Mark: This is a prospective, observational study to determine if negative electrocardiography (ECG) performed while the patient is having chest pain can reliably rule out coronary disease. Eligible participants presented to the emergency department with chest pain and had normal initial ECG. Eligibility criteria also included age older than 25 years, two negative troponins over six hours, and a...

BACKGROUND Lumbar spinal stenosis (LSS) is defined as narrowing of the spinal canal. LSS is commonly treated conservatively, primarily with flexion-based exercises. We present a patient diagnosed with LSS, refractory to a flexion-based protocol who ultimately responded to an extension-based protocol following establishment of directional preference with three-step treadmill testing. DESCRIPTI...

Modern X-ray imaging systems evolve toward digitization for reduced cost, faster time-to-diagnosis, and improved diagnostic confidence. For the digital X-ray systems, charge coupled device (CCD) technology is commonly used to detect and digitize optical X-ray image. This paper presents a novel soft-test/repair approach to overcome the defective pixel problem in CCD-based digital X-ray systems t...

A laboratory test is clinically useful only if it successfully answers a question of consequence to patient management. Unfortunately, the results and conclusions of many published test evaluations are misleading or of uncertain validity because common-sense principles of study design are overlooked. This is illustrated by examples from recent literature. We suggest that tests should be evaluat...

In quantum gravity interpretations, the role of spaceand time-related concepts is debated. Some argue that these concepts are not needed to describe physical reality at the Planck scale. Others object that an operational definition of magnitudes cannot get rid of spatiotemporal notions. We propose a “conceptual test” to assess if the mathematical content of a quantum gravity theory refers to so...