Effects of various triamines on cell-free polypeptide synthesis of Escherichia coli and on growth of its polyamine auxotrophs

The effects of various synthetic triamines having a general structure, H2N(CH2)xNH(CH2)yNH2, where x = 2-5 and y = 2-8 (abbreviated, x-y; with 3-4 being spermidine itself), on poly(U)-directed polypeptide synthesis of Escherichia coli and on growth of its polyamine-requiring mutants were examined in comparison with those of spermidine. Except for 2-2 and 2-3, all of the triamines stimulated more or less polypeptide synthesis at suboptimal Mg2+ concentrations, but the Mg2+ concentration required for the maximal stimulatory effect was different for each triamine. The degree of maximal stimulation caused by 3-3 (norspermidine), 4-4 (homospermidine), or 4-5 was nearly comparable with that by spermidine. The acetylspermidines were inactive, however, they inhibited the spermidine-stimulated polyphenylalanine synthesis. Many of the triamines examined reduced the ratio of leucine to phenylalanine incorporation into polypeptides during poly(U)-directed translation, and the degree of this effect did not necessarily correspond with that of the stimulatory effect. Moreover, 2-4, 2-5, 3-3 and 4-4 could stimulate the growth of a polyamine auxotroph of E. coli, MA 261, as effectively as did spermidine. However, 3-3 was the only triamine which could fully replaced spermidine in promoting growth of a mutant strain, KK 101, which is more dependent on polyamines than MA 261. Thus, these results demonstrated that some synthetic triamines were as active as spermidine in eliciting these effects, and also that there were some differences among these effects in the structural requirement for triamine.     

Reactions of group IV organometallic compounds : XXVII. Some reactions of [(trimethylsilyl)imino]phosphorane

The reaction of [(trimethylsilyl)imino]methyldiphenylphosphorane: Ph₂MePNSiMe₃ (I) with several acid anhydrides or alkyl isocyanates took place by the simple cleavage of silicon-nitrogen bond. In contrast the interaction of (I) with phenyl isocyanate, isothiocyanate or carbon disulphide led to addition-elimination reactions of the Wittig type. Detailed investigation in the case of phenyl isocyanate indicated the usual elimination of Ph₂MePO is suppressed by the strong affinity of the trimethylsilyl group for anionic oxygen atom.     

Potential acting on the trapped electron

If the absorption of a trapped electron can be shown to correspond to bound—free transitions, it should be possible to calculate the potential acting on the trapped electron inversely from its absorption spectrum. In this paper we present the method of calculating the potential acting on a trapped electron from the observed absorption spectrum.     

Synthesis of 8,9-dialkoxy-substituted tetrahydrobenz[h] isoquinolines

6,7-Dimethoxy-2-naphthylethylamine, prepared by the diborane reduction of 6,7-dimethoxy-2-naphtlialeneacetamide, underwent a Pictet-Spengler cyclization to form 8,9-dimethoxy-1,2,3,4-tetrahydrobenz[h]isoquinoline. This compound is identical with that obtained by reduction of the corresponding dihydrobenzisoquinoline prepared from formamide cyclization. 6,7-Dialkoxy-2-naphthaleneacetic acids, the key intermediates for the preparation of these amides, were obtained from 6,7-dialkoxy-2-acetonaphthones by a modified Willgerodt reaction.     

Public education in nuclear science at the Kyushu Museum of Energy in Japan

The Kyushu Museum of Energy, funded by the Kyushu Electric Power Company, Inc., was opened in September 1982. The planning and design were done by Dentsu, Inc., and the actual construction was shared among several construction and manufacturing companies. I was retained as the principal scientific advisor for the museum, both prior to its construction, throughhout the planning of the exhibits, and afterwards when it was opened to the public. This is an educational museum, which shows how people have developed and depended on energy and energy sources since the discovery of fire in prehistory. There are four major sections, devoted to fire itself, electricity, nuclear power by fission, and nuclear power by fusion. In addition, the museum will track visitors through the exhibits, in terms of The History of Energy as a beginning point for their tour, lead them through Present Energy Needs and Uses, and thence to Future Energy Developments and Needs. The museum is of a hands-on active display type design, with many large and attractive display panels, working models, pleasant mixes of sound, light, and images, and educational levels that encompass general public interest to semitechnical explanations that will satisfy the undergraduate with a technical, background. Visitors can not only operate the models themselves, but join in a variety of games based on energy consumption, usage, and needs. It is very much a participatory museum, and visitors are exposed to the many facets of day-to-day energy generation and consumption, as well as the estimated needs for the future, and possible ways to supply these needs. To date, there have been well over 200,000 visitors recorded. *** DIRECT SUPPORT *** A0653119 00004     

Extraction behaviors of Eu,Th, U and Am with diamides+thenoyltrifluoroacetone

N,N-dimethyl-N,N-dihexyl-3-oxapentanediamide, DMDHOPDA, N,N-dihexyl-3-thiopentanediamide, DHTPDA and N,N-dihexyl-3-oxapentanediamide, DHOPDA were synthesized and tested for the synergistic extraction of Eu³⁺, Th⁴⁺, UO ₂ ²⁺ , NpO ₂ ⁺ and Am³⁺ with thenoyltrifluoroacetone (HTTA). Although Eu³⁺, Th⁴⁺, UO ₂ ²⁺ and Am³⁺ were not extracted by DHTPDA or DHOPDA alone, they were extracted synergistically when combined with HTTA. Analysis of the dependency of extraction on pH and extractant concentration indicated that the dominant extracted species were Eu(TTA)₃(A), Th(TTA)₃(A)(X), UO₂(TTA)₂(A) and Am(TTA)₃(A) (where A is diamide, and X is chloroacetate or ClO ₄ ^– ).     

Thermal denaturation of some proteins and its effect on their electrospray mass spectrat

The effects of beat on the electrospray mass spectra of eight globular proteins in solution were studied. These ranged from hardly noticeable to a dramatic shift in the mass spectrometric profile and a concomitant increase in ion abundance. This change is believed to be the result of thermal denaturation of the protein species in solution resulting in a transition from a more compact to a less compact conformation. We accounted for this transition by means of a recently proposed model based on aqueous solution acid/base equilibria. For cytochrome c, profiles calculated by means of this model agree well with experimental data. The ΔH of the denaturation reaction of cytochrome c in aqueous solution containing 0.2% acetic acid was calculated from experimental data to be 103.8 ± 9.2 kJ mol^?1, in good agreement with previous measurements.