D11-13,the effect of mCREG was only reversed by Dll-13,indicating that the binding to domains 11-13 is required for CREG to modulate the proliferation of SMCs.Conclusions These data suggest that solubleCREG proteins can exert their biological function via binding to the extracellular domains 7-10 and 11-13 of cell surface M6P/IGF2R in both a glycosylation-dependent and -independent manner.
基金Chinese Foundation for Hepatitis Prevention and Control—Tian-Qing Liver Disease Research Fund Subject,No.TQGB20200118.
文摘BACKGROUND Previous studies have suggested that the costimulatory molecule 4-1BB plays pivotal roles in regulating immunity during chronic viral infection.However,up to now,there are few studies about 4-1BB in chronic hepatitis B(CHB).AIM To clarify this issue,we report our comprehensive study results on the expression levels of 4-1BB in patients with CHB.METHODS From September 2018 to June 2019,a total of 64 patients with CHB were recruited from the Department of Hepatology,The First Hospital of Jilin University.Peripheral blood samples were collected from 52 treatment-naïve and 12 entecavir-treated patients with CHB as well as 37 healthy donors(including 24 healthy adults and 13 healthy children).The levels of soluble 4-1BB(s4-1BB)in plasma were measured by ELISA.4-1BB mRNA expression in peripheral blood mononuclear cells was detected by real-time quantitative PCR.RESULTS The s4-1BB levels in the plasma of patients with CHB were significantly higher than those in healthy adults(94.390±7.393 ng/mL vs 8.875±0.914 ng/mL,P<0.001).In addition,the s4-1BB level in plasma was significantly increased in patients with a higher viral load and a disease flare up.However,there were no significant differences between treatment-naïve and entecavir-treated patients.Interestingly,among treatment-naïve patients with CHB,the levels of s4-1BB in plasma had a significant positive correlation with hepatitis B surface antigen,hepatitis B virus DNA,hepatitis B e antigen,and triglyceride levels(r=0.748,P<0.001;r=0.406,P=0.004;r=0.356,P=0.019 and r=-0.469,P=0.007,respectively).The 4-1BB mRNA expression was higher in the peripheral blood mononuclear cells of patients with CHB than in the peripheral blood mononuclear cells of healthy adults,but the difference was not statistically significant.CONCLUSION These results suggest that the levels of s4-1BB may be associated with pathogenesis of hepatitis B virus and therefore may be a promising biomarker for disease progression.
文摘Aggregate amyloid beta protein1-42 (Aβ1-42) can typically be found in the early stage of Alzheimer’s disease (AD). Aβ1-42 self-assembles and is highly toxic to neurons. Thus, recognizing aggregated Aβ1-42 is very important for elucidation of Aβ1-42 structure and for the diagnosis of AD. In this study, the specificity of the 79-3 monoclonal antibody against soluble aggre- gate Aβ1-42 was measured by sandwich Enzyme-Linked Immuno Sorbent Assay (ELISA). Eight monoclonal antibodies against both soluble aggregates and amorphous aggregates were used as primary antibodies. Soluble aggregates and amorphous aggregates were used as antigen. As secondary antibody, HRP was labeled with the 79-3 monoclonal antibody. The reactivity of the 79-3 monoclonal antibody against soluble aggregates was confirmed in all combinations, but little reactivity against amorphous aggregates was found. Furthermore, we performed the above sandwich ELISA using the 37-11 antibody, which is reactive against large oval aggregates (LOA) that occur in micro aggregates, instead of the 79-3 antibody. The 77-3 antibody is 1 of the 8 monoclonal antibodies against soluble aggregates;amorphous aggregates also reacted with the 37-11 antibody. These results indicated that soluble aggregates are specifically recognized by a combination of different antibodies. The combined use of these antibodies can be applied to the diagnosis of AD and to defining the structure of the Aβ1-42.
文摘（S）-（＋）-2,2-dimethylcyclopropane carbox amide is a key intermediate of Cilastatin, an inhibitor of dehydropeptidase-I. Its corresponding solid-liquid equilibrium data will provide essential support for industrial design and further theoretical studies. The solubilities of （S）-（＋）-2,2-dimethylcyclopropane carbox amide in toluene, dichloromethane, trichloromethane, ethyl acetate, ethanol and pure water at different temperature were measured using the synthetic method by a laser monitoring observation technique. The solubility data were correlated with the modified Apelblat equation.The calculated values were good in agreement with the experimental values.
文摘(S)-(+)-2,2-dimethylcyclopropane carbox amide is a key intermediate of Cilastatin, an inhibitor of de- hydropeptidase-I. Its corresponding solid-liquid equilibrium data will provide essential support for industrial design and further theoretical studies. The solubilities of (S)-(+)-2,2-dimethylcyclopropane carbox amide in toluene, di- chloromethane, trichloromethane, ethyl acetate, ethanol and pure water at different temperature were measured us- ing the synthetic method by a laser monitoring observation technique. The solubility data were correlated with the modified Apelblat equation. The calculated values were good in agreement with the experimental values.
文摘Solubilities of 2,4-dichlorobenzaldehyde in five single organic solvents,namely,n-propanol,n-butanol.cyclohexane,chloroform and dichloromethane as well as in two mixed solvents,namely,cyclohexane-acetone and cyclohexane n-butanol,have been measured.These data are correlated withWilson,NRTL and UNIQUAC activity coefficient models and can be used for the process design inthe purification of 2,4-dichlorobenzaldehyde.
基金supported by Natural Science Foundation of Hebei Province(B2018208154)Department of Education of Hebei Province,P.R.China(SLRC2019051)Key Foundation of Hebei Provincial Department of Science and Technology,P.R.China(21373703D).
文摘Nonaqueous amine-based system is an attractive solution to overcome high-energy-intensive CO_(2) capture process using the conventional aqueous amines.Advanced nonaqueous absorbent of 2-(butylamino)ethanol(BAE)with 2-butoxyethanol(2-BE)has been recently proposed for low-energyconsumption CO_(2) capture.In this work,Henry’s law constants of CO_(2) in the BAE/2-BE blend were obtained by N_(2)O/CO_(2) analogy,and correlated in the temperature range of(283–333)K.Vapor-liquid equilibrium(VLE)data for the BAE+CO_(2)+2-BE system at 65.4%(mass)BAE were also determined in a stirred equilibrium cell at temperatures of(313–393)K and CO_(2) partial pressures up to 275 kPa.A single apparent equilibrium constant KCO_(2);app was proposed for this system and correlated as a function of temperature,carbonated degree of amine and CO_(2) loading.Solubility data were well represented by the modified Kent-Eisenberg model with an average absolute relative deviation(AARD)of 13%.
基金supports from the National Basic Research Program of China(No. 2003CB 114407)
文摘A series of novel 2-（1-substituted-1,11-undecylidene）-5-arylimino-△^3-1,3,4-thiadiazolines （4） were synthesized and their structure was characterized by ^1H NMR, ^13C NMR and elemental analysis. Their solubility in both polar and non-polar solvents is significantly improved owing to the introduction of ethyl or methylthio group at cyclododecyl ring as compared with parent compounds [1, 2-（1,11-undecylidene）-5-arylimino-△^3-1,3,4-thiadiazolines]. However, their fungicidal activity against Rhizoctonia solani is less than that of parent compounds. X-ray diffraction analysis of a representative compound （4d） showed that the conformation of 12-membered ring is still [3333], in which the ethyl group present at the side-exo position and the thiadiazoline ring at the comer carbon. The thiadiazoline plane is perpendicular to the cyclododecyl one.
文摘Two kinds of Nd 1+ x Ba 2- x Cu 3O 7- δ , the sintered samples and zone melted samples, were treated in pure Ar at 950 ℃. The substitution of Nd ions for Ba ions in the Nd 1+ x Ba 2- x Cu 3O 7- δ before and after the heat treatment was investigated by XRD. In order to know the effects of heat treatment, the T c and J c of samples with and without the heat treatment in Ar were comparatively studied. The results show that the substitution of Nd for Ba decreases, whereas T c and J c increase after the treatment. The Nd 1+ x Ba 2- x Cu 3O 7- δ samples were oxygenated in pure oxygen at 300 ℃ . Based on the XRD spectra it was found that the samples with x <0.4 can transform from tetragonal phase into orthorhombic phase after the oxygenation, whereas in the sample with x >0.4 no phase transition occurs even after a long time oxygenation.
基金Supported by National Natural Science Foundation of China for Young Researchers ( No. 29606008) andTianjin Natural Science Foundation ( No. 993607111).
文摘Enhancing the dispersion and dissolution of substrate particles in substrate water suspension is a feasible way to improve steroid bioconversion. The aim of the present study is to investigate the effects of applying surfactant to microbial conversion system on the dispersion, solubilization and in turn bioconversion of steroid substrate. The model system is hydroxylation of substrate 19α- 17α-epoxy- 4-pregnene- 3.2It-dine by microbial enzymes from Rhizopus nigricanl. The results show that the presence of substrate leads to an increase in critical micelle concentration （ CMC） of surfactant PSE compared with the normal CMC of PSE in aqueous solution. The grinding time during substrate suspension preparation affects the substrate aqueous solubility differently with the varied surfactant concentrations while barely making any difference in substrate solubility in the absence of surfactant. The properly prolonged grinding time can make up for the loss in substrate solubility arising from the reduction in surfactant concentration. The surfactant complexes composed of surfactants PSE and MGE at appropriate ratios are screened out with orthodoxy experiment method. the interaction between PSE and MGE exerts the most prominent effects on substrate bioconversion, and the surfactant complexes show more beneficial effects on steroid bioconversion than the surfactant PSE used alone.
文摘Raising cattle in feedlots is becoming more common in Argentina, but there is little information available about the effects of this practice on soil phosphorus (P) dynamics. In this study, concentrations of water and Bray -1 extractable soil P were quantified in a feedlot (upper and lower slope positions in the feedlot pen), runoff area and pasture during 2006 - 2008. The feedlot showed higher P concentrations in all P forms, soluble reactive P, soluble nonreactive, total soluble P, and Bray-P1 when compared to runoff area and pasture. Most of the total soluble P was soluble reactive P from the soil in the feedlot and the runoff area, while soluble nonreactive P predominated in the pasture. Concentrations of total soluble P were elevated in the feedlot at the soil surface, ranging on average from 158.71 to 245.86 mg?P?kg?1, and had a rapid decrease within the first 20 cm and remained relatively low, about 25.53 - 27.33 mg?P?kg?1. The evidence that total soluble P concentration in the feedlot was significantly (p < 0.05) higher than that registered in the pasture at 20 - 40 and 40 - 60 cm soil depth suggests a potential transfer of P through the soil from the surface. Although the feedlot had a moderate increase of 23.05 to 24.55 mg?P?kg?1 from the background concentration, it may represent a long-term source of increased nutrient loading to groundwater. Soil extractable Bray-1 P in the top 0 - 2.5 cm fluctuated from 659.26 to 45.36 mg?P?kg?1 in the feedlot and pasture, respectively. The relationship between soil P extracted by test and TSP was linear, and correlation coefficient was r2 = 0.95.
基金This work received financial support from the National Science Fund for the National Natural Science Foundation of China(31730067)the National Natural Science Foundation of China(31972032)the National Natural Science Foundation of China(32001637).
文摘4,6-α-Glucanotransferase(4,6-α-GT)converts starch into product with increasedα(1-6)glycosidic bonds ratio,and this product is a new type of soluble dietary fiber with property of escaping small intestine digestion.4,6-α-GT gained interest recently because of their potential use in enzymatic synthesis of soluble dietary fiber.In this study,a putative GtfB sequence from Limosilactobacillus fermentum NCC 3057 was identified.This sequence was truncated and expressed in Escherichia coli to obtain the protein L.fermentum NCC 3057 GtfBΔN.GtfBΔN showed optimal activity at 35℃and pH 6.0,and it converted amylose V to isomalto-/maltopolysaccharide(IMMP)with low molecular mass(3.1 kDa).This IMMP product contains 72%α(1-6)glycosidic bonds,and it showed 64%indigestible content in vitro digestion experiment.These results indicate that the product of L.fermentum NCC 3057 GtfBΔN is a soluble dietary fiber.Finally the X-ray crystal structure of GtfBΔN(2.4Å)was resolved.Based on the GtfBΔN structure,we offer an insight about that three loops of domain C may be related to the molecular mass of IMMP product.
基金carried out within the framework of the state task program (No. AAAA-A19-119020890014-7)
文摘A new soluble polymer on 2-[(2 E)-1-methyl-2-buten-1-yl]aniline and its copolymers with aniline basis have been synthesized in various molar ratios. For all samples, the electrical conductivity, morphology, solubility, electrochemical properties, as well as spectral and molecular mass characteristics have been studied, and a comparative analysis with polyaniline has been carried out. The substituent introduced into the aniline aromatic ring significantly improves the solubility in typical organic solvents of a high molecular weight product. The morphology of the test compounds depends on the co-monomer ratio. As the content of the substituted aniline in the initial mixture increases, the morphology of the polymer changes from the inherent polyaniline fibrous microstructure to the globular one with irregular substituted polyaniline shapes and sizes. Electrochemical study of the samples revealed that the higher the oxidation potential, the wider the band gap(ranging from 2.00 to 2.15). The electrical conductivity decreases in proportion to the increase in the substituted aniline concentration of the initial co-monomer mixture and amounts to 12.5–35.7 × 10~6 nSm.
