Development and application of the Fraunhofer-diffraction method for measurements of plasma density fluctuations using infrared lasers

This paper is concerned with systematic developments of the Fraunhofer-diffraction method for studies of plasma density fluctuations in high-temperature plasmas using infrared lasers, namely (i) development of the general theory of the Fraunhofer-diffraction method, (ii) measurements of fluctuations propagating in an azimuthal direction, (iii) measurements of fluctuation intensities, and (iv) application in measurements on high-temperature plasmas.     

Molybdenum‐Catalyzed Stereospecific Deoxygenation of Epoxides to Alkenes

Mild and simple catalytic systems consisting of molybdenum(VI) dichloride dioxide [MoO₂Cl₂] as a catalyst and a phosphine as reductant have been developed for the stereospecific deoxygenation of epoxides to alkenes. The reactions using 1,2‐bis(diphenylphosphino)ethane (dppe) and triphenylphosphine (PPh₃) proceed with retention and inversion of stereochemistry, respectively. The mild reaction tolerates the presence of various functional groups and affords stereodefined substituted olefins in good yields.

     

An optical field-induced ionization X-ray laser using a preformedplasma scheme

Soft X-ray amplification by optical field-induced ionization (OFI) of a preformed plasma is investigated. A small-signal gain of 20 cm^-1 and a gain-length product of 4 at 13.5 nm on the Lyman-α transition in hydrogen-like lithium have been obtained using the modified OFI scheme. Experimental and numerical results ensure that we have produced a plasma with a significantly lower electron temperature than what is expected by an above-threshold ionization model. To explain the results, a two component plasma model in which relatively high temperature electrons are produced by OFI in a cold electron bath of the preformed plasma is presented. The model indicates that the average electron temperature of the OFI plasma rapidly decreases since a high-temperature part of the electrons escapes from the focal volume without interaction. The initial electrons produced prior to the field ionization, which survive after the OEI, also significantly contribute to the rapid three-body recombination. Based on the ionization-induced refractive index change, the pulse propagation of a high-intensity pump laser during the OFI is also discussed     

Assessment and treatment of liver disease in Japanese haemophilia patients

OBJECTIVES: To examine the efficacy of various parameters obtained by transrectal ultrasonography (TRUS) as predictors of the onset of acute urinary retention in patients with benign prostatic hyperplasia (BPH). METHODS: From April 1993 to March 1997, 331 men aged 51 to 84 years with symptoms of BPH were enrolled in this study. Among them, 64 patients presented to our clinic because of acute urinary retention. TRUS was used to calculate the transition zone (TZ) volume, the transition zone index (TZ index = TZ volume/total prostate volume), the total prostate volume, and presumed circle area ratio (PCAR). To compare the usefulness of the various indices, the area under the receiver-operator characteristic (ROC) curve was calculated for each index. RESULTS: There were significant differences in the American Urological Association (AUA) symptom score, total prostate volume, TZ volume, TZ index, and PCAR between patients with and without acute urinary retention, but no significant differences in age and quality of life score. In patients with acute urinary retention, the area under the ROC curve was 0.924 for the TZ index, 0.834 for the TZ volume, 0.753 for the PCAR, 0.684 for the total prostate volume, and 0.628 for the AUA symptom score. CONCLUSIONS: The TZ index is an accurate predictor of acute urinary retention in patients with BPH and may be a useful method for deciding between surgical intervention and antiandrogen treatment.     

Low-pass and high-pass filters using coaxial-type dielectric resonators

This paper proposes new low-pass and high-pass filters using coaxial-type dielectric resonators. The low-pass filter has a LC-type circuit structure and is composed of three inductances and two resonance circuits. The resonance circuits are the open-ended coaxial-type dielectric resonators whose length is λg/4. The high-pass filter has a CL-type circuit structure. Two high-pass filters are described, one of them is composed of three capacitances andtwo resonance circuits, the other is composed of five capacitances and four resonance circuits. The operating frequency range of the low-pass filter is 0.13–0.9 GHz and the cutoffency is 900 MHz, and the insertion loss is 0.3 dB. The corresponding quantities of the high-pass filter are 0.9–2.5 GHz, 900 MHz, and 0.3 dB, respectively.     

A novel treatment technique for DMSO wastewater

We have developed an efficient treatment technique for wastewater containing dimethyl sulfoxide [DMSO, (CH₃)₂SO], a compound used as a photoresist stripping solvent in semiconductor manufacturing processes. Generally, wastewater containing organic compounds can be treated biologically, but with DMSO wastewater, biological treatment is not available because noxious compounds are produced that harm the environment. Here, we present an effective DMSO wastewater treatment technique in which we add an oxidizing agent and irradiate the wastewater with ultraviolet light to prevent damage to the environment. The use of hydrogen peroxide (H₂O₂) as an oxidizing agent in combination with ultraviolet irradiation causes DMSO to decompose promptly into methanesulfonic acid (MSA, CH₃SO₂OH). With continued treatment, the resultant MSA decomposes gradually into the inorganic compound sulfuric acid (H ₂SO₄). In this reactive route, no noxious compounds are generated. We confirmed that MSA can be biologically treated comparatively easily, and that by combining the initial ultraviolet irradiation/H₂O₂ addition treatment to rapidly produce MSA with a biological treatment to convert the MSA to H ₂SO₄, the total processing can be treated at very low cost. These treatment techniques make use of the characteristically high reactivity of DMSO and are very effective as a means of treating DMSO wastewater     

Rupture of a dissecting aneurysm into the superior vena cava in Marfan's syndrome

Aneurysmal dilatation of the aorta with subsequent dissection or rupture occurs frequently in patients with Marfan's syndrome. These complications are among the major causes of death. We report the case of a 51-year-old man with annulo-aortic ectasia in Marfan's syndrome. Acute aortic dissection and rupture into the superior vena cava occurred 8 years after aortic valve replacement. The preoperative diagnosis was made by right heart catheterization and computed tomography. A markedly increased left-to-right shunt occurred with rapid enlargement of the fistula due to the fragility of the aortic wall characteristic of Marfan's syndrome. Postmortem examination demonstrated severe medial necrosis with rupture of the aortic wall into the superior vena cava which was adherent to the suture line of the aortotomy from the previous surgery. Type A aortic dissection with severe congestive heart failure strongly suggested rupture into the pulmonary circulation.     

Detection of glycosaminoglycans as a copper(II) complex in high-performance liquid chromatography

The steady state DC endocochlear potential (EP) in young chicks shows a large decrease after acoustic overstimulation followed by a rapid recovery that parallels the recovery of threshold (Poje et al., Hear. Res. 82 (1995) 197-204). These results raise a question as to whether or not the EP could account for the hearing loss and make a significant contribution to the recovery of the threshold. In contrast to results in young chicks, we show that acoustic overstimulation, which causes extensive hair cell damage, does not cause a decrease in the steady state EP in adult chickens. However, there is a significant reduction in the negative EP seen during anoxia which persists even after 4 weeks of recovery. Thus, our results indicate that the steady state EP cannot account for the hearing loss observed in adult chickens.     

Evaluation of counting efficiencies of a whole-body counter using Monte Carlo simulation with voxel phantoms

In the 2007 recommendations of the International Commission on Radiological Protection, it is mentioned that the reference voxel phantoms are used for calculation of effective dose. From the standpoint of internal dosimetry services, calibration methods of whole-body counters using the voxel phantoms are of considerable practical interest. In the present study, counting efficiencies of a whole-body counter at the Japan Atomic Energy Agency (JAEA) were evaluated using Monte Carlo simulations with two voxel phantoms, 'MAX06', which has organ masses corresponding to those of the reference male, and 'Otoko', which is a representation for average Japanese male. To validate the calculation methods of the present study, calculations for the bottle manikin absorption phantom were also performed and compared with experiments. Consequently, it was found that the Monte Carlo simulation with voxel phantoms is a significant tool for the calibration of the JAEA whole-body counter.     

Optical properties of alumina ceramics as a substrate of thin film solar cells

For full understanding of the optical properties of alumina ceramics which are used as a substrate of thin film c-Si solar cells, we carried out computer simulations of diffuse reflectance and measurements of angle-resolved reflectance. As the result of the computer simulations, we obtained a theoretical expression for the reflectance properties of alumina ceramics with flat surface. The expression can be applied for the measured reflectance of alumina ceramics with rough surface when an effect of surface condition was taken into account.