Hyperfine structure and isotope shifts of neutron-rich138?146Cs

1979

The 6s2S1/2-7p 2P3/2 transition in138–142Cs (λ=455.5 nm) has been investigated by high-resolution collinear laser spectroscopy in a fast atomic beam. The isotopes are obtained by on-line mass separation of fission products. Nuclear moments and changes of mean-square charge radii are derived from hyperfine structure and isotope shift.

Mononuclear heterocyclic rearrangements. Part 12. Rearrangement of 1,2,4-oxadiazoles into indazoles

1979

The first example of a mononuclear heterocyclic rearrangement involving an XYZ = CCN side-chain sequence is reported. The 3-(o-aminophenyl)-, and 3-(o-methylaminophenyl)-5-methyl-1,2,4-oxadiazoles (3a,b) gave a thermally induced rearrangement into 3-acylaminoindazoles (4a,b). On the other hand, the 3-(o-acetylaminophenyl)-5-methyl-1,2,4-oxadiazole (3c) produced a base induced rearrangement into 3-acetylaminoindazole (4a).

Centralizers and Multilinear Polynomials in Non-Commutative Rings

1979

Histologische und histoautoradiographische Untersuchungen zur Wanddicke und zum Zellumsatz am interponierten Hundedünndarm nach totaler Gastrektomie

1979

Total gastrectomy was performed on purebred beagle dogs and a 30--40 cm jejunal segment was grafted isoperistaltically between oesophagus and duodenum. Histological and histoautoradiographical examinations were carried out and the wall-thickness and the cell-transformation rate in the interponate determined. Despite the isoperistaltic substitute-stomach a muscular wall-hypertrophy of 140% of the interponated jejunum was found. The reason for this hypertrophy is thought to be the result of adhesions and the functional mechanical demands. Histoautoradiographical examinations confirmed that the regeneration time in the substitute-stomach decreased by 70% compared with the normal jejunum. The d…

Translationsstrukturen, die weder axial noch zentral sind

1979

Oligosaccharide and Ganglioside Neuraminidase Activities of Mucolipidosis I (Sialidosis) and Mucolipidosis II (I-Cell Disease) Fibroblasts

1979

Fibroblasts cultured from the skin of patients with the genetic diseases mucolipidosis I and mucolipidosis II were found deficient in a neuraminidase specific for both an α23 and and α2 6 type of neuraminosyl linkage of sialyl oligosaccharides. Obligate heterozygotes (parents) showed an intermediate activity in mucolipidosis I, but a normal one in mucolipidosis II. The neuraminidase activity of mucolipidosis I fibroblasts towards gangliosides, measured at pH 4.5 in the presence of Triton X-100, was within the range of normal controls with gangliosides Gm3 and GD3, but somewhat diminished with a bovine brain ganglioside preparation. In mucolipidosis II, neuraminidase activity was markedly de…

Ion storage technique for very long living states: The decay rate of the 5D 3/2 state of Ba II

1979

The metastable 5D 3/2 state of Ba+ is used to demonstrate the possibility of the ion storage technique for the measurement of extremely long lived states. The ions are confined in a r.f. quadrupole trap and excited by a strong pulsed tunable dye laser to the 6P 1/2 state which partially decays into the 5D 3/2 state. Sampling of the time development of the ground state population leads to the determination of the 5D 3/2 decay rate. Using He as a buffer gas at a pressure of about 10−6 mbar to initially store the ions, varying the gas density and extrapolating to zero pressure, we find for the lifetime $$\tau _{D_{3/2} } = 17.5 \pm 4s$$ .

An experimental study of the antineutron-light nucleus annihilation at 1.4 GeV/c

1979

The heavy liquid bubble chamber, Gargamelle, has been used to investigate the gross features of the annihilation of antineutrons in light nuclei (mainly Carbon). Results are presented on the distributions of multiplicity, momentum and emission angle for charged pions and protons together with a simple model to describe them.

Identification and quantitation of trace amounts of barbiturates with glass capillary gas chromatography

1979

Pre-chromatographic reactions are no longer a necessary evil. Equipment such as the microrefluxer now allows reproducible 7-μl-reactions to be carried out in a short time. Thus multiple derivatisations can be used together with glass capillary GC for routine identifications. The method has been succesfully applied to barbiturates. Retention data of their methyl-, allyl- and benzyl-derivatives are given. Quantitative blood level determinations are briefly discussed.

Singlet-groundstate magnetism in TbP

1979

Elastic neutron scattering and magnetic susceptibility data are reported for temperatures around the Neel-point,TN=7.3 K, and for zero magnetic field. AboveTN, the temperature dependence of the magnetic central peak intensity can adequately be described within the RPA assuming isotropic exchange between nearest and next-nearest neighbours as the only parameters. This two-parameter model is quantitatively confirmed by the susceptibility data. AtTN, magnetic Bragg-intensities arise almost discontinuously (reaching 70% of the saturation within 0.1 K) accompanied by thermal hysteresis. For all temperatures belowTN the sublattice magnetic moment is explained by solutions of meanfield equations, …

Pan African plate tectonics and its repercussions on the crust of northeast Africa

1979

Pan African belts of the African mainland and the Arabian-Nubian Shield exhibit evolutionary features which are either compatible with intracontinental ensialic development or with plate margin and Wilson cycle tectonics during the time period ∼ 1100–500 Ma ago.

Biosynthesis and transformation of 20α 21-dihydroxycholesterol by rat adrenal preparations

1979

Abstract The biosynthesis of [ 3 H]-20α, 21 dihydroxycholestderol from [ 3 H]-20α-hydroxycholesterol and its transformation to [ 3 H]-21-hydroxypregnenolone by rat adrenal preparations has been demonstrated. 20α-Hydroxycholesterol was transformed to 20α, 21-dihydroxycholesterol by microsomal preparations in the presence of NADPH and 20α-21-dihydroxycholesterol was metabolized to 21-hydroxypregnenolone by mitochondrial preparations in the presence of a NADPH-generating-system. Comparison of the Michaelis-Menten-Kinetics of the steps “20α, 21-dihydroxycholesterol → 21-hydroxycholesterol” and “20α-hydroxycholesterol → pregnenolone” revealed that both compounds behaved as analogue substrates of…

On the incidence of blood group O and Gm(-1) phenotypes in patients with malignant melanoma.

1979

Fifteen polymorphic systems of the blood (ABO, MNSs, Rhesus, P, Kell, Duffy, Kidd, Hp, Gc, Gm, Inv, aP, PGM1, EsD, and 6-PGD) were examined in 191 unrelated male and female patients suffering from malignant melanoma. These polymorphic systems were compared with the corresponding phenotype and gene frequencies of controls from the same geographical area (Rhineland-Palatinate). The only associations discovered were the ABO and Gm polymorphisms: The incidence of O and Gm(-1) phenotypes in patients is obviously higher than in controls. These observations agree with the findings in other population samples from Germany and Bulgaria.

IgE in patients with glomerulonephritis and minimal-change nephrotic syndrome

1979

Serum levels of IgE were studied in 30 children with minimal-change nephrotic syndrome and 32 children with mesangioproliferative glomerulonephritis during different stages of the disease and treatment. In addition, tissue obtained by renal biopsy was investigated by immunofluorescence histology; no deposits of IgE could be found. The serum IgE levels, however, were increased, particularly in patients with minimal-change nephrotic syndrome. It is concluded that IgE does not play a pathogenic role in the development of the renal disease, but that increased IgE levels are an indication of a disturbance of the immune system.

Gelchromatographische refraktionierung, 1. Ein verfahren zur korrektur von gelchromatogrammen

1979

A mathematical method is proposed for calculating the gel chromatogram w(v0) after correction with the instrument spreading function D(v, v0) and for calculating D(v,v0) using experimental data on the basis, that a gel chromatographic polymer fraction of the chromatogram e(v) is collected and injected again. The chromatogram of this fraction c(v) can be described by the integral equation: where v0 is the elution volume and v1 is the volume at which the fraction is collected. The solution of this equation simultaneously with Tung's equation by way of minimizing is suggested.

Field Desorption Mass Spectra of Gastrine Peptides and Glutathione Derivatives

1979

Oligopeptides comprising the sequence of the C-terminal tetrapeptide of gastrine, Trp-Met-Asp-Phe-NH2, and several derivatives of glutathione, γ-Glu-Cys(SR)-Gly, were characterized by field desorption mass spectrometry. The field desorption mass spectra obtained at various field ion emitter temperatures reveal abundant molecular ions and fragmentation reactions that yield partial sequence information. In the series of glutathione derivatives investigated, characteristic ions formed by cleavage of the γ-Glu-Cys peptide bond determine the substituent at the Cys residue and can therefore be used to identify corresponding conjugation products of drug metabolites with glutathione.

On a conjecture about class numbers of totally positive quadratic forms in totally real algebraic number fields

1979

Zusammenfassung Mittels einer fruheren Klassenzahlabschatzung fur quadratische Formen wird als Verallgemeinerung einer Vermutung von Siegel bewiesen, das Geschlechter totalpositiver Formen mit mindestens drei Variablen und vorgegebener Klassenzahl nur in endlich vielen totalreellen algebraischen Zahlkorpern vorkommen. Bei binaren Formen folgt mit einer neuen Klassenzahlformel aus der verallgemeinerten Riemannschen Vermutung dieselbe Aussage. Ohne Annahme einer Hypothese gilt, das die Anzahl der totalreellen Korper eines festen Grades mit totalpositiven binaren Formen vorgegebener Klassenzahl endlich ist.

ATTUALI ORIENTAMENTI NELLA DIAGNOSTICA DELLA MALATTIA DI HIRSCHSPRUNG

1979

Gli Autori analizzano l'ier diagnostico nella malattia di Hirschsprung sulla base del quadro clinico e dell'età del paziente

Lack of a diurnal plasma adenosine 3',5'-monophosphate rhythm.

1979

Abstract Plasma cAMP levels were measured using a protein- binding radioassay in nine healthy volunteer subjects over a period of 24 h under standardized conditions and also after an hour of orthostatism. No circadian variations of cAMP in plasma were observed. After orthostatism, however, there was a significant rise in cAMP concentrations.

Shear behaviour of undiluted polyisobutylenes

1979

Some new data in shear flow are presented for two commercial polyisobutylene samples, namely Vistanex LMMH and L 100. In particular beyond a few steady state results, the tangential stress build-up after a sudden imposition of a shear rate and the decay after cessation of steady shear flow have been collected. The data are used to further test a constitutive equation already advanced by some of the authors. The comparison seems to confirm the validity of the proposed model, whose single adjustable parameter is shown to be independent of molecular weight.

Existenzsätze für schwach nichtlineare Operatorgleichungen und Anwendung auf Randwertaufgaben mit gewöhnlichen Differentialgleichungen

1979

With Schauder's fixpoint principle we establish an existence theorem for solutions of two simultaneous nonlinear operator equations of the formL iu=Miu, i=1,2, Li linear,M i continous. By applying this result to boundary value problems with ordinary differential equations we generalize results of Conti and Ehrmann in various directions.

On the mechanism of catalytic isomerization of xylenes. Molecular orbital studies

1979

Abstract On the basis of CNDO/2 molecular orbital calculations, we postulate the following detailed mechanism for the catalytic isomerization of xylenes which explains the initial product distributions and also our previous finding that the reaction is intramolecular: (i) adsorption of xylene on a surface acid site to form a Wheland-type complex; (ii) disrotatory cyclization of the protonated species into a bicyclo[3, 1, 0]hexenyl complex; (iii) migration of the methylene bridge to a new side of the pentagonal ring; (iv) change of the new bicyclic species back into the corresponding Wheland-type complex; (v) desorption of the xylene isomer from the surface of the catalyst. The overall rate …

The fine structure of denervated and reinnervated muscle spindles: morphometric study of intrafusal muscle fibers.

1979

The fine structure of normal, denervated, and reinnervated muscle spindles in lower lumbrical muscles of rats was studied morphometrically at time intervals ranging from 3-14 months. In control spindles, the mean transverse area of mitochondria was estimated to be more than twice as large in nuclear chain than in typical nuclear bag fibers. Following denervation, there was a severe decrease of the mean number and transverse area of mitochondria, and a moderate, but statistically significant decrease of the mean transverse area of intrafusal muscle fibers (IMFs) despite an increase of the number of IMFs. At 12-14 months of reinnervation, changes of the transverse areas of IMFs were statistic…

false

1979

false

1979

false

1979

Polarographische Untersuchungen an monomeren und polymeren N-Chlorcarbonamiden

1979

The polarographic reduction of low molecular and high molecular N-chlorocarboxamides at the dropping mercury electrode proceeds in two one-electron-transfer steps, which are highly irreversible. In the case of the low molecular models 1 and 2 the reaction is diffusion-controlled, whereas in the case of the poly(N-chloroamide) 3 the reaction is adsorption-controlled. Reduction of several poly(N-chloroamide)s shows always two reduction waves with a distance of 0,5 V. There is, however, no relation between the polyamide-type and the position of the half-wave potentials. The polarographic reduction can be used as an analytical method for quantitative determination of N-chlorocarboxamide groups …

NMR Matrix Technique for Detecting Self Diffusion in Polymers

1979

A technique is discussed where monodisperse small spheres or cylindrical fibers of a polymer are embedded in a matrix of the corresponding fully deuterated polymer. On annealing the sample at a temperature above the glass transition the protonated macromolecules diffuse into the deuterated matrix and vice versa. Since the NMR spectrum depends upon the intermolecular proton proton dipolar coupling, the decrease of this coupling can be used to monitor the diffusion process. For particle diameters d ∼ 10−4 cm and annealing times t ∼ 105 s, extremely small diffusion constants D < d2/t are attainable. The NMR analysis of prospective diffusion experiments with polystyrene is discussed in some det…

Nebenreaktionen der radikalisch ausgelösten Cyclisierung von 2,2′-Methylen-bis(4-methyl-1,2-phenylen)-dimethacrylat

1979

2,2′-Methylene-bis(4-methyl-1,2-phenylene) dimethacrylate (1) was reacted with an excess of 2,2′-azoiso-butyronitrile (mole ratio 1:15) highly diluted in boiling benzene. The reaction products were separated by column chromatography. It was found that the 1-cyano-1-methylethyl radical induced the cyclization of 1 to yield the product of a head to tail addition (2) in 55% yield. In addition, the product of a head to head addition (3) was isolated in 4% yield. 35% of 1 reacted in the same way as it has already been observed as suppression of polymerization in the case of p-tolyl methacrylate to give the products 4 and 5. The structures of the products were confirmed by elemental analyses, by …

Thymic transplantation for relief of immunodeficiency diseases.

1979

Tremendous advances have been made in replacement therapy regimens for the correction of immunodeficiency in transplant patients. Recently, cultured thymic fragments were shown to be devoid of lethal graft-versus-host cells and research in this area indicates that thymic transplantation may have a sustained positive effect in immunosuppressed patients.

L'extension de l'offre d'enseignement supérieur : causes ou conséquences des scolarisations

1979

International audience

The Vesalian movement in sixteenth-century Spain.

1979

In the middle of the sixteenth-century under the direct influence of Vesalius's works there arose in Spain a movement devoted to the renewal of anatomical knowledge. It was one of the initial forces in the spread of the Vesalian reform, but in spite of that it has been almost completely ignored by specialized historical research.' The purpose of this article is to provide a general study of the movement with special emphasis on the conditions which determined its development. In the first place I should make it clear that the renewal in question did not arise from the relationship that Vesalius maintained throughout

Investigation of beta strength functions by neutron and gamma-ray spectroscopy

1979

Abstract Neutron spectra from the decay of the β− delayed neutron precursors 55.6 sec 87Br, 24.5 sec 137I, 2.05 sec 85As and 1.71 sec 135Sb have been studied with high resolution 3He ionization chambers. By γ-ray measurements, the partial neutron emission probabilities to excited states in 84Se and 134Te have been determined independently. For the neutron-emitter nuclei 87Kr and 137Xe, from which neutron decay proceeds only to the ground states of the final nuclei, 86Kr and 136Xe, unique information on the shape of the β− strength function Sβ(E) is obtained. For the emitter nuclei 85Se and 135Te, correlations between neutron transition energies and differences in level energies in 84Se and …

Inelastische Lichtstreuung von Polymeren in Lösung, Schwerpunktstransport und Polymolekularität

1979

Mittels der inelastischen Lichtstreuung wurden zwei Polystyrol-Praparate mit M = 200000 und 670000 und vier aus diesen Substanzen zusammengesetzte Mischungen in Toluol bei 20 °C vermessen. Die im Winkelbereich 11° ≤ ϑ≤40° aufgenommenen Autokorrelationsfunktionen wurden dazu benutzt, verschiedene Bestimmungsverfahren von z-Mitteln von Potenzen des Reibungs- und Diffusionskoeffizienten zu testen. Experimentell gelang es bei den Mischungen lediglich die ersten Potenzen dieser Grosen zu ermitteln. Diese werden zusammen mit den Reibungs- bzw. Diffusionskoeffizienten der einzelnen Komponenten zur Charakterisierung der Parameter der Molekulargewichtsverteilung der Mischungen benutzt. Inelastic lig…

Dynamical Scaling in Polymer Solutions Investigated by the Neutron Spin-Echo Technique

1979

Chain dynamics in polymer solutions was investigated by means of the recently developed neutron spin echo spectroscopy. — By this technique, it was possible for the first time to verify unambiguously the scaling predictions of the Zimm model in the case of single chain behaviour and to observe the cross over to many chain behaviour. The segmental diffusion of single chains exhibits deviations from a simple exponential law, indicating the importance of memory effects. Mit Hilfe der erst kurzlich entwickelten Neutronen-Spin-Echo-Spektroskopie wurde die Kettendynamik von Polymermolekulen im gelosten Zustand untersucht. - Die Methode eroffnete die Moglichkeit, zum ersten Mal fur das Einzelkette…

Hepatitis B virus markers among family contacts of asymptomatic HBsAg carriers.

1979

A study was undertaken to establish the risk of family contacts of HBsAg carriers acquiring a hepatitis B virus (HBV) infection. About one-third of all household contacts of asymptomatic HBsAg carriers had signs of past or ongoing HBV infection. Family contacts of HBsAg carriers with high numbers of circulating Dane particles were shown to have a higher risk of developing HBV infection than family contacts of HBsAg carriers without serological evidence of HBV synthesis. The probability of acquiring HBV infection was not different between spouses, parents, children, and brothers and sisters, respectively of asymptomatic HBsAg carriers.