Showing papers by "Solvay published in 1991"

Quantum theory of non-integrable systems

Abstract: In 1889 H. Poincare introduced a basic distinction between integrable and non-integrable dynamical systems. This distinction refers to the role of resonances which may lead to divergences. A specially important class of non-integrable systems are «large» Poincare systems (LPS) which have a continuous spectrum and present continuous sets of resonances. As has been shown earlier, LPS play an essential role both in classical and quantum mechanics. Essentially all nontrivial problems of field theory as well as kinetic theory belong this class. We consider here the well known Friedrichs model in which an unstable discrete level is coupled to a continuum. Poincare's theorem prevents the existence of solutions of the eigenvalue problem associated to the Hamiltonian which would be analytic in the coupling constant

Efficient KEX2-Like Processing of a Glucoamylase-Interleukin-6 Fusion Protein by Aspergillus Nidulans and Secretion of Mature Interleukin-6

Abstract: We have designed an expression vector for the secretion of human interleukin-6 (hIL-6) in which the mature protein is fused through a spacer peptide, containing a KEX-2 like protein processing signal, to the entire Aspergillus niger glucoamylase (glaA) gene. Transformation of Aspergillus nidulans with this vector results in fungal strains secreting equimolar amounts of the glucoamylase and IL-6 proteins. The KEX2-type processing signal, Lys-Arg, is recognized and cleaved efficiently by an enzyme present in A. nidulans resulting in the secretion of an authentic mature hIL-6 protein at levels of up to 5 mg/l.

Alternative formulation of classical and quantum dynamics for non-integrable systems

Abstract: We continue our work on large Poincare systems (LPS) characterized by a continuous spectrum and a continuous set of resonances. Poincare's theorem prevents the existence of solutions of the eigenvalue problem associated with the Hamiltonian (as well as the Liouville operator) which would be analytic in the coupling constant. In simple cases, such as the Friedrichs model studied in a recent paper, Poincare's «divergences» can be avoided using a natural time ordering of the dynamical states in the Hilbert space. However, in general, the time ordering has to be performed in the Liouville space of density matrices

Quantum Zeno effect

Abstract: In 1977, Misra and Sudarshan showed, based on the quantum measurement theory, that an unstable particle will never be found to decay when it is continuously observed. They called it the quantum Zeno effect (or paradox). More generally the quantum Zeno effect is associated to the inhibition of transitions by frequent measurements. This possibility has attracted much interest over the last years. Recently, Itano, Heinzen, Bollinger and Wineland have reported that they succeeded in observing the quantum Zeno effect. This would indeed be an important step towards the understanding of the role of the observer in quantum mechanics. However, in the present paper, we will show that their results can be recovered through conventional quantum mechanics and do not involve a repeated reduction (or collapse) of the wave function.

Preclinical pharmacology of flesinoxan: A potential anxiolytic and antidepressant drug

Abstract: Receptor binding studies revealed that flesinoxan potently and selectively binds to the 5-HT1A receptor (Ki = 1.7 nM). The anatomical distribution of [3H]-flesinoxan binding sites is very similar to the localization of the 5-HT1A sites labelled by [3H]-8-OH-DPAT. In several functional models flesinoxan acted as a 5-HT1A agonist. Flesinoxan has been investigated in a variety of animal models predictive for anxiolytic activity. In a conflict test in pigeons, flesinoxan has potent anxiolytic activity at low doses (0.03–1 mg/kg i.m.). Flesinoxan is also highly active to reduce separation-induced ultrasonic anxiety calls in infant rats and in an anticipatory anxiety model in adult mice. However, in the four-plate test and the light-dark model in mice, flesinoxan and other 5-HT1A agonists had no anxiolytic effects. Antidepressant properties of flesinoxan were shown in a behavioural despair model in rats: the forced-swim test. Flesinoxan was more active (0.2–1.8 mg/kg s.c.) than classical tricyclic antidepressants. The putative antidepressant properties are also supported by the desensitisation of β-adrenergic receptors in rats after subchronic administration of flesinoxan. In a functional test for β-receptor activity in the brain (noradrenaline induced c-AMP production in brain slices), a reduction of responsivity was observed after 2 weeks of treatment with flesinoxan (6 mg/kg/day). Therefore, based on the animal pharmacology there are strong indications that flesinoxan as a selective 5-HT1A agonist, has anxiolytic as well as antidepressant properties in man.

Polyvinylidene Fluoride (PVDF) Appearance, General Properties and Processing

Abstract: SOLEF1 polyvinylidene fluoride (PVDF or PVF2). characterized by a high crystallinity, possesses certain basic properties shared by all the varieties of PVDF: chemical inertness, thermal stability, ...

Solutions of peracids

Abstract: A dilute solution of a lower aliphatic peracid such as peracetic acid, having an equilibrium composition, is produced by contacting hydrogen peroxide with a lower aliphatic acid each at initial high concentrations in an aqueous reaction mixture to rapidly form a reaction mixture containing, for example, up to 30% wt of peracid and diluting the reaction mixture with water and with any required quantities of lower aliphatic acid and/or hydrogen peroxide to reproduce the equilibrium composition of the dilute solution, the process being characterised in that the reaction mixture rich in lower aliphatic peracid is diluted before it has itself reached equilibrium, for example when it contains from 20 to 80% of its potential equilibrated content of peracid The process provides a quick plant-efficient process for the production of stable dilute lower aliphatic peracid solutions for industrial disinfection purposes or for personal or domestic hygiene use

Chemical control in precipitation of spherical zirconia particles

Abstract: Monodisperse spherical zirconia particles are precipitated by hydrolysis of alcoholic solutions of zirconium alkoxides in the presence of long-chain carboxylic acids. The particle size can be finely tuned from 0.1 to 2.5 Μm by controlling the concentration of zirconium alkoxide, the water/zirconium ratio, the nature of alcohol from ethanol to butanol, the nature of carboxylic acid from caproic to oleic acid and its concentration. The relationships between the induction time before nucleation, the particle size and all the above parameters are tentatively explained on the grounds of the solubility of the carboxy-alkoxide derivatives and their tendency to form micelles. Calcination of precipitated powders between 300 and 600 ‡C produces mixtures of varying composition from cubic to monoclinic phases of small crystallite sizes, and brings out the loss of surface area and organic content. Different conditions of drying powders lead to variously ordered microstructures.

Bilayered oral pharmaceutical composition with pH dependent release

Abstract: An oral pharmaceutical composition comprises a core containing a drug, a first inner layer coating on the core which contains a drug, and a second inner layer coating on the first inner layer coating which also contains drug. This oral pharmaceutical composition is used especially for treating intestinal diseases.

Mixtures of polar polymers and dedoped conductive polymers, processes for obtaining these mixtures and use of these mixtures to produce electronic, optoelectrical, electrical and electromechanical devices

Abstract: A polymer mixture, including at least one conductive polymer which has been dedoped to provide at least one dedoped conductive polymer; and at least one polar polymer. The polymer mixture has outstanding dielectric properties so that the polymer mixture is useful for producing electronic, optoelectrical, electrical and electromechanical devices.

Metal foil supported catalyst

Abstract: A supported catalyst having a support body which is formed by one or more metal foils and which is well suited for catalytically decomposing ozone and for catalytically oxidizing carbon monoxide. Preferred embodiments further include a heat exchanger which permits the supported catalyst to be used as a catalytic heat exchanger, in particularly for treating fresh air for passenger compartments of vehicles.

An Ulster 2C strain-derived Newcastle disease vaccine: efficacy and excretion in maternally immune chickens.

Abstract: Summary Efficacy and excretion of an Ulster strain‐derived Newcastle disease (ND) vaccine (Poulvac® NDW Broiler) were examined in maternally immune chickens. The vaccine was effective in broilers following coarse spray or aerosol (Atomist) application at one to 10 days of age. Immunity did not differ significantly from immunity following vaccination with a La Sota type vaccine. Also, combined spray application of NDW‐ and infectious bronchitis (IB) (Poulvac® IB primer) vaccine at 1‐day‐old, resulted in sufficient protection against challenge with both virulent ND and IB virus. In layers the vaccine was less immunogenic, requiring large doses to induce sufficient protection in chickens with maternal antibodies. In layers this may make the vaccine economically non‐viable. Atomist vaccination using economically justified doses, was effective after maternal antibodies had waned. Clinical signs of vaccinal reaction were not observed in layers. In broilers respiratory signs of vaccinal reaction were absent afte...

Progress in the Enzymatic Saccharification of Wheat Starch

Abstract: Problems were noticed when trying to include wheat starch to the normal liquefaction and saccharification lines because of the formation of precipitations which are difficult to filter. The effects of different side activities of Aspergillus niger glucoamylases on the filterability of wheat syrups are demonstrated. In order to speed up filtration, viscosity has to be decreased by degradation of arabinoxylanes with present pentosanes. A new enzyme has been discovered which is able to split partially the lysophospholipids contained in wheat starch and let the insoluble components flocculate to big particles. This enzyme splits the phospholipids into free fatty acids and glycerophophorylcholines. The properties of this enzyme present in a novel glucoamylase preparation for the wheat starch processing are demonstrated by using an HPLC method, showing the degradation of wheat lipids as well as synthetic lysophopholipids. Fortschritte bei der enzymatischen Verzuckerung von Weizenstarke. Wegen der Bildung von schwer filtrierbaren Niederschlagen entstanden Probleme bei dem Versuch, Weizenstarke in die normale Verflussigung und Verzuckerung einzubeziehen. Der Einflus verschiedener Nebenaktivitaten von Aspergillus niger-Glucoamylase auf die Filtration werden demonstriert. Um die Filtration zu beschleunigen, mus die Viskositat durch Abbau der Arabinoxylane mit Hilfe von Pentosanasen verringert werden. Es wurde ein neues Enzym entdeckt, das in der Lage ist, die in Weizenstarke enthaltenen Lysophospholipide teilweise zu spalten und die unloslichen Komponenten zu grosen Partikeln auszuflocken. Dieses Enzym spaltet die Phospholipide in freie Fettsauren und Glycerophosphorylcholine. Die Eigenschaften dieses in einem neuen Glucoamylase-Praparat vorliegenden Enzyms fur die Weizenstarke-Verarbeitung werden unter Verwendung einer HPLC-Methode demonstriert, wobei der Abbau der Weizenlipide sowie von synthetischen Lysophospholipiden gezeigt wird.

Fuel sender locking ring

Abstract: A locking member is disclosed for use in a fuel tank assembly of the type having a pressurizable tank with an aperture and having a plurality of retaining lugs transversely extending along the periphery of the tank aperture. A fuel sender assembly having a first portion disposed within the aperture and a second portion having a plate-like shoulder in mating contact with an external tank surface. A seal element is disposed between the tank and the fuel sender assembly in an annular groove provided in the external tank surface intermediate the aperture and the retaining lugs. The locking member comprising a locking ring having an aperture through which a portion of the fuel sender assembly extends, the locking ring having a generally planar lower surface in mating contact with an upper surface of the plate-like shoulder of the fuel sender assembly and having a plurality of tabs corresponding to the plurality of retaining lugs. The tabs having a locking surface for lockingly engaging the retaining lugs and a flange section surrounding the retaining lugs for inhibiting permanent deformation thereof due to greater fluid pressure within the tank.

Serotonergic receptors in anxiety and aggression; evidence from animal pharmacology

Abstract: The present contribution describes the effects of 5-HT1A, 5-HT1B, 5-HT1C, 5-HT1D, 5-HT2 and 5-HT3 ligands in preclinical models of anxiety and aggression in rodents. 5-HT1A agonists show up as strong anxiolytic drugs in some animal paradigms, but not in all, and their behavioural profile is clearly different from that of benzodiazepines. 5-HT1B,1C,1D ligands have mixed effects in anxiety paradigms; anxiolytic as well as anxiogenic responses have been observed, and some compounds were devoid of activity. The 5-HT2 ligands have no clear-cut anxiolytic effects either, whereas 5-HT3 antagonists seem to exert anxiolytic effects, at least in some animal anxiety models. In offensive aggression, 5-HT1A agonists are not specifically anti-aggressive, presumably due to sedation and interference with serotonergic behaviour. Mixed 5-HT1A,1B agonists appear specific antiaggressive agents, reducing offence without sedative or other unwanted side-effects. Extensive studies have indicated that the 5-HT1B or some combination of 5-HT1A/1B receptors specifically modulates this anti-offence effect (serenic-profile). Neither 5-HT1C, 5-HT2 nor 5-HT3 receptor ligands appear to have antiaggressive effects. These preclinical data await human studies in order to find new clinically therapeutic entities.

Marek's disease virus isolates with unusual tropism and virulence for ocular tissues: Clinical findings, challenge studies and pathological features

Abstract: Summary Outbreaks of Marek's disease (MD) were diagnosed in two flocks from the same company. Clinical signs, mainly blindness (>90%), but also depression, mild paralysis, and 11 to 12% mortality by 20 weeks of age were observed. MD virus, serotype 1 was isolated. The isolates were designated NC‐1 (flock 1) and NC‐2 (flock 2). Challenge experiments were conducted with these isolates and with two reference MD virus strains (JM/102W and Md5) in unvaccinated, turkey herpesvirus‐ (HVT) vaccinated and bivalent‐ (HVT and SB‐1) vaccinated chickens. Blindness, gross ocular lesions and tumour formation were observed in a high proportion of all groups challenged with NC‐1 and NC‐2 when compared with chickens challenged with JM/102W and Md5. In chickens challenged with isolates NC‐1 and NC‐2, corneal changes included oedema, midstromal cellular infiltration consisting of macrophages, lymphocytes, plasma cells and lesser numbers of heterophils, collagen degeneration and keratic precipitates consisting primarily of ma...

Integrability and chaos in classical and quantum mechanics

Abstract: We present an outline of our recent work on Large Poincare Systems (LPS) which form an important class of “non-integrable” systems as classified by Poincare (1889). They are characterized by a continuous spectrum and the presence of continuous sets of resonances. As is well known, non-integrability leads to the appearance of random trajectories and chaos. Non-integrability is due to resonances responsible for divergences (the problem of “small denominators”). Generally, resonances are associated with a coupling parameter λ; then the KAM theory shows that for sufficiently small values of λ “most” trajectories remain periodic. On the contrary for LPS, almost all trajectories are random. We show that in this case the problem of the small denominators can be solved and new methods for the integration of these systems can be developed. These methods take into account the chaotic motion of the various degrees of freedom involved. These methods are applicable both to classical and quantum systems. They permit the solution of the eigenvalue problem associated with the time evolution of the distribution functions (the Liouville-von Neumann equation) in a constructive fashion, i.e., through a perturbation expansion analytic in the coupling constant. This can however be only done using non- unitary transformations (as the Poincare's theorem shows that unitary transformations lead to divergences). The specific form of the non-unitary transformation is obtained by a suitable time ordering of the dynamical states. Integration in the Newton-Schrodinger sense is based on the use of time as a parameter for the motion of the dynamical object (or the wave function associated with it). Here we need in addition a second time related to the flow of correlations involving an ever increasing number of degrees of freedom. We may say that, in addition to the Newton-Schrodinger time, we have to introduce a second “internal” time describing the relations (the “correlations”) between the particles. Our dynamical description refers to a statistical description. This situation is similar to that of the radioactivity, where the behavior of individual atoms cannot be predicted. This is quite consistent as the radioactive decay or spontaneous emission correspond indeed to LPS. We now find this type of behavior both in quantum and classical theory as the result of resonances and chaos on the microscopic level.

Stable, solid acetylperoxyborate compounds

Abstract: Stable, solid acetyl peroxyborate compounds which are active oxygen-containing compounds derived from acetic acid and boron-oxygen compounds. The compounds of the invention have a peracetic acid content which can be liberated instantly and directly in water with only minor formation of hydrogen peroxide The acetyl peroxyborates of the invention are useful in washing, bleaching and cleaning agent and disinfectant applications and as oxidizing agents in organic synthesis.

Evaluation of efficacy and safety of an inactivated virus vaccine against feline leukemia virus infection.

Abstract: An inactivated virus vaccine was developed for prevention of FeLV infection in domestic cats. When given in 2 doses, 3 weeks apart, to cats that were greater than or equal to 9 weeks old at the time of first vaccination, the vaccine prevented persistent viremia from developing in 132 of 144 (92%) vaccinates after oronasal challenge exposure with virulent FeLV. In contrast, persistent viremia developed after oronasal challenge exposure with FeLV in 39 of 45 (87%) age-matched nonvaccinated control cats. Transient viremia, indicated by early detection of p27 by ELISA in serum of cats protected from persistent viremia at 12 weeks after challenge exposure, was found in 10 of 132 (8%) vaccinates. Cats that were aviremic 12 to 16 weeks after challenge exposure were examined for reactivation of latent FeLV infection; 4 weekly doses of methylprednisolone were administered, followed by in vitro culture of bone marrow cells. Latent infection was readily reactivated in 6 of 8 (75%) nonvaccinated control cats that had been transiently viremic after challenge exposure. However, latent infection was reactivated in only 5 of 48 (10%) protected vaccinates, and in none of 38 vaccinates in which transient viremia had not been detected. In a safety field trial, only 34 mild reactions of short duration were observed after administration of 2,379 doses of vaccine to cats of various ages, breeds, and vaccination history, for a 1.43% reaction rate. Results indicate that the aforementioned inactivated virus vaccine is safe and efficacious for the prevention of infection with FeLV.

Aryl imido substituted peroxycarboxylic acids

Abstract: Peroxycarboxylic acids of formula (I) are disclosed wherein the substituents are defined by the disclosure. The peroxycarboxylic acids are useful for washing, bleaching and disinfecting, and methods for using them in such processes are also disclosed. Further, a process for preparing the peroxycarboxylic acids is disclosed. ##STR1##

Tierstreu und Verfahren zu ihrer Herstellung

Abstract: Beschrieben wird eine Tierstreu, erhaltlich durch Vermischen von Zellulose oder Zellulose enthaltenden Materialien, Beschwerungsmittel und Verdicker. Als Ausgangsmaterial kann man landwirtschaftliche oder industrielle Ruckstande oder Materialien aus der Wertstoffruckfuhrung, beispielsweise Holzabfalle, Papierabfalle, Zeolithe, Fullstoffe oder Pigmente verwenden.

Oxychlorination catalytic composition and ethylene oxychlorination process using this composition

Abstract: Catalyst composition for oxychlorination and a process for ethylene oxychlorination by means of such a catalyst composition based on copper chloride, magnesium chloride, lithium chloride and at least one other alkali metal chloride, which are deposited on an inert support. The oxychlorination carried out in this way makes it possible to obtain an excellent yield without adhesion of the catalyst composition to the walls of the reactor and without the latter being corroded by the catalyst composition used.

Poly(aryl ether sulfone)compositions comprising poly(phenylene ether sulfone)

Abstract: A poly(aryl ether sulfone) blend comprising (a) from about 25 to about 99 percent by weight of a poly(biphenyl ether sulfone) and (b) from about 1 to about 75 percent by weight of a second poly(phenylene ether sulfone).

Method and apparatus for crystallizing a mineral substance

Abstract: A method and an apparatus for crystallizing a mineral substance in a fluidized bed of crystals (14) generated by circulating a supersaturated solution of the substance to be crystallized upwards through a fluidized bed reactor distributor (12) located under the bed (14), whereafter a fraction (22) of the supersaturated solution is drawn off upstream from the distributor (12) and recycled downstream therefrom in the fluidized bed (14) or the mother liquor of crystallization, and said mother liquor is supersaturated to recreate the above-mentioned supersaturated solution.

Oral pharmaceutical composition

Abstract: An oral pharmaceutical composition comprises a core containing a drug, a first inner layer coating on the core which contains a drug, and a second inner layer coating on the first inner layer coating which also contains drug. This oral pharmaceutical composition is used especially for treating intestinal diseases.

Process for the production of chloroform from carbon tetrachloride, catalytic compositions and process for obtaining them

Abstract: The invention relates to a process for the production of chloroform from carbon tetrachloride using a catalytic composition comprising a support on which a hydrogenating metal is deposited, the support comprising an alkali metal aluminate or alkaline earth metal aluminate. The invention also relates to a catalytic composition comprising a support on which platinum is deposited, the support comprising an aluminate having an inverse spinel structure.

Process for the preparation of polythiophenes and electrically conducting devices containing them

Abstract: The invention relates to a process for the preparation of electrically conducting polymers based on polythiophenes by chemical polymerization of thiophene by means of a ferric salt, an alkyl halide and water. The invention also relates to the electrically conducting devices containing the polythiophenes obtained and a thermoplastic polymer.

Process for preserving the mechanical strength properties of chemical paper pulps

Abstract: Process for preserving the mechanical strength properties of a chemical paper pulp, comprising two treatment stages by means of a peroxidic reagent, with the first stage in an acidic medium and the second stage in an alkaline medium, according to which a treatment by means of a reducing compound is interposed between the two stages.

Quantum mechanics and the direction of time

Abstract: In recent papers the authors have discussed the dynamical properties of “large Poincare systems” (LPS), that is, nonintegrable systems with a continuous spectrum (both classical and quantum). An interesting example of LPS is given by the Friedrichs model of field theory. As is well known, perturbation methods analytic in the coupling constant diverge because of resonant denominators. We show that this Poincare “catastrophe” can be eliminated by a natural time ordering of the dynamical states. We obtain then a dynamical theory which incorporates a privileged direction of time (and therefore the second law of thermodynamics). However, it is only in very simple situations that this time ordering can be performed in an “extended” Hilbert space. In general, we need to go to the Liouville space (superspace) and introduce a time ordering of dynamical states according to the number of particles involved in correlations. This leads then to a generalization of quantum mechanics in which the usual Heisenberg's eigenvalue problem is replaced by a complex eigenvalue problem in the Liouville space.