The polystyrene affinity of methylglycosides,deoxysugars and glucooligosaccharides

The partition coefficients K _av of methylglycopyranosides, deoxysugars and glucooligosaccharides for partition between polystyrene gel and aqueous solvent systems were determined. Each group of sugars showed widely different polystyrene affinities and these affinities increased markedly in NaCl solution but were eliminated in 50% methanol. The K _av for methyl-D-mannoside (10.6) was remarkably greater than those of methyl--D-glucoside (3.0) and methyl--D-galactoside (2.2). Another notable feature was that the polystyrene affinity was affected by the position of the OH-H substitutions in deoxysugars and by the type of the glucosidic linkages of glucodisaccharides. The inspection of the overall K _av spectrum together with the accessible surface data of sugar molecules suggests that the hydrophobicity of sugars is determined by a set of several factors including CH-surface area, hydration effect of OH groups and molecular planarity and rigidity.     

Preparation and Characterization of Branched β-Cyclodextrins Having Manno-Oligosaccharide Side Chains Derived from Yeast Mannan and Study of Their Functions

Branched -cyclodextrins (-CDs) having manno-oligosaccharide side chains were investigated. Three kinds of monobranched -CDs and five kinds of dibranched -CDs were chemically synthesized using the trichloroacetimidate method. Their structures were analyzed by HPLC, MS, and NMR spectroscopies. The specific interaction between those compounds and mannose-binding lectins (Concanavalin A and Pisum sativum agglutinin) was investigated by inhibition tests of hemagglutinating activity and by using an optical biosensor of the IAsys apparatus with a resonant mirror detector. The results showed that all branched -CDs interactedwith lectins. The binding affinity was 6¹,6⁴-(Man₃)₂- 6¹,6⁴-(Man₂)₂- > 6¹,6⁴-(Man₄)₂--CD when the derivatives were compared on the basis of side chain length and 6¹,6³- 6¹,6⁴- > 6¹,6²-(Man₂)₂--CD when compared on the basis of side chain position.     

The polymorphism of copper-oxinate crystal

Summary a) Polymorphs Copper-oxinate dihydrate has three different crystal forms, namely, α-, γ-, Β-form. The γ-form is an intermediate crystal form in the course of the α → Β transformation in aqueous suspension. They gave three anhydrous polymorphs respectively, that is, the α′-,γ′- and Β′-forms by the dehydration and they are all transformed into the most stable anhydride (Β∼-form). The Β′-form is also precipitated directly from the solution at about boiling temperature. The relationships among the various crystal forms are also discussed. b) Crystal structure The cell dimensions of the γ-form dihydrated crystal are assumed to be a=13.10 ?. b=8.33 ?, c=9.49 ? and Β=106‡. The Β′-form anhydride has the following lattice Constants a=12.25 ?, b=3.78 ?, c=14.95 ? and Β=98.6‡ with the space group P2/c(C _2h ⁴ ).

---

Zusammenfassung a) Polymorphismus Kupferoxynat-Dihydrat hat drei verschiedene Kristall-formen, n?mlich die Alpha-, Gamma- und Beta-form. Die Gamma-Form ist eine intermedi?re Kristallform im Verlauf der Umwandlung von der Alpha- in die Beta-Form in w?\riger Suspension. Diese Umwandlungen ergeben 3 polymorphe Anhydrite, n?mlich die Alpha-, Gamma- und Beta-Form durch Dehydrierung, und sie alle gehen über in die stabilste Anhydritdibeta-Form. Die Beta-Form f?llt auch direkt aus der L?sung etwa bei der Siedetemperatur aus. Die Beziehung zwischen den verschiedenen Kristallformen wird ebenfalls diskutiert. b) Kristallstrukturen Die Parameter der Elementarzelle der Gamma-Form des dihydrierten Kristalls werden zu α=13,10 ?, b=8,3 ?, c=9,49 ? und Β=106‡ festgestellt. Die Beta-Form des Anhydrits hat die folgenden Gitterkonstanten α=12,2 ?, b=3,38 ?, c=14,95 ? und Β=98,6‡ und die Raumgruppe P2/c(C _2h ^7/4 ).

     

Precise measurements of bulk-wave ultrasonic velocity dispersion and attenuation in solid materials in the VHF range

A general method was established for precisely measuring velocity dispersion and attenuation in solid specimens with acoustic losses in the very high frequency (VHF) range, using the complex-mode measurement method and the diffraction correction method. Experimental procedures were presented for implementing such a method and demonstrated this measurement method in the frequency range of 50-230 MHz, using borosilicate glass (C-7740) as a dispersive specimen and synthetic silica glass (C-7980) as a nondispersive standard specimen. C-7980 exhibited no velocity dispersion; velocity was constant at 5929.14 +/- 0.03 m/s. C-7740 exhibited velocity dispersion, from 5542.27 m/s at 50 MHz to 5544.47 m/s at 230 MHz with an increase of about 2 m/s in the measured frequency range. When frequency dependence of attenuation was expressed as alpha = alpha(0)f(beta), the results were as follows: alpha0 = 1.07 x 10(-16) s2/m and beta = 2 for C-7980 and alpha0 = 5.16 x 10(-9) s(1.25)/m and beta = 1.25 for C-7740.     

Usefulness of MR-seminography using Gd-DTPA in intermediate magnetic field MRI equipment

T(2)-weighted fast advanced spin-echo imaging with gadolinium (hereinafter referred to as "MR-seminography") of the genital tract was evaluated for its usefulness in non-invasive investigation into the morphology of these organs. Twenty healthy male volunteers who are confirmed as free of genital tract obstruction were entered into the study. The genital tract was imaged using the 0.5 T MRI system by fast advanced spin echo (FASE) method. Based on quantitative evaluation, visibility evaluation, and the visualization of the genital tract in each subject, the contrast-enhanced images were assessed in comparison with those at pre-injection of the contrast agent by four specialists. Also examined were the morphology of the seminal vesicle according to age group using "Ishigami-Mori's classification," and the age angle of the main ducts. MR-seminography produced high contrast images and revealed a significantly decreased signal in the pelvic organs under investigation. In the analysis of individual subjects, the area from the proximal portion of the vas deferens to the ampulla and the seminal vesicles was on the whole well visualized except for the distal portion of the vas deferens and the ejaculatory duct. With regard to seminal vesicle morphology, type II was predominant. The age angle showed a trend toward widening with age. MR-seminography is non-invasive, useful, and therefore a highly recommended procedure for observation of the morphology in the area from the proximal portion of the vas deferens to the seminal vesicle.     

Einfluß von Wasser auf die anionische Polymerisation von α-substituiertem Acrylat

Ohne Zusammenfassung