7440 research outputs found
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Imaging for patients presenting to an emergency department with back pain : impact on patient pathway
No full textObjective: The objective of the present study is to quantify utilisation of imaging for patients presenting to an ED with back pain, their characteristics and dispositions. Methods: A retrospective cohort study of 1132 ED presentations for back pain to an Australian metropolitan ED in 2013 was performed. Patient demographics, rates of radiography, computed tomography or magnetic resonance imaging and rates of subsequent admission and ED re-presentation were analysed. Results: Patients aged 26-35 years were the largest group presenting with back pain (19.4% of presentations), with the majority being female (52.3%). Imaging was requested at 29.5% (n = 334) of presentations (radiography n = 297; advanced imaging n = 63). Patients over 70 years had higher imaging rates than younger patients (49.4% vs 25.5%, P < 0.001). Imaging was not associated with attendance during or outside office hours (29.3% vs 31.8%, P = 0.4). Of presentations, 34.1% resulted in admission, with no association between imaging and admission (31.8% vs 36.0%, P = 0.2) or ED re-presentation for back pain in the same year (6.5% vs 9.7%, P = 0.09). Conclusion: This study provides benchmark data on the use of imaging for back pain in an Australian ED, an area which has been largely unexplored. The rate of imaging in the ED was higher than previously reported in a General Practice setting. Consistent with guidelines, patients older than 70 were more than twice as likely to receive imaging compared to younger patients. It was beyond the scope of the current study to determine whether these images were clinically indicated and further research is required to determine if initiatives to reduce imaging in this population are warranted.7 page(s
Sensitive time-gated immunoluminescence detection of prostate cancer cells using a TEGylated europium ligand
No full textWe describe the application of a synthetically developed tetradentate β-diketonate-europium chelate with high quantum yield (39%), for sensitive immunodetection of prostate cancer cells (DU145). MIL38 antibody, a mouse monoclonal antibody against Glypican 1, conjugated directly to the chelate via lysine residues, resulted in soluble (hydrophilic) and stable immunoconjugates. Indirect labeling of the antibody by a europium chelated secondary polyclonal antibody and a streptavidin/biotin pair was also performed. All of these bright luminescent conjugates were used to stain DU145 cells, a prostate cancer cell line, using time gated luminescence microscopy for imaging, and their performances were compared to conventional FITC labeling. For all prepared conjugates, the europium chelate in conjunction with a gated autosynchronous luminescence detector (GALD) completely suppressed the cellular autofluorescence background to allow capture of vivid, high contrast images of immune-stained cancer cells.8 page(s
Energy consumption and economic growth in the United States
No full textWe study the relationship between energy consumption and real GDP in the USA using a multivariate time-varying model [1973Q1–2014Q1]. We show that the combination of disaggregation into specific fuels and time variation gives more nuanced results than the alternatives for the USA. Specifically, we find that the Granger causal relationship between total energy and real US GDP is bi-directional through much of the 1990s, but unidirectional running from real US GDP to energy consumption in the 2000s. As for each fuel, similar patterns of change were observed in the causal relationship between coal consumption and real US GDP. Oil consumption largely shows a bi-directional relationship between consumption and US GDP, especially after 2009. And natural gas consumption shows a brief period in the early-to-mid 2000s where US GDP predicts energy consumption, but primarily shows that natural gas consumption and economic growth are independent.11 page(s
The Nonlinear dust potential and collision frequencies in dusty plasmas
No full textThe nonlinear modification to the Debye-Hückel potential of a dust grain depends on the thermodynamic properties of the background plasma. When the grain carries more than one electronic charge, the nonlinear self-interaction of the potential substantially modifies the ion-dust collision frequency. The electron-negatively charged dust collision frequency on the other hand remains largely unaffected by such a nonlinear modification. In the absence of nonlinear modification, collisions between the electrons and the negatively charged dust cease completely when the potential energy is four times the electron thermal energy. Thus once the dust acquires maximum charge, it will encounter electrons only because of its induced dipole field. Our electron-dust collision frequency agrees well with the previously known result whereas ion-dust collision frequency is always small compared with the known fitting formula.8 page(s
The Genesis of silicic arc magmas in shallow crustal cold zones
No full textA number of currently popular models for the genesis of evolved arc-magmas (from basaltic andesite to dacite) invoke repeated intrusion, partial-melting and differentiation at the base of the crust. However, several observations suggest that this may be the exception rather than the norm: (1) geobarometry often indicates shallow pressure (0.1–0.3 GPa) evolution; (2) incongruent melting of amphibolite at elevated pressures should yield magmas in equilibrium with high pressure phases like garnet, but rare earth element patterns almost ubiquiously preclude this; (3) compositionally-zoned caldera forming eruptions suggest differentiation at near surface depths; (4) U-series data most commonly indicate differentiation over millennia time-scales. This requires rapid cooling that, in turn, is most easily explained by relatively small magma volumes undergoing crystal fractionation within the shallow (i.e. cool) crust. To further test these ideas, we combined published experimental-data for liquidus equilibria with appropriate silicic arc-magma compositions. On projections of the ternary liquidus system nepheline—silica—olivine, recent data for Tongan silicic lavas plot either on or close to low-pressure (1 atm) cotectics for the rocks' phenocryst phases, suggesting low-pressure differentiation. Using our own and published data from arc volcanoes around the world we find that the majority are consistent with differentiation at shallow depths, regardless of total crustal thickness. Combined with the typical timescales of differentiation, we estimate that the volumes of magma stored during differentiation in shallow crustal zones are usually on the order of only a few km³. There is also a clear role for mixing and recharge that involves magmas that are more deeply-sourced and primitive in character (typically evolved basalts and basaltic andesites). Whether the latter differentiated in the lower-crust or at the crust/mantle boundary has important implications for the constitution and average composition of arc crust. At present, we can only conclude that evidence for more silicic arc-magma generation at these depths is generally lacking.23 page(s
Anticipatory processing and post-event processing in social anxiety disorder : an update on the literature
No full textTwo repetitive thinking processes that have been proposed in prominent maintenance models of social anxiety disorder (SAD) are anticipatory processing and post-event processing. Research into these two processes has steadily increased over the last 20 years. This review highlights the main lines of existing research on anticipatory processing and post-event processing, including studies on the nature of these processes, their association with social anxiety, the predictors, and consequences of these processes, as well as how these processes respond to treatments for SAD. The review also highlights some of the conceptual and methodological issues that have prevented the literature on anticipatory processing and post-event processing from being more integrated and focused. Finally, the review draws together some new directions in terms of theory and research to further advance the field.9 page(s
The Effect of N-acetylcysteine on the incidence of contrast-induced kidney injury : a systematic review and trial sequential analysis
No full textBackground: There have been a myriad of studies investigating the effectiveness of N-acetylcysteine (NAC) in the prevention of contrast induced nephropathy (CIN) in patients undergoing coronary angiography (CAG) with or without percutaneous coronary intervention (PCI). However the consensus is still out about the effectiveness of NAC pre-treatment due to vastly mixed results amongst the literature. Objectives: The aim of this study was to conduct a meta-analysis and trial sequential analysis to determine the effects of pre-operative NAC in lowering the incidence of CIN in patients undergoing CAG and/or PCI. Methods: A systematic literature search was performed to include all randomized controlled trials (RCTs) comparing NAC versus control as pretreatment for CAG and/or PCI. A traditional meta-analysis and several subgroup analyses were conducted using traditional meta-analysis with relative risk (RR), trial sequential analysis, and meta-regression analysis. Results: 43 RCTs met our inclusion criteria giving a total of 3277 patients in both control and treatment arms. There was a significant reduction in the risk of CIN in the NAC treated group compared to control (OR 0.666; 95% CI, 0.532–0.834; I2 = 40.11%; p = 0.004). Trial sequential analysis, using a relative risk reduction threshold of 15%, indicates that the evidence is firm. Conclusions: The results of the present paper support the use of NAC in the prevention of CIN in patients undergoing CAG ± PCI. Future studies should focus on the benefits of NAC amongst subgroups of high-risk patients.9 page(s
Feeling, learning from and being aware of inner states : interoceptive dimensions in neurodegeneration and stroke
No full textInteroception is acomplex process encompassing multiple dimensions, such as accuracy, learning and awareness. Here, we examined whether each of those dimensions relies on specialized neural regions distributed throughout the vast interoceptive network. To this end, we obtained relevant measures of cardiac interoception in healthy subjects and patients offering contrastive lesion models of neurodegeneration and focal brain damage: behavioural variant fronto-temporal dementia (bvFTD), Alzheimer’s disease (AD) and frontoinsular stroke. Neural correlates of the three dimensions were examined through structural and functional resting-state imaging, and online measurements of the heart-evoked potential (HEP). The three patient groups presented deficits in interoceptive accuracy, associated with insular damage, connectivity alterations and abnormal HEP modulations. Interoceptive learning was differentially impaired in AD patients, evidencing a key role of memory networks in this skill. Interoceptive awareness results showed that bvFTD and AD patients overestimated their performance; this pattern was related to abnormalities in anterior regions and associated networks subserving metacognitive processes, and probably linked to well-established insight deficits in dementia. Our findings indicate how damage to specific hubs in a broad fronto-temporo-insular network differentially compromises interoceptive dimensions, and how such disturbances affect widespread connections beyond those critical hubs. This is the first study in which a multiple lesion model reveals fine-grained alterations of body sensing, offering new theoretical insights into neuroanatomical foundations of interoceptive dimensions. This article is part of the themed issue ‘Interoception beyond homeostasis: affect, cognition and mental health’.10 page(s
A hybrid health service accreditation program model incorporating mandated standards and continuous improvement : interview study of multiple stakeholders in Australian health care
No full textThe study aim was to investigate the understandings and concerns of stakeholders regarding the evolution of health service accreditation programs in Australia. Stakeholder representatives from programs in the primary, acute and aged care sectors participated in semi-structured interviews. Across 2011-12 there were 47 group and individual interviews involving 258 participants. Interviews lasted, on average, 1 h, and were digitally recorded and transcribed. Transcriptions were analysed using textual referencing software. Four significant issues were considered to have directed the evolution of accreditation programs: altering underlying program philosophies; shifting of program content focus and details; different surveying expectations and experiences and the influence of external contextual factors upon accreditation programs. Three accreditation program models were noted by participants: regulatory compliance; continuous quality improvement and a hybrid model, incorporating elements of these two. Respondents noted the compatibility or incommensurability of the first two models. Participation in a program was reportedly experienced as ranging on a survey continuum from "malicious compliance" to "performance audits" to "quality improvement journeys". Wider contextual factors, in particular, political and community expectations, and associated media reporting, were considered significant influences on the operation and evolution of programs. A hybrid accreditation model was noted to have evolved. The hybrid model promotes minimum standards and continuous quality improvement, through examining the structure and processes of organisations and the outcomes of care. The hybrid model appears to be directing organisational and professional attention to enhance their safety cultures.15 page(s
