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91.
Evidence for a reduction of heat transport inside the magnetic island O point is observed from the propagation of a cold pulse produced by a tracer encapsulated solid pellet in the Large Helical Device. A small peak and slow propagation of the cold pulse are observed inside the island. A significant result is that electron heat diffusivity inside the island is estimated to be 0.2 m(2)/s which is smaller than that outside the island by an order of magnitude.  相似文献   
92.
93.
Magnetic ordering of YFeMnO4 has been studied with Mössbauer spectroscopy in the temperature range between 4.2 K and 300 K on the conditions of gamma rays parallel to and perpendicular to thec-axis. It is revealed that the spin system orders like a Heisenberg spin system in a triangular antiferromagnet with an anisotropic axis parallel to thec-axis.  相似文献   
94.
The g-factor of the 27 isomer state of 152Dy has been measured using the Time-Integral Perturbed Angular Distribution (TIPAD) method. The high-spin states of 152Dy have been populated by 141Pr(16O,p4n)152Dy reaction at E = 115 MeV from the AVF cyclotron at CYRIC. The paramagnetic correction factor of Dy ions in Pr has been determined to be 4.2(5) by the Time-Differential Perturbed Angular Distribution (TDPAD) measurement of the 21 state of 152Dy. As a result, the g-factor of the 27 isomer state of 152Dy has been obtained to be +0.09(5). This shows the smaller value than the expected one of +0.39 deduced from a fully aligned configuration of π(h 11/2 2) ⊗ ν(f 7/2 2 h 9/2 i 13/2).  相似文献   
95.
The parametric dependence of a quantum map under the influence of a rank-1 perturbation is investigated. While the Floquet operator of the map and its spectrum have a common period with respect to the perturbation strength lambda, we show an example in which none of the quasienergies nor the eigenvectors obey the same period: After a periodic increment of lambda, the quasienergy arrives at the nearest higher one, instead of the initial one, exhibiting an anholonomy, which governs another anholonomy of the eigenvectors. An application to quantum state manipulations is outlined.  相似文献   
96.
97.
We investigated quantized modes of kinks in the phase space of superconducting gaps in a superconductor with multiple gaps. The kink is described by the sine-Gordon model in a two-gap superconductor and by the double sine-Gordon model in a three-gap superconductor. A fractional-flux vortex exists at the edge of the kink, and a fractional-flux vortex will be stable in a three-gap superconductor with time-reversal symmetry breaking. The kink and fractional-flux vortex exhibit massless modes as a sliding motion. We show further that there are one zero-energy mode (massless mode) and quantized excitation modes in kinks, which are characteristic features of multi-gap superconductors. The equation of quantized modes for the double sine-Gordon model is solved numerically. The correction to the ground-state energy is calculated based on the renormalization theory.  相似文献   
98.

Background

Results of the Women's Health Initiative Memory Study (WHIMS) raised concerns regarding the timing and formulation of hormone interventions. Conjugated equine estrogens (CEE), used as the estrogen therapy in the WHIMS trial, is a complex formulation containing multiple estrogens, including several not secreted by human ovaries, as well as other biologically active steroids. Although the full spectrum of estrogenic components present in CEE has not yet been resolved, 10 estrogens have been identified. In the present study, we sought to determine which estrogenic components, at concentrations commensurate with their plasma levels achieved following a single oral dose of 0.625 mg CEE (the dose used in the WHIMS trial) in women, are neuroprotective and whether combinations of those neuroprotective estrogens provide added benefit. Further, we sought, through computer-aided modeling analyses, to investigate the potential correlation of the molecular mechanisms that conferred estrogen neuroprotection with estrogen interactions with the estrogen receptor (ER).

Results

Cultured basal forebrain neurons were exposed to either β-amyloid25–35 or excitotoxic glutamate with or without pretreatment with estrogens followed by neuroprotection analyses. Three indicators of neuroprotection that rely on different aspects of neuronal damage and viability, LDH release, intracellular ATP level and MTT formazan formation, were used to assess neuroprotective efficacy. Results of these analyses indicate that the estrogens, 17α-estradiol, 17β-estradiol, equilin, 17α-dihydroequilin, equilinen, 17α-dihydroequilenin, 17β-dihydroequilenin, and Δ8,9-dehydroestrone were each significantly neuroprotective in reducing neuronal plasma membrane damage induced by glutamate excitotoxicity. Of these estrogens, 17β-estradiol and Δ8,9-dehydroestrone were effective in protecting neurons against β-amyloid25–35-induced intracellular ATP decline. Coadministration of two out of three neuroprotective estrogens, 17β-estradiol, equilin and Δ8,9-dehydroestrone, exerted greater neuroprotective efficacy than individual estrogens. Computer-aided analyses to determine structure/function relationships between the estrogenic structures and their neuroprotective activity revealed that the predicted intermolecular interactions of estrogen analogues with ER correlate to their overall neuroprotective efficacy.

Conclusion

The present study provides the first documentation of the neuroprotective profile of individual estrogens contained within the complex formulation of CEE at concentrations commensurate with their plasma levels achieved after an oral administration of 0.625 mg CEE in women. Our analyses demonstrate that select estrogens within the complex formulation of CEE contribute to its neuroprotective efficacy. Moreover, our data predict that the magnitude of neuroprotection induced by individual estrogens at relatively low concentrations may be clinically undetectable and ineffective, whereas, a combination of select neuroprotective estrogens could provide an increased and clinically meaningful efficacy. More importantly, these data suggest a strategy for determining neurological efficacy and rational design and development of a composition of estrogen therapy to alleviate climacteric symptoms, promote neurological health, and prevent age-related neurodegeneration, such as AD, in postmenopausal women.  相似文献   
99.
This study deals with the development of the approximate method to analyze the sound field around equally spaced finite obstacles, using the periodic boundary condition. First, on the assumption that the equally spaced finite obstacles are the periodically arranged obstacles, the sound field is analyzed by boundary integral equation method with a Green’s function which satisfies the periodic boundary condition. Furthermore, by comparing these results and the exact solution by using the fundamental solution as Green’s function, the validity of the approximate method is also investigated. Next, in order to evaluate the applicability of the approximate method, the simple formula using some parameters, i.e., the frequency, the period, and the number of obstacles, etc., is proposed. The results of the sound field analysis applied the formula are presented.  相似文献   
100.
We have developed an apparatus for investigating isomer-selected photodissociation reactions by ion mobility spectrometry coupled with time-of-flight mass spectrometry. By using this apparatus we optimized ion intensities under isomer-separation condition for carbon cluster ions. Among ions having linear and cyclic isomers, we demonstrated dissociation of isomer-selected C9 + ion at 355-nm photon irradiation. As a result we observed marked difference in the dissociation pathways between from linear isomer and from cyclic isomer. For the purpose of adopting this technique to metal-ligand cluster ions, we also investigated mobility spectrometry of vanadium metal ions with Ar, in addition to electronic state separation for free atomic ions.  相似文献   
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