Simultaneous effect of lead and cadmium on granulosa cells: A cellular model for ovarian toxicity

Lead (Pb) and cadmium (Cd) are known reproductive toxicants, which accumulate in granulosa cells of the ovary. Female Charles foster rats were treated with sodium acetate (control), lead acetate and cadmium acetate either alone or in combination at a dose 0.05 mg/kg body weight intra-peritoneally for 15 days daily. Animals were killed at proestrous stage and granulosa cells were isolated from the ovaries. Binding of I-125-luteinizing hormone (I-125-LH), I-125-follicle stimulating hormone (I-125-FSH) and 17 beta-hydroxysteroid dehydrogenase activity were measured. As these receptors are localized on the surface of the cell membrane, we also estimated the membrane parameters of these cells. Our results demonstrated that both lead and cadmium caused a significant reduction in gonadotropin binding, which altered steroidogenic enzyme activity of granulosa cells. These changes exhibited a positive correlation with membrane changes of the granulosa cells.

Structural, optical and electrical characteristics of transparent bismuth vanadate films deposited on indium tin oxide coated glass substrates

Bismuth vanadate (BVO) thin films were fabricated on indium tin oxide (ITO) coated glass substrates using pulsed laser ablation technique and investigated their structural, optical and electrical properties. The use of the indium tin oxide coated glass substrate resulted in reducing the leakage current characteristics of crystalline BVO thin films. The X-ray diffraction (XRD) studies confirmed the monophasic nature of the post annealed (500 A degrees C/1 h) films. The atomic force microscopy indicated the homogeneous distribution of crystallites in the as-deposited films. The as-deposited and the post annealed films were almost 90% transparent (380-900 nm) as confirmed by optical transmission studies. Dielectric constant of around 52 was attained accompanied by the low dielectric loss of 0.002 at 10 kHz for post annealed films. The leakage current of the post annealed BVO films on ITO coated glass substrates measured at room temperature was 8.1 x 10(-8) A at an applied electric field of 33 kV/cm, which was lower than that of the films with platinum and SrRuO3 as the bottom electrodes.

Thermodynamic properties of RhO2

A solid-state electrochemical cell, with yttria-stabilized zirconia as the electrolyte and pure O-2 gas at 0.1 MPa as the reference electrode, has been used to measure the oxygen chemical potential corresponding to the equilibrium between beta-Rh2O3 and RhO2 in the temperature range from 850 to 1050K. Using standard Gibbs energy of formation of beta-Rh2O3 available in the literature and the measured oxygen potential, the standard Gibbs free energy of formation of RhO2 is derived as a function of temperature: Delta G(f)degrees(RhO2)(+/- 71)/J mol(-1) = 238,418 + 179.89T Using an estimated value of Delta C-p degrees; for the formation reaction of RhO2 from its elements, the standard enthalpy of formation, standard entropy and isobaric heat capacity of RhO2 at 298.15 K are evaluated: Delta H-f degrees (298.15 K)(+/- 164)/kJ mol(-1) = -244.94, S degrees (298.15 K)(+/- 3.00)/J mol(-1) K-1 = 45.11 and C-p degrees(298.15 K)(+/- 2.6)1mol(-1) K-1 =64.28. (C) 2010 Elsevier B.V. All rights reserved.

Solar rechargeable battery—principle and materials

A brief survey of the historical development of a photoelectrochemical solar cell is given. The principle and future of solar chargeable battery is compared with a wet and a dry type photovoltaic cell. A solar chargeable battery, with or without a membrane and with an aqueous solution or with solid-state electrolytes is discussed. A new unique type of configuration “Sharon-Schottky” junction solar cell is described which can be used either as a charger for any secondary batteries or could be used for photoelectrolysis of water. All these configurations and their relative merits are discussed. A review on the various semiconductors and types of solar chargeable batteries is made. Finally, a conclusion is drawn for future direction of research for developing an economically viable photoelectrochemical (PEC) solar cell based on either the principle of a solar charger (to charge a Ni---Cd battery or lead—acid battery) and/or solar chargeable battery with or without without a membrane. Some new innovative ideas for the preparation of materials is discussed. The entire discussion is geared towards answering a relevant question: what has gone wrong to result in the stagnation and failure in commercialization of a PEC based solar cell?

Structure and superconducting properties of Tl1?yPbyY1?xCaxSr2Cu2O7star, open: Dependence of Tc on hole concentration

Structure and superconducting properties of Tl1?yPbyY1?xCaxSr2Cu2O7 (y=0.0, 0.1, 0.25 and 0.5) , derived from the parent insulator TlYSr2Cu2O7, have been investigated for different values of x. XANES studies show Pb to be in the 4+ state while Tl is in the 3+ state, suggesting thereby that in this series, (x?y) approximately corresponds to the hole concentration. The in-plane Cu---O distance decreases with increase in x for all values of y. The apical Cu---O distance as well as the Tl(Pb)---O(2) distance show anomalies at x=0.5 in the series with y=0.25; at this composition, Tc also reaches a maximum. In general, the composition (value of x) at which the Tc of Tl1?yPbyY1?xCaxSr2Cu2O7 reaches a maximum depends on the Pb content and the maximum Tc itself increases with increase in y, reaching a value of 105 K at y=0.5. More interestingly, a maximum Tc occurs at an (x?y) value of not, vert, similar0.25, which is close to the hole concentration at maximum Tc in other cuprate superconductors containing two CuO2 layers.

Five-fold quasiperiodic tilings generated by inflated rhombuses with identical boundaries: possible application to the growth of quasicrystals

In order to generate normal Penrose tilings by inflation/deflation, decisions have to be made regarding the matching of the rhombuses/tilings with their neighbours. We show here that this decision-making problem can be avoided by adopting a deflation/inflation procedure which uses the decorated rhombuses with identical boundaries. The procedure enables both kinds of inflated rhombuses to match in any orientation along their edges. The tilings so generated are quasiperiodic. These structures appear to have a close relationship with the growth mechanism of quasicrystals.

Random-Restart Reactive Tabu Search Algorithm for Detection in Large-MIMO Systems

We present a low-complexity algorithm based on reactive tabu search (RTS) for near maximum likelihood (ML) detection in large-MIMO systems. The conventional RTS algorithm achieves near-ML performance for 4-QAM in large-MIMO systems. But its performance for higher-order QAM is far from ML performance. Here, we propose a random-restart RTS (R3TS) algorithm which achieves significantly better bit error rate (BER) performance compared to that of the conventional RTS algorithm in higher-order QAM. The key idea is to run multiple tabu searches, each search starting with a random initial vector and choosing the best among the resulting solution vectors. A criterion to limit the number of searches is also proposed. Computer simulations show that the R3TS algorithm achieves almost the ML performance in 16 x 16 V-BLAST MIMO system with 16-QAM and 64-QAM at significantly less complexities than the sphere decoder. Also, in a 32 x 32 V-BLAST MIMO system, the R3TS performs close to ML lower bound within 1.6 dB for 16-QAM (128 bps/Hz), and within 2.4 dB for 64-QAM (192 bps/Hz) at 10(-3) BER.

Minimum weight design of fiber-reinforced laminated composite structures with maximum stress and Tsai-Wu failure criteria

In this article, a minimum weight design of carbon/epoxy laminates is carried out using genetic algorithms. New failure envelopes have been developed by the combination of two commonly used phenomenological failure criteria, namely Maximum Stress (MS) and Tsai-Wu (TW) are used to obtain the minimum weight of the laminate. These failure envelopes are the most conservative failure envelope (MCFE) and the least conservative failure envelope (LCFE). Uniaxial and biaxial loading conditions are considered for the study and the differences in the optimal weight of the laminate are compared for the MCFE and LCFE. The MCFE can be used for design of critical load-carrying composites, while the LCFE could be used for the design of composite structures where weight reduction is much more important than safety such as unmanned air vehicles.

Finite data performance of MUSIC and minimum norm methods

In the direction of arrival (DOA) estimation problem, we encounter both finite data and insufficient knowledge of array characterization. It is therefore important to study how subspace-based methods perform in such conditions. We analyze the finite data performance of the multiple signal classification (MUSIC) and minimum norm (min. norm) methods in the presence of sensor gain and phase errors, and derive expressions for the mean square error (MSE) in the DOA estimates. These expressions are first derived assuming an arbitrary array and then simplified for the special case of an uniform linear array with isotropic sensors. When they are further simplified for the case of finite data only and sensor errors only, they reduce to the recent results given in [9-12]. Computer simulations are used to verify the closeness between the predicted and simulated values of the MSE.

Regulation of diacylglycerol kinase in rat brain membranes by docosahexaenoic acid

The effect of docosahexaenoic acid (DHA) on the diacylglycerol kinase (DG kinase) activity in rat brain membranes was investigated. DHA at 500 mu M concentration, stimulated the enzyme activity by about 2 fold. This effect was concentration-and time-dependent and was observed after very short periods of incubation (one min). DHA stimulation of DG kinase was observed only with rat brain membranes, and not with rat brain cytosol or rat liver membranes. Treating the rat brain membranes with phospholipase A(2) which released free fatty acids including DHA, significantly stimulated the DG kinase activity. It is concluded that DHA through its stimulatory effect on DG kinase may regulate the signalling events in growth-related situations in the brain such as synaptogenesis.

In vitro and in vivo effect of methyl isocyanate on rat liver mitochondrial respiration

Previous work has shown that irrespective of the route of exposure methyl isocyanate (MIC) caused acute lactic acidosis in rats (Jeevaratnam et al., Arch. Environ. Contam. Toxicol. 19, 314�319, 1990) and the hypoxia was of stagnant type due to tissue hypoperfusion resulting from hypovolemic hypotension in rabbits administered MIC subcutaneously (Jeevarathinam et al., Toxicology 51, 223�240, 1988). The present study was designed to investigate whether MIC could induce histotoxic hypoxia through its effects on mitochondrial respiration. Male Wistar rats were used for liver mitochondrial and submitochondrial particle (SMP) preparation. Addition of MIC to tightly coupled mitochondria in vitro resulted in stimulation of state 4 respiration, abolition of respiratory control, decrease in ADP/O ratio, and inhibition of state 3 oxidation. The oxidation of NAD+-linked substrates (glutamate + malate) was more sensitive (fiveto sixfold) to the inhibitory action of MIC than succinate while cytochrome oxidase remained unaffected. MIC induced twofold delay in the onset of anerobiosis, and cytochrome b reduction in SMP with NADH in vitro confirms inhibition of electron transport at complex I region. MIC also stimulated the ATPase activity in tightly coupled mitochondria while lipid peroxidation remained unaffected. As its hydrolysis products, methylamine and N,N?-dimethylurea failed to elicit any change in vitro; these effects reveal that MIC per se acts as an inhibitor of electron transport and a weak uncoupler. Administration of MIC sc at lethal dose caused a similar change only with NAD+-linked substrates, reflecting impairment of mitochondrial respiration at complex I region and thereby induction of histotoxic hypoxia in vivo.

Field evaluation of unsaturated hydraulic conductivity models and parameter estimation from retention data

Predictions of two popular closed-form models for unsaturated hydraulic conductivity (K) are compared with in situ measurements made in a sandy loam field soil. Whereas the Van Genuchten model estimates were very close to field measured values, the Brooks-Corey model predictions were higher by about one order of magnitude in the wetter range. Estimation of parameters of the Van Genuchten soil moisture characteristic (SMC) equation, however, involves the use of non-linear regression techniques. The Brooks-Corey SMC equation has the advantage of being amenable to application of linear regression techniques for estimation of its parameters from retention data. A conversion technique, whereby known Brooks-Corey model parameters may be converted into Van Genuchten model parameters, is formulated. The proposed conversion algorithm may be used to obtain the parameters of the preferred Van Genuchten model from in situ retention data, without the use of non-linear regression techniques.

Structure of diaquadichlorobis(hydrazinium)iron(II) dichloride

[Fe(N2H5)2(H2O)2Cl2].Cl2, M(r) = 299.65, monoclinic, P2(1)/c, a = 8.027 (1), b = 5.725 (2), c = 11.430 (2) angstrom, beta = 97.08 (1)-degrees, V = 521.3 (2) angstrom 3, Z = 2, D(m) = 1.92, D(x) = 1.910 g cm-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 24.5 cm-1, F(000) = 304, T = 295 K, final R = 0.0242 and wR = 0.0292 for 1411 significant [F(o) > 5.0-sigma(F(o))] reflections. The crystal contains discrete Cl- ions and complex [Fe(N2H5)2(H2O)2Cl2]2+ cations. In the complex cation, the Fe atom is bonded to two hydrazinium cations, two Cl atoms and two water molecules. The coordinated atoms are trans to each other. The ions are connected by both N-H...Cl and O-H...Cl type hydrogen bonds.

Electrochemical Determination of L-Dopa in Mucuna pruriens Seeds, Leaves and Commercial Siddha Product Using Gold Modified Pencil Graphite Electrode

In the present work a gold modified pencil graphite electrode (GPGE) was used for the determination of L-dopa present in the aqueous extracts of Mucuna pruriens seeds (MPS), Mucuna pruriens leaves (MPL) and Commercial Siddha Product (CSP). The GPGE shows excellent electrocatalytic activity towards the oxidation of both L-dopa and ascorbic acid (AA), with the separation of peak potential of 98 mV. The differential pulse voltammetric (DPV) results indicated that the detection limit for L-dopa was 1.54 mu M (S/N=3). This method can be successfully applied for the determination of L-dopa in real samples.