ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Control of light polarization in InGaAsP/InP lasers by injection of light pulses (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 2064-2069 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Light emission from a ridge waveguide 1.3 μm InGaAsP/InP semiconductor laser pumped both electrically and optically was analyzed by polarization- and time-resolved measurements. The electric and the optical excitation was realized with a dc-bias current and with 150 ps pulses from a Q-switched Nd-YAG laser at 1.064 μm wavelength, respectively. The pump light was introduced into the InGaAsP/InP laser through a window opened in the substrate gold contact. The steady-state P–I characteristics of the semiconductor laser exhibited a transition from TM- to TE-polarized light emission if the injection current surpasses a certain value that depends on the heatsink temperature. Depending on the dc-bias current and the optical pulse power, a variety of different emission characteristics of the semiconductor laser were observed: pure TE or TM pulsations, in combination with a background cw emission in some cases; simultaneous emission of TE and TM pulses and switching between TM and TE emission states with switching times as short as 30 ps. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.364257
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Connexin 26 mutations in hereditary non-syndromic sensorineural deafness (1997)
    [s.l.] : Macmillan Magazines Ltd
    Nature 387 (1997), S. 80-83 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Initially we studied a caucasian pedigree in which both autosomal dominant palmoplantar keratoderma (PPK, in which there is abnormal callusing of palms and soles) and congenital sensorineuronal ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/387080a0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Detection and identification of individual antigen molecules in human serum with pulsed semiconductor lasers (1997)
    Springer
    Applied physics 65 (1997), S. 427-431 
    Details
    ISSN: 1432-0649
    Keywords: PACS: 42.80; 85.30; 878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: -11  M without separation steps.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003400050292
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Prevalence of Trabecular Microcallus Formation in the Vertebral Body and the Femoral Neck (1997)
    Springer
    Calcified tissue international 60 (1997), S. 479 -484 
    Details
    ISSN: 1432-0827
    Keywords: Key words: Trabecular microcallus formation — Vertebra — Femur — Histomorphometry — Bone density — Osteoporosis.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract. Trabecular microcallus formation (TMF) has been described previously in the human vertebra and femur, but the difference in TMF prevalence at these two sites has not been studied and the role of TMF remains controversial. In this study, the 4th lumbar vertebra (L4) and right proximal femur were removed from 27 male and 23 female cadavers. A 2 cm cube cut from the center of L4 and a 1 cm-thick slice cut from the femoral neck were cleaned, defatted, and dried. The apparent density of the L4 cubes was determined as dry weight/bulk bone volume. Using a dissecting microscope at low magnification (4–60×), TMF were identified and counted in both the vertebral and femoral samples. A 8 mm diameter core was then cut from the center of the L4 cubes in the vertical direction, and selected histomorphometric parameters of the core were evaluated with an X-ray microcomputed tomography system (μ-CT). There was a significantly greater prevalence of TMF in vertebral cubes (82%) than in the femoral slices (11%) (P 〈 0.001). TMF prevalence did not differ significantly between males and females, but the mean number of TMF in the vertebra was significantly (P 〈 0.05) greater in females (15.0/vertebra) than in males (7.7/vertebra). In the vertebra, the majority of the observed TMF were in vertical trabeculae. Subjects over 60 years old had a higher TMF prevalence than those under 60 years old (P 〈 0.01). TMF numbers increased with decreasing apparent density (P 〈 0.05), whereas no significant correlations were found between TMF and bone volume (BV/TV), trabecular number (Tb.N), or trabecular thickness (Tb.Th) as assessed by μ-CT. In two fractured vertebra, very few TMFs (2 and 4, respectively) were observed. These results demonstrated that the occurrence of TMF is strongly related to the anatomical site, probably due to differences in the applied loads and the trabecular structure between sites. The results were consistent with the hypothesis that TMF is a mechanism acting to maintain bone strength, but further studies are needed to clarify this important issue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002239900266
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Substrate inhibition under stationary growth conditions – nutristat experiments with Ralstonia eutropha JMP 134 during growth on phenol and 2,4-dichlorophenoxyacetate (1997)
    Springer
    Applied microbiology and biotechnology 48 (1997), S. 648-655 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Ralstonia eutropha (formerly Alcaligenes eutrophus) JMP 134 was continuously grown on phenol and 2,4-dichlorophenoxyacetate at elevated levels of stationary substrate concentration by using the nutristat principle in order to study the physiological impact exerted by these toxic substrates. Growth at stationary concentrations of both the substrates resulted in the reduction of growth efficiency and growth rate. The growth yield data revealed a pronounced dependence on the substrate concentration, and the growth yield increasingly diminished with rising substrate concentration. Inhibition was more pronounced with 2,4-dichlorophenoxyacetate, which reduced the growth yield coefficient by 50% at a substrate concentration of 0.1–0.25 mM. The same effect was obtained with phenol at about 5 mM. The growth rate profile had two distinct phases: after an initially strong reduction, the rate levelled-off at higher substrate concentrations. Standardizing the inhibition profiles, by taking into account the maximum effect after extrapolating the data to zero growth yield, revealed an almost identical pattern with both substrates, indicating some common mechanism. The growth yield data show that an increased amount of energy is required for both growth and maintenance. Homeostatic work was increased by a factor of 8 at 75% inhibition; growth collapsed once this amount of energy was no longer available. The effects are discussed with respect to the properties of these substrates functioning as potential uncouplers of energy conservation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002530051110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Information theory and systematic toxicological analysis in “general unknown” poisoning cases (1997)
    Springer
    Fresenius' journal of analytical chemistry 358 (1997), S. 785-792 
    Details
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract  If qualitative analysis is aimed to detect large, imprecisely confined groups comprising hundreds or thousands of compounds – like during the analysis of questionable poisoning cases without direct hints, the so called “general unknowns”–, the evaluation of the identification certainty becomes equally important like the associated estimation of the necessary information capacity of the analytical procedures to be applied [1–4]. On this basis, the authors have outlined factors, which influence the usable information provided by analytical principles or procedures depending of the number and types (analytical categories, differences and similarities, detectability) of the analytes to be detected or included. A correlation between the usable information (excess or deficiency) and the probability of failing identifications is defined, and the information loss by interfering analytical signals is discussed. The concepts of discrimination power DP, identification power IP, and mean list length MLL [4–7] are associated with these considerations. Examples of analytical tasks in this “general unknown” environment of toxicological analysis are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002160050510
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The use of 29Si NMR to characterize the sol-gel synthesis of cordierite (1997)
    Springer
    Fresenius' journal of analytical chemistry 357 (1997), S. 514-516 
    Details
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract  Cordierite powder was synthesized via different sol-gel procedures. The use of 29Si NMR spectra of all stages beginning from tetraethoxysilane (TEOS) up to final ceramic powder material is discussed. In the early stages of the sol-gel process all oligomeric structure units can be identified. Spectra of the higher condensed sols only allow the quantification of Qn-groups. MAS spectra of gels heated up to 750 °C show no fine structure to be evaluated. Spectra of samples heated to 1250 °C indicate a sluggish disorder-order transformation from hexagonal α-cordierite to orthorhombic cordierite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002160050204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Interindividual variation in the enzymatic 15-keto-reduction of 13,14-dihydro-15-keto-prostaglandin E1 in human liver and in human erythrocytes (1997)
    Springer
    European journal of clinical pharmacology 52 (1997), S. 147-153 
    Details
    ISSN: 1432-1041
    Keywords: Key wordsProstaglandin E1 ; Carbonyl reductase; 13 ; 14-dihydro-15-keto-PGE1 ; 13 ; 14-dihydro-PGE1 ; human ; liver ; erythrocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The therapeutic response to PGE1 is highly variable, and a contribution by variable formation of its active tertiary metabolite PGE0 is in question. Hence, the objective of this study was to assess the person-to-person variation of the reduction of the inactive intermediate metabolite 15-KD PGE1 by human liver and human erythrocytes in forming the active metabolite PGE0. Methods: Source of enzyme was lysed erythrocytes from 29 donors, and a bank of 37 donor livers including specimens from 15 children. Tritium-labelled 13,14-dihydro-15-keto-prostaglandin E1 (15-KD PGE1) was used at low nanomolar concentrations and found to be converted almost exclusively to the more polar compound 13,14-dihydro-prostaglandin E1 (PGE0) by an NADPH-dependent carbonyl reductase. The identity of the product PGE0 was established by comparison of its chromatographic and mass spectral characteristics with authentic PGE0. Results: Lysed erythrocytes had readily measurable enzymatic activity; differences between the preparations from 29 subjects were very small with only a twofold range of variation. In contrast to lysed erythrocytes, intact erythrocytes did not catalyse the reaction so that the erythrocyte activity should be medically immaterial. 15-KD PGE1 15-ketoreductase activity of liver cytosol averaged 61.1 fmol · min−1 · mg−1 protein in preparations from 37 human livers. Individual activities varied over an almost tenfold range, with indications of a non-normal distribution. Kinetic studies of selected specimens showed substantially different Vmax values but indistinguishable k M values, suggesting that the individual variation in 15-KD PGE1 15-ketoreduction is the result of differences in enzyme concentration rather than of structural enzyme variations. The activity in 15 livers from children was significantly lower than in those from adults. Inhibition data suggest that both the liver and the erythrocyte enzymes belong to the class of carbonyl reductases. Conclusions: The variations in hepatic enzyme activity may be expected to affect the transformation of 15-KD PGE1 to the active metabolite PGE0 in vivo. The clinical significance remains to be explored.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002280050264
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Isochorismate hydroxymutase from a cell-suspension culture of Galium mollugo L. (1997)
    Springer
    Planta 202 (1997), S. 206-210 
    Details
    ISSN: 1432-2048
    Keywords: Key words: Anthraquinone biosynthesis ; Galium ; Isochorismate hydroxymutase ; Rubiaceae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. Isochorismate hydroxymutase (i.e. isochorismate synthase, EC 5.4.99.6) was purified from an anthraquinone-producing cell-suspension culture of Galium mollugo L. Although attempts to stabilize the labile enzyme met with little success, a substantial increase in enzyme activity was observed in the presence of glycine betaine (500 mM). Column chromatography on solid supports other than diethylaminoethyl (DEAE)-Sephacel, Phenylsepharose Cl-4B or Cibacron Blue 3G-A did not give active enzyme preparations. In spite of these drawbacks the enzyme was purified 573-fold. Enzyme activity depended strictly on the presence of Mg2+. Kinetic data for chorismate in the forward reaction (K m = 807 μM, V max = 6.2 pkat · mg−1) and for isochorismate in the reverse reaction (K m = 675 μM, V max = 5.9 pkat · mg−1) were determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004250050120
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    facet.materialart.
    Unknown
    Cross sections and analyzing powersAyin the breakup reaction2H(p→,pp)nat 65 MeV: Star configurations (1997)
    American Physical Society
    Details
    Publication Date: 1997-01-01
    Print ISSN: 0556-2813
    Electronic ISSN: 1089-490X
    Topics: Physics
    Published by American Physical Society
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...