Observation of millimeter-wave radiation generated by the interaction between an electron beam and a photonic crystal.

We observed directional light emission in the millimeter-wave region when a high-energy (150 MeV) electron beam passes just above a photonic crystal made of polytetrafluoroethylene beads ( approximately 3.2 mm in diameter). The relation between the momentum and the energy of the emitted photons strongly suggests that the observed light is generated by the umklapp scattering process that changes the evanescent waves emitted by the electron beam into observable ones. By comparing the observed spectra with calculated ones based on the photonic band structure, we found that generated photons excite the photonic band modes making them observable as enhanced fine structures in the emission spectra.

Simultaneous electroanalysis of peroxyacetic acid and hydrogen peroxide.

The electrochemical behavior of peroxyacetic acid (PAA) in the presence of hydrogen peroxide (H2O2) has been investigated using cyclic voltammetry and hydrodynamic techniques [rotating disk electrode (RDE) voltammetry and rotating ring-disk electrode (RRDE) voltammetry]. The results have been analyzed aiming at simultaneous electroanalysis of both species. Glassy carbon and gold electrodes were used for this investigation. It was found that the reduction of PAA, as well as H2O2, is highly sensitive to the electrode material; for example, at 100 mV s-1, the reduction peak potentials of PAA were 0.2 and -1.1 V at gold and glassy carbon electrodes, respectively. The well-separated steady-state limiting currents were obtained using a gold electrode for the reduction of both PAA and H2O2 and also a well-defined one for the oxidation of H2O2. On the basis of the RDE experiments, good calibration curves were obtained for both species over a wide range of their concentrations, for PAA and H2O2 in the range of 0.36 to 110 and 0.11 to 34 mM, respectively. The simultaneous and selective electroanalysis of PAA and H2O2 in their coexistence is demonstrated for the first time.

Electroanalytical applications of cationic self-assembled monolayers: square-wave voltammetric determination of dopamine and ascorbate.

Gold electrodes modified with cationic self-assembled monolayers (SAMs) of 2,2'-dithiobisethaneamine (CYST) and 6,6'-dithiobishexaneamine (DTH) were used for the simultaneous determination of dopamine (DA) and ascorbate (AA). The cationic SAM modified electrodes have several advantages over the bare electrode for the oxidation of AA. A very large (approximately 450 mV) decrease in the overpotential for the oxidation of AA when compared with the bare electrode has been observed at the cationic monolayer-modified electrode. The electrostatic interaction of negatively charged AA with the monolayer shift the oxidation peak potential of AA to less positive potential and enhances the peak current. On the other hand, the positively charged DA is repelled from the monolayer and the oxidation potential shifts to more positive potential when compared to the bare electrode. The electrochemical oxidation of AA at the mixed monolayer of CYST and diethyl disulfide (DEDS) supports the influence of cationic terminal group of the monolayer on the oxidation of AA. Since the oxidation of AA occurs well before the oxidation potential of DA is reached, the homogeneous catalytic oxidation of AA by the oxidized DA has been advantageously eliminated at the monolayer-modified electrode. The cationic self-assembled monolayers successfully detect DA in the presence of high concentration of AA. The sensitivity of the electrode modified with CYST monolayer was found to be 0.036 and 0.021 microA/microM towards AA and DA, respectively.

Facilitated electrochemical oxidation of NADH and its model compound at gold electrode modified with terminally substituted electroinactive self-assembled monolayers.

The electrochemical oxidation of NADH and its model compound, N-benzyl-1,4-dihydronicotinamide (DHN), has been studied at gold electrode modified with self-assembled monolayer of terminally substituted thiols/disulfide, i.e., cystamine (CYST), mercaptopropionic acid (MPA) and mercaptoethanol (ME). A substantial decrease in the overpotential (approximately 250 mV) when compared to the bare electrode has been observed for the oxidation of NADH at the monolayer-modified electrodes, containing no so-called redox mediator. The bare electrode shows an ill-defined voltammetric peak for the oxidation of DHN, whereas the monolayer-modified electrodes showed a well-defined voltammetric peak. The monolayer assembly on the gold electrode prevents the fouling of electrode surface by the oxidation products, which favors the oxidation at the less positive potential. The square-wave voltammograms showed a sharp voltammetric signal for the oxidation of NADH at all the monolayer-modified electrodes. All the monolayer-modified electrodes showed a linear current response to change in the NADH concentration in its range of 25-300 microM and their sensitivities were found to be 0.005+/-0.0003, 0.0063+/-0.0002 and 0.0052+/-0.0003 microA/microM for CYST-Au, ME-Au and MPA-Au electrodes, respectively. The hydrodynamic voltammograms obtained at the rotating CYST-Au electrode for the oxidation of NADH and DHN were used to estimate the diffusion coefficient of DHN, and the number of electrons involved in the oxidation process of NADH.

Electrocatalytic oxidation of NADH at the self-assembled monolayer of nickel(II) macrocycle on gold electrode.

Electroactive self-assembled monolayers (SAMs) of macrocyclic Ni(II) complex (1) were fabricated on gold electrode and its electrochemistry has been studied in different supporting electrolytes. Substantial stabilization of tervalent nickel and a significant negative shift of formal potential of the Ni(3+/2+) couple have been observed when the supporting electrolyte is changed from nitrate to phosphate. Coordination of supporting electrolyte anion with the Ni(III) complex shifts the formal potential and thus tervalent nickel is stabilized. SAM of 1 electrode shows an excellent electrocatalytic activity towards the oxidation of NADH in aqueous NaNO3 solution, whereas it scarcely catalyzes the oxidation of NADH in aqueous phosphate buffer solution. The electrocatalytic oxidation of NADH in Na2SO4 solution is less efficient than that in NaNO3 solution. The anion-dependent electrocatalysis has been discussed on the basis of the difference in the coordinating ability of the anions with the tervalent nickel centers. Steady-state current has been measured for the oxidation of NADH and it was proportional to the concentration of NADH.

Anti-obesity effects of lipase inhibitor CT-II, an extract from edible herbs, Nomame Herba, on rats fed a high-fat diet.

OBJECTIVE: To investigate the inhibitory effects of CT-II, extract of Nomame Herba, on lipase activity in vitro and on obesity in rats fed a high-fat diet in vivo. DESIGN: The assay for the inhibitory effect of CT-II on lipase activity was performed by measuring released free fatty acids after the incubation of the medium with CT-II, porcine pancreatic lipase and triolein (experiment 1). In vivo experiments, lean rats or obese rats (570-718 g) were fed a high-fat diet containing 60% fat with or without CT-II for 8 weeks (experiment 2), for 14 days (experiment 3) or for 12 weeks (experiment 4), respectively. MEASUREMENT: The time course of body weight, food intake, organ weight (parametrial fat, liver, heart and kidney) and plasma parameters (triglyceride, total cholesterol, glucose, AST, ALT and insulin), fecal output of total fat and total cholesterol were measured. Hepatic histological examinations were also performed. RESULTS: CT-II inhibited the porcine lipase activity dose-dependently in vitro (experiment 1). Body and liver weight were reduced and hepatic histological examination showed an amelioration of fatty liver in CT II treated animals (experiment 2). CT-II significantly inhibited body weight gain and plasma triglyceride elevation in a dose-dependent manner, without affecting food intake in lean rats fed the high-fat diet. Elevated plasma AST and ALT were also decreased (experiment 3). When obese rats fed the high-fat diet were treated with CT-II for up to 6 months, body weight was initially reduced and thereafter weight gain was significantly suppressed. Total body fat was also significantly reduced and significant reduction of plasma AST and ALT was observed (experiment 4). CONCLUSIONS: These results demonstrated that the lipase inhibitor CT-II is effective in preventing and ameliorating obesity, fatty liver and hypertriglyceridemia in rats fed a high-fat diet.

[Alcohol-related problems in mortality in middle-aged urban-dwelling men from cerebro-cardiovascular diseases].

A survey was performed of the life-styles and medical histories of men, who died of cerebro-cardiovascular diseases at ages between 40 and 64 years in Hirakata, Neyagawa, Moriguchi and Kadoma cities in Osaka prefecture. Data was available on 127 of 172 men who died in 1988. Of these, 28 had histories of alcohol-related problems. Analysis showed that the amount of alcohol consumed was associated with disease history and serious alcohol-related problems. 1) Histories of hypertension, cerebrovascular and liver disease were found more often in heavy drinkers with a daily alcohol intake exceeding the equivalent of 46 g pure ethanol compared to either moderate drinkers with a daily alcohol intake of less than 46 g or abstainers. 2) Of 28 subjects with alcohol-related problems, one had been treated at a specialized alcoholic-clinic, two had been admitted to psychiatric hospitals and one subject had consulted a physician at a mental health clinic of the public health center in his community. 3) Although 18 of the 28 subjects with alcohol-related problems had their own regular doctors, they did not appear to have received adequate care. 4) Subjects with alcohol-related problems had histories of cerebrovascular and liver diseases more often than those without alcohol-related problems. 5) Subjects with alcohol-related problems were confronted with unemployment, divorce and housing problems more often than those without alcohol-related problems. With the increasing amount of alcohol consumption in Japan, alcohol-related problems need more attention. There is an urgent need to establish community-based strategies for prevention of alcohol-related problems and to organize a network of multi-disciplinary support teams for those with problems such as alcoholics in urban communities.

[Occupational skin hazards in hairdressers and their etiologic factors--results of mass health examination at health centers].

From 1986 to '88, mass health examinations for skin disorders among hairdressers were performed in 4 Health Centers in Osaka Prefecture. Among 306 female hairdressers examined, the prevalence of skin lesions was 49.0%, consisting of skin lesions of hands and arms alone 22.9%, nail lesion alone 13.7%, and both 12.4%. Characteristic features of the skin lesions were dryness, roughness, thickening of epidermis, redness, hyperkeratinization, scales, desquamation, etc. In the case of nails, thinning, onycholysis, onychoschisis, pitting, transverse grooves and onychorexis were characteristic. The relationship between prevalence of skin disorders and site of lesions to history or category of work was studied. For the prevention of these skin hazards, improved chemicals, equipment, and hygienic education are necessary. Periodical health-checks including participation by a dermatologist, and health supervision should be continued with cooperation between Health Centers and beauty salons, because these businesses are principally small-size enterprises.

[Regional distribution of perfusion and ventilation in hamartoangiomyomatosis of the lung].

We investigated regional distribution of perfusion and ventilation in three cases of hamartoangiomyomatosis (HAM) by 133Xe gas and 99mTc-MAA. In two cases, 133Xe washout were dominantly delayed in middle lung field and in the third case, it was delayed in upper lung field. This distribution was different from the result in the other chronic obstructive pulmonary disease (COPD). In most cases of COPD, 133Xe washout was prominently delayed in the lower lung field. Distribution of pulmonary perfusion in HAM were consistent with that of ventilation as in COPD.

Lipoprotein cholesterol concentrations in patients with Behçet's disease.

Serum cholesterol concentrations among very low, low, and high density lipoproteins (VLDL, LDL and HDL) in 12 male patients with Behçet's disease were compared with those of 12 normal male subjects. Serum lipoproteins were separated by a combination of ultracentrifugation and gel filtration chromatography. The patients had significantly (p less than 0.001) lower concentrations of HDL-cholesterol than the control subjects (356 +/- 62 mg/l vs. 573 +/- 108 mg/l, means +/- SD). The cholesterol concentrations in apolipoprotein B-containing lipoproteins (VLDL and LDL) from the patients tended to be reciprocally higher than those of the controls, though not statistically significant. There was no difference in serum total cholesterol concentrations. The chemical composition of HDL from the patient group was characterized by higher protein and lower cholesterol (both esterified and free) contents compared with the control HDL.

2-Arylidene-4-cyclopentene-1,3-diones designed as non-nitro radiosensitizers and hypoxic cytotoxins.

The radiosensitizing effects and hypoxic cytotoxicity of 2-(4'-hydroxybenzylidene)-cyclopentene-1,3-dione (KIH-200) and its 3'-methoxy and 3',5'-dimethoxy derivatives (KIH-201 and KIH-202) were investigated in vitro. These synthetic compounds were newly designed as non-nitro electron-affinic radiosensitizers and hypoxic cytotoxins on the basis of their high electron affinities and electrostatic potentials which were estimated by semiempirical molecular orbital calculation using the CNDO/2 program. The compounds were shown to have weak but apparent hypoxic cytotoxicity to FM3A cells from C3H mice. On irradiation in the presence of KIH-201 or KIH-202, hypoxic cells were more sensitive than aerobic cells at very low drug concentrations (below 10 microM), whereas KIH-200 was less effective.