Imaging phonon eigenstates and elucidating the energy storage characteristics of a honeycomb-lattice phononic crystal cavity.

We extend gigahertz time-domain imaging to a wideband investigation of the eigenstates of a phononic crystal cavity. Using omnidirectionally excited phonon wave vectors, we implement an ultrafast technique to experimentally probe the two-dimensional acoustic field inside and outside a hexagonal cavity in a honeycomb-lattice phononic crystal formed in a microscopic crystalline silicon slab, thereby revealing the confinement and mode volumes of phonon eigenstates-some of which are clearly hexapole in character-lying both inside and outside the phononic-crystal band gap. This allows us to obtain a quantitative measure of the spatial acoustic energy storage characteristics of a phononic crystal cavity. We also introduce a numerical approach involving toneburst excitation and the monitoring of the acoustic energy decay together with the integral of the Poynting vector to calculate the Q factor of the principal in-gap eigenmode, showing it to be limited by ultrasonic attenuation rather than by phonon leakage to the surrounding region.

Ultrafast vibrations of gold nanorings.

We investigate the vibrational modes of gold nanorings on a silica substrate with an ultrafast optical technique. By comparison with numerical simulations, we identify several resonances in the gigahertz range associated with axially symmetric deformations of the nanoring and substrate. We elucidate the corresponding mode shapes and find that the substrate plays an important role in determining the mode damping. This study demonstrates the need for a plasmonic nano-optics approach to understand the optical excitation and detection mechanisms for the vibrations of plasmonic nanostructures.

Giant extraordinary transmission of acoustic waves through a nanowire.

Wave concentration beyond the diffraction limit by transmission through subwavelength structures has proved to be a milestone in high-resolution imaging. Here, we show that a sound wave incident inside a solid over a diameter of 110 nm can be squeezed through a resonant meta-atom consisting of a nanowire with a diameter of 5 nm equal to λ/23, where λ is the incident acoustic wavelength, corresponding to a transmission efficiency of 500 or an energy densification of ~14,000. This remarkable level of extraordinary acoustic transmission is achieved in the absence of ultrasonic attenuation by connecting a tungsten nanowire between two tungsten blocks, the block on the input side being furnished with concentric grooves. We also demonstrate that these "solid organ pipes" exhibit Rayleigh end corrections to their effective longitudinal resonant lengths notably larger than their in-air analogs. Grooves on the output side lead to in-solid directed acoustic beams, important for nanosensing.

Vibrations of microspheres probed with ultrashort optical pulses.

We use ultrashort optical pulses to excite and detect vibrations of single silica spheres with a diameter of 5 microm placed at the surface of an acoustically mismatched substrate. In addition to the photoelastic detection of picosecond longitudinal acoustic pulses propagating inside the bulk, we detect gigahertz acoustic resonances of the sphere through probe beam defocusing. The mode frequencies are in close accord with those calculated from the elastic vibrations of a free sphere. We also record a resonant enhancement in the amplitude of specific modes of two touching spheres.

Microscale multiple scattering of coherent surface acoustic wave packets probed with gigahertz time-reversal acoustics.

The multiple scattering of coherent surface acoustic wave packets in a microstructure is studied using an ultrafast optical technique. By recording a set of acoustic transfer functions, we show that it is possible to implement time-reversal acoustics and refocus the wave packets up to the GHz range, two orders of magnitude higher than usual. Many applications in time-reversal acoustics are thus transposable to correspondingly smaller structures, opening the way to efficient nondestructive characterization and manipulation of multiple scattering on the microscale.

Hypouricemia due to an increment in renal tubular urate secretion.

Two patients had hypouricemia due to increased uric acid clearance. Their daily urinary uric acid excretions were normal. In both patients, pyrazinamide decreased urinary uric acid clearance to almost while probenecid increased it markedly. No other renal tubular or metabolic abnormalities were found. The serum electrolytes and the urinary electrolytes excretions showed no abnormalities. It appears that increased secretion of uric acid in the renal tubule is most probably responsible for hypouricemia in these patients. This report adds to the list of hypouricemic conditions due to a new isolated renal tubular abnormality.

Long-term effects of steroid treatment on nephrotic syndrome associated with Kimura's disease and a review of the literature.

A 68-year-old Japanese male (Case 1) and a 59-year-old Japanese male immigrant to Brazil (Case 2) who suffered from subcutaneous eosinophilic lymphoid granuloma (Kimura's disease) of several years duration, developed nephrotic syndrome. Renal biopsy demonstrated membranous nephropathy in Case 1 and minimal-change lesion in Case 2. Both patients were treated with prednisolone for several months. There was complete remission of nephrotic syndrome in eight years in Case 1 and in three months in Case 2. Proteinuria did not reappear after remission of nephrotic syndrome in either case. In contrast subcutaneous tumors subsided in both cases during steroid treatment but again became active immediately following discontinuation of the drug. These clinical observations suggest that, though some common factor(s) might mediate the development of both skin and renal lesions, the mechanism of action on these two target organs may differ, perhaps serving only as a "trigger" for the initiating mechanism of renal disease.

Sulbenicillin-induced kaliuresis in man.

The mechanism of kaliuresis induced by massive antibiotic administration was studied using alpha-sulfobenzyl penicillin (SBPC). In experimental group (n = 8), urinary electrolytes excretion were compared between following the infusion of 10 g SBPC in 200 ml water at a constant rate and following the infusion of 48 mmol of NaCl (equal to that contained in 10 g SBPC) in 200 ml water. For the control group, 96 mmol NaCl in 400 ml water was infused (n = 5). In the experimental group, urinary Na (UNaV) and urinary K excretion (UKV) increased relative to the control period. In the control group, UKV was not increased although UNaV was increased (p less than 0.05). UKV following SBPC infusion was correlated with UNaV (p less than 0.05) and urinary SBPC excretion (p less than 0.05). The ratio of urinary anion gap to urinary cation [1-(urinary Cl concentration/(urinary Na concentration + urinary K concentration))] was significantly increased following SBPC infusion (p less than 0.005) but not in the control group. This increase in anion gap is possibly due to urinary SBPC, which will be ionized over 90% as nonreabsorbable anion in maximally acidic urine. We conclude that the kaliuresis induced by massive SBPC administration in man is probably caused by the nonreabsorbable anion effect of SBPC itself.

An aged male patient with autoimmune hepatitis complicated by hepatocellular carcinoma.

An 82-year-old male patient was admitted for liver dysfunction. Laboratory test showed the following data; aspartate aminotransferase (AST) 79 IU/l, alanine aminotransferase (ALT) 28 IU/l, total bilirubin (T. Bil) 0.9 U, zinc sulfate turbidity test (ZTT) 48.9 U, gamma-globulin 4.9 g/dl, immunoglobulin G (IgG) 5,046 mg/dl, anti-nuclear antibodies x 320, anti-mitochondrial antibodies (-), hepatitis B virus surface antigen (HBsAg) (-), HBcAb (-), anti-hepatitis C virus (anti-HCV) (-), hepatitis C virus (HCV-RNA) (-), anti-hepatitis G virus (anti-HGV) (-), alpha-fetoprotein 306.8 ng/ml, carcinoembryonic antigen (CEA) 2.3 ng/ml, carbohydrate antigen (CA) 19-9 77.2 U/ml. Abdominal ultrasonography and computed tomography showed a large mass occupying most of the right lobe and portal thrombosis in the liver. Liver biopsy revealed cirrhosis with inactive hepatitis in the nontumorous lesion and well-differentiated hepatocellular carcinoma in the tumorous lesion. We report a rare case of an aged male patient with autoimmune hepatitis complicated by hepatocellular carcinoma.

Laser picosecond acoustics in a two-layer structure with oblique probe light incidence.

A theory for the analysis of experiments involving laser picosecond acoustics with obliquely incident probe light in a two-layer structure is outlined. The reflectance and phase changes of the reflected light are calculated with a theory that takes into account the effects of multiple optical reflections. The sample consists of a single partially transparent layer on a substrate, both with arbitrary optical constants. We discuss the conditions in which one may discriminate between components of the optical modulation of a probe beam arising from the photoelastic effect and from the displacement of the sample interfaces induced by the acoustic strain.

Laser picosecond acoustics in multilayer structures.

The field of laser picosecond acoustics has thrived owing to the ease of detection of propagating picosecond acoustic pulses through changes in optical reflectance. Reflectance changes are caused by the inhomogeneous modulation of the refractive index by the propagating elastic strain through the photoelastic effect and also by the associated induced motion of the surface and interfaces. In this paper we present a general formula for calculating the reflectance change based on a rigorous one-dimensional treatment of the perturbation in optical properties of arbitrary multilayer structures. The theory is applied to the quantitative analysis of data obtained by laser picosecond acoustics for a SiO2-Cr double-layer film on a fused silica substrate. The analysis allows the discrimination of the photoelastic contribution and the surface or interface motion contribution to the experimental reflectance variation.

Spatiotemporal mapping of surface acoustic waves in isotropic and anisotropic materials.

We demonstrate a new method for a real-time imaging of surface acoustic waves at frequencies up to 1 GHz with picosecond temporal and micron spatial resolutions using an ultrafast optical pump and probe technique combined with a common path interferometer. Using samples with isotropic or anisotropic substrates coated with metallic thin films, we observe the propagation of Rayleigh-like modes and surface-skimming bulk modes as well as resolving surface phonon focusing effects. In addition we image surface acoustic wave propagation in a laterally inhomogeneous sample.

[Therapeutic effect of hemodialysis on gouty arthritis and tophi in 2 patients with chronic renal failure].

Therapeutic effect of hemodialysis on gouty arthritis and tophi in 2 patients with chronic renal failure (CRF) is described. One patient was 74-year-old man with CRF due to benign nephrosclerosis, and had severe secondary gout. There were many tophi in metatarsophalangeal joints of the fingers and toes. Another patient was 44-year-old man with CRF probably due to familial gout. He had many tophi in elbows, knees, wrists, fingers and toes. In both cases initiation of hemodialysis treatment, at first temporally exacerbated gouty arthritis, but thereafter gradually eliminated the tophi. From these results, dialysis treatment is considered to be quite efficient method of treatment for gouty arthritis and tophi in patient with CRF. Gouty arthritis in CRF patient, which does not respond to the conservative therapy, should be considered to be one of the indices for commencement of hemodialysis.

[A case of myasthenia gravis, who developed minimal change nephrotic syndrome during immunosuppressive therapy after thymectomy].

Myasthenia gravis is caused by antibodies against acetylcholine receptors and is treated with inhibition or elimination of antibody production. We report a 58-year-old woman who had been suffering from myasthenia gravis and underwent thymectomy in July 1995. Her myasthenic symptoms improved with immunosuppressive treatment using corticosteroid(100 mg/day) and azathioprine(100 mg/day). However she presented edema with massive proteinuria(7.54 g/day) and was admitted to our hospital on July 1997. She was diagnosed as having nephrotic syndrome and a renal biopsy was performed. The histological findings showed minimal change nephrotic syndrome. After pulse therapy with methylprednisolone(1 g/day x 3 days) following oral administration of prednisolone(60 mg/day), proteinuria disappeared after one month. Nephrotic syndrome is a rare complication in patients with myasthenia gravis. The increase in lymphokine production caused by thymectomy may be closely associated with the occurrence of nephrotic syndrome in spite of intensive immunosuppressive treatment in the present case. In this report, we also summarized reported cases of minimal change nephrotic syndrome with thymoma and myasthenia gravis.

[A case of systemic lupus erythematosus associated with cryptococcal meningitis which was successfully cured by the administration of massive dose of amphotericin B].

A case of SLE with moderately deteriorated renal function due to lupus nephritis developed cryptococcal meningitis. Long term administration of amphotericin B (cumulative dose 5 g) combined with 5-flucytosine eradicated this fungal infection. Throughout amphotericin B administration urinary excretions of Na and K, as well as plasma HCO3 concentration were monitored, and, Na, K and HCO3 were supplemented orally and intravenously so much as to replace their urinary losses. Neither prominent water-electrolyte disturbance nor severe azotemia, which are the most serious side effects of amphotericin B, did not ensue. This case study indicates that sufficient water.electrolytes supplementation is important to prevent the nephrotoxicity of amphotericin B.

[A case of MPO ANCA associated glomerulonephritis with interstitial pneumonitis complicated with lung tuberculosis and pericarditis].

The main target organs of myeloperoxidase (MPO) antineutrophil cytoplasmic antibodies (ANCA)-related disease are the kidney and lung. This report describes a 71-year-old man with rapidly progressive glomerulonephritis (RPGN) and interstitial pneumonitis associated with MPO ANCA. The patient was admitted to our hospital because of bloody sputum, low grade fever and appetite loss on October, 1998. He was diagnosed as having interstitial pneumonitis from the findings of chest X-ray and CT examinations. Moderate proteinuria and hematuria, renal dysfunction(serum creatinine: 5.6 mg/dl, BUN: 58.0 mg/dl) and positivity for MPO ANCA were noted. He was negative for anti-glomerular antibody and PR3-ANCA. Renal biopsy was performed and revealed crescentic glomerulonephritis without deposition of immunoglobulins. Therefore, the diagnosis of pauci immune type RPGN was made. Pulse therapy with methylprednisolone(1.0 g/day x 3 days) following oral administration of prednisolone (60 mg/day) found marked improvement of renal function maintenance and interstitial pneumonitis, respectively. However, he died because of lung tuberculosis and acute tuberculous pericarditis during treatment with prednisolone. In this case, MPO ANCA might have been directly associated with both RPGN and interstitial pneumonitis. Furthermore, chronic lung disease, such as interstitial pneumonitis, is important as a preceding disease of RPGN. MPO ANCA-related disease is more frequent in aged persons, therefore particular attention should be paid during their treatment with an immunosuppressant.

Broadband evolution of phononic-crystal-waveguide eigenstates in real- and k-spaces.

Control of sound in phononic band-gap structures promises novel control and guiding mechanisms. Designs in photonic systems were quickly matched in phononics, and rows of defects in phononic crystals were shown to guide sound waves effectively. The vast majority of work in such phononic guiding has been in the frequency domain, because of the importance of the phononic dispersion relation in governing acoustic confinement in waveguides. However, frequency-domain studies miss vital information concerning the phase of the acoustic field and eigenstate coupling. Using a wide range of wavevectors k, we implement an ultrafast technique to probe the wave field evolution in straight and L-shaped phononic crystal surface-phonon waveguides in real- and k-space in two spatial dimensions, thus revealing the eigenstate-energy redistribution processes and the coupling between different frequency-degenerate eigenstates. Such use of k-t space is a first in acoustics, and should have other interesting applications such as acoustic-metamaterial characterization.