Specific interaction of desthiobiotin lipids and water-soluble biotin compounds with streptavidin

1991

As shown for biotin lipids (Ref. 1), the formation of perfect 2-D crystalline streptavidin domains can also be observed in the plane of desthiobiotin lipid monolayers. The binding constant of streptavidin with desthiobiotin (Ka = 5·1013 mol−1) is lower than that with biotin (Ka = 1015 mol−1) (Ref. 2). By adding free biotin into the subphase a competitive replacement and a detaching of the streptavidin domains from the desthiobiotin lipid monolayer takes place. Streptavidin domains built at receptor lipid monolayers are still functional. As could be shown, there are two biotin binding sites at each protein molecule that are fully accessible to biotin (Ref. 1). This can be proven by the inter…

Specific recognition, 2-d-crystallization and function of proteins in monolayers

1991

Scheinbares und partielles spezifisches volumen von polystyrol und polymethylmethacrylat in organischen lösungsmitteln

1957

Das scheinbare spezifische Volumen (v2*) von Polystyrol und Polymethacrylat in einer groseren Anzahl von Losungsmitteln wird in Abhangigkeit von der Konzentration, der Temperatur und dem Molekulargewicht gemessen. Es wird eine differentielle Dichtewaage verwendet, deren Genauigkeit dazu ausreicht, v2* in einprozentigerLosung auf etwa vier Dezimalen genau zu bestimmen. Der Gang von v2* mit der Konzentration ist in den untersuchten Losungsmitteln so gering, das fur praktische Zwecke (z. B. Sedimentationsmessungen) v2* = v2 gesetzt werden kann. Der Einflus des Molekulargewichts auf v2* ist unterhalb M = 10000 wegen der abweichenden Endgruppen nicht zu vernachlassigen. Der scheinbare Ausdehnung…

Role of correlated two-pion exchange in $K^+ N$ scattering

1995

A dynamical model for S-- and P--wave correlated $2 \pi$ (and $K \bar K$) exchange between a kaon and a nucleon is presented, starting from corresponding $N \bar N \rightarrow K \bar K$ amplitudes in the pseudophysical region, which have been constructed from nucleon, $\Delta$--isobar and hyperon ($\Lambda$, $\Sigma$) exchange Born terms and a realistic meson exchange model of the $\pi \pi \rightarrow K \bar K$ and $K \bar K \rightarrow K \bar K$ amplitude. The contribution in the s--channel is then obtained by performing a dispersion relation over the unitarity cut. In the $\rho$--channel, considerable ambiguities exist, depending on how the dispersion integral is performed. Our model, sup…

Grape root as habitat: overwintering and population dynamics of grape phylloxera (Daktulosphaira vitifoliae Fitch) in temperate climate viticulture

2016

Background and Aims Daktulosphaira vitifoliae Fitch (grape phylloxera, Phylloxeridae) is one of the most devastating pests in viticulture, mainly because of their root feeding activity. Up to today fundamental relations between belowground habitat and population dynamics remain unclear. In this 2-year study, we investigated the relations between grape phylloxera population and phenotypic traits of roots and feedings sites. Methods and Results We extracted root and soil samples frequently of two closely related mature rootstocks [Vitis berlandieri × V. riparia (cvs 5C and 125AA)]. We quantified and characterised larval population and crowding and assessed root gall pigmentation, root morphol…

Molecular recognition in biotin-streptavidin systems and analogues at the air-water interface

1992

Abstract Specific interaction between biotin and the protein streptavidin in monolayers of synthetic lipids with biotin headgroups has been shown to lead to formation of highly ordered two-dimensional streptavidin crystals. The same behaviour is observed when using desthiobiotin as lipid headgroup which exhibits a significantly lower binding constant compared with biotin (5 × 10 13 M -1 compared with 10 15 M -1 ). This offers the possibility of detaching competetively the 2D crystalline streptavidin layer by addition of free biotin to the aqueous phase. Use of lipoic acid as lipid headgroup ( K a = 7 × 10 7 M −1 ) leads to formation of small snisotropic protein domains indicating a crystall…

HIGH GRADE GLIOMAS AND DIPG

2014

17. Mainzer Allergie-Workshop

2005

Topological–chiral magnetic interactions driven by emergent orbital magnetism

2019

Two hundred years ago, Ampère discovered that electric loops in which currents of electrons are generated by a penetrating magnetic field can mutually interact. Here we show that Ampère’s observation can be transferred to the quantum realm of interactions between triangular plaquettes of spins on a lattice, where the electrical currents at the atomic scale are associated with the orbital motion of electrons in response to the non-coplanarity of neighbouring spins playing the role of a magnetic field. The resulting topological orbital moment underlies the relation of the orbital dynamics with the topology of the spin structure. We demonstrate that the interactions of the topological orbital …

Risk for non-AIDS-defining and AIDS-defining cancer of early versus delayed initiation of antiretroviral therapy

2021

BACKGROUND: Immediate initiation of antiretroviral therapy (ART) regardless of CD4 cell count reduces risk for AIDS and non-AIDS-related events in asymptomatic, HIV-positive persons and is the standard of care. However, most HIV-positive persons initiate ART when their CD4 count decreases below 500 × 10 9 cells/L. Consequences of delayed ART on risk for non-AIDS-defining and AIDS-defining cancer, one of the most common reasons for death in HIV, are unclear. OBJECTIVE: To estimate the long-term risk difference for cancer with the immediate ART strategy.DESIGN: Multinational prospective cohort study.SETTING: The D:A:D (Data collection on Adverse events of anti-HIV Drugs) study, which included…