Showing papers by "University of Hamburg published in 1970"
316 citations
TL;DR: Both catecholamine analogues markedly reduce neuronal noradrenaline in the large intestine, as demonstrated by fluorescence histochemistry and in fluorimetric determinations.
Abstract: Ganglia from Auerbach's plexus of the large intestine (caecum, appendix vermiformis, colon transversum and rectum) in man, rhesus monkey and guinea-pig are composed of nerve cells and their processes, typical Schwann cells and a vast neuropil. The neuropil consists of dendrites and axons of intrinsic nerve cell perikarya and axons of extrinsic neurons. Axonal profiles in large nerve fibre bundles are of uniform size and appearance, embedded in infoldings of Schwann cell cytoplasm and contain occasional large granular vesicles, mitochondria and neurotubules. Preterminal axons widen into vesicle filled varicosities, some of which establish synaptic contact with intrinsic nerve cell bodies. At least three different types of neuronal processes can be distinguished in the myenteric neuropil according to the size, appearance and commutual proportion of vesicles present in axonal varicosities, and their ability to accumulate exogenous 5- and 6-hydroxydopamine and 5-hydroxydopa: 1. Axonal enlargements containing a major population of small electron lucent “synaptic” vesicles (350–600 A in diameter) together with a small number of membrane-bound, opaque granules (800–1,100 A). These profiles have been identified as “cholinergic” axons. The boutons establish synaptic contacts with dendritic processes of intrinsic nerve cell bodies; membrane specializations are found at the preand postsynaptic sites. 2. Axonal beads of sometimes very large diameter, containing an approximately equal amount of large granular vesicles (850–1,600 A) and small, electron lucent or faintly opaque vesicles (400–600 A). The granular core of the large vesicles is of medium electron density and may either fill the entire vesicle or is separated from the limiting membrane by a more or less clear interspace. The fibres probably belong to intrinsic neurons, and because of the similarity of the large, membrane-bound vesicles with neurosecretory elementary granules, they have been designated “p-type fibres” (polypeptide fibres). The granular core of the vesicles in these fibres becomes more electron dense after treatment with 5-OH-dopa. The accumulation of an amine precursor analogue in combination with a possible storage of a polypeptide substance (or an ATP-like substance) resembles the situation in several diffusely distributed endocrine cell systems. 3. Varicosities of axons equipped with small (400–600 A) empty or sometimes granular vesicles, medium sized (500–900 A) vesicles with highly electron dense cores and occasional large (900–1,300 A) granular vesicles. Pretreatment with 5-OH-dopamine increases the electron density in almost all medium-sized granular vesicles and some of the large granular vesicles; an osmiophilic core develops in some small vesicles. 6-hydroxydopamine results in degenerative changes in the varicosities of this type of neurons. Concomitantly, both catecholamine analogues markedly reduce neuronal noradrenaline in the large intestine, as demonstrated by fluorescence histochemistry and in fluorimetric determinations. The ultrastructural features of these varicosities and their reaction to 5- and 6-OH-dopamine indicate that they belong to adrenergic, sympathetic nerves. No membrane specializations could be detected at sites of close contact of the adrenergic boutons with dendrites and cell bodies of intrinsic nerve cells.
252 citations
TL;DR: In this article, the surface loss of particles with radii of about 50 A is found at 2.99 ± 0.03 eV for silver and 2.34±0.03 EV for gold being in good agreement with calculated values.
Abstract: With 51 keV electrons surface plasma losses have been investigated on small spherical Ag and Au particles embedded in a medium with dielectric constantɛa=2.37. The surface loss of particles with radii of about 50 A is found at 2.99 ±0.03 eV for silver and 2.34±0.03 eV for gold being in good agreement with calculated values. For larger radii the loss shifts to higher energy values which agrees qualitatively with the theory of Fujimoto and Komaki for the free electron gas.
226 citations
TL;DR: In this paper, a compilation of coupling constants and low-energy parameters are given for pi N, KN, NN, YN, and meson-meson scattering, and a comparison of SU(3) comparison and predictions are discussed.
218 citations
TL;DR: In this paper, it is shown that a rotation of the system induces small in-phase perturbations, resulting in a mean Reynolds stress which can generate low frequency currents in a nonrotating system.
Abstract: In a nonrotating system, the shear Reynolds stresses exerted by surface or internal gravity waves vanish on account of the exact quadrature between the horizontal and vertical orbital velocities. It is shown that a rotation of the system induces small in‐phase perturbations, resulting in a mean Reynolds stress which can generate low frequency currents. If both the wave field and the ocean are homogeneous with respect to the horizontal coordinates, the low‐frequency response is an undamped inertial oscillation. If either the wave field or the ocean are weakly inhomogeneous, the oscillation disperses in the vertical and horizontal directions due to phase‐mixing of modes with closely neighboring frequencies. Other effects which produce small frequency shifts also contribute to phase‐mixing, for example the horizontal component of the Coriolis vector and nonlinear interactions with geo‐strophic currents. The analysis is based on operator representations which avoid normal mode decomposition and yield...
205 citations
TL;DR: The crystal structure of methyllithium has been refined from X-ray powder data as discussed by the authors, and the cubic unit cell (a = 7.24 °A, space group I 4 3m) contains two tetrameric units of (CH3Li)4 with the following refined bond distances: Li-Li: 2.68 °A; C-Li : 2.31
156 citations
139 citations
TL;DR: In this article, it was shown that the perturbation theory approach with respect to the amplitude of the roughness for the scattering of light by rough surfaces is equivalent to a model consisting of a smooth surface and surface current sources.
Abstract: It will be shown that the perturbation theory approach with respect to the amplitude of the roughness for the scattering of light by rough surfaces is equivalent to a model consisting of a smooth surface and surface current sources. This model has an obvious physical meaning and allows a simple calculation of the scattered fields, which are given. The model and the previous one given by Stern are identical up to the position of the surface currents, which have to be placed into the vacuum. Consequently the former explanation has to be corrected, which says that the peak of the scattered radiation at the plasma frequency is generated by surface roughness. We will show that it is possible to generate this maximum by statistical inhomogenities within the metal.
134 citations
TL;DR: In this article, the optical absorption of the rare earths Ce, Pr, Nd and Sm has been measured in the energy region 100 eV − 180 eV. Synchrotron radiation of DESY was used as a light source.
119 citations
TL;DR: In this paper, the authors reported on the emotional and physiological-sexual reactions as well as the changes in sexual behavior in men and women when they were confronted with sexual thematic slides (Sigusch, 1970).
Abstract: In a previous publication we reported on the emotional and physiological-sexual reactions as well as the changes in sexual behavior in men and women when they were confronted with sexual thematic slides (Sigusch, 1970). In contrast to the data of Kinsey (1953), we found relatively few sex-specific differences for the variables we covered. We were not able to establish any sex differences at all for physiological-sexual reactions during the showing of the pictures and for changes in sexual behavior in the 24 hours after the experiment. In this report, too, emotional and physio-sexual behavior will be described, with a special view on sex specific differences. This time, however, we are using a different set of stimuli, namely films and slides that show petting and coitus. In addition, more variables are isolated and examined.
100 citations
TL;DR: From the results of these experiments it can be concluded that brackish water races of these fishes are likely to exist in the Baltic Sea.
Abstract: 1. Die Eier von Dorsch (Gadus morhua L.), Flunder (Pleuronectes flesus L.) und Scholle (Pleuronectes platessa L.) der westlichen Ostsee wurden unter kombinierten Salzgehalts-Temperaturbedingungen (0°–16° C, 7‰–42‰ S) erbrutet. Es wurde untersucht, inwieweit die Embryonalentwicklung durch das Zusammenwirken von Temperatur und Salzgehalt beeinflust wird.
TL;DR: In this article, the activation method was used to measure excitation functions for total or isomeric (n, 2n) cross sections in the energy region 12-18 MeV for 93 Nb, 96 Ru, 104 Ru, 103 Rh, 102 Pd, 110 Pd and 128 Te, 130 Te.
TL;DR: The concept of locality in quantum physics leads to mathematical structures in which the basic object is an operator algebra with a net of distinguished subalgebras (the “local” subalgesas), which provide a classification of the states of this algebra in equivalence classes determined by local or asymptotic properties.
Abstract: The concept of locality in quantum physics leads to mathematical structures in which the basic object is an operator algebra with a net of distinguished subalgebras (the “local” subalgebras). Such nets provide a classification of the states of this algebra in equivalence classes determined by local or asymptotic properties. The corresponding equivalence relations are natural generalizations of the (more stringent) standard quasiequivalence relation (they are also useful for classifying states by their properties with respect to automorphism groups). After discussing general nets from this point of view we investigate in the last section more specialized nets (funnels of von Neumann algebras) with special emphasis on their locally normal states.
TL;DR: In this paper, the temperature coefficient of the long-wavelength refractive index of several group-IV and III-V semiconductors, using the Penn model for the electronic contribution to the dielectric constant, was calculated.
Abstract: We have calculated the temperature coefficient of the long-wavelength refractive index of several group-IV and III-V semiconductors, using the Penn model for the electronic contribution to the dielectric constant. The isotropic band gap of this model is identified with the band gap at the $X$ point of the Brillouin zone, which can be simply expressed in terms of pseudopotential coefficients. The explicit temperature dependence of this gap is calculated by applying to these pseudopotential coefficients the appropriate Debye-Waller factors. The thermal expansion effect is obtained in the manner suggested recently by Van Vechten. Good agreement between the calculated and the observed temperature dependence of the long-wavelength refractive index is found.
TL;DR: In this article, a criterion for the existence of a selfadjoint and semibounded momentum operator in a non-Fock representation of the free photon field given by a coherent state was derived.
Abstract: A criterion is derived for the existence of a selfadjoint and semibounded momentum operator in a non-Fock representation of the free photon field given by a coherent state. The representation of the translation group is constructed and it is shown that the rotation group, hence the homogeneous Lorentz group, cannot be unitarily implemented in the so-called infrared sectors.
TL;DR: The absorption structure of five light metals has been measured from the onset of K- and LII,III-absorption up to photon energies of 140 eV (170 eV for Be).
Abstract: The absorption structure of five light metals has been measured from the onset of K- and LII,III-absorption up to photon energies of 140 eV (170 eV for Be). The edges at the threshold are followed by several broad peaks which are distributed over the total energy region covered by these measurements. There is a striking similarity between the LII,III-absorption spectra of Na, Mg, and Al; a similarity can also be seen between the K-absorption spectra of Li and Be.
Das optische Absorptionsverhalten von funf Leichtmetallen wurde vom Einsatz der K- bzw. LII,III-Absorption bis zu Photonenenergien von 140 eV (bei Be bis 170 eV) gemessen. Neben den Kanten beim Einsatz wurden im ganzen Spektralbereich mehrere breite Absorptionsmaxima beobachtet. Der allgemeine Verlauf der LII,III-Absorptionsspektren von Na, Mg und Al stimmt gut uberein; Ahnlichkeiten zeigen sich auch bei den K-Absorptionsspektren von Li und Be.
TL;DR: In this article, the absorption spectra of evaporated thin films of all rubidium and cesium halides in the 50- to 250-eV region are reported. But the spectral properties of these materials are not discussed.
Abstract: The absorption spectra of evaporated thin films of all rubidium and cesium halides in the 50- to 250-eV region are reported. In this range, transitions from the $3d$ shell of ${\mathrm{Rb}}^{+}$ and from the $4d$ and $4p$ shells of ${\mathrm{Cs}}^{+}$ can be seen, as well as some transitions from inner shells of the halogen ions. Besides the absorption fine structure near the threshold for inner-shell transitions, broad absorption structure is observed and explained as due to $d\ensuremath{\rightarrow}f$ continuum transitions. The number of effective electrons whose oscillator strength has been exhausted in our spectral region has been computed from the absorption data; it is particularly strong for materials containing either Cs or I. Differences in the spectra of materials with NaCl and with CsCl structure are discussed. The measurements were performed using the DESY electron synchrotron as a light source.
TL;DR: In this article, a hexagonal structure was derived for the K-ions and CH3-groups (a = 4.278, c = 8.283 A, 2 formula units, density 1.37 g/cm3).
Abstract: Methylkalium konnte sowohl aus (CH3)2Hg und einer K/Na-Legierung als auch durch doppelte Umsetzung von CH3Li mit Kalium-tert.-butylat hergestellt werden. Die rontgenographische Untersuchung des Kristallpulvers ergab eine hexagonale Struktur vom NiAs-Typ fur die K-Ionen und CH3-Gruppen (a = 4.278, c = 8.283 A, 2 Formeleinheiten, Dichte 1.37 g/cm3).CH3 K ist die erste Methylmetall-Verbindung mit im Gitter isolierten Methyl-Carbanionen. Jede CH3-Gruppe ist trigonal-prismatisch von 6 K-Ionen koordiniert. Die H-Lagen liesen sich aus den experimentellen Daten nur angenahert bestimmen. Nach dem IR-Spektrum besitzt die CH3-Gruppe C3v-Symmetrie.
Metal Alkyl Compounds, XI *) Preparation and Crystal Structure of Methyl Potassium
Methyl potassium could be prepared from (CH3)2Hg and a K/Na-alloy as well as by a metathetical reaction between CH3Li and potassium tert-butoxide. From an X-ray investigation of the crystal powder a hexagonal structure (NiAs-type) was derived for the K-ions and CH3-groups (a = 4.278, c = 8.283 A, 2 formula units, density 1.37 g/cm3). CH3K is the first methyl metal compound with isolated methyl carbanions in the lattice. Each CH3-group is coordinated by 6 K-ions in a trigonal-prismatic array. Approximate H-positions could be derived from the experimental data. The i. r. spectrum shows that the CH3-group has C3v-symmetry.
TL;DR: In this paper, the relativistic energy losses and transition radiation for fast charged particles traversing a thin dielectric foil at oblique incidence were derived. But the transition radiation formula was generalized for foils with spatial dispersion.
Abstract: Semiclassical relativistic energy losses and the transition radiation are calculated for fast charged particles (e.g. electrons) traversing a thin dielectric foil at oblique incidence. The transition radiation formula is generalized for foils with spatial dispersion.
TL;DR: Three phases in the development of the obese-hyperglycemic syndrome in NZO andobob mice are differentiated, and the gluconeogenic capacity is increased during the dynamic and transitional phases, it declines during the static phase.
Abstract: Marked differences were shown in the development of the obese-hyperglycemic syndrome in NZO andobob mice. — In NZO mice glucose tolerance decreases continuously with increasing age and body weight. — Inobob mice three phases in the development of the obese-hyperglycemic syndrome are differentiated. In the first, dynamic phase glucose tolerance decreases and insulin secretion increases as does body weight. The intermediary or transitional phase, when the animals weigh about 55 g, is characterised by rapidly changing glucose patterns, i. e. an extremely poor glucose tolerance and extremely high serum insulin level is followed by improving glucose tolerance and decreasing insulin levels. In the third, static phase blood sugar values and serum insulin levels have nearly returned to those of the lean littermates. Body weight slowly decreases. The changes in glucose tolerance and serum insulin are parallelled by changes in islet cell morphology. The gluconeogenic capacity is increased during the dynamic and transitional phases, it declines during the static phase.
TL;DR: When added together, the dibutyryl derivative completely abolishes the anabolic action of cAMP on glycogen content.
TL;DR: In this paper, a consistent treatment of two-particle exchange currents in nuclei in the framework of the one-boson exchange model for the nucleon-nucleon interaction is given.
TL;DR: It seems that the neurosecretory neurons are innervated by neurons morphologically similar to cholinergic neurons and that part of them receive an adrenergic innervation, which supports the view that the caudal neuro secretory cells do not constitute a functionally homogeneous population.
Abstract: The lower spinal cord including the caudal neurosecretory system of the pike (Esox lucius) was investigated by means of light and electron microscopy and also with the fluorescence histochemical method of Falck and Hillarp for the visualization of monoamines. A system of perikarya displaying a specific green fluorescence of remarkably high intensity is disclosed in the basal part of the ventrolateral and lateral ependymal lining of the central canal. The area corresponding to the upper half of the urophysis has most cells; their number decreases caudally and cranially. A considerable number of their beaded neurites reach the neurosecretory neurons by different routes but are only occasionally present in the actual neurohemal region. An intensely fluorescent dendritic process is sometimes observed terminating with a bulbous enlargement at the ependymal surface in the central canal. Besides small, electron lucid vesicles in the terminal parts of the axons, the neurons contain numerous large dense-core vesicles which can apparently take up and store 5-hydroxydopa (5-OH-dopa) and 5-hydroxydopamine (5-OH-DA). These neurons are thought to be adrenergic and to contain a primary catecholamine, possibly noradrenaline. The varicosities of the adrenergic terminals are repeatedly observed contiguous to some of the neurosecretory axons, the membrane distance at places of contacts generally ranging from 150–200 A. Another type of nerve terminals that contain only small empty vesicles, also after pretreatment with 5-OH-dopa or 5-OH-DA, are frequent among the neurosecretory neurons. These axons establish synaptic contacts with membrane thickenings on most of the neurosecretory neurons. Thus it seems that the neurosecretory neurons are innervated by neurons morphologically similar to cholinergic neurons and that part of them receive an adrenergic innervation, which supports the view hat the caudal neurosecretory cells do not constitute a functionally homogeneous population.
TL;DR: In this paper, the authors show that in equilibrium of the four acetoxonium ions the gluco-ion 5 is present in 60%, the manno-ion 6 in 12%, the altro-ion 7 in 7% and the ido-ion 8 in 21 %.
Abstract: Aquilibrierungsversuche in Nitromethan zeigen, das von den vier Acetoxonium-Ionen das gluco-Ion 5 zu 60%, das manno-Ion 6 zu 12%, das altro-Ion 7 zu 7% und das ido-Ion 8 zu 21 % im Gleichgewicht vorliegen. Einheitliches Idose-4.6-Acetoxonium-Salz 8 kristallisiert aus CH2Cl2, da es uber das Gleichgewicht 5⇋6⇋7⇋8 standig nachgebildet wird. Das Glucose-1.2-Acetoxonium-Salz 5 kann durch Fallung aus CCl4 bei −10° erhalten werden. Penta-O-benzoyl-α-D-idopyranose (15) ist durch Benzoxonium-Umlagerung aus Glucose gewinnbar. Tetra-O-acetyl-6-brom-6-desoxy-α-D-idopyranose (16) wird durch „trans” Offnung des Idose-4.6-Acetoxonium-Salzes 8 mit LiBr dargestellt.
Carboxonium Compounds in Carbohydrate Chemistry, X. Investigations on Acetoxonium Rearrangement of D -Glucose to D-Idose
Equilibration experiments in nitromethane show that in equilibrium of the four acetoxonium ions the gluco-ion 5 is present in 60%, the manno-ion 6 in 12%, the altro-ion 7 in 7% and the ido-ion 8 in 21 %. Pure idose-4,6-acetoxonium salt 8 crystallizes from CH2Cl2 as it is formed from the equilibrium 5⇋6⇋7⇋8. The glucose-1,2-acetoxonium salt 5 is precipitated in CCl4 at −10°C. Penta-O-benzoyl-α-D-idopyranose (15) is obtained by benzoxonium rearrangement from glucose. Tetra-O-acetyl-6-bromo-6-deoxy-α-D-idopyranose (16) is formed by „trans”-opening of the idose-4,6-acetoxonium salt 8 with LiBr.
TL;DR: In this paper, the complex dielectric tensor elements ϵ(ω) and ϵ⊥ (ω) for the electric field vector parallel and perpendicular to the c axis of MoS2 are derived from the energy loss spectra of 60 keV electrons by means of a Kramers-Kronig analysis.
01 Jun 1970
TL;DR: It is thought that the storage of hormone plays only an unimportant role in parathyroid function, and a close functional relationship seems to exist between actual hormonal requirement, hormone synthesis, and cellular hormone secretion without a significant latency period.
Abstract: The functionally mediated ultrastructural changes of the parathyroid glands were studied in normocalcemic, hypercalcemic, and hypocalcemic rats. Hypercalcemia was induced by administration of parathyroid hormone or dihydrotachysterol. Hypocalcemia resulted from calcium deficient diet, calcium and phosphate deficient diet, ferric-glycerophosphate injections, and administration of thyrocalcitonin.
TL;DR: In this paper, the surface plasmons are excited in this experiment by light, and a relatively accurate determination of the optical constants is possible by using gold and silver foils of different thicknesses.
Abstract: Non radiative surface plasmons decay into photons on a rough surface. This light emission is studied with gold- and silver foils of different thicknesses. The surface plasmons are excited in this experiment by light. By this way a relatively accurate determination of the optical constants is possible.
TL;DR: Electron microscope studies were performed of the differentiation of myoblasts in the brachial somites and in the wing bud of chick embryos at stages 17 to 27 according to Hamburger and Hamilton to enable the following statement concerning the relationship between the dermomyotome and theWing bud as well as the ingrowing nerve fibers.
Abstract: Electron microscope studies were performed of the differentiation of myoblasts in the brachial somites and in the wing bud of chick embryos at stages 17 to 27 according to Hamburger and Hamilton Concurrent optical inspection of short series of stained thick sections enabled the following statement concerning the relationship between the dermomyotome and the wing bud as well as the ingrowing nerve fibers
TL;DR: The Feinstruktur der Zellen aus den Drusenkomplexen der Fruchtschale vonPoncirus trifoliata wurde in allen Altersstufen festgehalten.
Abstract: Die Feinstruktur der Zellen aus den Drusenkomplexen der Fruchtschale vonPoncirus trifoliata wurde in allen Altersstufen festgehalten. Die Piastiden zeigen stark geschlangelte, in alle Richtungen verlaufende Tubuli und enthalten lipophile Substanzen. Diese konnen nicht mit den Plastoglobuli verwechselt werden, die in den Piastiden des Flavedos reifenderPoncirus-Fruchte in groser Zahl auftreten. Mit Hilfe von Gefriertrocknung und durch Einbringen verschiedener atherischer Ole in Testpflanzen wird bewiesen, das die osmiophilen Substanzen in der Plastide grostenteils atherische Ole sind. Gefriertrocknung erlaubt es, fluchtige von nichtfluchtigen Komponenten in e-optischen Praparationen bei ausreichend guter Strukturerhaltung zu unterscheiden. Atherische Ole, die in Gewebe eingebracht werden, zerstoren rasch die Membransysteme von Pflanzen, die Monoterpene nicht in groserer Menge synthetisieren. In ahnlicher Weise schadigt Olsaure die Zellen. Die in fixierte Zellen eingebrachten Ole sind anders verteilt als die genuinen Ole der intakten Drusenzelle vonPoncirus. Glutaraldehyd-OsO4 gestattet atherische Olein situ zu fixieren. Diese werden dann wahrend der nachfolgenden Entwasserung weniger extrahiert als nach alleinigem Einwirken von OsO4. Tritiummarkiertes Mevalonat durfte nur sehr wenig eingebaut werden. Die in die Terpene inkorporierte Mevalonsaure wird durch die Acetonentwasserung extrahiert, die nicht eingebaute geht infolge der guten Wasserloslichkeit wahrend der Einbettung ebenfalls verloren. Es wird vermutet, das in den Drusenzellen derPoncirus-Frucht hauptsachlich die Plastiden Monoterpene erzeugen, wobei angelieferte Vorstufen der Terpensynthese in oder an den Tubuli der Piastiden zu Monoterpenen konvertiert werden. Die atherischen Ole verbleiben zu einem grosen Prozentsatz solange in der Plastide, bis diese degeneriert.
TL;DR: In this paper, a theory which takes account of multiple scattering effects is proposed, which is in reasonable agreement with experiments of other authors, and it is shown that at high densities the drift velocity of low energy electrons fails to be a function of E / N only.