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排序方式: 共有182条查询结果,搜索用时 15 毫秒
1.
Junko Hirota Dr. Kazuteru Usui Dr. Yasufumi Fuchi Masaomi Sakuma Shota Matsumoto Ryusuke Hagihara Prof. Dr. Satoru Karasawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(65):14943-14952
Water-soluble donor–acceptor-type fluorophore 15Nap-Cl having two trifluoromethyl groups and a Cl group on a 1,5-aminonaphthyridine framework was prepared. Fluorophore 15Nap-Cl showed strong solvatochromic fluorescence, and, as the solvent polarity increased, a bathochromic shift was observed accompanied by an increase in the fluorescence quantum yield. In addition, in the presence of amines such as ethylamine, diethylamine, and aniline, further considerable bathochromic shifts in the fluorescence were observed. Density functional calculations identified the source of the fluorescence behavior as exciplex formation between 15-Nap-Cl and the corresponding amine. The fluorescence behavior was exploited to fabricate a sensor that can identify various primary, secondary, and tertiary amines. 相似文献
2.
We study an assembly-like queueing system one of whose queues has items with generally distributed time-constraints, where this system has a single server providing services using each item individually. It is well-known that analysis of a queueing system which has items with time-constraint (i.e., impatient items) is difficult since the analytical model must involve all the departure times of these impatient items. We therefore propose to employ the techniques of Whitt’s approximation and show the method for obtaining the stationary distribution of the model. Through some simulation experiments, we discuss the validation of our approximation model, and show that the approximation is accurate in various kinds of situations (e.g., service time distribution and the number of queues). 相似文献
3.
Sainer Siagian Khairul Basar Takashi Sakuma Haruyuki Takahashi Naoki Igawa Yoshinobu Ishii 《Solid State Ionics》2009,180(6-8):480-482
Diffuse neutron scattering from a powder AgCl was measured from 10 to 260 K. The correlation effects among thermal displacements of atoms were obtained from the diffraction data. The values of the correlation effects decrease rapidly with the increase of the inter-atomic distance. The values also decrease with the decrease of temperature. The similar tendency was also obtained in AgBr and CuI. The temperature dependence of the values of correlation effects agrees with the result by a simple Debye model of lattice vibrations. 相似文献
4.
The ionic conduction of cation substituted CuBrTe, CuxAg1−xBrTe solid solutions, is investigated in the temperature range between 100 and 400 K. The change of electrical conductivities with temperature in the range of 0.94≤x<1 shows the characteristics of second-order rather than first-order phase transitions. The replacement of Cu with the Ag cation in CuxAg1−xBrTe leads to an increase in conductivity especially in the β and γ-phases. 相似文献
5.
Yoko Masuda Kozue Hirabayashi Keiko Sakuma Tadashi Nakanishi 《Colloid and polymer science》2002,280(5):490-494
The swelling behavior of poly(ethylene oxide) (PEO) gels in aqueous solutions of sodium dodecyl sulfate (SDS) with and without
NaCl was investigated. In the absence of NaCl, PEO gels with different degrees of cross-linking began to swell from a concentration
lower than the critical micelle concentration (cmc) of SDS, then showed sigmoidal enhancements of swelling in a higher SDS
concentration region until the degrees of swelling reached maximum values. The SDS concentration at which the swelling began
to appear was in reasonable agreement with the critical aggregation concentration (cac) value reported for the aqueous PEO
system. For the cases where NaCl was present, the swelling behavior of PEO gel was different from that when NaCl was absent
in the following way. The concentrations where the swelling begins to appear, and hence those where the degree of swelling
rises steeply, decreased with an increase in NaCl concentration. The ultimate degrees of swelling at higher concentration
regions also decreased with an increase in the NaCl concentration. The lowering of the SDS concentrations at which the PEO
gel began to swell is in line with the decreases in the cmc of SDS solutions containing NaCl and also with the decreases in
the cac of PEO solution.
Electronic Publication 相似文献
6.
Shingo Kato Kakuya Kitagawa Yeonyee E. Yoon Hiroshi Nakajima Motonori Nagata Shinichi Takase Shiro Nakamori Masaaki Ito Hajime Sakuma 《Magnetic resonance imaging》2014
Purpose
The purposes of this study were to evaluate the reproducibility for measuring the cold pressor test (CPT)-induced myocardial blood flow (MBF) alteration using phase-contrast (PC) cine MRI, and to determine if this approach could detect altered MBF response to CPT in smokers.Materials and methods
After obtaining informed consent, ten healthy male non-smokers (mean age: 28 ± 5 years) and ten age-matched male smokers (smoking duration ≥ 5 years, mean age: 28 ± 3 years) were examined in this institutional review board approved study. Breath-hold PC cine MR images of the coronary sinus were obtained with a 3 T MR imager with 32 channel coils at rest and during a CPT performed after immersing one foot in ice water. MBF was calculated as coronary sinus flow divided by the left ventricular (LV) mass which was given as a total LV myocardial volume measured on cine MRI multiplied by the specific gravity (1.05 g/mL).Results
In non-smokers, MBF was 0.86 ± 0.25 mL/min/g at rest, with a significant increase to 1.20 ± 0.36 mL/min/g seen during CPT (percentage change of MBF (?MBF (%)); 39.2% ± 14.4%, p < 0.001). Inter-study reproducibility for ?MBF (%) measurements by different MR technologist was good, as indicated by the intraclass correlation coefficient of 0.93 and reproducibility coefficient of 10.5%. There was no significant difference between smokers and non-smokers for resting MBF (0.85 ± 0.32 mL/min/g, p = 0.91). However, ?MBF (%) in smokers was significantly reduced (-4.0 ± 32.2% vs. 39.2 ± 14.4%, p = 0.011).Conclusion
PC cine MRI can be used to reproducibly quantify MBF response to CPT and to detect impaired flow response in smokers. This MR approach may be useful for monitoring the sequential change of coronary blood flow in various potentially pathologic conditions and for investigating its relationship with cardiovascular risk. 相似文献7.
The conjugate addition of arylboronic acids to alpha,beta-unsaturated amides was carried out in the presence of a chiral rhodium catalyst and an aqueous base. The catalyst prepared in situ from Rh(acac)(CH(2)=CH(2))(2) and (S)-binap provided (R)-N-benzyl-3-phenylbutanamide with 93% ee in the addition of phenylboronic acid to N-benzyl crotonamide. The reaction suffered from incomplete conversion resulting in moderate yields, but addition of an aqueous base, such as K(2)CO(3) (10-50 mol%) was found to be highly effective to improve the chemical yields. The role of the base giving a RhOH species active for transmetalation with arylboronic acids was discussed. 相似文献
8.
This is the second of a series of papers which give a necessary and sufficient condition for two essential simple loops on a 2-bridge sphere in a 2-bridge link complement to be homotopic in the link complement. The first paper of the series treated the case of the \(2\) -bridge torus links. In this paper, we treat the case of \(2\) -bridge links of slope \(n/(2n+1)\) and \((n+1)/(3n+2)\) , where \(n \ge 2\) is an arbitrary integer. 相似文献
9.
Ichiro Tsunenari Jyoji Yamate Masae Iwaki Mitsuru Kuwamura Takao Kotani Sadashige Sakuma 《Microscopy and microanalysis》2003,9(6):532-541
Angiogenesis, a biologic process whereby endothelial cells divide and migrate to form new blood vessels, is a key step in tumor growth, invasion, and metastasis. In the present study, we investigated the differences in angioarchitecture between two different tumors induced by cloned cell lines (MT-8 and MT-9), derived from a transplantable rat malignant fibrous histiocytoma, by scanning electron microscopy of vascular corrosion casts. During a 3-week observation period after implantation, the growth of MT-8 tumors appeared to be faster than that of MT-9 tumors. Histologically, MT-8 tumors were of the uniformly undifferentiated sarcoma type arranged in characteristic organoid structures, and MT-9 tumors showed a storiform growth pattern. In MT-8 tumors, neovascularization occurred by sprouting at postimplantation (PI) week 1, and the newly formed capillaries gradually became more tortuous. In MT-9 tumors, at PI week 1, the corrosion casts of newly formed capillaries mainly showed a wavy course but no finger-like outgrowths of capillaries were seen. At PI weeks 2 and 3, the sprouting was seen specifically in MT-9 tumors, forming basket-like structures and glomeruloid structures of capillaries. These results indicate that angiogenesis or angioarchitecture of MT-8 tumors is different from that of MT-9 tumors, depending on the differences in their tumor histology and by the features like absence or presence of basket-like structures and glomeruloid structures of capillaries. 相似文献
10.
Arai M. Sakuma T. Atake T. Kawaji H. 《Journal of Thermal Analysis and Calorimetry》2002,69(3):905-908
The phase transition and the crystal structures of CuITe were investigated by differential thermal analysis and X-ray powder
diffraction measurements in the temperature range between 300 and 683 K. The new phase transition in CuITe was observed at
592 K. The enthalpy of transition is ΔH=0.125 kJ mol-1. The new phase above 592 K belongs to tetragonal system with the space group I41
/amd.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献