BACKGROUND AND PURPOSE Fractures can be prevented if osteoporosis is identified and treated. In 2002, we initiated a screening program at our orthopedics department, in which patients between 50 and 75 years of age with a wrist, shoulder, vertebral, or hip fracture are assessed by DEXA of the hip and spine and encouraged to see their doctor for decision on treatment regarding osteoporosis. The ...

i ntroduction: vertical root fracture (vrf) is the longitudinal fracture of the root in endodontically treated teeth. considering the limitations of two-dimensional radiographic images in detection of vrf and introduction of cone-beam computed tomography (cbct), this study was designed to find the sensitivity, specificity and accuracy of cbct and periapical (pa) radiography in detection of vrfs...

The response of a la rge-crystal sodium-iodide spectrometer was studied fo[' individual monoenergetic electrons extracted from a 50-million-electron-volt betatron operatcd between 1 a nd 20 Mev. The energy resolut ion with crystals 5 inches in diameter by 4 inches in length a nd 5 inches in diameter by 9 inches in length reaches its optimum value fo r electrons of 6 Mev where t he total width o...

Oligonucleotide analysis, by a novel computerized procedure, was first applied to determine the sequence of an ideal E. coli promoter (Scherer et al., Nucl. Acids Res. 1978, 5:3759-3773) and has now been used to obtain the sequence of nucleotides that should be present in a messenger RNA for optimum binding to the E. coli ribosome. This sequence is: UU.UUAAAAAUUAAGGAGGUAUAUUAUGAAAAAAAUUAAAAAACU...

The onshore oil and natural gas industries of China have started a large-scale development when crude oil reserves have been difficult to recover. The stratum fracture modification is an indispensable measure to efficiently develop oil and gas fields. Hydraulic fracturing is the most important reservoir stimulation technique, but it is still faced with various problems such as the failure to fr...

This paper presents a procedure to determine an element-length dependent strain and stress relation until fracture that is suitable for implementation in finite element models. This material relation is obtained experimentally with an optical measuring system. The strain until fracture is calculated from the measured surface displacements. The stress is derived from the measured force and the c...

Many injection/production wells have been hydraulically fractured to enhance injectivity/productivity. Various engineering models for fracture geometry have been developed, which define the propagation of a fracture with time and wellbore treatment pressure. These models combine with elasticity, fluid flow, material balance, and propagation criterion/in-situ stresses. When this combination desc...

Following our innovative experimental spontaneous fracture models for frictional fractures (compression and shear) and mixed-mode fractures (tension and shear) in identical materials, we designed a laboratory model to investigate the effects of material contrast on mixed-mode spontaneous fracture along a bimate-rial interface. A series of interesting phenomena are observed, including asymmetry ...