conclusions higher age of cyclists and increasing speed of the accident opponent significantly increase the likelihood of sustaining facial fractures. the use of bicycle helmets does not significantly reduce the incidence of mid-facial fractures, while being correlated with an even increased incidence of mandibular fractures. background the effectiveness of bicycle safety helmets in preventing ...

YAMAMOTO, T.Y., TONOSAKI, A. and WATANABE, H. Complementary Faces of the Rod Disc Membrane in Freeze-Fracture Replicas. Tohoku J. exp. Med., 1974, 113 (4), 313-317 Replicas from complementary freeze-fracture faces of the rabbit rod outer segments were examined in an electron microscope. By this method two dissimilar faces, A and B, were visualized in a disc. The A face, toward the inteadisc spa...

Thylakoid membranes of the thermophilic cyanobacterium Phormidium laminosum have been fractionated into photosystem II and photosystem I particles. These fractions have been characterized by their partial electron transport activities, and biochemical and spectral properties. Exoplasmic fracture face and protoplasmic fracture face particles in the unfractionated thylakoid membranes were shown t...

Fresh, chemically unfixed, glycerinated specimens of mouse liver were examined by the technique of freeze-fracture replication without sublimation (i.e. they were not 'etched'). Where extensive areas of fractured lamellar membranes of the rough endoplasmic reticulum are revealed en face, 2 types of fracture face are distinguishable. One of these fracture faces (A) is directed towards the cytopl...

The significance of discontinuities frequently found in freeze-fracture replicas of the tight junction was evaluated using complementary replicas of hepatocyte junctions from control and bile duct-ligated rats. An extensive analysis of complementary replicas using rotary platinum shadowing indicates that discontinuities in the protoplasmic (P) fracture face do not represent structural breaks in...

Cyanidium caldarium wild type and III-C mutant lacking phycobilisomes were compared with respect to the ultrastructural organization of particles on the freeze-fractured thylakoid membrane.In the wild type, the particles on the exoplasmic fracture face were arranged in the same manner as that reported for the phycobilisomes on the membrane surface. The phycobilisomes constitute the major part o...