bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Exotoxin in Bacillus thuringiensis Cells
Authors: Horská K. , Vanková J, , Šebesta K. 
Published: August 2018

Abstract
The presence of exotoxin in Bacillus thuringiensis was demonstrated and its quantity in the cells determined. The concentration of exotoxin in the producing microorganism is approximately half the concentration of ATP. Exotoxin is produced at such a rate th at the cell excretes 1/5 to 1/4 of its exotoxin content into the medium per minute.
The Role of Electrical and Volume Transport in Heterogeneous Reaction Systems
Authors: Kahrig E. , Beßerdich H. , Brecht E. , Kirstein D. 
Published: August 2018

Abstract
For autocatalysis coupled with diffusion the local periodic concentration profiles are influenced essentially by electrical transport and convection.
When diffusion is negligible for Michaelis-Menten-kinetics equations are given to determine the kinetic parameters Vmax and Km from transport measurements.
Interaction between Cholesterol and Calcium Ions in Solution
Authors: Marfey S. P. , Van Meter R. , Bartlet M. E. 
Published: August 2018

Abstract
Dialysis rates of cholesterol, calcium chloride dihydrate and of their mixture in 90% aqueous dioxane through Visking cellulose membrane were characterized by half-escape times (t½) of 2.2, 1.0 and 10.5 hours, respectively. Slow dialysis rate observed with the mixture was due to complex formation between four molecules of cholesterol and two molecules of calcium chloride dihydrate, molecular weight 1800 to 2000. The association constant for this complex in 90% aqueous dioxane was estimated to be 3.9 × 1014. Rates of dialysis obtained with a natural protein membrane were in the reverse order to those obtained with cellulose membrane. Half-escape times for cholesterol, calcium chloride dihydrate and for their mixture were 0.6, 6.7 and 1.4 hours, respectively. Determinations of milliosmolality of the three solutions by freezing point depression indicated that in the mixture there were fewer osmotically active same molarity, also suggesting formation of the complex which was detected by dialysis experiments.
Synthese einer Partialsequenz aus dem aktiven Zentrum der Streptokokken-Proteinase / Synthesis of a Fragment of the Active Center of the Streptococcal Proteinase (EC 3.4.22.10), VII
Authors: Raschig Andreas , Schneider Friedhelm , Raschig Andreas , Schneider Friedhelm 
Published: August 2018

Abstract
The synthesis of the protected peptides Boc-Ala-Ala-Thr-Gly-ONp, Boc-Ala-Thr-Ala-Thr-Ala-ONB and Boc-Ala-Ala-Thr-Gly-His-Cys(X)-Val-Ala-Thr-Ala-Thr-Ala-ONB [X = p-methoxybenzyl, tertbutylmercapto, tetrahydropyranyl-(2)] is described. These peptides are fragments of an active center sequence of the streptococcal proteinase (EC 3.4.22.10) which contains the essential SH group of the enzyme.
An Improved Assay of UV-induced Thymine-Containing Dimers in Saccharomyces cerevisiae
Authors: Fäth W. W. , Brendel M. 
Published: August 2018

Abstract
The method for assaying thymine-containing dimers in yeast is based on highly efficient ([3H]-deoxythymidine-5′-monophosphate) DNA-specific labelling and employs ascending thin layer chromatography. It allows satisfactory quantitative analysis down to UV-doses of 500 erg/mm2.
The Ionization and Optical Properties of Oxoformycin
Authors: Davies R. J. H. 
Published: August 2018

Abstract
Details are given of the ultraviolet, optical rotatory dispersion and fluorescence spectra of oxoformycin. The pK of formation of the monoanion is 8.6, at 25 °C. As formycin B has the same pK value, the ionization of both compounds is ascribed to dissociation of a proton from N-1. Both the neutral and monoanionic forms of oxoformycin are strongly fluorescent.
In Vitro Transformation of Chicken Bone Marrow Cells with Avian Erythroblastosis Virus
Authors: Graf Thomas 
Published: August 2018

Abstract
An in vitro transformation of bone marrow cells has been demonstrated for two strains of avian erythroblastosis virus (AEV-R and AEV-ES4). The transformed cells were indistinguishable from in vivo transformed erythroblasts in morphology and staining characteristics and could be propagated to large numbers. The transformation efficiency could be greatly increased by the addition of dimethyl-sulfoxide (DMSO). The number of foci appearing in the presence of DMSO was proportional to the virus concentration.
Studies on the Nature of the Primary Reactions of Photosystem II in Photosynthesis I. The Electrochromic 515 nm Absorption Change as an A ppropriate Indicator for the Functional State of the Photochemical Active Centers of System II in DCMU Poisoned Chloroplasts
Authors: Renger G. , Wolff Ch. 
Published: August 2018

Abstract
The field indicating electrochromic 515 nm absorption change has been m easured under different excitation conditions in DCMU poisoned chloroplasts in the presence of benzylviologen as electron acceptor. It has been found :
1. The am plitude of the 515 nm absorption change is nearly completely suppressed under repetitive single turnover flash excitation conditions which kinetically block the back reaction around system II (P. Bennoun, Biochim. Biophys. Acta 216, 357 [1970]).
2. The am plitude of the 515 nm absorption change measured under repetitive single turnover flash excitation conditions which allow the completion of the back reaction during the dark time between the flashes (measuring light beam switched off) amounts in the presence of 2 /um DCMU nearly 50% of the electrochromic 515 nm am plitude obtained in the absence of DCMU. In DCMU poisoned chloroplasts this am plitude is significantly decreased by hydroxylaminhydrochloride, but nearly doubled in the presence of D C IP + ascorbate.
3. The dependence of the 515 nm amplitude on the time t& between the flashes kinetically resembles the back reaction around system II. The time course of the back reaction can be fairly described either by a second order reaction or by a two phase exponential kinetics.
4. 1,3-dinitrobenzene (DNB) or a-bromo-a-benzylmalodinitril (BBMD) reduce the 515 nm am plitude in DCMU poisoned chloroplasts, but seem to influence only slightly the kinetics of the back reaction.
5. The dependence of the 515 nm am plitude on the flash light intensity (the am plitude norm alized to 1 at 100% flash light intensity) is not changed by DNB.
Based on these experimental data it has been concluded that in DCMU poisoned chloroplasts the am plitude of the 515 nm absorption change reflects the functional state of photosystem II centers (designated as photoelectric dipole generators II) under suitable excitation conditions. Furtherm ore, it is inferred th at in DCMU poisoned chloroplasts the photoelectric dipole generators II either cooperate (probably as twin-pairs) or exist in two functionally different forms. With respect to BBMD and DNB it is assumed that these agents transform the photoelectric dipole generators II into powerful nonphotochemical quenchers, which significantly reduce the variable fluorescence in DCMU-poisoned chloroplasts
Absence of Plastocyanin in the Alga Bumilleriopsis and its Replacement by Cytochrome 553
Authors: Kunert Karl-Josef , Böger Peter 
Published: August 2018

Abstract
Different preparative procedures for isolation and purification of plastocyanin were successful to obtain the pure protein from Chlorella vulgaris, Scenedesm us acutus and Spinacia oleracea but not from B um illeriopsis filiform is. Lade of plastocyanin in this alga was further confirmed by the following in comparison with spinach chloroplast material:
a. Use of antibodies to block photosynthetic reactions generally dependent on plastocyanin;
b. epr spectral assessment;
c. treatment of chloroplasts with KCN and amphotericin B ;
d. light-induced changes at 553 nm ( = cytochrome f photooxidation).
The latter assays indicated that, in contrast to spinach, neither plastocyanin nor cytochrome f ( = Cyt 553) is present in sonified or pyridine treated Bumilleriopsis chloroplasts. Photooxidation of (added) cytochrome 553 takes place not only without plastocyanin but is counteracted by the copper protein
Stickstoff-Ausscheidung durch N2-fixierende Blaualgen, II / Nitrogen Excretion by Nitrogen Fixing Blue-green Algae, II
Authors: Pohl P. , Drath G. 
Published: August 2018

Abstract
Wachstum und Stickstoff-Ausscheidung von Anabaena solitaria bei Züchtung in Süß­ wasser bzw. in Mischungen aus Süß-und Seewasser sowie unter Zusatz von Fe, Mn und Mo Nitrogen Excretion by Nitrogen Fixing Blue-green Algae, II Growth and Nitrogen Excretion of Anabaena solitaria Grown in Freshwater and in Mixtures of Freshwater and Seawater, as Well as with Fe, Mn, and Mo Added to the Nutrient Medium Nitrogen Excretion, Nitrogen Fixing Blue-green Algae, Anabaena solitaria, Blue-green Algae The nitrogen fixing blue-green alga, Anabaena solitaria, was grown in freshwater and in mixtures of freshwater and seawater. Freshwater and a 5% mixture (95 volumes of freshwater and 5 volumes of seawater) proved to be most suitable: Growth (as expressed by the formation of chlorophylls; approx. 1.9 u g chlorophyll/ml) was comparatively high. The nitrogen content of the nutrient medium was increased to 750 - 760 //mol N/1. Upon addition of appropriate amounts of FeCl3 , MnCl2 , and Na2MoO4 , the nitrogen content reached 1060 -1080//mol N /1, whereas the chlorophyll formation remained at approximately the same level. Thus Fe, Mn, and Mo appear to have a stimulating effect on nitrogen excretion by Anabaena solitaria. Under the conditions de­ scribed, this organism may be suitable for the mass production of algae.
Gewinnung synchron wachsender und sich vermehrender Hefezellen ( Saccharomyces cerevisiae) / Preparation of Synchronously Growing and Multiplying Yeast Cells (Saccharomyces cerevisiae)
Authors: Braun R , Schmid W , Stossek K 
Published: August 2018

Abstract
From purchasable yeast small cells are preparated by repeated centrifugation. They grow and multiply in a good synchronisation
Conversion of D-Lysine to ʟ-Lysine via L-Pipecolic Acid in Neurospora crassa
Authors: Müller W.-U. , Leistner E. 
Published: August 2018

Abstract
Neurospora crassa, Biosynthesis, ᴅ-Lysine, ʟ-Lysine, Role of ʟ-Pipecolic Acid Neurospora crassa converts ᴅ-lysine to ʟ-pipecolic acid and the latter to ʟ-lysine by a pathway outlined herein and different from mechanisms hitherto known to be involved in interconversions of enantiomers of amino acids.
Die Bedeutung des Substrates bei der Induktion der Tyrosina- Ketoglutarat-Transaminase* in RLC-Zellen / The Importance of the Substrate for the Induction of Tyrosine-α-ketoglutarate- Transam inase in RLC-cells
Authors: Kröger Hans , Donner Ingrid , Voss Herbert , Plötze Gisela 
Published: August 2018

Abstract
1. Dexamethasone phosphate causes approximately a threefold increase of the tyrosine-a-ketoglutarate transaminase in the culture of RLC cells.
2. The induction of the enzyme depends on the presence of L-tyrosine. Omission of L-leucine or L-tryptophan, respectively, has no effect.
3. Omission of L-tyrosine influences the activity of the lactate dehydrogenase and malate dehydrogenase not at all and that of the glucose-6-phosphate-dehydrogenase only to a small extent.
4. In the absence of ʟ-tyrosine an super-induction takes also place by actinomycin
Structure-response Relationships in Noctuid Sex Pheromone Reception An Introductory Report
Authors: Priesner Ernst , Jacobson Martin , Bestmann Hans 
Published: August 2018

Abstract
Pheromones, Olfactory Receptors, Structure-response Relationships, Lepidoptera Electroantennogram (EAG) data reflecting response spectra of male pheromone receptors have been analyzed for 16 species of Noctuidae (Lepidoptera). The test compounds included 100 phero­ mone analogues, altered in chain length, in position and configuration of double bond(s), and in the functional end groups. On comparison of amounts of substance required to elicit an equivalent EAG response, a single compound was determined to be most effective on a given species; these structures, either known or proposed as the natural sex pheromones of the species, were cis-1-dodecen-1-yl acetate, cis-7-tetradecen-1-yl acetate, cts-9-tetradecen-1-yl acetate, Jrarcs-9-tetradecen-1-yl acetate, cis-ll-hexadecen-l-yl acetate, cis-9, trans-12-tetradecadien-l-yl acetate, cis-9-tetradecen-1-yl formate, and cts-9-tetradecen-1-ol, respectively. Elongation (shortening) of the chain by 1 or 2 methylene groups, the movement of a double bond 1 carbon from the optimum, a change to the opposite geometrical isomer, or the introduction of a second double bond invariably reduced EAG responses to 1.8 to 56 times below that observed with the most stimulating compound, in all 16 species. Further alterations in chain length or in double bond position caused even greater reduc­ tion in activity, as did certain changes in end group (Tables I and II).
A set of distinct rules could be derived from these structure-response relationships; one of these rules concerns the optimum position of the double bond(s) in relation to chain length, and another one the ratios in activity values produced by end group variations, irrespective of chain length. The same rules described here for 16 noctuid species held also for the structure-response relationships observed within various additional groups of Lepidoptera.
From EAG values determined in this study, an attempt has been made to calculate physico­ chemical propteries of underlying acceptor structures.
On the Kinetics and Mechanism of Spontaneous Intramolecular Reduction of the Central Metal Ion in K2[Mn(IV)-2-α-hydroxyethyl isochlorin e4] Acetate in Aqueous Alkaline Solutions and its Relation to the Binding Sites of Manganese in Photosynthesis
Authors: Vierke Gerhard , Müller Manfred 
Published: August 2018

Abstract
Spectrophotometric investigation of the kinetics of the spontaneous reduction of the central metal ion in K2[Mn (IV)-2-α-hydroxyethyl-isochlorine e4] acetate in aqueous alkaline solution in the absence of any reducing agent reveals that it is a pseudo-first order reaction which is specifically hydroxide ion catalyzed. The pKα-value of the acid-base equilibrium has been estimated to be 14.4.
Electron transfer to the central metal ion is the rate limiting step. The measurements of its temperature dependence yields an activation enthalpy of ∆H‡ = 12 kcal/mol and an entropy of activation ∆S‡ = - 30 e.u. thus indicating that the electron transfer step is a bimolecular reaction. The most likely reactant is water. The reduction reaction does not take place with appreciable reaction rates at physiological pH. Thus, when bound to a suitable ligand of the chlorin type, Mn (IV)-compounds are sufficiently stable with respect to autoxidation to play some role in biological redox reactions as postulated recently for the photoreactivation process of the water splitting system in photosynthesis.
Kinetic of Lipoquinone and Pigment Synthesis during Red Light-Induced Thylakoid Formation in Etiolated Barley Seedlings
Authors: Grumbach K. H. , Lichtenthaler H. K. 
Published: August 2018

Abstract
Red light induces in etioplasts of dark-grown barley seedlings (H ordeum vulgare L.) parallel to the formation of chlorophyll an increased synthesis of carotenoids, lipophilic benzoquinones and of vitamin K1.
1. Among the carotenoids red light initiates an enhanced synthesis of β-carotene, lutein, violaxanthine and neoxanthine whereas the pools of zeaxanthine and antheraxanthine are decreased.
2. The formation of plastoquinone-9, vitamin K1 and a-tocoquinone is more enhanced than that of a-tocopherol.
3. The red light-induced changes of carotenoid and lipoquinone metabolism are similar in a qualitative sense to those obtained under continuous far-red, white or blue light.
4. In contrast to blue light, red light induces in the first hours of illumination a lower rate of chlorophyll and vitamin K1 formation. There are also differences in the ratios of the individual pigments and lipoquinones throughout the greening period.
The Use of Argentation Chromatography for the Analysis of Fatty Acid Esters of Polyenes: The Structure of Carotenoid Esters of Aglais urticae (Lepidoptera, Insecta)
Authors: Kayser Hartmut 
Published: August 2018

Abstract
Argentation Thin-layer systems for argentation chromatography of fatty-acid esters of carotenoids have been developed. As two-dimensional reversed-phase partition system on paraffine impregnated cellulose this method permits a clear discrimination between saturated and unsaturated fatty acids. By adsorption on silver nitrate containing silica gel-G separation of carotenoid esters according to the degree of unsaturation of their fatty acids was established. With the use of known esters for comparison the fatty acids of whole carotenoid esters can be successfully analysed from minute amounts.
Using these methods the carotenoid esters of pupae of Aglais urticae have been studied. The pupae contain 5.3% β-carotene, 46% lutein diester, 7.8% lutein 3-monoester, 11.7% lutein 3′-mono-ester, and 29.2% unesterified lutein. The fatty acids of the esters are linoleic acid (18:2) and linolenic acid (18:3) only. The diester fraction was composed of 70% dilinolenate, 25% linolenate-linoleate, and 5% dilinoleate. The combined monoesters consisted of 81% linolenate and 19% linoleate. The two main diesters could be isolated in a preparative scale and their structure verified by mass spectrometry.
On the whole, in Aglais pupae 6.2 μg linolenic acid and 1.4 μg linoleic acid are bound to lutein. Since polyunsaturated fatty acids are of dietary origin, and represent essential factors for insect development, it is concluded, that their esterification with carotenoids may be a mode of storage comparable to the formation of glycerides.
ATPase Activity and Light Scattering of Acto-Heavy Meromyosin: Dependence on ATP Concentration and on Ionic Strength
Authors: Dancker Peter 
Published: August 2018

Abstract
1. The dependence on ATP concentration of ATPase activity and light scattering decrease of acto-HMM could be described at very low ionic strength by one hyperbolic adsorption isotherm with a dissociation constant of 3 × 10-6 м. Hence the increase of ATPase activity was paralleled by a decrease in light scattering. At higher values of ionic strength ATPase activity stopped rising before HMM was completely saturated with ATP. Higher ionic strength prevented ATPase activity from further increasing when the rigor links (links between actin and nucleotide-free m yosin), which have formerly protected the ATPase against the suppressing action of higher ionic strength, have fallen below a certain amount. This protecting influence of rigor links did not require tropo-myosin-troponin.
2. For complete activation of ATPase activity by actin less actin was needed when HMM was incompletely saturated with ATP than when it was completely saturated with ATP.
3. The apparent affinity of ATP to regulated acto-HMM (which contained tropomyosin-troponin) was lower than to unregulated acto-HMM (which was devoid of tropomyosin-troponin). In the presence of rigor complexes (indicated by an incomplete decrease of light scattering) the ATPase activity of regulated acto-HMM was higher than that of unregulated acto-HMM. At increasing ATP concentrations the ATPase activity of regulated acto-HMM stopped rising at a similar degree of saturation with ATP as the ATPase activity of unregulated acto-HMM at the same ionic strength. Introduction
A Study of the Neurohumoral Control of Glycolysis in the Mouse Brain in vivo: Role of Noradrenaline and Dopamine
Authors: Leonard B. E. 
Published: August 2018

Abstract
Noradrenaline, Dopamine, Glycolysis, Adenyl Cyclase Intraventricularly injected noradrenaline, dopamine and isoprenaline increased glycolysis as shown by the decrease in the concentration of “free” glycogen and increase in the concentration of lactate.
The effects of noradrenaline and isoprenaline were reduced in mice which had been pretreated with α-methyl-p-tyrosine. ʟᴅ-Propranolol blocked the increase in glycolysis caused by noradrenaline, isoprenaline, sodium fluoride and analogues of 3,5-cyclic adenosine monophosphate.
It is suggested that the results of this investigation can be explained by the various drugs and neurohormones acting on the adenyl cyclase system in vivo, either by blocking the action of the neurohormone on the membrane bound enzyme or monophosphate on glycolysis.
Computer Simulation of Primary Photosynthetic Reactions — Compared with Experimental Results on O2-Exchange and Chlorophyll Fluorescence of Green Plants
Authors: Holzapfel Christian , Bauer Robert 
Published: August 2018

Abstract
A computer model describing the “Z-scheme” of photosynthetic electron transport in terms of reduction and oxydation of coupled redox pools was built up. Starting from a certain initial state corresponding to the dark adapted state of the photosynthetic system the reduction and reoxidation levels of the pools were calculated during adaptation of the system to a steady state in the light. The changes of calculated redox levels were compared with experimental results of fluorescence and oxygen evolution induction curves. It is shown that the transients in prompt fluorescence and oxygen evolution can be described by reduction and reoxidation of the primary electron acceptor pool and the electron donor pool of photosystem II due to reduction and oxidation of the other pools during adaptation to light. The first depression D in the fluorescence induction curve is explained by the existence of a redox pool X between the primary electron acceptor pool Q of photosystem II and plastoquinone. It is shown that DCMU blocks the electron flow between Q and X. Furthermore, it is shown that the inhibitor DBMIB probably not only blocks the electron flow but also causes a successive disconnection of the plastoquinone pool from the electron transport chain.
Damage Caused by Tw o Finnish Mushrooms, Cortinarius speciosissimus and Cortinarius gentilis on the Rat Kidney
Authors: Möttönen M. , Nieminen L. , Heikkilä Heli 
Published: August 2018

The toxicity of two mushroom species found in Finland, Cortinarius speciosissimus and Cortinarius gentilis, on the rat was studied. Dried, homogenized mushroom was given orally by stomach tubing. A dose of 500 mg dried mushroom/kg body weight, was used.
It was demonstrated that both species caused renal damage. No damage could be shown in other organs. The renal histopathological changes corresponded to those of tubulo-interstitial nephritis. The sensitivity of different individuals to the fungal toxins varied greatly.
Chromosomale Strukturen von Pseudomonas testosteroni. I. Isolierung und Charakterisierung der chromosomalen Komplexe / Chromosomal Structures of Pseudomonas testosteroni. I. Isolation and Characterization of the Chromosomal Complexes
Authors: Reimer Günter , Drahovsky Dusan 
Published: August 2018

Abstract
After lysis of Pseudomonas testosteroni with lysozyme and non-ionic detergents different DNA-protein complexes can be separated in 5 -25% (w/v) neutral sucrose gradient. The protein to DNA ratio of these complexes varies between 0.5-4.5 to 1, whereby the faster sedimenting forms contain more protein than the slower sedimenting ones. Different initial rates of DNase digestion may indicate various degrees of DNA packing in these complexes. The chromosomal complexes of Pseudomonas testosteroni are relatively stable towards pronase. Treatment with RNase or sodium dodecylsulphate is accompanied by a dramatic increase in viscosity and decrease in relative density. It suggests that DNA in these complexes is maintained in its supercoiled form by RNA molecule (s) in a similar way as in isolated chromosome of E. coli.