155 research outputs found
EOSDB: The Database for Nuclear EoS
Nuclear equation of state (EoS) plays an important role in understanding the
formation of compact objects such as neutron stars and black holes. The true
nature of the EoS has been a matter of debate at any density range not only in
the nuclear physics but also in the astronomy and astrophysics. We have
constructed a database of EoSs by compiling data from the literature. Our
database contains the basic properties of the nuclear EoS of symmetric nuclear
matter and of pure neutron matter. It also includes the detailed information
about the theoretical models, for example the adopted methods and assumptions
in individual models. The novelty of the database is to consider new
experimental probes such as the symmetry energy, its slope relative to the
baryon density, and the incompressibility, which enables the users to check
their model dependences. We demonstrate the performance of the EOSDB through
the examinations of the model dependence among different nuclear EoSs. It is
reveled that some theoretical EoSs, which is commonly used in astrophysics, do
not satisfactorily agree with the experimental constraints.Comment: 30 pages, 5 figures, submitted to Publications of the Astronomical
Society of Japan (revised
SUCCESSFUL PAIN RELIEF BY MOTOR CORTEX STIMULATION FOR EXTENSIVE THALAMIC PAIN : CASE REPORT
Thalamic pain is known as the most difficult pain syndrome to treat. This paper describes our case treated successfully by motor cortex stimulation for extensive thalamic pain. A 59-year-old man with left thalamic pain was readmitted two years after an episode of right thalamic hemorrhage. He complained of tearing pain in the left eye, burning pain in the left upper and lower extremities, and chest pain. After one week of test stimulation, permanent implantation using two electrode arrays to include the area of the lower extremity was done. Excellent pain relief has been sustained for 10 months
Decay Profiles and Spectra of Stimulated Luminescence in CdI2
Decay profiles and spectral distributions of the stimulated luminescence in Cdl2 crystals
have been investigated at liquid nitrogen temperature under high density excitation
with a N2-gas laser in the excitonic absorption band. The observed luminescence decay
curve consists of two components, fast (< 20 ns) and slow (about 5 μs) ones. The slow
component is identical to the main decay component of the spontaneous emission which
is observed rather strongly in the case of low density excitation. The fast component
is peculiar to the case of high density excitation, and is connected to the stimulated
emission. This means that the stimulated luminescence appears in the early stage of
the luminescence decay. The spectral distribution of the fast component, namely, the
stimulated emission spectrum, consists of eight fine-structures and is different from the
usual spontaneous emission spectum from self trapped exciton (STE) states. Discussions
will be made on the origin of these structures relating it with fine-structures of the STE
states
POSTOPERATIVE VASOSPASM IN PITUITARY ADENOMA WITH PITUITARY APOPLEXY
A patient who developed complications relating to intracranial arterial vasospasm following transcranial removal of a pituitary adenoma with pituitary apoplexy
is reported. A 23-year-old female was admitted because of headache. Computed tomography (CT) and magnetic resonance (MR) imaging revealed a pituitary adenoma with suprasellar extension and pituitary apoplexy and sinusitis in the right maxillary and ethmoid sinuses. A transcranial approach was selected because of active sinusitis. A large, pink intra- and suprasellar neoplasm and intratumoral clot were removed smoothly. Postoperatively, the patient remained stuporous and showed right hemiplegia. Angiography demonstrated stenosis of the left internal carotid artery and severe spasm of perforating arteries from the left middle cerebral artery. Large pituitary adenoma with pituitary apoplexy requires careful perioperative management, with particular attention paid to the surgical approach and procedures
Supernova Nucleosynthesis and Extremely Metal-Poor Stars
We investigate hydrodynamical and nucleosynthetic properties of the
jet-induced explosion of a population III star and compare the
abundance patterns of the yields with those of the metal-poor stars. We
conclude that (1) the ejection of Fe-peak products and the fallback of
unprocessed materials can account for the abundance patterns of the extremely
metal-poor (EMP) stars and that (2) the jet-induced explosion with different
energy deposition rates can explain the diversity of the abundance patterns of
the metal-poor stars. Furthermore, the abundance distribution after the
explosion and the angular dependence of the yield are shown for the models with
high and low energy deposition rates and . We also find that the
peculiar abundance pattern of a Si-deficient metal-poor star HE 1424--0241 can
be reproduced by the angle-delimited yield for of
the model with .Comment: 6 pages, 3 figures. To appear in "ORIGIN OF MATTER AND EVOLUTION OF
GALAXIES: From the Dawn of Universe to the Formation of Solar System", AIP
Conf. Proc. 1016 (December 2007, Sapporo), eds. T. Suda, T. Nozawa, et al.
(Melville: AIP
Chemical Abundances in the Secondary Star of the Black Hole Binary V4641 Sagittarii (SAX J1819.3-2525)
We report on detailed spectroscopic studies performed for the secondary star
in the black hole binary (micro-quasar) V4641 Sgr in order to examine its
surface chemical composition and to see if its surface shows any signature of
pollution by ejecta from a supernova explosion. High-resolution spectra of
V4641 Sgr observed in the quiescent state in the blue-visual region are
compared with those of the two bright well-studied B9 stars (14 Cyg and
Cap) observed with the same instrument. The effective temperature of V4641 Sgr
(10500 200 K) is estimated from the strengths of He~{\sc i} lines, while
its rotational velocity, sin (95 10 km s), is
estimated from the profile of the Mg~{\sc ii} line at 4481 \AA. We obtain
abundances of 10 elements and find definite over-abundances of N (by 0.8 dex or
more) and Na (by 0.8 dex) in V4641 Sgr. From line-by-line comparisons of eight
other elements (C, O, Mg, Al, Si, Ti, Cr, and Fe) between V4641 Sgr and the two
reference stars, we conclude that there is no apparent difference in the
abundances of these elements between V4641 Sgr and the two normal late B-type
stars, which have been reported to have solar abundances. An evolutionary model
of a massive close binary system has been constructed to explain the abundances
observed in V4641 Sgr. The model suggests that the progenitor of the black hole
forming supernova was as massive as ~ 35 Msun on the main-sequence and, after
becoming a ~ 10 Msun He star, underwent "dark" explosion which ejected only N
and Na-rich outer layer of the He star without radioactive Ni.Comment: 13 pages, 14 figures. Accepted for publication in the PASJ:
Publications of the Astronomical Society of Japa
CLINICOPATHOLOGICAL STUDY OF CEREBRAL SUBCORTICAL CAVERNOUS ANGIOMA AS EPILEPTOGENIC FOCUS
The authors conducted a comparative histological study of two groups of patients with cerebral subcortical cavernous angioma. One group was composed of 5 asymptomatic cases detected accidentally. The other group was composed of 4 patients presenting as epilepsy. The results obtained may be summarized as follows ; 1) Hemosiderin deposit and gliosis were seen in all cases examined ; 2) Granulomatous change was a histological finding associated with epileptogenesis ; 3) The histological changes, starting with proliferation of collagen fibers and leading to hyaline degeneration, calcification, and then hemangioma calcificans, seem to represent a course of spontaneous healing, when viewed from epileptogenesis
In vivo microscopic voxel-based morphometry with a brain template to characterize strain-specific structures in the mouse brain
Hundreds of inbred mouse strains are established for use in a broad spectrum of basic research fields, including genetics, neuroscience, immunology, and cancer. Inbred mice exhibit identical intra-strain genetics and divergent inter-strain phenotypes. The cognitive and behavioral divergences must be controlled by the variances of structure and function of their brains; however, the underlying morphological features of strain-to-strain difference remain obscure. Here, in vivo microscopic magnetic resonance imaging was optimized to image the mouse brains by using an isotropic resolution of 80 mum. Next, in vivo templates were created from the data from four major inbred mouse strains (C57Bl/6, BALB/cBy, C3H/He, and DBA/2). A strain-mixed brain template was also created, and the template was then employed to establish automatic voxel-based morphometry (VBM) for the mouse brain. The VBM assessment revealed strain-specific brain morphologies concerning the gray matter volume of the four strains, with a smaller volume in the primary visual cortex for the C3H/He strain, and a smaller volume in the primary auditory cortex and field CA1 of the hippocampus for the DBA/2 strain. These findings would contribute to the basis of for understanding morphological phenotype of the inbred mouse strain and may indicate a relationship between brain morphology and strain-specific cognition and behavior
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