The electrochemical behavior of catechol oxidation by H2O2which catalyzed by the copper binding methanobactin in aqueous solutions had been studied using cyclic voltammetry with a glassy carbon electrode. The contribution described the production and purification of a novel copper-binding peptide, methanobactin from Methylosinus trichosporium 3011, among which the copper binding methanobactin exhibited efficient horseradish peroxidase-like catalytic activity. The determinations of mimetic peroxidase activity in human/rat blood, garlic, onion and scallion serve as models for the proposed method. A comparison of the results with established classical analysis is satisfactory.

In this Letter, we demonstrate a highly sensitive multi-stage terahertz (THz) wave parametric upconversion detector based on a KTiOPO4 (KTP) crystal pumped by a 1064-nm pulsed-laser (10 ns, 10 Hz). The THz wave was upconverted to near-infrared light in a trapezoidal KTP crystal based on stimulated polariton scattering. The upconversion signal was amplified in two KTP crystals based on non-collinear and collinear phase matching, respectively, to improve detection sensitivity. A rapid-response detection in the THz frequency ranges of 4.26–4.50 THz and 4.80–4.92 THz was achieved. Moreover, a dual-color THz wave generated from THz parametric oscillator using KTP crystal was detected simultaneously based on dual-wavelength upconversion. The minimum detectable energy of 2.35 fJ was realized with a dynamic range of 84 dB at 4.85 THz, which gives a noise equivalent power (NEP) of the order of 21.3 pW/Hz1/2. By changing the phase-matching angle or the wavelength of the pump laser, it is suggested that the detection of the THz frequency band of interest in a wide range from approximately 1 to 14 THz is possible.

In this paper, isobaric vapor–liquid equilibrium (VLE) data for the binary system of γ-butyrolactone + succinic anhydride were measured at pressures of 20.0, 30.0, and 40.0 kPa by a modified Rose still. There was no azeotropic phenomenon observed at each pressure. A thermodynamic consistency test is a way to verify the reliability of the experimental data. The VLE data were tested by a Herington area test and Van Ness point test. Then, the VLE data showed a good correlation with nonrandom two-liquid (NRTL) and Wilson activity coefficient models.

Methanobactin (mb) is a small copper-binding chromopeptide produced by methanotrophs. In this paper, a quantitative assay method for the content of mb was developed. The mb produced by Methylosinus trichosporium 3011growth with methane and methanol as carbon sources were detected from the culture supernatants by the CAS colorimetric assay at wavelengths 605 nm. The aim of this study was to evaluate the effect of copper ion on mb production by methane-growth and methanol-growth Methylosinus trichosporium 3011. The results of our experiments prove that Methylosinus trichosporium 3011 is able to utilize methanol as sole source of carbon and energy to produce mb. Cells grown on both methane and methanol exhibited differences in the accumulations of mb which were dependent on the concentration of copper (Ⅱ) present in the growth medium. An increase in the concentration of copper (Ⅱ) in the growth medium decreased mb content in the supernatant solutions. However, the mb was shown to exhibit maximal concentration at 0.5µmol/L copper (Ⅱ) with methanol as carbon source in contrast to the mb from cells grown on methane which as maximum concentration at 0 µmol/L copper (Ⅱ).

The isobaric vapor–liquid equilibria (VLE) data for two binary systems of propylene glycol methyl ether acetate (PMA) + N,N-dimethylformamide (DMF) and propylene glycol methyl ether acetate (PMA) + methanol (MeOH) at 30.0, 50.0, and 70.0 kPa were measured by utilizing a modified Rose–Williams still type apparatus which could be able to quickly form the dual cycle of continuous vapor and liquid phase in this work. On the basis of Herington area test and Van Ness point test, the thermodynamic consistency of the experiment data was verified. Meanwhile, VLE data that we obtained were correlated with nonrandom two-liquid (NRTL) and Margules activity coefficient models. The results demonstrated that the calculated values were in good conformity with the experimental data in this study. In addition, azeotropic behavior was observed in the binary system of PMA and DMF at reduced pressures.