Showing papers by "University of Jena published in 1981"
TL;DR: In this article, high-resolution 27AI NMR spectra of polycrystalline aluminates have been studied at 70.4 MHz and magic-angle spinning was used to reduce quadrupole effects and dipolar interaction.
332 citations
TL;DR: In this paper, the authors established inequalities between entropy numbers and approximation numbers for operators acting between Banach spaces, and derived inequalities between eigenvalues and entropy numbers for operator acting on a Banach space.
196 citations
TL;DR: In this article, the variations in the structure and optical properties of TiO2 films produced by reactive d.c. plasmatron sputtering with the most important deposition parameters are investigated.
100 citations
TL;DR: In the American cockroach, the distribution and connections of neuronal elements of the terminal ganglion-proctodeal nerve-hindgut system were investigated by means of immunohistochemical methods and axonal CoCl2 iontophoresis and strong proctolinlike immunoreactivity was found.
Abstract: In the American cockroach, the distribution and connections of neuronal elements of the terminal ganglion-proctodeal nerve-hindgut system were investigated by means of immunohistochemical methods and axonal CoCl2 iontophoresis. Proctolinlike immunoreactivity was localized within neurons of the terminal ganglion projecting into the proctodeal nerve on the one hand, and in nerve cells without a direct connection to this system on the other. Immunohistochemically, in whole mount preparations fibres of the proctodeal nerve and terminal structures in the hindgut musculature exhibit strong proctolinlike immunoreactivity. At the light- and electron-microscopic levels the pathways of about 30 somata of the proctodeal neural system were characterized by cobalt chloride iontophoresis. The relationships of cobalt filled and immunoreactive neuronal structures are discussed.
79 citations
01 Jan 1981
47 citations
TL;DR: Siccayne apparently interferes with the uptake of nucleoside precursors into eucaryotic cells as well as with the in vitro incorporation of nucleotides into DNA and RNA.
Abstract: From submerged cultures of the marine basidiomycete Halocyphina villosa we isolated siccayne (4-(2,4-dihydroxyphenyl)-2-methyl-1-buten-3-yne) (1), a metabolite first described from fermentations of the deuteromycete Helminthosporium siccans. Siccayne is a moderately active antibiotic, which inhibits Gram-positive bacteria and some fungi at concentrations of 10 approximately 50 micrograms/ml. Its cytotoxic effect is much more pronounced on both normal and Rous-sarcoma-virus transformed chicken embryo fibroblasts as compared to cells of the Ehrlich ascites carcinoma. Siccayne apparently interferes with the uptake of nucleoside precursors into eucaryotic cells as well as with the in vitro incorporation of nucleotides into DNA and RNA.
41 citations
TL;DR: In this paper, the mean number of intersection points of stationary fiber processes in the plane with arbitrary curved lines of finite total length is calculated from the intensity and angle distribution of the fiber process and the angle distribution on the curved line.
Abstract: Intersections of stationary fibre processes in the plane with arbitrary curved lines of finite total length are considered. It is shown that the mean number of intersection points can be calculated from the intensity and angle distribution of the fibre process and the angle distribution of the curved line. Conversely, if the mean number of intersection points is known for all positions of the cuived line? then it is possible to determine the intensity and angle distribution of the fibre process.
35 citations
TL;DR: A new technique is presented for the anastomosis of microvessels, using only a tissue adhesive (Fibrinkleber, Human-Immuno, produced by Immuno A. G. Vienna) without sutures, demonstrated experimentally on the femoral artery and vein in rats.
35 citations
TL;DR: In this paper, a steady-state product distribution containing CCl4, C2Cl4 and glow polymer as main products is formed via recombination processes, and the influence of plasma power density on this product distribution is given by gas-chromatographic results.
Abstract: The decomposition of CCl4 in an rf discharge starts by a very fast electron attachment mechanism
$$\begin{gathered} CCl_4 \xrightarrow{{ + e}}(CCl_4^ - ) \to CCl_3 + Cl^ - \hfill \\ \hfill \\ k_0 \hfill \\ \end{gathered}$$
A first-order rate constant, (k0 · ne) ≈ 10+2−10+3 s−1, is estimated by two-channel time-resolved emission spectroscopy. The ability of the method to detect the change of concentrations in plasma processes is discussed. A steady-state product distribution containing CCl4, C2Cl4, C2Cl6, Cl2, and glow polymer as main products is formed via recombination processes. The influence of plasma power density on this product distribution is given by gas-chromatographic results.
34 citations
TL;DR: In this paper, a theoretical treatment of the influence of a saturable absorber in close contact with a highly reflecting mirror on a light pulse is given, and the shaping of a Gaussian pulse during a single passage through such an absorber is calculated for various absorber lengths.
Abstract: A theoretical treatment of the influence of a saturable absorber in close contact with a highly reflecting mirror on a light pulse is given. The shaping of a Gaussian pulse during a single passage through such an absorber is calculated for various absorber lengths. The influence of absorber position and length on the pulse parameters and the stability of a continuously pumped dye laser are investigated. The shortest pulses and the most favourable operation conditions of the laser are to be expected in the case of a short contacted saturable absorber.
TL;DR: The formation of radiation damage in LiNbO3 crystals implanted at room temperature with N+, O+ and Ne+ ions, was analyzed by RBS, density and refractive index measurements.
TL;DR: The photochemical E-Z isomerization of the benzophenone-9-anthraldehyde azine (1) and 9-acridine aldehyde (2) is thermally reversible as discussed by the authors, and the thermal reaction gives the same isomers as the photochemical reaction.
TL;DR: In this paper, the light and electron microscopic findings of four cases of malignant fibrous histiocytoma (MFH) of bone were presented, in case 1 multiple bone tumors were observed and in case 4 the tumor developed after irradiation.
Abstract: Malignant fibrous histiocytoma (MFH) of bone is a well-defined tumor by light microscopy but no agreement has been achieved concerning its histogenesis. We present the light and electron microscopic findings of four cases of MFH of bone. In case 1 multiple bone tumors were observed and in case 4 the tumor developed after irradiation. It was our aim to document the cytological variability and to arrange the findings in a histogenetic concept of primary intraosseous MFH. We observed some undifferentiated cells but mainly histiocyte- and fibroblast-like cells including intermediate forms, and several types of giant cells. We should emphasize the fact that there were also some large cells with a light microscopic resemblance to rhabdomyoblasts and with electron microscopic characteristics of myoblastic differentiation. From the ultrastructural point of view, therefore, MFHs seem to derive from a primitive mesenchymal stem cell rather than from the ordinary histiocyte. It is suggested that osteosarcoma and MFH of bone may have a common progenitor cell but it is important to make a clear clinico-pathological distinction between the tumors because of differing biological behavior.
TL;DR: Aniline as well as sodium benzoate, though not metabolized by strain H, cause a concentration-dependent inhibition of phenol degradation in resting phenol-grown cells of that strain.
Abstract: In order to characterize the ability of Pseudomonas putida (TREVISAN 1889) MIGULA 1895 strain H to degrade various mono- and diphenolic aromatic compounds, respiratory activities towards phenol, catechol, and the cresol isomers were determined. The following rates of oxygen uptake (QO2) were obtained with resting phenol-grown cells: phenol -- 229, o-cresol -- 231, m-cresol -- 43, p-cresol -- 200, catechol -- 262. All these compounds were oxidized by a two-phase-kinetics, the first phase is characterized by a higher oxidation rate than the second. The oxidation of phenol as well as of p-cresol was found to be substrate-inhibited at concentrations above 0.25 mM. A Ki-value of 100 mg/l was calculated for phenol oxidation. The phenol-degrading enzyme system is induced, probably coordinately, by phenol and the cresol isomers. In strain H the degradation of phenol is carried out simultaneously with the assimilation of natural carbohydrates like glucose and sodium pyruvate. Aniline as well as sodium benzoate, though not metabolized by strain H, cause a concentration-dependent inhibition of phenol degradation in resting phenol-grown cells of that strain. The mechanism of this inhibition is discussed.
TL;DR: Triphenylformazan does not exhibit photochemical conversion of the red cis-syn form into the yellow cis-anti isomer nor does this reaction proceed thermally as reported previously.
01 Jun 1981
TL;DR: In this article, the authors evaluated two-phase properties in bubble column reactors with porous plate (5 μm pore diameter) or perforated plate (1 mm and/or 3 mm hole diameter) gas distributors using distilled water or a 1% methanol solution.
Abstract: The following two-phase properties were evaluated in bubble column reactors with porous plate (5 μm pore diameter) or perforated plate (1 mm and/or 3 mm hole diameter) gas distributors using distilled water or a 1% methanol solution: transverse profiles of the mean and Sauter bubble diameters, local gas holdups, true mean liquid and bubble velocities. Furthermore, swarm bubble velocity distributions were evaluted and compared with calculated values.
TL;DR: In this paper, equilibrium geometries, vibrational frequencies and normal coordinates have been calculated quantum chemically for the strained ring compound cycl oheptatriene and its phenyl substituted derivatives.
Abstract: Equilibrium geometries, vibrational frequencies and normal coordinates have been calculated quantum chemically for the strained ring compound cycl oheptatriene and its phenyl substituted derivatives. The calculated geometry of cycloheptatriene agrees with the experimental one. The 1-, 2- and 3-phenyl substituted derivatives have a more nearly planar shape for the seven membered ring than cycloheptatriene itself. Comparison with the experimental vibrational frequencies of cycloheptatriene and 7-d-cycloheptatriene results in a satisfactory interpretation of the vibrational spectra. The three carbon—carbon stretching frequencies of the cycloheptatriene π-system show only minor effects caused by phenyl substitution.
TL;DR: In this paper, the deformation of a crystal plate with a step-like distribution of dilatation centres is calculated according to the isotropic theory of elasticity, and analytical expressions for quantities which are interest for interpreting and calculating X-ray intensity distributions are derived and discussed.
Abstract: The deformation of a crystal plate with a step-like distribution of dilatation centres is calculated according to the isotropic theory of elasticity. Analytical expressions for quantities which are interest for interpreting and calculating X-ray intensity distributions are derived and discussed.
Die Deformation einer Kristallplatte mit einer stufenahnlichen Verteilung von Dilatationszentren wurde nach der isotropen Elastizitatstheorie berechnet. Es wurden analytisch Ausdrucke fur Grosen abgeleitet und diskutiert, welche bei der Interpretation und Berechnung von Rongtenstrahl-Intensitatsverteilungen von Interesse sind.
TL;DR: In this article, the analogy between the ray-optical theory of X-ray diffraction in distorted crystals and mechanics gives the possibility to explain qualitatively the contrast in section topographs of crystals containing one-directional varying lattice-plane distances.
Abstract: The analogy between the ray-optical (Eikonal) theory of X-ray diffraction in distorted crystals and mechanics gives the possibility to explain qualitatively the contrast in section topographs of crystals containing one-directional varying lattice-plane distances. The formation of topographic contrasts is discussed for the example of a step like varying lattice-plane distance. Experiments show a fairly good correspondence of the main characteristics to the predicted ones. In the case of strong absorption interference fringes are found similar to I3 fringes of stacking faults predicted by Epelboin.
Das mechanische Analogon der geometrisch-optischen Beschreibung (Eikonaltheorie) der Rontgenstrahlinterferenzen in gestorten Kristallen ermoglicht eine qualitative Interpretation des Kontrasts von Sektiontopogrammen an Kristallen, deren Netzebenenabstand in einer Richtung ortsabhangig ist. Die Kontrastentstehung wird am Beispiel eines stufenformig ortsabhangigen Netzebenenabstands diskutiert. Experimente zeigen eine gute Ubereinstimmung der wesentlichen Eigenschaften mit den vorausgesagten. Im Fall starker Absorption werden Interferenzstreifen beobachtet, die den von Epelboin vorhergesagten I3-Streifen an Stapelfehlern entsprechen.
Journal Article•
TL;DR: The results indicate that the bile acid dependence of the hepatobiliary transport of ICG is influenced by age, and the ICG excretion was enhanced only in adult animals.
Abstract: In rats of different ages bile flow and biliary excretion of indocyanine green (ICG) were estimated in dependence on bile acid excretion. In 20, 30, 60 and 180 day old rats bile acid excretion was diminished to a quarter of the control by pretreatment with cholestyramine (1.5 g/kg b.wt.). To enhance bile acid excretion, taurocholate sodium (TC, 50 mg/kg b.wt.) was given together with the dye. Bile acid depletion diminished the bile flow to a greater extent in young rats, which were found to have a higher bile acid dependent fraction of canalicular bile flow (60%) compared to 60 (35%) and 180 day old rats (20%). After bile acid depletion the decrease in ICG excretion was more pronounced in 30 and 60 day old rats which exhibit highest dye excretion rates. TC was able to enhance the bile flow in all age groups investigated, however, the ICG excretion was enhanced only in adult animals. Our results indicate that the bile acid dependence of the hepatobiliary transport of ICG is influenced by age.
TL;DR: Specific activity and Ca2+-affinity of (Ca2++Mg2+)ATPase of calmodulin-depleted ghosts progressively increase during preincubation with 0.1–2 mM Ca2+.
01 Jan 1981
TL;DR: The influence of the microorganisms on the oxygen transfer rate is discussed especially in the case of glucose repression.
Abstract: Hansenula polymorpha was cultured for extended periods in an air lift tower loop reactor (15 cm in diameter with a 275 cm bubbling layer height) with ethanol and/or glucose as the substrates. At constant operation conditions variations of the following parameters were measured: the consumption of the substrate and oxygen, the production of CO2 and biomass, the longitudinal concentration profile of dissolved oxygen, the oxygen and substrate yield coefficients, the respiratory quotient and the specific interfacial area and volumetric mass transfer coefficient. The influence of the microorganisms on the oxygen transfer rate is discussed especially in the case of glucose repression.
TL;DR: In this article, high-resolution 13C NMR spectra of solid poly(1,4-phenylenevinylene), poly( 1,4phenylene-1,2-diphenylvinylene) and three related, substituted polymers (CN, OCH3, O) were obtained with a combined technique of heteronuclear decoupling, cross-polarization and magic angle spinning.
Abstract: High-resolution 13C NMR spectra of solid poly(1,4-phenylenevinylene), poly(1,4-phenylene-1,2-diphenylvinylene) and of three related, substituted polymers (CN, OCH3, O) were obtained with a combined technique of heteronuclear decoupling, cross-polarization and magic angle spinning. The reported chemical shifts were assigned by means of solid model compounds (trans-stilbene, trans, trans-1,4-distyrylbenzene, tetraphenylethylene). Utilizing the high sensitivity of 13C NMR chemical shifts to chemical structure, this method is applied to structure confirmation, the determination of sp3-defects in poly(phenylenevinylene)s PPV, and the determination of sterical and electronical effects of phenyl and phenylene groups.
TL;DR: In this article, the dislocation density in KDP crystals has been determined by X-ray diffraction topography (LANG method) and a method for determining the laser damage thresholds in dependence on dislocations density is described.
Abstract: The dislocation density in KDP crystals has been determined by X-ray diffraction topography (LANG method). A method for determining the laser damage thresholds in dependence on dislocation density is described. It is found that dislocations with a density about 103 cm−2 reduce the laser damage threshold up to a factor of two compared with perfect regions. It is shown that experimentally measured damage results can be explained theoretically.
Die Versetzungsdichte in KDP Kristallen ist mit Hilfe der Rontgentopografie (LANG-Methode) bestimmt worden. Eine Methode zur Bestimmung der Laserdamage-Schwellen in Abhangigkeit von der Versetzungsdichte wird beschrieben und festgestellt, das Versetzungen mit einer Dichte von etwa 103 cm−2 die Laserdamage-Schwelle bis zum Faktor zwei verringert, verglichen mit einem perfekten Gebiet. Es wird gezeigt, das die experimentell ermittelten Ergebnisse theoretisch gedeutet werden konnen.
TL;DR: In this article, a mixed-state model of F-centres is used to give evidence of the occurrence of two-photon absorption in KCl, and the results, especially the unchanged fluorescence decay, are discussed on the basis of the mixed state model.
Abstract: Picosecond light pulses are used to give evidence of the occurrence of two-photon absorption of F-centres in KCl. The results, especially the unchanged fluorescence decay, are discussed on the basis of the mixed-state model of F-centres.
Unter Verwendung von Pikosekunden-Impulsen wird das Auftreten einer Zwei-Photonen-Absorption durch F-Zentren in KCl nachgewiesen. Diese Ergebnisse, insbesondere das unveranderte Fluoreszenzabklingen, werden auf der Basis des F-Zentren-Modells gemischter Zustande diskutiert.