Effects of Cu2+ and Ph on osteoclastic bone resorption in vitro

The effects of Cu2+ and pH on osteoclastic bone resorption lacunae are studied by culturing Japanese white rabbit osteoclasts on bone slices. The number and surface area of bone resorption lacunae are measured by photomicrography and image analysis. Concentration of calcium ion in the supernatant is measured by atomic absorption spectrometry to evaluate the activity of osteoclasts. The morphology of the lacunae is observed under a scanning electron microscope. The results indicate that Cu2+ at concentration of 1.00×10-6 mol/L and 1.00×10-7 mol/L inhibits osteoclastic activity and causes a dose-dependent reduction in the number and surface area of the lacunae. While the number of lanunae is increased and osteoclastic bone resorbing function is significantly improved at Cu2+ concentration of 1.00×10-8 mol/L. It is suggested that the effect of Cu2+ on osteoclastic bone resorption depends on Cu2+ concentration. pH had no significant effect on osteoclastic function in the near neutral range.     

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)     

Multi-color long-lasting phosphorescence of rare earth ions in CdSiO<Subscript>3</Subscript> matrix

A series of rare earth ions doped CdSiO3:RE^3 (RE=Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho,Er, Tin, Yb, Lu) multi-color long-lasting phosphorescence phosphors are prepared by the conventional hightemperature solid-state method. The results of XRD measurement indicate that the products fired under 1050~C for 3h have a good crystallization without any detectable amount of impurity phase. Rare earth ions doped CdSiO3 phosphors possess excellent Inmiuescence properties. When rare earth ions such as Y^3 , La^3 , Gd^3 , Lu^3 , Ce^3 , Nd^3 , Ho^3 , Er^3 ,Tm^3 and Yb^3 are introduced into the CdSiO3 host, one broadband centered at about 420 nm resulting from traps can be observed. In the case of other earth ions such as Pr^3 ,Sm^3 , Eu^3 , Tb^3 and Dy^3 , their characteristic line emitting as well as the -420 nm broadband luminescence can be obtained. The mixture of their characteristic line emitting with the -420 nm broadband Inminescence results in various afterglow color.     

Study on state of terbium ion in liposome by one-order derivative fluorescence quenching method

The state of Tb³⁺ is investigated in liposome. When the concentration of PC is below CMC (critical micell concentration), most of Tb³⁺ is associated with PC, the binding constant is about 3.35×10³ L/mol. When the concentration of PC is beyond CMC, most of Tb³⁺ is dimerized, the dimerization constant is about 3.92×10⁴L/mol. In PC−CH−H₂O system, the binding constant of Tb³⁺−CH complex 2.93×10⁴L/mol is obtained. Biography:Mu Xiao-jing (1974-), female, MS.     

Nd1-xZnxFeO3纳米材料的甲烷气体气敏性研究

采用Sol-gel法制备出Nd_1-xZn_xFeO₃（x=0, 0.04, 0.08, 0.2）粉体. XRD图谱表明Nd_1-xZn_xFeO₃粉体为正交钙钛矿结构，产物为纳米级颗粒(16～17.5nm)，平均粒径随x的增大有所减小. 用Nd_1-xZn_xFeO₃纳米粉体制成气敏元件，测试了材料对甲烷气体的气敏特性. 测试结果表明Zn的适量掺入可提高对甲烷的灵敏度. 其中以Nd_0.92Zn_0.08FeO₃对甲烷的灵敏度最大，在最佳工作温度200℃下对4×10^-6mol/L的甲烷气体灵敏度最大值为3.87，对2×10^-5mol/L的甲烷气体中灵敏度最大值为16. Nd_0.92Zn_0.08FeO₃还表现出了极好的响应恢复时间特性，工作温度200℃时对2×10^-5mol/L的甲烷响应、恢复时间分别为25s和45s.     

聚L-谷氨酸/石墨烯修饰电极对碘的测定

使用循环伏安法制备了聚L-谷氨酸/石墨烯修饰电极,应用扫描电镜和阻抗对修饰电极进行了表征,建立了示差脉冲伏安法测定碘的新方法。研究结果表明,在最佳实验条件下,使用示差脉冲伏安法(DPV)法测定碘,碘浓度在1.00×10-3～5.00×10-7 mol/L浓度范围内与峰电流呈现良好的线性关系,检出限为1.00×10-7 mol/L。该方法用于测定样品中的碘,结果令人满意。     

Zn release from fluid inclusions in a natural sphalerite

The type, size, and compositions of fluid inclusions in a natural sphalerite were investigated and the total concentration of Zn released from the fluid inclusions was measured. To compare the total concentration of Zn released from the fluid inclusions with that dissolved from the sphalerite itself, dissolution experiments and theoretical calculations for the dissolution equilibrium of the sphalerite were also performed. The results indicate that large numbers of fluid inclusions with various sizes exist in the sphalerite, which can be divided into four types, i.e., pure gaseous inclusions, pure liquid inclusions, gas-liquid inclusions, and gas-liquid inclusions containing solid minerals. These inclusions were broken open during the grinding process, and their compositions were released to the solution. The total concentration of Zn released from these inclusions reaches 18.35×10?6 mol/L, which is much higher than that of Zn dissolved from the sphalerite itself (1.93×10?6 mol/L) and the theoretical calculation value (2.73×10?8 mol/L).     

Study of the voltammetric behavior of heme and its direct analysis application

The electroanalytical method of ferriheme was studied by linear sweep voltammetry in medium of 0.05 mol/L Tris+0.05 mol/L NH₃−NH₄Cl buffer at hang mercury drop electrodes (HMDE). Heme exhibits two pair reversible redox peaks and one irreversible peak. The cathodic peak potentials are−;0.236 V, −0.422 V and −1.408 V respectively. The first and the third peaks can be used for directly quantitative determination of heme concentrations. The peak currents are good linear relationship with heme concentration in ranges of 3×10⁻⁶–6×10⁻⁵ mol/L and 3×10⁻⁷–1.5×10⁻⁵ mol/L respectively. Supported by the National Natural Science Foundation of China Lju Huihong: born in 1965, Lecturer. Visiting scholar from Xiangyang Teacher’s College, Hubei, 441053     

Icariin suppresses bone resorption activity of rabbit osteoclasts in vitro

The effect of icariin on the bone resorption activity of rabbit osteoclasts is assessed in vitro. Osteoclasts were isolated from Japanese white rabbits and cultured on plates with a sterilized bone slice in each well. After treatment with icariin at various concentrations, the bone resorption activity of osteoclasts was evaluated by examining pit areas, superoxide anion (·O2-) generation, size and number of actin rings and intracellular calcium concentration [Ca2 ]i. As revealed by these data, icariin elicited continuous decline of [Ca2 ]i, making actin ring constricted and ·O2- generation decreased. These events resulted in smaller and fewer pits which indicate suppressed bone resorption activity of rabbit osteoclasts by icariin.     

Preparation and application of electrochemical barbital sensor based on molecularly imprinting technique

A molecularly imprinted electrochemical sensor was prepared based on poly folic acid(PFA) for rapid detection of barbital(BAR). The PFA membrane was obtained via directly electropolymerization technique on the surface of chemically modified Au electrode(Au/CME) by means of cyclic voltammetry(CV) in the potential range between-0.4 and 1.0 V in phosphate buffer solution(PBS) pH 7.04. The molecularly imprinted polymers(MIP) membrane was synthesized with BAR as template molecules and folic acid(FA) as the functional monomer. The performance and surface feature of the proposed imprinted sensor were investigated using CV, differential pulse voltammetry(DPV), electrochemical impedance spectroscopy(EIS) and scanning electron microscope(SEM). Under the optimized conditions, the peak current decrease(ΔI_p) was proportional to the BAR concentration in the range of 1.00×10~(–7)-1.00×10~(–4) mol/L(R~2=0.998 2) with a detection limit(S/N=3) of 4.65×10~(–8) mol/L. The results indicated that the imprinted sensor exhibited an excellent selectivity for BAR and it was successfully used to determine BAR in real samples with recoveries of 94.7%-106.2% by using the standard addition method.     

Magnetic records of heavy metal pollution in urban topsoil in Lanzhou, China

This study is a systematic analysis of the magnetic characteristics and heavy metal elements in soil samples collected from Lanzhou City,China.The 117 surface soil samples were measured to study the feasibility and effectiveness of environmental magnetism for evaluating heavy metal pollution in urban soils.Results of the study indicate that low-coercivity magnetite dominates the magnetic properties in the samples.The high values of the soil magnetic mineral concentration parameters and low values of magnetic particle size parameters are distributed throughout the northern area of Xigu District,the industrial zones of the eastern section of Chengguan District and the districts of the narrow sections connecting Chengguan District and the other three districts;these parameters are fundamentally consistent with the distribution of the high values of the Pollution Load Index and Nemerow Pollution Index.Semi-quantitative studies which use the environmental magnetic method to monitor pollution of heavy metals(such as As,Cr,Cu,Ni,Pb,Zn,and Fe) have shown that when xlf≤35×10-8 m 3 kg-1,it is unpolluted;when 35≤xlf <150×10-8 m3 kg-1,it is moderately polluted to unpolluted;when 150≤xlf <365×10-8 m 3 kg-1,it is moderately polluted;when 365≤xlf <750×10-8 m3 kg-1,fd %<2.7 and ARM /SIRM<0.2×10-3m A-1,it is moderately to highly polluted;when xlf ≥750×10-8 m3 kg-1,xfd %<2.7 and xARM/SIRM<0.2×10-3m A-1,it is highly polluted.The region of moderately to highly polluted distribution is caused by industry and vehicles,showing that the change of pollution in Lanzhou City bears the trend of "vehicle emission + industrial".     

Determination of isocarbophos by cathodically sweeping oscilliopolarography

Determination of isocarbophos by cathodically sweeping oscilliopolarography is described. In a 1.0×10⁻⁵ mol/L sodium dodecylbenzene sulfonate (SDS)+0.1 mol/L HAC-NaAC (pH=4.0) buffer medium, isocarbophos and its alkaline hydrolysate exhibited sensitive second derivative wave at −0.50 V and −0.48 V respectively. The peak current was linearly proportional to the concentration of isocarbophos in the range of 5.40×10⁻⁶−1.05×10⁻⁴ mol/L by detecting isocarbophos directly. The detection limit was 3.60×10⁻⁶ mol/L with the relative standard derivation (RSD) of 7.3%. By employing an alkaline hydrolysis, the peak current was linearly proportional to the concentration of isocarbophos in the range from 7.70×10⁻⁷ mol/L to 1.24×10⁻⁴ mol/L, and the detection limit was 5.80×10⁻⁷ mol/L with RSD of 3.1%. The hydrolysis procedure and the electrode reaction were studied by voltammetry. Foundation item: Supported by the Foundation of Chinese-France Cooperation Program on Advanced Research Biography: ZHANG Wu-ming (1929-), female, Professor.     

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.     

铂微粒修饰固体石蜡碳糊电极对过氧化氢的电催化特征及分析应用

研究铂微粒修饰的固体石蜡碳糊电极(Pt-SCPE)对H2O2的电催化行为。在pH值4.6的柠檬酸盐-0.03 mol/L硝酸钾溶液中,用该电极H2O2在+0.18V(vs．SCE)可产生灵敏的还原电流,线性范围为1.0×10-1 mol/L～3.0×10-7 mol/L,检出限为7.5×10-8 mol/L。Pt-SCPE与液体石蜡碳糊电极比较,在峰电位、线性响应范围、检出限方面有更好的结果。用该电极测定样品中的过氧化氢,获得满意结果。     

Chemiluminescence determination of tetracycline and oxytetracycline in pharmaceutical preparations using Ru (bipy)3 2+-cerium (IV) system

A new chemiluminescence (CL) method for the determination of tetracycline and oxytetracycline is developed, based on the CL reaction of tetracycline and oxytetracycline with Ru (bipy)₃ ²⁺ and Ce (IV). In sulfuric acid medium, the CL emission is generated upon continuous oxidtion of Ru(bipy)₃ ²⁺ by cerium (IV). The emission intensity is greatly enhanced when tetracycline and oxytetracycline are introduced into the reaction system after acid degradation. Under the optimum conditions, the calibration curves are linear over the range of 8.0×10⁻⁸∼4.0×10⁻⁶ mol/L for tetracycline and of 2.0×10⁻⁷∼4.0×10⁻⁵ mol/L for oxytetracycline, with the detection limits are 4.2×10⁻⁸ mol/L for tetracycline and 1.5×10⁻⁷ mol/L for oxytetracycline, respectively. The proposed method was used for the determination of tetracycline and oxytetracycline in pharmaceutical formulations with good results. Foundation item: Supported by the National Natural Science Foundation of China and the Natural Science Foundation of Hubei Province. Biography: HAH He-you (1962), male, Associate profeddor, Ph.D graduate candidate. Present address, Department of Chemistry, Huainan Teacher's College, Huainan.     

The voltammetric behavior of concanavalin a at bare silver electrode and analytical application

The voltammetric behavior of concanavalin A at the bare silver electrode is described. Cyclic voltammograms show a pair of well-defined redox peaks for concanavalin A in the medium of phosphate buffer(pH=7.0) with electrochemical reaction rate constant ofK ₂=0.053 s^?1 and electron transfer number ofn=2. Moreover, both the oxidation currents and the reduction currents have linear relationship with concanavalin A concentrations in the range of 1.0×10^?6～2.0×10^?5 mol/L, which can be used as an analytical method for determining concanavalin A concentration.     

Purification and inhibition fungal growth of chitinases from<Emphasis Type="Italic">Vibrio pacini</Emphasis>

Vibrio pacini synthesizes multiple chitinases, of which three have been purified in this study by ammonium sulphate fractionation, chitin affinity chromatography and gel chromatography. Molecular weights of the three chitinases, Chi1, Chi2 and Chi3 are 27×10³, 39×10³ and 46×10³ respectively, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The purified enzymes have optimal activity at pH 7–8, and retain 50% enzymatic activity pH 4–9. The activities of chitinases are inhibited by Pb²⁺, Fe³⁺ and Cu²⁺, and increased by Ca²⁺, Mg²⁺ and Mn²⁺. Chi3 is found to inhibit the growth of six species of fungi. Such characters of chitinase are different from those of any other chitinase that were reported before. Foundation item: Supported by the Key Technologies Research and Development Programme of the Tenth Five-Year Plan of the Nation Scientific and Technological Development (2001 BA708B04-07) Biography: HAN Bao-qin (1963-), female, Professor.     

Determination of omethoate by cathodically sweeping oscillopolarography

Determination of omethoate by cathodically sweeping oscillopolarography is described. The product of the alkaline hydrolysis exhibited a sensitive second derivative wave at −0.50 V (vs. SCE) in a 1.0 ×10⁻⁵mol/L sodium dodecylbenzene sulfonate (SDBS)+0.1 mol/L HAc-NaAc (pH 4.0) buffer. The peak current was linearly proportional to the concentration of omethoate in the range from 6.4×10⁻⁷ to 5.1×10⁻⁵ mol/L. The detection limit is 2.0×10⁻⁷ mol/L with the relative standard derivation (RSD) of 3.5%. The hydrolysis procedure and the electrode reaction were studied by voltammetry. Supported by the Foundation of Chinese-Franch Cooperation Programme on the Advanced Research Wang Yu: born in 1964. Lecturer. Cangzhou Teacher’s College, Cangzhou, Hebei, 061001     

Antilocalization sensing of interactions between two-dimensional electrons and surface species

We apply antilocalization measurements to experimentally study the interactions and exchange between InAs surface accumulation electrons and local magnetic moments of the rare earth ions Sm3?,Gd3?,Ho3?,and Dy3?,of the transition metal ions Ni2?,Co2?,and Fe3?,and of Fe3O4nanoparticles and Fe3?-phthalocyanine deposited on the surface.The influence of the deposited species on the surface electrons is observed through the changes in the spin–orbit scattering and magnetic spin-flip scattering rates,which carry information about magnetic interactions.Experiments indicate a temperature-dependent magnetic spin-flip scattering for Ho3?,Dy3?,Ni2?,and Co2?.Concerning the spin–orbit scattering rate,we observe an increase,except for the cases of Ni2?,Fe3?,Fe3O4nanoparticles and Fe3?-phthalocyanine.We also observe an increase in SO scattering in another system where we study the interactions of Au nanoparticles and ferromagnetic Co0.6Fe0.4nanopillars and an In0.53Ga0.47As quantum well.Experimental results are analyzed and compared to theoretical models.Our method provides a controlled way to probe the quantum properties of two-dimensional electron systems,either on the surface of InAs or in a quantum well.