Kinetik der bromierung von phenolen und phenolischen mehrkernverbindungen, 2. Die reaktionsfähigkeit isomerer zweikernverbindungen

1976

Die Geschwindigkeit der Bromierung von 6 isomeren Zweikernverbindungen mit jeweils einer reaktionsfahigen Stelle (Hydroxydimethylbenzyl-methylphenole 1, 2 und 3) wurde in Eisessig bei 22°C UV-spektroskopisch bestimmt. Fur die Reaktion in ortho-Stellung zur phenolischen Hydroxy-Gruppe ergibt sich eine Verminderung der Geschwindigkeit um den Faktor 3–3,5 wenn zwischen den Hydroxy-Gruppen der beiden Phenolbausteine eine intramolekulare Wasserstoffbrucke sterisch moglich ist (1a). In den anderen Fallen (1b, 2a, 2b) verlauft die Bromierung ungefahr ebenso schnell wie bei 2,4-Dimethylphenol. Die schneller verlaufende Reaktion in para-Stellung (3a, 3b) wird durch eine Wasserstoffbrucke um den Fakt…

Gleichseitige Oberschenkelfraktur nach alloplastischem Gelenkersatz von Hüft- oder Kniegelenk

1976

Verletzungsmöglichkeiten durch den Sicherheitsgurt

1976

Der Dreipunktsicherheitsgurt stellt unter den handelsublichen Ruckhaltesystemen zur Zeit den besten Schutz vor Verletzungen dar. Die Tatsache, das ein Fahrzeuginsasse angeschnallt war, bedeutet jedoch nicht, das er unverletzt ist. Die Kenntnis gurtspezifischer Verletzungen ist besonders im Hinblick auf die gesetzliche Anschnallpflicht in vielen europaischen Landern wichtig.

Neurotropism in newborn hamsters of plaque purified measles virus clones

1976

Three plaque purified measles virus clones displayed a different neurotropism in newborn hamsters.

Mode of interaction of different polyanions with the first (), the second (C2) and the fourth (C4) component of complement—II

1976

Abstract Dextran sulfate, polyvinyl sulfate, liquoid, heparin and Sp 54, ∗ (a pentosanpoly-sulfoester) prevented the uptake of C2 by EAC4b. In contrast to EAC 4 b 2 a , treatment of EAC4b2 with polyanions led to dissociation into EAC4b and C2. The inhibition of C2 uptake by polyanions could be reduced by increasing magnesium concentration to levels which are normally inhibitory, suggesting that Mg ++ ions are sequestered by these sulfated polyanions.

Poly(N-vinylhalogenocarbazole). II. On the synthesis of some 1,3,6,8-tetrahalogenovinylcarbazoles

1976

This paper presents results of a research program in which several vinyl carbazole polymers containing chlorine and bromine atoms in their molecules were polymerized and characterized by IR spectroscopy and thermoanalysis. The compounds were synthesized by reacting 2-chloroethanol benzenesulfonate with the appropriate halogenocarbazoles (Clemo-Perkin method) obtaining in this way some halogen derivatives of 9-(2-chloroethyl)carbazole; these derivatives following dehydrochlorination produced relevant vinyl derivatives. Results are evaluated in terms of reaction mechanisms and molecular structures of polymers synthesized.

Studies on a measles virus variant inducing persistent infections in cultured cells

1976

Attempts were made to characterized by a plaque assay two variants of the Edmonston strain of measles virus and to obtain plaque purified virus populations. The UP non-cytocidal variant, in all the examined cell systems, mainly produced small but also large plaques; the DP cytocidal variant always large plaques. Three clones, UP-SP4, UP-LP4 and DP-LP4, were derived by plaque purfication respectively of the UP small plaque, UP large plaque and DP large plaque forming particles. The virus populations of the clones could be distinguished by some other biological and physical characters: cytopathic effect in roller tube cultures, growth potential in HeLa cells, thermal stability at 45 degrees C…

Investigation of gaseous discharge ion sources for isotope separation on-line

1976

Abstract Gaseous discharge ion sources with circular end extraction have been investigated with the aim of meeting the special requirements of on-line isotope separation. The studies represent an attempt to increase lifetime, temperature and ionization efficiency of the ion source under stable discharge conditions and to reduce the ion current density of usually 1–100 mA/cm2 of low intensity separator sources. The detailed investigation of a modified Nielsen Ion Source is described. The source yields in oscillating electron are operation reproducible ionization efficiencies of 32% for krypton and 45% for xenon. It was found that minor variations of geometry and potentials in a Nielsen-type …

Meßmethoden bei elektrooptischen Untersuchungen

1976

Es werden als Kernprobleme, wie sie bei optischen Untersuchungen an Molekulen in elektrischen Feldern auftreten, die relative und die absolute Mesgenauigkeit getrennt diskutiert. Mit einfachen Uberlegungen werden zur Optimierung der experimentellen Anordnung auf ihre relative Mesgenauigkeit hin Forderungen aus der Photonenstatistik abgeleitet. Die absolute Mesgenauigkeit wird als Problem der Bestimmung der mittleren Feldstarken in einer praktisch verwirklichbaren Meszelle behandelt, und eine geeignete Eichzelle wird beschrieben. The main problem of all optical research on molecules in electric fields is that of relative and absolute accuracy. From simple photon statistics, a procedure for o…

On optimal estimates for the solutions of linear difference equations on the circle

1976

A linear difference equation arising in the proof of Moser's twist mapping theorem is solved and optimal estimates for the solution are established.

Quantitative study of muscle fibre atrophy and restitution after nerve grafts.

1976

Our comparative experimental studies on rabbits using clinical, electromyographical, and quantitative histological examinations of long autologous and homologous nerve grafts in 35 rabbits, paying special attention to quantitative histological changes in the gastrocnemius muscles, allow the statement that, compared to the short homografts, the long homografts showed worse results. Moreover, it became obvious that the regeneration rate of autografts was not influenced by increasing the lengths of the grafts. The answer to the question of how far even longer grafts may influence the quality of regeneration will need further investigations.

Workhardening adaptation of rigid-plastic structures

1976

The paper considers discrete rigid-plastic structures which are subjected to the action of loads varying quasi-statically within given limits. It studies the conditions for workhoardening adaptation, that is the conditions to ensure that the structure, after an initial rigid-plastic phase, shows a purely rigid behavior. The safety factor against the workhardening inadaptation is defined by two dual optimization problems. Some characteristic features of the yielding surface at failure are pointed out, using also a proper geometric description. Static and kinematic theorems, which are similar to those of shakedown theory, are given. A simple application concludes the paper.

Kinetik der bromierung von phenolen und phenolischen mehrkernverbindungen, 3. Die reaktionsfähigkeit isomerer dreikernverbindungen und einer homologe…

1976

Die Geschwindigkeit der Bromierung von drei isomeren Dreikernverbindungen und einer homologen Reihe von Mehrkernverbindungen mit bis zu sechs Methylphenolbausteinen pro Molekul wurde in Eisessig bei 22°C UV-spektroskopisch gemessen. Alle Verbindungen waren so gewahlt, das sie nur eine reaktionsfahige ortho-Stellung in bezug auf die Hydroxy-Gruppe besasen. Es zeigte sich, das die Reaktionsgeschwindigkeit im wesentlichen dadurch bestimmt wird, ob zwischen den phenolischen Hydroxy-Gruppen des reagierenden Endbausteins und des unmittelbar benachbarten Bausteins eine intramolekulare Wasserstoffbrucke moglich ist. Ist dies nicht der Fall, so sind die Geschwindigkeitskonstanten zweiter und dritter…

A ten-fold divided total absorption Ge(Li) gamma-ray detector

1976

Abstract We have constructed a split-crystal total absorption Ge(Li) gamma-ray spectrometer and special logic electronics for rejecting Compton continuum in spectra. A 10 cm3 planar detector was divided into ten electrically separated detectors by grinding nine parallel slots on the n-surface of the detector. In operation both the n- and p-contacts are isolated from the ground. Using capacitive sharing, most of the released electrical charge is taken from the p-contact into an ordinary pulse amplifier line and analyzed. A small fraction of the charge collected at the n-strips is observed with voltage-sensitive FET-preamplifiers. The following logic electronics provides a gate pulse for the …

Investigations on organoantimony compounds

1976

Abstract Diorganoantimony(V) complexes of the type R 2 SbClTrid (R = Me, Ph) containing dianionic, potentially tridentate Schiff-base ligands with ONO donor atoms (Trid 2− ) have been prepared and characterized. IR and NMR data suggest an octahedral coordination environment for the antimony atom with meridional arrangement of the ONO ligand atoms and a linear CSbC skeleton.

On a new proof of Moser's twist mapping theorem

1976

Based on a new idea of the author, a new proof of J. Moser's twist mapping theorem is presented.

Dissociation-constants of metat-ion-complexes with alkaline phosphatase from pig kidney.

1976

Using metal-ion buffers it was possible to remove Zn2+, Mg2+ and Mn2+ ions of pig kidney alkaline phosphatase reversibly. The dissociation constants obtained are KEMg: 4 X 10(-7) M, KEMn: 4 X 10(-8) M and KEZn: 8 X 10(-13) M (22 degrees C, pH: 9.6, mu: 0.07).

Some aspects of the genesis and development of German dermatology.

1976

Pathogenicity factors of mycoplasmas

1976

The pathogenicity of mycoplasmas is caused by several factors, e.g. exotoxin, toxic properties of membrane components, exoenzymes, peroxide, and immunological factors. The absence of a rigid cell wall and the small genome tend to influence the interactions between mycoplasmas and host tissue. Mycoplasmas do not have a cell wass and are therefore resistant to the action of the host's lysozymes. They appear in some patients to be immunologically inconspicuous and in other patients they have been reported to have an immuno-suppressive effect. Recently there have been reports of central nervous system disorders due to mycoplasma. The pathogenic factors involved in these reactions have not been …

The use of high-pressure liquid cation-exchange chromatography for determination of the 5-methylcytosine content of DNA.

1976

Analysis of neuronal networks in the visual system of the cat using statistical signals

1976

If the input signals of the visual system in the cat are statistical patterns in space and time, a complete system analysis can be carried out. What counts here as a system are the neuronal networks between retina and recording site. In the case of linearity, one obtains the temporal impulse response functions at every point in the receptive field with the aid of correlation methods. The measuring time is about one minute. Some aspects of the procedure are explained in terms of examples. The method of measurement also makes it possible to determine the characteristic function of the system in time and space between different recording sites within the cortex. It is possible to specialize th…

Large-photon-number limit and the essential singularity in finite quantum electrodynamics

1976

It is shown that the essential singularity in finite quantum electrodynamics can be located by considering only those diagrams with a large number of photons exchanged in the single-fermion loop, without photons emitted and absorbed on a fermion line. (AIP)

Massenspektrometrischer Nachweis des cyclischen Trimeren im Polyäthylenterephthalat

1976

Beim direkten Abbau von kommerziellem Polyathylenterephthalat im Massenspektrometer last sich bei Temperaturen unterhalb des einsetzenden thermischen Abbaus des Polymeren das zu etwa 1% enthaltene cyclische trimere Athylenterephthalat ohne vorherige Isolierung nachweisen und durch Vergleich mit den EI- und FD-Massenspektren eines authentischen Trimeren identifizieren. By direct pyrolysis of commercial polyethyleneterephthalate in the mass spectrometer a content of about 1% of the cyclic trimer ethyleneterephthalate is indicated at temperatures below thermal degradation of the polymer. The comparison with EI- and FD-mass spectra of the authentic cyclic trimer allows its identification withou…

Opsonizing activities of IgG, IgM antibodies and the C3b inactivator-cleaved third component of complement in macrophage phagocytosis

1976

Phagocytosis of SRBC by guinea-pig peritoneal macrophages is enhanced by opsonizing IgG antibody alone. IgM antibody requires the presence of bound C3. Treatment of C3b coated SRBC with purified C3b inactivator (yielding EAIgM C1423d) does not reduce attachment to, and phagocytosis by, peritoneal macrophages. This finding suggests the existence of a C3d receptor on peritoneal macrophages. EC43b intermediates which have been produced by removing IgM antibody by mercaptoethanol treatment and by subsequent removal of C1 and C2, are phagocytosed despite the absence of IgM antibody. Furthermore, treatment of EC43b with C3b inactivator does not change phagocytosis. Thus, IgM antibody does not app…

Kinetics of alkaline phosphatase from pig kidney. Influence of complexing agents on stability and activity

1976

Metal ion-complexing agents, like KCN, EDTA etc., inactivate alkaline phosphatase of pig kidney. This inactivation is reversible at low concentrations of the complexing agents and irreversible at high concentrations. The reversible inhibition is probably due to removal of Zn2+ ions from the active site, where they are necessary for catalytic action, whereas the irreversible inhibition results from the removal of Zn2+ ions necessary for preservation of the structure. The inactivation is pseudo-first order. It depends on the concentration, size and charge of the complexing agents. β-Glycerophosphate and Mg2+ ions protect the enzyme from inactivation by complexing agents. Quantitative examinat…

Fixpunktmengen von halbeinfachen Automorphismen in halbeinfachen Lie-Algebren

1976

Let g be a semisimple Lie algebra over an algebraically closed field of characteristic 0. The set of fixed points of a semisimple inner automorphism of g is a regular reductive subalgebra of maximal rank [1], so it is defined by a subsystem of the root system Φ of g relative to a suitable Cartan subalgebra. The main theorem of the article characterizes the corresponding subsystems of Φ. The second part of the article shows how to compute the fixed point algebras of semisimple outer automorphisms of g. A complete list of all fixed point algebras is then easily obtainable. The results are applied to bounded symmetric domains. References

A semi-empirical extrapolation technique for atomic and molecular properties derived from correlated wavefunctions

1976

Abstract A semi-empirical extrapolation technique is suggested for recovering the correlation defect remaining in atomic and molecular properties calculated from highly correlated wavefunctions. These procedures are applied to PNO-CEPA and PNO-IPPA calculations on F, F + , F − , and HF in order to obtain “exact” estimates of the ionization potential, electron affinity, and dissociation energy.

Retinol and retinyl esters in pigment epithelium of rats with inherited retinal degeneration

1976

A comparative study of the retinol and retinyl ester concentrations was performed in the retinal pigment epithelium of the normal and affected rats. Our findings indicate that in dystrophic rat retinol content increases, whereas the amount of retinyl esters is always lower than normal. An hypothesis can be made on the deficiency of enzymic activities which regulate retinol retinol and retinyl esters levels in the pigment epithelium.

Los Teoremas de Alternativa y su relacion con la Teoria de Juegos y las propiedades topologico-algebraicas de Rn

1976

Chlorinated hydrocarbons and total mercury in the prey of the white-tailed eagle (Haliaeetus albicilla L.) in the quarken straits of the gulf of both…

1976

Samples of the white-tailed eagle population and its prey were collected from the Quarken straits area of the Gulf of Bothnia, Finland, and were analyzed for DDT, DDD, PCBs, aldrin, lindane, and mercury. Mercury, PCB, and DDE were detected in all animals studied. It was concluded that one of the most important reasons for the poor breeding results of the white-tained eagle (especially hatchability) are the combined effects of the studied pollutants originating for the most part from the fish-eating species in its prey (mergansers and great crested grebes). (JTE)

Signal Characteristics of EMG at Different Levels of Muscle Tension

1976

Electromyographic activity of m. rectus femoris at submaximal and maximal voluntary contractions was quantified by conventional integration technique and also be a more "qualitative" procedure of automated motor unit averaging and frequency spectrum analysis. By relating the EMG parameters to produced muscle tension it was observed that the integrated EMG increased in a slightly nonlinear fashion with the increase in muscle force. The other EMG variables also showed clear changes as a function of muscle tension. The averaged motor unit potential (AMUP) and its specific parameters (number of spikes, amplitude, rise time and amplitude-rise time ratio) showed such changes with muscle tension t…

Induction of secondary cytotoxic T-lymphocytes in vitro does not require cell proliferation.

1976

SummaryUsing a mouse in vitro allograft model, evidence has been obtained that, in contrast to the accepted view, the generation of cytotoxic effector function in T-lymphocytes does not necessarily require cell division.

Eine Verallgemeinerung eines Satzes von N. Kuiper

1976

Estimating norms inC*-algebras of discrete groups

1976

LetG be a discrete group, letK be a finite subset ofG and let χ K be the characteristic function ofK. Then χ K acts by convolution as a bounded operator onL2(G). We will prove that the norm |||χ K ||| of this operator always satisfies the following estimate: $$|||\chi _{\rm K} |||^2 \leqq k + 2\sqrt {w\left( {k - 1} \right)\left( {k - w} \right)} + \left( {k - 2} \right)\left( {k - w} \right)$$ . Here .

Enquête longitudinale 1, les "premières inscriptions"

1976

International audience

Tagesprofile von Plasmaaldosteron,-Cortisol, -Renin, -Angiotensinogen und -Angiotensinasen bei Normalpersonen

1976

Plasma cortisol and renin were estimated in 1 h intervals, plasma aldosterone, angiotensinogen and angiotensinases in 3 h intervals over periods of 24 h in six normal volunteers (age 20-26) under control conditions and subsequently under suppression of ACTH release by dexamethasone. Highest cortisol levels were found around 7 a.m., minimum levels between 9 p.m. and 1 a.m. Dexamethasone reduced cortisol to constantly low concentrations. Aldosterone was highest around 4 a.m. under control conditions and under dexamethasone, and showed lowest concentrations between 4 and 10 p.m. There were no significant differences between mean aldosterone concentrations at corresponding time points of the co…