showing 36 of ~574560 from 574555 documents
Die phänokopierende Wirkung der Phenylborsäure
1976
Zusammenfassung Mit dem Ausdruck „Phanokopie” werden somatisch induzierte Aberrationen des Phanotyps bezeichnet, die das Manifestationsmuster eines veranderten Genotyps imitieren (bekanntestes, wenn auch nicht unumstrittenes Beispiel: Die Thalidomid-induzierten Extremitaten-Misbildungen). Charakteristisch fur phanokopierende Noxen ist ihre Phasenspezifitat, d. h. sie sind nur wirksam, wenn sie eine eng begrenzte Entwicklungsstufe treffen (sensible Phase). Es wird an folgenden Beispielen gezeigt, das eine richtig terminierte, einmalige Applikation geeignet dosierter Phenylborsaure-Losungen bei Hoheren Pflanzen die Manifestationsmuster bekannter Mutationen hervorrufen kann und das der Effekt …
Pour une approche économique de la liaison éducation-loisir
1976
International audience
Epoxides derived from various polycyclic hydrocarbons as substrates of homogeneous and microsome-bound epoxide hydratase. A general assay and kinetic…
1976
A general assay for epoxide hydratase using epoxides derived from polycyclic aromatic hydrocarbons as substrates is described. Addition of dimethylsulphoxide to the incubation mixture after incubation allowed unreacted epoxide and its phenolic by-product to be extracted into light petroleum whilst the product dihydrodiol remained in the aqueous phase. The product was then extracted into ethyl acetate and estimated radiochemically. This assay gave low extraction blanks (0.8-3.8%) when six K-region epoxides of polycyclic hydrocarbons were used, with high recoveries of the corresponding dihydrodiol in the ethyl acetate phase (65-89%). Radiochromatograms demonstrated that all the radioactivity …
Localization and Activity of Naphthylamidases in Germinating Seeds of Scots Pine, Pinus sylvestris
1976
Extracts prepared from endosperms of germinating seeds of Scots pine, Pinus sylvestris L., rapidly hydrolysed the β-naphthylamides of L-phenylalanine and L-leucine optimally at pH 6.5 and that of L-arginine at pH 7.7. Disc electrophoresis followed by activity staining showed that the activities were due to two naphthylamidases (aminopeptidases) with different substrate specificities. Seeds were allowed to germinate at 20°C on agar gel in the dark and the activities on the three substrates were assayed from separated endosperms and seedlings at various stages of germination. The activities in the endosperm of resting seeds were relatively high and they remained unchanged throughout the perio…
A Method to Measure the Characteristics of Biological Materials at Millimeter Waves
1976
A new method of biological sample characterization at millimeter waves has been studied to verify and extend Webb's experimental results. This method, based on interferometric measurements, is suitable to obtain an absorption spectrum of a living bacterial sediment with a high sensitivity. It has been applied in the frequency range 66-73 GHz. Some experimental results are reported.
Plasma-cAMP bei prim�rem und sekund�rem Hyperparathyreoidismus
1976
Bei 3 Patienten mit operativ bestatigtem primaren Hyperparathyreoidismus wurden normale Plasma-cAMP-Konzentrationen festgestellt, wahrend bei 5 Dialysepatienten unabhangig vom Parathormonspiegel erhohte Plasma-cAMP-Konzentrationen gefunden wurden. Diese Befunde sprechen gegen eine Regulation des Plasma-cAMP durch Parathormon bei diesen Krankheitsbildern.
Pharmacokinetic analysis of the interaction between dicoumarol and tolbutamide in man
1976
The effect of repeated administration of tolbutamide on the elimination and anticoagulant action of a single oral dose of dicoumarol 600 mg was studied in four healthy male subjects using a crossover design. In all subjects the plasma concentration of dicoumarol in the postabsorptive phase was lower during concomitant tolbutamide treatment. However, the subjects differed with respect to the elimination kinetics of dicoumarol and the effect of tolbutamide on some of the measured pharmacokinetic paramaters. In two subjects dicoumarol was eliminated by apparent first-order kinetics. Tolbutamide led to a pronounced increase in the elimination rate and a shift in the plasma concentration-respons…
Criteria for the Discovery of Chemical Elements
1976
The availability of suitable heavy-ion accelerators should make it possible to synthesize and identify additional heavy transuranium elements. Criteria for adequate proof that a new element has been synthesized or found in nature and identified are suggested. The basic criterion must be the proof that the atomic number of the new element is different from the atomic numbers of all previously known elements. Chemical identification constitutes an ideal proof; the procedure must be valid for application to individual atoms in an unequivocal manner. Also satisfactory is the identification of characteristic x rays in connection with the decay of the isotope of the new element. This is likely to…
Observation of Meson-Exchange Effects in Deuteron Electrodisintegration
1976
Electrodisintegration of the deuteron has been measured for an incident energy of 300 MeV at 30\ifmmode^\circ\else\textdegree\fi{} and 90\ifmmode^\circ\else\textdegree\fi{} scattering angles. The maximum energy transfer was 116 MeV. Very good agreement with theory was achieved when the pionic-exchange currents were included. Near the threshold and for momentum transfer $\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}_{\mathrm{c}.\mathrm{m}.}^{}{}_{}{}^{2}=3.9$ ${\mathrm{fm}}^{\ensuremath{-}2}$, the meson-exchange currents contribute about 40% to the total cross section.
T-T cell collaboration during in vivo responses to antigens coded by the peripheral and central region of the MHC.
1976
MIXED lymphocyte culture (MLC)1 has been used extensively as an in vitro model to analyse the reactivity of T cells to antigens coded by the major histocompatibility complex (MHC). When murine T responder cells are exposed in vitro to allogeneic lymphoid cells (stimulator cells) they proliferate and cytotoxic T lymphocytes (CTL) are generated2,3. Antigens coded by the central I region of the MHC are chiefly responsible for triggering proliferation4,5, whereas the target antigen of the CTL generated is either a H–2K or H–2D region or a I–A subregion gene product5–8. This dichotomy in the antigenic requirement of a MLC seems to be reflected at the level of the responding T lymphocytes. Two di…
Efficacy of gut lavage, hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication
1976
Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents. Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1-2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be e…
Inhibition of Plant Lactate Dehydrogenase Isoenzymes by Benzoic Acid and Cinnamic Acid Derivatives
1976
Summary Several phenolic compounds such as derivatives of benzoic and cinnamic acid were investigated with respect to their inhibitory effect on potato tuber lactate dehydrogenase isoenzymes. Ki values were determined and it was found that they were in the range of 10−2 M for several benzoic acid derivatives while they were in the range of 10−5 M for several hydroxylated cinnamic acid derivatives such as 3,4-dihydroxy cinnamic acid, p(m)nitrocinnamic acid, and 7,8-dihydroxy-4-methyl coumarin as well as kynurenic acid. Also coumaric acid derivatives revealed a very strong inhibition: The K1 values for coumarin and p-coumaric acid were in the range of 10−4 M. The inhibition by all aromatic co…
false
1976
Poly[sulfadiazineacrylamide] (5), labeled with 14C in the main chain, was synthesized and its molecular weight viscosimetrically determined by comparison with unlabeled samples of poly[sulfadiazineacrylamide] with similar molecular weights which were determined by membrane osmometry. The material showed a polymer-specific prolongation of its systemic behaviour in mice. Rates of excretion of the polymer were negligibly low, whereas the toxicity was considerable. It was concentrated in the liver during the course of the experiment, but no affinity toward the PC6 plasmacytoma in mice could be detected. Poly[sulfadiazinacrylamid] (5) mit 14C-Hauptkettenmarkierung wurde synthetisiert und sein Mo…
Kationische polymerisation des styrols mit CF3SO3H als katalysator: Der einfluß der trocknungsmethode des lösungsmittels auf die polymerisation
1976
Shared determinants between virus-infected and trinitrophenyl-conjugated H-2-identical target cells detected in cell-mediated lympholysis
1976
Infection of H-2-identical mice with either lymphocytic choriomeningitis (LCM) virus, vaccinia virus, or paramyxo (Sendai) virus resulted in the generation of specifically sensitized cytotoxic T lymphocytes (CTL). CTL generated in vitro against 2,4,6-trinitrophenyl (TNP)-conjugated syngeneic stimulator cells were specifically cytotoxic for TNP-conjugated H-2K (D) region identical targets. Both LCM and vaccinia-induced CTL, however, were found to be strongly cytotoxic towards TNP-conjugated, H-2K(D) region-identical target cells. In contrast, Sendai virus-induced CTL did not lyse TNP-conjugated, syngeneic target cells. Inhibition experiments using cold targets suggested that shared antigenic…
PIANCALDOLI METEORITE: CHEMISTRY, MINERALOGY AND PETROLOGY
1976
The fall occurred near Piancaldoli, Florence, Italy, at 19.14 U.T. on the 10th August 1968. The fireball broke up in the atmosphere producing a cloud like a balloon. The trajectory and the terminal point were calculated, leading to the recovery of three small meteoritic fragments, found on the roof of a house. Chemical analysis gave the following results: SiO2 40.80; TiO2 0.15; Al2O3 2. 70; Cr2O3 0.47; FeO 17.20; MnO 0.07; MgO 25.18; CaO 1.95; Na2O 0.64; K2O 0.07; P2O5 0.20; NiS 0.93; FeS 6.24; Fe° 2.40; Ni° 0.40; Co 0.05; sum 99.45. In the lithic portion of the meteorite the following minerals were found: both clino and orthopyroxenes (En = 76 to 98%), olivines (Fo = 66 to 98%), troilite, …
Ein Verfahren zur Behandlung von Ausgleichsaufgaben mit Intervallkoeffizienten
1976
Es wird ein Verfahren beschrieben, das die Berechnung einer Intervalleinschliesung der Losungsmenge einer linearen Ausgleichsaufgabe mit Intervallkoeffizienten erlaubt. Es stellt eine Ubertragung des Bjorckschen Algorithmus der iterativen Verbesserung einer Naherungslosung zu einer linearen Ausgleichsaufgabe [5] auf ein bekanntes Verfahren zur Behandlung von Intervallgleichungssystemen dar.
The behaviour of children during a first encounter
1976
.— The behaviour of unacquainted children in a two-child play situation was compared with the behaviour of well acquainted children. Observations were made through a one-way-screen, mainly in accord with categories adopted from ethological child studies. Tape-recorded speech was coded into 27 content categories. Choice of activity and content of play seemed to be determined mostly by the children's sex, whereas nonverbal acts and also some aspects of speech showed considerable differences between strangers and acquaintances. Looking at the other's face, gaze avoidance, immobility, and automanipulation were more frequent among unacquainted children, and walking was less frequent among them. …
Structural representations of person perception A comparison between own and provided constructs
1976
.— The dimensions of perceiving other people were compared from two types of data, one representing a person's individual constructs and indexed by two different rating methods (Reptest technique and Similarity Ratings), the other constructs provided by the experimenter, also measured by two methods (Semantic Differential and Personality Differential). Thirty-one female psychology students, rated fifteen role figures by using the four methods. Indices of factorial and cluster similarity of roles showed that the different rating methods yielded highly similar role structures. Each congruent factor and cluster could also be characterized by identical trait properties, but there were also impo…
The enantiomers of phenprocoumon: pharmacodynamic and pharmacokinetic studies.
1976
The pharmacodynamics and pharmacokinetics of the optical enantiomers of phenprocoumon were studied in 5 normal subjects and compared to the racemic mixture. Each subject received a single oral dose of 0.6 mg/kg of racemic, S(-), and R(+) phenprocoumon. S(-) phenprocoumon was 1.6 to 2.6 times as a potent as R(+) phenprocoumon when the area under the effect/time curve was used to quantify the total anticoagulant effect per dose. Comparing the plasma concentrations that elicited the same anticoagulant effect, S(-) phenprocoumon was 1.5 to 2.5 times as potent as R(+) phenprocoumon. The anticoagulant activity of the racemic mixture was between that of the enantiomers. There was no distinct diffe…
false
1976
The thermal degradation of poly(oxycarbonylpentamethylene), (poly-e-caprolactone), (3), was investigated at 220°C and 80 mm Hg under nitrogen. 3 was found to be thermally much more stable than poly(oxycarbonylethylene), (poly-β-propiolactone), (1), although it decomposed faster than poly(oxycarbonyl-1,1-dimethylethylene), (polypivalolactone), (2). The reaction was of the first order with a rate constant of k=6,2.10−4 min−1 and proceeded via a “zipper mechanism” to yield monomeric e-caprolactone. Der thermische Abbau von Poly(oxycarbonylpentamethylen), (Poly-e-caprolacton), (3), wurde bei 220°C im Stickstoffstrom bei 80 mm Hg untersucht. Dabei wurde gefunden, das 3 thermisch wesentlich stabi…
Nuclear Radiation Detected Optical Pumping of neutron-deficient Hg isotopes
1976
The extension of the Nuclear Radiation Detected Optical Pumping method to mass-separated samples of isotopes far off stability is presented for a series of light Hg isotopes produced at the ISOLDE facility at CERN. The isotope under investigation is transferred by an automatic transfer system into the optical pumping apparatus. Zeeman scanning of an isotopically pure Hg spectral lamp is used to reach energetic coincidence with the hyperfine structure components of the 6s 2 1 S 06s6p 3P1,λ=2,537 A resonance line of the investigated isotope and the Hg lamp. The orientation built up by optical pumping is monitored via the asymmetry or anisotropy of the nuclear radiation. Nuclear spins, magneti…
Determinants of evaluation of team performance
1976
Abstract.— The purpose of this study was to examine factors affecting the evaluation of the achievement behavior of a group. Subjects were asked to play the role of team members who have to convey their feedback to the whole team right after the performance. 214 subjects (males and females, high and low achievers) evaluated the achievement behavior of a group, a sports team. They were given knowledge of the group's performance outcomes (5 outcomes from clear win to clear loss), of the group's ability (yes or no) and of the effort (yes or no) expended by the group members. These factors yielded the 20 situations judged by each subject. In addition, half of the subjects evaluated a team perfo…
Über Chalkogenolate, LXXI. Notiz zur Thiolyse von Alkylenbis (thioimidsäureestern)
1976
Finite perturbation calculation for the static dipole polarizabilities of the atoms Na through Ca
1976
Application of a new glass capillary chromatographic technique in the analysis of phenoxyacetic acid herbicides.
1976
Integrated Optical Technique for Detection of Electro-Optical Non-Linearities in Thin Films
1976
A simple method for detection of electro-optical non-linearities in thin films is presented. The method involves an easily fabricated structure and a little practice in integrated optical techniques. It is also possible to detect small induced variations of refractive index, using lower voltage with respect to those applied in a conventional Kerr cell. We have sucessfully tested our method using two different polymer materials as thin films. In both of these we have observed an induced ?n ? 3 10?5 with an electric field of 60 V/?, with a response time round about 300 nsec. The experimental values of induced ?n versus electric field fit very well a parabola, proving the quadratic behavior of…
Spins, moments and charge radii in the isotopic series181Hg-191Hg
1976
The hyperfine structure splitting and the isotope shift in the (6 s2 1S0 - 6s 6p3P1,λ=2,537 A) line of very neutron deficient Hg isotopes were determined by the β radiation detected optical pumping method (β-RADOP). In addition, nuclear magnetic resonance was observed in the atomic ground state. The results are Mean-square nuclear charge radii are calculated. Interpreting the sudden change of nuclear radius between187Hg and185Hg δ〈r2〉187,185=0.42(5)fm2 as oblate-prolate shape transition, one obtains δ〈β2〉 =0.054(5).
Social skills of aggressive and nonaggressive adolescents.
1976
.— Forty 14-year-old boys were selected on the basis of peer ratings to represent characteristic aggressive, controlled extravert, anxious, and controlled introvert patterns of behaviour. Each boy was asked to play the role of either a son or a chum with the corresponding father's or chum's role played by the male E in four tape recorded dialogues. The topics were “getting more pocket money”, “holiday making”, “choosing a TV channel”, and “agreeing on a favourite make of car”. The boys' ability to persuade the opponent and to express their disagreement in a socially acceptable manner was studied. In accordance with the hypotheses the results showed that the controlled extraverts were sensib…
Duodenogastrischer Reflux nach Vagotomie und Pyloroplastik
1976
Bei 27 Patienten mit selektiver oder trunkularer Vagotomie und Pyloroplastik wurde gepruft, ob ein duodenogastrischer Reflux vorliegt. Die Untersuchung erfolgte rontgenologisch durch Instillation von verdunntem Bariumbrei in das Duodenum und durch Nachweis von i.v. appliziertem Bromsulphalein im Magensaft. Es konnte bei 20 von 23 Patienten rontgenologisch und bei 18 von 27 Patienten durch den Bromsulphalein-Nachweis ein duodenogastrischer Reflux festgestellt werden. In Zusammenhang mit Reflux standen postoperative Beschwerden wie Vollegefuhl, Brechreiz und Oberbauchschmerzen, sowie der Nachweis morphologischer Veranderungen der Magenschleimhaut im Sinne von Gastritiden verschiedener Stadien.
Ein transplantierbarer embryogener Callus aus Nucellusgewebe vonCynanchum vincetoxicum und die Rolle globul�rer Vorstadien in der Entwicklungsgeschic…
1976
Unbestaubte Fruchtknoten vonCynanchum vincetoxicum, C. medium undC. nigrum wurden steril exzidiert und in Kultur genommen. Nach 5–10 Wochen brachen aus einigen derC. nigrum-Explantate zahlreiche grune Pflanzchen hervor. Schnittpraparaten war zu entnehmen, das es sich um von den Nucellus-Zellen der unbefruchteten Ovula abstammende Adventivembryonen handelt. Aus einem callusierenden Fruchtknoten vonC. vincetoxicum lies sich schlieslich ein embryogener Callus gewinnen, den wir schon seit mehr als 3 Jahren in Kultur haben. Sowohl die nucellaren als auch die callogenen Keimlinge konnten in Erde ubertragen und zu bluhenden Pflanzen weiterkultiviert werden.
Rapid chemical separation procedures
1976
Fast, discontinuous separation procedures are described for zirconium, niobium, technetium and antimony from fission products. Other rapid separation methods from aqueous solutions are summarized. The combination of a gas jet recoil transport system with a continuous solvent extraction technique and with a thermochromatographic separation method is presented. The application of such procedures to the investigation of new and already known short-lived nuclides is illustrated by some examples.
Niche relations among dung-inhabiting beetles.
1976
The whole dung-inhabiting (adult) beetle community living in southern Finland was studied with reference to the seasonal (6 summer months), macrohabitat (open field, half-open pine forest and closed spruce forest) and successional (30 days) gradients. The material comprised 50 coprophagous and 129 carnivorous species, represented by 26,650 and 35,850 individuals, respectively. The most important characteristics of each species are given in an Appendix.In the coprophages the species-abundance relations fitted the lognormal distribution well, but in the carnivores the distribution was strikingly less even. A great number of other differences (see below) apparent between the two trophic groups…
Comment on the Deuteron Structure FunctionA(q2)at High Momentum Transfers
1976
Calculations of A (q/sup 2/) were performed for various NN potentials and electromagnetic nucleon form factors at q/sup 2/=0--160 fm/sup -2/ with inclusion of isobar configurations and meson exchange currents, indicating that recent elastic electron scattering experiments do not rule out the existence of isobar configurations and meson exchange currents in the deuteron as has been conjectured. (AIP)
The bulbar respiratory centre in the rabbit. I. Changes of respiratory parameters caused by intermittent electrical bulbar stimulation during inspira…
1976
In anesthetized rabbits, spirogram and diaphragmatic activity were examined during electrical stimulation of the bulbar lateral reticular formation. The activity of bulbar respiratory neurons was recorded contra-or ipsilaterally to the stimulation site. One volley of repetitive stimuli per breath was delivered during either inspiration or expiration. 1. Each volley of about 120 ms duration at 100 pulses per second, delivered early ininspiration, caused an immediate and transient inhibition of the diaphragmatic activity. An inspiratory, rebound comprising lengthening of inspiration and increase in tidal volume occurred. a) “Inspiratory” and “expiratory-inspiratory” phase-spanning neurons exh…
Membrane-Bound F1 ATPase from Micrococcus Sp. ATCC 398E. Purification and Characterization by Affinity Chromatography
1976
A chemically reactive ATP analogue, 6-[(3-carboxy-4-nitrophenyl)thio]-9-β-D-ribofuranosylpurine 5′-triphosphate (Nbs6ITP) has been synthesized. It has the ability to form stable thioether bonds between the 6-position of the purine ring and aliphatic mercapto groups. The nucleotide moiety of the reagent has been covalently bound to agarose, via iminobispropylamine and N-acetyl-homocysteine as spacer with the purpose of producing an affinity chromatography material. The affinity matrix binds solubilized F1 ATPase from a crude extract of Micrococcus sp. membranes. Afterwards the enzyme can be selectively eluted from the column at a defined ATP concentration. This method is superior to the conv…