bluuebunny/crossref_metadata_2025_split huggingface dataset:
Über die Strahlenempfindlichkeit der Wasserstoffbrücken in der Desoxyribonucleinsäure
Authors: Ullrich M. , Hagen U. 
Published: February 2015

Calf thymus DNA was irradiated in aqueous solution and fractionated on columns of kieselgur with methylated serum albumin (MAK). Irradiated DNA was firmly bound by the MAK-column in neutral pH, exponentially to the radiation-dose; it could be eluted, however with 2 N-ammonia. There is only a limited region of the DNA-molecule, which is responsible for the retention, as the irradiated DNA-molecules could be degraded by ultrasound to fragments which are retained by the column and to those which can be eluted.
Experiments with DNA, degraded by DNase or ultrasound, have shown, that breaks of the double helix or breaks of a single strand are not responsible for this retention. Crosslinks between the molecules or alterations of the nucleotide bases could as well be excluded.
The sensitivity of the DNA concerning the observed radiation effect depends on the ionic strength of the solution during irradiation. In 0.4 M NaCl, where the helical structure of the DNA is more stable, the radiosensitivity is lower than in 0.01 M NaCl. This leads to the conclusion, that snort single stranded regions are formed by irradiation and are responsible for the binding by the column. The denatured regions in irradiated DNA can not be recognized, however, by alteration of absorbancy-temperature relationships. The size of these regions in the DNA-chain and the mechanism of their formation is discussed.
Die Abbildungseigenschaften autoradiographischer Systeme
Authors: Bleecken S. 
Published: February 2015

In autoradiographic transfer two characteristic ranges can be distinguished which result from the composed kind of dose function (e−kR/R2). In “photographic region” of transfer, i. e. when thickness of emulsion and object are comparable with the maximum range of beta particles, the influence of absorption or beta energy is predominant and that of geometry can be neglected. The autoradiographic transfer properties are very similiar to those of photographic transfer.
In the “crossfire region” of autoradiographic transfer i. e. when the thickness of emulsion and object are very small compared with the maximum particle range, the influence of geometric parameters is predominant. High crossfire causes blurred images, typical for microautoradiography with nuclides of high energies.
In addition to linear transfer of periodic and nonperiodic distributions of radioactivity, the nonlinear transfer is considered. The influence of exposure on contrast transfer and grain density is also considered.
Contrast measurements, made by using 131I- and 32P-labelled sine wave gratings, are in agreement with the calculated contrast transfer functions.
Bindungsverhältnisse in Prussiaten
Authors: Haberditzl W. , Schleinitz K.-D. , Bartel H.-G. 
Published: February 2015

Die Spektren im Bereich von 300—600 nm der wäßrigen Lösungen von Prussiaten (II) zeigen in den meisten Fällen drei Banden, denen die Übergänge 1A1→ 1E (1), 1A1→ A2 und 1A1→ 1E(2) zugeordnet werden konnten (C4v-Symmetrie, Dt &lt; 0). Durch vergleichende Überlegungen im Zusammenhang mit dem Spektrum des [Fe(CN)5NO] 2⊖ wurde eine Reihe für die Störwirkung erhalten. Der Komplex [Fe(CN)5NO2]4⊖ zeigt eine sehr geringe Störung der Oh-Symmetrie.
Für die Prussiate (III) wurden unter Vernachlässigung der gestörten Oh-Symmetrie nach einer von NAIMAN 6 angeführten Methode für [Fe(CN)6]3⊖ aus den Werten der Spektren von wäßrigen Lösungen die Dq-Werte abgeschätzt. Dabei zeigte wiederum das [Fe(CN)5NO2]3⊖ mit einem Wert Dq=3350 cm-1 die geringste Abweichung von dem des Hexacyanoferrates(III) (3495 cm-1), während die berechneten Werte der anderen Prussiate bei 3200±40 cm-1 lagen. Für die in den Spektren beobachteten Banden bei 17 500, 24 500 und 35 400 cm-1 wurden Zuordnungen getroffen. Die Banden bei 17 500 cm-1 sind bis auf den Fall des [Fe(CN)5NH3]2⊖ durch CT-Banden überlagert.
Polybenzoate und -acetate des Phorbols und Phorbol-3-ols und funktionelle Derivate der Allylgruppierung des Phorbols
Authors: Schairer Hans Ulrich , Thielmann Heinz Walter , Gschwendt Michael , Kreibich Gert , Schmidt Rainer , Hecker Erich 
Published: February 2015

Base catalysed transesterification of phorbol-12,13,20-tribenzoate yields phorbol-12,13-dibenzoate. By base catalysed transesterification of phorbol-pentaacetate phorbol-9,12,13-triacetate is obtained. This can be re-acetylated to give phorbol-9,12,13,20-tetraacetate which is also obtained by treatment of phorbol-12,13,20-triacetate with acetic anhydride/p-toluene-sulfonic acid.
Reduction of phorbol-12,13,20-triacetate with LiAlH4 yields phorbol-3-ol which reduces Fehling's and Tollen's reagent. Reduction of the 3-keto group alone can be accomplished with sodium borohydride. From all phorbol-esters investigated only in phorbol-pentaacetate an acetyl migration is observed during the sodium borohydride reduction leading to phorbol-3-ol-3,9,12,13,20-pentaacetate. By these findings those two tertiary hydroxyl groups of phorbol which are not acetylated with acetic anhydride/pyridine at room temperature were further characterized.
Oxidation of phorbol-12,13-diacetate with activated manganese dioxide yields phorbol-20-al-12,13-diacetate. By evaluation of nmr-spectra of this aldehyde and of some of its derivatives as well as of the epoxide of phorbol-12,13-diacetate and of 6-oxo-7-hydroxy- and 6,7-diacetoxy-20-nor-phorbol-12,13-diacetate the sequence of C-atoms around the allylic alcohol group of phorbol is further characterized.
DNS-Synthese nach Röntgenbestrahlung bei homozygoten Hefestämmen verschiedenen Ploidiegrades
Authors: Jannsen Sigrid , Lochmann Ernst-Randolf , Laskowski Wolfgang 
Published: February 2015

Since Saccharomyces cells have only a very small uptake of thymine or thymidine, the uptake of labelled samples of these compounds cannot be used to measure the rate of DNA synthesis.
Instead two other methods were used for both X-irradiated and unirradiated cells of a series of homozygous isogenic Saccharomyces strains of different ploidy:
1. Yeast cells were incubated with adenine-8-C14, the labelled DNA was isolated and completely separated from RNA, and the specific radioactivity of the DNA was determined. The reduction of the specific radioactivity after irradiation as a proportion of the specific radioactivity of unirradiated control cells gave the X-ray induced inhibition in the rate of DNA synthesis.
2. The uptake of thymine-2-C14-5′-monophosphate, which is the only thymine compound incorporated into the DNA of Saccharomyces in any appreciable amount, was measured after various incubation times for irradiated and control cells.
The results of the two methods are compared and the possibilities for their application are discussed.
The dose effect curve for the rate of DNA synthesis after X-irradiation shows two phases: a steep slope at low doses with a shallow slope at high doses.
For low doses the proportional decrease with X-irradiation in the rate of DNA synthesis is of the same order of magnitude as that of the colony forming ability, and is considerably greater than that of other metabolic processes such as protein and RNS synthesis, respiration or fermentation.
The dependence of this proportional decrease on degree of ploidy is also similar to that dependence shown by colony forming ability and is again different from the dependence shown by RNA or protein synthesis.
The reduction in DNA synthesis is greater the greater the time of incubation after irradiation.
Correlation between Field Formation, Proton Translocation, and the Light Reactions in Photosynthesis
Authors: Schliephake W. , Junge W. , Witt H. T. 
Published: February 2015

Electrical field changes across the function membrane of photosynthesis have been measured via special absorption changes. These occur by the action of the field on pigments which are located within the membrane. - Proton translocation has been measured by absorption changes of added pH indicators. Repetitive flash technique has been used for the sensitive detection of these absorption changes.
1. Each of the two light reactions of photosynthesis sets on one half of the electrical field.
2. The action spectra indicate that the two light reactions which set on the field are identical with those which promote the electron transfer.
3. The voltage set on in the elementary act both light reactions is V0=50 mV.
4. Each of the two light reactions translocates one proton across the membrane.
5. The proton uptake is faster than 8 · 10−3 sec.
6. Two protons are translocated per one electron transferred to a terminal acceptor.
7. A reaction scheme compatible with the measured correlation between the light reactions, electron transfer, field formation, and proton translocation is depicted in Fig. 7.
Transduction of Streptococcus pyogenes K 56 by Temperature-Sensitive Mutants of the Transducing Phage A 25
Authors: Malke Horst 
Published: March 2015

Experiments aimed at increasing the efficiency of transduction by the virulent group A streptococcal phage A 25 were carried out using temperature-sensitive phage mutants. Lysates of phages carrying ts mutations proved to transduce more efficiently than wild type lysates, the order of increasing effectiveness being ts+ &lt; tsl ~ ts2 &lt; tsl — 2. Differential survival of the recipient, K 56, appeared to be the principal reason for the improvement of transduction when cells decapsulated by hyaluronidase were transduced at the restrictive temperature. In transduction of encapsulated recipient cells, in which the superiority of ts lysates was less pronounced, the possibility was considered that mutant lysates might contain higher fractions of transducing particles than wild type lysates produced under parallel conditions.
The transducing activity of wild type lysates depended strongly on the temperature at which the phage had multiplied on the donor strain, the frequency of transduction increasing with decreasing temperature. Since the minimal latent period of the phage varied roughly in the same way with temperature, a connection is suggested between the time required for phage multiplication and the proportion of transducing particles formed.
Some Heterocyclic Nitrogenous Compounds as Radioprotectants for Hematological Levels in X-Irradiated Mice
Authors: Roushdy H. M. , Pierotti T. , Polverelli M. 
Published: February 2015

In normal controls, the levels of hemoglobin concentration and hematocrit values remained almost unchanged throughout the experimentation period.
Intraperitoneal administration of imidazole and benzimidazole affected rapid pharmacodynamic incidences which were not detected with cysteamine. Administration of imidazole did not induce detectable change in the level of hemoglobin concentration but slightly decreased the hematocrit value. Benzimidazole created slight depression in hemoglobin concentration and exerted no effect on hematocrit value. Cysteamine caused slight depression of both hemoglobin concentration and hematocrit value. Those changes were readily restorable with imidazole and benzimidazole while those with cysteamine lasted for more than three days.
Irradiation caused progressive decrease in hemoglobin concentration and hematocrit values which continued till the death of the animals. A significant increase in the sedimentation rate of red blood cells was recorded.
Irradiation of chemically protected animals caused initial decrease in hemoglobin concentration and hematocrit values which lasted till the fifths post-exposure day. Later, gradual restoration of normal levels of hematological values was recorded. Restoration was more rapid with benzimidazole than with imidazole, while cysteamine lied half way in its action. The increase in sedimentation rate of red blood cells was less pronounced and gradual restoration of the normal sedimentation rate was maintained during the post-irradiation time.
It seems likely that the radioprotectants act on cellular and subcellular levels in the protected tissues but the actual role played by such compounds still awaits further investigation.
Imidazole and benzimidazole proved to be effective radioprotectants of the hematopoietic tissue. Benzimidazole proved to exert the best radioprotective characters amongst the tested compounds in this concern.
Die Wirkung hoher Salzkonzentration auf die Permeabilität der pflanzlichen Zellmembran
Authors: Weigl Josef 
Published: February 2015

Using the device of Fig. 1 (this paper and 1. c. 3) efflux of Cl⊖ across the plasma membrane of root cortex cells was found to increase with increasing external concentration of various salts. We conclude that non-specific (passive) plasma membrane permeability (!) to anions increases with increasing external concentration of salts. As a primary result passive efflux of anions, which is downhill in the electrical gradient, increases.
Efflux of Rb⊕ across the plasma membrane is only slightly stimulated by external KCl and is inhibited by Ca2⊕.
The decrease in electrical potential with increasing external salt concentration is a consequence of the increase in passive plasma membrane permeability to anions.
Interaction of salts with charged groups of the plasma membrane is not unlikely to be the reason for the increase of the permeability to anions and for the multiple hyperbolic influx isotherm observed at high external concentrations (1-100 mM). We want to emplasize that a multiple hyperbolic isotherm may be considered a feature of passive ion movement across a barrier of different charged groups.
Die Beziehung zwischen der cytotoxischen und elektrokinetischen Wirkung von Humanserum auf L-Zellen und Yoshida-Hepatom- Asciteszellen
Authors: Boehmer H. von , Bayer Renate , Gladigau V. , Ruhenstroth-Bauer G. 
Published: February 2015

Humanserum reduziert die elektrophoretische Beweglichkeit von L- und Yoshida-Hepatom- Asciteszellen. Eine Ig-G-Globulin-Fraktion A1F1 aus dem Serum wirkt nur bei niedriger Ionen­starke (μ = 0,03), jedoch nicht bei einer dem Serum entsprechenden Ionenstärke. Die Untersuchung dieses Problems führte zu folgenden Befunden:
1.Im Humanserum kommen komplementabhängige cytotoxische Antikörper gegen L-Zellen und Yoshida-Hepatom-Asciteszellen (YA-Zellen) vor. Während 30 von 51 untersuchten Humanseren jeweils über 90% der YA-Zellen lysierten, wirkten alle 46 untersuditen Seren auf jeweils iiber 90% der L-Zellen cytotoxisch. Eine Korrelation zwischen den Blutgruppen ABO oder Rh und der cyto- toxischen Aktivitat des Humanserums gegeniiber YA-Zellen besteht nicht. Alle 6 untersuchten Kaninchenseren lysierten jeweils über 90% der YA-Zellen, jedoch nur weniger als 20% der L-Zellen. Die cytotoxische Wirkung des Kaninchenserums gegenüber YA-Zellen ist ebenfalls auf ein Anti- korper-Komplement-System zurückzuführen.
2.Der schon von FEDOROFF et al. 9 beschriebene Antikörper gegen L-Zellen kann von YA-Zellen bei 0° nicht adsorbiert werden.
3.Meerschweinchenkomplement kann weder Humankomplement bei L-Zellen noch Human- oder Kaninchenkomplement bei YA-Zellen ersetzen. Human- und Kaninchenkomplement dagegen sind bei beiden Zellarten austauschbar.
4.Bei L- und YA-Zellen sind nur cytotoxisch aktive Seren elektrokinetisch wirksam. Der verlangsamende Effekt auf die elektrophoretischen Beweglichkeit wird in der Hauptsache durch Anlagerung bestimmter Ig-G-Globuline, die in unserer Ig-G-Fraktion A1F1 enthalten sind, nach der Schädigung der Zellen durch das Antikorper-Komplement-System hervorgerufen, welches allein elektrokinetisch kaum wirksam ist.
5.Zellen, die durch Hitzebehandlung oder infolge der Präparation ihre Vitalität eingebüßt haben, werden auch durch cytotoxisch schwach wirksames oder inaktiviertes Serum in ihrer elektrophoretischen Beweglichkeit verlangsamt. Menschliche Leukozyten und Leberparenchymzellen werden ebenfalls nach einem nicht-antikörper-bedingten Vitalitätsverlust auch durch autologes Serum elek­trokinetisch verändert.
6.In Adsorptionsversuchen mit Humanserum und L-Zellen, YA-Zellen, autologen Leukozyten sowie Leberparenchymzellen der Ratte läßt sich jeweils die zellelektrophoretisch erfaßbare Aktivi­tät des Serum auf eine Zellart durch die andere Zellart vermindern. Das gleiche Ergebnis liefern analoge Versuche mit der Ig-G-Fraktion A1F1 und hitzegetöteten YA- und L-Zellen. Demnach zeigen die von nicht-vitalen Zellen adsorbierten elektrokinetisch wirksamen Ig-G-Globuline des Hu­manserums keine Zellspezifität.
7.Die Ig-G-Fraktion A1F1 allein vermindert die elektrophoretisdie Beweglichkeit von vitalen Zellen nur bei niedriger Ionenstärke (0,03), von nicht-vitalen Zellen jedoch auch bei hoher Ionen­starke (0,15).
Trifluormethylsulfonylstickstoff-Verbindungen
Authors: Roesky H. W. , Holtschneider G. , Giere H. H. 
Published: February 2015

Durch Umsetzung von Trifluormethylsulfonylamid, CF3SO2NH2, mit Phosphorpentachlorid, Thionylchlorid und Schwefeltetrafluorid konnten die Verbindungen Trichlorphosphoranylidensulfonylmethyltrifluorid CF3SO2N=PCl3,N-(Trifluormethylsulfonyl) schwefeloxidimid CF3SO2N=S=O und N-(Trifluormethylsulfonyl) iminoschwefeldifluorid CF3SO2N=SF2, hergestellt werden.
Trifluormethylsulfonylfluorid reagiert mit Dimethylamin zum Trifluormethylsulfonyldimethylamid.
Die neuen Verbindungen werden durch ihre Elementaranalyse, IR-Spektren und 19F- und 1H-KMR-Spektren charakterisiert.
Antibodies against Sulphoquinovosyl-diacyl glycerol and their Reactions with Chloroplasts
Authors: Radunz Alfons , Berzborn Richard 
Published: February 2015

Using immunological techniques we tried to determine the localization and orientation of the sulpholipid of diloroplasts in thylakoids. During immunization of rabbits with lamellar systems of chloroplasts of Antirrhinum majus antisera were obtained which precipitated sulpholipid emulsions. Antibodies against the sulpholipid were not detected until a second series of intravenous injections.
By immunizing purified sulpholipid of Fucus serratus, adsorbed to methylated bovine serum albumin, sulpholipid antisera were acquired. These antisera and the antisera against lamellar systems of Antirrhinum majus reacted with preparations of sulpholipid from widely different plant species. The sulpholipid antisera did not react with emulsions of the mono- or digalactosyl-diacyl glycerol, of lecithin or the anionic phosphatide phosphatidyl glycerol. Lamellar systems isolated without osmotic shock on a sucrose gradient were not agglutinated by sulpholipid antisera directly, but an indirect agglutination could be achieved in a Coombs-test or in a mixed antigen agglutination after Uhlenbruck. Broken chloroplasts, however, were agglutinated directly by sulpholipid antisera, as well lamellar systems which had been disrupted in a French-press or by ultrasonic treatment.
From agglutination and agglutination inhibition experiments with lamellar systems prepared by different methods it is concluded that the determinant groups of the sulpholipid are accessible for antibodies in the lamellar system of chloroplasts. But probably the sulpholipid molecules are located inside the thylakoids.
Unterschiede in der Kastendetermination zwischen den Hummelarten Bombus hypnorum und Bombus terrestris / Differences in the Caste Determination between the Bumblebee Species Bombus hypnorum and Bombus terrestris
Authors: Röseler Peter-Frank 
Published: February 2015

In colonies of Bombus hypnorum reared in captivity all intermediate body sizes between worker and queen are produced, the body size being determined by the amount of food for the larvae. Queens are produced, if the larvae are fed sufficiently. In captivity queens are produced at every time of the colony development, if one worker has to feed only two larvae in the maximum. In experiments where queens founded a colony together with workers, the larvae of the first brood also developed into queens.
In Bombus terrestris the castes are more differentiated. Workers have a maximal body size and there are no intermediate sizes to the queen size. Larvae are determined alternatively to be workers or queens in the first 3½ days of the development. Experiments with fences show that the queen produces a pheromon which inhibits the workers from rearing new queens. Workers are not able to pass the inhibiting factor from one to another. The inhibition by the queen terminates near the end of the colony development.
Röntgenkleinwinkelstudien an verdünnten Lösungen von Helix pomatia Hämocyanin
Authors: Pilz I. , Kratky O. , Moring-Claesson I. 
Published: February 2015

Das Hämocyanin der Schnecke Helix pomatia wurde mit Hilfe der Röntgenkleinwinkelstreuung in reinem Wasser und in 0,05 M Boratpuffer bei pH 8,2 untersucht.
In Wasser lagen homodisperse Lösungen des ganzen Hämocyaninmoleküles vor; das Mol.-Gew. betrug 8,95 · 106. Die Streukurve zeigt zahlreiche Nebenmaxima, die eindeutig auf die Gestalt eines Hohlzylinders hinweisen. Der Streumassenradius betrug 164 A; ein Formvergleich mit theoretischen Streukurven von Hohlzylindern ergibt die beste Übereinstimmung für folgende Achsenverhältnisse: Innenradius zu Außenradius 0,45 : 1 und Zylinderhöhe zu Außendurchmesser 1,1 : 1. Aus diesen Achsenverhältnissen und dem Streumassenradius errechnen sich für den streuungsäquivalenten Hohlzylinder die Dimensionen: Höhe = 360 A, Außendurchmesser 330 Å und Innendurchmesser 150 A. Das ermittelte Volumen (1,74 · 107 Å3) und der Quellungsgrad (1,6) sind relativ groß und weisen darauf hin, daß das Hämocyanin aus Untereinheiten aufgebaut sein muß.
Bei pH 8,2 lagen Bruchstücke des Hämocyanins vor, deren Mol.-Gew. etwa ein Zehntel des ganzen Teilchens betrug; häufig wurden durch Anteile von noch kleineren Bruchstücken auch niedrigere M-Werte gefunden.
The Effects of Linolenic Acid and Extracts of Ricinus Leaf on System I and System II
Authors: Brody Seymour Steven 
Published: February 2015

The action of extracts of Ricinus communis leaf (RLE) and of linolenic acid (LINO) on System I and System II of corn and spinach chloroplasts were investigated by an amperometric method.
RLE induced a time dependent decrease in the rate of oxygen production by corn chloroplasts (half time about one hour) at low white light intensity (900 ergs/cm2 sec.). At high white light intensity (7 x 103 ergs/cm2 sec.) the maximum value of the oxygen gush, V0, was observed to decrease with time in the presence of RLE; the steady state rate of oxygen production, Vm, also decreased under these conditions. The ratio, V0/Vm, decreased immediately upon addition of RLE, then increased with time. The effect of RLE on System I was much more rapid than on System II. In less than one hour all activity of System I disappeared.
At high white light intensity addition of 1.6 x 10-4 M LINO to spinach chloroplasts induced a time dependent decrease of V0 and increase of Vm. The latter effect is indicative of uncoupling of phosphorylation. The ratio V0/Vm decreased both with time of incubation and concentration of LINO. On the other hand, at concentrations less than 10-4 M, LINO has little effect on System I.
It is concluded that both RLE and LINO may be acting on the reaction center of System II. It appears that RLE contains a fraction that specifically acts to immediately reduce the number of System I reaction centers.