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M Hoshino

Publications and source records attributed to M Hoshino.

At least 19 recordsLinked to original sources
PubMed2007

Low energy electron energy-loss spectroscopy of CF3X (X=Cl,Br).

We report threshold electron energy-loss spectra for the fluorohalomethanes CF3X (X=Cl,Br). Measurements were made at incident electron energies of 30 and 100 eV in energy-loss range of 4-14 eV, and at scattering angles of 4 degrees and 15 degrees. Several new electronic transitions are observed which are ascribable to excitation of low-lying states as well as are intrinsically overlapped in the molecules themselves. Assignments of these electronic transitions are suggested. These assignments are based on present spectroscopic and cross-section measurements, high-energy scattering spectra, and ab initio molecular orbital calculations. The calculated potential curves along the C-X bond show repulsive nature, suggesting that these transitions may lead to dissociation of the C-X bond. The present results are also compared with the previous ones for CF3H, CF4, and CF3I.

Journal Article↗
PubMed2006

C1s and O1s photoelectron satellite spectra of CO with symmetry-dependent vibrational excitations.

The photoelectron shake-up satellite spectra that accompany the C1s and O1s main lines of carbon monoxide have been studied by a combination of high-resolution x-ray photoelectron spectroscopy and accurate ab initio calculations. The symmetry-adapted cluster-expansion configuration-interaction general-R method satisfactorily reproduces the satellite spectra over a wide energy region, and the quantitative assignments are proposed for the 16 and 12 satellite bands for C1s and O1s spectra, respectively. Satellite peaks above the pi(-1)pi(*) transitions are mainly assigned to the Rydberg excitations accompanying the inner-shell ionization. Many shake-up states, which interact strongly with three-electron processes such as pi(-2)pi(*2) and n(-2)pi(*2), are calculated in the low-energy region, while the continuous Rydberg excitations are obtained with small intensities in the higher-energy region. The vibrational structures of low-lying shake-up states have been examined for both C1s and O1s ionizations. The vibrational structures appear in the low-lying C1s satellite states, and the symmetry-dependent angular distributions for the satellite emission have enabled the Sigma and Pi symmetries to be resolved. On the other hand, the potential curves of the low-lying O1s shake-up states are predicted to be weakly bound or repulsive.

Journal Article↗
PubMed2006

Symmetry-dependent vibrational excitation in N 1s photoionization of N2: experiment and theory.

We have measured the vibrational structures of the N 1s photoelectron mainline and satellites of the gaseous N2 molecule with the resolution better than 75 meV. The gerade and ungerade symmetries of the core-ionized (mainline) states are resolved energetically, and symmetry-dependent angular distributions for the satellite emission allow us to resolve the Sigma and Pi symmetries of the shake-up (satellite) states. Symmetry-adapted cluster-expansion configuration-interaction calculations of the potential energy curves for the mainline and satellite states along with a Franck-Condon analysis well reproduce the observed vibrational excitation of the bands, illustrating that the theoretical calculations well predict the symmetry-dependent geometry relaxation effects. The energies of both mainline states and satellite states, as well as the splitting between the mainline gerade and ungerade states, are also well reproduced by the calculation: the splitting between the satellite gerade and ungerade states is calculated to be smaller than the experimental detection limit.

Journal Article↗
PubMed2006

Experimental and theoretical elastic cross sections for electron collisions with the C3H6 isomers.

In the present work we report cross sections for electron collisions with the isomers propene (C3H6) and cyclopropane (c-C3H6). Electron-scattering differential cross sections (DCS) are reported for measurements carried out for energies 1.5-100 eV and the angular range of 20 degrees-120 degrees. Elastic integral cross sections (ECS), DCS, and momentum-transfer cross sections (MTCS) are reported for calculations carried out using the Schwinger multichannel method with pseudopotentials for the energy range of 2.0-40 eV and angular range of 0 degrees-180 degrees. The resemblance of the pi* shape resonance in the cross sections, observed at 1.5-2.0 eV for propene, to those in C2H4 and C2F4 clearly points to the effect of the double bond in the molecular structures for these molecules. Below 60 eV, we observed clear differences in peak positions and magnitudes between the DCS, ECS, and MTCS for C3H6 and c-C3H6, which we view as the isomer effect.

Journal Article↗
PubMed2005

Symmetry-resolved absorption spectra of vibrationally excited CO2 molecules.

Symmetry-resolved x-ray absorption spectroscopy has been first carried out on high-temperature molecules. From the angle-resolved ion yield spectra of CO2 both at room temperature and at 430 degrees C, symmetry-resolved absorption profiles of the C 1s(-1) 2pi(u) and O 1s(-1) 2pi(u) resonances have been extracted for the vibrational ground state molecules and bending-vibration excited ones. The profiles change dramatically between them, and the Renner-Teller effect becomes more evident for the vibrationally excited molecules. The effects of the multimode vibronic coupling are suggested for the O 1s(-1) 2pi(u) and O 1s(-1) 3s sigma(g) resonances.

Journal Article↗
PubMed2005

Identification and gene expression of bovine C-type lectin dectin-2.

The C-type lectin receptor has been shown to recognize carbohydrate moieties of self and non-self antigens, thus serving as an innate immune receptor. Using bioinformatics and molecular cloning techniques, we isolated a bovine gene that encodes a polypeptide of 206 amino acids with structural features shared by mouse and human dectin-2, including a high homology with mouse dectin-2 (66%), a type II configuration, a short cytoplasmic domain without tyrosine-based signal motifs, a carbohydrate recognition domain, a putative N-glycosylation site, and an EPN motif involved in the Ca(2+)-dependent binding of hexose carbohydrates. These results reveal this bovine gene to be a counterpart of mouse dectin-2. Moreover, the bovine dectin-2 gene showed heterogeneity in mRNA (the generation of alternatively spliced transcript) and segmentation into six exons, which are also observed in mouse dectin-2. Inconsistent with mouse dectin-2 mRNA, the bovine counterpart is abundantly expressed by Langerhans cells compared to macrophages; however, lymph nodes showed the highest expression level of bovine dectin-2, while spleen and lung showed the highest expression levels of mouse and human dectin-2. In cattle, dectin-2 expressed by dendritic cells may be clinically involved in the recognition of invading antigens in lymph nodes.

Amino Acid Sequence↗
PubMed2005

Three-dimensional evolution of a relativistic current sheet: triggering of magnetic reconnection by the guide field.

The linear and nonlinear evolution of a relativistic current sheet of pair (e(+/-)) plasmas is investigated by three-dimensional particle-in-cell simulations. In a Harris configuration, it is obtained that the magnetic energy is fast dissipated by the relativistic drift kink instability (RDKI). However, when a current-aligned magnetic field (the so-called "guide field") is introduced, the RDKI is stabilized by the magnetic tension force and it separates into two obliquely propagating modes, which we call the relativistic drift-kink-tearing instability. These two waves deform the current sheet so that they trigger relativistic magnetic reconnection at a crossover thinning point. Since relativistic reconnection produces a lot of nonthermal particles, the guide field is of critical importance to study the energetics of a relativistic current sheet.

Journal Article↗
PubMed2005

Effect of inhaled corticosteroid on an immunoreactive thymus and activation-regulated chemokine expression in the bronchial biopsies from asthmatics.

BACKGROUND: Bronchial asthma is characterized by airway inflammation, notably because of eosinophils and T cells. Thymus and activation-regulated chemokine (TARC) is known to selectively attract Th2 cells, and is increased in response to interleukin (IL)-4 and IL-13, which share a common receptor, IL-4 receptor alpha (IL-4Ralpha). While corticosteroids have proven, very effective in modifying airway inflammation, the effect of corticosteroids on TARC in asthmatics has been little studied. OBJECTIVE: We examined the effects of inhaled budesonide (BUD) on the expression of TARC and the number of inflammatory cells in bronchial biopsy specimens taken from asthma patients. METHODS: Inhaled BUD 800 mug daily, or placebo was administered for 3 months in a double-blind, parallel-group study, and bronchial biopsies were performed before and after treatment. Biopsy specimens were examined by immunocytochemistry. RESULTS: We observed a significant decrease in the epithelial expression of TARC (P < 0.01) in the BUD group compared with the placebo group. This was accompanied by decreases in the number of eosinophils (P < 0.01), CD3(+) T cells (P < 0.05), and CD4(+) T cells (P < 0.01). A significant correlation was found between changes in epithelial TARC and in IL-4Ralpha immunoreactivity (r(s) = 0.66, P < 0.01). CONCLUSIONS: These findings suggest that corticosteroid asthma treatment can reduce infiltration of the airway by inflammatory cells, an effect modulated by down-regulation of bronchial epithelial TARC expression.

Administration, Inhalation↗
PubMed2005

Effect of suplatast tosilate on goblet cell metaplasia in patients with asthma.

BACKGROUND: Goblet cell metaplasia is a pathologic characteristic of asthma, associated with excess mucus secretion. Interleukin (IL)-4 and IL-13 plays an important role in mucus hypersecretion. Suplatast tosilate (suplatast), an antiallergic agent, is a Th2 cytokine inhibitor that suppresses the synthesis of IL-4, IL-5, IL-13, and eosinophilic airway inflammation. OBJECTIVE: We examined the effects of suplatast on mucus production in bronchial biopsy specimens taken from asthmatic subjects. METHODS: Oral suplatast 300 mg daily, or placebo was administered for 3 months in a double-blind, parallel-group study in 25 patients with asthma. Biopsy specimens were evaluated at before and after treatment for alcian blue/period acid-Schiff (AB/PAS), MUC5AC staining in bronchial epithelium and IL-4+, IL-13+ cells as well as inflammatory cells in lamina propria. RESULTS: There were significant decreases in the percentage of AB/PAS (P < 0.01) and MUC5AC (P < 0.01) stained area in the suplatast group. These changes were accompanied by significant decreases in IL-4+ and IL-13+ cells in suplatast-treated subjects. Additionally, we have observed that the number of infiltrating eosinophils and CD4+ T cells significantly decreased. CONCLUSIONS: These findings suggest that suplatast prevents goblet cell metaplasia through modulation of Th2 cytokine production and the recruitment of eosinophils and CD4+ T cells in the asthmatic airways.

Administration, Oral↗
PubMed2004

Electron scattering from perfluorocyclobutane (c-C4F8).

We report experimental results for electron scattering from perfluorocyclobutane, c-C(4)F(8), obtained from measurements in our two laboratories. A set of differential, integral, and momentum transfer cross sections is provided for elastic scattering for incident electron energies from 1.5 to 100 eV. Inelastic scattering (vibrational excitation) cross sections have been measured for incident electron energies of 1.5, 2, 5, 6, and 7 eV. In order to investigate the role of intermediate negative ions (resonances) in the scattering process we have also measured an excitation function for elastic scattering and vibrational excitation of the ground electronic state of C(4)F(8) for incident energies between 0.6 and 20 eV. These results are compared with the limited amount of data available in the literature for scattering from this molecule.

Journal Article↗
PubMed2004

Significant effects of diacylglycerol on body fat and lipid metabolism in patients on hemodialysis.

AIMS: The long-term effects of dietary diacylglycerol (DAG) on body fat and lipid metabolism were studied in patients undergoing hemodialysis (HD). METHODS: Ten patients (seven males, three females) ranging in age from 40 to 64 years were enrolled. During the test period, 9.8 g of DAG was ingested per day for 3 months. RESULTS: Body mass index did not change throughout the study. The abdominal fat area measured by CT scan decreased significantly at 3 months, and increased significantly 3 months after completion of the DAG ingestion period. The serum composition of very low-density lipoprotein (VLDL) decreased significantly at 3 months and high-density lipoprotein (HDL) increased significantly at 3 months; these were determined using polyacrylamide gel electrophoresis. Serum lipoprotein (a) decreased significantly at 3 months. CONCLUSIONS: Our study showed that 3-month ingestion of DAG reduced the amount of abdominal fat and improved serum lipid profiles in free-living HD patients.

Abdomen↗
PubMed2003

Benefit of IVIG for long-standing ataxic sensory neuronopathy with Sjögren's syndrome. IV immunoglobulin.

Ataxic sensory neuronopathy with Sjögren's syndrome is a devastating neurologic complication for which there is no established treatment. IV immunoglobulin (IVIG) was given to five patients with severe disabilities for an average of 12 years. Four patients showed remarkable improvement, two of whom responded after the first course. The authors conclude that IVIG is safe and effective to treat even chronically debilitated patients who have the disease, presumably because it ameliorates smoldering inflammation.

Aged↗
PubMed2003

In vitro reconstitution of signal transmission from a hair cell to the growth cone of a chick vestibular ganglion cell.

Signal transmission from a chick hair cell to the growth cone of a vestibular ganglion cell was examined by placing an acutely dissociated hair cell on the growth cone of a cultured vestibular ganglion cell. Electrical stimuli were applied to the hair cell while monitoring the intracellular Ca(2+) concentration ([Ca(2+)](i)) at the growth cone or recording whole-cell currents from the vestibular ganglion cell. Electrical stimulation of the hair cell induced [Ca(2+)](i) increases at the growth cone and inward currents in the vestibular ganglion cell. The [Ca(2+)](i) increase was blocked by 6-cyano-7-nitroquinoxaline (CNQX) (10 microM) but not by 2-amino-5-phosphonovaleric acid (APV; 50 microM). Glutamate (100 nM-300 microM) applied to the vestibular ganglion cell by the Y-tube method induced inward currents which were also antagonized by CNQX, but not by APV. These results indicate that the electrical stimulation of a hair cell induced glutamate or glutamate like agent release from the hair cell, which activated non-N-methyl-D-aspartate receptors at the growth cone of the vestibular ganglion cell, followed by action potentials and [Ca(2+)](i) elevation in the vestibular ganglion cell. This is the first demonstration of in vitro reconstitution of functional signal transmission from a hair cell to a vestibular ganglion cell.

6-Cyano-7-nitroquinoxaline-2,3-dione↗
PubMed2003

Bypass balloon pumping: a newly developed device for mechanical circulatory support in heart failure.

Various types of assist devices have been developed for severe heart failures. Among them, intra-aortic balloon pumping (IABP) has achieved popularity, mainly in the treatment of patients with either severe cardiac infarction or low cardiac output syndrome (LOS) after open-heart surgery. However, IABP has a limitation in that although it acts as a pressure support, it cannot directly support flow volume. In cases of severe pump failure, stronger pump support would be required. However, there is a limit in the clinical use of temporary mechanical support using a pump because of the costs of the expensive equipment. With this in mind, we came up with a new idea in which the motion of a balloon in IABP system is converted into a power source for creating a one-way stream. In order to realize our idea, we made a J-shaped sample model of pulsating chamber incorporating two ball valves. In the hydrodynamic experiment using our new device, flows over 2500 ml/min (Max. 3475 ml/min) were obtained. The percent changes in parameters such as TTI, DPTI and bypass flows obtained by the experiment of left ventricular bypass have demonstrated that our assist system is effective for reducing cardiac work.

Animals↗
PubMed2003

Increased immunoreactivity of stromal cell-derived factor-1 and angiogenesis in asthma.

Stromal cell-derived factor-1 (SDF-1) acts as a chemoattractant for leukocytes and can induce neovascularisation. To examine the role of SDF-1 in the development of angiogenesis, immunohistochemical studies were performed on bronchial biopsy specimens from asthmatic and control subjects. Bronchial biopsy specimens were obtained from 13 asthmatic and eight control subjects. The number of vessels and the percentage area they occupied were estimated after staining for type-IV collagen. In addition the number of SDF-1-positive cells was determined. There was a significant increase in the number of vessels and the percentage vascularity in the submucosa of asthmatic subjects compared with control subjects. Asthmatic subjects exhibited a greater number of SDF-1-positive cells in the airway mucosa than control subjects. The degree of vascularity was associated with the number of SDF-1-positive cells. Furthermore, the number of SDF-1-positive cells was inversely correlated with airway calibre and airway hyperresponsiveness. Colocalisation studies revealed that endothelial cells, macrophages and T-lymphocytes were the major sources of SDF-1. These findings suggest that increased vascularity of bronchial mucosa in asthmatic subjects is closely related to the expression of stromal cell-derived factor-1 positive cells, which may play a role in remodelling of airways via angiogenesis.

Adolescent↗
PubMed2001

Rapid large-scale magnetic-field dissipation in a collisionless current sheet via coupling between Kelvin-Helmholtz and lower-hybrid drift instabilities.

Rapid large-scale magnetic-field dissipation is observed in a full kinetic simulation of cross-field current instabilities in a current sheet even when the thickness of the current sheet is at ion scale. The Kelvin-Helmholtz instability caused by the velocity shear between the current-carrying ions and the cold background ions excites the lower-hybrid drift instability at the edges of the undulated current sheet. We show that the nonlinear coupling between these two instabilities is responsible for the observed rapid dissipation. The simulation result presents a new route for magnetic-field dissipation in an ion-scale current sheet and demonstrates the general significance of nonlinear cross-scale coupling in collisionless plasmas.

Journal Article↗