scholarly journals Self-Assembled Monolayer Formation on a Dental Orthodontic Stainless Steel Wire Surface to Suppress Metal Ion Elution

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 367 ◽  
Author(s):  
Hironori Tamaki ◽  
Shigeaki Abe ◽  
Shuichi Yamagata ◽  
Yasuhiro Yoshida ◽  
Yoshiaki Sato
Keyword(s):  
Stainless Steel ◽  
Inductively Coupled Plasma ◽  
Metal Ion ◽  
Steel Wire ◽  
Stainless Steel Surface ◽  
Wire Surface ◽  
Self Assembled Monolayer ◽  
Inductively Coupled ◽  
Self Assembled ◽  
Coated Wires

Metal ion elution, including Cr and Ni from dental orthodontic stainless steel, accounts for some allergies. In this study, a self-assembled monolayer (SAM) on a wire surface is proposed for suppressing such elution. This method involves modifying the stainless steel surface using phosphonic acid containing a long alkyl chain. The uncoated and coated wires are immersed in different acidic solutions, and the supernatant is analyzed by inductively coupled plasma mass spectrometry after 1–4 weeks. The results reveal that Cr and Ni ion elution is significantly suppressed by SAM modification. These findings will help in minimizing potential allergens from dental orthodontics.

Degradation and modification of stainless-steel surface using Cl2/Ar inductively coupled plasma

2013 ◽  
Vol 279 ◽  
pp. 41-45
Author(s):  
Hanbyeol Jang ◽  
Alexander Efremov ◽  
Sun Jin Yun ◽  
Geun Young Yeom ◽  
Kyoung Bo Kim ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Inductively Coupled Plasma ◽  
Steel Surface ◽  
Stainless Steel Surface ◽  
Inductively Coupled

Fungal trehalose phosphorylase: kinetic mechanism, pH-dependence of the reaction and some structural properties of the enzyme from Schizophyllum commune

2001 ◽  
Vol 356 (3) ◽  
pp. 757-767 ◽  
Author(s):  
Christian EIS ◽  
Mark WATKINS ◽  
Thomas PROHASKA ◽  
Bernd NIDETZKY
Keyword(s):  
Inductively Coupled Plasma ◽  
Metal Ion ◽  
Ph Dependence ◽  
Schizophyllum Commune ◽  
Structural Similarity ◽  
Kinetic Mechanism ◽  
Inductively Coupled ◽  
Peptide Mass ◽  
Dead End ◽  
Trehalose Phosphorylase

Initial-velocity measurements for the phospholysis and synthesis of α,α-trehalose catalysed by trehalose phosphorylase from Schizophyllum commune and product and dead-end inhibitor studies show that this enzyme has an ordered Bi Bi kinetic mechanism, in which phosphate binds before α,α-trehalose, and α-d-glucose is released before α-d-glucose 1-phosphate. The free-energy profile for the enzymic reaction at physiological reactant concentrations displays its largest barriers for steps involved in reverse glucosyl transfer to d-glucose, and reveals the direction of phospholysis to be favoured thermodynamically. The pH dependence of kinetic parameters for all substrates and the dissociation constant of d-glucal, a competitive dead-end inhibitor against d-glucose (Ki = 0.3mM at pH6.6 and 30°C), were determined. Maximum velocities and catalytic efficiencies for the forward and reverse reactions decrease at high and low pH, giving apparent pK values of 7.2–7.8 and 5.5–6.0 for two groups whose correct protonation state is required for catalysis. The pH dependences of kcat/K are interpreted in terms of monoanionic phosphate and α-d-glucose 1-phosphate being the substrates, and of the pK value seen at high pH corresponding to the phosphate group in solution or bound to the enzyme. The Ki value for the inhibitor decreases outside the optimum pH range for catalysis, indicating that binding of d-glucal is tighter with incorrectly ionized forms of the complex between the enzyme and α-d-glucose 1-phosphate. Each molecule of trehalose phosphorylase contains one Mg2+ that is non-dissociable in the presence of metal chelators. Measurements of the 26Mg2+/24Mg2+ ratio in the solvent and on the enzyme by using inductively coupled plasma MS show that exchange of metal ion between protein and solution does not occur at measurable rates. Tryptic peptide mass mapping reveals close structural similarity between trehalose phosphorylases from basidiomycete fungi.

scholarly journals In vitro Antimicrobial Effects of Virus Block, Which Contains Multiple Polyoxometalate Compounds, and Hygienic Effects of Virus Block-Supplemented Moist Hand Towels

Pharmacology ◽  
2019 ◽  
Vol 104 (1-2) ◽  
pp. 98-112 ◽  
Author(s):  
Katsuaki Dan ◽  
Naohiro Katoh ◽  
Takaaki Matsuoka ◽  
Katsuyuki Fujinami
Keyword(s):  
Inductively Coupled Plasma ◽  
Metal Ion ◽  
Bacterial Flora ◽  
Atomic Emission ◽  
Time Dependent ◽  
Antimicrobial Effects ◽  
Inductively Coupled ◽  
Before And After ◽  
Normal Bacterial Flora

Background: Historical evidence has verified the multifaceted antiviral efficacy of polyoxometalates (PMs). Methods: We carried out a study to investigate the antimicrobial effects of each of the 5 substances comprising virus block (VB): 3 PMs that have antibacterial and antiviral activity, an antibiotic agent, and an antibacterial agent. We also investigated the effectiveness of the addition of VB to moist hand towels in a study involving 120 volunteers. The time-dependent changes in metal ion concentrations in aqueous VB solution were analyzed using inductively coupled plasma atomic emission spectroscopy. Results: The metal elements in the aqueous VB solution remained stable for 12 weeks without undergoing time-dependent changes. Discussion: Further investigations were performed to study hand hygiene using moist hand towels in daily life settings. To this end, 120 volunteers provided 240 specimens that were used to investigate the presence of antibacterial compounds on the volunteers’ hands before and after hand towel use. An aliquot of each specimen was suspended in phosphate-buffered saline and plated on agar media, and the number of colonies formed was counted. Normal bacterial flora found on the hands of the volunteers was investigated before and after the use of 4 different moist hand towels. Conclusions: The effects of VB and PMs were superior to those of commercial moist hand towels, indicating that effective data were obtained that may be useful for the practical application of the tested items.

scholarly journals Impact of commonly used Ag-Cu ion doses on Desulfovibrio sp.: growth and microbiologically induced corrosion against stainless steel

2020 ◽  
Vol 82 (5) ◽  
pp. 940-953
Author(s):  
S. Arkan-Ozdemir ◽  
N. Cansever ◽  
E. Ilhan-Sungur
Keyword(s):  
Stainless Steel ◽  
Corrosion Rate ◽  
Inductively Coupled Plasma ◽  
Extracellular Polymeric Substances ◽  
Cooling Water ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Inductively Coupled ◽  
Microbiologically Induced Corrosion ◽  
Cu Ions

Abstract Ag-Cu ions in cooling water may inhibit the activity of sulfate-reducing bacteria and therefore provide solutions to microbiologically induced corrosion (MIC) problems, mainly caused by Desulfovibrio sp. To investigate this, the MIC behavior of Desulfovibrio sp. on 316L stainless steel in terms of growth and extracellular polymeric substances (EPS) production was investigated in the presence of Ag-Cu ions. Laboratory-scale systems were set up with final concentrations of 0.13 ppm Ag and 0.3 ppm Cu ions, as they are the frequently used doses for cooling waters, and operated over 720 hours. The corrosion rate was evaluated by gravimetric assay, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses. The growth of Desulfovibrio sp. was assessed by bacterial counting and EPS production. Ag-Cu ions in the biofilm were assessed by inductively coupled plasma - optical emission spectrometry (ICP-OES) and EDS-elemental mapping analyses. It was concluded that the ion concentrations used caused an increase in EPS production, especially of protein. The corrosion rate of the metal by Desulfovibrio sp. in the presence of ions was detected as being 29 times higher than that in the sterile medium with the ions after 720 hours. The results suggested that Desulfovibrio sp. exhibited more corrosive behavior in the presence of non-toxic concentrations of Ag-Cu ions.

Corrosion protection of stainless steel by a self-assembled organosilane bilayer

2014 ◽  
Vol 61 (5) ◽  
pp. 307-313 ◽  
Author(s):  
Hairen Wang ◽  
Minya Li ◽  
June Qu ◽  
Zhiyong Cao ◽  
Geng Chen ◽  
...  
Keyword(s):  
Contact Angle ◽  
Stainless Steel ◽  
Corrosion Inhibition ◽  
Self Assembly ◽  
Ethanol Solution ◽  
Organic Layer ◽  
Stainless Steel Surface ◽  
Nacl Solution ◽  
Content Type ◽  
Self Assembled

Purpose – The purpose of this paper is to construct a self-assembled double layer of organosilane on the surface of stainless steel and to investigate its corrosion inhibitive capability. Design/methodology/approach – A monolayer of 3-glycidoxypropyltrimethoxysilane (GPTMS) was grafted onto an oxidized AISI 430SS (AISI 430 stainless steel) surface substrate from dry toluene solution. The hydrolysis of 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDS) molecules was used to anchor a second organic layer from mixed water-ethanol solution. The adsorption behavior and corrosion inhibition properties of the monolayer and also the bilayer were investigated by potentiodynamic polarization, scanning electron microscope (SEM), Fourier transformed infrared spectroscopy (FTIR) and contact angle measurements. Findings – The GPTMS/PFDS bilayer was successfully deposited onto the oxidized AISI 430SS surface. The optimal assembling time for the filming of the first GPTMS monolayer is 6 hours. Suitable values of pH and temperature of the PFDS self-assembly solution were pivotal to the successful deposition of the second layer. Compared to the GPTMS monolayer, the GPTMS/PFDS bilayer exhibited a significant enhancement of the corrosion inhibition performance of AISI 430SS in NaCl solution. Research limitations/implications – The contact angle value measured on the bilayer-modified surface was somewhat lower than the reported value of a complete fluorinated surface. However, further optimization of the assembling condition is needed to obtain more orderly and denser films. Originality/value – This paper provides useful information regarding the preparation of an organosilane bilayer on the surface of stainless steel and its corrosion inhibition properties in NaCl solution. It illustrates potential application prospects of GPTMS/PFDS bilayers for surface treatment of stainless steel.

Metal Ion Release and Cytotoxicity of Titanium Orthodontic Miniscrews

2017 ◽  
Vol 730 ◽  
pp. 141-147
Author(s):  
Katha Kosayadiloka ◽  
Nathaphon Tangjit ◽  
Suwannee Luppanapornlarp ◽  
Peerapong Santiwong
Keyword(s):  
Inductively Coupled Plasma ◽  
Metal Ion ◽  
The Self ◽  
Cytotoxicity Test ◽  
Ion Release ◽  
Element Analysis ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Metal Ion Release ◽  
Plasma Mass Spectrometry

The aim of this study was to investigate the metal ion release and cytotoxicity of MU orthodontic miniscrews as well as two other brands of orthodontic miniscrews over time. Twenty-four orthodontic miniscrews were tested, divided into three groups of eight. Each sample extraction was performed following the ISO 10993-12:2012 method. Solutions were collected after 1, 7, and 30 days (T1, T2, and T3). The supernatants extracted from these three groups were added and exposed to mouse L929 fibroblastic cell line using an MTT cytotoxicity test. They were also tested for ion release by inductively coupled plasma-mass spectrometry (ICP-MS). Element analysis by energy-dispersive X-ray spectroscopy (EDS) was used to analyze the surfaces of the miniscrews. The quantification of three elements, namely, titanium (Ti), aluminum (Al), and vanadium (V) were assessed. The results indicated that there were no statistical differences between the self-made orthodontic miniscrews and those from two commercial groups (p<0.05). Throughout the testing period, the quantity of ions increased from T1 to T3. After 24 h, vanadium was the first to appear on the surface in small quantities in other two commercial groups. The self-made orthodontic miniscrews exhibited no toxic effects on living cells.

Application of Self Assembled 6-aminohexanol layers for corrosion protection of 304 stainless steel surface

2012 ◽  
Vol 520 (15) ◽  
pp. 4990-4995 ◽  
Author(s):  
Fei Yu ◽  
Shougang Chen ◽  
Houmin Li ◽  
Lejiao Yang ◽  
Yansheng Yin
Keyword(s):  
Stainless Steel ◽  
Corrosion Protection ◽  
Steel Surface ◽  
304 Stainless Steel ◽  
Stainless Steel Surface ◽  
Self Assembled
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