Nomimicin (1), a new spirotetronate-class polyketide, was isolated from the culture broth of an actinomycete of the genus Actinomadura. Its structure was established by spectroscopic methods, and the absolute configuration was determined by a combination of NOESY experiment, J-based configuration analysis and the modified Mosher method. Nomimicin (1) showed antimicrobial activity against Micrococcus luteus, Candida albincans and Kluyveromyces fragilis. Keywords: Actinomadura; polyketide; spirotetronate INTRODUCTION Microbial secondary metabolites have been the most productive source of small molecules for the development of drugs. 1 Almost a half of the known microbial bioactive compounds are derived from actinomycetes, and specifically Streptomyces accounts for more than 70% of the actinomycete-derived metabolites. 2 Among the nonStreptomyces species, Micromonospora is the leading producer of secondary metabolites, including polyketides, peptides and glycosides, whereas Actinomadura is known as a producer of chemically and biologically unique polyketides such as antitumor enediynes, 3 mannose-binding quinone glycosides with antifungal and anti-HIV activities 4 and anticoccidial polyethers, 5 accounting for up to 350 compounds reported as of 2005. 2 During our continuing investigation on the metabolites from actinomycetes of nonStreptomyces group, 6,7 a new spirotetronate antibiotic of polyketide origin, nomimicin (1, Figure 1), was isolated from the culture extract of Actinomadura sp. TP-A0878. In this paper, we describe the isolation, structural determination and biological properties of 1.
Hemotropic mycoplasmas are common pathogens in animals, but it remains unclear what role these pathogens play in human infections. We report clinical and biologic characterization of Candidatus Mycoplasma haemohominis infection in a 42-year-old man in Japan. The patient had severe hemophagocytic syndrome 1 month after an accidental needlestick injury. Metagenomic deep sequencing identified Candidatus M. haemohominis and determined its draft genome for an isolate from serum of the patient. A high copy number of the Candidatus M. haemohominis genome was detected in serum and bone marrow samples. Electron microscopy examination showed morphologic characteristics of Candidatus M. haemohominis. Levofloxacin monotherapy induced resistance caused by a gyrase A gene mutation in the quinolone resistance–determining region, but a combination treatment with moxifloxacin and minocycline was effective. We identified Candidatus M. haemohominis in a patient who had life-threatening symptoms related to multiple organ infection. Human infection with this mycoplasma might occur more frequently than has been generally recognized.
An 8-km long MgB2 wire for a prototype klystron magnet was made and evaluated. The wire was made by a typical in situ method; it has 10 filaments and 0.67 mm in outer diameter. The homogeneity of Ic of this wire was evaluated by several methods. Deviation of Ic values in short sample wires was very small. In addition, the current sharing temperature of the MgB2 magnet (made of two reels of wire 2.9 km long each) agreed well with the estimated value of the Ic-B-T properties in short sample wires. Based on the obtained results, it can be said that the Ic properties of the entire wire length are quite uniform.
Air pollution caused by fine particulate matter (PM 2.5 ), volatile organic compounds, and bioaerosols is a major environmental risk to health. We developed a photocatalytic air cleaner for reducing the pollution levels of indoor air; we improved the photocatalytic system by using UV-LED for the removal of acetaldehyde and PM 2.5 and by reducing the weight and size of the system. The efficiency of photocatalysis depends on the surface area and materials. Therefore, we prepared a nanosized titanium dioxide (TiO 2 )-coated aluminum plate irradiated by UV-LED lamps (wavelength: 375 nm) as a photocatalytic air cleaner. Passing air continuously through a TiO 2 -coated aluminum plate (5 × 10 × 1 cm) under black light for 200 min decomposed 90% of 5 ppm acetaldehyde (12.4 µmol h -1 ) and generated two carbon dioxide molecules (25.43 µmol h -1 ) at a molar ratio of 1:2, indicating complete decomposition of acetaldehyde with high efficiency. This photocatalytic air cleaner was applied to the decomposition of acetaldehyde and inactivation and removal of aerosolassociated influenza virus. Acetaldehyde (20 ppm) in a 1-m 3 cubic space was eliminated in 60 min at a half-life of 8 min. The aerosol-associated infectivity and the RNA genome of influenza virus A/PR/8/1934 (H1N1) produced by a nebulizer in a 779-L cubic space were eliminated within 7 min; however, they were detectable for up to 28 minutes when the functional photocatalytic air cleaner was not used. The presence of intermediate breakdown products of influenza virus indicated that the virus was broken down by photocatalysis. Thus, the photocatalytic air cleaner efficiently decomposed and eliminated organic chemicals, acetaldehyde, and aerosol-associated influenza virus infectivity and viral RNA, indicating that it can clean and detoxify the indoor air in a closed space for maintaining a safer environment.
A wind-and-react MgB2 solenoid magnet for klystrons has been developed. While the current normal-conducting (Cu) magnet consumes 20 kW per magnet, this MgB2 magnet consumes less than 3 kW in refrigerator power. The conduction-cooled half coil of the magnet is 337 mm in inner diameter; the winding pack, 19.4 mm wide × 136.6 mm high, uses 2.7 km of 10 filament circular conductor, which is insulated with glass 0.83 mm in diameter, and is reacted after being wound onto a stainless steel bobbin. The coil has Cu plates of 0.2 mm in thickness between each coil layer and on the inner and outer sides. The magnet has two coils and produces 0.8 T in the center and its stored energy is 11.8 kJ. Together with the above-mentioned coil structure, these coils can consume stored energy in itself at quench without a special quench protection system. A performance test of the magnet was successful.
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