Infrared study of spin crossover Fe-picolylamine complex

Infrared (IR) absorption spectroscopy has been used to probe the evolution of microscopic vibrational states upon the temperature- and photo-induced spin crossovers in [Fe(2-picolylamine)3]Cl2EtOH (Fe-pic). To overcome the small sizes and the strong IR absorption of the crystal samples used, an IR synchrotron radiation source and an IR microscope have been used. The obtained IR spectra of Fe-pic show large changes between high-spin and low-spin states for both the temperature- and the photo- induced spin crossovers. Although the spectra in the temperature- and photo-induced high-spin states are relatively similar to each other, they show distinct differences below 750 cm-1. This demonstrates that the photo-induced high-spin state involves microscopically different characters from those of the temperature-induced high-spin state. The results are discussed in terms of local pressure and structural deformations within the picolylamine ligands, and in terms of their possible relevance to the development of macroscopic photo-induced phase in Fe-pic.Comment: 6 pages (text) and 6 figures,submitted to J. Phys. Soc. Jp

Minimalism in Radiation Synthesis of Biomedical Functional Nanogels

A scalable, single-step, synthetic approach for the manufacture of biocompatible, functionalized micro- and nanogels is presented. In particular, poly(N-vinyl pyrrolidone)-grafted-(aminopropyl)methacrylamide microgels and nanogels were generated through e-beam irradiation of PVP aqueous solutions in the presence of a primary amino-group-carrying monomer. Particles with different hydrodynamic diameters and surface charge densities were obtained at the variance of the irradiation conditions. Chemical structure was investigated by different spectroscopic techniques. Fluorescent variants were generated through fluorescein isothiocyanate attachment to the primary amino groups grafted to PVP, to both quantify the available functional groups for bioconjugation and follow nanogels localization in cell cultures. Finally, a model protein, bovine serum albumin, was conjugated to the nanogels to demonstrate the attachment of biologically relevant molecules for targeting purposes in drug delivery. The described approach provides a novel strategy to fabricate biohybrid nanogels with a very promising potential in nanomedicine

Understanding and examining teacher resilience from multiple perspectives

In this chapter, I argue that differing conceptualisations of the construct of resilience shape and enrich the research questions and methodology used to examine it. In addition, the conceptual focus has implications for questions such as whose responsibility it is for the development of resilience. Research conducted within two Australian projects, Keeping Cool and BRiTE (Building Resilience in Teacher Education) is used as an illustration of the impact of a changing conceptual focus. For example, beginning with a psychological perspective led to an examination of risk and protective factors for individuals. More contextual approaches involved a comparison of countries. Recent systemic views support a model that encompasses both personal and contextual characteristics, as well as strategies used and outcomes achieved. It is argued that taking multiple perspectives in this programme of work has enabled the incorporation of a broad range of research methods and findings, and contributed to a deeper understanding of the construct of teacher resilience

Characterization of PLA-limonene blends for food packaging applications

Polymers derived from renewable resources are now considered as promising alternatives to traditional petro-polymers as they mitigate current environmental concerns (raw renewable materials/biodegradability). D-limonene can be found in a variety of citrus, indeed is the main component of citrus oils and one of most important contributors to citrus flavor. The incorporation of limonene in PLA matrix was evaluated and quantified by Pyrolysis Gas Chromatography Mass Spectrometry (Py-GC/MS). Transparent films were obtained after the addition of the natural compound. Mechanical properties were evaluated by tensile tests. The effect of limonene on mechanical properties of PLA films was characterized by an increase in the elongation at break and a decrease in the elastic modulus. The fracture surface structure of films was evaluated by scanning electron microscopy (SEM), and homogeneous surfaces were observed in all cases. Barrier properties were reduced due to the increase of the chain mobility produced by the D-limonene. (C) 2013 Elsevier Ltd. All rights reserved.This research was supported by the Ministry of Science and Innovation of Spain (MAT2011-28468-C02-02). Marina P. Arrieta thanks Generalitat Valenciana (Spain) for a Santiago Grisolia Fellowship. Authors thank Professor Alfonso Jimenez from the University of Alicante, for his useful discussions.Arrieta, MP.; López Martínez, J.; Ferrándiz Bou, S.; Peltzer, MA. (2013). Characterization of PLA-limonene blends for food packaging applications. Polymer Testing. 32(4):760-768. https://doi.org/10.1016/j.polymertesting.2013.03.016S76076832

Teachers' resilience: conceived, perceived or lived-in

[Extract] Schools in Western countries are places where work related conditions lead to teacher disaffection and attrition. To mitigate this employers and scholars advocate fostering teacher resilience. This chapter presents a critical examination of teacher resilience. Originally conceived as a personal trait, later research showed human resilience is an attribute that can be developed. Resilience is one’s ability to manage stressors and maintain adaptive functioning across all domains of life. Latterly, scholars investigated resilience in teachers, mainly through qualitative or quantitative self-report studies. This research constitutes perceived teacher resilience, because as formulated, teacher resilience is conceptually flawed, limited in scope, based on teachers’ functioning within their professional lives. We do not know what constitutes long serving teachers’ actual, lived-in resilience: what enables teachers to maintain their wellbeing and effectiveness in the classroom, reflecting human resilience as originally conceived. For an accurate profile of teacher resilience we must study those still teaching, and teachers who have exited the profession to determine why they left. Perhaps exiting the profession signals a resilient person who does accept working conditions that do not support wellbeing or teaching effectiveness. Perhaps ‘teacher resilience’ is inaccurately used in the context of teacher attrition and disaffection

Comparative genetic analysis: the utility of mouse genetic systems for studying human monogenic disease

One of the long-term goals of mutagenesis programs in the mouse has been to generate mutant lines to facilitate the functional study of every mammalian gene. With a combination of complementary genetic approaches and advances in technology, this aim is slowly becoming a reality. One of the most important features of this strategy is the ability to identify and compare a number of mutations in the same gene, an allelic series. With the advent of gene-driven screening of mutant archives, the search for a specific series of interest is now a practical option. This review focuses on the analysis of multiple mutations from chemical mutagenesis projects in a wide variety of genes and the valuable functional information that has been obtained from these studies. Although gene knockouts and transgenics will continue to be an important resource to ascertain gene function, with a significant proportion of human diseases caused by point mutations, identifying an allelic series is becoming an equally efficient route to generating clinically relevant and functionally important mouse models