134 research outputs found
Introduction to half-metallic Heusler alloys: Electronic Structure and Magnetic Properties
Intermetallic Heusler alloys are amongst the most attractive half-metallic
systems due to the high Curie temperatures and the structural similarity to the
binary semiconductors. In this review we present an overview of the basic
electronic and magnetic properties of both Heusler families: the so-called
half-Heusler alloys like NiMnSb and the the full-Heusler alloys like
CoMnGe. \textit{Ab-initio} results suggest that both the electronic and
magnetic properties in these compounds are intrinsically related to the
appearance of the minority-spin gap. The total spin magnetic moment
scales linearly with the number of the valence electrons , such that
for the full-Heusler and for the half-Heusler alloys,
thus opening the way to engineer new half-metallic alloys with the desired
magnetic properties.Comment: 28 pages, submitted for a special issue of 'Journal of Physics D:
Applied Physics' on Heusler alloy
Handlebar hernia: a case report and literature review on traumatic abdominal wall hernia in children
A rare case of abdominal trauma, a handlebar hernia, is described, as well as a review of the pertinent literature. A 7-year-old boy presented to our emergency room after sustaining blunt force to the abdomen; he fell on the handlebar of his bicycle. Immediately after the accident, a bulge was noticeable at the point of impact. Handlebar hernia is a diagnosis that is easily missed, which can lead to strangulation and incarceration of the bowel. With this case report, we hope to augment the knowledge on traumatic abdominal wall hernia, hopefully leading to early diagnosis and treatment
Slater-Pauling Behavior of the Half-Ferromagnetic Full-Heusler Alloys
Using the full-potential screened Korringa-Kohn-Rostoker method we study the
full-Heusler alloys based on Co, Fe, Rh and Ru. We show that many of these
compounds show a half-metallic behavior, however in contrast to the
half-Heusler alloys the energy gap in the minority band is extremely small.
These full-Heusler compounds show a Slater-Pauling behavior and the total
spin-magnetic moment per unit cell (M_t) scales with the total number of
valence electrons (Z_t) following the rule: M_t=Z_t-24. We explain why the
spin-down band contains exactly 12 electrons using arguments based on the group
theory and show that this rule holds also for compounds with less than 24
valence electrons. Finally we discuss the deviations from this rule and the
differences compared to the half-Heusler alloys.Comment: 10 pages, 8 figures, revised figure 3, new text adde
Accurate automated quantitative imaging of tortoise erythrocytes using the NIS image analysis system
The standard method for assessing blood cell characteristics using an ocular micrometer is time-consuming and limited. We used the Nikon NIS Elements imaging software and May-Grünwald-Giemsa staining to determine whether automated image analysis is suitable for rapid and accurate quantitative morphometry of erythrocytes. Blood was collected during four seasons from 126 geometric tortoises and the blood smears were evaluated for cell (C) and nuclear (N) characteristics of the erythrocytes. We measured area, length (L), width (W), perimeter, elongation and pixelation intensity, and calculated L/W and N/C areas. Erythrocyte size differed among cohorts; females, the larger sex, had smaller erythrocytes than either males or juveniles. Males had more elongated erythrocytes than females and erythrocytes of adults were more elongated than those of juveniles. Erythrocyte size and shape influence the efficiency of gas exchange owing to surface area to volume ratios, which are greater for small, elongated cells than for large, round cells. The high N/C ratio and low pixelation intensities of males and juveniles indicate that they may have had more immature erythrocytes in their circulation than females. The use of pixelation intensity to indicate the presence of immature erythrocytes was validated by seasonal differences that corresponded to the biology of the tortoises. Pixelation intensity was lowest in winter. We found that automated image analysis is a rapid and reliable method for determining cell size and shape, and it offers the potential for distinguishing among developmental stages that differ in staining intensity. The method should be useful for rapid health assessments, particularly of threatened species, and for comparative studies among different vertebrates.Web of Scienc
The historical change of brainstem glioma diagnosis and treatment: from imaging to molecular pathology and then molecular imaging
Medicinal plants – prophylactic and therapeutic options for gastrointestinal and respiratory diseases in calves and piglets? A systematic review
Guidelines for Brainstem Surgery with Functional Preservation(<SPECIAL ISSUES> Preservation of the Cranial Nerves)
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