showing 36 of ~574560 from 574555 documents

Expression of en and wg in the embryonic head and brain of Drosophila indicates a refolded band of seven segment remnants

1992

ABSTRACT Based on the expression pattern of the segment polarity genes engrailed and wingless during the embryonic development of the larval head, we found evidence that the head of Drosophila consists of remnants of seven segments (4 pregnathal and 3 gnathal) all of which contribute cells to neuromeres in the central nervous system. Until completion of germ band retraction, the four pregnathal segment remnants and their corresponding neuromeres become arranged in an S-shape. We discuss published evidence for seven head segments and morphogenetic movements during head formation in various insects (and crustaceans).

Metamerism (biology)biologyfungiEmbryogenesisGene ExpressionGenes InsectEmbryoAnatomyNeuromerebiology.organism_classificationengrailedSegment polarity geneCrustaceaDrosophilidaeHead segmentationMorphogenesisAnimalsDrosophilaHeadMolecular BiologyDevelopmental BiologyDevelopment

Environmental Gamma Radiation Measurements on the Island of Pantelleria

1992

The population exposure to those living on the island of Pantelleria, Italy, was estimated by measuring the natural gamma background. Gamma spectra of natural rocks and measurements of absorbed dose in air were taken. A correlation was found between the mean gamma exposure rate and the mean values of natural radionuclide concentrations in the investigated rocks.

Geological PhenomenaRadionuclideeducation.field_of_studyEpidemiologyHealth Toxicology and MutagenesisPopulationRadiochemistryGeologyRadiationAtmospheric sciencesDisastersMediterranean IslandsItalyGamma RaysRadiation MonitoringAbsorbed doseRadioactive contaminationBackground RadiationEnvironmental scienceDosimetryRadiology Nuclear Medicine and imagingPopulation exposureeducationNatural radioactivityEnvironmental MonitoringHealth Physics

Flow cytometric assay for quantifying opsonophagocytosis and killing of Staphylococcus aureus by peripheral blood leukocytes.

1992

We describe a novel flow cytometric method for quantifying opsonophagocytosis and killing of Staphylococcus aureus in cell-rich plasma obtained after dextran sedimentation of erythrocytes. To analyze opsonophagocytosis, phagocytes were labeled with a phycoerythrin-conjugated monoclonal antibody and were incubated with viable staphylococci containing carboxyfluorescein as a vital fluorescent dye. Phagocytosing cells assumed a dual, orange-green fluorescence. The relative numbers of bacteria associating with phagocytes could be determined by quantifying the decrease of free green fluorescent particles. A parallel incubation of fluorescent bacteria with unlabeled cell-rich plasma was performed…

Microbiology (medical)PhagocytePhagocytosisStaphylococcusmedicine.disease_causeMicrobiologyFlow cytometrychemistry.chemical_compoundPhagocytosismedicineLeukocytesHumansFluoresceinbiologymedicine.diagnostic_testAntibodies MonoclonalPhycoerythrinOpsonin ProteinsFlow CytometryFluoresceinsAntibody opsonizationKineticsmedicine.anatomical_structureSpectrometry FluorescencechemistryStaphylococcus aureusbiology.proteinAntibodyStaphylococcusResearch ArticleJournal of clinical microbiology

Localized crusted scabies in the acquired immunodeficiency syndrome

1992

Summary Crusted scabies (CrS) is an uncommon occurrence among patients with AIDS. Indeed to date only five cases have been described, all with widespread lesions. A case of localized CrS appearing as a yellowish and crusted plaque on the second right toe is reported in a woman with AIDS. Scraping off the verrucous surface, as well as punch-biopsy revealed many mites within the horny layer. The infestation is related to the cutaneous immune response and thus CrS should be considered an opportunistic infestation in AIDS. The importance of the early diagnosis of CrS in order to prevent disseminated lesions and involvement of other health-care workers is underlined.

AdultFoot DermatosesPathologymedicine.medical_specialtyAIDS-Related Opportunistic Infectionsintegumentary systembusiness.industryHorny layerDermatologyCrusted scabiesToesmedicine.diseaseScabiesAcquired immunodeficiency syndrome (AIDS)Immunopathologyparasitic diseasesotorhinolaryngologic diseasesmedicineScabiesHumansFemaleViral diseasebusinesssaRNASkinClinical and Experimental Dermatology

Redescription of Skrjabinodon medinae (García-Calvente, 1948) (Nematoda: Pharyngodonidae) from the cloaca of Podarcis pityusensis (Bosca, 1883) (Saur…

1992

Pharyngodon medinae Garcia-Calvente, 1948 (Nematoda: Pharyngodonidae) is redescribed from Podarcis pityusensis (Bosca, 1883) (Sauria: Lacertidae) of the Balearic Islands (Spain) and confirmed as a member of the genus Skrjabinodon Inglis, 1968. A systematic review of S. medinae and closely related species is also given. Parathelandros canariensis is referred to Skrjabinodon as a new combination and Parathelandros Magzoub et al., 1980 is dismissed as a junior homonym of Parathelandros Baylis, 1930.

Balearic islandsbiologyPodarcis pityusensisZoologygovernment.political_districtbiology.organism_classificationPharyngodonAnimal ecologygovernmentLacertidaeParasitologyTaxonomy (biology)SauriaSkrjabinodonSystematic Parasitology

OnK 0-functions and regular extension operators

1992

AlgebraRegular extensionGeneral MathematicsMathematicsArchiv der Mathematik

Crystal Data for Complexes of Co(II) and Ni(II) Perchlorates with Mepirizole

1992

AbstractMetal mepirizole perchlorates, M(C11H14N4O2)3 (C104)2 where M = Co(II) and Ni(II) have been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined by indexing programs from diffractometer data. Refined cell parameters (monoclinic with a C-centered cell), calculated density and Z values are presented.

RadiationMaterials scienceMepirizoleCondensed Matter PhysicsMetalCrystallographyCrystal datavisual_artvisual_art.visual_art_mediumGeneral Materials ScienceInstrumentationPowder diffractionDiffractometerMonoclinic crystal systemPowder Diffraction

T-odd andCP-odd triple momentum correlations in the exclusive semi-leptonic charm meson decayD→K *(Kπ)lv l

1992

We studyT-odd andCP-odd triple momentum correlations in exclusive semi-leptonic charm meson decaysD→K*(Kπ)lvl. We define asymmetry ratios that measure the trueCP-violating effects, andT-odd triple momentum correlation effects from unitarity contributions. Possible newCP-violating contributions are parametrized in terms of an effective four-fermion Hamiltonian whereCP-violating effects should come from new non-standard sources. A detailed analysis of the left-right model and the Weinberg Higgs-boson model ofCP-violation is carried out.

PhysicsParticle physicsPhysics and Astronomy (miscellaneous)MesonUnitaritymedia_common.quotation_subjectHigh Energy Physics::PhenomenologyAsymmetryNuclear physicssymbols.namesakesymbolsHigh Energy Physics::ExperimentHamiltonian (quantum mechanics)Engineering (miscellaneous)media_commonZeitschrift für Physik C Particles and Fields

Deletion of the Hunter gene and both DXS466 and DXS304 in a patient with mucopolysaccharidosis type II.

1992

Hunter syndrome is an X-linked mucopoly-saccharidosis due to deficiency of the lysosomal enzyme iduronate-2-sulfatase (IDS). A cDNA clone containing the entire coding region of the human IDS gene, mapped in Xq28, has been used as molecular probe to study a patient with Hunter syndrome. A submicroscopic deletion has been detected that spans the IDS gene as well as DXS466 and DXS304, 2 loci mapped probably not more than 900 kb from the IDS locus. A detailed clinical description of the patient is provided and his phenotype is compared to that of other patients with IDS deletion described recently. By following the segregation of a restriction fragment length polymorphism at the IDS locus in th…

MaleX ChromosomeLocus (genetics)Iduronate SulfataseBiologyGene mappingmedicineHumansMucopolysaccharidosis type IIChildGenetics (clinical)X chromosomeMucopolysaccharidosis IIGeneticsIduronate-2-sulfataseChromosome MappingHunter syndromeDNAmedicine.diseaseXq28PedigreeBlotting SouthernFemaleRestriction fragment length polymorphismChromosome DeletionPolymorphism Restriction Fragment LengthAmerican journal of medical genetics

Influence of loperamide and loperamide oxide on the anal sphincter

1992

The objective of this study was to investigate the effects of the opioid loperamide and its recently synthesized pharmacologically inactive prodrug loperamide oxide on the anal sphincter. In a double-blind, placebo-controlled crossover study, anorectal manometry was performed in 12 healthy volunteers five hours after oral bolus application of 10 mg of loperamide, loperamide oxide, or placebo. Loperamide significantly increased the threshold volumes for minimal perception and urgency to defecate (P less than 0.05) and raised the volume required to abolish recovery of the rectoanal inhibitory reflex (P less than 0.05). These findings suggest that loperamide has a specific continence-improving…

AdultMalemedicine.medical_specialtyLoperamideManometryAnal CanalPlaceboLoperamideGastroenterologyBolus (medicine)Double-Blind MethodInternal medicinePressuremedicineHumansDefecationbusiness.industryAnorectal manometryRectumGastroenterologyGeneral MedicineProdrugCrossover studyOpioidDefecationFemalebusinessmedicine.drugDiseases of the Colon & Rectum

Complement component deficiencies and infection: C5, C8 and C3 deficiencies in three families.

1992

Three families are described with complement component deficiencies. In one family, five children had C5 deficiency; in a second family, two children had C8 deficiency and one child in a third family had C3 deficiency. The index cases were identified during screening of patients with recurrent pyogenic infections, recurrent meningitis and meningococcaemia. Two of the five C5 deficient patients had recurrent meningitis and meningococcaemia, two had recurrent respiratory tract infections and otitis and one was healthy. One of the C8 deficient patients had meningitis, meningococcaemia and pneumonia, whereas his sibling with the same deficiency was healthy. The patient with C3 deficiency had fo…

MalePediatricsmedicine.medical_specialtyComplement Hemolytic Activity AssayMeningitis BacterialRecurrenceImmunopathologyRecurrent meningitisMedicineHumansSiblingChildRespiratory Tract Infectionsbusiness.industryMeningitis PneumococcalComplement C5Complement C3C5 Deficiencymedicine.diseaseComplement C8PedigreePneumoniaOtitisChild PreschoolPediatrics Perinatology and Child HealthImmunologyFemalemedicine.symptomComplicationbusinessMeningitisEuropean journal of pediatrics

Gastric Emptying in Infants with Gastroesophageal Reflux: Ultrasound Evaluation before and after Cisapride Administration

1992

The present study aimed to evaluate gastric emptying in children with gastroesophageal reflux (GER) by means of real-time ultrasonography, on the basis of measurements of the cross-sectional area of the gastric antrum. Twelve children with GER were studied (seven males, five females; age range, 3-13 months) and compared with 12 normal control children (six males, six females; age range, 3-13 months). The diagnosis of GER was confirmed by 24-h esophageal pH-monitoring. The GER patients had a significantly greater antral area than the controls at 90, 105, and 120 min after eating a standard meal (cow's milk formula, 300 ml/m2 body surface area); in addition, final gastric emptying time was si…

Malemedicine.medical_specialtyGastroenterologyPiperidinesInternal medicinemedicineHumansAntrumUltrasonographyBody surface areaCisaprideGastric Acidity DeterminationGastric emptyingEsophageal diseasebusiness.industryStomachStomachdigestive oral and skin physiologyGastroenterologyRefluxInfantGastric Acidity Determinationmedicine.diseasemedicine.anatomical_structureGastric EmptyingCisaprideGastroesophageal RefluxFemaleSerotonin Antagonistsbusinessmedicine.drugScandinavian Journal of Gastroenterology

Angular resolution of an array of tracking-chamber detectors for use in high-energy gamma-ray astronomy

1992

We describe a method of analysis for the reconstruction of the arrival direction of a high-energy photon impacting on the top of the atmosphere by using the directions of the particles on the shower front as measured by a ground-based array of tracking chambers uniformly distributed on a square surface; as an example, an array with enclosed surface of (120×120) m2 has been considered. Estimates on the accuracy of reconstruction are given, after application of the method to computer-simulated shower directions as a function of the number of «smapling» detectors and of their accuracy in the measurement of the «local» shower direction.

PhysicsPhotonOpticsPhysics::Instrumentation and Detectorsbusiness.industryDetectorScintillation counterCosmic rayAngular resolutionGamma-ray astronomyTracking (particle physics)businessSquare (algebra)Il Nuovo Cimento C

One electron transfer chain decomposition of trifluoroacetone diperoxide: The first 1,2,4,5-tetroxane with O-transfer capability

1992

Abstract Reaction of 1,1,1-trifluoropropanone (trifluoroacetone) ( 1a ) with 30% hydrogen peroxide in the presence of conc. sulfuric acid afforded in good yield 3,6-bis(trifluoromethyl)-3,6-dimethyl-1,2,4,5-tetroxane or trifluoroacetone diperoxide ( 2a ). Peroxide 2a is quantitatively converted into trifluoroacetone ( 1a ) and dioxygen by a catalytic amount of tetrabutylammonium iodide through a reductive electron transfer chain reaction carried out by the superoxide ion. Trifluoroacetone diperoxide ( 2a ) is capable of O-atom transfer to alkenes and sulfides.

Reaction mechanismOrganic peroxideTrifluoromethylChemistryOrganic ChemistryPhotochemistryBiochemistryPeroxideCatalysischemistry.chemical_compoundElectron transferYield (chemistry)Drug DiscoveryOrganic chemistryHydrogen peroxideTetrahedron Letters

false

1992

2H spin relaxation times, T1 and T2 and solid echo line shapes were investigated in 2-propanol (2-POH) solutions of poly(butyl methacrylate) (PBMA) in a wide concentration and temperature range, covering the solution, gel and glass states. From the results in deuterated 2-POH-d6 we found that the polymer influence upon solvent mobility is largely suppressed in the gel and glass states in contrast to normal polymer solutions where below the glass transition an increasing amount of solvent slows down with decreasing temperature. From 2H NMR of deuterated butyl side groups in the PBMA-d9/2-POH system we found that the side group motion is anisotropic and largely independent of solvent concentr…

Solventchemistry.chemical_classificationDeuteriumChemistryPolymer chemistryAnalytical chemistryOrganic chemistryConcentration effectPolymerAtmospheric temperature rangeAnisotropyGlass transitionPendant groupDie Makromolekulare Chemie

Endoscopic subfascial sectioning of incompetent perforating veins in treatment of primary varicosis

1992

Subfascial elimination of incompetent perforating veins is the most effective therapeutic principle in the treatment of trophic skin disorders associated with varicosis. A recently developed endoscopic technique allows accurate sectioning of perforating veins with direct observation of the veins and minor trauma. From November 1986 to July 1991 endoscopic sectioning of perforating veins was performed in 72 patients (103 legs). The most frequently transected perforating veins were Cockett's veins (n = 219), 24 cm perforating veins (n = 83), and Boyd's perforating veins (n = 82). Postoperative delayed wound healing was observed in 3 (2.9%) legs with pronounced trophic skin disorders in the lo…

AdultMalemedicine.medical_specialtySural nervePerforator veinVaricose VeinsPostoperative ComplicationsmedicineHumansAgedAged 80 and overDysesthesiaVarixRupture Spontaneousbusiness.industryEndoscopyAnatomyMiddle AgedVascular surgeryFasciotomySurgerySaphenous nerveVenous InsufficiencyFemaleSurgerymedicine.symptomVaricesbusinessVascular Surgical ProceduresFollow-Up StudiesAbdominal surgeryWorld Journal of Surgery

The floral nectaries in theIrvingiaceae

1992

TheIrvingiaceae generally possess large intrastaminal receptacular disc nectaries of the mesenchymatic histo-type, which receive numerous small phloematic bundles directly from the central stele. The non-glandular epidermis bears some 10 to 15 strictly localized stomata that are deeply sunken in the parenchyma. The nectar is assumed to be exposed on the disc surface. Flowers are of simple construction, lacking specialized organs to attract pollinators. A wide range of pollinators is thus expected. TheIrvingiaceae have more characters in common withSimaroubaceae thanIxonanthaceae and should therefore be retransferred as a family of their own next toSimaroubaceae.

PollinationPollinatorSteleBotanyNectarGeranialesPlant ScienceBiologybiology.organism_classificationEcology Evolution Behavior and SystematicsPlant Systematics and Evolution

The FIGARO II experiment: a general outline of the mission and the principal scientific results

1992

The FIGARO II (French Italian Gamma-Ray Observatory) experiment has been launched successfully three times: in July 1986 from Milo (Trapani), in November 1988 from Charleville (Australia) and in July 1990 again from Milo. In the first flight the observational program was limited to the Crab pulsar PSR0531+21 only because of a telemetry failure: the high sensitivity of FIGARO II allowed an accurate study of the pulse shape as well as a phase-resolved spectroscopy. It was also possible to evaluate the dispersion measure of the Crab pulsar at the flight date from the time delay between gamma-ray and radio pulses. The major results of the second flight were a stringent upper limit to the low-en…

PhysicsPulsarObservatoryCrab PulsarAstrophysics::High Energy Astrophysical PhenomenaGalactic CenterAstrophysics::Instrumentation and Methods for AstrophysicsAstronomyAstrophysicsGamma-ray astronomyVelaGalaxyPulse (physics)Il Nuovo Cimento C

In vitro secretion of specific antimitochondrial antibodies in primary biliary cirrhosis

1992

Antimitochondrial antibodies are present in the serum of virtually all patients with primary biliary cirrhosis. They have a well-defined antigen reactivity that is diagnostic for the disease. The role of these autoantibodies in the disease process remains to be defined. In this study we show that antimitochondrial antibodies can be produced in vitro by peripheral blood lymphocytes, that the cells producing antimitochondrial antibodies are present in the peripheral blood in a high frequency and seem to be maximally activated. Stimulation with pokeweed mitogen did not augment the in vitro production of antimitochondrial antibodies in patients nor did it induce the production of these antibodi…

Pathologymedicine.medical_specialtyLymphocyteImmunoblottingRadioimmunoassayEnzyme-Linked Immunosorbent AssayPrimary biliary cirrhosisAntigenAntibody SpecificitymedicineHumansCells CulturedAutoantibodiesHepatologybiologyLiver Cirrhosis Biliarybusiness.industryPokeweed mitogenAutoantibodyRadioimmunoassaymedicine.diseaseMitochondriamedicine.anatomical_structurePolyclonal antibodiesImmunologybiology.proteinAntibodybusinessJournal of Hepatology

The baryonic spectrum in a constituent quark model including a three-body force

1992

We analyze, within a non-relativistic quark model, the low energy part of the baryonic spectrum in the octet and decuplet flavour representations. The relevance of a strong Coulomb potential is emphasized in order to explain its general features. The addition of a three-body force allows to solve the ‘Roper puzzle’, giving a consistent explanation to its relative position in the spectrum.

PhysicsNuclear and High Energy PhysicsParticle physics[PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th]Octet010308 nuclear & particles physicsHigh Energy Physics::LatticeHigh Energy Physics::PhenomenologyNuclear TheoryQuark modelFlavourConstituent quark01 natural sciencesBottom quarkThree-body forceBaryonPosition (vector)0103 physical sciencesHigh Energy Physics::Experiment010306 general physicsZeitschrift f�r Physik A Hadrons and Nuclei

Stiffness-Adaptive Taylor method for the integration of non-stiff and stiff kinetic models

1992

A systematic derivation procedure that greatly facilitates the application of the Taylor method to the integration of kinetic models is developed. In addition, an algorithm that gives the integration step as a function of the required level of accuracy is proposed. Using the Taylor method, application of this algorithm is immediate and largely reduces the integration time. In addition, a new method of integration of kinetic models, whose most important feature is the self-adaptability to the stiffness of the system along the integration process, is developed. This “stiffness-adaptive” Taylor method (SAT method) makes use of several algorithms, combining them to meet the particular requireme…

Time delay and integrationProcess (engineering)MathematicsofComputing_NUMERICALANALYSISStiffnessGeneral ChemistryFunction (mathematics)Kinetic energyDerivation procedureComputational MathematicsTaylor methodFeature (computer vision)medicinemedicine.symptomAlgorithmMathematicsJournal of Computational Chemistry

Neuropsychological indicators of the vulnerability to schizophrenia

1992

Schizophrenia is associated with enduring deficits in neuropsychological functioning. It is widely undecided if the various aspects of neuropsychological impairment are a consequence of the disorder or if they are also present premorbidly and in populations at increased risk for schizophrenia (vulnerability markers). Neuropsychological deficits in healthy relatives of schizophrenic patients who are at an elevated risk for schizophrenia and who did not yet pass the period of risk would indicate that these deficits are vulnerability markers. This hypothesis was tested for three neuropsychological paradigms which have been proven to distinguish schizophrenic patients from controls. 33 siblings…

AdultMalePharmacologyProbandPsychosismedicine.medical_specialtyVulnerabilityNeuropsychologyCognitionNeuropsychological Testsmedicine.diseaseIncreased riskSchizophreniaApprehension testSchizophreniamedicineHumansFemaleSchizophrenic PsychologyDisease SusceptibilityPsychologyPsychiatryBiological PsychiatryClinical psychologyProgress in Neuro-Psychopharmacology and Biological Psychiatry

Stimulation of synovial fluid mononuclear cells with the human 65-kD heat shock protein or with live enterobacteria leads to preferential expansion o…

1992

SUMMARY T lymphocyte responses to heterologous or self 65-kD heat shock protein (hsp) have been implicated in the pathogenesis of various forms of arthritis. To delineate the relationship of 65-kD hsp to different synovial fluid (SF) T cell subsets, we stimulated synovial fluid (SFMC) and peripheral blood mononuclear cells (PBMC) from patients with different inflammatory rheumatic diseases and from healthy controls with human or mycobacterial 65-kD hsp, tetanus toxoid (TT), heat-killed or live Yersinia enterocotitica. Phenotyping of the resulting T cell lines revealed an increase of up to 97% TCR-γδ+ lymphocytes in the 65-kD hsp-stimulatcd SF-derived lines. This expansion of TCR-γδ+ cells w…

Cellular immunityT cellReceptors Antigen T-Cell alpha-betaT-LymphocytesImmunologyBiologyYersiniaLymphocyte ActivationPeripheral blood mononuclear cellMonocytesCell LineAntigenEnterobacteriaceaeHeat shock proteinSynovial FluidmedicineImmunology and AllergySynovial fluidHumansHeat-Shock ProteinsReceptors Antigen T-Cell gamma-deltaT lymphocytebiology.organism_classificationClone Cellsmedicine.anatomical_structurePhenotypeImmunologyResearch Article

Measures of the efficacy of psychotropic drugs in acute treatment: the current status of their validity

1992

Pharmacologymedicine.medical_specialtyDrug trialbusiness.industryPsychiatry and Mental healthNeurologyRating scaleMedicinePharmacology (medical)Neurology (clinical)Current (fluid)businessPsychiatryBiological PsychiatryClinical psychologyEuropean Neuropsychopharmacology

Use of famotidine in severe exocrine pancreatic insufficiency with persistent maldigestion on enzymatic replacement therapy. A long-term study in cys…

1992

In patients with pancreatic exocrine insufficiency, the use of pancreatic enzyme does not abolish steatorrhea in some cases. We carried out a long-term prospective study in an attempt to clarify the effectiveness of the associated use of famotidine to enzymatic supplementation on fat absorption and nutritional parameters of patients with pancreatic insufficiency due to cystic fibrosis. We studied 10 patients, mean age 12.5 years, with persistent steatorrhea on enzymatic supplementation. A double-blind crossover design was used and famotidine (1 mg/kg/day) or placebo was given as adjuvant to enzymatic preparations for either of two six-month periods. A statistically significative reduction i…

Malemedicine.medical_specialtyPancreatic diseaseAdolescentCystic FibrosisPhysiologyGrowthPlaceboCystic fibrosisGastroenterologyInternal medicinemedicineHumansProspective StudiesAdverse effectExocrine pancreatic insufficiencyChildbusiness.industryGastroenterologymedicine.diseaseFamotidineCrossover studySteatorrheaFamotidineCeliac DiseaseEndocrinologyPancreatinExocrine Pancreatic InsufficiencyFemalemedicine.symptombusinessmedicine.drugDigestive diseases and sciences

NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY OF EXCISED HUMAN HEARTS

1992

International audience; Abstract: Background-Phosphorus nuclear magnetic resonance spectroscopy has been proposed as a method of studying the metabolism of the myocardium in patients. Little is known about P-31 nuclear magnetic resonance spectroscopy of diseased human hearts. Methods-Two donor hearts meeting the requirements for heart transplantation and 11 diseased hearts were removed during a transplantation procedure and were studied in a horizontal 2-35 T superconducting magnet. Spectra were obtained at 0-degrees-C about 30 minutes after the excision. The areas of the inorganic phosphate peak (Pi) and of the phosphocreatine peak (PCr) were summed and expressed as a ratio with respect to…

[ INFO.INFO-IM ] Computer Science [cs]/Medical ImagingPHOSPHOCREATINE[INFO.INFO-IM] Computer Science [cs]/Medical Imaging[INFO.INFO-IM]Computer Science [cs]/Medical ImagingATP RATIOPIG-HEART

Champs de vecteurs analytiques commutants, en dimension 3 ou 4: existence de zeros communs

1992

One proves the existence of a common zero for any two ℝ-analytic commuting vector fields on a 4-dimensional manifold with not zero Euler characteristic. A local version of this result remains true on 3-manifolds.

symbols.namesakeGeneral MathematicsEuler characteristicMathematical analysisZero (complex analysis)symbolsVector fieldManifoldMathematicsBoletim da Sociedade Brasileira de Matem�tica

Polarized Fourier transform infrared microscopy as a tool for structural analysis of adsorbates in molecular sieves

1992

Using FTIR microscopy with polarized IR radiation on silicalite I single crystals fully loaded with p-xylene, the existence of an ordered adsorbate could be proven for the first time by IR spectroscopy. By analyzing the polarized absorption bands the orientation of the p-xylene molecules relative to the host structure could be determined. The results agree well with structural data obtained from X-ray diffraction experiments. These first results suggest that polarized IR microscopy could develop into a powerful tool for the analysis of adsorbate structures, assisting in complete structure resolution by diffraction techniques

DiffractionChemistryResolution (electron density)General EngineeringAnalytical chemistryInfrared spectroscopysymbols.namesakeFourier transformMicroscopyX-ray crystallographysymbolsPhysical and Theoretical ChemistryFourier transform infrared spectroscopyInfrared microscopyThe Journal of Physical Chemistry

Quenching of fluorescein-conjugated lipids by antibodies. Quantitative recognition and binding of lipid-bound haptens in biomembrane models, formatio…

1992

Three model biomembrane systems, monolayers, micelles, and vesicles, have been used to study the influence of chemical and physical variables of hapten presentation at membrane interfaces on antibody binding. Hapten recognition and binding were monitored for the anti-fluorescein monoclonal antibody 4–4-20 generated against the hapten, fluorescein, in these membrane models as a function of fluorescein-conjugated lipid architecture. Specific recognition and binding in this system are conveniently monitored by quenching of fluorescein emission upon penetration of fluorescein into the antibody's active site. Lipid structure was shown to play a large role in affecting antibody quenching. Interes…

Models MolecularTime FactorsProtein ConformationStereochemistry030303 biophysicsMolecular ConformationBiophysicsModels BiologicalMice03 medical and health scienceschemistry.chemical_compoundAnimalsFluoresceinBinding siteLipid bilayerMicellesPhospholipids030304 developmental biologyPhosphatidylethanolamine0303 health sciencesLiposomeVesicleCell MembraneAntibodies MonoclonalMembranes ArtificialBiological membraneFluoresceinsKineticsSpectrometry FluorescencechemistryLiposomeslipids (amino acids peptides and proteins)Binding Sites AntibodyHaptensHaptenResearch ArticleBiophysical Journal

Structural induced modifications in blends of polyamide with gamma irradiated low density polyethylene

1992

Abstract Blends of gamma irradiated and unirradiated low density polyethylene and polyamide 6 were made in order to study possible modifications induced by this irradiation. Results indicate that blends with gamma irradiated polyethylene have structure and properties significantly different with respect to blends made with the unirradiated one. This difference has been ascribed to the formation of functionalized groups in the polyethylene chains, which interact with polyamide.

chemistry.chemical_classificationRadicaleducationtechnology industry and agricultureInfrared spectroscopyGeneral MedicinePolymerPolyethyleneLow-density polyethylenechemistry.chemical_compoundChemical engineeringchemistryPolyamidePolymer chemistryMoleculeIrradiationInternational Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry

High-precision hyperfine spectroscopy inM1-M1 double-resonance transitions on trappedPb+207

1992

Optical pumping of the ground state of $^{207}\mathrm{Pb}^{+}$ ions, confined in a Paul ion trap on the weak 6${\mathit{P}}_{1/2\mathrm{\ensuremath{-}}}$6${\mathit{P}}_{3/2}$ M1 transition at \ensuremath{\lambda}=710 nm, and consequent magnetic-dipole transitions between the ground-state hyperfine Zeeman levels have resulted in an A factor of 12 968 180 601.61(0.22) Hz and linewidth of 0.5 Hz. The value includes corrections of Zeeman shifts from residual magnetic fields and second-order Doppler shifts in the several-eV-deep trap potential, while the ions were cooled by He buffer gas. Two M1 quanta have been applied simultaneously in a double-resonance experiment.

PhysicsZeeman effectBuffer gasResonanceAtomic and Molecular Physics and OpticsIonsymbols.namesakesymbolsPhysics::Atomic PhysicsIon trapAtomic physicsSpectroscopyGround stateHyperfine structurePhysical Review A

Growth factors and cell kinetics: a mathematical model applied to Il-3 deprivation on leukemic cell lines.

1992

We assume the existence of a specific G1 protein which is an initiator of DNA replication. This initiator is supposed to be synthesized according to Michaelis-Menten kinetics. In order to start DNA replication, it is assumed that this G1 specific protein must be produced in a required amount. Intra-cellular growth inhibitors and extra-cellular growth factors control the production of the initiator. This model allows to calculate the average G1 phase time as a function of the various chemical concentrations of nutrients, enzymes, growth inhibitors and growth factors. This model is compared to cell kinetics experiments on a leukemic cell line responding to Interleukin 3 deprivation. The curve…

medicine.medical_treatmentKineticsBiologyModels BiologicalGeneral Biochemistry Genetics and Molecular BiologymedicineCells CulturedGeneral Environmental ScienceInterleukin 3chemistry.chemical_classificationLeukemia ExperimentalApplied MathematicsGrowth factorDNA replicationG1 PhaseGeneral MedicineDNACell cyclePhilosophyKineticsEnzymeCytokineBiochemistrychemistryCell cultureBiophysicsInterleukin-3General Agricultural and Biological SciencesActa biotheoretica

Equivariance in topological gravity

1992

Abstract We present models of topological gravity for a variety of moduli space conditions. In four dimensions, we construct a model for self-dual gravity characterized by the moduli condition R + μν =0, and in two dimensions we treat the case of constant scalar curvature. Details are also given for both flat and Yang-Mills type moduli conditions in arbitrary dimensions. All models are based on the same fundamental multiplet which conveniently affords the construction of a complete hierarchy of observables. This approach is founded on a symmetry algebra which includes a local vector supersymmetry, in addition to a global BRST-like symmetry which is equivariant with respect to Lorentz transf…

PhysicsModuli of algebraic curvesHigh Energy Physics::TheoryNuclear and High Energy PhysicsModular equationEquivariant mapQuantum gravityInvariant (mathematics)TopologyMultipletGeneral Theoretical PhysicsModuliModuli space

Rule-guided identification of cosmic-ray patterns in PLASTEX

1992

Some techniques devised in the computer science fields of pattern recognition and expert systems are being applied to the interpretation of EAS responses in the PLASTEX experiment. An attempt is made to codity in a set of rules the expertise of trained researchers who are able to recognize and classify different hit patterns even in the presence of noisy background, and in spite of imperfections in the detector response. The patterns expected to be useful include, but are not limited to, track patterns. The software described here, as a progress report, automatically finds patterns corresponding to isolated tracks, and patterns composed of tracks that connect with each other in a layer of d…

Physicsbusiness.industryDetectorProbabilistic logiccomputer.software_genreExpert systemSet (abstract data type)Identification (information)SoftwareOpticsPattern recognition (psychology)Extensive air showersCosmic-raysData pre-processingbusinessComputation techniquesPACS 94.40.MyAlgorithmcomputer

Testing qcd with tau decays

1992

11 páginas, 2 tablas.-- CERN-TH-6422-92; LAL-92-10.

Quantum chromodynamicsPhysicsNuclear and High Energy PhysicsParticle physics[PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex]010308 nuclear & particles physicsHadronFísicaState (functional analysis)01 natural sciencesMeasure (mathematics)Distribution function0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]High Energy Physics::ExperimentPerturbation theory (quantum mechanics)Operator product expansionQuantum field theory010306 general physicsParticle Physics - Phenomenology

Depassivation Experiments by Laser‐Pulse‐Induced Spallation

1992

Depassivation experiments have been conducted by applying a technique developed for adhesion tests. A laser-pulse-induced spallation of the passive film is induced in situ without any contact between the laser beam and the passive film. The depassivation is controlled by the short pressures induced at the metal-film interface. The interfacial stresses at the metal-film interface could be studied by this technique

Interfacial stressRenewable Energy Sustainability and the EnvironmentChemistryMineralogyAdhesionCondensed Matter PhysicsLaserSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialslaw.inventionPulse (physics)lawMaterials ChemistryElectrochemistrySpallationComposite materialLaser beamsJournal of The Electrochemical Society