Revealing the Structure and Oxygen Transport at Interfaces in Complex Oxide Heterostructures via ¹⁷O NMR Spectroscopy

Vertically aligned nanocomposite (VAN) films, comprising nanopillars of one phase embedded in a matrix of another, have shown great promise for a range of applications due to their high interfacial areas oriented perpendicular to the substrate. In particular, oxide VANs show enhanced oxide-ion conductivity in directions that are orthogonal to those found in more conventional thin-film heterostructures; however, the structure of the interfaces and its influence on conductivity remain unclear. In this work, 17O NMR spectroscopy is used to study CeO2–SrTiO3 VAN thin films: selective isotopic enrichment is combined with a lift-off technique to remove the substrate, facilitating detection of the 17O NMR signal from single atomic layer interfaces. By performing the isotopic enrichment at variable temperatures, the superior oxide-ion conductivity of the VAN films compared to the bulk materials is shown to arise from enhanced oxygen mobility at this interface; oxygen motion at the interface is further identified from 17O relaxometry experiments. The structure of this interface is solved by calculating the NMR parameters using density functional theory combined with random structure searching, allowing the chemistry underpinning the enhanced oxide-ion transport to be proposed. Finally, a comparison is made with 1% Gd-doped CeO2–SrTiO3 VAN films, for which greater NMR signal can be obtained due to paramagnetic relaxation enhancement, while the relative oxide-ion conductivities of the phases remain similar. These results highlight the information that can be obtained on interfacial structure and dynamics with solid-state NMR spectroscopy, in this and other nanostructured systems, our methodology being generally applicable to overcome sensitivity limitations in thin-film studies

A Neutron Diffraction Study of the Electrochemical Double Layer Capacitor Electrolyte Tetrapropylammonium Bromide in Acetonitrile.

Neutron diffraction with isotopic substitution has been used to characterize the bulk liquid structure of the technologically relevant electrolyte solution, 1 M tetrapropylammonium bromide (TPA Br) in acetonitrile (acn), and of pure deuterated acetonitrile. Empirical potential structure refinement modeling procedures have been used to extract detailed structural information about solvent-solvent, solvent-ion, and ion-ion correlations. Analysis of the refined data shows the expected local dipolar conformation of acn in the pure solvent. This short-range dipolar ordering is also present within the solutions of TPA Br in acn, and it affects how the solvent orders itself around the ions. The solvation numbers of the TPA cations and the bromide anions are deduced, 8 and 5, respectively, as are the orientations of the solvent molecules that surround the ions. Evidence for ion association is also presented, with nearly two-thirds of the ions in the system being in associated pairs or clusters.E.K.H. acknowledges the European Research Council ERC Grant ERC-2009-AdG-247411 for funding. P.K.A acknowledges a Junior Research Fellowship from Gonville and Caius College, an Oppenheimer Fellowship from the University of Cambridge. R.J.L.W. acknowledges the EPSRC Grant 11220426 for funding.This is the author accepted manuscript. The final version is available from ACS via http://dx.doi.org/10.1021/acs.jpcb.5b0824

Medical students' perceptions of their development of ‘soft skills' Part II : The development of ‘soft skills' through ‘guiding and growing'

BackgroundThis paper reports on medical students' views on the ways in which their ‘soft skills' were developed. It is the result of a study on soft skills among two groups of students before and after curriculum reform at the School of Medicine of the University of Pretoria. One of the aims of the reform was to provide more teaching and learning opportunities for the development of soft skills. Soft skills include professional interpersonal and social skills, communication skills, and professional and ethical attitudes.MethodsAs symbolic interactionism was used as the theoretical framework to guide the research, qualitative methods were used to collect the data. A purposive-theoretical sample of 42 final-year medical students from the traditional curriculum and 49 from the reformed curriculum was recruited. Data were collected by means of focus groups, individual in-depth interviews and autobiographical sketches. ResultsThe same categories of comments emerged from the data collected from the study participants from both the traditional and the reformed curriculum. The students ascribed their behaviour related to soft skills to personality and innate features. They had varying opinions on whether soft skills could be taught, but there was as a strong feeling that teaching should focus on principles and guidelines for dealing with difficult situations. They believed that, in the end, they should take responsibility for their own development of soft skills. Most participants felt they could at least grow through exposure to teaching activities and the observation of role models. They also indicated that they had developed their soft skills and constructed their own identity through their interaction with others. Their definition of situations was shaped by their interactions with doctors and educators, fellow students and other health professionals. Interaction with patients was considered the most important. For both groups of students their third year was a watershed, as it is the first year of more intensive patient contact and the beginning of serious learning from interaction with patients. The views on the development of soft skills differed very little between the traditional and reformed curriculum groups, except that students who had followed the reformed curriculum felt more prepared through the increased teaching and training efforts. Further consideration needs to be given to the intention of the changed curriculum compared to the actual effect. The way in which the participants in the study described their development of soft skills could be categorised as a complex interplay between ‘being' and ‘becoming'. Instead of using the word ‘acquisition' of soft skills, ‘development' seemed to be more appropriate. The metaphor of ‘guiding' and ‘growing' also captures the development of these skills better than the terms ‘teaching' and ‘learning'.ConclusionTeaching activities in the clinical years should be adapted with a view to facilitating the students' professional growth. New models for the development of medical educators should be created and institutional barriers should be investigated.For full text, click here: SA Fam Pract 2006;48(8):15-15

The conceptualisation of "soft skills" among medical students before and after curriculum reform

Objective: This paper reports on the conceptualisation of "soft skills" as part of a study carried out among two groups of undergraduate medical students before and after curriculum reform at the School of Medicine of the University of Pretoria. Congruent with a call from the World Psychiatric Association, the curriculum reform that was undertaken aimed, inter alia, to place more emphasis on soft skills, including professional interpersonal and social skills, communication skills, and professional and ethical attitudes. Methods: Qualitative methods were used to arrive at a descriptive comparison of the conceptualisation of soft skills by final-year medical students of the traditional curriculum with those of final-year students who had followed the reformed curriculum. A purposive-theoretical sampling method was followed; 42 students from the traditional curriculum and 49 from the reformed curriculum were sampled. Data were collected from seven focus groups, 16 individual interviews, and 23 essays (autobiographical sketches). Results: Both groups of students revealed conceptualisations of soft skills that were similar in kind. The themes they pinpointed were the doctor-patient relationship; relationships with other professionals; being a good listener; explaining things to patients; using good communication skills; establishing rapport with patients from different cultural backgrounds; having a professionally correct attitude; being really interested in patients' well being; having empathy; coping with patients, managing difficult situations, and being ethical and professional. However, the traditional curriculum students offered fewer examples and described fewer experiences that exemplified their soft skills. Students following the reformed curriculum gave rich accounts of their conceptualisation in terms of their own experiences and practical examples of how soft skills had been or could be used, particularly in difficult interpersonal situations. Moreover, they came up with helpful ways of dealing with difficult situations, which surpassed the suggestions offered by the students following the traditional curriculum. Conclusion: The educational and training efforts of the reformed curriculum are associated with an adeptness on the part of the students at applying soft skills to the demands of difficult clinical situations. Keywords: soft skills, interpersonal skills, doctor-patient relationship, professional socialisation South African Psychiatry Review Vol. 9(1) 2006: 33-3

Medical students on the value of role models for developing 'soft skills' - "That's the way you do it

Objective: The Soft Skills Project examined the professional development of medical students at the University of Pretoria, especially their doctor-patient interaction skills and professional socialisation. This paper reports on one of the findings of the project, namely the importance that medical students attach to role models in the development of soft skills. Methods: We used a qualitative method with symbolic interactionism and grounded theory as framework. Fourty two final-year students from the last cohort following the traditional curriculum at the University of Pretoria in 2001, and 49 final years from the first cohort following the reformed curriculum in 2002 were recruited. Data were collected by applying focus groups, in-depth, individual interviews, as well as autobiographical sketches. Data were captured by means of audio tape recordings, transcripts of the tapes, researchers' field notes, and written accounts by students, and were analysed by using a general inductive approach. Results: There were no striking differences between the comments of the two groups. Students considered registrars to be the most influential role models in the clinical teaching context, followed by specialist consultants. Their idea of a good role model was a clinically and academically competent doctor that cared about patients, had good interpersonal skills, and who could inspire students. Students needed and appreciated good role models to help them to develop their own soft skills. They expected guidance and behavioural examples from clinical teachers. Although there were competent role models, the students were exposed to poor role models. Poor role models mainly affect students negatively. Students tend to imitate and perpetuate unacceptable behaviour. Furthermore, poor role models have a negative emotional effect on students and are detrimental to their moral and learning environment. Sometimes, poor role models have a paradoxical positive effect in the sense that they inform students how not to behave. Conclusion: Medical schools and medical doctors working with medical students should be consciously aware of the importance of role models both when allocating clinical teachers to students, and while performing duties with students. It is especially necessary to realise that poor role modelling has important detrimental effects on students. Therefore, an attempt should be made to ensure that not only clinical examination skills, but also soft skills, are demonstrated at the bedside. Measures to ensure adequate exposure of students to positive role models could include: staff development; the identification of good role models to guide registrars; and a reallocation of tasks, where possible, to increase the exposure of students to the ‘natural' role models. Keywords: soft skills, role models, medical students, professionalism South African Psychiatry Review Vol. 9(1) 2006: 28-3

When performativity fails: Implications for Critical Management Studies

This article argues that recent calls in this journal and elsewhere for Critical Management Studies scholars to embrace rather than reject performativity presents an overly optimistic view of (a) the power of language to achieve emancipatory organizational change and (b) the capability of lone Critical Management Studies researchers to resignify management discourses. We introduce the notion of failed performatives to extend this argument and discuss its implications for critical inquiry. If Critical Management Studies seeks to make a practical difference in business and society, and realize its ideals of emancipation, we suggest alternative methods of impact must be explored

Identification of a Novel Marine Fish Virus, Singapore Grouper Iridovirus-Encoded MicroRNAs Expressed in Grouper Cells by Solexa Sequencing

BACKGROUND: MicroRNAs (miRNAs) are ubiquitous non-coding RNAs that regulate gene expression at the post-transcriptional level. An increasing number of studies has revealed that viruses can also encode miRNAs, which are proposed to be involved in viral replication and persistence, cell-mediated antiviral immune response, angiogenesis, and cell cycle regulation. Singapore grouper iridovirus (SGIV) is a pathogenic iridovirus that has severely affected grouper aquaculture in China and Southeast Asia. Comprehensive knowledge about the related miRNAs during SGIV infection is helpful for understanding the infection and the pathogenic mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: To determine whether SGIV encoded miRNAs during infection, a small RNA library derived from SGIV-infected grouper (GP) cells was constructed and sequenced by Illumina/Solexa deep-sequencing technology. We recovered 6,802,977 usable reads, of which 34,400 represented small RNA sequences encoded by SGIV. Sixteen novel SGIV-encoded miRNAs were identified by a computational pipeline, including a miRNA that shared a similar sequence to herpesvirus miRNA HSV2-miR-H4-5p, which suggests miRNAs are conserved in far related viruses. Generally, these 16 miRNAs are dispersed throughout the SGIV genome, whereas three are located within the ORF057L region. Some SGIV-encoded miRNAs showed marked sequence and length heterogeneity at their 3' and/or 5' end that could modulate their functions. Expression levels and potential biological activities of these viral miRNAs were examined by stem-loop quantitative RT-PCR and luciferase reporter assay, respectively, and 11 of these viral miRNAs were present and functional in SGIV-infected GP cells. CONCLUSIONS: Our study provided a genome-wide view of miRNA production for iridoviruses and identified 16 novel viral miRNAs. To the best of our knowledge, this is the first experimental demonstration of miRNAs encoded by aquatic animal viruses. The results provide a useful resource for further in-depth studies on SGIV infection and iridovirus pathogenesis

miR-K12-7-5p Encoded by Kaposi's Sarcoma-Associated Herpesvirus Stabilizes the Latent State by Targeting Viral ORF50/RTA

Seventeen miRNAs encoded by Kaposi's sarcoma-associated herpesvirus (KSHV) have been identified and their functions have begun to be characterized. Among these miRNAs, we report here that miR-K12-7 directly targets the replication and transcription activator (RTA) encoded by open reading frame 50. We found that miR-K12-7 targeted the RTA 3′ untranslated region (RTA3′UTR) in a seed sequence-dependent manner. miR-K12-7-5p derived from miR-K12-7 mediates the inhibition of RTA expression, and the mutation of the seed match site totally abrogated the inhibitory effect of miR-K12-7 on RTA3′UTR. The inhibition of RTA expression by miR-K12-7 was further confirmed in the latently KSHV-infected 293/Bac36 cell line through transient transfection of miR-K12-7 expression plasmid or specific inhibitor of miR-K12-7-5p, respectively. The transient transfection of miR-K12-7 into 293/Bac36 cells reduced RTA expression and the expression of the downstream early genes regulated by RTA, and also the production of progeny virus was significantly reduced after treatment with chemical inducers. Our study revealed that another miRNA, miR-K12-7-5p, targets the viral immediate early gene RTA and that this miRNA contributes to the maintenance of viral latency

Spatially Resolved Operando Synchrotron-Based X-Ray Diffraction Measurements of Ni-Rich Cathodes for Li-Ion Batteries

Understanding the performance of commercially relevant cathode materials for lithium-ion (Li-ion) batteries is vital to realize the potential of high-capacity materials for automotive applications. Of particular interest is the spatial variation of crystallographic behavior across (what can be) highly inhomogeneous electrodes. In this work, a high-resolution X-ray diffraction technique was used to obtain operando transmission measurements of Li-ion pouch cells to measure the spatial variances in the cell during electrochemical cycling. Through spatially resolved investigations of the crystallographic structures, the distribution of states of charge has been elucidated. A larger portion of the charging is accounted for by the central parts, with the edges and corners delithiating to a lesser extent for a given average electrode voltage. The cells were cycled to different upper cutoff voltages (4.2 and 4.3 V vs. graphite) and C-rates (0.5, 1, and 3C) to study the effect on the structure of the NMC811 cathode. By combining this rapid data collection method with a detailed Rietveld refinement of degraded NMC811, the spatial dependence of the degradation caused by long-term cycling (900 cycles) has also been shown. The variance shown in the pristine measurements is exaggerated in the aged cells with the edges and corners offering an even lower percentage of the charge. Measurements collected at the very edge of the cell have also highlighted the importance of electrode alignment, with a misalignment of less than 0.5 mm leading to significantly reduced electrochemical activity in that area.</jats:p