118 research outputs found
Magnetic Materials: Experimental Evidence of Chiral Ferrimagnetism in Amorphous GdCo Films (Adv. Mater. 27/2018)
Launching a new dimension with 3D magnetic nanostructures
The scientific and technological exploration of three-dimensional magnetic nanostructures is an emerging research field that opens the path to exciting novel physical phenomena, originating from the increased complexity in spin textures, topology, and frustration in three dimensions. One can also anticipate a tremendous potential for novel applications with those systems in a magnetic sensor and information processing technologies in terms of improved energy efficiency, processing speed, functionalities, and miniaturization of future spintronic devices. These three-dimensional structures are distinct from traditional bulk systems as they harness the scientific achievements of nanomagnetism, which aimed at lowering the dimensions down to the atomic scale, but expand those now in a tailored and designed way into the third dimension. This research update provides an overview of the scientific challenges and recent progress with regard to advances in synthesis approaches and state-of-the-art nanoscale characterization techniques that are prerequisite to understand, realize, and control the properties, behavior, and functionalities of three-dimensional magnetic nanostructures
Origin of enhanced anisotropy in FePt-C granular films revealed by XMCD
We study the effect of carbon segregants on the spin and orbital moments of L10 FePt granular media using x-ray magnetic circular dichroism (XMCD) spectroscopy and report an effective decoupling of the structural film properties from the magnetic parameters of the grains. The carbon concentration reduces the grain size from (200 ± 160) nm2 down to (50 ± 20) nm2 for 40 mol. %C and improves sphericity and the order of grains, while preserving the crystalline order, spin and orbital moments, and perpendicular magnetocrystalline anisotropy. We identify the primary cause of enhanced saturation and coercive fields as the reduced demagnetization fields of individual grains. The ability to shrink grains without impairing their magnetic properties is a critical requirement for the commercialization of Heat-Assisted Magnetic Recording
Evolution of the C4 phosphoenolpyruvate carboxylase promoter of the C4 species Flaveria trinervia: the role of the proximal promoter region
<p>Abstract</p> <p>Background</p> <p>The key enzymes of photosynthetic carbon assimilation in C<sub>4 </sub>plants have evolved independently several times from C<sub>3 </sub>isoforms that were present in the C<sub>3 </sub>ancestral species. The C<sub>4 </sub>isoform of phosphoenolpyruvate carboxylase (PEPC), the primary CO<sub>2</sub>-fixing enzyme of the C<sub>4 </sub>cycle, is specifically expressed at high levels in mesophyll cells of the leaves of C<sub>4 </sub>species. We are interested in understanding the molecular changes that are responsible for the evolution of this C<sub>4</sub>-characteristic PEPC expression pattern, and we are using the genus <it>Flaveria </it>(Asteraceae) as a model system. It is known that <it>cis</it>-regulatory sequences for mesophyll-specific expression of the <it>ppcA1 </it>gene of <it>F. trinervia </it>(C<sub>4</sub>) are located within a distal promoter region (DR).</p> <p>Results</p> <p>In this study we focus on the proximal region (PR) of the <it>ppcA1 </it>promoter of <it>F. trinervia </it>and present an analysis of its function in establishing a C<sub>4</sub>-specific expression pattern. We demonstrate that the PR harbours <it>cis</it>-regulatory determinants which account for high levels of PEPC expression in the leaf. Our results further suggest that an intron in the 5' untranslated leader region of the PR is not essential for the control of <it>ppcA1 </it>gene expression.</p> <p>Conclusion</p> <p>The allocation of <it>cis</it>-regulatory elements for enhanced expression levels to the proximal region of the <it>ppcA1 </it>promoter provides further insight into the regulation of PEPC expression in C<sub>4 </sub>leaves.</p
Ich bin kein Etikett: Eine Ausstellung über Diskriminierung
Wir versehen Menschen oft allein aufgrund ihres Geschlechts, ihrer Hautfarbe, ihres Namens oder ihres Verhaltens mit einem Etikett. Dieses Etikett beruht auf Gedanken und Bildern, wie wir uns die Menschen vorstellen – ohne sie zu kennen. Etiketten transportieren Vorurteile. Die Folgen sind massiv. So können Vorurteile in diskriminierende Verhaltensweisen münden. Abwertende Bemerkungen, Beschimpfungen, Benachteiligungen erfahren bestimmte Menschen recht häufig. Dabei findet Diskriminierung unbewusst oder bewusst in allen Bereichen der Gesellschaft statt: u.a. in der Familie, auf dem Arbeits- und Wohnungsmarkt, in der Gesundheitsversorgung und in der Bildung.
Die Ausstellung im April 2016 im Hygienemuseum Dresden ist in Teilen finanziert über RomaRespekt, einem Modellprojekt des BMFSFJ im Rahmen des Bundesprogramms „Demokratie leben!“.
April 201
Электропривод питателя сушильного барабана
Проведен расчет параметров и выбор элементов электропривода питателя сушильного барабана; разработка и исследование математической модели электропривода. Организационно экономическая часть: технико-экономическая обоснование проекта. Проработка вопросов безопасности и экологичности проекта.The calculation of the parameters and the selection of the electric drive elements of the dryer drum feeder; development and research of a mathematical model of an electric drive. Organizational and economic part: feasibility study for the project. Development of safety and environmental issues of the project
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Retrieving spin textures on curved magnetic thin films with full-field soft X-ray microscopies
X-ray tomography is a well-established technique to characterize 3D structures in material sciences and biology; its magnetic analogue--magnetic X-ray tomography--is yet to be developed. Here we demonstrate the visualization and reconstruction of magnetic domain structures in a 3D curved magnetic thin films with tubular shape by means of full-field soft X-ray microscopies. The 3D arrangement of the magnetization is retrieved from a set of 2D projections by analysing the evolution of the magnetic contrast with varying projection angle. Using reconstruction algorithms to analyse the angular evolution of 2D projections provides quantitative information about domain patterns and magnetic coupling phenomena between windings of azimuthally and radially magnetized tubular objects. The present approach represents a first milestone towards visualizing magnetization textures of 3D curved thin films with virtually arbitrary shape
Three-dimensional nanomagnetism
Magnetic nanostructures are being developed for use in many aspects of our daily life, spanning areas such as data storage, sensing and biomedicine. Whereas patterned nanomagnets are traditionally two-dimensional planar structures, recent work is expanding nanomagnetism into three dimensions; a move triggered by the advance of unconventional synthesis methods and the discovery of new magnetic effects. In three-dimensional nanomagnets more complex magnetic configurations become possible, many with unprecedented properties. Here we review the creation of these structures and their implications for the emergence of new physics, the development of instrumentation and computational methods, and exploitation in numerous applications
Reconfigurable ferromagnetic liquid droplets.
Solid ferromagnetic materials are rigid in shape and cannot be reconfigured. Ferrofluids, although reconfigurable, are paramagnetic at room temperature and lose their magnetization when the applied magnetic field is removed. Here, we show a reversible paramagnetic-to-ferromagnetic transformation of ferrofluid droplets by the jamming of a monolayer of magnetic nanoparticles assembled at the water-oil interface. These ferromagnetic liquid droplets exhibit a finite coercivity and remanent magnetization. They can be easily reconfigured into different shapes while preserving the magnetic properties of solid ferromagnets with classic north-south dipole interactions. Their translational and rotational motions can be actuated remotely and precisely by an external magnetic field, inspiring studies on active matter, energy-dissipative assemblies, and programmable liquid constructs
Dipeptidylpeptidase IV (CD26) defines leukemic stem cells (LSC) in chronic myeloid leukemia
Chronic myeloid leukemia (CML) is a stem cell (SC) neoplasm characterized by the BCR/ABL1 oncogene. Although mechanisms of BCR/ABL1-induced transformation are well-defined, little is known about effector-molecules contributing to malignant expansion and the extramedullary spread of leukemic SC (LSC) in CML. We have identified the cytokine-targeting surface enzyme dipeptidylpeptidase-IV (DPPIV/CD26) as a novel, specific and pathogenetically relevant biomarker of CD34+/CD38─ CML LSC. In functional assays, CD26 was identified as target enzyme disrupting the SDF-1-CXCR4-axis by cleaving SDF-1, a chemotaxin recruiting CXCR4+ SC. CD26 was not detected on normal SC or LSC in other hematopoietic malignancies. Correspondingly, CD26+ LSC decreased to low or undetectable levels during successful treatment with imatinib. CD26+ CML LSC engrafted NOD-SCID-IL-2Rγ−/− (NSG) mice with BCR/ABL1+ cells, whereas CD26─ SC from the same patients produced multilineage BCR/ABL1– engraftment. Finally, targeting of CD26 by gliptins suppressed the expansion of BCR/ABL1+ cells. Together, CD26 is a new biomarker and target of CML LSC. CD26 expression may explain the abnormal extramedullary spread of CML LSC, and inhibition of CD26 may revert abnormal LSC function and support curative treatment approaches in this malignancy
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