Incidence and Outcomes of Acute Implant Extrusion Following Anterior Cervical Spine Surgery.

STUDY DESIGN: Multi-institutional retrospective case series of 8887 patients who underwent anterior cervical spine surgery. OBJECTIVE: Anterior decompression from discectomy or corpectomy is not without risk. Surgical morbidity ranges from 9% to 20% and is likely underreported. Little is known of the incidence and effects of rare complications on functional outcomes following anterior spinal surgery. In this retrospective review, we examined implant extrusions (IEs) following anterior cervical fusion. METHODS: A retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, were reviewed to identify occurrence of 21 predefined treatment complications. RESULTS: Following anterior cervical fusion, the incidence of IE ranged from 0.0% to 0.8% across 21 institutions with 11 cases reported. All surgeries involved multiple levels, and 7/11 (64%) involved either multilevel corpectomies or hybrid constructs with at least one adjacent discectomy to a corpectomy. In 7/11 (64%) patients, constructs ended with reconstruction or stabilization at C7. Nine patients required surgery for repair and stabilization following IE. Average length of hospital stay after IE was 5.2 days. Only 2 (18%) had residual deficits after reoperation. CONCLUSIONS: IE is a very rare complication after anterior cervical spine surgery often requiring revision. Constructs requiring multilevel reconstruction, especially at the cervicothoracic junction, have a higher risk for failure, and surgeons should proceed with caution in using an anterior-only approach in these demanding cases. Surgeons can expect most patients to regain function after reoperation

An Ethical Framework for Research in Maternal-Fetal Intervention in the Presence of Maternal Human Immunodeficiency Virus or Hepatitis B and C Infection

© 2018 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved. Maternal-fetal interventions continue to be a groundbreaking and rapidly expanding area. In this article, we examine whether it is ethically permissible to conduct investigation into the expansion of inclusion criteria for existing maternal-fetal interventions to include pregnant patients with human immunodeficiency virus (HIV) and hepatitis B or C infection with low or undetectable viral loads. We addressed this ethical question by appealing to ethical principle of respect for the autonomy of the pregnant patient; the patient status of the fetus; the balance of overall benefits and risks of the procedure(s) to pregnant, fetal, and neonatal patients; and to the ethical principle of justice. The ethical framework we have provided supports the conclusion that research on maternal-fetal interventions with pregnant women with HIV and hepatitis B and C infection with low or undetectable viral loads is ethically permissible. To accumulate sufficient numbers, such research should be multicenter

Platinum–Dysprosium Alloys as Oxygen Electrodes in Alkaline Media: An Experimental and Theoretical Study

Platinum–dysprosium (Pt–Dy) alloys prepared by the arc melting technique are assessed as potential electrodes for the oxygen reduction reaction (ORR) using voltammetry and chronoamperometry in alkaline media. A relatively small change (10 at.%) in the alloy composition brought a notable difference in the alloys’ performance for the ORR. Pt40Dy60 electrode, i.e., the electrode with a lower amount of Pt, was identified to have a higher activity towards ORR as evidenced by lower overpotential and higher current densities under identical experimental conditions. Furthermore, DFT calculations point out the unique single-atom-like coordination and electronic structure of Pt atoms in the Pt40Dy60 surface as responsible for enhanced ORR activity compared to the alloy with a higher Pt content. Additionally, Pt–Dy alloys showed activity in the oxygen evolution reaction (OER), with the OER current density lower than that of pure Pt

Effects of heat treatment atmosphere on the structure and activity of Pt3Sn nanoparticle electrocatalysts: a characterisation case study

Comprehensive identification of the phases and atomic configurations of bimetallic nanoparticle catalysts are critical in understanding structure–property relationships in catalysis. However, control of the structure, whilst retaining the same composition, is challenging. Here, the same carbon supported Pt3Sn catalyst is annealed under air, Ar and H2 resulting in variation of the extent of alloying of the two components. The atmosphere-induced extent of alloying is characterised using a variety of methods including TEM, XRD, XPS, XANES and EXAFS and is defined as the fraction of Sn present as Sn0 (XPS and XANES) or the ratio of the calculated composition of the bimetallic particle to the nominal composition according to the stoichiometric ratio of the preparation (TEM, XRD and EXAFS). The values obtained depend on the structural method used, but the trend air < Ar < H2 annealed samples is consistent. These results are then used to provide insights regarding the electrocatalytic activity of Pt3Sn catalysts for CO, methanol, ethanol and 1-butanol oxidation and the roles of alloyed Sn and SnO2

Effects of heat treatment atmosphere on the structure and activity of Pt3Sn nanoparticle electrocatalysts: a characterisation case study

Comprehensive identification of the phases and atomic configurations of bimetallic nanoparticle catalysts are critical in understanding structure–property relationships in catalysis. However, control of the structure, whilst retaining the same composition, is challenging. Here, the same carbon supported Pt₃Sn catalyst is annealed under air, Ar and H₂ resulting in variation of the extent of alloying of the two components. The atmosphere-induced extent of alloying is characterised using a variety of methods including TEM, XRD, XPS, XANES and EXAFS and is defined as the fraction of Sn present as Sn⁰ (XPS and XANES) or the ratio of the calculated composition of the bimetallic particle to the nominal composition according to the stoichiometric ratio of the preparation (TEM, XRD and EXAFS). The values obtained depend on the structural method used, but the trend air < Ar < H₂ annealed samples is consistent. These results are then used to provide insights regarding the electrocatalytic activity of Pt₃Sn catalysts for CO, methanol, ethanol and 1-butanol oxidation and the roles of alloyed Sn and SnO₂