80 research outputs found

    Application of a small oscillating magnetic field to reveal the peak effect in the resistivity of Nb3Sn

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    By the application of a small oscillating magnetic field parallel to the main magnetic field and perpendicular to the transport current, we were able to unveil the peak effect in the resistivity data of Nb3_3Sn near the upper critical field Hc2H_{c2}. We investigated the dependence of this effect on the frequency and the amplitude of the oscillating magnetic field and show that the used technique can be more sensitive to detect the peak effect in a certain range of temperatures and magnetic fields than conventional magnetization measurements.Comment: 17 pages, 10 figure

    Upper Critical Field of Superconducting Amorphous Alloy Zr_<85>Si_<15>

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    The upper critical field H_ is measured for the amorphous superconductor Zr_Si_ (T_c=2.70 K, ρ_n=270 μΩ・cm) in the wide temperature range down to 50 mK. The conventional V-H recording in sweeping magnetic field and measurements of the flux flow resistivity defined by the I-V curve at constant field are done in order to clarify the resistive transition of the superconducting mixed-to-normal state in an amorphous superconductor with extreme softness in the flux pinning interaction. The results show the strong suppression of H_ at low temperatures, which is quite different from the upward deviation from the theoretical values H_^* due to the orbital pair breaking effect in the dirty limit, reported for some amorphous alloys. Analysis with the Werthamer-Helfand-Hohenberg theory which takes into account the effects of the orbital pair breaking, spin paramagnetism and spin-orbit interaction gives 1.51≤α≤1.77 and 1.0≤λ_≤1.7, where α is the impurity parameter and λ_ the spin orbit interaction parameter. This is the first implication for the superconductivity in amorphous alloys that the spin paramagnetic effect plays an important role in determining the low temperature H_ and the spin-orbit (spin-flip) scattering enhances H_ moderately. The counterevidence is produced to the previous observation that the upward deviation anomaly (H_>H_^*) is an intrinsic property in amorphous metals with high resitivity

    Ripple Shielding for Accurate Resistivity Measurements in Hybrid Magnets(Part II. Several Instruments and Techniques Developed in HFLSM)

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    After a preliminary test of ripple shielding by a coil using a prereacted pure Nb_3Sn multifilamentary superconducting wire, a few ripple shielding coils were developed employing a Ti-doped Nb-tube method processed multifilamentary Nb_3Sn superconducting wire with so far highest J_c by the so called W&R method, making it possible to measure the temperature dependence of the resistivity in Nb_Ti_ alloy within the accuracy of 10^ at very high magnetic fields above 20 T in the hybrid magnets in the High Field Laboratory for Superconducting Materials at Tohoku University

    Optical conductivity from local anharmonic phonons

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    Recently there has been paid much attention to phenomena caused by local anharmonic vibrations of the guest ions encapsulated in polyhedral cages of materials such as pyrochlore oxides, filled skutterdites and clathrates. We theoretically investigate the optical conductivity solely due to these so-called rattling phonons in a one-dimensional anharmonic potential model. The dipole interaction of the guest ions with electric fields induces excitations expressed as transitions among vibrational states with non-equally spaced energies, resulting in a natural line broadening and a shift of the peak frequency as anharmonic effects. In the case of a single well potential, a softening of the peak frequency and an asymmetric narrowing of the line width with decreasing temperature are understood as a shift of the spectral weight to lower level transitions. On the other hand, the case of a double minima potential leads to a multi-splitting of a spectral peak in the conductivity spectrum with decreasing temperature.Comment: 8 pages, 11 figures, accepted for publication in Phys. Rev.

    Prediction of p53 target genes based on integrative analysis of chromatin immunoprecipitated and sequenced tags,by using Galaxy,a web-based interactive platform for large-scale genome analysis

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    Chromatin immunoprecipitation (ChIP) followed by sequencing of immunoprecipitated DNA fragments is the high throughput method for identifying transcription factor binding sites. In one such method, ChIP PET, paired end ditags (PETs) derived from both ends of the immunoprecipitated DNA fragments are sequenced and mapped to the genome. We report here the prediction of p53 target genes by meta analyzing tags of p53 ChIP PET and by combining with other genomic annotations, using Galaxy, a web based platform for large scale genome analysis. We found 327 of p53 binding sites on the genome of 5-fluorouracil (5-FU)-treated HCT116 colon cancer cells by searching the total 65,509 PETs for PET clusters. The search for p53 target gene, which focused on PET clusters with computationally-predicted p53 binding motif, identified 20 of putative p53 target genes as well as 11 of known p53 targets. Another search for p53 target genes, which focused on PET clusters located within 50-kb flanking regions of transcription start sites of genes, identified 278 of Refseq genes, 79 of non-coding RNAs and 5 of microRNAs as p53 targets which included lots of known validated targets. Our results indicate that sequencing-based ChIP analysis combined with the existing genome annotation is effective method to predict p53 binding loci and target genes, and also show that the Galaxy platform is well-suited for multiple-type analyses and visualization of ChIP data, leading to functional annotation of transcription factor binding sites

    Clinical value of the determination of serum guanase activity in patients with chronic hepatitis type C

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    The study examines the clinical significance of guanase (GU) measurement inpatients with hepatitis C. 688 patients in whom either ALT was abnormal, or in whom HBsAg or HCVAb was detected in the serum, were enrolled into this study. The percentage of cases in which normal ALT while elevated GU was compared among the different disease groups. Then, the percentage of cases with normal ALT but elevated GU was compared between HBV and HCV groups. For the entire population, a significant correlation was observed between ALT and GU (r=0.872). The overall percentage of cases with normal ALT but elevated GU activity was 11.4%. In HCV group, 449 cases had normal ALT. Of these cases, 20.3% had elevated GU, while ALT was normal. Before 1989, no test to check donated blood for HCV antibody was available. However, screening of donated blood for high GU was associated with a reduced incidence of post-transfusion hepatitis. This is probably because following the screening, blood donated by patients with hepatitis C who had normal ALT but elevated GU was rejected. After the introduction of HCV antibody measurement, GU measurement is still useful to reveal the pathophysiological condition in-patients with chronic hepatitis type C

    トクシマシ イシカイ ガ ウンエイ スル トクシマシ チイキ ホウカツ シエン センター ノ トリクミ

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    The Tokushima City Integrated Community Care Support Center, a public institution responsible for the Long-Term Care Insurance and welfare administration of Tokushima City, has high business operations fair and neutrality. The only support center in Tokushima City has been entrusted to the Tokushima City Medical Association and is a large center unusual in Japan. We are working to cooperation with relevant organizations to support the medical and health, welfare and care of the community. We try to establish an Integrated Community Care system, as elderly can continue to live so long and dignified. We divided a daily living area of Tokushima City into four, and have placed the staff for each area. The current number of staff is 54 people in total, including public health nurses, social workers, chief care managers, and so on. Number of consultations reaches 36,000 per year. Occasionally, we received over 160 consultations a day. There are a wide variety of consultation contents such as Dementia and long-term care services, elder abuse and consumer damage. Because of Medical Association’s operation, we are able to easily construct cooperation with the healthcare and the long-time care system. Therefore, the all citizens of Tokushima City can receive standard services equally, fair, and neutrally. There is no regional disparity, there is no user of the enclosure. Because we have14branches of the support center in the city, they can bring a high level convenience to the citizens. It seems necessary to focus on the development of four promotions for the future citizens, ① Enhancement of the center output ② Cooperation of the healthcare and the long-term care ③ Improvement of the area community care conference ④ Increase of measures against Dementia

    Inter-rater agreement in the assessment of abnormal chest X-ray findings for tuberculosis between two Asian countries

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    <p>Abstract</p> <p>Background</p> <p>Inter-rater agreement in the interpretation of chest X-ray (CXR) films is crucial for clinical and epidemiological studies of tuberculosis. We compared the readings of CXR films used for a survey of tuberculosis between raters from two Asian countries.</p> <p>Methods</p> <p>Of the 11,624 people enrolled in a prevalence survey in Hanoi, Viet Nam, in 2003, we studied 258 individuals whose CXR films did not exclude the possibility of active tuberculosis. Follow-up films obtained from accessible individuals in 2006 were also analyzed. Two Japanese and two Vietnamese raters read the CXR films based on a coding system proposed by Den Boon et al. and another system newly developed in this study. Inter-rater agreement was evaluated by kappa statistics. Marginal homogeneity was evaluated by the generalized estimating equation (GEE).</p> <p>Results</p> <p>CXR findings suspected of tuberculosis differed between the four raters. The frequencies of infiltrates and fibrosis/scarring detected on the films significantly differed between the raters from the two countries (<it>P </it>< 0.0001 and <it>P </it>= 0.0082, respectively, by GEE). The definition of findings such as primary cavity, used in the coding systems also affected the degree of agreement.</p> <p>Conclusions</p> <p>CXR findings were inconsistent between the raters with different backgrounds. High inter-rater agreement is a component necessary for an optimal CXR coding system, particularly in international studies. An analysis of reading results and a thorough discussion to achieve a consensus would be necessary to achieve further consistency and high quality of reading.</p

    Temperature dependence of electronic optical absorption in (NMe4+· TCNQ-·)2TCNQ

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    The temperature dependence of the linearly polarized optical absorption spectrum has been measured in single crystals of (NMe4+·TCNQ−·)2TCNQ, where NMe4 and TCNQ are tetramethylammonium and tetracyanoqui nodi methane, respectively, in the temperature range between −100 and +150 ℃. In addition to intense TCNQ−· dimer bands, strongly temperature-dependent satellite bands appear at around 1.3 eV and 1.9 eV. The singular behavior of the intensity and peak position of the 1.3 eV band shows that a second order phase transition takes place at 126 ℃. The origin of this band is discussed in relation to the mechanism of the phase transition
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