Crystal structure and spectroscopic studies of bis(N-2-pyridinylcarbonyl-2-pyridinecarboximidato)copper(II) monohydrate. Local bonding effects

1989

Abstract The crystal and molecular structure of bis(N-2- pyridinylcarbonyl-2-pyridinecarboximidato)copper(II) monohydrate, Cu(BPCA)2·H2O, has been determined from single crystal X-ray data. It crystallizes in the monoclinic space group P21/c with four formula units in a cell of dimensions: a = 8.917(1), b = 8.932(1), c = 28.794(17) A, β= 95.49(2)°.Least- squares refinement of 2754 reflections with I > 2.5σ(I) and 379 parameters gave a final R = 0.037 (Rw = 0.036). The structure consists of discrete neutral Cu(BPCA)2 entities linked two by two through water molecules hydrogen bonded to ligand carbonyl groups. The coordination geometry around copper ions can approximately be described as orth…

Temperature Effects on the Phonon Spectrum in YBa2Cu3O7 Single Crystals and Thin Films

1989

We have performed a detailed investigation of the temperature dependence of the 385cm-1 phonon in single crystals and thin films of the YBa2Cu3O7 superconductor by means of Raman spectroscopy. In the single crystal the frequency of this phonon shows a downshift of about 5 cm-1 on passing the superconducting transition from above, which is referred to a strong electron-phonon interaction in the superconductor. The shift of the phonon in thin epitaxial films on MgO or SrTiO3 substrates is only about 2.5 cm-1. This difference may be a result of a structural transition in the single crystal which is possibly suppressed in the films because of the epitaxy. The electron-phonon interaction is also…

Non-specific Hyperreactivity to Pharmacological Stimuli in Tracheal and Lung Parenchymal Strips of Actively Sensitized Guinea-pigs

1989

Abstract The responsiveness of tracheal and lung parenchymal strips isolated from actively sensitized guinea-pigs to CaCl2 (in K+-depolarized tissue), KCl, acetylcholine and histamine was compared with that of strips from unsensitized animals. The concentration-response curves to the mentioned agonists exhibited, in the sensitized group, a left upward displacement (greater maximal effect, lesser effective concentration 50% and a steeper slope) compared with those obtained in the unsensitized group. These results indicate the existence of a non-specific increase in responsiveness in the airway smooth muscle from sensitized animals.

The Peter Pan syndrome: Was James M. Barrie anorexic?

1989

Recently, anorexia nervosa has been referred to as the “Peter Pan syndrome,” a metaphor based on the theme of not growing up. Beside the fact that Peter Pan was a “boy who would not grow up,” another parallelism with anorexia nervosa may lie within the creator himself. We discuss the possibility that James M. Barrie, author of “Peter Pan,” might have been himself anorexic in childhood and adolescence.

Effects of zinc acexamate on blood flow and prostanoid levels in the gastric mucosa of the rat

1989

The effects of the new antiulcer compound zinc acexamate on blood flow and prostanoid levels in the gastric mucosa have been studied. Zinc acexamate (30 and 300 mg/kg) dose-dependently prevents the reduction induced by the perfusion of noradrenaline (3.5 micrograms/kg.min, 30 min) in gastric mucosal blood flow, as measured by 3H-aniline clearance. Zinc acexamate pretreatment also increases the levels of prostaglandin E2 in the gastric mucosa of the rat, both under control conditions and after infusion with noradrenaline. The levels of thromboxane A2 and prostacyclin were not modified by zinc acexamate. These results confirm the importance of microcirculation in pathogenesis and the idea tha…

Rubberlike elasticity?a molecular primer. ByJ. E. Mark andB. Erman. Wiley, Chichester 1988. viii, 196 pp., bound, � 23.70.?ISBN 0-471-61499-8

1989

Les dépenses publiques pour l'enseignement universitaire et le rendement fiscal : le cas du Québec et de la France

1989

International audience

A study of beta-adrenoceptors in rat lung parenchymal strip.

1989

Abstract The aim of the present study was to characterize the β-adrenoceptor population in rat lung strip. For this purpose, Schild plots were obtained for the β-adrenoceptor antagonists atenolol (β1-selective), butoxamine (β2-selective) and propranolol (nonselective), using three different agonists: isoprenaline (non-selective), salbutamol (β2-selective) and noradrenaline (β11-selective). The slopes of these Schild plots were close to the theoretical value of unity, and pA2 values determined with isoprenaline, salbutamol and noradrenaline as agonists were: for propranolol, 7·86 ± 0·22, 7·72 ± 0·15 and 7·89 ± 0·23; for atenolol, 5·19 ± 0·05, 5·33 ± 0·07 and 5·47 ± 0·22 and for butoxamine, 6…

Day-night differences in the sensitivity of adrenoceptors in the Syrian hamster pineal gland: an in vivo iontophoretic study.

1989

Abstract Investigations on the regulation of pineal melatonin synthesis in the Syrian hamster revealed distinct differences compared to this well-understood mechanism in rat. E.g., a circadian profile of pineal norepinephrine (NE) is absent, there is no β-adrenoceptor sensitivity during daytime and adrenergic receptor supersensitivity is not easily achieved. To elucidate the action of NE on pineal receptor sites, the effects of iontophoretic application of adrenergic compounds on spontaneous electrical discharge rates of pinealocytes were investigated during day- and nighttime. Following application of either NE, isoproterenol or clonidine, cells were activated, inhibited or not affected. W…

Radikalpolymerisation von methylmethacrylat im gesamten umsatzbereich. Stationäre und instationäre experimente zur bestimmung von wachstums- und abbr…

1989

Free-radical polymerization of methyl methacrylate in bulk at 0°C over the full range of conversion is reported. Details for stationary and non-stationary experiments are described allowing to measure both kinetically relevant ratios fk/ka and kw/ka, f representing radical efficiency, kw rate constants of propagation and ka rate constant of termination. From these ratios the absolute rate constants kw and ka are available. The photochemical decay of the initiator 1,1′-azodicyclohexanenitrile in connection with the rotating-sector technique and observation of the post-effect after stopping the initiator decay were used. The rate of polymerization and the number- and weight-average molar mass…

Elements of the Archean thermal history and apparent polar wander of the eastern Kaapvaal Craton, Swaziland, from single grain dating and paleomagnet…

1989

Abstract Single grains of zircon, hornblende, biotite and feldspar have been dated to define the thermal history of the Archean Mbabane Pluton, Swaziland. Coincident207Pb/206Pb zircon and40Ar/39Ar hornblende ages suggest that the pluton underwent rapid cooling to about 450°C at the time of emplacement at ∼ 2690 Ma. Because the Mbabane Pluton is one of a suite of granites which represent the last major Archean intrusive event in the eastern Kaapvaal Craton, this time of emplacement marks the end of cratonization. Much younger biotite and feldspar ages indicate argon loss, perhaps due to several low-temperature events related to dike intrusion at 2000–2300 Ma. From such a thermal history, the…

On the structure of the similarity orbits of Jordan operators as analytic homogeneous manifolds

1989

For Jordan elementsJ in a topological algebraB with unite, an open groupB−1 of invertible elements and continuous inversion we consider the similarity orbitsS G (J)={gJg−1:g∈G} (G the groupB−1⋂{e+c:c∈I},I⊂B a bilateral continuous embedded topological ideal). We construct rational local cross sections to the conjugation mapping\(\pi ^J G \to S_G \left( J \right)\left( {\pi ^J \left( g \right) = gJg^{ - 1} } \right)\) and give to the orbitS G (J) the local structure of a rational manifold. Of particular interest is the caseB=L(H) (bounded linear operators on a separable Hilbert spaceH),I=B, for which we obtain the following: 1. If for a Hilbert space operator there exist norm continuous local…

Are there individual concepts? Proper names and individual concepts in SI—Nets

1989

We discuss some aspects of the role played by descriptional knowledge in expressions denoting individual objects. In knowledge representation systems such as KL-ONE and KRYPTON which use semantic networks to express descriptional information, the problem is to establish whether the use of individual concepts in a network is justified. In the light of theoretical and applicational considerations, in the proposed solution only definite descriptions are considered as being characterizable by means of definitions. Vice versa, proper names, in the strict sense, will be treated as having no definitional dimension, and as such only appear in the assertional knowledge base. A description is given o…

The preparation of four- and six-membered chalcogenametallacyclic derivatives of group 4 metallocenes

1989

Abstract Four-membered metallacycles [(RC 5 H 4 ) 2 M(μ-E)] 2 (M = Zr, Hf; 1 , E = Se; 2 , E = S) were obtained by UV irradiation of dialkyl- or diaryl-metallocenes and equimolecular amounts of elemental chalcogen, but this method works only for bulky R groups. A more general route to compounds 1 and 2 involves the reaction of metallocene dichloride with chalcogenide anions. Six-membered metallacyclohexasulfanes (t-BuC 5 H 4 ) 2 MS 5 ( 3 , M = Zr, Hf) are obtained rather than compounds 2 when an excess of sulfur is used in the photolytic experiments, whereas compounds 1 were still formed when an excess of selenium was used. The observed difference is explained in terms of the solubility of …

Successful treatment of HSV encephalitis during pregnancy.

1989

A propos d'une femme presentant une grossesse de 23 semaines. Description des signes cliniques et electroencephalographiques. Les effets de l'aciclovir sur l'encephalite et sur l'evolution de la grossesse sont etudies

Biochemical Aspects of Chick Embryo Retina Development: The Effects of Glucocorticoids

1989

In chick embryo retina during development, DNA synthesis and the activities of DNA polymerase, thymidine kinase, thymidylate synthetase, and ornithine decarboxylase (ODC) declined in parallel from day 7 to 12. The administration in ovo of hydrocortisone reduced significantly, particularly at 8-10 days of incubation, both DNA synthesis and the four enzyme activities tested. The effect was dose dependent, reaching the maximum with 50-100 nmol of hydrocortisone, 8-16 h after treatment. The highest inhibition was found for ODC activity (70%), followed by thymidine kinase activity (62%) and DNA synthesis (45%), whereas activities of DNA polymerase and thymidylate synthetase were reduced only by …

Hyperchargeless triplet Majoron model.

1989

We study the general conditions to maintain the scale of the lepton-number-breaking vacuum expectation value at the electroweak scale. It is shown that the only possibilities are if the main component of the resulting Majoron is a hyperchargeless complex triplet or a neutral singlet. Models with a hyperchargeless triplet, even though phenomenologically more interesting, seem to be very difficult to build because they like to break charge conservation. However, we have found a particular extension, by adding an additional neutral singlet, that solves this problem. The model can give a Majorana mass to the neutrinos in the eV range, ..mu -->..e..gamma.. can proceed with branching ratios at th…

Mutagenicity spectra in Salmonella typhimurium strains of glutathione, L-cysteine and active oxygen species

1989

Glutathione and L-cysteine, in the presence of rat kidney post-mitochondrial supernatant (S9) fraction, and various forms of active oxygen were investigated for mutagenicity in seven his- strains of Salmonella typhimurium. Glutathione and L-cysteine showed qualitatively and quantitatively virtually identical mutagenic activities. The number of mutants induced in strain TA97 was 3-4 times higher than in TA100, the strain in which the mutagenicity was originally detected. Mutagenic effects were also observed in strains TA92, TA102 and TA104, but not in TA1535 and TA1537. Hydrogen peroxide, superoxide and glucose/glucose oxidase in the presence and absence of kidney S9 fraction showed pronounc…

QCD JETS AT HERA I.: O(αs) RADIATIVE CORRECTIONS TO ELECTROWEAK CROSS SECTIONS AND JET RATES

1989

We present the complete O(αs) corrections to the electroweak cross sections of both neutral current and charged current deep inelastic e±p scattering including lepton polarization effects. Changes in the cross section due to the inclusion of next-to-leading-log (NLL) effects are parametrized by K factors, which are defined as the ratio of the NLL O(αs) cross sections and the Born cross section. Using the standard redefinition scheme of the parton densities, we find that the K factors deviate substantially from unity for small values of the Bjorken-Scaling variable x. We also elaborate on problems that arise when defining jet cross sections in ep scattering and present numerical results for…

Screening of positrons in semiconductors and insulators

1989

Theoretical models are presented for the enhancement of the electron density at a positron in a semiconductor or insulator host. The model better suited for typical semiconductors is based on the many-body theory for the screening of a positron in electron gas. The starting point of the model for insulators is the atomic polarizability. The common parameter in both models is the high-frequency dielectric constant. Moreover, the enhancement depends on the ambient electron density in the semiconductor model and on the unit-cell volume in the insulator model. With use of the models developed, positron lifetimes in perfect semiconductor and insulator crystals have been calculated. In the calcul…

Facteurs économiques et psycho-physiologiques de la typologie de la collection du Musée du Jouet de Moirans (France)

1989

International audience

ChemInform Abstract: Synthesis of Uvarovite Garnet.

1989

A garnet with interesting optical properties is synthesized by means of the ceramic method and the formation of gels. Colloidal silica or tetraethoxysilane (TEOS) is used as a starting reagent in the latter method of synthesis, together with nitrate and chloride salts of the remaining components. Use is made of ultraviolet-visible and infrared spectroscopy techniques and X-ray diffraction in studying the evolution of the system. Formation of the garnet phase at lower temperatures is observed when using the gel methods, as well as the absence of chromates during the process in the samples which contained chlorides.

Simulation of the field drying of hay

1989

International audience

The electromagnetic field of an accelerated charge in the proper reference frame of a noninertial observer

1989

The Lienard-Wiechert formulae for the electric and magnetic fields of an accelerated charge moving along an arbitrary world-line are generalized so that they can be applied by noninertial observers using accelerating and rotating reference frames. For this purpose, a relativistic coordinate-independent formalism suggested by DeFacio, Dennis and Eetzloff is extended to the description of all kinematical aspects required in the theory of the retarded fields of a point charge. The generalized Lienard-Wiechert formula is applied to a number of special situations, demonstrating that it allows a lucid and concise treatment of a number of subtle problems such as the role of the «relativity of acce…

Relaxation of self-entangled many-arm star polymers

1989

We present a description of the relaxation of star polymers based on the conformational scaling properties predicted by Daoud and Cotton and confirmed in our recent simulations. We identify three typical relaxation mechanisms. The first describes elastic deformation of the overall shape. Its relaxation time is nearly independent off. A second type of relaxation occurs via rotational diffusion. We predict that the relaxation time should scale with Nwlfz-v where Y is the correlation length exponent. A third relaxation process is the disentanglement of two or more arms. Here the longest relaxation time should increase exponentially with f llz. We measure various relaxation processes by molecul…

Granulocyte-macrophage colony-stimulating factor induces cytokine secretion by human polymorphonuclear leukocytes.

1989

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is known as an inducer of proliferation and functional activation of myeloid cells. This study was carried out to characterize the effects of GM-CSF on polymorphonuclear leukocytes (PMN) more extensively. Using Northern blot analysis, we show that PMN are able to accumulate mRNAs for different cytokines, including tumor necrosis factor-alpha (TNF-alpha); G-CSF, and M-CSF, all of which are involved in inflammation and hematopoiesis. Biological assays and immunoassays demonstrate that PMN translate these mRNAs, except TNF-alpha, into secretory proteins. However, the expression of these cytokines is dependent on stimulation by exogenous…

Do multiple oestrogen receptor assays give significant additional information for the management of breast cancer?

1989

In 101 breast cancer patients, measurement of oestrogen receptor status in multiple biopsies across a tumour reveals a highly significant difference in the proportion of patients remaining either disease-free (P less than 0.04) or alive (P less than 0.005), when those with uniformly receptor positive (++) primary tumours are matched with clinically comparable patients whose tumours were homogeneously receptor negative (--). Mean follow-up time was 85 months. The prognostic value of this discriminant is particularly striking in the 53 patients with involved nodes at presentation. Of these, 13 were (++) and seven remain alive of whom six are disease-free, whereas 24 of the 29 (--) patients ar…

A case of combined Farber and Sandhoff disease

1989

We describe a patient with the biochemically established combination of Farber and Sandhoff disease. A 6-month-old girl of consanguineous Turkish parents presented with hoarseness, stridor, scattered skin nodules, painful swelling of hand joints and ankles, and cherry-red macular spots. Until the age of 2 years her motor and physical condition deteriorated distinctly, however her mental state remained unchanged. A biopsied skin nodule disclosed lysosomal inclusions within storage cells that were typical of Farber disease (curved tubular structures). However, other inclusions (e.g. zebra bodies) were also found. Biochemical findings included ceramide accumulation in skin nodules and cultured…

Heat Shock Proteins in Sea Urchin Embryos. (heat shock proteins/sea urchin embryos)

1989

Decreased level of cardiac antioxidants in endurance-trained rats.

1989

Han-Wistar rats were exposed to a 194-200 h swimming protocol which caused a significant increase in the cardiac weight. The levels of various tissue antioxidants were assayed from the myocardium of the right ventricle and from the left ventricle (subendo- and subepimyocardium). This endurance training decreased the activities of catalase in the right ventricle and in the subendo- and subepimyocardium and Cu,Zn-superoxide dismutase in the subendomyocardium as well as the concentration of vitamin E in the right ventricle and in the subendomyocardium. Also, the activity of thioredoxin reductase decreased in each part of myocardium and that of glutathione reductase in the right ventricle and i…

Different prevalence of some indices of cardiac and vascular impairment in normal weight and obese patients with essential arterial hypertension

1989

Certain physiopathological features that differentiate essential arterial hypertension in normal weight and obese patients are recalled. The results of a retrospective study carried out in 293 hypertensive patients admitted to the Clinic in recent years are reported with a view to evaluating the prevalence of certain parameters (ischaemic cardiopathy, left ventricular hypertrophy, renal, vasculo-cerebral and retinal impairment) in patients subdivided into two groups: normal weight and obese. The study showed in the first group a higher prevalence of signs of ischaemic cardiopathy; in the second a higher prevalence of left ventricular hypertrophy. This difference is accentuated in the subgro…

A phase-II study of low-dose cyclophosphamide and recombinant human interleukin-2 in metastatic renal cell carcinoma and malignant melanoma.

1989

Recent preclinical and clinical studies that have demonstrated antitumor activity of high-dose recombinant interleukin-2 (rIL-2), and animal models that demonstrated a synergistic effect of low-dose cyclophosphamide, led us to study rIL-2 (Cetus Corp., Emeryville, Calif) in a phase II clinical trial in combination with low-dose cyclophosphamide in 32 patients, 18 with malignant melanoma and 14 with renal cell carcinoma. rIL-2 was given once daily at 3 x 10(6) U/m2, as a 30-min infusion for 14 days in cycle I and for 2 x 5 days in cycles II and III respectively; if tolerated, the dose was increased to a maximum of 6 x 10(6) U m-2 day-1; the cycles, separated by 1 week treatment-free interval…

Mitochondria-related encephalomyopathies.

1989

Owing to advances in morphological and biochemical techniques, the mitochondria-related myopathies and encephalomyopathies have emerged as a still rapidly growing group of primary and secondary metabolic disorders, which may extend from infancy to late adulthood. Impairment of the biochemically diversified mitochondria is reflected in an enormous number of deficiencies, often affecting several mitochondrial enzymes in the same patient; morphologically abnormal mitochondria are common and are thus not specific to individual mitochondrial enzyme deficiencies. Skeletal muscle biopsies have provided a wealth of data through histological and histochemical studies and from isolated mitochondria. …

Simulation investigations of the position of Fatigue Fracture Plane in materials with biaxial loads

1989

In the paper three methods of determination of the expected fatigue fracture plane position under random triaxial stress state have been presented. They are: weight function method, variance method and damage cumulation method. The weight function method for biaxial cyclic loadings has been analysed with digital simulation. The fatigue fracture plane position has been determined with mean values of the direction cosines of principal stress axes. Averaging has been done at angle values with use of weights. Eleven various weights have been presented and their usability has been analysed on the basis of experimental results obtained by Rotvel, and Nishihara-Kawamoto. The weights with good agre…

Regio- and stereoselective regulation of monooxygenase activities by isoenzyme-selective phosphorylation of cytochrome P450.

1989

The phosphorylation of the two major phenobarbital-inducible cytochrome P450 isoenzymes IIB1 and IIB2 was increased in hepatocytes by the action of the membrane permeating cAMP derivatives N6-dibutyryl-cAMP and 8-thiomethyl-cAMP. Under these conditions the dealkylation of 7-pentoxyresorufin, a selective substrate of cytochrome P450IIB1 and P450IIB2 was markedly reduced. 16 beta-Hydroxylation of testosterone which is catalyzed specifically only by cytochrome P450IIB1 and IIB2 was strongly reduced; for 16 alpha-hydroxylation which is also catalyzed by cytochrome P450IIB1 and IIB2 but additionally by 3 further cytochrome P450 isoenzymes, this reduction was less pronounced; for the oxidation of…

Synthesis of polymeric derivatives of isoniazid: characterization and in vitro release from a water-soluble adduct with polysuccinimide.

1989

Coupling of isoniazid with polysuccinimide afforded a water-insoluble polymeric pro-drug; by reaction with ethanolamine it was chemically transformed in a water-soluble adduct. The in vitro release of isoniazid from the drug-polymer adduct was studied by using an artificial stomach wall lipid membrane. The transfer rate constant from simulated gastric juice to simulated plasma was defined and compared with that of an equivalent dose of pure drug.