312 MAX Phases: Elastic Properties and Lithiation.

Interest in the Mn+1AXn phases (M = early transition metal; A = group 13-16 elements, and X = C or N) is driven by their ceramic and metallic properties, which make them attractive candidates for numerous applications. In the present study, we use the density functional theory to calculate the elastic properties and the incorporation of lithium atoms in the 312 MAX phases. It is shown that the energy to incorporate one Li atom in Mo3SiC2, Hf3AlC2, Zr3AlC2, and Zr3SiC2 is particularly low, and thus, theoretically, these materials should be considered for battery applications.

Randomized controlled trial of plain English and visual abstracts for disseminating surgical research via social media.

BACKGROUND: Patients are increasingly taking an active role in the design and delivery of surgical research. Public communication of results should also be encouraged, but this is often limited to non-expert commentary. This study assessed the role of plain English abstracts disseminated via social media in engaging patients and clinicians in the communication of surgical research. METHODS: A three-arm randomized controlled trial with crossover of two intervention arms was performed. Manuscripts accepted for publication in BJS were allocated to one of three arms and disseminated via Twitter: plain English abstracts, visual abstracts and standard tweets. The primary outcome was online engagement (a composite of tweets, replies and likes) by members of the public within 14 days. The secondary outcome was online engagement by healthcare professionals. RESULTS: Forty-one manuscripts were randomized to plain English abstracts (14), visual abstracts (14) and standard tweets (13). The number of public engagements was low, with a mean of 1·8 (range 0-8), 2·5 (0-11), and 1·2 (0-4) for plain English abstracts, visual abstracts and standard tweets respectively. The mean number of engagements by healthcare professionals was 29·4 (6-66), 45·3 (6-161) and 28·8 (10-52) respectively. Overall, visual abstracts attracted a significantly greater number of engagements than plain English ones (P < 0·001). CONCLUSION: Online, public engagement with surgical research was low. Overall engagement (predominantly from healthcare professionals) was enhanced by the use of visual abstracts.

ANTECEDENTES: Los pacientes están tomando cada vez más un papel activo en el diseño y en la difusión de la investigación quirúrgica. También se debe fomentar la comunicación pública de los resultados, pero a menudo ésta se limita a comentarios de personas no expertas. Este estudio evaluó el papel de los resúmenes redactados en un inglés sencillo difundidos a través de las redes sociales para involucrar a pacientes y médicos en la comunicación de la investigación quirúrgica. MÉTODOS: Se realizó un ensayo aleatorizado y controlado de tres brazos con un diseño cruzado de los dos brazos de intervención. Los manuscritos aceptados para publicación en BJS se asignaron a tres brazos y se difundieron vía twitter: resúmenes redactados en un inglés sencillo, resúmenes visuales, y tweets estándar. El criterio de valoración principal fue la interacción online (variable compuesta de tweets, respuestas y me gusta) por parte del público durante los primeros 14 días. El criterio de valoración secundario fue la interacción online de los profesionales de la salud. RESULTADOS: Un total de 41 manuscritos se asignaron al azar a resúmenes redactados en un inglés sencillo (n = 14), resúmenes visuales (n = 14) y tweets estándar (n = 13). El número de interacciones por parte del público fue bajo, con una media de 1,8 (rango 0-8), 2,5 (rango 0-11) y 1,2 (rango 0-4) para resúmenes en inglés sencillo, resúmenes visuales y tweets estándar, respectivamente. El número medio de interacciones por profesionales de la salud fue de 29,4 (rango 6-66), 45,3 (6-161) y 28,8 (10-52). En general, los resúmenes visuales atrajeron un número significativamente mayor de interacciones que los de inglés sencillo (P = 0,001). CONCLUSIÓN: La interacción online del público con la investigación quirúrgica fue baja. La participación general (predominantemente de profesionales de la salud) mejoró mediante el uso de resúmenes visuales. Los próximos trabajos podrían considerar si el público desea interaccionar y de qué modo con resúmenes redactados en un inglés sencillo.

Neutron diffraction residual strain measurements in nanostructured hydroxyapatite coatings for orthopaedic implants.

The failure of an orthopaedic implant can be initiated by residual strain inherent to the hydroxyapatite coating (HAC). Knowledge of the through-thickness residual strain profile in the thermally sprayed hydroxyapatite coating/substrate system is therefore important in the development of a new generation of orthopaedic implants. As the coating microstructure is complex, non-destructive characterization of residual strain, e.g. using neutron diffraction, provides a useful measure of through thickness strain profile without altering the stress field. This first detailed study using a neutron diffraction technique, non-destructively evaluates the through thickness strain measurement in nanostructured hydroxyapatite plasma sprayed coatings on a titanium alloy substrate (as-sprayed, heat treated, and heat treated then soaked in simulated body fluid (SBF)). The influence of crystallographic plane orientation on the residual strain measurement is shown to indicate texturing in the coating. This texturing is expected to influence both the biological and fracture response of HA coatings. Results are discussed in terms of the influence of heat-treatment and SBF on the residual stress profile for these biomedical coatings. The results show that the through thickness residual strain in all three coatings was different for different crystallographic planes but was on average tensile. It is also concluded that the heat-treatment and simulated body fluid exposure had a significant effect on the residual strain profile in the top layers of HAC.

Forensic engineering: applying materials and mechanics principles to the investigation of product failures.

Forensic engineering is the application of engineering principles or techniques to the investigation of materials, products, structures or components that fail or do not perform as intended. In particular, forensic engineering can involve providing solutions to forensic problems by the application of engineering science. A criminal aspect may be involved in the investigation but often the problems are related to negligence, breach of contract, or providing information needed in the redesign of a product to eliminate future failures. Forensic engineering may include the investigation of the physical causes of accidents or other sources of claims and litigation (for example, patent disputes). It involves the preparation of technical engineering reports, and may require giving testimony and providing advice to assist in the resolution of disputes affecting life or property.This paper reviews the principal methods available for the analysis of failed components and then gives examples of different component failure modes through selected case studies.

Biomodulation of the toxic and nutritional effects of small bowel bacterial overgrowth in end-stage kidney disease using freeze-dried Lactobacillus acidophilus.

Small bowel bacterial overgrowth (SBBO), well known to occur in end-stage kidney failure, is responsible for producing uremic toxins and contributing to the patient's decreased nutritional well-being. In this study, 8 hemodialysis patients were treated with a course of oral Lactobacillus acidophilus (LBA) in an attempt to alter this SBBO. LBA treatment was effective in lowering 2 compounds generated in vivo. Serum dimethylamine (DMA) levels dropped from 224 +/- 47 to 154 +/- 47 micrograms/dl at the end of LBA treatment (p < 0.001). Nitrosodimethylamine, a carcinogen, levels also decreased significantly from 178 +/- 67 (untreated) to 83 +/- 49 ng/kg (after LBA treatment). Patients nutritional status, assessed as serum albumin, body weight, caloric intake, midarm muscle area (MAMA) and appetite improved modestly, but not significantly. LBA changed small bowel pathobiology by modifying metabolic actions of SBBO, reducing in vivo generation of toxins and carcinogens and promoting nutrition with no adverse side effects.