Concentration-Dependent Effect of Nickel Ions on Amyloid Fibril Formation Kinetics of Hen Egg White Lysozyme:a Raman Spectroscopy Study

Nickel,an important transi-tion metal element,is one of the trace elements for hu-man body and has a crucial impact on life and health.Some evidences show the excess exposure to metal ions might be associated with neurological diseases.Herein,we applied Raman spectroscopy to study the Ni(II)ion effect on kinetics of amyloid fibrillation of hen egg white lysozyme(HEWL)in thermal and acidic conditions.Using the well-known Raman indicators for protein tertiary and secondary structures,we monitored and analyzed the concentration effect of Ni(II)ions on the unfolding of tertiary structures and the transformation of sec-ondary structures.The experimental evidence validates the accelerator role of the metal ion in the kinetics.Notably,the additional analysis of the amide I band profile,combined with thioflavin-T fluorescence assays,clearly indicates the inhibitory effect of Ni(II)ions on the formation of amyloid fibrils with organizedβ-sheets structures.Instead,a more significant promotion influence is affirmed on the assembly into other aggregates with disordered struc-tures.The present results provide rich information about the specific metal-mediated protein fibrillation.

Study on a Novel Disphase Supplying Supported Liquid Membrane for Transport Behavior of Divalent Nickel Ions

A novel d!sphase supplying supported liquid membrane （DSSLM）, containing supplying feed phase andsupplying stripping phase tor transport behavior ot NI（Ⅱ）, have been studied. The supplying supported feed phase included feed solution and di（2-ethyhexyl） phosphoric acid （HDEHP） as the carrier in kerosene, and supplying stripping phase included HDEHP as the cartier in kerosene and HC1 as the stripping agent. The effects of volume ratio of membrane solution to feed solution （O/F）, pH, initial concentration of Ni（Ⅱ） and ionic strength in the feedsolution, volume ratio of membrane solution to stripping solution （O/S）, concentration of H2SO4 solution, HDEHP concentration in the supplying stripping phase on transport of Ni（/I）, the advantages of DSSLM compared to the traditional supported liquid membrane （SLM）, the system stability, the reuse of membrane solution and the reten- tion of membrane phase were studied. Experimental results indicated that the optimum transpgrt of Ni（Ⅱ） was oh-tained when H2SO4 concentration was 2.00 mol＇L-＇, HDEHP concentration was 0.120 mol·L-1, and O/S was 4· 1 in the supplying stripping phase, O/F was 1 ： 10 and pH was 5.20 in the supplying feed phase. The ionic strength in supplying feed phase had no obvious effect on transport of Ni（Ⅱ）. When initial Ni（Ⅱ） concentration was 2.00x 10-4 mol/L, the transport percentage of Ni（Ⅱ） was up to 93.1% in 250 min. The kinetic equation was deduced in terms of the law of mass diffusion and the interface chemistry.

Evaluation of carbon-based nanosorbents synthesised by ethylene decomposition on stainless steel substrates as potential sequestrating materials for nickel ions in aqueous solution

The present work covers the preparation of carbon-based nanosorbents by ethylene decomposition on stainless steel mesh without the use of external catalyst for the treatment of water containing nickel ions （Ni2＋）. The reaction temperature was varied from 650 to 850℃, while reaction time and ethylene to nitrogen flow ratio were maintained at 30 rain and 1：1 cma/min, respectively. Results show that nanosorbents synthesised at a reaction temperature of 650℃ had the smallest average diameter （75 nm）, largest BET surface area （68.95 m2/g） and least amount of impurity （0.98 wt.% Fe）. A series of batch sorption tests were performed to evaluate the effects of initial pH, initial metal concentration and contact time on Ni2~ removal by the nanosorbents. The equilibrium data fitted well to Freundlich isotherm. The kinetic data were best correlated to a pseudo second-order model indicating that the process was of chemisorption type. Further analysis by the Boyd kinetic model revealed that boundary layer diffusion was the controlling step. This primary study suggests that the prepared material with Freundiich constants compared well with those in the literature, is a promising sorbent for the sequestration of Ni2＋ in aqueous solutions.

The interaction mechanism of nickel ions with L929 cells based on integrative analysis of proteomics and metabolomics data

The aim of this article was to study the toxicity mechanism of nickel ions(Ni^(2+))on L929 cells by combining proteomics and metabolomics.First,iTRAQ-based proteomics and LC/MS metabolomics analyses were used to determine the protein and metabolite expression profiles in L929 cells after treatment with 100μMNi^(2+)for 12,24 and 48 h.A total of 177,2191 and 2109 proteins and 40,60 and 74 metabolites were found to be differentially expressed.Then,the metabolic pathways in which both differentially expressed proteins and metabolites were involved were identified,and three pathways with proteins and metabolites showing upstream and downstream relationships were affected at all three time points.Furthermore,the protein-metabolite-metabolic pathway network was constructed,and two important metabolic pathways involving 4 metabolites and 17 proteins were identified.Finally,the functions of the important screened metabolic pathways,metabolites and proteins were investigated and experimentally verified.Ni^(2+)mainly affected the expression of upstream proteins in the glutathione metabolic pathway and the arginine and proline metabolic pathway,which further regulated the synthesis of downstream metabolites,reduced the antioxidant capacity of cells,increased the level of superoxide anions and the ratio of GSSG to GSH,led to oxidative stress,affected energy metabolism and induced apoptosis.

Application of Modified Nickel Slag Adsorbent on the Removal of Pb^(2＋) and Cu^(2＋) from Aqueous Solution

Al（OH）_3 modified nickel slag adsorbent was prepared by sintering technology. The structure of the sample was characterized by BET, XRD, IR, SEM and EDAX. The sample＇s adsorption performance of Pb^（2＋） and Cu^（2＋） from aqueous solution was studied. Results indicated that the adsorbent is a loose and porous mesoporous material. Its surface had mass aluminosilicate, high-activity γ-Al_2O_3 and its p H ranges from 4 to 12 that all have negative charges. The BET surface of the adsorbent is 23.90 m^2/g. Furthermore, its surface contains rich oxygenic functional groups, which could not only provide abundant adsorption sites for Pb^（2＋） and Cu^（2＋）, but also improve the adsorption performance of Pb^（2＋） and Cu^（2＋） from waste water through the complexation of heavy metal ions. The best p H values selected in the adsorption of Pb^（2＋） and Cu^（2＋） are 6 and 5, respectively. With the increase of the initial concentration of simulated solution, the adsorption capacities of Pb^（2＋） and Cu^（2＋） gradually increased but the removal rates showed a downward trend. The competitive adsorption results of Pb^（2＋） and Cu^（2＋） showed that Pb^（2＋） has better preferential adsorption than Cu^（2＋）.

Adsorption of Pb^2+and Cu^2+with Unburned Desulphurization Slag Modified Nickel Slag

Desulphurization slag modified nickel slag adsorbent was prepared by unburned forming technology. The structure of the sample was characterized by BET,XRD,IR,SEM and EDAX. The adsorption performance of Pb^2＋ and Cu^2＋ onto the resultant adsorbent from aqueous solution was studied. Results indicated that the adsorbent possesses a network pore structure formed by the AFt and C–S–H through cross lapping; the adsorbent contains a large number of Si–OH and Al–OH functional groups. The presence of functional groups not only provides abundant adsorption sites for Pb^2＋ and Cu^2＋,but also improves the adsorption performance of Pb^2＋ and Cu^2＋ from waste water through the complexation of heavy metal ions. The result of specific surface area analysis showed that the adsorbent sample possesses mesoporous structure and the BET specific surface area is 27.15 m^2/g. The solution p H values for the adsorption of Pb^2＋ and Cu^2＋ were optimized to be 6 and 5.5,respectively. The adsorption capacities of Pb^2＋ and Cu^2＋ gradually increase,whereas the removal rates of the two metal ions decrease with increasing the initial concentration of simulated solution. The resultant adsorbent gives a higher adsorption capacity for Cu^2＋ than for Pb^2＋ in the single ion solution. However,it shows preferential adsorption of Pb^2＋ rather than that of Cu^2＋. Meanwhile,results of recyclability indicate the remarkable regeneration capacity,re-adsorption ability and reusability performance of the adsorbent sample.

Reclaim nickel and remove organics from the spent electroless nickel-plating bath by electrolysis

Typical wastes from nickel plating operations include excess drag-out solution. An electrochemical approach was made to recover the nickel and remove the organic pollutants from the spent electroless nickelplating bath. An electrolyte cell which was constructed by the cathode of porous nickel foam and the anode of Ti/RuO2 was used. During electrolysis, the nickel ion was electrodeposited at the cathode and the oxidation of the organics in the hath was conducted at the anode. The current （i） , time （t） , temperature （T） and pH of the solution affected the recovery efficiency of nickel with constant potential electrolysis. With the optimum experimental conditions of pH=7.6, i = 0.45 A. T = 65℃ andt = 2 h, the concentration of nickel ion was reduced from 2.09 g/L to 0. 053 g/L and the recovery rate of nickel, the current efficiency and the consumed energy wer 97.5%, 17. 1%, 12.2 kWh/kg Ni, respectively. Meanwhile, total organic carbon （TOC） of the bath was reduced from 5 800 mg/L to 152.5 mg/L and the removal efficiency of TOC was 97.3%. The recovery rate of nickel could keep to about 97% when eleetrodeposit was used to recover nickel for 40 hours in a laboratol.w batch reactor containing the spent bath. Dull nickel containing phosphorus was obtained on the cathode.

A STUDY ON Ti ELECTRODE MODIFIED BY NICKEL ION BEANS

The reduction of H^+ on Ti electrodes which were treated by implanting nickel ions and thermodiffusing in vacuum has been studied.The calytic activity of the afore- mentioned electroes for H^+ reduction is much higher than that of the untreated Ti electrodes.

Removal of Nickel（II） from Aqueous Solution Using Activated Charcoal Derived from the Leaves of Bitter Orange Tree （Citrus aurantium）

The present work deals with the removal of Ni（II） ion using activated charcoal prepared from the dry leaves of bitter orange tree （Citrus aurantium）. The effects of its concentration, adsorbent dosage, particle size, pH and temperature on removal of Ni（II） ion have been studied. The removal of Ni（II） ion is higher at lower concentration and gradually decreases as the concentration increases. The pH of 5 was the most suitable. The removal of Ni（II） ion increases with the increases in the adsorbent dosage. The effect of particle size reveals that the percentage removal of Ni（II） ion decreases with increase in particle size of adsorbent. The effect of temperature shows that as temperature increases, the percentage removal of Ni（II） ion decreases and this is due to the interaction forces weakening at high temperature. Thermodynamic parameters from the effect of temperature were calculated.

Experimental Study on Urease Activity and Cementation Characteristics of Soybean

A new and more ecologically sound cementing material known as“bio-cement”has been found to have the capacity to consolidate loose gravel into sand columns offering a certain degree of strength,and to fill and repair cracks in concrete to restore resilience.The typical representative is the microbial induced calcium carbonate deposition technology(MICP)and enzyme induced calcite precipitation(EICP).As part of this research,EICP with soybean urease as the core was studied.The test results show that soybean urease activity is significantly affected by pH and urea concentration values,while the external nickel source is not found to impair a stimulating effect on activity.When the concrete specimens were immersed in the composite solution of soybean urease,urea,and calcium chloride after having been subjected to a high temperature,a continuous layer of white precipitations quickly appeared on the surface of the specimens.Measured using a metalloscope,the thickness of the precipitations was found to reach up to 2.0 mm,while the surface water absorption rate was reduced by 70%.The effects of this combined outcome are believed to significantly protect and improve the durability of the concrete specimens previously subjected to a high temperature.At the same time,the composite solution is shown to be capable of cementing fly ash,with the cubic strength of the finished samples reaching 4.0 MPa after 3 days.Results from the use of a scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and X-ray diffraction(XRD),reveal that both the white precipitations on the surface of the concrete specimens and the cement binding the fly ash particles are calcite crystals.It is concluded from these preliminary study results that the use of soybean urease as a bio-cement had proved successful.

Nano mesocellular foam silica（MCFs）:An effective adsorbent for removing Ni2+ from aqueous solution

Nano mesocellular foam silica(MCFs)was synthesized through the hydrothermal method in this study.Powder X-ray diffraction and scanning electron microscopy were used to characterize the MCFs sample.The sample presented spherical particles and regular morphology.The results of transmission electron microscopy showed that synthesized MCFs has a three-dimensional honeycomb pore structure,which aids in the adsorption of nickel ion(Ni^2+).The results of low-temperature nitrogen gas adsorption-desorption showed that the pore diameter of the synthesized MCFs was 19.6 nm.The impacts of pH,temperature,amount of adsorbent,initial concentration of Ni^2+,and contact time on the adsorption effect of Ni^2+ by MCFs were studied.Under the optimized adsorption conditions,the adsorption rate reached 96.10%and the adsorption capacity was 7.69 mg/g.It has been determined through the study of kinetics and adsorption isotherms that the adsorption of Ni^2+ by MCFs follows the pattern of the pseudo-second-order kinetic model,simultaneously belonging to the Freundlich adsorption type.The thermodynamic results of adsorption showed that,when the temperature is between 25℃ and 45℃,the adsorption is a spontaneous exothermic reaction.

Ni^(2+)-PAA Adsorbent for Purifying 6His-OmpTS Recombinant Protein

Functional Ni2+-polyacrylic acid (Ni2+-PAA) adsorbent has been prepared for metal chelate affinity chromatography. DNA elements coding for adjacent histidines were fused to the Aeromonas hydrophila ompTS gene. Subsequent expression in E. coli resulted in the production of hybrid protein 6His-OmpTS that could be purified by Ni2+-PAA affinity chromatography.

New Nano-Film Single-Rivet Patent Ductus Arteriosus Occluders:A Prospective,Randomized and Double-blind Study

Nitinol alloy occluders are widely used in the transcatheter intervention treatment of congenital heart diseases like patent ductus arteriosus（PDA）.However,nitinol alloy contains high levels of nickel,which can lead to toxic effects in the immune and hematopoietic systems if released in sufficient quantities.A new type of single-rivet occluder coated with nano-film has been developed to limit the release of nickel.In total,23 patients were recruited and randomly assigned to the experimental group（n=12） with the new nano-film single-rivet occluders or the control group（n=11） with the traditional occluders.One case in the control group was lost to follow-up.The remaining 22 cases were followed up at 24 h,7 days,1 month,3 months,and 6 months after the procedure.There were no statistically significant differences in routine blood test,alanine aminotransferase,creatinine,and troponin between the experimental and control groups.Serum nickel concentration in both two groups increased at 24 h after the procedure,peaked at 1 month,and returned to preoperative levels at 6 months.Serum nickel levels in the experimental group were significantly lower than in the control group at 24 h,7 days,1 month,and 3 months after the procedure.These data suggested that the nano-film coating effectively prevented nickel release from the new occluders,and therefore has a preferable safety profile.

NICKEL(Ⅱ)ion-intercalated MXene membranes for enhanced H_(2)/CO_(2) separation

Hydrogen fuel has been embraced as a potential long-term solution to the growing demand for clean energy.A membrane-assisted separation is promising in producing high-purity H_(2).Molecular sieving membranes(MSMs)are endowed with high gas selectivity and permeability because their well-defined micropores can facilitate molecular exclusion,diffusion,and adsorption.In this work,MXene nanosheets intercalated with Ni^(2+) were assembled to form an MSM supported on Al_(2)O_(3) hollow fiber via a vacuum-assisted filtration and drying process.The prepared membranes showed excellent H_(2)/CO_(2) mixture separation performance at room temperature.Separation factor reached 615 with a hydrogen permeance of 8.35×10^(-8) mol·m^(-2)·s^(-1) ·Pa^(-1).Compared with the original Ti_(3)C_(2)T_(x)/Al_(2)O_(3) hollow fiber membranes,the permeation of hydrogen through the Ni^(2+)-Ti_(3)C_(2)T_(x)/Al_(2)O_(3) membrane was considerably increased,stemming from the strong interaction between the negatively charged MXene nanosheets and Ni^(2+).The interlayer spacing of MSMs was tuned by Ni^(2+).During 200-hour testing,the resultant membrane maintained an excellent gas separation without any substantial performance decline.Our results indicate that the Ni2+tailored Ti_(3)C_(2)T_(x)/Al_(2)O_(3) hollow fiber membranes can inspire promising industrial applications.

Ion-imprinted silica gel and its dynamic membrane for nickel ion removal from wastewaters

An ion-imprinted sorbent(IIP)was prepared by using Ni^2+ as template,3-[2(2-aminoethylamino)ethylamino]propyl-trimethoxysilane as functional monomer,and silica gel as carrier.The adsorption performance of IIP towards Ni^2+ was investigated.IIP showed a higher adsorption capacity than that of non-imprinted sorbent,and it also exhibited high selectivity for Ni^2+ in the presence of Cu^2+ and Zn^2+ ions.Then,IIP was used to form a dynamic membrane onto the surface of ceramic membrane for treatment of electroplating wastewater containing Ni^2+.Compared with ceramic membrane,IIP dynamic membrane had much higher steady membrane flux,and also rejected Ni^2+ to obtain a lower concentration of Ni2+ in the permeate fluid.Perhaps it is suitable for future practice applications.

Screening and validation of nickel ion cytotoxicity biomarkers based on transcriptomic and proteomic technology

The aimof this study was to screen cytotoxicity biomarkers of nickel ions(Ni^(2+))using transcriptomic and proteomic approaches combined with molecular biology validation.First,the MTT method was used to evaluate cytotoxicity in L929 cells treated with Ni^(2+)at different concentrations.Ni^(2+)at both 100μM and 200 lMaffected cell proliferation.Then,transcriptomic and proteomic technology was used to study the effects of Ni^(2+)on the expression of genes/proteins in cells.It was found that 1490,789,652 and 729 genes(12,24,48 and 72 h,respectively)and 177,2191 and 2095 proteins(12,24 and 48 h,respectively)were differentially expressed after treatment with 100μM Ni^(2+).In total,1403,963,916 and 1230 genes(12,24,48 and 72 h,respectively)and 83,1681 and 2398 proteins(12,24 and 48 h,respectively)were differentially expressed after treatment with 200μMNi^(2+).Then,four target gene/protein biomarkers were filtered by combined screening using gene/proteomic experimental data and biological pathway analyses.Further expression level validation of all these target biomarkers and functional validation of selected gene/protein biomarkers were carried out,and a final gene/protein biomarker(UQCRB)was identified.