Hybridization effects on the magnetic ground state of ruthenium in double perovskite LaZnRuTiO.

An exotic quantum mechanical ground state, i.e. the nonmagnetic= 0 state, has been predicted for higher transition metal tsystems, due to the influence of strong spin-orbit coupling (SOC) or in other words, due to unquenched orbital moment contribution.

Probing the Magnetic Ground State of BaYIrO: Impact of Nonmagnetic Dopants and Spin-Orbit Coupling.

Strong spin-orbit coupling (SOC) in iridates has long been predicted to lead to exotic electronic and magnetic ground states. Ba2YIrO6 (BYIO) has attracted particular attention due to the expectation of a Jeff = 0 state for Ir5+ ions under the jj-coupling scheme. However, controversies surround the actual realization of this state, as finite magnetic moments are consistently observed experimentally.

Structural Rearrangement Followed by Entrapment of Subnanometer Building Blocks of Iron Oxyhydroxide in Aqueous Iron Chloride Solutions.

Iron oxyhydroxide, a natural nanophase of iron found in the environment, plays a crucial role in regulating surface and groundwater composition. Recent research proposes that within the nonclassical prenucleation cluster growth model, subnanometer-sized clusters (olation clusters/Fe δ-Keggin oxolation clusters) might act as the prenucleation clusters (PNCs) of ferrihydrite or iron oxyhydroxide solid phase. However, these clusters are difficult to characterize as they are only observable momentarily in low-pH, high-Fe concentration solutions before agglomerating into extended solids, keeping the controversy over the true nature of the PNCs alive.

Curious Behavior of Fe-As Chemical Interactions and Nucleation of Clusters in Aqueous Medium.

The simultaneous presence of Fe and As ions in groundwater (higher ppb or lower ppm level concentrations at circumneutral pH) as well as in acid mine drainages (AMDs)/industrial wastewater (up to few thousand ppm concentration at strongly acidic pH) are quite common. Therefore, understanding the chemical interactions prevalent between Fe and As ions in aqueous medium leading to nucleation of ionic clusters/solids, followed by aggregation and growth, is of great environmental significance. In the present work, we attempt to probe the nucleation process of Fe-As clusters in solutions of various concentrations and pHs (from AMD to groundwater-like) using a combination of experimental and theoretical techniques.

Immunomodulatory therapy with glatiramer acetate reduces endoplasmic reticulum stress and mitochondrial dysfunction in experimental autoimmune encephalomyelitis.

Endoplasmic reticulum (ER) stress and mitochondrial dysfunction are found in lesions of multiple sclerosis (MS) and animal models of MS such as experimental autoimmune encephalomyelitis (EAE), and may contribute to the neuronal loss that underlies permanent impairment. We investigated whether glatiramer acetate (GA) can reduce these changes in the spinal cords of chronic EAE mice by using routine histology, immunostaining, and electron microscopy. EAE spinal cord tissue exhibited increased inflammation, demyelination, mitochondrial dysfunction, ER stress, downregulation of NAD+ dependent pathways, and increased neuronal death.

The Critical Role of Stereochemically Active Lone Pair in Introducing High Temperature Ferroelectricity.

In this paper, a comparative structural, dielectric, and magnetic study of two langasite compounds BaTeCoPO (absence of lone pair) and PbTeCoPO (Pb 6s lone pair) have been carried out to precisely explore the development of room temperature spontaneous polarization in the presence of a stereochemically active lone pair. In the case of PbTeCoPO, mixing of both Pb 6s with Pb 6p and O 2p helps the lone pair to be stereochemically active. This stereochemically active lone pair brings a large structural distortion within the unit cell and creates a polar geometry, while the BaTeCoPO compound remains in a nonpolar structure due to the absence of any such effect.

Revisiting Goodenough-Kanamori rules in a new series of double perovskites LaSrCaNiReO.

The magnetic ground states in highly ordered double perovskites LaSrCaNiReO (x = 0.0, 0.5, 1.

Hopping-Induced Ground-State Magnetism in 6H Perovskite Iridates.

Investigation of elementary excitations has advanced our understanding of many-body physics governing most physical properties of matter. Recently spin-orbit excitons have drawn much attention, whose condensates near phase transitions exhibit Higgs mode oscillations, a long-sought-after physical phenomenon [A. Jain, et al.

Development of half metallicity within mixed magnetic phase of Cu Co MnSb alloy.

Cubic half-Heusler Cu Co MnSb ([Formula: see text]) compounds have been investigated both experimentally and theoretically for their magnetic, transport and electronic properties in search of possible half metallic antiferromagnetism. The systems (Cu,Co)MnSb are of particular interest as the end member alloys CuMnSb and CoMnSb are semi metallic (SM) antiferromagnetic (AFM) and half metallic (HM) ferromagnetic (FM), respectively. Clearly, Co-doping at the Cu-site of CuMnSb introduces changes in the carrier concentration at the Fermi level that may lead to half metallic ground state but there remains a persistent controversy whether the AFM to FM transition occurs simultaneously.

Glomerular mitochondrial changes in HIV associated renal injury.

HIV-associated nephropathy (HIVAN) is an AIDs-related disease of the kidney. HIVAN is characterized by severe proteinuria, podocyte hyperplasia, collapse, glomerular, and tubulointerstitial damage. HIV-1 transgenic (Tg26) mouse is the most popular model to study the HIV manifestations that develop similar renal presentations as HIVAN.

Renal aquaporin-4 associated pathology in TG-26 mice.

Human immunodeficiency virus-associated nephropathy (HIVAN) is a leading cause of end-stage renal disease in HIV patients, which is characterized by glomerulosclerosis and renal tubular dysfunction. Aquaporin-4 (AQP-4) is a membrane bound water channel protein that plays a distinct role in water reabsorption from renal tubular fluid. It has been proven that failure of AQP-4 insertion into the renal tubular membrane leads to renal dysfunction.

Rapid decadal evolution in the groundwater arsenic content of Kolkata, India and its correlation with the practices of her dwellers.

Increasing arsenic contamination in the groundwater is one of the biggest environmental challenges that the Bengal delta is facing today. Groundwater is still the main source of water for a large number of population in this region and therefore, significant presence of toxic arsenic has a direct consequence on human lives here. Moreover, arsenic also enters into the food chain through the consumed agricultural products grown in this area.

Efficient artificial mineralization route to decontaminate Arsenic(III) polluted water - the Tooeleite Way.

Increasing exposure to arsenic (As) contaminated ground water is a great threat to humanity. Suitable technology for As immobilization and removal from water, especially for As(III) than As(V), is not available yet. However, it is known that As(III) is more toxic than As(V) and most groundwater aquifers, particularly the Gangetic basin in India, is alarmingly contaminated with it.

Origin of the Spin-Orbital Liquid State in a Nearly J=0 Iridate Ba_{3}ZnIr_{2}O_{9}.

We show using detailed magnetic and thermodynamic studies and theoretical calculations that the ground state of Ba_{3}ZnIr_{2}O_{9} is a realization of a novel spin-orbital liquid state. Our results reveal that Ba_{3}ZnIr_{2}O_{9} with Ir^{5+} (5d^{4}) ions and strong spin-orbit coupling (SOC) arrives very close to the elusive J=0 state but each Ir ion still possesses a weak moment. Ab initio density functional calculations indicate that this moment is developed due to superexchange, mediated by a strong intradimer hopping mechanism.

Investigating the development of spurious magnetism in single crystalline BaTi₀.₉₅Fe₀.₀₅O₃-δ with high δ by local structural probes.

BaTi₀.₉₅Fe₀.₀₅O₃-δ has been suggested to be an intrinsic dilute magnetic oxide with a clear dependence of magnetism on oxygen vacancy concentration.

Microscopic distribution of metal dopants and anion vacancies in Fe-doped BaTiO(3-δ) single crystals.

A detailed microscopic structural study on two single crystalline dilute magnetic oxides, BaTi0.95Fe0.05O(3-δ) with and without perceptible δ, has been carried out.

Mobilization of progenitor cells into peripheral blood by gamma-tocotrienol: a promising radiation countermeasure.

Gamma-tocotrienol (GT3), a vitamin E isoform, is shown to induce high levels of granulocyte colony stimulating factor (G-CSF) in mice. G-CSF is a key cytokine used for stimulation of hematopoiesis, and mobilization of hematopoietic stem and progenitor cells into peripheral blood. GT3 is also shown to induce vascular endothelial growth factor (VEGF), another important cytokine necessary for vasculogenesis and endothelial progenitor mobilization.

Defect controlled room temperature ferromagnetism in Co-doped barium titanate nanocrystals.

Defect mediated high temperature ferromagnetism in oxide nanocrystallites is the central feature of this work. Here, we report the development of room temperature ferromagnetism in nanosized Co-doped barium titanate particles with a size of around 14 nm, synthesized by a solvothermal drying method. A combination of x-ray diffraction with state-of-the-art electron microscopy techniques confirms the intrinsic doping of Co into BaTiO3.

Spin-valve-type magnetoresistance: a generic feature of ferromagnetic double perovskites.

An unusual magnetoresistance (MR) behavior in Sr(2)FeMoO(6), recently termed as spin-valve-type MR (SVMR), presents several anomalies that are little understood so far. The formation of a magnetically distorted skin layer around every soft, ferromagnetic grain seems to be the reason behind such an unprecedented tunneling MR (TMR) response. However, initially it appeared that Sr(2)FeMoO(6) is an exclusive TMR material showing an unusual SVMR effect, while other well-known magnetoresistive compounds do not exhibit such behavior.

Nature of "disorder" in the ordered double perovskite Sr2FeMoO6.

The degree of B/B;{'} alternate cation order is known to heavily influence the magnetic properties of A_{2}BB;{'}O_{6} double perovskites although the nature of such disorder has never been critically studied. Our detailed x-ray absorption fine structure studies in conjunction with synchrotron radiation x-ray diffraction experiments on polycrystalline Sr_{2}FeMoO_{6} samples with various degrees of disorder reveal that a very high degree of short range order is preserved even in samples with highly reduced long range chemical order. Based on these experimental results and with the help of detailed structural simulations, we are able to model the nature of the disorder in this important class of materials and discuss the consequent implications on its physical properties.

Local structure of Sr(2)FeMo(x)W(1-x)O(6) double perovskites across the composition-driven metal to insulator transition.

Sr(2)FeMoO(6) oxides exhibit a half-metallic ferromagnetic (HM-FM) ground state and peculiar magnetic and magnetotransport properties, which are interesting for applications in the emerging field of spintronics and attractive for fundamental research in the field of heavily correlated electron systems. Sr(2)FeWO(6) is an insulator with an antiferromagnetic (I-AFM) ground state. The solid solutions Sr(2)FeMo(x)W(1-x)O(6) also have peculiar properties-W doping enhances chemical order which allows stabilization of the HM-FM state; as the W content exceeds a certain value a metal to insulator transition (MIT) occurs.

A role for lengsin, a recruited enzyme, in terminal differentiation in the vertebrate lens.

Lengsin is an eye lens-specific member of the glutamine synthetase (GS) superfamily. Lengsin has no GS activity, suggesting that it has a structural rather than catalytic role in lens. In situ hybridization and immunofluorescence showed that lengsin is expressed in terminally differentiating secondary lens fiber cells.

Critical test for Altshuler-Aronov theory: evolution of the density of states singularity in double perovskite Sr2FeMoO6 with controlled disorder.

With high-resolution photoemission spectroscopy measurements, the density of states (DOS) near the Fermi level (E(F)) of double perovskite Sr(2)FeMoO(6) having different degrees of Fe/Mo antisite disorder has been investigated with varying temperature. The DOS near E(F) showed a systematic depletion with increasing degree of disorder, and recovered with increasing temperature. Altshuler-Aronov (AA) theory of disordered metals well explains the dependences of the experimental results.

Intergranular magnetoresistance in Sr2FeMoO6 from a magnetic tunnel barrier mechanism across grain boundaries.

We present magnetization (M) and magnetoresistance (MR) data for a series of Sr2FeMoO6 samples with independent control on antisite defect and grain-boundary densities, which reveal several unexpected features, including a novel switching-like behavior of MR with M. These, in conjunction with model calculations, establish that the MR in Sr2FeMoO6 is dominantly controlled by a new mechanism, derived from the magnetic polarization of grain-boundary regions acting like spin valves, leading to behavior qualitatively different from that usually encountered in tunneling MR. We show that a simple and useful experimental signature for the presence of this spin-valve-type MR (SVMR) is a wider hysteresis in MR compared to that in M.