showing 36 of ~574560 from 574555 documents

Über eine Reaktion vono-Hydroxybenzylalkoholen mit Estern von Säuren des Phosphors mit der Koordinationszahl 3

1978

Abstract o-Hydroxybenzyl alcohol reacts with trimethyl phosphite under smooth conditions to o-hydroxyphenylmethane phosphonic acid dimethyl ester. This unusual reaction is of widest applicability. Derivatives of o-hydroxybenzyl alcohol independent of type, number or position of substituents in the ring, react with alkyl esters of phosphorous, phosphonous or phosphinous acids in an analogous process, forming the corresponding o-hydroxyphenylmethane phosphonic or phosphinic esters or phosphine oxides.

chemistry.chemical_classificationchemistry.chemical_compoundchemistryTrimethyl phosphiteOrganic chemistryAlcoholRing (chemistry)Medicinal chemistryDimethyl esterAlkylPhosphinePhosphorus and Sulfur and the Related Elements

Description of three new species oftyphlodromusscheuten from italy with redescription oftyphlodromus baccettiiLombardini (acari: phytoseiidae)

1978

Abstract Three new species of predacious mites from Italy, Typhlodromus ernesti , T. laurentii and T. pegazzani are described and illustrated. T. baccettii Lombardini, 1960 is redescribed.

PhytoseiidaebiologyEcologyTyphlodromusInsect ScienceZoologyAcaribiology.organism_classificationInternational Journal of Acarology

false

1978

A reaction vessel automatically controlled by magnetic valves is described which allows kinetic measurements of reactions with half lives t1/2≥2s by gravimetric determination of the conversion. Thus, it covers the gap between the flow tube and the conventional reaction vessel. The influence of mixing time and filling time on the molecular weight distribution of an anionically prepared polymer is discussed.

chemistry.chemical_classificationChemical engineeringPolymerizationChemistryPolymer chemistryMixing (process engineering)Gravimetric analysisMolar mass distributionHalf-lifePolymerChemical reactorKinetic energyDie Makromolekulare Chemie

Les colloïdes solubles du vin de champagne. Relation avec le « remuage »

1978

<p style="text-align: justify;">Dans ce travail on étudie un échantillonnage de vins de champagne, en vue d'établir une relation entre leur composition en colloïdes et la facilité du « remuage ».</p><p style="text-align: justify;">Après champagnisation, les teneurs en colloïdes totaux sont toujours supérieures à celles des vins tranquilles correspondants. Plus la durée de clarification et de remuage est grande plus la teneur en colloïdes est élevée.</p><p style="text-align: justify;">Le fractionnement des colloïdes glucidiques solubles, en quatre fractions, sur Sépharose 6 B montre que celle de plus haut poids moléculaire a l'influence la plus directe sur les d…

Sepharose 6 Bsoluble glucidic colloidsparkleChemistrystirring-uplcsh:SHorticulturelcsh:QK1-989lcsh:Agriculturepolyphenolstill winelcsh:Botanycolloidchampagne wineHumanitiesFood ScienceOENO One

false

1978

A newly designed automatically controlled stirred reactor suitable for kinetic measurements of reactions with half lives ≥2s has been applied to follow the anionic polymerization of methyl methacrylate in THF with Na+ as a counter ion in the presence of an excess of NaB(C6H5)4. As initiators were used: benzylsodium reacted with α-methylstyrene (I), fluorenylsodium (II), and 9-methylfluorenylsodium (III). With I the initiation is fast as compared with the polymerization reaction which is first order in monomer concentration. Within the range of −50°C to −100°C an almost unperturbed “living” polymerization is observed. The Arrhenius plot of the rate constants results in a straight line with a…

chemistry.chemical_compoundAnionic addition polymerizationMonomerReaction rate constantPolymerizationChemistryTacticityPolymer chemistryActivation energyMethyl methacrylateArrhenius plotDie Makromolekulare Chemie

Anthropology as a natural science

1978

On the basis of materials collected by the research project System Analysis of Anthropology (SAA) the author discusses problems of the structure and relationships of biological anthropology. o (1) In the eastern, southeastern and southern European countries anthropology is strictly defined as natural science (source: conversation lexicons); also in Germany and some neighbouring countries other anthropologies, particularly the philosophical one, exist and have increased in recent years; a third group is represented by the Anglo-Saxon anthropology which comprises social and cultural as well as physical (Figure 1). The proportion of physical anthropological papers in anthropological periodical…

HistoryAnthropologyAnthropologyAnthropology of artAnthropogenySociocultural anthropologyFour field approachApplied anthropologyDigital anthropologyHistory of anthropologyHistory and AnthropologyEcology Evolution Behavior and SystematicsJournal of Human Evolution

Latent measles virus infection in Vero cells depending on a temperature-sensitive phenomenon.

1978

A latent infection by measles virus in a line of Vero cells could be maintained only at 37 degrees C. The conditions of temperature nonpermissiveness were associated with some block in virus production and/or release and with the establishment of an autointerference phenomenon. Reduction of the incubation temperature to 33.5 degrees C induced a rather rapid transition from the latent to a lytical infection with a recue of virus. The rescued virus exhibited a restricted capacity to grow at 37 degrees C.

biologyvirusesTemperatureGeneral MedicineHaplorhinibiology.organism_classificationVirus ReplicationVirologyVirusMicrobiologyCell LineMeasles virusIncubation temperatureCytopathogenic Effect ViralMeasles virusVirologyViral InterferenceVero cellAnimalsTemperature sensitiveAntigens ViralArchives of virology

Monolayer Polymerization of Diacetylene Monocarbonic Acids at the Gas-Water-Interface

1978

chemistry.chemical_compoundMaterials scienceDiacetylenechemistryPolymerizationChemical engineeringInterface (Java)General Chemical EngineeringMonolayerBerichte der Bunsengesellschaft für physikalische Chemie

EEG-responses caused by environmental noise during sleep their relationships to exogenic and endogenic influences.

1978

Abstract At a certain level of intensity acoustical stimuli occurring during the night lead to sleep disorders. Whereas presumed after-effects (decrease of performance, functional and organic diseases) can as yet not be related to noise, it is evident that the primary effects which can be recorded immediately after stimulus onset are caused by noise. Because of the small number of experimental trials carried out in different investigations, the results of each single paper can only be tentative. Therefore — concerning awakening reactions and reactions less than a change of at least one sleep stage — the data from publications of comparable method and evaluation have been summarised. With th…

Sleep Wake Disordersmedicine.medical_specialtyEnvironmental Engineeringmedicine.diagnostic_testStage onlyElectroencephalographyStimulus (physiology)AudiologyElectroencephalographyPollutionNoise TransportationmedicineForensic engineeringNoise OccupationalEnvironmental ChemistryHumansSleep StagesEnvironmental noisePsychologyNoiseSleepWaste Management and DisposalThe Science of the total environment

Improved reliability estimates for the serial color-word test

1978

Starting from Lennart Sjoberg's serial scoring of the Color-Word Test and his critical review of the test, the possibilities of attaining better reliability estimates are briefly surveyed. As a simple step, the orthogonalization of the regression model is suggested. Ways of maximizing the reliability estimate are demonstrated. On the basis of 261 subjects from five differing subsamples, clinical and control groups, the reliability estimates of the oblique system of the orthogonalized system and of the maximum reliability solutions are compared empirically. The significance of the results for test theoretic evaluation of the Color-Word Test is discussed.

Arts and Humanities (miscellaneous)StatisticsColor wordDevelopmental and Educational PsychologyOblique caseRegression analysisGeneral MedicineStroop color word testPsychologyOrthogonalizationGeneral PsychologyReliability (statistics)Test (assessment)Scandinavian Journal of Psychology

Ecdysone and ecdysterone in physogastric termite queens and eggs of Macrotermes bellicosus and Macrotermes subhyalinus

1978

Abstract Physogastric queens and freshly laid eggs of two species of termites ( Macrotermes bellicosus and Macrotermes subhyalinus ) are found to contain high levels of ecdysteroids (molting hormones) as indicated by radioimmunoassay and Musca bioassay. Ecdysteroids are accumulated in the ovaries of the queen and then stored in the eggs since newly laid eggs contain ecdysteroid concentrations similar to those found in the ovaries. Gas chromatography-mass spectrometry demonstrates that ecdysone (α-ecdysone) as well as ecdysterone (β-ecdysone) are present in queen ovaries and in eggs and that ecdysone is quantitatively the more important ecdysteroid in both ovary and eggs.

0106 biological sciencesOvum/*analysisEcdysoneanimal structuresInsectaEcdysteroneeducationOvary (botany)Ecdysterone/*analysis01 natural sciencesMacrotermes bellicosus03 medical and health scienceschemistry.chemical_compoundEndocrinologyInsects/*analysisHemolymphHemolymphBotanyHemolymph/analysisAnimals030304 developmental biologyOvum0303 health sciencesEcdysteroidintegumentary systembiologyfungiOvarybiology.organism_classification3. Good health010602 entomologyEcdysteroneEcdysone/*analysischemistryOvary/analysisembryonic structuresAnimal Science and ZoologyFemaleMuscaMoultingEcdysone

A Theoretical Model to Describe the Motion of Aerosol Particles Due to the Combined Action of Inertia, Brownian Diffusion and Phoretic and Electric F…

1978

Abstract General principles of non-equilibrium thermodynamics are used to formulate a model which describes the motion of aerosol particles affected simultaneously by Brownian diffusion, inertial impaction, electric forces and phoretic forces. The theory presented applies to an ideal mixture consisting of dry air, water vapor and aerosol particles where temperature, pressure as well as vapor and particle concentration inhomogeneities are to be considered. In addition, the system is subjected to the earth's gravity, to an external electric field as well as to a Coulomb force due to a charged collecting water drop. The basic model assumptions are as follows: 1) the diffusive kinetic energy of…

PhysicsAtmospheric ScienceInternal energyEntropy productionmedia_common.quotation_subjectInertiaAerosolCoulomb's lawEntropy (classical thermodynamics)symbols.namesakeClassical mechanicsElectric fieldsymbolsPhysics::Atmospheric and Oceanic PhysicsBrownian motionmedia_commonJournal of the Atmospheric Sciences

Isotope Distributions in the Reaction ofU238withU238

1978

Radiochemically determined cross sections $\ensuremath{\sigma}(Z, A)$ were used to construct charge and mass distributions for the reaction of 1785-MeV $^{238}\mathrm{U}$ ions with thick $^{238}\mathrm{U}$ targets. Fission of the colliding nuclei is found to dominate. For the surviving uraniumlike fragments an enhancement of yields compared to the Kr + U and Xe + U reactions is observed. The formation of heavy actinides is shown to be associated with the low-energy tails of the broad excitation energy distributions in damped collisions.

Nuclear reactionPhysicsFissionNuclear TheoryKryptonGeneral Physics and AstronomyCharge densitychemistry.chemical_elementCharge (physics)Spectral lineIonNuclear physicschemistryMass spectrumAtomic physicsNuclear ExperimentPhysical Review Letters

Changes of the ratio between myelin thickness and axon diameter in the human developing sural nerve

1978

Axon caliber and myelin sheath thickness of individual nerve fibers were evaluated in the developing human sural nerve using three different methods of measurement: 1. ocular micrometer evaluation of large fibers, 2. photographic enlargements for evaluating large numbers of nerve fibers of all sizes, and 3. electron microscopic enlargements for more precise measurements in selected nerves. The average axonal diameter doubles from 5 months gestation to about 5 years of age. Large fiber group axons increase, during the same period, by a factor of 3--3.5 with a slight decrease thereafter. The myelin thickness increases more slowly, but continuously, between 5 months gestation until the age of …

MaleAdolescentSural nervePathology and Forensic MedicineCellular and Molecular NeuroscienceMyelinSural NervemedicineHumansAxonChildElectron microscopicMyelin SheathOcular micrometerChemistryMyelin sheathsInfant NewbornInfantAnatomyAxonsMicroscopy ElectronSpinal Nervesmedicine.anatomical_structurenervous systemCaliberChild PreschoolMyelin sheathFemaleNeurology (clinical)MathematicsActa Neuropathologica

Mechanisms of polymer crystallization from flowing solutions

1978

The recent experimental results on flow-induced crystallization by Pennings and coworkers show that extremely rigid polyethylene fibers can be obtained in a shear flow. On the other hand, the mechanism by which these flow-induced crystals are produced is still open to investigation. In this work a few aspects of fibrous crystal growth are theoretically investigated. The molecular dynamics of chains partly attached to the crystal and partly immersed in the solution is considered. The influence of temperature and of geometrical factors is also discussed.

Work (thermodynamics)Materials sciencePolymers and PlasticsCrystallization of polymersPhysics::OpticsCrystal growthGeneral ChemistryPolyethylenelaw.inventionCrystalMolecular dynamicschemistry.chemical_compoundchemistrylawChemical physicsPolymer chemistryMaterials ChemistryCrystallizationShear flowPolymer Engineering and Science

High-dose behaviour of CaSO4: Dy thermoluminescent phosphors as deduced by a continuous model for trap depths

1978

Abstract The high-dose behaviour of CaSO4: Dy TL dosimeters observed by some authors is compared with the one deduced by the continuous distribution of trap depths previously proposed by us. A general agreement results.

Materials scienceDosimeterContinuous modellingPhosphorGeneral MedicineTrap (plumbing)Atomic physicsThermoluminescenceNuclear Instruments and Methods

Observability of γ-ray pulsars

1978

PULSARS seem to play a major role as γ-ray emitters. Of the 13 objects listed in the first COS B catalogue1 the two brightest, CG185-5 and CG263-2, have been identified with the Crab (PSR0531+21) and Vela (PSR0833–;45) pulsars respectively. This privileged role of pulsars as identified γ-ray sources could be simply related to observational reasons: in fact, because of the poor angular resolution intrinsic to the γ-ray telescopes, the only possibility of identification for individual sources is the time structure of the emission, and the periodical pattern of pulsars is particularly suited. On the other hand, for PSR0531+21 and PSR0833−45, the observed pulsed energy release is essentially in…

PhysicsNeutron starMultidisciplinaryPulsarAstrophysics::High Energy Astrophysical PhenomenaStellar rotationGamma rayAstronomyAngular resolutionAstrophysicsGamma-ray astronomyVelaLuminosityNature

Isobar excitation in proton-proton bremsstrahlung

1978

Abstract The contribution of intermediate nucleon isobars to proton-proton bremsstrahlung is calculated in a relativistic model. Using conventional coupling constants and form factors for the exchange of π - and ρ-mesons we find that for photon energies ω > 100 MeV isobar excitation increases the cross section markedly over the prediction of soft-photon calculations. Our results agree well with recent experiments at incident proton energy T lab =730 MeV.

PhysicsCoupling constantNuclear and High Energy PhysicsSoft photonPhotonProtonNuclear TheoryBremsstrahlungNuclear physicsIsobarPhysics::Accelerator PhysicsAtomic physicsNuclear ExperimentNucleonExcitationNuclear Physics A

Inhibitoren der Korrosion 22 (1) - Einfluß von pH, Sauerstoff, Fremdionen, Art und Konzentration von Säuren auf den Korrosionsverlauf von Aluminium

1978

Die Korrosion von Aluminium unter Sauerstoff verlauft praktisch unabhangig vom pH-Wert, und zwar sowohl unter Sauerstoffverbrauch als auch unter Wasserstoffentwicklung. Dieses Verhalten wird sowohl in einer Acetatpuffer/Natriumchloridlosung als auch in anorganischen (Salpeter-, Schwefel-Phosphor- und Salzsaure) als auch in organischen Sauren gefunden. Bei den organischen Sauren sind die Ergebnisse jedoch nicht so eindeutig; in Essigsaure wird die Korrosionsgeschwindigkeit durch Natriumchloridzusatz nicht beeinflust, ebenso in Ameisensaure, wahrend Oxalsaure nur bei Anwesenheit von Natriumchlorid Wasserstoff entwickelt. Zitronensaure bewirkt uberhaupt keine Wasserstoffentwicklung. Als am bes…

Formic acidMechanical EngineeringSodiumOxalic acidMetals and Alloyschemistry.chemical_elementHydrochloric acidGeneral MedicineOxygenSurfaces Coatings and Filmschemistry.chemical_compoundAcetic acidchemistryMechanics of MaterialsAluminiumMaterials ChemistryEnvironmental ChemistryCitric acidNuclear chemistryMaterials and Corrosion

The Lich-Gregoir antireflux plasty: experiences with 371 children.

1978

AbstractThe Lich-Gregoir antireflux procedure is a simple and safe method for the treatment of primary reflux of all grades if the ureter is not grossly dilated on the excretory urogram. Reflux was cured in 97.7 per cent of 429 ureters in 371 children. A stenosis of the terminal ureter requiring reimplantation occurred in 0.5 per cent. The over-all rate of reinterventions was 3.7 per cent. This low complication rate makes surgical correction of reflux advisable if urinary tract infection and primary reflux cannot be eradicated by continuous antimicrobial therapy within 6 months.

Malemedicine.medical_specialtyAdolescentUrologyUrinary systemUrinary BladderUretermedicineMethodsHumansComplication rateChildVesico-Ureteral Refluxbusiness.industryRefluxInfantSurgical correctionmedicine.diseasedigestive system diseasesSurgeryStenosismedicine.anatomical_structureChild PreschoolFemaleUreterbusinessThe Journal of urology

MEASUREMENTS OF THE ATTENUATION OF FOURTH SOUND IN HELIUM II

1978

Physicsgeographygeography.geographical_feature_categorychemistryAcousticsAttenuationGeneral Engineeringchemistry.chemical_elementHeliumSound (geography)Le Journal de Physique Colloques

The Influence of Thiol Reagents on the Isoenzyme Pattern of Plant L+Lactate Dehydrogenase (EC 1.1.1.27)

1978

Summary Lactate dehydrogenase from potato tubers was incubated together with various thiol reagents and the effect on the electrophoretic behavior of its isoenzymes studied. while disulfides, alkylating agents, and H202 did not alter the number and electrophoretic behavior of the isoenzymes of L + LDH, reduced glutathione and 2-mercaptoethanol led to an increase in the number of isoenzymes. The reaction was dependent on concentration and pH. On the other hand, cysteine and cysteamine had no such effect. Results are discussed in view of the possible secondary nature of the plant LDH isoenzymes.

Thiol Reagentsfood and beveragesGeneral MedicineGlutathioneIsozymeMolecular biologyIsoenzyme patternElectrophoresischemistry.chemical_compoundchemistryBiochemistryLactate dehydrogenaseCysteamineCysteineZeitschrift für Pflanzenphysiologie

Acupuncture: its neurophysiological basis: an anaesthetist's foreword.

1978

PharmacologyCentral Nervous SystemNeurotransmitter Agentsbusiness.industryAcupuncture TherapyPainCell BiologyNeurophysiologyCellular and Molecular NeuroscienceAnesthesiaNeural PathwaysAcupunctureCatsMolecular MedicineMedicineAnimalsHumansRabbitsAnalgesiabusinessMolecular BiologyExperientia

Die orientierung der kristallinen und der nichtkristallinen bereiche in verstreckten polyethylenterephthalat-folien

1978

Films of poly(ethylene terephthalate) were stretched at 100°C with different stretching rates. By this, oriented films with birefringences between 3.10−3 and 100.10−3 were produced. After a crystallization with fixed ends at 150°C, 200°C and 240°C, the orientation function of the crystalline regions, the density, and the birefringence were measured. From this data, the orientation function of the noncrystalline regions was computed. The results obtained show, that only a qualitative but not a quantitative computation of the orientation function is possible. With increasing birefringence of the material before crystallization, the orientation of the crystalline and the noncrystalline regions…

Crystallization temperatureCrystallographyOrientation functionBirefringenceMaterials scienceCondensed matter physicslawOrientation (geometry)Polymer chemistryCrystallizationlaw.inventionDie Makromolekulare Chemie

Physical and chemical properties of skin in habitually trained and sedentary men.

1978

A number of physical and chemical properties of skin were examined in a study of 29 habitually trained and 29 sedentary men. Compared to the control group, the trained subjects had significantly higher values in the weights of skin samples of equal surface areas as well as the contents of hydroxyproline and nitrogen per skin surface area. When measured by a diaphragm method in vivo, the 'elastic stiffness' (uncorrected for thickness) and 'elastic efficiency' (the recovery of the deformation energy) of skin were significantly higher in the trained men compared to those in the untrained men. The results suggest that skin reflects the adaptation to habitual endurance training by increasing its…

AdultMaleSkin Physiological Phenomenamedicine.medical_specialtyintegumentary systembusiness.industryNitrogenPhysical fitnessDermatologyMiddle AgedElasticityHydroxyprolineEndurance trainingAgeingPhysical FitnessSkin Physiological PhenomenaTensile StrengthSkin surfacePhysical therapyMedicineHumansbusinessTrained subjectsAgedSkinThe British journal of dermatology

Three new species of phytoseiid mites from Kenya (Mesostigmata: Phytoseiidae)

1978

The following 13 species of predacious mites of the family Phytoseiidae are recorded from various plants in Kenya: Amblyseius albizziae sp. nov., A. kenyae sp. nov., A. natalensis Van der Merwe, A. lokele Pritchard & Baker, A. largoensis (Muma), A. rykei Pritchard & Baker, A. teke Pritchard & Baker, Typholdromus kikuyuensis sp. nov., T. magdalenae Pritchard & Baker, Phytoseius amba Pritchard & Baker, p. ferox Pritchard & Baker, Iphiseius degenerans (Berlese), I. gongylus Pritchard & Baker. The new species and the male of A. natalensis are described.

PhytoseiidaebiologyBotanyAmblyseiusAnimal Science and ZoologyMesostigmataIphiseius degeneransbiology.organism_classificationPhytoseiusEcology Evolution Behavior and SystematicsZoological Journal of the Linnean Society

A simplified description of viscoelastic behavior of polymers as illustrated with biaxially-oriented poly(ethylene terephthalate)

1978

A rheological model of solid polymers is proposed. Its mechanical analog is a parallel of a linear spring and a Maxwell element with variable viscosity. The viscosity of the dashpot is allowed to change with stress both directly, by an Eyring-type mechanism, and through free volume changes according to the Doolittle equation. Predictions of the model reproduce many of the features shown, especially after yielding, by constant velocity stress-strain, stress-relaxation and creep data taken at room temperature on biaxially-oriented poly(ethylene terephthalate) over a wide range of loading rates.

chemistry.chemical_classificationMaterials sciencePolymers and PlasticsGeneral ChemistryPolymerDashpotViscoelasticityStress (mechanics)ViscosityRheologychemistryCreepSpring (device)Materials ChemistryComposite materialPolymer Engineering and Science

THE THERMAL EXPANSION OF HELIUM II IN RESTRICTED GEOMETRIES

1978

Materials sciencechemistryGeneral Engineeringchemistry.chemical_elementAtomic physicsHeliumThermal expansionLe Journal de Physique Colloques

The axial isoscalar neutral current from inelastic electron-nuclear scattering

1978

Abstract Parity violating effects due to neutral currents in isoscalar 0+→1+ nuclear transitions induced by electron scattering are enhanced owing to the small isoscalar magnetic dipole strength. A polarization asymmetry of the order 10−4 is expected at q ∼ 100 MeV for the 12C transition to the 1+(T = 0) state at 12.71 MeV. It would allow to single out the (electron vector current) × (hardonic axial isoscalar current) quantum numbers and couplings of the neutral current interaction.

PhysicsNuclear and High Energy PhysicsNeutral currentIsoscalarmedia_common.quotation_subjectNuclear TheoryFísicaParity (physics)ElectronQuantum numberAsymmetryNuclear physicsElectron scatteringMagnetic dipolemedia_commonParticle Physics - Phenomenology

Structure and closure mechanism of the human umbilical artery

1978

The structure of the fully-patent umbilical artery and rearrangement of its structural elements with postnatal closure were examined in 10 centimeter long umbilical cord segments which were double-clamped at different time intervals after delivery. The fully-patent umbilical artery consists of two main layers: an outer layer of circularly arranged smooth muscle cells and an inner layer which shows rather irregularly and loosely arranged cells embedded in abundant metachromatic ground substance. No predominantly longitudinal arrangements of cells and fibers reported by earlier investigators could be identified in the inner layer. Closure of the umbilical arteries is initiated by numerous loc…

MyofilamentGround substanceLumen (anatomy)Cell DifferentiationMuscle SmoothUmbilical arteryAnatomyBiologyUmbilical ArteriesLong umbilical cordlaw.inventionMicroscopy Electronmedicine.anatomical_structurelawmedicine.arteryPediatrics Perinatology and Child HealthmedicineHumansMyocyteElectron microscopeBlood vesselEuropean Journal of Pediatrics

[1,2,3]Triazoloazine/(Diazomethyl)azine Valence Tautomers from 5-Azinyltetrazoles

1978

[1,2,3]Triazoloazines are formed by thermolysis of 5-azinyltetrazoles in the gasphase or in solution. Thus, 5-(2-pyridyl)tetrazole (7) and 5-(2-pyrazinyl)tetrazole (11) yield [1,2,3]triazolo[1,5-a]pyridine (9) and [1,2,3]triazolo[1,5-a]pyrazine (13), respectively, at 400°/10−3 - 10−5 Torr. 5-(2-Phenyl-4-quinazolinyl)tetrazole (15) gives 5-phenyl[1,2,3]triazolo[1,5-c]quinazoline (17) in 75% yield by heating under reflux in mesitylene solution. 2-(Diazomethyl)pyridine (8), a valence tautomer of 9, can be trapped by fumaronitrile, leading to 3-(2-pyridyl)-1, 2-cyclopropanedicarbonitrile (19). The [1,2,3]triazoloazines undergo base catalysed H/D-exchange in D2O solution.

Valence (chemistry)PyrazineStereochemistryOrganic ChemistryBiochemistryTautomerMedicinal chemistryCatalysisInorganic ChemistryAzinechemistry.chemical_compoundchemistryDrug DiscoveryPyridineQuinazolineTetrazolePhysical and Theoretical ChemistryMesityleneHelvetica Chimica Acta

Interpretation of the High-Energy ProcessesO16(γ,p0)N15andO16(γ,n0)O15

1978

Calculations based on a two-nucleon ($n\ensuremath{-}p$) absorption mechanism show that the form factor of the residual nucleus plays an important role in determining the shape of the photoproduction cross section in a wide energy range $60 \mathrm{MeV}l~{E}_{\ensuremath{\gamma}}l~300 \mathrm{MeV}$.

PhysicsNuclear reactionBaryonCrystallographyNuclear TheoryHadronForm factor (quantum field theory)General Physics and AstronomyElementary particleAbsorption (logic)Nuclear ExperimentNucleonEnergy (signal processing)Physical Review Letters

Studium zum Vorgang der Wasserstoffübertragung, 50. Elektroreduktion und phasentransferkatalysierte Borhydrid-reduktion prochiraler Ketone

1978

Prochirale Carbonylverbindungen wurden in die entsprechenden sekundaren Alkohole ubergefuhrt a) durch Elektroreduktion und b) mit NaBH4, in beiden Fallen mit den gleichen Ephedriniumsalzen, und zwar fur a) als optisch aktive Leitsalze und fur b) als optisch aktive Phasentransfer-Katalysatoren. Es wurden bei der Elektroreduktion und bei der Phasentransfer-Katalyse die Ausbeuten an Carbinol (und Pinakol)3), die optische Ausbeute und die absolute Konfiguration des bevorzugt gebildeten Enantiomeren bestimmt. In der uberwiegenden Mehrzahl der untersuchten Beispiele besitzen die unter Mitwirkung optisch aktiver Ephedriniumsalze nach beiden Methoden erhaltenen Uberschusenantiomeren die entgegenges…

Supporting electrolyteChemistryHydrideOrganic ChemistryPolymer chemistryAbsolute configurationChiral phasePhysical and Theoretical ChemistryOptically activeEnantiomerPhase-transfer catalystCatalysisJustus Liebigs Annalen der Chemie

Occurrence and regional distribution of striated muscle fibers in the rat pineal gland

1978

In a total of 96 rat pineals studied 31 were found to contain striated muscle fibers or their precursors. The muscle fibers were most frequently present in the stalk region and more frequently found in the left than in the right hemisphere. Size measurements revealed that the lengths of pineal muscle cell nuclei differ only slightly from those of the sphincter muscle of the iris. However, the yellowish appearance of pineal muscle cell nuclei under darkfield investigation, a phenomenon observed in all muscular tissues of mesenchymal origin and connective tissue cells, may support the hypothesis that pineal musculature is of mesenchymal rather than ectodermal origin.

endocrine systemPathologymedicine.medical_specialtyHistologyMusclesMesenchymal stem cellConnective tissueCell BiologyAnatomyBiologyPineal GlandRatsPathology and Forensic MedicineRat Pineal GlandPineal glandmedicine.anatomical_structuremedicineAnimalsMyocyteRight hemisphereIris (anatomy)Sphincter muscleCell and Tissue Research

Papaverine enhances the negative inotropic effect of acetylcholine in rat auricles

1978

The negative inotropic effect of acetylcholine in rat left auricles is enhanced in the presence of the phosphodiesterase inhibitor papaverine. This result favours the idea of a cyclic GMP-mediated action of acetylcholine in the heart.

Inotropemedicine.medical_specialtyAction PotentialsIn Vitro TechniquesCellular and Molecular NeurosciencePapaverineInternal medicinemedicineAnimalsHeart AtriaPhosphodiesterase inhibitorCyclic GMPMolecular BiologyPharmacologyPapaverineChemistryPhosphodiesteraseDrug SynergismCell BiologyMyocardial ContractionAcetylcholineRatsEndocrinologyDepression ChemicalMolecular MedicineAcetylcholinemedicine.drugExperientia

Raman spectroscopic method for determining the crystallinity of polyethylene

1978

The Raman spectrum of partially crystalline polyethylene can be described as a superposition of three components, which originate from the orthorhombic crystalline phase, a meltlike amorphous phase, and a disordered phase of anisotropic nature, where chains are stretched but have lost their lateral order. The mass fractions involved in the three phases can be derived directly from the integral intensities of characteristic bands without an additional calibration procedure. A comparison of the results obtained for a variety of samples shows agreement with the crystallinities derived from the density, and the small-angle and wide-angle x-ray diagrams. Data indicate that the disordered anisotr…

Materials scienceGeneral EngineeringAnalytical chemistryPolyethyleneAmorphous solidCondensed Matter::Materials ScienceCrystallographychemistry.chemical_compoundsymbols.namesakeCrystallinitychemistryPhase (matter)symbolsOrthorhombic crystal systemAnisotropyRaman spectroscopyMass fractionJournal of Polymer Science: Polymer Physics Edition