Forecasting of Corrosion Properties of Steel Wires for Production of Guide Wires for Cardiological Treatment

Abstract

The study presents evaluation of the influence of strain in drawing process and of surface modification on resistance to electrochemical corrosion of wires made of stainless steel for production of guide wires used in invasive cardiology. The results of static tensile test enabled us to determine the course of flow curve of wires made of X10CrNi 18-8 steel as well as mathematical form of flow stress function. Resistance to electrochemical corrosion was evaluated on the ground of registered anodic polarisation curves by means of potentiodynamic method. The tests were performed in solution simulating human blood on samples that were electrolytically polished and samples that were polished and then chemically passivated. Exemplary anodic polarisation curves were given. It was proved that with the applied strain, corrosion properties decrease. It was found that chemical passivation improves wire corrosion characteristics. Statistical analysis showed that there is a significant dependence between corrosion properties (polarisation resistanceRp) and strainεapplied in drawing process. Functions that present the changeRp=f(ε)were selected. The issue is of importance to guide wire manufacturers because application of the suggested methodology will enable us to forecast corrosion characteristics of wire with the required strength drawn with the applied strain.

Solid-Phase Microextraction Enables Isolation of BRAF V600E Circulating Tumor DNA from Human Plasma for Detection with a Molecular Beacon Loop-Mediated Isothermal Amplification Assay

“…To determine the effect of these salts on the extraction, a solution was prepared to mimic the salts present in plasma. 38 Extractions were performed from this salt solution, resulting in Cq values (26.43 ± 0.52) higher than those from Tris (25.21 ± 0.28), as shown in Figure 5B. These results suggest that the salts present in plasma can cause a moderate decrease in the extraction.…”

“…Since PIL-based sorbent coatings predominantly extract DNA through an ion exchange mechanism, it is possible that higher ionic strength extraction solutions can affect interactions between the sorbent and DNA. To determine the effect of these salts on the extraction, a solution was prepared to mimic the salts present in plasma . Extractions were performed from this salt solution, resulting in Cq values (26.43 ± 0.52) higher than those from Tris (25.21 ± 0.28), as shown in Figure B.…”

Chemosensory Optode Array Based on Pluronic-Stabilized Microspheres for Differential Sensing

“…Dopamine hydrochloride, L-epinephrine, L-norepinephrine, γ-aminobutyric acid (GABA), acetylcholine chloride, histamine, taurine, phenylethylamine, sodium phosphate monohydrate, disodium phosphate dodecahydrate, Tris-HCl, Pluronic F127 were supplied by Sigma-Merck (Pozna ń, Poland). Milli-Q water was used for the preparation of all aqueous solutions, including phosphate buffer pH 7.4, Tris-HCl buffer pH 9.0, and simulated Blood Plasma Solution (BPS: 6.800 g/L NaCl, 0.200 g/L CaCl 2 , 0.400 g/L KCl, 0.205 g/L MgSO 4 * 7 H 2 O, 2.200 g/L NaHCO 3 , 0.318 g/L Na 2 HPO 4 * 12 H 2 O, 0.026 g/L NaH 2 PO 4 ) according to [11].…”

Impact of Sterilisation and Strain Hardening in Drawing Process on Resistance to Electrochemical Corrosion of Wires Intended in Cardiology

“…Curves of yield stress changes in strain function (so called flow curves) enable to predict material behaviour during plastic forming processes [13]. Strain applied in drawing process also has a significant influence on corrosion properties of the wire [14,15]. Production engineers make use of flow curves for such selection of drawing parameters that would enable to obtain wires with mechanical properties required for a specific purpose.…”