Molekulargewichte von dextran und dextrantricarbanilat des bakterienstammes leuconostoc mesenteroides B 512

Molecular weights and limiting viscosity numbers of six acid hydrolysed dextrans, one crude sample, and one middle fraction, were determined in aqueous 4 M ZnCl₂ solution. The same samples were converted into the corresponding dextrantricarbanilates by treating the dextrans with phenylisocyanate. The molecular weights and intrinsic viscosities were determined in dimethylformamide. The reaction was found to be polymeranalogous up to a degree of polymerisation of 150,000. The P_W of the crude dextran sample turned out to be 5,7 times higher than the corresponding carbanilate. From this result association of the dextran molecules is concluded. This association is much more pronounced in H₂O (no ZnCl₂ added). A procedure is described which permits estimation of the mass fractions and molecular weights of the sol and associated moieties. According to that the molecular weight of the crude dextran is M_{W, Sol} = 79.6·10⁶, and the particle weight of the aggregates is M_W,ASS. = ca. 4000·10⁶. Only 17–30% of the mass is associated.     

Über die zusammenhänge,zwischen den exponenten in den beziehungen zwischen molekulargewicht einerseits und staudinger-index,sedimentationskoeffizient und diffusionskoeffizient andererseits

The preparation of 3.4-diaminostyrene from 1-(3′.4′-diamino-phenyl)ethanol as well as from 3.4-diamino cinnamic acid is accompanied by the formation of 3.4-diaminoethylbenzene as by-product. 3.4-Diaminostyrene is prepared without by-product by the reduction of 3-nitro-4-aminostyrene; it can be condensed to corresponding vinylheterocycles.     

Mykoflora der Onychomykosen

Es werden die Befunde von mykologischen Untersuchungen von Onychomykosen im Verlaufe von 10 Jahren (1955–1964) in Mittelböhmen mitgeteilt. Die am häuflgsten auftretenden haben wir in vier Gruppen unterteilt: Onychomykosen durch 1. Dermatophyten, 2. Scopulariopsis, 3. Candida, 4. Trichosporon.
Aus der Gesamtzahl von 680 Erkrankungen entflelen 65,6% auf Dermatophyten, 18,9% auf Hefen, 6,3% auf Scopulariopsis (meistens S. brevicaulis, vereinzelt S. Candida), der Rest auf gemischte Infektionen (Tabelle 1).
Von 455 Erkrankungen der Zehennagel waren 77,8% durch Dermatophyten hervorgerufen und nur 4,4 % durch Hefen. Von 199 Erkrankungen der Fingernägel waren 52,2% hervorgerufen durch Hefen und durch Dermatophyten 37,7%. Scopulariopsis wurde nur in den Zehennägeln nachgewiesen (Tabelle 2).
Der häufigste Befund betrifft das Trichophyton rubrum (57,5%), weiter Candida parapsilosis (9,7%), Trichophyton mentagrophytes var. interdigitale (8,5%) Scopulariopsis brevicaulis (7,1%), Candida albicans (5,5%), Trichosporon cutaneum (2,7%), Candida tropicalis (2,5%) usw. (Tabelle 3).
Weiter werden einige Pilze angeführt, die am haufigsten als zufällige Befunde auftreten.     

A complication associated with a forgotten intrauterine device (IUD)

A nylon ring provoked in a post-menopausal woman a severe pyometra, 16 years after its insertion. Removal of the device was curative. A review of the literature pertaining to the complications of IUDs was made, and conclusions drawn.     

Frühzeitige Relaparotomie bei Peritonitis,Intraabdominalen Abscessen und Dünndarmfisteln

Ohne ZusammenfassungMit 3 Abbildungen     

Die kationische polymerisation von monomerem formaldehyd in lösung. 39. Mitt. über polyoxymethylene

The heterogeneous cationic polymerization of dissolved formaldehyde was investigated between ?30 and ?78°C using various initiators and solvents. The rate of polymerization is first order with respect to monomer and initiator. In toluene at ?78°C the reactivity of the initiators decreases in the following order: SnCl₄ > CH₃COClO₄ > HClO₄ > AlBr₃ > BF₃?O(C₂H₅)₂ > TiCl₄ > FeCl₃ > SbCl₅ > H₂SO₄ > Cl₃CCOOH > HCOOH > I₂. The overall activation energies are in the range 1.0 to 10 kcal/mole. In most systems the degrees of polymerization (viscosity average P_v) increase roughly proportionally with monomer concentration and with conversion. Values up to P_v ～ 15,000 have been reached. Upon variation of the solvent the rates of polymerization increased and P_v decreased in the following order: n-pentane, toluene, diethyl ether, nitroethane, rnethylene dichloride, tetrahydrofuran, acetone. The low degrees of polymerization obtained in tetrahydrofuran and in acetone are due to chain transfer. Small concentrations of added water, methanol, formic acid, acetone or acetic anhydride apparently act as cocatalysts and accelerate the polymerization. In higher concentrations, however, they cause retardation and chain transfer. In many systems a drastic decrease in the rate of polymerization or complete stand-still was observed even after small conversions. This can be diminished or delayed by the above-mentioned polar additives or by using more polar solvents. In order to find the reason for this decrease in the rate of polymerization, the concentration of active cationic chain ends was determined by terminating the polymerization with a large excess of added amyl alcohol. The amyloxy endgroups formed in this termination reaction are determined by acid hydrolysis of the isolated and purified polymer and by gas chromatography of the amyl alcohol formed from the endgroups. In many systems this method led to the conclusion that initiation is fast and complete while propagation is increasingly inhibited by diffusion of monomer to the active centres occluded in the solid polymer. No indications of a genuine kinetic termination have been found.