showing 36 of ~574560 from 574555 documents
Biophysikochemische Strukturen des glomerulären Filters
1985
Die Feinstrukturen sowie die biophysikalischen und biochemischen Eigenschaften des glomerularen Filters fur die Permeation von Makromolekulen werden dargestellt. Unter Berucksichtigung der unterschiedlich lokalisierten Immunkomplexablagerungen bei den verschiedenen Formen der Glomerulonephritis des Menschen orientieren sich Beschreibung und Diskussion an bestimmte Schichten des Filters: 1. endothelial — subendothelial (=porenhaltiges Endothel und lamina rara interna der Basalmembran), 2. membranos (=Lamina densa der Basalmembran) und 3. subepithelial — epithelial (=Lamina rara externa der Basalmembran und Podozyten mit Fusfortsatzen und Schlitzmembranen). Dabei wird hervorgehoben, das die g…
Fitting Simpson's neutrino into the standard model
1985
Abstract I show how to accomodate the 17 keV state recently reported by Simpson as one of the neutrinos of the standard model. Experimental constraints can only be satisfied if the μ and τ neutrino combine to a very good approximation to form a Dirac neutrino of 17 keV leaving a light ν e . Neutrino oscillations will provide the most stringent test of the model. The cosmological bounds are also satisfied in a natural way in models with Goldstone bosons. Explicit examples are given in the framework of majoron-type models. Constraints on the lepton symmetry breaking scale which follow from astrophysics, cosmology and laboratory experiments are discussed.
Identification and quantification of metabolite conjugates of activated cyclophosphamide and ifosfamide with mesna in urine by ion-pair extraction an…
1985
The high bladder toxicity of the alkylating oxazaphosphorine anticancer drugs, cyclophosphamide and ifosfamide is effectively reduced by the concomitant administration of mesna (sodium 2-mercaptoethane sulphonate). The formation and rapid urinary excretion of conjugates of the activated (4-hydroxylated) oxazaphosphorine metabolites with mesna has been suggested as the pharmacological basis for the selective detoxification, but separation and identification of such metabolites in vivo have been extremely difficult due to their high polarity and chemical lability. In this study an ion-pair extraction procedure in combination with positive and negative ion fast atom bombardment mass spectromet…
Loss of surface fibronectin after infection of cultured cells by HSV-1 and 2
1985
Fibronectin is lost from the surface of HSV infected cells during cell rounding. In order to investigate also the fate of fibronectin during the process of HSV-induced cell-fusion, BHK, Vero as well as primary or secondary rabbit kidney cells were infected with HSV-1 strains producing cell-fusion. By immunofluorescence and immunoelectron microscopy a considerable loss of fibronectin after HSV infection could be demonstrated leaving only irregular clumps of fibronectin containing virus particles on the cell surface. Decrease and disarrangement of fibronectin was similar during cell rounding and cell fusion. Loss of Fibronectin was closely connected with the two types of the cytopathic effect…
Follow-up results of embolization therapy for palliation of incurable bladder carcinoma
1985
Embolization therapy of the renal artery (N=10), hypogastric arteries (N=18) and ureter (N=24) was performed in 41 patients with incurable bladder carcinoma for palliation of gross hematuria and severe dysuria. Careful follow-up of the patients until death gave a mean survival time of 12.3 months after embolization; 6 patients are still alive. The results show that embolization therapy is justified for management of bleeding and dysuric complaints. Ureteral occlusion alone has almost no effect on hematuria. Combined embolization procedures yield better results than occlusion of the vessels or the ureter. Ureteral occlusion with a detachable balloon is superior to embolization with tissue ad…
Absence of delayed fission in the? ?-decay of 2.3 min238Pa
1985
We have searched for beta-delayed fission in the decay of 2.3 min238Pa produced in the238U(n,p) reaction with 14.7 MeV neutrons. Through microprocessor-controlled chemical separations of protactinium about 109 atoms of238Pa were isolated and exposed to fission track detectors. From the absence of fission tracks an upper limit for the betadelayed fission probability of238Pa, i.e.Pβf<2.6 10−8, is obtained at 95% confidence level. This rules out positive evidence for this decay mode of238Pa reported elsewhere. Simple theoretical estimates ofPβf range from 10−7 to 10−9.
On the status of Mabokopithecus clarki
1985
The discovery of a second specimen of Mabokopithecus clarki at Maboko, Western Kenya, has allowed the reassessment of this enigmatic genus and species. The new specimen, unlike the holotype is complete and undamaged, which dispels the uncertainty about the morphology of the distal part of the tooth, a fact that has always hindered proper assessment of the holotype. It is suggested that the two teeth now assigned to the taxon are teratogenic lower molars of Kenyapithecus africanus . The record of the family Oreopithecidae at Maboko based on Mabokopithecus can now be deleted; only to be replaced by abundant records of a new genus of Oreopithecidae quite different in morphology from Mabokopith…
The new neutron-rich nuclei231Fr and231Ra
1985
The new neutron-rich isotope231Fr has been produced in a spallation reaction of238U induced by 600 MeV protons and identified by mass-separation and decay spectroscopy. In addition, the so far unknown231Ra and the known231Ac have been observed as daughter products. The Z-assignments were performed via the decay of KX-rays, and genetic relationships. Half-lives of 17.5(8) s and 103(3) s were obtained for231Fr and231Ra, respectively.
Measurement ofN14(γ, π+)C14(g.s.)at 200 MeV: A Test of the Distorted-Wave Impulse Approximation for Charged-Pion Photoproduction below theΔ(1232)Reso…
1985
Differential cross sections for $^{14}\mathrm{N}(\ensuremath{\gamma}, {\ensuremath{\pi}}^{+})^{14}\mathrm{C}(\mathrm{g}.\mathrm{s}.)$ (${0}^{+}$1) have been measured for an incident photon energy ${E}_{\ensuremath{\gamma}}=200$ MeV at laboratory angles of 45\ifmmode^\circ\else\textdegree\fi{}, 60\ifmmode^\circ\else\textdegree\fi{}, 75\ifmmode^\circ\else\textdegree\fi{}, 90\ifmmode^\circ\else\textdegree\fi{}, 120\ifmmode^\circ\else\textdegree\fi{}, and 140\ifmmode^\circ\else\textdegree\fi{}. Momentum-space distorted-wave-impulse-approximation calculations, using a complete treatment of a one-body pion-photoproduction operator, are found to be in excellent agreement with the experimental data…
Reaktive Metabolite cancerogener polycyclischer Kohlenwasserstoffe: Synthese und Abfangreaktion von 9-Hydroxybenzo[a]pyren-4,5-oxid
1985
Le compose du titre est prepare a partir de l'acetate-9 de benzo [a] pyrene et piege par l'ethanethiol. Mecanismes
Effects of forest regeneration on the structure of bird communities in northern Finland
1985
Breeding bird communities in five stages of secondary forest succession were studied in northeastern Finland in 1980–82. Three groups of communities were distinguished: open land, brush phase and forest communities, dominated by Motacilla alba and Oenanthe oenanthe, Phylloscopus trochilus and Anthus trivialis, Phylloscopus trochilus and Fringilla montifringilla, respectively. Pair density, number of species, biomass of adult birds and species diversity increased in the course of succession, none of these, however, monotonously. Average bird weight showed a decreasing trend although the variation was considerable. The degree of specialization in communities (measured by ratios derived from n…
X-ray crystal structure and antimony-121 Mössbauer spectrum of catecholato bis(1,10-phenanthroline)antimony(III) tetraphenylborate
1985
The crystal structure of the title compound was solved by means of X-ray diffraction at room temperature. The salt consists of a tetrahedral tetraphenylborate anion and a complex cation containing a catecholatoantimony(III) unit chelated by two 1,10-phenanthrolines. The three bidentate ligands are essentially arranged in one half of the Sb coordination sphere, leaving ample space to accomodate the lone pair of electrons. The Mossbauer parameters of the title compound and of the complex (C6H4O2)SbF·Phen were measured and their rationalization accomplished in the light of their respective molecular structures.
Re-investigation of the conformational interconversion of the 1,2,3,6,7,8-hexahydropyrene cation radical by EPR, ENDOR and TRIPLE spectroscopy
1985
The conformational interconversion of the 1,2,3,6,7,8-hexahydropyrene cation radical has been re-examined by EPR, ENDOR and TRIPLE spectroscopy, and the Arrhenius plot is presented for a wider temperature range than that used earlier. The EPR spectra were measured from 143 to 369 K and the ENDOR spectra from 143 to 263 K. The thermodynamic constants of the conformational interconversion of the cation radical were determined on the basis of the temperature-dependent spectra. The high-resolution spectra clearly show that there are two overlapping spectra at low temperature, and this is confirmed by simulation.
Insertion des jeunes en 1985 : premiers résultats
1985
Adaptive response of human skeletal muscle to simulated hypergravity condition
1985
The mechanical behaviour of leg extensor muscles of five international-level athletes was evaluated during 13 months training period. Drop jumps, average mechanical power during 15 S continuous jump, and vertical jumps performed with and without extra weights were used to measure explosive power characteristics. The data recorded in vertical jumps was utilized for construction of force-velocity relationship (F-V curve). The athletes did not show improvement in any of the variables studied after 12 months of intensive systematic training programme. It was assumed that the subjects already had reached their upper limit of performance. However, after that the athletes underwent a simulated 3 w…
The influence of branching isomerization on the product distribution obtained during cracking of n-heptane on acidic zeolites
1985
Abstract The initial selectivities for the primary products occurring during the cracking of n-heptane on a rare-earth (RE)-HY ultrastable zeolite up to 470°C have been calculated. The activation energies for the cracking of n-heptane and its branched isomers in the fraction C4 + C3 have been obtained by molecular orbital calculations, and these values and the predicted product distribution have been compared with those obtained experimentally. It is concluded that the cracking of n-heptane on large-pore zeolites may take place by different parallel routes involving protolytic and β-cracking of n-heptane and β-cracking of the readily formed branched carbenium ions. The relative importance o…
Some new examples of polymer modification
1985
This lecture summarizes some of our recent results about reactions with synthetic polymers. By cationic ring-opening polymerization of 4H, 7H-1,3-dioxepin a linear polyacetal containing one C-C-double bond per repeating unit is obtained. Copolymerization of this monomer with trioxane or dioxolane is possible. Various addition reactions can be carried out with these unsaturated polyacetals, polymeric epoxides being of special interest. Some other unsaturated cycloacetals are briefly mentioned. Amide moieties in linear polyamides can be modified by different reactions. Preparation and properties of poly-N-chloroamides and poly-N-trifluoroacetyl-amides are described. By reaction of metalated p…
Optical measurements of ground-state properties of short-lived nuclei in resonance cells
1985
Hyperfine structure and isotope shift of radioactive Hg, Au and Cd isotopes have been determined by optical spectroscopy. In all cases the atoms were confined in a resonance cell. The various variants of the cell technique and alternative methods as the resonance ionization spectroscopy related to the investigation of short-lived nuclei are described, and some results are discussed.
Laser applications in nuclear physics
1985
A morphogenetic role for ethylene in hypocotyl cultures of Digitalis obscura L.
1985
The effect of exogenously applied ethylene on organogenesis in Digitalis obscura L. hypocotyls cultured in vitro was studied. Interactions of this gas with other growth regulators was also tested. Ethylene by itself only promoted root formation. Shoot regeneration was obtained in presence of indoleacetic acid and kinetin. The addition of ethylene (10 ppm) increased the caulogenetic action of this medium; higher concentrations than 10 ppm reduced this response. Kinetin alone did not promote organogenesis and nullified the promotive effect of ethylene on rhizogenesis.
Direct measurement of the radiative tail in electron scattering from atomic nuclei
1985
We have made a direct measurement of the radiative tail of the eleastic peak from several tungsten targets. The measured data have been compared to the results expected for both internal and external bremsstrahlung contributions. Even for targets as thick as 4% of a radiation length of tungsten, agreement between the results of the experiment and the predictions of the theory has been found to be unexpectedly good.
Preparation and protonation of 2-pyrimidyl- and 2-pyrazylpalladium(II) complexes
1985
Abstract The oxidative addition of 2-chloropyrimidine or 2-chloropyrazine to [Pd(PPh 3 ) 4 ] yields a mixture of trans -[PdCl(C 4 H 3 N 2 - C 2 )(PPh 3 ) 2 ] (I) and [PdCl(μ-C 4 H 3 N 2 - C 2 , N 1 )(PPh 3 (II) (C 4 H 3 N 2 = 2-pyrimidyl or 2-pyrazyl group). The mononuclear complexes I are quantitatively converted into the binuclear species II upon treatment with H 2 O 2 . The reaction of II with HCl gives the N -monoprotonated derivatives cis -[PdCl 2 (C 4 H 4 N 2 - C 2 )(PPh 3 )] (III), from which the cationic complexes trans -[PdCl(C 4 H 4 N 2 - C 2 )(L) (L = PPh 3 , IV; PMe 2 Ph, V; PEt 3 , VI) can be prepared by ligand substitution reactions. Reversible proton dissociation occurs in so…
L'évolution des systèmes d'enseignement dans le monde de 1960 à nos jours : aspects économiques et financiers
1985
référence interne : 85035; La présente étude a un triple objectif : - actualiser les observations sur l'évolution des dépenses d'enseignement et de l'effort public en faveur de l'éducation présentées en 1979,- à l'aide de ces observations statistiques et des résultats d'études plus ponctuelles, mettre en lumière les principaux problèmes qui se posent aujourd'hui à l'éducation dans le monde et plus particulièrement dans certaines régions, - esquisser les solutions aux graves problèmes financiers actuels de l'éducation et montrer leurs limites.
The prognostic value of thyroid function tests in predominantly non-alcoholic cirrhotic patients: A prospective investigation
1985
The prognostic value of thyroid function parameters (T3, T4, rT3 and the rT3: T3 ratio) and common liver tests (serum bilirubin, albumin and prothrombin activity) was investigated on hospital admission in 100 consecutive patients with predominantly non-alcoholic liver cirrhosis. Twenty-nine out of 100 patients had a well compensated cirrhosis and their mean values of thyroid tests were similar to those of 40 healthy controls. A low T3 syndrome was found in the remaining 71 decompensated patients. In these thyroid function parameters were correlated with serum bilirubin and prothrombin activity. Moreover mean values of all thyroid and liver tests, except serum albumin, were significantly dif…
Vitamin K epoxide reductase activity in the metabolism of epoxides
1985
Abstract The importance of vitamine K epoxide reductase for the metabolism of a range of structurally diverse epoxides has been investigated. Vitamin K 1 epoxide is reduced by rat liver microsomes at a rate of 0.47 nmoles/g liver/min. The rate of menadione oxide reduction is not significantly higher than the non-enzymatic reduction rate. No measurable reduction of benzo[ a ]pyrene 4,5-oxide, benzo[ a ]pyrene 7,8-oxide, phenanthrene 9,10-oxide, styrene 7,8-oxide, and dieldrin has been detected, nor could trichothecene T-2 toxin inhibit reduction of vitamin K 1 epoxide. Thus, vitamin K epoxide reductase is very specific for vitamin K 1 epoxide. Taking into account the range of structurally di…
Histological and fine structural features of pancreatic ductal adenocarcinomas in relation to growth and prognosis: studies in xenografted tumours an…
1985
Histology and fine structure of pancreatic ductal adenocarcinomas were assessed with respect to their significance for tumour growth and prognosis. The histological parameters included glandular differentiation, nuclear anaplasia, nuclear size, and mitotic activity (number of mitoses per high power field). Using these criteria three grades of malignancy were distinguished. They correlated well with the growth kinetics of seven human pancreatic ductal adenocarcinomas transplanted into nude mice. The tumour doubling time of a G 3 carcinoma was about half that of a G 1 carcinoma. On electron microscopy the tumour grade was reflected in the degree of functional differentiation of the neoplastic…
Epitheloid Hemangioendothelioma of the Scalp
1985
A case of an epitheloid hemangioendothelioma of the skin and subcutaneous tissue of the scalp is described. Clinically and histologically a (metastatic) carcinoma had been considered in differential diagnosis. Of great help in recognition of the endothelial nature of this tumor was the immunohistochemical reaction with Factor-VIII associated antigen and Ulex europaeus antigen. Not only tumor cells in solid areas, but also intracytoplasmic vacuoles revealed positive staining. Thereby it could be shown, that this paranuclear vacuoles are actually compatible with developing capillary lumina. Only few tumor cells showed positive reaction with alpha-1-antichymotrypsin, pointing to a possible sma…
Collinear laser spectroscopy on unstable isotopes—A tool of nuclear physics
1985
Atomic hyperfine structures and isotope shifts yield basic information about nuclear ground-state spins, moments and mean square charge radii. Recently, the collinear-beam laser experiments at ISOLDE have considerably enlarged the range of elements for which these studies can be extended into regions far from β-stability. The essential features of these experiments are outlined, and examples of the results on the rare-earth and radium isotopic chains are given. Finally, further improvements in sensitivity using non-optical detection are discussed.
Characterization of a proton pump from Acer pseudoplatanus cell microsomes
1985
Abstract An Acer pseudoplatanus cell microsomal fraction was enriched in ATPase by sedimentation through a sucrose cushion and treatment with Triton X-100. This activity, which reached 0.9 μmol P i min −1 mg −1 protein, was specific for ATP, slightly stimulated by K + , inhibited by orthovanadate and diethylstilbestrol, insensitive to oligomycin and azide, and had a K m - value of 0.51 mM for MgATP. ATP-dependent proton translocation was demonstrated by the ΔpH probe acridine orange. This activity had a optimum at pH 6.5, was substrate specific for ATP, and was strongly dependent on K + . Preparations of plasma membrane ATPase from A. pseudoplatanus cell culture thus posses biochemical prop…
Concluding remarks application of lasers to nuclear physics
1985
Le coût de formation des personnels de santé : note méthodologique
1985
référence interne : 85053
Degree-problems I squarefree character degrees
1985
αααanti-4.2 Haplotype and heterozygous β° thalassemia in a Sicilian family
1985
The presence of the αααanti-4.2 haplotype and heterozygous β° thalassemia in a Sicilian family is described. These findings confirm the presence in Italy of a leftward deletion (−α4.2) and indicate that this may not be rare. Furthermore, although the β thalassemia determinant in this family has a severe expression, the interaction with the triplicated α gene does not necessarily express itself as thalassemia intermedia.
false
1985
Samples of ring and open chain polystyrene in dilute perdeuterated toluene solution were measured by small angle neutron scattering up to a value of the scattering vector Q = 2 nm−1. The molar masses 12000 ≤ M/(g/mol) ≤ 22000, the mean square radii of gyration 〈R2〉 and the second virial coefficients A2 of the samples were determined. The results are compared to theories which describe the dependencies 〈R2〉 = f(M) and A2 = f(M) for both cyclic and linear chain molecules. A qualitative agreement between theory and experiment is obtained.
Estudios sobre la Medicina y la Ciencia Valencianas. Siglos XVI-XIX
1985
pp. 190
ChemInform Abstract: LEAD TETRAACETATE OXIDATION OF PHENYLHYDRAZONES OF 3-BENZOYLAZOLES. SYNTHESIS OF AZOACETATES AND THEIR CONVERSION INTO INDAZOLES
1985
Lead tetraacetate (LTA) oxidation of (E)- and (Z)-phenylhydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazole, 3-benzoyl-5-phenylisoxazole, and 3-benzoyl-4-methyl-1,2,5-oxadiazole has been studied. Conversion of azoacetate products into 3-(azol-3-yl)-substituted indazoles has been achieved by reacting them with aluminium chloride in benzene at room temperature.