Development of a graphic program for quantitative drug design

A graphic program for quantitative drug design is described; it is used for the design stage of candidate compounds after a regression equation has been established for estimation of biological potencies in the Hansch—Fujita and Free—Wilson methods. Information flow is controlled by function-key and concomitant alphanumeric-key operations. In the program, substituents are easily introduced into a parent structure, and a perspective molecular model of the resulting derivative is displayed. Conformational changes of a molecule can be followed by rotating atomic groups. The data bank contains 337 possible substituents with 20 physicochemical parameter values and constituent atomic coordinates for each substituent. Examples are shown to illustrate the program.     

Application of arsenic to electrophotoreceptors

Arsenic has been applied to many electronic devices such as electrophotoreceptors, gallium arsenide (GaAs) semiconductors and solid-state image pickup devices. For electrophotoreceptors selenium–arsenic (Se? As) alloys are coated onto the conductive substrate of the receptors. Arsenic is mostly used in electophotoreceptors in electronic devices. During the coating process, a part of the gaseous arsenic is released through an exhaust system. In order to avoid arsenic being discharged to the atmosphere, bag filters and high-efficiency particulate air filters are set before the exhaust port. Any arsenic which still exists in the waste water after washing tools and jigs from the coating process is collected by sedimentation before discharging. The Ames salmonella/microsome plate test for As₂Se₃ indicated no mutagenic activity under the test system used. For the safety of workers engaged in arsenic-related jobs, they received a medical examination once every six months. No negative trends from the examination was found in 428 men who received the examination from Autumn 1980 to Spring 1987.     

Four-line method for correction of inter-element effects on excitation and ionization processes in atomic emission spectrometry in plasmas

A four-line method is described for correction of inter-element effects caused by variations of excitation temperatures and the degree of ionization in a plasma. Four lines with different upper-level energies in the atomic-ionic system are compared. The total number of atoms and ions is used as the response instead of the spectral intensity. Plasma torch symmetry is one of the most important factors for successful corrections. The correction method is demonstrated for the determination of manganese in a capacitively coupled plasma torch, where strontium interferes strongly.     

Ca2+- and Ba2+-selective receptors based on site-selective transmetalation of multinuclear polyoxime-zinc(II) complexes

Ca2+-selective recognition was achieved by using the site-selective transmetalation of homotrinuclear metallohost [L1Zn3]2+ containing a linear tetraoxime ligand. The selectivity (log(KCa/KMg) > 5.1) is comparable to those of the excellent Ca2+ receptors or sensors such as BAPTA, Quin2, and K23E1. X-ray crystallography revealed that the Ca2+ complex [L1Zn2Ca]2+ has a helical structure. On the other hand, the larger analogue H6L2 gave a mixture of [L2Zn4]2+ isomers, which selectively recognizes Ba2+ to give a single tetranuclear complex, [L2Zn3Ba]2+.     

Integral Formulas for the Minimal Representation of O(p,2)

The minimal representation of O(p,q) (p+q: even) is realized on the Hilbert space of square integrable functions on the conical subvariety of R^p+q–2. This model presents a close resemblance of the Schrödinger model of the Segal–Shale–Weil representation of the metaplectic group. We shall give explicit integral formulas for the inversion together with the analytic continuation to a certain semigroup of O(p+2,C) of the minimal representation of O(p,2) by using Bessel functions.Mathematics Subject Classifications (2000) primary 22E30; secondary 22E46, 20M20, 43A80.     

A novel method for the terpene synthesis by the ring-opening reaction of β-methyl-β-propiolactone

A new route for the terpene synthesis is investigated, which undergoes via terpene carboxylic acids as key intermediates obtained by the regiospecific ring opening of β-methyl-β-propiolactone with a cuprate or with a Grignard reagent in the presence of a copper catalyst.     

Caesium-selective PVC membrane electrodes based on bis(crown ether)s

Caesium-selective PVC membrane electrodes based on bis(crown ether)s containing benzo-18-crown-6 moieties were prepared using two kinds of plasticizers. Selectivity coefficients for various interfering monovalent ions were determined by the mixed solution method, and were found to relfect the complexing property and extractability of the bis-(benzo-18-crown-6)s. The electrochemical selectivity was also compared with that of the corresponding monocyclic analog and valinomycin.