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
    Simple apparatus for producing single liquid drops (1994)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 65 (1994), S. 2388-2394 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A simple experimental apparatus has been used to produce individual mercury and sodium amalgam drops in the size range of 0.3–2.5 mm diam. A high resistance to the flow of liquid was provided by a capillary tube. The cross section consisted of a 0.20 mm o.d. tungsten wire placed in a 0.25 mm capillary bore. By this method, flow rates of 1 μl/s and lower were obtained, which enabled the formation of drops as small as 1 mm diam in a time interval of 20 s. The drops were formed at a plastic tip, and on reaching the desired size, were stripped off by a stream of argon. An optical sensor was used to detect the growing drop and to switch on the argon stream at the desired time. The growth of the drops at the tip was observed using an image analysis system which showed good agreement between the observed and calculated drop sizes at various instants. The consistency in size from drop to drop, for any particular setting of the apparatus, was evaluated by analyzing magnified pictures of the drops as well as by measuring their weights. The variation in the drop size was found to be within ±2% of the mean value.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1144692
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Recombination in AIDS viruses (1995)
    Springer
    Journal of molecular evolution 40 (1995), S. 249-259 
    Details
    ISSN: 1432-1432
    Keywords: AIDS ; Human immunodeficiency virus ; Simian immunodeficiency virus ; Phylogenetics ; Recombination ; Superinfection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recombination contributes to the generation of genetic diversity in human immunodeficiency viruses (HIV) but can only occur between viruses replicating within the same cell. Since individuals have not been found to be simultaneously coinfected with multiple divergent strains of HIV-1 or HIV-2, recombination events have been thought to be restricted to the rather closely related members of the quasispecies that evolves during the course of HIV infection. Here we describe examples of both HIV-1 and HIV-2 genomes that appear to be hybrids of genetically quite divergent viruses. Phylogenetic analyses were used to examine the evolutionary relationships among multiple HIV strains. Evolutionary trees derived from different genomic regions were consistent with respect to most of the viruses investigated. However, some strains of HIV-1 and HIV-2 exhibited significantly discordant branching orders indicative of genetic exchanges during their evolutionary histories. The crossover points of these putative recombination events were mapped by examining the distribution of phylogenetically informative sites supporting alternative tree topologies. A similar example of a recombinant simian immunodeficiency virus identified in West African green monkeys has also been described recently. These results indicate that coinfection with highly divergent viral strains can occur in HIV-infected humans and SIV-infected primates and could lead to the generation of hybrid genomes with significantly altered biological properties. Thus, future characterization of primate lentiviruses should include careful phylogenetic investigation of possible genomic mosaicism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00163230
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Liquid household hazardous wastes in the United States: Identification, disposal, and management plan (1987)
    Springer
    Environmental management 11 (1987), S. 735-742 
    Details
    ISSN: 1432-1009
    Keywords: Hazardous liquid wastes ; Waste disposal ; Waste management ; Household chemicals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Present methods of disposal of today's hazardous household chemicals in the United States are frequently not acceptable because of pathways to groundwater, surface water, and the atmosphere. This report identifies potentially hazardous liquid waste in the household, notes current disposal practices, and recommends an improved management plan that utilizes consumer education, manufacturer cooperation, and governmental intervention. Laws requiring uniform disposal labeling on packaging are critical. Local, county, and state governments must be encouraged to coordinate the necessary infrastructure. Managing hazardous household wastes now will mitigate potential disposal problems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01867241
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Glutamic Acid Decarboxylase-positive Neuronal Cell Bodies and Terminals in the Human Cerebellar Cortex (2000)
    Springer
    Journal of molecular histology 32 (2000), S. 557-564 
    Details
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of γ-aminobutyric acid (GABA) in the human cerebellar cortex was studied using immunohistochemistry for glutamic acid decarboxylase (GAD), the enzyme that catalyses GABA synthesis. Observations by light microscopy revealed, in all layers of the cerebellar cortex, strong, punctate positivity for GAD, related to putative GABAergic nerve terminals, as well as a diffuse cytoplasmic immunoreactivity within neuronal cell bodies. GAD-positive nerve terminals were found in close relationship with the walls of the cerebellar cortex microvessels. Observations by electron microscopy revealed positive nerve terminals in contact with the astrocyte perivascular sheath of capillaries. GAD immunoreactivity was also detected within astroglial perivascular endfeet and endothelial cells. The findings provide further insights into the GABAergic synapses of the circuitry of the human cerebellar cortex. The detection of ‘vascular’ GAD immunoreactivities suggests that GABAergic mechanisms may regulate cerebellar microvessel function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004106428844
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    An immunohistochemical and morphometric study on astrocytes and microvas culature in the human cerebral cortex (1997)
    Springer
    Journal of molecular histology 29 (1997), S. 655-660 
    Details
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In this study, astrocytes and microvessels of the human cerebral cortex were analysed morphometrically with the aim of acquiring quantitative information on the glio-vascular relationships, considered to be of great importance in the formation and functioning of the blood--brain barrier. Immunohistochemistry for the astrocytic marker, glial fibrillary acidic protein, was used with a computerized image analysis system. The brain tissue was embedded using the progressive lowering of temperature method, and the image analyser was applied to semithin sections subjected to immunogold--silver staining and viewed by epipolarization microscopy. The results show that, in the human cerebral cortex, astrocytes cover 11.4% of the cortex area and that their perivascular processes are nearly as extensive as the vascular bed (0.8% versus 1.72% of the cortex area). These processes form a virtually continuous sheath around the vascular walls, only 11% of the vessel perimeter lacking this astrocytic glia covering. The present results, compared with previous unpublished data obtained by conventional immunocytochemical procedures on wax sections, indicate that low-temperature methods combined with gold--silver immunolabelling on semithin sections significantly improve the detection of immunoreactivity and the performance of the image analyser
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026448614647
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Identification of vascular endothelial cells in murine omentum using the lectin,Dolichos biflorus agglutinin: Possible applications in the study of angiogenesis (1989)
    Springer
    Journal of molecular histology 21 (1989), S. 271-278 
    Details
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The purpose of this study was to determine whether the plant lectin,Dolichos biflorus agglutinin (DBA), can be used to recognize capillary endothelial cells and their processes during angiogenesis. By means of a peroxidase conjugate of DBA, blood vessels were visualized in whole mounts and ultrathin sections of mouse omentum. A part of this mesentery normally comprises an avascular membrane that is approximately 30 µm in thickness. Changes in the vascular plexus bordering this membrane were induced by intraperitoneal injection of irradiated Landschutz cells. Vascular endothelial cells were precisely and intensely stained, and vasculogenic processes were reliably distinguished from those of other cells. This technique permitted observation of the structure and distribution of capillary sprouts, and their relationship to each other and to pre-existing blood vessels. It was discovered that filiform projections extend from sprout apices. These projections may fuse allowing adjacent sprouts to form a new capillary loop.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01757179
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    An equal-time quantized field theory on the light cone (1992)
    Springer
    The European physical journal 53 (1992), S. 661-671 
    Details
    ISSN: 1434-6052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The isomorphism between the equal-time and light-cone Fock space representations of the scalarcoupled Yukawa theory in 3+1 dimensions is constructed to lowest order in perturbation theory. The light-cone vacuum is shown to be the physical vacuum state of the theory, and the equal-x + commutation relations between the fields are determined. The dynamical operators are shown to be correctly given by components of the energymomentum tensor integrated over the surfacex +=0.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01559745
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Bosonic zero modes in discretized light-cone field theory (1992)
    Springer
    The European physical journal 53 (1992), S. 679-685 
    Details
    ISSN: 1434-6052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that for theories with bosonic fields a constrained zero mode is a necessary ingredient for a consistent discretized light-cone quantization (DLCQ). Inclusion of this zero mode is shown to remove a non-covariant, quadratically divergent contribution to the fermion self-energy in 3+1 dimensional Yukawa theory which would otherwise be present. It is further shown to result in a fully consistent set of Heisenberg equations. The possibility of maintaining parity in DLCQ is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01559747
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Light-cone quantization of gauge fields (1994)
    Springer
    The European physical journal 62 (1994), S. 349-355 
    Details
    ISSN: 1434-6052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Light-cone quantization of gauge field theory is considered. With a careful treatment of the relevant degrees of freedom and where they must be initialized, the results obtained in equal-time quantization are recovered, in particular the Mandelstam-Leibbrandt form of the gauge field propagator. Some aspects of the “discretized” light-cone quantization of gauge fields are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01560250
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The Mandelstam-Leibbrandt prescription in light-cone quantized gauge theories (1995)
    Springer
    The European physical journal 68 (1995), S. 345-351 
    Details
    ISSN: 1434-6052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Quantization of gauge theories on characteristic surfaces and in the light-cone gauge is discussed. Implementation of the Mandelstam-Leibbrandt prescription for the spurious singularity is shown to require two distinct null planes, with independent degrees of freedom initialized on each. The relation of this theory to the usual light-cone formulation of gauge field theory, using a single null plane, is described. A connection is established between this formalism and a recently given operator solution to the Schwinger model in the light-cone gauge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01566681
    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...