ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Springer  (308)
  • 1995-1999  (294)
  • 1960-1964  (3)
  • 1935-1939  (8)
  • 1920-1924
Sammlung
Schlagwörter
Verlag/Herausgeber
Erscheinungszeitraum
Jahr
  • 1
    Digitale Medien
    Digitale Medien
    Propionyl-CoA carboxylase of Myxococcus xanthus: catalytic properties and function in developing cells (1998)
    Springer
    Archives of microbiology 170 (1998), S. 179-184 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Key wordsMyxococcus xanthus ; Propionyl-CoA ; carboxylase ; Acetyl-CoA carboxylase ; Kinetic constant
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract An acyl-coenzyme A carboxylase that carboxylates acetyl-CoA, butyryl-CoA, propionyl-CoA, and succinyl-CoA was purified from Myxococcus xanthus. Since the enzyme showed maximal rates of carboxylation with propionyl-CoA, the enzyme is thought to be propionyl-CoA carboxylase. The apparent K m values for acetyl-CoA, butyryl-CoA, propionyl-CoA, and succinyl-CoA were found to be 0.2, 0.2, 0.03, and 1.0 mM, respectively. The native enzyme has a molecular mass of 605–615 kDa and is composed of nonidentical subunits (α and β) with molecular masses of 53 and 56 kDa, respectively. The enzyme showed maximal activity at pH 7.0–7.5 and at 25–30°C, and was affected by variation in concentrations of ATP and Mg2+. During development of M. xanthus, the propionyl-CoA carboxylase activity increased gradually, with maximum activity observed during the sporulation stage. Previous work has shown that a propionyl-CoA-carboxylase-deficient mutant of M. xanthus reduces levels of long-chain fatty acids. These results suggest that the propionyl-CoA carboxylase is also responsible for the carboxylation of acetyl-CoA to malonyl-CoA used for the synthesis of long-chain fatty acids during development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002030050631
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Structural study of fucoidan from Cladosiphon okamuranus tokida (1999)
    Springer
    Glycoconjugate journal 16 (1999), S. 19-26 
    Details
    ISSN: 1573-4986
    Schlagwort(e): fucoidan ; sulfated fucan ; seaweed
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract A structural study was carried out on a fucoidan isolated from the brown seaweed Cladosiphon okamuranus. The polysaccharide contained fucose, glucuronic acid and sulfate in a molar ratio of about 6.1 : 1.0 : 2.9. The results of Smith degradation showed that this polysaccharide has a linear backbone of 1→3-linked α-fucopyranose with a half sulfate substitution at the 4-positions, and a portion of the fucose residues was O-acetylated. The data obtained from partial acid hydrolysis, a methylation analysis and NMR spectra indicated that the α-glucuronic acid residue is linked to the 2-positions of the fucose residues, which were not substituted by a sulfate group. These results indicated that the average structure of this fucoidan is as follows: -[(→3Fuc-4(±OSO3-)α1−)5→3[GlcAα1→2]Fucα1−]n−. (Half of each fucose residue was sulfated. One O-acetyl ester was present in every 6 fucose residues.)
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1006945618657
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    facet.materialart.
    Unbekannt
    Single crystals of Dy1-xGdxVO4 for magnetic applications (1998)
    Springer
    Details
    Publikationsdatum: 1998-05-01
    Print ISSN: 0022-2461
    Digitale ISSN: 1573-4803
    Thema: Maschinenbau , Physik
    Publiziert von Springer
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 4
    facet.materialart.
    Unbekannt
    Propionyl-CoA carboxylase of Myxococcus xanthus : catalytic properties and function in developing cells (1998)
    Springer
    Details
    Publikationsdatum: 1998-08-03
    Print ISSN: 0302-8933
    Digitale ISSN: 1432-072X
    Thema: Biologie
    Publiziert von Springer
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 5
    Digitale Medien
    Digitale Medien
    Synthesis of polymers bearing azo-dye chromophore with photocrosslinkable moiety for nonlinear optics (1996)
    Springer
    Polymer bulletin 36 (1996), S. 407-414 
    Details
    ISSN: 1436-2449
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Summary Novel photocrosslinkable second-order nonlinear optical(NLO) polymers were synthesized from radical homopolymerization of 4-[N-ethyl-N-(2-methacryloyloxyethyl)]amino-4′-(2-cinnamoyloxyethyloxycarbonyl)-2′-nitroazobenzene(MACN) or copolymerization of MACN with 2-(cinnamoxyloxy)ethyl methacrylate(CM), and from polycondensation of 4-[N,N-bis(2-hydroxyethyl)]amino-4′-(2-cinnamoyloxyethyloxycarbonyl)-2′-nitroazobenzene(HACN) with p-phenylenediacyloyl chloride(PD). For the purpose of obtaining an optimized condition of UV irradiation for poling treatment involving photocrosslinking, photoreactivity of these NLO polymer films was investigated. There was observed considerably different photoreaction behavior, especially in photofading of the NLO chromophore, between MACN polymer and HACNPD polycondensate; the latter faded more rapidly than the former. A reason for this phenomenon was considered.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315056
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    High output power operation of 1.3-μm strained MQW lasers with low threshold currents at high temperature (1996)
    Springer
    Optical and quantum electronics 28 (1996), S. 503-511 
    Details
    ISSN: 1572-817X
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Elektrotechnik, Elektronik, Nachrichtentechnik , Physik
    Notizen: Abstract We have investigated the temperature dependencies of the slope efficiency and the threshold current for strained multiquantum well (MQW) lasers as a parameter of the well number. Smaller well numbers mean larger temperature dependencies of the slope efficiency and the threshold current, while larger well numbers mean larger internal loss and broadening of the photoluminescence linewidth of the MQW structure. Furthermore, the change in the slope efficiency with temperature change is related to the change in internal loss. In this work, the 1.3-μm strained MQW laser with a compressive strain of 1.0% and 7 wells shows the highest output power of 6.8 mW for an injection current of 50 mA and the lowest threshold current of 5.5 mA at 85°C, and the lowest variation in output power of 2.0 dB from 25–85°C at injection current of 50 mA.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00943618
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Blue Luminescence from Silicon Nanoparticles Suspended in Organic Liquids (1999)
    Springer
    Journal of cluster science 10 (1999), S. 359-380 
    Details
    ISSN: 1572-8862
    Schlagwort(e): Silicon ; nanoparticles ; luminescence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Physik
    Notizen: Abstract We have prepared several nanometer-sized silicon colloids in organic liquids in the range from 3.7 to 9.8 nm with a constant weight density of 1 mg/ml by a gas evaporation technique. The blue–green luminescent energy was found to be independent of size, in contrast to its intensity and optical absorption, which showed a clear size effect. Special emphasis is placed on the advantage of using a colloidal system: controllability of mass density in a unit volume, isolation of each particle, selection of wide band-gap substances, capability of absolute quantum efficiency, and easy surface modification. As an example of the above advantages, we have determined the absolute quantum yield as a function of size. From the quantum yield thus derived and the proposed model that combines surface as well as volume effects, experimentally obtained parameters such as the diffusion velocity of an electron–hole pair and the initial flight distance of this pair are found to be consistent with those obtained from other data.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1021981714227
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Cu/Ni colloidal dispersions stabilised by calcium and barium stearates for the amination of oxo-alcohols (1996)
    Springer
    Catalysis letters 40 (1996), S. 123-130 
    Details
    ISSN: 1572-879X
    Schlagwort(e): Cu/Ni colloidal dispersion ; barium stearate ; calcium stearate ; protective colloid ; amination of oxo-alcohols ; tertiary amine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Bimetallic Cu/Ni colloidal dispersions (the core catalyst) stabilised by a combination of calcium and barium stearates as protective colloids (catalyst C) showed a remarkable catalytic activity-several times higher than that of the core catalyst stabilised by barium stearate only (catalyst A) for the amination reaction of low reactive oxo-alcohols, having steric hindrance by branched alkyls, with dimethylamine to prepare N,N-dimethyl tertiary amines. Application of the catalyst C for the same amination reaction of dodecyl alcohol could be performed at a lower catalyst concentration of even 100 ppm based on copper at 220° C with a tertiary amine yield of 92% in a three hours' reaction. The reaction mixture containing catalyst C formed a gel at room temperature and formed a stable homogeneous solution with acetone as a polar solvent. It is postulated that water-repellency of calcium stearate and further incorporation of barium stearate as a second promoter yields a doubly stabilised structure for the core catalyst resulting in a remarkable increase in catalytic activity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00807469
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Cellulose/poly(acryloyl morpholine) composites: synthesis by solution coagulation/bulk polymerization and analysis of phase structure (1998)
    Springer
    Cellulose 5 (1998), S. 123-134 
    Details
    ISSN: 1572-882X
    Schlagwort(e): cellulose ; poly(acryloyl morpholine) ; composite ; interpenetrating polymer network
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract Cellulose/poly(acryloyl morpholine) (CELL/PACMO) compo sites were synthesized by bulk polymerization in the gel state of cellulose impregnated with reactive ACMO monomer. The thermal transition behaviour and phase structure of the CELL/PACMO composites obtained in film form were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and solid-state 13C NMR spectroscopy. For compositions rich in PACMO (CELL ≤ 30 wt %), it was revealed by DSC and DMA that the synthesized samples gave a composition-dependent Tg value higher than that of PACMO homopolymer, and the magnitude of the lowering of their dynamic modulus E′ in the glass transition region became extremely small in comparison with the corresponding drop in E′ noted for plain PACMO samples. These observations were interpreted as being due to the development of an interpenetrating polymer network (IPN)-type organization, resulting from successful fixation of an original netw ork structure of cellulose gels into the polymerized bulks. From the measurements of proton spin-lattice relaxation times in the NMR study, the IPN-like composites were estimated to be substantially homogeneous on a scale of a few nanometers. 0969--0239 © 1998 Blackie Academic & Professional
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009224931504
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Lattice path counting andM/M/c queueing systems (1995)
    Springer
    Queueing systems 19 (1995), S. 193-214 
    Details
    ISSN: 1572-9443
    Schlagwort(e): M/M/c queue ; transient solution ; lattice path counting ; depth of path
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik
    Notizen: Abstract We apply the lattice path counting method to the analysis of the transientM/M/c queueing system. A closed-form solution is obtained for the probability of exactlyi arrivals andj departures within a time interval of lengtht in anM/M/c queueing system that is empty at the initial time. The derivation of the probability is based on the counting of paths from the origin to(i,j) on thexy-plane, that have exactly rd x-steps whose depth from the liney=x isd (d=0,1,...,c−1). The closed-form solution has an expression useful for numerical calculation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01148946
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...