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1.
A case of giant internal carotid ophthalmic aneurysm was presented. In order to clarify whether the patient could tolerate carotid occlusion, a balloon clamping test was performed. before surgery. The cerebral blood flow was measured using early imaging by single photon emission computed tomography (SPECT) with N-isopropyl-(iodine-123)-p-iodoamphetamine (123I-IMP). When the balloon clamping test was performed the tracer was injected, and scanning was performed 35 minutes after removing the catheter. This tracer enabled a "memory of blood flow" during temporary ischemia to determine the character of quick diffusion and slow wash out, that could not be performed by other methods of cerebral blood flow measurement. SPECT with 123I-IMP can simplify the measurement of cerebral blood flow during the balloon clamping test. 相似文献
2.
Hayashi T. Toya H. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1991,19(5):740-742
To clean the surfaces of parts inside a vacuum-switch tube (VST) the authors propose a technique which generates a glow discharge between the inner electrodes and the copper grid surrounding it. Photographic observation reveals that the glow discharge spreads out and cleans the whole surface inside the VST. A breakdown test between the inner electrodes shows the effect of the cleaning with this technique. Higher breakdown voltage between the inner electrodes is attained by performing this glow discharge cleaning in argon rather than hydrogen gas. The difference of the cleaning effect seems to be attributed to that of the energy transfer from ion species to the adsorbed molecules and microprotrusions on the surfaces 相似文献
3.
Structure of biluciferyl (luciferyl radical dimer), which is produced by chemical oxidation of . luciferin with such as ferricyanide, was determined to be the symmetric 5,5′-dimer of . luciferin. It gives light in the presence of . luciferase, although the bioluminescent rate is very low. We suggest that the biluciferyl is an intermediate in the oxidation of the luciferin to . luciferinol. 相似文献
4.
Structure of amipurimycin was determined chemically to be . 相似文献
5.
Yokoyama K Teranishi Y Toya Y Shirai T Fukuda Y Aoyama M Akahane Y Inoue N Ueda H Yamakawa K Yokoyama A Yamada H Yabushita A Sugita A 《The Journal of chemical physics》2004,120(20):9446-9449
Optimal laser control for ultrafast selection of closely lying excited states whose energy separation is smaller than the laser bandwidth is reported on the two-photon transition of atomic cesium; Cs(6S-->7D(J), J=5/2 and 3/2). Selective excitation was carried out by pulse shaping of ultrashort laser pulses which were adaptively modulated in a closed-loop learning system handling eight parameters representing the electric field. Two-color fluorescence from the respective excited states was monitored to measure the selectivity. The fitness used in the learning algorithm was evaluated from the ratio of the fluorescence yields. After fifty generations, a pair of nearly transform-limited pulses were obtained as an optimal pulse shape, proving the effectiveness of the "Ramsey fringes" mechanism. The contrast of the selection ratio was improved by approximately 30% from the simple "Ramsey fringes" experiment. 相似文献
6.
Jaron Frost Kara KellerJonathan Lowe Toya SkeeteShonté Walton Jessie CastilleNabendu Pal 《Applied Mathematical Modelling》2013
Traditional process control charts for a measurement standard deviation are based on the assumption of normality, which may not always be valid. Assuming that measurements follow a gamma distribution, we have obtained an approximate distribution of the sample variance, scaled appropriately. This approximate distribution, which happens to be another gamma model, is used to derive an interval estimate of the population standard deviation. Further, the above approximate gamma model for the sample variance can be used to develop a process control chart as demonstrated by a simulated data set. 相似文献
7.
Toya H Okano K Takasu K Ihara M Takahashi A Tanaka H Tokuyama H 《Organic letters》2010,12(22):5196-5199
The enantioselective total synthesis of (-)- and (+)-petrosin is described. The union of two key segments was executed by Suzuki-Miyaura coupling. The quinolizidine rings were stereoselectively constructed via a diastereoselective Mannich reaction and an aza-Michael reaction. The 16-membered ring was constructed by ring-closing metathesis with the second-generation Grubbs catalyst. 相似文献
8.
This paper presents our numerical and experimental results of the bifurcation found in Taylor-Couette system with a free surface.
The lengths of the two concentric cylinders are finite and their axes are parallel to the direction of the gravitational force.
When the end walls of the cylinders are fixed and stationary, numerical and experimental studies have shown that the flow
has multiple patterns depending on the cylinder lengths and the Reynolds numbers. Experimental studies on flows with free
surfaces also gave various flow modes. Our result shows that the measured and predicted time-dependent displacements of the
free surface are in favorable agreement. In case of the cylinder length comparable with the gap width between the cylinders,
gradual accelerations of the inner cylinder bring the normal mode flows with one, three and five toroidal vortices. The exchanges
of stabilities between these flow modes are summarized in a phase diagram. 相似文献
9.
Energy levels, interparticle distances and dipole transition rates of H2Mu+ molecules were calculated with the coupled rearrangement channel method. The structure of the ground state of H2Mu+ is an isosceles triangle, while that of H3
+ is an equilateral triangle. The calculated dipole transition rates are small compared with the muon decay rate.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
10.
Wells–Dawson-type polyoxometalates are formed by heating an acidic Mo(VI) or W(VI) solution containing significantly higher concentrations of hetero ions, P(V) or As(V), than the ideal molar ratio [M]/[X] = 1/9 (M = Mo, W; X = P, As). Most of the phosphate and arsenate remains unreacted in the reaction mixture. These reaction conditions are unusual, even though more reagents than the stoichiometric amounts are frequently needed to obtain complete reactions. In the present study, the replacement of a large amount of unreacted hetero ions containing salts by normal ions (salts) was investigated. The formation of Wells–Dawson-type polyoxometalates, [X2M18O62]6? (X = P, As; M = Mo, W), in the presence of LiCl and NaCl was investigated by Raman spectroscopy and 31P NMR in aqueous solution. The addition of LiCl enhanced the formation of Wells–Dawson-type polyoxometalates, which formed under solution conditions close to the ideal molar ratio [M]/[X] = 1/9. 相似文献