Neutron diffraction study of the magnetic order in NdMn2Ge1.6Si0.4

Here we report a detailed investigation of NdMn 2 Ge 1.6 Si 0.4 ; this forms part of our investigation of the magnetic order across the NdMn 2 Ge 2− x Si x (x = 0–2.0) series by magnetometry, x-ray diffraction and neutron diffraction over the temperature range 6–465 K. On decreasing the temperature from 465 K, NdMn 2 Ge 1.6 Si 0.4 exhibits four magnetic transitions: (i) from paramagnetism to intralayer antiferromagnetism AFl at T Intra N ~ 430 K; (ii) AFl to canted ferromagnetism Fmc at T Inter C ~ 330 K; (iii) Fmc to conical magnetic ordering of the Mn sublattice Fmi at T cc ~ 178 K and (iv) Fmi(Mn) to Fmi(Mn)+F(Nd) at T Nd C ~ 72 K. (c) 2011 IOP Publishing LT

Visualization of vortex motion in FeAs-based BaFe<inf>1.9</inf>Ni <inf>0.1</inf>As<inf>2</inf> single crystal by means of magneto-optical imaging

Superconductivity has been found in newly discovered iron-based compounds. This paper studies the motion of magnetic vortices in BaFe1.9Ni 0.1As2 single crystal by means of the magneto-optical imaging technique. A series of magneto-optical images reflecting magnetic flux distribution at the crystal surface were taken when the crystal was zero-field cooled to 10 K. The behavior of the vortices, including penetration into and expulsion from the single crystal with increasing and decreasing external fields, respectively, is discussed. The motion behavior is similar to that observed in high-Tc superconducting cuprates with strong vortex pinning; however, the flux-front is irregular due to randomly distributed defects in the crystal. © 2011 American Institute of Physics

Direct observation of local K variation and its correlation to electronic inhomogeneity in (Ba1-xKx)Fe2As2 Pnictide

Local fluctuations in the distribution of dopant atoms are a suspected cause of nanoscale electronic disorder or phase separation observed within the pnictide superconductors. Atom probe tomography results present the first direct observations of dopant nano-clustering in a K-doped 122-phase pnictides. First-principles calculations suggest the coexistence of static magnetism and superconductivity on a lattice parameter length scale over a large range of doping concentrations. Collectively, our results provide evidence for a mixed scenario of phase coexistence and phase separation originating from variation of dopant atom experiments distroibutions.Comment: 4 pages, 4 figures and 1 table, accepted by Physical Review Letter 201

An ultrathin rechargeable solid-state zinc ion fiber battery for electronic textiles.

Electronic textiles (e-textiles), having the capability of interacting with the human body and surroundings, are changing our everyday life in fundamental and meaningful ways. Yet, the expansion of the field of e-textiles is still limited by the lack of stable and biocompatible power sources with aesthetic designs. Here, we report a rechargeable solid-state Zn/MnO2 fiber battery with stable cyclic performance exceeding 500 hours while maintaining 98.0% capacity after more than 1000 charging/recharging cycles. The mechanism of the high electrical and mechanical performance due to the graphene oxide–embedded polyvinyl alcohol hydrogel electrolytes was rationalized by Monte Carlo simulation and finite element analysis. With a collection of key features including thin, light weight, economic, and biocompatible as well as high energy density, the Zn/MnO2 fiber battery could seamlessly be integrated into a multifunctional on-body e-textile, which provides a stable power unit for continuous and simultaneous heart rate, temperature, humidity, and altitude monitoring

Advances in Social Media Research:Past, Present and Future

Social media comprises communication websites that facilitate relationship forming between users from diverse backgrounds, resulting in a rich social structure. User generated content encourages inquiry and decision-making. Given the relevance of social media to various stakeholders, it has received significant attention from researchers of various fields, including information systems. There exists no comprehensive review that integrates and synthesises the findings of literature on social media. This study discusses the findings of 132 papers (in selected IS journals) on social media and social networking published between 1997 and 2017. Most papers reviewed here examine the behavioural side of social media, investigate the aspect of reviews and recommendations, and study its integration for organizational purposes. Furthermore, many studies have investigated the viability of online communities/social media as a marketing medium, while others have explored various aspects of social media, including the risks associated with its use, the value that it creates, and the negative stigma attached to it within workplaces. The use of social media for information sharing during critical events as well as for seeking and/or rendering help has also been investigated in prior research. Other contexts include political and public administration, and the comparison between traditional and social media. Overall, our study identifies multiple emergent themes in the existing corpus, thereby furthering our understanding of advances in social media research. The integrated view of the extant literature that our study presents can help avoid duplication by future researchers, whilst offering fruitful lines of enquiry to help shape research for this emerging field

MLL-fusion-driven leukemia requires SETD2 to safeguard genomic integrity

MLL-fusions represent a large group of leukemia drivers, whose diversity originates from the vast molecular heterogeneity of C-terminal fusion partners of MLL. While studies of selected MLL-fusions have revealed critical molecular pathways, unifying mechanisms across all MLL-fusions remain poorly understood. We present the first comprehensive survey of protein-protein interactions of seven distantly related MLL-fusion proteins. Functional investigation of 128 conserved MLL-fusion-interactors identifies a specific role for the lysine methyltransferase SETD2 in MLL-leukemia. SETD2 loss causes growth arrest and differentiation of AML cells, and leads to increased DNA damage. In addition to its role in H3K36 tri-methylation, SETD2 is required to maintain high H3K79 di-methylation and MLL-AF9-binding to critical target genes, such as Hoxa9. SETD2 loss synergizes with pharmacologic inhibition of the H3K79 methyltransferase DOT1L to induce DNA damage, growth arrest, differentiation, and apoptosis. These results uncover a dependency for SETD2 during MLL-leukemogenesis, revealing a novel actionable vulnerability in this disease

Bone marrow-derived cells in ocular neovascularization: contribution and mechanisms

Ocular neovascularization often leads to severe vision loss. The role of bone marrow-derived cells (BMCs) in the development of ocular neovascularization, and its significance, is increasingly being recognized. In this review, we discuss their contribution and the potential mechanisms that mediate the effect of BMCs on the progression of ocular neovascularization. The sequence of events by which BMCs participate in ocular neovascularization can be roughly divided into four phases, i.e., mobilization, migration, adhesion and differentiation. This process is delicately regulated and liable to be affected by multiple factors. Cytokines such as vascular endothelial growth factor, granulocyte colony-stimulating factor and erythropoietin are involved in the mobilization of BMCs. Studies have also demonstrated a key role of cytokines such as stromal cell-derived factor-1, tumor necrosis factor-α, as well as vascular endothelial growth factor, in regulating the migration of BMCs. The adhesion of BMCs is mainly regulated by vascular cell adhesion molecule-1, intercellular adhesion molecule-1 and vascular endothelial cadherin. However, the mechanisms regulating the differentiation of BMCs are largely unknown at present. In addition, BMCs secrete cytokines that interact with the microenvironment of ocular neovascularization; their contribution to ocular neovascularization, especially choroidal neovascularization, can be aggravated by several risk factors. An extensive regulatory network is thought to modulate the role of BMCs in the development of ocular neovascularization. A comprehensive understanding of the involved mechanisms will help in the development of novel therapeutic strategies related to BMCs. In this review, we have limited the discussion to the recent progress in this field, especially the research conducted at our laboratory

Activating Titania for Efficient Electrocatalysis by Vacancy Engineering

© 2018 American Chemical Society. Pursuing efficient and low-cost electrocatalysts is crucial for the performance of water-alkali electrolyzers toward water splitting. Earth-abundant transition-metal oxides, in spite of their alluring performances in the oxygen evolution reaction, are thought to be inactive in the hydrogen evolution reaction in alkaline media. Here, we demonstrate that pure TiO2 single crystals, a typical transition-metal oxide, can be activated toward electrocatalytic hydrogen evolution reaction in alkaline media through engineering interfacial oxygen vacancies. Experimental and theoretical results indicate that subsurface oxygen vacancies and low-coordinated Ti ions (Ti3+) can enhance the electrical conductivity and promote electron transfer and hydrogen desorption, which activate reduced TiO2 single crystals in the hydrogen evolution reaction in alkaline media. This study offers a rational route for developing reduced transition-metal oxides for low-cost and highly active hydrogen evolution reaction catalysts, to realize overall water splitting in alkaline media

Hierarchical Ru nanospheres as highly effective cathode catalysts for Li-O<inf>2</inf> batteries

© The Royal Society of Chemistry. Carbon-free, hierarchical Ru nanospheres are reported as an effective cathode catalyst for Li-O2 batteries. The hierarchical Ru nanospheres were synthesized by a simple one-step hydrothermal method. As evaluated by electrochemical measurements, it was found that the carbon-free hierarchical Ru nanosphere cathode can significantly reduce discharge and charge overpotential (∼0.3 V with the capacity limited to 1000 mA h g-1) with a high discharge capacity of 3445 mA h g-1 at a current density of 200 mA g-1 (ORR). This superior oxygen evolution reaction (OER) and oxygen reduction reaction catalytic performance can be maintained over long time cycling at different current densities. Ex situ scanning electron microscopy, X-ray diffraction, and Raman measurements reveal that leaf-shaped Li2O2 is the only reaction product during the discharge process, and the hierarchical Ru nanospheres can effectively decompose the Li2O2 discharge product, facilitate the OER, and promote a high round-trip efficiency. Therefore, the carbon-free hierarchical Ru nanospheres are a promising cathode catalyst for rechargeable Li-O2 batteries with low charge overpotential, long cycle life, and high specific capacity