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The performance of modern laser-driven inertial confinement fusion (ICF) experiments is degraded by contamination of the deuterium-tritium (DT) fuel with high-Z material during compression. Simulations suggest that this mix can be described by the ion temperature distribution of the implosion, given that such contaminants deviate in temperature from the surrounding DT plasma. However, existing neutron time-of-flight (nTOF) diagnostics only measure the spatially integrated ion temperature. This paper describes the techniques and forward modeling used to develop a novel diagnostic imaging system to measure the spatially resolved ion temperature of an ICF implosion for the first time. The technique combines methods in neutron imaging and nTOF diagnostics to measure the ion temperature along one spatial dimension at yields currently achievable on the OMEGA laser. A detailed forward model of the source and imaging system was developed to guide instrument design. The model leverages neutron imaging reconstruction algorithms, radiation hydrodynamics and Monte Carlo simulations, optical ray tracing, and more. The results of the forward model agree with the data collected on OMEGA using the completed diagnostic. The analysis of the experimental data is still ongoing and will be discussed in a separate publication.
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Reduction of secondary ischemic stroke risk following an initial stroke is an important goal. The 2021 Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack assembles opportunities for up to 80% secondary stroke reduction. Homocysteine reduction was not included in the recommendations. The reduction of homocysteine with low doses of folic acid has been shown to reduce ischemic stroke and all stroke. This has been obscured by studies using high doses of folic acid and cyanocobalamin in patients with renal failure and Methylenetetrahydrofolate reductase (MTHFR) polymorphisms. The confounding impacts of high dose folic acid and cyanocobalamin toxicity in renal failure and MTHFR C677T subgroups are discussed. New studies show that their toxicity is due to non-bioequivalence to the natural dietary forms, L-methylfolate and methylcobalamin. Low doses of folic acid and cyanocobalamin are safer than high doses for these subpopulations. Even lower toxicity with greater effectiveness for reducing homocysteine is seen with L-methylfolate and methylcobalamin, which are safe at high doses. Retinal vascular imaging is a noninvasive method for evaluating central nervous system (CNS) microangiopathy. A formulation containing l-methylfolate and methylcobalamin has been shown to reduce homocysteine and increase perfusion in diabetic retinopathy. This supports homocysteine intervention for CNS ischemia. Future ischemic stroke intervention studies could benefit from monitoring retinal perfusion to estimate the impact of risk reduction strategies. The omission of a recommendation for homocysteine and secondary stroke reduction through the use of B vitamins should be reconsidered in light of re-analysis of major B vitamin intervention studies and new technologies for monitoring CNS perfusion. We recommend revision of the 2021 Guideline to include homocysteine reduction with low doses of folic acid and cyanocobalamin, or better yet, L-methylfolate and methylcobalamin, making a good clinical guideline better.
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INTRODUCTION: Sleep disorder is often the first symptom of age-related cognitive decline associated with Alzheimer's disease (AD) observed in primary care. The relationship between sleep and early AD was examined using a patented sleep mattress designed to record respiration and high frequency movement arousals. A machine learning algorithm was developed to classify sleep features associated with early AD. METHOD: Community-dwelling older adults (N = 95; 62-90 years) were recruited in a 3-h catchment area. Study participants were tested on the mattress device in the home bed for 2 days, wore a wrist actigraph for 7 days, and provided sleep diary and sleep disorder self-reports during the 1-week study period. Neurocognitive testing was completed in the home within 30-days of the sleep study. Participant performance on executive and memory tasks, health history and demographics were reviewed by a geriatric clinical team yielding Normal Cognition (n = 45) and amnestic MCI-Consensus (n = 33) groups. A diagnosed MCI group (n = 17) was recruited from a hospital memory clinic following diagnostic series of neuroimaging biomarker assessment and cognitive criteria for AD. RESULTS: In cohort analyses, sleep fragmentation and wake after sleep onset duration predicted poorer executive function, particularly memory performance. Group analyses showed increased sleep fragmentation and total sleep time in the diagnosed MCI group compared to the Normal Cognition group. Machine learning algorithm showed that the time latency between movement arousals and coupled respiratory upregulation could be used as a classifier of diagnosed MCI vs. Normal Cognition cases. ROC diagnostics identified MCI with 87% sensitivity; 89% specificity; and 88% positive predictive value. DISCUSSION: AD sleep phenotype was detected with a novel sleep biometric, time latency, associated with the tight gap between sleep movements and respiratory coupling, which is proposed as a corollary of sleep quality/loss that affects the autonomic regulation of respiration during sleep. Diagnosed MCI was associated with sleep fragmentation and arousal intrusion.
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Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/psicologia , Privação do Sono/complicações , Disfunção Cognitiva/psicologia , Cognição , Sono , Testes NeuropsicológicosRESUMO
Contact and projection electron radiography of static targets was demonstrated using a laser-plasma accelerator driven by a kilojoule, picosecond-class laser as a source of relativistic electrons with an average energy of 20 MeV. Objects with areal densities as high as 7.7 g/cm2 were probed in materials ranging from plastic to tungsten, and radiographs with resolution as good as 90 µm were produced. The effects of electric fields produced by the laser ablation of the radiography objects were observed and are well described by an analytic expression relating imaging magnification change to electric-field strength.
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Associations between fermented dairy products and blood pressure are unclear. The current study therefore examined the association between yogurt and blood pressure in hypertensive and non-hypertensive individuals. Cross-sectional analyses were undertaken on 915 community-dwelling adults from the Maine-Syracuse Longitudinal Study. Habitual yogurt consumption was measured using a food frequency questionnaire. The primary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure. Secondary outcomes included BMI (kg m-2), total cholesterol (mg dL-1), glucose (mg dL-1), HDL (mg dL-1), LDL (mg dL-1), triglycerides (mg dL-1), and plasma homocysteine (µmol L-1). Multivariable regression analyses revealed significant inverse associations between yogurt and both SBP (p < 0.05) and MAP (p < 0.05) in hypertensive (n = 564) but not non-hypertensive participants (n = 351). Future observational and intervention studies should continue to focus on at-risk individuals to examine the potential benefits of yogurt.
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Background: Adherence to a Mediterranean diet is associated with higher cognitive function and reduced risk of dementia in Mediterranean populations. However, few studies have investigated the association between Mediterranean diet adherence and cognition in populations outside of the Mediterranean basin. Furthermore, it is currently unknown whether the association between Mediterranean diet adherence and cognitive function differs between middle-aged and older individuals.Methods: Cross-sectional (n = 894) and longitudinal (n = 530) multivariable analyses were undertaken using data from community-dwelling adults from the Maine-Syracuse Longitudinal Study (MSLS). Mediterranean diet adherence was measured by applying a literature-based Mediterranean diet score to food frequency questionnaire data. Cognitive function was assessed with a battery of tests and composites scores were computed for global cognitive function, Visual-Spatial Organisation and Memory, verbal memory, working memory, scanning and tracking and abstract reasoning.Results: No cross-sectional associations between Mediterranean diet adherence and cognitive function were detected. Over a period of five years, higher adherence to a Mediterranean diet was associated with improvements in Global Cognitive Function, Visual-Spatial Organisation and Memory and scanning and tracking in participants ≥70 years. No significant longitudinal associations were observed for participants <70 years.Conclusion: Our findings suggest that higher adherence to a Mediterranean diet is associated with better cognitive performance, and therefore less cognitive decline, in older but not middle-aged individuals.
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Cognição , Dieta Mediterrânea , Idoso , Estudos Transversais , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-IdadeRESUMO
In this review of the literature and commentary, we examine the literature on automated blood pressure (BP) measurements in the office and clinic. Our purpose is to revisit issues as to the pros and cons of automated BP measurement published in Hypertension in June 2020 and to identify areas needing additional research. Despite initial reservations about automated BP, it is here to stay. A number of experts suggest that human error will be reduced when we move from the more complex skills required by aneroid sphygmomanometer measurement to the fewer skills and steps required by automated BP measurement. Our review indicates there is still need for reduction in errors in automated BP assessment, for example, retraining programs and monitoring of assessment procedures. We need more research on the following questions: (1) which classes of health care providers are least likely to measure BP accurately, usually by ignoring necessary steps; (2) how accurate is BP assessment by affiliated health care providers for example the dental office, the optometrist; and (3) why do some dedicated and well-informed health care professionals fail to follow simple directions for automated BP measurement? We offer additional solutions for improving automated BP assessment in the office and clinic.
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Determinação da Pressão Arterial/métodos , Automação , Determinação da Pressão Arterial/economia , Determinação da Pressão Arterial/normas , Erros de Diagnóstico , Pessoal de Saúde , HumanosRESUMO
Hypertension is a key modifiable risk factor for cardiovascular disease. The Mediterranean diet (MedDiet) may be associated with improvements in blood pressure. However, few studies have examined the association between MedDiet adherence and blood pressure in non-Mediterranean populations, and findings are mixed. We analyzed cross-sectional data (Wave 6) for 851 participants of the Maine-Syracuse Longitudinal Study. MedDiet adherence was calculated using food frequency questionnaire data and a literature-based MedDiet adherence score. Dependent variables included systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and mean arterial pressure (MAP). Separate linear robust regression analyses revealed significant associations between MedDiet adherence and for SBP (b = -0.69, 95% CI = [-1.25, -0.20]), DBP (b = -0.33, 95% CI = [-0.58, -0.04]), and MAP (b = -0.45, 95% CI = [-0.77, -0.11]), but not for PP. These findings indicate that the MedDiet is associated with some metrics of blood pressure in a large, community-based, non-Mediterranean sample.
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Dieta Mediterrânea , Hipertensão , Pressão Sanguínea , Estudos Transversais , Humanos , Hipertensão/epidemiologia , Hipertensão/prevenção & controle , Estudos LongitudinaisRESUMO
A recent meta-analysis identified a prospective association between depression and cardiovascular disease; however, there was no association for studies with long-term follow-up periods. The literature has primarily focused on baseline depression status or symptoms, which may not capture the chronic nature of depression. This study examined the prospective relationship between depressive symptoms and cardiovascular disease up to 15 years later in 274 cardiovascular disease-free older adults. Depressive and anxiety symptoms, mean arterial pressure, and cardiovascular disease status were assessed. Baseline and chronic depressive symptoms predicted increased risk of cardiovascular disease, underscoring the importance of assessing and treating depression in older adults.
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Doenças Cardiovasculares , Depressão , Idoso , Doenças Cardiovasculares/epidemiologia , Depressão/epidemiologia , Humanos , Estudos Longitudinais , Maine , Estudos Prospectivos , Fatores de RiscoRESUMO
This study compared the intake of yogurt and other dairy foods in relation to other dietary habits, and associations with cardiovascular health indicators. Comparative analyses of dietary intakes and cardiometabolic health indicators were conducted in participants from the Maine-Syracuse Longitudinal Study, conducted in 2001-2006 (n = 699). Participants (10.2% of sample) who consumed yogurt more frequently (≥ 5 serves per week) also consumed more fruit, vegetables, nuts, and fish, but fewer sweets, sugar-sweetened soft drinks, and alcohol. The yogurt-healthy food score was significantly inversely associated with fasting plasma glucose (p = 0.044), waist circumference (p = 0.004), and smoking (p = 0.004), and significantly positively associated with physical activity (p < 0.001). In addition, the yogurt-healthy food score was associated with protection against MetS abdominal obesity (OR: 0.80, 95% CI: 0.66-0.07, p = 0.02). The yogurt-healthy dietary pattern was significantly associated with a better cardiometabolic profile.
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Disfunção Cognitiva , Idoso , Pressão Sanguínea , Diástole , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , SístoleRESUMO
OBJECTIVES: Prior studies have found associations between visual acuity (VA) and cognitive function. However, these studies used a limited range of cognitive measures and did not control for cardiovascular disease risk factors (CVD-RFs) and baseline function. The primary objective of this study was to analyze the associations of VA and cognitive performance using a thorough neuropsychological test battery. METHODS: This study used community-dwelling sample data across the sixth (2001-2006) and seventh (2006-2010) waves of the Maine-Syracuse Longitudinal Study (n=655). Wave 6 VA as measured by the Snellen Eye Test was the primary predictor of wave 6 and wave 7 Global cognitive performance, Visual-Spatial Organization and Memory, Verbal Episodic Memory, Working Memory, Scanning and Tracking, and Executive Function. Additionally, VA was used to predict longitudinal changes in wave 7 cognitive performance (wave 6 performance adjusted). We analyzed these relationships with multiple linear and logistic regression models adjusted for age, sex, education, ethnicity, depressive symptoms, physical function deficits in addition to CVD-RFs, chronic kidney disease, homocysteine, continuous systolic blood pressure, and hypertension status. RESULTS: Adjusted for demographic covariates and CVD-RFs, poorer VA was associated with concurrent and approximate 5-year declines in Global cognitive function, Visual-Spatial Organization and Memory, and Verbal Episodic Memory. DISCUSSION: VA may be used in combination with other screening measures to determine risk for cognitive decline. (JINS, 2018, 24, 746-754).