bluuebunny/crossref_metadata_2025_split huggingface dataset:
RNA Gehalt und Antigeneigenschaften von Polioviren vor und nach Hitzeinaktivierung / RNA Content and Antigenicity of Polioviruses before and after Inactivation by Heating
Authors: Mietens C. , Koschel K. 
Published: February 2015

The question of a possible relationship between the RNA content of poliovirus and its reactivity as N- or H-antigen was examined with double-labeled virus preparations (32P-RNA, 14C-Protein). The following results were obtained: 1. Complete virus particles containing RNA may be N- or H-reactive. 2. Heat inactivation of poliovirus causes dissociation of capsid and RNA. 3. Under certain experimental conditions of thermal inactivation, the N/H conversion preceeds RNase sensitivity of viral RNA.
The results lead to the conclusion that during thermal inactivation N/H conversion is independent of the presence of RNA in the particles and that it preceeds the dissociation of viral RNA and viral capsid.
Der Redoxmechanismus des Systems Folsäure—Dihydrofolsäure— Tetrahydrofolsäure II / The Redox Mechanism of the System Folic Acid — Dihydrofolic Acid—Tetrahydrofolic Acid II
Authors: Kretzschmar Klaus , Jaenicke Walther 
Published: February 2015

The electrochemical behaviour of folic acid, 7,8-dihydrofolic acid, and tetrahydrofolic acid was studied with polarographic, coulometric and spectroscopic methods in the pH range between 1,8 and 11,9.
From the experiments a mechanism is derived which contains the formation of radicals and dimers, and the proton catalyzed reductive and non reductive cleavage of the side chain.
Biosynthesis of 5,6-Dimethylbenzimidazole Precursor-Function of 6,7-Dimethyl-8-ribityllumazine
Authors: Kühnle Hans F. , Renz Paul 
Published: February 2015

6,7-Dimethyl-14C-8-ribityllumazine was added to cell homogenates of Propionibacterium shermanii, previously grown anaerobically in the presence of cobaltous sulfate. This homogenates were shaken under aerobic conditions for 48 hours in order to produce vitamin B12 from the corrinoids formed during the anaerobic growth phase. The vitamin B12 was isolated and its 5,6-dimethylbenzimidazole moiety split off by acid hydrolysis. It was shown that the radioactive label of 6,7-dimethyl-14C-8-ribityllumazine was exclusively localized in the 5,6-dimethylbenzimidazole moiety of the vitamin B12 molecule. The specific radioactivity of the 5,6-dimethylbenzimidazole isolated was 18 per cent of the specific radioactivity of the 6,7-dimethyl-14C-8-ribityllumazine added.
The radioactive 5,6-dimethylbenzimidazole was further degraded in order to determine the radioactivity in the different carbon atoms. It was found that 45 percent of the total radioactivity was localized in the two methyl carbons (C-10+C-11) and 47 percent in carbon atoms 4 + 7 indicating that 5,6-dimethylbenzimidazole had been formed from two molecules of 6,7-dimethyl-8-ribityllumazine.
Stimulierung von Kulturen embryonaler Rattenzellen durch eine Proteinfraktion aus fötalem Kälberserum / Stimulation of Embryonic Rat Cells in Culture by a Protein Fraction Isolated from Fetal Calf Serum
Authors: Hülser Dieter F. , Frank Werner 
Published: February 2015

Normal embryonic rat cells incubated in serum-free medium accumulate in G1-phase of the cell cycle. On addition of a growth-stimulating protein isolated from fetal calf serum they are triggered to proceed through the cycle, and they resume DNA-synthesis 15 to 20 hours later. In this paper it is demonstrated that the surface membrane potential difference (PD) decreases immediately after changing serum-free medium against culture medium containing either calf serum or the isolated serum protein; the original PD is restored 2 to 3 hours later. Serumprotein without growthstimulating activity does not affect the PD.
A permanent rat cell line which grows independently of serum also has been tested. The PD of these cells is not significantly influenced by calf serum.
On the Reaction between Chlorophyll-a, and its Primary Electron Donors in Photosynthesis
Authors: Haehnel W. , Döring G. , Witt H. T. 
Published: February 2015

Electrons produced by Chl-aII in a short flash are finally transfered to Chl-ai after having passed several intermediates. The reaction between Chl-aI and its primary electron donators PD (probably Cyt-f and PC) has been studied by means of high time resolution flash photometry in isolated spinach chloroplasts with the following results:
1. When PD are in the oxidized state, the reduction of Chl-aI
⊕ takes place with the rate limiting reaction time of the electron transport chain (≈ 20 ms).
2. When PD are in the reduced state, the reduction of Chl-aI
⊕ takes place with the reaction times between the PD and Chl-ai. We found two half life times: one of about 200 μs and one of about 10 μs.
The reduced state of PD is realized when weak monitoring light or hvII-preillumination is used.
The two reaction times of ≈ 200 μs and of ≈ 10 µs are interpreted to represent the electron transfers between Cyt-f and Chl-aI and between PC and Chl-aI resp.
Equilibrium constants of the electron transfer from PD to Chl-aI and the arrangement of the intermediates in the electron transport chain are discussed.
Studies on the Biosynthesis of Some Furocoumarins Present in Ruta graveolens
Authors: Caporale G. , Dall’Acqua F. , Capozzi A. , Marciani S. , Crocco R. 
Published: February 2015

The biosynthesis of some furocoumarins present in Ruta graveolens has been studied administering labeled psoralen, xanthotoxin, rutaretin, marmesin and 7-hydroxycoumarin-derivatives.
The results obtained indicate that the biosynthetic pathway involves not only psoralen, but also xanthotoxin and bergapten, by means of methoxylation or demethoxylation reactions.
Moreover results achieved from administering rutaretin demonstrate that this substance is a new very effective natural precursor for xanthotoxin; in a parallel way marmesin is incorporated into psoralen. The reported results indicate that also at the stage of natural 4′,5′-dihydrofurocoumarins intermediates an interconversion can occur.
Finally the essential role of umbelliferone in the biosynthesis of furocoumarins has been confirmed.
Über Bürzeldrüsensekrete von Finkenvögeln
Authors: Jacob Jürgen , Zeman Alfred 
Published: February 2015

The uropygial gland fats of the greenfinch, bullfinch and the linnet are mixtures of ester waxes, composed of 3-methyl-substituted fatty acids and normal and 3-methyl-substituted alkanols. In addition there are found traces of 2-methyl-substituted fatty acids and alkanols. As to the waxes there are close relations between the 9th and 6th family of the 4th suborder within the 32nd order of the natural system.
The simultaneously investigated depot fat of the bullfinch shows no relation to the uropygial gland fat.
Auswertung nmr-spektroskopischer Messungen der Mischassoziation von Nucleosid-Derivaten bei vergleichbaren Konzentrationsverhältnissen / Evaluation of NMR-spectroscopical Results about Co-association of Nucleoside Derivatives in Comparable Concentrations
Authors: Breuer H. , Perkampus H.-H. 
Published: February 2015

In this paper we described a method how to calculate from NMR the association - caused by Η-bonds - of two components. These components may be present in equal concentration and may be partially self-associated.
The may act as Η-donors and acceptors. The method is demonstrated using some nucleoside derivatives as examples.
Untersuchungen über den Kaliumtransport bei Escherichia coli B / Potassium Transport in Escherichia coli B
Authors: Pilwat G. , Zimmermann U. 
Published: February 2015

The stationary intracellular potassium concentration in E. coli B 525 has been studied as a function of the extracellular potassium and sodium concentrations.
The ratio of extracellular to intracellular potassium concentration is shown to be a linear function of the extracellular potassium concentration if the extracellular sodium concentration is low (20 mmoles/l). In the case of high sodium concentration (100 mmoles/l) the ratio is independent of the extracellular potassium concentration if the potassium concentration is below 1,2 mmoles/l.
In order to describe the distribution of potassium uniformly over the whole range of the extracellular potassium and sodium concentrations a carrier system with two sites has to be supposed.
On the Impossibility of an OH-Radical Model for Photosynthetic Water Oxidation / Über die Unmöglichkeit eines OH-Radikalmodells für die photosynthetische Wasseroxidation
Authors: Vierke Gerhard 
Published: February 2015

If it is assumed that the oscillating O2 flash yield sequence of algae and chloroplasts predominantly reflects an inherent property of the O2 evolving system of the photosynthetic apparatus it is shown that the OH-radical model (O2 production by recombination of four OH radicals) is contradictory to the experimental results because it predicts an aperiodic O2 flash yield sequence.
Several experimental facts already known strongly indicate that the OH-radical model is not consistent with the kinetic model for O2 evolution of KOK et al. either.
Effect of Poly I : C-induced Interferon on Herpes Virus Hominis Infection in Vitro and in Vivo
Authors: Munk Klaus , Frick Thomas 
Published: February 2015

In this study the effect of poly I : C-induced interferon on Herpesvirus hominis (HVH) infection in vitro and in vivo was investigated.
The in vitro results revealed a significant effect of interferon on infections of HVH strains of different origin in mouse embryonic cells.
The in vivo experiments performed in the HVH-mouse system indicate that the effective induction of interferon in an aminal increases its resistance to subsequent infection with HVH.
Massenspektrometrische und Emissionsspektroskopische Untersuchungen an Bernstein zur Herkunftsbestimmung
Authors: Eichhoff H. J. , Mischer G. 
Published: February 2015

Amber samples of different provenance have been investigated by electron impact and fieldionisation mass-spectrometry. Whereas electron-impact mass-spectra are not specific enough, fieldionisation spectra enable one to identify amber from Baltic-, Sicilian-, Canadian- and Libanese areas.
Fe, Na, B, Ca, Mn, Al, Ti, Cu, Cr, V and Si could be determined by emission spectroscopy. Baltic amber shows a smaller trace-element content than all other samples investigated. Canadian amber shows a higher manganese content.
UV-Photolyse von 5-Joduracil / UV Photolysis of 5-Iodouracil
Authors: Gilbert E. , Wagner G. , Schulte-Frohlinde D. 
Published: February 2015

UV Photosylis (254 nm) of 5-iodouracil in aqueous, oxygenated solution in presence of KI, FeSO4, KBr and K2SO4 was investigated over a pH-range of 1—6. Uracil, isodialuric acid, and isobarbituric acid were identified as photoproducts.
At a constant pH-value (pH=1) at high KI-concentrations (10-1 mole/1) the main product is uracil. With decreasing KI-concentrations the yield of uracil decreases and isobarbituric acid appears as a photoproduct. On further decreasing KI-concentrations (&lt; 10-2 mole/1) the yield of isobarbituric acid decreases and the formation of isodialuric acid commences.
UV Photolysis of iodouracil at constant KI-concentrations (10—1 mole/1) and increasing pH (pH = 1—6) yields similar results with one exception. At higher pH-values on account of isodialuric acid at least four further compounds are formed. The yield of these products increases with increasing pH value. Addition of KBr and K2SO4 has no effect on the product distribution.
The possible mechanisms for the formation of the reaction products are discussed.
Lokalisierung des Monogalaktosyldiglycerids in Thylakoidmembranen mit serologischen Methoden / Serological Localisation of Monogalactosyl Diglyceride in Thylakoid Membranes
Authors: Radunz Alfons 
Published: February 2015

Immunoglobulins to monogalactosyl diglyceride have been found in antisera to different chloroplast preparations. A specific antiserum to this lipid has been obtained by injection of monogalactosyl diglyceride which was adsorbed onto methylated bovine serum albumin. Inhibition tests with mono- and oligosaccharides, as well as with mono- and digalactosyl glycerol, showed that the immunoglobulin was directed to the β-galactosyl-(1 → 1) -glycerol configuration. Digalactosyl diglyceride and sulphoquinovosyl diglyceride did not react with the antiserum. The immunoglobulin is of the Ig M-type.
The antiserum to monogalactosyl diglyceride agglutinates stroma-freed chloroplasts. Fragments of the thylakoid membrane, obtained by ultrasonication and fractioning centrifugation, thylakoids and thylakoid stacks are all precipitated. In a preparation of stroma-containing chloroplasts agglutination takes place but after rupture of the chloroplast membrane and loss of the stroma. The ultrasonicated lamellar system binds a larger amount of the monogalactosyl diglyceride immunoglobulins than does stroma-freed chloroplasts. It is concluded from these experiments that some of the chloroplasts monogalactosyl diglyceride is located at the surface of the thylakoids.
Zur Strukturchemie ternärer Telluride der Alkali- und Erdalkalimetalle mit den Elementen der 3. Hauptgruppe / On the Structural Chemistry of Ternary Tellurides of Alkali- and Earthalkalimetalls with the Group- (III) -Elements
Authors: Franke Erich R. , Schäfer Herbert 
Published: February 2015

The new compounds SrAl2Te4, SrGa2Te4, SrIn2Te4, BaAl2Te4, BaGa2Te4, BaIn2Te4, Ba7Al6Te16, NaInTe2 and KInTe2 have been prepared by melting together stoichiometric amounts of the elements. All compounds crystallize tetragonal in variants of the TlSe- (B 13) -structure.
SrAl2Te4: α = 8.25 Å, c = 6.72 Å ( ± 0.02 Å)
SrGa2Te4: α = 8.21 Å, c = 6.75 Å ( ± 0.02 Å)
SrIn2Te4: α = 8.27 Å, c = 7.22 Å ( ± 0.02 Å)
BaAl2Te4: α = 8.50 Å, c = 6.72 Å ( ± 0.02 Å)
BaGa2Te4: α = 8.42 Å, c = 6.78 Å ( ± 0.02 Å)
BaIn2Te4: α = 8.44 Å, c = 7.20 Å ( ± 0.02 Å)
NaInTe2: α = 8.33 Å, c = 7.27 Å ( ± 0.02 A)
KInTe2: α = 8.52 Å, c = 7.39 Å ( ± 0.02 A)
Ba7Al6Te16: α = 34.24 Å, c = 6.70 Å ( ± 0.02 Å)
(=4 × 8.57 Å),
Complexes of Bismethyl-imido-triphosphoric-acid-pentakis-dimethyl-amide (TRIPA), a New Tridentate Ligand
Authors: De Bolster M. W. G. , Den Heijer J. , Groeneveld W. L. 
Published: February 2015

A number of new complexes containing TRIPA, chemical formula [ (CH3) 2N]2 P (O) N (CH3)P (O) [N (CH3) 2] N (CH3) P (O) [N (CH3) 2] 2, is reported The compounds have the general formula M (TRIPA) n (anion) p, where M = Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn, Cd (p = 2) and Al, Fe (p = 3), n=1,2 and anion stands for BF4⁻, [B (C6H5)4]⁻, NO3⁻ and Cl⁻. They are characterized and identified by chemical analysis and physical measurements.
It is shown that the bis-compounds contain octahedrally solvated metal ions, the ligand acting as a tridentate phosphoryl donor. Electron paramagnetic resonance measurements show some distortion of the octahedrons. The mono-compounds with the nitrate anion probably possess a fivecoordinated structure whereas the chloride complexes are probably dimeric.
The occurrence of more than one geometric isomer for the group [M (TRIPA) 2] P* is discussed. It is concluded that the s-facial and u-facial isomers may occur; a possible connection with the size of the metal ions is indicated. The mer form is rejected because of steric requirements.
Mesosomen-ähnliche Strukturen im Mycobionten von Lichina pygmaea / Mesosome-like Structures in the Mycobiont of Lichina pygmaea
Authors: Peveling Elisabeth 
Published: February 2015

In the mycobiont of the lichen Lichina pygmaea mesosome-like structures are described which mainly occur in the fungi cells close to the algal layer. These structures consist of numerous irregularly arranged tubuli which are most distinct after fixation with glutaraldehyde at pH 7.0. Using different fixatives at varying pH they tend to visiculate.
In the cytoplasm neighboured to the mesosome-like structures zones of very high contrast appear. They consist of a homogenous and a granular substance. Staining the samples with Best Carmin or treating them with amylase it could be shown that at least the granular component of the darkly stained area represents glycogen.
The function of the mesosome-like structures in glycogen synthesis is discussed.
Schichteinlagerungsverbindungen des Komplex-Carbids Ta.2S2C / Layer Intercalation Compounds of the Complex Carbide Ta2S2C
Authors: Schöllhorn Robert , Weiss Armin 
Published: February 2015

A new series of nonstoichiometric intercalation compounds has been found with the complex carbide Ta2S2C as host lattice. Typical compositions of the new compounds arc Ta2S2C · nY with nY = 0,57 N2H4, 0,26 H3CHNNHCH3, 0,78 n-C8H17NH2, 0,52 C6H11NH2, 0,23 piperidine, 0,26 pyrrolidine, 0,26 dimethylaniline, 0,4, imidazole, 0,39 N-methylimidazole, 0,43 pyrazole, 0,38 pyridine, 0,32 4-methylpyridine, 0,37 2-aminopyridine, 0,40 3-aminopyridine, 0.36 4-aminopyridine, 1,45 HCONH2, 0,41 HCONHCH3, 0,25 (HOCH2)3PO and 0,28(HOCH2)3PO, 0,29 HCONHC2H5,0,26HCON(CH3)2,0,21HCON(C2H5)2,0,70H2NCONH2, 0,19 (H3C)2NCON(CH3)2, 0,46 pyridine-N-oxide, 0,72 2-methylpyridine-N-oxide, 0,39 4-methylpyridine-N-oxide, 0,91 (CH3)2SO, 0,64 (CH3)3PO, 0.23 hexamethylphosphortriamide.
These intercalation compounds resemble those obtained with transition metal dichalcogenides, e.g. TaS2,the basal spacings being about 2,6-2,8 Å higher than in the latter ones. The observed increment of 2,7 Å confirms the proposed structuref or the host lattice with S Ta C Ta S-sandwich layers.
Isomerisierung und Hydrolyse biozider cyclischer Sulfitester-Endosulfan und 10.10-Dihydro-Endosulfan / Isomerisation and Hydrolysis of Biocidal Cyclic Sulfurous Acid Esters-Endosulfan and 10,10-Dihydro-endosulfan
Authors: Schlüter Horst , Ballschmiter Karlheinz 
Published: February 2015

Two isomeric 10,10-dihydro-endosulfans are isolated, and their configurations are determined by means of infrared and nuclear magnetic resonance spectra.
The isomerisation of the sulfurous ester ring of 10,10-dihydro-endosulfan yields a 67/33 ratio for the α/β isomers, while the endosulfan gives a 45/55 ratio.
Both the 10,10-dihydro-endosulfans prove to be less easily hydrolised than endosulfan.
A high‐resolution genomic analysis of multidrug‐resistant hospital outbreaks of Klebsiella pneumoniae
Authors: Chung The Hao , Karkey Abhilasha , Pham Thanh Duy , Boinett Christine J , Cain Amy K , Ellington Matthew , Baker Kate S , Dongol Sabina , Thompson Corinne , Harris Simon R , Jombart Thibaut , Le Thi Phuong Tu , Tran Do Hoang Nhu , Ha Thanh Tuyen , Shretha Shrijana , Joshi Suchita , Basnyat Buddha , Thwaites Guy , Thomson Nicholas R , Rabaa Maia A , Baker Stephen 
Published: February 2015

AbstractMultidrug‐resistant (MDR) Klebsiella pneumoniae has become a leading cause of nosocomial infections worldwide. Despite its prominence, little is known about the genetic diversity of K. pneumoniae in resource‐poor hospital settings. Through whole‐genome sequencing (WGS), we reconstructed an outbreak of MDR K. pneumoniae occurring on high‐dependency wards in a hospital in Kathmandu during 2012 with a case‐fatality rate of 75%. The WGS analysis permitted the identification of two MDR K. pneumoniae lineages causing distinct outbreaks within the complex endemic K. pneumoniae. Using phylogenetic reconstruction and lineage‐specific PCR, our data predicted a scenario in which K. pneumoniae, circulating for 6 months before the outbreak, underwent a series of ward‐specific clonal expansions after the acquisition of genes facilitating virulence and MDR. We suggest that the early detection of a specific NDM‐1 containing lineage in 2011 would have alerted the high‐dependency ward staff to intervene. We argue that some form of real‐time genetic characterisation, alongside clade‐specific PCR during an outbreak, should be factored into future healthcare infection control practices in both high‐ and low‐income settings.
Soft Shoulders Ahead: Spurious Signatures of Soft and Partial Selective Sweeps Result from Linked Hard Sweeps
Authors: Schrider Daniel R , Mendes Fábio K , Hahn Matthew W , Kern Andrew D 
Published: February 2015

AbstractCharacterizing the nature of the adaptive process at the genetic level is a central goal for population genetics. In particular, we know little about the sources of adaptive substitution or about the number of adaptive variants currently segregating in nature. Historically, population geneticists have focused attention on the hard-sweep model of adaptation in which a de novo beneficial mutation arises and rapidly fixes in a population. Recently more attention has been given to soft-sweep models, in which alleles that were previously neutral, or nearly so, drift until such a time as the environment shifts and their selection coefficient changes to become beneficial. It remains an active and difficult problem, however, to tease apart the telltale signatures of hard vs. soft sweeps in genomic polymorphism data. Through extensive simulations of hard- and soft-sweep models, here we show that indeed the two might not be separable through the use of simple summary statistics. In particular, it seems that recombination in regions linked to, but distant from, sites of hard sweeps can create patterns of polymorphism that closely mirror what is expected to be found near soft sweeps. We find that a very similar situation arises when using haplotype-based statistics that are aimed at detecting partial or ongoing selective sweeps, such that it is difficult to distinguish the shoulder of a hard sweep from the center of a partial sweep. While knowing the location of the selected site mitigates this problem slightly, we show that stochasticity in signatures of natural selection will frequently cause the signal to reach its zenith far from this site and that this effect is more severe for soft sweeps; thus inferences of the target as well as the mode of positive selection may be inaccurate. In addition, both the time since a sweep ends and biologically realistic levels of allelic gene conversion lead to errors in the classification and identification of selective sweeps. This general problem of “soft shoulders” underscores the difficulty in differentiating soft and partial sweeps from hard-sweep scenarios in molecular population genomics data. The soft-shoulder effect also implies that the more common hard sweeps have been in recent evolutionary history, the more prevalent spurious signatures of soft or partial sweeps may appear in some genome-wide scans.