Diffusion of Chemically Reacting Fluids through Nonlinear Elastic Solids and 1D Stabilized Solutions

This paper summarizes a 1D adaptation (Hall et al., Math Mech Solids, 2014) of the reactive fluid–solid mixture theory of Hall and Rajagopal (Math Mech Solids 17(2):131–164, 2012), which considers an anisotropic viscous fluid diffusing and chemically reacting with an anisotropic elastic solid. The present implementation introduces a stabilized mixed finite element method for advection–diffusion–reaction phenomena, which is applied to 1D isothermal problems involving Fickian diffusion, oxidation of PMR-15 polyimide resin, and slurry infiltration. The energy and entropy production relations are captured via a Lagrange multiplier that results from imposing the constraint of maximum rate of entropy production, reducing the primary PDEs to the balance equations of mass and linear momentum for the fluid and the solid, together with an equation for the Lagrange multiplier. The Fickian diffusion application considers a hyperbolic first order system with a boundary discontinuity and stable approach to the usual parabolic model. Results of the oxidation modeling of Tandon et al. (Polym Degrad Stab 91(8):1861–1869, 2006) are recovered by employing the reaction kinetics model and properties assumed there, while providing in addition the individual constituent kinematic and kinetic behaviors, thus adding rich interpretive detail in comparison to the original treatment (Tandon et al., Polym Degrad Stab 91 (8):1861–1869, 2006); two adjustable parameters describing coupled chemomechanical and purely chemical dissipation are added. The slurry infiltration application simulates the imposed mass deposition process and consequent effects on the kinematic and kinetic behaviors of the constituents.Ope

Chronic low-grade postoperative endophthalmitis in a child with Marfan syndrome

Darakhshanda Khurram Butt,1 Robert A Scott,1,2 Muralidharan R Upendran1 1Moorfields Eye Hospital, Dubai, UAE; 2SpaMedica, Manchester, UK Abstract: This case report describes a 9-year-old male who presented to the emergency department with 2 days’ history of left painful red eye. On initial examination, his outside medical records indicated that he had bilateral subluxated lenses and had undergone left eye lensectomy with glued intrascleral fixation of an intraocular lens 8 weeks earlier. Vision in left eye was poor from first postoperative day but with no undue pain or redness, and poor vision was attributed to possible vitreous bleed. Subsequent postoperative course was uneventful. He was discharged from ophthalmic care on topical steroids and antibiotic drops, one week postsurgery. The eye was healing well until he developed pain, for which ophthalmic care was sought. He underwent anterior chamber tap with intravitreal injections. Aqueous samples were positive for Staphylococcus aureus DNA by polymerase chain reaction. Post vitrectomy and implant removal, his recovery was good and vision improved to 0.50 LogMar with aphakic correction. Keywords: glued intrascleral fixation IOL, subluxated lens, post-op endophthalmiti

Investigation of laser texture density and diameter on the tribological behavior of hydrogenated DLC coating with line contact configuration

The technique of laser texturing has been gaining popularity in recent years because of its use in enhancement of tribological performance. In this paper, the effect of indirect laser texturing is analyzed on hydrogenated DLC coating under line contact configuration. Most previous research studies have been carried out for point contact configuration. The aim of this study is to investigate the effectiveness of indirect laser textured DLC for cam/tappet contact in an engine. For this reason, this study focuses on line contact. The tribological performance of textures is dependent on their geometric parameters. Therefore, textures' diameters and densities were varied. The results indicated that at a diameter of 50-μm and 20% density, tribological performance of a cylinder on a coated plate tribo-pair can be enhanced

Psychological Factors and Their Association with Ideal Cardiovascular Health Among Women and Men

Background: The cardiovascular effects of stress and other psychological factors may be different between women and men. We assessed whether self-perceived adverse psychological factors were associated with achievement of ideal cardiovascular health (CVH) as measured by the American Heart Association’s Life’s Simple Seven (LS7) and whether this differed by sex. Methods: This was a cross-sectional study of employees from a large healthcare organization. The LS7 metrics (smoking, physical activity, diet, body mass index, blood pressure, cholesterol, and glucose) were each scored as ideal (2), intermediate (1), or poor (0). Total scores were categorized as optimal (11–14), average (9–10), and inadequate (0–8). Using logistic regression, we tested whether psychological factors obtained by questionnaire (self-perceived stress, low life satisfaction, hopelessness, sadness, depression, and anxiety) were associated with CVH, after adjustment for age, ethnicity, and education. Results: Among 9,056 participants, the mean (SD) age was 43 (12) years, 74% were women, 57% Hispanic/ Latino, 17% white, and 16% black. Stress was associated with reduced odds of having optimal/average CVH [OR 0.58 (95% CI 0.50–0.66) and 0.63 (0.50–0.81), for women and men, respectively]. Similarly, depression was associated with reduced odds of optimal/average CVH [0.58 (0.43–0.78) and 0.44 (0.26–0.76), for women and men, respectively]. Low life satisfaction, hopelessness, sadness, and anxiety were also associated with statistically significantly lower odds of optimal/average CVH in women, but not in men; however, there were no interactions by sex. Conclusions: In an ethnically diverse population, both women and men with several adverse self-perceived psychological factors were less likely to have optimal or adequate CVH. Future studies are needed to determine whether addressing psychological stressors can improve CVH