Comparative Study of Electrodeposited Zn and Zn–Ni Alloy Coatings for Improved Corrosion Protection in Chloride Medium

Protection of Metals and Physical Chemistry of Surfaces - The anti-corrosive Zn and Zn–Ni alloy coatings were electrodeposited on different copper substrates using an optimized sulphate...     

Flow Behaviour of Modified 9Cr–1Mo Steel at Elevated Temperatures

In this investigation, the flow behaviour of modified 9Cr–1Mo steel at elevated temperatures is reported. To understand the flow behaviour of the steel, tensile tests were performed at nominal strain rate of 3 × 10^?3 s^?1 and temperatures in the range of 300–823 K. The yield strength and ultimate tensile strength were found to decrease with increase in temperature with a plateau in a intermediate temperature regime (523–673 K). Serrations were also observed in the tensile curve at intermediate temperatures which caused plateau/peak in tensile behaviour of material and was a typical manifestation of dynamic strain ageing. An attempt was made to represent the flow behaviour of the material using different constitutive equations viz., Hollomon, Ludwik, Swift, Ludwigson and Voce. It was observed that the Voce equation could describe the experimental flow curve at different temperatures quite well. Instantaneous work hardening rate with respect to flow stress exhibited two stages of hardening especially at relatively lower temperatures.     

First-Principles Investigation of Electronic Properties of GaAsxSb1 –x Ternary Alloys

Semiconductors - Compositional variations in GaAs based ternary alloys have exhibited wide range alterations in electronic properties. In the present paper, first-principles study of...     

Silver nanoparticle anchored with novel crosslinked beaded polystyrene/polyamidoxime sequential interpenetrating polymer networks (IPNs) and its antibacterial activity

The present article describes the synthesis of silver nanoparticles (SNPs) impregnatated crosslinked beaded polystyrene/polyamidoxime (PSD/PAMD) interpenetrating polymer networks (IPNs). The developed SNPs‐IPNs were tested for the antibacterial activity for water purification. Intially, the crosslinked beaded polystyrene/polyacrylonitrile (PSD/PAN) polymer was synthesized by radical sequential suspension polymerization method therafter, it has been converted into PSD/PAMD‐IPN comprising amidoxime group, which acts as capping agent to anchor the silver ions. The silver ions impregnated with PSD/PAMD‐IPN were converted into SNPs by chemical reduction methodology followed by stabilization without any deterioration or loss in polymer. IR and solid‐state ¹³C NMR spectra were use for the structural characterization of developed SNPs‐IPN, while morphological characterization was examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X‐ray diffraction (XRD). The size of the SNPs formed with the networks were found less than 5 nm. The disinfection potential of SNPs‐IPN was evaluated by different antibacterial test. The bactericidal test of SNPs‐IPN revealed the promissing antibacterial efficieny with complete microbial inhibition within 4–6 h. The reusability of the SNPs‐IPN beads was also tested for its repeated use for industrial application. POLYM. COMPOS., 70–80, 2016. © 2014 Society of Plastics Engineers     

Oxidative Stress in Aging-Matters of the Heart and Mind

Oxidative damage is considered to be the primary cause of several aging associated disease pathologies. Cumulative oxidative damage tends to be pervasive among cellular macromolecules, impacting proteins, lipids, RNA and DNA of cells. At a systemic level, events subsequent to oxidative damage induce an inflammatory response to sites of oxidative damage, often contributing to additional oxidative stress. At a cellular level, oxidative damage to mitochondria results in acidification of the cytoplasm and release of cytochrome c, causing apoptosis. This review summarizes findings in the literature on oxidative stress and consequent damage on cells and tissues of the cardiovascular system and the central nervous system, with a focus on aging-related diseases that have well-documented evidence of oxidative damage in initiation and/or progression of the disease. The current understanding of the cellular mechanisms with a focus on macromolecular damage, impacted cellular pathways and gross morphological changes associated with oxidative damage is also reviewed. Additionally, the impact of calorific restriction with its profound impact on cardiovascular and neuronal aging is addressed.     

A low-temperature attachment for a four-circle neutron diffractometer

A single-stage closed-cycle helium gas cryogenerator, capable of cooling between 77 K and 300 K, has been installed on the 4-circle neutron diffractometer at CIRUS. The cryo-tip assembly has been incorporated directly on the ϕ-circle of the full-circle crystal orienter in place of the goniometer head used in room temperature experiments. The salient features of this low-temperature attachment and its performance are discussed.     

A light and electron microscopic study of cytoplasmic phospholipase A2 and cyclooxygenase-2 in the hippocampus after kainate lesions

Tamoxifen, the major adjuvant drug treatment for estrogen-dependent breast cancer, has been shown previously to affect both estrogen-dependent and calcium/calmodulin-dependent pathways. In the current study, we developed an in vitro slice system to study the effects of tamoxifen on ATP levels in hypothalamic (HTH) and preoptic areas (POA) of the rat brain. Baseline data showed that, following a 2-h incubation, HTH and POA slices had comparable ATP levels to hippocampal slices, a system used extensively by researchers examining the metabolic responsiveness of the hippocampal region (HPC) of the brain. HTH-POA slice ATP levels remained steady for 2, 4 and 6 h, but fell to 11% of initial levels by 12 h. Neurons from HTH-POA slices incubated for 4 h appeared healthy and demonstrated robust protein synthesis as measured autoradiographically by incorporation of [3H]leucine. We explored the effects of tamoxifen (TAM), fluphenazine (FLU) and estradiol (E2) on ATP levels in HTH and POA slices. The effects of TAM were complex: a 4-h incubation with 10-6 M TAM led to decreased ATP levels in HTH (but not POA), and a 4-h incubation with 10-8 M led to increased ATP levels in POA (but not HTH); a 15-min exposure to 10-6 M TAM decreased ATP levels in POA (but not HTH) slices, while the exposure of slices to the lower concentration of TAM was without effect in either area. As with higher concentrations of TAM, 4-h incubation with 10-6 M FLU decreased ATP levels in HTH (but not POA), while incubation with E2 did not affect slice ATP levels. These data are consistent with the hypothesis that both TAM and FLU alter ATP levels in HTH slices via calmodulin- or calcium-mediated processes.