Assembly of TiO2 -on-Cu2 O Nanocubes with Narrow-Band Cu2 O-Induced Visible-Light-Enhanced Photocatalytic Activity.

Newly designed TiO2 -on-Cu2 O nanocubes have been constructed as visible-light-driven photocatalysts with high efficiency by means of a facile self-assembly approach at room temperature. In the resultant TiO2 -on-Cu2 O nanocubes, the TiO2 nanoparticles with a diameter of 6-8 nm show a well-monodispersed distribution of the 200-300 nm-sized Cu2 O single-crystal nanocubes, which can form sub-monolayer, monolayer, and multilayer coverage through controlling the ratio of the two phases. In particular, the coupling of the wide-bandgap semiconductor TiO2 with narrow-bandgap Cu2 O can lead to the markedly enhanced high visible-light photocatalytic activity in the TiO2 -on-Cu2 O nanocomposite systems toward the photodegradation of rhodamine B, which is induced by the bandgap-adjusting effect. This promising self-assembly route can be extended to the preparation of other nanocomposite materials.

Electrospinning preparation and electrical and biological properties of ferrocene/poly(vinylpyrrolidone) composite nanofibers.

Nanofibers containing ferrocene (Fc) have been prepared for the first time by electrospinning. In this paper, Fc was dispersed uniformly throughout the poly(vinypyrrolidone) (PVP) matrix for the purpose of combining the properties of PVP and Fc. The effects of solvents and Fc concentration on the morphologies and diameters of nanofibers were investigated. In the DMF/ethanol solvent, the morphologies of the obtained nanofibers significantly changed with the increase of Fc concentration. The results demonstrated that the morphologies of the nanofibers could be controlled through adjusting solvents and Fc concentration. Scanning electron microscopy (SEM) showed that the diameters of the obtained composite fibers were about 30-200 nm at different Fc concentrations. Thermogravimetric analysis (TGA) results confirmed the presence of ferrocene within the PVP nanofibers. X-ray diffraction (XRD) results showed that the crystalline structure of Fc in the fibers was amorphous after the electrospinning process. A biological evaluation of the antimicrobial activity of Fc/PVP nanofibers was carried out by using Gram-negative Escherichia coli (E. coli) as model organisms. The nanofibers fabricated by this method showed obvious antibacterial activity. Electrochemical properties were characterized based on cyclic voltammetry measurements. The CV results showed redox peaks corresponding to the Fc(+)/Fc couple, which suggested that Fc molecules encapsulated inside PVP nanofibers retian their electrochemical activity. The properties and facile preparation method make the Fc/PVP nanofibers promising for antibacterial and sensing applications.

Development of validated quantitative structure-retention relationship models for retention indices of plant essential oils.

Quantitative structure-retention relationship (QSRR) models were developed for the retention indices of 505 frequently reported components of plant essential oils. Multiple linear regression was used to build QSRR models for the dimethyl silicone, dimethyl silicone with 5% phenyl groups, and polyethylene glycol stationary phases. We tried to improve the variable selection and modeling method based on prediction method for selecting the optimum descriptors from the molecular weight, 75 topological indices, and 170 atom-type E-state indices. The three-variable QSRR models perform high correlation coefficients of 0.937 for dimethyl silicone and 0.933 for dimethyl silicone with 5% phenyl groups stationary phase. Four variables were selected to developed QSRR model for the polyethylene glycol stationary phase. The leave-one-out and leave-many-out cross-validations, bootstrapping, and y-randomization test showed the three models are robust and have no chance correlation. The external validation with the test set showed the three models present high externally predictive power. The three models presented high-quality fit, internally, and externally predictive power. It is expected that the models can effectively predict retention indices of essential oils components without experimental value.

Chemometric model for predicting retention indices of constituents of essential oils.

Quantitative structure-retention relationships (QSRRs) model was developed for predicting the gas chromatography retention indices of 169 constituents of essential oils. The ordered predictors selection algorithm was used to select three descriptors (one constitutional index and two edge adjacency indices) from 4885 descriptors. The final QSRR model (model M3) with three descriptors was internal and external validated. The leave-one-out cross-validation, leave-many-out cross-validation, bootstrapping, and y-randomization test indicated the final model is robust and have no chance correlation. The external validations indicated that the model M3 showed a good predictive power. The mechanistic interpretation of QSRR model was carried out according to the definition of descriptors. The results show that the larger molecular weight, the greater the values of retention indices. More compact structures have stronger intermolecular interactions between the components of essential oils and the capillary column. Therefore, the result meets the five principles recommended by the Organization for Economic Co-operation and Development (OECD) for validation of QSRR model, and it is expected the model can effectively predict retention indices of the essential oils.

One-Step Synthesis and High-Efficiency Decoloration of Multifunctional Porous-C/Fe3 O4 Nanospheres by Using a Sandwich-Structured Precursor with Three Roles.

A new strategy for the one-step synthesis of multifunctional porous-C/Fe3 O4 nanospheres has been successfully developed by using ferrocenyl formic acid as a precursor. Based on its special structure, this sandwich structural precursor of ferrocenyl formic acid plays three roles in the synthesis process: it simultaneously serves as the carbon and iron source, templating agent, and pore-forming agent. The proposed synthesis is corroborated by characterization through SEM, TEM, XRD, FTIR spectroscopy, Raman spectroscopy, BET surface area measurements, BJH distributions, and vibrating sample magnetometry. The average diameter of as-synthesized porous-C/Fe3 O4 nanospheres is about 400 nm. Because of the porous structure of carbon nanospheres and its surface plasmon resonance with attached Fe3 O4 nanoparticles, the as-synthesized porous-C/Fe3 O4 nanospheres exhibit high activity toward the decoloration of rhodamine B. In addition, the resultant composites present ferromagnetic behavior with a magnetization saturation of 13.76 emu g-1 , can be easily separated and recycled by an external magnet field for use in a variety of applications.

A controlled release system of titanocene dichloride by electrospun fiber and its antitumor activity in vitro.

In order to improve both safety and efficacy of cancer chemotherapy of titanocene dichloride and overcome the shortcomings such as instability and short half-life in the human body, we report a controlled release system of titanocene dichloride by electrospun fiber and its in vitro antitumor activity against human lung tumor spca-1 cells. The system was developed by electrospinning. The release profiles of titanocene dichloride in PBS were researched by UV-Vis spectrophotometer. In vitro antitumor activities of the fibers were examined by MTT method. Titanocene dichloride was well incorporated in biodegradable poly(L-lactic acid) fibers. XRD results suggest that titanocene dichloride exists in the amorphous form in the fibers. The controlled release of titanocene dichloride can be gained for long time. MTT showed actual titanocene dichloride content 40, 80, 160 and 240 mg/L from the fibers mat, cell growth inhibition rates of 11.2%, 22.1%, 44.2% and 68.2% were achieved, respectively. The titanocene dichloride released has obvious inhibition effect against lung tumor cells. The system has an effect of controlled release of titanocene dichloride and may be used as an implantable anticancer drug in clinical applications in the future.

Inducing synthesis of amorphous EuFePt nanorods and their comprehensive enhancement of magnetism, thermostability and photocatalysis.

EuFePt ternary amorphous alloy nanorods are first synthesized through Eu itself inducing action, and this nanoalloy including 4f electrons exhibits excellent properties on magnetism, thermostability, especially the cooperation photocatalysis activity of TiO(2).

Characterization of the transient species generated by the photoionization of Berberine: a laser flash photolysis study.

Using 266 nm laser flash photolysis it has been demonstrated that Berberine (BBR) in aqueous solution is ionized via a mono-photonic process giving a hydrated electron, anion radical that formed by hydrated electron react with steady state of BBR, and neutral radical that formed from rapid deprotonation of the radical cation of BBR. The quantum yield of photoionization is determined to be 0.03 at room temperature with KI solution used as a reference. Furthermore utilizing pH changing method and the SO(4.)(-) radical oxidation method, the assignment of radical cation of BBR was further confirmed, the pK(a) value of it was calculated, and the related set up rate constant was also determined.

Degradation of phenanthrene by bacterial strain isolated from soil in oil refinery fields in Shanghai China.

A bacterial strain Pseudomonas stutzeri ZP2 was identified with phenanthrene-degrading ability based on Gram staining, oxydase reaction, biochemical tests, FAME analysis, G+C content and 16S rDNA gene sequence analysis. It is the first time that P. stutzeri is reported to process the capability for phenanthrene degradation. The strain was isolated from soil samples contaminated with polycyclic aromatic hydrocarbon (PAH)-containing waste from an oil refinery field in Shanghai, China. Strain P sp. ZP2 can utilize naphthalene, phenanthrene and Tween 80 as its sole carbon source and can degrade phenanthrene very fast, 6 days for 96% phenanthrene at 250 ppm concentration. The optimal growth conditions of strain ZP2 was determined to be at pH 8.0, 37 degrees C, respectively. The results also indicate that strain ZP2 can remove more than 90% of phenanthrene at any concentrations ranged from 250 to 1000 ppm in 6 days. It suggests that strain ZP2 can endure high concentrations of phenanthrene. Besides, the effects of non-ionic surfactants such as Brij 30, Triton X100 and Tween 80, on the phenanthrene degradation were examined. Therefore, this strain may find great application in bioremediation practices.

[Evaluation of diagnosing cervical vertigo with computerized static posturography].

OBJECTIVE: To provide a quantitative base for diagnosing cervical vertigo by establishing a biomechanics method. METHODS: From July 2004 to Nov 2005, the static posturography (SPG) of normal 86 health individuals and 75 patients with cervical vertigo were quantitatively measured and qualitative diagnosis respectively in closed and open eyes. There were 40 male and 46 female in health adults, ranging from 20 to 74 years old (mean 30 years). There were 16 male and 59 female in vertigo patients, ranging from 20 to 74 years old (mean 44.5 years). In contrast to current diagnosis method of patients with cervical vertigo, the clinical value was evaluated. RESULTS: Under the state of closed eyes, the sensitivity of SPG diagnosing cervical vertigo was 76%; the specificity was 93%; the Youden index was 69%; the coincidence was 85.1%; the positive predictive value was 90.5%; the negative predictive value was 93%; the positive and negative likelihood ratio were 10.893 and 0.258 respectively. Under the state of open eyes, the sensitivity was 49.3%; the specificity was 87.2%; the Youden index was 38.6%; the coincidence was 69.6%; the positive predictive value was 77.1%; the negative predictive value was 87.2%; the positive likelihood ratio was 3.857; the negative one was 0.581. Regardless of closed or open eyes, foreword-backward type shift orbit was the with cervical vertigo. CONCLUSION: The patients with cervical vertigo and normal individuals can be diagnosed objectively and quantitatively with SPG under the state of closed eyes, which can achieve the basic requirements of diagnosing cervical vertigo with validity, reliability and good clinical application. However, the rate of missed diagnosis with SPG under the state of open eyes is too high to meet the diagnostic needs.

Preparation of ferrocene nanocrystals by the ultrasonic-solvent-substitution method and their electrochemical properties.

Ferrocene nanocrystals are successfully prepared by the ultrasonic-solvent-substitution method. Transmission electron microscopy images show that the average diameter of the nanocrystals is about (40+/-5) nm and X-ray diffraction analysis indicated that the products obtained have a high purity. The optical properties of the products are studied by IR and UV/Vis spectroscopy. UV/Vis spectra indicate that, compared with ferrocene bulk material, the nanospheres show an obvious blue shift. Cyclic voltammetry is used to test the electrocatalytic oxidation properties of the ferrocene nanospheres towards ascorbic acid on the glassy carbon electrode. The results show that the ferrocene-nanosphere-modified glassy carbon electrode exhibits a better electrocatalytic effect than that modified by the ferrocene bulk material in phosphate buffer (pH 5.00). The important factors in the preparation of and a possible mechanism for the formation of ferrocene nanospheres is also discussed. The method could potentially be applied to the preparation of nanomaterials of other organometallic compounds.

[Spectroscopy study of the immobilized cellulase of magnetic nanoparticles Fe3O4].

Fe3O4 magnetic nanoparticles were synthesized by chemical coprecipitation method using ammonia as the precipitator in the present paper. And then cellulase was immobilized on Fe3O4 magnetic nanoparticles via carbodiimide activation, which was testified by FTIR and lots of repeating catalysis experiments. The morphology of nanoparticles immobilized by cellulase was characterized by TEM, and the activity of cellulase was measured by DNS spectrophotometry. The optimum temperature (60 degrees C) and pH value (3.94-5.50) for the catalysis ablility of immobilized cellulose were studied. The result showed that compared with the native enzyme the cellulase immobilized on Fe3O4 magnetic nanoparticles has the advantages of thermal stability, storage stability, and more extensive optimum pH value.

Multivariate calibration analysis for metal porphyrin mixtures by an ant colony algorithm.

A new biomimetic algorithm, Chemical Ant Colony Algorithm, has been developed, which has the characteristics of intelligent search, global optimization, robustness, distributed computation and easy combination with other heuristic. The proposed method has been successfully applied to the spectroscopy analysis of the Zn2+, Cd2+, Pb(2+)-porphyin tribasic color system with supramolecular properties; the errors are within +/-8.0%.