bluuebunny/crossref_metadata_2025_split huggingface dataset:
ü . On the Construction of a Phylogenetic Tree
Authors: Tohá J. , Soto M. A. , Pieber M. 
Published: August 2018

Abstract
Phylogenetic Dendrograms, Molecular Evolution For the construction of a phylogenetic tree an algorithm is described. This, allows the correction of the original data and the proper selection, in each step of the process, of the nearest neighbours of a common ancestor.
Distribution of Thioredoxins in Cyanobacteria
Authors: Schmidt Ahlert , s Ursula 
Published: August 2018

Abstract
The presence of thioredoxin was demonstrated in 20 strains of cyanobacteria as well as in one phototrophic bacterium Rhodopseudomonas sulfidophila and in Thiobacillus denitrificans. Thioredoxin activity was not found in Cyanophora paradoxa and in Porphyridium cruentum using the thioredoxin-dependent PAPS-sulfotransferase activity from Synechococcus 6301 as assay system.
Observations on the Chromatin Staining by Aluminium-Hematoxylin
Authors: Stockert Juan C. 
Published: August 2018

Abstract
The staining reaction of chromatin by aluminium -hematoxylin was investigated. Intense staining, which proved dependent on nucleic acid content, was achieved by using either the preformed lake, mordanting followed by hematoxylin, hematoxylin alone or the lake at high ionic strength. Extraction procedures removed aluminium ions from chromatin but the lake was retained. Chromatin fluorescence induced by ethidium bromide and acridine orange was abolished after staining with the lake. Intercalating-like forces are suggested for aluminium -hematoxylin binding to chromatin.
Carotenoids of Rhizobia. III. 2',3'-trans-Dihydroxy-2-nor-β, β-carotene-3,4-dione, a Novel Carotenoid from a Mutant of Rhizobium lupini
Authors: Beyer Peter , Kleinig Hans , Meister Walter , Englert Gerhard 
Published: August 2018

Abstract
Nor-Carotenoid, Rhizobium lupini The mutant strain 1-289 of Rhizobium lupini containes in addition to the normal carotenoid pattern a violet carotenoid whose structure was derived by MS and 270 1H-NMR as 2′,3′-trans-dihydroxy-2-nor-β,β-carotene-3,4-dione. The possible biochemical origin of this compound is dis cussed.
Thioether Formation of Phycocyanobilin: A Model Reaction of Phycocyanin Biosynthesis
Authors: Klein Gerhard , Rüdiger Wolfhart 
Published: August 2018

Abstract
The reaction of phycocyanobilin dim ethylester (1 a) with ethanethiol is studied. The spectral shifts during a slow reaction correspond to the disappearance of the double bonds at the ethylidene group (595 → 580 nm) and at the methine bridge between rings B and C (365 → 395 nm). Chromic acid degradation of the reaction products reveiles that the thiol has been added at the ethylidene double bond yielding two stereoisomers as expected. The reaction is considered as a model reaction for the presumed last step of phycocyanin biosynthesis, namely the formation of the thioether between cysteine residues of the apoprotein and phycocyanobilin.
Circular Dichroism and Ultraviolet Absorbance of Calf Thymus DNA in Presence of CH3HgOH
Authors: Clegg Michael S. , Gruenwedel Dieter W. 
Published: August 2018

Abstract
The changes that one observes upon the addition of CH3HgOH in the circular dichroism spec­trum and ultraviolet absorbance spectrum of native calf thymus DNA, dissolved in buffered (pH 6.8) solutions of Na2SO4 at pNa 2.0, 1.5, 1.0, and 0.0, respectively (pNa = - log [Na+]), are shown to be due to denaturation brought about by the organomercurial interacting with the base moieties of the polymer. The changes are characterized by an extensive shift of both spectra to longer wavelengths, by a decrease of the rotational strength of the long-wavelength positive dichroic absorption band, and by an increase in the UV absorbance at λmax . Both the hyperchromicity Hλ of calf thymus DNA and the normalized decrease of the rotational strength of its long-wavelength positive dichromic band, Ω , display cooperativity when plotted against the methylmercury concentration pM (pM = - log [CH3HgOH]added) at a given salt strength. Rotational strength data, evaluated by integration of the area under the positive and negative dichroic absorption bands, have been tabulated for selected values of pNa and pM. They are compared with data available from the literature. In absence of CH3HgOH, and with varying salt strength, native calf thymus DNA exhibits alterations in the long-wavelength positive dichroic absorption band that are interpreted as representing B → C transitions in agreement with currently held views regarding their origin. Similar salt-induced alterations have been noted in the case of denatured DNA; their meaning in terms of DNA geometry remains unclear at this point in time.
Amanitin Content and Toxicity of Amanita verna Bull
Authors: Seeger Ruth , Stijve Tjakko 
Published: August 2018

Abstract
The α-, β-, and γ-amanitin content of 11 samples of Amanita verna Bull., collected during 1975 - 1978 in Germany and Switzerland, has been determined by high performance thin-layer chromatography (HPTLC) of crude methanolic extracts. The toxicity (i. v. LD50 for mice of defatted, lyophilized, methanolic extracts) of 3 samples has been compared with that of A.phalloides from the same site of collection.
The amanitin content of A. verna ranged from 2250 to 4570 mg/kg dry weight; the fungi contained almost as much β- as α-amanitin, whereas the γ-amanitin content amounted to about 12% of the total amanitin. A. verna contained less amanitin (65% on the average) than A. phalloides from the same collection site, but it was not significantly less toxic, since the phallotoxins contributed to the toxicity of either species in our tests.
Spectroscopic and Thermodynamic Studies of Chlorophyll Containing Monolayers and Vesicles
Authors: Luisetti J. , Möhwald H. , Galla H. J. 
Published: August 2018

Abstract
Absorption and fluorescence experiments on pheophytin and chlorophyll containing lipid bilayer vesicles are reported. Pheophytin aggregates on the vesicles are established from an additional red shifted band (at 695 nm) in the absorption spectrum. These aggregates contain pheophytin in an arrangement with the molecular planes of the porphyrin rings being parallel and cover about 10% of the vesicle surface. The lipid phase dissolves pheophytin up to a molar ratio of 15% above the lipid phase transition. This solubility limit decreases hardly on solidification of the lipid.
For chlorophyll a containing vesicles the aggregates are not observed in the absorption spectrum. The chlorophyll solubility is about equal to that of pheophytin. This suggests that the phase separa­ tion indicated from fluorescence measurements at temperatures below the lipid phase transition does not lead to the formation of strongly bound chlorophyll aggregates.
Presence and Biosynthetic Implications of β, β-Carotene-2-one in the Moth Cerura vinula
Authors: Kayser Hartmut 
Published: August 2018

Abstract
β, β-Carotene-2-one was isolated in minute amounts from Cerura vinula and identified on the basis of spectra, hydride reduction, and chromatography. The implications on the biosynthesis of 2-hydroxylated carotenoids in in sects are discussed.
Verteilung und enzymatische Hypermethylierung invers repetitiver DNA-Sequenzen in verschiedenen Mäuse-und menschlichen Zellen / Distribution and Enzymic Hypermethylation of Inverted DNA Repeats in Different Murine and Human Cells
Authors: Boehm Thomas L. J. , Drahovsky Dusan 
Published: August 2018

Abstract
A specific class of DNA sequences, the inverted repetitive sequences, forms a double-stranded structure within a single linear polynucleotide chain in denatured DNA. The reassociation process is unimolecular and occurs very fast. Quantitative analyses have shown that these sequences com-E rise about 4-5% of the nuclear DNA of various mammalian cells (P815 mouse mastocytoma, Hela, L cells, Raji and Chang cells, and human embryonic hepatocytes) and are interspersed within sequences of other degrees of repetitiveness.
After labeling the cells with L-[Metnyl-3H]methionine and [14C]deoxycytidine, relative rates of enzymic DNA methylation were computed on the basis of 3H and 14C radioactivities found in py­ rimidine residues of the nuclear DNA. The results indicate that DNA of inverted repetitive sequences is methylated to a level about 50% higher than the ordinary repetitive sequences and to about 300% higher than the unique and intermediary sequences.
The biological function of the inverted repeats as well as the role of their enzymic hypermethyl­ ation is unknown.
Evidence for Carbon Monoxide Insensitive Respiration in the Aerobic Nitrogen Fixing Bacteria Azotobacter vinelandii OP and Xanthobacter autotrophicus GZ 29
Authors: Berndt H. , Wölfle D. , Bahl H. , Steinbüchl A. 
Published: August 2018

Abstract
In intact cells of the non-gummy Azotobacter vinelandii OP CO-insensitivity of the respiratory activity increased with decreasing dissolved oxygen tension in the bacterial suspension. Upon changing from low to high aeration conditions the CO-sensitive respiration was restored. Measurement of the oxidative activity of small particles of A. vinelandii OP with NADH , ascorbate-DCPIP and ascorbate-TMPD as substrate in the presence and absence of CO indicated that the CO-insensitive site is probably identical with cytochrome a1, which preferably is reduced by elec­ trons from ascorbate-DCPIP. Small particles of the gum producing A. vinelandii NCIB 8660 appeared to be more sensitive towards CO with ascorbate DCPIP than the non-gummy A. vinelandii OP. In small particles the CO-insensitive DCPIP oxidase was present irrespective of the dissolved oxygen tension during cell growth. In intact cells, however, CO-insensitivity was only expressed at low dissolved oxygen tension when electrons are directed to cytochrome a1/o in the branched re­ spiratory chain. Intact cells of Xanthobacter autotrophicus GZ 29 exhibited a similar CO-insensitive respiration as A. vinelandii OP.
Interactions between Photosynthetic Pigments Bound to Lipid and Protein Particles. Spectroscopic Properties
Authors: Techy Framçoise , Dinant Monique , Aghion Jacques 
Published: August 2018

Abstract
The spectroscopic (visible) properties of pigment-bearing lipid and protein particles extract­ ed from milk show that: 1) chlorophylls a and b bound to separate particles can form aggregates provided their relative concentration is high enough. Neither pheophytin a nor β-carotene, in the same conditions, form observable aggregates. 2) Chlorophylls a and b can co-aggregate when they are bound to the same particles. Pheophytin a as well as β-carotene seem to prevent the aggregation of chlorophyll a. β-carotene has no effect on the aggregation of chlorophyll b.
Untersuchungen zur Wirkung von injiziertem β-Ecdyson auf die Strandkrabbe Carcinus maenasL. / Investigations on the Effects of Injected Ecdysone upon the Green Shore Crab Carcinus maenas L.
Authors: Buchholz F. , Adelung D. 
Published: August 2018

Abstract
In order to accelerate and artificially induce molting, unoperated crabs, crabs without eye-stalks, Y-organ ectomized and Y-organ-and eyestalkless animals were injected with multiple doses of β-ecdysone. Molting itself was not induced in any case, whereas in double operated animals, both destalked and Y-organless, an acceleration of longer duration of molt preparatory processes was achieved. In all other crabs premolt processes were observed to a much lesser extent, and were only short termed.
These findings lead to the conclusion that the Molt Inhibiting Hormone, which is produced in the eyestalks, might not inhibit the action of the Y-organ alone, but acts also onto the peripheral tissues.
Furtheron it is concluded that phases of increased susceptibility to the injected hormone might not exist.
Isoflavonoid Phytoalexins from Leaflets of Dalbergia sericea
Authors: Ingham John L. 
Published: August 2018

Abstract
The fungus-inoculated leaflets of Dalbergia sericea produce several isoflavonoid phytoalexins including the known pterocarpans, medicarpin and maackiain, ana the isoflavan, vestitol. A fourth, previously undescribed, phytoalexin has been identified as 7-methoxy-2′,4′-dihydroxyisoflavan (neovestitol) by comparison with synthetic material.
Radicals Produced in Single Crystals of Thymine Derivatives by UV and X-Rays
Authors: Flossmann Wolfgang , Zehner Herbert , Müller Adolf 
Published: August 2018

Abstract
Single crystals of anhydrous thymine (T), thymine monohydrate (T · H2O), 5,6-dihydrothymine (TH2), 1-methylthymine (mT) and thymidine (dT) were irradiated with X-rays and UV between 77 K and 300 K. Six types of radicals were analyzed by ESR-spectroscopy at 9.5 GHz and 35 GHz after exposure to X-rays. The anion radical occurred only in T · H2O at 77 K, the 4-yl radical only in TH2 at 77 K and the 1-yl radical only in T between 77 K and 300 K. The 6-yl radical was found in T, TH2 and mT. It was converted into the 5-yl radical irreversibly by heat or white light (λ < 600 nm). The 5-yl radical appeared in all compounds at room temperature. The highest thermal stability was found for the 7-yl radical which was present at room temperature in all compounds except TH2.
UV-irradiation (λ = 320 nm) produced radicals only in three crystals (T, TH2, dT). In T the 5-yl radical was found after exposure at 300 K, and two other radicals, 1-yl and 7-yl, at 77 K. Also at 77 K, the 7-yl radical was present in dT and the 5-yl radical in TH2 and dT.
Über eine durch Benzo-und Naphtho[1.3]dioxolcarbonsäuren an Mäusen erzeugbare Krampfwirkung / Spasm-Activity Caused by Interaction of Benzo-and Naphtho-1.3-Dioxole-carboxylic Acids of Mice
Authors: Dallacker Franz , Reichrath Germanus , Schnackers Gerard 
Published: August 2018

Abstract
We describe the preparation of 4,7-dim ethyl-benzo[1,3]dioxole-5-carboxylic acid (7 d), 5,6-dim ethyl-benzo[l,3]dioxole-4-carboxylic acid (14), 6,7-dim ethoxy-benzo[1,4]dioxane-5-carboxylic acid (16), 7,8-dim ethyl-3,4-dihydro-2H -benzo[1,5]dioxepin-6-carboxylic acid (17), and of 8,9-dim ethyl-2,3,4,5-tetrahydro-benzo[l,6]dioxocin-carboxylic acid (18) by reaction of the lithium com - pounds with carbondioxide. For testing the spasm -activity of benzo [1,3] dioxole-5-carboxylic acids (Table I), benzo[1,3]dioxole-4-carboxylic acids (Table II), and of naphtho[1,3]dioxole-carboxylic acids (Table III) these componds were orally given to mice.
Lipid Metabolism of Ehrlich Ascites Tumor Cells Grown in Chemically Defined Albumin Medium
Authors: Teschner Regina , Löffler Monika , Schneider Friedhelm 
Published: August 2018

Abstract
Total lipids of Ehrlich ascites tumor cells grown in nutrient medium supplemented with 1% bovine serum albumin instead of 15% native horse serum and rate of incorporation of [3H] acetate into total lipids are reduced, while the cholesterol content of the cells is higher than of controls grown in normal medium. The lower lipid content of cells cultured in albumin supplemented medium is explained by a lack of exogenous lipids, which are normally taken up from the serum containing nutrient medium. A several fold increase of incorporation of labelled choline and ethanolamine into the phospholipids of the cells grown in the modified medium is observed. We suggest, that the observed stimulation of the incorporation of phospholipid precursors reflects changes in the dynamic state of the membranes produced by serum depletion.
Flash-Induced Electrochromic Band Shifts, is It a Simple Mechanism?
Authors: Symons Marc , Crofts Anthony 
Published: August 2018

Abstract
The flash-induced carotenoid bandshifts have been studied for various strains of both Rho-dopseudomonas sphaeroides and capsulata. A technique for calculating shifts of isobestic points down to 0.05 nm is described. To this end, special attention has been paid to the appropriate correction for reaction center absorbance changes occuring concommitantly with the carotenoid bandshifts. Plots of the wavelength of the isobestic point versus the corresponding absorption changes at the maximum of the difference spectrum have been made, suggesting the existence of different pools of carotenoids. The various pools of carotenoids seem to have different sizes, inducing non-linearities in the plots. In some cases spectral differences of the pools have to be assumed. A possible interpretation of the results would be that each electrogenic span of the electron transport chain is to be associated with its own pool of carotenoids, all the pools behaving in somewhat independant way. We discuss possible difficulties in making those measurements.
Two New Reactions of the Activated Sulfates Adenylylsulfate and 3′-Phosphoadenylylsulfate with Ammonia
Authors: Cooper Bryan P. , Baumgarten Franziska E. , Schmidt Ahlert 
Published: August 2018

Abstract
Two substances, P1 and P2, have been isolated from the ammonium bicarbonate solutions of adenylylsulfate and 3′- phosphoadenylylsulfate, respectively. Using radiochemical, spectroscopic, chromatographic and enzymatic methods it could be shown that P1 was identical to adenosine 5′- monophosphoramidate and that P2 was a closely related phosphorylated derivative of the same substance, namely 3′-phosphoadenosine 5′-monophosphoramidate.
Adenosine Triphosphate Sulfurylase and O-Acetylserin Sulfhydrylase in Photoheterotropically and Heterotrophically Cultured Tobacco Cells
Authors: Bergmann Ludwig , Schwenn Jens-Dirk , Urlaub Herbert 
Published: August 2018

Abstract
Photoheterotrophic and heterotrophic cell suspension cultures of Nicotiana tabacum have been examined for changes in specific activity of ATP-sulfurylase (EC 2.1.1 A) and OAS-sulfhydrylase (EC 4.2.99.8) during growth on different nitrogen sources. During exponential growth the specific activity of ATP-sulfurylase and OAS-sulfhydrylase remained constant and was on the same level in cells with high and with low rates of sulfate assimilation. The specific activity of both enzymes rapidly increased in green photoheterotrophic cells as well as in chloroplast-free heterotrophic cells after the sulfur from the medium had been used up. This increase was reversed when the cells were transfered back to a sulfate supplemented nutrient solution. The changes in enzyme activity due to sulfur depletion seem to indicate a regulatory mechanism for these enzymes.
TMV Inoculation of Tobacco Protoplasts in the Presence of Protoplast Fusion Agents
Authors: Cassells Alan C. , Cocker Frances M. 
Published: August 2018

Abstract
Two methods used to induce protoplast fusion, involving polyethylene glycol (PEG) and high calcium/high pH, respectively, have been investigated in procedures for the inoculation of isolated tobacco protoplasts with TMV. It has been shown that inoculation in the presence of fusion agents involves two stages. Firstly, virus precipitation on to the protoplast surface and secondly, entrapment of virus particles between protoplasts in zones (putatively) of transient protoplast fusion.
Evidence for Uptake of Plamid DNA into Intact Plants (Lemna perpusilla) Proved by an E. coli Transformation Assay
Authors: Frey M. , Rail S. , Roth A. , Hemleben V. 
Published: August 2018

Abstract
The water plant Lemna perpusilla has been incubated with the E. coli plasmids pMB9 and pBR325, respectively. Uptake of plasmids has been shown by subsequent trans­ formation of E. coli cells to tetracycline resistance after treatment with Lemna DNA from plasmid-incubated plants. In 7 out of 15 assays we found stable transformants. From the transformation rate an amount of 10-4 to 10-6 μg plasmid DNA per 10 μg of plant DNA can be calculated.
Dielectrophoretic Rotation in Budding Yeast Cells
Authors: Mischel Maja , Lamprecht Ingolf 
Published: August 2018

Abstract
Rotation of budding yeast cells in an alternating non-uniform electric field of low frequency was investigated. Rotation frequency was found to be proportional to field strength above a threshold, and varied from cell to cell. The threshold is inversely correlated with the moment of inertia of the cells, while the slope of rotation frequency versus field strength increases with the moment. Rotation frequencies varied between 1 and 10 cycles per second. Clear differences between the dielectrophoretic behaviour of living and heat-inactivated yeast cells were observed.
Effects of an Electric Field of Sinusoidal Waves on the Amino Acid Biosynthesis by Azotobacter
Authors: Gonzalez A. Martin , Izquierdo M. T. 
Published: August 2018

Abstract
Electric Field Electric fields of sinusoidal waves have been applied in cultures of Azotobacter vinelandii, with potentials between 0 V and 10 V, intensities from 0 mA to 16 mA and frequencies between 5 Hz and 200 KHz.
The influence of the electric field of sinusoidal waves on the nitrogen fixation on the post­ culture medium composition has a maximum at 5 V, 8 mA and 20 Hz. The rate of synthesis of specific amino acids by Azotobacter depends on the frequency and potential of the electric field applied. The concentration of each amino acid present in the post-culture medium is increased according to the electric field employed and the amino acid biosynthesis in culture medium is activated during the first days of incubation.
Luminescence from Photosystem I at High Temperatures
Authors: Sane P. V. , Desai T. S. , Tatake V. G. 
Published: August 2018

Abstract
The changes in the fluorescence and delayed fluorescence intensity of spinach leaf as affected by temperature were studied. It was observed that the delayed fluorescence showed a maximum at about 45 °C whereas the fluorescence maximum was at about 55 °C. An examination of the emission spectra of delayed fluorescence at different temperatures showed that at higher temperatures the relative emission at 735 nm was increased. It is argued that at higher temperatures the luminescence from photosystem I contributes to delayed fluorescence.
Enzymatische Bildung und Isolierung von 2-Hydroxymuconsäure, ein Metabolit im bakteriellen Abbau des Herbizids Chloridazon / Enzymatic Formation and Isolation of 2-Hydroxymuconic Acid, a Metabolit in the Bacterial Degradation of the Herbicide Chloridazon
Authors: Müller Rudolf , Lingens Franz 
Published: August 2018

Abstract
2-Hydroxymuconic acid, formerly postulated as an in­termediate of the bacterial degradation of chloridazon (5-amino-4-chlor-2-phenyl-2H-pyridazin-3-on), could be isolated after incubation of 5-amino-4-chlor-2-(2,3-dihydroxy-phenyl)-2H-pyridazin-3-on (1) with purified metapyrocate-chase and enriched am idase from chloridazon-degrading bacteria by reversed phase high performance liquid chromatography.
Chemical Synthesis of Tropoyl Coenzyme A
Authors: Gross Georg G. , Koelen Karl J. 
Published: August 2018

Abstract
Tropoyl coenzyme A has been synthesized in good yields via the corresponding N-hydroxysuc-cinimide ester. The UV-spectrum of the purified thioester has an absorption maximum at 257 nm; at this wavelength, a molar extinction coefficient of 19.2 × 106 [cm2 mol-1] has been determined. Upon alkaline hydrolysis of the thioester bond a difference spectrum with Amax at 235 nm (Δe235= 4.8 × 106 [cm2 mol-1]) has been observed. Attempts to prepare 2-phenylmalonyl coenzyme A by the same technique gave negative results.
A Sex Attractant for the European Fir Budworm Moth, Choristoneura murinana
Authors: Priesner Ernst , Bogenschütz Hermann , Am Heinrich 
Published: August 2018

Traps baited with 100 μg (Z)-9-dodecenyl acetate and 10|ig (Z)-ll-tetradecenyl acetate are highly effective in attracting C. murinana males at varying population densities. The attractive mixture was established by electrophysiological and Field screening studies combined with chemical analysis of the female pheromone secretion.
(Z)-9-dodecenyl acetate is a major constituent in washes of pheromone glands of calling C. murinana females. This compound, the first dodecenyl ester pheromone known for a species of the Archipini tribe, is moderately attractive on its own at low doses. Attraction is strongly synergized by 10% (Z)-11-tetradecenyl acetate but is inhibited by small amounts of (Z)-9- tetradecenyl acetate. Each of the three compounds acts upon a separate type of receptor cell in hair sensilla of the male antenna.