RE2O3 Nanoparticles Embedded in SiO2 Glass Matrix — A Colossal Dielectric and Magnetodielectric Response

Significant experimental effort has been inspected to consider and implement favorable high-k gate dielectrics with magnetodielectric (MD) effect of series of rare earth oxide (RE2O3, RE ~ rare earth ions) nanoparticles (NPs) embedded in sol–gel derived SiO2 glass matrix. Properly calcined RE2O3 NP-glass composite systems (in which RE ~ Sm, Gd and Er) show an intriguing colossal enhancement of dielectric constant along with MD effect near room temperature. The enhancement of dielectric constant is closely related to oxygen vacancy induced dielectric relaxation (or, more correctly, particle size effect from different calcined temperature), reconstructed from extended X-ray absorption fine structure. The MD response is strongly depended on the superparamagnetic property of the rare earth ions. From application point of view, the enhancement of dielectric constant associated with MD response can be achieved by tuning the NPs size through varying annealing temperature and/or increasing the doping concentration of magnetic rare earth oxide, which will be the key guidelines to accomplish the compatibility, performance and reliability requirements for future complementary metal-oxide-semiconductor (CMOS) technology

Metamagnetic behavior and effect of field cooling on sharp magnetization jumps in multiferroic Y2CoMnO6

We present sharp magnetization jumps and field induced irreversibility in magnetization in multiferroic Y2CoMnO6. Appearance of magnetic relaxation and field sweep rate dependence of magnetization jumps resemble the martensite like scenario and suggests the coexistence of E*-type antiferromagnetic and ferromagnetic phases at low temperatures. In Y2CoMnO6, the critical field required for the sharp jump can be increased or decreased depening on the magnitude and direction of the cooling field; this is remarkably different from manganites or other metamagnetic materials where the critical field increases irrespective of the direction of the field cooling. The cooling field dependence on the sharp magnetization jumps has been described by considering exchange pinning mechanism at the interface, like in exchange bias model

Observation of Griffiths-like phase and its tunability in La2Ni1-xCoxCoxO6 (0 <= x <= 1) nanoparticles

Temperature and magnetic field dependent magnetic properties of La2Ni1-xCoxMnO6 (0 <= x <= 1) nanoparticles prepared by sol-gel method with average particle size similar to 25-60 nm have been investigated. X-ray diffraction and Raman spectra study have revealed the suppression of structural disorder with the increase of Co content. Magnetic ordering and magnetization properties like, transition temperature (T-C), coercive field (H-C) and spontaneous magnetization (M-S) increases with the Co substitution at the Ni site. The inverse magnetic susceptibility above T-C has shown a broad temperature regime with a downward deviation from the Curie-Weiss law, a characteristic feature of Griffiths-like phase. This temperature regime of magnetic inhomogeneity decreases with the increase of Co content and completely absent for La2CoMnO6. (C) 2016 Elsevier B.V. All rights reserved

Magnetic Glassy Behavior of Pr_0.6Ca_0.4MnO₃ Nanoparticles: Effect of Intra and Interparticle Magnetic Interactions on Magnetodielectric Property

Studies of the dc and ac magnetization on Pr_0.6Ca_0.4MnO₃ (PCMO) nanoparticles indicate the metastable magnetic behavior with random ferromagnetic and antiferromagnetic interactions that led to spin glass (SG) behavior below 90 K. Magnetodielectric (MD) effect has been investigated by dispersing the SG PCMO nanoparticles in a polyvinylidene fluoride (PVDF) matrix. It is found that for low volume fraction of PCMO the MD varies as <i>M</i>², which indicates the intrinsic magnetoelectric (ME) coupling in PCMO nanoparticles. For higher volume fractions (above the percolation threshold) MD goes with the <i>M</i>⁴. The magnetization along with microstructural investigations suggested the significant role of inter/intraclusters magnetic interactions on MD property

Gln48His is the prevalent myocilin mutation in primary open angle and primary congenital glaucoma phenotypes in India.

Contains fulltext : 47799.pdf (publisher's version ) (Open Access)PURPOSE: Myocilin gene defects have been originally implicated in primary open angle glaucoma (POAG). Based on multiple reports for the occurrence of Gln48His mutation (c.144G>T; HGMD accession number CM023962) among Indian POAG patients, we wanted to estimate the prevalence of this mutation in primary open angle and primary congenital glaucoma (PCG) in India and assess its role in the causation of the disease. METHODS: Two hundred cases each of POAG and PCG were screened for the Gln48His mutation by RFLP (AccI) analysis of the PCR amplicons followed by confirmation of the c.144G>T change by direct sequencing. RESULTS: The Gln48His mutation was detected in 9 different glaucoma patients (four POAG and five PCG). While all four POAG cases were heterozygous, among PCG cases, four were heterozygous and one exhibited homozygous genotype for the mutation. One each of POAG and PCG patients was detected to be heterozygous for CYP1B1 mutation (c.1656C>T, Pro437Leu) and (c.1449G>A, Arg368His), respectively. None of the 300 ethnically matched normal controls contained either the MYOC or CYP1B1 mutation(s). CONCLUSIONS: The myocilin mutation, Gln48His, represents an allelic condition involving a spectrum of glaucoma phenotypes in Indian populations, and could be a potential risk factor towards disease predisposition among patients of Indian origin. The study also highlights the role of MYOC as a candidate in different glaucoma subtypes that needs to be investigated further

PHARMACOLOGICAL EVALUATION OF ANTIDEPRESSANT ACTIVITY OF AQUEOUS EXTRACT OF ROSA CENTIFOLIA PETALS IN MICE

ABSTRACT To study the antidepressant activity with aqueous extract of Rosa centifolia. The extract was primarily subjected for preliminary phytochemical investigation and for Maximum Tolerance Dose (MTD). Antidepressant activity was evaluated in various animal models like Forced swim test, Tail suspension test, Apomorphine induced hypothermia and 5-HTP potentiation of head twitches in mice. The aqueous extract of Rosa centifolia was positively identified with carbohydrates, tannins, proteins, amino acids, alkaloids, flavonoids, flavanone, glycosides and phenolic compounds. The extract was subjected for maximum tolerance dose upto the dose level of 2000mg/kg has not produced any mortality. The extract of Rosa centifolia showed significant antidepressant activity at high dose (100 mg/kg) in Tail suspension test, Forced swim test and Potentiation of 5-HTP induced head twitches. The extract didn&apos;t antagonized the hypothermia induced by apomorphine