conclusion fs t2 w and ce fs t1 w sequences of axial planes were the most useful sequences in determination of active sacroiliitis. therefore, in patients with renal failure or allergy to contrast media, fs t2 wi can be obtained to detect active sacroiliitis. objectives the aim of this retrospective study was to assess the value of different magnetic resonance imaging (mri) sequences in evaluat...

Introduction: All of the Imaging modalities have advantages and disadvantages alone. So if we want to have the best and perfect image, combining these modalities produces something we desired. PET-MR images consist of morphologic and metabolic data. MRI and PET provide high spatial and contrast resolution and high sensitivity and molecular information respectively. Hybrid PET-...

Delineating industry groups of related firms and identifying strategic peers is important for both financial practitioners and scholars. Our study explores whether the degree to which pairs of companies are associated with each other in an online stock forum is related to the comovement of their stocks. We find that our news-based measure of relatedness can explain stock returns with the same p...

This paper starts with a definition and review of barter and countertrade and the reasons for their growth in modern times. The author develops a classification scheme for the various forms of countertrade based on the time horizon and the degree of capitalinvolved. In addition, he provides a conceptual framework for understanding the various forms of countertrade. He concludes by examining cor...

The ability of a nation to participate in the global knowledge economy depends to some extent on its capacities in science and technology. In an effort to assess the capacity of different countries in science and technology, this article updates a classification scheme developed by RAND to measure science and technology capacity for 150 countries of the world.

The quantification of valvular regurgitations requires the accurate measurement of fast flow jets of 5-7 m/s. Conventional phase contrast imaging sequences are usually corrupted by flow artifacts at these high velocities. We present a CINE gated breath held method based on short-TR spiral phase contrast, which has a sufficiently short measurement time (< 4 ms) to minimize flow artifacts. Simula...

Computer simulations are used to design more hydrated bilayers, formed from amine-modified porphyrin-phospholipids (PoPs). Experiments confirm that the new constructs give rise to bilayers with greater water content. When chelated with manganese, amine-modified PoPs provide improved contrast for magnetic resonance and are safely used for imaging in vivo.

We give a classification of non-orthogonality classes of trivial order 1 strongly minimal sets in differentially closed fields. A central idea is the introduction of τ -forms, functions on the prolongation of a variety which are analogous to 1-forms. Order 1 strongly minimal sets then correspond to smooth projective curves with τ -forms. We also introduce τ -differentials, algebraic versions of...

The term “flexible learning’ has been used by many institutions with regard to their methods of course delivery, particularly by those seeking to attract external students. In almost no cases is the use of the term justified, since the flexibility concerned relates only to certain very limited components of the learning process. This paper outlines the very real problems that are faced by insti...

The superior scattering properties of gas bubbles compared with blood cells have made microbubble ultrasound contrast agents important tools in ultrasound diagnosis. Over the past 2 years they have become the focus of a wide and rapidly expanding field of research, with their benefits being repeatedly demonstrated, both in ultrasound image enhancement, and more recently in drug and gene deliver...