360 research outputs found
Development of the (d,n) proton-transfer reaction in inverse kinematics for structure studies
Transfer reactions have provided exciting opportunities to study the
structure of exotic nuclei and are often used to inform studies relating to
nucleosynthesis and applications. In order to benefit from these reactions and
their application to rare ion beams (RIBs) it is necessary to develop the tools
and techniques to perform and analyze the data from reactions performed in
inverse kinematics, that is with targets of light nuclei and heavier beams. We
are continuing to expand the transfer reaction toolbox in preparation for the
next generation of facilities, such as the Facility for Rare Ion Beams (FRIB),
which is scheduled for completion in 2022. An important step in this process is
to perform the (d,n) reaction in inverse kinematics, with analyses that include
Q-value spectra and differential cross sections. In this way, proton-transfer
reactions can be placed on the same level as the more commonly used
neutron-transfer reactions, such as (d,p), (9Be,8Be), and (13C,12C). Here we
present an overview of the techniques used in (d,p) and (d,n), and some recent
data from (d,n) reactions in inverse kinematics using stable beams of 12C and
16O.Comment: 9 pages, 4 figures, presented at the XXXV Mazurian Lakes Conference
on Physics, Piaski, Polan
Variation and disparities in awareness of myocardial infarction symptoms among adults in the United States
Importance: Prompt recognition of myocardial infarction symptoms is critical for timely access to lifesaving emergency cardiac care. However, patients with myocardial infarction continue to have a delayed presentation to the hospital.Objective: To understand the variation and disparities in awareness of myocardial infarction symptoms among adults in the United States.Design, setting, and participants: This cross-sectional study used data from the 2017 National Health Interview Survey among adult residents of the United States, assessing awareness of the 5 following common myocardial infarction symptoms among different sociodemographic subgroups: (1) chest pain or discomfort, (2) shortness of breath, (3) pain or discomfort in arms or shoulders, (4) feeling weak, lightheaded, or faint, and (5) jaw, neck, or back pain. The response to a perceived myocardial infarction (ie, calling emergency medical services vs other) was also assessed.Main outcomes and measures: Prevalence and characteristics of individuals who were unaware of myocardial infarction symptoms and/or chose not to call emergency medical services in response to these symptoms.Results: Among 25 271 individuals (13 820 women [51.6%; 95% CI, 50.8%-52.4%]; 17 910 non-Hispanic white individuals [69.9%; 95% CI, 68.2%-71.6%]; and 21 826 individuals [82.7%; 95% CI, 81.5%-83.8%] born in the United States), 23 383 (91.8%; 95% CI, 91.0%-92.6%) considered chest pain or discomfort a symptom of myocardial infarction; 22 158 (87.0%; 95% CI, 86.1%-87.8%) considered shortness of breath a symptom; 22 064 (85.7%; 95% CI, 84.8%-86.5%) considered pain or discomfort in arm a symptom; 19 760 (77.0%; 95% CI, 76.1%-77.9%) considered feeling weak, lightheaded, or faint a symptom; and 16 567 (62.6%; 95% CI, 61.6%-63.7%) considered jaw, neck, or back pain a symptom. Overall, 14 075 adults (53.0%; 95% CI, 51.9%-54.1%) were aware of all 5 symptoms, whereas 4698 (20.3%; 95% CI, 19.4%-21.3%) were not aware of the 3 most common symptoms and 1295 (5.8%; 95% CI, 5.2%-6.4%) were not aware of any symptoms. Not being aware of any symptoms was associated with male sex (odds ratio [OR], 1.23; 95% CI, 1.05-1.44; P = .01), Hispanic ethnicity (OR, 1.89; 95% CI, 1.47-2.43; P \u3c .001), not having been born in the United States (OR, 1.85; 95% CI, 1.47-2.33; P \u3c .001), and having a lower education level (OR, 1.31; 95% CI, 1.09-1.58; P = .004). Among 294 non-Hispanic black or Hispanic individuals who were not born in the United States, belonged to the low-income or lowest-income subgroup, were uninsured, and had a lower education level, 61 (17.9%; 95% CI, 13.3%-23.6%) were not aware of any symptoms. This group had 6-fold higher odds of not being aware of any symptoms (OR, 6.34; 95% CI, 3.92-10.26; P \u3c .001) compared with individuals without these characteristics. Overall, 1130 individuals (4.5%; 95% CI, 4.0%-5.0%) chose a different response than calling emergency medical services in response to a myocardial infarction.Conclusions and relevance: Many adults in the United States remain unaware of the symptoms of and appropriate response to a myocardial infarction. In this study, several sociodemographic subgroups were associated with a higher risk of not being aware. They may benefit the most from targeted public health initiatives
Effect of Sleep Apnea and Continuous Positive Airway Pressure on Cardiac Structure and Recurrence of Atrial Fibrillation
Background: Sleep apnea (SA) is associated with an increased risk of atrial fibrillation (AF). We sought to determine the effect of SA on cardiac structure in patients with AF, whether therapy for SA was associated with beneficial cardiac structural remodelling, and whether beneficial cardiac structural remodelling translated into a reduced risk of recurrence of AF after pulmonary venous isolation (PVI). Methods and Results: A consecutive group of 720 patients underwent a cardiac magnetic resonance study before PVI. Patients with SA (n=142, 20%) were more likely to be male, diabetic, and hypertensive and have an increased pulmonary artery pressure, right ventricular volume, atrial dimensions, and left ventricular mass. Treated SA was defined as duration of continuous positive airway pressure therapy of >4 hours per night. Treated SA patients (n=71, 50%) were more likely to have paroxysmal AF, a lower blood pressure, lower ventricular mass, and smaller left atrium. During a followāup of 42 months, AF recurred in 245 patients. The cumulative incidence of AF recurrence was 51% in patients with SA, 30% in patients without SA, 68% in patients with untreated SA, and 35% in patients with treated SA. In a multivariable model, the presence of SA (hazard ratio 2.79, CI 1.97 to 3.94, P<0.0001) and untreated SA (hazard ratio 1.61, CI 1.35 to 1.92, P<0.0001) were highly associated with AF recurrence. Conclusions: Patients with SA have an increased blood pressure, pulmonary artery pressure, right ventricular volume, left atrial size, and left ventricular mass. Therapy with continuous positive airway pressure is associated with lower blood pressure, atrial size, and ventricular mass, and a lower risk of AF recurrence after PVI
Incremental value of extracellular volume assessment by cardiovascular magnetic resonance imaging in risk stratifying patients with suspected myocarditis
Cardiovascular magnetic resonance imaging (CMR) has become a key investigative tool in patients with suspected myocarditis. However, the prognostic implications of T1 mapping, including extracellular volume (ECV) calculation, is less clear. Patients with suspected myocarditis who underwent CMR evaluation, including T1 mapping at our institution were included. CMR findings including late gadolinium enhancement (LGE), left ventricular ejection fraction (LVEF), native T1 mapping, and ECV calculation were associated with first major adverse cardiac events (MACE). MACE included a composite of all-cause death, heart failure hospitalization, heart transplantation, documented sustained ventricular arrhythmia, and recurrent myocarditis. One hundred seventy-nine patients with a mean age of 49āĀ±ā15Ā years were identified. Seventy nine individuals (44%) were female. Mean LVEF was 48āĀ±ā16. At a median follow-up of 4.1 [interquartile-range (IQR) 2.2-6.1] years, 22 (12%) patients experienced a MACE. Mean ECV (per 10%) was significantly associated with MACE (HR 2.09, 95% CI 1.07-4.08, pā=ā0.031). Presence of ECVāā„ā35% demonstrated significant univariable association with MACE (HR 3.3, 95% CI 1.43-7.97, pā=ā0.005) and such association was maintained when adjusted to LVEF (HR 3.42, 95% CI 1.42-7.94, pā=ā0.006). ECVāā„ā35% portended a greater than threefold increased hazards to MACE adjusted to LGE presence (HR 3.14, 95% CI 1.29-7.36, pā=ā0.012). In patients without LGE, ECVāā„ā35% portended a greater than sixfold increased hazards (HR 6.6, pā=ā0.010). In the multivariable model including age, LVEF and LGE size, only ECVāā„ā35% maintained its significant association with outcome. ECV calculation by CMR is a useful tool in the risk stratification of patients with clinically suspected myocarditis, incremental to LGE and LVEF
Contextual and Granular Policy Enforcement in Database-backed Applications
Database-backed applications rely on inlined policy checks to process users'
private and confidential data in a policy-compliant manner as traditional
database access control mechanisms cannot enforce complex policies. However,
application bugs due to missed checks are common in such applications, which
result in data breaches. While separating policy from code is a natural
solution, many data protection policies specify restrictions based on the
context in which data is accessed and how the data is used. Enforcing these
restrictions automatically presents significant challenges, as the information
needed to determine context requires a tight coupling between policy
enforcement and an application's implementation. We present Estrela, a
framework for enforcing contextual and granular data access policies. Working
from the observation that API endpoints can be associated with salient
contextual information in most database-backed applications, Estrela allows
developers to specify API-specific restrictions on data access and use. Estrela
provides a clean separation between policy specification and the application's
implementation, which facilitates easier auditing and maintenance of policies.
Policies in Estrela consist of pre-evaluation and post-evaluation conditions,
which provide the means to modulate database access before a query is issued,
and to impose finer-grained constraints on information release after the
evaluation of query, respectively. We build a prototype of Estrela and apply it
to retrofit several real world applications (from 1000-80k LOC) to enforce
different contextual policies. Our evaluation shows that Estrela can enforce
policies with minimal overheads
Twenty Year Trends and Sex Differences in Young Adults Hospitalized with Acute Myocardial Infarction: The ARIC Community Surveillance Study
Background: Sex differences are known to exist in the management of older patients presenting with acute myocardial infarction (AMI). Few studies have examined the incidence and risk factors of AMI among young patients, or whether clinical management differs by sex. Methods: The Atherosclerosis Risk in Communities (ARIC) Surveillance study conducts hospital surveillance of AMI in 4 US communities (MD MN, MS and NC). AMI was classified by physician review, using a validated algorithm. Medications and procedures were abstracted from the medical record. Our study population was limited to young patients aged 35 to 54 years. Results: From 1995 to 2014, 28 732 weighted hospitalizations for AMI were sampled among patients aged 35 to 74 years. Of these, 8737 (30%) were young. The annual incidence of AMI hospitalizations increased for young women but decreased for young men. The overall proportion of AMI admissions attributable to young patients steadily increased, from 27% in 1995 to 1999 to 32% in 2010 to 2014 (P for trend=0.002), with the largest increase observed in young women. History of hypertension (59% to 73%, P for trend<0.0001) and diabetes mellitus (25% to 35%, P for trend<0.0001) also increased among young AMI patients. Compared to young men, young women presenting with AMI were more often black and had a greater comorbidity burden. In adjusted analyses, young women had a lower probability of receiving lipid-lowering therapies (relative risk [RR]=0.87; 95% confidence interval [CI], 0.80-0.94), nonaspirin antiplatelets (RR=0.83; 95% CI, 0.75-0.91), beta blockers (RR=0.96; 95% CI, 0.91-0.99), coronary angiography (RR=0.93; 95% CI, 0.86-0.99) and coronary revascularization (RR = 0.79; 95% CI, 0.71-0.87). However, 1-year all-cause mortality was comparable for women versus men (HR=1.10; 95% CI, 0.83-1.45). Conclusions: The proportion of AMI hospitalizations attributable to young patients increased from 1995 to 2014 and was especially pronounced among women. History of hypertension and diabetes among young patients admitted with AMI increased over time as well. Compared with young men, young women presenting with AMI had a lower likelihood of receiving guideline-based AMI therapies. A better understanding of factors underlying these changes is needed to improve care of young patients with AMI
The FAITH and HEALTH Trials: Are We Studying Different Hip Fracture Patient Populations?
BACKGROUND: Over the past decade, 2 randomized controlled trials were performed to evaluate 2 surgical strategies (internal fixation and arthroplasty) for the treatment of low-energy femoral neck fractures in patients aged ā„50 years. We evaluated whether patient populations in both the FAITH and HEALTH trials had different baseline characteristics and compared the displaced femoral neck fracture cohort from the FAITH trial to HEALTH trial patients. METHODS: Patient demographics, medical comorbidities, and fracture characteristics from both trials were compared. FAITH trial patients with displaced fractures were then compared with HEALTH patients. T-tests and Ļ tests were performed to compare differences for sex, age, osteoporosis status, and ASA class. RESULTS: The mean age of the 1079 FAITH trial patients was 72 versus 79 years for the 1441 HEALTH trial patients. HEALTH patients were older, mostly White, used more medication, and had more comorbidities than FAITH patients. Of the 1079 FAITH trial patients, 32% (346/1079) had displaced fractures. Their mean age was significantly lower than that of HEALTH patients (66 vs. 79 years; P < 0.001). HEALTH trial patients were significantly more likely to be female, have ASA classification Class III/IV/V, and carry a diagnosis of osteoporosis, as compared with the subgroup of FAITH patients with displaced femoral neck fractures (P < 0.001). CONCLUSION: This study demonstrates significant differences between patients enrolled in the 2 trials. Although both studies focused on femoral neck fractures with similar enrollment criteria, patient
Using \u3csup\u3e19\u3c/sup\u3eF(\u3csup\u3e3\u3c/sup\u3eHe, t)\u3csup\u3e19\u3c/sup\u3eNe\u3csup\u3eā\u3c/sup\u3e(Ī³) to study astrophysically important levels near the \u3csup\u3e18\u3c/sup\u3eF+ p threshold
A direct test of nova explosion models comes from the observation of Ī³ rays created in the decay of radioactive isotopes produced in the nova. One such isotope, 18F, is believed to be the main source of observable Ī³ rays at and below 511 keV. The main destruction mechanism of 18F is thought to be the 18F(p,Ī±)15O reaction, and uncertainties in the reaction rate arise from uncertainties in the energies, spins, and parities of the nuclear levels in 19Ne above the 18F+p threshold. To measure the properties of these levels, the 19F(3He,t)19Ne-(Ī³) reaction was studied at Argonne National Laboratory and the Nuclear Science Laboratory at the University of Notre Dame
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