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  • 1
    Electronic Resource
    Electronic Resource
    A flow cryostat for cooling of eight independent pipe guns (1991)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 62 (1991), S. 1783-1786 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A flow cryostat allowing independent cooling of eight pipe guns in a multishot deuterium pellet injector is described. The pipe guns are placed symmetrically around the flow cryostat and with a liquid helium consumption of 4–5 l/h the cooling is sufficient for simultaneous formation of eight pellets at 8–9 K with a diameter of 2.1 mm containing up to 8×1020 atoms/pellet. The thermal interaction between the eight pipe guns is sufficiently low to allow successive firing of the guns with time intervals of up to 1 s.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1142422
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  • 2
    Electronic Resource
    Electronic Resource
    A microwave cavity for measurement of the mass of hydrogen pellets (1990)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 61 (1990), S. 3464-3466 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A description is given of a nondestructive method utilizing a microwave cavity for measuring the mass of high-speed pellets of solid hydrogen. The cavity is designed for use on a multishot pellet injector, where eight pellets are fired successively with trajectories being parallel and symmetrical around the injector axis. The cavity is cylindrical with the axis coinciding with the injector axis. When a pellet passes through the cavity through holes of 15–16 mm diameter, the change in resonant frequency is proportional to the pellet mass. As a result of the cylindrical symmetry the sensitivity will be identical for all pellets. The frequency shift is measured directly and is converted to a signal proportional to the size of the pellet. The cavity was calibrated with pellets of H2 and D2 containing around 6×1020 atoms and with velocities between 1200 and 1500 m/s. The sensitivity was found to be 300±15 mV/1020 atoms in both cases. This is in fair agreement with estimates made from the dielectric constants of solid H2 and D2. The cavity is built together with two optical detectors for time of flight measurements to form an integrated diagnostic unit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1141604
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  • 3
    Electronic Resource
    Electronic Resource
    Identification of an N-linked glycan in the V1-loop of HIV-1 gp120 influencing neutralization by anti-V3 antibodies and soluble CD4 (1994)
    Springer
    Archives of virology 139 (1994), S. 253-261 
    Details
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Glycosylation is necessary for HIV-1 gp120 to attain a functional conformation, and individual N-linked glycans of gp120 are important, but not essential, for replication of HIV-1 in cell culture. We have constructed a mutant HIV-1 infectious clone lacking a signal for N-linked glycosylation in the V1-loop of HIV-1 gp120. Lack of an N-linked glycan was verified by a mobility enhancement of mutant gp120 in SDS-gel electrophoresis. The mutated virus showed no differences in either gp120 content per infectious unit or infectivity, indicating that the N-linked glycan was neither essential nor affecting viral infectivity in cell culture. We found that the mutated virus lacking an N-linked glycan in the V1-loop of gp120 was more resistant to neutralization by monoclonal antibodies to the V3-loop and neutralization by soluble recombinant CD4 (sCD4). Both viruses were equally well neutralized by ConA and a conformation dependent human antibody IAM-2G12. This suggests that the N-linked glycan in the V1-loop modulates the three-dimensional conformation of gp120, without changing the overall functional integrity of the molecule.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01310789
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  • 4
    Electronic Resource
    Electronic Resource
    Isotopieverschiebung der natürlichen geraden und ungeraden Sm- und Nd-Isotope (1967)
    Springer
    The European physical journal 203 (1967), S. 296-329 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The isotope shift of the natural isotopes of Sm and Nd was investigated by a digital recording Fabry-Perot spectrometer using highly enriched samples. By the accuracy achieved in the measurements it was possible to verify earlier results indicating different relative isotope shifts for lines with positive and negative displacements, and to show that also lines with the same sign of the displacement may have different relative isotope shifts. It is shown that these non-constant relative isotope shifts can be explained for the even isotopes by the different contributions of the mass and volume effect to the isotope shifts in the different lines, but this explanation seems only to be partly valid for some distances between even and odd isotopes. The size of the mass effect is estimated and its influence especially on the results of the odd-even staggering is considered. The odd-even staggering is compared to earlier results for Hg. The estimation of the mass effect shows that the results forδ〈r 2〉 determined from the measured isotope shifts without correcting for the mass effect may be considerably wrong. Nevertheless it is possible by a suitable combination of the measured distances to calculate a quantity which only depends on nuclear properties and which therefore enables to check the known theories of the volume dependent isotope shift also without calculating the probability density of thes-electrons at the nucleus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01325919
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  • 5
    Electronic Resource
    Electronic Resource
    Evidence for global warming in the past decade (1988)
    [s.l.] : Nature Publishing Group
    Nature 332 (1988), S. 790-790 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] SIR-The global-mean surface air tem-perature is the most common measure of the state of the climate system. Variations of this parameter are probably deter-mined largely by the sensitivity of the climate system to external forcing factors such as solar output, explosive volcanic eruptions and the ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/332790b0
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  • 6
    Electronic Resource
    Electronic Resource
    The HIV-1 V3 domain on field isolates: participation in generation of escape virus in vivo and accessibility to neutralizing antibodies (1995)
    Springer
    Archives of virology 140 (1995), S. 655-670 
    Details
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The V3 domain is highly variable and induces HIV neutralizing antibodies (NA). Here we addressed the issues of 1) the participation of mutations in V3 in generation of neutralization resistant escape virus in vivo and 2) the applicability of synthetic V3 peptides corresponding to field isolates to induce neutralizing immune sera. Seven peptides corresponding to the V3 region of primary and escape virus from 3 HIV-1 infected patients were synthesized and used for antibody (Abs) studies and immunizations. The anti-V3 Abs titre in patient serum was generally low against peptides corresponding to autologous virus isolated later than the serum sample in contrast to the titre against peptides corresponding to virus isolated earlier than the serum sample. Furthermore, neutralizing anti-V3 monoclonal antibodies (MAbs) raised against V3 peptides from laboratory strains of HIV-1 showed distinct binding patterns against V3 peptides corresponding to sequential primary and escape field isolates, with the strongest reactivity against late isolated escape virus. These observations suggest that the neutralization epitope was influenced by the appearance of mutations. When used as immunogen in rabbits, V3 peptides corresponding to field isolates were highly immunogenic but failed to induce neutralizing or gp120-precipitating Abs. On the contrary, V3 peptide corresponding to the laboratory strain HXB2 induced HIV neutralizing, gp120-precipitating immune serum. In conclusion, these data suggest a participation of the V3 domain in the immunoselection of escape virus, and that V3 on early field virus is less accessible to NA than that on laboratory strains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01309956
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  • 7
    Electronic Resource
    Electronic Resource
    Demonstration of peripheral fucose units in N-linked glycans of human immunodeficiency virus type 1 gp 120: effects on glycoprotein conformation (1997)
    Springer
    Archives of virology 142 (1997), S. 2465-2481 
    Details
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary.  Fucosylated N-linked glycans are important constituents of membrane glycoproteins, owing to their significance as biologically active ligands for several selectins and their role in modulating protein conformation of viral glycoproteins. The human immunodeficiency virus type 1 (HIV-1) glycoprotein contains more than 30 different glycan structures but so far fucose was found associated solely with the innermost GlcNAc of N-linked glycans. In the present report we determined whether fucose units also were linked to the distal GlcNAc via α(1–3) or α(1–4) linkages in N-linked glycans of gp 120. [3H]-fucose labelled gp 120 was subjected to endoglycosidase F digestion, releasing diantennary complex type N-linked glycans, but leaving the inner polypeptide-bound carbohydrates, GlcNAc and possibly associated fucose units, intact. Gel filtration of the digested material revealed that [3H]-fucose label was released from gp 120 by this treatment, indicating presence of peripheral fucose units. Furthermore, [3H]-focuse label was also released by treatment of the labelled gp 120 with an α-L-fucosidase specifically removing fucose in α(1–3) and α(1–4) linkages. Altogether the results indicated presence of fucose units linked to peripheral GlcNAc of gp 120 N-linked glycans. We have earlier shown that other peripheral carbohydrate determinants, i.e. β(1–4)-galactose on N-linked glycans, maintain a correct antigenic conformation of gp 120. Using a coupled ELISA system, where changes in antigenic behaviour of a viral glycoprotein were correlated to stepwise elimination of peripheral monosaccharides from N-linked glycans, we found that treatment of gp 120 with a pan-specific α-fucosidase as well as an enzyme specific for α(1–3)- or α(1–4)-linked fucose disclosed a hidden linear epitope situated in the gp 120 C2 region. The effects of the general fucosidase on epitope exposure was more prominent than those obtained with the enzyme with narrow specificity, suggesting that peripheral and inner fucose units co-operate in the maintenance of gp 120 conformation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007050050255
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  • 8
    Electronic Resource
    Electronic Resource
    HIV-1 infection of in vitro cultured human monocytes: early events and influence of anti HIV-1 antibodies (1994)
    Springer
    Archives of virology 136 (1994), S. 35-52 
    Details
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To characterize the role of the humoral immune response on HIV-1 infection of monocytes and macrophages (Mφs) we examined the susceptibility of in vitro cultured monocyte/Mφs to various HIV-1 isolates and the influence of heterologous and particularly autologous anti HIV-1 sera on this infection. Depending on the period of in vitro cultivation and the virus isolate used different patterns of susceptibility were detected. One week old monocyte/Mφs were highly susceptible to HIV-1 infection, in contrast to monocyte/Mφs cultured 4 weeks. The infection by virus isolated immediately after seroconversion lead to persistent infection with high level of antigen production in contrast to infection by homologous virus isolated later. MAb against the V3-IIIB loop and sCD4 inhibited the infection of monocyte/Mφs in a dose dependent manner, indicating that infection requires binding to CD4 and that post binding events may be common to the infection of lymphocytes. Anti HIV-1 sera showed neutralizing activity against heterologous and even autologous escape virus. This finding, together with the observation that monocytes and Mφs are infected in vivo, suggests that protection against HIV-1 infection of monocytes and Mφs in vivo may not be obtainable by the humoral immune response alone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01538815
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  • 9
    Electronic Resource
    Electronic Resource
    Antibody to HIV-1 Tat protein inhibits the replication of virus in culture (1994)
    Springer
    Archives of virology 139 (1994), S. 263-271 
    Details
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The HIV-1 transactivator protein Tat is essential for viral replication. Tat is released from infected cells and can be taken up and transactivate HIV-LTR in LTR-CAT transfected cell lines. The present study shows that the addition of monoclonal antibody to Tat in IIIB and MN-infected cultures reduces the HIV antigen production in a concentration dependent manner. These data suggest that external Tat might be important in the replication of HIV, exerting the effect in a paracrine fashion. Using 1 µg/ml of anti-Tat antibody resulted in a decline of HIV antigen production to 33% and 45% of controls in IIIB and MN infected H9 cells, respectively. A time course experiment showed progressively increased inhibition of replication during 7 days of exposure to anti-Tat antibody, which could be due to increasing Tat concentration. The inhibitory effect of anti-Tat antibodies on the replication of HIV could play an important regulatory role during infection in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01310790
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  • 10
    Electronic Resource
    Electronic Resource
    An O-linked carbohydrate neutralization epitope of HIV-1 gp 120 is expressed by HIV-1env gene recombinant vaccinia virus (1992)
    Springer
    Archives of virology 126 (1992), S. 11-20 
    Details
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Previous studies have disagreed about the presence of O-linked carbohydrate epitopes on gp 120 of HIV, although antibodies against short-chain O-linked glycans neutralize HIV infection and block syncytium formation in vitro. To settle this question, we analysed the O-linked glycans of gp 120 by chemical methods using purified HIV-1 gp 120 from cells infected with recombinant vaccinia virus solely expressing gp 160 or gp 120. Alkaline borohydride degradation of recombinant gp 120 released monosaccharides and also slightly larger structures (di/trisaccharides) by a β-elimination, confirming the presence of simple O-linked oligosaccharides. The functional activity as neutralisation epitopes of the O-linked oligosaccharides expressed on recombinant gp 120 was preserved, since fusion between uninfected CD 4+ cells and cells infected with recombinant vaccinia was blocked by monoclonal antibodies to the O-linked oligosaccharides of gp 120. Although the mechanism for HIV induction of O-linked oligosaccharide neoantigens is unknown, these results indicate that the O-linked neutralization epitopes are inherent to the glycoprotein itself, and that the unusual appearance of simple O-linked oligosaccharides on gp 120 is independent of any interaction between the host cell and retroviral genes other thanenv.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01309680
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