Collective dynamics underlying allosteric transitions in hemoglobin.

Hemoglobin is the prototypic allosteric protein. Still, its molecular allosteric mechanism is not fully understood. To elucidate the mechanism of cooperativity on an atomistic level, we developed a novel computational technique to analyse the coupling of tertiary and quaternary motions.

Not only enthalpy: large entropy contribution to ion permeation barriers in single-file channels.

The effect of channel length on the barrier for potassium ion permeation through single-file channels has been studied by means of all-atom molecular dynamics simulations. Using series of peptidic gramicidin-like and simplified ring-structured channels, both embedded in model membranes, we obtained two distinct types of behavior: saturation of the central free energy barriers for peptidic channels and a linear increase in simplified ring-structured channels with increasing channel length. The saturation of the central free energy barrier for the peptidic channels occurs at relatively short lengths, and it is correlated with the desolvation from the bulk water.

[Experiences in the treatment of midfacial fractures using a fixed-angle osteosynthetic system. Biomechanical results].

Aim: Fixed-angle osteosynthetic systems are characterized by mechanical "locking" of the osteosynthetic screw and plate. These systems have found increasing acceptance and use for osteosynthetic fixation and temporary reconstruction of the mandible. The aim of this study was to investigate the applicability and performance of fixed-angle systems in the treatment of midfacial fractures.

Digital transversal slice imaging in dental-maxillofacial radiology: from pantomography to digital volume tomography.

With digital transversal slice imaging (TSI) as a supplementary program to pantomographic devices and digital volume tomography (DVT), images of the viscerocranium are now possible in several planes. The two procedures, TSI and DVT, are complementary. They should be applied where the indication justifies it in dentistry and maxillofacial surgery for diagnostic and forensic purposes.