55 research outputs found
The first quadrupole excitations in spherical nuclei and nuclear pairing
Excitation energies and transition probabilities of the first 2+ excitations
in even lead, tin and nickel isotopes are calculated within the self-consistent
Theory of Finite Fermi Systems based on the Energy Density Functional by Fayans
et al. A reasonable agreement with available experimental data is obtained. The
effect of the density dependence of the effective pairing interaction is
analyzed in detail by comparing results obtained with volume and surface
pairing. The effect is found to be noticeable, especially for the 2+ energies
which are systematically higher at 200-300 keV for the volume paring as
compared with the surface pairing case, the latter being in a better agreement
with the data.Comment: Presented at International Conference on Nuclear Structure and
Related Topics, Dubna, July 2 - 7, 201
Survival After MI in a Community Cohort Study: Contribution of Comorbidities in NSTEMI
Background: Non–ST-segment elevation myocardial infarction (NSTEMI) comprises the majority of MI worldwide, yet mortality remains high. Management of NSTEMI is relatively delayed and heterogeneous compared with the “time is muscle” approach to ST-segment elevation MI, though it is unknown to what extent comorbid conditions drive NSTEMI mortality. Objectives: We sought to quantify mortality due to MI versus comorbid conditions in patients with NSTEMI. Methods: Participants of the ARIC (Atherosclerosis Risk in Communities) study cohort ages 45 to 64 years, who developed incident NSTEMI were identified and incidence-density matched to participants who did not experience an MI by age group, sex, race, and study community. We estimated hazard ratios for all-cause mortality, comparing those who developed NSTEMI to those who did not experience an MI. Results: ARIC participants with incident NSTEMI were more likely at baseline to be smokers, have diabetes and renal dysfunction, and take blood pressure or cholesterol-lowering medications than were participants who did not have an MI. Over one-half of participants experiencing NSTEMI died over a median follow-up of 8.4 years; incident NSTEMI was associated with 30% higher risk of mortality after adjusting for comorbid conditions (hazard ratio: 1.30; 95% confidence interval: 1.11 to 1.53). Conclusions: NSTEMI confers a significantly higher mortality hazard beyond what can be attributed to comorbid conditions. More consistent and effective strategies are needed to reduce mortality in NSTEMI amid comorbid conditions
Integrating coronary atherosclerosis burden and progression with coronary artery disease risk factors to guide therapeutic decision making
ImportanceAlthough atherosclerosis represents the primary driver of coronary artery disease, evaluation and treatment approaches have historically relied upon indirect markers of atherosclerosis that include surrogates (cholesterol), signs (angina), and sequelae (ischemia) of atherosclerosis. Direct quantification and characterization of atherosclerosis may encourage a precision heart care paradigm that improves diagnosis, risk stratification, therapeutic decision-making, and longitudinal disease tracking in a personalized fashion.ObservationsThe American College of Cardiology Innovations in Prevention Working Group introduce the Atherosclerosis Treatment Algorithms that personalize medical interventions based upon atherosclerosis findings from coronary computed tomography angiography (CTA) and cardiovascular risk factors. Through integration of coronary CTA-based atherosclerosis evaluation, clinical practice guidelines, and contemporary randomized controlled trial evidence, the Atherosclerosis Treatment Algorithms leverage patient-specific atherosclerosis burden and progression as primary targets for therapeutic intervention. After defining stages of atherosclerosis severity by coronary CTA, Atherosclerosis Treatment Algorithms are described for worsening stages of atherosclerosis for patients with lipid disorders, diabetes, hypertension, obesity, and tobacco use. The authors anticipate a rapid pace of research in the field, and conclude by providing perspectives on future needs that may improve efforts to optimize precision prevention of coronary artery disease. Importantly, the Atherosclerosis Treatment Algorithms are not endorsed by the American College of Cardiology, and should not be interpreted as a statement of American College of Cardiology policy.Conclusions and RelevanceWe describe a precision heart care approach that emphasizes atherosclerosis as the primary disease target for evaluation and treatment. To our knowledge, this is the first proposal to use coronary atherosclerosis burden and progression to personalize therapy selection and therapy changes, respectively.Cardiolog
Inertial and fluctuational effects on the motion of a Bose superfluid vortex
We study the motion of a vortex under the influence of a harmonic force in an
approximately two dimensional trapped Bose-condensed gas. The
Hall-Vinen-Iordanskii equations, modified to include a fluctuational force and
an inertial mass term, are solved for the vortex motion. The mass of the vortex
has a strong influence on the time it takes the vortex to escape the trap.
Since the vortex mass also depends on the trap size we have an additional
dependence on the trap size in the escape time which we compare to the massless
case.Comment: Submitted to J. Low. Temp. Phy
Women physicians in cardiovascular magnetic resonance: past, present, and future
Women's engagement in medicine, and more specifically cardiovascular imaging and cardiovascular MRI (CMR), has undergone a slow evolution over the past several decades. As a result, an increasing number of women have joined the cardiovascular imaging community to contribute their expertise. This collaborative work summarizes the barriers that women in cardiovascular imaging have overcome over the past several years, the positive interventions that have been implemented to better support women in the field of CMR, and the challenges that still remain, with a special emphasis on women physicians
Worldwide variation in cardiovascular magnetic resonance practice models
INTRODUCTION: The use of cardiovascular magnetic resonance (CMR) for diagnosis and management of a broad range of cardiac and vascular conditions has quickly expanded worldwide. It is essential to understand how CMR is utilized in different regions around the world and the potential practice differences between high-volume and low-volume centers. METHODS: CMR practitioners and developers from around the world were electronically surveyed by the Society for Cardiovascular Magnetic Resonance (SCMR) twice, requesting data from 2017. Both surveys were carefully merged, and the data were curated professionally by a data expert using cross-references in key questions and the specific media access control IP address. According to the United Nations classification, responses were analyzed by region and country and interpreted in the context of practice volumes and demography. RESULTS: From 70 countries and regions, 1092 individual responses were included. CMR was performed more often in academic (695/1014, 69%) and hospital settings (522/606, 86%), with adult cardiologists being the primary referring providers (680/818, 83%). Evaluation of cardiomyopathy was the top indication in high-volume and low-volume centers (p = 0.06). High-volume centers were significantly more likely to list evaluation of ischemic heart disease (e.g., stress CMR) as a primary indicator compared to low-volume centers (p < 0.001), while viability assessment was more commonly listed as a primary referral reason in low-volume centers (p = 0.001). Both developed and developing countries noted cost and competing technologies as top barriers to CMR growth. Access to scanners was listed as the most common barrier in developed countries (30% of responders), while lack of training (22% of responders) was the most common barrier in developing countries. CONCLUSION: This is the most extensive global assessment of CMR practice to date and provides insights from different regions worldwide. We identified CMR as heavily hospital-based, with referral volumes driven primarily by adult cardiology. Indications for CMR utilization varied by center volume. Efforts to improve the adoption and utilization of CMR should include growth beyond the traditional academic, hospital-based location and an emphasis on cardiomyopathy and viability assessment in community centers
Cardiac magnetic resonance stress perfusion imaging for evaluation of patients with chest pain
Background: Stress cardiac magnetic resonance imaging (CMR) has demonstrated excellent diagnostic and prognostic value in single-center studies. Objectives: This study sought to investigate the prognostic value of stress CMR and downstream costs from subsequent cardiac testing in a retrospective multicenter study in the United States. Methods: In this retrospective study, consecutive patients from 13 centers across 11 states who presented with a chest pain syndrome and were referred for stress CMR were followed for a target period of 4 years. The authors associated CMR findings with a primary outcome of cardiovascular death or nonfatal myocardial infarction using competing risk-adjusted regression models and downstream costs of ischemia testing using published Medicare national payment rates. Results: In this study, 2,349 patients (63 ± 11 years of age, 47% female) were followed for a median of 5.4 years. Patients with no ischemia or late gadolinium enhancement (LGE) by CMR, observed in 1,583 patients (67%), experienced low annualized rates of primary outcome (4-fold higher annual primary outcome rate and a >10-fold higher rate of coronary revascularization during the first year after CMR. Patients with ischemia and LGE both negative had low average annual cost spent on ischemia testing across all years of follow-up, and this pattern was similar across the 4 practice environments of the participating centers. Conclusions: In a multicenter U.S. cohort with stable chest pain syndromes, stress CMR performed at experienced centers offers effective cardiac prognostication. Patients without CMR ischemia or LGE experienced a low incidence of cardiac events, little need for coronary revascularization, and low spending on subsequent ischemia testing. (Stress CMR Perfusion Imaging in the United States [SPINS]: A Society for Cardiovascular Resonance Registry Study; NCT03192891)
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
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