Time-resolved fluorometric analysis of carbohydrates labeled with amino-aromatic compounds by reductive amination

We examined the formation of complexes between terbium ion (Tb3+) and carbohydrates labeled with aminobenzene compounds. Of the examined compounds, carbohydrates labeled with 4-aminosalicylic acid showed intense fluorescence with Tb3+ in the presence of cetylpyridinium chloride at pH 6.0. Calibration curves for maltose derivative showed good linearity between 5 pmol and at least 600 pmol, with good reproducibility. We applied the proposed technique to binding studies between manno-oligosaccharides and Concanavalin A.     

Ultrasonic butt welding of aluminum,aluminum alloy and stainless steel plate specimens

Welding characteristics of aluminum, aluminum alloy and stainless steel plate specimens of 6.0 mm thickness by a 15 kHz ultrasonic butt welding system were studied. There are no detailed welding condition data of these specimens although the joining of these materials are required due to anticorrosive and high strength characteristics for not only large specimens but small electronic parts especially. These specimens of 6.0 mm thickness were welded end to end using a 15 kHz ultrasonic butt welding equipment with a vibration source using eight bolt-clamped Langevin type PZT transducers and a 50 kW static induction thyristor power amplifier. The stainless steel plate specimens electrolytically polished were joined with welding strength almost equal to the material strength under rather large vibration amplitude of 25 microm (peak-to-zero value), static pressure 70 MPa and welding time of 1.0-3.0 s. The hardness of stainless steel specimen adjacent to a welding surface increased about 20% by ultrasonic vibration.     

Prostaglandin analogs modified at the 10 and 11 positions

A simplified methodology for the building of prostaglandins substituted at the 10 and 11 positions is presented.     

Formation of cyclic organosilicon compounds via organopolysilyl anions starting from methoxymethyldisilanes. A mechanistic study

In the presence of a catalytic amount of sodium methoxide, sym-dimethoxytetramethyldisilane was converted into α,ω-dimethoxypermethylpolysilanes, MeO(SiMe₂)_nOMe where n ? 3, at room temperature. On the other hand, similar treatment of the disilane in THF solution gave cyclic polysilanes, (Me₂Si)_n where n = 5–7. Decomposition of the disilane in the presence of diphenylacetylene afforded a trisilacyclopentene derivative under similar conditions. This compound was obtained also by the reaction between α,ω-dimethoxypermethylpolysilanes and diphenylacetylene in the presence of sodium methoxide. These cyclic products most likely were formed via permethyl polysilyl anion intermediates derived from α,ω-dimethoxypermethylpolysilanes. Also, the formation of α,ω-dimethoxypermethylpolysilanes could be elucidated in terms of the mechanism involving the base-assisted, concerted nucleophilic substitution or stepwise substitution by silyl anions, rather than the successive dimethylsilylene (Me₂Si:) insertion reaction.     

Photochemical vapor deposition of amorphous silicon through 185 nm excitation of monosilane

Photochemical vapor deposition of a-Si films at a high rate using SiH₄ and a 185 nm low pressure mercury lamp is described. A maximum rate of 1 nm/sec was attained using the 185 nm lamp. This rate was about ten times higher than that using a 254 nm lamp. Assuming that there is no interaction between the effects of the two wavelengths, the deposition rate per light output power of 184.9 nm light is 160 times larger than that for 253.7 nm light. The absorption cross-section of the 184.9 nm light is ten times greater than that for the 253.7 nm light.     

Tin(IV) chloride-chiral pyrogallol derivatives as new Lewis acid-assisted chiral Brønsted acids for enantioselective polyene cyclization

[reaction: see text] New Lewis acid-assisted Br?nsted acids (LBAs), tin(IV) chloride-2,6-dialkoxyphenols, serve as artificial cyclases for biomimetic polyene cyclization. For example, the enantioselective cyclization of 4-(homogeranyl)toluene using tin(IV) chloride-2,6-di[(1'R,2'R)-trans-2'-(3' ',5' '-xylyl)cyclohexanoxy]phenol gave a trans-fused tricyclic compound with 85% ee.     

Diffusive Logistic Equations with Degenerate Boundary Conditions

The purpose of this paper is to provide a careful and accessible exposition of static bifurcation theory for a class of degenerate boundary value problems for diffusive logistic equations with indefinite weights that model population dynamics in environments with spatial heterogeneity. We discuss the changes that occur in the structure of the positive solutions as a parameter varies near the first eigenvalue of the linearized problem, and prove that the most favorable situations will occur if there is a relatively large favorable region (with good resources and without crowding effects) located some distance away from the boundary of the environment.Dedicated to Professor Mitsuru Ikawa on the occasion of his 60th birthday     

Ten new Lycopodium alkaloids having the lycopodane skeleton isolated from Lycopodium serratum Thunb

Ten new alkaloids, lycoposerramines-F (1), -G (2), -H (3), -I (4), -J (5), -K (6), -L (7), -M (8), -N (9), and -O (10), having lycopodine-related structures, were isolated from the club moss Lycopodium serratum THUNB. and their structures were elucidated on the basis of spectroscopic analysis and/or chemical transformation.     

Champion data comparison in nuclear research institutes in Europe,the U. S., and Japan

Bibliometric analysis was carried out for champion data comparisons among prestigious nuclear research institutes (PNRI) existed in Japan, the U. S., France, and Germany. The analysis was relied on database INIS (IAEA), ECD (DOE), WOS (Thomson), and SCOPUS (Elsevier). INIS is advanced, key ex-post evaluating tool for determining general research paper-based champion. Over the 30-year time span of research paper publication, the world champion among 11 PNRI is JAERI confirmed by INIS but ORNL confirmed by ECD, WOS, and SCOPUS, the latter two collected journal submitted research paper. Five years ago JAERI is the 3rd ranked institutes following ORNL and ANL. INIS database results revealed that CEA/Grenoble is the French domestic champion regarding research paper publication. Five years ago it was CEA/Saclay. Results from analytical tools used in bibliometric studies should be viewed with careful consideration to learn of any influencing factors because different characteristics exhibited by individual databases can sometimes generate conflicting bibliometric results. This was true among INIS, ECD, WOS, and SCOPUS when looking at trends especially between 5-year periods.