showing 36 of ~574560 from 574555 documents
Combining two mutations of human interleukin-6 that affect gp130 activation results in a potent interleukin-6 receptor antagonist on human myeloma ce…
1995
The pleiotropic cytokine interleukin-6 (IL-6) interacts with the specific ligand binding subunit (IL-6R alpha) of the IL-6 receptor, and this complex associates with the signal-transducing subunit gp130 (IL-6R beta). Human IL-6 acts on human and murine cells, whereas murine IL-6 is only active on murine cells. The construction of a set of chimeric human/murine IL-6 proteins has recently allowed us to define a region (residues 43-55) within the human IL-6 protein, which is important for the interaction with gp130. Subdividing this region shows that mainly residues 50-55 of the human IL-6 are necessary for this interaction. Recently, another human IL-6 double mutant (Q159E and T162P) showed r…
Relativistic two-body processes in axial-charge transitions
1995
We study the contribution of two-body meson-exchange processes to axial charge transitions for nuclei in the lead, tin and oxygen regions. We conduct calculations in the Dirac-Hartree (the Walecka model) and the relativistic Hartree (where the full one-nucleon-loop effects are included) approximations. We present results indicating that one- and two-body processes enhance the matrix elements of the axial-charge operator by some (100+-20)% in all three regions studied. This agrees well with the fit of eighteen first-forbidden beta-decay transitions conducted by Warburton in the lead region. We also discuss some sensitivities present in the calculation.
Future $\nu_\tau$ Oscillation Experiments and Present Data
1995
Our goal in this paper is to examine the discovery potential of laboratory experiments searching for the oscillation $\nu_\mu(\nu_e) \rightarrow \nu_\tau$, in the light of recent data on solar and atmospheric neutrino experiments, which we analyse together with the most restrictive results from laboratory experiments on neutrino oscillations. In order to explain simultaneously $all$ present results we use a four-neutrino framework, with an additional sterile neutrino. Our predictions are rather pessimistic for the upcoming experiments NOMAD and CHORUS, which, we find, are able to explore only a small area of the oscillation parameter space. On the other hand, the discovery potential of futu…
Atoms and molecules in cavities: A method for study of spatial confinement effects
1995
A general method for solving the problems of spatially confined quantum mechanical systems is proposed. The method works within the framework of the model space approximation. In the case of atoms and molecules trapped into any-shape microscopic cavity (like molecular sieves or fullerenes), the method reduces to a simple modification of the commonly used basis-set quantum chemical calculations. The modification consists of a particular rotation and projection in the model space, leading to solutions better adapted to the boundary conditions of the spatial confinement than the functions that describe the free systems. To illustrate how this method works, it has been applied to the hydrogen a…
Les échanges convectifs au sein du couvert
1995
National audience
Bilan d'énergie et microclimats en situation de relief
1995
National audience
Un exemple de modèle d'échanges d'énergie et d'eau adapté au cas d'une forêt
1995
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La mesure des flux turbulents
1995
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Enhanced susceptibility of cholesteryl sulfate-enriched low density lipoproteins to copper-mediated oxidation
1995
AbstractCholesteryl sulfate (CS) is a minor component of cell membranes, also present in lipoproteins, and its exact function is unknown. Since oxidation of low density lipoproteins (LDL) is thought to be an important determinant of atherogenesis, we investigated the influence of CS enrichment on copper-mediated oxidation of LDL. CS was found to act as a pro-oxidant, as measured by lipid oxidation parameters. The results also suggest that these effects were dependent on the sulfate group since pure cholesterol or cholesteryl acetate did not promote Cu2+-mediated oxidation. Our findings imply that CS may affect the oxidizability and hence the potential atherogenicity of LDL.
Hypothèses et principes de la représentation de la diffusion du CO2 à différentes échelles, de la feuille au couvert
1995
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ALiBi : un exemple de modèle de transferts sol-végétation-atmosphère
1995
National audience
Modélisation des transferts radiatifs dans le domaine solaire : modèles classiques
1995
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Use of transoesophageal echocardiography in the diagnosis of abscess in infective endocarditis
1995
Transoesophageal echocardiography is invaluable clinically since it accurately images abscess cavities or aneurysms. It provides the information about the site and extension of abscesses which is needed by surgeons to time and define surgical intervention. Early diagnosis is advantageous, and abscesses should be expected in 5%-30% of patients with echocardiographically discernible vegetations. Since there is no 'abscess typical' organism, transoesophageal echocardiographic examination is helpful at the first indication of infective endocarditis, to identify high-risk patients. Involvement of the aortic valve, growth in the size of vegetations, and the presence of spontaneous echo contrast a…
Histologic and Cytogenetic Patterns in Benign, Atypical, and Malignant Meningiomas
1995
Atypical meningiomas comprise an intermediate category of meningeal neoplasmas with some microscopic features of aggressivity and a capacity for recurrence. We present a clin ical, morphologic, and cytogenetic study of 15 meningiomas. Morphologic and cytogenetic analysis suggested the existence of morphologically typical meningiomas with normal karyotype or monosomy 22 and morphologically atypical meningiomas, with increasing chromosomal abnormalities (complex karyotype) between these two types. Present results suggest the existence of a third type of morphologically typical meningioma that lacks a phenotypical aggressivity but has a complex karyotype. These genotypical characteristics may…
Huge shift of fundamental electronic absorption edge in Sr1−xBaxNb2O6 crystals at elevated temperatures
1995
Quasimolecular luminescence centers formed by photoinduced recombination of exciton-created defects in KI
1995
Abstract The photoinduced recombination of exciton-created lattice defects - the F,H center pairs was studied in KI crystal at low temperatures. Two different luminescence centers with quasimolecular structure can be distinguished. One of them is the self-trapped exciton, the other one could be the H-plus-electron (H+e) center.
2nu3 band of 12CF4 and its simultaneous analysis with nu3
1995
Abstract A nearly Doppler-limited spectrum of the 2ν 3 band of the 12 CF 4 molecule between 2536.0 and 2599.8 cm −1 was recorded at T = 77 K using difference-frequency laser spectroscopy. The simultaneous analysis of the ground (G.S.), ν 3 = 1, and ν 3 = 2 states was performed using an isolated band model to sixth order in the tetrahedral formalism. Fourteen hundred seventy-five transitions were assigned through J = 35 to the F 2 and E vibrational components of the ν 3 = 2 level. A total of 1864 transition frequencies were fit simultaneously (1000 2ν 3 - G.S. newly assigned transitions together with 575 ν 3 - G.S. and 289 ν 3 - ν 3 transitions already reported in the literature). The ground…
X-ray Photoelectron-spectroscopy Investigation of Pumice-supported Nickel-catalysts
1995
Pumice-supported nickel catalysts, prepared by the method of slow homogeneous precipitation with urea, were analysed by x-ray photoelectron spectroscopy (XPS). By comparison with similarly prepared silica- and alumina-supported nickel catalysts, a preferential interaction of Ni2+ with Al3+ of the support has been determined. A quantitative XPS analysis indicated large segregation of nickel to the surface. The treatment with H2 at 673 K and 1073 K produced a partial reduction of Ni+2 to Ni0. The extent of the reduction was largest at 1073 K and in this case the reduced Ni in the metallic phase was detectable by x-ray diffraction. A decrease of the Ni 2p/Si 2p intensity ratio occurring in the…
(γ,2N) reaction inC12
1995
The $^{12}$C(\ensuremath{\gamma},pn) and $^{12}$C(\ensuremath{\gamma},pp) reactions have been measured for photon energies between 80 and 157 MeV using a photon tagging spectrometer and plastic scintillator detectors. The overall energy resolution was \ensuremath{\sim}7 MeV, sufficient to determine the initial shells of the emitted nucleons. Corrections were made for solid angle and threshold effects by means of Monte Carlo simulations. For the (\ensuremath{\gamma},pn) reaction both the missing energy and recoil momentum distributions are largely consistent with a two-nucleon absorption process on p-shell an sp nucleon pairs. For the much smaller $^{12}$C(\ensuremath{\gamma},pp) cross secti…
Phylogenetic relationship of the green alga Nanochlorum eukaryotum deduced from its chloroplast rRNA sequences.
1995
The marine green coccoidal alga Nanochlorum eukaryotum (N.e.) is of small size with an average diameter of 1.5 microns. It is characterized by primitive-appearing biochemical and morphological properties, which are considerably different from those of other green algae. Thus, it has been proposed that N.e. may be an early developed algal form. To prove this hypothesis, DNA of N.e. was isolated by a phenol extraction procedure, and the chloroplast DNA separated by preparative CsCl density-gradient centrifugation. The kinetic complexity of the nuclear and of the chloroplast DNA was evaluated by reassociation kinetics to 3 x 10(7) bp and 9 x 10(4) bp, respectively. Several chloroplast genes, i…
Monoclonal antibody TeM 106 reacts with a tonoplast intrinsic protein of 106 kDa from Brassica oleracea L
1995
A monoclonal antibody, designated TeM 106, that recognizes an intrinsic protein from the vacuole membrane (tonoplast) of cauliflower (Brassica oleracea L. var. botrytis) is described. Mice were immunized with a tonoplast fraction that had been purified from differentiating meristematic cells from the cauliflower head. Hybridomas were generated and screened by means of Enzyme Linked Immuno Sorbent Assays for differential reactivity to tonoplast over non-related proteins (bovine serum albumin). One out of 14 reactive murine clones was selected on the basis of its stability, secretory efficiency, and high affinity of the secreted antibodies. TeM 106 is an IgM which was shown by indirect immuno…
Fracture Plane of Cruciform Specimen in Biaxial Low Cycle Fatigue—Estimate by Variance Method and Experimental Verification
1995
This paper presents the variance method of determining the fracture plane under random multiaxial stress states. The fracture plane was estimated analytically by the variance method with the three fatigue criteria. The estimated fracture planes were compared with experimental results using type SUS 304 and 1Cr-1Mo-1/4V steel cruciform specimens. The variance method with the maximum normal strain criterion, by neglecting the strain in direction in which no external forces act, could estimate the actual fracture planes of cruciform specimens in high temperature biaxial low cycle fatigue.
An upper limit for the τ neutrino mass from τ → 5π(π0)ντ decays
1995
An upper limit for the tau-neutrino mass has been determined from the decay tau -> 5pi+- \nu_tau using data collected with the OPAL detector from 1991 to 1995 in e+e- collisions at \sqrt{s} ~ M_Z. A limit of 43.2 MeV at 95% CL is obtained using a two-dimensional method in the 5pi invariant mass and energy distribution from 22 selected events. Combining this result with OPAL's previously published measurement using tau+tau- -> 3h+- \bar{nu}_tau 3h-+ \nu_tau decays, a new combined limit of m_{nu_tau} < 27.6 MeV (95% CL) is obtained.
Observations on mucus aggregates along Sicilian coasts during 1991–1992
1995
Abstract The results of some observations on gelatinous material accumulating on the sea ground and free floating in the water column along Sicilian coasts are reported. The phenomenon showed different development patterns moving from the Tyrrherian to the Jonian coast and to the Sicilian Channel. Moreover, in 1991, mucus aggregates in the Tyrrhenian sea showed a similar structure, behaviour and origin to those observed in the Adriatic sea, whereas, in 1992, only a massive growth of metaphytic threadlike algae, more or less producing gelatinous sheaths, occurred.
The gap junctional intercellular communication is no prerequisite for the stabilization of xenobiotic metabolizing enzyme activities in primary rat l…
1995
In primary monocultures of adult rat liver parenchymal cells (PC), the activities of the xenobiotic metabolizing enzymes microsomal epoxide hydrolase (mEHb), soluble epoxide hydrolase (sEH), glutathione S-transferases (GST), and phenolsulfotransferase (ST) were reduced after 7 d to values below 33% of the initial activities. Furthermore, the gap junctional intercellular communication (GJIC), measured after microinjection by dye transfer, decreased from 90% on Day 1 to undetectable values after 5 d in monoculture. Co-culture of PC with nonparenchymal rat liver epithelial cells (NEC) increased (98% on Day 1) and stabilized (82% on Day 7) the homotypic GJIC of PC. Additionally, most of the mea…
Continuous fractionation of poly[(dimethylimino)decamethylene bromide] and molecular weight dependence of the glass transition
1995
30 g of the ionene poly[(dimethylimino)decamethylene bromide] were fractionated by a continuous counter-current extraction method (CPF) using ethylene glycol monoethyl ether as the solvent and diisopropyl ether as the non-solvent component. The efficiency of the separation was checked by viscometry and gel-permeation chromatography (GPC) measurements. Eight fractions of different molar mass were prepared for differential scanning calorimetry (DSC) experiments. With bromide as counter-ion, the glass transition temperature of the ionene increases from ca. 60 to 85°C as the intrinsic viscosity of this material (in 0,4 M aqueous solutions of KBr at 25°C) rises from ca. 14 to 22 mL/g. When bromi…
Release of [3H]Acetylcholine in Human Isolated Bronchi: Effect of Indomethacin on Muscarinic Autoinhibition
1995
Receptor-mediated regulation of acetylcholine release in the airways, particularly in humans, remains unclear. In the present study, the tissue content of acetylcholine and release of [3H]acetylcholine were measured in freshly dissected human bronchi obtained at thoracotomy. Large (main and lobar bronchi) and small (segmental and subsegmental bronchi) airways contained considerable amounts of endogenous acetylcholine (300 +/- 50 pmol/100 mg wet weight), whereas significantly less was found in lung parenchyma (60 +/- 30 pmol/100 mg). Isolated small bronchi incubated in an organ bath with the precursor [3H]choline synthesized significant amounts of [3H]acetylcholine (26,000 +/- 4,000 dpm/100 …
Inhibition by interleukin-1 beta of noradrenaline release in rat spleen: involvement of lymphocytes, NO and opioid receptors.
1995
Effects of indomethacin, N omega-nitro-L-arginine (NNA) and naloxone, and of pretreatment with cyclophosphamide (CY), on the interleukin (IL)-1 beta induced inhibition of exocytotic noradrenaline release were investigated in the isolated, vascularly perfused spleen of the rat. Neurotransmitter release was evoked by perivascular electrical stimulation (4 Hz) and the overflow of endogenous noradrenaline was determined by HPLC with electrochemical detection. Perfusion of the spleen with Tyrode's solution containing IL-1 beta (100 pg/ml) for 90 min caused an inhibition of the stimulation-evoked noradrenaline overflow which persisted for at least 20 min after washout of the IL. The evoked overfl…
Recristallisation Dynamique au Cours de la Déformation à Chaud de Quatre Nuances de Bronze à 9% d'Etain
1995
Pour cerner les techniques metallurgiques des artisans protohistoriques, il est necessaire de connaitre les evolutions microstructurales obtenues selon les deformations imposees. La compression a chaud de deux bronzes industriels (contenant soit 0,026% soit 0,26% de zinc) et deux bronzes «archeologiques» (contenant soit 0,5% de soufre soit 0,5% de soufre et 0,5% de plomb) permet les observations suivantes : - Les comportements des bronzes «archeologiques» sont tres similaires : jusqu'a 600°C pour e = 0,1 on n'observe pas de recristallisation ; pour e = 1,2 on observe une recristallisation en collier le long des joints de grains. A 750°C la recristallisation semble homogene dans tout le mate…
Biochemical and toxigenic properties of Vibrio furnissii isolated from a European eel farm
1995
Abstract The present study describes for the first time the isolation of Vibrio furnissii strains from a European eel culture system which are pathogenic for eels ( Anguilla anguilla ) (LD 50 dose, 10 6 cfu/fish). Biochemical characterization of the isolates was performed by API 20E system and by classical numerical taxonomy. Growth at 4 °C, and with 6–8% (w/v) NaCl in a broth medium were necessary to differentiate Vibrio furnissii from Aeromonas species when the API 20E system was used. Virulence for eels of V. furnissii isolates was demonstrated by intraperitoneal injection of living cells. The extracellular products (ECPs) produced by V. furnissii were lethal to elvers and induced some o…
Evaluation of regional haemodynamic and alterations of vascular wall of the lower limbs in hypertensive subjects.
1995
Calculations of the geometry and optical properties ofFMgcenters and dimer (F2-type) centers in corundum crystals
1995
CALCULATIONS OF THE GEOMETRY AND OPTICAL-PROPERTIES OF F-MG CENTERS AND DIMER (F-2-TYPE) CENTERS IN CORUNDUM CRYSTALS
Modulatory control by non-competitive agonists of nicotinic cholinergic neurotransmission in the central nervous system
1995
Abstract Several exogenous and endogenous compounds have been discovered that act on nicotinic acetylcholine receptors as non-competitive agonists (NCA) of low efficacy, and probably also as allosteric regulators of the receptor's sensitivity to acetylcholine. Nicotinic NCAs may be viewed as another facet in the increasingly complex picture of vertebrate brain organization, i.e. they may be part of a higher level ‘chemical’ network that overlays the neuronal network of the CNS. Furthermore, exogenous NCAs may provide a new therapeutic approach to Alzheimer's dementia.
Nitric oxide is involved in non-adrenergic, non-cholinergic inhibitory neurotransmission in rat duodenum
1995
1. In rat duodenum, electrical field stimulation (EFS) induced a relaxation due to activation of non-adrenergic, non-cholinergic (NANC) inhibitory intramural neurones. 2. Nitric oxide synthase (NOS) inhibitors, N omega-nitro-L-arginine (L-NNA) and N omega-nitro-L-arginine methyl ester (L-NAME), caused a dose-dependent reduction in amplitude of the NANC relaxation. Responses to low frequencies of stimulation were more sensitive to NOS inhibitors than those to high frequencies. 3. Effects induced by NOS inhibitors were stereospecific since D-NNA and D-NAME did not affect NANC relaxation. L-arginine, but not D-arginine, partially prevented the effects induced by NOS inhibitors on NANC relaxati…
Correlation of cerebral blood flow and MCA flow velocity measured in healthy volunteers during acetazolamide and CO2 stimulation
1995
Abstract The assessment of the cerebrovascular reserve capacity (RC) has become a widely used tool in the management of cerebrovascular disease. Discrepancies become obvious, however, if results obtained with different methods are compared. Aim of the present study, therefore, was to compare blood velocity and cerebral perfusion data in the same group of healthy test persons. In 32 volunteers regional cerebral blood flow (rCBF) was measured with the 133 Xe-inhalation method. F1 as grey matter flow and the initial slope index (ISI) were computed. Simultaneously flow velocity in the middle cerebral artery (V MCA ) was assessed by transcranial Doppler sonography (TCD). Measurements were perfor…
Knee osteoarthritis in former runners, soccer players, weight lifters, and shooters.
1995
Objective. To determine the relationship between different physical loading conditions and findings of knee osteoarthritis (OA). Methods. We selected 117 male former top-level athletes (age range 45–68 years) who had participated in sports activities with distinctly different loading conditions: 28 had been long-distance runners, 31 soccer players, 29 weight lifters, and 29 shooters. Histories of lifetime occupational and athletic knee loading, knee injuries, and knee symptoms were obtained, and subjects were examined clinically and radiographically for knee findings of OA. Results. The prevalence of tibiofemoral or patellofemoral OA based on radiographic examination was 3% in shooters, 29%…