Biomedical subjects
Publications and source records attributed to H Shinohara.
The publisher regrets that this was an accidental duplication of an article that has already been published in Eur. J. Echocardiogr., 4 (2003) 191-195, . The duplicate article has therefore been withdrawn.
The magnetic and electronic properties of a single atom and a pair of Dy atoms encapsulated inside fullerene carbon cages have been examined using X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) as well as resonant photoelectron spectroscopy (RESPES) across the Dy M(4,5)-edge. The comparison of the measured XAS spectra with multiplet calculations indicates that the encaged Dy has a 4f( 9) configuration. The presence of Dy 5d spectral weight in the valence band is not detected by RESPES, indicating that Dy is in a formally trivalent state. The evolution of the encaged Dy orbital and spin moments of the 4f orbitals as a function of the applied magnetic field and temperature has been obtained from XMCD measurements. At 6.9 T and 4 K, both the orbital and the spin magnetic moments of the encaged Dy 4f electrons are dramatically smaller than those expected for the free Dy(3+) at saturation.
We report that entirely end-bonded multiwalled carbon nanotubes (MWNTs) can exhibit superconductivity with a transition temperature (T(c)) as high as 12 K, which is approximately 30 times greater than T(c) reported for ropes of single-walled nanotubes. We find that the emergence of this superconductivity is highly sensitive to the junction structures of the Au electrode/MWNTs. This reveals that only MWNTs with optimal numbers of electrically activated shells, which are realized by end bonding, can allow superconductivity due to intershell effects.
The radiative cooling of positively charged fullerene and endohedral fullerene fragments of C60, C70, C84, and La@C82 has been measured in a time-of-flight mass spectrometer. The radiative cooling is measured via its influence on the metastable decay. The emissivity extracted from the data is between 4x10(-4) and 13x10(-4). These values agree fairly well with the emissivity calculated from considering the low-energy tail of the surface plasmon. No major difference is found in the emission behavior of empty and endohedral fullerenes.
We have measured the elastic and inelastic tunneling properties of isolated Gd@C(82) molecules on Ag(001) using cryogenic scanning tunneling spectroscopy. We find that the dominant inelastic channel is spatially well localized to a particular region of the molecule. Ab initio pseudopotential density-functional theory calculations indicate that this channel arises from a vibrational cage mode. We further show that the observed inelastic tunneling localization is explained by strong localization in the molecular electron-phonon coupling to this mode.
B-cell precursor (BCP) leukemia cells infiltrate into peripheral organs and the disease often relapses. Inhibition of tissue infiltration may improve the treatment outcome of BCP-leukemia patients. Selectin ligand has been suggested to play an important role in the infiltration of leukemia cells. However, the regulation mechanisms and involvement in tissue infiltration of selectin ligand expression in BCP-leukemia cells are not fully understood. In this study, we report that BCP-leukemia cells express selectin ligand on O-sialoglycoproteins. Core 2 beta1,6-N-acetylglucosaminyltransferase-1 (C2GnT-1) is mainly expressed in BCP-leukemia cells. Transfection of the antisense C2GnT-1 cDNA resulted in a significant reduction of either selectin ligand expression or selectin-dependent cell adhesion in BCP-leukemia cell line KM3 cells. Migration ability into mouse peripheral organs was reduced significantly in the antisense transfectant. These findings suggest that C2GnT-1 regulates selectin ligand expression. Downregulation of the selectin ligand expression level inhibits tissue infiltration of BCP-leukemia cells. C2GnT-1 may be a candidate of therapeutic target for the inhibition of infiltration of leukemia cells.
A 63-year-old man, with atypical pulmonary mycobacteriosis and also with hepatic dysfunction due to chronic hepatitis C, underwent wedge resection of the right lower lobe for non-small cell lung cancer. On the 9th postoperative day, the patient developed acute tetraplegia and then respiratory failure. Neither computed tomography (CT) nor magnetic resonance imaging (MRI) of brain and cervical vertebrae showed any cancer metastases. The neurological symptoms were those of Guillain-Barre syndrome. Therefore, we speculate that the cause of the neuromyopathy might be autoimmune antibodies from lung cancer. Steroid pulse therapy and plasma exchange treatment were effective and the patient's symptoms disappeared in a month. We reported the extremely rare case of a lung cancer patient with acute tetraplegia in the early postoperative period.
OBJECTIVE: We studied for the purpose of revealing the long-term prognosis of the surgical treatment for pathological stage III lung cancer. METHOD: Two hundred fifty-four patients with pathological stage III disease who underwent surgical procedures in our hospital from 1981 to 2000 were investigated retrospectively. RESULTS: The 5- and 10-year survival rates of 144 patients with stage IIIA disease were 35 and 25%, while those of 110 patients with IIIB disease were 30 and 16%. The 5- and 10-year survival rates were 40 and 27% for 52 patients with T1N2 disease, 33 and 23% for 70 patients with T2N2 disease, 34 and 0% for 9 patients with T3N1 disease, and 33 and 26% for 13 patients with T3N2 disease, respectively. In the patients with IIIB disease, the 5- and 10-year survival rates of 56 patients only with pml were 47 and 26%, those of the other patients were 9 and 0%. There is significant difference among them (p < 0.0001). In 54 patients with IIIB disease in addition to pm1, the 5-year survival rates of 19 patients with exploration only and the other patients were 7 and 14%, respectively. There were no 10-year survivors in both groups. CONCLUSION: The long-term prognosis of pathological stage III disease was still not satisfactory. Therefore, we should make efforts to get a sufficient informed-consent before the surgery for the patients with stage III disease.
Electronic standing waves with two different wavelengths were directly mapped near one end of a single-wall carbon nanotube as a function of the tip position and the sample bias voltage with high-resolution position-resolved scanning tunneling spectroscopy. The observed two standing waves caused by separate spin and charge bosonic excitations are found to constitute direct evidence for a Luttinger liquid. The increased group velocity of the charge excitation, the power-law decay of their amplitudes away from the scattering boundary, and the suppression of the density of states near the Fermi level were also directly observed or calculated from the two different standing waves.
We report the observation of quantized rotational states of a diatomic C2 unit in solid endohedral fullerene C(2)Sc(2)@C(84). The rotational transitions induce a periodic line pattern in the low energy Raman spectrum. The rotational constant B and the C-C distance were found to be 1.73 cm(-1) and 0.127 nm, respectively. Density functional calculations revealed an intrinsic rotational barrier of the order of only a few meV for the C2 unit. The Schrödinger equation involving the potential barrier was solved and the Raman tensor matrix elements were calculated, yielding good quantitative agreement with the experiment. To our best knowledge this is the first intrinsic rotational spectrum of a diatomic plane molecular rotor.
Metal-carbon cage vibrations of crystalline endohedral D2d-M2@C84 (M=Sc,Y,Dy) dimetallofullerenes were analyzed by temperature dependent Raman scattering and a dynamical force field model. Three groups of metal-carbon cage modes were found at energies of 35-200 cm(-1) and assigned to metal-cage stretching and deformation vibrations. They exhibit a textbook example for the splitting of molecular vibrations in a crystal field. Induced dipole-dipole and quadrupole-quadrupole interactions account quantitatively for the observed mode splitting. Based on the metal-cage vibrational structure it is demonstrated that D2d-Y2@C84 dimetallofullerene retains a monoclinic crystal structure up to 550 K and undergoes a transition from a disordered to an ordered orientational state at a temperature of approximately 150 K.
Fifty-eight patients who had small lung tumors 2 cm or less with ground-glass opacity (GGO) component more than 50% on high resolution computed tomography (HRCT) underwent intentional limited resection. After bronchioloalveolar carcinoma without both active fibroblastic proliferation and invasive sign to the stroma was confirmed, limited resection was completed in 50 patients. In 8 patients, procedure was converted lobectomy because of microscopic invasive sign in 4, active fibroblastic proliferation in 2, and other reasons in 2. Unexpected invasive sign was found by detailed post-operative examination in 2 cases. Five-year survival rate was 98% with a mean follow-up period of 48.8 months. A limitation of intra-operative diagnosis was revealed and the accuracy of diagnosis should be improved by not only intra-operative pathological diagnosis but also HRCT images.
Intramolecular structure of the scandium dimetallofullerene (Sc(2)@C(84)) has been clearly revealed by high resolution transmission electron microscopy with the single-atom sensitivity. Direct observation of two Sc atoms inside each fullerene molecule has led to a successful determination of the molecular symmetry among the three possible structural isomers for the Sc(2)@C(84). The present work introduces a new electron microscopic approach to investigate individual molecular structures and demonstrates the possibility for determining the molecular isomer on a single-molecular basis.
BACKGROUND: Total gastrectomy with D2 dissection is the standard treatment in Japan for early upper-third gastric cancer. The purpose of this study was to confirm the safety and radicality of proximal gastrectomy as an alternative operation. METHODS: Between 1993 and 1999, 45 patients with an apparent primary early gastric cancer in the upper third of the stomach were treated by proximal gastrectomy with jejunal interposition. The spleen was preserved, but the suprapancreatic nodes were cleared. RESULTS: Histology confirmed early gastric cancer in 37 patients while eight had advanced disease. Nodal metastasis was observed in six patients. There was no hospital death and no early postoperative complications. One patient died from nodal recurrence and two from unrelated causes. Two patients had reflux symptoms without endoscopic oesophagitis. Mean weight loss was 11.5 per cent of initial bodyweight. CONCLUSION: Proximal gastrectomy for early upper-third gastric cancer can be performed safely with an excellent cure rate. This procedure deserves further clinical evaluation to assess patients' quality of life.
AIM: We validated transthoracic echocardiographic measurements of left atrial appendage flow velocity by comparing them with transoesophageal echocardiographic measurements. METHODS AND RESULTS: Eighty-four consecutive patients (mean age, 64.6 years) with various cardiac diseases, who underwent both transthoracic echocardiography and transoesophageal echocardiography were studied. Thirty-two patients were in sinus rhythm, and the remaining 52 patients were in atrial fibrillation. On transthoracic echocardiography, the transducer was placed somewhat superior and outside from the position viewing the conventional parasternal short-axis image of the aortic valve, so that the angle between left atrial appendage midline and Doppler beam could be narrowed. The left atrial appendage flow velocity pattern was recorded by pulsed Doppler mode with a sampling volume placed at the left atrial appendage orifice on both transthoracic echocardiography and transoesophageal echocardiography. In both approaches, the peak emptying velocity (LAA-E) and the peak filling velocity (LAA-F) of the left atrial appendage were measured. In sinus rhythm, the LAA-E was detectable in 25 of the 32 patients (78.1%) and the LAA-F in 20 of the 32 patients (62.5%). Both LAA-E and LAA-F were detectable in 46 of the 52 patients (88.5%) in atrial fibrillation. Good correlations of LAA-E and LAA-F were observed between transthoracic echocardiography and transoesophageal echocardiography measurements in sinus rhythm (r=0.94, r=0.95, respectively; both, P<0.0001) and in atrial fibrillation (r=0.89, r=0.95, respectively; both, P<0.0001). CONCLUSIONS: The left atrial appendage flow velocities could be sufficiently recorded and assessed by transthoracic echocardiography in 84 Japanese unselected consecutive patients with sinus rhythm or atrial fibrillation.
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Motivated by the technical and economic difficulties in further miniaturizing silicon-based transistors with the present fabrication technologies, there is a strong effort to develop alternative electronic devices, based, for example, on single molecules. Recently, carbon nanotubes have been successfully used for nanometre-sized devices such as diodes, transistors, and random access memory cells. Such nanotube devices are usually very long compared to silicon-based transistors. Here we report a method for dividing a semiconductor nanotube into multiple quantum dots with lengths of about 10nm by inserting Gd@C82 endohedral fullerenes. The spatial modulation of the nanotube electronic bandgap is observed with a low-temperature scanning tunnelling microscope. We find that a bandgap of approximately 0.5eV is narrowed down to approximately 0.1eV at sites where endohedral metallofullerenes are inserted. This change in bandgap can be explained by local elastic strain and charge transfer at metallofullerene sites. This technique for fabricating an array of quantum dots could be used for nano-electronics and nano-optoelectronics.
AIMS: We evaluated the relationship between the mitral inflow velocities by pulsed Doppler echocardiography and mitral annular motion velocities by pulsed Doppler tissue imaging in patients with mitral annular calcification. METHODS AND RESULTS: Fifty-three patients with mitral annular calcification were divided into two groups: severe mitral annular calcification (n=15, mitral annular calcification bigger than or equal 5mm in width) and mild mitral annular calcification (n=38, mitral annular calcification <5mm in width). In addition, 20 patients with hypertensive heart disease (HHD group) and mild left ventricular hypertrophy but no mitral annular calcification and 30 normal individuals (normal group) were studied. The early diastolic mitral inflow velocity (E) was higher in the severe mitral annular calcification group (0.75+/-0.26 m/s) than in the HHD and normal groups (mild mitral annular calcification, 0.65+/-0.21; HHD, 0.57+/-0.24; normal, 0.55+/-0.15m/s), and the late diastolic mitral inflow velocity (A) was higher in the severe mitral annular calcification group (1.24+/-0.23 m/s) than in the other three groups (mild mitral annular calcification, 0.96+/-0.20; HHD, 0.84+/-0.23; normal, 0.75+/-0.13 m/s). In contrast, the early and late diastolic annular velocities (Ea, Aa) were lower in the severe mitral annular calcification group (Ea: 5.7+/-2.2; Aa: 11.9+/-4.4 cm/s) than in the other three groups (Ea: mild mitral annular calcification, 8.3+/-2.5; HHD, 7.7+/-2.2; normal, 9.0+/-1.8 cm/s; Aa: mild mitral annular calcification, 14.2+/-4.1; HHD, 14.3+/-2.8; normal, 14.2+/-2.1cm/s). Mitral valve area was smaller in the severe mitral annular calcification group (2.6+/-1.0 cm(2)) than in the other three groups (mild mitral annular calcification, 3.1+/-0.7; HHD, 4.1+/-0.7; normal, 4.2+/-0.9 cm(2)). In the mitral annular calcification and normal groups, the A correlated inversely with mitral valve area (r=-0.67, P<0.01) and directly with severity of mitral annular calcification (r=0.65, P<0.01), and the Ea correlated inversely with left ventricular wall thickness (r=-0.37, P<0.01) and severity of mitral annular calcification (r=-0.45, P<0.01). CONCLUSION: Patients with severe mitral annular calcification have higher mitral inflow velocities due to mitral annular restriction and lower mitral annular velocities caused by decreased mitral annular motion and abnormal left ventricular relaxation.