showing 36 of ~574560 from 574555 documents
A herança clássica da categoria do trabalho no pensamento do último Lukács
1992
Service policies of German manufacturers: Critical factors in international competition
1992
Abstract German companies perform well in export markets, based on product quality and technology. But the competitive advantages and value-added of service are expected to grow sharply in the coming decade — especially product-focused service. Hermann Simon has identified ‘Hidden Champions’ in Germany — companies like Heidelberg Printing Machines, BMW and Mercedes-Benz, which integrate market and technology as equal driving forces and provide quick and reliable customer service. But there is much room for improvement in service provided by German manufacturing companies. They could upgrade their design and marketing of service, and apply better quality control such as setting quantitative …
Cohomology and associated deformations for not necessarily co-associative bialgebras
1992
In this Letter, a cohomology and an associated theory of deformations for (not necessarily co-associative) bialgebras are studied. The cohomology was introduced in a previous paper (Lett. Math. Phys.25, 75–84 (1992)). This theory has several advantages, especially in calculating cohomology spaces and in its adaptability to deformations of quasi-co-associative (qca) bialgebras and even quasi-triangular qca bialgebras.
Bioaccumulation of organochlorine compounds in earthworms
1992
Abstract Bioaccumulation of chlorophenolic wood preservatives 2,3,4,6-tetrachlorophenol (2346-TeCP) and pentachlorophenol (PeCP) and their metabolites in earthworms were studied in the laboratory, and by taking worm samples from the contaminated soil of a sawmill which was abandoned 28 yr ago. In two laboratory experiments 2346-TeCP (containing PeCP as impurity) was added into the soil, and samples were taken at certain intervals both from the soil and the earthworms ( Lumbricus rubellus in experiment 1 and Aporrectodea caliginosa tuberculata in experiment 2). Considerable amounts of chlorophenols were found in field samples. Soil concentrations ranged from 157 to 338 μg 2346-TeCP g −1 dry …
Structure functions from the NMC
1992
The New Muon Collaboration has measured deep inelastic muon scattering on hydrogen and deuterium at incident energies of 90 and 280 GeV. From the measured cross section ratios σd/σp the difference of R, the ratio of longitudinally to transversely polarised virtual photon absorption cross sections, was obtained. Covering a range in x from 0.01 to 0.3 at a typical Q2 of 9 GeV2 the results are compatible with zero. The structure functions F2p and F2d were extracted in a wide kinematic range: 0.006 1 GeV2. Extrapolation to small χ of recent parton distributions are shown to disagree with the NMC results.
Synthesis of undulin by rat liver fat-storing cells: Comparison with fibronectin and tenascin
1992
Abstract Fat-storing cells (FSCs) are known to synthesize various components of the hepatic extracellular matrix and thereby play an important role during liver fibrogenesis. The aim of our study was to investigate the synthesis of undulin, a recently described connective tissue protein belonging to the fibronectin—tenascin superfamily of glycoproteins, by fat-storing cells in primary culture. SDS-PAGE analysis of immunoprecipitates from cell layer lysates or media pulse-labeled with radioactive methionine revealed undulin-specific bands A (270 kDa), B1 (190 kDa), and B2 (180 kDa) after reduction. A single undulin-specific transcript was detected at about 7 kb. Undulin synthesized by cell-f…
Lepton-hadron correlations to O(αs2) in (2+1) jet production processes at hera
1992
Abstract We give a qualitative account of some of the technical features that go into the calculation of the one-loop improved O(αs2) (2+1) jet production rates in deep inelastic scattering which was completed only recently. We present some numerical results on (2+1) jet production with an emphasis on lepton-hadron correlation effects by exhibiting the contribution of the longitudinal structure function.
Prevention of deep vein thrombosis in neurosurgical patients: a prospective double-blind comparison of two prophylactic regimen.
1992
In a prospective, randomized, double-blind investigation of anticoagulant agents for prevention of deep vein thrombosis in patients undergoing operations at the lumbar-vertebral disc, 179 patients were randomly allocated to two groups. 87 patients received a fixed combination of low-molecular weight heparin 1,500 U-aPTT plus dihydroergotamine 0.5 mg (LMWH/DHE) once a day and additionally one injection of placebo per day, 92 patients received a fixed combination of sodium heparin 5,000 U plus dihydroergotamine 0.5 mg (HDHE) twice a day. Treatment was initiated two hours preoperatively in both groups and continued for at least seven days. Deep vein thrombosis (DVT), detected by the 125Iodine-…
Sensitive determination of ethacrynic acid in urine samples by reversed-phase liquid chromatography with ultraviolet detection using solid-phase extr…
1992
Abstract A rapid method is described for the identification and determination of ethacrynic acid in human urine samples by liquid chromatography with UV detection, the retention time of the analyte being 4.9 min. The samples were previously conditioned using C 18 solid-phase extraction columns and chromatographed on an HP-LiChrospher RP C 18 column (5 μm; 125 mm × 4 mm i.d.) with gradient elution with acetonitrile-acetate buffer (pH 4). The detector was set at 275 nm and furosemide was used as an internal standard. The procedure was applied to the determination of ethacrynic acid at concentrations of 0.01-10 μg ml -1 and the limit of detection was 6 ng ml -1 .
Valence bands of poly(methylmethacrylate) and photoion emission in vacuum ultraviolet region
1992
Photoion and photoelectron yields were measured for poly(methylmethacrylate) in the photon energy region of 8–40 eV using synchrotron radiation. Further, the valence‐band structure was investigated with ultraviolet photoelectron spectra and valence effective Hamiltonian calculations. A significant difference was observed between the photon energy dependencies of photoion and photoelectron yields. The threshold energy for photoion emission was found to be 10.5 eV, while that for photoelectron emission was 8.5 eV, indicating holes created near the valence‐band top do not contribute to the ion emission. At the higher‐energy region, the ion emission efficiency was found to be enhanced in the ph…
Growth increase of birch seedlings under the influence of earthworms—a laboratory study
1992
The effects of the earthworm Lumbricus rubellus (Hoffm.) on net production and nitrogen content of birch seedlings were studied in laboratory microcosms. Coniferous forest floors with litter, humus and mineral horizons were simulated in transparent plastic cylinders. The materials were partially sterilized by microwaving, and re-inoculated with microflora and -fauna. A young (9 cm) birch seedling (Betula pendula Roth) was planted in each container. Earthworms were added to half of the replicates. The microcosms, through which a constant air flow was maintained, were incubated in a climate chamber. After two growth periods, leaf and stem biomasses of birch in treatments with earthworms incre…
Single particle motion in a Penning trap: description in the classical canonical formalism
1992
This paper aims at the development of methods for the calculation of the characteristic frequencies of a Penning trap, taking into account deviations of the actual geometry from the ideal one, anharmonicities of the electric potential, misalignments and inhomogeneities of the magnetic field, additional time dependent electromagnetic fields, and so on. The paper starts by describing the motion of a single charged particle in an ideal hyperbolic Penning trap using the formalism of classical hamiltonian mechanics. The usefulness of rotating coordinates is pointed out, and the importance of conservation of canonical angular momentum is stressed. After transformation to action-angle variables th…
Quaternary and subunit structure of Calliphora arylphorin as deduced from electron microscopy, electrophoresis, and sequence similarities with arthro…
1992
Arylphorin was purified from larvae of the blowfly Calliphora vicina and studied in its oligomeric form and after dissociation at pH 9.6 into native subunits. In accordance with earlier literature, it was electrophoretically shown to be a 500 kDa hexamer (1 x 6) consisting of 78 kDa polypeptides (= subunits). Electron micrographs of negatively stained hexamers show a characteristic curvilinear, equilateral triangle of 12 nm in diameter (top view) and a rectangle measuring 10 x 12 nm (side view). Alternatively, particles in the top view orientation exhibit a roughly circular shape 12 nm in diameter. Crossed immunoelectrophoresis revealed the presence of a major subunit type; the nature of a …
Feuilletages deCP(n) : de l’holonomie hyperbolique pour les minimaux exceptionnels
1992
Let ℱ be a holomorphic foliation ofCP(n). If ℱ has a leaf L, the closure L of which is disjoint from the singular set of the foliation, we prove that there exists a loop in a leaf contained in L with contracting hyperbolic holonomy.
Experimental evidence for a local disorder in pure and doped perovskites
1992
Abstract In the soft mode picture, the ferroelectric phase transitions in most of ABO3 perovskites are triggered by the long wavelength oscillations of the B ions against their oxygen cage. There is now a lot of experimental evidence that this picture is incomplete. An extra contribution has to be included in the dynamical response. This contribution is usually thought to arise from local lattice distorsions; this is what will be called local disorder. A complete understanding of this local disorder requires the experimental determination of the microscopic origin, of the dynamics and spatial extension of the lattice distorsions. A useful way to summarize these requirements is to use the co…
Einfluss des polymerrückgrats auf eigenschaften von thermoplastischen elastomeren
1992
4-Urazoyl benzoic acid groups were statistically attached to various hydrocarbon elastomers, polar elastomers and partially crystalline polymers via a polymer-analogous reaction. DSC, FTIR, stress-strain experiments and dynamic-mechanical analysis were used to analyse whether these systems, analogous to functionalized polybutadienes, would form ordered supra-molecular structures of the polar side-groups that would lead to a thermoreversible crosslinking. While the structure formation is suppressed for elastomers with a large cross-sectional area of the chain (e.g. butyl rubber) or polar side-groups, (e.g. polychloroprene), the mechanical propertie can be controlled by balancing supermolecul…
Asymptotics for thenth-degree Laguerre polynomial evaluated atn
1992
We investigate the asymptotic behaviour of ? n (n),n?? where ? n (x) denotes the Laguerre polynomial of degreen. Our results give a partial answer to the conjecture ?? n (n)>1 forn>6, made in 1984 by van Iseghem. We also show the connection between this conjecture and the continued fraction approximants of $$6\sqrt {{3 \mathord{\left/ {\vphantom {3 \pi }} \right. \kern-\nulldelimiterspace} \pi }} $$ .
Diastereoselective synthesis of enantiomeric tertiary alcohols via nucleophilic additions to protected D- and L-erythrulose derivatives
1992
Abstract The diastereoselectivity of the addition of several organometallic reagents to the carbonyl group of protected D - and L -erythrulose derivatives has been investigated. Tertiary alcohols are stereoselectively formed, the diastereomeric ratio being markedly dependent on the reagent type, solvent and temperature.
B‐Mode ultrasonography of the paranasal sinuses compared with CT findings
1992
Ultrasound as a diagnostic aid in the evaluation of the sinuses has been a controversial issue. Sensitivities have been reported from 29% to 100% and specificities from 55% to 99%. These wide variations in results from previous studies may have resulted from technical differences. However, the "gold standard" most often used for comparison has been a Water's view radiograph, which has been shown to correlate poorly with intraoperative and CT scan findings. To our knowledge, no one in the English language literature has evaluated sonography of the sinuses with computed tomography as the gold standard. In addition, evaluation of the ethmoid sinus has been neglected by previous studies that ha…
t-Curves for n-Hexane
1992
The adsorption and desorption isotherms of n-hexane on powdered alumina and silica have been studied at 25°C over a wide range of relative pressures. Two t-curves for pore structure analysis are proposed, one for alumina (C = 12) and the second for silica (3 ≤ C ≤ 9). The statistical thickness t of the adsorbed n-hexane layer has been drawn as a function of the relative pressure assuming a maximal thickness of 0.55 nm and a mean thickness of 0.42 nm for the monolayer. The results are discussed in relation to previous published data.
Rat hepatocytes in primary culture synthesize and secrete cellular fibronectin
1992
Fibronectins, involved in cell-matrix interactions and cell attachment, are glycoproteins which show a remarkable heterogeneity, due to alternative splicing. The type III-related domains, ED-A and ED-B, are present in cellular fibronectin in a variety of ratios whereas they are absent in circulating plasma fibronectin. Fibronectin synthesis by hepatocytes which are accepted as suppliers of plasma fibronectin was studied in primary cultures during a 6-day culture period. Using site-specific antibodies we demonstrate that rat hepatocytes are also able to synthesize and secrete fibronectin bearing the ED-A domain from Day 3 on after inoculation. By immunocytological characterization of the hep…
The RICH counter in the CERN hyperon beam experiment
1992
Abstract The hyperon beam experiment WA89 at the CERN-SPS uses a ring imaging Cherenkov counter (RICH) for identification of secondaries from ∑ − N reactions. Cherenkov photons are generated in a 5 m long radiator volume filled with nitrogen at atmospheric pressure and detected in drift chambers. The drift chambers cover an active surface of 1.6 × 0.75 m 2 , with a maximum drift path of 41 cm. Photoelectrons are counted on 1280 wires with a pitch of 2.54 mm, equipped with multihit TDCs. The counting gas is ethane saturated with TMAE at 30°C. The counter was operated in two beam periods in 1990 and 1991. The spatial resolution of the chambers is better than 2 mm and under normal running cond…
Theoretical gain spectrum of coherently pumped mid-infrared Fabry-Pérot lasers
1992
Abstract We study the gain spectrum of a coherently pumped mid-infrared laser which operates in a linear-cavity (Fabry-Perot), using a three-level density matrix theory. Arbitrary pump and emission field strengths as well as pressure and Doppler broadening are considered. A new strong directional gain asymmetry is found, which is related to the presence of two counterpropagating components in the standing-wave generated field. Gain lineshapes in a wide range of operating conditions are obtained and analysed.
Pixel-to-pixel correlation between images of absolute ATP concentrations and blood flow in tumours
1992
Iodo(14C-)antipyrine autoradiography and imaging bioluminescence have been combined to obtain pixel-to-pixel correlations between absolute values for local blood flow and ATP concentrations at a microscopical level within designated areas in hamster melanomas. Positive pixel-to-pixel correlations were obtained in 4 of 6 tumours. Both flow and ATP values were less in mostly necrotic than in mostly viable tumour regions. The data provide evidence for the energetic state of cancer cells being strongly influenced by the efficiency of tumour microcirculation in several but not in all malignancies investigated. Images Figure 1
Fast electroclinic switching in a ferroelectric LC-polysiloxane
1992
L'accès à la formation professionnelle continue dans le secteur de la construction : le cas de l'Espagne et du Grand-Duché de Luxembourg
1992
série Panorama, analyse comparéeRéférence interne : 92091; Pour les deux pays concernés ces monographies analysent l'organisation de la formation professionnelle dans le secteur du BTP, les modalités d'accès à la formation et l'état du secteur. Des éléments de comparaison sont ensuite proposés.
: African Stars: Studies in Black South African Performance . Veit Erlmann.
1992
Polymer-supported bilayer on a solid substrate
1992
La detención en el nuevo proceso penal peruano
1992
No contiene resumen
Crystal Data for Metal Cimetidine Isotiocionates: M(CM)2(NCS)2 (M = Co(II), Ni(II), Cu(II))
1992
AbstractMetal cimetidine isothiocyanates, M(C10H16SN6)2(NCS)2, where M = Co(II), Ni(II) and Cu(II), have been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined from powder diffractometer data. Refined cell parameters (monoclinic with a primitive cell), powder data, calculated densities and Z value are presented.
Effect of nimodipine on rheologic parameters in patients with chronic cerebrovascular disease
1992
Abstract Sixteen patients with chronic cerebrovascular disease were treated with a monotherapeutic regimen of nimodipine 30 mg orally three times a day. At baseline and after 45 and 90 days of therapy, the patients' whole blood filterability, erythrocyte membrane fluidity, red blood cell membrane protein lateral mobility, and red blood cell Ca 2+ content (total and cytosolic) were evaluated. After 45 days, an increase in whole blood filterability and a decrease in the cytosolic red cell Ca 2+ content was seen. At the end of treatment, whole blood filterability, erythrocyte membrane fluidity, and red cell membrane protein lateral mobility had increased, compared with baseline values, while t…
Experiments on polarised lepton scattering off polarised nucleons
1992
Abstract The current experimental status of the spin dependent structure functions as measured in polarised deep inelastic scattering of charged leptons from nucleons is reviewed. The proposals for new experiments at SLAC and HERA are discussed. Special emphasis is put on the experiment of the Spin Muon Collaboration at CERN which has started taking data in 1991.
Weekly 5-fluorouracil and folinic acid plus escalating doses of cisplatin with glutathione protection in patients with advanced head and neck cancer.
1992
Twenty-two patients with advanced head and neck carcinoma were treated with 5FU 400 mg-2 m-1 week and folinic acid 500 mg m-2 week-1 plus CDDP in escalating doses from 20 to 40 mg m-2 week-1 without forced diuresis. Reduced gluthatione at the dose of 1.5 g m-2 was employed to protect patients from CDDP-related nephrotoxicity. The aims of the study were: a) to evaluate the therapeutic efficacy of this schedule, and b) to evaluate reduced gluthatione as uroprotector. Out of 20 evaluable patients 14 (70 %) had a major objective response. A CR with a mean duration of 9.0+ months was achieved in 15 % of the patients, a PR of 5.8+ months in 55 % of the patients, while 3 patients had stable diseas…
Letters to the editor
1992
Purification and characterization of a pore-forming protein from the marine sponge Tethya lyncurium
1992
A pore-forming protein was detected and purified for the first time from a marine sponge (Tethya lyncurium). The purified protein has a polypeptide molecular mass of 21 kDa and a pI of 6.4. Tethya pore-forming protein (also called Tethya hemolysin) rapidly lysed erythrocytes from a variety of organisms. After binding to target membranes, the hemolysin resisted elution with EDTA, salt or solutions of low ionic strength and hence resembled an integral membrane protein. Erythrocytes could be protected from hemolysis induced by Tethya hemolysin by addition of 30 mM dextran 4 (4-6 kDa; equivalent hydrodynamic diffusion radius, 1.75-2.3 nm) to the extracellular medium, but not by addition of unch…
false
1992
Semi-IPN's of different composition, based on linear poly(methyl vinyl ether) (PVME) and crosslinked polystyrene are studied using stress and birefringence measurements in simple elongation. From quasistatic stress-strain experiments at constant T(experiment)-Tg, it can be deduced that the stress results only from the deformation of the polystyrene network, while the PVME chains do not contribute to the macroscopic stress. The concentration dependence of the network modulus is adequately described by the rubber elastic theories