Multi-mode resistive spectroscopy for precisely controlling morphology of extremely narrow gap palladium nanocluster array.

During the deposition of a metallic material on a substrate, a nanocluster-array structure with an extremely narrow gap is formed transiently at the transition between isolated clusters and the continuous film. It is known that the nanocluster array shows a unique electrical property different from that of isolated clusters and the continuous film. The electrical property of the nanocluster array changes significantly depending on its morphology, and precise control of the deposition time is indispensable to obtain a desired electrical property. However, the detection of the transition is not straightforward. To overcome this problem, we develop the multi-mode resistive spectroscopy. It evaluates the morphological change during deposition using resonant vibrations of a piezoelectric material and enables the fabrication of nanocluster arrays with a slightly different morphology. Palladium nanocluster arrays with different morphologies are fabricated using this method, and the availability of the multi-mode resistive spectroscopy is demonstrated by evaluating their electrical response to hydrogen gas.

Use of vertebral left atrial size for staging of dogs with myxomatous valve disease.

INTRODUCTION/OBJECTIVES: The American College of Veterinary Internal Medicine (ACVIM) guidelines suggest that pimobendan should be initiated in dogs which meet all criteria of stage B2 myxomatous mitral valve disease (MMVD): murmur intensity ≥ 3/6, left atrial-to-aortic ratio ≥ 1.6, normalized left ventricular internal diameter in diastole ≥ 1.7, and vertebral heart size > 10.5. Recently, a new radiographic index for left atrial enlargement, vertebral left atrial size (VLAS), was proposed. The objective of the present study was to evaluate whether VLAS is useful in staging MMVD and if it can distinguish between ACVIM stages B1 and B2. ANIMALS: Ninety-seven client-owned dogs with MMVD were evaluated and classified as ACVIM stage B1, B2, or C-D. MATERIALS AND METHODS: The echocardiographs and radiographs of all the dogs were retrospectively evaluated to obtain left atrial-to-aortic ratio, normalized left ventricular internal diameter in diastole, and VLAS values. The data were analyzed to assess the correlation between these measurements and VLAS, and the optimal cutoff value of VLAS was determined. RESULTS: A VLAS cutoff value of 2.6 provided the greatest diagnostic accuracy for identification of dogs with ACVIM stage B2 MMVD (area under the curve, 0.96; sensitivity, 95%; specificity, 84%). A VLAS ≥2.5 exhibited the highest sensitivity (sensitivity, 100%; specificity, 78%), and a VLAS ≥ 3.1 exhibited the highest specificity (sensitivity, 47%; specificity, 100%). CONCLUSIONS: VLAS is a helpful index for monitoring MMVD using radiography. A VLAS cutoff value of 2.5 could be used to identify dogs that may benefit from echocardiography to determine if they have reached ACVIM stage B2.

Quantitative imaging of Young's modulus of solids: a contact-mechanics study.

We developed equipment and methods for measuring quantitatively the local Young's modulus of solids. It consists of an electrodeless langasite oscillator and line antennas, and oscillator vibrations are generated and detected contactlessly. A constant biasing force results from oscillator mass and is independent of surface roughness. The effect of material anisotropy on the measured stiffness is theoretically discussed for studying the limitation of the quantitative measurement. The microscopy has been applied to polycrystalline copper, and the measured modulus is compared to calculations based on electron-backscatter-diffraction measurements. Also, we applied it to a duplex stainless steel and an embedded silicon-carbide fiber. The results reveal textured regions, defects with high sensitivity, and even stiffness distribution in a single grain.

The oncogenic role of the cochaperone Sgt1.

Sgt1/Sugt1, a cochaperone of Hsp90, is involved in several cellular activities including Cullin E3 ubiqutin ligase activity. The high level of Sgt1 expression in colorectal and gastric tumors suggests that Sgt1 is involved in tumorigenesis. Here, we report that Sgt1 is overexpressed in colon, breast and lung tumor tissues and in Ewing sarcoma and rhabdomyosarcoma xenografts. We also found that Sgt1 heterozygous knockout resulted in suppressed Hras-mediated transformation in vitro and tumor formation in p53(-/-) mouse embryonic fibroblast cells and significantly increased survival of p53(-/-) mice. Moreover, depletion of Sgt1 inhibited the growth of Ewing sarcoma and rhabdomyosarcoma cells and destabilized EWS-FLI1 and PAX3-FOXO1 oncogenic fusion proteins, respectively, which are required for cellular growth. Our results suggest that Sgt1 contributes to cancer development by stabilizing oncoproteins and that Sgt1 is a potential therapeutic target.

Distribution and characterization of anandamide amidohydrolase in mouse brain and liver.

Anandamide (N-Arachidonoylethanolamine) amidohydrolase catalyzing hydrolysis of anandamide was characterized in mice. The enzymatic activity was highest in the liver, followed by the brain and testis. Negligible activity was found in heart, lung and spleen. The activity in brain and liver was mainly localized in the microsomal fractions. Kinetic experiments demonstrated that Km (microM) and Vmax (nmol/min/mg protein) for the brain microsomes were 9.3 and 2.58, respectively, while those for the hepatic microsomes were 180 and 18.9, respectively. The activity in the microsomes from the liver and brain was markedly inhibited by Cu2+, Hg2+, Se4+, phenylmethylsulfonylfluoride and sodium dodecylsulfate. Brain but not hepatic microsomal enzyme activity was inhibited by delta9-tetrahydrocannabinol, cannabidiol and cannabinol. Kinetic parameters demonstrated that the inhibition by the cannabinoids was competitive in nature. Relatively high distribution of the enzyme activity in brain suggests an importance of the enzyme in the central nervous system to regulate the neuromodulatory fatty-acid amides.

Line-focusing electromagnetic acoustic transducers for the detection of slit defects.

This paper describes the design principles of a line-focusing electromagnetic acoustic transducer (LF-EMAT) and the results of a feasibility test for detecting slit-type defects in metals. The LF-EMAT excites shear vertical (SV) elastic waves and focuses them to a line in a metal body. It consists of a permanent magnet block and a meanderline coil, whose spacing is continuously varied so that the excited SV waves become coherent on a focal line after traveling oblique paths. The measured directivity of generation and reception show a sharp peak at the designed focal line. The LF-EMATs are then applied to detecting slit defects in the bottom surface of steel blocks, on which the focal lines are located. Portions of the scattered defect signals are received by the same EMAT. When operated at 4 MHz, the LF-EMATs are capable of detecting slits deeper than 0.05 mm. The sensitivity decreases with liftoff and the LF-EMATs are usable with liftoff up to 0.6 mm.

Determination of elastic, anelastic, and piezoelectric coefficients of piezoelectric materials from a single specimen by acoustic resonance spectroscopy.

We describe an advanced methodology to determine all the independent elastic-stiffness coefficients Cijkl, the associated internal frictions Qijkl(-1), and piezoelectric coefficients eijk of piezoelectric materials from a single monocrystal specimen using resonant-ultrasound spectroscopy with laser-Doppler interferometry. The mechanical-resonance frequencies of a piezoelectric solid depend on all of the elastic and piezoelectric coefficients, and their accurate measurement allows one to determine the elastic and piezoelectric coefficients simultaneously. Resonance-peak-width measurements yield the internal-friction tensor. Successful determination requires correct vibration-mode identification for the observed resonance frequencies. This is achieved unambiguously by measuring deformation distributions on the vibrating-specimen surface with laser-Doppler interferometry and comparing them with calculated displacement distributions. The methodology is applied to lithium niobate (LiNbO3) and langasite (La3Ga5SiO14) crystals.

Elastic constants of langasite and alpha quartz at high temperatures measured by antenna transmission acoustic resonance.

A method for measuring elastic constants of piezoelectric materials at high temperature up to 1224 K is proposed. It determines all independent elastic constants by measuring resonance frequencies of a rectangular parallelepiped piezoelectric specimen contactlessly using its own piezoelectricity with an antenna. Without using conventional contacting piezoelectric transducers, vibrational sources are excited directly in the specimen by the oscillating electric field. Capability of the method is demonstrated by measuring the elastic constants of langasite at high temperature up to 1224 K, and temperature coefficients of the elastic constants are determined. In addition, elastic constants of alpha quartz are measured at high temperature up to just below the alpha-beta phase transition temperature. Considering the local deformation with temperature increment, an interpretation based on the strain energy reduction is proposed for the unusual temperature dependence of C(66). Furthermore, the internal-friction tensor is measured, and the relationship between the observed anisotropy in internal friction and the structural evolution with temperature increment is discussed.

BUB3 that dissociates from BUB1 activates caspase-independent mitotic death (CIMD).

The cell death mechanism that prevents aneuploidy caused by a failure of the spindle checkpoint has recently emerged as an important regulatory paradigm. We previously identified a new type of mitotic cell death, termed caspase-independent mitotic death (CIMD), which is induced during early mitosis by partial BUB1 (a spindle checkpoint protein) depletion and defects in kinetochore-microtubule attachment. In this study, we have shown that survived cells that escape CIMD have abnormal nuclei, and we have determined the molecular mechanism by which BUB1 depletion activates CIMD. The BUB3 protein (a BUB1 interactor and a spindle checkpoint protein) interacts with p73 (a homolog of p53), specifically in cells wherein CIMD occurs. The BUB3 protein that is freed from BUB1 associates with p73 on which Y99 is phosphorylated by c-Abl tyrosine kinase, resulting in the activation of CIMD. These results strongly support the hypothesis that CIMD is the cell death mechanism protecting cells from aneuploidy by inducing the death of cells prone to substantial chromosome missegregation.

Resonant-ultrasound spectroscopy for studying annealing effect on elastic constant of thin film.

In this paper, we study the elastic property of thin films using resonant-ultrasound spectroscopy (RUS). RUS determines the elastic constants of a solid from its resonance frequencies of free vibration. There were two problems to be solved for applying RUS to thin films: accurate measurement of the resonance frequencies and mode identification of each resonance frequency. We solve these problems using the tripod needle transducers and the laser-Doppler interferometry (LDI). In this paper, we describe the RUS/LDI measurement setup we developed, and show the relationship between the elastic constant and annealing temperature for Cu thin films. Then, we discuss the effects of recrystallization and recovery on the elastic constant referring the X-ray diffraction measurement.

Unusual elastic behavior of nanocrystalline diamond thin films.

This Letter studies the relationship between the elastic constants and the microstructure of nanocrystalline diamond thin films deposited by the chemical vapor deposition method doping various concentration of N2 gas. The elastic constants were measured by resonant ultrasound spectroscopy and picosecond laser ultrasounds. The increase of N2 gas decreases the diagonal elastic constants, but increases the off-diagonal elastic constants. The micromechanics calculation can explain this unusual elastic behavior, and it predicts thin graphitic phases at grain boundaries.

Stiffened ultrathin Pt films confirmed by acoustic-phonon resonances.

Resonances of coherent acoustic phonons were excited and detected by femtosecond light pulses for determining the normal elastic constant of ultrathin platinum films. The elastic constant increases with the decrease of the film thickness, exceeds the bulk value at the thickness near 5 nm, and significantly increases at low temperatures. It shows a correlation with the normal lattice distance. Thus, this Letter provides evidence of the stiffness enhancement in ultrathin films caused by lattice anharmonicity.

Cutaneous metastasis of CNS chordoma.

A rare case of cutaneous skin metastasis from an intracranial chordoma is presented. A large nodule developed in the left thigh of a 22-year-old woman who had been previously diagnosed to have a chordoma at the base of her skull. Sections from the biopsied specimens of the nodule showed proliferations of physaliphorous cells and stellate cells in cords and in nests in a myxoid stroma. Immunohistochemically, neoplastic cells were stained positively with antibodies to S-100 protein and cytokeratin. The results of the histopathological and immunohistochemical studies of the nodule were interpreted as pointing to a diagnosis of metastatic chordoma based on their similarity to the results of studies of the primary neoplasm in the cranial region. Based on the number of cases of skin metastasis from chordoma reported in the literature, skin should be kept in mind as one of the target organs, although such metastases are still rare.

Metal concentrations in pelagic seabirds from the North Pacific Ocean.

Concentrations of four essential elements (Fe, Mn, Zn, and Cu) and two toxic metals (Cd and Hg) were measured in selected tissues of 19 pelagic seabird species collected in the North Pacific and neighboring waters. Essential metal concentrations were generally highest in the liver and less variable than toxic metals among species and also within each species. Fe concentrations in the muscle were higher in Alcidae than in the other families, whereas the opposite trend was found for Fe and Mn in the liver. Zn concentrations varied among species, depending on the Cd concentrations. On the other hand, toxic metal concentrations were highest in the liver or kidney and varied widely among species, greatly depending on differences in the diet among species. Extraordinarily high Hg concentrations were found in Black-footed Albatrosses,Diomedea nigripes, exceeding 300 µg/g wet weight in some, and seemed to be due to constraints on the elimination of Hg. Also, some geographical differences in Cd and Hg concentrations of the seabirds were observed. The concentrations of Cd and Hg reported here, however, seem to be natural rather than due to environmental pollution.