An ABC transporter involved in the control of streptomycin production in Streptomyces griseus.

We screened for a gene that inhibits streptomycin production in Streptomyces griseus when it is introduced on a high-copy-number plasmid pIJ702, and obtained a plasmid pKM545. The introduction of pKM545 abolished streptomycin production on all media tested including YMP-sugar and Nutrient broth. S1 protection analysis demonstrated that the introduction of this plasmid downregulated the transcriptional activity of the promoter preceding strR, the pathway-specific transcriptional regulator for streptomycin biosynthesis. The 2.8-kb BamHI fragment cloned onto pKM545 contained two coding sequences SGR_5442 and 5443. These coding sequences and the two downstream ones (SGR_5444 and 5445) constituted a possible operon structure designated to be rspABCD (regulation of streptomycin production). RspB and RspC exhibited a marked similarity with an ATP-binding domain and a membrane-associating domain of an ABC-2 type transporter, respectively, suggesting that the Rsp proteins comprise a membrane exporter. The gene cluster consisting of the rsp operon and the upstream divergent small coding sequence (SGR_5441) was widely distributed to Streptomyces genome. An rspB mutant of S. griseus produced 3-fold streptomycin of the parental strain in YMP liquid medium. The evidence implies that the Rsp translocator is involved in the export of a substance that specifies the expression level of streptomycin biosynthesis genes in S. griseus.

Streptomyces metabolites in divergent microbial interactions.

Streptomyces and related bacteria produce a wide variety of secondary metabolites. Of these, many compounds have industrial applications, but the question of why this group of microorganism produces such various kinds of biologically active substances has not yet been clearly answered. Here, we overview the results from our studies on the novel function and role of Streptomyces metabolites. The diverged action of negative and positive influences onto the physiology of various microorganisms infers the occurrence of complex microbial interactions due to the effect of small molecules produced by Streptomyces. The interactions may serve as a basis for the constitution of biological community.

Physical and physiological effectiveness of an overall health care program for middle-aged Japanese women with mild obesity: A pilot study.

This study aimed to verify the effectiveness of an overall health care program (OHCP) for middle-aged Japanese women through assessing physical and physiological changes. The OHCP consisted of diet modification with natural alternative foods, walking and stretching exercises, and body massage and cupping treatments. Sixty-seven participants were assigned to one of three groups during a 3-year study period (2011-2013). The OHCP was performed for 3 months in each year. After the OHCP, most participants had significant decreases in the blood levels of triglycerides, low-density lipoprotein cholesterol, total cholesterol, alkaline phosphatase, γ-glutamyl transferase, and cholinesterase; body weight; body fat percentage; and body-mass index. The oxidative stress markers varied among the study years; however, a significant decrease in blood reactive oxygen-derived metabolites and a significant increase in the relative antioxidative potential were observed in 2013. In 2013, participants who were randomly selected for autonomic nervous activity measurements immediately before and after body massage and cupping treatments showed a significant predominance in parasympathetic nervous activity after the treatments. These results indicate that the OHCP in the present study is an effective and prompt method as a complementary treatment to improve the pre-obese or mild obese status without any noticeable physiological stress in most middle-aged women. However, because of the limitations of this study, the findings of this study need to be confirmed.

Laser plasma cryogenic target on translating substrate for generation of continuously repetitive EUV and soft X-ray pulses.

To generate continuously repetitive EUV and soft X-ray pulses with various wavelengths from laser-produced plasmas, a one-dimensionally translating substrate system with a closed He gas cryostat that can continuously supply various cryogenic targets for ~10 Hz laser pulses has been developed. The system was successfully operated at a lowest temperature of 15 K and at a maximum up-down speed of 12 mm/s. Solid Ar, Kr, and Xe layers were formed, and their growth rates and the laser crater sizes on them were studied. By optimization of the operational parameters in accordance with our design rule, it was shown that stable output power was achieved continuously from the plasma emission at frequencies of 1-10 Hz. The average soft X-ray and EUV powers obtained were 19 mW at 3.2 nm, 33 mW at 10.0 nm, and 66 mW at 10.8 nm, with 10% bandwidths, from the Ar, Kr, and Xe solid targets, respectively, with a laser power of 1 W. We will be able to achieve higher frequencies using a high beam quality laser that produces smaller craters, and can expect higher powers. Although only Ar, Kr, and Xe gases were tested in this study, the target system achieved a temperature of 15 K and can thus solidify almost all target gases, apart from H and He, and can continuously supply the solid target. The use of various target materials will enable expansion of the EUV and soft X-ray emission wavelength range.

Agaricus brasiliensis KA21 improves circulatory functions in spontaneously hypertensive rats.

The present study aimed to clarify the effects of Agaricus brasiliensis KA21 (i.e., Agaricus blazei) mushroom on circulatory function. Spontaneously hypertensive rats (SHRs) were fed 10% A. blazei-containing pellets (agaricus group) or normal pellets (control group) for 5 weeks from 6 to 11 weeks of age. For Experiment 1, tail blood pressure and heart rate were measured in the conscious SHRs. For Experiment 2, echocardiographic and blood biochemical measurements were performed in the anesthetized SHRs. In Experiment 1, blood pressure and heart rate were significantly lower in the agaricus group compared with the control group throughout the observation period. In Experiment 2, the agaricus group also showed a significant decrease in cardiac output accompanied by a decrease in heart rate and an increase in early and late ventricular filling velocity (E/A ratio). Moreover, levels of escape enzymes such as creatine kinase (CK), CK-BB, CK-MB, asparate aminotransferase, lactate dehydrogenase, and aldolase were significantly lower than in the control group. We concluded that the ingestion of feed containing A. brasiliensis KA21 can improve hypertensive cardiovascular hemodynamics by decreasing the working load of the heart, presumably by lowering the sympathetic nervous tone in SHRs.

Plasma debris sputter resistant x-ray mirror.

A diamond-like carbon (DLC) mirror, used as a grazing incident mirror in a plasma x-ray source, exhibits a high resistance to plasma debris sputtering. Good mirror reflectivity at a wavelength of 13.5 nm was confirmed using synchrotron radiation at the NewSUBARU facility. The erosion rate due to plasma debris sputtered at the incident debris angle of 20° was measured using a laser-produced Xe plasma source developed by the authors. The results indicate that the DLC film has a 5- and 15-fold higher sputtering resistance compared to films made of the traditional mirror materials Ru and Au, respectively. Because the DLC mirror retains a high sputtering resistance to Sn ions, it may be effective in Sn plasma source applications. We conclude that a grazing incident x-ray mirror coated with DLC can be of use as a plasma debris sputtering resistant mirror.

Characteristics of a cylindrical collector mirror for laser-produced xenon plasma soft X-rays and improvement of mirror lifetime by buffer gas.

The focusing characteristics of a ruthenium-coated cylindrical mirror were investigated on the basis of its ability to collect and focus broadband 5-17-nm soft X-rays emitted from a laser-produced plasma. Based on the plasmas spectral intensity distribution and the reflectivity function of the mirror, we defined the optimum position of the integrated cylindrical mirror at which the X-ray energy flux transported and focused through the mirror was maximum. A minimum spot diameter of 22 mm at a distance of approximately 200 mm from a soft X-ray source was confirmed. The maximum intensity of the collected soft X-rays was 1.3 mJ/cm(2) at the center of the irradiation zone. Thus, the irradiation intensity was improved by approximately 27 times when compared to that of 47 µJ/cm(2) without the mirror. The debris sputtering rate on the reflection surface of the mirror can be reduced to 1/110 by argon gas at 11 Pa, while the attenuation rate of the soft X-rays due to absorption by the buffer gas can be suppressed to less than 10% at the focal point. The focusing property of the mirror is expected to be maintained for 3000 h or longer without significant degradation for a 100 W/320 pps laser shot if the ruthenium layer is thicker than 10 µm. These results suggest that a stand-alone broadband soft X-ray processing system can be realized by using laser-produced plasma soft X-rays.

Promomycin, a polyether promoting antibiotic production in Streptomyces spp.

Widespread interspecific stimulation of antibiotic production occurs in strains of Streptomyces owing to the activity of diffusible substances, as previously determined in our investigations of the cross-feeding effect. In this study, we newly isolated a substance produced by a Streptomyces strain closely related to Streptomyces scabrisporus, based on the observation that this substance induced the production of an unknown antibiotic in another strain related to Streptomyces griseorubiginosus. This substance, named promomycin, is a polyether structurally related to lonomycin. Promomycin itself had an antibiotic activity, but it stimulated antibiotic production in multiple Streptomyces strains at sub-inhibitory concentrations. Evidence implies that this stimulation effect is widespread within this group of bacteria.

Laser-plasma debris from a rotating cryogenic-solid-Xe target.

We investigate the characteristics of laser plasma debris that is responsible for damaging optics. The debris is composed of fast ions, neutral particles, and fragments, and originates from a solid Xe target on a rotating drum that we developed as an extreme ultraviolet (EUV) source. The ice fragments appear to be a problem most notably with solid Xe targets; however, we find that the damage induced by Xe ice fragments can be avoided by simply reducing the laser pulse energy. We find the number of fast neutral particles to be an order of magnitude less than the number of ions, and we clarify that the plasma debris is primarily composed of fast ions. In addition, we find that the number of fast ions having a few dozen keV of energy decreases when using the rotating target compared with the rest target. We attribute this to a gas curtain effect from the Xe gas localized at the rotating target surface. We estimate the sputtering rate of the Mo/Si mirror, which is caused primarily by the fast ions, to be 104 nm/1x10(6) shots at 190 mm from the source plasma and at an 11.25 degree angle from the incident laser beam. Up to the 1x10(6) shots exposure, remarkable degradation of the mirror reflectivity is not observed though the sputtering damages the mirror. Mitigation of the ions by using gas and/or magnetic fields will further improve the mirror lifetime. By comparing with a liquid jet Xe target, we conclude that the sputtering rate per conversion efficiency when using the solid Xe targets on the rotating drum is the same as that when using the liquid Xe targets. The high conversion efficiency of 0.9% in the rotating drum solid Xe target makes this technique useful for developing laser plasma EUV sources.

Xe capillary target for laser-plasma extreme ultraviolet source.

A cryogenic Xe jet system with an annular nozzle has been developed in order to continuously fast supply a Xe capillary target for generating a laser-plasma extreme ultraviolet (EUV) source. The cooling power of the system was evaluated to be 54 W, and the temperature stability was +/-0.5 K at a cooling temperature of about 180 K. We investigated experimentally the influence of pressure loss inside an annular nozzle on target formation by shortening the nozzle length. Spraying caused by cavitation was mostly suppressed by mitigating the pressure loss, and a focused jet was formed. Around a liquid-solid boundary, a solid-Xe capillary target (10070 microm phi) was formed with a velocity of < or =0.01 ms. Laser-plasma EUV generation was tested by focusing a Nd:YAG laser beam on the target. The results suggested that an even thinner-walled capillary target is required to realize the inertial confinement effect.

Highly time-resolved correlation measurement between laser and synchrotron radiation pulses without synchronization control.

A mode-locked laser has been introduced in combination with synchrotron radiation to establish a versatile technique for highly time-resolved correlation measurements utilizing the short-pulse and high-pulse frequency characteristics of both photon sources. Successive pulse timing delay detected by nonlinear optical mixing between the two sources yields a cross-correlation profile capable of accurate measurement of the picosecond pulse profile of the synchrotron radiation without any synchronization control. Although the experiment was performed in the visible spectral domain, the present technique opens up a methodology for time-resolved spectroscopy in femtosecond and higher-energy domains by introducing a suitable nonlinear process that informs of the pulse coincidence between the two radiation sources.

Propagation characteristics of a diffracted M2 beam.

The propagation characteristics of a beam diffracted by a circular aperture are investigated. The beam-quality factor M2 defined by an 86.5% power-content radius is given theoretically and experimentally as a function of the truncation ratio. It is found that the theoretical limit of M2 is 2.37 times as great as that of an incident beam as the truncation ratio approaches 0. For a weakly diffracted beam a simple formula giving M2 is derived. Although M2 does not increase much with diffraction, the influence of diffraction should be taken into account in beam brightness.