Broken Time Reversal Symmetry and Superconducting States in the Cuprates

Recently, Kaminski et al. have reported that time reversal symmetry is broken in the pseudogap phase in the high temperature superconducting material Bi_2Sr_2CaCu_2O_{2+\delta} (Bi-2212). Here we examine the role of translationally invariant broken time reversal states on d_{x^2-y^2} superconductors. In particular, we determine the change in the superconducting order parameter structure. We find that the broken time reversal pseudogap state that is consistent with the experiment of Kaminski et al., gives rise to a novel mixed singlet-triplet pairing d+ip phase. This d+ip state is shown to give rise to a helical superconducting phase. Consequences of this d+ip state on Josephson experiments are discussed.Comment: 5 pages, 1 figur

Quasi-classical determination of the in-plane magnetic field phase diagram of superconducting Sr_2RuO_4

We have carried out a determination of the magnetic-field-temperature (H-T) phase diagram for realistic models of the high field superconducting state of tetragonal Sr_2RuO_4 with fields oriented in the basal plane. This is done by a variational solution of the Eilenberger equations.This has been carried for spin-triplet gap functions with a {\bf d}-vector along the c-axis (the chiral p-wave state) and with a {\bf d}-vector that can rotate easily in the basal plane. We find that, using gap functions that arise from a combination of nearest and next nearest neighbor interactions, the upper critical field can be approximately isotropic as the field is rotated in the basal plane. For the chiral {\bf d}-vector, we find that this theory generically predicts an additional phase transition in the vortex state. For a narrow range of parameters, the chiral {\bf d}-vector gives rise to a tetracritical point in the H-T phase diagram. When this tetracritical point exists, the resulting phase diagram closely resembles the experimentally measured phase diagram for which two transitions are only observed in the high field regime. For the freely rotating in-plane {\bf d}-vector, we also find that additional phase transition exists in the vortex phase. However, this phase transition disappears as the in-plane {\bf d}-vector becomes weakly pinned along certain directions in the basal plane.Comment: 12 pages, 8 figure

Studies on HDL associated enzymes under experimental hypercholesterolemia: possible modulation on selenium supplementation

<p>Abstract</p> <p>Background</p> <p>Atherosclerosis is a chronic disorder of the arterial wall that starts by formation of fatty streaks and gradually evolves into atherosclerotic plaques. High-density lipoproteins (HDL) blood levels are inversely correlated with atherosclerosis. This beneficial effect of HDL has been partly attributed to its antioxidant properties mediated by paraoxonase1 (PON1) or platelet-activating factor acetylhydrolase (PAF-AH). The present study was aimed to study HDL associated enzymes i.e. PON1 and PAF-AH under experimental hypercholesterolemia and their possible modulation on selenium (Se; an antioxidant) supplementation. Male Sprague Dawley rats were divided into three groups and fed on the control diet, high fat diet (HFD) and HFD + Se respectively for the period of 4 months.</p> <p>Results</p> <p>Cholesterol, triglycerides, HDL and LDL levels were significantly increased by HFD feeding. Selenium supplementation lowered the triglyceride level, whereas the other lipid values remained unchanged. Serum selenium levels were reduced by 31% and ROS levels in the liver were 2-fold increased by HFD. Se supplementation, however, diminished the HFD-induced ROS levels by 29%. Furthermore, Se also improved the HFD-mediated reduction of serum PON1 enzyme activity by 34% and PON1 protein levels by 21%. However, no significant effect of Se was detected on the reduced PAF-AH proteins levels in HFD fed rats. mRNA expression of PON1 and PAF-AH in the liver was not affected in the Se treated groups.</p> <p>Conclusion</p> <p>Se supplementation appears to be protective in hypercholesterolemia by restoring the antioxidant properties of the HDL associated enzyme i.e. PON1 whereas biological system aims towards maintaining the same PAF-AH levels even on selenium supplementation indicating its probable role in both anti and pro-atherogenic activities. Therefore, Se supplementation might be a valuable approach to limit the adverse effects of hypercholesterolemia and may need further investigations.</p

Formulation and characterization of chewable tablets of paracetamol and metoclopramide hydrochloride

The present study was aimed to formulate and characterized chewable tablets of Paracetamol and Metoclopramide hydrochloride. Paracetamol and Metoclopramide hydrochloride is an oral fixed dose combination for the preparation of chewable tablets used to treat the symptoms of migraine as it comply with physicochemical properties require to improve the effectiveness of therapeutic agent, better bioavailability, improved patient acceptance (especially pediatrics) through pleasant taste, patient convenience; need no water for swallowing, fasten the absorption of drug and for rapid onset of action. The investigation was carried out to study the effect of different proportion of Avicel 101, Avicel 102 and moringa gum, which are superdisintegrating agents. The chewable tablets of Paracetamol and Metoclopramide hydrochloride were prepared by wet granulation method. Several physicochemical parameters like thickness, diameter, hardness, %weight variation, %loss in weight, drug content, disintegration time, in vitro dissolution studies, kinetics of drug release and stability studies for all the formulations were studied and were found within the acceptance limits. Formulation F7 (containing moringa gum 1%) showed the best cumulative drug release and disintegration time of 56 secs

Helical vortex phase in the non-centrosymmetric CePt_3Si

We consider the role of magnetic fields on the broken inversion superconductor CePt_3Si. We show that upper critical field for a field along the c-axis exhibits a much weaker paramagnetic effect than for a field applied perpendicular to the c-axis. The in-plane paramagnetic effect is strongly reduced by the appearance of helical structure in the order parameter. We find that to get good agreement between theory and recent experimental measurements of H_{c2}, this helical structure is required. We propose a Josephson junction experiment that can be used to detect this helical order. In particular, we predict that Josephson current will exhibit a magnetic interference pattern for a magnetic field applied perpendicular to the junction normal. We also discuss unusual magnetic effects associated with the helical order.Comment: 5 pages, 2 figures, Accepted as Phys Rev. Lette

Studies on thermoluminescence parameters of erbium doped Y2O3 nanophosphors

The thermoluminescence (TL) glow curve of Y2O3:Er3+ with different radiation time has been studied. The experimental glow curve shows the presence of two peaks at linear heating rate 10&deg;C/min. The activation Energy and frequency factor are determined by thermoluminescence glow curve

Improving Mix-CLAHE with ACO for Clearer Oceanic Images

Oceanic pictures have poor visibility attributable to various factors; weather disturbance, particles in water, lightweight frames and water movement which results in degraded and low contrast pictures of underwater. Visibility restoration refers to varied ways in which aim to decline and remove the degradation that have occurred whereas the digital image has been obtained. The probabilistic Ant Colony Optimization (ACO) approach is presented to solve the problem of designing an optimal route for hard combinatorial problems. It\u27s found that almost all of the prevailing researchers have neglected several problems i.e. no technique is correct for various reasonably circumstances. the prevailing strategies have neglected the utilization of hymenopter colony optimization to cut back the noise and uneven illuminate downside. The main objective of this paper is to judge the performance of ANT colony optimization primarily based haze removal over the obtainable MIX-CLAHE (Contrast Limited adaptive histogram Equalization) technique. The experiment has clearly showed the effectiveness of the projected technique over the obtainable strategies

High-redshift blazars through nustar eyes

The most powerful sources among the blazar family are MeV blazars. Often detected at $z>2$, they usually display high X- and \gm-ray luminosities, larger-than-average jet powers and black hole masses $\gtrsim 10^9 M_{\odot}$. In the present work we perform a multiwavelength study of three high redshift blazars: 3FGL J0325.5+2223 ($z=2.06$), 3FGL J0449.0+1121 ($z= 2.15$), and 3FGL J0453.2$-$2808 ($z=2.56$), analysing quasi simultaneous data from GROND, \swift-UVOT and XRT, \nustar, and \fermi-LAT. Our main focus is on the hard X-ray band recently unveiled by \nustar~(3$-$79 keV) where these objects show a hard spectrum which enables us to constrain the inverse Compton peak and the jet power. We found that all three targets resemble the most powerful blazars, with the synchrotron peak located in the sub-millimeter range and the inverse Compton peak in the MeV range, and therefore belong to the MeV blazar class. Using a simple one zone leptonic emission model to reproduce the spectral energy distributions, we conclude that a simple combination of synchrotron and accretion disk emission reproduces the infrared-optical spectra while the X-ray to \gm-ray part is well reproduced by the inverse Compton scattering of low energy photons supplied by the broad line region. The black hole masses for each of the three sources are calculated to be $\gtrsim 4 \times 10^{8} M_{\odot}$. The three studied sources have jet power at the level of, or beyond, the accretion luminosity.Comment: 4 figures, 3 tables, accepted for publication in Ap

Cytotoxic Effect and Antioxidant Activity of Bioassay-guided Fractions from Solanum nigrum Extracts

Purpose: To evaluate the cytotoxic effect and antioxidant activity of bioassay-guided fractions from Malaysian species of Solanum nigrum.Methods: Methanol leaf and ethanol fruit extracts of Solanum nigrum were subjected to bioassay-guided fractionation using column chromatography. The semi-purified fractions were investigated for their in vitro cytotoxic effect against various cancer cell lines using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay, and for antioxidant activity using 2, 2-diphenyl-1- picryhydrazyl (DPPH) assay.Results: From bioassay-guided fractionation, 13 and 17 fractions were obtained from the methanol leaf and ethanol fruit extracts, respectively. In MTT assay, fractions 1, 2 and 4 from methanol extract showed the highest cytotoxic effect against the cancer cells with IC50 of 13.0 μg/mL at 48 h incubation. For the ethanol extract, fractions 14 and 15 showed the highest cytotoxic effect with IC50 of 12.0 μg/mL against K-562 cells, while fractions 13, 14 and 17 showed IC50 of 13.0 μg/mL against HeLa cells. Doxorubicin hydrochloride and vinblastine sulfate inhibited the cancer cells with IC50 range of 1.3 to 17.0 μg/mL. The highest radical scavenging activity was exhibited by fraction 2 from methanol extract with ED50 value of 0.10 mg/ml, while fraction 15 from ethanol extract showed ED50 of 0.79 mg/mL. Ascorbic acid and α-tocopherol exhibited radical scavenging activity of 95.0 ± 0.01 % (ED50 = 0.05 mg/mL) and 93.0 ± 0.01 % (ED50 = 0.10 mg/mL), respectively.Conclusion: Solanum nigrum leaves and fruits are potential sources of cytotoxic and antioxidant agents.Keywords: Solanum nigrum, Cytotoxic Activity, Anti-oxidant Activity, Bioassay-guided Fractionation, Doxorubicin, Vinblastin