Construction and application of a new cell electrochemical detecting system based on the hyposmotic principle.

A new cell electrochemical detecting system has been constructed based on the hyposmotic principle, in which the electrochemical signals have been strengthened by about 109.75% for the signal at about +0.70 V and 532.94% for the signal at about +1.03 V. The electrochemical detection limits of the cells have been improved by one order of magnitude. The individual concentrations of intracellular purines have been obtained.

Reducing coherent noise in interference systems using the phase modulation technique.

The phase modulation technique is adopted to reduce the coherent noise that arises from spurious interference. By choosing an appropriate driving signal, the method can reduce the coherent function of coherent noise to a great degree while keeping the coherent function of a coherent signal nearly unchanged. Simulation results show that for the grating interferometer, the phase error caused by coherent noise is reduced by 81.53% on average. For the Twyman interferometer, the fringe quality and contrast deteriorated by coherent noise are significantly improved. Furthermore, an experiment is set up in the phase-modulated Twyman interferometer to verify the feasibility of the principle. It is concluded that the method is effective to reduce the coherent noise in interference systems.

Low-level expression of purine bases in BALB/3T3 cells monitored by ultrasensitive graphene-based glass carbon electrode.

Using an ultrasensitive chemically reduced graphene oxide and ionic liquid modified glass carbon electrode (RGI-GCE), separated electrochemical signals of adenine and hypoxanthine in both human breast cancer (MCF-7) and mouse embryonic fibroblast (BALB/3T3) cells were observed. For the first time, low-level expression of purine bases in noncancerous BALB/3T3 cells can be electrochemically monitored. The metabolism of purine bases in carcinogen agent-contaminated BALB/3T3 cells was also investigated through the change of electrochemical signals ascribed to different purine bases, which opens a new electrochemical approach to the exploration of a low-level purine mechanism in noncancerous cells.

Penta-potassium µ-arsenato-bis-(hy-droxy-tetra-molybdate) dihydrate.

The title arsenatomolybdate, K(5)[Mo(8)O(24)(OH)(2)(AsO(4))]·2H(2)O, which was obtained hydro-thermally, features an [AsMo(8)O(28)(OH)(2)](5-) anion, which is formed by two Mo(4)O(14)(OH) units that are linked by As in a sandwich-like fashion. The overall symmetry of the anion is m2m. The {Mo(4)O(14)(OH)} core is composed of two pairs of confacial biocta-hedral {Mo(2)O(9)} units with two µ(4)-O atoms which have been characterized as hydroxyl groups. The anions are further inter-connected by potassium cations, forming a three-dimensional network structure with the uncoordinated water mol-ecules occupying the channels. The structure is further stabilized by O-H⋯O hydrogen bonding.

Poly[tetra-kis(2,2'-bipyridine)undeca-µ-oxido-hexa-oxidodicopper(II)hexa-vanadium(V)].

In the title organic-inorganic hybrid vanadate complex, [Cu(2)V(6)O(17)(C(10)H(8)N(2))(4)](n), the Cu(II) atom is six-coordinated by two chelating 2,2'-bipyridine (bipy) ligands and two vanadate O atoms in a distorted octa-hedral geometry. Two [Cu(bipy)(2)V(3)O(8)] units are linked by a bridging O atom, which lies on an inversion center, forming a dimeric unit. The dimeric units are further connected by bridging vanadate O atoms into a two-dimensional layer parallel to (100). The layers are connected by weak C-H⋯O hydrogen bonds.

A Mini-Electrochemical System with Integrated Micropipet Tip and Pencil Graphite Electrode for Measuring Cytotoxicity.

A novel mini-electrochemical system has been developed for evaluating cytotoxicity of anticancer drugs based on trace cell samples. The mini-electrochemical system was integrated by using pencil graphite modified with threonine as working electrode, an Ag/AgCl reference electrode and a micropipet tip as electrochemical cell. The mini-electrochemical system dramatically reduces sample volumes from 500 µL in a traditional electrochemical system to 10 µL, and exhibits excellent electrocatalytic activity toward oxidation of purine from MCF-7 cells due to increased sensitivity provided by threonine. Moreover, the relationship between peak current and the cell concentration in the range from 3.0 × l03 to 7.0 × l06 cells/mL was studied, and a nonlinear exponential relationship between them was established over a wide concentration range. In evaluating the effect of anticancer drugs on cell viability, the results of drug cytotoxicity test based on cyclophosphamide were in close agreement with classical 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assays. The proposed device is so simple, cheap, and easy to operate that it could be applied to single-use applications. The mini-electrochemical system proved to be a useful tool and can be applied to electrochemical studies of cancer cells as well as other biological samples such as proteins and DNA.

Hydrothermal synthesis and structural characterization of the first mixed molybdenum-tungsten capped-keggin polyoxometal complex: {[Co(dien)]4[(AsVO4)MoV8WVI4O33(micro2-OH)3]}.2H2O.

The first polyoxometal complex possessing affirmatory mixed molybdenum-tungsten capped Keggin-type structure has been hydrothermally synthesized.