Study of the dynamics of excited states in CdS and CuCl by transient grating techniques

Transient grating measurements on sample with an anisotropy or with multiple excited states are described. The general formula for the intensity of the diffracted light from a transient grating in a sample with an anisotropic diffusion coefficient is presented and is applied to CdS. A transient grating spectroscopic technique for a sample with multiple excited states is discussed in detail. In addition to these, the contribution of a population and a thermal grating to the observed signals is discussed.     

Thermodynamics applied to compatibility of UN with Ni,Cr and Fe

The compatibility of UN with Ni, Cr and Fe has been studied from the viewpoint of phase equilibrium relationships. The free energies of formation of UNi₅ and U₂CrN₃ have been determined from the measurement of equilibrium pressures of nitrogen for the reactions, $\text{U}{}_2\text{N}{}_3\text{+ 10 Ni ? 2UNi}{}_5\text{+}\text{3}\text{2}\text{N}{}_2$ and $\text{U}{}_2\text{CrN}{}_3\text{? 2 UN +}\text{1}\text{2}\text{Cr}{}_2\text{N +}\text{1}\text{4}\text{N}{}_2$, respectively, and the values are expressed by $\text{ΔG(UNi}{}_5\text{) = ?67 650 + 22.9T}$, $\text{ΔG(U}{}_2\text{CrN}{}_3\text{) = ? 165 900 + 54.64 T}$. Combination of these and other thermodynamic data with some additional experimental work has generated a log $\text{P}$ versus $\text{1/T}$ diagram which shows the phase relationships in the U-N-Ni-Cr system. It is concluded that UN is not compatible with Ni and Cr simultaneously but, for practical purposes, is compatible with Fe below 1400°C.     

Seroprevalence of Bartonella henselae and Toxoplasma gondii infections among pet cats in Kanagawa and Saitama Prefectures

Seroprevalence of Bartonella henselae and Toxoplasma gondii was investigated among 471 pet cats obtained from seven private animal hospitals in Kanagawa and Saitama Prefectures during the period from May 1994 to June 1995. 'Furthermore, 67 randomly selected from the 471 serum samples were examined for the feline immunodeficiency virus (FIV) antibody and feline leukemia virus (FeLV) antigen. The antibody to B. henselae was examined by an indirect immunofluorescent antibody test. T. gondii, FIV and FeLV infections in cats were detected with respective commercial kits. Of the cat serum samples tested, 43 (9.1%) were found to be seropositive for B. henselae and 41 (8.7%) for T. gondii. The B. henselae-positive rate (12.9%) of male cats was significantly higher than that (5.2%) of female cats. On the other hand, T. gondii-positive rate was 9.1% in male and 8.7% in female cats and there was no significant difference in the positivity between sexes. The positive rate in each hospital varied from 0 to 19.5% for B. henselae and 4.9 to 18.8% for T. gondii. The ages of B. henselae- and T. gondii-positive cats were distributed from < 1-year-old to 14-year-old and the seropositivity increased with age of cats. Of the 67 cat serum samples, 16 and 6 cases were positive for FIV and FeLV, respectively. There was no relationship between these viral and B. henselae infections in cats.     

Aldose reductase inhibitory constituents of the root of Salvia miltiorhiza Bunge

The constituents of the MeOH extract of Salvia miltiorhiza BUNGE, which showed strong aldose reductase (AR) inhibitory activity, were examined, and two new abietane-type diterpenoids, danshenol A (1) and danshenol B (2), were isolated together with six known ones: dihydrotanshimme I (3), cryptotanshinone (4), tanshinone I (5), tanshinone IIA (6), (-)-danshexinkun A (7), and sugiol (8). Among them, 4, 5, and 8 were weak AR inhibitors with IC50 from 4.80 to > 10.0 microM, while 1, 2, 3, 6, and 7 were strong inhibitors (IC50 from 0.10 to 1.75 microM). Danshenol A (1), the strongest inhibitor, had IC50 of 0.10 microM which is comparable to that of epalrestat in clinical use. Moreover, from a consideration of IC50, and yield of each compound, it was concluded that tanshinone IIA (6) is the major active constituent of the MeOH extract and danshenol A (I) and (-)danshexinkun A(7) are the minor ones.     

Auger analysis of thick silver films and of silver layers grown on copper

A sensitive new measure of the line broadening of an Auger doublet, called the R factor, was applied to the growth of (1) thick silver films and (2) thin silver films on a thick copper substrate. It is shown that periodic fluctuations in R with thickness give evidence for monocrystalline layer growth while the absence of such fluctuations is characteristic of polycrystalline growth. By combining measurements of the Auger amplitude and the R factor as functions of the silver film thickness for silver films deposited onto copper, it was shown that a Stranski-Krastanov growth mode is characteristic of the epitaxial growth of Ag(111) on Cu(111) at 210°C. The initial layer in this case is two (111) atom spacings thick on which high flat islands form. Continued growth of these islands is shown to take place by two-atom-thick flat islands.     

Direct Hydroxylation of Methyl Benzoate to Methyl Salicylate by Using New Pd Membrane Reactor

The direct hydroxylation of methyl benzoate was carried out using a newly developed Pd membrane reactor in which the active oxygen species is formed on the surface of Pd by the reaction between oxygen gas and the active hydrogen atoms that permeate through the Pd membrane from the opposite side. By using this Pd membrane reactor system, methyl salicylate showed a 4.7% yield at 423 K. The reaction mechanism was clarified based on the distribution of by-products.     

Relationship between structure and inhibitory effect of arginine analogues on neuronal nitric oxide synthase activity

2,3,5-Trimethyl-6-(3-pyridylmethyl)1,4-benzoquinone (CV-6504), an inhibitor of 5-lipoxygenase and thromboxane A2 synthase and a scavenger of active oxygen species, has been shown to exhibit profound anti-tumour activity against three established murine adenocarcinomas (MACs) that are generally refractory to standard cytotoxic agents. For the cachexia-inducing MAC16 tumour, optimal anti-tumour activity was seen at dose levels of 10 and 25 mg kg-1 day-1, together with a reversal of cachexia and a doubling of the time to sacrifice of the animals through cachexia from 8 days to 17 days. The remaining tumour fragments showed extensive necrosis in regions distal from the blood supply. Growth of the MAC13 tumour was also effectively suppressed at dose levels between 5 and 50 mg kg-1 day-1, resulting in a specific growth delay between 1.0 and 1.2. Growth of the MAC26 tumour was also inhibited a concentration-related manner, with doses of 25-50 mg kg-1 day-1 being optimal. Anti-tumour activity towards all three tumours at low dose levels of CV-6504 was effectively suppressed by concurrent administration of linoleic acid (1 g kg-1 day-1), suggesting that inhibition of linoleate metabolism was responsible for the anti-tumour effect. Tumour sensitivity may be correlated with increased DT-diaphorase that are required to metabolise CV-6504 to the active hydroquinone, which inhibits 5-lipoxygenase activity.     

Aggravation of experimental allergic conjunctivitis by environmental chemical and physical factors

The effects of trichlorfon (DEP, Dipterex, anticholinesterase pesticide) and paraquat dichloride (Gramoxon, inhibitor of superoxide dismutase) on passive anaphylactic reaction in guinea pig conjunctiva using Japanese cedar pollen were quantitatively studied. For estimation of allergic conjunctivitis, Evans blue after i.v. injection was extracted from conjunctiva and measured spectrophotometrically. Allergic conjunctivitis was apparently aggravated by extremely low dosages of organophosphorus pesticide (10(-5) mg/kg) and organochlorine herbicide (10(-4) mg/kg). The aggravation of allergic conjunctivitis was also observed after exposure to cathode ray tubes used in commercial television, possibly due to electromagnetic waves. IgE-mediated allergic reaction could be non-specifically potentiated by such environmental factors.     

Assay for antiviral activity of herbal extracts using their absorbed sera

We evaluated an antiviral assay procedure using serum obtained from guinea pigs administered 32 herbal extracts. In this assay, 21 of the 32 showed anti-herpes simplex virus type 1 (HSV-1) activity in serum. Ten of the 21 exhibited therapeutic anti-HSV-1 activity, and this was consistent with our previous results that 12 of the 32 were effective in murine infection models. Therefore, the serum pharmacological assay procedure was suitable for the selection of possible herbal extracts with biological activity in vivo as a pre-screening method before animal experiments.