Coverage-dependent desorption kinetics of water on a well-ordered alumina thin film surface.

We have developed an experimental and analytical setup for thermal desorption spectroscopy of solid water films on surfaces. We obtain the coverage-dependent desorption kinetics of water molecules from a well-defined ultra-thin alumina/NiAl(110) surface in the coverage range of 0-2 monolayers. We use a novel deconvolution technique to eliminate the pumping delay of water vapor in the vacuum system, which has previously hindered the accurate estimation of desorption kinetic parameters, such as activation energy and pre-exponential factor. The coverage-dependent Arrhenius analysis reveals that the desorption activation energy decreases with increasing coverage in the sub-monolayer range, indicating that the water-water interaction is not attractive. We also find that the pre-exponential factor for the second layer is higher than that for the sub-monolayer. We explain this difference in terms of transition state theory and propose that entropic effects play a significant role in water desorption kinetics.

Focusing and spin polarization of atomic hydrogen beam.

We have developed a spin-polarized-hydrogen beam with a hexapole magnet. By combining the beam chopper and pulsed laser ionization detection, the time-of-flight of the hydrogen beam was measured, and the dependence of the beam profile on the velocity was acquired, which was consistent with the beam trajectory simulations. The spin polarization of the beam was analyzed by using the Stern-Gerlach-type magnet in combination with the spatial scan of the detection laser. The spin polarization was about 95% at a focusing condition due to the hexapole magnet. The polarization was, on the other hand, reduced to about 70% for the beam at higher velocities, which is consistent with simulation results.

Nuclear Dynamics and Electronic Effects of Hydrogen on Solid Surfaces.

Hydrogen is involved in a variety of chemical processes on surfaces. While hydrogen exhibits vibrational and rotational dynamics in its adsorption state, it in some cases undergoes diffusion into the substrate as well as on the surface, and participates in chemical reactions. Furthermore, hydrogen exchanges an electron with surfaces having a significant effect on the surface electronic structure. In this personal account, we review our recent studies on surface nuclear dynamics of hydrogen, hydrogen transport across surfaces, catalytic hydrogenation/isotope exchange reactions, and charge transfer between the surface and hydrogen by using a depth-resolved technique of nuclear reaction analysis and a quantum-state-selective detection of resonance enhanced multiphoton ionization in combination with surface science techniques. As a future prospect, we refer to ultraslow µ spin rotation spectroscopy for a direct probe of the hydrogen charge state at surfaces.

Low-energy electron diffraction study of the phase transition of Si(001) surface below 40 K.

The phase transition of Si(001) surface below 40 K was studied by low-energy electron diffraction (LEED). The temperature dependence of the intensities and widths of the quarter order diffraction spots and LEED intensity versus electron energy curves (I-V curves) were obtained in the temperature region from 20 to 300 K. While the spot intensities of the quarter order spots decrease and the widths broaden, the I-V curves do not change so much below 40 K. This clearly shows that a phase transition occurs from an ordered phase above 40 K to a disordered phase below 40 K.

Photostimulated desorption and ortho-para conversion of H2 on Ag surfaces.

Photostimulated desorption and change of the ortho-para ratio of H2 physisorbed on Ag at 7 K are reported. After pump laser excitation at 193 nm neutral H2 desorbing in a nonthermal process is state selectively detected by resonance-enhanced multiphoton ionization. At weak pump laser fluence the natural ortho-para conversion of H2 on Ag was monitored to proceed with a conversion time of approximately 780 s, which is in good agreement with predictions based on an electron-exchange-hyperfine-contact model. With increasing pump laser fluence, the ortho-para ratio decreases faster, suggesting photoassisted ortho-para H2 conversion.

Zero-point vibration of hydrogen adsorbed on Si and Pt surfaces.

Hydrogen atoms adsorbed on Si(111) and Pt(111) were investigated by nuclear reaction analysis (NRA) using 1H(15N,alphagamma)12C. From measurements of the NRA spectrum at normal and tilted ion incidences the zero-point vibrational energies of H on Si(111) in the perpendicular and parallel directions were found to be 123.4+/-4.6 and 44.6+/-6.2 meV, respectively, which are consistent with harmonic potentials. The zero-point energies obtained for Pt(111)-H were 80.8+/-3.9 and 62.1+/-6.0 meV for perpendicular and parallel directions, respectively. These results indicate that the stretching mode is harmonic, while the bending mode is strongly anharmonic.

47,XXX male: A clinical and molecular study.

We report a 53-year-old Japanese male with a 47,XXX karyotype. His clinical features included hypoplastic scrotal testes (4 ml bilaterally), normally formed small penis (3.8 cm), relatively poor pubic hair development (Tanner stage 3), gynecomastia, age-appropriate male height (159.1 cm), and mental retardation (verbal IQ of 56). Serum testosterone was markedly reduced (0.6 nmol/L). A needle biopsy showed severe testicular degeneration. FISH analysis revealed complex mosaicism consisting of (1) 47,XXX cells with a single copy of SRY (n = 177), two copies of SRY (n = 3), and no SRY (n = 1); (2) 46,XX cells with a single copy of SRY (n = 9) and no SRY (n = 3); (3) 45,X cells with no SRY (n = 5); and (4) 48,XXXX cells with a single copy of SRY (n = 1) and two copies of SRY (n = 1). PCR analysis showed the presence of Yp portion with the breakpoint between DYS264 and AMELY. Microsatellite analysis demonstrated three alleles for DMD and AR. X-inactivation analysis for the methylation status of the AR gene showed random inactivation of the three X chromosomes. The results suggest that this 47,XXX male has resulted from abnormal X-Y interchange during paternal meiosis and X-X nondisjunction during maternal meiosis. Complex mosaicism may be due to the age-related increase in mitotic nondisjunction which is prone to occur in rapidly dividing lymphocytes and to the presence of two randomly inactivated X chromosomes which may behave asynchronously during mitosis, and clinical features of this male would primarily be explained by the genetic information on the SRY (+) der(X) chromosome and his advanced age.

Photorefractive multiple quantum wells at 1064 nm.

We have fabricated photorefractive InGaAs/GaAs multiple quantum wells that are sensitive at wavelengths near 1.06 mum for what is believed to be the first time. We have measured four-wave-mixing diffraction efficiency, using a Nd:YAG laser. A maximum diffraction efficiency of 7 x 10(-4) and a cutoff grating period of ~2 mum are obtained.

Observation of nuclear excitation by electron transition in 197Au with synchrotron X rays and an avalanche photodiode

We have succeeded in observing nuclear excitation by electron transition (NEET) in 197Au by a new method. Monochromatic x-rays of synchrotron radiation were used to ionize the K shell of gold atoms in a target foil. The internal-conversion electrons emitted from excited nuclei were detected with a silicon avalanche photodiode. At a photon energy of 80.989 keV, the NEET probability in 197Au was determined to be (5.0+/-0.6)x10(-8) from a comparison of the event number per photon between NEET and the nuclear resonance at 77.351 keV.

[Pranlukast allows reduction of inhaled steroid dose without deterioration in lung function in adult asthmatics].

We undertook a community based case-control study to measure the effect of pranlukast on the reduction of inhaled steroid in adult asthmatics. Forty-one adults completed a run-in period of 4 weeks on 800 microgram of beclomethasone dipropionate (BDP) documenting twice daily peak expiratory flow (PEF) and symptom score and therapeutic score on a standard diary. Forced expiratory volume in one second (FEV1.0), V50, V25 was measured once during the run-in period. Patients were then randomized to receive either pranlukast with 400 microgram of BDP or 400 microgram alone for 8 weeks. There was no difference in the symptom score and therapeutic between the two groups at any time point. However, morning and evening % PEF run-in expressed as a % of the PEF average during the run-in period was significantly lower at 8 weeks in the groups without pranlukast. There were subjects in the group without pranlukast (35.3%) compared to those with (20.8%) who had a 10% or more reduction in % PEF from the run-in period. The patients with an FEV1.0 < 80% predicted who were randomized to the control group were more likely (5 of 7) to have a fall in % PEF run-in and those randomized to received pranlukast were less likely to have a fall in % PEF run-in though this was not significant (2 of 6). In this study, pranlukast has demonstrated steroid sparing effect. Severe asthmatics (FEV1.0 < 80%) who deteriorate after reduction of inhaled steroid may benefit most from pranlukast. Larger studies are now required to explore this important effect.

Resonant photorefractive effect in InGaAs/GaAs multiple quantum wells.

Semi-insulating InGaAs/GaAs multiple quantum wells are fabricated by metal-organic vapor-phase epitaxy and proton implantation. Two-wave mixing gain and four-wave mixing diffraction efficiency are measured at wavelengths of 0.91-0.94microm in the Franz-Keldysh geometry. We observe a large photorefractive effect caused by the excitonic electro-optic effect. The maximum diffraction efficiency reaches ~1.5x10(-4) .

[Male pseudohermaphroditism].

Male pseudohermaphroditism is a condition of sex differentiation disorders in which the gonads are tests, but the genital ducts and/or external genitalia are incompletely masculinized. This syndrome is caused by a failure of the sequential process in embryonal development of the testis. In the presence of functioning testis the Müllerian ducts regress, while the mesonephric ducts and urogenital sinus differentiate into the internal and external male genitalia. Male pseudohermaphroditism is classified to subtypes according to etiological factors: (1) testicular unresponsiveness to hCG and LH; (2) defect in testosterone biosynthesis; (3) end-organ resistance to androgen; (4) defects in the intracellular metabolism of testosterone; (5) aberrations in testicular organogenesis; (6) defects in anti-Müllerian hormone.

Expression of adhesion molecules on mononuclear cells from individuals with stable atopic asthma.

Activated mononuclear cells (lymphocytes and monocytes) (MNCs) circulate in peripheral blood and accumulate in the airways of individuals with steady-state asthma. The expression of adhesion molecules on MNCs of 10 patients with steady-state atopic asthma and 10 non-atopic control subjects was measured by flow cytometry. The mean fluorescence intensity of CD23 (P = 0.0003), CD11a (P = 0.034), and very late antigen-4 (VLA-4) (P = 0.016) was increased on lymphocytes of asthmatic patients relative to those of controls. Although the expression of CD16 (P = 0.002) and CD23 (P = 0.002), which are associated with differentiation into macrophages, was increased on monocytes of patients relative to those of controls, monocyte expression of VLA-4 (P = 0.006) and sialyl Lewis x (P = 0.005) was reduced. The concentration of interleukin-4 (IL-4) in serum was significantly higher in asthmatic patients than in normal subjects (P = 0.023), and a significant correlation was apparent between the serum concentration of IL-4 and the expression of VLA-4 on lymphocytes (p = 0.71, P = 0.03) or on monocytes (p = -0.72, P = 0.03) in asthmatic patients. Results suggest that IL-4 may contribute to the priming of adhesion molecule expression on lymphocytes even in steady-state conditions in individuals with chronic allergic inflammation.

Modulation of N-methyl-N-amylnitrosamine-induced rat oesophageal tumourigenesis by dietary feeding of diosmin and hesperidin, both alone and in combination.

The modifying effects of flavonoids diosmin and hesperidin during the initiation and post-initiation phases of oesophageal carcinogenesis initiated with N-methyl-N-amylnitrosamine (MNAN) were investigated in male Wistar rats. At 7 weeks of age, all animals except those treated each test chemical alone and control groups were given weekly intraperitoneal injections of MNAN (12.5 mg/kg body weight/injection) for 12 weeks to induce oesophageal neoplasms. For examining the modifying effects of 'initiation' treatment of test compounds, groups of animals were fed the diets containing 1000 ppm diosmin and 1000 ppm hesperidin, and the diet containing both compounds (900 ppm diosmin and 100 ppm hesperidin) for 13 weeks, starting 7 days before the MNAN dosing and then switched to the basal diet. For examining the modifying effects of 'post-initiation' treatment of these compounds, the groups given MNAN and a basal diet were switched to the experimental diets containing diosmin, hesperidin or diosmin combined with hesperidin at 1 week after the stop of MNAN injection, and maintained on these diets for 7 weeks. The other groups consisted of rats given test compounds alone or untreated rats. All animals were necropsied at the termination of the study (week 20) to determine the incidences of oesophageal neoplasms and preneoplasms, blood polyamine levels, and cell proliferation activity estimated by 5-bromodeoxyuridine (BrdU)-labelling index and by morphometric analysis of silver-stained nucleolar organizer regions' protein (AgNORs). A number of oesophageal neoplasms developed in rats treated with MNAN alone (75% and 100% incidences of carcinoma and papilloma, respectively). 'Initiation' feeding of diosmin significantly decreased the incidence of squamous cell carcinoma (P < 0.05). Also, 'initiation feeding' of both compounds singly or in combination caused a significant reduction in the multiplicities of oesophageal carcinoma and papilloma (diosmin, 78 and 58% reduction; hesperidin, 70 and 50% reduction; and the combination regimen, 70 and 30% reduction, P < 0.005). 'Post-initiation' feeding slightly decreased the multiplicities of these oesophageal neoplasms. Also, these dietary regimens reduced the multiplicities of preneoplastic lesions (hyperplasia and severe dysplasia; P < 0.05). There were no pathological alterations in rats treated with both compounds alone or the combined regimen alone or those in an untreated control group. Similarly, feeding of these compounds significantly decreased the expression of cell proliferation biomarkers (BrdU-labelling index and AgNORs number) of the non-lesional oesophageal epithelium (P < 0.05). Blood polyamine concentrations were also lowered in rats given the carcinogen and test compounds, both alone and in combination, when compared with those of rats given MNAN alone (P < 0.05). These findings suggest that diosmin and hesperidin supplementation, individually or in combination, is effective in inhibiting the development of oesophageal cancer induced by MNAN when given during the initiation phase, and such inhibition might be related to suppression of increased cell proliferation caused by MNAN in the oesophageal mucosa.

[Primary pulmonary aspergilloma presenting as an isolated nodular shadow].

A 55-year-old man was admitted to our hospital because of an abnormal shadow at the right hilum on a chest radiograph. The chest radiograph and the chest CT scan showed a nodular showed in the right S6. There was no air-crescent sign in the shadow, but CT-guided percutaneous needle biopsy led to the diagnosis of pulmonary aspergillosis. Anti-fungal agents (miconazole, fluconazole, and itraconazole) were given but the patient's condition did not improve. Surgical resection was done and the postoperative course was uneventful. The resected lung had a bronchiectatic area with a fungus ball. Attempts to culture the fungus ball were not successful. Histologic examination revealed conidial heads characteristic of Aspergillus fumigatus. This case is interesting because the pulmonary aspergilloma appeared as an isolated nodular shadow. This might have been a case of primary pulmonary aspergilloma.

Chemoprevention of 4-nitroquinoline 1-oxide-induced oral carcinogenesis in rats by flavonoids diosmin and hesperidin, each alone and in combination.

The modifying effects of the two flavonoids diosmin and hesperidin given during the initiation and postinitiation phases of oral carcinogenesis initiated with 4-nitroquinoline 1-oxide (4-NQO) were investigated in male F344 rats. The compounds were tested alone and in combination. At 6 weeks of age, animals were divided into experimental and control groups and fed diets containing 1000 ppm diosmin and 1000 ppm hesperidin and a diet containing both compounds (900 ppm diosmin and 100 ppm hesperidin). At 7 weeks of age, all animals except those treated with each test chemical alone and control groups were given 4-NQO (20 ppm) in the drinking water for 8 weeks to induce oral cancer. Starting 7 days before the 4-NQO exposure, groups of animals were fed the diets containing test chemicals for 10 weeks and then switched to the basal diet. Starting 1 week after the cessation of 4-NQO exposure, the groups given 4-NQO and a basal diet were switched to the diets containing diosmin, hesperidin, or diosmin combined with hesperidin and maintained on these diets for 22 weeks. The other groups consisted of rats given diosmin (1000 ppm), hesperidin (1000 ppm), and the combination regimen of these two compounds (900 ppm diosmin with 100 ppm hesperidin) alone, and untreated rats. All animals were necropsied at the termination of the study (week 32). The incidences of tongue lesions (neoplasms and preneoplasms), polyamine levels in the tongue tissue, and cell proliferation activity estimated by a 5-bromodeoxyuridine-labeling index and by morphometric analysis of silver-stained nucleolar organizer regions protein were compared among the groups. Feeding of both compounds singly or in combination during the initiation phase caused a significant reduction in the frequency of tongue carcinoma [diosmin, 68% reduction (P < 0.01); hesperidin, 75% reduction (P < 0.005); and the combination regimen, 69% (P < 0.05)]. When fed the test compounds singly or the combination regimen after 4-NQO exposure, the frequency of tongue cancer was also decreased [diosmin, 77% reduction (P < 0.005); hesperidin, 62% reduction (P < 0.05); and the combination regimen, 77% (P < 0.005)]. The incidences of oral preneoplasia (hyperplasia and dysplasia) in these groups were also decreased when compared with carcinogen controls (P < 0.05-P < 0.001). There were no pathological alterations in rats treated with test compounds or the combined regimen alone or those in an untreated control group. Dietary administration of these compounds significantly decreased the expression of cell proliferation biomarkers (5-bromodeoxyuridine-labeling index and silver-stained nucleolar organizer regions protein number) of the nonlesional tongue squamous epithelium (P < 0.05). Also, polyamine concentrations in the oral mucosa were lowered in rats given the carcinogen and test compounds, alone and in combination, compared with those of rats given 4-NQO alone (P < 0.05). These findings suggest that supplementation with the flavonoids diosmin and hesperidin, individually and in combination, is effective in inhibiting the development of oral neoplasms induced by 4-NQO, and such inhibition might be related to suppression of increased cell proliferation caused by 4-NQO in the oral mucosa.

[Respiratory function in students who had asthma in childhood].

Students who had asthma in childhood can be divided into three groups: "asthma-remission" group "asthma-relapsing" group and "non-asthma-remission" group. When we made inquiries about three different groups, the incidence of each group was 58%, 27% and 15%, respectively. In order to determine if childhood asthma affects respiratory function in adulthood, we measured respiratory functions by spirometry in 26 students who had asthma in childhood, and in seven control students. There was no significant difference between students with childhood asthma and control students in terms of FEV1.0% of predicted value. However, students who had asthma in childhood had lower levels of V25/HT% of predicted value in comparison with control students. The effects of deep inhalation in the three groups were evaluated by determining the values of maximal expiratory flow at 40% (MEF40) of vital capacity from partial (P) and maximal (M) flow-volume curves. There was no difference between the remission group and the control group in the MEF40 M/P ratio. This suggests that childhood asthma may deteriorate respiratory functions in adulthood by remodeling of peripheral airways.

Identification and characterization of monocyte subpopulations from patients with bronchial asthma.

Monocytes are inflammatory cells that accumulate in the airway in asthma. Monocytes constitute a heterogenous cell population in normal subjects. The heterogeneity of monocytes from nine patients with mild asthma and nine normal subjects was studied by means of discontinuous density gradient centrifugation with use of bovine serum albumin. The rate of low-density monocytes recovered from patients with asthma was higher than that obtained from normal subjects. The functional activity of monocyte fractions from asthmatic and control subjects was assessed by using the release of interleukin-1 beta (IL-1 beta) and the intensity of lysosomal enzymes, such as acid phosphatase and nonspecific esterase. The low-density cells produced less IL-1 beta than did cells of higher density in normal subjects. The IL-1 beta release was increased in low-density monocytes from subjects with asthma when compared with the same fraction from normal subjects (p < 0.01). The low-density monocytes had a higher activity of lysosomal enzymes than did cells of higher density in both asthmatic and normal subjects. Electron microscopic studies showed that low-density monocytes from the subjects with mild asthma appeared to have the morphologic characteristics of activated cells with more vacuoles in this periphery. This study shows that low-density monocytes from subjects with asthma retain the ability to be activated in vivo and in vitro and may orchestrate immune reactions in mild asthma.