Activation by ATP and an Undefined Substance in the Supernatant of Mycolic Acid Synthesis in an in vitro System of Bacterionema matruchotii

The present investigation was undertaken to identify the promoting factor in the supernatant that greatly stimulates mycolic acidbiosynthetic activity localized in the cell wall fraction of B. matruchotii cells. The data obtained indicated that the factor was composed of at least two components: ATP and an undefined substance. ATP provoked activation in mycolic acid synthesis in the presence of small quantities of the supernatant whereas it had no stimulant effect in the absence of the supernatant. In view of the results of partial characterization of the promoting substance(s), it is assumed that the undefined substance is a cofactor or intermediate different from the those previously expected

Motion-tracking skill assist and power assist for sinusoidal motions with a semi-active assist mechanism using energy control

This paper describes a skill assist method for sinusoidal motions using a semi-active assist mechanism through an energy control method. In a previous study, we had developed and verified the effectiveness of a power assist device with a semi-active assist mechanism and a control method for reducing loads during periodic motion. Here, we have developed a skill assist method as an extension of our power assist device for periodic motion. The skill of performing sinusoidal motions is defined in this study as an operator’s ability to track such motions. Therefore, our skill assist method attempts to improve the operator’s tracking ability. The proposed skill assist method is implemented using our previous power assist device; therefore, the device provides not only a power assist effect but also a skill assist effect to correct the motion. Hence, an operator obtains both the power and the skill assist effects simultaneously

High-fidelity conversion of photonic quantum information to telecommunication wavelength with superconducting single-photon detectors

We experimentally demonstrate a high-fidelity visible-to-telecommunication wavelength conversion of a photon by using a solid-state-based difference frequency generation. In the experiment, one half of a pico-second visible entangled photon pair at 780 nm is converted to a 1522-nm photon, resulting in the entangled photon pair between 780 nm and 1522 nm. Using superconducting single-photon detectors with low dark count rates and small timing jitters, we selectively observed well-defined temporal modes containing the two photons. We achieved a fidelity of $0.93 \pm 0.04$ after the wavelength conversion, indicating that our solid-state-based scheme can be used for faithful frequency down-conversion of visible photons emitted from quantum memories composed of various media.Comment: 5 pages, 4 figure

Purification and Characterization of l-Methionine Decarboxylase from Streptomyces sp. 590

L-Methionine decarboxylase [EC 4.1.1.57] catalyzes the decarboxylation of L-methionine and is a pyridoxal 5’-phosohate(PLP)-dependent enzyme. L-Methionine decarboxylase has been purified 630-fold by DEAE-Toyopearl 650M, Phenyl-Toyopearl 650M and Sephacryl S-300 column chromatographies from Streptomyces sp.590. The enzyme has a dimeric structure with identical subunits of Mr 60,000. This enzyme shows optimum activity at pH7.0 and 45°C, and is stable between pH5.7 and pH9.0. L-Methionine decarboxylase has antitumor activity against RERF-LC-AI and HeLa cells. Ten N-terminal amino acid sequence of L-methionine decarboxylase was determined, and the sequence showed no homology with other reported proteins