Effect Of Ni Ions Research Articles

Effect of Ni ions on the DNA spectral properties and photostability

The optical absorption, fluorescence, phosphorescence in UV and visible spectral range, and effect of light irradiation on spectral properties of DNA with the presence of nickel ions are studied. The quantity of nickel ions varies from 1 ion per 500 base pairs of DNA to 2 ions per base pair. Three important features fixed: the shape of fluorescence and phosphorescence spectra of the DNA do not change in presence of Ni, but their intensity depends on the number of nickel ions in solution; phosphorescence intensity decreases more rapidly than fluorescence; the small decrease of DNA photodegradation rate in presence of Ni is observed. The average of triplet exciton path length evaluated from the dependence of phosphorescence/fluorescence intensity ratio on the relative concentration of nickel ions is 30–20 DNA pair sequence length. It was proposed that nickel ions interact in the outer side of DNA with the phosphate groups and do not penetrate intra macromolecular space.

Effect of Ni ions on thermal condensation kinetics and morphology of g-C3N4 nanosheets and their photo- and electro-chemical activity evolution

The effect of Ni ions on the thermal condensation kinetics, morphology, microstructure and photoelectric properties of layered g-C3N4 were tested. Ni ions were first incorporated into melamine before thermal polymerization. The morphologies of g-C3N4 from nanosheets to irregular tubular structure was created because of the effect of Ni atoms. The photo- and electro-chemical performance depended strongly on the morphologies of g-C3N4. Irregular tubular sample NCN675 with multiple scattering effect of light exhibited fast degradation for Rh B under visible light with a maximum degradation rate constant of 0.046 min−1. Electrocatalysis test indicates that NCN680 as N-doped carbon nanotubes with excellent electrocatalytic hydrogen and oxygen evolution rate (HER and OER), in which Tafel slopes of HER and OER are 111 and 107 mV/dec respectively. In addition, charge discharge test of supercapacitor confirms that NCN680 is the most suitable electrode material for supercapacitors and have larger specific capacitance (SC = 203.95F/g) when its current density is 1A/g. This study provides an important supplement for structure and performance transformation of carbon nitride compounds catalyzed by Ni.

Nickle(II) ions exacerbate bleomycin-induced pulmonary inflammation and fibrosis by activating the ROS/Akt signaling pathway.

Nickle (Ni) is a heavy metal found in particulate matter. We previously reported that Ni ions are strongly associated with high apoptosis rates and high expression of IL-1β in human bronchial epithelial cells following exposure to PM2.5; however, the effects of Ni ions on pulmonary fibrosis have not been fully elucidated. In the current study, we evaluated whether Ni ions can exacerbate bleomycin (BLM)-induced pulmonary fibrosis in a mouse model and illustrated the potential mechanism. Ni ions inhibited cell proliferation and induced apoptosis in A549 and MRC-5 cells. BLM-induced lung injury and fibrosis in mice were significantly enhanced by nickel treatment, and these findings were also supported by inflammatory cell accumulation in bronchoalveolar lavage fluid and elevated levels of pro-inflammatory cytokines in lung tissues. Ni ions also increased extracellular matrix protein levels, including those of type I collagen and MMP9 in mouse lung tissues and cell lines. Moreover, Ni ions promoted the phosphorylation of AKT in this mouse model. The effect of increased collagen levels and MMP9 expression was inhibited by blocking the AKT phosphorylation. Together, these findings suggest AKT activation as a critical contributor to this Ni-exacerbated pulmonary fibrotic process.

Effect of Mn-Site Doping with Nickel on the Electric and Magnetic Properties of Sm0.55Sr0.45MnO3 Manganites

We present the effect of Ni-ions doping on the magnetoresistance and magnetic properties of Sm0.55Sr0.45Mn1−xNixO3 in the temperature range 4.2–300 K and the magnetic field range 0–90 kOe, for 0<x<10 %. The Ni-ion doping significantly reduces the metal-ferromagnetic to insulating-paramagnetic transition temperature (TC). The Sm0.55Sr0.45Mn1−xNixO3 undergoes a transition from low-temperature ferromagnetic metallic state to high-temperature paramagnetic insulating-like state. Magnetic susceptibility measurements for samples with various Ni-concentrations showed a reduction in the paramagnetic transition temperature with increasing Ni-concentration. Moreover, the sharp peak in the susceptibility shown by the Ni-free samples has disappeared completely. The susceptibility becomes more round at 10 % Ni, while for lower Ni-concentration it becomes flat, indicating almost pure ferromagnetic behavior. Magnetization isotherms measurements have also been performed for Ni-ions samples doped with up to 10 %. With increasing Ni-doping, the irreversibility region in both M vs. T and M vs. H curves have decreased considerably, almost vanishing at 5 % Ni. For 5 % Ni and above, the FC and ZFC states basically coincide on top of each other, no spin-glass-like transition has been seen.

Effect of Ni&lt;sup&gt;2+&lt;/sup&gt; on Chromium Electrodeposition in Cr(III) Plating Bath

A small amount of nickel ions is added to trivalent chromium chloride plating bath to study effect of Ni ions on trivalent chromium electrodeposition. The obtained Cr-Ni alloy coatings and Cr coatings are characterized by means of EDS and SEM. Cathodic polarization curves of trivalent chromium chloride plating bath show that right amount of Ni ions contained in bath make the LSV more positive, exerting a catalytic effect on electrodeposition of Cr ( ) ions. EDS results of the obtained coatings also demonstrate the catalytic effect of Ni ions on trivalent chromium electrodeposition. Analysis of SEM indicate that the surface morphology of coatings obtained from Cr( ) bath containing 0.03g/L Ni2+ bath are similar to the ones obtained from pure Cr( ) ions bath.

ニッケルイオンがチオグリコレート刺激マウス腹腔滲出細胞(PEC)の細胞生存率とNO産生に及ぼす影響評価

ニッケルイオンがチオグリコレート刺激マウス腹腔滲出細胞(PEC)の細胞生存率とNO産生に及ぼす影響評価

Effect of Ni ions on expression of intercellular adhesion molecule 1 by endothelial cells.

Previous studies have shown that Ni-based alloys implanted into soft tissues cause an infiltration of inflammatory cells around the implant. This phenomenon is potentially important to dental alloys which are adjacent to oral tissues. To help define the mechanisms by which Ni causes an infiltration of inflammatory cells, we exposed endothelial cells in vitro to Ni ions and measured the expression of intercellular adhesion molecule 1 (ICAM-1). ICAM-1 is known to be involved in the recruitment of inflammatory cells from the bloodstream. We also exposed macrophages to Ni ions to test the hypothesis that Ni might alter cytokine secretion and subsequently cause expression of ICAM-1 on endothelial cells. The results showed that Ni ions could promote the expression of ICAM-1 on endothelial cells, but only at concentrations which were high enough (850 mumol/L for 24 h) to suppress cell metabolic activity. Although we had previous evidence that Ni could cause macrophages to secrete cytokines such as interleukin 1 beta, Ni-exposed macrophage supernatants did not induce expression of ICAM-1 on endothelial cells at concentrations subtoxic to the macrophages (85 mumol/L). At subtoxic concentrations, Ni ions were able to suppress ICAM-1 expression on endothelial cells which were stimulated with lipopolysaccharide. Thus, Ni ions either promoted or suppressed the expression of ICAM-1 depending on their concentration. This dual action of Ni ions may be important in vivo where a gradient of concentrations of released ions is likely to exist around the implanted biomaterial. Further studies are necessary to determine the effect of time of exposure and the molecular mechanisms of increased ICAM-1 expression.

Purification of Soybean Urease (Glycine max) by DEAE-Sepharose CL- 6B Column Chromatography and Effect of Ni Ions on the Enzyme

Soybean urease has been purified 76.51 fold by the use of the DEAE-Sepharose CL-6B column chromatography technique. The purified enzyme was applied to the SDS-PAGE electrophoresis. The effect on Ni ions to the enzyme was tested. Activation determinations were carried out by the Nesslerization method detecting the ammonia content at 425 nm, the protein content was detected by the Warburg and Christian method.