A limiting speed for protein folding at low solvent viscosity

Because protein folding dynamics are heavily overdamped, Kramers theory predicts the rate of folding to scale inversely with the reaction friction, which is usually interpreted to mean the solvent viscosity. This does not mean, however, that the speed of folding can increase without limit as solvent viscosity decreases. We show that, in a sufficiently fast-folding protein, the folding speed approaches a finite limit at low solvent viscosity, indicating a reaction controlled by internal friction.     

Estimation of higher-order magnetic spin interactions of Fe(III) and Gd(III) ions doped in α-alumina powder with multifrequency EPR

Fe(III) and Gd(III) ions in α-alumina (A1₂O₃) exhibit spin states ofS = 5/2 andS = 7/2 respectively. The magnitude of the zero-field interaction (ZFI) (D = 0.10?0.15 cm^?1) gives rise to an inter Kramers doublet splitting in the same order of magnitude as the X-band electron paramagnetic resonance (EPR) quantum (0.3 cm^?1). It is demonstrated that through a careful step-by-step analysis and spectral simulation of EPR spectra taken at D-band (130 GHz), Q-band (35 GHz), and X-band (9 GHz) at room temperature, the (relative) sign and magnitude of the ZFI parameters, b ₂ ⁰ , b ₄ ⁰ , and b ₄ ³ , can be reliably estimated.     

Die Spannung des Quecksilberdampfes bei niedrigen Temperaturen

Ohne Zusammenfassung     

Strong Photoluminescence Enhancement from Colloidal Quantum Dot Near Silver Nano-Island Films

We present the fabrication and optical investigation of highly random self-assembled, nano-scale films, probing their influence on the luminescence properties of near surface CdSe/ZnS colloidal quantum dots. When compared to quantum dots distributed on unstructured quartz substrates, the average luminescence intensity is found to be enhanced by a factor of 160×. The silver nanoparticles are prepared using slow thermal evaporation on quartz substrates and post-deposition annealing to produce a randomly-arranged layer of smooth nano-islands. Clear polarization dependent hot spots are observed. Such hot spots deliver a maximal enhancement of the emission intensity of 240× and have a spatial density of (0.050±0.002) μm^− 2. The results show that silver nano-island films strongly enhance the optical efficiency of near quantum dots emitters.