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91.
Terahertz (THz) dichroism of a nematic liquid N-(p-methoxybenzylidene)-p-butylaniline (MBBA) was measured using a GaP Raman THz spectrometer. MBBA on a rubbed plastic substrate generates a band at around 4.0 THz: its liquid crystal phase shows strong dichroism, which well corresponds to that of the IR absorption caused by π(CH) of MBBA molecule reported in the literature. Based on inferences drawn from the present THz and the published IR dichroic results, the 4.0 THz band probably stems from lateral intermolecular or intramolecular interactions of MBBA molecules aligned to the rubbing direction. The results clearly demonstrate that THz spectroscopy is powerful for discussing of phase transition and dichroism of liquid crystals.  相似文献   
92.
An interpretation of quantum mechanics is discussed. It is assumed that quantum is energy. An algorithm by means of the energy interpretation is discussed. An algorithm, based on the energy interpretation, for fast determining a homogeneous linear function f(x) := s.x = s 1 x 1 + s 2 x 2 + ? + s N x N is proposed. Here x = (x 1, … , x N ), x j R and the coefficients s = (s 1, … , s N ), s j N. Given the interpolation values \((f(1), f(2),...,f(N))=\vec {y}\), the unknown coefficients \(s = (s_{1}(\vec {y}),\dots , s_{N}(\vec {y}))\) of the linear function shall be determined, simultaneously. The speed of determining the values is shown to outperform the classical case by a factor of N. Our method is based on the generalized Bernstein-Vazirani algorithm to qudit systems. Next, by using M parallel quantum systems, M homogeneous linear functions are determined, simultaneously. The speed of obtaining the set of M homogeneous linear functions is shown to outperform the classical case by a factor of N × M.  相似文献   
93.
In investigating potent sodium (Na(+)) channel blockers for the treatment of ischemic stroke, we synthesized a novel series of 3-amino-1-(5-indanyloxy)-2-propanol derivatives and evaluated their inhibitory effects on neuronal Na(+) channels. The 3-amino-1-(5-indanyloxy)-2-propanol derivatives exhibited potent blocking activity for Na(+) channels and a significantly low affinity for dopamine D(2) receptors, which demonstrates a minimal clinical risk for extrapyramidal side effects. In particular, compound 4b, a 3-amino-1-(5-indanyloxy)-2-propanol derivative bearing a benzimidazole moiety, showed desirable neuroprotective activity in a rat transient middle cerebral artery occlusion model. Furthermore, compound 4b displayed a high binding affinity for neurotoxin receptor site 2 of the Na(+) channels, which suggests that 4b would act as a use-dependent Na(+) channel blocker in sustained depolarization during ischemic stroke.  相似文献   
94.
We have examined several combinations of solvents with the aim of optimizing the ionization conditions for molecular diagnosis of malignant tumours by PESI-MS. Although the best conditions may depend on the actual species in the sample, the optimal conditions for renal cell carcinoma (RCC) were achieved by using alcohols. PESI-MS successfully delineated the differential expression of phospholipids (PCs) and triacylglycerols (TAGs) in noncancerous and RCC tissues by using these solvent systems. This study paves the way for the application of PESI-MS in medical samples.  相似文献   
95.
The DMPM (3,4-dimethoxybenzyl) protection for hydroxy function was deprotected more readily than the MPM (p-methoxybenzyl) protection by DDQ oxidation under neutral conditions, and applied to the synthesis of some synthons to macrolide and polyether antibiotics.  相似文献   
96.
A sensitive method for the determination of nicotinic acid in serum is described which employs high-performance liquid chromatography with fluorescence detection. Nicotinic acid and 2-chloronicotinic acid as an internal standard in deproteinized serum are reacted with N,N'-dicyclohexyl-O-(7-methoxycoumarin-4-yl)methylisourea in acetone to give the corresponding fluorescent 4-hydroxymethyl-7-methoxycoumarin esters. The compounds are separated by reversed-phase chromatography on LiChrosorb RP-18 with isocratic elution using aqueous acetonitrile containing a small amount of sodium 1-hexanesulphonate as a mobile phase. The detection limit of nicotinic acid in serum was 0.2 nmol/ml. The method requires only 100 microliters of serum.  相似文献   
97.
On the basis of the relaxation mode theory, quasi-Debye response in the dynamic conductivity by hopping ions is theoretically investigated in three-dimensional random lattices with a uniform distribution of activation energies. It is shown at lowest frequencies that the dynamic conductivity is approximately given by σ(ω)∼σ(0)+Aωs, s″=2−n, where n is a non-integer exponent originated from the mode diffusion length and density of states. The numerical analyses give rise to some values of s″<2, for example s″∼1.5, which behaves as s″→2 with increasing temperature.  相似文献   
98.
99.
Diphenylphosphinothioyl compounds were ortho-lithiated and alkyldiphenyl phosphine sulfides were α-lithiated and the resulting lithio compounds reacted to give the corresponding o- and α-substituted products.  相似文献   
100.
On DDQ oxidation under anhydrous conditions, hydroxy groups located at α or β position to methoxybenzyl ether groups were readily protected by the intramolecular oxidative formation of acid-sensitive methoxybenzylidene acetals, which were further oxidized to alkali-sensitive hydroxy esters in the presence of H2O.  相似文献   
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