Steady General Relativistic Magnetohydrodynamic Inflow/Outflow Solution along Large-Scale Magnetic Fields that Thread a Rotating Black Hole

General relativistic magnetohydrodynamic (GRMHD) flows along magnetic fields threading a black hole can be divided into inflow and outflow parts, according to the result of the competition between the black hole gravity and magneto-centrifugal forces along the field line. Here we present the first self-consistent, semi-analytical solution for a cold, Poynting flux-dominated (PFD) GRMHD flow, which passes all four critical (inner and outer, Alfven and fast magnetosonic) points along a parabolic streamline. By assuming that the dominating (electromagnetic) component of the energy flux per flux tube is conserved at the surface where the inflow and outflow are separated, the outflow part of the solution can be constrained by the inflow part. The semi-analytical method can provide fiducial and complementary solutions for GRMHD simulations around the rotating black hole, given that the black hole spin, global streamline, and magnetizaion (i.e., a mass loading at the inflow/outflow separation) are prescribed. For reference, we demonstrate a self-consistent result with the work by McKinney in a quantitative level.Comment: 13 Pages, incliding 2 tables and 5 Figures; accepted by Ap

High-temperature creep strength and room-temperature fracture toughness of MoSiBTiC alloy

Quite recently, the author and his coworkers have developed a new high-temperature material based on Mo-Si-B alloys with TiC addition for ultrahigh temperature applications. The alloys are produced not by powder sintering but by casting, and the constituent phases are of Mo solid solution, Mo5SiB2 (T2), (Ti, Mo)C and (Mo, Ti)2C. The density is reduced to less than 9.0 g/cm3, which is comparable to that of Ni-base superalloys. The high-temperature compressive strength is much stronger than that of commercial heat-resistant molybdenum alloys such as TZM and MHC in a wide high-temperature range. In this paper, the recent progress of our research and development of the MoSiBTiC alloys is reviewed focusing on high-temperature creep strength and room temperature fracture toughness. The alloy having a primary phase during solidification of (Ti, Mo)C and thus a higher (Ti, Mo)C volume fraction was examined for tensile creep properties, and it was found that the alloy showed typical tensile creep curves accompanying transient, steady-state and acceleration creep stages in all the test conditions. The creep strength was relatively good, for example, the rupture time at 1350 °C under 170 MPa was about 750 h. The stress exponents, n, in the temperature range of 1400 – 1600 °C and the stress range of 100 – 300 MPa were ≈ 3 while it was 5 – 6 at 1350 °C, suggesting that the rate-controlling process of creep deformation is different between at and below 1350 °C and at and above 1400 °C in the stress range. Room-temperature fracture toughness of the MoSiBTiC alloys was measured by three-point or four-point bending tests using Chevron-notched specimens. The alloy having the primary phase of (Ti, Mo)C showed the fracture toughness value of better than 15 MPa(m)1/2 at room temperature. The value was better than that of the alloy having a primary phase of Moss and thus a higher Moss volume fraction. The obtained results indicated that (Ti, Mo)C phase works for improving not only high-temperature strength but also room-temperature fracture toughness

Cerebral Glycogen Distribution and Aging

In the brain, glycogen metabolism has been implied in synaptic plasticity and learning, yet the distribution of this molecule has not been fully described. We investigated cerebral glycogen of the mouse by immunohistochemistry (IHC) using two monoclonal antibodies that have different affinities depending on the glycogen size. The use of focused microwave irradiation yielded well‐defined glycogen immunoreactive signals compared with the conventional periodic acid‐Schiff method. The IHC signals displayed a punctate distribution localized predominantly in astrocytic processes. Glycogen immunoreactivity (IR) was high in the hippocampus, striatum, cortex, and cerebellar molecular layer, whereas it was low in the white matter and most of the subcortical structures. Additionally, glycogen distribution in the hippocampal CA3‐CA1 and striatum had a ‘patchy’ appearance with glycogen‐rich and glycogen‐poor astrocytes appearing in alternation. The glycogen patches were more evident with large‐molecule glycogen in young adult mice but they were hardly observable in aged mice (1–2 years old). Our results reveal brain region‐dependent glycogen accumulation and possibly metabolic heterogeneity of astrocytes

Distribution and densitometry mapping of L1-CAM Immunoreactivity in the adult mouse brain – light microscopic observation

BACKGROUND: The importance of L1 expression in the matured brain is suggested by physiological and behavioral studies showing that L1 is related to hippocampal plasticity and fear conditioning. The distribution of L1 in mouse brain might provide a basis for understanding its role in the brain. RESULTS: We examined the overall distribution of L1 in the adult mouse brain by immunohistochemistry using two polyclonal antibodies against different epitopes for L1. Immunoreactive L1 was widely but unevenly distributed from the olfactory bulb to the upper cervical cord. The accumulation of immunoreactive L1 was greatest in a non-neuronal element of the major fibre bundles, i.e. the lateral olfactory tract, olfactory and temporal limb of the anterior commissure, corpus callosum, stria terminalis, globus pallidus, fornix, mammillothalamic tract, solitary tract, and spinal tract of the trigeminal nerve. High to highest levels of non-neuronal and neuronal L1 were found in the grey matter; i.e. the piriform and entorhinal cortices, hypothalamus, reticular part of the substantia nigra, periaqueductal grey, trigeminal spinal nucleus etc. High to moderate density of neuronal L1 was found in the olfactory bulb, layer V of the cerebral cortex, amygdala, pontine grey, superior colliculi, cerebellar cortex, solitary tract nucleus etc. Only low to lowest levels of neuronal L1 were found in the hippocampus, grey matter in the caudate-putamen, thalamus, cerebellar nuclei etc. CONCLUSION: L1 is widely and unevenly distributed in the matured mouse brain, where immunoreactivity was present not only in neuronal elements; axons, synapses and cell soma, but also in non-neuronal elements

Phosphodiesterase 3 inhibition and cough in elderly asthmatics

AIMS: Cough is a common symptom of bronchial asthma, a chronic inflammatory airway disease. Recently, the therapeutic effects of selective phosphodiesterase (PDE) inhibitors have been focused on bronchial asthma. This study was designed to investigate the clinical effect of PDE 3 inhibition on cough reflex sensitivity in elderly patients with bronchial asthma. METHODS: Effects of cilostazol, a PDE 3 inhibitor, on cough response to inhaled capsaicin were examined in 11 patients over 70 years with stable asthma in a randomized, placebo-controlled cross over study. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of airway cough reflex sensitivity. RESULTS: The cough threshold was significantly (p < 0.05) increased after two-week treatment with cilostazol (100 mg twice a day orally) compared with placebo [48.8 (GSEM 1.4) vs. 29.2 (GSEM 1.3) μM]. CONCLUSION: These findings indicate that PDE 3 inhibition may be a novel therapeutic option for elderly patients with asthma, especially for their cough symptoms

A Novel Concentrating System of Chicken Stem Cells by Bone Marrow Side Population Cells

Numerous studies in mammalian species have recently been reported that many stem cells have an ability to efficiently efflux the vital DNA-binding dye Hoechst 33342, and it is called side population (SP) cells. However, few study have been reported on the avian SP cells. It could be possible that concentration of hematopoietic stem cells (HSCs) in birds since the characteristic of SIP cells should be shared in various tissues and species. In this study, we first attempted the isolation of SP cells from chicken bone marrow and the assessment by gene expression and morphologic analyses. Bone marrow cells (BMCs) were flushed from the femurs and tibias of chicks aged at 10 days with PBS. The BMCs were layered on lymphocyte separation medium and centrifuged for excluding the erythrocytes. The separated cells were adjusted to 10(6)/ml in HBSS. Hoechst 33342 were added (1.25 mu g/ml) and incubated 60 to 90 minutes at 37 degrees C. Propidium iodide was added (2 mu g/ml) to exclude dead cells. The SP cells were isolated with flow cytometer. The sorted cells were stained with May-Gruenwald Giemsa (MG) for morphological analysis and RNA was extracted for gene expression analysis. The avian SP cells which was vanished by addition verapamil counld be separated. The percentage of SP cells in chicken bone marrow was about 2.6%. The morphological analysis by MG staining indicated that the SP cells had a larger nuclear and little cytoplasm which were typical characterisation of mouse HSCs. The pattern of gene expressions (CD34, c-Kit, CD4 and CD8) in SP cells also resembled that of the mouse HSCs. These results suggested that the HSCs could be enriched from avian bone marrow cells. Together with these results, it was concluded that SP is one of powerful tools for concentration of avian stem cells.ArticleJOURNAL OF POULTRY SCIENCE. 47(1): 53-56(2010)journal articl