University of Cologne

About: University of Cologne is a education organization based out in Cologne, Germany. It is known for research contribution in the topics: Population & Gene. The organization has 32050 authors who have published 66350 publications receiving 2210092 citations. The organization is also known as: Universität zu Köln & Universitatis Coloniensis.

Transition Metal Compounds

Abstract: Describing all aspects of the physics of transition metal compounds, this book provides a comprehensive overview of this unique and diverse class of solids. Beginning with the basic concepts of the physics of strongly correlated electron systems, the structure of transition metal ions, and the behaviours of transition metal ions in crystals, it goes on to cover more advanced topics such as metal-insulator transitions, orbital ordering, and novel phenomena such as multiferroics, systems with oxygen holes, and high-Tc superconductivity. Each chapter concludes with a summary of key facts and concepts, presenting all the most important information in a consistent and concise manner. Set within a modern conceptual framework, and providing a complete treatment of the fundamental factors and mechanisms that determine the properties of transition metal compounds, this is an invaluable resource for graduate students, researchers and industrial practitioners in solid state physics and chemistry, materials science, and inorganic chemistry.

Fermionic transport and out-of-equilibrium dynamics in a homogeneous Hubbard model with ultracold atoms

Abstract: The transport measurements of an interacting fermionic quantum gas in an optical lattice provide a direct experimental realization of the Hubbard model—one of the central models for interacting electrons in solids—and give insights into the transport properties of many-body phases in condensed-matter physics.

Bone tunnel enlargement after anterior cruciate ligament reconstruction: fact or fiction?

Abstract: Radiographic enlargement of bone tunnels following anterior cruciate ligament (ACL) reconstruction has been recently introduced in the literature; however, the etiology and clinical relevance of this phenomenon remain unclear. While early reports suggested that bone tunnel enlargement is mainly the result of an immune response to allograft tissue, more recent studies imply that other biological as well as mechanical factors play a more important role. Biological factors associated with tunnel enlargement include foreign-body immune response (against allografts), non-specific inflammatory response (as in osteolysis around total joint implants), cell necrosis due to toxic products in the tunnel (ethylene oxide, metal), and heat necrosis as a response to drilling (natural course). Mechanical factors contributing to tunnel enlargement include stress deprivation of bone within the tunnel wall, graft-tunnel motion, improper tunnel placement, and aggressive rehabilitation. Graft-tunnel motion refers to longitudinal and transverse motion of the graft within the bone tunnel and can occur with various graft types and fixation techniques. Aggressive rehabilitation programmes may contribute to tunnel enlargement as the graft-bone interface is subjected to early stress before biological incorporation is complete. Further basic research is required to verify the effect of the various proposed factors on the etiology of bone tunnel enlargement. We recommend that routine follow-up examinations after ACL reconstruction should include the measurement of bone tunnel size in order to contribute to a better understanding of the incidence, time course, and clinical relevance of this phenomenon. Improved and more anatomical surgical fixation techniques may be useful for the prevention of bone tunnel enlargement.