Age-dependent doses to members of the public from intake of radionuclides Part 4: Inhalation dose coefficients

Otolith microstructure examination has found an increasing number of applications in recent years. However, few workers have critically assessed the assumptions upon which the age and growth infere...

Microstructure of Fish Otoliths

Molecular Biology of Mineralized Tissues with Particular Reference to Bone

This paper presents a review of the current understanding of the structure, self-assembly mechanisms, and properties of mineralized collagen fibril composites in connective tissues, such as in lamellar bones, woven bones, zebrafish skeletal bone, and ivory. Recent work involving biomimetic synthesis of new materials with the structure of mineralized collagen is described. The focus in the paper is mainly on materials containing type I collagen, with mineralization by Ca–P crystals although some other systems are also described. Investigation and simulation of naturally occurring fibril structures can offer some new ideas in the design and fabrication of new functional materials, for applications such as bone grafts or for use as scaffolds in tissue engineering and biomimetic engineering materials. The development of bone grafts based on the mineralization of self-assembled collagen fibrils in vivo and in vitro is an active area of research. This kind of bone graft composite has already shown great promise and success in clinical applications, on account of its compositional and structural similarity to autologous bone. It is suggested that future work in this should focus on both basic theoretical aspects as well as the development of applications. In particular issues including control of morphology, incorporation of foreign ions, interaction with biomolecules, and the assembly of organic and inorganic phases are all still not well understood. In the area of applications, the design of composite materials with a hierarchical structure closer to that of natural hard tissues, and the synthesis of bone grafts and tooth regenerative materials, as well as biomimetic functional materials, are areas currently being examined by many research groups.

Self-assembly of mineralized collagen composites

Sections from 3 μ to over 100 μ thick of fresh, unfixed, unembedded, unde-calcified and undehydrated bone are made by grinding 1 to 2 mm slabs of the desired orientation on waterproof carborundum a...

Preparation of thin undecalcified bone sections by rapid manual method.

Pathology and familial incidence of orchitis and its relation to thyroiditis in a closed beagle colony

Retention of radioactive bone-seekers.

Comparative metabolism of radium, strontium, and calcium

A rapid technic for the preparation of 6 μ serial sections of undecalcified bone is described. The specimen is fixed and dehydrated in acetone and ether. It is then treated with a 1:1 mixture of the monomers of ethyl and n-butyl methacrylate catalyzed with benzoyl peroxide. The monomers are removed with ether and the ether is removed under vacuum. Infiltration is accomplished under vacuum using a partial polymer of the same mixture of monomers. Polymerization is completed in 36 hours under pressure at 50°C. The tissue is sectioned with a heavy-duty microtome, the sections are mounted on glass slides and nuclear emulsions applied. Young and adult bone of laboratory animals and man have been cut successfully. Microscopic structural detail is preserved and there is no evidence of translocation of the radioactivity.

Sectioning of undecalcified bone; with special reference to radioautographic applications.

Police trainees who were ready to graduate from the Federal Law Enforcement Training Center (FLETC) volunteered to participate in an exercise designed to evaluate their survivability. In a highly stressful interactive scenario, which included a hostage situation, performance was evaluated for a range of responses, including: shooting judgment and accuracy, communications, and coping with a weapon malfunction. Nineteen percent of subjects shot the hostage, a failure rate that falls in the reported range of friendly fire casualties in military combat. The Spielberger Trait Anger Scale showed an association with shot placement and performance during the gunfight as well as with overall performance scores.

William P. Norris

Papers

Pathology and familial incidence of orchitis and its relation to thyroiditis in a closed beagle colony

Retention of radioactive bone-seekers.

Comparative metabolism of radium, strontium, and calcium

Sectioning of undecalcified bone; with special reference to radioautographic applications.

Evaluating Performance of Law Enforcement Personnel during a Stressful Training Scenario