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hydrogen peroxide (HO) sensor was developed by electrodepositing Prussian blue (PB) on a gold electrode modified with (3-mercaptopropyl)-trimethoxysilane (MPS) polymer. The characterization of the self-assembled electrode was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The results of electrochemical experiments showed that such constructed sensor had a favorable catalytic ability to reduce HO. The MPS film on the modified gold electrode greatly enhanced the pH-adaptive range of PB. Large surface-to-volume ratio property of double-layer 2d-network MPS-modified PB electrode enabled stable and highly sensitive performance of the non-enzymatic HO sensor. The linear range of HO determined is from 2.0 × 10 to 2.0 × 10 mol L with a correlation coefficient of 0.9991 and a detection limit for HO of 1.8 × 10 mol L. The influences of the potentially interfering substances on the determination of HO were investigated. This modified electrode exhibits a good selectivity and high sensitivity with satisfactory results. [ABSTRACT FROM AUTHOR]

A poly(thionine) thin film modified electrode was successfully assembled on the surface of the glassy carbon electrode by means of electrochemical polymerization, which was carried out with cyclic voltammetric sweeping in the potential range 0 to +1.4 V (vs. Ag/AgCl) in perchloric acid solution containing 0.1 mmol L−1 thionine. The film modified electrode exhibited a couple of well-defined redox peaks, and the redox peaks decreased correspondingly without a shift of the peak potential after the addition of heparin. The conditions of the binding reaction and the electrochemical detection were optimized. Under the optimum conditions the decrease of the peak current was proportional to the concentration of heparin in the range 4.0 to 22.0 μg mL−1 and the detection limit was 0.28 μg mL−1. The relative standard deviation (RSD) for five parallel determinations of 10.0 μg mL−1 heparin was 0.93%. The effects of potentially interfering species were investigated and the method was successfully applied to the determination of heparin in a pharmaceutical formulation. [ABSTRACT FROM AUTHOR]

We discuss three classes of generalized implicit vector equilibrium problems in topological ordered spaces. Under some conditions, we prove three new existence theorems of solutions for the generalized implicit vector equilibrium problems in topological ordered spaces by using the Fan- Browder fixed point theorem. [ABSTRACT FROM AUTHOR]

The concept of essential component of weakly efficient solution set is introduced first. Then we obtain some sufficient conditions for the existence of an essential component or an essential weakly efficient solution in the weakly efficient solution sets for multiobjective optimization problems. [ABSTRACT FROM AUTHOR]

2,5-Dimercapto-1,3,4-thiadiazole (DMTD) self-assembled monolayer on gold electrode was prepared and investigated by electrochemical measurement. The DMTD/Au electrode exhibited a significantly increased sensitivity and selectivity for Pb(II) in acetate buffer (pH 5.5) at a potential of −1.0 V (vs Ag/AgCl) for 4 min by anodic stripping voltammetry. The influence of various experimental parameters on the voltammetric response was studied. Under the optimized working conditions, the dependence of the stripping peak current response on concentration of Pb(II) was linear in the range of 1–45 µmol L−1 with a correlation coefficient of 0.9988, and the detection limit was 0.10 µmol L−1. The relative standard deviation of the results was 3.4% for six successive determinations of a 20 µmol L−1 Pb(II) solution. A study of interfering substances was also performed. The method was applied to the determination of Pb(II) in water samples with satisfactory results. [ABSTRACT FROM AUTHOR]

Aim: To investigate the antitumor activities of an anti-ErbB2 scFv-Fc-interleukin 2 (IL-2) fusion protein (HFI) in vitro and in vivo. Methods: Fusion pr otein HFI was constructed. The efficacy of HFI in mediating tumor cell lysis was determined by colorimetric lactate dehydrogenase release assays. The antitumor activity of HFI was evaluated in tumor xenograft models. Results: The fusion protein was folded as a homodimer formed by covalently linking Fc portions and it retained ErbB2 specificity and IL-2 biological activity. HFI mediated antibody-dependent cell-mediated cytotoxicity (ADCC) at low effector-to-target ratios in vitro and improved the therapeutic efficacy of IL-2 in experiments in vivo. Conclusion: The genetically-engineered anti-ErbB2 scFv-Fc-IL-2 fusion protein exhibited high efficiency both in mediating ADCC in vitro and significant antitumor activity in tumor xenograft models. [ABSTRACT FROM AUTHOR]

In the paper, by using Ky Fan’s section theorem, we obtain an existence theorem for vector equilibrium problems. Motivated by the ideas of Kinoshita and McLennan, we introduce the concept of the essential component of the solution set for vector equilibrium problems, and we prove that there exists at least one essential component of the solution set for every vector equilibrium problem satisfying some conditions. [ABSTRACT FROM AUTHOR]

A self-assembled electrode with a meso-2,3-dimercaptosuccinic acid (DMSA) monolayer has been characterized by electrochemical quartz crystal microbalance and complex impedance analysis, surface enhanced Raman spectroscopy and cyclic voltammetry. The self-assembled electrode was used for the simultaneous electrochemical detection of epinephrine (EP) and uric acid (UA) in phosphate buffer of pH 7.7. The simultaneous oxidation of EP and UA was performed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), and the signals for each method were well separated with a potential difference of over 330 mV and without interference by each other. The detection limit of EP is 5.4 × 10−8 mol L−1 by CV and 5.3 × 10−8 mol L−1 by DPV and that of UA is 8.4 × 10−8 mol L−1 by CV and 4.2 × 10−8 mol L−1 by DPV. The DMSA self-assembled electrode can be applied to the simultaneous determination of EP and UA. [ABSTRACT FROM AUTHOR]

The fabrication and electrochemical characteristics of a penicillamine (PCA) self-assembled monolayer modified gold electrode were investigated. The self-assembled electrode shows obvious electrocatalytic activity for the oxidation of epinephrine (EP). In phosphate buffer (pH 7.73), a sensitive oxidation peak was observed at 0.190?V with the PCA modified Au electrode. The peak current is proportional to the concentration of EP in the range of 2.0?×?10-5?~6.0?×?10-4?mol?L-1 and 5.0?×?10-6?~ 2.0?×?10-4?mol?L-1 for cyclic voltammetry (CV) and differential pulse voltammetry (DPV) with the detection limits of 1.8?×?10-7 and 1.3?×?10-7?mol?L-1, respectively. The possible reaction mechanism is also discussed. The PCA self-assembled monolayer modified gold electrode is highly stable and can be applied to the determination of EP in practical injection samples. Application is simple, rapid and produces accurate results. [ABSTRACT FROM AUTHOR]

The adsorptive and electrochemical behaviors of medecamycin were investigated on a glassy carbon electrode (GCE) pretreated by anodic oxidation at +1.8 V for 5 min in 0.025 mol l-1 NH3-NH4Cl (pH 8.6) solution. An adsorptive stripping voltammetric method for the determination of medecamycin at the pretreated glassy carbon electrode has been developed. Medecamycin was accumulated in NH3-NH4Cl buffer (pH 9.0) at a potential of -0.7 V (vs. saturated calomel electrode (SCE)) for a certain time, and then determined by second-order differential anodic stripping voltammetry. The second-order differential anodic stripping peak current at +0.72 V was proportional to the concentration of medecamycin in the range 2.0 µg ml-1 to 50.0 µg ml-1. The detection limit (three times the signal-to-noise) was 1.0 µg ml-1 and the relative standard deviation of the results was 3.28% for eight successive determinations of 10.0 µg ml-1 medecamycin. This method has been applied to the direct determination of medecamycin in commercial tablets and spiked urine samples with satisfactory results. [ABSTRACT FROM AUTHOR]

Micron-sized, monodisperse PMMA microspheres were produced in TEOS, under static condition by one step. The mechanism of this novel self-formation method was studied based on experiment results; it was found that the growth of PMMA microspheres was in two ways. The properties of the intermediate particles were studied by several methods. The size of finally obtained polymer particles could be controlled by adjusting the content of monomer in initial polymerization solution. The influence of the polymerization temperature on the preparation of polymer microspheres was also investigated. [ABSTRACT FROM AUTHOR]