Oxidative Stress in Lead and Cadmium Toxicity and Its Amelioration

Oxidative stress has been implicated to play a role, at least in part, in pathogenesis of many disease conditions and toxicities in animals. Overproduction of reactive oxygen species and free radicals beyond the cells intrinsic capacity to neutralize following xenobiotics exposure leads to a state of oxidative stress and resultant damages of lipids, protein, and DNA. Lead and cadmium are the common environmental heavy metal pollutants and have widespread distribution. Both natural and anthropogenic sources including mining, smelting, and other industrial processes are responsible for human and animal exposure. These pollutants, many a times, are copollutants leading to concurrent exposure to living beings and resultant synergistic deleterious health effects. Several mechanisms have been explained for the damaging effects on the body system. Of late, oxidative stress has been implicated in the pathogenesis of the lead- and cadmium-induced pathotoxicity. Several ameliorative measures to counteract the oxidative damage to the body system aftermath or during exposure to these toxicants have been assessed with the use of antioxidants. The present review focuses on mechanism of lead- and cadmium-induced oxidate damages and the ameliorative measures to counteract the oxidative damage and pathotoxicity with the use of supplemented antioxidants for their beneficial effects

Ion-ion correlations: an improved one-component plasma correction

Based on a Debye-Hueckel approach to the one-component plasma we propose a new free energy for incorporating ionic correlations into Poisson-Boltzmann like theories. Its derivation employs the exclusion of the charged background in the vicinity of the central ion, thereby yielding a thermodynamically stable free energy density, applicable within a local density approximation. This is an improvement over the existing Debye-Hueckel plus hole theory, which in this situation suffers from a "structuring catastrophe". For the simple example of a strongly charged stiff rod surrounded by its counterions we demonstrate that the Poisson-Boltzmann free energy functional augmented by our new correction accounts for the correlations present in this system when compared to molecular dynamics simulations.Comment: 5 pages, 2 figures, revtex styl

Seasonal variation of low-latitude E-region plasma irregularities studied using Gadanki radar and ionosonde

In this paper, we present seasonal variation of E region field-aligned irregularities (FAIs) observed using the Gadanki radar and compare them with the seasonal variation of Es observed from a nearby location SHAR. During daytime, FAIs occur maximum in summer and throughout the day, as compared to other seasons. During nighttime, FAIs occur equally in both summer and winter, and relatively less in equinoxes. Seasonal variations of Es (i.e. ftEs and fbEs) show that the daytime activity is maximum in summer and the nighttime activity is maximum in equinoxes. No relation is found between FAIs occurrence/SNR and ftEs/fbEs. FAIs occurrence, however, is found to be related well with (ftEs-fbEs ). This aspect is discussed in the light of the present understanding of the mid-latitude Es-FAIs relationship. The seasonal variations of FAIs observed at Gadanki are compared in detail with those of Piura, which show a significant difference in the daytime observations. The observed difference has been discussed considering the factors governing the generation of FAIs

Photonic excess noise and wave localization

This is a theory for the effect of localization on the super-Poissonian noise of radiation propagating through an absorbing disordered waveguide. Localization suppresses both the mean photon current I and the noise power P, but the Fano factor P/I is found to remain unaffected. For strong absorption the Fano factor has the universal value 1+3f/2 (with f the Bose-Einstein function), regardless of whether the waveguide is long or short compared to the localization length.Comment: 3 pages including 3 figure

Theory for the photon statistics of random lasers

A theory for the photon statistics of a random laser is presented. Noise is described by Langevin operators, where both fluctuations of the electromagnetic field and of the medium are included. The theory is valid for all lasers with small outcoupling when the laser cavity is large compared to the wavelength of the radiation. The theory is applied to a chaotic laser cavity with a small opening. It is known that a large number of modes can be above threshold simultaneously in such a cavity. It is shown the amount of fluctuations is increased compared to the Poissonian value by an amount that depends on that number

Učinak antioksidanata askorbinske kiseline, lmetionina i α tokoferola zasebno ili u kombinaciji s kelatom na srčano tkivo štakora izloženih olovu.

An experiment was conducted using 42 IVRI 2CQ rats to evaluate the effects of three antioxidants, ascorbic acid, l methionine or α tocopherol alone, or chelator CaNa2EDTA alone or along with antioxidant α tocopherol, on lead accumulation, status of lipid peroxidation, and of copper and zinc concentration in cardiac tissue of lead-treated rats. Lead was given intraperitoneally as 1% lead acetate solution at the dose rate of 1mg of Pb2+/kg body mass for a period of 30 days. The lead was then withdrawn and the lead-exposed rats (n=36) were randomly divided into six groups, six lead-treated rats in each group. A further six rats were given no treatment, including lead exposure, to serve as negative controls. The rats were sacrificed under light anaesthesia one day after one week of treatment with antioxidant ascorbic acid, l-methionine or α tocopherol or with chelator CaNa2EDTA alone or along with antioxidant α tocopherol. Blood samples were collected and heart was quickly excised. Mean lead concentration in cardiac tissue was significantly higher in the lead-treated group, even after its withdrawal for a period of seven days (5.02 ± 1.06 vs. 0.40 ± 0.09 μg/gm). The treatment with chelator plus antioxidant α tocopherol lowered the cardiac lead burden but the level remained significantly higher than that of the negative control. There was a non-significant increase in lipid peroxide levels in the cardiac tissue of lead-exposed untreated rats and either of the antioxidants lowered the lipid peroxide level, but the differences between the different treatment groups remained statistically comparable at P>0.05. The mean concentration of copper and zinc in cardiac tissue remained statistically comparable among the different treatment groups.U pokusu su korištena 42 štakora IVRI 2CQ. Cilj je bio utvrditi učinke antioksidanata askorbinske kiseline, l-metionina i α tokoferola na nakupljanje olova, peroksidaciju lipida te koncentraciju bakra i cinka u srčanom tkivu nakon davanja olova. Osim toga, isti pokazatelji analizirani su nakon aplikacije kelata CaNa2EDTA zasebno, odnosno u kombinaciji s α tokoferolom. Olovo je aplicirano intraperitonealno u obliku 1% otopine olovnoga acetata, u dozi od 1 mg Pb2+ na kilogram tjelesne mase tijekom razdoblja od 30 dana. Nakon prestanka davanja olova, štakori (n = 36) su slučajnim odabirom razdijeljeni u šest skupina po šest jedinki u svakoj skupini. Prva skupina bila je izložena samo učincima olova, a pet skupina su osim olova primile navedene antioksidante, kelat ili njegovu kombinaciju s α tokoferolom. Dodatnih šest štakora u 7. skupini nisu bili izloženi olovu, antioksidantu ili kelatu te su poslužili kao negativna kontrola. Štakori su žrtvovani u laganoj anesteziji nakon sedmodnevnog dobivanja olova odnosno antioksidanta i kelata. Uzeti su uzorci krvi, a odmah po žrtvovanju izvađeno je srce. Srednja vrijednost koncentracije olova u srčanom tkivu bila je statistički značajno viša u skupini štakora koji su dobivali olovo, čak i nakon prekida sedmodnevnog davanja (5,02 ± 1,06 prema 0,40 ± 0,09 μg/g). Liječenje kelatom u kombinaciji s α tokoferolom smanjilo je razinu olova u srčanom mišiću, ali je ona i dalje ostala značajno viša u odnosu na negativnu kontrolu. Nije utvrđeno statistički značajno povećanje razine peroksidacije lipida u srčanom tkivu štakora izloženih samo djelovanju olova. Ni jedan antioksidant nije smanjio razinu peroksidacije lipida, a i srednje koncentracije bakra odnosno cinka nisu se statistički značajno (P>0,05) razlikovale između skupina različito tretiranih štakora

Superheavy nuclei in relativistic effective Lagrangian model

Isotopic and isotonic chains of superheavy nuclei are analyzed to search for spherical double shell closures beyond Z=82 and N=126 within the new effective field theory model of Furnstahl, Serot, and Tang for the relativistic nuclear many-body problem. We take into account several indicators to identify the occurrence of possible shell closures, such as two-nucleon separation energies, two-nucleon shell gaps, average pairing gaps, and the shell correction energy. The effective Lagrangian model predicts N=172 and Z=120 and N=258 and Z=120 as spherical doubly magic superheavy nuclei, whereas N=184 and Z=114 show some magic character depending on the parameter set. The magicity of a particular neutron (proton) number in the analyzed mass region is found to depend on the number of protons (neutrons) present in the nucleus.Comment: 26 pages, REVTeX, 10 ps figures; changed conten

Superheavy nuclei in relativistic effective Lagrangian model

Isotopic and isotonic chains of superheavy nuclei are analyzed to search for spherical double shell closures beyond Z=82 and N=126 within the new effective field theory model of Furnstahl, Serot, and Tang for the relativistic nuclear many-body problem. We take into account several indicators to identify the occurrence of possible shell closures, such as two-nucleon separation energies, two-nucleon shell gaps, average pairing gaps, and the shell correction energy. The effective Lagrangian model predicts N=172 and Z=120 and N=258 and Z=120 as spherical doubly magic superheavy nuclei, whereas N=184 and Z=114 show some magic character depending on the parameter set. The magicity of a particular neutron (proton) number in the analyzed mass region is found to depend on the number of protons (neutrons) present in the nucleus.Comment: 26 pages, REVTeX, 10 ps figures; changed conten

Propagation of squeezed radiation through amplifying or absorbing random media

We analyse how nonclassical features of squeezed radiation (in particular the sub-Poissonian noise) are degraded when it is transmitted through an amplifying or absorbing medium with randomly located scattering centra. Both the cases of direct photodetection and of homodyne detection are considered. Explicit results are obtained for the dependence of the Fano factor (the ratio of the noise power and the mean current) on the degree of squeezing of the incident state, on the length and the mean free path of the medium, the temperature, and on the absorption or amplification rate.Comment: 8 pages, 4 figure