showing 36 of ~574560 from 574555 documents
Eine quantitative Bestimmungsmethode des Uracilgehaltes biologischen Materials im Nanogramm-Bereich mit Hilfe der Hochdruck-Flüssigchromatografie / A…
1974
Abstract A method is described for the estimation of the uracil content in biological materials by means of high-pressure liquid chromatography. Hydrolysis of the tissues and total liberation of RNA bases are carried out in 70% perchloric acid. Less than 1 mg of the materials are needed for analysis. A pre-purification of the hydrolyzates is carried out by anion-exchange chromatography. Recoveries are estimated by isotope dilution analysis with [2-14C] labelled uracil. The method is highly sensitive - about 6000 pmol of uracil content can at least be estimated quantitatively - and analysis time is short. In routine analysis a single sample needs 4 hours to be completed. When preparing sever…
Les transformations de l'enseignement supérieur en France depuis 1966
1974
International audience
Scanning electron microscopy of the cervix uteri.
1974
Scanning electron microscopy has been used in the study of five cases of the cervix uteri: two normal cases; one case of indirect metaplasia; one case of carcinoma in situ whose colposcopic examination showed an erosio vera surrounded by leucoplasia, mosaic, base, and an area of atipic transformation zone and one case of invasive carcinoma.
Influence of temperature on the oviposition rate and longevity ofOpius concolor siculus [Hymenoptera: Braconidae]
1974
The author has studied the influence of different temperatures (22°, 24°, 26°, 28°C) on oviposition and longevity ofOpius concolor siculusMon., studying separately 13 couples at 22°, 15 at 24°, 100 at 26° and 11 at 28°C.
false
1974
The formation and behaviour of radiation-induced free radicals in statistical copolymers of ethoxyvinylthiomethane (1a) with N-vinylpyrrolidone (2) (1:2,5) and of ethylthiovinylthiomethane (1b) with 2 (1:3,5) has been studied using electron spin resonance spectroscopy. After a γ-irradiation of the copolymers at 77K Cα-radicals in the vinylpyrrolidone moieties could be detected. Investigations on the behaviour of these radicals with an annealing procedure revealed that only in the copolymer (3b) with the dithioacetal group a transfer reaction of hydrogen atoms to the Cα-radicals in the vinylpyrrolidone moieties occurs. This process may be regarded as a repair mechanism. Es wurde die Bildung …
La réinsertion professionnelle des femmes : l'exemple de la région dijonnaise
1974
International audience
Über die wirkung des phytochroms beim laubmooskallus II. Sauerstoffmetabolismus und acetylcholinwirkung
1974
Summary The oxygen metabolism is a good parameter for the determination of rapid responses of green moss callus to light. We measured the oxygen uptake with the Warburg method and polarographically with a Clark electrode and the YSI-oxygen monitor. The exposure of dark grown moss callus to red light (5–20 min) induced a rapid increase in O2-uptake after switching off the light. The respiration change depends on the exposure duration and the light intensity. During the first 2 or 3 h after irradiation with red light and with red-far red light, the rates of the O2-uptake show no differences but after this lag-phase the 2 curves are splitting. The respiration of the red irradiated cells remain…
Les dépenses d'éducation des collectivité locales : évaluation nationale et comportement de quelques villes du Centre-Est
1974
International audience
A Comparison of the Histodynamics of Sebaceous Glands and Epidermis in Man: a Microanatomic and Morphometric Study
1974
On the existence of kinetic equations
1974
The existence of the Boltzmann equation and its generalizations is studied by analysing the order of magnitude of their terms. As a consequence we conclude that the reduced distribution functions are not analytic in the density.
Limit analysis of frame systems stiffended by panels
1974
Limit analysis of frame systems stiffened by nonperforated and perforated panels by discretisation of the panels into one-dimensional finite elements. The fundamental equation of the problem arrived at is very general in scope and is of particular interest for the analysis of the structural-systems subjected to shear as the effect of the wind or of the earthquake one.
Inhibition of giant cell formation by compound 48/80 after infection with herpesvirus hominis
1974
Choline kinase has been found to be a soluble enzyme with a molecular weight of 105,000 in the cytoplasm of primary rabbit kidney cells. It has been purified 150-fold. It was investigated whether the inhibiting effect of Cpd 48/80 on virus-induced giant cell formation is due to interference with this enzyme. Cpd 48/80-dimer was shown to inhibit the choline kinase activityin vitro without a concomitant inhibition of giant cell formation. Likewise, another competitive inhibitor of choline kinase, purinyl-6-histamine, does not prevent giant cell formation. This finding suggests that there is no correlation between choline kinase activity and giant cell formation.
Limit analysis of arch-beam structures by dynamic programming
1974
We study one-dimensional structures like arch-beams in the limit state of plastic collapse, on the ground of a two-dimensional yielding surface (bending moment and normal generalized stress). The proposed method, which is able to give a numerical solution of the problem of finding the limit load, rests on the upper bound theorem of limit analysis and uses dynamic programming. We examine also some questions linked with numerical procedures. A future work devoted to applications will complete the treatment.
Cellul�re Immunreaktionen gegen�ber homologen leberspezifischen Antigenen (HLP) bei chronischen Leberentz�ndungen
1974
Es wird eine Zweiphasentechnik des Leukocyten-Migrations-Inhibitionstestes beschrieben und zum Nachweis einer cellularen Immunreaktion gegenuber Leberantigenen bei chronisch-entzundlichen Lebererkrankungen eingesetzt. Mit dieser Technik wurde bei 85% der Patienten mit hypergammaglobulinamischer Verlaufsform einer chronisch-aktiven Hepatitis und 42% der Patienten mit aktiv fortschreitenden kryptogenen Lebercirrhosen eine Migrationshemmung nachgewiesen. Lebergesunde Kontrollen zeigten keine, Patienten mit dem Zustand nach Hepatitis und chronisch-persistierender Hepatitis selten eine Leukocytenmigrationsinhibition gegenuber leberspezifischen Antigenen. 17% der Patienten mit chronisch-aktiver H…
The effects of training on the grammar of preschool children
1974
The acquisition of morphological and syntactic rules of language during early childhood has been the object of intensive study in many languages during the last few years. As regards English, some surveys have already been published on the results (McNeill, 1970; Slobin, 1971). Research on the acquisition of morphological and syntactic patterns has been influenced on the one hand by psycholinguistics, on the other by the psychology of learning. This duality of starting points manifests itself also in the way of presenting problems and in the interpretation of results. One of the methodological difficulties when studying the acquisition of grammar was for a long time how to separate those la…
On the generalization of the Boltzmann equation
1974
Starting from the Liouville equation and making use of projection operator techniques we obtain a compact equation for the rate of change of then-particle momentum distribution function to any order in the density. This equation is exact in the thermodynamic limit. The terms up to second order in the density are studied and expressions are given for the errors committed when one makes the usual hypothesis to derive generalized Boltzmann equations. Finally the Choh-Uhlenbeck operator is obtained under additional assumptions.
The isolated perfused rat brain as a model for studying drugs acting on the CNS
1974
An isolated perfused brain preparation is regarded as offering some important advantages over intact animals or tissue slices for studying drug effects on the CNS. The rat is by far the most suitable laboratory animal for this technique because of low cost, ease of preparation and extensive literature available for comparative purposes. In this paper various preparation techniques and perfusion systems for an isolated rat brain are reported. Investigations are presented proving the viability of the isolated perfused rat brain for more than seven hours and its suitability for studies on cerebral metabolism. Until now this preparation has been successfully used for pharmacological investigati…
Precipitation chromatography. III. Optimization of the experimental conditions and determination of the polydispersity of fractions
1974
The influence of the solvent–nonsolvent gradient and the temperature gradient on the efficiency of the precipitation chromatography is investigated with radically and anionically prepared polystyrene samples. Only a combination of both gradients gives optimal effectiveness of the column. The separating power of the column was determined by using mixtures of well defined samples. From the elution curves of the mixtures the nonuniformity Ufr of fractions can be estimated. For fractions of anionically prepared polystyrenes Ufr is on the average 0.001; this value is of the same order of magnitude as the statistical error. These results show that with this chromatographic method it is possible t…
Decay properties of neutron deficient Kr isotopes
1974
The decay properties of the neutron deficient isotopes73–77Kr and73–76Br have been studied at the ISOLDE facility at CERN. The total decay energiesQ, as determined fromβ + singles orβ + -γ coincidence measurements, are compared with mass formulae.
The decay of 8.7 min237Pa
1974
The beta and gamma radiations of237Pa have been investigated employing semiconductor and scintillation spectrometers and coincidence techniques. Sources of237Pa were obtained after bombardments of238U with bremsstrahlung and 14-MeV neutrons and subsequent chemical separation. From the total of 18γ-rays following the decay of 8.7±0.2 min237Pa 17 transitions, representing 99.9% of theγ-ray intensity, could be placed in a level scheme of237U. AQ β- value of 2.25±0.1 MeV has been determined.
Polyreaktionen in orientierten Systemen, 3. Polymerisation ungesättigter Benzylidenaniline mit flüssig-kristallinen Eigenschaften
1974
Die Acrylsaure- und Methacrylsaureester 3a–m wurden synthetisiert und auf ihr nematogenes Verhalten untersucht. Zwei Monomertypen wurden zur Untersuchung des Polymerisationsverhaltens herangezogen. Dabei zeigte sich, das die Polymerisationsgeschwindigkeit beim ubergang vom nematischen in den isotropen Bereich sprungartig ansteigt. In Abhangigkeit von der Darstellungsweise des Polymeren ergaben sich Unterschiede in der Struktur. Polymere, die bei 20°C in Losung dargestellt werden, sind amorph, wahrend Losungsmittel-polymerisate, die bei −78°C hergestellt und anschliesend getempert wurden, eine Struktur aufweisen, die mit der der Polymeren aus der nematischen Phase nahezu ubereinstimmt. Diese…
Polyreaktionen in orientierten Medien, 4. Fotoreaktionen von Fumar- und Maleinsäurederivaten in Multischichten
1974
Adaptive Responses in Hepatic and Intestinal Cholesterogenesis Following Ileal Resection in the Rat
1974
Contributions to the electromagnetic form factors of the deuteron from isobar configurations
1974
A nonrelativistic calculation of the elastic electron deuteron scattering has been performed in which the effects arising from nucleon polarization have been systematically investigated. These effects have been taken into account by admixing isobar configurations into the deuteron wave function. Explicit expressions for the various contributions to the respective deuteron form factors have been given. At higher momentum transfers inclusion of the isobar configurations leads to a substantial increase in the form factors which qualitatively appears to account for at least some of the discrepancies between theory and experiment.
Untersuchungen zur Reaktionsfähigkeit statistisch verteilter Estergruppierungen in Copolymeren aus Styrol und Acrylsäureestern
1974
Die Aminolyse der ortho- und para-Nitrophenylester von Propionsaure, Isobuttersaure, 4-Phenylbuttersaure und 4-Phenylvaleriansaure sowie von Copolymeren aus Styrol und geringen Mengen Acrylsaure wurde mit Butylamin in Dioxan untersucht. Bei grosem Aminuberschus reagieren die niedermolekularen Ester streng nach erster Ordnung, wobei die Reaktionsgeschwindigkeit durch Zugabe von Polystyrol nicht beeinflust wird. Fur Copolymere, deren Reaktionsgeschwindigkeit deutlich geringer ist, erhalt man dagegen keine Beziehung erster Ordnung, obwohl die Anfangsgeschwindigkeit der Gesamtkonzentration der Estergruppen direkt proportional ist. Bei den Copolymeren erhalt man annahernd die gleichen Aktivierun…
THERAPEUTIC AND COLATERAL EFFECTS OF 25-HYDRXYCHOLECAICI FEROL IN VITAMIN D DEFICIENCY
1974
Vitamin D polar metabolite, 25–HCC has been used in 2 infant groups whose ages range from 0–18 months. In the 1st group of 15 infants, all of them suffered from rickets, clinically, biochemistry and radiologically and no prophylactic vitamin D administration could be demonstrated. The control group (15 infants too) was admitted with similar diseases but no one suffered from rickets. Routine determinations for metabolic assesment of Ca phosphoric metabolism were perforaed in plasma and in 240. urine collections, prior and after 25–HCC adBinietration. The rickets group received 20 mcg/day, orally for 20 days and the control 10mcg/day in the same way. The biochemical study demonstrated that bo…
Inelastische Lichtstreuung von Cellulosenitratlösungen
1974
Es wird ein Homodyngerat zur Messung der inelastischen Lichtstreuung beschrieben, das mit einem Argon-Ionenlaser ausgerustet ist und mit einem Autokorrelator arbeitet. Das Gerat wird benutzt, um das Verhalten der Fadenmolekule von Cellulosenitrat in verdunnter Losung zu untersuchen. Mit dieser Technik wird es moglich, sogar fur unabgebaute native Cellulose die Diffusionskoeffizienten der Translation D zu bestimmen, die ein sehr niedriges D (<10−7 cm2 s−1) aufweisen und bisher nur naherungsweise bekannt waren, da die konventionellen Mestechniken der optischen Beobachtung eines Konzentrationsausgleiches dann recht ungenau werden. A homodyne light beat spectrometer equipped with an argon ion l…
COMPLEMENT-DEPENDENT B-CELL ACTIVATION BY COBRA VENOM FACTOR AND OTHER MITOGENS?
1974
It has been proposed that two distinct signals are required for the triggering of the precursors of antibody-forming bone marrow-derived cells (B cells): (a) the binding of antigen or of a mitogen to the corresponding receptor sites on B-cell membranes and (b) the interaction of activated C3 with the C3 receptor of B lymphocytes. There is growing evidence that B-cell mitogens and T (thymus-derived cell)-independent antigens are capable of activating the alternate pathway of the complement system (bypass). Therefore, the effect of another potent bypass inducer was investigated with regard to B-cell activation and the role of C3. Purified, pyrogen-free cobra venom factor was mitogenic for bot…
The carrier-loaded helium-jet transport method
1974
Abstract The suitability of commercial helium loaded with small amounts of different gases or vapors for the transport of radioactive reaction products over distances of several meters has been investigated experimentally. Negative results were obtained with gaseous carriers. Transport efficiencies of 50 to 100% were obtained with carrier vapors. The vapor appears to form droplets in the system. The recoils are adsorbed physically by the droplets and carried with them through a capillary. There appears to be an active mechanism that forces the heavy constituents to the centre of the capillary cross section. The heavy constituents emerge from the capillary as a very narrow beam. Collection o…
Charge and current distributions in elastic electron scattering by 1P shell nuclei
1974
The authors study the charge and magnetic form factors appearing in elastic electron scattering by 1p shell nuclei. The question that the form factors may be obtained from simple nuclear models by simply introducing a scaling factor has been examined using the j-j coupling, the L-S coupling and the intermediate coupling of Cohen-Kurath (CK) resulting from effective interactions. Results for /sup 6/Li, /sup 7 /Li, /sup 9/Be and /sup 13/C are given and the q/sup 2/ dependences of their form factors are compared in the three models and with experiment. The CK scheme gives similar results to the L-S coupling for /sup 6/Li and /sup 7/Li in agreement with experiment, whereas it is intermediate be…
The solution of a ‘ fixed-target’—model by an approach of system analysis
1974
Abstract A general approach fur economic systems is combined with a concrete ‘ fixed-target’—model. The consideration of convergence leads—under conditions of a stable solution and two targets—to the result that five numerical restrictions must be recognized when treating the two instruments. Generalizations of the discussed illustrative model are possible.
Topochemische Reaktionen von Monomeren mit konjugierten Dreifachbindungen, 10. Elektrische Leitfähigkeit von Einkristallen aus Polydiacetylenen
1974
Makroskopische Einkristalle von Poly[but-1-in-3-enylen-3,4-di(p-toluolsulfonat)] (2) (pT) wurden bezuglich ihrer elektrischen und optischen Eigenschaften untersucht. Die Dunkelleitfahigkeiten parallel zur Kettenrichtung (σ∥b) und senkrecht zur Kettenrichtung (σ⊥b) verhalten sich wie 6:1. Die zugehorigen thermischen Aktivierungsenergien betragen ΔE∥b = 2,14 eV (= 3,43.10−19 J) und ΔE⊥b = 1,96 eV (= 3,14.10−19 J). Die Absolutwerte der Dunkelleitfahigkeit sind relativ gering (σ∥b = 10−10Ω−1 bei 60°C). Die Abhangigkeit der Photoleitfahigkeit von Wellenlange und Polarisationsrichtung des eingestrahlten Lichtes wurde untersucht. Das Aktionsspektrum besitzt im Bereich des Maximums der optischen Di…
false
1974
Study of some serum group systems in the Mahishyas and the Muslims in 24-Parganas district, West Bengal
1974
A survey of serum Pi, Cp, Hp and Tf was carried out in 104 Bengali Hindu Mahishya and 123 Bengali Muslim of West Bengal, India.
Investigations on organoantimony compounds XI. Triorganoantimony(V) compounds containing potentially tridentate ligands
1974
Triorganoantimony(V) compounds of the types RSbVL, in which R = Me or Ph, and L represents a potentially tridentate dianionic Schiff base ligand of the ONO or SNO type, have been synthesized and investigated by spectroscopic (UV, IR, PMR) methods. Molecular weight determinations in benzene reveal the monomeric nature of these compounds. The free ligands, HL, used in this study are:,′-(methylidynenitrilo)diphenol (HSab), -(o-hydroxyphenyl)benzothiazoline (H-Sat), -(o_hydroxyanilino)crotonophenone (HBah), 4-(o-hydroxyphenylimino)--pentanone (HAah) and -acetonyl--methylbenzothiazoline (HAat). Both the UV and the IR data suggest hexacoordinate molecular structures for the complexes RSbL in whic…
Trennung des Insecticidgehaltes der Luft in den Aerosol-gebundenen und den gasf�rmigen Anteil
1974
Eine Differenzierung des staubgebundenen und des freien Anteils der Insecticide in der Luft ist moglich, wenn man die Aerosolfraktion mit Hilfe von Glasfaserfiltern abscheidet und die die Filter passierenden gasformigen Insecticide an Drahtnetze adsorbiert, die mit Polyathylenglykol 400 beschichtet sind.