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

Sound attenuation enhancement of acoustic meta-atoms via coupling.

Arrangements of acoustic meta-atoms, better known as acoustic metamaterials, are commonly applied in acoustic cloaking, for the attenuation of acoustic fields or for acoustic focusing. A precise design of single meta-atoms is required for these purposes. Understanding the details of their interaction allows improvement of the collective performance of the meta-atoms as a system, for example, in sound attenuation. Destructive interference of their scattered fields, for example, can be mitigated by adjusting the coupling or tuning of individual meta-atoms. Comprehensive numerical studies of various configurations of a resonator pair show that the coupling can lead to degenerate modes at periodic distances between the resonators. We show how the resonators' separation and relative orientation influence the coupling and thereby tunes the sound attenuation. The simulation results are supported by experiments using a two-dimensional parallel-plate waveguide. It is shown that coupling parameters like distance, orientation, detuning, and radiation loss provide additional degrees of freedom for efficient acoustic meta-atom tuning to achieve unprecedented interactions with excellent sound attenuation properties

Affordable dye sensitizer by waste

Abstract The development of dye sensitizer is growing in line with the increasing demand for renewable energy. A research to obtain a dye sensitizer that is economical, safe, and produces a great value of DSSC efficiency is a challenge unresolved. On the other hand, the efforts for waste reduction are also intensively conducted to create better environment. In this paper, the variation of synthetic dye wastes from batik industries have been successfully applied as dye sensitizer and fabricated on DSSC cells. Congo red (1.0133%) yielded higher efficiency than rhodamine B (0.0126%), methyl orange (0.7560%), and naphthol blue black (0.0083%). The divergence of the efficiency of DSSC is very dependent upon the chromophore group owned by dye. This study has proven that the more chromophore group possessed by dye, the higher the efficiency of DSSC generated. This research concludes that the dye wastes have a bright future to be implemented as dye sensitizer on solar cells

Effect of HPV self-collection kits on cervical cancer screening uptake among under-screened women from low-income US backgrounds (MBMT-3): a phase 3, open-label, randomised controlled trial

Background: Most cervical cancer in the USA occurs in under-screened women. The My Body, My Test-3 (MBMT-3) trial sought to assess the efficacy of mailed human papillomavirus (HPV) self-collection kits with appointment-scheduling assistance to increase uptake of cervical cancer screening among under-screened women from low-income backgrounds compared with scheduling assistance alone. Methods: MBMT-3 is a phase 3, open-label, two-arm, randomised controlled trial. Participants were recruited from 22 counties in North Carolina state, USA, and we partnered with 21 clinics across these counties. Participants were eligible for inclusion if they were aged 25–64 years, had an intact cervix, were uninsured or enrolled in Medicaid or Medicare, had an income of 250% or less of the US Federal Poverty Level, were living within the catchment area of a trial-associated clinic, and were overdue for screening (ie, Papanicolaou test ≥4 years ago or high-risk HPV test ≥6 years ago). Participants were randomly assigned (2:1) to receive a mailed HPV self-collection kit and assistance for scheduling a free screening appointment (intervention group) or to receive scheduling assistance alone (control group). Randomisation was conducted by county using permuted blocks of nine patients and assignment to group was not masked. Participants in the intervention group were mailed HPV self-collection kits to collect a cervical-vaginal sample and return it by mail for testing. Samples were tested with the Aptima HPV assay (Hologic, San Diego, CA, USA), and participants were informed of high-risk HPV results by telephone call. Trial staff made up to three telephone call attempts to provide scheduling assistance for in-clinic screening for all participants. The primary outcome was cervical cancer screening uptake (ie, attending an in-clinic screening appointment or testing negative for high-risk HPV with a returned self-collected sample) within 6 months of enrolment in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT02651883, and has been completed. Findings: Recruitment occurred between April 11, 2016, and Dec 16, 2019. 4256 women contacted the trial to participate, of whom 899 (21%) were eligible for inclusion and 697 (78%) returned consent forms. Of those who consented, 461 (66%) women were randomly assigned to the intervention group and 236 (34%) women were randomly assigned to the control group. We excluded 32 ineligible women post-randomisation, leaving 665 for primary analysis. Screening uptake was higher in the intervention group (317 [72%] of 438) than control group (85 [37%] of 227; risk ratio 1·93, 95% CI 1·62–2·31). Among intervention participants, 341 (78%) of 438 returned a self-collection kit. Three participants reported hurt or injury when using the self-collection kit; no participants withdrew due to adverse effects. Interpretation: Among under-screened women from low-income backgrounds, mailed HPV self-collection kits with scheduling assistance led to greater uptake of cervical cancer screening than scheduling assistance alone. At-home HPV self-collection testing has the potential to increase screening uptake among under-screened women. Funding: National Cancer Institute

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