4,198 research outputs found
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
Two Dimensional Multigap Superconductivity in Bulk 2H-TaSSe
Superconducting transition metal dichalcogenides emerged as a prime candidate
for topological superconductivity. This work presents a detailed investigation
of superconducting and transport properties on 2H-TaSeS single crystals using
magnetization, transport, and specific heat measurements. These measurements
suggest multigap anisotropic superconductivity with the upper critical field,
breaking Pauli limiting field in both in-plane and out-of-plane directions. The
angle dependence of the upper critical field suggests 2-dimensional
superconducting nature in bulk 2H- TaSeS.Comment: 7 pages, 7 figure
Nitrous oxide emissions from the Arabian Sea: A synthesis
We computed high-resolution (1º latitude x 1º longitude) seasonal and annual nitrous oxide (N2O) concentration fields for the Arabian Sea surface layer using a database containing more than 2400 values measured between December 1977 and July 1997. N2O concentrations are highest during the southwest (SW) monsoon along the southern Indian continental shelf. Annual emissions range from 0.33 to 0.70 Tg N2O and are dominated by fluxes from coastal regions during the SW and northeast monsoons. Our revised estimate for the annual N2O flux from the Arabian Sea is much more tightly constrained than the previous consensus derived using averaged in-situ data from a smaller number of studies. However, the tendency to focus on measurements in locally restricted features in combination with insufficient seasonal data coverage leads to considerable uncertainties of the concentration fields and thus in the flux estimates, especially in the coastal zones of the northern and eastern Arabian Sea. The overall mean relative error of the annual N2O emissions from the Arabian Sea was estimated to be at least 65%
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
Environmental and Waste Management in Some Mining Operations in Orissa
This paper attempts to provide a survey on environmental parameters, viz. solids and liquids collected from five different mines in Orissa. These mines are (i) Dolomite Quarry, or Gomardih (Tisco) (ii) Fireclay Mines, Talabasta (Grind)(iii) Iron Ore Mines, Joribahal (Patnaik Minerals Pvt.Ltd.) (iv) Limestone Quarry,Lanjiherna (O CL) and (v) Graphite Mines, Patnagarh (T. Pradhan). The solid
samples consisted of (a) top more often the undisturbed soil near the mine, (b) the overburdenlwastelspoilt dump, (c) soil from nearby paddyfield, (d) plantation area
and (e) garden. These are analysed for agricultural parameters .such aspll, organic carbon content, available phosphate and potassium, heavy metals such as copper,
lead, zinc, chromium etc. and bacterial count. The liquid sample consisted of water and effluent collected from (i) mine pit/flow both active and abandoned, (ii) mine
discharge, (iii) mineral spring, (iv) accumulated water in mines, (v) piped water in mine office and residential colony and (vi) dug well used by mine workers. These
samples were analysed for heavy metals similar to solid samples, physical parameters such as total suspended solids (TSS), total dissolved solids (TDS) and the
bacterial count. The analysed results were compared with the standards set by the Bureau of Indian Standards (BIS) and Central Pollution Control Board (CPCB) and recommendations on pollution control measures and strategy by other means are made for better environmental management
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
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