Thermal and photochemical reactions of a stable thiobenzaldehyde, 2,4,6-tri-t-butylthiobenzaldehyde

Thermal and photochemical reactions of the title compound gave benzothiolane $\text{2}$ in high yield; the reaction with free radicals also afforded $\text{2}$ along with some other products.     

Vince alkaloids XXXIV). Preparation of des-Na-methyl-vindoline by microbiological conversion of vindoline, a major alkaloid from Vinca rosea L

The conversion of vindoline (II) using S. albogriseolus led to the isolation of several compounds including des-N_a-methyl vindoline (III) in 8–10% yield.     

Gamma-rays from an incomplete fusion reaction induced by 95 MeV 14N

Gamma-rays from the ${}^{159}\text{Tb}\text{(}{}^{14}\text{N}\text{, αx}\text{n}\text{)}{}^{\mathrm{169?x}}\text{Yb}$ reaction, in which non-evaporation α-particles are emitted, have been identified. Yields of E2 cascade transitions suggest that the angular momentum distribution of the entrance channel leading to this reaction is localized just above the critical angular momentum for complete fusion.     

Derivation of the effective potential

A simple derivation of the effective potential for single and composite operators is given. Green functions under general constraints are considered and compact expressions for derivatives of the effective potential are given.     

Solution properties of high molecular weight polystyrene

A series of polystyrenes with weight-average molecular weight M?_w up to 1.3 × 10⁷ was prepared by anionic polymerization in tetrahydrofuran (THF). Each sample was characterized by gel-permeation chromatography, light scattering, and viscometry. It was found that each sample had an almost symmetrical and very narrow molecular weight distribution (M?_w/M?_n < 1.07). The mean-square unperturbed radius of gyration 〈S²〉₀ was determined in trans-decalin at 20.4°C as 〈S²〉₀ = 7.8₆ × 10^?18M?_w (cm²). The particle scattering factor was well represented by the Debye equation irrespective of solvent in the range of M?_w < 4 × 10⁶, and only a small deviation was observed in benzene at higher molecular weights. The penetration function Ψ ≡ A₂M²/4π^3/2N_A〈S〉^23/2 was found to approach a relatively low asymptotic value of 0.21–0.23 at molecular weights above 2 × 10⁶ in benzene at 30°C, where A₂ is the second virial coefficient and N_A is Avogrado's number. It was also found that the theta temperature in trans-decalin was affected by the nature of polymer samples. A difference of about 3°C in the theta temperature was observed between two series of anionic polystyrenes, one prepared in THF and the other in benzene, but there was practically no difference in unperturbed chain dimension.     

Experimental studies on clinical application of 13N-ammonia; a metabolic model and functional image based on animal experiment

Ammonia has been known to be an inducing agent of hepatic coma associated with liver cirrhosis. In order to establish a non-invasive method of investigating the portal circulation and the metabolism of ammonia at liver the following studies were performed, by using cyclotron produced 13N-labeled ammonia and delayed line-camera interphased with on-line computer system. 1) Animal experiment. Dynamic scintigraphy of thoraco-abdominal region of a rabbit after intrasigmoidal as well as intravenous administration of 13N-ammonia were performed. 2) Theoretical consideration on the functional image of liver: According to the results of the animal experiments, a model of ammonia metabolism having the minimal complexity necessary to represent data in the case of intrasigmoidal administration was proposed. Starting from the solution to the differential equation describing the model, relevant parameters characterizing the dynamic curve of liver were duded.     

Carbon-13 NMR chemical shift and electronic structure of polypeptide as studied by tight-binding MO theory: poly (β-benzyl L-aspartate) with the right-handle α-helix and left-handed α-helix forms

An attempt was made to calculate ¹³C NMR chemical shifts of poly(β-benzyl L-aspartate) having the right-handed α-helix (α_R-helix) and left-handed α-helix (α_L-helix) forms by a tight-binding MO sum-over-states theory within the extended Hückel framework, in order to examine whether or not the conformation-dependent ¹³C chemical shifts previously determined by the cross polarization-magic angle spinning technique are reproduced by a change of electronic structure of the polymer. It is found that the relative displacements of the observed C_α, C_β and carbonyl ¹³C chemical shifts between the α_R- and α_L-helices are reproduced qualitatively by the calculation.