396 research outputs found
Hysteretic characteristics of a double stripline in the critical state
Analytical investigations of the critical state are carried out for a
superconducting stripline consisting of two individual coplanar strips with an
arbitrary distance between them. Two different cases are considered: a
stripline with transport current and strips exposed to a perpendicular magnetic
field. In the second case, the obtained solutions correspond to "fieldlike"
(for unclosed strips) and "currentlike" (for a long rectangular superconducting
loop) states in an isolated strip to which both a transport current and a
magnetic field are applied with constant ratio.Comment: 8 pages, 6 figures. accepted by SS
Identifying critically important cardiovascular outcomes for trials in hemodialysis: an international survey with patients, caregivers and health professionals
BACKGROUND: Cardiovascular disease (CVD) is a major contributor to morbidity and mortality in people on hemodialysis (HD). Cardiovascular outcomes are reported infrequently and inconsistently across trials in HD. This study aimed to identify the priorities of patients/caregivers and health professionals (HPs) for CVD outcomes to be incorporated into a core outcome set reported in all HD trials. METHODS: In an international online survey, participants rated the absolute importance of 10 cardiovascular outcomes (derived from a systematic review) on a 9-point Likert scale, with 7-9 being critically important. The relative importance was determined using a best-worst scale. Likert means, medians and proportions and best-worst preference scores were calculated for each outcome. Comments were thematically analyzed. RESULTS: Participants included 127 (19%) patients/caregivers and 549 (81%) HPs from 53 countries, of whom 530 (78%) completed the survey in English and 146 (22%) in Chinese. All but one cardiovascular outcome ('valve replacement') was rated as critically important (Likert 7-9) by all participants; 'sudden cardiac death', 'heart attack', 'stroke' and 'heart failure' were all rated at the top by patients/caregivers (median Likert score 9). Patients/caregivers ranked the same four outcomes as the most important outcomes with mean preference scores of 6.2 (95% confidence interval 4.8-7.5), 5.9 (4.6-7.2), 5.3 (4.0-6.6) and 4.9 (3.6-6.3), respectively. The same four outcomes were ranked most highly by HPs. We identified five themes underpinning the prioritization of outcomes: 'clinical equipoise and potential for intervention', 'specific or attributable to HD', 'severity or impact on the quality of life', 'strengthen knowledge and education', and 'inextricably linked burden and risk'. CONCLUSIONS: Patients and HPs believe that all cardiovascular outcomes are of critical importance but consistently identify sudden cardiac death, myocardial infarction, stroke and heart failure as the most important outcomes to be measured in all HD trials
Reactive amine surfaces for biosensor applications, prepared by plasma-enhanced chemical vapour modification of polyolefin materials
Here we have demonstrated a solventless plasma-based process that integrates low-cost, high throughput, high reproducibility and ecofriendly process for the functionalization of the next-generation point-of-care device platforms. Amine functionalities were deposited by plasma-enhanced chemical vapour deposition (PECVD) using a new precursor. The influence of the plasma RF power and the deposition time on surfacial properties, as well as their effect on the reactivity and content of amino groups was investigated. The key process determinants were to have a sufficient power in the plasma to activate and partially fragment the monomer but not too much as to lose the reactive amine functionality, and sufficient deposition time to develop a reactive layer but not to consume or erode the amine reactivity. An immunoassay performed using human immunoglobulin (IgG) as a model analyte showed an improvement of the detection limit by two orders of magnitude beyond that obtained using devices activated by liquid-phase reaction. ΓΒ© 2010 Elsevier B.V. All rights reserved
Technical challenges of providing record linkage services for research
Background: Record linkage techniques are widely used to enable health researchers to gain event based longitudinal information for entire populations. The task of record linkage is increasingly being undertaken by specialised linkage units (SLUs). In addition to the complexity of undertaking probabilistic record linkage, these units face additional technical challenges in providing record linkage βas a serviceβ for research. The extent of this functionality, and approaches to solving these issues, has had little focus in the record linkage literature. Few, if any, of the record linkage packages or systems currently used by SLUs include the full range of functions required. Methods: This paper identifies and discusses some of the functions that are required or undertaken by SLUs in the provision of record linkage services. These include managing routine, on-going linkage; storing and handling changing data; handling different linkage scenarios; accommodating ever increasing datasets. Automated linkage processes are one way of ensuring consistency of results and scalability of service. Results: Alternative solutions to some of these challenges are presented. By maintaining a full history of links, and storing pairwise information, many of the challenges around handling βopenβ records, and providing automated managed extractions are solved. A number of these solutions were implemented as part of the development of the National Linkage System (NLS) by the Centre for Data Linkage (part of the Population Health Research Network) in Australia.Conclusions: The demand for, and complexity of, linkage services are growing. This presents as a challenge to SLUs as they seek to service the varying needs of dozens of research projects annually. Linkage units need to be both flexible and scalable to meet this demand. It is hoped the solutions presented here can help mitigate these difficulties
Noninvasive Assessment of Coronary Artery Disease in Women: Whatβs Next?
Significant progress in research has been made in the areas of sex-specific aspects of cardiovascular disease. Despite these advances, coronary artery disease (CAD) is the leading cause of death of women in the Western world. Over the past decade, the focused research on women at risk for ischemic heart disease has helped to clarify our understanding of some of the sex-specific factors, which are important in detecting CAD. In women, the detection and evaluation of physiologically significant CAD is challenging, especially given that traditional tests designed to detect focal areas of coronary artery stenosis are less sensitive and specific in female patients who have a lower prevalence of obstructive coronary disease, greater burden of symptoms, and a high atherosclerotic burden. In this article, we review the available evidence on the role of contemporary cardiovascular imaging techniques in evaluating ischemic heart disease in women
A New Acoustic Portal into the Odontocete Ear and Vibrational Analysis of the Tympanoperiotic Complex
Global concern over the possible deleterious effects of noise on marine organisms was catalyzed when toothed whales stranded and died in the presence of high intensity sound. The lack of knowledge about mechanisms of hearing in toothed whales prompted our group to study the anatomy and build a finite element model to simulate sound reception in odontocetes. The primary auditory pathway in toothed whales is an evolutionary novelty, compensating for the impedance mismatch experienced by whale ancestors as they moved from hearing in air to hearing in water. The mechanism by which high-frequency vibrations pass from the low density fats of the lower jaw into the dense bones of the auditory apparatus is a key to understanding odontocete hearing. Here we identify a new acoustic portal into the ear complex, the tympanoperiotic complex (TPC) and a plausible mechanism by which sound is transduced into the bony components. We reveal the intact anatomic geometry using CT scanning, and test functional preconceptions using finite element modeling and vibrational analysis. We show that the mandibular fat bodies bifurcate posteriorly, attaching to the TPC in two distinct locations. The smaller branch is an inconspicuous, previously undescribed channel, a cone-shaped fat body that fits into a thin-walled bony funnel just anterior to the sigmoid process of the TPC. The TPC also contains regions of thin translucent bone that define zones of differential flexibility, enabling the TPC to bend in response to sound pressure, thus providing a mechanism for vibrations to pass through the ossicular chain. The techniques used to discover the new acoustic portal in toothed whales, provide a means to decipher auditory filtering, beam formation, impedance matching, and transduction. These tools can also be used to address concerns about the potential deleterious effects of high-intensity sound in a broad spectrum of marine organisms, from whales to fish
A Full Suite of Histone and Histone Modifying Genes Are Transcribed in the Dinoflagellate Lingulodinium
BACKGROUND: Dinoflagellates typically lack histones and nucleosomes are not observed in DNA spreads. However, recent studies have shown the presence of core histone mRNA sequences scattered among different dinoflagellate species. To date, the presence of all components required for manufacturing and modifying nucleosomes in a single dinoflagellate species has not been confirmed. METHODOLOGY AND RESULTS: Analysis of a Lingulodinium transcriptome obtained by Illumina sequencing of mRNA shows several different copies of each of the four core histones as well as a suite of histone modifying enzymes and histone chaperone proteins. Phylogenetic analysis shows one of each Lingulodinium histone copies belongs to the dinoflagellate clade while the second is more divergent and does not share a common ancestor. All histone mRNAs are in low abundance (roughly 25 times lower than higher plants) and transcript levels do not vary over the cell cycle. We also tested Lingulodinium extracts for histone proteins using immunoblotting and LC-MS/MS, but were unable to confirm histone expression at the protein level. CONCLUSION: We show that all core histone sequences are present in the Lingulodinium transcriptome. The conservation of these sequences, even though histone protein accumulation remains below currently detectable levels, strongly suggests dinoflagellates possess histones
Extreme weather events in developing countries and related injuries and mental health disorders - a systematic review
Chronic kidney disease and valvular heart disease: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference
Chronic kidney disease (CKD) is a major risk factor for valvular heart disease (VHD). Mitral annular and aortic valve calcifications are highly prevalent in CKD patients and commonly lead to valvular stenosis and regurgitation, as well as complications including conduction system abnormalities and endocarditis. VHD, especially mitral regurgitation and aortic stenosis, is associated with significantly reduced survival among CKD patients. Knowledge related to VHD in the general population is not always applicable to CKD patients because the pathophysiology may be different, and CKD patients have a high prevalence of comorbid conditions and elevated risk for periprocedural complications and mortality. This Kidney Disease: Improving Global Outcomes (KDIGO) review of CKD and VHD seeks to improve understanding of the epidemiology, pathophysiology, diagnosis, and treatment of VHD in CKD by summarizing knowledge gaps, areas of controversy, and priorities for research
The reasons for betel-quid chewing scale: assessment of factor structure, reliability, and validity
- β¦