showing 36 of ~574560 from 574555 documents

Prognostic factors in the treatment of Ewing's sarcoma

1987

From 1981 up to February 1985, a total of 93 protocol patients entered the study CESS 81. The protocol recommended an initial 18-week period of polychemotherapy (VACA) followed by local therapy and two additional cycles of chemotherapy. Local therapy consisted either of radical surgery or of incomplete resection plus postoperative irradiation with 36 Gy or of radiotherapy alone (46 and 60 Gy). Centrally located lesions were always irradiated with 60 Gy. This article summarizes the data after 5 years. Data of 93 patients were analysed in October 1986 after a median follow-up of 37 months. The projected 5-year survival is 50%. The relapse rate was 42%, distant relapses occurred in 19%, local …

medicine.medical_specialtyChemotherapybusiness.industryPaediatric oncologymedicine.medical_treatmentPostoperative irradiationEwing's sarcomaHematologymedicine.diseaseSurgeryRadiation therapyOncologyMedicineCombined Modality TherapyRadiology Nuclear Medicine and imagingSarcomaRadical surgerybusinessRadiotherapy and Oncology

Soret Effect In Forced Rayleigh-scattering

1987

In forced Rayleigh scattering of mixtures or suspensions the temperature gratings generate, by the Soret effect, concentration gratings that may be very important since they produce both a phase and an amplitude grating superimposed on the principal one. The experimental evidence of their influence was given by Thyagarajan and Lallemand using a mixture of carbondisulfide and ethanol. In this paper we study the temporal behaviour of the concentration grating versus the sample properties and its effect on the detected diffracted beam. Explicit expressions are given for the output intensity taking into account both the generated amplitude and phase gratings.

DiffractionMaterials sciencePhysics and Astronomy (miscellaneous)business.industryscatteringGeneral EngineeringPhase (waves)Physics::OpticsGeneral Physics and AstronomySoret effectGratingThermophoresisIntensity (physics)symbols.namesakeOpticsAmplitudesymbolsPhysics::Atomic PhysicsRayleigh scatteringAtomic physicsbusinessBeam (structure)

Reaction of α,β-poly(N-hydroxyethyl)-DL-aspartamide with derivatives of carboxylic acids

1987

Polymers and PlasticsStereochemistryChemistryOrganic ChemistryMaterials ChemistryJournal of Polymer Science Part A: Polymer Chemistry

Deformation recovery behaviour of a solid polymer after tensile yielding

1987

In this work the deformation recovery behavior of an amorphous polymer after large tensile deformation is studied at different temperatures. The effect of three parameters other than temperature has been pointed out in previous works (1–3). The data here presented indicate that the influence of all parameters, including temperature, on recovery behavior can be related to the residual stress, σ *, at the beginning of recovery test. This suggests to plot the recovery versus time curves, relative to different sets of parameters including temperature, by means of the same normalizing groups which were adopted in (2), thus shifting all curves towards a single master curve.

chemistry.chemical_classificationWork (thermodynamics)Materials sciencePolymers and PlasticsGeneral ChemistryPolymerDeformation (meteorology)Condensed Matter PhysicsAmorphous solidchemistryResidual stressvisual_artUltimate tensile strengthMaterials Chemistryvisual_art.visual_art_mediumPolycarbonateComposite materialPolymer Bulletin

Detectors and Chromatography. Ed. by A.J.C. Nicholson. Pp viii + 198, Australian Scientific Industry Association, ISBN 0 949761 087

1987

ChromatographyChemistryGeneral Chemical EngineeringJournal of High Resolution Chromatography

Lepton flavour violating decay of the Z0 in the scalar triplet model

1987

Abstract The lepton flavour violating Z→μme, Z→μτ and Z→eτ decays are evaluated in the framework of the majoron triplet model of Gelmini and Roncadelli. The process is dominated by the diagrams with charged scalars in the loops, so the GIM cancellation is avoided. We obtain branching ratios for Z→μτ and Z→eτ which might be detectable at SLC and/or LEP.

Nuclear physicsPhysicsNuclear and High Energy PhysicsParticle physicsFlavourScalar (mathematics)High Energy Physics::PhenomenologyFísicaHigh Energy Physics::ExperimentLeptonMajoronParticle Physics - Phenomenology

The commensurate-incommensurate transition of hydrogen monolayers physisorbed on graphite

1987

We present a neutron diffraction study of the commensurate-incommensurate (C-IC) transition of hydrogen monolayers physisorbed on the basal planes of exfoliated graphite. It is shown that the solid intermediate phase detected by specific-heat measurements can be described in terms of a striped domain-wall phase with superheavy walls. Comparison with simple models with fixed domain sizes is made. The results are in agreement with recent LEED experiments of Cui and Fain and provide an experimental realization of C-IC transition theories.

Materials scienceHydrogenNeutron diffractionchemistry.chemical_elementSurfaces and InterfacesCondensed Matter PhysicsMolecular physicsSurfaces Coatings and FilmsCrystallographychemistryPhase (matter)MonolayerMaterials ChemistryGraphiteSurface Science Letters

A Theoretical Study of the Wet Removal of Atmospheric Pollutants. Part II: The Uptake and Redistribution Of (NH4)2SO4Particles and SO2Gas Simultaneou…

1987

Abstract A theoretical model has been formulated which allows the processes which control the wet deposition of atmospheric aerosol particles and pollutant gases to be included in cloud dynamic models. The cloud considered in the model was allowed to grow by condensation and collision–coalescence, to remove aerosol particles by nucleation and impaction scavenging, and to remove pollutant gases by convective diffusion. The model was tested by using a simple air-parcel model as the dynamic framework. In this form the model was used to determine the fate of ammonium sulfate [(NH4)2SO4] particles and sulfur dioxide (SO2) gas as they became scavenged by cloud and precipitation drops. Special emp…

PollutantAtmospheric ScienceAmmonium sulfateNucleationchemistry.chemical_elementcomplex mixturesSulfurAerosolchemistry.chemical_compoundchemistryEnvironmental chemistryAtmospheric chemistryScavengingAstrophysics::Galaxy AstrophysicsPhysics::Atmospheric and Oceanic PhysicsSulfur dioxideJournal of the Atmospheric Sciences

Temperature dependence of slow-positron production and of positronium formation on untreated surfaces

1987

Low-energy positron emission from tungsten moderators, placed at a electron accelerator beam stop slows down with increasing moderator temperature. Efficient positronium formation is reported on untreated and unoriented metal surfaces at higher target temperatures.

Materials sciencePhysics and Astronomy (miscellaneous)General Engineeringchemistry.chemical_elementParticle acceleratorGeneral ChemistryTungstenMathematics::Geometric Topologylaw.inventionPositroniumMetalPositronchemistrylawvisual_artvisual_art.visual_art_mediumPhysics::Accelerator PhysicsGeneral Materials SciencePositron emissionAtomic physicsBeam (structure)Applied Physics A Solids and Surfaces

Die Lichtsammelkomplexe der verschiedenen Algenstämme Phylogenetische Vielfalt eukaryotischer Photosyntheseapparate

1987

ChemistryGeneral Agricultural and Biological SciencesBiologie in unserer Zeit

Catalytic activity of large-pore high Si/Al zeolites: Cracking of heptane on H-Beta and dealuminated HY zeolites

1987

Abstract The catalytic activity, selectivity, catalyst decay, thermal and hydrothermal stability, and acidity of H-Beta and HY zeolites with Si Al ratios of 7.5 and 10, respectively, have been studied during cracking of n-heptane at 450 °C and atmospheric pressure. It has been found that the H-Beta zeolite is more active and decays more slowly than HY. H-Beta presents a higher steric hindrance for dibranched molecules and therefore its open structure should be smaller than that of HY. A lower hydrogen transfer activity and hydrothermal stability is observed for H-Beta in comparison with the corresponding HY.

Heptanechemistry.chemical_compoundChemistryInorganic chemistryPhysical and Theoretical ChemistryZeoliteFluid catalytic crackingSelectivityChemical reactionPyrolysisCatalysisHydrothermal circulationCatalysisJournal of Catalysis

Changes of electrically elicited reflexes in hand and forearm muscles in man.

1987

Cutaneo-muscular reflexes with short and long latency excitatory phases following digital nerve stimulation were observed in the first dorsal interosseus muscle of the hand in healthy subjects. The short latency reflex was obtained also with the H-reflex method in the flexor carpi radialis muscle, stimulating the median nerve, with a mean latency (+/- SE) of 15.4 +/- 0.5 ms. The height of the subject correlated with the H-reflex latency. The amplitudes of maximal M-response and maximal H-reflex were higher in athletes than in normals. During weak voluntary contraction of the muscle studied the 50% H-reflex amplitude increased and during passive stretching of wrist flexors the resting amplit…

AdultMaleFlexor carpi radialis musclePhysical Therapy Sports Therapy and RehabilitationPassive stretchingElectromyographyH-ReflexForearmmedicineHumansLatency (engineering)medicine.diagnostic_testbusiness.industryElectromyographyReflex MonosynapticMusclesRehabilitationAnatomyHandMedian nerveElectric Stimulationbody regionsForearmmedicine.anatomical_structurePhysical FitnessReflexUpper limbFemalebusinessMuscle ContractionAmerican journal of physical medicine

Inhibition of glial proliferation in vitro by serum from patients with multiple sclerosis

1987

Primary cell cultures from fetal rat CNS have been employed to evaluate the effects caused by the addition of serum from patients affected by multiple sclerosis (MS). MS-serum supplemented media caused a decrease in [3H]-thymidine incorporation into the cultures, thus indicating an inhibitory effect on proliferating glial cells. Sera from patients in remission stage of the disease showed an inhibitory effect not significatively lower than those from patients in acute stage. These results suggest that glial cells may be a target of circulating factors present in MS.

AdultMalemedicine.medical_specialtyPathologyMultiple SclerosisDiseaseBiologyTritiumSettore BIO/19 - Microbiologia GeneraleInternal medicineSettore BIO/10 - BiochimicamedicineAnimalsHumansCells CulturedFetusNeuroscience (all)Cell growthMultiple sclerosisGeneral MedicineMiddle Agedmedicine.diseaseIn vitroAcute stageRatsEndocrinologymedicine.anatomical_structureNeurologyCell cultureNeurogliaFemaleSettore MED/26 - NeurologiaNeurology (clinical)NeurogliaCell DivisionThymidine

Bimodal sensory stimulation-induced seizures.

1987

Abstract A curious case is reported in which the patient, a young woman, exibited convulsive seizures when approaching closely to a television. The visual and acoustic stimulation did not change her EEG, whereas simultaneous stimulation with both the modalities induced bilateral and symmetrical high-voltage spikes (with their diffusion) that led to a convulsive seizure. Results are discussed with relation to the literature.

AdultSensory stimulation therapymedicine.diagnostic_testStimulationElectroencephalographyGeneral MedicineElectroencephalographyConvulsive seizureSimultaneous stimulationConvulsive SeizuresNeurologyAcoustic StimulationSeizuresmedicineHumansFemaleTelevisionsense organsNeurology (clinical)PsychologyNeurosciencePhotic StimulationActa neurologica Scandinavica

Isomerisierung der Dihydropentalene und Umsetzung mit Tetracyanethylen

1987

Zwischen den sechs isomeren Dihydropentalenen 1–6 existieren eine Reihe von H-Verschiebungen (Schema 1), die in Gasphasenpyrolysen untersucht werden. Der thermodynamisch kontrollierte irreversible Ausgang aus den Gleichgewichten von 1–6 fuhrt uber 1-Vinylfulven (14) zu Styrol (15). Praparativ nutzlich ist besonders die katalytische Isomerisierung zwischen 1,5-DHP (4) und 1,2-DHP (1) bei Raumtemperatur. Die Umsetzung der Dihydropentalene mit Tetracyanethylen liefert bei 1 das [2+2]-Addukt 24, bei 3 und 5 die [4+2]-Addukte 25 bzw. 26 und bei 4 das doppelte [4+2]-Addukt 22.2 und 6 lassen sich unter Blitzpyrolyse-Bedingungen mit TCNE nicht abfangen. Isomerization of Dihydropentalenes and Reacti…

Inorganic Chemistrychemistry.chemical_compoundCyclopentadieneBicyclic moleculeNitrileChemistryStereochemistryNuclear magnetic resonance spectroscopyTetracyanoethyleneMedicinal chemistryIsomerizationStyreneAdductChemische Berichte

Comparative investigations on the actions of ACTH1-24, somatostatin, neurotensin, substance P and vasopressin on locus coeruleus neuronal activity in…

1987

A considerable number of neuropeptides have been localized immunohistochemically in the area of the locus coeruleus of the rat. The objective of this study was to assess the actions of some of these transmitter candidates on spontaneously active locus coeruleus neurons in vitro. The effects of bath-applied peptides on the discharge rate of individual locus coeruleus neurons were investigated. A midpontine slice preparation of the gerbil brain was used. Excitatory dose-dependent effects were found with four peptides with the following rank order of potency: Substance P, (Arg8)-vasopressin, neurotensin, ACTH1–24. Somatostatin hyperpolarized all neurons tested. Given the pronounced effects see…

Maleendocrine systemmedicine.medical_specialtyVasopressinVasopressinsNeuropeptideSubstance PIn Vitro TechniquesSubstance Pchemistry.chemical_compoundSlice preparationInternal medicinemedicinePremovement neuronal activityAnimalsNeurotensinPharmacologyNeuronsChemistryNeuropeptidesGeneral MedicineArginine VasopressinEndocrinologySomatostatinnervous systemLocus coeruleusCosyntropinLocus CoeruleusGerbillinaeSomatostatinhormones hormone substitutes and hormone antagonistsNeurotensinNaunyn-Schmiedeberg's archives of pharmacology

Endoskopische Diagnostik und Therapie der akuten biliären Pankreatitis

1987

Endoskopische retrograde Cholangiopankreatikographie (ERCP) und endoskopische Papillometrie (EPT) sind wesentliche Saulen der Diagnostik und Therapie der akuten biliaren Pankreatitis. Patienten mit Pankreatitis sowie klinischen und laborchemischen Hinweisen auf eine extrahepatische Cholestase sollten unbedingt endoskopiert werden. Die EPT ermoglicht eine effektive und komplikationsarme Therapie, wenn die Pankreatitis mit Konkrementen in den Gallenwegen oder der Papille assoziert ist. Bei Patienten mit akuter Cholezystitis bei Cholezystolithiasis lassen sich mittels endoskopischer Manometrie funktionele Storungen der Papillenmotilitat nachweisen, die als Ursache von Cholestase und Pankreatit…

Gynecologymedicine.medical_specialtybusiness.industryMedicineGlyceroltrinitratbusinessActa Chirurgica Austriaca

The metabolism of phenol and substituted phenols in zebra fish.

1987

1. The metabolism of five phenols in zebra fish was studied after uptake from the medium. The results showed no qualitative differences to other Cyprinid fish species, only the oxidation rate seemed to be lower. 2. Phenyl glucuronide, phenyl sulphate, and quinol sulphate were identified as metabolites of phenol. 3. Identified metabolites of 2-cresol were 2-cresyl glucuronide, 2-cresyl sulphate, and 2-hydroxybenzoic acid in trace amounts. 4. Only the glucuronide and sulphate conjugates were detected as metabolites of 4-nitrophenol, 4-chlorophenol, and pentachlorophenol.

PentachlorophenolHealth Toxicology and MutagenesisFish speciesCyprinidaeToxicologyBiochemistryNitrophenolschemistry.chemical_compoundCresolsPhenolsPhenolAnimalsPhenolsChromatography High Pressure LiquidZebrafishPharmacologyo-CresolGeneral MedicineMetabolismPentachlorophenolBiochemistrychemistryFish <Actinopterygii>FemaleChromatography Thin LayerGlucuronideChlorophenolsXenobiotica; the fate of foreign compounds in biological systems

The use of operative ultrasonography for the localization of renal calculi.

1987

The ultrasonically guided nephrotomy technique using B-scanning to identify the localization of stones and Doppler sonography to identify avascular parenchymal areas for nephrotomies allows for transparenchymal stone removal without the need for renal artery clamping and renal cooling. In 175 procedures the average blood loss was 1,350 ml and the rate of residual stones requiring a secondary intervention was 2.8%. Despite the advent of new noninvasive treatment modalities, this technique is still applied in 23% of staghorn stones.

medicine.medical_specialtyIntraoperative Carebusiness.industrymedicine.medical_treatmentVascular surgerySurgeryCardiac surgeryKidney CalculiOperative ultrasonographyBlood lossCardiothoracic surgerymedicine.arterymedicineHumansSurgeryRadiologyRenal arterybusinessNephrotomyAbdominal surgeryUltrasonographyWorld journal of surgery

Duplexsonographie abdomineller Gefäße

1987

Duplex sonography is a non-invasive procedure which permits the determination of flow velocity and direction in visceral vessels. Results in 50 normals have shown that small arteries can be evaluated in about 50% of cases. The portal venous system can be demonstrated in all cases; average flow velocity and volume is 15.2 +/- 2.8 cm/s and 694 +/- 230 ml/min, corresponding with the values obtained by invasive methods. Clinical application for duplex examinations can be found in portal hypertension, varices, thromboses, aneurysms and transplant kidneys.

medicine.medical_specialtybusiness.industryPortal venous systemfood and beveragesmedicine.diseaseSurgerymedicine.anatomical_structureFlow velocityDuplex (building)Duplex sonographyMedicineAbdomenPortal hypertensionRadiology Nuclear Medicine and imagingVaricesNuclear medicinebusinessAbdominal vesselsRöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren

Genetic polymorphism and high detrimental load in natural populations of Drosophila melanogaster from cellar and vineyard

1987

Two Spanish natural populations of Drosophila melanogaster have been analysed with respect to genetic variability in third chromosome viability. The two populations, although from the same locality, belong to relatively different habitats: the inside of a cellar and a vineyard. The patterns of homozygote and heterozygote viability are similar in both populations. The homozygous detrimental loads estimated are very high and the values for the D:L (detrimental/lethal) ratio close to 2.5, which is higher than any previously found. The environmental variance of viability, average degrees of dominance of lethal genes and of viability polygenes and effective population sizes were estimated in eac…

MaleHeterozygoteeducation.field_of_studyPolymorphism GeneticHomozygotePopulationGenetic VariationPopulation geneticsBiologyhumanitiesGenetic loadDrosophila melanogasterGenetics PopulationEffective population sizePolygeneEvolutionary biologyGenetic variationGeneticsAnimalsLethal alleleFemaleGenes LethalGenetic variabilityeducationGenetics (clinical)Heredity

Summaries of presentations during the sixth Workshop of the International Association of Phytoplankton Ecology and Taxonomy, Mondsee, Austria, 15–25 …

1987

GeographyEcologyEcology (disciplines)Taxonomy (general)Association (object-oriented programming)PhytoplanktonLibrary scienceAquatic ScienceEcology Evolution Behavior and SystematicsWater Science and TechnologySwiss Journal of Hydrology

Ecdysteroid-dependent larval-adult oviduct transformation in the milkweed bugOncopeltus fasciatus requires absence of juvenile hormone

1987

It has been tested whether juvenile hormone plays a role in the larval-adult transformation of lateral oviducts in the milkweed bug. The transformation is ecdysteroid-dependent, as was reported previously2. Application of precocene or juvenile hormone III proved that the absence of juvenile hormone is required.

Pharmacologymedicine.medical_specialtyEcdysteroidLarvaanimal structuresfungiCell BiologyBiologyLygaeidaebiology.organism_classificationCellular and Molecular NeuroscienceTransformation (genetics)chemistry.chemical_compoundEndocrinologychemistryJuvenile hormone IIIInternal medicineJuvenile hormonemedicineMolecular MedicineOviductMolecular BiologyExperientia

Explicit solutions for a system of coupled Lyapunov differential matrix equations

1987

This paper is concerned with the problem of obtaining explicit expressions of solutions of a system of coupled Lyapunov matrix differential equations of the typewhere Fi, Ai(t), Bi(t), Ci(t) and Dij(t) are m×m complex matrices (members of ℂm×m), for 1≦i, j≦N, and t in the interval [a,b]. When the coefficient matrices of (1.1) are timeinvariant, Dij are scalar multiples of the identity matrix of the type Dij=dijI, where dij are real positive numbers, for 1≦i, j≦N Ci, is the transposed matrix of Bi and Fi = 0, for 1≦i≦N, the Cauchy problem (1.1) arises in control theory of continuous-time jump linear quadratic systems [9–11]. Algorithms for solving the above particular case can be found in [1…

Cauchy problemLyapunov functionSequenceDifferential equationGeneral MathematicsMathematical analysisIdentity matrixsymbols.namesakeMatrix (mathematics)symbolsInitial value problemApplied mathematicsBoundary value problemMathematicsProceedings of the Edinburgh Mathematical Society

Small round blue cell sarcoma of bone mimicking atypical Ewing's sarcoma with neuroectodermal features. An analysis of five cases with immunohistoche…

1987

Ewing's sarcoma (ES) of bone may occasionally display rosette-like textures mimicking Homer-Wright ones, as seen in neuroectodermic neoplasms (neuroblastoma, peripheral neuroepithelioma). Of a group of 39 cases of ES, reviewed with electron microscopic study, the authors have isolated five atypical ES, which histologically also possessed neuroectodermic traces. These tumors were composed of small round blue cells with rosette-like figures and cytoplasmic glycogen. The immunohistochemical analysis showed positivity for neuron-specific enolase (NSE) as well as for HNK-1 (leu-7) monoclonal antibody. Electron microscopic examination confirmed the tumor cell as being of small round type, with a …

Antigens Differentiation T-LymphocyteCancer ResearchPathologymedicine.medical_specialtyEnolaseBone NeoplasmsSarcoma EwingBiologylaw.inventionNeuroblastomaPeripheral Nervous System NeoplasmslawNeuroblastomamedicineNeuroectodermal Tumors Primitive PeripheralIntermediate filamentHistocytochemistryAntibodies MonoclonalSoft tissueAnatomymedicine.diseaseMicroscopy ElectronOncologyCytoplasmPhosphopyruvate HydrataseAntigens SurfaceImmunologic TechniquesMicroscopy Electron ScanningImmunohistochemistrySarcomaElectron microscopeGlycogenCancer

Plasma membrane glycoproteins covalently bound to silica beads as a model for molecular studies of cell-cell interactions in culture.

1987

Abstract In previous studies, we have shown that plasma membrane glycoproteins are of major importance in the density-dependent regulation of growth of normal diploid fibroblasts. Due to the hydrophobic portions of these molecules, functional studies in cell culture are often diffucult to perform and to interpret. Specially, the addition of these molecules in soluble form to cell culture, after depletion of detergents needed for their solubilization, leads to aggregation and internalization. Therefore, we developed a method for the covalent immobilization of the solubilized plasma membrane proteins to derivatized silica beads for further investigations on the molecular nature of the active …

media_common.quotation_subjectCellBiophysicsBiochemistryModels BiologicalmedicineHumansCentrifugationInternalizationCells Culturedmedia_commonMembrane GlycoproteinsbiologyChemistryCell growthContact InhibitionFibroblastsSilicon DioxideMembrane glycoproteinsmedicine.anatomical_structureBiochemistryMembrane proteinCell cultureCovalent bondbiology.proteinCell DivisionProtein BindingJournal of biochemical and biophysical methods

A macrophage-suppressing 40-kD protein in a case of pulmonary alveolar proteinosis.

1987

Pulmonary alveolar proteinosis (PAP) is a rare disease of unknown etiology. Macrophage dysfunctions are claimed to be involved in the pathogenesis. We investigated phagocytosis and oxidative metabolism of alveolar macrophages in a case of pulmonary alveolar proteinosis. These cells phagocytize normally and phagocytizable stimulants cause a normal oxidative burst. In response to the membrane signals phorbolmyristate acetate and aggregated immunoglobulin, however, no stimulated turnover of the oxidative metabolism can be observed. A 40-kD protein found in the lavage fluid mediates this macrophage-inhibiting effect. This phenomenon may contribute to the frequent opportunistic infections seen i…

AdultMalePathologymedicine.medical_specialtyPhagocytosisOpportunistic InfectionsPulmonary Alveolar ProteinosisPathogenesisPhagocytosisDrug DiscoverymedicineMacrophageHumansMacrophage Migration-Inhibitory FactorsGenetics (clinical)Lungmedicine.diagnostic_testbiologyMacrophagesfood and beveragesProteinsGeneral MedicineMacrophage Activationmedicine.diseaseRespiratory burstMolecular WeightPulmonary AlveoliBronchoalveolar lavagemedicine.anatomical_structureImmunologyLuminescent Measurementsbiology.proteinMolecular MedicineAntibodyPulmonary alveolar proteinosisEnergy MetabolismBronchoalveolar Lavage FluidKlinische Wochenschrift

Neutrino mass and new light gauge boson in superstring models

1987

Abstract The proposal that the neutrino owes the smallness of its mass to the spontaneous breaking of R parity in superstring models with an additional gauge boson coupled to the right-handed neutrino is analysed. The right-handed neutrino can not in general decouple from the low-energy theory in models with supersymmetry at the TeV scale and which possess the light Higgs doublets necessary for generating fermion masses. Experimental limits on neutrino mass then imply an upper limit on the new gauge boson mass m Zr ⪅ 220 GeV.

PhysicsNuclear and High Energy PhysicsGauge bosonSterile neutrinoParticle physicsNeutrino theory of lightAstrophysics::High Energy Astrophysical PhenomenaHigh Energy Physics::PhenomenologySupersymmetryHigh Energy Physics::TheoryHiggs bosonMeasurements of neutrino speedHigh Energy Physics::ExperimentNeutrinoNeutrino oscillationPhysics Letters B

false

1987

Diffusion coefficients D of singly and doubly end-labeled polystyrenes (PS) with molecular weights in the range 6500 ≤ M ≤ 75400 were measured in a PS matrix of molecular weight M′ = 111000, and in matrices with M′ = M. At 212°C, we find no influence of the label. In a power-law description D = D0 · M−α · M′−β we find α = 2,0 for M′ = 111000 and α + β = 2,4 for M = M′. The crossover to Rouse-like behavior for short-M chains is at Me ≈ 18000 for the former (high M′), and at Mc ≈ 33000 in the latter (M′ = M) case. At 185°C, we find a more complex scaling behavior and different D values for singly and doubly labeled PS.

chemistry.chemical_compoundMatrix (mathematics)Range (particle radiation)End-groupchemistryChain (algebraic topology)Molecular massDiffusionPolymer chemistryPolystyreneScalingDie Makromolekulare Chemie

Antiproton-Proton-Wechselwirkung bei niedrigen Energien

1987

PhysicsGeneral MedicineEcology Evolution Behavior and SystematicsNaturwissenschaften

Molecular dynamics investigation of the premelting effects of Lennard-Jones (111) surfaces

1987

Molecular dynamics simulations have been performed to study the premelting effects of noble-gas surfaces (argon) close to but below the bulk melting temperature. In particular, the increase of disorder as a function of temperature at (111) surface has been considered. The truncated Lennard-Jones (6-12) potential is used to describe the interactions between particles. Surface premelting has been analyzed by means of total energies, trajectory plots, mean sequare displacement functions, diffusion coefficients, vacancy concentrations and two-dimensional order parameters. The (111) surface starts to disorder by vacancy formation, which leads to the premelting of the surface layer far below the …

Materials scienceArgonDiffusionThermodynamicschemistry.chemical_elementCondensed Matter PhysicsAtomic and Molecular Physics and OpticsPremeltingMolecular dynamicsSphere packingchemistryVacancy defectPhysics::Atomic and Molecular ClustersSurface layerDisplacement (fluid)Mathematical PhysicsPhysica Scripta

Flavonoids and Others Constituents from Onopordon macracanthum.

1987

Pharmacologychemistry.chemical_classificationStereochemistryOrganic ChemistryFlavonoidPharmaceutical ScienceSesquiterpeneAnalytical Chemistrychemistry.chemical_compoundComplementary and alternative medicinechemistryDrug DiscoveryMolecular MedicineOrganic chemistryLactonePlanta medica

Entwicklung eines Wachstumsmodells für fetale Kopf- und Rumpfmaße

1987

Head parameters BPD, FOD and HC and abdomen parameters ATD, APD and AC have been ascertained in a prospective cross-sectional study in 515 healthy single fetuses between 13 and 40 weeks of gestation by ultrasound. In all cases ultrasound velocity was 1540 m/sec. From these data, a growth model was achieved for each parameter and corresponding growth curves with 5%, 10%, 50%, 90% and 95% percentiles were established.

Fetusbusiness.industryUltrasoundObstetrics and GynecologyGrowth modelmedicine.anatomical_structureMaternity and MidwiferymedicineAbdomenGestationHead (vessel)Fetal headbusinessNuclear medicineGeburtshilfe und Frauenheilkunde

Representing compact sets of compact operators and of compact range vector measures

1987

symbols.namesakeApproximation propertyNuclear operatorGeneral MathematicsHilbert spacesymbolsFinite-rank operatorCompact operatorTopologyInvariant subspace problemContinuous functions on a compact Hausdorff spaceCompact operator on Hilbert spaceMathematicsArchiv der Mathematik

Prevalence of residual B-cell function related to age at onset and genetic profile in newly diagnosed type I diabetics.

1987

Patients with type I (insulin-dependent) diabetes mellitus maintain B-cell function for a varying period of time after onset. This is commonly held to account for post-initial remission. To estimate residual B-cell function we measured plasma and 24-h urinary C-peptide in 68 type I diabetic patients (age range 4-35 years, within 10-180 days of the onset of symptoms, typed for HLA-A, -B, -C and DR loci. A positive correlation (r = 0.26; p less than 0.05) was found between urinary C-peptide levels and the age of the patient. The analysis of variance of urinary C-peptide values on the basis of the presence or absence of DR3 and DR4 antigens revealed that the DR3-positive patients had reduced e…

AdultMalemedicine.medical_specialtyAdolescentEndocrinology Diabetes and MetabolismUrinary systemLate onsetGastroenterologyExcretionchemistry.chemical_compoundIslets of LangerhansEndocrinologyAntigenInternal medicineDiabetes mellitusInternal MedicinemedicineHumansChildB cellC-PeptideC-peptidebusiness.industryAge FactorsGeneral MedicineHLA-DR Antigensmedicine.diseaseEndocrinologymedicine.anatomical_structureDiabetes Mellitus Type 1chemistryChild PreschoolFemaleAnalysis of variancebusinessActa diabetologica latina

A kinetic-catalytic method for iodide based on the simultaneous addition of inhibitor and substrate

1987

Abstract A kinetic-catalytic method of analysis, based on the addition of a mixture of inhibitor and substrate, at a constant rate, over the catalyst in the presence of the other component of the indicator reaction is studied. The method is applied to the determination of iodide using the Ce(IV)As(III) catalytic reaction and Hg(II) as inhibitor. Under suitable experimental conditions the absorbance of the unconsumed Ce(IV) is inversely proportional to the initial iodide concentration.

Absorbancechemistry.chemical_classificationChemistryInorganic chemistryIodideSubstrate (chemistry)Reaction inhibitorKinetic energyChemical reactionSpectroscopyCatalytic methodAnalytical ChemistryCatalysisMicrochemical Journal