Low-pT pion enhancement from partial thermalization in nuclear collisions

1991

Abstract We attribute the enhancement of pions measured at low transverse momenta and central rapidities in 200 A GeV nucleus-nucleus collisions to the partial thermal equilibration of a superdense pion fluid. Transport theory calculations are compared to recent S+S and O+Au data, and predictions are made for Pb+Pb.

Redshifts of southern clusters. II

1991

New redshifts are given for 21 clusters of galaxies from the Abell, Corwin, and Olowin Rich Cluster Catalogue. The redshift of the brightest cluster galaxy - where the brightest member is brighter than 15.5 - is employed as an indicator of the mean cluster redshift. The redshifts of first-, second-, and third-ranked galaxies are shown to agree, confirming the value of the survey procedure, although some clusters require more information than simply the redshift of the brightest cluster. 7 refs.

Dialyseassoziierte Amyloidosteopathie - Radiologische Aspekte

1991

Amongst the complications of dialysis, amyloid osteopathy is getting increasingly significant. It is due to deposition of beta 2-microglobulin. To determine the incidence and time of development of this complication, the skeletal radiographs of 185 patients undergoing dialysis, some for up to ten years, were analysed retrospectively. In about 10% of patients, the presence of beta 2-microglobulin osteopathy may be expected. The radiological features, sites of predilection and differential diagnosis of amyloid osteopathy and of other skeletal changes due to dialysis are discussed.

Human immunodeficiency virus infection in cells of myeloid-monocytic lineage.

1991

We established persistent infection with a strain of human immunodeficiency virus type 1, HTLV-IIIB, in a promyelomonocytic cell line, ML-1 (CD4 antigen nearly negative and CD4 mRNA negative), and a promonocytic cell line, THP-1 (CD4 antigen positive). Different reaction of giant cell formation was found after co-cultivation of infected and uninfected cells of ML-1, HL-60, THP-1 and U-937 cell lines with uninfected and infected MOLT4 (a T-lymphoma cell line).

Differentiation of herpes simplex virus-induced fusion from without and fusion from within by cyclosporin A and compound 48/80.

1991

Treating strains of herpes simplex virus (HSV) in culture with either cyclosporin A or compound 48/80, allowed the strains to be divided into two groups. Group 1 contains the strains ANG and HFEM of HSV-1 and Lux syn (HSV-2) producing fusion from within (FFWI) and fusion from without (FFWO). Cyclosporin A fails to inhibit both types of fusion at concentrations up to 100 microM. Strains ANG and HFEM belong to the syn 3 marker locus group identified for HSV-1. Group 2 contains all other fusion-producing strains of HSV tested so far. Cyclosporin A inhibits FFWI at concentrations as low as 10 to 20 microM. These strains belong to the syn locus marker groups 1, 2, 4 and 5. From the fact that mut…

Concentration dependence of the electro-optical spectra from two-dimensional aggregated chromophore systems

1991

The linear and the quadratic Stark effects have been employed to characterize aggregate formation of an amphiphilic cyanine dye mixed with arachidic acid in various concentrations within Langmuir-Blodgett multilayers. Two different electrode configurations with the electric field directions parallel and normal to the films have been employed to test the responses of the electronic spectra to external fields. The observations have been used to quantify the induced and static dipole moment changes on excitation of the chromophores. A comparison of the results obtained from different multilayer arrangements is suggestive of inter-layer couplings for the case of head-to-head configurations of t…

Self-diffusion in polymer solutions using the bond-fluctuation MC-algorithm

1991

Abstract A lattice Monte Carlo study of the self-diffusion of polymer chains in an athermal solution of equal chains is presented. The examined chain lengths, N (= 20–200), and volume fractions, φ (= 0.025-0.5), cover the range from dilute solution to concentrated solution, respectively. The dynamics show a gradual crossover from Rouse to reptation-like behaviour. Analysing the data according to a scaling theory and taking into account the density dependence of the microscopic length and time-scales, an almost perfect scaling of the self-diffusion coefficient is achieved. The high statistical accuracy of the data (103–104 chains per parameter combination) was obtainable by using a transpute…

Trauma in cirrhosis: an indicator of the pattern of alcohol abuse in different societies.

1991

While some morbidities associated with the excessive use of alcohol are related to the total amount of alcohol consumed--cirrhosis being an example--other pathologies, such as trauma and those of psycho-social origin, are mainly related to the frequency of acute alcoholic intoxication rather than to the total amount consumed. The balance between these two types of alcohol-associated morbidities can provide an indication of the relative frequency of intoxication, and thus of the pattern of alcohol abuse in a population. Since trauma is highly associated with acute alcoholic intoxication, the prevalence of bone fractures was determined in cirrhotics in nine countries. The prevalence of rib an…

Inclusive production ofp-resonaces in πN-interactions

1991

A theoretical analysis of the inclusive production ofp-mesons in πN-collisions is carried out. It is shown that the reggeized pion exchange mechanism describes well a large set of the experimental data in the region of the Feynman variablex>0.6. The combination with the model of quark-gluon strings leads to a good agreement with the experiment for allx. The inclusive production of high spin resonances is discussed.

QCD generates the ϱ-resonance

1991

Abstract The question whether the asymptotic QCD amplitude contains potentially hadronic resonances is examined by a mathematically rigorous method, based on the theory of maximally converging sequences of polynomials and conformal mappings. It is shown that the extrapolated amplitude to the physical cut exhibits indeed a bump structure which corresponds to the ϱ-resonance.

Reptation and constraint release

1991

Abstract The reptation and constraint release models are discussed by considering three recent experimental examples: (1) the diffusion of hydrogenated polybutadiene in matrices of molecular weights raning between 1 ⩽ Mw / Me ⩽ 253; (2) the diffusion of polystyrene (PS) chains in matrices of star branched PS; (3) the diffusion of very long PS chains in chemically cross-linked PS-networks. It is concluded that the reptation and constraint release models are applicable, but ‘constraint release’ should be understood in a wider sense allowing for non-reptative removal of barriers to lateral chain motion. The analysis of the third example proves that lateral modes of motion have a negligible inf…

Electron-transfer dynamics in a donor—acceptor complex

1991

Abstract Density matrix theory is used for the study of the dissipative quantum dynamics of electron transfer in a donor—acceptor complex. The vibrational modes of the complex are divided into a single interaction coordinate coupling to the transferred electron and the remaining modes which form a dissipative environment. With increase of the coupling of the interaction coordinate to the environment and, thus, of the corresponding damping rate of the vibrational quanta, the results of the numerical calculations display a change from the coherent to the incoherent transfer regime. In contrast to the case of small values of the damping, the transfer dynamics become independent of the number o…

Solitary excitations in one-dimensional magnets

1991

Abstract The present status of theoretical and experimental investigations of solitary excitations in one-dimensional magnetic systems is reviewed. A survey of exact solutions to the nonlinear equations of motion for pertinent classical chain systems (sine-Gordon chain and ferromagnetic Heisenberg chains with various anisotropies) is given. Particular emphasis is devoted to the role of solitons in the thermodynamics of such systems. Models corresponding to real quasi-one-dimensional magnets are broadly discussed to demonstrate the properties of their solitary excitations. The experimental significance of such nonlinear excitations in the static and dynamic quantities of such systems is disc…

Hydrogen bonds in unpolar matrix — Comparison of complexation in polymeric and low molecular-weight systems

1991

By ene-reaction of 4-phenyl-1,2,4-triazoline-3,5-dione with double bonds, polar 4-phenyl-1,2,4-triazolidine-3,5-dione (phenyl urazole) groups are introduced into unpolar matrices. Hydrogen-bond complexes are formed between two amide-like units. The temperature dependence of complex formation in dilute hydrocarbon medium is obtained from remperature-dependent IR spectra in the region of the C=O stretching vibration. Results obtained for a low molecular-weight model system are compared with modified polybutadienes, where the groups are attached statistically along the polymer backbone. The enthalpy and the entropy of complex formation (ΔH f =−28.6 kJ/mol; ΔS f =−52 J/mol K−1) obtained for the…

Ellipsometric studies of behenic acid at the air-water interface

1991

The rich phase behaviour of monolayers of behenic acid (=docosanoic acid) has been analyzed by null ellipsometry in isothermic and isobaric measurements. By using structural data known from x-ray measurements the anisotropy and refractive indices in the vicinity of the S-CS phase transition have been calculated with a minimum of model assumptions. The calculated values are: nsx=1.47. ncsx=1.48. nsz=1.54. ncsz=1.55. and anisotropy γ=nx/nz ≈0.95. It is also shown that ellipsometry is a very sensitive and convenient method of detecting phase transitions. Its value for quantifying the roughness of the monolayer in the close vicinity of phase transitions due to thickness and density fluctuations…

Phase transition in NaSn2(PO4)3 and thermal expansion of NaMIV2 (PO43; MIV = Ti, Sn, Zr

1991

Abstract NaSn2(PO4)3 presents a fast and reversible second order phase transition about 575°C. Both phases above and below the transition point are rhombohedral. The high temperature phase is isostructural with NaTi2(PO4)3 and NaZr2(PO4)3, NZP structure. The lattice thermal expansion of these three compounds has been determined from x-ray diffraction data at different temperatures ranging from room temperature up to 1000°C. Differences in behaviour are discussed in relation to the structure.

X-ray scattering studies of fatty acid films on water and on Cdcl2 solutions

1991

X-ray diffraction methods for Langmuir films on the surface of water are briefly presented, together with recent results for docosanoic acid monolayers on pure water and for eicosanoic acid monolayers on an ionic subphase.

Synthesis of Cyclometalated Rhodium(III) Complexes. Study of the Carbonyl Insertion Reactions into the Rh-C Bond of the Metalocycle

1991

Abstract In this paper we report the preparation of new orthometalated rhodium(III) compounds of the formula Rh(oq)(AB)(PC), from Rh(oq)(Br)(PC)(H20), AB being a bidentade anionic ligand, oq= 8-oxyquinolate and PC = P(o-C6F4)Ph2. Their redox behaviour is also described. The reaction of Rh(Oq)(Br)(PC)(H20) [Oq = 5-Me-8-oxyquinolate (5-Meoq), 8-oxyquinolate] with carbon monoxide under pressure leads to expansion of the metalocycle ring by CO insertion into the Rh-C bond.

La formation de l'ingénieur hydraulicien aujourd'hui. Table ronde

1991

A Phase I Study of Cisplatinum plus 5-Fluorouracil in Modulation with Citrovorum Factor in Metastatic Colorectal Carcinoma

1991

A phase I study of 5-fluorouracil 600 mg/m2/week and folinic acid 500 mg/m2/week on day 1 and cisplatin administered weekly on day 2 was carried out on 30 patients with metastatic colorectal carcinoma of which 20 patients were pretreated with 5-fluorouracil. The first group of patients received cisplatin at the dose of 5 mg/m2/week. Cisplatin was then escalated to 10, 15, 20, 25, 30, and 35 mg/m2/week for subsequent groups of patients. Gastrointestinal side-effects were the dose-limiting toxicity. A therapy related death was seen at the dose of 35 mg/m2/week of cisplatin. The maximally tolerated dose of cisplatin in combination with 5-fluorouracil and citrovorum factor is 20 mg/m2/week. The…

Ultrasound imaging of the quadriceps muscle in elderly athletes and untrained men.

1991

Ultrasound (US) technique was applied to measure the thickness, cross-sectional area (CSA), and internal structure of the quadriceps muscle in 70- to 80-year-old endurance and power athletes and untrained men. Isometric knee extension strength was higher in the power athletes than in the other groups. The mean values for thickness and CSA did not differ between the athletes and the untrained men. The intensity of the intramuscular echo was, however, lower and the echo reflected from the connective tissue septa and bone was higher in the athletes than in the untrained men. Both the CSA and internal structure of the muscle group correlated significantly with muscle strength and number of trai…

Sublingual administration of captopril in patients with acute myocardial ischemia.

1991

Summary: To investigate the anti-ischemic capability of the angiotensin-converting enzyme inhibitor captopril, 10 patients with acute myocardial ischemia (angina pectoris >1 h, ST-segment depression ±0.1 mV, no rise in creatine phosphokinase) received 25 mg captopril sublingually after being treated with an intravenous infusion of nitroglycerin (3 mg/h) and heparin (1200 IU/h) for 1 hour. A control group of 10 patients received placebo instead of captopril. Results showed a decrease of the initial ST-segment depression from 0.25±0.04 to 0.2±0.03 mV (p>0.01) with nitroglycerin for the captopril group and from 0.26±0.05 to 0.21±0.05 mV (p>0.01) for the control group. An additional decrease to…

Epithelium modulates the reactivity of sensitized guinea-pig trachea: influence of the surface of drug entry.

1991

Abstract A technique by which drug access was restricted to either the mucosal or the adventitial surface of tracheal rings isolated from sensitized guinea-pigs was applied to study the role of the epithelium in modulating responses to KCl, acetylcholine, histamine and antigen (bovine serum albumin, BSA). Epithelium removal did not alter the responsiveness or sensitivity of tracheal rings to KCl. In contrast, a leftward shift occurred for concentration-response curves to acetylcholine (concentration ratio (CR) = 4·1), histamine (CR = 2·9) and BSA (CR = 33·9) entering from the mucosal surface of de-epithelialized trachea. This shift was not associated with changes in the maximal effect of th…

Studies of monolayer/substrate adhesion as function of the monolayer headgroup charge: DMPE and DMPA

1991

The variation of the work of adhesion between lipid monolayers and a plane silicon oxide surface in a typical LB-configuration is measured as function of the subphase pH. The adhesion energy is deduced via fluorescence microscopy from the equilibrium meniscus height. With increasing pH the negative headgroup charge of both, dimyristoylphosphatidylethanolamine (DMPE) and dimyristoylphosphatidic acid (DMPA) monolayers increases. The increasing charge of DMPE is reflected in a measured decrease of the work of adhesion at higher pH. The DMPA/SiO2 interaction is not affected by increasing headgroup charges. These results are qualitatively understood in terms of an electrostatic double layer inte…

The First Cell Division Cycle in Nicotiana Mesophyll Protoplasts Cultured in vitro II. Microtubules and the Plane of Division

1991

Summary Reorganization of the microtubular cytoskeleton prior to and during the first cell division cycle of Nicotiana mesophyll protoplasts was investigated using immunofluorescence microscopy. Bands of microtubules reminiscent of PPBs were found. However, their structure was comparatively diffuse. In addition, frequencies were low compared to those in meristem cells of organized tissues. Abnormalities during phragmoplast and cell plate formation were observed. The question is raised whether the formation of abnormal PPBs is related to strategic difficulties in co-ordinating the formation of a coherent plate of cytoplasm (phragmosome) traversing the vacuole to permit smooth bisecting of th…

Monolayer phases of the fatty acids and their ethyl esters

1991

The miscibility correspondence between water-surface monolayer phases of the fatty acids and their ethyl esters was determined. Ester phases were found corresponding to all the known phases of the acids, and vice versa, in similar relative positions of the π-T diagram. Evidence is presented for the existence of a ninth distinct miscibility category, represented by a phase in each of the pure materials, and a tenth found only in mixtures. We propose a tentative correspondence to bulk smectic miscibility categories.

Photoelectrochemical study on anodic aluminum oxide films. Internal photoemission processes at the metal-oxide interface

1991

A photoelectrochemical investigation has been carried out on aluminum oxide films grown anodically at constant rate up to different thicknesses. Depending on the potential both anodic and cathodic photocurrents were observed at photon energies well below the optical bandgap expected for these layers. This finding is explained with the presence of internal photoinjection processes both for electrons and holes from the base metal into the oxide film. The analysis of the photocurrent spectra has given the threshold energies for both processes. The effect of the image force at the metal/oxide interface has been taken into account in order to derive the mobility gap of the films and the energeti…

25-kW/50-kHz generator for induction heating

1991

The authors present the features, technology, and construction of a transistorized generator for induction heating operating over the 4-50 kHz frequency range. This type of 25 kW output-power generator allows replacement of the electronic tube generators for most of their applications. The advantages of this new generator are more energy efficiency, extended life, reduced size, separated heating station of the generator, and connection by flexible cable. In addition, the generator has incorporated a frequency automatic tracking system that allows operating without any adjustments over a wide frequency range. >

Columnar phases from semi-discoid molecules. Phase induction via hydrogen bonding and charge transfer interactions

1991

Abstract To investigate the non-linear optical properties of nitrophenylhydrazones, a series of 4-nitro- and 2,4-dinitrophenylhydrazones of substituted aromatic aldehydes were synthesized. It was found that many of the dinitrophenythydrazone derivatives are liquid-crystalline and X-ray investigations show that the mesophase corresponds to a hexagonal columnar structure. To explain this unusual behaviour it is necessary to assume that a mesogenic structure is formed by intramolecular hydrogen bonding of the dinitrophenylhydrazones. Charge transfer induced antiparallel alignment of these moleculer dipoles leads to discoid structures, forming the columnar phases.

Lack of plasmic beta-endorphin response to a gastronomic meal in healthy humans.

1991

Abstract In order to study the relationship between the endogenous opiate system and food intake in man, plasma concentrations of beta-endorphin were measured in ten healthy subjects. Time course of beta-endorphinemia was compared under the following conditions: basal (fasting), after an injection of pentagastrin (6 μg/kg), or after a gastronomic meal. No changes in plasma beta-endorphin or ACTH concentrations were observed with pentagastrin nor after the meal, despite the combination of very high sensory pleasure with intake of a very large amount of food. It is concluded that blood beta-endorphin concentration is not a sensitive index of the effects of food intake on the endogenous opioid…

Cyclophosphamide plus Epidoxorubicin and 5-Fluorouracil with Folinic Acid as a Novel Treatment in Metastatic Breast Cancer: Preliminary Results of a …

1991

Twenty consecutive patients with advanced breast cancer were treated with a combination of cyclophosphamide 600 mg/m2 i.v. on day 1, epidoxorubicin 75 mg/m2 on day 1, and 5-fluorouracil 375 mg/m2 i.v. with folinic acid 200 mg/m2 i.v. on days 1----3. The overall response rate was 60%, with 10% of patients showing a complete response with a mean duration of 11.1 + months, and 50% of patients a partial response of 7.4 + months. A stabilization of 5.2 + months was obtained in 20% of cases, while 20% of patients progressed. The most frequently observed toxicity was leukopenia, while expected mucosal toxicities were rather mild.

Frequency-dependent response and dynamic disorder

1991

Abstract This paper discusses selected aspects of the application of dynamic percolation models to ionic transport in mixed-ion superionic conductors. The discussion is based on an AB lattice gas model with hard-core repulsions and a ratio of τ, 0 ⩽ τ ⩽ ∞, between the transition rates of particles A and B. The frequency-dependent conductivity for a tracer particle is calculated within an effective-medium theory. The motion of the background B-particles is regarded as providing a fluctuating disordered environment for the tracer particles A. A crossover frequency separating high-frequency and low-frequency response is found which scales with τ as ω c ∼ τ 1 2 . The results for the dc limit ar…

The role of the hydrophobic force in bilayer adhesion and fusion

1991

The Surface Forces Apparatus technique was used for measuring the adhesion, deformation, and fusion of bilayers supported on mica. The technique allows the molecular rearrangements to be followed in real time during the fusion process, and the most important forces involved to be identified. The adhesion between two bilayers can be increased by two orders of magnitude if they are thinned so as to expose more hydrophobic groups. For all the bilayer systems studied a single basic fusion mechanism was found in which the bilayers do not “overcome” the short-range repulsive steric-hydration forces; instead, local bilayer deformations allow these repulsive forces to be “bypassed”. The results fur…

Charged particle multiplicity distributions in restricted rapidity intervals in Z0 hadronic decays.

1991

The multiplicity distributions of charged particles in restricted rapidity intervals in Z0 hadronic decays measured by the DELPHI detector are presented. The data reveal a shoulder structure, best visible for intervals of intermediate size, i.e. for rapidity limits around ±1.5. The whole set of distributions including the shoulder structure is reproduced by the Lund Parton Shower model. The structure is found to be due to important contributions from 3-and 4-jet events with a hard gluon jet. A different model, based on the concept of independently produced groups of particles, "clans", fluctuating both in number per event and particle content per clan, has also been used to analyse the pres…

Discotic liquid crystals at the air water interface

1991

The monolayer properties of two types of discotic liquid crystals, hexasubstituted triphenylenes 1 and azo derivatives of phloroglucinol 5, were examined. First investigations show that these discotic liquid crystals form stable monolayers. It could be shown that electron acceptors insert into the monolayer of 1. Azo discs display a packing behaviour at the monolayer that is ascribed to a side-on packing of the molecules.

Local control of antibody binding to hapten-presenting interfaces: Steric and electrostatic interaction

1991

The binding of labeled antibodies to hapten substituted monolayers at the air/water interface has been studied by means of fluorescence microscopy. Haptens with various spacer lengths between the epitope and a hydrocarbon chain, anchoring the molecule to the interface, have been synthesized. With DMPC,a unspecific binding has been shown to predominate over specific binding due to electrostatic interactions. At high surface pressures the bound antibody is detached because of steric interference with the lipid head groups. Due to a reduction of electrostatic interactions, no unspecific binding is observed to monolayers of cholesterol, which carries a small dipole moment. Mixed monolayers of c…