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
    Semiclassical model of atomic collisions: Stopping and capture of heavy charged particles and exotic atom formation (2000)
    Springer
    Physics of atomic nuclei 63 (2000), S. 635-641 
    Details
    ISSN: 1063-7788
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The semiclassical approach to modeling atomic collision systems lies between the easy classical model, which is most useful for simple systems in which quantum effects can be neglected, and the full quantum mechanical description, which is generally too difficult for more than simple systems. By adding a mathematical model of quantum-mechanical effects to a classical Hamiltonian, the calculational simplicity of the manybodied classical model can be extended to the quantum realm; the validity of this approach can be measured by the degree to which the semiclassical model can replicate experimental data. Evolving from earlier work by Kirschbaum and Wilets, our model uses momentum-dependent pseudopotentials to exclude particles from quantum mechanically forbidden regions of phase space: a Heisenberg pseudopotential stabilizes the system by preventing atomic electrons from collapsing into the nucleus, while a Pauli pseudopotential holds identical electrons apart in phase space, structuring the electron configuration. This semiclassical model of an atom is then used as a target in collision simulations with a heavy projectile, which is itself treated classically. Collision cross sections are calculated from a series of simulation runs with Monte Carlo target orientations and impact parameters. The model is dialed in to match published experimental proton stopping powers, then applied to other systems of interest. Here, we present stopping and capture cross sections for antiprotons colliding with our semiclassical model of He. Antiproton stopping on He is compared with the results reported recently by the OBELIX group, and initial capture states are discussed in some detail, including a comparison with the quantum-mechanical calculations originally presented by Yamazaki and Ohtsuki and the later paper by Shimamura; among the differences: (1) In our calculations, the angular momentum of captured antiprotons obeys the classical limit l=n, and (2) the angular momentum distribution of our $$He^ + \bar p$$ states extends beyond that of the quantum calculations. It should be emphasized that our calculations are for times much shorter than the metastable lifetimes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.855679
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Responsiveness of cardiac Na+ channels to a site-directed antiserum against the cytosolic linker between domains III and IV and their sensitivity to other modifying agents (1993)
    Springer
    The journal of membrane biology 134 (1993), S. 231-239 
    Details
    ISSN: 1432-1424
    Keywords: Noninactivating cardiac Na+ channels ; Removal of inactivation ; Cardiac Na+ channel protein ; α-subunit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Elementary Na+ currents were recorded in inside-out patches from neonatal rat heart cardiocytes to analyze the influence of a site-directed polyclonal anti-serum against the linker region between the domains III and IV (amino acids 1489–1507 of the cardiac Na+ channel protein) on Na+ channel gating and to test whether this part of the α-subunit may be considered as a target for modifying agents such as the (−)-enantiomer of DPI 201-106. Anti-SLP 1 serum (directed against amino acids 1490–1507) evoked, usually within 10–15 min after cytosolic administration, modified Na+ channel activity. Antiserum-modified Na+ channels retain a single open state but leave, at −60 mV for example, their conducting configuration consistently with an about threefold lower rate than normal Na+ channels. Another outstanding property of noninactivating Na+ channels, enhanced burst activity, may be quite individually pronounced, a surprising result which is difficult to interpret in terms of structure function relations. Removal of inactivation led to an increase of reconstructed peak I Na (indicating a rise in NP o) and changed I Na decay to obey second-order kinetics, i.e., open probability declined slowly but progressively during membrane depolarization. The underlying deactivation process is voltage dependent and responds to a positive voltage shift with a deceleration but may operate even at the same membrane potential with different rates. Iodatemodified Na+ channels exhibit very similar properties including a conserved conductance. They are likewise controlled by an efficient, voltage-dependent deactivation process. Modification by (−)-DPI 201-106 fundamentally contrasts to the influence of anti-SLP 1 serum and the protein reagent iodate since (−)-DPI-modified Na+ channels maintain their open probability for at least 120 msec, i.e., a deactivation process seems lacking. This functional difference suggests that the linker region between the domains III and IV of the α-subunit may not be the only target for (−)-DPI 201-106 and related compounds, if at all.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234504
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Platinum determination in nutrient plants by inductively coupled plasma mass spectrometry with special respect to the hafnium oxide interference (1997)
    Springer
    Fresenius' journal of analytical chemistry 357 (1997), S. 1157-1163 
    Details
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract  Platinum, emitted from automobile exhaust catalysts, is mainly oxidised in a humic soil, as described previously [1]. An experiment with nutrient plants was carried out to elucidate the bioavailability and accumulation of these platinum containing species. The plants [Allium cepa L. (Weiß, Frühling), Rephanus sativus L. (Riesenbutter), Vicia faba L. (Hedin, Herzfreya), Zea mays L. (Delis) and Solanum tuberosum L. (Selma)] were grown under natural conditions. For mass balances all ways of platinum transport into and out of the system were monitored during the growing period. Plants growing in untreated soil took up less than 1% of the platinum naturally present in the soil [0.15±0.11 μg kg-1 (78%)]. Plants growing in soil treated with a platinum containing tunnel dust took up slightly more platinum. The comparison of ICPquadrupole-MS results with those obtained by a double focusing magnetic sector ICP-MS showed a strong dependence of the platinum concentration on the Hf-content in the sample. An evaluation method for the correction of the Hf-influence for ICP-quadrupole-MS is presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002160050323
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Two types of modified cardiac Na+ channels after cytosolic interventions at the α-subunit capable of removing Na+ inactivation (1997)
    Springer
    European biophysics journal 25 (1997), S. 189-200 
    Details
    ISSN: 1432-1017
    Keywords: Key words Single cardiac Na+ channels ; Site-directed antipeptide antibody ; Proteolysis ; Protein reagents ; Calpain ; Stochastic mode switching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract Failure of inactivation is the typical response of voltage-gated Na+ channels to the cytosolic presence of proteolytic enzymes, protein reagents such as N-bromoacetamide (NBA) or iodate, and antibodies directed against the linker between domains III and IV of the α-subunit. The present patch clamp experiments with cardiac Na+ channels aimed to test the hypothesis that these interventions may provoke the occurrence of non-inactivating Na+ channels with distinct kinetic properties. A site-directed polyclonal antibody (anti-SLP2, target sequence 1481–1496 of the cardiac Na+ channel α-subunit) eliminated fast Na+ inactivation to induce burst activity which was accompanied by the occurrence of two open states. A deactivation process terminated channel activity during membrane depolarization proceeding with time constants of close to 40 ms (at –40 mV). NBA-modified and iodate-modified Na+ channels were kinetically indistinguishable from the anti-SLP2-modified type since they likewise deactivate and, thus, attain an only moderate Po of close to 20%. This is fundamentally different from the behaviour of enzymatically-modified Na+ channels: after cytosolic proteolysis with α-chymotrypsin, trypsin or pronase, mean Po during membrane depolarization amounted to approximately 40% because deactivation operated extremely slowly and less efficiently (time constants 100–200 ms at –40 mV, as a minimum) or was virtually non-operating. In-vitro cleavage of the synthetic linker sequence 1481–1496 confirmed that this part of the α-subunit provides a substrate for these peptidases or reactants for NBA but cannot be chemically modified by iodate. This iodate resistance indicates that iodate-modified Na+ channels are based on a structural alteration of still another region which is also involved in Na+ inactivation, besides the linker between domains III and IV of the α-subunit. Endogenous peptidases such as calpain did not affect Na+ inactivation. This stresses the stochastic nature of a kinetic peculiarity of cardiac Na+ channels, mode-switching to a non-inactivating mode.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002490050031
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    External-field-dependent enhancement of internal Coulomb interactions in time-resolved four-wave mixing (1995)
    Springer
    Il nuovo cimento della Società Italiana di Fisica 17 (1995), S. 1355-1358 
    Details
    ISSN: 0392-6737
    Keywords: Time-resolved optical phenomena (including electron-hole drops) ; Optical properties of thin films surfaces, and layer structures (superlattices, heterojunctions and multilayers) ; Electron states in low-dimensional structures (including quantum wells, superlattices, layer structures, and intercalation compounds) ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary We show that a detailed understanding of the influence of the exciton-exciton interaction on the non-linear excitonic response in a GaAs/AlGaAs superlattice can be obtained by changing the external applied field. In time-resolved four-wave mixing this implies a change from a third-order polarization signal dominated by phase space occupation to a Coulomb interaction-induced signal when the bias is increased at high excitation densities. The experimental data are compared with theoretical results based on the numerical solution of the semiconductor Bloch equations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02457209
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Time-Temperature Effects on the Bacteriological Quality of Stored Shellfish. (1967)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 32 (1967), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: —The effect of storage in crushed ice and at 3 and 10°C on the bacteriological quality of shucked Pacific osyters and Olympia osyters was determined. The indices used were the 35°C plate count, coliform MPN, fecal coliform MPN, and pH. Fifteen lots of Pacific oysters and 12 lots of Olympia oysters, collected at various seasons, were examined. The 35°C plate count showed the best correlation with time and temperature OF storage. Fecal coliform MPN's showed the greatest stability under all storage conditions. Coliform MPN's increased at all three temperatures, but the patterns of change were less uniform than those of the 35°C plate count. The pH changes generally showed poor correlation with bacteriological changes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.1967.tb01971.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Time-Temperature Effects on the Bacteriological Quality of Stored Shellfish. (1967)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 32 (1967), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: -The effects of storage at 10, 20, and 27.5°C on the bacteriological quality and pH of living oyster and clam shellstock was studied. Bacteriological indices used were coliform MPN, fecal coliform MPN, and 35°C plate counts. Twelve lots of each oyster species and eleven lots of each clam species were studied. No distinct seasonal patterns in bacteriological changes were found. The 35°C plate count showed the most consistent response, the rate of increase being more rapid at the higher temperatures. Coliform MPN changes were less consistent in their response to temperature, and patterns of change were observed in different species. The fecal coliform MPN showed the greatest stability, with increases occurring only at 27.5°C. The pH changed little at any of the three temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.1967.tb01970.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The Possibility of obtaining E.M.F. directly from Acid-Base Reactions: Electrodes of the Third Kind reversible to Alkaline Earth and Other Ions (1961)
    [s.l.] : Nature Publishing Group
    Nature 190 (1961), S. 712-713 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Fig. 1. E.m.f. of the cell: glass electrode To check this possibility, solutions of barium chloride ranging in concentration from 0-005 to 0 -5 M have been shaken with mixtures of solid lauric acid and solid barium laurate at 25 C. and the potential difference between a glass and silver-silver ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/190712b0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Selectively protected chiral 1,2,4-triaminobutanes and chiral vicinal 1,2-diamines
    Amsterdam : Elsevier
    Tetrahedron: Asymmetry 5 (1994), S. 887-894 
    Details
    ISSN: 0957-4166
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/S0957-4166(00)86240-0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Metal complexes of biologically important ligands. Part LXIV. Pentamethylcyclopentadienyl-rhodium(III) complexes with α-amino acid derivatives as bridging ligands and with several chiral metal centers: synthesis and structure of [Cp*Rh(μ-L-phenylalaninato)]"3(BF"4)"3 and [Cp*Rh(μ-NHCOCH"2NCO"2CH"2Ph)]"2
    Amsterdam : Elsevier
    Inorganica Chimica Acta 198-200 (1992), S. 415-420 
    Details
    ISSN: 0020-1693
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/S0020-1693(00)92384-3
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...