Search

Abstract: Antibacterial surface modification of biomedical materials has evolved as a potentially effective method for preventing bacterial proliferation on the surfaces of devices. However, thin antibacterial coatings or modified layers can be easily worn down when interacting with other surfaces in relative motion, thus leading to a low durability of the antibacterial surface. To this end, novel biomaterial surfaces with antibacterial Ag agents and a wear-resistant S-phase have been generated on stainless steel by duplex plasma silvering–nitriding techniques for application to load-bearing medical devices. The chemical composition, microstructure, surface topography, roughness and wettability of SS surfaces were characterised using glow discharge optical emission spectroscopy, energy-dispersive spectroscopy/wavelength dispersive spectrometry (WDS), X-ray diffraction, atomic force microscopy and a contact angle goniometer. Optimal surface design for high antimicrobial activity and prolonged durability has been achieved, as evidenced by rapid bacterial killing rates (within 6h), an ultra hard matrix (875±25Hv), high load-bearing capacity (critical load 37N) and excellent wear resistance (wear rate 4.9×10−6 mm3 m−1). Ag embedded in the hard substrate of fcc compounds M4N (M=Fe, Cr, Ag, etc.) and the expanded fcc nitrogen S-phase shows deep infiltration of 6±1μm, and provides bactericidal activity against both Gram-negative Escherichia coli NCTC 10418 and Gram-positive Staphylococcus epidermidis NCTC 11047 of over 97% and 90%, respectively, within 6h. The presence of silver in the surface before and after scratching under a progressive load applied up to 60N using a diamond stylus was confirmed by WDS. [ABSTRACT FROM AUTHOR]

Abstract: Samples of an AISI 410 martensitic stainless steel were plasma nitrided at a temperature of 420°C, 460°C or 500°C for 20h. The composition, microstructure and hardness of the nitrided samples were characterised using a variety of analytical techniques. In particular, the corrosion properties of the untreated and plasma nitrided samples were evaluated using anodic polarisation tests in 3.5% NaCl solution and immersion tests in 1% HCl acidic water solution. The results showed that plasma nitriding produced a relatively thick nitrided case consisting of a compound layer and a nitrogen diffusion layer on the 410 stainless steel surface. Plasma nitriding not only increased the surface hardness but also improved the corrosion resistance of the martensitic stainless steel. In the immersion test, nitrided samples showed lower weight loss and lower corrosion rate than untreated one. In the electrochemical corrosion tests, the nitrided samples showed higher corrosion potentials, higher pitting potentials and greatly reduced current densities. The improved corrosion resistance was believed to be related to the iron nitride compound layer formed on the martensitic stainless steel surface during plasma nitriding, which protected the underlying metal from corrosive attack under the testing conditions. [Copyright &y& Elsevier]

AISI 316 austenitic stainless steel has been plasma nitrided using the active screen plasma nitriding (ASPN) technique. Corrosion properties of the untreated and AS plasma nitrided 316 steel have been evaluated using various techniques, including qualitative evaluation after etching in 50%HCl + 25%HNO3 + 25%H2O, weight loss measurement after immersion in 10% HCl, and anodic polarisation tests in 3.5% NaCl solution. The results showed that the untreated 316 stainless steel suffered severe localised pitting and crevice corrosion under the testing conditions. AS plasma nitriding at low temperature (420 °C) produced a single phase nitrided layer of nitrogen expanded austenite (S-phase), which considerably improved the corrosion properties of the 316 austenitic stainless steel. In contrast, AS plasma nitriding at a high temperature (500 °C) resulted in chromium nitride precipitation so that the bulk of the nitrided case had very poor corrosion resistance. However, a thin deposition layer on top of the nitrided case, which seems to be unique to AS plasma nitriding, could have alleviated the corrosion attack of the higher temperature nitrided 316 steel. [Copyright &y& Elsevier]

A low temperature plasma carburising technique has recently been developed to engineer the surfaces of austenitic stainless steels to achieve combined improvement in wear and corrosion resistance. The resultant carburised layer is free from carbide precipitates and contains a single austenite phase supersaturated with carbon. In order to evaluate the tribological behaviour of the carburised layers produced on AISI 316 austenitic stainless steel, dry sliding wear tests have been carried out in the present work. Three carburised layers with varying thickness, ranging from 15 to 40 μm, have been tested using the pin-on-disc configuration. The results show that the hard and corrosion resistant carburised layers are effective in preventing surface plastic deformation, eliminating adhesive and severe abrasive wear. Under dry sliding conditions, all the carburised layers exhibit increased wear resistance by more than one order of magnitude and wear of the layers occurs in a mild micro-abrasion mode. The wear resistance increases with increasing layer thickness and hardness. [Copyright &y& Elsevier]

Examines the efficacy and tolerability of the angiotensin receptor blocker Candesartan cilexetil for systemic hypertension. Drug dosages; Efficacy parameters; Effectiveness in reducing sitting diastolic and systolic blood pressure; Consistency of effects over a 24-hour period; Incidence and intensity of adverse effects.

Cancer treatment includes conventional clinic-based infusions and various options for home administration of medication. Methods A targeted PubMed review was undertaken, with supplemental gray literature searches, for reports of patient preference and patient/caregiver-reported outcomes regarding cancer treatment administration settings. While treatment decisions should account for patient preference for home-based treatment, some treatment pathways will require care at an outpatient or inpatient facility. [Extracted from the article]

Summary Introduction The use of administrative health data for research has prompted questions about its validity for this purpose. Objective/Study design The purpose of this study was to determine the concordance of Pediatric Health Information System (PHIS) perioperative antibiotic charges with the institution's medication administration data for males <10 years old and who underwent outpatient penile/inguinal procedures from July 2013 to March 2015. Results There was 93.9% positive and negative agreement between perioperative antibiotic charges versus administration. The sensitivity and specificity were 96.8% and 87.2%, respectively. The positive and negative predictive values were 94.6% and 92.2%, respectively. Conclusion This study indicated strong agreement between PHIS pharmacy charges and medication administration. [ABSTRACT FROM AUTHOR]