Bibliothek

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
  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 6610-6613 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: An analysis of the nonexponential behavior of the kinetics of the initial laser level for three-micron generation (4I11/2) in an Er3+(45 at. %):YAlO3 crystal under intense pump in the 4S3/2 level is performed. The observed nonexponential 4I11/2 decay can be satisfactorily described by the rate equation model which includes energy transfer processes inside the system of erbium ions, such as up-conversion from 4I13/2 and 4I11/2 and cross-relaxation from 4S3/2 and 4I9/2 provided only a small fraction (β21≈0.11) of the excitation from 4I11/2 level reaches the terminal laser level, 4I13/2. The low value of β21 and the observed reduction of the fluorescent lifetime of 4I11/2 with the increasing erbium doping could be related to the presence of accidental impurities. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 65 (1994), S. 73-75 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The integrated photoluminescence (PL) intensities of both ordered and disordered epilayers of InGaP grown on GaAs have been measured as a function of temperature. The highest PL efficiency occurs in the most disordered sample. We find that the PL intensities can drop from 2 to almost 4 orders of magnitude between 12 and 280 K. The samples show an Arrhenius behavior characterized by two activation energies. Below 100 K the activation energies lie in the region of 10–20 meV. Above 100 K the activation energy is approximately 50 meV except in the most disordered sample where it increases to 260 meV. We conclude that the low-temperature PL efficiency is most likely controlled by carrier thermalization from spatial fluctuations of the band edges followed by nonradiative recombination. At higher temperatures the PL efficiency is dominated by a nonradiative path whose characteristic activation energy and transition probability depend upon the degree of sublattice ordering.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    The @journal of organic chemistry 55 (1990), S. 6223-6225 
    ISSN: 1520-6904
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    Berkeley, Calif. : Berkeley Electronic Press (now: De Gruyter)
    The @B.E. journal of economic analysis & policy 7.2007, 1, art65 
    ISSN: 1555-0494
    Quelle: Berkeley Electronic Press Academic Journals
    Thema: Wirtschaftswissenschaften
    Notizen: Beef food safety events have contributed to considerable market volatility, produced varied consumer reactions, created policy debates, sparked heated trade disputes, and generally contributed to beef industry frustrations. Utilizing data from a total of 4,005 consumers in the United States, Canada, Mexico and Japan in a Double-Hurdle modeling framework, we examine whether consumers altered their beef consumption behavior because of their risk aversion and risk perceptions stemming from information about beef food safety in recent years. Results reveal stark differences in risk perceptions and risk aversion regarding beef food safety across consumers in the four countries and that these differences are revealed through different beef consumption behavior. An improved understanding of food safety perceptions and attitudes will enable policy makers and agricultural industries to better anticipate consumers changing consumption behavior, if a food safety event occurs. Food safety management strategies vary across countries because of identified differences in food safety risk attitudes and risk perceptions.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    ISSN: 1432-0843
    Schlagwort(e): Key words Aplidine ; Didemnin B ; Isohomohalichondrin B (IHB) ; Neurocytotoxicity ; Cytotoxicity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Purpose: New classes of anticancer drugs, isolated from marine organisms, have been shown to possess cytotoxic activity against multiple tumor types. Aplidine, didemnin B, and isohomohalichondrin B (IHB), among the more promising antitumor candidates, have been evaluated in the present study on a comparative basis in terms of their antiproliferative activity and neurotoxic effects in vitro. Methods: Using a panel of different human, prostatic cancer cell lines (DU 145, PC-3 and LNCaP-FGC) the effects of Aplidine, didemnin B, and IHB on tumor cell proliferation were tested in a colorimetric (XTT) assay and compared with the effects of vincristine, vinorelbine, and Taxol. Under analogous in vitro conditions these drugs were also monitored for neurocytotoxic effects using a PC 12 cell line based model. Results: Didemnin B and – especially – Aplidine were more effective in the inhibition of prostate cancer cell proliferation than vincristine, vinorelbine or Taxol at concentration levels between 5 and 50 pmol/ml. At these same concentrations, however, Didemnin B and Aplidine were also most potent in the in vitro neurotoxicity assays. IHB was found to exert even more potent antiproliferative activity (at concentration levels between 0.05 and 0.1 pmol/ml). However, neurotoxic effects were also found to be present at these levels. After drug withdrawal, the neurotoxic damage, inflicted by aplidine or IHB appeared to be more long lasting than after vincristine or vinorelbine exposure. Conclusions: These results point to high antiproliferative activity of aplidine and IHB in prostate cancer. At the same time, the data urge some caution in the clinical use of these agents because of potential neurotoxic side-effects. The use of a newly formulated Aplidine may involve a more favorable therapeutic profile.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    Nuclear Instruments and Methods in Physics Research Section A: 236 (1985), S. 359-362 
    ISSN: 0168-9002
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Methods in cell science 12 (1989), S. 57-59 
    ISSN: 1573-0603
    Schlagwort(e): cell culture ; hard microplate ; in vitro bioassay ; organic solvents ; solvent evaporation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A nondisposable, or “hard”, multiwell microplate is described for use with small volumes of biological solutions containing organic solvents. The design of this teflon-coated, aluminum device resembles the 96-well layout of the disposable variety of tissue culture microplates. The reusable, hard microplate has been specifically developed to hold and evaporate volatile organic solvents from aliquots of crude sample extractions or partitions intended for testing in various in vitro biological screening assays. This device is a valuable adjunct for converting numerous small volumes of nonpolar or nonaqueous dissolved compounds into reconstituted solutions containing acceptable assay solvents.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Methods in cell science 12 (1989), S. 63-65 
    ISSN: 1573-0603
    Schlagwort(e): in vitro biological assays ; microplate rack ; 96-well microplate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A microplate rack has been designed for use with in vitro biological assays. The microplate rack can hold up to 15, 96-well microplates and easily fits into most incubator chambers. Placement and retrieval of large numbers of microplates is convenient and quick. Incubation conditions(e.g. temperature and gas diffusion) surrounding microplates arranged in the rack are more uniform than when microplates are stacked directly atop one another. Moreover, the incubator environment is disturbed less by virtue of the efficient quick entry and access afforded by the rack design.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Methods in cell science 12 (1989), S. 61-62 
    ISSN: 1573-0603
    Schlagwort(e): adjustable platform angles ; cell culture ; microplate platform
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary An adjustable platform has been designed to facilitate the addition of biological assay components to a multiwell microplate. Nonmanifold additions of liquid components to microplate wells are made especially easy by using this device. The microplate platform can accommodate any of the common formats of disposable microplates. Moreover, it can be adjusted to varying angles allowing the investigator to view into all the wells as assay components are being added.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Skeletal radiology 18 (1989), S. 29-31 
    ISSN: 1432-2161
    Schlagwort(e): Hip, arthrography ; Hip, computed tomography ; Hip, dislocation ; Hip, injuries
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The newer diagnostic modalities such as computed tomography and magnetic resonance imaging are becoming increasingly used in the evaluation of joint trauma. The combination of computed tomography and arthrography can also be of significant diagnostic value in certain specific situations. In our case report, we describe its use in post-traumatic recurrent hip dislocation and its value, not only in depicting a posterior capsular tear, but also in the diagnosis of an internal joint derangement which may contribute to incongruous reduction of the hip joint.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...