Synthesis and Characterisation of Complex Oxychalcogenides

Mixed-anion compounds like oxychalcogenides, where there are both oxide anions and chalcogen anions (S-Te) create quite a rare class of materials which is gaining increasing attention. The anions have different sizes and chemical requirements which promise ordering of the oxide crystallographically, whereby their structures can be described as a mixture of 2-D structural building blocks (e.g. perovskite, fluorite, or rock-salt) stacked on top of each other along a given direction, thus giving a layered structure. These results in interesting electrical, optical and physical properties. This thesis reports a study of oxychalcogenide compounds with general formula Ln2O2Fe2OQ2 (Ln = lanthanide, Q = chalcogenides) and LnMOCh2 (Ln = Lanthanides, M = cation and Ch = chalcogenides). These compounds offer big opportunities for chemical substitution and doping within and between the layers, hence it is possible to tune the layer distances and in turn, tune the properties of these solids. The crystal structures and properties of all materials were investigated using several in-house techniques and those at central facilities. Electron doping La2O2Fe2OSe2 with Co and Ni ions onto the Fe2+ site gave limited solid solutions and semiconductor materials. Co-doping increased the transition temperature of La2O2Fe2OSe2 indicating that the distance between the Fe2O layers is reduced. Variable temperature neutron powder diffraction data of La2O2Fe2OS2 showed 2-D short range order while neutron powder diffraction data in applied magnetic field of Pr2O2Fe2OSe2 showed a subtle orthorhombic distortion around 23 K. Additional magnetic Bragg reflections, seen in both compounds, are consistent with a 2-k magnetic structure with a 2a x 2a x 2c unit cell. Moreover, both compounds showed stacking faults in the magnetic ordering on the Fe2+ sublattice which are absent in Mn2O or Co2O systems, implying that they are exclusively to the Fe2O layers and could be sensitive to the distance between Fe2O layers. Isovalent doping LaGaOS2 with Nd and Ce ions onto the La site gave limited solid solutions. From the diffuse reflectance spectroscopy data, Nd-doping and Ce-doping the parent compound gave no significant change in optical band gaps and the colour change observed in colour in Nd-doped samples are presumably due to f-f transitions. This work suggests that LaGaOS2 has a quite limited compositional flexibility in its structure and that it is not easy to modify its electronic structure using chemical pressure. Electron doping BiCuOSe with Ce (onto the Bi3+ site) and F ions (onto the O2- site) gave limited solid solutions. BiCuOSe had some Cu vacancies. The Ce-doped samples contained Ce4+ ions. Electron doping BiCuOSe with F gave metallic compounds, while doping BiCuOSe with Ce gave compounds with both semiconducting and metallic behaviour. The semiconducting behaviour may be due to impurities

Delay Discounting as a Transdiagnostic Process in Psychiatric Disorders: A Meta-analysis

Importance Delay discounting is a behavioral economic index of impulsive preferences for smaller-immediate or larger-delayed rewards that is argued to be a transdiagnostic process across health conditions. Studies suggest some psychiatric disorders are associated with differences in discounting compared with controls, but null findings have also been reported. Objective To conduct a meta-analysis of the published literature on delay discounting in people with psychiatric disorders. Data Sources PubMed, MEDLINE, PsycInfo, Embase, and Web of Science databases were searched through December 10, 2018. The psychiatric keywords used were based on DSM-IV or DSM-5 diagnostic categories. Collected data were analyzed from December 10, 2018, through June 1, 2019. Study Selection Following a preregistered Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol, 2 independent raters reviewed titles, abstracts, and full-text articles. English-language articles comparing monetary delay discounting between participants with psychiatric disorders and controls were included. Data Extraction and Synthesis Hedges g effect sizes were computed and random-effects models were used for all analyses. Heterogeneity statistics, one-study-removed analyses, and publication bias indices were also examined. Main Outcomes and Measures Categorical comparisons of delay discounting between a psychiatric group and a control group. Results The sample included 57 effect sizes from 43 studies across 8 diagnostic categories. Significantly steeper discounting for individuals with a psychiatric disorder compared with controls was observed for major depressive disorder (Hedges g = 0.37; P = .002; k = 7), schizophrenia (Hedges g = 0.46; P = .004; k = 12), borderline personality disorder (Hedges g = 0.60; P < .001; k = 8), bipolar disorder (Hedges g = 0.68; P < .001; k = 4), bulimia nervosa (Hedges g = 0.41; P = .001; k = 4), and binge-eating disorder (Hedges g = 0.34; P = .001; k = 7). In contrast, anorexia nervosa exhibited statistically significantly shallower discounting (Hedges g = –0.30; P < .001; k = 10). Modest evidence of publication bias was indicated by a statistically significant Egger test for schizophrenia and at the aggregate level across studies. Conclusions and Relevance Results of this study appear to provide empirical support for delay discounting as a transdiagnostic process across most of the psychiatric disorders examined; the literature search also revealed limited studies in some disorders, notably posttraumatic stress disorder, which is a priority area for research

Clinical Educators’ Perceptions of Students Following a Simulation-Based Learning Program

Purpose: Clinical education is a key component of speech-language pathology university curriculum, whereby students have the opportunity to apply theoretical knowledge and practical skills learned in the classroom into a real workplace. However, more recently the availability of high quality, consistent clinical placements and learning experiences across the range of practice areas in the discipline is reducing. Therefore, alternative clinical learning opportunities that enable students to develop skills and competencies are being explored. Recently, replacing clinical time with a simulated learning program has been shown to achieve equivalent levels of clinical competency in speech pathology. However, it is unknown how simulation impacts on student learning in traditional clinical placements. Therefore, this research explored clinical educators’ perceptions of students undertaking clinical placements in their workplace immediately following a five-day simulation-based learning program related to the same area of practice. Method: Thirty-five clinical educators who supervised students in the workplace immediately after they completed the simulation program participated in semi-structured interviews. All interviews were transcribed verbatim and analyzed using qualitative methods described by Graneheim and Lundman (2004). Result: The analysis identified four key themes related to the impact of students in the workplace, simulation priming students for learning, the importance of the transition from simulation-based learning to the workplace, and the role of simulation in clinical education programs. Conclusion: The use of simulation to support student learning and develop clinical skills and competencies in adult speech pathology practice is supported by workplace clinical educators. However, results of this study suggest that the simulation program needs to be embedded within the curriculum and clinical education program to enhance transition between learning experiences and maximize benefits of learning experiences in real workplace contexts

“Same But Different”: The Role and Perceptions of the Simulation Clinical Educator

Simulated learning programs are an important component of allied health education. Although the role of simulation clinical educators has been highlighted as critical for student learning within simulation, their perceptions of their role have not yet been investigated. This study aimed to explore the experiences of simulation clinical educators. Participants were ten simulation clinical educators who had supported speech-language pathology students’ learning during a 5-day simulation program focussed on speech-language pathology practice with adult clients in acute hospital and rehabilitation settings. Educators participated in individual semi-structured interviews exploring their role and their perceptions of the simulation-based learning program. Data were analysed using inductive thematic analysis. Three inter-related themes emerged from participants’ views. The major theme of Unique teaching and learning environment incorporated five subthemes: focus on teaching; safe learning environment; authenticity and engagement; structure and intensity of learning, and; feedback opportunities. Two additional themes were identified: Clinical educator role same but different, and Simulation bridges the gap between theory and practice. This study offers new insights into simulation clinical educators’ perceptions of their role when supporting students within simulation and highlight the importance of harnessing the unique benefits of simulation as a teaching pedagogy to maximize its impacts on student learning and justify its costs

Magnetostriction-polarization coupling in multiferroic Mn2MnWO6

Double corundum-related polar magnets are promising materials for multiferroic and magnetoelectric applications in spintronics. However, their design and synthesis is a challenge, and magnetoelectric coupling has only been observed in Ni3TeO6 among the known double corundum compounds to date. Here we address the high-pressure synthesis of a new polar and antiferromagnetic corundum derivative Mn2MnWO6, which adopts the Ni3TeO6-type structure with low temperature first-order field-induced metamagnetic phase transitions (T N = 58 K) and high spontaneous polarization (~ 63.3 μC·cm−2). The magnetostriction-polarization coupling in Mn2MnWO6 is evidenced by second harmonic generation effect, and corroborated by magnetic-field-dependent pyroresponse behavior, which together with the magnetic-field-dependent polarization and dielectric measurements, qualitatively indicate magnetoelectric coupling. Piezoresponse force microscopy imaging and spectroscopy studies on Mn2MnWO6 show switchable polarization, which motivates further exploration on magnetoelectric effect in single crystal/thin film specimens

The establishment, maintenance, and adaptation of high- and low-impact chronic pain: a framework for biopsychosocial pain research

We present a framework for the study of states of chronic pain and transitions between those states. We capture in the framework the dynamic nature of pain: people live with pain that changes over time. First, we offer definitions of both acute and chronic pain and explore the contextual considerations related to the common use of this temporal dichotomy. Second, we promote the importance of incorporating the impact pain has on a person's life. Finally, we discuss the challenges and opportunities inherent in implementing this common approach. Our goal is to produce a framework for the study of the development, maintenance, and resolution of chronic pain. Whether a single brief event or a constant feature of life, pain interrupts to prioritise protection, interferes with activity, reduces quality of life, and can alter identity.44 Protection is achieved by escape from harm, avoidance of perceived danger, withdrawal for respite and repair, and communication of incapacity and environmental risk; longer-term protection is achieved by learning the cues for pain and injury.53 From this perspective, pain is most usefully considered a need state, fundamentally a motivational drive to protect.49 This approach centres our attention on the consequences of pain for the person in their context, on its duration and its impact

Miscellaneous Rheumatic Diseases [73-83]: 73. Is There a Delay in Specialist Referral of Hot Swollen Joint?

Background: Patients with acute, hot, swollen joints commonly present to general practitioners, emergency departments and/or acute admitting teams rather than directly to rheumatology. It is imperative to consider septic arthritis in the differential diagnosis of these patients. The British Society of Rheumatology (BSR) has produced guidelines for the management of this condition, which include recommendations for early specialist referral and joint aspiration of all patients with suspected septic arthritis. We examined whether the initial management of patients with acute hot swollen joint(s) at University College London Hospital (UCLH) follows BSR guidelines. Methods: For the period Feb to Nov 2009, appropriate patients were identified by searching the UCLH database using the diagnostic terms, "pyogenic arthritis”, "septic arthritis” and "gout”; and from all joint aspirate requests sent to microbiology. Medical notes were obtained and any patients who had elective arthroscopies or chronic (> 6 weeks) symptoms were excluded. Data were collected on the time taken from the onset of symptoms to specialist (orthopaedic/rheumatology) referral and joint aspiration, collection of blood cultures and antibiotic treatment with or without microbiology advice. Results: Twenty patients were identified with hot swollen (18 monoarticular, 3 prosthetic) joint(s) of < 2 weeks duration. Of whom, 3/20 (15%) were admitted directly to rheumatology, 7/20 (35%) to the acute admissions unit, 3/20 (15%) to orthopaedic, 4/20 (20%) to a medical team and 1/20 (5%) to general surgery. In 19 (95%) cases, specialist (rheumatology/orthopaedic) advice was sought. Of 14 cases not seen directly by specialists 9 (64%) were referred at 24-48 h and 5 (36%) at 48-192 h. All 20 patients had joint aspiration. In 9/20 (45%) of cases, joint aspiration was performed in less than 6 h, 3/20 (15%) cases at 6-24h and 6/20 (30%) cases at 24-192 h and was not recorded in two patients. Of these, crystals were identified in two and one was culture positive. Blood cultures were received for only 6/20 (30%) of cases and only clearly documented to have been taken prior to antibiotic therapy and none were positive. Of 14/20 (70%) started on antibiotic treatment empirically, only 6 (42%) were preceded by joint aspiration. In the 6 patients not treated with antibiotics due to low index of suspicion of septic arthritis, synovial fluid and blood cultures were negative. Microbiology advice was sought in 10/20 (50%) of cases by the admitting teams but the timing of this advice is unclear. Conclusions: Despite the provision of 24 h rheumatology and orthopaedic cover at UCLH, we found a significant delay in acute medical firms seeking specialist advice on the management of patients with acute, hot swollen joints with subsequent deviation from BSR guidelines. Consequently, we plan to increase awareness of these guidelines amongst medical firms at UCLH. Disclosure statement: All authors have declared no conflicts of interes