271 research outputs found

    Reaction of Tetrahydrofuran and Acetic Anhydride Catalyzed by Electrogenerated Acid

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    Abstract The anodic oxidation of tetrahydrofuran with acetic anhydride and lithium perchlorate undergoes the ring opening reaction catalyzed by electrogenerated acid to yield diacetates of 1,4-butanediol, 4,4\u27-oxybis(1-butanol) and α-hydro-ω-hydroxy-poly (oxytetramethylene). The distribution of these products depends on the quantity of acetic anhydride and the electrogenrated acid foromed during the progress of electrolysis

    In-situ measurement of the atmospheric CO concentration at Syowa Station, Antarctica

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    A high-precision measurement system for the atmospheric CO concentration was developed. With some modifications to a gas chromatograph CO analyzer, instrumental reproducibility of 0.5 ppbv was achieved. This could be sufficient for detection of short-term, seasonal and long-term variations of the atmospheric CO concentration in the Antarctic region. A standard gas system to maintain a consistent calibration scale for the CO measurements was also prepared. The measurement system was installed at Syowa Station in March 2000 and has been maintained up to the present. The first-year\u27s observation showed a clear seasonal cycle of CO concentration

    冠動脈高度石灰化病変に対するスコアリングバルーンラクロスNon-Slip Elementを用いた冠動脈形成術-光干渉断層法による有用性の評価

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    Percutaneous coronary intervention (PCI) for heavily calcified lesions is challenging because these lesions are resistant to balloon dilatation and stenting. Lacrosse non-slip element (NSE) may have the potential to dilate heavily calcified lesions. We aimed to investigate predictors of successful lesion modification using Lacrosse NSE angioplasty via optical coherence tomography (OCT)-guided PCI. We investigated 32 patients with severe target lesion calcification treated with OCT-guided PCI. Successful lesion modification was defined as the complete fracture of calcification after Lacrosse NSE angioplasty. Before PCI, 172 segments with calcification were identified. After pre-dilatation using Lacrosse NSE, successful lesion modification was achieved in 117 segments (68.0%). Calcification was significantly thinner in successfully disrupted segments than in non-disrupted segments (p < 0.001). Calcification angle tended to be larger in disrupted than in non-disrupted segments (p = 0.08). Convex types were less frequently observed in disrupted than in non-disrupted segments (p < 0.001). At minimal lumen area sites, 26 segments (81.3%) were successfully modified. Similar to the overall results, the disrupted group had significantly thinner calcification than the non-disrupted group (p < 0.001). The angle of the calcified plaque was similar between the 2 groups (p = 0.39). Convex-type calcifications were less frequently observed in the disrupted group than in the non-disrupted group (p = 0.05). Receiver-operating characteristic curve analysis showed that calcification thickness < 565 μm was the best predictor of completely disrupted calcification. The thickness and shape of calcifications were predictors of successful lesion modification after Lacrosse NSE angioplasty.博士(医学)・乙第1426号・平成31年3月15日© Japanese Association of Cardiovascular Intervention and Therapeutics 2018This is a post-peer-review, pre-copyedit version of an article published in Cardiovascular intervention and therapeutics. The final authenticated version is available online at: http://dx.doi.org/10.1007/s12928-018-0553-6

    Sensorimotor Modulation Differs with Load Type during Constant Finger Force or Position

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    During submaximal isometric contraction, there are two different load types: production of a constant force against a rigid restraint (force task), and maintenance of position against a constant load (position task). Previous studies reported that the time to task failure during a fatigue task was twice as long in the force task compared with the position task. Sensory feedback processing may contribute to these differences. The purpose of the current study was to determine the influence of load types during static muscle contraction tasks on the gating effect, i.e., attenuation of somatosensory-evoked potentials (SEPs) and the cortical silent period (cSP). Ten healthy subjects contracted their right first dorsal interosseus muscle by abducting their index finger for 90 s, to produce a constant force against a rigid restraint that was 20% of the maximum voluntary contraction (force task), or to maintain a constant position with 10° abduction of the metacarpophalangeal joint against the same load (position task). Somatosensory evoked potentials (SEPs) were recorded from C3′ by stimulating either the right ulnar or median nerve at the wrist while maintaining contraction. The cortical silent period (cSP) was also elicited by transcranial magnetic stimulation. Reduction of the amplitude of the P45 component of SEPs was significantly larger during the position task than during the force task and under control rest conditions when the ulnar nerve, but not the median nerve, was stimulated. The position task had a significantly shorter cSP duration than the force task. These results suggest the need for more proprioceptive information during the position task than the force task. The shorter duration of the cSP during the position task may be attributable to larger amplitude of heteronymous short latency reflexes. Sensorimotor modulations may differ with load type during constant finger force or position tasks.This work was supported by a Grant-in-Aid for Scientific Research (C) No. 08042773 from the Japan Society for the Promotion of Science (JSPS) (http://www.jsps.go.jp/english/e-grants/index.html) and a Research Grant from Niigata University of Health and Welfare (NUHW) (http://www.nuhw.ac.jp/e/). HK received both grants. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Angiocardiographic quantitative evaluation of double-outlet right ventricle: special reference to the morphology of the common outflow tract.

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    Geometrical measurements of angiocardiograms of the common outflow tract (COT) of 13 patients were made to determine in which cases internal conduit repair was feasible, and under which conditions a patch enlargement of the COT was indicated. In the pulmonary stenosis (PS) group, the area of the narrowest cross-section of the COT was significantly smaller than that in the pulmonary hypertension (PH) group (p less than 0.025). In the PS group, the area was rarely sufficient to be shared by systemic and pulmonary circulation. Therefore, stenosis in the outflow tract to the pulmonary artery will occur if the intraventricular tunnel technique is applied, without patch enlargement of this portion, to patients with PS. On the contrary, the cross-sectional areas of the COT and pulmonary arteries were significantly larger in the PH group than in the PS group. Accordingly, the intracardiac conduit operation may be possible in such patients without a patch enlargement, even in young patients if other intracardiac conditions allow. Preoperative angiocardiographic evaluation of the COT is helpful in preoperatively selecting the proper operative procedure for this anomaly.</p

    Systematic Study of Lattice Specific Heat of Filled Skutterudites

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    The lattice specific heat C lat of La-based filled skutterudites La T 4 X 12 ( T = Fe, Ru and Os; X = P, As, and Sb) has been systematically studied, and both the Debye temperature Θ D and the Einstein temperature Θ E of La T 4 X 12 were carefully estimated. We confirmed that a correlation exists between Θ D and the reciprocal of the square root of average atomic mass for La T 4 P 12 , La T 4 As 12 , and La T 4 Sb 12 . The Θ D of filled skutterudites was found to depend mainly on the nature of the species X forming the cage. The temperature dependence of C lat / T 3 for La T 4 X 12 exhibited a large broad maximum at low temperatures (10–30 K), which suggests a nearly dispersionless low-energy optical mode characterized by Einstein specific heat. Since no such broad maximum exists for the unfilled skutterudite RhP 3 , the low-energy optical modes are associated with vibration involving La ions in the X 12 cage (the so-called “guest ion modes”). The Θ E of filled skutterudites was found to roughly correspond to the energy of low-energy guest ion optical modes. Furthermore, a good correlation was shown to exist between Θ E and r R–X - r R3+ , where r R–X is the R – X distance and r R3+ is the effective ionic radius of R 3+ . As r R–X - r R3+ increased, Θ E was found to decrease
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