bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymerisation induced by silver salts
Authors: Salomon G. 
Published: September 2010

AbstractThe formation of complex compounds between polymerisable donor molecules and silver salts has been studied in organic solvents. The “solubility” of silver nitrate depends on the availability of π‐electrons in the donor molecule and on steric factors. This liquid‐complex formation is favoured by a high dielectric constant of the medium.A concentrated solution of AgNO3 in acrylonitrile polymerises quickly at low temperatures, whereas dilute solutions are sluggish to react and do so only at higher temperatures. AgClO4 is less effective under the same conditions. Ethylene imine is polymerised by high concentrations of AgNO3 but needs only small quantities of AgClO4 to undergo the like process.AgNO3 does not induce the bulk polymerisation of other vinyl compounds and dienes, whereas AgClO4 is an extremely efficient catalyst (discovered by Richards and Eley). The majority of these reactions are inhibited or delayed by trinitrobenzene and hydroquinone.Results are interpreted in terms of one‐electron transfer reactions involving the intermediate formation of Ag++. Two types can be distinguished, viz. intermolecular, leading to the formation of “odd ions”, and intramolecular, leading to the release of active oxygen from perchlorates.
The formation of hydrocarbons by hydrogenation of fats
Authors: Hosman B. B. A. , van Steenis J. , Waterman H. I. 
Published: September 2010

AbstractHydrogenation of a fat with a nickel‐ or nickel copper on guhr catalyst under about 200 at pressure and 300‐350° C yields unbranched paraffins. These paraffins contain one carbon atom less than the original fatty acids.
Über 3‐Desaza‐Adenin (4‐amino‐1‐imidazo‐(c)‐pyridin) und Verwandte Basen. 3. Mitteilung über Desazapurin‐Derivate
Authors: Salemink C. A. , van der Want G. M. 
Published: September 2010

AbstractIn der 1. Mitteilung1) dieser Reihe sind die Gründe dargelegt worden, welche uns veranlasst haben, Strukturanaloge von Adenin und verwandter Naturstoffe zu synthetisieren. Der früher beschriebenen Darstellung von 1‐Desaza‐adenin schliesst sich in der vorliegenden Mitteilung die Synthese von 3‐Desaza‐adenin an. Ferner wird die Darstellung von 2‐Methyl‐1‐desaza‐adenin, von 2‐Methyl‐3‐desaza‐adenin und von 2‐Amino‐1‐desaza‐purin beschrieben, sowie in Zusammenhang hiermit die Konstitution einiger Substitutionsprodukte des Pyridins aufgeklärt.
Visible light and x‐ray scattering by concentrated solutions of macromolecules
Authors: Oster Gerald 
Published: September 2010

AbstractThe problem of X‐ray scattering by macromolecules in solution is identical with that for visible light if the relative visible index of refraction of the particles is near unity. The theory of the angular distribution and decrease of transmission due to scattering by independent particles of various shapes and sizes is outlined. For a system of non‐independent particles, the interparticle interferences of the scattered wavelets must also be considered. The Zernike and Prins expression for spherically symmetric distributions is applied to a dilute system of hard spheres and to the Kirkwood idealized liquid of hard spheres. The role of repulsive forces is considered and the correlation between the angular distribution of scattering and the osmotic pressure of the system is indicated. An extension of the theory to non‐spherically symmetric systems such as concentrated solutions of elongated particles is suggested. Applications are made to solutions of the rod‐shaped tobacco mosaic virus. A theory of the two‐phase formation of solutions of the virus is presented and evidence of the existence of three‐dimensional virus crystals in a 2.5% solution of tobacco mosaic virus is given.
Formation d'un époxyde de la butadiènesulfone
Authors: van Lohuizen O. E. , Backer H. J. 
Published: September 2010

AbstractLorsqu'on enlève de l'acide bromhydrique au 3‐bromo‐4‐hydroxy‐thiacyclopentane‐1,1‐dioxyde (III), on peut obtenir des produits différents selon le procédé que l'on utilise. En se servant du carbonate de baryum pour fixer l'acide bromhydrique, les auteurs ont obtenu un époxyde (V). L'anneau époxyde est ouvert par chauffage avec les hydracides halogénés, l'acide acétique et l'eau.En utilisant la pyridine pour éliminer le brome de l'alcool bromé (III), on obtient l'alcool non saturé IV, qui s'isomérise sous l'influence d'alcali. Nous considérons le produit isomérisé comme le dimère XII, dérivé du dioxane.
La biréfringence acoustique des solutions macromoléculaires
Authors: Peterlin Anton 
Published: September 2010

AbstractUne solution macromoléculaire devient biréfringente sous l'influence des ondes ultrasonores. Nous avons développé la théorie de l'effet pour le modèle de la pelote statistique pénétrable et à l'immobilisation partielle du solvent. La biréfringence est proportionnelle à la racine carrée de l'intensité de l'onde acoustique, à la fréquence de l'onde et à la biréfringence dynamique de la solution. Si l'on considère aussi les phénomènes de relaxation, la biréfringence acoustique donne les mêmes informations sur la macromolécule en solution que la biréfringence d'écoulement.
The kinetics of the polymerisation of sarcosine carbonic anhydride
Authors: Waley S. G. , Watson J. 
Published: September 2010

AbstractThe polymerisation of carbonic anhydrides, a reaction important both as a preparative method for the synthesis of polypeptides, and as an example of a less familiar type of polymerisation, has been studied in detail, using sarcosine carbonic anhydride (I). The propagation reaction has been shown to involve a reversibly formed compound between the carbonic anhydride and the polymer; this compound decomposes by both a unimolecular and a bimolecular route. The equilibrium constant for the formation of the intermediate compound, and both velocity constants for its decomposition have been determined in two solvents, and the activation energies and frequency factors calculated.The molecular weight distribution has been calculated from the kinetic scheme; the distribution is extremely sharp.
The dissociation and specific viscosity of polymethacrylic acid
Authors: Arnold R. , Overbeek J. Th. G. 
Published: September 2010

AbstractSolutions of polymethacrylic acid have been partially neutralized to different extents, and the pH values and viscosities of the resulting solutions determined. These measurements were carried out at several different potassium chloride concentrations, and on several polymer samples. The calculated dissociation constants of the polymer acid were substituted in the equation developed by J. Th. G. Overbeek, which expresses the change in dissociation constant of a polybasic acid as a function of the radius of the molecular coil and of the charge on the molecule. The derivation of this equation treats the polymer molecule as a sphere containing a continuous charge. The radii found are of the right order and change in the expected way with changing ionic strength and ionisation. Substitution of these radii in the Debije viscosity equation gives satisfactory agreement between observed and experimental viscosities at low degrees of ionisation. At higher degrees of dissociation it would seem that the treatment of the polymer coil as a sphere is no longer satisfactory, although a better approximation is obtained if the charge is considered to be entirely on the surface of the sphere.
On 9‐aminofluorene and derivatives. Some chemical and physiological properties
Authors: Neish W. J. P. 
Published: September 2010

Abstract2‐methoxy‐ and 3‐methoxy‐9‐aminofluorene have been prepared. Their reactions with ethyl chloroformate, maleic anhydride and carbon dioxide are described and similar reactions have been studied with the parent base, 9‐aminofluorene. These reactions lead to the formation of N‐carbethoxy derivatives, 9‐maleamic acids and substituted ammonium carbamates respectively.Attempts to obtain the 9‐amino derivatives by reduction of the oximes with sodium amalgam in alcohol‐acetic acid medium were unsuccessful. In each case, the corresponding fluorene derivative was obtained. Thus the hitherto undescribed 3‐methoxyfluorene has been prepared.2‐Methoxy‐ and 3‐methoxy‐9‐aminofluorene hydrochlorides produce local anaesthesia of the tongue and of guinea pig skin, the former action having been noted byNakamurafor 9‐aminofluorene hydrochloride. Kymograph studies with the above mentioned amines indicate that stimulation or relaxation of the contracting pregnant rat uterus may be obtained depending on the concentrations employed. These effects are reversible. Inhibition of contraction but no stimulation was noted with a non‐pregnant rat uterus. Data concerning the effects of related compounds including 2‐amino‐hydrochloride on uterine contraction are presented.
An estimate of the volume effect in coiling long chain molecules
Authors: Hermans J. J. 
Published: September 2010

AbstractAn approximate treatment of the volume effect in coiling molecules is suggested. It is based upon the assumption that the probability of finding the end of a chain element at a given point at distance A from the preceding chain element is determined by the average density at this point.From the results obtained an estimate of the volume effect in certain polymers is derived.
Contributions to the chemistry of ionones. I. On physical properties and structures in the methyliononeseries
Authors: Beets M. G. J. , Witjens P. H. 
Published: September 2010

AbstractA comparative study of refractivity data and ultraviolet absorption spectra of some carefully purified methylionones confirms a conclusion resulting from calculations on structural models, to wit, that in the β‐isomethylionone molecule steric hindrance must play a part.
Fatty acid analysis by partition chromatography
Authors: Boldingh J. 
Published: September 2010

AbstractApplying the principle of partition chromatography for the quantitative determination of fatty acids, a technique was developed in which new carriers for the immobile solvent phase have been introduced. In contrast to the carriers used by Martin et al. and by other workers, those used in our experiments are all of a very low polar character. They include the group of synthetic elastomers as well as natural elastomers, the latter being the most extensively studied. With systems containing benzene absorbed in e.g. vulzanized natural Hevea rubber, as the immobile solvent, and with a strong polar solvent as the mobile phase, a straight quantitative micro determination of the saturated n‐fatty acids from C6‐C18 has been made possible. Moreover hydroxy fatty acids too are readily separated from their mixtures with normal fatty acids.
1‐(X‐hydroxyphenyl)‐naphthalene: (Discrepancies in the literature VIII)
Authors: van Alphen J. , Drost G. 
Published: September 2010

AbstractA 1‐(x‐hydroxyphenyl)‐naphthalene can be obtained by reaction between phenol and diazotized 1‐aminonaphthalene or from the Zn double salt of naphthalene‐1‐diazonium chloride on heating with phenol, but its methyl ether is different from 1‐(4‐methoxyphenyl)‐naphthalene. Thus it is probably 1‐(2‐hydroxyphenyl)‐naphthalene.
Sur le Radical Méthylsulfonyle (Propriétés du Groupe Sulfonyle IX)
Authors: Backer H. J. 
Published: September 2010

AbstractLe chauffage du dibromo‐bis‐méthylsulfonyl‐méthane avec du cuivre au sein de toluène bouillant, suivi d'un traitement à l'ammoniaque froide, conduit au tris‐méthylsulfonyl‐méthane. Un radical méthylsulfonyle provenant d'une molécule est donc entré dans une autre molécule. Le mécanisme de cette transposition est discuté.
The decomposition of aliphatic azo‐compounds. I
Authors: Bickel A. F. , Waters W. A. 
Published: September 2010

AbstractThe thermal decompositons of dimethyl 2,2′‐azo‐isobutyrate and of ω,ω′‐azo‐toluene, which yield the radicals (CH3)2CCOOCH3 and C6H5CH2‐ respectively, have been investigated with a view to obtaining information on the nature of the radical‐radical interactions occurring on polymerization of methyl methacrylate and styrene respectively.The results of these model experiments with monomeric radicals may indicate that the chain termination processes in both the above polymerizations involve combination and disproportionation in comparable amounts.The benzyl radical, C6H5CH2, seems to be prone to disproportionate into the benzal radical, C6H5CH and toluene.
The elimination of methylthiol and dimethyl sulphide from methylthiol‐ and dimethyl‐sulphonium compounds by moulds
Authors: Challenger Frederick , Liu Y. Cheng 
Published: September 2010

AbstractThe behaviour of salts of dimethylthetin and dimethyl α‐ and β‐propriothetins, of alkylthiol derivatives of acetic and propionic acids, of α‐keto‐β‐methylthiolpropionic acid and α‐keto‐γ‐methylthiolbutyric acid in mould cultures has been investigated. A study has been made of the behaviour of S‐methylthiouronium chloride, 4‐methyl‐2‐thiouracil and 4‐methyl‐2‐S‐methylthiouracil and of certain aliphatic disulphides in similar cultures. Some, but not all, of the thetins evolve dialkyl sulphide, some of the methylthiol compounds yield methyl mercaptan, but the uracil derivatives evolve no sulphur compounds. Certain green Penicillia cause fission but not methylation of the dialkyl disulphides.
Preparation of cholesterol from wool grease by means of addition products
Authors: Hackmann J. Th. 
Published: September 2010

AbstractA simple method is described by which it is possible to prepare cholesterol from the unsaponifiable part of wool grease. The method serves as a base for the technical production of pure cholesterol. It consists in preparing addition compounds of cholesterol with inorganic metal salts and separating these addition compounds from the other components by means of a suitable solvent in which the addition compound is not soluble. After separating the addition product, it is decomposed by water, yielding the cholesterol, which is purified by crystallization.
Identification and quantitative analysis of a mixture of methylglyoxal and acetol
Authors: Neuberg Carl 
Published: September 2010

AbstractIn the course of various reactions of sugars with alkaline materials substances of the 3‐carbon series are formed, i.e. methylglyoxal (MG) or acetol (A) or mixtures of the two. MG may be determined quantitatively by enzymatic dismutation with the enzyme ketonealdehydmutase and manometric measurement of the lactic acid formed. A remains unchanged during this procedure and may be determined as its 2,4‐dinitrophenylosazone or by a reduction method. By oxidation with bromine water MG is quantitatively converted into pyruvic acid which can be determined as its 2,4‐dinitrophenylhydrazone. MG and A can be precipitated together as 2,4‐dinitrophenylosazone; substraction of the value corresponding to the MG and found by bromine water oxydation or enzymatic dismutation indicates the A content.
Die Stellung des Zuckers in den Sennosiden A und B: 5. Mitteilung über Anthraglykoside
Authors: Stoll A. , Becker B. 
Published: September 2010

AbstractIn der vorliegenden Arbeit wird bewiesen, dass in den Sennosiden A und B die D‐Glucose mit der 8‐Hydroxygruppe des Anthraolgerüsts verknüpft ist.
The chlorination of naphthalene in the vapour phase
Authors: Wibaut J. P. , Bloem G. P. 
Published: September 2010

AbstractThe chlorination of naphthalene in the vapour phase has been studied between 220° and 500° under the catalytic influence of small quantities of iodine. At 250° the reaction product contained α‐ and β‐chloronaphthalene in the ratio of 9:1; this ratio decreases rapidly as the reaction is carried out at a higher temperature. At 340° and above both isomers are produced in almost equal quantities. The course of the reaction is qualitatively the same as in the non‐catalytic bromination of naphthalene in the vapour phase.
Chemical studies on insecticides II: The hydrolysis of OO′‐diethyl‐ and ‐dimethyl‐O″‐p‐nitrophenyl thiophosphonate (parathion and dimethylparathion (E 605)).
Authors: Ketelaar J. A. A. 
Published: September 2010

AbstractThe hydrolysis with alkali is measured from 10‐75° C in water and in a 50% alcohol‐water mixture of OO′‐diethyl‐, and ‐dimethyl‐O″‐p‐nitrophenyl thiophosphonate (parathion and dimethylparathion or E 605) in dilute solutions with concentrations of sodium hydroxide ranging from 0.002 N to 1 N. The reaction was strictly bimolecular and the reaction constant at 15° C was found to be k = 2, 15. 10−2 mol−1 min−1 and in general: \documentclass{article}\pagestyle{empty}\begin{document}$ \log \,{\rm k} = 10.95 - \frac{{16600}}{{2.303\,{\rm RT}}} $\end{document}The constant k = 9.20. 10−2 mol−1 min−1 for the dimethyl analogue is 4.3 times higher (at 15° C). The expression is \documentclass{article}\pagestyle{empty}\begin{document}$ \log \,{\rm k} = 10.71 - \frac{{15450}}{{2.303\,{\rm RT}}} $\end{document}The heats of activation thus were 16.6 kcal/mol and 15.45 kcal/mol respectively. This difference in the speed of hydrolysis can be used for the identification of both compounds in proprietary mixtures as was confirmed by infra red absorption spectra.
Adsorption of ammonia on surfaces of oxides: (Preliminary communication)
Authors: Rijnders G. W. A. , Schuit G. C. A. 
Published: September 2010

AbstractThe adsorption of ammonia as a function of temperature and pressure on some oxides and oxide mixtures was studied. The adsorption can be separated in two processes; one with a high adsorption energy and entropy, the other with a much lower adsorption energy and entropy. A tentative explanation was suggested.
The dihydroxy‐ and diethoxypyridines
Authors: den Hertog H. J. , Wibaut J. P. , Schepman F. R. , van der Wal A. A. 
Published: September 2010

AbstractThe preparation of 2,5‐ and 3,4‐diethoxypyridine and a new method for the synthesis of 2,5‐dihydroxypyridine are described.A survey is given of some properties, including the ultraviolet absorption spectra, of the six dihydroxypyridines and the six diethoxypyridines.
Synthèses Dans le Domaine des Auxines: II. Simples analogues de l'auxine‐b. 40e Communication sur les substances favorisant la croissance végétale
Authors: Kögl F. , de Bruin O. A. 
Published: September 2010

AbstractLe présent travail envisage en particulier la synthèse de composés qui, en ce qui concerne la constellation des groupements fonctionnels, peuvent être des substances du type de l'auxine‐b. Une méthode générale est indiquée pour synthétiser les lactones des acides β‐céto‐δ‐hydroxy‐carboniques par la réaction de Reformatsky. On décrit la préparation d'une série de composés montrant une certaine analogie de structure avec les auxines. La constitution de ces composés est déduite de la préparation et des données analytiques. Les formules de constitution en question sont encore vérifiées par les conclusions des spectres d'absorption dans l'ultra‐violet.II faut mentionner particulièrement la préparation de la lactone de l'acide δ(cyclopentényl‐1)‐δhydroxy‐β‐céto‐pentanoïque. La constitution de ce composé ne diffère de celle qui est attribuée à la lactone de l'auxine‐b que par l'absence des deux groupements butyliques secondaires du cycle penténique.
The determination of sodium and potassium in blood serum and urine by means of the flame photometer
Authors: Willebrands A. F. 
Published: September 2010

AbstractA method is described for the determination of sodium and potassium in blood serum and urine by means of the flame photometer. Sodium is determined by diluting serum or urine 100 times with distilled water, by spraying the solution obtained into a flame fed by a mixture of butane and air and measuring the intensity of the yellow sodium light with a selenium barrier‐layer photocell. Potassium is determined by diluting serum 25 times and urine 100 times with distilled water and measuring the intensity of the red K doublet, which is excited when these solutions are sprayed into the flame, with the help of a gas‐filled caesium cell with D.C. amplifier. The potassium and sodium content of the serum of 35 normal persons was determined in this way.
Studien über den D‐Glutaminsäure‐Stoff‐Wechsel von Tumoren I. Erhöhung des D2O‐Gehalts der Körperflüssigkeit von Tumorratten. 14. Mitteilung über die Chemie der Tumoren )
Authors: Kögl F. , Klein A. J. , Erxleben H. , van Veersen G. J. 
Published: September 2010

AbstractEs wurde untersucht, ob die Verabreichung von Trinkwasser mit erhöhtem D2O‐Gehalt beim D‐Glutaminsäure‐Baustein von Tumorproteinen in gleicher Weise wie bei der L‐Form einen Einbau von stabil gebundenen Deuterium‐Atomen zur Folge hat. Als Versuchstiere dienten Ratten mit Chemotumoren. Es zeigte sich, dass der Einbau bei der D‐Form erheblich langsamer folgt, dass aber schliesslich der gleiche Deuterium‐Gehalt erreicht werden kann wie beim L‐Glutaminsäure‐Baustein der Tumorproteine und der normalen Leberproteine.
Studien über den D‐Glutaminsäure‐Stoffwechsel von Tumoren. II. Fütterungsversuche mit Deuterio‐ DL‐glutamat. 15. Mitteilung über die Chemie der Tumoren)
Authors: Kögl F. , Erxleben H. , Klein A. J. , van Veersen G. J. 
Published: September 2010

AbstractWährend die in der Nahrung reichlich vorhandene L‐Glutaminsäure für den Organismus der Ratte eine entbehrliche Aminosäure ist, liess sich bezüglich des Tumors der Ratte über die Bedeutung per os zugeführter D‐Glutaminsäure nichts vorhersagen.Bei 5 bzw. 15 Tage währenden Fütterungsversuchen mit Deuterio‐DL‐glutamat zeigte es sich, dass die aus den Tumorproteinen isolierte D‐Glutaminsäure (im Gegensatz zur L‐Form) einen Deuteriumgehalt aufwies, der die Fehlergrenze der Bestimmungsmethode um eine Grössenordnung übertraf2).
Studien über den D‐Glutaminsäure‐Stoffwechsel von Tumoren. III. Injektionsversuche mit der DL‐, L‐ und D‐ Form von Deuterioglutamat. 16. Mitteilung über die Chemie der Tumoren)
Authors: Kögl F. , Erxleben H. , Klein A. J. , van Veersen G. J. 
Published: September 2010

AbstractRatten mit Benzpyren‐Tumoren erhielten während 4 Tagen subcutane Injektionen von Deuterio‐DL‐glutaminsäure in Form wässeriger Lösungen des Mono‐natriumsalzes. Wie bei den in der vorhergehenden Mitteilung beschriebenen Fütterungsversuchen zeigte sich auch hier, dass der Deuteriumgehalt des D‐Glutaminsäure‐Bausteins jenen der L‐Form wesentlich übertraf. In weiteren Versuchsserien wurden die Antipoden getrennt injiziert. Während die Injektion der D‐Form zu einem gleichsinnigen Resultat führte, war die nach Injektion der deuterierten L‐Form aus dem Tumor isolierte D‐Glutaminsäure praktisch deuteriumfrei.
The measurement of rates of spread
Authors: Burgers W. G. , Greup D. H. , Korvezee A. E. 
Published: September 2010

AbstractA description is given of an apparatus for the measurement of the rate of spread under free expansion of liquid fatty acids and similar substances on water surfaces.Preliminary measurements on valeric, caproic, heptylic, caprylic and nonylic acid with varying degree of acidity of the water indicate that there is an essential difference between valeric and caproic acid on the one hand and heptylic, caprylic and nonylic acid on the other in the manner of spreading of the drop placed on the water surface. Reproducible values are obtained only with the two first mentioned acids.With all the acids a new impulse seems to occur during spreading which increases the velocity of displacement of the film boundary.The values obtained for valeric and caproic acid appear to be mostly independent of the degree of acidity. The course of the displacement of the film boundary can be represented in case of both acids by the same formula which takes into account the transition from a close packed film into a less closely packed film.
On the retention of water existing in biocolloids subjected to desiccation in standard ovens
Authors: Mosse D. A. A. 
Published: September 2010

AbstractThe retention of water, occurring when biocolloids and food products, consisting chiefly of macromolecular substances, were dried at 102.5° C (average) in a well‐ventilated standard oven (water vapour pressure ∼ 10 mm Hg), varied from 0.5‐0.8% abs.