Analytical transmission electron microscopy at organic interfaces

Organic materials are ubiquitous in all aspects of our daily lives. Increasingly there is a need to understand interactions between different organic phases, or between organic and inorganic materials (hybrid interfaces), in order to gain fundamental knowledge about the origin of their structural and functional properties. In order to understand the complex structure–property–processing relationships in (and between) these materials, we need tools that combine high chemical sensitivity with high spatial resolution to allow detailed interfacial characterisation. Analytical transmission electron microscopy (TEM) is a powerful and versatile technique that can fulfil both criteria. However, the application of analytical TEM to organic systems presents some unique challenges, such as low contrast between phases, and electron beam sensitivity. In this review recent analytical TEM approaches to the nanoscale characterisation of two systems will be discussed: the hybrid collagen/mineral interface in bone, and the all-organic donor/acceptor interface in OPV devices

Sex, Drugs, and Reckless Driving: Are Measures Biased Toward Identifying Risk-Taking in Men?

This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this record.We investigated whether risk-taking measures inadvertently focus on behaviors that are more normative for men, resulting in the overestimation of gender differences. Using a popular measure of risk-taking (Domain-Specific Risk-Taking) in Study 1 (N = 99), we found that conventionally used behaviors were more normative for men, while, overall, newly developed behaviors were not. In Studies 2 (N = 114) and 3 (N = 124), we demonstrate that differences in normativity are reflected in gender differences in self-reported risk-taking, which are dependent on the specific items used. Study 3 further demonstrates that conventional, masculine risk behaviors are perceived as more risky than newly generated, more feminine items, even when risks are matched. We conclude that there is confirmation bias in risk-taking measurement.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by an internal competitive grant from the Melbourne Business School, University of Melbourne, awarded to Cordelia Fine, who is also grateful for the support of the Women’s Leadership Institute Australia. This work was also supported by an internal competitive grant from the College of Life and Environmental Sciences, University of Exeter, awarded to Thekla Morgenroth and Michelle Ryan. Michelle Ryan was also supported by a British Academy Mid-Career Fellowshi

Comparison of 20nm silver nanoparticles synthesized with and without a gold core: Structure, dissolution in cell culture media, and biological impact on macrophages

Widespread use of silver nanoparticles raises questions of environmental and biological impact. Many synthesis approaches are used to produce pure silver and silver-shell gold-core particles optimized for specific applications. Since both nanoparticles and silver dissolved from the particles may impact the biological response, it is important to understand the physicochemical characteristics along with the biological impact of nanoparticles produced by different processes. The authors have examined the structure, dissolution, and impact of particle exposure to macrophage cells of two 20 nm silver particles synthesized in different ways, which have different internal structures. The structures were examined by electron microscopy and dissolution measured in Rosewell Park Memorial Institute media with 10% fetal bovine serum. Cytotoxicity and oxidative stress were used to measure biological impact on RAW 264.7 macrophage cells. The particles were polycrystalline, but 20 nm particles grown on gold seed particles had smaller crystallite size with many high-energy grain boundaries and defects, and an apparent higher solubility than 20 nm pure silver particles. Greater oxidative stress and cytotoxicity were observed for 20 nm particles containing the Au core than for 20 nm pure silver particles. A simple dissolution model described the time variation of particle size and dissolved silver for particle loadings larger than 9 μg/ml for the 24-h period characteristic of many in-vitro studies

Transitioning to practice: a qualitative investigation of Australian graduate naturopath's experiences of being in practice.

BACKGROUND: The transition from student to practitioner can be challenging, resulting in stress, burnout and attrition. While there has been ample research examining graduate medical and allied health practitioner experiences of transitioning to practice, there is a paucity of research exploring such experiences in newly qualified naturopathic medicine practitioners. In light of this knowledge gap, the objective of this study was to ascertain the experiences of practicing as a naturopath in Australia within the first 5 years post-graduation. METHODS: Using a qualitative descriptive approach, recent graduates of an Australian Bachelor of Naturopathy (or equivalent) program were invited to participate in a semi-structured telephone interview to address the study objective. Data were analysed utilising a framework approach. RESULTS: A total of 19 new graduates (94.7% female; 57.9% aged 40-59 years) undertook an interview. Five inter-related themes emerged from the data: practitioner, practice, proprietorship, professions, and perceptions. Connected with these themes were contrasting feelings, multiplicity of duties, small business challenges, professional collaboration, and professional identity, respectively. CONCLUSIONS: Participants were generally content with their decision to become a naturopath. However, most were confronted by a range of challenges as they transitioned from graduate to practitioner, for which many felt ill-prepared. In light of the complexity of the issue, and the potential impact on the sustainability of the profession, it is evident that a multi-pronged, multi-stakeholder approach would be needed to better support graduate naturopath transition to practice

Chemical speciation of nanoparticles surrounding metal-on-metal hips.

Spectromicroscopy of tissue surrounding failed CoCr metal-on-metal hip replacements detected corroded nanoscale debris in periprosthetic tissue in two chemical states, with concomitant mitochondrial damage. The majority of debris contained Cr(3+), with trace amounts of oxidised cobalt. A minority phase containing a core of metallic chromium and cobalt was also observed