Concentrations and spatial distributions of organic carbon (OC) and elemental carbon (EC) in atmospheric particles were measured at 8 sites in four cities (Hong Kong, Guangzhou, Shenzhen and Zhuhai) of Pearl River Del...Concentrations and spatial distributions of organic carbon (OC) and elemental carbon (EC) in atmospheric particles were measured at 8 sites in four cities (Hong Kong, Guangzhou, Shenzhen and Zhuhai) of Pearl River Delta Region (PRDR), China during 2001 winter period and 2002 summer period. PM2.5 (particie diameter smaller than 2.5 um) and PM10 (particie diameter smaller than 10 um) samples were collected on pre-fired quartz filters with mini-volume samplers and analyzed using thermal optical reflectance (TOR) method. The average PM2.5and PM10 Ievel were 60.1 and 93.1 μg·m-3, respectively, with PM2.5 constituting 65.3% of the PM10 mass. The average OC and EC concentrations in PM2.5 were 12.0 and 5.1 μg·m-3, respectively, while those in PM10 were 16.0 and 6.5 μg·m-3, respectively. The carbo-naceous aerosol accounted for 37.2% of the PM2.5 and 32.8% of the PM10. The highest concentrations of OC and EC were observed at Guangzhou city in both vvinter and summer seasons. The average OC/EC ratios were 2.4 for PM2.5 and 2.5 for PM10, indicating the presence of secondary organic aerosols. The OC and EC in PRDR were found to be strongly correlated (correlation coefficients > 0.6), which implied that similar emission source contribute to the ambient carbon particles.展开更多
Nanosized NaY crystals have been prepared from metakaolin and sodium silicate by confined space synthesis with starch additive. It is found that the product has a narrow crystal size distribution (50-100 nm), high Si...Nanosized NaY crystals have been prepared from metakaolin and sodium silicate by confined space synthesis with starch additive. It is found that the product has a narrow crystal size distribution (50-100 nm), high Si/Al ratio (Si/Al=4.6-6.1), high surface area (1090 m2/g) and the average diameter of nanosized NaY (75 nm) synthesized is 30 nm, it is smaller than that of without starch additive.展开更多
AIM: To investigate the anti-lipid peroxidation and protection of liver mitochondria against injuries in mice with liver damage by picroside Ⅱ. METHODS: Three animal models of liver damage induced by carbon tetrachlo...AIM: To investigate the anti-lipid peroxidation and protection of liver mitochondria against injuries in mice with liver damage by picroside Ⅱ. METHODS: Three animal models of liver damage induced by carbon tetrachloride (CCl4: 0.1 mL/10 g, ip), D-galactasamine (D-GaIN: 500 mg/kg, ip) and acetaminophen (AP: 0.15 g/kg, ip) were respectively treated with various concentrations of picroside Ⅱ (5, 10, 20 mg/kg, ig). Then we chose the continuously monitoring method (recommended by International Clinical Chemistry League) to analyze serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) values, Marland method to detect the activity of manganese-superoxide dismutase (SOD) in liver mitochondria, TBA colorimetry to determine the content of malonicdialdehyde (MDA) in liver tissue, DTNB method to evaluate the activity of glutathioneperoxidase (GSH-Px) and Lowry method to detect protein level in liver tissue. Meanwhile, effects of picroside Ⅱ on the activity of ATPase and swelling extent of mitochondria in hepatocytes damaged by AP were also evaluated. RESULTS: Picroside Ⅱ could significantly prevent liver toxicity in the three models of liver damage. It decreased the high levels of ALT and AST in serum induced by the administration of CCl4, D-GaIN and AP, reduced the cellular damage of liver markedly, and appeared to be even more potent than the positive control drug of biphenyl dimethyl dicarboxylate pilules (DDB). In groups treated with different doses of picroside Ⅱ, compared to the model group, the content of MDA in serum decreased evidently, whereas the content of SOD and GSH-Px increased in a dose dependent manner, and the difference was statistically significant. Further, in the study of AP model, picroside Ⅱ inhibited AP-induced liver toxicity in mice, enhanced the activity of ATPase, improved the swelling extent of mitochondria and helped to maintain a normal balance of energy metabolism. CONCLUSION: Picroside II can evidently relieve hepatocyte injuries induced by CCI4, D-GaIN and AP展开更多
AIM：To detect the expression pattern of FAK(focal adhesion kinase)and integrinα5andβ1 subunits in different kinds of cancerous tissues and to study their correlation with clinicopathological data including tumor ty...AIM：To detect the expression pattern of FAK(focal adhesion kinase)and integrinα5andβ1 subunits in different kinds of cancerous tissues and to study their correlation with clinicopathological data including tumor type,grade and lymph node status.METHODS:Using an immunohistochemical technique,we examined the expression of FAK and integrin and subunits in cancerous and noncancerous tissues obtained from75patients with gastric carcinomas,21colorectal carcinomas,16 hepatocellular carcinomas,20uterocervical carcinomas,and20breast carcinomas.RESULTS:The staining of FAK was stronger in cancerous than in noncancerous areas,Enhanced expression of FAKwas detected in poor-differentiated carcinoma of the stomach and colorectum.Tumors with lymph node metastases had more FAKprotein than those without metastases.In addition.the deeper the extent of tumor infiltration,the higher the FAKexpression.The expression of integrinα5andβ1subunits was lower in cancerous areas than in noncancerous areas,but it was higher in well-differentiated cancerous tissues than in poor differentiated tissues.The relationship between the expression of integrinα5andβ1subunits and infiltration or metastasis was not significant.Cancerous tissues with stronger FAK expression(++or+++)also had a higher expression of integrinα5andβ1subunits in the tumor and its unaffected margins.CONCLUSION:FAKis a better marker for carcinogenesis and the progression of cancer than integrinα5orβ1subunit,and it may be not only a transformation-linked enzyme but also a progression-linked enzyme.展开更多
Objective To investigate the anti-HIV effects of ampelopsin and its interaction with HIV-1 coreceptor CXCR4. Methods Through anti-virus experiments in vitro, the inhibitory effect of ampelopsin on HTV-1 infection was ...Objective To investigate the anti-HIV effects of ampelopsin and its interaction with HIV-1 coreceptor CXCR4. Methods Through anti-virus experiments in vitro, the inhibitory effect of ampelopsin on HTV-1 infection was verified. Chemotaxis assay was performed to show the ability to induce PBMCs migration by ampelopsin, RANTES and SDF-la. Fluorescence labelling monoclonal antibody was utilized to observe the interaction of ampelopsin and CXCR4. Mice immunosuppressant model was also established to detail the role ampelopsin played in regulating cellular immunological functions. Results Ampelopsin could protect sensitive cells against HTV-1 infection and dramatically reduce HIV-1 antigen P24 expression. HTV-1SF33 attaching to MT-4 cells was interfered by ampelopsin, and the EC50 was 0.175 mg/mL for cellular protection and 0.024 mg/mL for P24 inhibition. At co-cultivating phase, EC50 was 0.229 mg/mL and 0.197 mg/mL respectively. Furthermore, the EC50 was 0.179 mg/mL and 0.348 mg/mL in acute infection. Human PBMCs migration was induced after being challenged with ampelopsin or chemokines, and synergistic action was observed during co-treatment. Ampelopsin alone resulted in maximal chemotaxis at 1 mg/mL. HIV-1 co-receptor CXCR4 on the surface of PBMCs was decreased by internalization, which indicated the effect of ampelopsin on CXCR4. About 70% CXCR4 was reduced by ampelopsin at 1 mg/mL. Ampelopsin also augmented cellular immunological functions in immunosuppressive mice. Conclusion Ampelopsin displays a strong inhibitive role during HIV-1 absorption, incubation and acute infection. These results are coincident with its immune enhancement.展开更多
The adsorption behavior and the mechanism of a novel chelate resin, amino methylene phosphonic acid resin(APAR) for Cu(Ⅱ) were investigated. Cu(Ⅱ) was quantitatively adsorbed by APAR in the medium of pH=4 09. The s...The adsorption behavior and the mechanism of a novel chelate resin, amino methylene phosphonic acid resin(APAR) for Cu(Ⅱ) were investigated. Cu(Ⅱ) was quantitatively adsorbed by APAR in the medium of pH=4 09. The statically saturated adsorption capacity is 181 mg/(g resin). Cu(Ⅱ) adsorbed on APAR can be eluted by 1 0-3 0 mol/L HCl. The rate constant is k 298 =5 58×10 -5 s -1 . The adsorption of Cu(Ⅱ) on APAR follows the Freundlich isotherm. The Δ H of the adsorption is 3 91 kJ/mol. The apparent activation energy is E a=21 4 kJ/mol. The coordination molar ratio of APAR to Cu(Ⅱ) is 1/1. It is shown that the nitrogen and the oxygen atoms in the functional group of APAR coordinate to Cu(Ⅱ).展开更多
The corrosion process of the X70 pipeline steel in 3.0wt% NaCl solution were studied using polarization method, and the chronological characteristics during the entire polarization plot were investigated in detail usi...The corrosion process of the X70 pipeline steel in 3.0wt% NaCl solution were studied using polarization method, and the chronological characteristics during the entire polarization plot were investigated in detail using EIS technique. In the active region of X70 steel, such as 20mV potential bias applied on open circuit potential (OCP), the impedance spectra was comprised of three parts: a high-frequency capacitive loop, a middle-frequency capacitive loop and a low-frequency inductive component. When positive polarization potential increased, the capacitive loops at high and middle frequency range merged, and the inductive component at low frequency shrunk. At high positive polarization potential bias (500-800mV vs. OCP), the high-frequency capacitive loop and the low-frequency inductive loop exhibited as disheveled points due to the synergism of the inhomogeneity of the corroding material and the localized corrosion. The results were fitted utilizing the equivalent circuits to simulate the impedance spectra and to interpret the electrochemical features shown during the experiments.展开更多
By combining vertical deposition with micro- molding in capillaries method, we have demonstrated the two-substrate vertical deposition, an alternative and versatile procedure for fabricating high-quality stable colloi...By combining vertical deposition with micro- molding in capillaries method, we have demonstrated the two-substrate vertical deposition, an alternative and versatile procedure for fabricating high-quality stable colloidal crystal chips. Apparent bright colors, special UV-vis spectra, scan- ning electron microscopy (SEM) and atomic force micros- copy (AFM) images all prove that high-quality colloidal crystal structures are formed in between the two substrates. During the two-substrate vertical deposition for colloidal crystal chips, capillary force and evaporation of the medium are critical to the formation of the colloidal crystals; while the confinement in between two close substrates makes the resulting colloidal crystal chips more stable. Due to the ex- cellent stability, these colloidal crystal chips can be used to construct some composite optical devices via a simpler and more flexible process. Meanwhile, they can also be further used as the templates for ordered multiporous materials.展开更多
Two new norditerpenoid alkaloids, spicatine A (1) and spicatine B (2) were isolated from the root of Aconitum spicatum. The new compounds were deduced on the basis of their spectral data (IR, HREIMS, EIMS, 1D, 2D-NM...Two new norditerpenoid alkaloids, spicatine A (1) and spicatine B (2) were isolated from the root of Aconitum spicatum. The new compounds were deduced on the basis of their spectral data (IR, HREIMS, EIMS, 1D, 2D-NMR). This is the first whole report on the isolation of diterpenoid alkaloids from the A.spicatum Stapf.展开更多
The theoretical linear solvation energy relationship(TLSER) approach was adopted to predict the aqueous solubility and n -octanol/water partition coefficient of three groups of environmentally important chemicals-poly...The theoretical linear solvation energy relationship(TLSER) approach was adopted to predict the aqueous solubility and n -octanol/water partition coefficient of three groups of environmentally important chemicals-polychlorinated biphenyls(PCBs), polychlorinated dibenzodioxins and dibenzofurans(PCDDs and PCDFs). For each compound, five quantum parameters were calculated using AM1 semiempirical molecular orbital methods and used as structure descriptors: average molecular polarizability(α), energy of the lowest unoccupied molecular orbit( E _ LUMO ), energy of the highest occupied molecular orbit( E _ HOMO ), the most positive charge on a hydrogen atom( q _+), and the most negative atomic partial charge( q _-) in the solute molecule. Then standard independent variables in TLSER equation was extracted and two series of quantitative equations between these quantum parameters and aqueous solubility and n -octanol/water partition coefficient were obtained by stepwise multiple linear regression(MLR) method. The developed equations have both quite high accuracy and explicit meanings. And the cross-validation test illustrated the good predictive power and stability of the established models. The results showed that TLSER could be used as a promising approach in the estimation of partition and solubility properties of macromolecular chemicals, such as persistent organic pollutants.展开更多
A mathematical method was proposed for the determination of absolute adsorption from experimental isotherms. The method is based on the numerical equality of the absolute and the excess adsorption when either the gas ...A mathematical method was proposed for the determination of absolute adsorption from experimental isotherms. The method is based on the numerical equality of the absolute and the excess adsorption when either the gas phase density or the amount adsorbed is not quite considerable. The initial part of the experimentalisotherms, which represents the absolute adsorption, became linear with some mathematical manipulations. The linear isotherms were reliably formulated. As consequence, either the volume or the density of the supercritical adsorbate could be determined by a non-empirical way. This method was illustrated by the adsorption data of supercritical hydrogen and methane on a superactivated carbon in large ranges of temperature and pressure.展开更多
Oxidation of cyclohexene under 1 atmospheric pressure of molecular oxygen at 70C in the absence of solvent catalyzed by PAMAM-SA-M (Where PAMAM = polyamidoamine; SA = salicyaldehyde; M = metal ions Fe3+, Co2+, Ni2+, M...Oxidation of cyclohexene under 1 atmospheric pressure of molecular oxygen at 70C in the absence of solvent catalyzed by PAMAM-SA-M (Where PAMAM = polyamidoamine; SA = salicyaldehyde; M = metal ions Fe3+, Co2+, Ni2+, Mn2+, Cu2+, Zn2+, respectively) dendrimers, afforded 2-cyclohexen-1-ol 1, 2-cyclohexen-1-one 2, 7-oxabicyclo [4,1,0] heptane 3 and 7-oxabicyl [4,1,0] heptan-2-one 4 as the major products. The factors that affect this reaction are also discussed.展开更多
From rhizomes of Hemsleya giganthy collected in Shichuan of China, 16 compounds were isolated. Among them, three compounds (8, 9, 15) are new natural products called Hemslecins G; Hemsgiganosides A and B; respectivel...From rhizomes of Hemsleya giganthy collected in Shichuan of China, 16 compounds were isolated. Among them, three compounds (8, 9, 15) are new natural products called Hemslecins G; Hemsgiganosides A and B; respectively. Their structures were elucidated as 7- hydroxy-23, 24-dihydro-cucurbitacin F-25-O-acetate (8); 3-O-(6-butyl ester-)-b-D-glu- curono- pyranosyl)-oleanolic acid-28-O-a-L-arabinopyranoside(9); 3-O-b-D-glucuropyranosyl oleanolic acid -28-O-b-D-gluco pyranosyl-(16)- b-D-glucopyranoside(15) by spectroscopic and chemical means.展开更多
A novel kinetic mechanism of esterification reaction of 1-hexanoic acid with 1-butanol, catalyzed by lipase, was studied in water-in-oil microemulsions. The microemulsions were formed by alkyl polyglucoside C10G1.54/1...A novel kinetic mechanism of esterification reaction of 1-hexanoic acid with 1-butanol, catalyzed by lipase, was studied in water-in-oil microemulsions. The microemulsions were formed by alkyl polyglucoside C10G1.54/1-butanol / cyclohexane/phosphate buffer solution. The result shows that when the ratio of mol concentration of 1-butanol to 1-hexanoic acid is about 3.0, the initial rate V0 get the maximum values. This phenomenon was explained by the modified fishlike phase diagrams.展开更多
基金This study is supported by China NSFC project(40205018)Research Grants Council of Hong Kong(BQ-500)G-V951 of the Hong Kong Polytechnic University.
文摘Concentrations and spatial distributions of organic carbon (OC) and elemental carbon (EC) in atmospheric particles were measured at 8 sites in four cities (Hong Kong, Guangzhou, Shenzhen and Zhuhai) of Pearl River Delta Region (PRDR), China during 2001 winter period and 2002 summer period. PM2.5 (particie diameter smaller than 2.5 um) and PM10 (particie diameter smaller than 10 um) samples were collected on pre-fired quartz filters with mini-volume samplers and analyzed using thermal optical reflectance (TOR) method. The average PM2.5and PM10 Ievel were 60.1 and 93.1 μg·m-3, respectively, with PM2.5 constituting 65.3% of the PM10 mass. The average OC and EC concentrations in PM2.5 were 12.0 and 5.1 μg·m-3, respectively, while those in PM10 were 16.0 and 6.5 μg·m-3, respectively. The carbo-naceous aerosol accounted for 37.2% of the PM2.5 and 32.8% of the PM10. The highest concentrations of OC and EC were observed at Guangzhou city in both vvinter and summer seasons. The average OC/EC ratios were 2.4 for PM2.5 and 2.5 for PM10, indicating the presence of secondary organic aerosols. The OC and EC in PRDR were found to be strongly correlated (correlation coefficients > 0.6), which implied that similar emission source contribute to the ambient carbon particles.
文摘Nanosized NaY crystals have been prepared from metakaolin and sodium silicate by confined space synthesis with starch additive. It is found that the product has a narrow crystal size distribution (50-100 nm), high Si/Al ratio (Si/Al=4.6-6.1), high surface area (1090 m2/g) and the average diameter of nanosized NaY (75 nm) synthesized is 30 nm, it is smaller than that of without starch additive.
基金Supported by the China Postdoctoral Science Foundation and the National Natural Science Foundation of China, No. 90209046
文摘AIM: To investigate the anti-lipid peroxidation and protection of liver mitochondria against injuries in mice with liver damage by picroside Ⅱ. METHODS: Three animal models of liver damage induced by carbon tetrachloride (CCl4: 0.1 mL/10 g, ip), D-galactasamine (D-GaIN: 500 mg/kg, ip) and acetaminophen (AP: 0.15 g/kg, ip) were respectively treated with various concentrations of picroside Ⅱ (5, 10, 20 mg/kg, ig). Then we chose the continuously monitoring method (recommended by International Clinical Chemistry League) to analyze serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) values, Marland method to detect the activity of manganese-superoxide dismutase (SOD) in liver mitochondria, TBA colorimetry to determine the content of malonicdialdehyde (MDA) in liver tissue, DTNB method to evaluate the activity of glutathioneperoxidase (GSH-Px) and Lowry method to detect protein level in liver tissue. Meanwhile, effects of picroside Ⅱ on the activity of ATPase and swelling extent of mitochondria in hepatocytes damaged by AP were also evaluated. RESULTS: Picroside Ⅱ could significantly prevent liver toxicity in the three models of liver damage. It decreased the high levels of ALT and AST in serum induced by the administration of CCl4, D-GaIN and AP, reduced the cellular damage of liver markedly, and appeared to be even more potent than the positive control drug of biphenyl dimethyl dicarboxylate pilules (DDB). In groups treated with different doses of picroside Ⅱ, compared to the model group, the content of MDA in serum decreased evidently, whereas the content of SOD and GSH-Px increased in a dose dependent manner, and the difference was statistically significant. Further, in the study of AP model, picroside Ⅱ inhibited AP-induced liver toxicity in mice, enhanced the activity of ATPase, improved the swelling extent of mitochondria and helped to maintain a normal balance of energy metabolism. CONCLUSION: Picroside II can evidently relieve hepatocyte injuries induced by CCI4, D-GaIN and AP
基金National Natural Science Foundation of China,No 39970373the grant from the Science Committee of Shanghai No.00JC 14042
文摘AIM：To detect the expression pattern of FAK(focal adhesion kinase)and integrinα5andβ1 subunits in different kinds of cancerous tissues and to study their correlation with clinicopathological data including tumor type,grade and lymph node status.METHODS:Using an immunohistochemical technique,we examined the expression of FAK and integrin and subunits in cancerous and noncancerous tissues obtained from75patients with gastric carcinomas,21colorectal carcinomas,16 hepatocellular carcinomas,20uterocervical carcinomas,and20breast carcinomas.RESULTS:The staining of FAK was stronger in cancerous than in noncancerous areas,Enhanced expression of FAKwas detected in poor-differentiated carcinoma of the stomach and colorectum.Tumors with lymph node metastases had more FAKprotein than those without metastases.In addition.the deeper the extent of tumor infiltration,the higher the FAKexpression.The expression of integrinα5andβ1subunits was lower in cancerous areas than in noncancerous areas,but it was higher in well-differentiated cancerous tissues than in poor differentiated tissues.The relationship between the expression of integrinα5andβ1subunits and infiltration or metastasis was not significant.Cancerous tissues with stronger FAK expression(++or+++)also had a higher expression of integrinα5andβ1subunits in the tumor and its unaffected margins.CONCLUSION:FAKis a better marker for carcinogenesis and the progression of cancer than integrinα5orβ1subunit,and it may be not only a transformation-linked enzyme but also a progression-linked enzyme.
基金This work was supported by Science Foundation of Guangdong Province (No.97002).
文摘Objective To investigate the anti-HIV effects of ampelopsin and its interaction with HIV-1 coreceptor CXCR4. Methods Through anti-virus experiments in vitro, the inhibitory effect of ampelopsin on HTV-1 infection was verified. Chemotaxis assay was performed to show the ability to induce PBMCs migration by ampelopsin, RANTES and SDF-la. Fluorescence labelling monoclonal antibody was utilized to observe the interaction of ampelopsin and CXCR4. Mice immunosuppressant model was also established to detail the role ampelopsin played in regulating cellular immunological functions. Results Ampelopsin could protect sensitive cells against HTV-1 infection and dramatically reduce HIV-1 antigen P24 expression. HTV-1SF33 attaching to MT-4 cells was interfered by ampelopsin, and the EC50 was 0.175 mg/mL for cellular protection and 0.024 mg/mL for P24 inhibition. At co-cultivating phase, EC50 was 0.229 mg/mL and 0.197 mg/mL respectively. Furthermore, the EC50 was 0.179 mg/mL and 0.348 mg/mL in acute infection. Human PBMCs migration was induced after being challenged with ampelopsin or chemokines, and synergistic action was observed during co-treatment. Ampelopsin alone resulted in maximal chemotaxis at 1 mg/mL. HIV-1 co-receptor CXCR4 on the surface of PBMCs was decreased by internalization, which indicated the effect of ampelopsin on CXCR4. About 70% CXCR4 was reduced by ampelopsin at 1 mg/mL. Ampelopsin also augmented cellular immunological functions in immunosuppressive mice. Conclusion Ampelopsin displays a strong inhibitive role during HIV-1 absorption, incubation and acute infection. These results are coincident with its immune enhancement.
基金Supported by Zhejiang Provincial Natural Science Foundation of China( No.2 0 0 0 72 )
文摘The adsorption behavior and the mechanism of a novel chelate resin, amino methylene phosphonic acid resin(APAR) for Cu(Ⅱ) were investigated. Cu(Ⅱ) was quantitatively adsorbed by APAR in the medium of pH=4 09. The statically saturated adsorption capacity is 181 mg/(g resin). Cu(Ⅱ) adsorbed on APAR can be eluted by 1 0-3 0 mol/L HCl. The rate constant is k 298 =5 58×10 -5 s -1 . The adsorption of Cu(Ⅱ) on APAR follows the Freundlich isotherm. The Δ H of the adsorption is 3 91 kJ/mol. The apparent activation energy is E a=21 4 kJ/mol. The coordination molar ratio of APAR to Cu(Ⅱ) is 1/1. It is shown that the nitrogen and the oxygen atoms in the functional group of APAR coordinate to Cu(Ⅱ).
基金the National Key Basic Research Foundation of China(No.G19990650)the National Natural Science Foundation of China(No.50071054).
文摘The corrosion process of the X70 pipeline steel in 3.0wt% NaCl solution were studied using polarization method, and the chronological characteristics during the entire polarization plot were investigated in detail using EIS technique. In the active region of X70 steel, such as 20mV potential bias applied on open circuit potential (OCP), the impedance spectra was comprised of three parts: a high-frequency capacitive loop, a middle-frequency capacitive loop and a low-frequency inductive component. When positive polarization potential increased, the capacitive loops at high and middle frequency range merged, and the inductive component at low frequency shrunk. At high positive polarization potential bias (500-800mV vs. OCP), the high-frequency capacitive loop and the low-frequency inductive loop exhibited as disheveled points due to the synergism of the inhomogeneity of the corroding material and the localized corrosion. The results were fitted utilizing the equivalent circuits to simulate the impedance spectra and to interpret the electrochemical features shown during the experiments.
基金supported by the National Natural Science Foundation of China(Grant Nos.90401020 and 200340062).
文摘By combining vertical deposition with micro- molding in capillaries method, we have demonstrated the two-substrate vertical deposition, an alternative and versatile procedure for fabricating high-quality stable colloidal crystal chips. Apparent bright colors, special UV-vis spectra, scan- ning electron microscopy (SEM) and atomic force micros- copy (AFM) images all prove that high-quality colloidal crystal structures are formed in between the two substrates. During the two-substrate vertical deposition for colloidal crystal chips, capillary force and evaporation of the medium are critical to the formation of the colloidal crystals; while the confinement in between two close substrates makes the resulting colloidal crystal chips more stable. Due to the ex- cellent stability, these colloidal crystal chips can be used to construct some composite optical devices via a simpler and more flexible process. Meanwhile, they can also be further used as the templates for ordered multiporous materials.
文摘Two new norditerpenoid alkaloids, spicatine A (1) and spicatine B (2) were isolated from the root of Aconitum spicatum. The new compounds were deduced on the basis of their spectral data (IR, HREIMS, EIMS, 1D, 2D-NMR). This is the first whole report on the isolation of diterpenoid alkaloids from the A.spicatum Stapf.
基金TheNationalKeyBasicResearchFoundationofChina (No .G1 9990 4 571 1 )
文摘The theoretical linear solvation energy relationship(TLSER) approach was adopted to predict the aqueous solubility and n -octanol/water partition coefficient of three groups of environmentally important chemicals-polychlorinated biphenyls(PCBs), polychlorinated dibenzodioxins and dibenzofurans(PCDDs and PCDFs). For each compound, five quantum parameters were calculated using AM1 semiempirical molecular orbital methods and used as structure descriptors: average molecular polarizability(α), energy of the lowest unoccupied molecular orbit( E _ LUMO ), energy of the highest occupied molecular orbit( E _ HOMO ), the most positive charge on a hydrogen atom( q _+), and the most negative atomic partial charge( q _-) in the solute molecule. Then standard independent variables in TLSER equation was extracted and two series of quantitative equations between these quantum parameters and aqueous solubility and n -octanol/water partition coefficient were obtained by stepwise multiple linear regression(MLR) method. The developed equations have both quite high accuracy and explicit meanings. And the cross-validation test illustrated the good predictive power and stability of the established models. The results showed that TLSER could be used as a promising approach in the estimation of partition and solubility properties of macromolecular chemicals, such as persistent organic pollutants.
基金the National Natural Science Foundation of China (No. 29936100).
文摘A mathematical method was proposed for the determination of absolute adsorption from experimental isotherms. The method is based on the numerical equality of the absolute and the excess adsorption when either the gas phase density or the amount adsorbed is not quite considerable. The initial part of the experimentalisotherms, which represents the absolute adsorption, became linear with some mathematical manipulations. The linear isotherms were reliably formulated. As consequence, either the volume or the density of the supercritical adsorbate could be determined by a non-empirical way. This method was illustrated by the adsorption data of supercritical hydrogen and methane on a superactivated carbon in large ranges of temperature and pressure.
文摘Oxidation of cyclohexene under 1 atmospheric pressure of molecular oxygen at 70C in the absence of solvent catalyzed by PAMAM-SA-M (Where PAMAM = polyamidoamine; SA = salicyaldehyde; M = metal ions Fe3+, Co2+, Ni2+, Mn2+, Cu2+, Zn2+, respectively) dendrimers, afforded 2-cyclohexen-1-ol 1, 2-cyclohexen-1-one 2, 7-oxabicyclo [4,1,0] heptane 3 and 7-oxabicyl [4,1,0] heptan-2-one 4 as the major products. The factors that affect this reaction are also discussed.
基金The authors are grateful to the financial support of the National Natural Science Foundation of China(Grant No.39970086)Natural Science Foundation of Yunnan(Grant No.98C089M)also thank the members of analytical group in Phytochemistry LaboratoTy,Kunming Institute of Botany for their measuring spectral data.
文摘From rhizomes of Hemsleya giganthy collected in Shichuan of China, 16 compounds were isolated. Among them, three compounds (8, 9, 15) are new natural products called Hemslecins G; Hemsgiganosides A and B; respectively. Their structures were elucidated as 7- hydroxy-23, 24-dihydro-cucurbitacin F-25-O-acetate (8); 3-O-(6-butyl ester-)-b-D-glu- curono- pyranosyl)-oleanolic acid-28-O-a-L-arabinopyranoside(9); 3-O-b-D-glucuropyranosyl oleanolic acid -28-O-b-D-gluco pyranosyl-(16)- b-D-glucopyranoside(15) by spectroscopic and chemical means.
文摘A novel kinetic mechanism of esterification reaction of 1-hexanoic acid with 1-butanol, catalyzed by lipase, was studied in water-in-oil microemulsions. The microemulsions were formed by alkyl polyglucoside C10G1.54/1-butanol / cyclohexane/phosphate buffer solution. The result shows that when the ratio of mol concentration of 1-butanol to 1-hexanoic acid is about 3.0, the initial rate V0 get the maximum values. This phenomenon was explained by the modified fishlike phase diagrams.
