Delayed-neutrons from arsenic isotopes 84As, 85As and 86As

1973

Abstract Short-lived arsenic isotopes were produced by thermal-neutron fission of 235U and isolated within 2·5 sec by volatilization of arsenic hydride. The existence of a strong delayed-neutron precursor of 2·05±0·05 sec half-life among the arsenic isotopes is confirmed and its assignment to 85As ascertained by milking of the daughter product 33 sec 85Se and 3·1 min 84Se, which is the final nucleus in the neutron decay branch of 85As. A delayed-neutron yield of 7·8 ± 1·2 neutrons/104 fissions was obtained for 85As. A new isotope, 0·9 ± 0·2 sec 86As, was detected by delayed-neutron counting and by following the decay of its most prominent γ-ray. The mass assignment was verified by milking o…

Blendensysteme für Streulichtphotometer

1973

The geometrical arrangement of slits in the secondary beam of light scattering photometers has been investigated. The hitherto applied configuration of slits, vertically fixed on the secondary beam, requires a volume correction-sinϑ-for the determination of the angle-dependent scattered intensity. Arrangements of slits with varying width which depends on the angle of observation ϑ are proposed. They avoide the volume correction, or render the scattering volume independent of ϑ, and at the same time increase the measuring accuracy.

Reaktionen an Aluminiumoxiden

1973

Untersuchungen �ber den Einflu� von Guanethidin (Ismelin�) auf die Katecholaminausscheidung im Harn von Hypertonikern

1973

Bei 5 Patienten mit essentieller Hypertonie wurde der Einflus einer einmaligen Injektion von 12,1 mg Guanethidinbase auf Blutdruck und Katecholaminausscheidung im Harn verglichen. Nach der Injektion des Antihypertensivums kam es zu einem Abfall der Noradrenalinausscheidung bei unveranderter Adrenalinausscheidung. Der am liegenden und am stehenden Patienten gemessene systolische und diastolische Blutdruck fiel nach Injektion des Pharmakons deutlich ab. Die Kreatininausscheidung im Harn anderte sich nicht.

Über das Anfangsstadium des oxidativen Abbaus nativer Cellulose durch molekularen Sauerstoff

1973

Comparative study of the effects of chloral hydrate and trichloroethanol on cerebral metabolism

1973

The isolated perfused rat brain was used for a comparative study of the effects of chloral hydrate and trichloroethanol on cerebral energy metabolism. After a perfusion period of 30 min the brain levels of the following substrates and metabolites were measured spectrophotometrically: P-creatine, creatine, ATP, ADP, AMP, glycogen, glucose, glucose-6-P, fructose diphosphate, α-glycero-P, dihydroxyacetone-P, pyruvate, lactate, glutamate, α-ketoglutarate and ammonia. Furthermore, the concentration of chloral hydrate and trichloroethanol in the isolated brain and in the perfusion medium was measured colorimetrically. Little more than 10% of chloral hydrate in the isolated brain and in the perfus…

Comparison of the effects of chloral hydrate and trichlorethanol on the EEG of the isolated perfused rat brain.

1973

An isolated perfused rat brain preparation was used to compare the effects of chloral hydrate and its metabolite trichloroethanol on the EEG. The concentrations of chloral hydrate and trichloroethanol in the perfusion medium ranged from 1.5 to 5.5 mM. 5, 10, 15, and 30 min after the beginning of the perfusions EEG-recordings were taken. The recordings were evaluated both by a descriptive method and by a simple quantitative appraoch, counting the waves with an amplitude greater than 50 microvolts and averaging this value for a period of 1 sec. The following results were obtained: Both drugs exhibited CNS depressant activity. Between 5 and 10 min of perfusion the effect of trichloroethanol wa…

Tieftemperatur-Remissionsspektren oktaedrisch koordinierter Cu2+ -Ionen im Ligandenfeldbereich / Low temperature reflectance spectra of octahedrally …

1973

Abstract The ligand field reflectance spectra of octahedrally coordinated Cu2+-ions in different host lattices and at different temperature (300 °K - 4 °K) are critically compared. Especially the band shifts with decreasing temperature are analysed with respect to transitions from a dynamical to a static Jahn-Teller effect (macroscopic Jahn -Teller distortion of the lattice). In addition the square planar coordination of Cu2+ is discussed and alternative descriptions in the crystal field formalism and the angular overlap model are given.

Solid-state polymerization of oxetanes. I. Lattice parameters and packing properties of the monomers

1973

The crystallographic unit cells of melt-crystallized 3,3-bischloromethyloxetane and 3,3-bisbromomethyloxetane were determined by the Weissenberg method. The two isomorphous lattices are triclinic with two molecules in the unit cell. 3,3-Bisfluoromethyloxetane forms plastic crystals in the temperature range between −36°C and +22°C, as shown by differential calorimetry and NMR broad-line spectroscopy. The Debye-Scherrer diagram and the general physical properties indicate the formation of a face-centered cubic lattice. No correlation between the lattice parameters of the monomer and polymer can be found On the basis of these results, the question is raised as to whether a topochemical polymer…

Binding of concanavalin A to the surface of unfertilized and fertilized ascidian eggs.

1973

STUDIES with certain carbohydrate-binding proteins of plant origin (as concanavalin A and wheat germ agglutinin) have indicated that some surface properties of embryonic1,2 and of virally transformed cells3–6 are different from those of adult cells. The interpretation of the differences in terms of structural organization of the cell surface is, however, still controversial (see for example refs. 7 and 8).

Infectious transfer of a fertility factor inStreptomyces coelicolor

1973

SUMMARYInitial Fertility (IF) strains ofStreptomyces coelicolorare able to convert recipient strains (UF) to the IF condition by contact, without concomitant transfer of chromosomal markers. The conversion is prevented by the presence of acridine orange in the medium of the mixed culture. Acridine orange is also moderately effective in inducing the formation of UF variants from IF-treated strains. No effect of the drug is observed on UF variant formation from Normal Fertility (NF) strains nor on the behaviour of the fertility factor in NF × UF mixed cultures. The hypothesis is put forward that the fertility factor works as an episome inS. coelicolor, fixed to the chromosome in the NF strain…

Identification of Thorium-236

1973

Abstract The new nuclide 236Th has been produced via the (γ, 2 p) reaction by irradiation of 238U with 140 MeV bremsstrahlung. After chemical separation of thorium, the half-life was determined to be 36 ± 3 min -from the growth-decay curve of the strongest γ-ray transition of the daughter nuclide, 9 min 236Pa.

The compensatory regeneration of the operculum ofHydroides norvegica: Identification of the inhibiting substance

1973

In the polychete Hydroides norvegica there are two opercula with different degrees of organization: one is completely developed and functional, the other, present only in rudimentary outline. The latter only begins to develop when the functional operculum is removed. It was observed that in the whole body of the Hydroides, but particularly in the functional operculum, there is a substance which inhibits the development of the rudimental operculum. This substance was purified in order to determine its chemical nature. From preparation of opercular homogenates we chemically separated numerous fractions, each of which was tested for inhibitory activity and chemical and physical properties. The…

Gaschromatographie von Dialkyldithiophosphinatochelaten

1973

Three-nucleon calculations with local potentials

1973

The integral equations approach to the three-nucleon problem is reviewed. The results of different calculations with local potentials are compared.

26. ATHEROSCLEROTIC CHANGES OF THE ILIAC ARTERIES IN CHILDREN WITH A SINGLE UMBILICAL ARTERY — THE EARLIEST FORM OF ATHEROSCLEROSIS IN HUMANS

1973

Alkylation of acidic organic compounds for gas chromatographic analysis

1973

A new alkylation method is proposed. Organic solutions of fatty acids, phenols or barbituric acids are refluxed with an alkylating reagent and solid K2CO3. The reaction mixture is injected directly into the gas chromatograph. The scope of this convenient method for quantitative and qualitative analyses is considerable as different classes of alkylating agents can be used.

Dispersion relations of wave modes in helium II layers

1973

Dispersion relations of (sound-like) wave modes, which can exist in a helium II layer of arbitrary width, are calculated numerically. The basis of our considerations is the complete system of the linearized Landau-Khalamikov equations, in which only the dissipative processes involved with η and ζ2 are taken into account. Apart from the linearization, no approximation or averaging is performed. The thermal expansion of helium II is taken into account. Symmetry properties of the velocities of flow, usually required, are dropped here. A hint is given as to how all the Khalatnikov coefficients may be measured by sound absorption experiments.

Solid-state polymerization of oxetanes. II. Investigation of the growth of the polymer phase as related to the mechanism of polymerization

1973

The radiation-induced solid-state polymerization of 3,3-bischloromethyloxetane (BCMO) was investigated by direct observation of the development of the morphology of the growing polymer phase in single crystals of the monomer. Electron microscopy shows that the polymerization gives rise to amorphous polymer in the first step. The polymer forms irregular platelets which aggregate into larger units without reflecting the crystalline order of the monomer. Subsequent to polymerization, the amorphous polymer crystallizes to the β-modification of poly-BCMO. If the partially polymerized crystals are extracted by solvents of the monomer, crystallization of the polymer is enhanced, and morphological …

Abbau und Toxizität von Hexachlorbicyclo [2.2.1]-hept-5-en- Derivaten (Cyclodien-Insektizide) / Structural Aspects of Biological Conversion and Toxic…

1973

The aspects of molecular-structure and biological conversion have been studied for 12 derivatives of the endosulfan ether 1 [4, 5, 6, 7, 8, 8- hexachloro- 1, 3, 3a, 4, 7, 7a- hexahydro- 4, 7-methanoisobenzofuran]. Adults of a normal house-fly strain (Musca domestica) have been used in the assay. Derivatives of 1 monosubstituted in position I are found to be converted substantially faster than products disubstituted in position I and 3, respectively. Metabolism is inhibited for all compounds studied after application of piperonyl butoxide as a synergist. Besides proving that on oxidative metabolism has to be discussed and in fact could be proved for some derivatives, the intrinsic toxicity o…

Lösungseigenschaften von äthylcellulose. Vergleichende bestimmungen von molekulargewichten und zweiten virialkoeffizienten mittels osmose, lichtstreu…

1973

Es wurden osmotische und Lichtstreuungsmessungen an Athylcellulose in Aceton, Athylacetat, Butanol-(2), n-Butylchlorid und Benzol (nur Osmose) ausgefuhrt und die Ergebnisse in einigen Fallen mit Hilfe der Sedimentation/Diffusion kontrolliert. Durch Vergleich der verschiedenen Mesmethoden konnten die von Gelen unbeeinflusten Mesergebnisse gegen die durch Gele verfalschten Werte abgegrenzt werden. Die osmotisch und hydrodynamisch bestimmten A2-Werte sind hoch im Vergleich zu denen von Vinylpolymeren. Im Gegensatz dazu steht der niedrige Exponent e der Tragheitsradius-Molekulargewichtsbeziehung der sich fur negative Exponenten e nur durch Geleinflus deuten last. fur die zweiten Virialkoeffizie…

Eine apparatur zur gaschromatographischen verfolgung der metathesereaktion kurzkettiger olefine

1973

Es wird eine Apparatur beschrieben, die einen Reaktor, kombiniert mit einem Gaschromatographen, umfast und die es gestattet, Umsetzungen kurzkettiger Olefine bei der Metathesereaktion schnell und einfach zu erfassen. Die Leistungsfahigkeit der Apparatur wird u. a. am Beispiel der Metathesereaktion von Penten-2 in Gegenwart des Katalysator-systems WCl6/C2H5OH/(C2H5)3Al2Cl3 demonstriert. An apparatus consisting of a reactor tube in conjunction with a gaschromatograph is described which allows to follow instantaneously the progress of the metathesis reaction of short chain olefins. The ability of the apparatus is demonstrated among other things by means of the metathesis reaction of pentene-2 …

false

1973

The mechanism of radiation-induced polymerizations in the solid state has been a subject mostly open to speculation. As radiation usually generates several kinds of active species (radicals and ions) it is difficult to find out, which of these actually causes polymerization. We have developped a method distinguishing between cationic and anionic active centers. Cationic polymerizations are terminated by addition of a base such as sodium alkoxide in a suitable solvent. The alkoxide is incorporated into the polymer as an endgroup. This endgroup is determined analytically after isolation and purification of the polymer. The incorporation of alkoxy endgroups into the polymer is a proof of the o…

false

1973

The thermal degradation of poly(oxycarbonylethylene) (poly-β-propiolactone) has been investigated within a temperature range of 180–220°C and under various pressures. The degradation begins with a considerable decrease in molecular weight, followed by an accelerating formation of acrylic acid. The reaction involves the following steps: 1 Random chain scission of polymer chains by typical ester pyrolysis with the formation of fragments one of which containing a carboxylic group the other one a CC-double bond at the chain end (Eq. (1)). 2 Formation of the volatile acrylic acid by scissions at the chain end, the amount of acrylic acid or the weight-loss increasing with the number of fragmentat…

false

1973

La cyclopolymerisation du dimethacrylate de dihydroxy-2,2′-dimethyl-5,5′-diphenylmethane (II) a ete realisee en milieu benzene a 80° avec l'azobisisobutyronitrile comme amorceur, en milieu toluene a −500°C avec le butyllithium comme amorceur et en tetrahydrofuranne (THF) avec le naphthalene sodium. Les polymeres obtenus ont ete soumis a l'hydrolyse basique, les polyacides resultants traites par le diazomethane donnent les polymethacrylates de methyle correspondants dont la tacticite a ete etudiee en NMR (100 MHz). La reduction des polyme;res a ete effectuees par LiAlH4 en milieu THF. Des alcools polymethylallyliques ont ete isoles. Les resultats semblent montrer l'influence de la matrice II…

Regional cerebral blood flow and regional metabolism in cold induced oedema.

1973

24 hours following a cold induced oedema in cats rCBF was measured in the lesion area, the bluish stained cortex immediately adjacent to the lesion, a cortical area remote from the lesion, and in the contralateral uninjured hemisphere. Thereafter the brain was frozen and the respective tissue areas were removed and analyzed for water and electrolyte content as well as metabolite concentrations. It seems, that in the neighbourhood of a local lesion at least 3 different brain regions can be differentiated with regard to their characteristic pattern of data. In non-oedematous regions either hyperaemia or hypoaemia could be observed. In areas with local brain oedema rCBF was reduced inversely p…

Hirnabsze� durch fehlerhafte Crutchfield-Zange

1973

Mitteilung uber einen Fall von Hirnabszes nach Anwendung der Crutch-field-Zange. Ursache: Fehlende Kropfung am Dorn der Zange, der so den gesamten Schadelknochen und die Dura mater durchdringen konnte. Unerlaslich ist eine ausreichende Kropfung am Ansatzdorn der Zange und die Anlage des Bohrlochs parietal, nicht, wie vielfach durchgefuhrt, in der dunneren Temporalschuppe.

Measurement of brain tissue pressure in cold induced cerebral oedema.

1973

Experiments were performed in order to evaluate the concept that brain oedema is associated with an increase in local interstitial fluid pressure. Assuming that the pressure measured by the cotton wick technique represents the hydrostatic interstitial fluid pressure, the tissue pressure was recorded with pressure transducers in the white matter adjacent and remote to a local cold injury, in the opposite hemisphere, and in the cisterna magna. In 9 cats during steady-state conditions mean tissue pressures between 1.20±0.30 mm Hg and 2.33±0.80 mm Hg were found, as compared to a mean CSF pressure of 5.17±0.82 mm Hg. The tissue pressure was found to increase significantly adjacent to the lesion …

Extracellular space and electrolyte distribution in cortex and white matter of dog brain in cold induced oedema

1973

24 hours after a circumscribed cold injury of the cortex dog brains were perfused from the lateral ventricle and the frontal subarachnoidal space to the cisterna magna with an artificial CSF containing trace amounts of35S-labelled thiosulphate. Simultaneously the extracellular tracer was administered intravenously. Extracellular fluid volume was estimated and found to be increased from 10 to 15% in the oedematous cortex and from 10 to 27% in the oedematous white matter. The actual size of ECS in oedematous white matter, however, must be larger as indicated by the relative alterations of thiosulphate distribution, tissue water, sodium and chloride. Apparently a small part of the fluid accumu…

Wortfeld-Störung und Satzfeld-Störung

1973

Schizophrene Spracheigentumlichkeiten werden vom erfahrenen Untersucher oft intuitiv, als Anmutungsqualitat des “typisch” Schizophrenen erfast. Sie machen daher einen Teil des Praecox-Gefuhls Rumkes aus. Es wird mit Mitteln der strukturalen Linguistik versucht, in einem Teilbereich zu einer genaueren Umschreibung zu gelangen. An einem als “Wortfeld-Storung” und “Satzfeld-Storung” bezeichneten Phanomen last sich zeigen, das eine bestimmte Formulierung von einem Schizophrenen eventuell in unkorrigierbarer Weise misverstanden werden kann. Es bedarf aber einer Reflexion des Untersuchers, um dieses Misverstehen klar erkennbar zu machen. Dann wird aber eine wichtige Teilerscheinung der intellektu…

Automorphismen des Siegelschen Quotienten zweiten Grades

1973

Comparison of the ventilating and injection bronchoscopes.

1973

Die Bedeutung des Serumeiweissbildes zur Diagnose vonBufo calamita Laur.,Bufo viridis Laur. und deren Bastarden (Amphibia, Anura, Bufonidae)

1973

Electrophoretic investigations of the serum protein patterns of natterjacks (Bufo calamita Laur.) from the Iberian Peninsula and from Western and Central Europe, and of green toads (Bufo viridis Laur.) from Central Europa, Asia Minor and North Africa show that the two species differ disctinctly in the position of their albumin fractions. The identification of problematic specimens can result from the production of mixed serum with specimens of both species. As the albumin fraction of hybrids is doubled according to this method, it is also suitable for demonstrating the existence of such hybrids in natural populations.

Die Sauerstoff-Abgabe menschlicher Erythrocyten unter Hyperoxie

1973

Die Sauerstoff-Abgabe menschlicher Erythrocyten wurde sowohl in Ruhe als auch in schneller Stromung (Platte-Kegel-Viscosimeter) nach Sattigung mit unterschiedlichen Sauerstoffpartialdrucken von 50–600 mm Hg gemessen. Unter diesen experimentellen Bedingungen erreicht die Sauerstoff-Abgabe einen Maximalwert, der fur ruhende Erythrocyten bei einem initialen Sauerstoffpartialdruck von etwa 300 mmHg liegt und fur Erythrocyten in schneller Stromung bei einem initialen Sauerstoffpartialdruck von 100 bis 200 mmHg. Aus diesen Befunden wird der Schlus gezogen, das nur das gleichzeitige Zusammenwirken aller vier, an der Sauerstoff-Abgabe beteiligter Mechanismen, namlich intracellulare Diffusion und Ko…

Dualistisches Fortpflanzungsverhalten bei dem protogynen LippfischThalassoma bifasciatum und einige Beobachtungen über dessen Tag-Nacht-Wechsel

1973

1.Thalassoma bifasciatum is a protogynous wrasse with (partial) sexual dimorphism and male dichromatism. Sex-inversion takes place without affecting the color pattern. 2. Males with female-like color dress indulge in group spawning; males with the bright color pattern perform pair spawning. 3. Among the brightly colored males exists a well-established hierarchy. Dominant males only have a particular spawning area in which they spawn daily at a certain time around noon. The spawning area is optically marked by conspicuous behavior of the bright male. Courtship activities towards individual partners are rather superficial. 4. The female has the leading role in pair spawning. In the extremely …

Cooperative onset of a different state of water in the presence of macromolecules.

1973