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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 75 (1969), S. 219-232 
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary A modified Gerdien cell was designed, evaluated, and built for measurement of the polar conductivities in clouds. This conductivity dropsonde was attached to a U.S. Weather Bureau, 1680 mHz, radiosonde for telemetry and to measure pressure, temperature, and relative humidity profiles. The combined instruments were ejected from aircraft, and others were released from balloons into the region of interest. Eight flights were made during the 1967 thunderstorm season. Three of these drops were successful in measuring conductivity inside of electrically active clouds. Two fair-weather profiles were measured for comparison purposes, and three of the drops were faulty. These very preliminary results tend to indicate considerable electrical conductivity in thunderclouds. The data are too few to support a strong statement in favor of increased conductivity, but the instruments were sufficiently reliable to prove that the conductivity was not reduced, as is normally assumed, in the clouds investigated.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 3 (1969), S. 198-210 
    ISSN: 1432-0827
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 9 (1967), S. 30-47 
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The combination of pyronin, methyl green, malachite green, crystal violet, and Alcian Blue with a large number of polynucleotides and acidic polysaccharides has been investigated. The “critical electrolyte concentration” approach has been used to provide a measure of affinity between dye and substrate. The interaction of methyl green with DNA, RNA and heparin has been examined spectroscopically. Previously published results are re-examined, and with the new experiments permit consistent interpretations of the specificities of dye binding in terms of modern ideas of nucleic acid and dye structure. All dyestuffs except Alcian Blue bind more strongly to polynucleotides than would be expected if solely electrostatic bonds were present. Pyronin and planar monovalent cationic dyes interact best with polynucleotides in which purine and pyrimidine bases are freely accessible, as in single stranded molecules without extensive secondary structure, such as RNA, denatured DNA, etc. Non-planar triphenylmethane dyes, e.g. methyl green, malachite green etc. bind less strongly to such substrates, but because of their shape they fit well into the secondary structure of native DNA. Tumour RNA and DNA did not differ from “normal” RNA and DNA. By varying the electrolyte concentration, pyronin-methyl green selectivity e.g. for DNA or RNA, can be controlled, and non-nucleotide staining suppressed. The relevance of the new interpretation to the ribonuclease-pyronin technique is discussed.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 14 (1968), S. 215-220 
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. The intense negative electrostatic field of acid polysaccharides excludes negatively charged periodate ions from the domain of the polysaccharide, thus reducing rates of oxidation. This effect is suppressed by adding salt (0.2 M sodium perchlorate). There is a consequent increase in oxidation rates. Polymer charge due to weakly acidic groups (-COOH) is greatly reduced in periodic acid (〈 pH 3), and oxidation in periodic acid is faster than in equivalent concentrations of sodium periodate (〉pH 5). Oxidations of uncharged polysaccharides are largely unaffected by changes in salt concentration or pH. 2. The periodate oxidation of hyaluronate and heparin, although considerably increased by the addition of 0.2 M sodium perchlorate, is still slow or very slow in comparison with that of dextran and polygalacturonate. The C2–C3 glycol group of the uronic acid portion is primarily the target for oxidation. 3. Comparison of oxidation rates of polyanions are better carried out in the presence of added salt, to reduce the non-specific effects of the electrostatic fields.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 19 (1969), S. 295-301 
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. A two-step PAS method for acid mucopolysaccharides containing 1∶4 linked uronio acid (e.g. chondroitin sulphate) is described. A primary oxidation with sodium periodate oxidises rapidly reacting substrates. The aldehydes are reduced with aqueous sodium borohydride to Schiff-negative materials. A secondary, longer, oxidation step produces aldehyde from the slowly reacting acid mucopolysaccharides, which are demonstrated with Schiff. 2. The distribution of stain in the two-step PAS method in rabbit liver, human lung and nasal septal cartilage is as predicted from model experiments. 3. This, the first chemical method for localising acid mucopolysaccharides, is compared with “critical electrolyte concentration” techniques using Alcian blue for the same purposes. Preliminary data presented here show that both sets of results are compatible.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 19 (1969), S. 155-161 
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Chondroitin sulphates “A”, “B” and “C”, mucous and lung heparins, hyaluronates from four sources, and seaweed and plant polyuronides have been oxidised by periodate. The reaction is slow but specific for the uronic acid moiety. 2. Comparisons of oxidation rates in aqueous medium containing 0.2 M sodium perchlorate (to swamp the electrostatic field effect) show that polymer-bound L-uronic acids (iduronic and guluronic) are more quickly oxidised than their D-analogues (glucuronic and mannuronic). 3. The development of a new PAS method, relatively specific for uronic-acid containing mucopolysaccharides, is discussed.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 5 (1965), S. 221-233 
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The application of the “critical electrolyte concentration” (CEC) concept to the differentiation of acidic glycosaminglycans (mucopolysaccharides) is described. Alcian Blue 8GX stains with increasing selectivity as increasing amounts of magnesium chloride are incorporated into the dye solution. Model experiments with pure polyanions, or artifically carboxylated, phosphorylated and sulphated liver sections, showed that binding of dye to carboxylate or phosphate groups ceased at low electrolyte concentrations (〈 0.3M) whereas dye continued to be held by sulphate ester groups at concentrations five to ten times as high. The similarity to the well established cetylpyridinium system for polyanion fractionation is discussed. Sections of tissues chosen to contain predominantly or characteristically carboxylated mucins, and/or sulphate ester polyanions showed a staining pattern entirely similar to the model sections. Goblet cell mucin in rat ileum stained at 〈 0.4M MgCl2, Cartilage at 〈 0.6M MgCl2, mast cells at 〈 0.75M, and corneal stroma at 〈 1.0M. These results are in agreement with the known contents of sialo-mucin, chondroitin sulphate, heparin and keratansulphate, respectively. The conditions in which this principle can be used in a practical technique are described.
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  • 8
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Zusammenfassung Es wurde ein Verfahren zur Bestimmung der Ligninverteilung in der Holzzellwand entwickelt, das sich der Ultraviolett-Mikroskopie bedient. Das beschriebene Verfahren beinhaltet einige wichtige Fortschritte genenüber früheren Anwendungen der UV-Mikroskopie beim Studium der Ligninverteilung. Wie für die Elektronenmikroskopie müssen durch Schnitttechnik und Probenpräparation ultradünne Querschnitte der untersuchten Hölzer angefertigt werden. Die Proben werden dann in monochromatischem UV-Licht durchmustert unter Verwendung wendung eines Quarzreflektors. Das mikroskopische Bild wird photographisch festgehalten und das Negativ anschließend einer densiometrischen Analyse unterworfen. Jede Stufe dieses Untersuchungsverfahrens wurde kritisch untersucht, um Gültigkeit und Grenzen des Verfahrens festzulegen. Das Verfahren eignet sich in idealer Weise zur Untersuchung der Herauslösung von Lignin aus der Holzzellwand während des Kochprozesses; es dürfte darüber hinaus andere wichtige Anwendungsmöglichkeiten in der Holzforschung besitzen.
    Notes: Abstract A method has been developed for the determination of lignin distribution in the wood cell wall by ultraviolet microscopy. The method incorporates some important advances on previus applications of UV microscopy to the study of lignin distribution. Ultrathin cross-sections of wood are obtained by the sample preparation and sectioning techniques of electron microscopy. The specimens are examined in monochromatic ultraviolet light using quartz reflection optics. The microscope image is photographically recorded and the negative is subsequently subjected to densitometric analysis. Each stage of the analytical procedure has been critically assessed to determine its validity and limitations. The method is ideally suited to the study of the removal of lignin from the wood cell wall during cooking and possesses other important applications in wood technology.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Wood science and technology 3 (1969), S. 117-138 
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Zusammenfassung Die Verteilung des Lignins in Fichtenholz wurde quantitativ durch Untersuchung von 0,5 μm dicken Querschnitten unter dem UV-Mikroskop bestimmt. Die mittlere Ligninkonzentration war in der Mittelschicht etwa doppelt so hoch wie in der Sekundärwand. Die Ligninkonzentration der Mittelschicht war in den an die Tracheiden anstoßenden Zellecken annähernd viermal höher als in der Sekundärwand, wogegen das Volumen der Sekundärwand wesentlich größer war als das der Mittelschicht. Dagegen befand sich beim Frühholz 72% des gesamten Lignins in der Sekundärwand und nur 28% fanden sich in der Mittelschicht selbst und in ihren Zelleckbereichen. Die entsprechenden Werte für Spätholz betragen 82% bzw. 18%. Die Anwendung von schrägen Längsschnitten von 0,1 μm Dicke erlaubte die Auflösung der Mittelschicht. Die Ligninkonzentration in der Mittllamelle war gleich groß wie in der in den Zellzwickeln befindlichen Mittellamelle und der Ligningehalt der Primärwand war etwa doppelt so groß wie derjenige in der Sekundärwand.
    Notes: Abstract The distribution of lignin in black spruce has been determined quantitatively by the study of 0.5 μm transverse sections in a UV microscope. The average lignin concentration in the compound middle lamella was about twice that in the secondary wall. The lignin concentration of the middle lamella at the cell corners of adjacent tracheids was nearly four times that in the secondary wall but the volume of the secondary wall was much greater than the volume of the middle lamella. Thus, for earlywood, 72% of the total lignin was in the secondary wall leaving only 28% in the compound middle lamella and cell corner middle lamella regions. The corresponding values for latewood were 82% and 18% respectively. Use of oblique longitudinal sections of 0.1 μm thick permitted the resolution of the compound middle lamella. The lignin concentration in the true middle lamella was found to be equal to that in the cell corner middle lamella and the primary wall lignin content to be about twice that in the secondary wall.
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  • 10
    Publication Date: 1969-12-01
    Print ISSN: 0018-2222
    Electronic ISSN: 1432-119X
    Topics: Biology , Medicine
    Published by Springer
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