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In this study, the characteristics of thin semi-rigid cables composed of different conductors and with outer diameters ranging from 0.86 to 1.19 mm were investigated at low temperatures. The thermal conductance was measured between approximately 1 and 8 K, and the frequency dependence of the attenuation in the cables was obtained at 3 K. The electrical conductors used in the cables were alloys: beryllium copper, brass, stainless steel (SUS304), phosphor bronze, cupronickel (CuNi), and niobium-titanium (NbTi). The thermal conductance of a commercial miniature coaxial cable with braided wires forming the outer electrical conductor was also examined for reference. The measured thermal conductance was compared to published data and that generated from material libraries and databases. Among the measured cables using normal metals, the semi-rigid cable composed of SUS304 conductors and a polytetrafluoroethylene insulator showed the lowest thermal conductance. The transmission performance of the semi-rigid cables using SUS304 or CuNi was improved by plating the central conductors with a silver coating of approximately 3μm thickness, and their thermal conductance with the plating increased by approximately one order of magnitude. The superconducting NbTi semi-rigid cable exhibited the lowest thermal conductance of all the cables considered in the present study along with very small attenuation up to above 5 GHz. [ABSTRACT FROM AUTHOR]

An ozone (O $$_{3})$$ oxidation process was introduced for Nb/Al-based superconducting tunnel junctions (STJs) in order to form defect-free tunnel barriers at high critical current and to improve the energy resolution ( $$\Delta E$$ ) for X-rays. The dependence of critical current ( $$J_\mathrm{C})$$ and leak current ( $$I_\mathrm{leak})$$ on the O $$_{3}$$ exposure was measured to optimize the oxidation condition. The 50-square- $$\upmu $$ m STJs produced by the O $$_{3}$$ oxidation process exhibited an extremely small $$I_\mathrm{leak}$$ of less than 50 pA. As expected, the lower or shorter the O $$_{3}$$ exposure, the higher $$J_\mathrm{C}$$ and the smaller the normal resistance ( $$R_\mathrm{N})$$ . However, the maximum $$J_\mathrm{C}$$ was 8 A/cm $$^{2}$$ at an O $$_{3}$$ exposure of 0.72 Pa min, which is much smaller than those of STJs with the conventional O $$_{2}$$ oxidation process. It is expected that the high $$J_\mathrm{C}$$ of 1,000 A/cm $$^{2}$$ , at which a 9-eV-energy resolution for 277 eV photons is predicted, can be reached by an O $$_{3}$$ exposure of 3.5 $$\times $$ 10 $$^{-4}$$ Pa min. [ABSTRACT FROM AUTHOR]

We constructed a fluorescence yield X-ray absorption fine structure (XAFS) apparatus for the measurement of local structure around trace light element impurities in light element matrices. Our XAFS instrument with a 100-pixel STJ detector is now in the stage of routine operation and open to users at a synchrotron radiation facility (KEK PF). The average energy resolution of the 100 pixels is 11.8 $$\pm $$ 0.6 at 400 eV in a sensitive area of 1 mm $$^{2}$$ . As an example of functional materials, we successfully measured nitrogen K-edge XAFS spectra of a compound semiconductor, 4H-SiC, with a nitrogen dopant concentration of 300 ppm. The faint N-K line was clearly separated from the strong C-K line. [ABSTRACT FROM AUTHOR]

Superconducting tunnel junction (STJ) detectors have excellent energy resolution, high detection efficiency, and high counting rate in the soft X-ray energy range. These properties are suitable for synchrotron radiation facilities. However, in order to achieve a high throughput analysis for dopants with a lower concentration, the pixel number of STJ array detectors should be further increased to enlarge the sensitive area. As a first step, we have fabricated 400-pixel STJ array detectors and checked the operation yield and the uniformity of leakage current ( $$I_{leak}$$ ) values. Fabricated STJs showed excellent current-voltage curves having low subgap current. The operation yield of STJs with $$I_{leak}$$ values of less than 10 nA was 96 $$\%$$ . The average $$I_{leak}$$ of 3.6 nA is roughly equivalent to that of the 100-pixel STJ array detector, which is open to users at synchroton radiation beam lines and have 12 eV energy resolution at 400 eV. [ABSTRACT FROM AUTHOR]

Mass spectrometry (MS) is widely used in analytical chemistry for such fields as environmental science, life science, and space science. However, MS has two fundamental limits: the mass peak overlap of ions with the same mass/charge-number ( m/ z) ratio but different charge states ( m/ z overlap), and no ability to distinguish different neutral molecules (neutral loss). We show that these limits can be overcome by using superconducting detectors. Superconducting tunnel junctions (STJ) molecule detectors and superconducting nanostripline detectors (SSLDs) are suitable for MS because of the choice of fast ns response. [ABSTRACT FROM AUTHOR]

We present our achievements in the development of superconducting strip-line detectors (SSLDs) with parallel configuration for application in time-of-flight mass spectrometry. We have fabricated 2×2 mm SSLDs by electron beam nano-lithography. In spite of the large area, the detector has a fast time response. To our knowledge our device is the largest cryogenic detector for macromolecules with nanosecond temporal response. Based on the obtained results, our simulations show that the presented parallel SSLD design should be able to cover an area of 4×2 mm while keeping the signal pulse risetime below 1 ns. [ABSTRACT FROM AUTHOR]

The overall performance of a 100-pixel superconducting tunnel junction (STJ) array detector in the soft X-ray region was determined by measuring fluorescent X-rays from light elements. The yield of working STJs in the fabricated detector was 90%, and the leakage current for these 90 STJs was 11.6±2.5 nA. The STJs had an intrinsic energy resolution for O-K α X-rays (524.9 eV) of 10.2±1.7 eV (FWHM). The deviation from energy linearity was −0.042±0.45%, 0.793±0.91%, and 0.135±1.31% for O-K α (524.9 eV), N-K α (392.4 eV) and B-K α (183.3 eV) X-rays, respectively. Most of the STJs exhibited uniform X-ray detection characteristics. In addition, the detector could discriminate the N-K α peak in the fluorescent X-ray spectrum from n-type SiC doped with 300 ppm nitrogen. [ABSTRACT FROM AUTHOR]

An experimental technique for measuring a temperature field in an axisymmetric non-luminous flame is developed using the flame reaction technique combined with the inverse Abel transformation. Flame visualization is carried out using alkali metal solution of Potassium (K), which is supplied to a premixed methane/air flame in a form of spray mist. The basic principle of this technique is based on the measurement of local emission intensity distribution visualized by the flame reaction, which is a function of temperature according to the Maxwell-Boltzmann statistics of thermodynamics. The relationship between the local intensity and the temperature is obtained from the calibration study, in which the local intensity is evaluated from the line of sight intensity by the inverse Abel transformation, and the temperature is measured by thermocouple. This technique is successfully applied to the measurement of local temperature distribution in steady and flickering premixed methane/air flame. The temperature field in the flickering flame indicates that the local temperature oscillates periodically with the flickering frequency, and the highest temperature is found along the flame front and in the merging region. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The recent progress in the nanofabrication of superconducting films opens the road toward detectors with highly improved performances. This is the case for superconducting nano-striplines where the thickness and the width are pushed down to the extreme limits to realize detectors with unprecedented sensitivity and ultra fast response time. In this way quantum detectors for single photons at telecommunication wavelengths and for macromolecules such as proteins can be realized. As is often the case in applied nanotechnology, it is a challenge to make devices with the necessary macroscopic dimensions that are needed to interface present technologies, while maintaining the performance improvements. For nano-stripline detectors, both the fast temporal response and the device sensitivity is generally degraded when the area is increased. Here, we present how such detectors can be scaled up to macroscopic dimensions without losing the performance of the nano-structured active elements by using an innovative configuration. In order to realize ultrathin superconducting film the nano-layer is growth with a careful setup of the deposition technique which guarantees high quality and thickness uniformity at the nano-scale size. The active nano-strips are defined with the state-of-the-art electron beam nanolithography to achieve a highly uniform linewidth. We present working detectors based on nano-strips with thicknesses 9-40 nm and widths of 100-1000 nm which exhibit unprecedented speed and area coverage (40 × 40 μm for single photon detectors and 1 × 1 mm for single molecule detectors) based on niobium nitride thus enabling practical use of this nanotechnology. [ABSTRACT FROM AUTHOR]

In this paper, temperature measurement of axisymmetric dilute hydrogen flame is described using digital laser-speckle technique, which allows the measurement of refractive index field of the flame without any tracers. The measurement system consists of laser and CCD camera, which are placed in-line configuration. The temperature field of the flame is derived from the refractive index field using the cross-correlation analysis of the speckle pattern with and without flame. The influence of the species concentration on the temperature measurement is evaluated from the gas composition in the flame using gas chromatography. It is found that the temperature field measured by the present method with concentration correction agrees with that of the thermocouple measurement within an experimental accuracy, suggesting the usefulness of this measurement technique. [ABSTRACT FROM AUTHOR]

Summary. CD8+ T cells in FIV-infected cats inhibit feline immunodeficiency virus (FIV) replication by producing a soluble factor(s). In the present study, four SPF cats were experimentally infected with FIV. The period during which the anti-FIV activity of CD8+ T cells became detectable was investigated, and the presence or absence of this activity in the lymph nodes and spleen was examined. Furthermore, we investigated which step(s) of the FIV replication cycle are affected by this antiviral activity. This antiviral activity became detectable five weeks after FIV infection in early cases, and it was simultaneous with or one week after the induction of humoral immunity. All cats having CD8+ T cells with anti-FIV activity in the peripheral blood also possessed CD8+ T cells with anti-FIV activity in the lymph nodes. In contrast, CD8+ T cells from the spleens of some, but not all cats showed anti-FIV activity. CD8+ T cell-depleted peripheral blood mononuclear cells were cultured and reconstituted with CD8+ T cells on day 12 of culture after confirming FIV replication. The number of FIV proviral DNA copies in the cells did not change, but the amount of FIV p24 antigen production in the culture supernatant and the number of FIV mRNA copies in the cells decreased. These findings suggested that CD8+ T cell anti-FIV activity acts at the level of FIV mRNA synthesis from the FIV proviral DNA, inhibiting FIV replication by a non-cytolytic mechanism. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the accuracy of simplified methods for quantifying rCBF with acetazolamide challenge by using 123I-N-isopropyl-p-iodoamphetamine (IMP) and SPECT with one-point arterial sampling. After acetazolamide administration we quantified rCBF in 12 subjects by the following three methods: (a) the modified microsphere method, (b) the IMP-autoradiographic (ARG) method based on a two-compartment one-parameter model, and (c) the simplified method based on a two-compartment two-parameter model (functional IMP method). The accuracy of these methods was validated by comparing rCBF values with those obtained by the standard method: the super-early microsphere method with continuous withdrawal of arterial blood. On analyzing rCBF in each flow range (0-0.25, 0.25-0.5, 0.5-0.75 and more than 0.75 ml/g/min), rCBF values obtained by both methods (a) and (c) showed significant correlations (p < 0.01) with those obtained by the standard method in every range, but rCBF values obtained by method (b) did not significantly correlated in the high flow range (0.5-0.75 and more than 0.75 ml/g/min). Method (c) was found to be the most accurate, even though it needs two serial SPECT scans. When requiring one SPECT scan, method (a) was considered to be superior to method (b) because of its accuracy, especially in high flow regions loaded with acetazolamide. [ABSTRACT FROM AUTHOR]

Behavioral and in vitro receptor binding methods were used to evaluate and compare the effects of FR115427 ((+)-1-methyl-1-phenyl-1,2,3,4-tetrahydroisoquinoline hydrochloride) with those of MK801, a non-competitive NMDA antagonist. FR115427 inhibited NMDA-induced convulsions in mice by intracerebroventrical(ICV) and systematic injection. FR115427 was found to be about ten times less potent than MK801. Furthermore, the inhibitory effect of FR115427 and MK801 on NMDA-induced convulsions was evaluated in time course studies in mice. MK801 exhibited a more sustained anticonvulsive activity than FR115427. In addition, PCP-like behaviors were examined in mice after ICV injection of these compounds. At the lowest dose FR115427 significantly increased locomotor activity, although the effect of this compound was about hundred times less potent than that of MK801. At higher dose a more complex pattern of behavior, e.g. head-movement and eventually ataxia was observed. In binding assays with rat brain membranes, FR115427 inhibited the binding of (H)TCP (IC=0.249 µM) and (H)MK801 (IC=0.312 µM) but did not inhibit the binding of (H)CPP or (H)glycine. These results suggest that FR115427 is a novel non-competitive NMDA antagonist that acts on a binding site located within the NMDA receptor associated ion channel. [ABSTRACT FROM AUTHOR]

Endothelin (ET) is a potent vasoconstrictor peptide with an as yet uncertain physiological role in cardiovascular disease. We measured blood plasma ET concentrations using a recently developed radioimmunoassay and analysed the relations between ET concentration, systemic arterial pressure and systemic vascular resistance. In addition, ET levels before and after percutaneous balloon valvuloplasty and angioplasty were measured. Fifty-one patients were studied: (1) 13 patients with small left-to-right shunting or Kawasaki heart disease (age ranged from 4 to 144 months); (2) 10 patients who had undergone balloon valvuloplasty or angioplasty (age ranged from 1 to 233 months) and (3) 28 healthy infants and children (age ranged from 3 to 152 months). Systemic vascular resistance was calculated by the formula (mean aortic pressure--mean right atrial pressure) X 80/cardiac output (dyne.sec.cm-5). Plasma ET concentrations in healthy children less than 2 years were significantly higher than those over 2 years (2.48 +/- 0.62 vs 1.31 +/- 0.53 pg/ml). In eight patients in groups 1 and 2, plasma ET concentration in the pulmonary artery (2.00 +/- 0.43 pg/ml) was significantly lower than that in the femoral vein (2.39 +/- 0.69 pg/ml) and aorta (2.23 +/- 0.59 pg/ml), suggesting ET secretion derived from endothelial cells in peripheral pulmonary vessels. There was a significant positive correlation between ET concentrations in the femoral vein and systemic vascular resistance (r = 0.55, p less than 0.05). After balloon dilatation ET concentration rose from 2.15 +/- 0.82 pg/ml to 2.61 +/- 1.38 pg/ml.(ABSTRACT TRUNCATED AT 250 WORDS) [ABSTRACT FROM AUTHOR]

A boy with multicore myopathy associated with multiple pterygium syndrome and hypertrophic cardiomyopathy is described. Light microscopy of biopsy samples from the skeletal muscle and myocardium revealed multiple cores in the muscle fibers in the former but their absence in the latter. These results suggest that the pathogenesis of the histologic changes might differ between skeletal muscle and myocardium, and that further electron microscopic examination be done on both types of specimen. The prognosis of multicore myopathy is not usually good when cardiac involvement is present. [ABSTRACT FROM AUTHOR]