Investigation of Ru （ phen ）3^2＋-Hydrazine-Ce（Ⅳ） Chemiluminescence System and Its Analytical Application

0 IntroductionThbiep ycroidmipnlee)xru ctahteinoinu mof(Ⅱ r)u t(he Rniuu(mbip,y m)3ai2n +ly) atrnids- t(r2is -,(21’ -,10-phenanthroline)ruthenium(Ⅱ) (Ru(phen)32 +) ,is a kindof sensitive analytical reagent for electrogenerated chemilumi-nescence(ECL) and chemiluminescence(CL) ,on which a par-ticular review has been presented[1]. The earliest publicationon the synthesis of Ru(bipy)32 +appeared in 1936[2], andduringthefollowing30 years ,theinvestigations relatedtothissubstance were only in…     

Sensitive Determination of DNA by RLS Enhancement of Metal Ions

0　IntroductionThequantitativeanalysisofnucleicacids,especiallythemi cro determinationofnucleicacids,isbecomingmoreandmoreimportantinmanybiologicalstudies.Recently ,apromisingspectraltechnique ,whichwasbasedonthemeasurementofen hancedresonancelightscattering (RLS) [1 ,2 ] ,hasgivenrisetostronginterestbyanalystsandbiochemistsfornucleicacidsandproteinassay[3 9] .Uptonow ,manykindscompoundshavebeenfoundRLSenhancementwhilebindingtoDNA ,andallthesecompoundsarecharacterizedofpositivechargewhicha…     

Effects of the rare earth ions on bone resorbing function of rabbit mature osteoclasts<Emphasis Type="Italic">in vitro</Emphasis>

The osteoclast plays initiating and vanguard roles in the course of bone remodeling. The resorption and formation of bone is the basic clues of bone remodeling, which results from the mutual dependent functions of osteoclasts and osteoblasts. When the osteoclasts are activated, the bone resorption function is increased. The excess bone resorption leads to osteoporosis, characterized by formation of many hollows, lacunae and tunnels on the bone surface or in depth[1,2]. The differentiation, pro…     

灰毛豆Tephrosia purpurea中查尔酮类化合物的分离鉴定

【目的】为探讨灰毛豆属植物Tephrosia purpurea化学成分中的查尔酮类化合物,对其枝、叶部位进行化学成分分离及结构解析。【方法】采用乙醇提取、溶剂萃取、柱层析分离方法得到多种灰毛豆属T.purpurea化学成分,并用波谱分析手段对其进行结构表征。【结果】从灰毛豆属T.purpurea中共分离鉴定出11个查尔酮类化合物,分别为elatadihydrochalcone(1),spinochalcone A(2),3′,5′-diisopentenyl-2′,4′-dihydroxychalcone(3),candidachalcone(4),O-methylpongamol(5),(+)-tephrosone(6),spinochalcone C(7),epoxyobovatachalcone(8),tunicatachalcone(9),crassichalone(10),(S)-elatadihydrochalcone(11)。【结论】以上化合物均为查尔酮,且均属首次从该植物中分离得到。     

Electrochemical determination of trace amounts of lead (II) and cadmium (II) at a calix[6]arene modified carbon paste electrode

An electrochemical method for the simultaneous determination of lead(II) and Cadmium(II) with a calix[6]arene modified carbon paste electrode (CPE) has been developed. Pb²⁺ and Cd²⁺ were accumulated at the surface of the modified electrode via formation of chemical complexes with calix[6]arene, and reduced at 1.40 V. During the following anodic potential sweep, reduced lead and cadmium were oxidized, and two well-defined striping peaks appeared at about −0.60 V and −0.84 V. Compared with a bare carbon paste electrode, the calix[6]arene modified CPE greatly improves the sensitivity of determining lead and cadmium. The stripping peak currents change linearly with the concentration of Pb²⁺ 3.0×10⁻⁸–8.0×10⁻⁶ mol·L⁻¹ and with that of Cd²⁺ 6.0×10⁻⁸–1.0×10⁻⁵ mol ·L⁻¹. The detection limits of Pb²⁺ and Cd²⁺ are found to be 8.0×10⁻⁹ mol·L⁻¹ and 2.0×10⁻⁸ mol·L⁻¹, respectively. The modified carbon paste electrode was applied to determine trace levels of lead and cadmium in water samples. Comparing with that of atomic absorption spectrometry, the results suggests that the calix[6]arene modified CPE has great potential for the practical sample analysis. Foundation item: Supported by the National Natural Science Foundation of China (60171023) Biography: JI Xiao-bo (1980-), male, Master, research direction: electroanalytical chemistry.     

Degradation of 2, 4-D acid using Mn2+ as catalyst under UV irradiation

In this paper, the oxidative degradation of 2, 4-dichlorophenoxyacetic acid (2, 4-D) using Mn²⁺/H₂O₂ reagent under UV irradiation was studied. The results show that 2, 4-D was degraded more completely in Mn²⁺/H₂O₂ solution than traditional Fenton solutions. The effects of the concentration of Mn²⁺, H₂O₂ and pH were also investigated. And under the optimal condition of 1.48×10⁻⁴ mol/L, 8.99×10⁻⁵ mol/L and pH 3.38, the formation of ·OH was the most, both the decomposition rate of H₂O₂ and the degradation rate of 2, 4-D were the fastest. In addition, the photoreaction process was monitored using spin-trapping electron paramagnetic resonance (EPR), and the results indicated that the oxidative process was predominated mainly by the hydroxyl radical (·OH) gennerated in the system. Biography: HUANG Yingping (1964–), Professor, Ph. D., research direction: pollution ecology and water pollution control.     

Study on peptide-peptide interaction using high-performance affinity chromatography and quartz crystal microbalance biosensor

The specific interaction between sense and antisense peptides was studied by high-performance affinity chromatography （HPAC） and quartz crystal microbalance （QCM） biosensor. Fragment 1-14 of human interferon-β （hlFN-βwas chosen as sense peptide and its three antisense peptides （AS-IFN 1, AS-IFN 2, and AS-IFN 3） were designed according to the degeneracy of genetic codes. The affinity column was prepared with sense peptide as ligand and the affinity chromatographic behavior was evaluated. Glu-substituted antisense peptide （AS-IFN 3） showed the strongest binding to immobilized sense peptide at pH 7.5. A quartz crystal microbalance-flow injection analysis （QCM-FIA） system was introduced to investigate the recognition process in real-time. The equilibrium dissociation constants between sense peptide and AS-IFN 1, AS-IFN 2 and AS-IFN 3 measured 2.08×10^-4, 1.31×10^-4 and 2.22×10^-5 mol/L, respectively. The mechanism study indicated that the specific recognition between sense peptide and AS-IFN 3 was due to sequence-dependent and multi-modal affinity interaction.     

Experimental investigation of incremental reactivity of di-tert-butyl peroxide

Large quantities of di-tert-butyl peroxide (DTBP) have been emitted into the troposphere due to human activities. Its role in the atmospheric photochemical reaction has not been understood. This study presents the results of the photochemical reactions of DTBP and NOx, which have been simulated in a self-made smog chamber under the temperature of (29±1)℃. Both the wall decays of ozone and NO2 could be neglected, compared to the results in simulative experiments. The effective intensity of UV light used in the experiments was 1.28×10-3 s-1, which was expressed by the rate constant of NO2 photolysis in purified air. The reaction mechanism was proposed according to our results and reports of other researchers. The maximum values of incremental reactivity (IR) in the three simulative ex- periments were 9.53×10-2, 5.23×10-2 and 3.78×10-2, respectively. The incremental reactivity decreased with the increase of initial concentrations of DTBP. The IR value of DTBP obtained in this study was comparable to that of acetylene reported in our previous research.     

Spectrofluorimetric method for the determination of triamcinolone acetonide

0　IntroductionTriamcinoloneAcetonide,9 fluoro 11β,2 1 dihydroxy 16α,17[(1 methylethylidene)bis (oxy) ] pregn 1,4 diene 3,2 0 dione,Mris 4 34.4 8(abr.TA ) .Itbelongstoaclassofadrenalcortexhormonedrug ,whosefunctionsareaffectionofsugarmetabolism ,anti inflammationandresistancehypersusceptibilityetc.TAcanbesuitabletorheumatoidarthritisanddermatosissuchashypersusceptibilityandneuropathicdermatitis .ThefunctionsofTAisstrongerandlongerthantriamcinolone[1 ,2 ] .ThecommonmethodsofdetectingTAm…     

Effect of Dy3+on osteogenic and adipogenic differentiation of mouse primary bone marrow stromal cells and adipocytic trans-differentiation of mouse primary osteoblasts

A series of experimental methods including 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test, alkaline phosphatase (ALP) activity measurement, mineralized function, Oil Red O stain and measurement were employed to assess the effect of Dy³⁺ on the osteogenic and adipogenic differentiation of mouse primary bone marrow stromal cells (BMSCs) and the adipogenic trans-differentiation of mouse primary osteoblasts (OBs). The results showed that Dy³⁺ had no effect on BMSC proliferation at concentrations of 1×10⁻⁸ and 1×10⁻⁵ mol/L, but inhibited BMSC proliferation at other concentrations. Dy³⁺ had no effect on OB proliferation at concentrations of 1×10⁻¹⁰ and 1×10⁻⁹ mol/L, but inhibited OB proliferation at other concentrations. Dy³⁺ had no effect on the osteogenic differentiation of BMSCs at concentrations of 1×10⁻⁹ and 1×10⁻⁷ mol/L, and promoted osteogenic differentiation of BMSCs at other concentrations at the 7th day. The osteogenic differentiation of BMSCs was inhibited by Dy³⁺ at concentration of 1×10⁻⁵ mol/L at the 14th day, but promoted osteogenic differentiation of BMSCs at concentrations of 1×10⁻⁹, 1×10⁻⁸, 1×10⁻⁷ and 1×10⁻⁶ mol/L with the maximal effect at concentration of 10⁻⁶ mol/L. Dy³⁺ promoted mineralized function of BMSCs at any concentration. Dy³⁺ had no effect on adipogenic differentiation of BMSCs at concentration of 1×10⁻⁷ mol/L, but inhibited adipogenic differentiation of BMSCs at other concentrations. Dy³⁺ inhibited adipocytic trans-differentiation of OBs at any concentration, suggesting that Dy³⁺ had protective effect on bone and the protective effect on bone may be mediated by modulating differentiation of BMSCs away from the adipocyte and inhibiting adipocytic trans-differentiation of OBs which may promote differentiation and mineralization of OBs. These results may be valuable for better understanding the mechanism of the effect of Dy³⁺ on pathogenesis of osteoporosis. Supported by the Foundation for Key Program of Ministry of Education of China (Grant No. 208018)     

Electrocatalytic oxidation of H<Subscript>2</Subscript>O<Subscript>2</Subscript> at a carbon paste electrode modified with a nickel (II)-5, 11, 17, 23-tetra-tert-butyl-25, 27-bis(Diethylcarbamoylmethoxy) calix[4] arene complex and its application

Electrochemical behavior of a carbon paste electrode (CPE) modified with nickel(II)-5, 11, 17, 23-tetra-tert-butyl-25, 27-bis(diethylcarbamoylmethoxy) calix[4]arene (Ni (II)-L) complex and its electrocatalytic activity towards the oxidation of hydrogen peroxide were investigated by cyclic voltammetric technique in a 5.0×10⁻² mol/L NaClO₄+1.0×10⁻³ mol/L NaOH solution. It was found that Ni(II)-L acts as an effective catalyst for the oxidation of hydrogen peroxide. The modified electrode exhibited a linear response over a hydrogen peroxide concentrations in the range of 2.0×10⁻⁵−1.0×10⁻⁴ mol/L with a detection limit as low as 1.0×10⁻⁶ mol/L. The relative standard deviation was 3.5% for 5 successive determinations of H₂O₂ at 1.0×10⁻⁵ mol/L. The modified electrode was used successfully in rainwater analysis. Foundation item: Supported by the Natural Science Foundation of Hubei Province (98J040). Biography: Li Chun ya(1972-), Ph. D. candidate, research direction: electroanalysis and electrosynthesis.     

Solid-phase preparation and characterization of Chitosan

0　IntroductionChitosanhasbeenwidelyusedinpharmaceu tical,agriculturalandindustrialfieldbe causeofitsintriguing properties[1 ] .Chemicalmethodstopreparechitosanfromchitinhavebeenbroadlystudiedincludingsolutionmethod ,meltedalkalinemethod,microwavesemi drymethod ,improvedLinelbergmethod ,dissolution precipita tionmethodandsoon ,inwhichalkalinewasallusedasthecatalyst[2 ] .Biologicalmethodwasapromisingwayinthatitproducedlittleenviron mentalpollutionanditsreactionconditionsweremild .However,thism…     

Analysis of the characteristics of the harmonics coefficient <Emphasis Type="Italic">J</Emphasis><Subscript>2</Subscript> of the Earth’s gravity field in different periods

The characteristics of the geopotential coefficient J2 in different periods are analyzed using satellite laser ranging data spanning the last 27 years.The satellites used in the analysis are Lageos1 and Lageos2.The variations in J2 are obtained by determining the dynamic orbit.The results show that there are strong seasonal and long-term variations.For different data spans,the seasonal variations agree well in terms of both amplitude and phase.Using all the data,the amplitude and phase of the annual term are 2.5 10-10 and 127°,respectively,while the amplitude and phase of the semiannual term are 0.94 10-10 and 213°,respectively.In the case of long-term variation,the secular variation in J2(J2) is-2.2 10-11 a-1 from 1984 to 2010.J2 differs for the different periods because of interannual variations,such as the "1998 anomaly".Another anomaly may have taken place during 2007-2010.Although the cause of the anomaly is unknown,it is an important observational constraint on the shape of the Earth.     

Electrochemical Behavior and Determination of Trifluoperazine at Decanethiol Self-Assembled Monolayer Modified Gold Electrodes

0　IntroductionTrifluoperazine is a derivative of phenothiazine. It hasneuroleptic and antidepressive actions, hence has beenwidely used in the treatment of psychotic patients[1]. As it hassuch function and application, trifluoperazine’s characteristicsand detection methods were studied by means of spectropho tometry[2], capillary zone electrophoresis[3], titrimetry[4],fluorometry[5], high performance liquid chromatographyetc[6]. Because of the electroactivity of trifluoperaz…     

Isotopic composition of helium in eclogite from the Dabie Mountains, central China and its geological significance

Isotopic geochemical characteristics of helium in garnet and omphacite of eclogite in the Dabie Mountains are discussed. Concentrations of³He and⁴He in garnet and omphacite are 3.9 × 10⁻¹⁴–24.0 × 10⁻¹⁴ and 0.48 × 10⁻⁷–9.42 × 10⁻⁷cm¹³.g⁻¹, respectively. Values of³He/⁴He have a range of (1.19–4.63) × 10⁻⁷. Helium In the eclogite is derived from both mantle and crust. Isotopic geochemical data of helium indicate that eclogite in the Dabie Mountains might be formed in depleted mantle and the age of the cologite would be Indo-China epoch.     

Adsorption and reduction of palladium (Pd<Superscript>2+</Superscript>) by <Emphasis Type="Italic">Bacillus licheniformis</Emphasis> R08

Preliminary study on the mechanism of Pd²⁺ biosorption by resting cells of Bacillus licheniformis R08 biomass has been carried out by means of chemical kinetics and AAS, TEM, XRD and FTIR methods. The results showed that at 30℃ and pH 3.5, when dry R08 biomass powder (800 mg/L) was mixed with Pd²⁺ (100 mg/L) for 45 min, the rate constant k of biosorption of Pd²⁺ attained a maximum of 5.97×10^-2 min^-1 and the half life period of the reaction reached 12 min. The part of Pd²⁺ adsorbed by R08 biomass was reduced to elemental, cell-bound Pd⁰ at the same condition. The cell wall of R08 biomass was the primary location for accumulating Pd²⁺ , and aldoses, i. e. hydrolysate of a part of polysaccharides on the peptidoglycan layer in the acidic medium, serving as the electron donor, in situ reduced the Pd²⁺ to Pd⁰.     

Microcalorimetric study on the antibiotic activity of clarithromycin and erythromycin

By using LKB-2277 Bioactivity Monitoring System, the heat effect changes in the process of inhibitory action of clarithromycin and erythromycin onEscherichia coli at 37°C were determined. Quantitative analysis showed that relationship between antibiotic concentrationc and rate contantk ofEscherichia coli growth, and half inhibitory ratio concentration IC₅₀: clarithromycin:k=0. 030 03–1. 1736×10⁻³ c, 8. 45 mg ·L⁻¹; erythromycin:k=0.031 08–8.4657×10⁻⁴ c, 14. 45 mg·L⁻¹. As a result of the microcalorimetry experiments, it not only indicated that antibacterial activity of clarithromycin was stronger than that of erythromycin, but also reported the changeable features of thermodynamics of the bacterial cell in biological, biochemical and metabolic process under different drug action. Foundation item: Supported by Natinal Natural Science Fundation of China (29973030), Natural Science Fundation of Hubei Province (98J052) and Post-doctoral Science Fundation of China Biography, SHEN Xue-song (1956-), Associate professor Research direction: biothermochemistry.     

Synthesis mechanism of LiNiVO4 by wet chemical method and mixed valence of nickel and vanadium

The single phase LiNiVO₄ has been successfully synthesized by adopting a new mild liquid route with oxalic acid as both complexant and precipitant, and this method is named the CPG method. The products were obtained by sintering the dry gel precursor which was prepared by the CPG method at 200—850℃ for 2—10 h in air. The products were tested by XRD, XPS, ESR and TGA-DTA, and the results indicate that the single phase LiNiVO₄ could be obtained at 450℃ for 2—3 h in air and LiNiVO₄ was still steady at 850℃ for 10 h. The valence analyses show that in LiNiVO₄ the valence of lithium is +1, both nickel and vanadium have the mixed valence, namely +2, +3 for nickel and +4, +5 for vanadium respectively. The LiNiVO₄ can be expressed as LiNi³⁺_xNi²⁺_1-xV⁴⁺_xV⁵⁺_1-xO₄ (0≤x<1). The pyrolysis mechanism of the dry gel is also discussed.     

Near-infrared to visible up-conversion emissions of Er^3＋ doped Al2O3 powders derived from the sol-gel method

The Er3 doped Al2O3 powders were prepared by the sol-gel method using the aluminium isopropoxide [Al(OC3H7)3]-derived Al2O3 sols with addition of the erbium nitrate [Er(NO3)3.5H2O]. The different phase structure, including three crystalline types of (Al,Er)2O3 phases, γ, θ, α, and two Er-Al-O phases, ErAlO3 and Al10Er6O24, was obtained with the 1 mol% Er3 doped Al2O3 powders at the different sintering temperatures of 600―1200℃. The green and red up-conversion emissions centered at about 523, 545 and 660 nm, corresponding respectively to the 2H11/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of Er3 , were detected by a 978 nm semiconductor laser diodes excitation. The phase structure and OH content had evident influence on the up-conversion emissions intensity. The maximum intensities of both the green and red emissions were obtained respectively for the Er3 doped Al2O3 powders sintered at 1200 ℃, which was composed mainly of α-(Al,Er)2O3, less of ErAlO3 and Al10Er6O24 phases, and with the least OH content. The two-photon absorption up-conversion process was involved in the green and red up-conversion emissions of the Er3 doped Al2O3 powders.     

Biosorption of Cu（Ⅱ） and Pb（Ⅱ） by Auricularia polytricha

For searching biological material for heavy metal removal of waste-water, using macrofungus Auricularia polytricha as biosorbent for Cu^2＋ and Pb^2＋ removal was investigated. After shaking and biosorbing Cu^2＋ and Pb^2＋ in solution by biosorbents, the filtrates were tested by AAS and the adsorbed quantity of Cu^2＋ and Pb^2＋ was calculated. The biosorbents were effective in removal of Cu^2＋ and Pb^2＋ on the biosorbents that showed a high- est value around pH 5-6. The biosorption rate of Cu^2＋ and Pb^2＋ on A. polytricha biomass decreased with increasing the initial concentration of Cu^2＋ and Pb^2＋ in the medium. The biosorption of Cu^2＋ and Pb^2＋ on the biomasses follows pseudo-second order kinetics. The determined maximum biosorption capacities presented by the fungus biomass were 3.34 and 13.03 mg·g^-1 dry weight for Cu^2＋ and Pb^2＋, respectively by the biosorption equilibrium with Langmuir adsorption isotherm. According to the whole data analysis in each experiment of studying Cu^2＋ and Pb^2＋ biosorption including condition factors and adsorption isotherm, the adsorbed capacity of Pb^2＋ by A. polytricha biomass was bigger than Cu^2＋. The biosorption by A. polytricha was most effective when pH 5-6. The biosorbents are suitable for low Cu^2＋ and Pb^2＋ concentration waste-water, especially for Pb^2＋ removal.