Bibliothek

X
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
    facet.materialart.
    Unbekannt
    Quantifying the impact of nevirapine-based prophylaxis strategies to prevent mother-to-child transmission of HIV-1 (2011)
    Details
    Publikationsdatum: 2023-08-03
    Sprache: Englisch
    Materialart: article , doc-type:article
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    OPUS
  • 2
    Digitale Medien
    Digitale Medien
    Ab initio simulation of defects in energetic materials: Hydrostatic compression of cyclotrimethylene trinitramine (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4428-4434 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: An isotropic compression of both the perfect solid cyclotrimethylene trinitramine (C3H6N6O6), also known as RDX, and of the solid containing vacancies is simulated using the ab initio Hartree–Fock method combined with two different crystal models: a periodic (band structure) and a molecular cluster. We show that an external pressure causes a significant decrease of the optical gap for both the perfect material and the crystal with vacancies. The solid RDX is found to be highly compressible; a pure crystal could be compressed to 57% of its equilibrium volume, whereas crystals containing vacancies are even more compressible. The critical pressure necessary for the insulator–metal transition is also predicted. It is shown that the voids present in a real RDX solid lower the metallization pressure by about 30%. Theoretical results are in close agreement with the experimental data on solid and porous RDX. The influence of defects present in the crystal and the relation to control of the sensitivity to detonation are discussed in detail. © 1999 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.371381
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Electronic structure of molecular crystals containing edge dislocations (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 4962-4970 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: An attempt to model the electronic structure of molecular crystals containing an edge dislocation at the ab initio Hartree–Fock level is performed. The experimentally determined configurations for edge-type dislocations with the Burgers vector [001] in crystalline cyclotrimethylene trinitramine (RDX) and pentaetythritol tetranitrate (PETN) are theoretically simulated. It is shown that a shear stress, induced by the dislocations, produces local electronic states in the fundamental band gap of the crystal. These states are mainly formed by molecular orbitals of critical bonds (which are the N–NO2 group in RDX and the O–NO2 group in PETN) responsible for the stability of the materials. Optical absorption attributed to these electronic states is predicted and compared to the available experimental data. Properties of the defective solids are compared with those of the perfect crystals. Correlation of the electronic structure and sensitivity of the materials to initiation of a chemical reaction as well as some practical applications of the obtained results are discussed. © 2001 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1359171
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Compression-induced effect on the electronic structure of cyclotrimethylene trinitramine containing an edge dislocation (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 2215-2218 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: An effect of a hydrostatic compression on the electronic structure of cyclotrimethylene trinitramine (C3H6N6O6), also known as RDX, with an edge dislocation has been studied by means of the ab initio Hartree–Fock method for a periodic system combined with the many-body perturbation theory. An external pressure causes a significant decrease of the optical gap for both the perfect material and the crystal with dislocations. The edge dislocations produce local electronic states in the optical gap whereas the external pressure moves these states deep within the band gap. This contributes strongly to properties of the RDX crystals creating favorable conditions for the N–NO2 chemical bond rupture due to exciton formation. The relationship between the edge dislocations, hot spot formation, and the sensitivity of RDX to detonation are discussed in detail. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.372163
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Molecular orbital calculations on (MgO)n and (MgO)n+ clusters (n=1–13) (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 4783-4792 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: We report ab initio molecular orbital calculations on neutral and single-ionized stoichiometric clusters of MgO containing up to 26 atoms. Geometrical parameters of the neutral clusters are optimized at the Hartree–Fock level, whereas for the ionized clusters we have applied the vertical approximation. Correlation corrections in the clusters with 2–12 atoms are included at the equilibrium geometries by means of second order Moller–Plesset calculations. We have found that the structures based on the (MgO)3 subunit are preferred in comparison to cubelike configurations, although the energy difference decreases with the increase in cluster size. The relative stability of neutral and single-ionized clusters has been studied by means of the fragmentation path involving the loss of a neutral MgO molecule. The calculated "magic numbers'' for the charged clusters, (MgO)n+, are in complete agreement with the abundance maxima observed in the mass spectra. Finally, we explore the size dependence of structural, energetic, and electronic properties. These properties show a large variation from the monomer to the (three-dimensional) eight atom cluster, followed by a softer approach towards the corresponding bulk limit.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.464982
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Identification of Transcripts of the T Cell Antigen Receptor β Chain Gene and Major Histocompatibility Complex Class II Genes in Antigen-Presenting Cloned BK-BI-2.6.C6 Cells (1988)
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of immunology 27 (1988), S. 0 
    Details
    ISSN: 1365-3083
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The cloned murine cell line BK-B1-2.6.C6 has previously been shown to exhibit T cell characteristics, to synthesize and express MHC class II molecules, and to present protein antigens to antigen-dependent I cell clones. As a more definitive proof of the T-cell nature of these cells, transcripts of the rearranged T cell antigen receptor (TcR) β gene were assessed by Northern bios analysis. BK-BI-2.6.C6 cells constitutively transcribe mRNA for the light chain of TcR and express the disulphide-linked α,β TcR heterodimer at the cell surface. In addition mRNA For the polymorphic MHC class II subunits Aα and Aβ as well as for the invariant γ chain were detected. BK-BI-2.6.C6T cells effectively stimulated bovine insulin-reactive T hybridoma cells to lymphokine production in the presence of this antigen. Since the antigen-presenting and the responding T cell populations are maintained in culture in the absence of feeder cells, contamination by conventional accessory cells is excluded. These data unequivocally demonstrate that cloned murine Ia-expressing T cells can act as antigen-presenting accessory cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-3083.1988.tb02327.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Regulation of Interleukin 2 Receptor Expression by Interleukin 2 (1986)
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of immunology 23 (1986), S. 0 
    Details
    ISSN: 1365-3083
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The regulatory influence of Interleukin 2 (IL-2) on the expression of IL-2 receptors (IL.-2R) was studied using long-term cultured T-cell lines and recombinant IL-2 (r-IL-2). Three T-cell lines with different growth requirements were used as model systems: insulin-specific BK-BI-1.2 cells express IL-2R transiently after antigenic restimulation, ovalbumin-reactive BK-OVA-1R cells express IL-2R permanently, and BK-BI-2.6.C6 cells bear IL-2R constilutively but do not exhibit antigen reactivity. All three T-cell lines exhibited the property of increased IL-2R expression in the presence of r-IL-2, as tested by cyto-fluoromelry employing monoclonal antibody AMT-13 directed at the murine IL-2R. IL-2R density was influenced selectively by r-IL-2. because the level of Thy-1.2 molecules was similar in the presence and absence of r-IL-2. With BK-BI-2.6.C6 cells, r-IL-2 was shown to upregulate high-affinity receptors. Since BK-BI-2.6.C6 and BK-OVA-IR cells were grown in the absence of feeder cells, these data show that r-IL-2 can regulate the expression of its own receptor without the participation of monokines. Results obtained with the T-cell line BK-BI-1.2, representing insulin-specific T cells with transient IL-2R expression, show that the presence of r-IL-2 did not prevent a decline in IL-2R density occurring on day 5 after antigenic stimulus. This indicates that additional mechanisms besides antigen- and IL-2-induced IL-2R upregulation are operative in controlling IL-2R density on the cell surface.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-3083.1986.tb02006.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Analysis of the (H-2b× H-2k)F1Restricted Response to Insulin (1984)
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of immunology 20 (1984), S. 0 
    Details
    ISSN: 1365-3083
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The aim of these studies was to characterize the (H-2b× H-2k)F1-unique restriction element(s) responsible for presentation of bovine insulin (BI) to a long-term cultured T-cell line (BK-BI-1.2). (B10.BR × bm12)F1 spleen cells, which express a normal Abα Akβ molecule but a mutated Akα AAbm12β product on their cell surface, were perfectly able to act as BI-presenting cells. Antibody inhibition experiments with antibodies directed at I-Ak products revealed that monoclonal antibody 10–2.16, which reacts with the Akβ polypeptide chain, abrogated BI-directed T-cell proliferation, whereas antibody H116–32.R5 with specificity for the Akα chain was not inhibitory. These results identified the AbαAkβ complex as restriction structure. Recognition of BI in the context of the Abα Akβ molecule depended on the glutamic acid residue in position 4 of the A chain of bovine insulin. Twenty to twenty-five percent of the secondary proliferative response of (B10 × B10.BR)F1 lymph node T cells primed with BI in vivo was directed at the A4 determinant, suggesting that BK-BI-1.2 T blasts are representative of T-cell clones with measurable frequency. In (B10.BR × bm12)F1 mice, which lack a functional Abα Abβ restriction element, up to 80% of the proliferative response was dependent on the A4 epitope.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-3083.1984.tb00982.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Augmented Antigen Presentation by Mouse Ia+ T Clone Cells BK-BI–2.6.O4.1 Mediated by Transferrin Receptors (1996)
    Oxford, U.K. and Cambridge, USA : Blackwell Science Ltd
    Scandinavian journal of immunology 43 (1996), S. 0 
    Details
    ISSN: 1365-3083
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The murine T clone cells BK-BI–2.6.O4.1 (BI/O4.1) synthesize and express MHC class II molecules constitutively. BI/O4.1 cells are able to present various protein antigens to antigen-specific CD4+ T cells. However, a 10-fold higher concentration of antigen is needed to activate specific T cells to lymphokine secretion by BI/O4.1 cells in comparison with spleen cells or with the more homogeneous population of bone marrow-derived macrophages (BMMph). The authors tested whether the reduced antigen presentation potential of BI/O4.1 cells was augmented by transferrin- mediated uptake of the model antigen ovalbumin (OVA) coupled to human ferric transferrin. It was shown that 240-fold less OVA was sufficient to induce proliferation of an OVA-specific T-cell clone when the conjugate and not native OVA was used. The presence of ferric TF in the cultures competitively inhibited this effect of the conjugate. A similar shift in the dose–response curve to lower doses of antigen was induced by the conjugate when B lymphoma cells were used as antigen-presenting cells. BMMph and P388D1 cells processed and presented the conjugate with similar efficiency as native OVA, although both cell types exposed transferrin receptors. These data suggest that the reduced antigen presentation potential of BI/O4.1 T clone cells is due to the inefficient uptake of OVA by pinocytosis and delivery into the processing compartment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-3083.1996.d01-77.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Standard liquids for the microscopic determination of refractive index (1936)
    s.l. : American Chemical Society
    Industrial and engineering chemistry 8 (1936), S. 485-485 
    Details
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/ac50104a034
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...