Stromrichter als Aktive Filter zur Verminderung von Oberschwingungen im Versorgungsnetz

Available from TIB Hannover: DW 4832 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Binding of oral streptococci to human fibrinogen

The interaction of oral streptococci with human fibrinogen was investigated. Streptococcus gordonii was chosen as a representative species to study the binding to fibrinogen. S. gordonii DL1 adhered to immobilized fibrinogen and bovine serum albumin. Binding to immobilized fibrinogen was saturable, concentration and temperature dependent. The binding of S. gordonii DL1 to fibrinogen was inhibited by anti-fibrinogen antibody. Heating of the bacteria for 1 h at 95째C resulted in 90% inhibition of the binding. Trypsin treatment of the bacteria resulted in decreased binding. Neither lipoteichoic acid nor culturing of the bacteria in a sucrose-supplemented medium had any effect on the binding. S. gordonii, Streptococcus sanguinis, Streptococcus mitis, and Streptococcus oralis bound to the immobilized fibrinogen, but mutans streptococci did not. None of the oral streptococci tested bound to the fibrinogen in fluid phase. These results suggest that the binding of S. gordonii DL1 to immobilized fibrinogen is mediated through a specific protein adhesin-receptor interaction, and fibrinogen acts as a cryptitope.

Scaling of the entropy change at the magnetoelastic transition in Gd5(SixGe1-x)4

Differential scanning calorimetry under a magnetic field H has been used to measure the entropy change DS at the magnetoelastic transition in Gd5(SixGe12x)4 alloys, for x<0.5. We show that DS scales with the transition temperature, Tt , which is tuned by x and H, from 70 to 310 K. Such a scaling demonstrates that Tt is the relevant parameter in determining the giant magnetocaloric effect in these alloys, and proves that the magnetovolume effects due to H are of the same nature as the volume effects caused by substitutio