Analysis of class D inverter with irregular driving patterns

This paper presents an analysis of Class D inverter when irregular driving patterns are given to the gate drive of the switch devices. The analysis has been carried out with focusing on the waveforms, harmonics, low-frequency components, output power, and equivalent dc resistance, which are numerically analyzed and discussed. Class D inverters with six different Q factors from 0.1 to 20 are analyzed about 2/sup 16/ driving patterns for each Q. Superior four models of the six inverters are built and tested in circuit experiments. The calculated waveforms are compared to the experimental results. Both of them are agreed well in time domain and frequency domain. Analytical results show a possibility of a novel control method with irregular driving patterns. In spite of discontinuous control, the output power or voltage can be strictly changed as if continuous using the selected driving patterns in some ranges.     

Monte Carlo simulation of hydrogen absorption in palladium and palladium–silver alloys

A modified Monte Carlo (MC) simulation was performed to investigate the hydrogen absorption behavior in Pd and Pd–Ag alloys of the composition Pd_xAg_1−x (x=0.7–0.8) under H₂ pressure (0.1 MPa) at different temperatures. The present method employed can consider the dissociative adsorption of hydrogen molecule and the subsequent absorption of hydrogen atom by formalizing the relationship between the pressure of hydrogen molecule and hydrogen atom. The potential parameters were determined to reproduce the solution enthalpy of hydrogen in pure metals. The results are in good agreement with experimental findings as well as previous theoretical studies. We confirmed that our method is useful to simulate the absorption of hydrogen in metals and alloys.     

Halo congenital nevus undergoing spontaneous regression. Involvement of T-cell immunity in involution and presence of circulating anti-nevus cell IgM antibodies

BACKGROUND: Halo congenital nevus is a condition in which halo formation is associated with congenital nevocellular nevi. Although several theories have been proposed, the immunologic mechanisms of halo formation and concomitant nevus regression still remain unclear. We presented immunologic findings in a case of halo congenital nevus with unique histologic location of inflammatory cells. OBSERVATIONS: Histologically, the present case of halo congenital nevus undergoing spontaneous regression showed a marked inflammatory infiltrate with remnants of original nevus cell nests. In the infiltrating T cells, CD8+ cells outnumbered CD4+ cells and the infiltrate of natural killer cells was not substantial. Direct and indirect immunofluorescence studies demonstrated the presence of IgM antibodies against nevus cells as well as melanoma cells and cultured melanocytes in the patient's serum. CONCLUSIONS: Our findings suggest that both T-cell-mediated immunity and IgM antibodies may be involved in the regression of halo congenital nevus. However, it is important to point out that our results may simply be epiphenomena and not directly responsible for the destruction of nevus cells.     

Two cases of cancer with bone metastases treated with local therapy

Two cases with osteolytic bone metastases from cervical cancer and esophageal cancer treated by local therapy were reported. The first case is a 53-year-old female with bone metastases of left ischium developed 1 year after hysterectomy. She was treated by intratumor injection of sizofiran (SPG) 20 mg/w and radiation therapy. After 4 weeks, ischias pain decreased and bone lesion showed remarkable calcification (PR) 8th months later. The second case is a 58-year-old male with bone metastases of the left tibia and fibula developed 1 year after surgery. He was treated by intratumor injection of SPG 20 mg/w x 4 and OK-432 1.0 KE/w x 8 after radiation therapy. After 4 weeks, pain and swelling of left leg decreased and bone lesions showed remarkable calcification (PR) three months later. We suggest that intratumor injection of SPG and OK-432 with radiation therapy was effective for osteolytic bone metastases.     

Enhanced production of rat interleukin-8 by in vitro and in vivo infections with influenza A NWS virus

We investigated the interleukin-8 (IL-8)-producing activity of influenza A NWS virus in cultured rat kidney NRK-52E cells and a rat influenza model. The production of rat IL-8 increased significantly in the virus-infected cells but not in UV-inactivated virus- or split-product-treated cells. The increase in IL-8 production could be detected in the bronchoalveolar lavage of infected rats. These data suggest that infectious virus has the potential to accelerate the production of IL-8 in cultured cells and in vivo in airway-lining cells.     

Preparation and photoconduction of rapidly quenched films in the Bi2O31bM2O5 system (M=V,Nb and Ta)

The Bi₂O₃1bM₂O₅ films (M=V, Nb and Ta) were prepared by a rapid quenching technique using a twin-roller type equipment. Quenched film of pure Bi₂O₃ partially precipitated a tetragonal phase which differs from well-known β-Bi₂O₃ in structure. In every (Bi₂O₃)_0.975 (M₂O₅)_0.025 composition (2.5% M₂O₅), the tetragonal phase was obtained as single phase, and the tetragonality became greater than that of the pure Bi₂O₃. Beyond this composition, the tetragonality decreased to form δ-phase with a fcc structure with increasing the M₂O₅ content. The lowest V₂O₅ content forming a δ-phase was 5%, while a slight tetragonality still remained in the samples containing 10% Nb₂O₅ and 10% Ta₂O₅, respectively. From the measurement of the photoconductivities of the quenched films, it was proved that a photoconduction appeared in the tetragonal phase while no photoconductivity was observed in the cubic phase. The characteristic of the photoconduction was that a remarkable decrease in the resistivity was observed when a light of ca. 500 nm in wave length was irradiated on the films.     

Soliton self-frequency shift in orthogonally polarised femtosecondsolitons

The soliton self-frequency shift (SSFS) in orthogonally polarised femtosecond soliton pulses is reported for the first time. It is shown that SSFS for orthogonally polarised solitons is approximately 1/3 of that for parallel polarised solitons. This is attributed to the orthogonal Raman term. The 2π and π dependences of the SSFS on the phase difference between the two solitons are newly obtained for parallel and orthogonal polarisations, respectively. The largest SSFS occurs in-phase under parallel polarisation     

Room temperature pulsed operation of 1.5 μm GaInAsP/InPvertical-cavity surface-emitting laser

Room-temperature pulsed operation of a GaInAsP/InP vertical-cavity surface-emitting laser diode (VCSELD) with an emission wavelength near 1.55 μm is reported. A double heterostructure with a 34-pair GaInAsP (λ_g=1.4 μm)/InP distributed Bragg reflector (DBR) was grown by metalorganic chemical vapor deposition (MOCVD). The measured reflectivity of the semiconductor DBR is over 97% and threshold current is 260 mA for a 40-μmφ device with a 0.88-μm-thick active layer. Threshold current density is as low as 21 kA/cm² at room temperature     

Studies on calcium antagonistic and alpha 1-adrenergic receptor blocking activities of monatepil maleate, its metabolites and their enantiomers

The calcium antagonistic and alpha 1-adrenergic receptor blocking activities of monatepil maleate (CAS 103377-41-9, (+/-)-N-(6,11-dihydrodibenzo [b, e] thiepin-11-yl) -4-(4-fluorophenyl)-1-piperazinebutanamide monomaleate, AJ-2615), a novel calcium antagonist, its metabolites and their enantiomers were studied in vitro. Monatepil maleate inhibited calcium-induced contractions of rat thoracic aorta (pA2 = 8.71) and l-phenylephrine-induced contractions of rabbit superior mesenteric artery (IC50 = 56.6 nmol/l). The calcium antagonistic activities of the metabolites of monatepil maleate (AJ-2615-sulfoxide A, AJ-2615-sulfoxide B and AJ-2615-sulfone) were 1/10 of that of monatepil maleate. However, their alpha 1-adrenergic receptor blocking activities were similar to or slightly more potent than that of monatepil maleate. The potencies of the calcium antagonistic activities of monatepil maleate and its enantiomers [(S)-AJ-2615 and (R)-AJ-2615] were in the order of (S)-AJ-2615 > monatepil maleate > (R)-AJ-2615 whereas no difference was observed among them in alpha 1-adrenergic receptor blocking activity. In calcium antagonistic and alpha 1-adrenergic receptor blocking activities, there was no difference between the enantiomers of monatepil maleate metabolites. In conclusion, there was a difference with several times in calcium antagonistic activity between the two enantiomers of monatepil maleate but not in their alpha 1-adrenergic receptor blocking activity.