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Background A high minute ventilation/rate of carbon dioxide production (V̇E/V̇co2) slope during exercise is prognostic for cardiovascular death. Recent data indicate that adults with either controlled or untreated primary hypertension, but not those with uncontrolled hypertension, exhibit a higher V̇E/V̇co2 slope during exercise. However, the sample sizes were modest. Therefore, we used the Fitness Registry and the Importance of Exercise National Database to determine whether adults with hypertension, particularly those with controlled or untreated hypertension, exhibit higher V̇E/V̇co2 slopes compared with adults without hypertension. Methods and Results Using the Fitness Registry and the Importance of Exercise National Database, we isolated primary hypertension by excluding those with any disease other than hypertension or taking any medications other than antihypertension medications. We also excluded current smokers and those with obesity. The V̇E/V̇co2 slope was determined during a peak cycling exercise test. All data are presented as median [interquartile range]. We compared groups using linear regression adjusted for age, male/female, and body mass index. The characteristics of the entire sample (n=4109) were age, 42 [18] years; 48% women; body mass index, 26 [4] kg/m2. The V̇E/V̇co2 slope did not differ between adults with hypertension (n=1940; 24.7 [3.7]) compared with those without hypertension (n=2169; 24.9 [3.8]) (hypertension versus no hypertension, P=0.31; overall model: R2=0.07, F4,4104=73.0; P

A complex interplay of social, lifestyle, and physiological factors contribute to Black Americans having the highest blood pressure (BP) in America. One potential contributor to Black adult's higher BP may be reduced nitric oxide (NO) bioavailability. Therefore, we sought to determine whether augmenting NO bioavailability with acute beetroot juice (BRJ) supplementation would reduce resting BP and cardiovascular reactivity in Black and White adults, but to a greater extent in Black adults. A total of 18 Black and 20 White (∼equal split by biological sex) young adults completed this randomized, placebo-controlled (nitrate (NO3−)-depleted BRJ), crossover design study. We measured heart rate, brachial and central BP, and arterial stiffness (via pulse wave velocity) at rest, during handgrip exercise, and during post-exercise circulatory occlusion. Compared with White adults, Black adults exhibited higher pre-supplementation resting brachial and central BP (Ps ≤ 0.035; e.g., brachial systolic BP: 116(11) vs. 121(7) mmHg, P = 0.023). Compared with placebo, BRJ (∼12.8 mmol NO3−) reduced resting brachial systolic BP similarly in Black (Δ-4±10 mmHg) and White (Δ-4±7 mmHg) adults (P = 0.029). However, BRJ supplementation reduced BP in males (Ps ≤ 0.020) but not females (Ps ≥ 0.299). Irrespective of race or sex, increases in plasma NO3− were associated with reduced brachial systolic BP (ρ = −0.237, P = 0.042). No other treatment effects were observed for BP or arterial stiffness at rest or during physical stress (i.e., reactivity); Ps ≥ 0.075. Despite young Black adults having higher resting BP, acute BRJ supplementation reduced systolic BP in young Black and White adults by a similar magnitude, an effect that was driven by males.

Abstract Sub‐acute (e.g., inhalation injury) and/or acute insults sustained during a severe burn injury impairs pulmonary function. However, previous work has not fully characterized pulmonary function in adults with well‐healed burn injuries decades after an injury. Therefore, we tested the hypothesis that adults with well‐healed burn injuries have lower pulmonary function years after recovery. Our cohort of adults with well‐healed burn‐injuries (n = 41) had a lower forced expiratory volume in one second (Burn: 93 ± 16 vs. Control: 103 ± 10%predicted, mean ± SD; d = 0.60, p = 0.04), lower maximal voluntary ventilation (Burn: 84 [71–97] vs. Control: 105 [94–122] %predicted, median [IQR]; d = 0.84, p

Abstract A high sodium (Na+) meal impairs peripheral vascular function. In rodents, chronic high dietary Na+ impairs cerebral vascular function, and in humans, habitual high dietary Na+ is associated with increased stroke risk. However, the effects of acute high dietary Na+ on the cerebral vasculature in humans are unknown. The purpose of this study was to determine if acute high dietary Na+ impairs cerebrovascular reactivity in healthy adults. Thirty‐seven participants (20F/17M; 25 ± 5 years; blood pressure [BP]: 107 ± 9/61 ± 6 mm Hg) participated in this randomized, cross‐over study. Participants were given a low Na+ meal (LSM; 138 mg Na+) and a high Na+ meal (HSM; 1,495 mg Na+) separated by ≥ one week. Serum Na+, beat‐to‐beat BP, middle cerebral artery velocity (transcranial Doppler), and end‐tidal carbon dioxide (PETCO2) were measured pre‐ (baseline) and 60 min post‐prandial. Cerebrovascular reactivity was assessed by determining the percent change in middle cerebral artery velocity to hypercapnia (via 8% CO2, 21% oxygen, balance nitrogen) and hypocapnia (via mild hyperventilation). Peripheral vascular function was measured using brachial artery flow‐mediated dilation (FMD). Changes in serum Na+ were greater following the HSM (HSM: Δ1.6 ± 1.2 mmol/L vs. LSM: Δ0.7 ± 1.2 mmol/L, p

Abstract Older adults have reduced fluid intake and impaired body fluid and electrolyte regulation. Older female adults exhibit exaggerated exercise blood pressure (BP) responses, which is associated with an increased risk of adverse cardiovascular events. However, it is unclear if dysregulated body fluid homeostasis contributes to altered exercise BP responses in older female adults. We tested the hypothesis that short‐term water deprivation (WD) increases exercise BP responses in older female adults. Fifteen female adults (eight young [25 ± 6 years] and seven older [65 ± 6 years]) completed two experimental conditions in random crossover fashion; a euhydration control condition and a stepwise reduction in water intake over three days concluding with a 16‐hr WD period. During both trials, beat‐to‐beat BP (photoplethysmography) and heart rate (electrocardiogram) were continuously assessed during rest, handgrip exercise (30% MVC), and post‐exercise ischemia (metaboreflex isolation). At screening, older compared to young female adults had greater systolic and diastolic BP (p ≤ .02). Accelerometer‐assessed habitual physical activity was not different between groups (p = .65). Following WD, 24‐hr urine flow rate decreased, whereas thirst, urine specific gravity, and plasma osmolality increased (condition: p

Background High sodium (Na+) intake is a widespread cardiovascular disease risk factor. High Na+ intake impairs endothelial function and exaggerates sympathetic reflexes, which may augment exercising blood pressure (BP) responses. Therefore, this study examined the influence of high dietary Na+ on BP responses during submaximal aerobic exercise. Methods and Results Twenty adults (8F/12M, age=24±4 years; body mass index 23.0±0.6 kg·m−2; VO2peak=39.7±9.8 mL·min−1·kg−1; systolic BP=111±10 mm Hg; diastolic BP=64±8 mm Hg) participated in this randomized, double‐blind, placebo‐controlled crossover study. Total Na+ intake was manipulated via ingestion of capsules containing either a placebo (dextrose) or table salt (3900 mg Na+/day) for 10 days each, separated by ≥2 weeks. On day 10 of each intervention, endothelial function was assessed via flow‐mediated dilation followed by BP measurement at rest and during 50 minutes of cycling at 60% VO2peak. Throughout exercise, BP was assessed continuously via finger photoplethysmography and every 5 minutes via auscultation. Venous blood samples were collected at rest and during the final 10 minutes of exercise for assessment of norepinephrine. High Na+ intake increased urinary Na+ excretion (placebo=140±68 versus Na+=282±70 mmol·24H−1; P

The possibility of revealing the presence and identifying the nature of conductive targets is of central interest in many fields, including security, medicine, industry, archaeology and geophysics. In many applications, these targets are shielded by external materials and thus cannot be directly accessed. Hence, interrogation techniques are required that allow penetration through the shielding materials, in order for the target to be identified. Electromagnetic interrogation techniques represent a powerful solution to this challenge, as they enable penetration through conductive shields. In this work, we demonstrate the power of resonant electromagnetic induction imaging to penetrate through metallic shields (1.5-mm-thick) and image targets (having conductivities σ ranging from 0.54 to 59.77 MSm−1) concealed behind them.

The ability to image through metallic enclosures is an important goal of any scanning technology for security applications. Previous work demonstrated the penetrating power of electromagnetic imaging through thin metallic enclosures, thus validating the technique for security applications such as cargo screening. In this work we study the limits of electromagnetic imaging through metallic enclosures, considering the performance of the imaging for different thicknesses of the enclosure. Our results show, that our system can image a Copper disk, even when enclosed within a 20 mm thick Aluminum box. The potential for imaging through enclosures of other materials, such as Lead, Copper, and Iron, is discussed.