Electron-heating induced by a tunable, supplementary dc-current (Idc) helps to vary the observed magnetoresistance in the high mobility GaAs/AlGaAs 2D electron system. The magnetoresistance at B = 0.3 T is shown to progressively change from positive to negative with increasing Idc, yielding negative giant-magnetoresistance at the lowest temperature and highest Idc. A two-term Drude model succes...

BACKGROUND Intracranial vertebral artery dissection (VAD) is a well-recognized cause of stroke in young and middle-aged individuals, especially in Asian populations. However, a long-term natural course remains unclear. We investigated the long-term time course of VAD using imaging findings to examine the rate and predisposing factors for improvement. METHODS We registered 56 consecutive patie...

BACKGROUND AND PURPOSE Early hematoma growth is not uncommon in patients with intracerebral hemorrhage and is an independent predictor of poor functional outcome. The purpose of our study was to report and validate the use of our newly identified computed tomographic (CT) blend sign in predicting early hematoma growth. METHODS Patients with intracerebral hemorrhage who underwent baseline CT s...

OBJECTIVE The purpose of this study was to retrospectively review cases of intracerebral hemorrhage (ICH) medically treated at our institution to determine if the CT angiography (CTA) 'spot sign' predicts in-hospital mortality and clinical outcome at 3 months in patients with spontaneous ICH. METHODS We conducted a retrospective review of all consecutive patients who were admitted to the depa...

OBJECTIVE To assess if the Hawkins sign can predict whether or not astragalus fractures of the neck will develop avascular necrosis. It is also assessed whether the occurrence of this complication is related to the displacement of the fracture, soft tissue injury, or delay in the reduction or surgery. The results were compared with those found in the literature. MATERIAL AND METHODS A retrosp...

BACKGROUND The meniscal flounce is wavy fold in free inner border of meniscus seen during knee arthroscopy. The presence of this flounce in medial meniscus has been found to be highly predictive of normal medial meniscus. With meniscus related symptoms being commonest indication for undergoing knee arthroscopy, presence or absence of medial meniscus flounce, can be a good guiding sign. In this ...

Existence of a surface wave along the boundary between the semi-infinite materials, one of which is a free-space and the other is a material with either negative permeability or negative permittivity, is presented theoretically in this paper. Surface waves exist in only limited combination of negative and positive sign of the material parameters. In addition, by analyzing the surface wave in a ...

in this paper, we study l1 -solutions of the following two-direction poly-scale refinement equationwe prove that the vector space of all l1 -solutions of the above equation is at most one-dimensional andconsists of compactly supported functions of constant sign. we also show that any- l1 solution of the aboveequation is either positive or negative on its support under a special assumption. with...

There is a conspicuous gap in the literature about feedback and circular causality between intuitive statements about shifts in loop dominance and precise statements about how to define and detect such important nonlinear phenomena. This paper provides a consistent, rigorous, and useful set of definitions of loop polarities, dominant polarity, and shift in loop dominance, and illustrates their ...