scholarly journals Relationship between Dislocation Density and Antibacterial Activity of Cryo-Rolled and Cold-Rolled Copper

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 200 ◽  
Author(s):  
Vinod Parmar ◽  
Kandarp Changela ◽  
B. Srinivas ◽  
Manimuthu Mani Sankar ◽  
Sujata Mohanty ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Dislocation Density ◽  
Inductively Coupled Plasma ◽  
Copper Ions ◽  
Pure Copper ◽  
Bacterial Cells ◽  
Inductively Coupled ◽  
Initial Adhesion ◽  
Elemental Copper ◽  
Cold Rolled

In the present work, cold rolling and cryo-rolling were performed on 99% commercially pure copper substrates. Both cold and cryo-rolling processes caused severe plastic deformation that led to an increase in dislocation density by 14× and 28× respectively, as compared to the pristine material. Increases in average tensile strengths, by 75% (488 MPa) and 150% (698 MPa), were observed in the two rolled materials as the result of the enhancement in dislocation density. In addition to strength, enhanced antibacterial property of cryo-rolled copper was observed in comparison to cold rolled and pristine copper. Initial adhesion and subsequent proliferation of bio-film forming Gram-positive bacteria Staphylococcus aureus was reduced by 66% and 100% respectively for cryo-rolled copper. Approximately 55% protein leakage, as well as ethidium bromide (EtBr) uptake, were observed confirming rupture of cell membrane of S. aureus. Inductively coupled plasma-mass spectroscopy reveals higher leaching of elemental copper in nutrient broth media from the cryo-rolled copper. Detailed investigations showed that increased dislocation led to leaching of copper ions that caused damage to the bacterial cell wall and consequently killing of bacterial cells. Cryo-rolling enhanced both strength, as well as antibacterial activity, due to the presence of dislocations.

A REVERSIBLE OPTICAL SENSOR BASED ON CHITOSAN FILM FOR THE SELECTIVE DETECTION OF COPPER IONS

2012 ◽  
Vol 24 (05) ◽  
pp. 453-459 ◽  
Author(s):  
Shenhsiung Lin ◽  
Chia-Chen Chang ◽  
Chii-Wann Lin
Keyword(s):  
Functional Groups ◽  
Inductively Coupled Plasma ◽  
Copper Ions ◽  
Three Dimensional ◽  
Copper Ion ◽  
Chitosan Film ◽  
Detection Limits ◽  
Dimensional Structure ◽  
Optical Detectors ◽  
Inductively Coupled

Heavy metals greatly influence animal physiology, even at small doses. Among these metals, the copper ion is of great concern due to its effects on humans and wide applications in industry. Compared to atomic absorption spectroscopy and inductively coupled plasma-mass spectrometry, which destroy the samples that are analyzed, optical techniques do not decompose the analyte and have become a popular field of recent research. In this paper, we combined a novel optical detector that did not require sample-labeling, called surface plasmon resonance (SPR), with chitosan to detect copper ions by modifying the functional groups of chitosan through pH modification. Compared to other optical detectors, the SPR system was relatively fast and involved fewer experimental confounding factors. The three-dimensional structure of chitosan was used to obtain lower detection limits. Moreover, modification of the chitosan functional groups resulted in efficient regeneration by controlling the pH. A detection limit of 0.1 μM was obtained (linear range: 0.5–10 μM, R2 = 0.976), and the specificity was certified by comparing the copper ion with six other ions. Additionally, we successfully regenerated the SPR chips by modifying the functional groups. In conclusion, the chitosan–SPR system detected copper ions with improved detection limits using a quick and simple regeneration method.

scholarly journals The influence of different compounds of trace elements on the biomass and synthesis of exopolysaccharides of mycelium Trametes versicolor (Polyporaceae, Polyporales)

2017 ◽  
Vol 25 (4) ◽  
Author(s):  
G. A. Al-Maali
Keyword(s):  
Trace Elements ◽  
Copper Sulfate ◽  
Inductively Coupled Plasma ◽  
Metal Ion ◽  
Trametes Versicolor ◽  
Copper Ions ◽  
Optical Emission ◽  
Nitrogen Sources ◽  
Physiological Indicators ◽  
Inductively Coupled

This article presents the results of research on the influence of citrates of zinc, manganese and copper, obtained by the method of aquanotechnology, on a number of physiological indicators of a valuable medicinal mushroom Trametes versicolor 353. Previously we detected that these metal citrates stimulated the growth of mycelium more intensively than sulfates of the above-mentioned metals in equal concentrations. In the present research we investigated the influence of these metal citrates on the parameters of assimilation of carbon and nitrogen sources, metal ion accumulation and synthesis of exopolysaccharides. The degree of metals ions accumulation in the mycelium was studied by the  method of optical emission spectroscopy with an inductively coupled plasma. The economic coefficient of biomass synthesis and impact of nitrogen assimilation were higher on media with the metals citrate than on the medium with the sulfates of the studied metals. Thus, the highest economic coefficient of biomass synthesis (36%) was observed on the medium with copper citrate. Also, copper citrate (amongst the studied metals) increased the level of assimilation of the nitrogen source by up to 35%, versus 18% on the control medium. Quantitative analysis of trace elements in biomass showed that the mycelium accumulated an equal amount of zinc or manganese ions on both types of media (with citrate or sulfate of these metals). However, on the medium with copper citrate, mycelium of T. versicolor 353 accumulated copper ions better then on a medium with copper sulfate: 82.9 μg/g of biomass on the medium with copper sulfate versus 162.0 μg/g of biomass on the medium with copper citrate. Also the results show that a significant increase of biomass (by 79% relative to the control) on the copper citrate medium is due to a threefold reduction of the exopolysaccharides amount. This data indicates a greater biological activity of copper citrate,  relative to copper sulfate. Only zinc citrate raised both the synthesis of biomass and the synthesis of exopolysaccharides by 37% and 29% respectively ( relative to the control trial).

scholarly journals Green preparation and characterization of silver nanocolloids used as antibacterial material in soap

2022 ◽  
Author(s):  
M. Nowak ◽  
A. Tolińska ◽  
L. Marciniak ◽  
M. Skrobańska ◽  
B. Tylkowski ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Inductively Coupled Plasma ◽  
Antibacterial Properties ◽  
Dirty Hands ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Pure Soap ◽  
Vis Spectroscopy ◽  
Plasma Mass Spectrometry

AbstractThis study aimed to assess the characteristics, including morphology, physicochemical properties, and antibacterial properties, of silver nanocolloids obtained by D-glucose reduction. Silver nanoparticles were synthesized in accordance with the principles of green chemistry using D-glucose as a reductor. The obtained nanostructures were characterized by UV–vis spectroscopy, transmission electron microscopy, and dynamic light scattering. Stability tests performed after 1 month of storage revealed that the colloids prepared with and without polyvinylpyrrolidone as a stabilizer had the same properties. Distribution of the nanoparticles was tested using inductively coupled plasma mass spectrometry by doping the silver colloids into a natural soap mass. The antibacterial activity of the soap containing silver nanoparticles was tested on dirty hands. The antibacterial activity test demonstrated that the novel green soap materials improved with D-glucose-reduced silver nanoparticles possessed better antibacterial properties than a pure soap, and thus, they could be recommended for quotidian use by dermatological patients.

Elemental composition and bacterial incidence in firn-cores at Midre Lovénbreen glacier, Svalbard

Polar Record ◽  
2013 ◽  
Vol 51 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Shiv Mohan Singh ◽  
Puja Gawas-Sakhalkar ◽  
Simantini Naik ◽  
Rasik Ravindra ◽  
Jagdev Sharma ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Elemental Concentration ◽  
Salt Spray ◽  
Enrichment Factors ◽  
Sea Salt ◽  
Anthropogenic Sources ◽  
Total Count ◽  
Bacterial Cells ◽  
Inductively Coupled ◽  
Crustal Enrichment Factors

ABSTRACTThe present study was conducted to measure the elemental concentration and bacterial deposition in the firn-cores at the Midre Lovénbreen glacier, Svalbard. Firn-cores up to 1m deep were collected and divided into three subsections. These were subjected to elemental analysis using inductively coupled plasma mass spectroscopy (ICPMS). In all 20 elements were analysed. The crustal enrichment factors calculated for these elements on the basis of Fe values, demonstrate that the elements have derived from both crustal and anthropogenic sources. For certain elements there also exists a possibility of input from sea salt spray. Total bacterial counts in these firn samples ranged from 1.03 × 105to 3.67 × 105per ml of meltwater. Culturability of these bacterial cells, in comparison to the total count was very low. At 4°C the maximum culturability was <1.4% of the total count while at 15°C it was still lower (~1%).

scholarly journals Architectured Cu–TNTZ Bilayered Coatings Showing Bacterial Inactivation under Indoor Light and Controllable Copper Release: Effect of the Microstructure on Copper Diffusion

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 574
Author(s):  
Akram Alhussein ◽  
Sofiane Achache ◽  
Regis Deturche ◽  
Sami Rtimi
Keyword(s):  
Antibacterial Activity ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Copper Ions ◽  
Maximum Height ◽  
Bacterial Inactivation ◽  
Average Roughness ◽  
Working Pressure ◽  
X Ray ◽  
Copper Release

A Ti–23Nb–0.7Ta–2Zr–1.2O alloy (at %), called “gum metal”, was deposited by direct-current magnetron sputtering (DCMS) on an under layer of copper. By varying the working pressure during the deposition, columnar TNTZ (Ti–Nb–Ta–Zr) nanoarchitectures were obtained. At low working pressures, the upper layer was dense with a coarse surface (Ra = 12 nm) with a maximum height of 163 nm; however, the other samples prepared at high working pressures showed columnar architectures with voids and an average roughness of 4 nm. The prepared coatings were characterized using atomic force microscopy (AFM) for surface topography, energy dispersive X-ray spectroscopy (EDX) for atomic mapping, scanning electron microscopy (SEM) for cross-section imaging, contact angle measurements for hydrophilic/hydrophobic balance of the prepared surfaces, and X-ray diffraction (XRD) for the crystallographic structures of the prepared coatings. The morphology and the density of the prepared coatings were seen to influence the hydrophilic properties of the surface. The antibacterial activity of the prepared coatings was tested in the dark and under low-intensity indoor light. Bacterial inactivation was seen to happen in the dark from samples presenting columnar nanoarchitectures. This was attributed to the diffusion of copper ions from the under layer. To verify the copper release from the prepared samples, an inductively coupled plasma mass spectrometer (ICP-MS) was used. Additionally, the atomic depth profiling of the elements was carried out by X-ray photoelectron spectroscopy (XPS) for the as-prepared samples and for the samples used for bacterial inactivation. The low amount of copper in the bulk of the TNTZ upper layer justifies its diffusion to the surface. Recycling of the antibacterial activity was also investigated and revealed a stable activity over cycles.

scholarly journals Antimicrobial Properties of Copper Nanoparticles and Amino Acid Chelated Copper Nanoparticles Produced by Using a Soya Extract

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
I. DeAlba-Montero ◽  
Jesús Guajardo-Pacheco ◽  
Elpidio Morales-Sánchez ◽  
Rene Araujo-Martínez ◽  
G. M. Loredo-Becerra ◽  
...  
Keyword(s):  
Amino Acids ◽  
Antibacterial Activity ◽  
Copper Nanoparticles ◽  
Copper Ions ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Bacterial Cells ◽  
Microdilution Method ◽  
Diphenyltetrazolium Bromide ◽  
Specific Strain

This paper reports a comparison of the antibacterial properties of copper-amino acids chelates and copper nanoparticles againstEscherichia coli,Staphylococcus aureus, andEnterococcus faecalis. These copper-amino acids chelates were synthesized by using a soybean aqueous extract and copper nanoparticles were produced using as a starting material the copper-amino acids chelates species. The antibacterial activity of the samples was evaluated by using the standard microdilution method (CLSI M100-S25 January 2015). In the antibacterial activity assays copper ions and copper-EDTA chelates were included as references, so that copper-amino acids chelates can be particularly suitable for acting as an antibacterial agent, so they are excellent candidates for specific applications. Additionally, to confirm the antimicrobial mechanism on bacterial cells, MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) was carried out. A significant enhanced antimicrobial activity and a specific strain were found for copper chelates overE. faecalis. Its results would eventually lead to better utilization of copper-amino acids chelate for specific application where copper nanoparticles can be not used.

scholarly journals Cerium-modified cryptomelane: an antibacterial activity against Pseudomonas aeruginosa

2021 ◽  
Vol 947 (1) ◽  
pp. 012027
Author(s):  
Tuyet-Mai Tran-Thuy ◽  
Ngoc-Thuy Nguyen-Thi ◽  
Trong-Phu Tran ◽  
Ngoc-Hung Tran-Le ◽  
Minh-An Dang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Inductively Coupled Plasma ◽  
Inhibition Zone ◽  
Molar Ratio ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry

Abstract K-OMS-2 (non-modified sample) and Ce-modified OMS-2 with different Ce-loading amounts were prepared by the refluxed method. The cryptomelane structure and elemental composition of synthesized samples were characterized with X-ray diffraction (XRD) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. ICP-MS analysis revealed ~0.06 – 0.11 of K/Mn molar ratio and the Ce-loading amounts increased from 0 to —11.27 wt.% under increasing Ce-precursor concentration. Antibacterial activity against Pseudomonas aeruginosa was evaluated by the agar well diffusion method. The antibacterial ability against Pseudomonas aeruginosa was not recorded over K-OMS-2 (Ce0; 4.5 wt.% of K; 0 wt.% of Ce) and Ce3 (0.89 wt.% of K; 11.27 wt.% of Ce) samples while Ce2 sample (1.89 wt.% of K; 8.7 wt.% of Ce) showed a comparable antibacterial activity against Pseudomonas aeruginosa with ~12 mm of inhibition-zone diameter. This suggested the potentiality of using metal-modified cryptomelane in acceleration of antimicrobial ability.

scholarly journals An Investigation on Dislocation Density in Cold-Rolled Copper Using Electrochemical Impedance Spectroscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Elyas Rafiee ◽  
Mansour Farzam ◽  
Mohammad Ali Golozar ◽  
Ali Ashrafi
Keyword(s):  
Charge Transfer ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Dislocation Density ◽  
Electrochemical Impedance ◽  
Pure Copper ◽  
Annealed Sample ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Cold Rolled

Variation of electrochemical impedance with dislocation density was investigated using electrochemical impedance spectroscopy (EIS). For this purpose, EIS measurements were carried out on 10, 20, 30, 40, and 50% cold-rolled commercially pure copper in 0.1 M NaCl (pH = 2) solution. Nyquist plots illustrated that the electrochemical reactions are controlled by both charge transfer and diffusion process. Increasing dislocation density, the magnitude of electrochemical impedance of samples was decreased. Decreasing magnitude of impedance at intermediate frequencies indicated increasing double-layer capacitance. Charge transfer resistance decreased from value 329.6 Ωcm2 for annealed sample to 186.3 Ωcm2 for sample with maximum dislocation density (1.72×1015 m−2). Phase angles were lower for samples that contained more dislocation density, indicating more tendencies to loss of electrons and releasing atoms into electrolyte.

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