Vergleich von Immunoblot- und Immunpr?zipitationsmethoden zum Nachweis und zur Identifikation von Antik?rpern gegen nucle?re und cytoplasmatische Ribonucleoproteine

Ohne Zusammenfassung

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Comparison of immunoblot and immunoprecipitation methods for detection and identification of antibodies to nuclear and cytoplasmatic ribonucleoproteins

     

LCVD of copper: Deposition rates and deposit shapes

Laser chemical vapor deposition of copper has been performed under a variety of conditions. The results are interpreted using the kinetic model of Ehrlich and Tsao. We find that the kinetics of the process are limited by the rates of surface reactions and not by diffusion of reactant molecules to the surface. Furthermore, we find that deposit shapes are quite sensitive to laser intensity and scan rate.     

Phase-coherent generation of tunable visible femtosecond pulses

Stable interference between the outputs of two noncollinearly phase-matched optical parametric amplifiers seeded by separate white-light continua has been observed. This means that the tunable visible pulses have a well-defined relative phase and that the temporal jitter between them is less than 1 fs. The residual phase variations are due to fluctuations of the pump power.     

Multivalent interactions between lectins and supramolecular complexes: Galectin-1 and self-assembled pseudopolyrotaxanes

Supramolecular chemistry has been employed to develop flexible and adaptable multivalent neoglycoconjugates for binding galectin-1 (Gal-1). Gal-1, a dimeric lectin with two galactoside-binding sites, regulates cancer progression and immune responses. Self-assembled pseudopolyrotaxanes consisting of lactoside-displaying cyclodextrin (LCD) "beads" threaded onto polyviologen "strings" display mobile ligands as a result of cyclodextrin rotation about, and limited translation along, the polymer chain. The pseudopolyrotaxanes rapidly and efficiently precipitate Gal-1 and provide valency-corrected enhancements of up to 30-fold compared to native lactose and 20-fold over free LCD in a T-cell agglutination assay. A supramolecular statistical effect was observed, wherein the efficacy of Gal-1 inhibition correlates with the number of ligands connected to each other solely through mechanical and noncovalent interactions. Such flexible and adaptable self-assembled pseudopolyrotaxanes show promise for the study of multivalent interactions and targeting of therapeutically relevant lectins.     

Lithium-silylindolide als Precursor für 1,2-, 1,3-Bis(silyl)indole und Bis(indol-1,3-yl)silane

Lithium-silylindolide as Precursor of 1,2-, 1,3-Bis(silyl)indoles and Bis(indole-1,3-yl)silane Lithium-indolide reacts with difluorosilanes (F₂SiR₂: R = CHMe₂ ( 1 ); CMe₃ ( 2 )) in a molar ratio 2 : 1 with formation of bis(indole-1-yl)silanes. The 1-(di-tert-butylfluorosilyl)-3-(fluorodiisopropylsilyl)indole ( 3 ) is obtained in the reaction 1-(di-tert-butylfluorosilyl)-3-lithium-indolide and F₂Si(CHMe₂)₂. In a molar ratio 2 : 1 the bis(1-di-tert-butylfluorosilyl-indole-3-yl)diisopropylsilane 4 is formed. As a byproduct bis(1-di-tert-butylfluorosilyl-indole-3-yl)dimethylmethane ( 5 ) is isolated. A cleavage of THF and the formation of (indole-1-yl)diisopropylvinyloxysilan ( 6 ) occurs in the reaction of 1-diisopropylfluorosilylindole with t-BuLi in THF. 1-(di-tert-butylfluorosilyl)indole reacts with n-BuLi/TMEDA accompanied by an 1,2-anionic silyl group migration to give the 2-(di-tert-butylfluorosilyl)-1-lithiumindolide 7 . Hydrolysis of 7 gives the 2-(di-tert-butylfluorosilyl)indole ( 8 ). In the reaction of 7 with F₂Si(CHMe₂)₂ the 1-(diisopropylfluorosilyl)-2-(di-tert-butylfluorosilyl)indole 9 is obtained. 1-n-Butyl-diisopropylsilylindole ( 10 ) is the product of the reaction of F₂Si(CHMe₂)₂, n-BuLi/TMEDA and indole at –70 °C. Lithium-indolide reacts with 3 to give the 1-(di-tert-butylfluorosilyl)indole-3-yl)(indole-1-yl)-diisopropylsilane ( 11 ), the first example of this class of substances. In the reaction of 1 , F₂SiMe₂, and t-BuLi in THF the 1-(diisopropyl(indole-1-yl)silyl)-3-dimethyl-(3.3-dimethylbutylsilyl)indole 12 is isolated. The crystal structures of 2 , 5 and 9 are discussed.     

Molekulare Verbindungen mit SiAl4-, SiAl3- und GeAl4-Einheiten: Synthese und Struktur von Si(AlCl2 · OEt2)4, Ge(AlCl2 · OEt2)4 und HSi(Cp*AlBr)3

Molecular Compounds containing SiAl₄, SiAl₃, and GeAl₄ Units: Sythesis and Structure of Si(AlCl₂ · OEt₂)₄, Ge(AlCl₂ · OEt₂)₄, and HSi(Cp*AlBr)₃ In the scope of our investigations of the reactivity and the potential for synthesis of solutions of Al^I halides we performed reactions between these solutions and SiCp or GeCp, respectively. From these reactions we could isolate an unusual cluster with a central Al₁₄Si unit, described elsewhere, and the compounds Si(AlCl₂ · OEt₂)₄, Ge(AlCl₂ · OEt₂)₄, and HSi(Cp*AlBr)₃, which will be presented and discussed here. In these species the Si respectively the Ge atoms are connected to 4 respectively 3 Al atoms. This bonding results in strong negative polarized Si/Ge centres. The change of the polarization with respect to “normal” Si–R or Ge–R linking leads to a drastic weakening of the Si–R respectively the Ge–R bonds.