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  • 1
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Streptomyces coelicolor “Müller” DSM3030 excretes a lysozyme comprising both β-1,4-N-acetyl-and β-1,4-N,6-O-diacetyl muramidase activities. The lysozyme is named Cellosyl. Gene libraries have been established using genomic DNA from the wild-type strain, S. coelicolor DSM3030, and from an overproducing mutant, S. coelicolor HP1, which exhibits about a twofold increase in lysozome production. The lysozyme-encoding genes (cel) from both strains were detected by oligodeoxynucleotide hybridization. The nucleotide sequence of the cel genes isolated from both strains was shown to be identical. The different levels of lysozyme production could not be correlated with any mutations at the cel gene locus. The cel gene isolated from the wild-type strain could not be expressed in some other species of Streptomyces. However, self-cloning of the cel gene into S. coelicolor DSM3030 and HP1 resulted in a 2.5-fold increase in lysozyme production.
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  • 2
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Low molecular weight β, 1 → 4-glucans (cellodextrins) are favorably prepared by cleavage of cellulose in liquid hydrogen fluoride at temperatures between -15 and -30°C. This is due to the suppression of the reversion reaction in that low temperature range. Under conditions favorable for reversion the presence of water leads to a competing hydrolysis and lower the average degree of polycondensation. For the preparation of defined O-glycosides from glucose and alcohols, hydrogen fluoride is not suitable as a reaction medium. Under reversion conditions, monohydroxy compounds are inferior in their reactivity to the competing carbohydrate molecules, and polyols like sorbitol furnish mixtures of isomeric glycosides. Gaseous hydrogen fluoride represents a highly suitable agent for the degradation of carbohydrate and lignin containing biomass, such as waste wood, for the purpose of providing fermentation raw material. As a model, lignocellulose was studied and the heat of reaction of the hydrogen fluoride sorption and desorption processes were examined. The practically important desorption value was found to be approximately 870 kJ/kg HF.
    Additional Material: 8 Ill.
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  • 3
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tricyclic Transition Metal Complexes with Ring Systems Containing Silicon: The Structures of Ni(C6H17N5S4Si2) und Co(C4H12N4S4OSi2)Crystals of Ni(C6H17N5S4Si2) 3 b are orthorhombic, space group Pbcn, with a = 10.341, b = 11,650, c = 14.163 Å and Z = 4 and crystals of Co(C4H12N4S4OSia) 4b are monoclinic, space group P21/c, with a = 7.304, b = 17.866, c = 11.805 Å, β = 100.88° and Z = 4. The structures have been determined by an X-ray crystallographic analysis and were refined to R = 0.060 for 3b and 0.114 for 4b. The two almost planar MN3S2 chelate rings per molecule intersect with an angle pf 16.2° in 3 b and 27.0° in 4 b. The six-membered rings containing silicon are puckered in such a way that both molecules exhibit (approximate) C2 symmetry.
    Notes: Der Komplex Ni(C6H17N5S4Si2) 3b kristallisiert in der orthorhombischen Raumgruppe Pbcn mit a = 10.341, b = 11.650, c = 14.163 Å und Z = 4 und der Komplex Co(C4H12N4S4OSi2) 4b kristallisiert in der monoklinen Raumgruppe P21/c mit a = 7.304, b = 17.866, c = 11,805 Å, β= 100.88° und Z = 4. Die Strukturen wurden röntgenographisch bestimmt und bis zu R = 0.060 bzw. 0.114 verfeinert. Die praktisch ebenen MN2S2-Chelatringe bilden Flächenwinkel von 16.2° in 3b und 27.0° in 4b. Die Silicium enthaltenden sechsgliedrigen Ringe sind derart gewellt, daß beide Moleküle die (angenäherte) Eigensymmetrie C2 aufweisen.
    Additional Material: 3 Ill.
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  • 4
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Vibrational Spectra of Mono and Spirocyclic Five-membered Ring Systems with NSiSiN UnitsThe main features of the i.r. and Raman spectra of several derivatives of type I (El = element of groups IVb, Vb, VIb) and of type II (El = Si, Ge, Sn, Ti, Zr) are reported. The stretching vibrations of the skeleton are assigned and discussed. Variation of El causes a shift of nearly all skeletal vibrations.
    Notes: Die IR- und Raman-Spektren einer Reihe von Verbindungen vom Typ I (El = Element der IV., V. oder VI. Hauptgruppe) und Typ II (El = Si, Ge, Sn, Ti, Zr) werden auszugsweise mitgeteilt und hinsichtlich der Skelett-Streckschwingungen zugeordnet und ausgedeutet. Eine Variation von El wirkt sich auf nahezu alle Skelettschwingungen aus. .
    Additional Material: 1 Ill.
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  • 5
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of Silicon-Nitrogen Compounds. CXXX. N.M.R. and I.R. Spectroscopic Investigations on MethylaminosilanesThe attachment of a silicon atom to methylamino groups leads in the pure compounds I to VII to a HNCH coupling constant for the protons of J = 6-7 Hz. A similar effect is also observed in solution, except in CH2Cl2 and CHCl3. The correct assignment of the n.m.r. signals for IV is shown in Fig. 1. I to VII have practically the same basic properties as can be concluded from the invariable shift of the C—D stretching vibration of 35 cm-1 for CDCl3.
    Notes: Die Nachbarschaft von Siliciumatomen zu einer Methylaminogruppe in den Verbindungen I bis VII führt stets zu einer HNCH-Kopplung der Protonen mit J = 6-7 Hz in der reinen Substanz wie meist auch in Lösung, nicht aber mehr in CH2Cl2 und CHCl3. Die einwandfreie Zuordnung der NMR-Signale von IV ergibt sich aus Abb. 1. I-VII besitzen praktisch gleiche Basizität, wie aus der gleichbleibenden Verschiebung von etwa 35 cm-1 der C-D-Streckschwingung im IR-Spektrum von CDCl3 zu erkennen ist.
    Additional Material: 2 Ill.
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  • 6
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Novel Inorganic Ring Systems. XIX. Additional Novel Cyclosilazanes and Cyclosiloxazanes Containing N—N Bonds in the Ring StructureAccording to the reaction paths of Schema 1 the compounds I-XIII have been prepared, confirmed in their constitution (Tab. 1-4) and described in their properties (Tab. 1). The seven membered ringsystem Si3N2O2 of compound X and the eight membered ring system Si4N4 (=SiNSi2NSiN2 of compound XIII have been unknown so far. The properties of the 3 isomeric Si4N4-ringsystems (Schema 2) are compared.
    Notes: Auf den Reaktionswegen des Schema 1 wurden die Verbindungen I-XIII dargestellt, in ihrer Struktur aufgeklärt (Tab. 1-4) und in ihren Eigenschaften beschrieben (Tab. 1). Das in X enthaltene siebengliedrige Ringsystem Si3N2O2 und das achtgliedrige Ringsystem Si4N4 (=SiNSi2NSiN2) der Verbindung XIII warden bisher unbekannt. Die Eigenschaften der 3 isomeren Ringsysteme Si4N4 (Schema 2) werden verglichen.
    Additional Material: 4 Tab.
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  • 7
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Novel Inorganic Ring Systems. XX. Tricyclic Inorganic Ring Systems with Four and Five Different ElementsThe four ring systems D, E, F and G unknown solong, could be synthesized according to Schema 1. Their structure was confirmed by mass, proton resonance, and infrared spectroscopy. The single compounds are characterized by a deep green colour and an unusually high solubility in indifferent organic solvents.
    Notes: Die vier bisher unbekannten Ringsysteme D, E, F und G konnten nach den Angaben des Schema 1 synthetisiert werden. Ihre Struktur wurde durch Massen-, NMR- und IR-Spektren sowie Röntgenstrukturanalysen sichergestellt. Die einzelnen Verbindungen zeichnen sich durch eine tiefgrüne Farbe und ungewöhnlich hohe Löslichkeit in inerten organischen Lösungsmitteln aus.
    Additional Material: 5 Tab.
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  • 8
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of Silicon-Nitrogen Compounds. CXXXI. 1,2-Bis (organylamino) - tetramethyldisilaries and their Transformation into N,N′-Bis (organyl) octamethyltetrasiladiaza-cyclohexanes1,2-Bis(organylamino)disilanes A 1-4 were prepared via equ. 3 by aminolysis of 1,2-dichlorotetramethyldisilane and transformed by three different methods (equ. 7; 8/9 and 10/11) into the N,N′ variied tetrasiladiazacyclohexanes B 2-5. Physical, analytical and structural information can be taken from tables 1-3. The bond increments (N)Si—Si(N) of the EISENLOHR molar refractions MRE were reinvestigated with 24.5 instead of 30.0.
    Notes: Organylaminolyse des 1,2-Dichlortetramethyldisilans führt nach Rk. 3 zu den entsprechenden 1,2-Bis(organylamino)-Derivaten A 1-4. Sie ließen sich auf 3 verschiedenen Wegen (Rkk, 7, 8/9 bzw. 10/11) in die N,N′-variierten Tetrasiladiazacyclohexane B 2-5 überführen. Physikalische, analytische und strukturelle Daten der neu dargestellten Verbindungen finden sich in Tab. 1-3. Das Bindungsinkrement (N)Si-Si(N) für die Molrefraktionen MRE nach EISENLOHR wurde neu bestimmt zu 24,5, bisher 30,0.
    Additional Material: 3 Tab.
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  • 9
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry of Silicon-Nitrogen Compounds. CXXXII. Derivatives of the 1,2,4-Trisila-3,5-diaza-cyclopentane Ring SystemThe derivatives B1-B6 of the title ring system could be prepared for the first time by reaction of 1,2-bis(alkylamino)disilanes (A1, A2) with dihalosilanes (Scheme 1). They were transformed by additional reactions with methanol or amines into B7-B9. The Cl2Si derivative B2 is characterized by an unusual stability against aqueous solutions.
    Notes: Durch Reaktion von Dihalogensilanen mit 1,2-Bis(alkylamino)disilanen (A1, A2) konnten die Derivate B1-B6 des Titelringsystems und durch deren weitere Umsetzung die Verbindungen B7-B9 erstmalig dargestellt werden (Schema 1). B2 zeichnet sich durch eine ungewöhnliche Stabilität gegenüber neutralen wäßrigen Lösungen aus.
    Additional Material: 4 Tab.
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  • 10
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Novel Inorganic Ring Systems. XXIII. Hetero Spirosilazanes with Ge, Sn, and Zr in the Spiral CenterSymmetrical SiN-spiro[4,4]-nonanes of the skeleton composition Si5N4, Si4N4Ge, Si4N4Sn and Si4N4Zr and with the hetero atoms in the spiral center could be prepared for the first time in shape of their permethylated derivatives A1 to E1 via equations (1/2) as well as (3/4/5/6) respectively. They were confirmed in their structure by elemental analysis, proton n.m.r., mass, i.r., and Raman spectra.
    Notes: Symmetrische Silaza-spiro[4,4]-nonane der Gerüsttypen Si5N4, Si4N4Ge, Si4N4Sn und Si4N4Zr und mit den Heteroatomen als spiralen Zentren konnten in Form ihrer permethylierten Derivate A1 bis E1 über die Reaktionswege (1/2) bzw. (3/4/5/6) erstmalig dargestellt und in ihrer Struktur über Elementaranalyse, 1H-NMR, Massen-, IR- und Raman-Spektren eindeutig bestätigt werden.
    Additional Material: 3 Tab.
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