Synthesis of Amino Acid Derived β-Cyclodextrins Used in Chiral Separation by Capillary Electrophoresis

Six new kinds of amino acid derived β-cyclodextrins were synthesized to improve their water solubility and chiral separation properties. They are heptakis {2,6-di-O-[3-L-(1-isopropyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Val-β-CD), heptakis {2,6-di-O-[3-L-(1-benzyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Phe-β-CD), heptakis{2,6-di-O-[3-(D, L-1-benzyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. D,L-Phe-β-CD), heptakis {2,6-di-O-[3-(L-1-hydrox-ymethyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Ser-β-CD), heptakis{2,6-di-O-[3-(L-1-carboxylmethyl carboxyl methyl amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Asp-β-CD), heptakis{2,6-di-O-[3-(L-2-carboxyl tetramethylene amino)-2-hydroxy propyl]}-β-cyclodextrin (i.e. L-Pro-β-CD).Their chemical structures were certified using FTIR and ^1H NMR. Except for L-Phe-β-CD and D,L-Phe-β-CD,that are in soluble in water, the other amino acid derived β-CDs all have good water solubility. D,L-tyrosine and promethazine were baselinely separated by L-Val-β-CD in capillary electrophoresis.     

Chiral Separation of Chlorpheniramine by Capillary Electrophoresis

目的研究谷氨酸βＣＤ和βＣＤ混合手性剂对扑尔敏对映体的分离．方法谷氨酸βＣＤ和βＣＤ混合，然后用作手性剂，重点考察βＣＤ和谷氨酸βＣＤ的浓度、操作电压、背景电解质溶液ｐＨ值对βＣＤ和谷氨酸βＣＤ混合体系分离扑尔敏对映体的影响．结果混合手性剂的手性识别能力大于单一手性剂的手性识别能力；在ｐＨ４以下，该混合体系对扑尔敏对映体的分离基本不受背景电解质溶液ｐＨ值的影响且具有较高的重现性．结论采用βＣＤ和谷氨酸βＣＤ混合体系作手性剂有利于扑尔敏的分离．     

The Synthesis and Characterization of β-cyclodextrin Derivated Pancreatin Used as Chiral Selector in Capillary Electrochromatography

1Introduction Cyclodextrins(CDs)andproteinsplayaveryimpor tantroleintheseparationofenantiomericisomers,and thousandsofenantiomericisomerswereseparatedonCDs andprotein,andtheirderivativesbygaschromatography(GC),highperformanceliquidchromatography(HPLC),hig…     

Preparation and Characterization of β-Cyclodextrin Derivatized Ovalbumin Used as Chiral Selector in Pressure Capillary Electrochromatography

Synthesis and properties of β-cyclodextrin derivatized ovalbumin used as chiral selector were investigated. β-cyclodextrin derivatized ovalbumin was synthesized using β-cyclodextrin and ovalbumin in the presence of ethylene glycol diglycidyl ether in boric acid buffer at pH value 8.7 at 37 ℃. Amino group was coated on the internal surface of the silica capillary by sol-gel technology with triethoxylmethylsiloxane and (3-aminopropyl)trimethoxysiloxane. Covalent binding of β-cyclodextrin derivatized ovalbumin was performed by glutaraldehyde. Enantiomers of chlorpheniramine, phenylalanine and atropine were separated by pressure capillary electrochromatography column coated with β-cyclodextrin derivatized ovalbumin.     

Verification of Existence of Harmonic Suppression in Error Separation by Prony Spectrum Analysis

ＶｅｒｉｆｉｃａｔｉｏｎｏｆＥｘｉｓｔｅｎｃｅｏｆＨａｒｍｏｎｉｃＳｕｐｐｒｅｓｉｏｎｉｎＥｒｏｒＳｅｐａｒａｔｉｏｎｂｙＰｒｏｎｙＳｐｅｃｔｒｕｍＡｎａｌｙｓｉｓＳＵＮＴｏｎｇＴＡＮＪｉｕｂｉｎＱＩＡＮＧＸｉｆｕＦＡＮＬｉ（孙彤）（谭久彬）（强锡富...     

Synthesis of Fullerene by Pyrolysis of Acetylene in Thermal HF-Plasma

Carbon soot containing fullerene was continuously produced in volume by pyrolyzing acetylene in thermal HF-Plasma. The characteristics of the carbon soot and C60 were analyzed by thtransmission electron microscopy, UV/visible, IR and Raman spectroscopy. The results show that the main ingredients of the carbon soot with size of about 25 nm are amorphous carbon, graphite and fullerene. The fullerene yield in carbon soot is about 2.5 g·h^-1. Compared with the graphite arc discharge method, the acetylene thermal plasma method is a preferential one for synthesis of fullerene.     

Synthesis of aluminum nitride nano-powder by decomposed diethylaluminum azide in aerosols

An aerosol process for making aluminum nitride nano-powder by decomposition of single compound diethylaluminun azide was described. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to study characters of the A1N powder. It is shown that the process can produce spherical A1N powder with mean particle diameters ranging from 10 to 50 nm at 500-800℃. The generated amorphous A1N powder is characterized by a BET (Brunauer-Emmett-Teller) surface area of 103 m^2/g and is very reactive to moisture.     

Preparation of β-SiC by combustion synthesis in a large-scale reactor

The feasibility of 5 kg β-SiC synthesized in one batch was demonstrated through igniting the mixture of Si, C-black and polytetrafluoroethylene (PTFE) under different nitrogen pressures. The effect of experimental parameters, including the contents of PTFE, nitrogen pressure, preheating, and raw materials distribution forms were investigated. The results show that the products are β-SiC with equiaxed grains. The average grain size is less than 200 nm. The powders loaded loosely promote reaction heat dispers...     

Low Temperature Dechlorination of Densified Refuse Derived Fuel in Pyrolysis

Study on behavior of chlorine contained in oval-shaped densified refuse derived fuel (d-RDF) prepared from municipal solid waste in pyrolysis was carried out by means of temperature-programmed electrical furnace, and the gas evolving from pyrolysis was investigated by FFIR. De-HC1 rate was calculated by determining the emission fraction of HC1 in the flue gas and the fraction of C1 left in the pyrolysis residue. The results show that C1 in the d-RDF releases primarily in the form of HC1 during the pyrolysis, and the initial releasing temperature of HC1 enhances with the increase of heating rate. Meanwhile, the higher the end temperature of pyrolysis, the more the C1 released. De-HCl rate is about 70% when the end temperature of pyrolysis is around 600℃. Besides, mechanism of C1 release is discussed.     

The Mechanism of Sol-Gel Synthesis of Normal Spinel LiMn_2O_4 with Chelation of Citric Acid

1　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｔｒａｄｉｔｉｏｎａｌｓｏｌ ｇｅｌｍｅｔｈｏｄａｎｄｃｏ ｐｒｅｃｉｐｉｔａｔｉｏｎｐｒｏｃｅｓｓ,ｗｈｉｃｈａｒｅｅａｓｙｔｏｃａｕｓｅｅｘｃｓｏｌｕｔｉｏｎａｎｄｓｅｇｒｅｇａ ｔｉｏｎｗｈｅｎｈｅａｔｉｎｇ ,ａｒｅｎｏｔａｌｗａｙｓｅｆｆｅｃｔｉｖｅｏｎｍａｉｎｔａｉｎｉｎｇａｈｏｍｏｇｅｎｏｕｓｄｉｓｔｒｉｂｕｔｉｏｎｏｆｐｒｅｃｕｒｓｏｒ .Ａｓａｒｅｓｕｌｔ,ｕｎｄｅ ｓｉｒａｂｌｅｐｈａｓｅｓｆｏｒｍｄｕｒｉｎｇｔｈｅｐｒｏｃｅｓｓｏｆｃａｌｃｉｎａｔｉ…     

The Mechanism of Sol-Gel Synthesis of Normal Spinel LiMn2O4 with Chelation of Citric Acid

The sol-gel process of citric acid chelating with metal cations for the synthesis of normol spinel LiMn2O4 and the reaction mechanion mechavism were investigated by means of XRD,TG-DTA,and SEM ,the results show that at the beginning lithium citrate and chelate compound of citic acid with manganese ions formed ,and then with heating the esterification and condensation reacions occured between them and glyol ,The products obtained are polymers in which metal cations are distibuted homogeneously on atomic scale that ensur hight reacivity to cations of Li^ and Mn^2 ,Firing the gel grepared by this process ,the lattice diffusions of solid reactant ions caused by non-homogeneity of reactants are elinimated and avoided .At 400℃ phase-pure LiMn2O4 with nanometer scale crystallization having precise stoichiometry and perfect crystallization can be obtained ,The model of chelate coordinated of double -molecule between citric acid and Mn^2 in the gel network is proosed ,It is important for explaining the dispersion state of Mn^2 and the formaiton process of gel by this model.     

Size Depending Separation of HAP:Eu Nanoparticles in Dispersed Sol

1Introduction Hydroxyapatite(Ca10(PO4)6(OH)2)isanimportant biomaterialthatiswidelyusedassubstituteorfillingma terialforscleroustissuesduetoitsgoodbiocompatibility andosteoconductivity[1,2].Inordertoinvestigatethein teractionsbetweenHAPnanoparticleswithana…     

Quantitative analysis of trace levels of β-ionone in water by liquid-liquidphase extraction-gas chromatography-mass spectrometry(LLE-GC-MS)

A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrument parameters including programmed oven temperature, injection temperature and ion source temperature were evaluated and optimized. Effects of extraction time, ionic strength and p H on the detection efficiency were investigated and optimum conditions were 8 min of extraction time, without Na Cl addition at p H=9. Good linearity(R2=0.9997) was obtained when the linear range was 10-500 μg/L. The recoveries of β-ionone in ultrapure water and tap water samples were 88%-95% and 110%-114%, respectively. The relative standard deviations(RSD) were less than 10%. The method detection limit(MDL) and rejection quality level(RQL) were achieved at1.98 μg/L and 6.53 μg/L, respectively. LLE-GC-MS was demonstrated to be a rapid and convenient method for the determination ofβ-ionone in water samples.     

The Influence of Type and Thickness of Sol-gel Derived Coatings on the in vitro Osteoblasts Behavior

1Introduction Numerousmethodswereexploredtoimprovethebio activity(osteoconductivityandosteoinductivity)oftitani umimplants.Amongthem,sol gelprocesshasbeenahot topicbecauseofitshigherchemicalhomogeneity,finer grainstructure(nanometerscale),lowerprocessingtem perature,easierandcontrollableprocedure.Andthe thicknessofthecoatingcouldbeeasilycontrolledby changingthetimesofcoating[1].3kindsofSol gelde rivedcoatingsareintensivelystudiedinrecentyears.Hydroxyapatite[HA,Ca10(PO4)6(OH)2]haslongbeen r…     

Synthesis of dimethyl carbonate by gas-phase oxidative carbonylation of methanol in the presence of solid catalyst I. Catalyst preparation and catalytic Properties

1IntroductionDboethylCarbonate(DMC)isabasicmaterialillorganicsynthesisandrecentlymore~onisbeingpaidtoicTwomethoxygroupsas.1acarbonylgroupmakeDaalalivetowardvarioussubsthesincarbonylationandmethylinonreactions.TheactivityorDMCmakesitPOssibletOsubtit'areforhighlytoxicPhosgeneanddimethylsulfatei:1manychemicalprocdses.Thisisveryimportantfor~rionmentalProtectionTherearethree;DMCsynthesisprocesses,i.e.phosgene-methanolprocess,esterexchangerrocessandgasorliquid.phase-,Okichive-Carbonylatiorl-…     

Synthesis of γ-Al2O3 nanoparticles by chemical precipitation method

Highly pure active γ-Al₂O₃ nanoparticles were synthesized from aluminum nitrate and ammonium carbonate with a little surfactant by chemical precipitation method. The factors affecting the synthesis process were studied. The properties of γ-Al₂O₃ nanoparticles were characterized by DTA, XRD, BET, TEM, laser granularity analysis and impurity content analysis. The results show that the amorphous precursor Al(OH)₃ sols are produced by using 0.1 mol/L Al(NO₃)₃ · 9H₂O and 0.16 mol/L (NH₄)₂CO₃ · H₂O reaction solutions, according to the volume ratio 1.33, adding 0.024% (volume fraction) surfactant PEG600, and reacting at 40 °C, 1 000 r/min stirring rate for 15 min. Then, after stabilizing for 24 h, the precursors were extracted and filtrated by vacuum, washed thoroughly with deionized water and dehydrated ethanol, dried in vacuum at 80°C for 8 h, final calcined at 800 °C for 1 h in the air, and high purity active γ-Al₂O₃ nanoparticles can be prepared with cubic in crystal system, O _H ⁷ -FD3M in space group, about 9 nm in crystal grain size, about 20 nm in particle size and uniform size distribution, 131. 35 m²/g in BET specific surface area, 7 – 11 nm in pore diameter, and not lower than 99.93% in purity. Foundation item: Project(03JJY3015) supported by the Natural Science Foundation of Hunan Province     

Synthesis of Composite Nanoparticles Bearing Epoxy Functional Groups：Encapsulation of Silica by Emulsion Polymerization of GMA

Poly （ glycidyl methacrylate ） / silica （PGMA/silica） composite nanoparticles , containing epoxy functional groups on the surface, were synthesized via emulsion polymerization. With batch process, high yield and binding efficiency （ both around 90% ） were achieved. The amount of crosslinked GMA was approximately 8wt%- 14wt% to the polymerized monomer. It was found that both the encapsulating ratio and the number of the original silica beads per composite particles altered with the amount of silica added. The obtained particles, with their average particle size of about 60- 70 nm, had a spherical shape and a clear core- shell structure.     

Synthesis of nanoscale multilayered ZrN/W coatings by ion beam assisted deposition

ZrN/W multilayered coatings with different modulation periods at the nanoscale have been synthesized at different N+ beam bombarding energies using IBAD. Various characterization techniques such as XRD, AES, nano indenter and profiler were employed to investigate the influence of modulation period and bombarding energy on microstructure and mechanical properties of the coatings. The results showed that all superlattice coatings had better mechanical properties than the monolithic ZrN and W coatings. At an optimal condition with 300 eV N+ beam bombarding energy and 8―9 nm modulation period, XRD pattern possessed a sig- nificantly structural mixture of strong ZrN (111), W (110), as well as weak ZrN (220) textures in the multilayered coating. The optimal condition resulted in higher hardness (26 GPa), elastic modulus (310 GPa) and fracture resistance of the coat- ing than other conditions.     

Synthesis of mesoporous carbon as electrode material for supercapacitor by modified template method

The pore structures and electrochemical performances of mesoporous carbons prepared by silica sol template method as electrode material for supercapacitor were investigated. The mean pore size and mass specific capacitance of the mesoporous carbons increase with the increase of mass ratio of silica sol to carbon source （glucose）. A modified template method, combining silica sol template method and ZnCl2 chemical activation method, was proposed to improve the mass specific capacitance of the mesoporous carbon with an improved BET surface area. The correlation of rate capability and pore structure was studied by constant current discharge and electrochemical impedance spectroscopy. A commercially available microporous carbon was used for comparison. The result shows that mesoporous carbon with a larger pore size displays a higher rate capability. Mesoporous carbon synthesized by modified template method has both high mass specific capacitance and good rate capability.     

Eetopie Bone Formation in vivo Indueed by a Novel Synthetie Peptide Derived from BMP-2 Using Porous Collagen Scaffolds

To investigate the osteoinductive and ectopicly osteogenic effects of a novel peptide P24 derived from bone morphogenetic protein 2 （BMP2）, biodegradable collagen scaffolds （CS） were used to load BMP-2-derived peptide solutions with different concentrations （0.4 mg peptide/CS, 0.1 mg peptide/CS and pure CS, respectively）, and the implants were implanted into muscular pockets on the back of Wistar rats. Radiographs and histological analysis were performed to evaluate the ectopic bone effects. Active ectopic bone formation was seen in both groups containing the peptide at different concentration （0.4 mg and 0.1 mg）, whereas no bone formation and only fibrous tissue was seen in the pure CS group. The new bone formation induced by the peptide P24 displayed a dose-dependent and time-dependent efficiency. The new bone formation in the 0.4 mg peptide/CS group significantly increased than that of the 0.1 mg peptide/CS group. This novel BMP-2-derived peptide had excellent osteoinductive and ectopicly osteogenic properties which were similar to those of BMP2.