674 research outputs found
Anomalous supersolidity in a weakly interacting dipolar Bose mixture on a square lattice
We calculate the mean-field phase diagram of a zero-temperature, binary Bose mixture on a square optical lattice, where one species possesses a non-negligible dipole moment. Remarkably, this system exhibits supersolidity for anomalously weak dipolar interaction strengths, which are readily accessible with current experimental capabilities. The supersolid phases are robust, in that they occupy large regions in the parameter space. Further, we identify a first-order quantum phase transition between supersolid and superfluid phases. Our results demonstrate the rich features of the dipolar Bose mixture, and suggest that this system is well suited for exploring supersolidity in the experimental setting
Nephrotoxicity in Patients With or Without Cystic Fibrosis Treated With Polymyxin B Compared to Colistin
Nephrotoxicity is the primary adverse effect of the polymyxins. The relative rates of toxicity of polymyxin B and colistin have not been fully elucidated, especially in patients with cystic fibrosis (CF). A retrospective cohort study of adults treated with polymyxin B or colistin for at least 48 h was conducted. The primary endpoint was the incidence of kidney injury assessed by RIFLE (i.e., risk, injury, failure, loss, end-stage renal disease) criteria. Risk factors for kidney injury were evaluated using multivariate Cox regression. A total of 414 patients were evaluated, 220 of whom had CF. In patients without CF, there was no difference in kidney injury with polymyxin B and colistin (42.9% versus 50.3%, P = 0.46). Loop diuretic exposure was a risk factor for kidney injury (adjusted hazard ratio [aHR], 1.82; 95% confidence interval [CI], 1.16 to 2.83) in this population. In patients with CF, polymyxin B and colistin were associated with similar rates of kidney injury (34.5% versus 29.8%, P = 0.77). Diabetes (aHR, 2.68; 95% CI, 1.01 to 7.11), loop diuretics (aHR, 3.02; 95% CI, 1.36 to 6.73), and progressive care unit admission (aHR, 8.21; 95% CI, 2.55 to 26.46) were risk factors for kidney injury, while higher baseline serum creatinine levels (per 1 mg/dl) were protective (aHR, 0.08; 95% CI, 0.01 to 0.48). Total unadjusted kidney injury in polymyxin-treated patients was less frequent in those who had CF (30.5% versus 48.5%, P \u3c 0.001). Polymyxin B and colistin are associated with a high incidence of kidney injury; cystic fibrosis may be protective against polymyxin nephrotoxicity, but further investigation is needed to confirm this conjecture
A New Look at Aubrites: Investigating 3D Modal Mineralogy with X-Ray Computed Tomography
The aubrites (approximately 30 known meteorites) are a unique group of differentiated meteorites that formed on asteroids with oxygen fugacities (O2) from approximately 2 to approximately 6 log units below the iron-wustite buffer. At these highly reduced conditions, elements deviate from the geochemical behavior exhibited at terrestrial O2, forming FeO-poor silicates and exotic sulfides. While previous studies have described the petrology and 2D modal abundances of aubrites, this work investigates the 3D modal mineralogies of silicate, metal, and sulfide phases in aubrite samples, which are then compared to the available 2D data. In addition to 3D modal mineralogies, we have examined the geochemistry of fourteen aubrites, including mineral major-element compositions, bulk-rock compositions, and oxygen isotopic compositions to understand their formation and evolution at extreme O2 conditions. We utilize X-ray computed tomography (XCT) to non-destructively analyze the distribution and abundances of mineral phases in aubrites and locate composite clasts of sulfide grains for future analytical study. In order to better constrain elemental behavior under reduced conditions, we specifically target minerals phases that comprise moderately volatile elements (i.e. oldhamite [CaS], caswellsilverite [NaCrS2] and djerfisherite [K6Na(Fe,Cu,Ni)25S26Cl]) as it has been shown that their geochemical behavior changes as a function of O2. Currently, we have produced 3D scans of the Norton County aubrite. The results of the XCT data have allowed for the determination of the abundances of silicate groundmass (i.e., enstatite, forsterite, albite, and diopside), light (based on electron density) sulfides (i.e. alabandite [MnS] and daubrelite [FeCr2S4]), heavy (based on electron density) sulfides (i.e., troilite [FeS]), and Fe,Ni metal by segmenting a density histogram in Volume Graphics Studio software. XCT scans of additional aubrites are underway. By combining the 3D representation of the exotic phases found in aubrites with existing 2D characterizations, we are able to better determine modal abundances. By integrating 3D and 2D modal abundances and geochemistry, we can ultimately better constrain aubrite petrogenesis and elemental partitioning under reduced conditions. Furthermore, application of this new 3D approach offers the opportunity to identify and select clasts for future study prior to cutting the sample, which will minimize sample loss of this precious material
The Geochemistry of Aubrites: Investigating Reduced Parent Bodies
The aubrites (~30 known meteorites) are a unique group of differentiated meteorites that formed on asteroids with oxygen fugacities (O2) from ~2 to ~6 log units below the iron-wstite buffer [12]. At these highly reduced conditions, elements deviate from the geochemical behavior exhibited at terrestrial O2, forming FeO-poor silicates, Si-bearing metals, and exotic sulfides [3]. Here we examine the 3D mineralogy and the geochemistry of fourteen aubrites, including mineral major element compositions, bulk-rock compositions, and oxygen isotopic compositions to understand their formation and evolution at extreme O2 conditions. While previous studies have described the petrology and 2D modal abundances of aubrites, this work investigates the 3D modal mineralogies of silicate, metal, and sulfide phases in aubrite samples, which are then com-pared to the available 2D data. We utilize X-ray computed tomography (XCT) to non-destructively analyze the distribution and abundances of mineral phases in aubrites and locate composite clasts of sulfide grains for future analysis
Perspectives of healthcare professionals in Qatar on causes of medication errors : A mixed methods study of safety culture
This publication was made possible by NPRP grant NPRP 7-388-3-095 from Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Peer reviewedPublisher PD
Exploring facilitators and barriers to medication error reporting among healthcare professionals in Qatar using the theoretical domains framework : A mixed-methods approach
This work was supported by the Qatar National Research Fund, NPRP-7-388-3-095.Peer reviewedPublisher PD
Views and experiences of decision-makers on organisational safety culture and medication errors
ACKNOWLEDGEMENTS The authors wish to acknowledge the contributions of all interviewees, as well as support departments at Hamad Medical Corporation, Doha, Qatar. This work was supported by NPRP grant NPRP 7‐388‐3‐095 from Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Peer reviewedPublisher PD
Exploring Medication Error Causality and Reporting: A Cross Sectional Survey of Hamad Medical Corporation Health Professionals
Introduction: Medication errors are a major global issue, adversely impacting patient safety and health outcomes. Promoting patient safety through minimizing medication errors is therefore a key global healthcare objective. The most widely used and accepted definition of the term 'medication error' is that of the United States (US) National Coordinating Council for Medication Error Reporting and Prevention (NCCMERP), which defines 'medication error' as 'any preventable event that may cause or lead to inappropriate medication use or patient harm while the medication is in control of the health care professional, patient or consumer'.1 This definition has been adopted by Hamad Medical Corporation (HMC). Medication error reporting within HMC is policy driven and has migrated from paper-based to computer-based system. The Performance and Monitoring Department within HMC data highlights the scale of medication errors, with 19,498 errors reported between January 2012 and September 2013. A wide variation in reporting rates was observed among different hospitals (NCCCR 897, Heart Hospital 1046, Hamad General Hospital 1516, Women's Hospital 3041, Al-Khor Hospital 3842, Rumailah Hospital 9156). Alsulami et al. recently reported the findings of the first systematic review of the literature on medication errors in Middle Eastern countries, highlighting that studies were relatively few in number and of poor quality, voicing the need for original, robust research.2 QNRF has provided funding for a two year research study which aims to explore medication error causality and reporting in HMC from the perspectives of health professionals and other key stakeholders. The data presented in this abstract represents the first phase, the aim of which is to quantify the views and attitudes of health professionals. Method: Design - a web based cross-sectional survey of all health professionals (doctors, nurses and pharmacists) working in HMC hospitals. Questionnaire development, validation and piloting - questionnaire items were derived from Reason's Model of Accident Causation and Harm Error,3 the theoretical domains framework of behavioural change,4 and the 'Hospital Survey on Patient Survey'.5 The questionnaire was reviewed for face and content validity by a panel of experts in the United Kingdom and Qatar. This was followed by piloting in a sample of 100 HMC health professionals and test-retest reliability for all attitudinal items (all highly reliable, Kappa statistics, all p < 0.05). Questionnaire distribution - all health professionals in HMC were invited to complete the web based questionnaire. The study commenced at the end of October 2015 and will be data collection will continue until the end of January 2016. Data collected to 12 November 2015 are presented in the abstract and full study data will be presented at the conference. Ethics - the study was approved by HMC ethics committee and the ethics committees of Qatar University and Robert Gordon University (United Kingdom). Results: To date, 767 responses have been received from 522 nurses (68.1%), 143 pharmacists (18.6%) and 102 doctors (13.3%). More than two thirds (69.4%) of respondents had been registered as health professionals for 10 years or less and most (83.8%) had direct patient contact. In terms of their involvement with medicines related processes, 14.1% were involved in prescribing, 30.1% in medicines preparation and dispensing, 55.4% in administering medicines and 45.0% in monitoring the effectiveness and toxicity of medicines. Responses to key statements from the 'Hospital Survey on Patient Survey' are given in Table 1 and responses to key statements on medication error reporting in Table 2. While there were positive responses in terms of the efforts to promote patient safety and knowing how to submit a medication error report, there were less positive responses around staff pressures, patient and information transfers and the perceived consequences of submitting a medication error report. Notably there were concerns around the lack of feedback following submitting a medication error report, fears of reprimands and potential impact on career progression. Conclusion: These preliminary data indicate that there are issues which may compromise patient safety and the effectiveness and efficiency of the medication error reporting system within HMC. While these data are specific to HMC it is likely that they are generalizable to other settings in the Middle East and beyond. Full study data will be analysed in due course and will inform the next stages of the research programme. These stages comprise focus groups of samples of questionnaire respondents to discuss further the issues raised, followed by one to one interviews with key policy makers, health professional leaders, and educators. Full study data will facilitate the development of interventions to reduce medication errors, increase the effectiveness and efficiency of the medication error reporting processes and ultimately enhanced patient safety.qscienc
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