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Sample records for altered cardiac energetics

  1. Multiscale measurement of cardiac energetics.

    Science.gov (United States)

    Goo, Soyeon; Pham, Toan; Han, Jun-Chiew; Nielsen, Poul; Taberner, Andrew; Hickey, Anthony; Loiselle, Denis

    2013-09-01

    Herein we describe our laboratories' experimental methods for interrogating cardiac energetics at the organ (whole heart), tissue (trabecula) and perforated fibre (mitochondrial) levels. In whole heart and trabecula experiments, we focus on measuring pressure-volume (force-length) work and oxygen consumption (heat production) from which mechanical efficiency is derived. In both preparations (i.e. across scales differing by three orders of magnitude) we find efficiency values of 10%-15%. Mitochondrial experiments invoke a trio of titration protocols to yield information on oxygen consumption, ATP flux, membrane potential, electron leak and reactive oxygen species production, the latter two of which index energy transfer inefficiencies. Copyright © 2013 Wiley Publishing Asia Pty Ltd.

  2. ENERGETIC VENTRICULAR BALANCE DURING CARDIAC RESYNCHRONIZATION THERAPY: NUMERICAL SIMULATION

    OpenAIRE

    De Lazzari, Claudio; Alessandri, Nicola

    2011-01-01

    Cardiac Resynchronization Therapy (CRT), realised using biventricular pacemaker is used to treat patients with in systolic heart failure (HF) and with prolonged QRS. The goal of CRT is to eliminate or reduce the electromechanical dyssynchrony processes often responsible of cardiac remodelling. The aim of this work is to study the effects of CRT on the energetic left ventricular variables as external work, the pressure-volume area and the potential energy. In order to study the effects produce...

  3. Determination of myocardial energetic output for cardiac rhythm pacing

    Czech Academy of Sciences Publication Activity Database

    Heřman, D.; Převorovská, Světlana; Maršík, František

    2007-01-01

    Roč. 7, č. 4 (2007), s. 156-161 ISSN 1567-8822 R&D Projects: GA ČR GA106/03/1073 Institutional research plan: CEZ:AV0Z20760514 Keywords : heart arrhythmia * cardiac pacing modes * numerical simulation Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  4. Photochemical Reaction Altered Cardiac Toxicity of Diesel Exhaust Inhalation

    Science.gov (United States)

    Rationale: Epidemiological studies have indicated an association between urban air pollution exposure and cardiovascular morbidity and mortality. The present study was designed to evaluate the cardiac effects of inhaled diesel exhaust and compared with photochemically altered d...

  5. The Mitochondrial Calcium Uniporter Matches Energetic Supply with Cardiac Workload during Stress and Modulates Permeability Transition

    Directory of Open Access Journals (Sweden)

    Timothy S. Luongo

    2015-07-01

    Full Text Available Cardiac contractility is mediated by a variable flux in intracellular calcium (Ca2+, thought to be integrated into mitochondria via the mitochondrial calcium uniporter (MCU channel to match energetic demand. Here, we examine a conditional, cardiomyocyte-specific, mutant mouse lacking Mcu, the pore-forming subunit of the MCU channel, in adulthood. Mcu−/− mice display no overt baseline phenotype and are protected against mCa2+ overload in an in vivo myocardial ischemia-reperfusion injury model by preventing the activation of the mitochondrial permeability transition pore, decreasing infarct size, and preserving cardiac function. In addition, we find that Mcu−/− mice lack contractile responsiveness to acute β-adrenergic receptor stimulation and in parallel are unable to activate mitochondrial dehydrogenases and display reduced bioenergetic reserve capacity. These results support the hypothesis that MCU may be dispensable for homeostatic cardiac function but required to modulate Ca2+-dependent metabolism during acute stress.

  6. Hypothyroidism and its rapid correction alter cardiac remodeling.

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    Georges Hajje

    Full Text Available The cardiovascular effects of mild and overt thyroid disease include a vast array of pathological changes. As well, thyroid replacement therapy has been suggested for preserving cardiac function. However, the influence of thyroid hormones on cardiac remodeling has not been thoroughly investigated at the molecular and cellular levels. The purpose of this paper is to study the effect of hypothyroidism and thyroid replacement therapy on cardiac alterations. Thirty Wistar rats were divided into 2 groups: a control (n = 10 group and a group treated with 6-propyl-2-thiouracil (PTU (n = 20 to induce hypothyroidism. Ten of the 20 rats in the PTU group were then treated with L-thyroxine to quickly re-establish euthyroidism. The serum levels of inflammatory markers, such as C-reactive protein (CRP, tumor necrosis factor alpha (TNF-α, interleukin 6 (IL6 and pro-fibrotic transforming growth factor beta 1 (TGF-β1, were significantly increased in hypothyroid rats; elevations in cardiac stress markers, brain natriuretic peptide (BNP and cardiac troponin T (cTnT were also noted. The expressions of cardiac remodeling genes were induced in hypothyroid rats in parallel with the development of fibrosis, and a decline in cardiac function with chamber dilation was measured by echocardiography. Rapidly reversing the hypothyroidism and restoring the euthyroid state improved cardiac function with a decrease in the levels of cardiac remodeling markers. However, this change further increased the levels of inflammatory and fibrotic markers in the plasma and heart and led to myocardial cellular infiltration. In conclusion, we showed that hypothyroidism is related to cardiac function decline, fibrosis and inflammation; most importantly, the rapid correction of hypothyroidism led to cardiac injuries. Our results might offer new insights for the management of hypothyroidism-induced heart disease.

  7. Hypothyroidism and its rapid correction alter cardiac remodeling.

    Science.gov (United States)

    Hajje, Georges; Saliba, Youakim; Itani, Tarek; Moubarak, Majed; Aftimos, Georges; Farès, Nassim

    2014-01-01

    The cardiovascular effects of mild and overt thyroid disease include a vast array of pathological changes. As well, thyroid replacement therapy has been suggested for preserving cardiac function. However, the influence of thyroid hormones on cardiac remodeling has not been thoroughly investigated at the molecular and cellular levels. The purpose of this paper is to study the effect of hypothyroidism and thyroid replacement therapy on cardiac alterations. Thirty Wistar rats were divided into 2 groups: a control (n = 10) group and a group treated with 6-propyl-2-thiouracil (PTU) (n = 20) to induce hypothyroidism. Ten of the 20 rats in the PTU group were then treated with L-thyroxine to quickly re-establish euthyroidism. The serum levels of inflammatory markers, such as C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL6) and pro-fibrotic transforming growth factor beta 1 (TGF-β1), were significantly increased in hypothyroid rats; elevations in cardiac stress markers, brain natriuretic peptide (BNP) and cardiac troponin T (cTnT) were also noted. The expressions of cardiac remodeling genes were induced in hypothyroid rats in parallel with the development of fibrosis, and a decline in cardiac function with chamber dilation was measured by echocardiography. Rapidly reversing the hypothyroidism and restoring the euthyroid state improved cardiac function with a decrease in the levels of cardiac remodeling markers. However, this change further increased the levels of inflammatory and fibrotic markers in the plasma and heart and led to myocardial cellular infiltration. In conclusion, we showed that hypothyroidism is related to cardiac function decline, fibrosis and inflammation; most importantly, the rapid correction of hypothyroidism led to cardiac injuries. Our results might offer new insights for the management of hypothyroidism-induced heart disease.

  8. Caffeine exposure alters cardiac gene expression in embryonic cardiomyocytes

    Science.gov (United States)

    Fang, Xiefan; Mei, Wenbin; Barbazuk, William B.; Rivkees, Scott A.

    2014-01-01

    Previous studies demonstrated that in utero caffeine treatment at embryonic day (E) 8.5 alters DNA methylation patterns, gene expression, and cardiac function in adult mice. To provide insight into the mechanisms, we examined cardiac gene and microRNA (miRNA) expression in cardiomyocytes shortly after exposure to physiologically relevant doses of caffeine. In HL-1 and primary embryonic cardiomyocytes, caffeine treatment for 48 h significantly altered the expression of cardiac structural genes (Myh6, Myh7, Myh7b, Tnni3), hormonal genes (Anp and BnP), cardiac transcription factors (Gata4, Mef2c, Mef2d, Nfatc1), and microRNAs (miRNAs; miR208a, miR208b, miR499). In addition, expressions of these genes were significantly altered in embryonic hearts exposed to in utero caffeine. For in utero experiments, pregnant CD-1 dams were treated with 20–60 mg/kg of caffeine, which resulted in maternal circulation levels of 37.3–65.3 μM 2 h after treatment. RNA sequencing was performed on embryonic ventricles treated with vehicle or 20 mg/kg of caffeine daily from E6.5-9.5. Differential expression (DE) analysis revealed that 124 genes and 849 transcripts were significantly altered, and differential exon usage (DEU) analysis identified 597 exons that were changed in response to prenatal caffeine exposure. Among the DE genes identified by RNA sequencing were several cardiac structural genes and genes that control DNA methylation and histone modification. Pathway analysis revealed that pathways related to cardiovascular development and diseases were significantly affected by caffeine. In addition, global cardiac DNA methylation was reduced in caffeine-treated cardiomyocytes. Collectively, these data demonstrate that caffeine exposure alters gene expression and DNA methylation in embryonic cardiomyocytes. PMID:25354728

  9. Caffeine exposure alters cardiac gene expression in embryonic cardiomyocytes.

    Science.gov (United States)

    Fang, Xiefan; Mei, Wenbin; Barbazuk, William B; Rivkees, Scott A; Wendler, Christopher C

    2014-12-15

    Previous studies demonstrated that in utero caffeine treatment at embryonic day (E) 8.5 alters DNA methylation patterns, gene expression, and cardiac function in adult mice. To provide insight into the mechanisms, we examined cardiac gene and microRNA (miRNA) expression in cardiomyocytes shortly after exposure to physiologically relevant doses of caffeine. In HL-1 and primary embryonic cardiomyocytes, caffeine treatment for 48 h significantly altered the expression of cardiac structural genes (Myh6, Myh7, Myh7b, Tnni3), hormonal genes (Anp and BnP), cardiac transcription factors (Gata4, Mef2c, Mef2d, Nfatc1), and microRNAs (miRNAs; miR208a, miR208b, miR499). In addition, expressions of these genes were significantly altered in embryonic hearts exposed to in utero caffeine. For in utero experiments, pregnant CD-1 dams were treated with 20-60 mg/kg of caffeine, which resulted in maternal circulation levels of 37.3-65.3 μM 2 h after treatment. RNA sequencing was performed on embryonic ventricles treated with vehicle or 20 mg/kg of caffeine daily from E6.5-9.5. Differential expression (DE) analysis revealed that 124 genes and 849 transcripts were significantly altered, and differential exon usage (DEU) analysis identified 597 exons that were changed in response to prenatal caffeine exposure. Among the DE genes identified by RNA sequencing were several cardiac structural genes and genes that control DNA methylation and histone modification. Pathway analysis revealed that pathways related to cardiovascular development and diseases were significantly affected by caffeine. In addition, global cardiac DNA methylation was reduced in caffeine-treated cardiomyocytes. Collectively, these data demonstrate that caffeine exposure alters gene expression and DNA methylation in embryonic cardiomyocytes. Copyright © 2014 the American Physiological Society.

  10. Alterations in cardiac autonomic control in spinal cord injury.

    Science.gov (United States)

    Biering-Sørensen, Fin; Biering-Sørensen, Tor; Liu, Nan; Malmqvist, Lasse; Wecht, Jill Maria; Krassioukov, Andrei

    2018-01-01

    A spinal cord injury (SCI) interferes with the autonomic nervous system (ANS). The effect on the cardiovascular system will depend on the extent of damage to the spinal/central component of ANS. The cardiac changes are caused by loss of supraspinal sympathetic control and relatively increased parasympathetic cardiac control. Decreases in sympathetic activity result in heart rate and the arterial blood pressure changes, and may cause arrhythmias, in particular bradycardia, with the risk of cardiac arrest in those with cervical or high thoracic injuries. The objective of this review is to give an update of the current knowledge related to the alterations in cardiac autonomic control following SCI. With this purpose the review includes the following subheadings: 2. Neuro-anatomical plasticity and cardiac control 2.1 Autonomic nervous system and the heart 2.2 Alteration in autonomic control of the heart following spinal cord injury 3. Spinal shock and neurogenic shock 3.1 Pathophysiology of spinal shock 3.2 Pathophysiology of neurogenic shock 4. Autonomic dysreflexia 4.1 Pathophysiology of autonomic dysreflexia 4.2 Diagnosis of autonomic dysreflexia 5. Heart rate/electrocardiography following spinal cord injury 5.1 Acute phase 5.2 Chronic phase 6. Heart rate variability 6.1 Time domain analysis 6.2 Frequency domain analysis 6.3 QT-variability index 6.4 Nonlinear (fractal) indexes 7. Echocardiography 7.1 Changes in cardiac structure following spinal cord injury 7.2 Changes in cardiac function following spinal cord injury 8. International spinal cord injury cardiovascular basic data set and international standards to document the remaining autonomic function in spinal cord injury. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Comparison of the Gibbs and Suga formulations of cardiac energetics: the demise of “isoefficiency”

    Science.gov (United States)

    Han, J.-C.; Taberner, A. J.; Tran, K.; Goo, S.; Nickerson, D. P.; Nash, M. P.; Nielsen, P. M. F.; Crampin, E. J.

    2012-01-01

    Two very different sorts of experiments have characterized the field of cardiac energetics over the past three decades. In one of these, Gibbs and colleagues measured the heat production of isolated papillary muscles undergoing isometric contractions and afterloaded isotonic contractions. The former generated roughly linear heat vs. force relationships. The latter generated enthalpy-load relationships, the peak values of which occurred at or near peak isometric force, i.e., at a relative load of unity. Contractile efficiency showed a pronounced dependence on afterload. By contrast, Suga and coworkers measured the oxygen consumption (V̇o2) while recording the pressure-volume-time work loops of blood-perfused isolated dog hearts. From the associated (linear) end-systolic pressure-volume relations they derived a quantity labeled pressure-volume area (PVA), consisting of the sum of pressure-volume work and unspent elastic energy and showed that this was linearly correlated with V̇o2 over a wide range of conditions. This linear dependence imposed isoefficiency: constant contractile efficiency independent of afterload. Neither these data nor those of Gibbs and colleagues are in dispute. Nevertheless, despite numerous attempts over the years, no demonstration of either compatibility or incompatibility of these disparate characterizations of cardiac energetics has been forthcoming. We demonstrate that compatibility between the two formulations is thwarted by the concept of isoefficiency, the thermodynamic basis of which we show to be untenable. PMID:22879535

  12. Comparison of the Gibbs and Suga formulations of cardiac energetics: the demise of "isoefficiency".

    Science.gov (United States)

    Han, J-C; Taberner, A J; Tran, K; Goo, S; Nickerson, D P; Nash, M P; Nielsen, P M F; Crampin, E J; Loiselle, D S

    2012-10-01

    Two very different sorts of experiments have characterized the field of cardiac energetics over the past three decades. In one of these, Gibbs and colleagues measured the heat production of isolated papillary muscles undergoing isometric contractions and afterloaded isotonic contractions. The former generated roughly linear heat vs. force relationships. The latter generated enthalpy-load relationships, the peak values of which occurred at or near peak isometric force, i.e., at a relative load of unity. Contractile efficiency showed a pronounced dependence on afterload. By contrast, Suga and coworkers measured the oxygen consumption (Vo(2)) while recording the pressure-volume-time work loops of blood-perfused isolated dog hearts. From the associated (linear) end-systolic pressure-volume relations they derived a quantity labeled pressure-volume area (PVA), consisting of the sum of pressure-volume work and unspent elastic energy and showed that this was linearly correlated with Vo(2) over a wide range of conditions. This linear dependence imposed isoefficiency: constant contractile efficiency independent of afterload. Neither these data nor those of Gibbs and colleagues are in dispute. Nevertheless, despite numerous attempts over the years, no demonstration of either compatibility or incompatibility of these disparate characterizations of cardiac energetics has been forthcoming. We demonstrate that compatibility between the two formulations is thwarted by the concept of isoefficiency, the thermodynamic basis of which we show to be untenable.

  13. Cardiac energetics analysis after aortic valve replacement with 16-mm ATS mechanical valve.

    Science.gov (United States)

    Ushijima, Tomoki; Tanoue, Yoshihisa; Uchida, Takayuki; Matsuyama, Sho; Matsumoto, Takashi; Tominaga, Ryuji

    2014-09-01

    The 16-mm ATS mechanical valve is one of the smallest prosthetic valves used for aortic valve replacement (AVR) in patients with a very small aortic annulus, and its clinical outcomes are reportedly satisfactory. Here, we analyzed the left ventricular (LV) performance after AVR with the 16-mm ATS mechanical valve, based on the concept of cardiac energetics analysis. Eleven patients who underwent AVR with the 16-mm ATS mechanical valve were enrolled in this study. All underwent echocardiographic examination at three time points: before AVR, approximately 1 month after AVR, and approximately 1 year after AVR. LV contractility (end-systolic elastance [Ees]), afterload (effective arterial elastance [Ea]), and efficiency (ventriculoarterial coupling [Ea/Ees] and the stroke work to pressure-volume area ratio [SW/PVA]) were noninvasively measured by echocardiographic data and blood pressure measurement. Ees transiently decreased after AVR and then recovered to the pre-AVR level at the one-year follow-up. Ea significantly decreased in a stepwise manner. Consequently, Ea/Ees and SW/PVA were also significantly improved at the one-year follow-up compared with those before AVR. The midterm LV performance after AVR with the 16-mm ATS mechanical valve was satisfactory. AVR with the 16-mm ATS mechanical valve is validated as an effective treatment for patients with a very small aortic annulus. The cardiac energetics variables, coupling with the conventional hemodynamic variables, can contribute to a better understanding of the patients' clinical conditions, and those may serve as promising indices of the cardiac function.

  14. ENerGetIcs in hypertrophic cardiomyopathy: traNslation between MRI, PET and cardiac myofilament function (ENGINE study).

    Science.gov (United States)

    Güçlü, A; Germans, T; Witjas-Paalberends, E R; Stienen, G J M; Brouwer, W P; Harms, H J; Marcus, J T; Vonk, A B A; Stooker, W; Yilmaz, A; Klein, P; Ten Berg, J M; Kluin, J; Asselbergs, F W; Lammertsma, A A; Knaapen, P; van Rossum, A C; van der Velden, J

    2013-12-01

    Hypertrophic cardiomyopathy (HCM) is an autosomal dominant heart disease mostly due to mutations in genes encoding sarcomeric proteins. HCM is characterised by asymmetric hypertrophy of the left ventricle (LV) in the absence of another cardiac or systemic disease. At present it lacks specific treatment to prevent or reverse cardiac dysfunction and hypertrophy in mutation carriers and HCM patients. Previous studies have indicated that sarcomere mutations increase energetic costs of cardiac contraction and cause myocardial dysfunction and hypertrophy. By using a translational approach, we aim to determine to what extent disturbances of myocardial energy metabolism underlie disease progression in HCM. Hypertrophic obstructive cardiomyopathy (HOCM) patients and aortic valve stenosis (AVS) patients will undergo a positron emission tomography (PET) with acetate and cardiovascular magnetic resonance imaging (CMR) with tissue tagging before and 4 months after myectomy surgery or aortic valve replacement + septal biopsy. Myectomy tissue or septal biopsy will be used to determine efficiency of sarcomere contraction in-vitro, and results will be compared with in-vivo cardiac performance. Healthy subjects and non-hypertrophic HCM mutation carriers will serve as a control group. Our study will reveal whether perturbations in cardiac energetics deteriorate during disease progression in HCM and whether these changes are attributed to cardiac remodelling or the presence of a sarcomere mutation per se. In-vitro studies in hypertrophied cardiac muscle from HOCM and AVS patients will establish whether sarcomere mutations increase ATP consumption of sarcomeres in human myocardium. Our follow-up imaging study in HOCM and AVS patients will reveal whether impaired cardiac energetics are restored by cardiac surgery.

  15. TNFα Modulates Cardiac Conduction by Altering Electrical Coupling between Myocytes

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    Sharon A. George

    2017-05-01

    Full Text Available Background: Tumor Necrosis Factor α (TNFα upregulation during acute inflammatory response has been associated with numerous cardiac effects including modulating Connexin43 and vascular permeability. This may in turn alter cardiac gap junctional (GJ coupling and extracellular volume (ephaptic coupling respectively. We hypothesized that acute exposure to pathophysiological TNFα levels can modulate conduction velocity (CV in the heart by altering electrical coupling: GJ and ephaptic.Methods and Results: Hearts were optically mapped to determine CV from control, TNFα and TNFα + high calcium (2.5 vs. 1.25 mM treated guinea pig hearts over 90 mins. Transmission electron microscopy was performed to measure changes in intercellular separation in the gap junction-adjacent extracellular nanodomain—perinexus (WP. Cx43 expression and phosphorylation were determined by Western blotting and Cx43 distribution by confocal immunofluorescence. At 90 mins, longitudinal and transverse CV (CVL and CVT, respectively increased with control Tyrode perfusion but TNFα slowed CVT alone relative to control and anisotropy of conduction increased, but not significantly. TNFα increased WP relative to control at 90 mins, without significantly changing GJ coupling. Increasing extracellular calcium after 30 mins of just TNFα exposure increased CVT within 15 mins. TNFα + high calcium also restored CVT at 90 mins and reduced WP to control values. Interestingly, TNFα + high calcium also improved GJ coupling at 90 mins, which along with reduced WP may have contributed to increasing CV.Conclusions: Elevating extracellular calcium during acute TNFα exposure reduces perinexal expansion, increases ephaptic, and GJ coupling, improves CV and may be a novel method for preventing inflammation induced CV slowing.

  16. Methylphenidate treatment causes oxidative stress and alters energetic metabolism in an animal model of attention-deficit hyperactivity disorder.

    Science.gov (United States)

    Comim, Clarissa M; Gomes, Karin M; Réus, Gislaine Z; Petronilho, Fabrícia; Ferreira, Gabriela K; Streck, Emílio L; Dal-Pizzol, Felipe; Quevedo, João

    2014-04-01

    To evaluate oxidative damage through the thiobarbituric acid-reactive species (TBARS) and protein carbonyl groups; antioxidant enzymatic system - superoxide dismutase (SOD) and catalase (CAT); and energetic metabolism in the brain of spontaneously hypertensive adult rats (SHR) after both acute and chronic treatment with methylphenidate hydrochloride (MPH). Adult (60 days old) SHRs were treated during 28 days (chronic treatment), or 1 day (acute treatment). The rats received one i.p. injection per day of either saline or MPH (2 mg/kg). Two hours after the last injection, oxidative damage parameters and energetic metabolism in the cerebellum, prefrontal cortex, hippocampus, striatum and cortex were evaluated. We observed that both acute and/or chronic treatment increased TBARS and carbonyl groups, and decreased SOD and CAT activities in many of the brain structures evaluated. Regarding the energetic metabolism evaluation, the acute and chronic treatment altered the energetic metabolism in many of the brain structures evaluated. We observed that both acute and chronic use of methylphenidate hydrochloride (MPH) in adult spontaneously hypertensive rats (SHRs) was associated with increased oxidative stress and energetic metabolism alterations. These data also reinforce the importance of the SHR animal model in further studies regarding MPH.

  17. Alterations in cardiac autonomic control in spinal cord injury

    DEFF Research Database (Denmark)

    Biering-Sørensen, Fin; Biering-Sørensen, Tor; Liu, Nan

    2018-01-01

    parasympathetic cardiac control. Decreases in sympathetic activity result in heart rate and the arterial blood pressure changes, and may cause arrhythmias, in particular bradycardia, with the risk of cardiac arrest in those with cervical or high thoracic injuries. The objective of this review is to give an update...

  18. Focused cardiac ultrasound is feasible in the general practice setting and alters diagnosis and management of cardiac disease

    Directory of Open Access Journals (Sweden)

    James Yates

    2016-08-01

    Full Text Available Background: Ultrasound-assisted examination of the cardiovascular system with focused cardiac ultrasound by the treating physician is non-invasive and changes diagnosis and management of patient’s with suspected cardiac disease. This has not been reported in a general practice setting. Aim: To determine whether focused cardiac ultrasound performed on patients aged over 50 years changes the diagnosis and management of cardiac disease by a general practitioner. Design and setting: A prospective observational study of 80 patients aged over 50 years and who had not received echocardiography or chest CT within 12 months presenting to a general practice. Method: Clinical assessment and management of significant cardiac disorders in patients presenting to general practitioners were recorded before and after focused cardiac ultrasound. Echocardiography was performed by a medical student with sufficient training, which was verified by an expert. Differences in diagnosis and management between conventional and ultrasound-assisted assessment were recorded. Results and conclusion: Echocardiography and interpretation were acceptable in all patients. Significant cardiac disease was detected in 16 (20% patients, including aortic stenosis in 9 (11% and cardiac failure in 7 (9%, which were missed by clinical examination in 10 (62.5% of these patients. Changes in management occurred in 12 patients (15% overall and 75% of those found to have significant cardiac disease including referral for diagnostic echocardiography in 8 (10%, commencement of heart failure treatment in 3 (4% and referral to a cardiologist in 1 patient (1%. Routine focused cardiac ultrasound is feasible and frequently alters the diagnosis and management of cardiac disease in patients aged over 50 years presenting to a general practice.

  19. Warming alters energetic structure and function but not resilience of soil food webs

    Science.gov (United States)

    Schwarz, Benjamin; Barnes, Andrew D.; Thakur, Madhav P.; Brose, Ulrich; Ciobanu, Marcel; Reich, Peter B.; Rich, Roy L.; Rosenbaum, Benjamin; Stefanski, Artur; Eisenhauer, Nico

    2017-12-01

    Climate warming is predicted to alter the structure, stability, and functioning of food webs1-5. Yet, despite the importance of soil food webs for energy and nutrient turnover in terrestrial ecosystems, the effects of warming on these food webs—particularly in combination with other global change drivers—are largely unknown. Here, we present results from two complementary field experiments that test the interactive effects of warming with forest canopy disturbance and drought on energy flux in boreal-temperate ecotonal forest soil food webs. The first experiment applied a simultaneous above- and belowground warming treatment (ambient, +1.7 °C, +3.4 °C) to closed-canopy and recently clear-cut forest, simulating common forest disturbance6. The second experiment crossed warming with a summer drought treatment (-40% rainfall) in the clear-cut habitats. We show that warming reduces energy flux to microbes, while forest canopy disturbance and drought facilitates warming-induced increases in energy flux to higher trophic levels and exacerbates the reduction in energy flux to microbes, respectively. Contrary to expectations, we find no change in whole-network resilience to perturbations, but significant losses in ecosystem functioning. Warming thus interacts with forest disturbance and drought, shaping the energetic structure of soil food webs and threatening the provisioning of multiple ecosystem functions in boreal-temperate ecotonal forests.

  20. Correlation of cardiac performance with cellular energetic components in the oxygen-deprived turtle heart

    DEFF Research Database (Denmark)

    Stecyk, Jonathan; Bock, Christian; Overgaard, Johannes

    2009-01-01

    of an anoxia-tolerant vertebrate, the freshwater turtle (Trachemys scripta) during long-term anoxia exposure ( 3 h at 21°C and 11 days at 5°C). During anoxia, phosphocreatine (PCr), unbound levels of inorganic phosphate (effective Pi2–), intracellular pH (pHi), and free energy of ATP hydrolysis (d......G/d ) exhibited asymptotic patterns of change, indicating that turtle myocardial high-energy phosphate metabolism and energetic state are reset to new, reduced steady states during long-term anoxia exposure. At 21°C, anoxia caused a reduction in pHi from 7.40 to 7.01, a 69% decrease in PCr and a doubling...

  1. Residential development alters behavior, movement, and energetics in an apex predator, the puma.

    Science.gov (United States)

    Wang, Yiwei; Smith, Justine A; Wilmers, Christopher C

    2017-01-01

    Human development strongly influences large carnivore survival and persistence globally. Behavior changes are often the first measureable responses to human disturbances, and can have ramifications on animal populations and ecological communities. We investigated how a large carnivore responds to anthropogenic disturbances by measuring activity, movement behavior, and energetics in pumas along a housing density gradient. We used log-linear analyses to examine how habitat, time of day, and proximity to housing influenced the activity patterns of both male and female pumas in the Santa Cruz Mountains. We used spatial GPS location data in combination with Overall Dynamic Body Acceleration measurements recorded by onboard accelerometers to quantify how development density affected the average distances traveled and energy expended by pumas. Pumas responded to development differently depending on the time of day; at night, they were generally more active and moved further when they were in developed areas, but these relationships were not consistent during the day. Higher nighttime activity in developed areas increased daily caloric expenditure by 10.1% for females and 11.6% for males, resulting in increases of 3.4 and 4.0 deer prey required annually by females and males respectively. Our results support that pumas have higher energetic costs and resource requirements in human-dominated habitats due to human-induced behavioral change. Increased energetic costs for pumas are likely to have ramifications on prey species and exacerbate human-wildlife conflict, especially as exurban growth continues. Future conservation work should consider the consequences of behavioral shifts on animal energetics, individual fitness, and population viability.

  2. Residential development alters behavior, movement, and energetics in an apex predator, the puma.

    Directory of Open Access Journals (Sweden)

    Yiwei Wang

    Full Text Available Human development strongly influences large carnivore survival and persistence globally. Behavior changes are often the first measureable responses to human disturbances, and can have ramifications on animal populations and ecological communities. We investigated how a large carnivore responds to anthropogenic disturbances by measuring activity, movement behavior, and energetics in pumas along a housing density gradient. We used log-linear analyses to examine how habitat, time of day, and proximity to housing influenced the activity patterns of both male and female pumas in the Santa Cruz Mountains. We used spatial GPS location data in combination with Overall Dynamic Body Acceleration measurements recorded by onboard accelerometers to quantify how development density affected the average distances traveled and energy expended by pumas. Pumas responded to development differently depending on the time of day; at night, they were generally more active and moved further when they were in developed areas, but these relationships were not consistent during the day. Higher nighttime activity in developed areas increased daily caloric expenditure by 10.1% for females and 11.6% for males, resulting in increases of 3.4 and 4.0 deer prey required annually by females and males respectively. Our results support that pumas have higher energetic costs and resource requirements in human-dominated habitats due to human-induced behavioral change. Increased energetic costs for pumas are likely to have ramifications on prey species and exacerbate human-wildlife conflict, especially as exurban growth continues. Future conservation work should consider the consequences of behavioral shifts on animal energetics, individual fitness, and population viability.

  3. Residential development alters behavior, movement, and energetics in an apex predator, the puma

    OpenAIRE

    Wang, Yiwei; Smith, Justine A.; Wilmers, Christopher C.

    2017-01-01

    Human development strongly influences large carnivore survival and persistence globally. Behavior changes are often the first measureable responses to human disturbances, and can have ramifications on animal populations and ecological communities. We investigated how a large carnivore responds to anthropogenic disturbances by measuring activity, movement behavior, and energetics in pumas along a housing density gradient. We used log-linear analyses to examine how habitat, time of day, and pro...

  4. Patient position alters attenuation effects in multipinhole cardiac SPECT.

    Science.gov (United States)

    Timmins, Rachel; Ruddy, Terrence D; Wells, R Glenn

    2015-03-01

    Dedicated cardiac cameras offer improved sensitivity over conventional SPECT cameras. Sensitivity gains are obtained by large numbers of detectors and novel collimator arrangements such as an array of multiple pinholes that focus on the heart. Pinholes lead to variable amounts of attenuation as a source is moved within the camera field of view. This study evaluated the effects of this variable attenuation on myocardial SPECT images. Computer simulations were performed for a set of nine point sources distributed in the left ventricular wall (LV). Sources were placed at the location of the heart in both an anthropomorphic and a water-cylinder computer phantom. Sources were translated in x, y, and z by up to 5 cm from the center. Projections were simulated with and without attenuation and the changes in attenuation were compared. A LV with an inferior wall defect was also simulated in both phantoms over the same range of positions. Real camera data were acquired on a Discovery NM530c camera (GE Healthcare, Haifa, Israel) for five min in list-mode using an anthropomorphic phantom (DataSpectrum, Durham, NC) with 100 MBq of Tc-99m in the LV. Images were taken over the same range of positions as the simulations and were compared based on the summed perfusion score (SPS), defect width, and apparent defect uptake for each position. Point sources in the water phantom showed absolute changes in attenuation of ≤8% over the range of positions and relative changes of ≤5% compared to the apex. In the anthropomorphic computer simulations, absolute change increased to 20%. The changes in relative attenuation caused a change in SPS of position-dependent changes were removed with attenuation correction. Translation of a source relative to a multipinhole camera caused only small changes in homogeneous phantoms with SPS changing position-dependent changes in attenuation.

  5. Cardiac dysfunction induced by high-fat diet is associated with altered myocardial insulin signalling in rats

    NARCIS (Netherlands)

    Ouwens, D.M.; de Boer, C.; Fodor, M.; Galan, P.; Heine, R.J.; Maassen, J.A.; Diamant, M.

    2005-01-01

    Aims/hypothesis: Diabetic cardiomyopathy (DCM) is common in type 2 diabetes. In DCM, insulin resistance may alter cardiac substrate supply and utilisation leading to changes in myocardial metabolism and cardiac function. In rats, exposure to excessive alimentary fat, inducing a type 2 diabetic

  6. Increased Arctic Sea Ice Drift Alters Polar Bear Movements and Energetics

    Science.gov (United States)

    Douglas, D. C.; Durner, G. M.; Albeke, S. E.; Whiteman, J. P.; Amstrup, S. C.; Richardson, E.; Wilson, R. R.; Ben-David, M.

    2015-12-01

    Recent thinning of Arctic sea ice has increased its drift from currents and winds. Increased ice drift could affect movements and energy balance of polar bears (Ursus maritimus) which rely, almost exclusively, on this substrate for hunting seals. Foraging by polar bears is a relatively sedentary behavior, as they typically capture their main prey by waiting at breathing holes, where seals haul-out along leads, or by short-distance stalking. We examined the response of polar bears to ice drift in the Beaufort (BS) and Chukchi (CS) seas, and between two periods with different sea ice characteristics: 1987-1998 and 1999-2013. We used satellite-tracked adult female polar bear locations, standardized by a continuous-time correlated random walk, coupled with modeled ice drift, to estimate displacement and drift-corrected bear movements along east-west and north-south axes. Sea ice drift in both regions increased with greater westward and more extreme northward and southward rates from 1987-1998 to 1999-2013. Polar bears responded with greater eastward movements and, in the CS greater movements north and south. We show that efforts by polar bears to compensate for greater westward ice drift in recent years translated into a model-derived estimate of 5.7-7.2% increase in energy expenditure. We also estimated that polar bears increased their travel time 18-20% between the two time periods, suggesting time allocated to foraging was reduced. Increased energetic costs and travel time resulting from greater ice drift, in conjunction with ongoing habitat loss, suggest that recent changes to Arctic sea ice may affect movements and energy balance of polar bears.

  7. Subgenual anterior cingulate cortex activity covariation with cardiac vagal control is altered in depression.

    Science.gov (United States)

    Lane, Richard D; Weidenbacher, Hollis; Smith, Ryan; Fort, Carolyn; Thayer, Julian F; Allen, John J B

    2013-09-05

    We tested the hypothesis that subgenual anterior cingulate cortex (sgACC) participates in concurrently regulating shifts in both affective state and cardiac vagal control. Eleven healthy adults and 8 depressed subjects performed the Emotional Counting Stroop task in alternating 15-second blocks of emotion words and neutral words while undergoing functional magnetic resonance imaging (fMRI) and electrocardiography (ECG). We measured the absolute value of change between adjacent 15-second blocks in both cardiac vagal control and the BOLD signal in specific regions of interest. Strong positive correlations were observed in healthy control participants between changes in cardiac vagal control and changes in BOLD signal intensity in sgACC (BA25) (right: r=.67, pemotion blocks to neutral blocks, the correlation between BOLD signal change in BA25 and cardiac vagal control change was significantly greater in controls than in depressed subjects (paffective state shifting. The latter function appears to be altered in depressed individuals, and may have implications for the unvarying mood and vagal dysfunction associated with depression. Limitations include a small sample size, an inability to disentangle afferent versus efferent contributions to the results, and the lack of a whole-brain analysis. Published by Elsevier B.V.

  8. Exercise at depth alters bradycardia and incidence of cardiac anomalies in deep-diving marine mammals.

    Science.gov (United States)

    Williams, Terrie M; Fuiman, Lee A; Kendall, Traci; Berry, Patrick; Richter, Beau; Noren, Shawn R; Thometz, Nicole; Shattock, Michael J; Farrell, Edward; Stamper, Andy M; Davis, Randall W

    2015-01-16

    Unlike their terrestrial ancestors, marine mammals routinely confront extreme physiological and physical challenges while breath-holding and pursuing prey at depth. To determine how cetaceans and pinnipeds accomplish deep-sea chases, we deployed animal-borne instruments that recorded high-resolution electrocardiograms, behaviour and flipper accelerations of bottlenose dolphins (Tursiops truncatus) and Weddell seals (Leptonychotes weddellii) diving from the surface to >200 m. Here we report that both exercise and depth alter the bradycardia associated with the dive response, with the greatest impacts at depths inducing lung collapse. Unexpectedly, cardiac arrhythmias occurred in >73% of deep, aerobic dives, which we attribute to the interplay between sympathetic and parasympathetic drivers for exercise and diving, respectively. Such marked cardiac variability alters the common view of a stereotypic 'dive reflex' in diving mammals. It also suggests the persistence of ancestral terrestrial traits in cardiac function that may help explain the unique sensitivity of some deep-diving marine mammals to anthropogenic disturbances.

  9. {sup 31}P magnetic resonance spectroscopy to measure in vivo cardiac energetics in normal myocardium and hypertrophic cardiomyopathy: Experiences at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Shivu, Ganesh Nallur [Department of Cardiovascular Medicine, University of Birmingham, Vincent Drive, Edgbaston, Birmingham B15 2TT (United Kingdom)], E-mail: drgani23@gmail.com; Abozguia, Khalid; Phan, Thanh Trung; Ahmed, Ibrar [Department of Cardiovascular Medicine, University of Birmingham, Vincent Drive, Edgbaston, Birmingham B15 2TT (United Kingdom); Henning, Anke [Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, CH-8092, Zurich CH ETZ F97 (Switzerland); Frenneaux, Michael [Department of Cardiovascular Medicine, University of Birmingham, Vincent Drive, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2010-02-15

    Background: {sup 31}P magnetic resonance spectroscopy (MRS) allows measurement of in vivo high-energy phosphate kinetics in the myocardium. While traditionally {sup 31}P cardiac spectroscopy is performed at 1.5 T, cardiac MRS at higher field strength can theoretically increase signal to noise ratio (SNR) and spectral resolution therefore improving sensitivity and specificity of the cardiac spectra. The reproducibility and feasibility of performing cardiac spectroscopy at 3 T is presented here in this study in healthy volunteers and patients with hypertrophic cardiomyopathy. Methods: Cardiac spectroscopy was performed using a Phillips 3T Achieva scanner in 37 healthy volunteers and 26 patients with hypertrophic cardiomyopathy (HCM) to test the feasibility of the protocol. To test the reproducibility a single volunteer was scanned eight times on separate occasions. A single voxel {sup 31}P MRS was performed using Image Selected In vivo Spectroscopy (ISIS) volume localization. Results: The mean phosphocreatine/adenosine triphosphate (PCr/ATP) ratio of the eight measurements performed on one individual was 2.11 {+-} 0.25. Bland Altman plots showed a variance of 12% in the measurement of PCr/ATP ratios. The PCr/ATP ratio was significantly reduced in HCM patients compared to controls, 1.42 {+-} 0.51 and 2.11 {+-} 0.57, respectively, P < 0.0001. (All results are expressed as mean {+-} standard deviation). Conclusions: Here we demonstrate that cardiac {sup 31}P MRS at 3 T is a reliable method of measuring in vivo high-energy phosphate kinetics in the myocardium for clinical studies and diagnostics. Based on our data an impairment of cardiac energetic state in patients with hypertrophic cardiomyopathy is indisputable.

  10. Epilepsy-induced electrocardiographic alterations following cardiac ischemia and reperfusion in rats

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, J.G.P. [Departamento de Farmacologia, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Universidade Iguaçu, Campos V, Itaperuna, RJ (Brazil); Faculdade de Minas, Muriaé, MG (Brazil); Vasques, E.R. [Departamento de Gastroenterologia, LIM 37, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Arida, R.M. [Departamento de Fisiologia, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Cavalheiro, E.A. [Departamento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Cabral, F.R.; Torres, L.B. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Menezes-Rodrigues, F.S.; Jurkiewicz, A.; Caricati-Neto, A. [Departamento de Farmacologia, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Godoy, C.M.G. [Departamento de Ciência e Tecnologia, Universidade Federal de São Paulo, São José dos Campos, SP (Brazil); Gomes da Silva, S. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Núcleo de Pesquisas Tecnológicas, Programa Integrado em Engenharia Biomédica, Universidade de Mogi das Cruzes, Mogi das Cruzes, SP (Brazil)

    2015-01-13

    The present study evaluated electrocardiographic alterations in rats with epilepsy submitted to an acute myocardial infarction (AMI) model induced by cardiac ischemia and reperfusion. Rats were randomly divided into two groups: control (n=12) and epilepsy (n=14). It was found that rats with epilepsy presented a significant reduction in atrioventricular block incidence following the ischemia and reperfusion procedure. In addition, significant alterations were observed in electrocardiogram intervals during the stabilization, ischemia, and reperfusion periods of rats with epilepsy compared to control rats. It was noted that rats with epilepsy presented a significant increase in the QRS interval during the stabilization period in relation to control rats (P<0.01). During the ischemia period, there was an increase in the QRS interval (P<0.05) and a reduction in the P wave and QT intervals (P<0.05 for both) in rats with epilepsy compared to control rats. During the reperfusion period, a significant reduction in the QT interval (P<0.01) was verified in the epilepsy group in relation to the control group. Our results indicate that rats submitted to an epilepsy model induced by pilocarpine presented electrical conductivity alterations of cardiac tissue, mainly during an AMI episode.

  11. Increased Arctic sea ice drift alters adult female polar bear movements and energetics.

    Science.gov (United States)

    Durner, George M; Douglas, David C; Albeke, Shannon E; Whiteman, John P; Amstrup, Steven C; Richardson, Evan; Wilson, Ryan R; Ben-David, Merav

    2017-09-01

    Recent reductions in thickness and extent have increased drift rates of Arctic sea ice. Increased ice drift could significantly affect the movements and the energy balance of polar bears (Ursus maritimus) which forage, nearly exclusively, on this substrate. We used radio-tracking and ice drift data to quantify the influence of increased drift on bear movements, and we modeled the consequences for energy demands of adult females in the Beaufort and Chukchi seas during two periods with different sea ice characteristics. Westward and northward drift of the sea ice used by polar bears in both regions increased between 1987-1998 and 1999-2013. To remain within their home ranges, polar bears responded to the higher westward ice drift with greater eastward movements, while their movements north in the spring and south in fall were frequently aided by ice motion. To compensate for more rapid westward ice drift in recent years, polar bears covered greater daily distances either by increasing their time spent active (7.6%-9.6%) or by increasing their travel speed (8.5%-8.9%). This increased their calculated annual energy expenditure by 1.8%-3.6% (depending on region and reproductive status), a cost that could be met by capturing an additional 1-3 seals/year. Polar bears selected similar habitats in both periods, indicating that faster drift did not alter habitat preferences. Compounding reduced foraging opportunities that result from habitat loss; changes in ice drift, and associated activity increases, likely exacerbate the physiological stress experienced by polar bears in a warming Arctic. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  12. Therapeutic Hypothermia Reduces Oxidative Damage and Alters Antioxidant Defenses after Cardiac Arrest

    Science.gov (United States)

    Hackenhaar, Fernanda S.; Medeiros, Tássia M.; Heemann, Fernanda M.; Behling, Camile S.; Putti, Jordana S.; Mahl, Camila D.; Verona, Cleber; da Silva, Ana Carolina A.; Guerra, Maria C.; Gonçalves, Carlos A. S.; Oliveira, Vanessa M.; Riveiro, Diego F. M.; Vieira, Silvia R. R.

    2017-01-01

    After cardiac arrest, organ damage consequent to ischemia-reperfusion has been attributed to oxidative stress. Mild therapeutic hypothermia has been applied to reduce this damage, and it may reduce oxidative damage as well. This study aimed to compare oxidative damage and antioxidant defenses in patients treated with controlled normothermia versus mild therapeutic hypothermia during postcardiac arrest syndrome. The sample consisted of 31 patients under controlled normothermia (36°C) and 11 patients treated with 24 h mild therapeutic hypothermia (33°C), victims of in- or out-of-hospital cardiac arrest. Parameters were assessed at 6, 12, 36, and 72 h after cardiac arrest in the central venous blood samples. Hypothermic and normothermic patients had similar S100B levels, a biomarker of brain injury. Xanthine oxidase activity is similar between hypothermic and normothermic patients; however, it decreases posthypothermia treatment. Xanthine oxidase activity is positively correlated with lactate and S100B and inversely correlated with pH, calcium, and sodium levels. Hypothermia reduces malondialdehyde and protein carbonyl levels, markers of oxidative damage. Concomitantly, hypothermia increases the activity of erythrocyte antioxidant enzymes superoxide dismutase, glutathione peroxidase, and glutathione S-transferase while decreasing the activity of serum paraoxonase-1. These findings suggest that mild therapeutic hypothermia reduces oxidative damage and alters antioxidant defenses in postcardiac arrest patients. PMID:28553435

  13. Pacemaker stimulus amplitude alteration without loss of capture: an unusual ECG finding in cardiac tamponade from pacemaker lead perforation.

    Science.gov (United States)

    Suksaranjit, P; Prasidthrathsint, K

    2014-01-01

    A variation in pacemaker stimulus amplitude can represent pacemaker system dysfunction from generator malfunction, lead insulation defect, lead fracture, or artefact of digital signal processing of the electrocardiography recorder. Pacemaker lead perforation into the pericardial space typically results in loss of capture which was not demonstrated in our patient. In summary, we report an unusual ECG finding of pacemaker stimulus amplitude alteration without loss of capture in the setting of cardiac tamponade from pacemaker lead perforation. Copyright © 2013 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  14. Reversing dobutamine-induced tachycardia using ivabradine increases stroke volume with neutral effect on cardiac energetics in left ventricular post-ischaemia dysfunction.

    Science.gov (United States)

    Bakkehaug, J P; Naesheim, T; Torgersen Engstad, E; Kildal, A B; Myrmel, T; How, O-J

    2016-10-01

    Compensatory tachycardia can potentially be deleterious in acute heart failure. In this study, we tested a therapeutic strategy of combined inotropic support (dobutamine) and selective heart rate (HR) reduction through administration of ivabradine. In an open-chest pig model (n = 12) with left ventricular (LV) post-ischaemia dysfunction, cardiac function was assessed by LV pressure catheter and sonometric crystals. Coronary flow and blood samples from the coronary sinus were used to measure myocardial oxygen consumption (MVO2 ). LV energetics was assessed by comparing MVO2 with cardiac work at a wide range of workloads. In the post-ischaemia heart, dobutamine (5 μg kg(-1)  min(-1) ) increased cardiac output (CO) by increasing HR from 102 ± 21 to 131 ± 16 bpm (beats per min; P efficiency. Similar findings on efficiency and LV function were also seen using an ex vivo working mouse heart protocol. A combined infusion of dobutamine and ivabradine had a neutral effect on post-ischaemia LV efficiency and increased left ventricular output without an increase in HR. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  15. Non-dipper treated hypertensive patients do not have increased cardiac structural alterations

    Directory of Open Access Journals (Sweden)

    Magrini Fabio

    2003-02-01

    Full Text Available Abstract Background Non-dipping pattern in hypertensive patients has been shown to be associated with an excess of target organ damage and with an adverse outcome. The aim of our study was to assess whether a reduced nocturnal fall in blood pressure (BP, established on the basis of a single 24-h BP monitoring, in treated essential hypertensives is related to more prominent cardiac alterations. Methods We enrrolled 229 treated hypertensive patients attending the out-patient clinic of our hypertension centre; each patient was subjected to the following procedures : 1 clinic BP measurement; 2 blood and urine sampling for routine blood chemistry and urine examination; 3 standard 12-lead electrocardiogram; 4 echocardiography; 5 ambulatory BP monitoring (ABPM. For the purpose of this study ABPM was carried-out in three subgroups with different clinic BP profile : 1 patients with satisfactory BP control (BP 2 in men and 110 g/m2 in women, ≥51/gm2.7 in men and 47/g/m2.7 in women. Results Of the 229 study participants 119 (51.9% showed a fall in SBP/DBP Conclusions In treated essential hypertensives with or without BP control the extent of nocturnal BP decrease is not associated with an increase in LV mass or LVH prevalence; therefore, the non-dipping profile, diagnosed on the basis of a single ABPM, does not identify hypertensive patients with greater cardiac damage.

  16. Prior exercise training does not prevent acute cardiac alterations after myocardial infarction in female rats

    Directory of Open Access Journals (Sweden)

    Eduardo C. A. Veiga

    2011-01-01

    Full Text Available OBJECTIVE: This study aimed to investigate whether previous exercise training could prevent or attenuate acute cardiac alterations after myocardial infarction. METHODS: Female rats were submitted to swim training (1 h/day; 5 days/week or allowed to remain sedentary for 8 weeks. Afterwards, they were randomly assigned to left coronary artery occlusion or sham surgery. After this procedure, the rats remained sedentary for one week until euthanasia. Cardiac structural and functional analyses were performed using Doppler echocardiography. The rats that had a moderate or large infarct size were included in the evaluations. The data (mean + SEM were analyzed using a two-way ANOVA model followed byTukey's post-hoc test. RESULTS: After the surgery, no significant difference between the exercise and sedentary groups was observed in the left ventricular infarct sizes (34.58 + 3.04 vs. 37.59 + 3.07. In another group of rats evaluated with Evans blue 1 h after myocardial infarction, no siginificant difference in the area at risk was observed between the exercised and sedentary rats (49.73 + 1.52 vs. 45.48 + 3.49. The changes in the left ventricular fractional areas for the exercised and sedentary myocardial infarction groups (36 + 2% and 39 + 3%, respectively were smaller than those for the exercise sham surgery (ES, 67+1% and sedentary sham surgery (SS, 69 + 2% groups. The E/A was higher in the sedentary myocardial infarction (4.4 + 0.3 and exercised myocardial infarction (5.5 + 0.3 rats than in the SS (2.4 + 0.1 and ES (2.2 + 0.1 rats. CONCLUSION: Previous swim training of female rats does not attenuate systolic and diastolic function alterations after myocardial infarction induced by left coronary artery occlusion, suggesting that cardioprotection cannot be provided by exercise training in this experimental model.

  17. Restricted N-terminal truncation of cardiac troponin T: a novel mechanism for functional adaptation to energetic crisis.

    Science.gov (United States)

    Feng, Han-Zhong; Biesiadecki, Brandon J; Yu, Zhi-Bin; Hossain, M Moazzem; Jin, J-P

    2008-07-15

    The N-terminal variable region of cardiac troponin T (TnT) is a regulatory structure that can be selectively removed during myocardial ischaemia reperfusion by mu-calpain proteolysis. Here we investigated the pathophysiological significance of this post-translational modification that removes amino acids 1-71 of cardiac TnT. Working heart preparations were employed to study rat acute myocardial infarction and transgenic mouse hearts over-expressing the N-terminal truncated cardiac TnT (cTnT-ND). Ex vivo myocardial infarction by ligation of the left anterior descending coronary artery induced heart failure and produced cTnT-ND not only in the infarct but also in remote zones, including the right ventricular free wall, indicating a whole organ response in the absence of systemic neurohumoral mechanisms. Left ventricular pressure overload in mouse working hearts produced increased cTnT-ND in both ventricles, suggesting a role of haemodynamic stress in triggering an acute whole organ proteolytic regulation. Transgenic mouse hearts in which the endogenous intact cardiac TnT was partially replaced by cTnT-ND showed lowered contractile velocity. When afterload increased from 55 mmHg to 90 mmHg, stroke volume decreased in the wild type but not in the transgenic mouse hearts. Correspondingly, the left ventricular rapid-ejection time of the transgenic mouse hearts was significantly longer than that of wild type hearts, especially at high afterload. The restricted deletion of the N-terminal variable region of cardiac troponin T demonstrates a novel mechanism by which the thin filament regulation adapts to sustain cardiac function under stress conditions.

  18. Alterations in cardiac sarcolemmal Ca2+ pump activity during diabetes mellitus

    International Nuclear Information System (INIS)

    Heyliger, C.E.; Prakash, A.; McNeill, J.

    1987-01-01

    Diabetes mellitus is frequently associated with a primary cardiomyopathy. The mechanisms responsible for this heart disease are not clear, but an alteration in myocardial Ca 2+ transport is believed to be involved in its development. Even though sarcolemma plays a crucial role in cellular Ca 2+ transport, little appears to be known about its Ca 2+ transporting capability in the diabetic myocardium. In this regard, the authors have examined the status of the cardiac sarcolemmal Ca 2+ pump during diabetes mellitus. Purified sarcolemmal membranes were isolated from male Wistar diabetic rat hearts 8 wk after streptozotocin injection. Ca 2+ pump activity assessed by measuring its Ca 2+ -stimulated adenosine triphosphatase and Ca 2+ -uptake ability in the absence and presence of calmodulin was significantly depressed in the diabetic myocardium relative to controls. These results did not appear to have been influenced by the minimal sarcoplasmic reticular and mitochondrial contamination of this membrane preparation. Hence, it appears that the sarcolemmal Ca 2+ pump is defective in the diabetic myocardium and may be involved in the altered Ca 2+ transport of the heart during diabetes mellitus

  19. The impact of vascular endothelial growth factor and basic fibroblast growth factor on cardiac fibroblasts grown under altered gravity conditions

    DEFF Research Database (Denmark)

    Ulbrich, Claudia; Leder, Annekatrin; Pietsch, Jessica

    2010-01-01

    Myocardium is very sensitive to gravitational changes. During a spaceflight cardiovascular atrophy paired with rhythm problems and orthostatic intolerance can occur. The aim of this study was to investigate the impact of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor...... (VEGF) on cardiac fibroblasts (CF) grown under altered gravity conditions....

  20. β-adrenergic receptor-dependent alterations in murine cardiac transcript expression are differentially regulated by gefitinib in vivo.

    Directory of Open Access Journals (Sweden)

    Jennifer A Talarico

    Full Text Available β-adrenergic receptor (βAR-mediated transactivation of epidermal growth factor receptor (EGFR has been shown to promote cardioprotection in a mouse model of heart failure and we recently showed that this mechanism leads to enhanced cell survival in part via regulation of apoptotic transcript expression in isolated primary rat neonatal cardiomyocytes. Thus, we hypothesized that this process could regulate cardiac transcript expression in vivo. To comprehensively assess cardiac transcript alterations in response to acute βAR-dependent EGFR transactivation, we performed whole transcriptome analysis of hearts from C57BL/6 mice given i.p. injections of the βAR agonist isoproterenol in the presence or absence of the EGFR antagonist gefitinib for 1 hour. Total cardiac RNA from each treatment group underwent transcriptome analysis, revealing a substantial number of transcripts regulated by each treatment. Gefitinib alone significantly altered the expression of 405 transcripts, while isoproterenol either alone or in conjunction with gefitinib significantly altered 493 and 698 distinct transcripts, respectively. Further statistical analysis was performed, confirming 473 transcripts whose regulation by isoproterenol were significantly altered by gefitinib (isoproterenol-induced up/downregulation antagonized/promoted by gefinitib, including several known to be involved in the regulation of numerous processes including cell death and survival. Thus, βAR-dependent regulation of cardiac transcript expression in vivo can be modulated by the EGFR antagonist gefitinib.

  1. Delineating the role of alterations in lipid metabolism to the pathogenesis of inherited skeletal and cardiac muscle disorders

    NARCIS (Netherlands)

    Saini-Chohan, Harjot K.; Mitchell, Ryan W.; Vaz, Frédéric M.; Zelinski, Teresa; Hatch, Grant M.

    2012-01-01

    As the specific composition of lipids is essential for the maintenance of membrane integrity, enzyme function, ion channels, and membrane receptors, an alteration in lipid composition or metabolism may be one of the crucial changes occurring during skeletal and cardiac myopathies. Although the

  2. An analysis of the energetic cost of the branchial and cardiac pumps during sustained swimming in trout

    DEFF Research Database (Denmark)

    FARRELL, AP; STEFFENSEN, JF

    1987-01-01

    Experimental data are available for the oxygen cost of the branchial and cardiac pumps in fish. These data were used to theoretically analyze the relative oxygen cost of these pumps during rest and swimming in rainbow troutSalmo gairdneri. Efficiency of the heart increases with activity and so...

  3. Effects of exenatide on cardiac function, perfusion, and energetics in type 2 diabetic patients with cardiomyopathy: a randomized controlled trial against insulin glargine.

    Science.gov (United States)

    Chen, Weena J Y; Diamant, Michaela; de Boer, Karin; Harms, Hendrik J; Robbers, Lourens F H J; van Rossum, Albert C; Kramer, Mark H H; Lammertsma, Adriaan A; Knaapen, Paul

    2017-05-19

    Multiple bloodglucose-lowering agents have been linked to cardiovascular events. Preliminary studies showed improvement in left ventricular (LV) function during glucagon-like peptide-1 receptor agonist administration. Underlying mechanisms, however, are unclear. The purpose of this study was to investigate myocardial perfusion and oxidative metabolism in type 2 diabetic (T2DM) patients with LV systolic dysfunction as compared to healthy controls. Furthermore, effects of 26-weeks of exenatide versus insulin glargine administration on cardiac function, perfusion and oxidative metabolism in T2DM patients with LV dysfunction were explored. Twenty-six T2DM patients with LV systolic dysfunction (cardiac magnetic resonance (CMR) derived LV ejection fraction (LVEF) of 47 ± 13%) and 10 controls (LVEF of 59 ± 4%, P efficiency, measured using [ 11 C]acetate PET and CMR derived stroke volume, were not different between the groups. Eleven patients in the exenatide group and 12 patients in the insulin glargine group completed the trial. Systemic metabolic control was improved after both treatments, although, no changes in cardiac function, perfusion and metabolism were seen after exenatide or insulin glargine. T2DM patients with LV systolic dysfunction did not have altered myocardial efficiency as compared to healthy controls. Exenatide or insulin glargine had no effects on cardiac function, perfusion or oxidative metabolism. Trial registration NCT00766857.

  4. Activation of protein kinase C alters the intracellular distribution and mobility of cardiac Na+ channels.

    Science.gov (United States)

    Hallaq, Haifa; Wang, Dao W; Kunic, Jennifer D; George, Alfred L; Wells, K Sam; Murray, Katherine T

    2012-02-01

    Na(+) current derived from expression of the cardiac isoform SCN5A is reduced by receptor-mediated or direct activation of protein kinase C (PKC). Previous work has suggested a possible role for loss of Na(+) channels at the plasma membrane in this effect, but the results are controversial. In this study, we tested the hypothesis that PKC activation acutely modulates the intracellular distribution of SCN5A channels and that this effect can be visualized in living cells. In human embryonic kidney cells that stably expressed SCN5A with green fluorescent protein (GFP) fused to the channel COOH-terminus (SCN5A-GFP), Na(+) currents were suppressed by an exposure to PKC activation. Using confocal microscopy, colocalization of SCN5A-GFP channels with the plasma membrane under control and stimulated conditions was quantified. A separate population of SCN5A channels containing an extracellular epitope was immunolabeled to permit temporally stable labeling of the plasma membrane. Our results demonstrated that Na(+) channels were preferentially trafficked away from the plasma membrane by PKC activation, with a major contribution by Ca(2+)-sensitive or conventional PKC isoforms, whereas stimulation of protein kinase A (PKA) had the opposite effect. Removal of the conserved PKC site Ser(1503) or exposure to the NADPH oxidase inhibitor apocynin eliminated the PKC-mediated effect to alter channel trafficking, indicating that both channel phosphorylation and ROS were required. Experiments using fluorescence recovery after photobleaching demonstrated that both PKC and PKA also modified channel mobility in a manner consistent with the dynamics of channel distribution. These results demonstrate that the activation of protein kinases can acutely regulate the intracellular distribution and molecular mobility of cardiac Na(+) channels in living cells.

  5. Gestational exposure to diethylstilbestrol alters cardiac structure/function, protein expression and DNA methylation in adult male mice progeny

    International Nuclear Information System (INIS)

    Haddad, Rami; Kasneci, Amanda; Mepham, Kathryn; Sebag, Igal A.

    2013-01-01

    Pregnant women, and thus their fetuses, are exposed to many endocrine disruptor compounds (EDCs). Fetal cardiomyocytes express sex hormone receptors making them potentially susceptible to re-programming by estrogenizing EDCs. Diethylstilbestrol (DES) is a proto-typical, non-steroidal estrogen. We hypothesized that changes in adult cardiac structure/function after gestational exposure to the test compound DES would be a proof in principle for the possibility of estrogenizing environmental EDCs to also alter the fetal heart. Vehicle (peanut oil) or DES (0.1, 1.0 and 10.0 μg/kg/da.) was orally delivered to pregnant C57bl/6n dams on gestation days 11.5–14.5. At 3 months, male progeny were left sedentary or were swim trained for 4 weeks. Echocardiography of isoflurane anesthetized mice revealed similar cardiac structure/function in all sedentary mice, but evidence of systolic dysfunction and increased diastolic relaxation after swim training at higher DES doses. The calcium homeostasis proteins, SERCA2a, phospholamban, phospho-serine 16 phospholamban and calsequestrin 2, are important for cardiac contraction and relaxation. Immunoblot analyses of ventricle homogenates showed increased expression of SERCA2a and calsequestrin 2 in DES mice and greater molecular remodeling of these proteins and phospho-serine 16 phospholamban in swim trained DES mice. DES increased cardiac DNA methyltransferase 3a expression and DNA methylation in the CpG island within the calsequestrin 2 promoter in heart. Thus, gestational DES epigenetically altered ventricular DNA, altered cardiac function and expression, and reduced the ability of adult progeny to cardiac remodel when physically challenged. We conclude that gestational exposure to estrogenizing EDCs may impact cardiac structure/function in adult males. -- Highlights: ► Gestational DES changes cardiac SERCA2a and CASQ2 expression. ► Echocardiography identified systolic dysfunction and increased diastolic relaxation. ► DES

  6. Altered cardiac rhythm in infants with bronchiolitis and respiratory syncytial virus infection

    Directory of Open Access Journals (Sweden)

    Galeone Carlotta

    2010-10-01

    Full Text Available Abstract Background Although the most frequent extra-pulmonary manifestations of respiratory syncytial virus (RSV infection involve the cardiovascular system, no data regarding heart function in infants with bronchiolitis associated with RSV infection have yet been systematically collected. The aim of this study was to verify the real frequency of heart involvement in patients with bronchiolitis associated with RSV infection, and whether infants with mild or moderate disease also risk heart malfunction. Methods A total of 69 otherwise healthy infants aged 1-12 months with bronchiolitis hospitalised in standard wards were enrolled. Pernasal flocked swabs were performed to collect specimens for the detection of RSV by real-time polymerase chain reaction, and a blood sample was drawn to assess troponin I concentrations. On the day of admission, all of the infants underwent 24-hour Holter ECG monitoring and a complete heart evaluation with echocardiography. Patients were re-evaluated by investigators blinded to the etiological and cardiac findings four weeks after enrolment. Results Regardless of their clinical presentation, sinoatrial blocks were identified in 26/34 RSV-positive patients (76.5% and 1/35 RSV-negative patients (2.9% (p Conclusions RSV seems associated with sinoatrial blocks and transient rhythm alterations even when the related respiratory problems are mild or moderate. Further studies are needed to clarify the mechanisms of these rhythm problems and whether they remain asymptomatic and transient even in presence of severe respiratory involvement or chronic underlying disease.

  7. Systemic and Cardiac Depletion of M2 Macrophage through CSF-1R Signaling Inhibition Alters Cardiac Function Post Myocardial Infarction.

    Directory of Open Access Journals (Sweden)

    Anne-Laure Leblond

    Full Text Available The heart hosts tissue resident macrophages which are capable of modulating cardiac inflammation and function by multiple mechanisms. At present, the consequences of phenotypic diversity in macrophages in the heart are incompletely understood. The contribution of cardiac M2-polarized macrophages to the resolution of inflammation and repair response following myocardial infarction remains to be fully defined. In this study, the role of M2 macrophages was investigated utilising a specific CSF-1 receptor signalling inhibition strategy to achieve their depletion. In mice, oral administration of GW2580, a CSF-1R kinase inhibitor, induced significant decreases in Gr1lo and F4/80hi monocyte populations in the circulation and the spleen. GW2580 administration also induced a significant depletion of M2 macrophages in the heart after 1 week treatment as well as a reduction of cardiac arginase1 and CD206 gene expression indicative of M2 macrophage activity. In a murine myocardial infarction model, reduced M2 macrophage content was associated with increased M1-related gene expression (IL-6 and IL-1β, and decreased M2-related gene expression (Arginase1 and CD206 in the heart of GW2580-treated animals versus vehicle-treated controls. M2 depletion was also associated with a loss in left ventricular contractile function, infarct enlargement, decreased collagen staining and increased inflammatory cell infiltration into the infarct zone, specifically neutrophils and M1 macrophages. Taken together, these data indicate that CSF-1R signalling is critical for maintaining cardiac tissue resident M2-polarized macrophage population, which is required for the resolution of inflammation post myocardial infarction and, in turn, for preservation of ventricular function.

  8. Neurotransmission to parasympathetic cardiac vagal neurons in the brain stem is altered with left ventricular hypertrophy-induced heart failure.

    Science.gov (United States)

    Cauley, Edmund; Wang, Xin; Dyavanapalli, Jhansi; Sun, Ke; Garrott, Kara; Kuzmiak-Glancy, Sarah; Kay, Matthew W; Mendelowitz, David

    2015-10-01

    Hypertension, cardiac hypertrophy, and heart failure (HF) are widespread and debilitating cardiovascular diseases that affect nearly 23 million people worldwide. A distinctive hallmark of these cardiovascular diseases is autonomic imbalance, with increased sympathetic activity and decreased parasympathetic vagal tone. Recent device-based approaches, such as implantable vagal stimulators that stimulate a multitude of visceral sensory and motor fibers in the vagus nerve, are being evaluated as new therapeutic approaches for these and other diseases. However, little is known about how parasympathetic activity to the heart is altered with these diseases, and this lack of knowledge is an obstacle in the goal of devising selective interventions that can target and selectively restore parasympathetic activity to the heart. To identify the changes that occur within the brain stem to diminish the parasympathetic cardiac activity, left ventricular hypertrophy was elicited in rats by aortic pressure overload using a transaortic constriction approach. Cardiac vagal neurons (CVNs) in the brain stem that generate parasympathetic activity to the heart were identified with a retrograde tracer and studied using patch-clamp electrophysiological recordings in vitro. Animals with left cardiac hypertrophy had diminished excitation of CVNs, which was mediated both by an augmented frequency of spontaneous inhibitory GABAergic neurotransmission (with no alteration of inhibitory glycinergic activity) as well as a diminished amplitude and frequency of excitatory neurotransmission to CVNs. Opportunities to alter these network pathways and neurotransmitter receptors provide future targets of intervention in the goal to restore parasympathetic activity and autonomic balance to the heart in cardiac hypertrophy and other cardiovascular diseases. Copyright © 2015 the American Physiological Society.

  9. Energetic Systems

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    Federal Laboratory Consortium — The Energetic Systems Division provides full-spectrum energetic engineering services (project management, design, analysis, production support, in-service support,...

  10. Embryonic caffeine exposure acts via A1 adenosine receptors to alter adult cardiac function and DNA methylation in mice.

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    Daniela L Buscariollo

    Full Text Available Evidence indicates that disruption of normal prenatal development influences an individual's risk of developing obesity and cardiovascular disease as an adult. Thus, understanding how in utero exposure to chemical agents leads to increased susceptibility to adult diseases is a critical health related issue. Our aim was to determine whether adenosine A1 receptors (A1ARs mediate the long-term effects of in utero caffeine exposure on cardiac function and whether these long-term effects are the result of changes in DNA methylation patterns in adult hearts. Pregnant A1AR knockout mice were treated with caffeine (20 mg/kg or vehicle (0.09% NaCl i.p. at embryonic day 8.5. This caffeine treatment results in serum levels equivalent to the consumption of 2-4 cups of coffee in humans. After dams gave birth, offspring were examined at 8-10 weeks of age. A1AR+/+ offspring treated in utero with caffeine were 10% heavier than vehicle controls. Using echocardiography, we observed altered cardiac function and morphology in adult mice exposed to caffeine in utero. Caffeine treatment decreased cardiac output by 11% and increased left ventricular wall thickness by 29% during diastole. Using DNA methylation arrays, we identified altered DNA methylation patterns in A1AR+/+ caffeine treated hearts, including 7719 differentially methylated regions (DMRs within the genome and an overall decrease in DNA methylation of 26%. Analysis of genes associated with DMRs revealed that many are associated with cardiac hypertrophy. These data demonstrate that A1ARs mediate in utero caffeine effects on cardiac function and growth and that caffeine exposure leads to changes in DNA methylation.

  11. Embryonic Caffeine Exposure Acts via A1 Adenosine Receptors to Alter Adult Cardiac Function and DNA Methylation in Mice

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    Greenwood, Victoria; Xue, Huiling; Rivkees, Scott A.; Wendler, Christopher C.

    2014-01-01

    Evidence indicates that disruption of normal prenatal development influences an individual's risk of developing obesity and cardiovascular disease as an adult. Thus, understanding how in utero exposure to chemical agents leads to increased susceptibility to adult diseases is a critical health related issue. Our aim was to determine whether adenosine A1 receptors (A1ARs) mediate the long-term effects of in utero caffeine exposure on cardiac function and whether these long-term effects are the result of changes in DNA methylation patterns in adult hearts. Pregnant A1AR knockout mice were treated with caffeine (20 mg/kg) or vehicle (0.09% NaCl) i.p. at embryonic day 8.5. This caffeine treatment results in serum levels equivalent to the consumption of 2–4 cups of coffee in humans. After dams gave birth, offspring were examined at 8–10 weeks of age. A1AR+/+ offspring treated in utero with caffeine were 10% heavier than vehicle controls. Using echocardiography, we observed altered cardiac function and morphology in adult mice exposed to caffeine in utero. Caffeine treatment decreased cardiac output by 11% and increased left ventricular wall thickness by 29% during diastole. Using DNA methylation arrays, we identified altered DNA methylation patterns in A1AR+/+ caffeine treated hearts, including 7719 differentially methylated regions (DMRs) within the genome and an overall decrease in DNA methylation of 26%. Analysis of genes associated with DMRs revealed that many are associated with cardiac hypertrophy. These data demonstrate that A1ARs mediate in utero caffeine effects on cardiac function and growth and that caffeine exposure leads to changes in DNA methylation. PMID:24475304

  12. Cardiac energy metabolic alterations in pressure overload–induced left and right heart failure (2013 Grover Conference Series)

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    Lopaschuk, Gary D.

    2015-01-01

    Abstract Pressure overload of the heart, such as seen with pulmonary hypertension and/or systemic hypertension, can result in cardiac hypertrophy and the eventual development of heart failure. The development of hypertrophy and heart failure is accompanied by numerous molecular changes in the heart, including alterations in cardiac energy metabolism. Under normal conditions, the high energy (adenosine triphosphate [ATP]) demands of the heart are primarily provided by the mitochondrial oxidation of fatty acids, carbohydrates (glucose and lactate), and ketones. In contrast, the hypertrophied failing heart is energy deficient because of its inability to produce adequate amounts of ATP. This can be attributed to a reduction in mitochondrial oxidative metabolism, with the heart becoming more reliant on glycolysis as a source of ATP production. If glycolysis is uncoupled from glucose oxidation, a decrease in cardiac efficiency can occur, which can contribute to the severity of heart failure due to pressure-overload hypertrophy. These metabolic changes are accompanied by alterations in the enzymes that are involved in the regulation of fatty acid and carbohydrate metabolism. It is now becoming clear that optimizing both energy production and the source of energy production are potential targets for pharmacological intervention aimed at improving cardiac function in the hypertrophied failing heart. In this review, we will focus on what alterations in energy metabolism occur in pressure overload induced left and right heart failure. We will also discuss potential targets and pharmacological approaches that can be used to treat heart failure occurring secondary to pulmonary hypertension and/or systemic hypertension. PMID:25992268

  13. The influence of midazolam on heart rate arises from cardiac autonomic tones alterations in Burmese pythons, Python molurus.

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    Lopes, Ivã Guidini; Armelin, Vinicius Araújo; Braga, Victor Hugo da Silva; Florindo, Luiz Henrique

    2017-12-01

    The GABA A receptor agonist midazolam is a compound widely used as a tranquilizer and sedative in mammals and reptiles. It is already known that this benzodiazepine produces small to intermediate heart rate (HR) alterations in mammals, however, its influence on reptiles' HR remains unexplored. Thus, the present study sought to verify the effects of midazolam on HR and cardiac modulation in the snake Python molurus. To do so, the snakes' HR, cardiac autonomic tones, and HR variability were evaluated during four different experimental stages. The first stage consisted on the data acquisition of animals under untreated conditions, in which were then administered atropine (2.5mgkg -1 ; intraperitoneal), followed later by propranolol (3.5mgkg -1 ; intraperitoneal) (cardiac double autonomic blockade). The second stage focused on the data acquisition of animals under midazolam effect (1.0mgkg -1 ; intramuscular), which passed through the same autonomic blockade protocol of the first stage. The third and fourth stages consisted of the same protocol of stages one and two, respectively, with the exception that atropine and propranolol injections were reversed. By comparing the HR of animals that received midazolam (second and fourth stages) with those that did not (first and third stages), it could be observed that this benzodiazepine reduced the snakes' HR by ~60%. The calculated autonomic tones showed that such cardiac depression was elicited by an ~80% decrease in cardiac adrenergic tone and an ~620% increase in cardiac cholinergic tone - a finding that was further supported by the results of HR variability analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. VANADIUM EXPOSURE ALTERS SPONTANEOUS BEAT RATE AND GENE EXPRESSION OF CULTURED CARDIAC MYOCYTES

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    Ambient air pollution particulate matter (PM) exposure is associated with increased morbidity and mortality. Recent toxicological studies report PM-induced changes in a number of cardiac parameters, including heart rate variability, arrhythmias, repolarization, and internal defib...

  15. Disruption of pdgfra alters endocardial and myocardial fusion during zebrafish cardiac assembly

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    Suzan El-Rass

    2017-03-01

    Full Text Available Cardiac development in vertebrates is a finely tuned process regulated by a set of conserved signaling pathways. Perturbations of these processes are often associated with congenital cardiac malformations. Platelet-derived growth factor receptor α (PDGFRα is a highly conserved tyrosine kinase receptor, which is essential for development and organogenesis. Disruption of Pdgfrα function in murine models is embryonic lethal due to severe cardiovascular defects, suggesting a role in cardiac development, thus necessitating the use of alternative models to explore its precise function. In this study, we generated a zebrafish pdgfra mutant line by gene trapping, in which the Pdgfra protein is truncated and fused with mRFP (Pdgfra-mRFP. Our results demonstrate that pdgfra mutants have defects in cardiac morphology as a result of abnormal fusion of myocardial precursors. Expression analysis of the developing heart at later stages suggested that Pdgfra-mRFP is expressed in the endocardium. Further examination of the endocardium in pdgfra mutants revealed defective endocardial migration to the midline, where cardiac fusion eventually occurs. Together, our data suggests that pdgfra is required for proper medial migration of both endocardial and myocardial precursors, an essential step required for cardiac assembly and development.

  16. Happiness and Stress Alter Susceptibility to Cardiac Events in Long QT Syndrome

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    Lane, Richard D.; Reis, Harry T.; Peterson, Derick R.; Zareba, Wojciech; Moss, Arthur J.

    2014-01-01

    Objective We sought to determine whether the circumstances preceding an arrhythmic event differed from those preceding a prior control occasion in patients with Long QT Syndrome (LQTS), a well-characterized genetically-based disorder that puts affected individuals at risk for sudden cardiac death. Methods 38 patients (89% female) with LQTS completed a “case-crossover interview” in which each patient served as his/her own control by reporting on circumstances preceding an arrhythmic event (syncope, aborted cardiac arrest or defibrillator discharge) and preceding a control occasion (the next-to-last birthday). On average the interview was conducted 17 months after the cardiac event and control occasion. Results During the 24-hour period preceding the cardiac event compared to the day before the control occasion, psychological stress was elevated, peak happiness was reduced, and peak exertion was not significantly different. Rated for the 6-month intervals preceding the event and control occasions, none of these three variables was significantly associated with events. Conclusions Happiness is associated with a reduction in the 24-hour risk of cardiac events in patients with LQTS, with stress having an opposite effect. To our knowledge this is the first report indicating that positive emotion may have a protective effect on life-threatening ventricular arrhythmias. This study lends further support to the role of emotions in influencing cardiac events in arrhythmia-prone patients. PMID:19419405

  17. Altered cardiac rhythm in infants with bronchiolitis and respiratory syncytial virus infection.

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    Esposito, Susanna; Salice, Patrizia; Bosis, Samantha; Ghiglia, Silvia; Tremolati, Elena; Tagliabue, Claudia; Gualtieri, Laura; Barbier, Paolo; Galeone, Carlotta; Marchisio, Paola; Principi, Nicola

    2010-10-24

    Although the most frequent extra-pulmonary manifestations of respiratory syncytial virus (RSV) infection involve the cardiovascular system, no data regarding heart function in infants with bronchiolitis associated with RSV infection have yet been systematically collected. The aim of this study was to verify the real frequency of heart involvement in patients with bronchiolitis associated with RSV infection, and whether infants with mild or moderate disease also risk heart malfunction. A total of 69 otherwise healthy infants aged 1-12 months with bronchiolitis hospitalised in standard wards were enrolled. Pernasal flocked swabs were performed to collect specimens for the detection of RSV by real-time polymerase chain reaction, and a blood sample was drawn to assess troponin I concentrations. On the day of admission, all of the infants underwent 24-hour Holter ECG monitoring and a complete heart evaluation with echocardiography. Patients were re-evaluated by investigators blinded to the etiological and cardiac findings four weeks after enrollment. Regardless of their clinical presentation, sinoatrial blocks were identified in 26/34 RSV-positive patients (76.5%) and 1/35 RSV-negative patients (2.9%) (p < 0.0001). The blocks recurred more than three times over 24 hours in 25/26 RSV-positive patients (96.2%) and none of the RSV-negative infants. Mean and maximum heart rates were significantly higher in the RSV-positive infants (p < 0.05), as was low-frequency power and the low and high-frequency power ratio (p < 0.05). The blocks were significantly more frequent in the children with an RSV load of ≥100,000 copies/mL than in those with a lower viral load (p < 0.0001). Holter ECG after 28 ± 3 days showed the complete regression of the heart abnormalities. RSV seems associated with sinoatrial blocks and transient rhythm alterations even when the related respiratory problems are mild or moderate. Further studies are needed to clarify the mechanisms of these rhythm

  18. Fibroblast proliferation alters cardiac excitation conduction and contraction: a computational study*

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    Zhan, He-qing; Xia, Ling; Shou, Guo-fa; Zang, Yun-liang; Liu, Feng; Crozier, Stuart

    2014-01-01

    In this study, the effects of cardiac fibroblast proliferation on cardiac electric excitation conduction and mechanical contraction were investigated using a proposed integrated myocardial-fibroblastic electromechanical model. At the cellular level, models of the human ventricular myocyte and fibroblast were modified to incorporate a model of cardiac mechanical contraction and cooperativity mechanisms. Cellular electromechanical coupling was realized with a calcium buffer. At the tissue level, electrical excitation conduction was coupled to an elastic mechanics model in which the finite difference method (FDM) was used to solve electrical excitation equations, and the finite element method (FEM) was used to solve mechanics equations. The electromechanical properties of the proposed integrated model were investigated in one or two dimensions under normal and ischemic pathological conditions. Fibroblast proliferation slowed wave propagation, induced a conduction block, decreased strains in the fibroblast proliferous tissue, and increased dispersions in depolarization, repolarization, and action potential duration (APD). It also distorted the wave-front, leading to the initiation and maintenance of re-entry, and resulted in a sustained contraction in the proliferous areas. This study demonstrated the important role that fibroblast proliferation plays in modulating cardiac electromechanical behaviour and which should be considered in planning future heart-modeling studies. PMID:24599687

  19. Endotoxemia Engages the RhoA Kinase Pathway to Impair Cardiac Function By Altering Cytoskeleton, Mitochondrial Fission, and Autophagy.

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    Preau, Sebastien; Delguste, Florian; Yu, Yichi; Remy-Jouet, Isabelle; Richard, Vincent; Saulnier, Fabienne; Boulanger, Eric; Neviere, Remi

    2016-04-01

    The RhoA/ROCK pathway controls crucial biological processes involved in cardiovascular pathophysiology, such as cytoskeleton dynamics, vascular smooth muscle contraction, and inflammation. In this work, we tested whether Rho kinase inhibition would beneficially impact cardiac cytoskeleton organization, bioenergetics, and autophagy in experimental endotoxemia induced by lipopolysaccharides (LPSs) in mice. Fasudil, a potent ROCK inhibitor, prevented LPS-induced cardiac inflammation, oxidative stress, cytoskeleton disarray, and mitochondrial injury. ROCK inhibition prevented phosphorylation of cofilin and dynamin-related protein-1, which promotes stabilization-polymerization of F-actin and mediates mitochondrial fission, respectively. Pyr1, which exclusively alters actin dynamics, prevented LPS-induced myocardial dysfunction, suggesting that beneficial impact of ROCK inhibition was not mainly related to pleiotropic effects of fasudil on cardiac inflammation and oxidative stress. Fasudil reduced mitochondrial fragmentation, stimulated initiation of autophagy, and elicited cardioprotection in LPS heart. Mdivi-1, a potent mitochondria fission inhibitor, converted cardioprotective autophagy to an inefficient form due to cargo loading failure in which autophagic vacuoles fail to trap cytosolic cargo, despite their formation at enhanced rates and lysosomal elimination. In experimental endotoxemia, cardioprotection by RhoA/ROCK inhibition may be related to changes in actin cytoskeleton reorganization and mitochondrial homeostasis. Improvement of LPS-induced mitochondrial dysfunction by fasudil was attributed to inhibition of ROCK-dependent Drp1 phosphorylation and activation of autophagic processes that can limit mitochondrial fragmentation and enhance degradation of damaged mitochondria, respectively. Fasudil prevented LPS-induced heart oxidative stress, abnormal F-actin distribution, and oxidative phosphorylation, which concur to improve cardiac contractile and

  20. Cardiac metabolism and mechanics are altered by genetic loss of lipoprotein triglyceride lipolysis.

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    Noh, Hye-Lim; Yamashita, Haruyo; Goldberg, Ira J

    2006-12-01

    Most circulating fatty acids are contained in lipoprotein triglycerides. For the heart to acquire these lipids, they must be broken down into free fatty acids via the enzyme lipoprotein lipase (LpL). Although it has long been known that hearts primarily use esterified fatty acids as fuel, different sources of fatty acids were thought to be interchangeable. By creating mice with neonatal and acute LpL deletion we showed that lipoprotein-derived fatty acids could not be replaced by albumin-associated free fatty acids. Loss of cardiac LpL forces the heart to increase its uptake of glucose, reduce fatty acid oxidation, and eventually leads to cardiac dysfunction. In contrast, cardiomyocyte specific overexpression of an anchored form of LpL leads to excess lipid uptake, induction of fatty acid oxidation genes, and dilated cardiomyopathy. Increasing lipid secretion from the heart or redirecting lipids to adipose tissue can alleviate this lipotoxic situation.

  1. The expression of the rare caveolin-3 variant T78M alters cardiac ion channels function and membrane excitability

    Science.gov (United States)

    Campostrini, Giulia; Bonzanni, Mattia; Lissoni, Alessio; Bazzini, Claudia; Milanesi, Raffaella; Vezzoli, Elena; Francolini, Maura; Baruscotti, Mirko; Bucchi, Annalisa; Rivolta, Ilaria; Fantini, Matteo; Severi, Stefano; Cappato, Riccardo; Crotti, Lia; J. Schwartz, Peter; DiFrancesco, Dario; Barbuti, Andrea

    2017-01-01

    Abstract Aims Caveolinopathies are a family of genetic disorders arising from alterations of the caveolin-3 (cav-3) gene. The T78M cav-3 variant has been associated with both skeletal and cardiac muscle pathologies but its functional contribution, especially to cardiac diseases, is still controversial. Here, we evaluated the effect of the T78M cav-3 variant on cardiac ion channel function and membrane excitability. Methods and results We transfected either the wild type (WT) or T78M cav-3 in caveolin-1 knock-out mouse embryonic fibroblasts and found by immunofluorescence and electron microscopy that both are expressed at the plasma membrane and form caveolae. Two ion channels known to interact and co-immunoprecipitate with the cav-3, hKv1.5 and hHCN4, interact also with T78M cav-3 and reside in lipid rafts. Electrophysiological analysis showed that the T78M cav-3 causes hKv1.5 channels to activate and inactivate at more hyperpolarized potentials and the hHCN4 channels to activate at more depolarized potentials, in a dominant way. In spontaneously beating neonatal cardiomyocytes, the expression of the T78M cav-3 significantly increased action potential peak-to-peak variability without altering neither the mean rate nor the maximum diastolic potential. We also found that in a small cohort of patients with supraventricular arrhythmias, the T78M cav-3 variant is more frequent than in the general population. Finally, in silico analysis of both sinoatrial and atrial cell models confirmed that the T78M-dependent changes are compatible with a pro-arrhythmic effect. Conclusion This study demonstrates that the T78M cav-3 induces complex modifications in ion channel function that ultimately alter membrane excitability. The presence of the T78M cav-3 can thus generate a susceptible substrate that, in concert with other structural alterations and/or genetic mutations, may become arrhythmogenic. PMID:28898996

  2. Association between obesity and heart rate variability indices: an intuition toward cardiac autonomic alteration – a risk of CVD

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    Yadav RL

    2017-02-01

    Full Text Available Ram Lochan Yadav,1 Prakash Kumar Yadav,1 Laxmi Kumari Yadav,2 Kopila Agrawal,3 Santosh Kumar Sah,4 Md Nazrul Islam1 1Department of Physiology, 2Department of Microbiology, Chitwan Medical College, Bharatpur, 3Department of Physiology, BP Koirala Institute of Health Sciences, Dharan, 4Department of Biochemistry, Janaki Medical College, Janakpur, Nepal Background: Obese people have a higher prevalence of cardiovascular disease, which is supposed to be due to autonomic dysfunction and/or metabolic disorder. The alterations in cardiac autonomic functions bring out the changes in the heart rate variability (HRV indicators, an assessing tool for cardiac autonomic conditions.Objective: To compare the cardiac autonomic activity between obese and normal weight adults and find out the highest association between the indices of HRV and obesity.Methods: The study was conducted in 30 adult obese persons (body mass index [BMI] >30 kg/m2 and 29 healthy normal weight controls (BMI 18–24 kg/m2. Short-term HRV variables were assessed using standard protocol. Data were compared between groups using Mann–Whitney U test. Obesity indices such as waist circumference, hip circumference, waist–hip ratio (WHR, and BMI were measured and calculated, and they were correlated with HRV indices using Spearman’s correlation analysis.Results: In the obese group, there was a significant increase in the mean heart rate, whereas the HRV parasympathetic indicators were less (eg, root mean square of differences of successive RR intervals [28.75 {16.72–38.35} vs 41.55 {30.6–56.75} ms, p=0.018], number of RR intervals that differ by >50 ms, that is, NN50 [15.5 {2–39} vs 83.5 {32.75–116.25}, p=0.010], etc and the sympathetic indicator low frequency (LF/high frequency (HF ratio (1.2 [0.65–2.20] vs 0.79 [0.5–1.02], p=0.045 was more than that of the normal weight group. Spearman’s correlation between HRV and obesity indices showed significant positive correlation of

  3. Monoamine Oxidases, Oxidative Stress, and Altered Mitochondrial Dynamics in Cardiac Ageing

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    Damien Maggiorani

    2017-01-01

    Full Text Available The advances in healthcare over the past several decades have resulted in populations now living longer. With this increase in longevity, a wider prevalence of cardiovascular diseases is more common and known to be a major factor in rising healthcare costs. A wealth of scientific evidence has implicated cell senescence as an important component in the etiology of these age-dependent pathologies. A number of studies indicate that an excess of reactive oxygen species (ROS contributes to trigger and accelerate the cardiac senescence processes, and a new role of monoamine oxidases, MAO-A and MAO-B, is emerging in this context. These mitochondrial enzymes regulate the level of catecholamines and serotonin by catalyzing their oxidative deamination in the heart. MAOs’ expression substantially increases with ageing (6-fold MAO-A in the heart and 4-fold MAO-B in neuronal tissue, and their involvement in cardiac diseases is supposedly related to the formation of ROS, via the hydrogen peroxide produced during the substrate degradation. Here, we will review the most recent advances in this field and describe why MAOs could be effective targets in order to prevent age-associated cardiovascular disease.

  4. Cardiac alterations in human African trypanosomiasis (T.b. gambiense with respect to the disease stage and antiparasitic treatment.

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    Johannes A Blum

    Full Text Available In Human African Trypanosomiasis, neurological symptoms dominate and cardiac involvement has been suggested. Because of increasing resistance to the available drugs for HAT, new compounds are desperately needed. Evaluation of cardiotoxicity is one parameter of drug safety, but without knowledge of the baseline heart involvement in HAT, cardiologic findings and drug-induced alterations will be difficult to interpret. The aims of the study were to assess the frequency and characteristics of electrocardiographic findings in the first stage of HAT, to compare these findings to those of second stage patients and healthy controls and to assess any potential effects of different therapeutic antiparasitic compounds with respect to ECG changes after treatment.Four hundred and six patients with first stage HAT were recruited in the Democratic Republic of Congo, Angola and Sudan between 2002 and 2007 in a series of clinical trials comparing the efficacy and safety of the experimental treatment DB289 to the standard first stage treatment, pentamidine. These ECGs were compared to the ECGs of healthy volunteers (n = 61 and to those of second stage HAT patients (n = 56.In first and second stage HAT, a prolonged QTc interval, repolarization changes and low voltage were significantly more frequent than in healthy controls. Treatment in first stage was associated with repolarization changes in both the DB289 and the pentamidine group to a similar extent. The QTc interval did not change during treatment.Cardiac involvement in HAT, as demonstrated by ECG alterations, appears early in the evolution of the disease. The prolongation of the QTC interval comprises a risk of fatal arrhythmias if new drugs with an additional potential of QTC prolongation will be used. During treatment ECG abnormalities such as repolarization changes consistent with peri-myocarditis occur frequently and appear to be associated with the disease stage, but not with a specific drug.

  5. In-utero exposure to nicotine alters the development of the rabbit cardiac conduction system and provides a potential mechanism for sudden infant death syndrome.

    Science.gov (United States)

    Ton, Anh Tuan; Biet, Michael; Delabre, Jean-Francois; Morin, Nathalie; Dumaine, Robert

    2017-12-01

    In-utero exposure to tobacco smoke remains the highest risk factor for sudden infant death syndrome (SIDS). To alleviate the risks, nicotine replacement therapies are often prescribed to women who wish to quit smoking during their pregnancy. Cardiac arrhythmias is considered the final outcome leading to sudden death. Our goal in this study was to determine if exposing rabbit fetus to nicotine altered the cardiac conduction system of newborn kittens in a manner susceptible to cause SIDS. Using neuronal markers and a series of immunohistological and electrophysiological techniques we found that nicotine delayed the development of the cardiac pacemaker center (sinoatrial node) and decreased its innervation. At the molecular level, nicotine favored the expression of cardiac sodium channels with biophysical properties that will tend to slow heart rate and diminish electrical conduction. Our results show that alterations of the cardiac sodium current may contribute to the bradycardia, conduction disturbances and other cardiac arrhythmias often associated to SIDS and raise awareness on the use of replacement therapy during pregnancy.

  6. Alteration of Cardiac Deformation in Acute Rejection in Pediatric Heart Transplant Recipients.

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    Chanana, Nitin; Van Dorn, Charlotte S; Everitt, Melanie D; Weng, Hsin Yi; Miller, Dylan V; Menon, Shaji C

    2017-04-01

    The objective of this study is to assess changes in cardiac deformation during acute cellular- and antibody-mediated rejection in pediatric HT recipients. Pediatric HT recipients aged ≤18 years with at least one episode of biopsy-diagnosed rejection from 2006 to 2013 were included. Left ventricular systolic S (SS) and SR (SSr) data were acquired using 2D speckle tracking on echocardiograms obtained within 12 h of right ventricular endomyocardial biopsy. A mixed effect model was used to compare cardiac deformation during CR (Grade ≥ 1R), AMR (pAMR ≥ 2), and mixed rejection (CR and AMR positive) versus no rejection (Grade 0R and pAMR 0 or 1). A total of 20 subjects (10 males, 50%) with 71 rejection events (CR 35, 49%; AMR 21, 30% and mixed 15, 21%) met inclusion criteria. The median time from HT to first biopsy used for analysis was 5 months (IQR 0.25-192 months). Average LV longitudinal SS and SSr were reduced significantly during rejection (SS: -17.2 ± 3.4% vs. -10.7 ± 4.5%, p < 0.001 and SSr: -1.2 ± 0.2 s - 1 vs. -0.9 ± 0.3 s - 1 ; p < 0.001) and in all rejection types. Average LV short-axis radial SS was reduced only in CR compared to no rejection (p = 0.04), while average LV circumferential SS and SSr were reduced significantly in AMR compared to CR (SS: 18.9 ± 4.2% vs. 20.8 ± 8.8%, p = 0.03 and SSr: 1.35 ± 0.8 s - 1 vs. 1.54 ± 0.9 s - 1 ; p = 0.03). In pediatric HT recipients, LV longitudinal SS and SSr were reduced in all rejection types, while LV radial SS was reduced only in CR. LV circumferential SS and SSr further differentiated between CR and AMR with a significant reduction seen in AMR as compared to CR. This novel finding suggests mechanistic differences between AMR- and CR-induced myocardial injury which may be useful in non-invasively predicting the type of rejection in pediatric HT recipients.

  7. Trpm4 gene invalidation leads to cardiac hypertrophy and electrophysiological alterations.

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    Marie Demion

    Full Text Available RATIONALE: TRPM4 is a non-selective Ca2+-activated cation channel expressed in the heart, particularly in the atria or conduction tissue. Mutations in the Trpm4 gene were recently associated with several human conduction disorders such as Brugada syndrome. TRPM4 channel has also been implicated at the ventricular level, in inotropism or in arrhythmia genesis due to stresses such as ß-adrenergic stimulation, ischemia-reperfusion, and hypoxia re-oxygenation. However, the physiological role of the TRPM4 channel in the healthy heart remains unclear. OBJECTIVES: We aimed to investigate the role of the TRPM4 channel on whole cardiac function with a Trpm4 gene knock-out mouse (Trpm4-/- model. METHODS AND RESULTS: Morpho-functional analysis revealed left ventricular (LV eccentric hypertrophy in Trpm4-/- mice, with an increase in both wall thickness and chamber size in the adult mouse (aged 32 weeks when compared to Trpm4+/+ littermate controls. Immunofluorescence on frozen heart cryosections and qPCR analysis showed no fibrosis or cellular hypertrophy. Instead, cardiomyocytes in Trpm4-/- mice were smaller than Trpm4+/+with a higher density. Immunofluorescent labeling for phospho-histone H3, a mitosis marker, showed that the number of mitotic myocytes was increased 3-fold in the Trpm4-/-neonatal stage, suggesting hyperplasia. Adult Trpm4-/- mice presented multilevel conduction blocks, as attested by PR and QRS lengthening in surface ECGs and confirmed by intracardiac exploration. Trpm4-/-mice also exhibited Luciani-Wenckebach atrioventricular blocks, which were reduced following atropine infusion, suggesting paroxysmal parasympathetic overdrive. In addition, Trpm4-/- mice exhibited shorter action potentials in atrial cells. This shortening was unrelated to modifications of the voltage-gated Ca2+ or K+ currents involved in the repolarizing phase. CONCLUSIONS: TRPM4 has pleiotropic roles in the heart, including the regulation of conduction and cellular

  8. Therapy with mesenchymal stromal cells or conditioned medium reverse cardiac alterations in a high-fat diet-induced obesity model.

    Science.gov (United States)

    Daltro, P S; Barreto, B C; Silva, P G; Neto, P Chenaud; Sousa Filho, P H F; Santana Neta, D; Carvalho, G B; Silva, D N; Paredes, B D; de Alcantara, A C; Freitas, L A R; Couto, R D; Santos, R R; Souza, B S F; Soares, M B P; Macambira, S G

    2017-10-01

    Obesity is associated with numerous cardiac complications, including arrhythmias, cardiac fibrosis, remodeling and heart failure. Here we evaluated the therapeutic potential of mesenchymal stromal cells (MSCs) and their conditioned medium (CM) to treat cardiac complications in a mouse model of high-fat diet (HFD)-induced obesity. After obesity induction and HFD withdrawal, obese mice were treated with MSCs, CM or vehicle. Cardiac function was assessed using electrocardiography, echocardiography and treadmill test. Body weight and biochemical parameters were evaluated. Cardiac tissue was used for real time (RT)-polymerase chain reaction (PCR) and histopathologic analysis. Characterization of CM by protein array showed the presence of different cytokines and growth factors, including chemokines, osteopontin, cystatin C, Serpin E1 and Gas 6. HFD-fed mice presented cardiac arrhythmias, altered cardiac gene expression and fibrosis reflected in physical exercise incapacity associated with obesity and diabetes. Administration of MSCs or CM improved arrhythmias and exercise capacity. This functional improvement correlated with normalization of GATA4 gene expression in the hearts of MSC- or CM-treated mice. The gene expression of connexin 43, troponin I, adiponectin, transforming growth factor (TGF) β, peroxisome proliferator activated receptor gamma (PPARγ), insulin-like growth factor 1 (IGF-1), matrix metalloproteinase-9 (MMP9) and tissue inhibitor of metalloproteinases 1 (TIMP1) were significantly reduced in MSCs, but not in CM-treated mice. Moreover, MSC or CM administration reduced the intensity of cardiac fibrosis. Our results suggest that MSCs and CM have a recovery effect on cardiac disturbances due to obesity and corroborate to the paracrine action of MSCs in heart disease models. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  9. Left Recumbent Position Decreases Heart Rate without Alterations in Cardiac Autonomic Nervous System Activity in Healthy Young Adults.

    Science.gov (United States)

    Sasaki, Konosuke; Haga, Mayu; Endo, Yoichi; Fujiwara, Junko; Maruyama, Ryoko

    2017-04-01

    Some studies have reported that recumbent position may have advantages in patients with heart disease and in pregnancy. However, it remains controversial whether recumbent position affects autonomic nervous system activity and hemodynamics in healthy adults. The aim of this study was to evaluate alterations in heart rate variability (HRV) and hemodynamics in the supine, left recumbent and right recumbent positions in healthy young adults. A total of 80 participants aged 22.8 ± 3.1 years were enrolled in this observational study. Fifty-eight volunteers (29 men and 29 women) maintained the supine position followed by the left and right recumbent positions, while electrocardiographic data were recorded for spectral analysis of HRV to assess cardiac vagal nerve and sympathetic nerve activities. The heart rate (HR) was significantly lower in the left recumbent position than in the other positions. There were no statistically significant differences in HRV among the three positions. Considering the possibility that the echographic procedure affects autonomic nervous system (ANS) activity, the other 22 participants (11 men and 11 women) underwent an echographic evaluation of hemodynamics in the heart and inferior vena cava (IVC) across the three positions. Although a low HR was also observed, there were no statistically significant differences in the IVC or the heart blood volume between the supine and the left recumbent positions. A postural change to the left recumbent position does not affect the cardiac blood circulation or ANS activity, though it does decrease HR in healthy young adults. This finding indicates that the lower HR in the left recumbent position is not attributable to the ANS activity.

  10. Cardiac structure and function during ageing in energetically compromised Guanidinoacetate N-methyltransferase (GAMT-knockout mice – a one year longitudinal MRI study

    Directory of Open Access Journals (Sweden)

    Clarke Kieran

    2008-02-01

    Full Text Available Abstract Background High-resolution magnetic resonance imaging (cine-MRI is well suited for determining global cardiac function longitudinally in genetically or surgically manipulated mice, but in practice it is seldom used to its full potential. In this study, male and female guanidinoacetate N-methyltransferase (GAMT knockout, and wild type littermate mice were subjected to a longitudinal cine-MRI study at four time points over the course of one year. GAMT is an essential enzyme in creatine biosynthesis, such that GAMT deficient mice are entirely creatine-free. Since creatine plays an important role in the buffering and transfer of high-energy phosphate bonds in the heart, it was hypothesized that lack of creatine would be detrimental for resting cardiac performance during ageing. Methods Measurements of cardiac structure (left ventricular mass and volumes and function (ejection fraction, stroke volume, cardiac output were obtained using high-resolution cine-MRI at 9.4 T under isoflurane anaesthesia. Results There were no physiologically significant differences in cardiac function between wild type and GAMT knockout mice at any time point for male or female groups, or for both combined (for example ejection fraction: 6 weeks (KO vs. WT: 70 ± 6% vs. 65 ± 7%; 4 months: 70 ± 6% vs. 62 ± 8%; 8 months: 62 ± 11% vs. 62 ± 6%; 12 months: 61 ± 7% vs. 59 ± 11%, respectively. Conclusion These findings suggest the presence of comprehensive adaptations in the knockout mice that can compensate for a lack of creatine. Furthermore, this study clearly demonstrates the power of cine-MRI for accurate non-invasive, serial cardiac measurements. Cardiac growth curves could easily be defined for each group, in the same set of animals for all time points, providing improved statistical power, and substantially reducing the number of mice required to conduct such a study. This technique should be eminently useful for following changes of cardiac structure and

  11. Alteration of the Cardiac Sympathetic Innervation Is Modulated by Duration of Diabetes in Female Rats

    Directory of Open Access Journals (Sweden)

    Jitka Švíglerová

    2011-01-01

    Full Text Available To evaluate the sympathetic innervation of the female diabetic heart, resting heart rate and sympathetic tone were assessed in vivo, and effect of tyramine on spontaneous beating rate, norepinephrine atrial concentrations, uptake, and release were determined in vitro in streptozotocin- (STZ- treated rats and respective controls aged 3 months to 2 years. Resting bradycardia, decreased sympathetic tone, deceleration of spontaneous beating rate, and slightly declining carrier-mediated, but preserved exocytotic norepinephrine release from the atria were found in younger diabetic rats while the reactivity of the right atria to tyramine was not affected with age and disease duration. Diabetic two-year-old animals displayed symptoms of partial spontaneous recovery including normoglycemia, increased plasma insulin concentrations, fully recovered sympathetic tone, but putative change, in releasable norepinephrine tissue stores. Our data suggested that female diabetic heart exposed to long-lasting diabetic conditions seems to be more resistant to alteration in sympathetic innervation than the male one.

  12. Effect of cardiac glycosides from Nerium indicum on feeding rate, digestive enzymes activity and ultrastructural alterations of hepatopancreas in Pomacea canaliculata.

    Science.gov (United States)

    Dai, Lingpeng; Qian, Xiaowei; Nan, Xuyang; Zhang, Yejian

    2014-01-01

    Cardiac glycosides from Nerium indicum showed potent molluscicide activity against Pomacea canaliculata (GAS), but the toxicological mechanism is still far less understood. Effects of sublethal treatments of cardiac glycosides on feeding rate, digestive enzymes and ultrastructural alterations of the hepatopancreas in GAS were evaluated in this study. Exposure of GAS to sublethal concentrations of cardiac glycosides resulted in a significant reduction of feeding rate of GAS. The amylase, cellulose and protease activity were increase significantly at the end of 24 h followed by significant inhibition after 48 h of exposure while lipase activity was not affected significantly at the end of 24 h followed by a significant inhibition after 48 h of exposure during experimental period. The main ultrastructural alterations of hepatopancreas observed in snails under cardiac glycosides treatment comprised disruption of nuclear membrane, increased vesiculation and dilatation of endoplasmic reticulum, and vacuolization and swelling of mitochondrial compared to the untreated GAS. These results, for the first time, provide systematic evidences showing that cardiac glycosides seriously impairs the hepatopancreas tissues of GAS, resulting in inhibition of digestive enzymes activity and feeding rate and cause GAS death in the end. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Administration of granulocyte-colony stimulating factor accompanied with a balanced diet improves cardiac function alterations induced by high fat diet in mice.

    Science.gov (United States)

    Daltro, Pâmela Santana; Alves, Paula Santana; Castro, Murilo Fagundes; Azevedo, Carine M; Vasconcelos, Juliana Fraga; Allahdadi, Kyan James; de Freitas, Luiz Antônio Rodrigues; de Freitas Souza, Bruno Solano; Dos Santos, Ricardo Ribeiro; Soares, Milena Botelho Pereira; Macambira, Simone Garcia

    2015-12-03

    High fat diet (HFD) is a major contributor to the development of obesity and cardiovascular diseases due to the induction of cardiac structural and hemodynamic abnormalities. We used a model of diabetic cardiomyopathy in C57Bl/6 mice fed with a HFD to investigate the effects of granulocyte-colony stimulating factor (G-CSF), a cytokine known for its beneficial effects in the heart, on cardiac anatomical and functional abnormalities associated with obesity and type 2 diabetes. Groups of C57Bl/6 mice were fed with standard diet (n = 8) or HFD (n = 16). After 36 weeks, HFD animals were divided into a group treated with G-CSF + standard diet (n = 8) and a vehicle control group + standard diet (n = 8). Cardiac structure and function were assessed by electrocardiography, echocardiography and treadmill tests, in addition to the evaluation of body weight, fasting glicemia, insulin and glucose tolerance at different time points. Histological analyses were performed in the heart tissue. HFD consumption induced metabolic alterations characteristic of type 2 diabetes and obesity, as well as cardiac fibrosis and reduced exercise capacity. Upon returning to a standard diet, obese mice body weight returned to non-obese levels. G-CSF administration accelerated the reduction in of body weight in obese mice. Additionally, G-CSF treatment reduced insulin levels, diminished heart fibrosis, increased exercise capacity and reversed cardiac alterations, including bradycardia, elevated QRS amplitude, augmented P amplitude, increased septal wall thickness, left ventricular posterior thickening and cardiac output reduction. Our results indicate that G-CSF administration caused beneficial effects on obesity-associated cardiac impairment.

  14. Fetal programming alters reactive oxygen species production in sheep cardiac mitochondria.

    Science.gov (United States)

    von Bergen, Nicholas H; Koppenhafer, Stacia L; Spitz, Douglas R; Volk, Kenneth A; Patel, Sonali S; Roghair, Robert D; Lamb, Fred S; Segar, Jeffrey L; Scholz, Thomas D

    2009-04-01

    Exposure to an adverse intrauterine environment is recognized as an important risk factor for the development of cardiovascular disease later in life. Although oxidative stress has been proposed as a mechanism for the fetal programming phenotype, the role of mitochondrial O(2)(*-) (superoxide radical) production has not been explored. To determine whether mitochondrial ROS (reactive oxygen species) production is altered by in utero programming, pregnant ewes were given a 48-h dexamethasone (dexamethasone-exposed, 0.28 mg.kg(-1) of body weight.day(-1)) or saline (control) infusion at 27-28 days gestation (term=145 days). Intact left ventricular mitochondria and freeze-thaw mitochondrial membranes were studied from offspring at 4-months of age. AmplexRed was used to measure H(2)O(2) production. Activities of the antioxidant enzymes Mn-SOD (manganese superoxide dismutase), GPx (glutathione peroxidase) and catalase were measured. Compared with controls, a significant increase in Complex I H(2)O(2) production was found in intact mitochondria from dexamethasone-exposed animals. The treatment differences in Complex I-driven H(2)O(2) production were not seen in mitochondrial membranes. Consistent changes in H(2)O(2) production from Complex III in programmed animals were not found. Despite the increase in H(2)O(2) production in intact mitochondria from programmed animals, dexamethasone exposure significantly increased mitochondrial catalase activity, whereas Mn-SOD and GPx activities were unchanged. The results of the present study point to an increase in the rate of release of H(2)O(2) from programmed mitochondria despite an increase in catalase activity. Greater mitochondrial H(2)O(2) release into the cell may play a role in the development of adult disease following exposure to an adverse intrauterine environment.

  15. Metabonomics Indicates Inhibition of Fatty Acid Synthesis, β-Oxidation, and Tricarboxylic Acid Cycle in Triclocarban-Induced Cardiac Metabolic Alterations in Male Mice.

    Science.gov (United States)

    Xie, Wenping; Zhang, Wenpeng; Ren, Juan; Li, Wentao; Zhou, Lili; Cui, Yuan; Chen, Huiming; Yu, Wenlian; Zhuang, Xiaomei; Zhang, Zhenqing; Shen, Guolin; Li, Haishan

    2018-02-14

    Triclocarban (TCC) has been identified as a new environmental pollutant that is potentially hazardous to human health; however, the effects of short-term TCC exposure on cardiac function are not known. The aim of this study was to use metabonomics and molecular biology techniques to systematically elucidate the molecular mechanisms of TCC-induced effects on cardiac function in mice. Our results show that TCC inhibited the uptake, synthesis, and oxidation of fatty acids, suppressed the tricarboxylic acid (TCA) cycle, and increased aerobic glycolysis levels in heart tissue after short-term TCC exposure. TCC also inhibited the nuclear peroxisome proliferator-activated receptor α (PPARα), confirming its inhibitory effects on fatty acid uptake and oxidation. Histopathology and other analyses further confirm that TCC altered mouse cardiac physiology and pathology, ultimately affecting normal cardiac metabolic function. We elucidate the molecular mechanisms of TCC-induced harmful effects on mouse cardiac metabolism and function from a new perspective, using metabonomics and bioinformatics analysis data.

  16. Energetic map

    International Nuclear Information System (INIS)

    2012-01-01

    This report explains the energetic map of Uruguay as well as the different systems that delimits political frontiers in the region. The electrical system importance is due to the electricity, oil and derived , natural gas, potential study, biofuels, wind and solar energy

  17. Prenatal exposure to dexamethasone in the mouse alters cardiac growth patterns and increases pulse pressure in aged male offspring.

    Directory of Open Access Journals (Sweden)

    Lee O'Sullivan

    Full Text Available Exposure to synthetic glucocorticoids during development can result in later cardiovascular and renal disease in sheep and rats. Although prenatal glucocorticoid exposure is associated with impaired renal development, less is known about effects on the developing heart. This study aimed to examine the effects of a short-term exposure to dexamethasone (60 hours from embryonic day 12.5 on the developing mouse heart, and cardiovascular function in adult male offspring. Dexamethasone (DEX exposed fetuses were growth restricted compared to saline treated controls (SAL at E14.5, but there was no difference between groups at E17.5. Heart weights of the DEX fetuses also tended to be smaller at E14.5, but not different at E17.5. Cardiac AT1aR, Bax, and IGF-1 mRNA expression was significantly increased by DEX compared to SAL at E17.5. In 12-month-old offspring DEX exposure caused an increase in basal blood pressure of ~3 mmHg. In addition, DEX exposed mice had a widened pulse pressure compared to SAL. DEX exposed males at 12 months had an approximate 25% reduction in nephron number compared to SAL, but no difference in cardiomyocyte number. Exposure to DEX in utero appears to adversely impact on nephrogenesis and heart growth but is not associated with a cardiomyocyte deficit in male mice in adulthood, possibly due to compensatory growth of the myocardium following the initial insult. However, the widened pulse pressure may be indicative of altered vascular compliance.

  18. Preventive effects of p-coumaric acid on cardiac hypertrophy and alterations in electrocardiogram, lipids, and lipoproteins in experimentally induced myocardial infarcted rats.

    Science.gov (United States)

    Roy, Abhro Jyoti; Stanely Mainzen Prince, P

    2013-10-01

    The present study evaluated the preventive effects of p-coumaric acid on cardiac hypertrophy and alterations in electrocardiogram, lipids, and lipoproteins in experimentally induced myocardial infarcted rats. Rats were pretreated with p-coumaric acid (8 mg/kg body weight) daily for a period of 7 days and then injected with isoproterenol (100mg/kg body weight) on 8th and 9th day to induce myocardial infarction. Myocardial infarction induced by isoproterenol was indicated by increased level of cardiac sensitive marker and elevated ST-segments in the electrocardiogram. Also, the levels/concentrations of serum and heart cholesterol, triglycerides and free fatty acids were increased in myocardial infarcted rats. Isoproterenol also increased the levels of serum low density and very low density lipoprotein cholesterol and decreased the levels of high density lipoprotein cholesterol. It also enhanced the activity of liver 3-hydroxy-3 methyl glutaryl-Coenzyme-A reductase. p-Coumaric acid pretreatment revealed preventive effects on all the biochemical parameters and electrocardiogram studied in myocardial infarcted rats. The in vitro study confirmed the free radical scavenging property of p-coumaric acid. Thus, p-coumaric acid prevented cardiac hypertrophy and alterations in lipids, lipoproteins, and electrocardiogram, by virtue of its antihypertrophic, antilipidemic, and free radical scavenging effects in isoproterenol induced myocardial infarcted rats. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Partial IGF-1 deficiency is sufficient to reduce heart contractibility, angiotensin II sensibility, and alter gene expression of structural and functional cardiac proteins.

    Science.gov (United States)

    González-Guerra, José Luis; Castilla-Cortazar, Inma; Aguirre, Gabriel A; Muñoz, Úrsula; Martín-Estal, Irene; Ávila-Gallego, Elena; Granado, Miriam; Puche, Juan E; García-Villalón, Ángel Luis

    2017-01-01

    Circulating levels of IGF-1 may decrease under several circumstances like ageing, metabolic syndrome, and advanced cirrhosis. This reduction is associated with insulin resistance, dyslipidemia, progression to type 2 diabetes, and increased risk for cardiovascular diseases. However, underlying mechanisms between IGF-1 deficiency and cardiovascular disease remain elusive. The specific aim of the present work was to study whether the partial IGF-1 deficiency influences heart and/or coronary circulation, comparing vasoactive factors before and after of ischemia-reperfusion (I/R). In addition, histology of the heart was performed together with cardiac gene expression for proteins involved in structure and function (extracellular matrix, contractile proteins, active peptides); carried out using microarrays, followed by RT-qPCR confirmation of the three experimental groups. IGF-1 partial deficiency is associated to a reduction in contractility and angiotensin II sensitivity, interstitial fibrosis as well as altered expression pattern of genes involved in extracellular matrix proteins, calcium dynamics, and cardiac structure and function. Although this work is descriptive, it provides a clear insight of the impact that partial IGF-1 deficiency on the heart and establishes this experimental model as suitable for studying cardiac disease mechanisms and exploring therapeutic options for patients under IGF-1 deficiency conditions.

  20. Mechanisms Involving Ang II and MAPK/ERK1/2 Signaling Pathways Underlie Cardiac and Renal Alterations during Chronic Undernutrition

    Science.gov (United States)

    Pereira-Acácio, Amaury; Luzardo, Ricardo; Sampaio, Luzia S.; Luna-Leite, Marcia A.; Lara, Lucienne S.; Einicker-Lamas, Marcelo; Panizzutti, Rogério; Madeira, Caroline; Vieira-Filho, Leucio D.; Castro-Chaves, Carmen; Ribeiro, Valdilene S.; Paixão, Ana D. O.; Medei, Emiliano; Vieyra, Adalberto

    2014-01-01

    Background Several studies have correlated protein restriction associated with other nutritional deficiencies with the development of cardiovascular and renal diseases. The driving hypothesis for this study was that Ang II signaling pathways in the heart and kidney are affected by chronic protein, mineral and vitamin restriction. Methodology/Principal Findings Wistar rats aged 90 days were fed from weaning with either a control or a deficient diet that mimics those used in impoverished regions worldwide. Such restriction simultaneously increased ouabain-insensitive Na+-ATPase and decreased (Na++K+)ATPase activity in the same proportion in cardiomyocytes and proximal tubule cells. Type 1 angiotensin II receptor (AT1R) was downregulated by that restriction in both organs, whereas AT2R decreased only in the kidney. The PKC/PKA ratio increased in both tissues and returned to normal values in rats receiving Losartan daily from weaning. Inhibition of the MAPK pathway restored Na+-ATPase activity in both organs. The undernourished rats presented expanded plasma volume, increased heart rate, cardiac hypertrophy, and elevated systolic pressure, which also returned to control levels with Losartan. Such restriction led to electrical cardiac remodeling represented by prolonged ventricular repolarization parameters, induced triggered activity, early after-depolarization and delayed after-depolarization, which were also prevented by Losartan. Conclusion/Significance The mechanisms responsible for these alterations are underpinned by an imbalance in the PKC- and PKA-mediated pathways, with participation of angiotensin receptors and by activation of the MAPK/ERK1/2 pathway. These cellular and molecular alterations culminate in cardiac electric remodeling and in the onset of hypertension in adulthood. PMID:24983243

  1. Cardiac Connexin-43 and PKC Signaling in Rats With Altered Thyroid Status Without and With Omega-3 Fatty Acids Intake

    Czech Academy of Sciences Publication Activity Database

    Szeiffová Bačová, B.; Egan Beňová, T.; Viczenczová, C.; Soukup, Tomáš; Rauchová, Hana; Pavelka, Stanislav; Knezl, V.; Barančík, M.; Tribulová, N.

    2016-01-01

    Roč. 65, Suppl.1 (2016), S77-S90 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA305/09/1228; GA ČR(CZ) GAP304/12/0259 Institutional support: RVO:67985823 Keywords : thyroid hormones * cardiac arrhythmias * Connexin-43 * omega-3 polyunsaturated fatty acids Subject RIV: ED - Physiology Impact factor: 1.461, year: 2016

  2. Intracellular Na⁺ and cardiac metabolism.

    Science.gov (United States)

    Bay, Johannes; Kohlhaas, Michael; Maack, Christoph

    2013-08-01

    In heart failure, alterations of excitation-contraction underlie contractile dysfunction. One important defect is an elevation of the intracellular Na(+) concentration in cardiac myocytes ([Na(+)]i), which has an important impact on cytosolic and mitochondrial Ca(2+) homeostasis. While elevated [Na(+)]i is thought to compensate for decreased Ca(2+) load of the sarcoplasmic reticulum (SR), it yet negatively affects energy supply-and-demand matching and can even induce mitochondrial oxidative stress. Here, we review the mechanisms underlying these pathophysiological changes. The chain of events may constitute a vicious cycle of ion dysregulation, oxidative stress and energetic deficit, resembling characteristic cellular deficits that are considered key hallmarks of the failing heart. This article is part of a Special Issue entitled "Na(+) Regulation in Cardiac Myocytes". Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Prevention of cardiac dysfunction, kidney fibrosis and lipid metabolic alterations in l-NAME hypertensive rats by sinapic acid--Role of HMG-CoA reductase.

    Science.gov (United States)

    Silambarasan, Thangarasu; Manivannan, Jeganathan; Raja, Boobalan; Chatterjee, Suvro

    2016-04-15

    The present study was designed to evaluate the effect of sinapic acid, a bioactive phenolic acid on high blood pressure associated cardiac dysfunction, kidney fibrosis and lipid alterations in N(ω)-nitro-l-arginine methyl ester hydrochloride (l-NAME) induced hypertensive rats. Sinapic acid was administered to rats orally at a dosage of 40 mg/kg everyday for a period of 4 weeks. Sinapic acid treatment significantly decreased mean arterial pressure, left ventricular end diastolic pressure, organ weights (liver and kidney), lipid peroxidation products in tissues (liver and kidney), activities of hepatic marker enzymes and the levels of renal function markers in serum of l-NAME rats. Sinapic acid treatment also significantly increased the level of plasma nitric oxide metabolites, and enzymatic and non-enzymatic antioxidants in tissues of l-NAME rats. Tissue damage was assessed by histopathological examination. Alterations in plasma angiotensin-converting enzyme activity, level of plasma lipoproteins and tissue lipids were corrected by sinapic acid treatment in l-NAME rats. Sinapic acid treatment significantly decreased the activity of 3-hydroxy-3-methylglutaryl-Coenzyme A (HMG-CoA) reductase in plasma and liver, whereas the activity of lecithin cholesterol acyl transferase was significantly increased in the plasma of hypertensive rats. Docking result showed the interaction between sinapic acid and HMG-CoA reductase. Sinapic acid has shown best ligand binding energy of -5.5 kcal/M. Moreover, in chick embryo model, sinapic acid improved vessel density on chorioallantoic membrane. These results of the present study concludes that sinapic acid acts as a protective agent against hypertension associated cardiac dysfunction, kidney fibrosis and lipid alterations. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Ecstasy (MDMA) Alters Cardiac Gene Expression and DNA Methylation: Implications for Circadian Rhythm Dysfunction in the Heart.

    Science.gov (United States)

    Koczor, Christopher A; Ludlow, Ivan; Hight, Robert S; Jiao, Zhe; Fields, Earl; Ludaway, Tomika; Russ, Rodney; Torres, Rebecca A; Lewis, William

    2015-11-01

    MDMA (ecstasy) is an illicit drug that stimulates monoamine neurotransmitter release and inhibits reuptake. MDMA's acute cardiotoxicity includes tachycardia and arrhythmia which are associated with cardiomyopathy. MDMA acute cardiotoxicity has been explored, but neither long-term MDMA cardiac pathological changes nor epigenetic changes have been evaluated. Microarray analyses were employed to identify cardiac gene expression changes and epigenetic DNA methylation changes. To identify permanent MDMA-induced pathogenetic changes, mice received daily 10- or 35-day MDMA, or daily 10-day MDMA followed by 25-day saline washout (10 + 25 days). MDMA treatment caused differential gene expression (p 1.5) in 752 genes following 10 days, 558 genes following 35 days, and 113 genes following 10-day MDMA + 25-day saline washout. Changes in MAPK and circadian rhythm gene expression were identified as early as 10 days. After 35 days, circadian rhythm genes (Per3, CLOCK, ARNTL, and NPAS2) persisted to be differentially expressed. MDMA caused DNA hypermethylation and hypomethylation that was independent of gene expression; hypermethylation of genes was found to be 71% at 10 days, 68% at 35 days, and 91% at 10 + 25 days washout. Differential gene expression paralleled DNA methylation in 22% of genes at 10-day treatment, 17% at 35 days, and 48% at 10 + 25 days washout. We show here that MDMA induced cardiac epigenetic changes in DNA methylation where hypermethylation predominated. Moreover, MDMA induced gene expression of key elements of circadian rhythm regulatory genes. This suggests a fundamental organism-level event to explain some of the etiologies of MDMA dysfunction in the heart. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. Benznidazole biotransformation in rat heart microsomal fraction without observable ultrastructural alterations: comparison to Nifurtimox-induced cardiac effects

    Directory of Open Access Journals (Sweden)

    María Montalto de Mecca

    2008-09-01

    Full Text Available Benznidazole (Bz and Nifurtimox (Nfx have been used to treat Chagas disease. As recent studies have de-monstrated cardiotoxic effects of Nfx, we attempted to determine whether Bz behaves similarly. Bz reached the heart tissue of male rats after intragastric administration. No cytosolic Bz nitroreductases were detected, although microsomal NADPH-dependent Bz nitroreductase activity was observed, and appeared to be mediated by P450 reductase. No ultrastructurally observable deleterious effects of Bz were detected, in contrast to the overt cardiac effects previously reported for Nfx. In conclusion, when these drugs are used in chagasic patients, Bz may pose a lesser risk to heart function than Nfx when any cardiopathy is present.

  6. Comprehensive MRI for the detection of subtle alterations in diastolic cardiac function in apoE/LDLR(-/-) mice with advanced atherosclerosis.

    Science.gov (United States)

    Tyrankiewicz, Urszula; Skorka, Tomasz; Orzylowska, Anna; Jablonska, Magdalena; Jasinski, Krzysztof; Jasztal, Agnieszka; Bar, Anna; Kostogrys, Renata; Chlopicki, Stefan

    2016-06-01

    ApoE/LDLR(-/-) mice represent a reliable model of atherosclerosis. However, it is not clear whether cardiac performance is impaired in this murine model of atherosclerosis. Here, we used MRI to characterize cardiac performance in vivo in apoE/LDLR(-/-) mice with advanced atherosclerosis. Six-month-old apoE/LDLR(-/-) mice and age-matched C57BL/6J mice (control) were examined using highly time-resolved cine-MRI [whole-chamber left ventricle (LV) imaging] and MR tagging (three slices: basal, mid-cavity and apical). Global and regional measures of cardiac function included LV volumes, kinetics, time-dependent parameters, strains and rotations. Histological analysis was performed using OMSB (orceine with Martius, Scarlet and Blue) and ORO (oil red-O) staining to demonstrate the presence of advanced coronary atherosclerosis. MR-tagging-based strain analysis in apoE/LDLR(-/-) mice revealed an increased frequency of radial and circumferential systolic stretch (25% and 50% of segments, respectively, p ≤ 0.012), increased radial post-systolic strain index (45% of segments, p = 0.009) and decreased LV untwisting rate (-30.3° (11.6°)/cycle, p = 0.004) when compared with control mice. Maximal strains and LV twist were unchanged. Most of the cine-MRI-based LV functional and anatomical parameters also remained unchanged in apoE/LDLR(-/-) mice, with only a lower filling rate, longer filling time, shorter isovolumetric contraction time and slower heart rate observed in comparison with control mice. The coronary arteries displayed severe atherosclerosis, as evidenced by histological analysis. Using comprehensive MRI methods, we have demonstrated that, despite severe coronary atherosclerosis in six-month-old apoE/LDLR(-/-) mice, cardiac performance including global parameters, twist and strains, was well preserved. Only subtle diastolic alterations, possibly of ischemic background, were uncovered. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley

  7. The Protective Effect of Proponyl-L-Carnitine Against Ultrastructural Alterations in Cardiac Muscle of Irradiated and / or diabetic Rats

    International Nuclear Information System (INIS)

    Abu Nour, S.M.; Abdel-Azeem, M.G.; El-Nashar, D.E.M.

    2011-01-01

    Heart dysfunction in chronic diabetes has been observed to be associated with depressed myofibrillar adenosine triphosphatase activities. Oxidative stress a factor implicated in the heart injury may contribute towards some of these alterations. The present study was designed to evaluate the efficacy of L-carnitine on gamma radiation and diabetes induced oxidative damage in the heart by investigating alterations in the ultrastructural level. Streptozotocin was intraperitoneally injected (i.p) to rats at a dose of 28 mg/Kg b.wt / day for 2 weeks pre-irradiation. In irradiated groups, animals were exposed to 6.5 Gy whole body gamma radiation. L-carnitine was intraperitoneally injected (i.p) to rats at a dose of 250 mg/Kg b.wt/day for 2 weeks pre-irradiation. Animals were sacrificed on the 7th day after irradiation. The results demonstrated that the whole body exposure of rats to ionizing radiation induce oxidative stress which showed alterations on the ultrastructural level included dis organization with mayofibrillolysis relatively intact z-band (Z), fibrosis, swollen mitochondria, apoptotic nuclei and thickened walls of capillaries. In diabetic rats cardio muscle focal loss of myofilaments, also swelling of mitochondria and rupture of sacroplasmic reticulum, apoptotic nuclei with dilation of capillaries were evident. Administration of L-carnitine pre-irradiation has improved the ultrastructural alterations of the heart tissue. It is proposed that the oxidative stress is associated with a deficit in the status of the antioxidant defense system which may play a critical role in subcellular remodeling, calcium-handling abnormalities and subsequent diabetic cardiomyopathy

  8. Targeted disruption of the mouse Csrp2 gene encoding the cysteine- and glycine-rich LIM domain protein CRP2 result in subtle alteration of cardiac ultrastructure

    Directory of Open Access Journals (Sweden)

    Stoll Doris

    2008-08-01

    Full Text Available Abstract Background The cysteine and glycine rich protein 2 (CRP2 encoded by the Csrp2 gene is a LIM domain protein expressed in the vascular system, particularly in smooth muscle cells. It exhibits a bimodal subcellular distribution, accumulating at actin-based filaments in the cytosol and in the nucleus. In order to analyze the function of CRP2 in vivo, we disrupted the Csrp2 gene in mice and analysed the resulting phenotype. Results A ~17.3 kbp fragment of the murine Csrp2 gene containing exon 3 through 6 was isolated. Using this construct we confirmed the recently determined chromosomal localization (Chromosome 10, best fit location between markers D10Mit203 proximal and D10Mit150 central. A gene disruption cassette was cloned into exon 4 and a mouse strain lacking functional Csrp2 was generated. Mice lacking CRP2 are viable and fertile and have no obvious deficits in reproduction and survival. However, detailed histological and electron microscopic studies reveal that CRP2-deficient mice have subtle alterations in their cardiac ultrastructure. In these mice, the cardiomyocytes display a slight increase in their thickness, indicating moderate hypertrophy at the cellular level. Although the expression of several intercalated disc-associated proteins such as β-catenin, N-RAP and connexin-43 were not affected in these mice, the distribution of respective proteins was changed within heart tissue. Conclusion We conclude that the lack of CRP2 is associated with alterations in cardiomyocyte thickness and hypertrophy.

  9. Altered cardiac gene expression of noradrenaline enzymes, transporter and β-adrenoceptors in rat model of rheumatoid arthritis.

    Science.gov (United States)

    Dronjak, Sladjana; Stefanovic, Bojana; Jovanovic, Predrag; Spasojevic, Natasa; Jankovic, Milica; Jeremic, Ivica; Hoffmann, Markus

    2017-12-01

    Baseline sympathetic activity was found to be elevated in rheumatoid arthritis (RA) patients and it is related to increased cardiovascular risk in these patients. Although many studies have highlighted the association between RA and increased cardiac sympathetic activity, the underlying mechanistic links remain unclear. The aim of the present study was to understand how diseases-triggered changes in gene expression may result in maladaptive physiological changes. Our results suggest that the equilibrium between noradrenaline synthesis, release and reuptake was disrupted in the ventricles of arthritic rats. In the acute phase of the arthritic process, decreased gene expression of MAO-A might lead to accumulation of noradrenaline in myocardial interstitial space, whereas increased gene expression of NET protected cardiomyocytes from the deleterious effects of enhanced noradrenaline. During the chronic phase, reduced expression of β 1 -adrenoceptor and decreased efficiency of noradrenaline reuptake contribute to progressive damage of the myocardium and limits heart efficiency. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Pioglitazone improves cardiac function and alters myocardial substrate metabolism without affecting cardiac triglyceride accumulation and high-energy phosphate metabolism in patients with well-controlled type 2 diabetes mellitus

    NARCIS (Netherlands)

    van der Meer, Rutger W.; Rijzewijk, Luuk J.; de Jong, Hugo W. A. M.; Lamb, Hildo J.; Lubberink, Mark; Romijn, Johannes A.; Bax, Jeroen J.; de Roos, Albert; Kamp, Otto; Paulus, Walter J.; Heine, Robert J.; Lammertsma, Adriaan A.; Smit, Johannes W. A.; Diamant, Michaela

    2009-01-01

    Cardiac disease is the leading cause of mortality in type 2 diabetes mellitus (T2DM). Pioglitazone has been associated with improved cardiac outcome but also with an elevated risk of heart failure. We determined the effects of pioglitazone on myocardial function in relation to cardiac high-energy

  11. Energetics Conditioning Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Energetics Conditioning Facility is used for long term and short term aging studies of energetic materials. The facility has 10 conditioning chambers of which 2...

  12. Alteration in cardiac uncoupling proteins and eNOS gene expression following high-intensity interval training in favor of increasing mechanical efficiency

    Science.gov (United States)

    Fallahi, Ali Asghar; Shekarfroush, Shahnaz; Rahimi, Mostafa; Jalali, Amirhossain; Khoshbaten, Ali

    2016-01-01

    Objective(s): High-intensity interval training (HIIT) increases energy expenditure and mechanical energy efficiency. Although both uncoupling proteins (UCPs) and endothelial nitric oxide synthase (eNOS) affect the mechanical efficiency and antioxidant capacity, their effects are inverse. The aim of this study was to determine whether the alterations of cardiac UCP2, UCP3, and eNOS mRNA expression following HIIT are in favor of increased mechanical efficiency or decreased oxidative stress. Materials and Methods: Wistar rats were divided into five groups: control group (n=12), HIIT for an acute bout (AT1), short term HIIT for 3 and 5 sessions (ST3 and ST5), long-term training for 8 weeks (LT) (6 in each group). The rats of the training groups were made to run on a treadmill for 60 min in three stages: 6 min running for warm-up, 7 intervals of 7 min running on treadmill with a slope of 5° to 20° (4 min with an intensity of 80-110% VO2max and 3 min at 50-60% VO2max), and 5-min running for cool-down. The control group did not participate in any exercise program. Rats were sacrificed and the hearts were extracted to analyze the levels of UCP2, UCP3 and eNOS mRNA by RT-PCR. Results: UCP3 expression was increased significantly following an acute training bout. Repeated HIIT for 8 weeks resulted in a significant decrease in UCPs mRNA and a significant increase in eNOS expression in cardiac muscle. Conclusion: This study indicates that Long term HIIT through decreasing UCPs mRNA and increasing eNOS mRNA expression may enhance energy efficiency and physical performance. PMID:27114795

  13. Acebutolol in Cardiac Arrhythmias

    African Journals Online (AJOL)

    1974-04-20

    Apr 20, 1974 ... the cardiac output at rest and on exercise is not altered by the administration of acebutolol, and in patients with coronary artery disease, intravenous acebutolol produces a small fall in cardiac index, stroke index and in the parameters which are used to measure left ventricular. contractilityYo. We have used ...

  14. Dietary nitrate increases arginine availability and protects mitochondrial complex I and energetics in the hypoxic rat heart.

    Science.gov (United States)

    Ashmore, Tom; Fernandez, Bernadette O; Branco-Price, Cristina; West, James A; Cowburn, Andrew S; Heather, Lisa C; Griffin, Julian L; Johnson, Randall S; Feelisch, Martin; Murray, Andrew J

    2014-11-01

    Hypoxic exposure is associated with impaired cardiac energetics in humans and altered mitochondrial function, with suppressed complex I-supported respiration, in rat heart. This response might limit reactive oxygen species generation, but at the cost of impaired electron transport chain (ETC) activity. Dietary nitrate supplementation improves mitochondrial efficiency and can promote tissue oxygenation by enhancing blood flow. We therefore hypothesised that ETC dysfunction, impaired energetics and oxidative damage in the hearts of rats exposed to chronic hypoxia could be alleviated by sustained administration of a moderate dose of dietary nitrate. Male Wistar rats (n = 40) were given water supplemented with 0.7 mmol l(-1) NaCl (as control) or 0.7 mmol l(-1) NaNO3, elevating plasma nitrate levels by 80%, and were exposed to 13% O2 (hypoxia) or normoxia (n = 10 per group) for 14 days. Respiration rates, ETC protein levels, mitochondrial density, ATP content and protein carbonylation were measured in cardiac muscle. Complex I respiration rates and protein levels were 33% lower in hypoxic/NaCl rats compared with normoxic/NaCl controls. Protein carbonylation was 65% higher in hearts of hypoxic rats compared with controls, indicating increased oxidative stress, whilst ATP levels were 62% lower. Respiration rates, complex I protein and activity, protein carbonylation and ATP levels were all fully protected in the hearts of nitrate-supplemented hypoxic rats. Both in normoxia and hypoxia, dietary nitrate suppressed cardiac arginase expression and activity and markedly elevated cardiac l-arginine concentrations, unmasking a novel mechanism of action by which nitrate enhances tissue NO bioavailability. Dietary nitrate therefore alleviates metabolic abnormalities in the hypoxic heart, improving myocardial energetics. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

  15. Energetics of Si(001)

    NARCIS (Netherlands)

    Zandvliet, Henricus J.W.

    2000-01-01

    A classical thermodynamic description of a surface requires the introduction of a number of energetic parameters related to the surface steps. These parameters are the step free energy, the kink creation energy, and the energetic and entropic interactions between steps. This review will demonstrate

  16. Energetic Techniques For Planetary Defense

    Science.gov (United States)

    Barbee, B.; Bambacus, M.; Bruck Syal, M.; Greenaugh, K. C.; Leung, R. Y.; Plesko, C. S.

    2017-12-01

    Near-Earth Objects (NEOs) are asteroids and comets whose heliocentric orbits tend to approach or cross Earth's heliocentric orbit. NEOs of various sizes periodically collide with Earth, and efforts are currently underway to discover, track, and characterize NEOs so that those on Earth-impacting trajectories are discovered far enough in advance that we would have opportunities to deflect or destroy them prior to Earth impact, if warranted. We will describe current efforts by the National Aeronautics and Space Administration (NASA) and the National Nuclear Security Administration (NNSA) to assess options for energetic methods of deflecting or destroying hazardous NEOs. These methods include kinetic impactors, which are spacecraft designed to collide with an NEO and thereby alter the NEO's trajectory, and nuclear engineering devices, which are used to rapidly vaporize a layer of NEO surface material. Depending on the amount of energy imparted, this can result in either deflection of the NEO via alteration of its trajectory, or robust disruption of the NEO and dispersal of the remaining fragments. We have studied the efficacies and limitations of these techniques in simulations, and have combined the techniques with corresponding spacecraft designs and mission designs. From those results we have generalized planetary defense mission design strategies and drawn conclusions that are applicable to a range of plausible scenarios. We will present and summarize our research efforts to date, and describe approaches to carrying out planetary defense missions with energetic NEO deflection or disruption techniques.

  17. Particles Alter Diesel Exhaust Gases-Induced Hypotension, Cardiac Arrhythmia,Conduction Disturbance, and Autonomic Imbalance in Heart Failure-Prone Rats

    Science.gov (United States)

    Epidemiologic studies indicate that acute exposures to vehicular traffic and particulate matter (PM) air pollution are key causes of fatal cardiac arrhythmia, especially in those with preexisting cardiovascular disease. Researchers point to electrophysiologic dysfunction and auto...

  18. Nuclear energetics of Japan

    International Nuclear Information System (INIS)

    Sivintsev, Yu.V.

    2001-01-01

    Data on the current state and development of the nuclear energetics of Japan are reviewed. Preference of the strategy of tolerant development of the nuclear energetics of Japan including creation of the power nuclear energetics with the closed nuclear fuel cycle is noted. Realization and development of the program for the creating fast breeder reactor will provide to achieve total independence from import of any types of energy carriers including the fuel for nuclear fuel cycle. Scientific elaborations in Japan are conjectured the correlation of different types of fuel (oxide, metal, nitride), energy carriers (sodium, heavy metals, gas and water) and reactor power (large NPP, middle and small power plants) [ru

  19. Stimulating endogenous cardiac regeneration

    Directory of Open Access Journals (Sweden)

    Amanda eFinan

    2015-09-01

    Full Text Available The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration,a combination of these approaches couldameliorate the overall repair process to incorporate the participation ofmultiple cell players.

  20. Energetics Laboratory Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — These energetic materials laboratories are equipped with explosion proof hoods with blow out walls for added safety, that are certified for safe handling of primary...

  1. Mitochondrial adaptations to physiological vs. pathological cardiac hypertrophy

    Science.gov (United States)

    Abel, E. Dale; Doenst, Torsten

    2011-01-01

    Cardiac hypertrophy is a stereotypic response of the heart to increased workload. The nature of the workload increase may vary depending on the stimulus (repetitive, chronic, pressure, or volume overload). If the heart fully adapts to the new loading condition, the hypertrophic response is considered physiological. If the hypertrophic response is associated with the ultimate development of contractile dysfunction and heart failure, the response is considered pathological. Although divergent signalling mechanisms may lead to these distinct patterns of hypertrophy, there is some overlap. Given the close relationship between workload and energy demand, any form of cardiac hypertrophy will impact the energy generation by mitochondria, which are the key organelles for cellular ATP production. Significant changes in the expression of nuclear and mitochondrially encoded transcripts that impact mitochondrial function as well as altered mitochondrial proteome composition and mitochondrial energetics have been described in various forms of cardiac hypertrophy. Here, we review mitochondrial alterations in pathological and physiological hypertrophy. We suggest that mitochondrial adaptations to pathological and physiological hypertrophy are distinct, and we shall review potential mechanisms that might account for these differences. PMID:21257612

  2. Alterations of left ventricular deformation and cardiac sympathetic derangement in patients with systolic heart failure: a 3D speckle tracking echocardiography and cardiac {sup 123}I-MIBG study

    Energy Technology Data Exchange (ETDEWEB)

    Leosco, Dario; Parisi, Valentina; Pagano, Gennaro; Femminella, Grazia Daniela; Bevilacqua, Agnese; Formisano, Roberto; Ferro, Gaetana; De Lucia, Claudio; Ferrara, Nicola [University Federico II, Department of Translational Medical Science, Naples (Italy); Pellegrino, Teresa [Italian National Research Council (CNR), Institute of Biostructure and Bioimaging, Naples (Italy); University Federico II, Department of Advanced Biomedical Science, Naples (Italy); Paolillo, Stefania [University Federico II, Department of Advanced Biomedical Science, Naples (Italy); SDN Foundation, Institute of Diagnostic and Nuclear Development, Naples (Italy); Prastaro, Maria; Filardi, Pasquale Perrone; Cuocolo, Alberto [University Federico II, Department of Advanced Biomedical Science, Naples (Italy); Rengo, Giuseppe [University Federico II, Department of Translational Medical Science, Naples (Italy); Salvatore Maugeri Foundation, IRCCS, Istituto di Telese, Benevento, BN (Italy)

    2015-09-15

    Myocardial contractile function is under the control of cardiac sympathetic activity. Three-dimensional speckle tracking echocardiography (3D-STE) and cardiac imaging with {sup 123}I-metaiodobenzylguanidine ({sup 123}I-MIBG) are two sophisticated techniques for the assessment of left ventricular (LV) deformation and sympathetic innervation, respectively, which offer important prognostic information in patients with heart failure (HF). The purpose of this investigation was to explore, in patients with systolic HF, the relationship between LV deformation assessed by 3D-STE and cardiac sympathetic derangement evaluated by {sup 123}I-MIBG imaging. We prospectively studied 75 patients with systolic HF. All patients underwent a 3D-STE study (longitudinal, circumferential, area and radial) and {sup 123}I-MIBG planar and SPECT cardiac imaging. 3D-STE longitudinal, circumferential and area strain values were correlated with {sup 123}I-MIBG late heart to mediastinum (H/M) ratio and late SPECT total defect score. After stratification of the patients according to ischaemic or nonischaemic HF aetiology, we observed a good correlation of all 3D-STE measurements with late H/M ratio and SPECT data in the ischaemic group, but in patients with HF of nonischaemic aetiology, no correlation was found between LV deformation and cardiac sympathetic activity. At the regional level, the strongest correlation between LV deformation and adrenergic innervation was found for the left anterior descending coronary artery distribution territory for all four 3D-STE values. In multivariate linear regression analyses, including age, gender, LV ejection fraction, NYHA class, body mass index, heart rate and HF aetiology, only 3D-STE area and radial strain values significantly predicted cardiac sympathetic derangement on {sup 123}I-MIBG late SPECT. This study indicated that 3D-STE measurements are correlated with {sup 123}I-MIBG planar and SPECT data. Furthermore, 3D-STE area and radial strain values

  3. Photoactive energetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, David E.; Hanson, Susan Kloek; Scharff, Robert Jason; Veauthier, Jacqueline Marie; Myers, Thomas Winfield

    2018-02-27

    Energetic materials that are photoactive or believed to be photoactive may include a conventional explosive (e.g. PETN, nitroglycerine) derivatized with an energetic UV-absorbing and/or VIS-absorbing chromophore such as 1,2,4,5-tetrazine or 1,3,5-triazine. Absorption of laser light having a suitably chosen wavelength may result in photodissociation, decomposition, and explosive release of energy. These materials may be used as ligands to form complexes. Coordination compounds include such complexes with counterions. Some having the formula M(L).sub.n.sup.2+ were synthesized, wherein M is a transition metal and L is a ligand and n is 2 or 3. These may be photoactive upon exposure to a laser light beam having an appropriate wavelength of UV light, near-IR and/or visible light. Photoactive materials also include coordination compounds bearing non-energetic ligands; in this case, the counterion may be an oxidant such as perchlorate.

  4. Acacia hydaspica R. Parker prevents doxorubicin-induced cardiac injury by attenuation of oxidative stress and structural Cardiomyocyte alterations in rats.

    Science.gov (United States)

    Afsar, Tayyaba; Razak, Suhail; Batoo, Khalid Mujasam; Khan, Muhammad Rashid

    2017-12-29

    The use of doxorubicin (DOX) an anthracycline antineoplastic agent is withdrawn due to its cardio-toxic side effects. Oxidative stress has been recognized as the primary cause of DOX induced cardiotoxicity. We have investigated whether polyphenol rich ethyl acetate extract of Acacia hydaspica (AHE) can attenuate doxorubicin-induced cardiotoxicity via inhibition of oxidative stress. AHE was administered orally to rats once daily for 6 weeks at doses of 200 and 400 mg/kg b.w. DOX (3 mg/kg b.w. i.p., single dose/week) was administered for 6 weeks (chronic model). The parameters studied to evaluate cardioprotective potential were the serum cardiac function biomarkers (CK, CKMB, AST and LDH), hematological parameters, cardiac tissue antioxidant enzymatic status and oxidative stress markers, and histopathological analysis to validate biochemical findings. Chronic 6 week treatment of DOX significantly deteriorated cardiac function biomarkers and decreased the activities of antioxidant enzymes, whereas significant increase in oxidative stress biomarkers was noticed in comparison to control group. AHE dose dependently protected DOX-induced leakage of cardiac enzymes in serum and ameliorated DOX-induced oxidative stress; as evidenced by decreasing lipid peroxidation, H 2 O 2 and NO content with increase in phase I and phase II antioxidant enzymes. Doxorubicin treatment produced severe morphological lesions, leucopenia, decrease in red blood cell counts and hemoglobin concentrations. AHE co-treatment protected the heart and blood elements from the toxic effects of doxorubicin as indicated by the recovery of hematological parameters to normal values and prevention of myocardial injuries in a dose dependent way. The protective potency of AHE (400 mg/kg b.w) was equivalent to silymarin. Results revealed that AHE showed protective effects against DOX induce cardiotoxicity. The protective effect might attribute to its polyphenolic constituents and antioxidant properties. AHE

  5. The pathogenesis of cardiac fibrosis.

    Science.gov (United States)

    Kong, Ping; Christia, Panagiota; Frangogiannis, Nikolaos G

    2014-02-01

    Cardiac fibrosis is characterized by net accumulation of extracellular matrix proteins in the cardiac interstitium, and contributes to both systolic and diastolic dysfunction in many cardiac pathophysiologic conditions. This review discusses the cellular effectors and molecular pathways implicated in the pathogenesis of cardiac fibrosis. Although activated myofibroblasts are the main effector cells in the fibrotic heart, monocytes/macrophages, lymphocytes, mast cells, vascular cells and cardiomyocytes may also contribute to the fibrotic response by secreting key fibrogenic mediators. Inflammatory cytokines and chemokines, reactive oxygen species, mast cell-derived proteases, endothelin-1, the renin/angiotensin/aldosterone system, matricellular proteins, and growth factors (such as TGF-β and PDGF) are some of the best-studied mediators implicated in cardiac fibrosis. Both experimental and clinical evidence suggests that cardiac fibrotic alterations may be reversible. Understanding the mechanisms responsible for initiation, progression, and resolution of cardiac fibrosis is crucial to design anti-fibrotic treatment strategies for patients with heart disease.

  6. Conditional FKBP12.6 overexpression in mouse cardiac myocytes prevents triggered ventricular tachycardia through specific alterations in excitation-contraction coupling.

    Science.gov (United States)

    Gellen, Barnabas; Fernández-Velasco, María; Briec, François; Vinet, Laurent; LeQuang, Khai; Rouet-Benzineb, Patricia; Bénitah, Jean-Pierre; Pezet, Mylène; Palais, Gael; Pellegrin, Noémie; Zhang, Andy; Perrier, Romain; Escoubet, Brigitte; Marniquet, Xavier; Richard, Sylvain; Jaisser, Fréderic; Gómez, Ana María; Charpentier, Flavien; Mercadier, Jean-Jacques

    2008-04-08

    Ca(2+) release from the sarcoplasmic reticulum via the ryanodine receptor (RyR2) activates cardiac myocyte contraction. An important regulator of RyR2 function is FKBP12.6, which stabilizes RyR2 in the closed state during diastole. Beta-adrenergic stimulation has been suggested to dissociate FKBP12.6 from RyR2, leading to diastolic sarcoplasmic reticulum Ca(2+) leakage and ventricular tachycardia (VT). We tested the hypothesis that FKBP12.6 overexpression in cardiac myocytes can reduce susceptibility to VT in stress conditions. We developed a mouse model with conditional cardiac-specific overexpression of FKBP12.6. Transgenic mouse hearts showed a marked increase in FKBP12.6 binding to RyR2 compared with controls both at baseline and on isoproterenol stimulation (0.2 mg/kg i.p.). After pretreatment with isoproterenol, burst pacing induced VT in 10 of 23 control mice but in only 1 of 14 transgenic mice (P<0.05). In isolated transgenic myocytes, Ca(2+) spark frequency was reduced by 50% (P<0.01), a reduction that persisted under isoproterenol stimulation, whereas the sarcoplasmic reticulum Ca(2+) load remained unchanged. In parallel, peak I(Ca,L) density decreased by 15% (P<0.01), and the Ca(2+) transient peak amplitude decreased by 30% (P<0.001). A 33.5% prolongation of the caffeine-evoked Ca(2+) transient decay was associated with an 18% reduction in the Na(+)-Ca(2+) exchanger protein level (P<0.05). Increased FKBP12.6 binding to RyR2 prevents triggered VT in normal hearts in stress conditions, probably by reducing diastolic sarcoplasmic reticulum Ca(2+) leak. This indicates that the FKBP12.6-RyR2 complex is an important candidate target for pharmacological prevention of VT.

  7. Nitroamino and Nitro Energetics

    Science.gov (United States)

    2012-09-13

    bis(oxyamine) (Scheme 5), and to investigate energetic ionic liquids based on this bisoxyamine. Nitration of 18 with 100% nitric acid led to the...dihydro-5-nitroimino-l//-tetrazol-l-ly)ethane (43) was obtained.20 The colorless crystals are stable at room temperature and are not hygroscopic ...guanidinium) tetrazine resulted in the formation of dianionic salts 68-72. All of the salts are non hygroscopic , stable in air, and were isolated as

  8. Cardiac rehabilitation

    Science.gov (United States)

    ... rehab; Heart failure - cardiac rehab References Anderson L, Taylor RS. Cardiac rehabilitation for people with heart disease: ... of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed ...

  9. In utero undernutrition programs skeletal and cardiac muscle metabolism

    Directory of Open Access Journals (Sweden)

    Brittany eBeauchamp

    2016-01-01

    Full Text Available In utero undernutrition is associated with increased risk for insulin resistance, obesity, and cardiovascular disease during adult life. A common phenotype associated with low birth weight is reduced skeletal muscle mass. Given the central role of skeletal muscle in whole body metabolism, alterations in its mass as well as its metabolic characteristics may contribute to disease risk. This review highlights the metabolic alterations in cardiac and skeletal muscle associated with in utero undernutrition and low birth weight. These tissues have high metabolic demands and are known to be sites of major metabolic dysfunction in obesity, type 2 diabetes, and cardiovascular disease. Recent research demonstrates that mitochondrial energetics are decreased in skeletal and cardiac muscles of adult offspring from undernourished mothers. These effects apparently lead to the development of a thrifty phenotype, which may represent overall a compensatory mechanism programmed in utero to handle times of limited nutrient availability. However, in an environment characterized by food abundance, the effects are maladaptive and increase adulthood risks of metabolic disease.

  10. Soluble epoxide hydrolase inhibition improves coronary endothelial function and prevents the development of cardiac alterations in obese insulin-resistant mice.

    Science.gov (United States)

    Roche, Clothilde; Besnier, Marie; Cassel, Roméo; Harouki, Najah; Coquerel, David; Guerrot, Dominique; Nicol, Lionel; Loizon, Emmanuelle; Remy-Jouet, Isabelle; Morisseau, Christophe; Mulder, Paul; Ouvrard-Pascaud, Antoine; Madec, Anne-Marie; Richard, Vincent; Bellien, Jeremy

    2015-05-01

    This study addressed the hypothesis that inhibiting the soluble epoxide hydrolase (sEH)-mediated degradation of epoxy-fatty acids, notably epoxyeicosatrienoic acids, has an additional impact against cardiovascular damage in insulin resistance, beyond its previously demonstrated beneficial effect on glucose homeostasis. The cardiovascular and metabolic effects of the sEH inhibitor trans-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (t-AUCB; 10 mg/l in drinking water) were compared with those of the sulfonylurea glibenclamide (80 mg/l), both administered for 8 wk in FVB mice subjected to a high-fat diet (HFD; 60% fat) for 16 wk. Mice on control chow diet (10% fat) and nontreated HFD mice served as controls. Glibenclamide and t-AUCB similarly prevented the increased fasting glycemia in HFD mice, but only t-AUCB improved glucose tolerance and decreased gluconeogenesis, without modifying weight gain. Moreover, t-AUCB reduced adipose tissue inflammation, plasma free fatty acids, and LDL cholesterol and prevented hepatic steatosis. Furthermore, only the sEH inhibitor improved endothelium-dependent relaxations to acetylcholine, assessed by myography in isolated coronary arteries. This improvement was related to a restoration of epoxyeicosatrienoic acid and nitric oxide pathways, as shown by the increased inhibitory effects of the nitric oxide synthase and cytochrome P-450 epoxygenase inhibitors l-NA and MSPPOH on these relaxations. Moreover, t-AUCB decreased cardiac hypertrophy, fibrosis, and inflammation and improved diastolic function, as demonstrated by the increased E/A ratio (echocardiography) and decreased slope of the end-diastolic pressure-volume relation (invasive hemodynamics). These results demonstrate that sEH inhibition improves coronary endothelial function and prevents cardiac remodeling and diastolic dysfunction in obese insulin-resistant mice. Copyright © 2015 the American Physiological Society.

  11. Energetics and environment

    International Nuclear Information System (INIS)

    Abdullayev, K.M.

    2005-01-01

    The amount of harmful substances (SO 2 ; NO 3 ; CO; CO 2 ) emitted into the atmosphere in 1992-2002 years in the thermal power stations in A zerenerji i s given in this article. As a result of the waste in thermal power stations and electromagnetic emissions in order to reduce the harmful effects of a number of proposals were put forward. It is known that, one of the main polluting areas is energetic. That is why in our opinion the most important issue to look for ways to reduce the harmful effects is the main causes of the environmental impact study

  12. Energetics Manufacturing Technology Center (EMTC)

    Data.gov (United States)

    Federal Laboratory Consortium — The Energetics Manufacturing Technology Center (EMTC), established in 1994 by the Office of Naval Research (ONR) Manufacturing Technology (ManTech) Program, is Navy...

  13. Altered Protein Expression of Cardiac CYP2J and Hepatic CYP2C, CYP4A, and CYP4F in a Mouse Model of Type II Diabetes—A Link in the Onset and Development of Cardiovascular Disease?

    Directory of Open Access Journals (Sweden)

    Benoit Drolet

    2017-10-01

    Full Text Available Arachidonic acid can be metabolized by cytochrome P450 (CYP450 enzymes in a tissue- and cell-specific manner to generate vasoactive products such as epoxyeicosatrienoic acids (EETs-cardioprotective and hydroxyeicosatetraenoic acids (HETEs-cardiotoxic. Type II diabetes is a well-recognized risk factor for developing cardiovascular disease. A mouse model of Type II diabetes (C57BLKS/J-db/db was used. After sacrifice, livers and hearts were collected, washed, and snap frozen. Total proteins were extracted. Western blots were performed to assess cardiac CYP2J and hepatic CYP2C, CYP4A, and CYP4F protein expression, respectively. Significant decreases in relative protein expression of cardiac CYP2J and hepatic CYP2C were observed in Type II diabetes animals compared to controls (CYP2J: 0.80 ± 0.03 vs. 1.05 ± 0.06, n = 20, p < 0.001; (CYP2C: 1.56 ± 0.17 vs. 2.21 ± 0.19, n = 19, p < 0.01. In contrast, significant increases in relative protein expression of both hepatic CYP4A and CYP4F were noted in Type II diabetes mice compared to controls (CYP4A: 1.06 ± 0.09 vs. 0.18 ± 0.01, n = 19, p < 0.001; (CYP4F: 2.53 ± 0.22 vs. 1.10 ± 0.07, n = 19, p < 0.001. These alterations induced by Type II diabetes in the endogenous pathway (CYP450 of arachidonic acid metabolism may increase the risk for cardiovascular disease by disrupting the fine equilibrium between cardioprotective (CYP2J/CYP2C-generated and cardiotoxic (CYP4A/CYP4F-generated metabolites of arachidonic acid.

  14. New fluidized bed reactor for coating of energetic materials

    NARCIS (Netherlands)

    Abadjieva, E.; Huijser, T.; Creyghton, Y.L.M.; Heijden, A.E.D.M. van der

    2009-01-01

    The process of altering and changing the properties of the energetic materials by coating has been studied extensively by several scientific groups. According to the desired application different coating techniques have been developed and applied to achieve satisfactory results. Among the already

  15. Rural energetic development: cuban experience

    International Nuclear Information System (INIS)

    Aguilera Barciela, M.

    1994-01-01

    The development of electro energetic national system in Cuba has been directed to the following objectives: to brake the rural population's exodus toward the cities, electrification of dairy farm, interconnection to the system electro energetic of all the sugar central production, these improves the rural population's conditions life

  16. About Russian nuclear energetic perspectives

    International Nuclear Information System (INIS)

    Laletin, N.I.

    2003-01-01

    My particular view about Russian nuclear energetics perspectives is presented. The nearest and the further perspectives are considered. The arguments are adduced that the most probable scenario of nuclear energetic development is its stabilization in the near future. Fur further development the arguments of supporters and opponents of nuclear energetics are analyzed. Three points of view are considered. The first point of view that there is not alternative for nuclear energetics. My notes are the following ones. a) I express a skeptic opinion about a statement of quick exhaustion of fossil organic fuel recourses and corresponding estimations are presented. b) It is expressed skeptic opinion about the statement that nuclear energetics can have a visual influence on ''steam effect''. c) I agree that nuclear energetics is the most ecological technology for normal work but however we can't disregard possibilities of catastrophic accidents. The second point of view that the use of nuclear energetics can't have the justification. I adduce the arguments contrary to this statement. The third point of view that nuclear energetics is a usual technology and the only criteria for discussions about what dimension and where one ought develop it is total cost of its unit. Expressed an opinion that the deceived for the choose of a way the skill of the estimate correctly and optimized so named the external parts of the unit energy costs for different energy technologies. (author)

  17. Cardiac Dysautonomia in Huntington's Disease.

    Science.gov (United States)

    Abildtrup, Mads; Shattock, Michael

    2013-01-01

    Huntington's disease is a fatal, hereditary, neurodegenerative disorder best known for its clinical triad of progressive motor impairment, cognitive deficits and psychiatric disturbances. Although a disease of the central nervous system, mortality surveys indicate that heart disease is a leading cause of death. The nature of such cardiac abnormalities remains unknown. Clinical findings indicate a high prevalence of autonomic nervous system dysfunction - dysautonomia - which may be a result of pathology of the central autonomic network. Dysautonomia can have profound effects on cardiac health, and pronounced autonomic dysfunction can be associated with neurogenic arrhythmias and sudden cardiac death. Significant advances in the knowledge of neural mechanisms in cardiac disease have recently been made which further aid our understanding of cardiac mortality in Huntington's disease. Even so, despite the evidence of aberrant autonomic activity the potential cardiac consequences of autonomic dysfunction have been somewhat ignored. In fact, underlying cardiac abnormalities such as arrhythmias have been part of the exclusion criteria in clinical autonomic Huntington's disease research. A comprehensive analysis of cardiac function in Huntington's disease patients is warranted. Further experimental and clinical studies are needed to clarify how the autonomic nervous system is controlled and regulated in higher, central areas of the brain - and how these regions may be altered in neurological pathology, such as Huntington's disease. Ultimately, research will hopefully result in an improvement of management with the aim of preventing early death in Huntington's disease from cardiac causes.

  18. Analysis of the energetic sector through the national energetic matrix

    International Nuclear Information System (INIS)

    Garzon Lozano, Enrique

    2007-01-01

    The author shows the results of the national energetic balance 1975-2005, through the energetic matrix of the country, giving an annual growth of 5.1% in this period of offer of primary energy, where the mineral coal participates with 9,6%, the hydraulic energy with 4,8%, natural gas with 4,2%, trash with 2,4% and petroleum with 2,2%, while the firewood fell in 0,5%

  19. Energetic policies 2005-2030

    International Nuclear Information System (INIS)

    2008-01-01

    This power point exhibition shows the following topics: energy analysis, production and use, supply and demand, consumption, energy sources, energetic prospective of Uruguay country, medium and long term perspectives.

  20. Photodecomposition of energetic nitro compounds

    Energy Technology Data Exchange (ETDEWEB)

    Mialocq, J.C.

    1989-03-14

    The photodecomposition of energetic nitrocompounds depends on the excitation energy, the light intensity which determines the mono-, bi- or multiphotonic character of the initial process and their gaseous, liquid or solid state. The initial processes of the photodecomposition of nitromethane and nitroalcanes are reviewed and their relevance to the initiation of energetic nitrocompounds detonation is discussed. The case of nitramines (dimethylnitramine and tutorial) is also briefly introduced.

  1. Cardiac Rehabilitation

    Science.gov (United States)

    ... may also do muscle-strengthening exercises, such as lifting weights or other resistance training exercises, two or three ... health concerns. Education about nutrition, lifestyle and healthy weight ... the most benefits from cardiac rehabilitation, make sure your exercise and ...

  2. Cardiac MRI

    Science.gov (United States)

    ... such as coronary heart disease, heart valve problems, pericarditis, cardiac tumors, or damage from a heart attack. ... Palpitations Heart Valve Disease Implantable Cardioverter Defibrillators Pacemakers Pericarditis Stress Testing RELATED NEWS April 26, 2013 | News ...

  3. Cardiac Angiosarcoma

    Directory of Open Access Journals (Sweden)

    Monique Esteves Cardoso

    2011-01-01

    Full Text Available Despite cardiac metastases are found in about 20% of cancer deaths, the presence of primary cardiac tumors is rare. Most primary tumors are benign, and malignant tumors comprise about 15%. We report a 21-year-old man with fever, dyspnea, and hemoptysis that was diagnosed with angiosarcoma of the right atrium and pulmonary metastasis. Patient was submitted to surgical tumor resection without adjuvant therapy and died four months after diagnosis.

  4. Cardiac Angiosarcoma

    OpenAIRE

    Cardoso, Monique Esteves; Canale, Leonardo Secchin; Ramos, Rosana Grandelle; Salvador Junior, Edson da Silva; Lachtermacher, Stephan

    2011-01-01

    Despite cardiac metastases are found in about 20% of cancer deaths, the presence of primary cardiac tumors is rare. Most primary tumors are benign, and malignant tumors comprise about 15%. We report a 21-year-old man with fever, dyspnea, and hemoptysis that was diagnosed with angiosarcoma of the right atrium and pulmonary metastasis. Patient was submitted to surgical tumor resection without adjuvant therapy and died four months after diagnosis.

  5. Cardiac Angiosarcoma

    Science.gov (United States)

    Cardoso, Monique Esteves; Canale, Leonardo Secchin; Ramos, Rosana Grandelle; Salvador Junior, Edson da Silva; Lachtermacher, Stephan

    2011-01-01

    Despite cardiac metastases are found in about 20% of cancer deaths, the presence of primary cardiac tumors is rare. Most primary tumors are benign, and malignant tumors comprise about 15%. We report a 21-year-old man with fever, dyspnea, and hemoptysis that was diagnosed with angiosarcoma of the right atrium and pulmonary metastasis. Patient was submitted to surgical tumor resection without adjuvant therapy and died four months after diagnosis. PMID:24826214

  6. Interactions between antiarrhythmic drugs and cardiac memory

    NARCIS (Netherlands)

    Plotnikov, A. N.; Shvilkin, A.; Xiong, W.; de Groot, J. R.; Rosenshtraukh, L.; Feinmark, S.; Gainullin, R.; Danilo, P.; Rosen, M. R.

    2001-01-01

    Ventricular pacing or arrhythmias can induce cardiac memory (CM). We hypothesized that clinically administered antiarrhythmic drugs alter the expression of CM, and that the repolarization changes characteristic of CM can modulate the effects of antiarrhythmic drugs. We studied conscious,

  7. Targeting sodium channels in cardiac arrhythmia

    NARCIS (Netherlands)

    Remme, Carol Ann; Wilde, Arthur A. M.

    2014-01-01

    Cardiac voltage-gated sodium channels are responsible for proper electrical conduction in the heart. During acquired pathological conditions and inherited sodium channelopathies, altered sodium channel function causes conduction disturbances and ventricular arrhythmias. Although the clinical,

  8. Musical Tasks and Energetic Arousal.

    Science.gov (United States)

    Lim, Hayoung A; Watson, Angela L

    2018-03-08

    Music is widely recognized as a motivating stimulus. Investigators have examined the use of music to improve a variety of motivation-related outcomes; however, these studies have focused primarily on passive music listening rather than active participation in musical activities. To examine the influence of participation in musical tasks and unique participant characteristics on energetic arousal. We used a one-way Welch's ANOVA to examine the influence of musical participation (i.e., a non-musical control and four different musical task conditions) upon energetic arousal. In addition, ancillary analyses of participant characteristics including personality, age, gender, sleep, musical training, caffeine, nicotine, and alcohol revealed their possible influence upon pretest and posttest energetic arousal scores. Musical participation yielded a significant relationship with energetic arousal, F(4, 55.62) = 44.38, p = .000, estimated ω2 = 0.60. Games-Howell post hoc pairwise comparisons revealed statistically significant differences between five conditions. Descriptive statistics revealed expected differences between introverts' and extraverts' energetic arousal scores at the pretest, F(1, 115) = 6.80, p = .010, partial η2= .06; however, mean differences failed to reach significance at the posttest following musical task participation. No other measured participant characteristics yielded meaningful results. Passive tasks (i.e., listening to a story or song) were related to decreased energetic arousal, while active musical tasks (i.e., singing, rhythm tapping, and keyboard playing) were related to increased energetic arousal. Musical task participation appeared to have a differential effect for individuals with certain personality traits (i.e., extroverts and introverts).

  9. Cardiac and Metabolic Effects of Dietary Selenomethionine Exposure in Adult Zebrafish.

    Science.gov (United States)

    Pettem, Connor M; Weber, Lynn P; Janz, David M

    2017-10-01

    Selenium (Se) is an essential micronutrient involved in important metabolic functions for all vertebrate species. As Se is reported to have a narrow margin between essentiality and toxicity, there is growing concern surrounding the adverse effects of elevated Se exposure caused by anthropogenic activities. Recent studies have reported that elevated dietary exposure of fish to selenomethionine (Se-Met) can alter aerobic metabolic capacity, energetics and swimming performance. This study aims to further investigate mechanisms of sublethal Se-Met toxicity, particularly potential underlying cardiovascular implications of chronic exposure to environmentally relevant concentrations of dietary Se-Met in adult zebrafish (Danio rerio). Adult zebrafish were fed either control food (1.1 μg Se/g dry mass [d.m.]) or Se-Met spiked food (10.3 or 28.8 μg Se/g d.m.) for 90 d at 5% body weight per day. Following exposure, ultrahigh resolution B-mode and Doppler ultrasound was used to characterize cardiac function. Chronic dietary exposure to elevated Se-Met significantly reduced ventricular contractile rate, stroke volume, and cardiac output. Exposure to Se-Met significantly decreased mRNA expression of methionine adenosyltransferase 1 alpha and glutathione-S-transferase pi class in liver, and a key cardiac remodelling enzyme, matrix metalloproteinase 2, in adult zebrafish heart. Se-Met significantly increased echodensity at the junction between atrium and ventricle, and these results combined with increased matrix metalloproteinase 2 expression are consistent with cardiac remodelling and fibrosis. The results of this study suggest that chronic exposure to dietary Se-Met can negatively impact cardiac function, and such physiological consequences could reduce the aerobic capacity and survivability of fish. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Second School of Nuclear Energetics

    International Nuclear Information System (INIS)

    2009-01-01

    At 3-5 Nov 2009 Institute of Nuclear Energy POLATOM, Association of Polish Electrical Engineers (SEP) and Polish Nuclear Society have organized Second School of Nuclear Energetics. 165 participants have arrived from all Poland and represented both different central institutions (e.g. ministries) and local institutions (e.g. Office of Technical Inspection, The Voivodship Presidential Offices, several societies, consulting firms or energetic enterprises). Students from the Warsaw Technical University and Gdansk Technical University, as well as the PhD students from the Institute of Nuclear Chemistry and Technology (Warsaw) attended the School. 20 invited lectures presented by eminent Polish specialists concerned basic problems of nuclear energetics, nuclear fuel cycle and different problems of the NPP construction in Poland. [pl

  11. Cardiac echinococcosis

    Directory of Open Access Journals (Sweden)

    Ivanović-Krstić Branislava A.

    2002-01-01

    Full Text Available Cardiac hydatid disease is rare. We report on an uncommon hydatid cyst localized in the right ventricular wall, right atrial wall tricuspid valve left atrium and pericard. A 33-year-old woman was treated for cough, fever and chest pain. Cardiac echocardiograpic examination revealed a round tumor (5.8 x 4 cm in the right ventricular free wall and two smaller cysts behind that tumor. There were cysts in right atrial wall and tricuspidal valve as well. Serologic tests for hydatidosis were positive. Computed tomography finding was consistent with diagnosis of hydatid cyst in lungs and right hylar part. Surgical treatment was rejected due to great risk of cardiac perforation. Medical treatment with albendazole was unsuccessful and the patient died due to systemic hydatid involvement of the lungs, liver and central nervous system.

  12. Energetics of metastudtite and implications for nuclear waste alteration.

    Science.gov (United States)

    Guo, Xiaofeng; Ushakov, Sergey V; Labs, Sabrina; Curtius, Hildegard; Bosbach, Dirk; Navrotsky, Alexandra

    2014-12-16

    Metastudtite, (UO2)O2(H2O)2, is one of two known natural peroxide minerals, but little is established about its thermodynamic stability. In this work, its standard enthalpy of formation, -1,779.6 ± 1.9 kJ/mol, was obtained by high temperature oxide melt drop solution calorimetry. Decomposition of synthetic metastudtite was characterized by thermogravimetry and differential scanning calorimetry (DSC) with ex situ X-ray diffraction analysis. Four decomposition steps were observed in oxygen atmosphere: water loss around 220 °C associated with an endothermic heat effect accompanied by amorphization; another water loss from 400 °C to 530 °C; oxygen loss from amorphous UO3 to crystallize orthorhombic α-UO2.9; and reduction to crystalline U3O8. This detailed characterization allowed calculation of formation enthalpy from heat effects on decomposition measured by DSC and by transposed temperature drop calorimetry, and both these values agree with that from drop solution calorimetry. The data explain the irreversible transformation from studtite to metastudtite, the conditions under which metastudtite may form, and its significant role in the oxidation, corrosion, and dissolution of nuclear fuel in contact with water.

  13. [Cardiac amyloidosis].

    Science.gov (United States)

    Boussabah, Elhem; Zakhama, Lilia; Ksontini, Iméne; Ibn Elhadj, Zied; Boukhris, Besma; Naffeti, Sana; Thameur, Moez; Ben Youssef, Soraya

    2008-09-01

    PREREQUIS: Amyloidosis is a rare infiltrative disease characterized by multiple clinical features. Various organs are involved and the cardiovascular system is a common target of amyloidosis. Cardiac involvement may occur with or without clinical manifestations and is considered as a major prognostic factor. To analyze the clinical features of cardiac involvement, to review actual knowledgement concerning echocardiographic diagnostic and to evaluate recent advances in treatment of the disease. An electronic search of the relevant literature was carried out using Medline and Pubmed. Keys words used for the final search were amyloidosis, cardiopathy and echocardiography. We considered for analysis reviews, studies and articles between 1990 and 2007. Amyloidosis represents 5 to 10% of non ischemic cardiomyoparhies. Cardiac involvement is the first cause of restrictive cardiomyopathy witch must be evoked in front of every inexplained cardiopathy after the age of forty. The amyloid nature of cardiopathy is suggered if some manifestations were associated as a peripheric neuropathy, a carpal tunnel sydrome and proteinuria > 3g/day. Echocardiography shows dilated atria, a granular sparkling appearance of myocardium, diastolic dysfunction and thickened left ventricle contrasting with a low electric voltage. The proof of amyloidosis is brought by an extra-cardiac biopsy, the indications of endomyocardial biopsy are very limited. The identification of the amyloid nature of cardiopathy has an direct therapeutic implication: it indicates the use of digitalis, calcium channel blockers and beta-blockers. Today the treatment of amyloidosis remains very unsatisfactory especially in the cardiac involvement. An early diagnosis before the cardiac damage may facilitate therapy and improve prognosis.

  14. Cardiac Pacemakers

    International Nuclear Information System (INIS)

    Fiandra, O.; Espasandin, W.; Fiandra, H.

    1984-01-01

    A complete survey of physiological biophysical,clinical and engineering aspects of cardiac facing,including the history and an assessment of possible future developments.Among the topics studied are: pacemakers, energy search, heart stimulating with pacemakers ,mathematical aspects of the electric cardio stimulation chronic, pacemaker implants,proceeding,treatment and control

  15. About the wind energetics development

    International Nuclear Information System (INIS)

    Strebkov, D.S.; Kharitonov, V.P.; Murugov, V.P.; Sokol'skij, A.K.

    1996-01-01

    The review of wind power energetics state in USA, Europe, Russia is given. The data of EC on wind power plants production in different periods are presented. The directions of scientific-research works with the purpose of increasing the level of wind power industry of Russia corresponding to economics demands were elaborated. (author). 8 refs., 3 tabs

  16. Effects of weight loss on myocardial energetics and diastolic function in obesity.

    Science.gov (United States)

    Rider, O J; Francis, J M; Tyler, D; Byrne, J; Clarke, K; Neubauer, S

    2013-06-01

    A reduced myocardial phosphocreatine/adenosine triphosphate (PCr/ATP) ratio is linked to both diastolic dysfunction and heart failure. Although obesity is well known to cause diastolic dysfunction a link to impaired cardiac energetics has only recently been established. We assessed whether or not long-term weight loss in obesity, which is known to reduce mortality, is accompanied by both improved cardiac energetics and diastolic function. Normal weight (BMI 22 ± 2; n = 18) and obese subjects (BMI 34 ± 4; n = 13) underwent cine-MRI (1.5 Tesla) to determine left ventricular diastolic function using volume-time curve analysis, and (31)P-MR spectroscopy (3 Tesla) to assess cardiac energetics (PCr/ATP ratio). Obese subjects (n = 13) underwent repeat assessment after 1 year of supervised weight loss. Obesity, in the absence of identifiable cardiovascular risk factors, was associated with significantly impaired myocardial high energy phosphate metabolism (PCr/ATP ratio, normal; 2.03 ± 0.27 vs. obese; 1.58 ± 0.47, p = 0.002) and significantly lower peak diastolic filling rate (normal; 4.8 ± 0.8 vs. obese; 3.8 ± 0.7 EDV/s, p = 0.01). Weight loss (on average 9 kg, 55% excess weight) over 1 year resulted in a 24% increase in PCr/ATP ratio (p = 0.01) and an 18% improvement in peak diastolic filling rate (p = 0.01). Myocardial PCr/ATP ratio remained positively correlated with peak diastolic filling rate after weight loss (r = 0.63, p = 0.02). In obesity, weight loss improves impaired cardiac energetics and myocardial relaxation. Improved myocardial energetics appear to play a key role in diastolic functional recovery accompanying weight loss.

  17. Energetic materials research using scanning electron microscopy

    NARCIS (Netherlands)

    Elshout, J.J.M.H. van den; Duvalois, W.; Benedetto, G.L. Di; Bouma, R.H.B.; Heijden, A.E.D.M. van der

    2016-01-01

    A key-technique for the research of energetic materials is scanning electron microscopy. In this paper several examples are given of characterization studies on energetic materials, including a solid composite propellant formulation. Results of the characterization of energetic materials using

  18. The location of energetic compartments affects energetic communication in cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Rikke eBirkedal

    2014-09-01

    Full Text Available The heart relies on accurate regulation of mitochondrial energy supply to match energy demand. The main regulators are Ca2+ and feedback of ADP and Pi. Regulation via feedback has intrigued for decades. First, the heart exhibits a remarkable metabolic stability. Second, diffusion of ADP and other molecules is restricted specifically in heart and red muscle, where a fast feedback is needed the most. To explain the regulation by feedback, compartmentalization must be taken into account. Experiments and theoretical approaches suggest that cardiomyocyte energetic compartmentalization is elaborate with barriers obstructing diffusion in the cytosol and at the level of the mitochondrial outer membrane (MOM. A recent study suggests the barriers are organized in a lattice with dimensions in agreement with those of intracellular structures. Here, we discuss the possible location of these barriers. The more plausible scenario includes a barrier at the level of MOM. Much research has focused on how the permeability of MOM itself is regulated, and the importance of the creatine kinase system to facilitate energetic communication. We hypothesize that at least part of the diffusion restriction at the MOM level is not by MOM itself, but due to the close physical association between the sarcoplasmic reticulum (SR and mitochondria. This will explain why animals with a disabled creatine kinase system exhibit rather mild phenotype modifications. Mitochondria are hubs of energetics, but also ROS production and signaling. The close association between SR and mitochondria may form a diffusion barrier to ADP added outside a permeabilised cardiomyocyte. But in vivo, it is the structural basis for the mitochondrial-SR coupling that is crucial for the regulation of mitochondrial Ca2+-transients to regulate energetics, and for avoiding Ca2+-overload and irreversible opening of the mitochondrial permeability transition pore.

  19. Stochastic Energetics of Quantum Transport

    OpenAIRE

    Ghosh, Pulak Kumar; Ray, Deb Shankar

    2006-01-01

    We examine the stochastic energetics of directed quantum transport due to rectification of non-equilibrium thermal fluctuations. We calculate the quantum efficiency of a ratchet device both in presence and absence of an external load to characterize two quantifiers of efficiency. It has been shown that the quantum current as well as efficiency in absence of load (Stokes efficiency) is higher as compared to classical current and efficiency, respectively, at low temperature. The conventional ef...

  20. Research@ARL: Energy & Energetics

    Science.gov (United States)

    2012-06-01

    CuO , CoFe2O4 and Co3O4, 10 carbon supported Pt and Au,11 and carbon supported pyrolyzed Co macrocyles,2 have not shown much improvement to the Li/O2...behavior in semiconductors ,7, 8 C60 fullerene,9 sodium azide21 as well as elements 10 and energetic materials.19 Despite the critical scientific insight

  1. Life cycles of energetic systems

    International Nuclear Information System (INIS)

    Adnot, Jerome; Marchio, Dominique; Riviere, Philippe; Duplessis, B.; Rabl, A.; Glachant, M.; Aggeri, F.; Benoist, A.; Teulon, H.; Daude, J.

    2012-01-01

    This collective publication aims at being a course for students in engineering of energetic systems, i.e. at learning how to decide to accept or discard a project, to select the most efficient system, to select the optimal system, to select the optimal combination of systems, and to classify independent systems. Thus, it presents methods to analyse system life cycle from an energetic, economic and environmental point of view, describes how to develop an approach to the eco-design of an energy consuming product, how to understand the importance of hypotheses behind abundant and often contradicting publicised results, and to be able to criticise or to put in perspective one's own analysis. The first chapters thus recall some aspects of economic calculation, introduce the assessment of investment and exploitation costs of energetic systems, describe how to assess and internalise environmental costs, present the territorial carbon assessment, discuss the use of the life cycle assessment, and address the issue of environmental management at a product scale. The second part proposes various case studies: an optimal fleet of thermal production of electric power, the eco-design of a refrigerator, the economic and environmental assessment of wind farms

  2. Exercise-induced cardiac remodeling.

    Science.gov (United States)

    Weiner, Rory B; Baggish, Aaron L

    2012-01-01

    Early investigations in the late 1890s and early 1900s documented cardiac enlargement in athletes with above-normal exercise capacity and no evidence of cardiovascular disease. Such findings have been reported for more than a century and continue to intrigue scientists and clinicians. It is well recognized that repetitive participation in vigorous physical exercise results in significant changes in myocardial structure and function. This process, termed exercise-induced cardiac remodeling (EICR), is characterized by structural cardiac changes including left ventricular hypertrophy with sport-specific geometry (eccentric vs concentric). Associated alterations in both systolic and diastolic functions are emerging as recognized components of EICR. The increasing popularity of recreational exercise and competitive athletics has led to a growing number of individuals exhibiting these findings in routine clinical practice. This review will provide an overview of EICR in athletes. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Pamidronate Attenuates Oxidative Stress and Energetic Metabolism Changes but Worsens Functional Outcomes in Acute Doxorubicin-Induced Cardiotoxicity in Rats

    Directory of Open Access Journals (Sweden)

    Paula Bernardo de Carvalho

    2016-11-01

    Full Text Available Background: Cardiotoxicity is the major side effect of doxorubicin. As mechanisms that are involved in cardiotoxicity are ambiguous, new methods for attenuating cardiotoxicity are needed. Recent studies have shown that bisphosphonates can decrease oxidative stress. Therefore, the objective of this study was to evaluate the effect of pamidronate on preventing acute doxorubicin-induced cardiotoxicity. Methods: Sixty-four male Wistar rats were allocated into four groups: the control group (C, the pamidronate group (P, the doxorubicin group (D and the doxorubicin/pamidronate group (DP. The rats in the P and DP groups received pamidronate injections (3 mg/kg, IP. After 24 hours, the rats in the D and DP groups received doxorubicin injections (20 mg/kg, IP. Forty-eight hours after doxorubicin injection, the rats were killed. Echocardiography, isolated heart study and biochemical analysis were performed. Results: Doxorubicin-induced acute cardiotoxicity showed increased matrix metalloproteinases (MMP-2 activation, oxidative damage and induced alterations in myocardial energetic metabolism. Pamidronate did not inhibit MMP-2 activation but attenuated oxidative stress and improved myocardial energetic metabolism. Regarding cardiac function, the DP group exhibited a decrease in the left ventricular ejection fraction in the echocardiography and a decrease in +dP/dt in the isolated heart study compared with other groups. The same DP group presented serum hypocalcaemia. Conclusions: Despite its ability to reduce oxidative stress and improve energy metabolism in the heart, pamidronate worsened systolic function in rats treated with doxorubicin, and therefore we cannot recommend its use in conjunction with anthracycline chemotherapy.

  4. Cardiac conduction system anomalies and sudden cardiac death: insights from murine models

    Directory of Open Access Journals (Sweden)

    Amelia Eva Aranega

    2012-06-01

    Full Text Available The cardiac conduction system (CCS is a series of specialized tissues in the heart responsible for the initiation and co-ordination of the heartbeat. Alterations in the CCS, especially the His-Purkinje system, have been identified as an important player in the generation of lethal arrhythmias. Unstable arrhythmias secondary to channelopathies highly increase the risk of sudden cardiac death (SCD. Sudden cardiac death is a major contributor to mortality in industrialized nations, and most cases of SCD in the young are related to inherited ion channel diseases. In this review we examine how murine transgenic models have contributed to understanding that a broad variety of cardiac arrhythmias involve the cardiac specialized conduction system and may lead to sudden cardiac death.

  5. Cardiac conduction system

    Science.gov (United States)

    The cardiac conduction system is a group of specialized cardiac muscle cells in the walls of the heart that send signals to the ... contract. The main components of the cardiac conduction system are the SA node, AV node, bundle of ...

  6. Energetic Stress: The Reciprocal Relationship between Energy Availability and the Stress Response

    Science.gov (United States)

    Harrell, C.S.; Gillespie, C.F.; Neigh, G.N.

    2015-01-01

    The worldwide epidemic of metabolic syndromes and the recognized burden of mental health disorders have driven increased research into the relationship between the two. A maladaptive stress response is implicated in both mental health disorders and metabolic disorders, implicating the hypothalamic-pituitary-adrenal (HPA) axis as a key mediator of this relationship. This review explores how an altered energetic state, such as hyper- or hypoglycemia, as may be manifested in obesity or diabetes, affects the stress response and the HPA axis in particular. We propose that changes in energetic state or energetic demands can result in “energetic stress” that can, if prolonged, lead to a dysfunctional stress response. In this review, we summarize the role of the hypothalamus in modulating energy homeostasis and then briefly discuss the relationship between metabolism and stress-induced activation of the HPA axis. Next, we examine seven mechanisms whereby energetic stress interacts with neuroendocrine stress response systems, including by glucocorticoid signaling both within and beyond the HPA axis; by nutrient-induced changes in glucocorticoid signaling; by impacting the sympathetic nervous system; through changes in other neuroendocrine factors; by inducing inflammatory changes; and by altering the gut-brain axis. Recognizing these effects of energetic stress can drive novel therapies and prevention strategies for mental health disorders, including dietary intervention, probiotics, and even fecal transplant. PMID:26454211

  7. Regulation of cardiac remodeling by cardiac Na/K-ATPase isoforms

    Directory of Open Access Journals (Sweden)

    Lijun Catherine Liu

    2016-09-01

    Full Text Available Cardiac remodeling occurs after cardiac pressure/volume overload or myocardial injury during the development of heart failure and is a determinant of heart failure. Preventing or reversing remodeling is a goal of heart failure therapy. Human cardiomyocyte Na+/K+-ATPase has multiple α isoforms (1-3. The expression of the α subunit of the Na+/K+-ATPase is often altered in hypertrophic and failing hearts. The mechanisms are unclear. There are limited data from human cardiomyocytes. Abundant evidences from rodents show that Na+/K+-ATPase regulates cardiac contractility, cell signaling, hypertrophy and fibrosis. The α1 isoform of the Na+/K+-ATPase is the ubiquitous isoform and possesses both pumping and signaling functions. The α2 isoform of the Na+/K+-ATPase regulates intracellular Ca2+ signaling, contractility and pathological hypertrophy. The α3 isoform of the Na+/K+-ATPase may also be a target for cardiac hypertrophy. Restoration of cardiac Na+/K+-ATPase expression may be an effective approach for prevention of cardiac remodeling. In this article, we will overview: (1 the distribution and function of isoform specific Na+/K+-ATPase in the cardiomyocytes. (2 the role of cardiac Na+/K+-ATPase in the regulation of cell signaling, contractility, cardiac hypertrophy and fibrosis in vitro and in vivo. Selective targeting of cardiac Na+/K+-ATPase isoform may offer a new target for the prevention of cardiac remodeling.

  8. Energetics of the midlatitude thermosphere

    Science.gov (United States)

    Stolarski, R. S.

    1976-01-01

    Thermospheric energetics is examined from the point of view of atomic and molecular processes which convert solar EUV radiative energy into kinetic energy of the ambient electron, ion, and neutral gases. The energy flow from photon to photoelectron-ion pair through energy loss and ion-molecule transfer to eventual electron-ion recombination is traced in detail. Upper and lower bounds are placed on the efficiency of conversion of radiative to thermal energy. Implications for the question of consistency of measured solar EUV fluxes and ionospheric models are discussed.

  9. Energetic particles in the heliosphere

    CERN Document Server

    Simnett, George M

    2017-01-01

    This monograph traces the development of our understanding of how and where energetic particles are accelerated in the heliosphere and how they may reach the Earth. Detailed data sets are presented which address these topics. The bulk of the observations are from spacecraft in or near the ecliptic plane. It is timely to present this subject now that Voyager-1 has entered the true interstellar medium. Since it seems unlikely that there will be a follow-on to the Voyager programme any time soon, the data we already have regarding the outer heliosphere are not going to be enhanced for at least 40 years.

  10. Running Economy from a Muscle Energetics Perspective

    Directory of Open Access Journals (Sweden)

    Jared R. Fletcher

    2017-06-01

    Full Text Available The economy of running has traditionally been quantified from the mass-specific oxygen uptake; however, because fuel substrate usage varies with exercise intensity, it is more accurate to express running economy in units of metabolic energy. Fundamentally, the understanding of the major factors that influence the energy cost of running (Erun can be obtained with this approach. Erun is determined by the energy needed for skeletal muscle contraction. Here, we approach the study of Erun from that perspective. The amount of energy needed for skeletal muscle contraction is dependent on the force, duration, shortening, shortening velocity, and length of the muscle. These factors therefore dictate the energy cost of running. It is understood that some determinants of the energy cost of running are not trainable: environmental factors, surface characteristics, and certain anthropometric features. Other factors affecting Erun are altered by training: other anthropometric features, muscle and tendon properties, and running mechanics. Here, the key features that dictate the energy cost during distance running are reviewed in the context of skeletal muscle energetics.

  11. Cardiac pacemaker

    International Nuclear Information System (INIS)

    Kolenik, S.A.

    1976-01-01

    The construction of a cardiac pacemaker is described which is characterized by particularly small dimensions, small weight and long life duration. The weight is under 100g, the specific weight under 1.7. Mass inertia forces which occur through acceleration and retardation processes, thus remain below the threshold values, above which one would have to reckon with considerable damaging of the surrounding body tissue. The maintaining of small size and slight weight is achieved by using an oscillator on COSMOS basis, where by considerably lower energy consumption, amongst others the lifetimes of the batteries used - a lithium anode with thionyl chloride electrolyte - is extended to over 5 years. The reliability can be increased by the use of 2 or more batteries. The designed dimension are 20x60x60 mm 3 . (ORU/LH) [de

  12. Cardiac sarcoplasmic reticulum

    International Nuclear Information System (INIS)

    Jacobson, M.S.; Ambudkar, I.S.; Young, E.P.; Naseem, S.M.; Heald, F.P.; Shamoo, A.E.

    1985-01-01

    The effect on the cardiac sarcoplasmic reticulum of an atherogenic (1% cholesterol) diet fed during the neonatal vs the juvenile period of life was studied in Yorkshire swine. Male piglets were randomly assigned at birth to 1 of 4 groups: group I (control), group II (lactation feeding), group III (juvenile period feeding) and group IV (lactation and juvenile feeding). All animals were killed at 55 weeks of age and cardiac sarcoplasmic reticulum (SR) isolated for assay of calcium uptake, Ca 2+ -Mg 2+ ATPase activity, and lipid analysis by thin-layer chromatography and gas chromatography. The amount of cholesterol/mg SR protein and the cholesterol/phospholipid ratio were higher in the animals fed during lactation (groups II and IV) and lower in those fed only during the juvenile period (group III). Phospholipid fatty acid patterns as measured by gas chromatography were unaltered in any group. Calcium uptake was markedly diminished in all experimental conditions: group II 47%, group III 65% and group IV 96%. Compared to the observed changes in calcium transport, the ATP hydrolytic activity was relatively less affected. Only in group IV a significant decrease (41%) was seen. Groups II and III show no change in ATP hydrolytic activity. The decrease in calcium uptake and altered cholesterol/phospholipid ratio without effect on ATP hydrolytic activity is consistent with an uncoupling of calcium transport related to the atherogenic diet in early life. (author)

  13. Armor Solutions for Energetic and Non-Energetic Novel Defeat Mechanisms

    Science.gov (United States)

    2015-09-28

    Final Technical Status Report For DOTC-13-01-INIT112 Armor Solutions for Energetic and Non-Energetic Novel Defeat Mechanisms Reporting...REPORT TYPE Final 3. DATES COVERED 4. TITLE AND SUBTITLE Final Report: Armor Solutions for Energetic and Non-Energetic Novel Defeat...distribution unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Summary of prototyping efforts for next generation armor designs using advanced

  14. Ventricular Energetics in Pediatric Left Ventricular Assist Device Patients: A Retrospective Clinical Study.

    Science.gov (United States)

    Di Molfetta, Arianna; Ferrari, Gianfranco; Iacobelli, Roberta; Filippelli, Sergio; Di Chiara, Luca; Guccione, Paolo; Amodeo, Antonio

    The aim of this study is to estimate the trend of right and left energetic parameters in left ventricular assist device (LVAD) pediatric patients. Echocardiographic data were retrospectively collected at the baseline, in the acute phase after and at the monthly follow-ups till the LVAD explantation to estimate left and right ventricular energetic parameters. A significant relationship between the left and right ventricular energetic parameter trends was found along all the study period. Left ventricular end-systolic pressure-volume relationship improved till the follow-up of 2 months and then progressively decreases. Left arteroventricular coupling decreases after the LVAD, and right arteroventricular coupling decreases at the short-term follow-up. Left ventricular external work, potential energy, and pressure-volume area decrease at the short-term follow-up and then increase progressively. Right ventricular external work, potential energy, and pressure-volume area increase after the LVAD implantation. Left (right) cardiac mechanical efficiency is improved (worsened) by the LVAD. Energetic variables show that the LVAD benefits could decrease over time. A continuous and patient tailored LVAD setting could contribute to prolong LVAD benefits. The introduction of energetic parameters could lead to a more complete evaluation of LVAD patients' outcome which is a multiparametric process.

  15. Effect of Aging on Mitochondrial Energetics in the Human Atria.

    Science.gov (United States)

    Emelyanova, Larisa; Preston, Claudia; Gupta, Anu; Viqar, Maria; Negmadjanov, Ulugbek; Edwards, Stacie; Kraft, Kelsey; Devana, Kameswari; Holmuhamedov, Ekhson; O'Hair, Daniel; Tajik, A Jamil; Jahangir, Arshad

    2017-08-19

    Energy production in myocardial cells occurs mainly in the mitochondrion. Although alterations in mitochondrial functions in the senescent heart have been documented, the molecular bases for the aging-associated decline in energy metabolism in the human heart are not fully understood. In this study, we examined transcription profiles of genes coding for mitochondrial proteins in atrial tissue from aged (≥65 years old) and comorbidities-matched adult (energetic pathways. These changes were associated with a significant decrease in respiratory capacity of mitochondria oxidizing glutamate and malate and functional activity of complex I activity that correlated with the downregulation of NDUFA6, NDUFA9, NDUFB5, NDUFB8, and NDUFS2 genes coding for NADH dehydrogenase subunits. Thus, aging is associated with a decline in activity of OXPHOS within the broader transcriptional downregulation of genes regulating mitochondrial energetics, providing a substrate for reduced energetic efficiency in the senescent human atria. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Extramitochondrial domain rich in carbonic anhydrase activity improves myocardial energetics.

    Science.gov (United States)

    Schroeder, Marie A; Ali, Mohammad A; Hulikova, Alzbeta; Supuran, Claudiu T; Clarke, Kieran; Vaughan-Jones, Richard D; Tyler, Damian J; Swietach, Pawel

    2013-03-05

    CO2 is produced abundantly by cardiac mitochondria. Thus an efficient means for its venting is required to support metabolism. Carbonic anhydrase (CA) enzymes, expressed at various sites in ventricular myocytes, may affect mitochondrial CO2 clearance by catalyzing CO2 hydration (to H(+) and HCO3(-)), thereby changing the gradient for CO2 venting. Using fluorescent dyes to measure changes in pH arising from the intracellular hydration of extracellularly supplied CO2, overall CA activity in the cytoplasm of isolated ventricular myocytes was found to be modest (2.7-fold above spontaneous kinetics). Experiments on ventricular mitochondria demonstrated negligible intramitochondrial CA activity. CA activity was also investigated in intact hearts by (13)C magnetic resonance spectroscopy from the rate of H(13)CO3(-) production from (13)CO2 released specifically from mitochondria by pyruvate dehydrogenase-mediated metabolism of hyperpolarized [1-(13)C]pyruvate. CA activity measured upon [1-(13)C]pyruvate infusion was fourfold higher than the cytoplasm-averaged value. A fluorescent CA ligand colocalized with a mitochondrial marker, indicating that mitochondria are near a CA-rich domain. Based on immunoreactivity, this domain comprises the nominally cytoplasmic CA isoform CAII and sarcoplasmic reticulum-associated CAXIV. Inhibition of extramitochondrial CA activity acidified the matrix (as determined by fluorescence measurements in permeabilized myocytes and isolated mitochondria), impaired cardiac energetics (indexed by the phosphocreatine-to-ATP ratio measured by (31)P magnetic resonance spectroscopy of perfused hearts), and reduced contractility (as measured from the pressure developed in perfused hearts). These data provide evidence for a functional domain of high CA activity around mitochondria to support CO2 venting, particularly during elevated and fluctuating respiratory activity. Aberrant distribution of CA activity therefore may reduce the heart's energetic

  17. Theoretical studies on energetic materials bearing pentaflurosulphyl ...

    Indian Academy of Sciences (India)

    Heats of formation (HOF) for a series of energetic materials containing SF5 group were studied by density functional theory. Results show that HOFs increase with the augmention of field effects of substituted groups. Addition of furazan or furoxan ring increases HOF of the energetic materials. All the SF5-containing ...

  18. Theoretical studies on energetic materials bearing pentaflurosulphyl

    Indian Academy of Sciences (India)

    Heats of formation (HOF) for a series of energetic materials containing SF5 group were studied by density functional theory. Results show that HOFs increase with the augmention of field effects of substituted groups. Addition of furazan or furoxan ring increases HOF of the energetic materials. All the SF5-containing ...

  19. Energetics of borelike internal waves

    Science.gov (United States)

    Henyey, Frank S.; Hoering, Antje

    1997-02-01

    The net integrated energy flux into a train of internal waves is evaluated in a two-layer model. The nonzero value for this integral results from the difference in the stratification between the initial and final state, similar to the energy supply to a surface bore. We apply this expression to waves measured by Wesson and Gregg [1988] in the Strait of Gibraltar and to waves measured by Farmer and Smith [1980] in Knight Inlet. We find the energy supply to be important to the energetics, but the data do not allow a definitive test of the conjecture that the primary energy balance is between this supply and dissipation. We contrast our conjecture to the solitary-wave considerations of Bogucki and Garrett [1993].

  20. Cosmic Ray Energetics and Mass

    CERN Multimedia

    Baylon cardiel, J L; Wallace, K C; Anderson, T B; Copley, M

    The cosmic-ray energetics and mass (CREAM) investigation is designed to measure cosmic-ray composition to the supernova energy scale of 10$^{15}$ eV in a series of ultra long duration balloon (ULDB) flights. The first flight is planned to be launched from Antarctica in December 2004. The goal is to observe cosmic-ray spectral features and/or abundance changes that might signify a limit to supernova acceleration. The particle ($\\{Z}$) measurements will be made with a timing-based charge detector and a pixelated silicon charge detector to minimize the effect of backscatter from the calorimeter. The particle energy measurements will be made with a transition radiation detector (TRD) for $\\{Z}$ > 3 and a sampling tungsten/scintillator calorimeter for $\\{Z}$ $\\geq$1 particles, allowing inflight cross calibration of the two detectors. The status of the payload construction and flight preparation are reported in this paper.

  1. Albiglutide, a long lasting glucagon-like peptide-1 analog, protects the rat heart against ischemia/reperfusion injury: evidence for improving cardiac metabolic efficiency.

    Directory of Open Access Journals (Sweden)

    Weike Bao

    Full Text Available BACKGROUND: The cardioprotective effects of glucagon-like peptide-1 (GLP-1 and analogs have been previously reported. We tested the hypothesis that albiglutide, a novel long half-life analog of GLP-1, may protect the heart against I/R injury by increasing carbohydrate utilization and improving cardiac energetic efficiency. METHODS/PRINCIPAL FINDINGS: Sprague-Dawley rats were treated with albiglutide and subjected to 30 min myocardial ischemia followed by 24 h reperfusion. Left ventricle infarct size, hemodynamics, function and energetics were determined. In addition, cardiac glucose disposal, carbohydrate metabolism and metabolic gene expression were assessed. Albiglutide significantly reduced infarct size and concomitantly improved post-ischemic hemodynamics, cardiac function and energetic parameters. Albiglutide markedly increased both in vivo and ex vivo cardiac glucose uptake while reducing lactate efflux. Analysis of metabolic substrate utilization directly in the heart showed that albiglutide increased the relative carbohydrate versus fat oxidation which in part was due to an increase in both glucose and lactate oxidation. Metabolic gene expression analysis indicated upregulation of key glucose metabolism genes in the non-ischemic myocardium by albiglutide. CONCLUSION/SIGNIFICANCE: Albiglutide reduced myocardial infarct size and improved cardiac function and energetics following myocardial I/R injury. The observed benefits were associated with enhanced myocardial glucose uptake and a shift toward a more energetically favorable substrate metabolism by increasing both glucose and lactate oxidation. These findings suggest that albiglutide may have direct therapeutic potential for improving cardiac energetics and function.

  2. Cardiac regeneration therapy: connections to cardiac physiology.

    Science.gov (United States)

    Takehara, Naofumi; Matsubara, Hiroaki

    2011-12-01

    Without heart transplantation, a large number of patients with failing hearts worldwide face poor outcomes. By means of cardiomyocyte regeneration, cardiac regeneration therapy is emerging with great promise as a means for restoring loss of cardiac function. However, the limited success of clinical trials using bone marrow-derived cells and myoblasts with heterogeneous constituents, transplanted at a wide range of cell doses, has led to disagreement on the efficacy of cell therapy. It is therefore essential to reevaluate the evidence for the efficacy of cell-based cardiac regeneration therapy, focusing on targets, materials, and methodologies. Meanwhile, the revolutionary innovation of cardiac regeneration therapy is sorely needed to help the millions of people who suffer heart failure from acquired loss of cardiomyocytes. Cardiac regeneration has been used only in limited species or as a developing process in the rodent heart; now, the possibility of cardiomyocyte turnover in the human heart is being revisited. In the pursuit of this concept, the use of cardiac stem/progenitor stem cells in the cardiac niche must be focused to usher in a second era of cardiac regeneration therapy for the severely injured heart. In addition, tissue engineering and cellular reprogramming will advance the next era of treatment that will enable current cell-based therapy to progress to "real" cardiac regeneration therapy. Although many barriers remain, the prevention of refractory heart failure through cardiac regeneration is now becoming a realistic possibility.

  3. Acute alteration of cardiac ECG, action potential, IKr and the human ether-a-go-go-related gene (hERG) K+ channel by PCB 126 and PCB 77

    International Nuclear Information System (INIS)

    Park, Mi-Hyeong; Park, Won Sun; Jo, Su-Hyun

    2012-01-01

    Polychlorinated biphenyls (PCBs) have been known as serious persistent organic pollutants (POPs), causing developmental delays and motor dysfunction. We have investigated the effects of two PCB congeners, 3,3′,4,4′-tetrachlorobiphenyl (PCB 77) and 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) on ECG, action potential, and the rapidly activating delayed rectifier K + current (I Kr ) of guinea pigs' hearts, and hERG K + current expressed in Xenopus oocytes. PCB 126 shortened the corrected QT interval (QTc) of ECG and decreased the action potential duration at 90% (APD 90 ), and 50% of repolarization (APD 50 ) (P 20 ). PCB 77 decreased APD 20 (P 90 , and APD 50 . The PCB 126 increased the I Kr in guinea-pig ventricular myocytes held at 36 °C and hERG K + current amplitude at the end of the voltage steps in voltage-dependent mode (P + current amplitude. The PCB 77 increased the diastolic Ca 2+ and decreased Ca 2+ transient amplitude (P 90 possibly by increasing I Kr , while PCB 77 decreased the APD 20 possibly by other modulation related with intracellular Ca 2+ . The present data indicate that the environmental toxicants, PCBs, can acutely affect cardiac electrophysiology including ECG, action potential, intracellular Ca 2+ , and channel activity, resulting in toxic effects on the cardiac function in view of the possible accumulation of the PCBs in human body. -- Highlights: ► PCBs are known as serious environmental pollutants and developmental disruptors. ► PCB 126 shortened QT interval of ECG and action potential duration. ► PCB 126 increased human ether-a-go-go-related K + current and I Kr . ► PCB 77 decreased action potential duration and increased intracellular Ca 2+ content. ► PCBs acutely change cardiac electrophysiology and rhythmicity.

  4. Cardiac function of the naked mole-rat: ecophysiological responses to working underground.

    Science.gov (United States)

    Grimes, Kelly M; Voorhees, Andrew; Chiao, Ying Ann; Han, Hai-Chao; Lindsey, Merry L; Buffenstein, Rochelle

    2014-03-01

    The naked mole-rat (NMR) is a strictly subterranean rodent with a low resting metabolic rate. Nevertheless, it can greatly increase its metabolic activity to meet the high energetic demands associated with digging through compacted soils in its xeric natural habitat where food is patchily distributed. We hypothesized that the NMR heart would naturally have low basal function and exhibit a large cardiac reserve, thereby mirroring the species' low basal metabolism and large metabolic scope. Echocardiography showed that young (2-4 yr old) healthy NMRs have low fractional shortening (28 ± 2%), ejection fraction (43 ± 2%), and cardiac output (6.5 ± 0.4 ml/min), indicating low basal cardiac function. Histology revealed large NMR cardiomyocyte cross-sectional area (216 ± 10 μm(2)) and cardiac collagen deposition of 2.2 ± 0.4%. Neither of these histomorphometric traits was considered pathological, since biaxial tensile testing showed no increase in passive ventricular stiffness. NMR cardiomyocyte fibers showed a low degree of rotation, contributing to the observed low NMR cardiac contractility. Interestingly, when the exercise mimetic dobutamine (3 μg/g ip) was administered, NMRs showed pronounced increases in fractional shortening, ejection fraction, cardiac output, and stroke volume, indicating an increased cardiac reserve. The relatively low basal cardiac function and enhanced cardiac reserve of NMRs are likely to be ecophysiological adaptations to life in an energetically taxing environment.

  5. Cardiac myofibrillar contractile properties during the progression from hypertension to decompensated heart failure.

    Science.gov (United States)

    Hanft, Laurin M; Emter, Craig A; McDonald, Kerry S

    2017-07-01

    Heart failure arises, in part, from a constellation of changes in cardiac myocytes including remodeling, energetics, Ca 2+ handling, and myofibrillar function. However, little is known about the changes in myofibrillar contractile properties during the progression from hypertension to decompensated heart failure. The aim of the present study was to provide a comprehensive assessment of myofibrillar functional properties from health to heart disease. A rodent model of uncontrolled hypertension was used to test the hypothesis that myocytes in compensated hearts exhibit increased force, higher rates of force development, faster loaded shortening, and greater power output; however, with progression to overt heart failure, we predicted marked depression in these contractile properties. We assessed contractile properties in skinned cardiac myocyte preparations from left ventricles of Wistar-Kyoto control rats and spontaneous hypertensive heart failure (SHHF) rats at ~3, ~12, and >20 mo of age to evaluate the time course of myofilament properties associated with normal aging processes compared with myofilaments from rats with a predisposition to heart failure. In control rats, the myofilament contractile properties were virtually unchanged throughout the aging process. Conversely, in SHHF rats, the rate of force development, loaded shortening velocity, and power all increased at ~12 mo and then significantly fell at the >20-mo time point, which coincided with a decrease in left ventricular fractional shortening. Furthermore, these changes occurred independent of changes in β-myosin heavy chain but were associated with depressed phosphorylation of myofibrillar proteins, and the fall in loaded shortening and peak power output corresponded with the onset of clinical signs of heart failure. NEW & NOTEWORTHY This novel study systematically examined the power-generating capacity of cardiac myofilaments during the progression from hypertension to heart disease. Previously

  6. A common genetic variant within SCN10A modulates cardiac SCN5A expression

    NARCIS (Netherlands)

    van den Boogaard, Malou; Smemo, Scott; Burnicka-Turek, Ozanna; Arnolds, David E.; van de Werken, Harmen J. G.; Klous, Petra; McKean, David; Muehlschlegel, Jochen D.; Moosmann, Julia; Toka, Okan; Yang, Xinan H.; Koopmann, Tamara T.; Adriaens, Michiel E.; Bezzina, Connie R.; de Laat, Wouter; Seidman, Christine; Seidman, J. G.; Christoffels, Vincent M.; Nobrega, Marcelo A.; Barnett, Phil; Moskowitz, Ivan P.

    2014-01-01

    Variants in SCN10A, which encodes a voltage-gated sodium channel, are associated with alterations of cardiac conduction parameters and the cardiac rhythm disorder Brugada syndrome; however, it is unclear how SCN10A variants promote dysfunctional cardiac conduction. Here we showed by high-resolution

  7. Energetic and spatial constraints of arterial networks

    Directory of Open Access Journals (Sweden)

    Sandro Rossitti

    1995-06-01

    Full Text Available The principle of minimum work (PMW is a parametric optimization model for the growth and adaptation of arterial trees. A balance between energy dissipation due to frictional resistance of laminar flow (shear stress and the minimum volume of the blood and vessel wall tissue is achieved when the vessel radii are adjusted to the cube root of the volumetric flow. The PMW is known to apply over several magnitudes of vessel calibers, and in many different organs, including the brain, in humans and in animals. Animal studies suggest that blood flow in arteries is approximately proportional to the cube of the vessel radius, and that arteries alter their caliber in response to sustained changes of blood flow according to PMW. Remodelling of the retinal arteriolar network to long-term changes in blood flow was observed in humans. Remodelling of whole arterial networks occurs in the form of increase or diminishing of vessel calibers. Shear stress induced endothelial mediation seems to be the regulating mechanism for the maintenance of this optimum blood flow/vessel diameter relation. Arterial trees are also expected to be nearly space filing. The vascular system is constructed in such a way that, while blood vessels occupy only a small percentage of the body volume leaving the bulk to tissue, they also crisscross organs so tightly that every point in the tissue lies on the boundary between an artery and a vein. This review describes how the energetic optimum principle for least energy cost for blood flow is also compatible with the spatial constraints of arterial networks according to concepts derived from fractal geometry.

  8. Acute alteration of cardiac ECG, action potential, I{sub Kr} and the human ether-a-go-go-related gene (hERG) K{sup +} channel by PCB 126 and PCB 77

    Energy Technology Data Exchange (ETDEWEB)

    Park, Mi-Hyeong; Park, Won Sun; Jo, Su-Hyun, E-mail: suhyunjo@kangwon.ac.kr

    2012-07-01

    Polychlorinated biphenyls (PCBs) have been known as serious persistent organic pollutants (POPs), causing developmental delays and motor dysfunction. We have investigated the effects of two PCB congeners, 3,3′,4,4′-tetrachlorobiphenyl (PCB 77) and 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) on ECG, action potential, and the rapidly activating delayed rectifier K{sup +} current (I{sub Kr}) of guinea pigs' hearts, and hERG K{sup +} current expressed in Xenopus oocytes. PCB 126 shortened the corrected QT interval (QTc) of ECG and decreased the action potential duration at 90% (APD{sub 90}), and 50% of repolarization (APD{sub 50}) (P < 0.05) without changing the action potential duration at 20% (APD{sub 20}). PCB 77 decreased APD{sub 20} (P < 0.05) without affecting QTc, APD{sub 90}, and APD{sub 50}. The PCB 126 increased the I{sub Kr} in guinea-pig ventricular myocytes held at 36 °C and hERG K{sup +} current amplitude at the end of the voltage steps in voltage-dependent mode (P < 0.05); however, PCB 77 did not change the hERG K{sup +} current amplitude. The PCB 77 increased the diastolic Ca{sup 2+} and decreased Ca{sup 2+} transient amplitude (P < 0.05), however PCB 126 did not change. The results suggest that PCB 126 shortened the QTc and decreased the APD{sub 90} possibly by increasing I{sub Kr}, while PCB 77 decreased the APD{sub 20} possibly by other modulation related with intracellular Ca{sup 2+}. The present data indicate that the environmental toxicants, PCBs, can acutely affect cardiac electrophysiology including ECG, action potential, intracellular Ca{sup 2+}, and channel activity, resulting in toxic effects on the cardiac function in view of the possible accumulation of the PCBs in human body. -- Highlights: ► PCBs are known as serious environmental pollutants and developmental disruptors. ► PCB 126 shortened QT interval of ECG and action potential duration. ► PCB 126 increased human ether-a-go-go-related K{sup +} current and I{sub Kr}.

  9. Optimization of some eco-energetic systems

    International Nuclear Information System (INIS)

    Purica, I.; Pavelescu, M.; Stoica, M.

    1976-01-01

    An optimization problem of two eco-energetic systems is described. The first one is close to the actual eco-energetic system in Romania, while the second is a new one, based on nuclear energy as primary source and hydrogen energy as secondary source. The optimization problem solved is to find the optimal structure of the systems so that the objective functions adopted, namely unitary energy cost C and total pollution P, to be minimum at the same time. The problem can be modelated with a bimatrix cooperative mathematical game without side payments. We demonstrate the superiority of the new eco-energetic system. (author)

  10. Energetic funnel facilitates facilitated diffusion.

    Science.gov (United States)

    Cencini, Massimo; Pigolotti, Simone

    2018-01-25

    Transcription factors (TFs) are able to associate to their binding sites on DNA faster than the physical limit posed by diffusion. Such high association rates can be achieved by alternating between three-dimensional diffusion and one-dimensional sliding along the DNA chain, a mechanism-dubbed facilitated diffusion. By studying a collection of TF binding sites of Escherichia coli from the RegulonDB database and of Bacillus subtilis from DBTBS, we reveal a funnel in the binding energy landscape around the target sequences. We show that such a funnel is linked to the presence of gradients of AT in the base composition of the DNA region around the binding sites. An extensive computational study of the stochastic sliding process along the energetic landscapes obtained from the database shows that the funnel can significantly enhance the probability of TFs to find their target sequences when sliding in their proximity. We demonstrate that this enhancement leads to a speed-up of the association process. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  11. Insulin receptor substrate signaling controls cardiac energy metabolism and heart failure.

    Science.gov (United States)

    Guo, Cathy A; Guo, Shaodong

    2017-06-01

    The heart is an insulin-dependent and energy-consuming organ in which insulin and nutritional signaling integrates to the regulation of cardiac metabolism, growth and survival. Heart failure is highly associated with insulin resistance, and heart failure patients suffer from the cardiac energy deficiency and structural and functional dysfunction. Chronic pathological conditions, such as obesity and type 2 diabetes mellitus, involve various mechanisms in promoting heart failure by remodeling metabolic pathways, modulating cardiac energetics and impairing cardiac contractility. Recent studies demonstrated that insulin receptor substrates 1 and 2 (IRS-1,-2) are major mediators of both insulin and insulin-like growth factor-1 (IGF-1) signaling responsible for myocardial energetics, structure, function and organismal survival. Importantly, the insulin receptor substrates (IRS) play an important role in the activation of the phosphatidylinositide-3-dependent kinase (PI-3K) that controls Akt and Foxo1 signaling cascade, regulating the mitochondrial function, cardiac energy metabolism and the renin-angiotensin system. Dysregulation of this branch in signaling cascades by insulin resistance in the heart through the endocrine system promotes heart failure, providing a novel mechanism for diabetic cardiomyopathy. Therefore, targeting this branch of IRS→PI-3K→Foxo1 signaling cascade and associated pathways may provide a fundamental strategy for the therapeutic and nutritional development in control of metabolic and cardiovascular diseases. In this review, we focus on insulin signaling and resistance in the heart and the role energetics play in cardiac metabolism, structure and function. © 2017 Society for Endocrinology.

  12. Hydro energetic inventory study from Chapecozinho river

    International Nuclear Information System (INIS)

    Pimenta, S.C.; Sureck, M.A.A.; Nascimento, P.R.; Kawasaki, M.; Silva Felipe, R. da.

    1990-01-01

    The Hydro energetic Inventory Study in Chapecozinho River Basin, Brazil is described, comparing the proposed results in 1979 with the actual review in 1989. An analysis for solution the socio-economic and environment problems is also presented. (author)

  13. Global Positioning System (GPS) Energetic Particle Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Energetic particle data from the CXD and BDD instrument on the GPS constellation are available to the space weather research community. The release of these data...

  14. Energetic particle observations at the subsolar magnetopause

    Directory of Open Access Journals (Sweden)

    A. A. Eccles

    2002-04-01

    Full Text Available The pitch-angle distributions (PAD of energetic particles are examined as the ISEE-1 satellite crosses the Earth’s magnetopause near the subsolar point. The investigation focuses on the possible existence of a particular type of distribution that would be associated with a source of energetic particles in the high-latitude magnetosphere. PADs, demonstrating broad, persistent field-aligned fluxes filling a single hemisphere (upper/northern or lower/southern, were observed just sunward of the magnetopause current layer for an extended period of many minutes. These distributions are a direct prediction of a possible source of energetic particles located in the high altitude dayside cusp and we present five examples in detail of the three-dimensional particle distributions to demonstrate their existence. From these results, other possible causes of such PADs are examined.Key words. Magnetospheric physics (energetic particles, precipitating; magnetopause, cusp and boundary layers; magnetospheric configuration and dynamics

  15. Organization of the national energetic institutions

    International Nuclear Information System (INIS)

    Waltenberg, D.A.M.

    1983-01-01

    This text broaches, in a critical pourt of view, the organization of national energetic institutions, the need of a law revision, the problem of the rising of tariff and shows the decisions of GC01 [pt

  16. Modeling Thermal Ignition of Energetic Materials

    National Research Council Canada - National Science Library

    Gerri, Norman J; Berning, Ellen

    2004-01-01

    This report documents an attempt to computationally simulate the mechanics and thermal regimes created when a threat perforates an armor envelope and comes in contact with stowed energetic material...

  17. Cardiac sodium channelopathies

    NARCIS (Netherlands)

    Amin, A.S.; Asghari-Roodsari, A.; Tan, H.L.

    2010-01-01

    Cardiac sodium channel are protein complexes that are expressed in the sarcolemma of cardiomyocytes to carry a large inward depolarizing current (I-Na) during phase 0 of the cardiac action potential. The importance of I-Na for normal cardiac electrical activity is reflected by the high incidence of

  18. Energetic Tuning in Spirocyclic Conjugated Polymers

    OpenAIRE

    Hugo Bronstein; Frank D. King

    2016-01-01

    Precise control of the energy levels in a conjugated polymer is the key to allowing their exploitation in optoelectronic devices. The introduction of spirocycles into conjugated polymers has traditionally been used to enhance their solid state microstructure. Here we present a highly novel method of energetic tuning through the use of electronically active spirocyclic systems. By modifying the size and oxidation state of a heteroatom in an orthogonal spirocycle we demonstrate energetic fine t...

  19. Safer energetic materials by a nanotechnological approach

    Science.gov (United States)

    Siegert, Benny; Comet, Marc; Spitzer, Denis

    2011-09-01

    Energetic materials - explosives, thermites, populsive powders - are used in a variety of military and civilian applications. Their mechanical and electrostatic sensitivity is high in many cases, which can lead to accidents during handling and transport. These considerations limit the practical use of some energetic materials despite their good performance. For industrial applications, safety is one of the main criteria for selecting energetic materials. The sensitivity has been regarded as an intrinsic property of a substance for a long time. However, in recent years, several approaches to lower the sensitivity of a given substance, using nanotechnology and materials engineering, have been described. This feature article gives an overview over ways to prepare energetic (nano-)materials with a lower sensitivity.Energetic materials - explosives, thermites, populsive powders - are used in a variety of military and civilian applications. Their mechanical and electrostatic sensitivity is high in many cases, which can lead to accidents during handling and transport. These considerations limit the practical use of some energetic materials despite their good performance. For industrial applications, safety is one of the main criteria for selecting energetic materials. The sensitivity has been regarded as an intrinsic property of a substance for a long time. However, in recent years, several approaches to lower the sensitivity of a given substance, using nanotechnology and materials engineering, have been described. This feature article gives an overview over ways to prepare energetic (nano-)materials with a lower sensitivity. Electronic supplementary information (ESI) available: Experimental details for the preparation of the V2O5@CNF/Al nanothermite; X-ray diffractogram of the V2O5@CNF/Al combustion residue; installation instructions and source code for the nt-timeline program. See DOI: 10.1039/c1nr10292c

  20. Energetic Optimal Control Of Adjustable Drive Systems

    Directory of Open Access Journals (Sweden)

    Ion BIVOL

    2002-12-01

    Full Text Available n the paper is developed a new control strategy for the adjustable speed drives. The strategy consists in the energetic optimal control of the dynamic regimes as starting, stopping and reversing. The main developed problems: formulation of energetic optimal problem, solution, experimental results via simulation and some considerations concerning the use of the control. The optimal developed solution can be applied for the both AC and DC drives, but only for linear systems.

  1. Structure of Energetic Particle Mediated Shocks Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Mostafavi, P.; Zank, G. P. [Department of Space Science, University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Webb, G. M. [Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

    2017-05-20

    The structure of collisionless shock waves is often modified by the presence of energetic particles that are not equilibrated with the thermal plasma (such as pickup ions [PUIs] and solar energetic particles [SEPs]). This is relevant to the inner and outer heliosphere and the Very Local Interstellar Medium (VLISM), where observations of shock waves (e.g., in the inner heliosphere) show that both the magnetic field and thermal gas pressure are less than the energetic particle component pressures. Voyager 2 observations revealed that the heliospheric termination shock (HTS) is very broad and mediated by energetic particles. PUIs and SEPs contribute both a collisionless heat flux and a higher-order viscosity. We show that the incorporation of both effects can completely determine the structure of collisionless shocks mediated by energetic ions. Since the reduced form of the PUI-mediated plasma model is structurally identical to the classical cosmic ray two-fluid model, we note that the presence of viscosity, at least formally, eliminates the need for a gas sub-shock in the classical two-fluid model, including in that regime where three are possible. By considering parameters upstream of the HTS, we show that the thermal gas remains relatively cold and the shock is mediated by PUIs. We determine the structure of the weak interstellar shock observed by Voyager 1 . We consider the inclusion of the thermal heat flux and viscosity to address the most general form of an energetic particle-thermal plasma two-fluid model.

  2. Structure of Energetic Particle Mediated Shocks Revisited

    Science.gov (United States)

    Mostafavi, P.; Zank, G. P.; Webb, G. M.

    2017-05-01

    The structure of collisionless shock waves is often modified by the presence of energetic particles that are not equilibrated with the thermal plasma (such as pickup ions [PUIs] and solar energetic particles [SEPs]). This is relevant to the inner and outer heliosphere and the Very Local Interstellar Medium (VLISM), where observations of shock waves (e.g., in the inner heliosphere) show that both the magnetic field and thermal gas pressure are less than the energetic particle component pressures. Voyager 2 observations revealed that the heliospheric termination shock (HTS) is very broad and mediated by energetic particles. PUIs and SEPs contribute both a collisionless heat flux and a higher-order viscosity. We show that the incorporation of both effects can completely determine the structure of collisionless shocks mediated by energetic ions. Since the reduced form of the PUI-mediated plasma model is structurally identical to the classical cosmic ray two-fluid model, we note that the presence of viscosity, at least formally, eliminates the need for a gas sub-shock in the classical two-fluid model, including in that regime where three are possible. By considering parameters upstream of the HTS, we show that the thermal gas remains relatively cold and the shock is mediated by PUIs. We determine the structure of the weak interstellar shock observed by Voyager 1. We consider the inclusion of the thermal heat flux and viscosity to address the most general form of an energetic particle-thermal plasma two-fluid model.

  3. Cardiac gated ventilation

    Science.gov (United States)

    Hanson, C. William, III; Hoffman, Eric A.

    1995-05-01

    There are several theoretic advantages to synchronizing positive pressure breaths with the cardiac cycle, including the potential for improving distribution of pulmonary and myocardial blood flow and enhancing cardiac output. We evaluated the effects of synchronizing respiration to the cardiac cycle using a programmable ventilator and electron beam CT (EBCT) scanning. The hearts of anesthetized dogs were imaged during cardiac gated respiration with a 50msec scan aperture. Multislice, short axis, dynamic image data sets spanning the apex to base of the left ventricle were evaluated to determine the volume of the left ventricular chamber at end-diastole and end-systole during apnea, systolic and diastolic cardiac gating. We observed an increase in cardiac output of up to 30% with inspiration gated to the systolic phase of the cardiac cycle in a nonfailing model of the heart.

  4. Changes in cardiac physiology after severe burn injury.

    Science.gov (United States)

    Williams, Felicia N; Herndon, David N; Suman, Oscar E; Lee, Jong O; Norbury, William B; Branski, Ludwik K; Mlcak, Ronald P; Jeschke, Marc G

    2011-01-01

    Cardiac stress, mediated by increased catecholamines, is the hallmark of severe burn injury typified by marked tachycardia, increased myocardial oxygen consumption, and increased cardiac output (CO). It remains one of the main determinants of survival in large burns. Currently, it is unknown for how long cardiac stress persists after a severe injury. Therefore, the aim of this study was to determine the extent and duration of cardiac stress after a severe burn. To determine persistence of cardiac alteration, the authors determined cardiac parameters of all surviving patients with burns ≥ 40% TBSA from 1998 to 2008. One hundred ninety-four patients were included in this study. Heart rate, mean arterial pressure, CO, stroke volume, cardiac index, and ejection fractions were measured at regular intervals from admission up to 2 years after injury. Rate pressure product was calculated as a correlate of myocardial oxygen consumption. All values were compared with normal nonburned children to validate the findings. Statistical analysis was performed using log transformed analysis of variance with Bonferroni correction and Student's t-test, where applicable. Heart rate, CO, cardiac index, and rate pressure product remained significantly increased in burned children for up to 2 years when compared with normal ranges (P < .05), indicating vastly increased cardiac stress. Ejection fraction was within normal limits for 2 years. Cardiac stress persists for at least 2 years postburn, and the authors suggest that attenuation of these detrimental responses may improve long-term morbidity.

  5. A high-resolution thermoelectric module-based calorimeter for measuring the energetics of isolated ventricular trabeculae at body temperature.

    Science.gov (United States)

    Johnston, Callum M; Han, June-Chiew; Ruddy, Bryan P; Nielsen, Poul M F; Taberner, Andrew J

    2015-07-15

    Isolated ventricular trabeculae are the most common experimental preparations used in the study of cardiac energetics. However, the experiments have been conducted at subphysiological temperatures. We have overcome this limitation by designing and constructing a novel calorimeter with sufficiently high thermal resolution for simultaneously measuring the heat output and force production of isolated, contracting, ventricular trabeculae at body temperature. This development was largely motivated by the need to better understand cardiac energetics by performing such measurements at body temperature to relate tissue performance to whole heart behavior in vivo. Our approach uses solid-state thermoelectric modules, tailored for both temperature sensing and temperature control. The thermoelectric modules have high sensitivity and low noise, which, when coupled with a multilevel temperature control system, enable an exceptionally high temperature resolution with a noise-equivalent power an order of magnitude greater than those of other existing muscle calorimeters. Our system allows us to rapidly and easily change the experimental temperature without disturbing the state of the muscle. Our calorimeter is useful in many experiments that explore the energetics of normal physiology as well as pathophysiology of cardiac muscle. Copyright © 2015 the American Physiological Society.

  6. The Martian Energetic Radiation Environment Models

    Science.gov (United States)

    Gonçalves, Patrícia; Keating, Ana; Truscott, Pete; Lei, Fan; Desorgher, Laurent; Heynderickx, Daniel; Crosby, Norma Bock; Nieminen, Petteri; Santin, Giovanni

    The Martian Energetic Radiation Environment Models The high energy ionising radiation environment in the solar system consists of three main sources: the planetary radiation belts, galactic cosmic rays and solar energetic particles. Future Mars missions potentially carry significant risk from long-term exposure to ionising radiation. The Martian Energetic Radiation Environment Models, MEREM, were developed in order to simulate the Martian radiation environment. The models, eMEREM and dMEREM, respec-tively engineering and detailed Martian Energetic Radiation Environment Models, are based on the Geant4 and FLUKA radiation transport programs, combined with Mars Climate Database model for the atmosphere. MOLA (Mars Orbiter Laser Altimeter) data and gamma-ray spec-trometer data have been used to define surface topology and surface composition (including presence of water), respectively. Although the models are capable of operating on standalone mode, a SPENVIS (space envi-ronment information system) compatible, web-based user interface was developed to provide an integrated environment to predict the Martian radiation and greatly simplify the operation of the software by non-experts and by future mission developers. Results of the Mars Energetic Radiation Environment Models concerning the estimate of effec-tive doses and ambient dose equivalents for potential Martian landing sites having regard to the combined incidence, under solar minimum and solar maximum conditions, of flare related particle radiation and background galactic cosmic ray radiation are presented.

  7. Transcriptional profile of isoproterenol-induced cardiomyopathy and comparison to exercise-induced cardiac hypertrophy and human cardiac failure

    Directory of Open Access Journals (Sweden)

    McIver Lauren J

    2009-12-01

    Full Text Available Abstract Background Isoproterenol-induced cardiac hypertrophy in mice has been used in a number of studies to model human cardiac disease. In this study, we compared the transcriptional response of the heart in this model to other animal models of heart failure, as well as to the transcriptional response of human hearts suffering heart failure. Results We performed microarray analyses on RNA from mice with isoproterenol-induced cardiac hypertrophy and mice with exercise-induced physiological hypertrophy and identified 865 and 2,534 genes that were significantly altered in pathological and physiological cardiac hypertrophy models, respectively. We compared our results to 18 different microarray data sets (318 individual arrays representing various other animal models and four human cardiac diseases and identified a canonical set of 64 genes that are generally altered in failing hearts. We also produced a pairwise similarity matrix to illustrate relatedness of animal models with human heart disease and identified ischemia as the human condition that most resembles isoproterenol treatment. Conclusion The overall patterns of gene expression are consistent with observed structural and molecular differences between normal and maladaptive cardiac hypertrophy and support a role for the immune system (or immune cell infiltration in the pathology of stress-induced hypertrophy. Cross-study comparisons such as the results presented here provide targets for further research of cardiac disease that might generally apply to maladaptive cardiac stresses and are also a means of identifying which animal models best recapitulate human disease at the transcriptional level.

  8. Chemistry and structure of giant molecular clouds in energetic environments

    Science.gov (United States)

    Anderson, Crystal Nicole

    2016-09-01

    Throughout the years many studies on Galactic star formation have been conducted. This resulted in the idea that giant molecular clouds (GMCs) are hierarchical in nature with substructures spanning a large range of sizes. The physical processes that determine how molecular clouds fragment, form clumps/cores and then stars depends strongly on both recent radiative and mechanical feed- back from massive stars and, on longer term, from enhanced cooling due to the buildup of metals. Radiative and mechanical energy input from stellar populations can alter subsequent star formation over a large part of a galaxy and hence is relevant to the evolution of galaxies. Much of our knowledge of star formation on galaxy wide scales is based on scaling laws and other parametric descriptions. But to understand the overall evolution of star formation in galaxies we need to watch the feedback processes at work on giant molecular cloud (GMC) scales. By doing this we can begin to answer how strong feedback environments change the properties of the substructure in GMCs. Tests of Galactic star formation theory to other galaxies has been a challenging process due to the lack of resolution with current instruments. Thus, only the nearest galaxies allow us to resolve GMCs and their substructures. The Large Magellanic Cloud (LMC), is one of the closest low metallicity dwarf galaxies (D˜ 50 kpc) and is close enough that current instruments can resolve the sub- structure of its GMCs to gas tracers (e.g. HCO+, HCN, HNC, CS, C2H, N2H+) detected in the LMC at 1.5-40 pc scales and in NGC 5253 at 40 pc scales. I then compare the molecular gas detections to the Central Molecular Zone in our Galaxy. Dense molecular gas was detected in all of the sources. For the regions in the LMC, molecular lines of CS, N2H+, C 2H, HNC, HCO+ and HCN were all detected in N159W and N113 while only HCN, HCO+, HNC, and C2H were detected in 30Dor-10. Toward NGC 5253 only HCO+, HCN, C2H and CS were detected. I observe

  9. Cardiac sodium channelopathies.

    Science.gov (United States)

    Amin, Ahmad S; Asghari-Roodsari, Alaleh; Tan, Hanno L

    2010-07-01

    Cardiac sodium channel are protein complexes that are expressed in the sarcolemma of cardiomyocytes to carry a large inward depolarizing current (INa) during phase 0 of the cardiac action potential. The importance of INa for normal cardiac electrical activity is reflected by the high incidence of arrhythmias in cardiac sodium channelopathies, i.e., arrhythmogenic diseases in patients with mutations in SCN5A, the gene responsible for the pore-forming ion-conducting alpha-subunit, or in genes that encode the ancillary beta-subunits or regulatory proteins of the cardiac sodium channel. While clinical and genetic studies have laid the foundation for our understanding of cardiac sodium channelopathies by establishing links between arrhythmogenic diseases and mutations in genes that encode various subunits of the cardiac sodium channel, biophysical studies (particularly in heterologous expression systems and transgenic mouse models) have provided insights into the mechanisms by which INa dysfunction causes disease in such channelopathies. It is now recognized that mutations that increase INa delay cardiac repolarization, prolong action potential duration, and cause long QT syndrome, while mutations that reduce INa decrease cardiac excitability, reduce electrical conduction velocity, and induce Brugada syndrome, progressive cardiac conduction disease, sick sinus syndrome, or combinations thereof. Recently, mutation-induced INa dysfunction was also linked to dilated cardiomyopathy, atrial fibrillation, and sudden infant death syndrome. This review describes the structure and function of the cardiac sodium channel and its various subunits, summarizes major cardiac sodium channelopathies and the current knowledge concerning their genetic background and underlying molecular mechanisms, and discusses recent advances in the discovery of mutation-specific therapies in the management of these channelopathies.

  10. Hyperplastic Cardiac Sarcoma Recurrence

    Directory of Open Access Journals (Sweden)

    Masood A. Shariff

    2015-01-01

    Full Text Available Primary cardiac sarcomas are rare tumors with a median survival of 6–12 months. Data suggest that an aggressive multidisciplinary approach may improve patient outcome. We present the case of a male who underwent resection of cardiac sarcoma three times from the age of 32 to 34. This report discusses the malignant nature of cardiac sarcoma and the importance of postoperative multidisciplinary care.

  11. Giant cardiac myxoma.

    Science.gov (United States)

    Barlis, Peter; Lim, Eu Jin; Gow, Paul J; Seevanayagam, Siven; Calafiore, Paul; Chan, Robert K

    2007-10-01

    Although cardiac myxomas remain an uncommon group of malignancies, they are the most common form of primary cardiac tumour. Clinical presentations can be varied with local cardiac haemodynamic consequences, valvular insufficiency or even embolic phenomena. We present a case of a 46-year-old man with chronic abdominal pain and discuss a number of diagnostic challenges that were confronted up until a definitive diagnosis of cardiac myxoma was made. The resultant outcome was excellent with the patient achieving complete recovery from long term disabling symptoms.

  12. Cardiac event monitors

    Science.gov (United States)

    ... ECG) - ambulatory; Continuous electrocardiograms (EKGs); Holter monitors; Transtelephonic event monitors ... attached. You can carry or wear a cardiac event monitor up to 30 days. You carry the ...

  13. Cardiac resynchronization therapy induces adaptive metabolic transitions in the metabolomic profile of heart failure.

    Science.gov (United States)

    Nemutlu, Emirhan; Zhang, Song; Xu, Yi-Zhou; Terzic, Andre; Zhong, Li; Dzeja, Petras D; Cha, Yong-Mei

    2015-06-01

    Heart failure (HF) is associated with ventricular dyssynchrony and energetic inefficiency, which can be alleviated by cardiac resynchronization therapy (CRT). The aim of this study was to determine the metabolomic signature in HF and its prognostic value regarding the response to CRT. This prospective study consisted of 24 patients undergoing CRT for advanced HF and 10 control patients who underwent catheter ablation for supraventricular arrhythmia but not CRT. Blood samples were collected before and 3 months after CRT. Metabolomic profiling of plasma samples was performed with the use of gas chromatography-mass spectrometry and nuclear magnetic resonance. The plasma metabolomic profile was altered in the HF patients, with a distinct panel of metabolites, including Krebs cycle and lipid, amino acid, and nucleotide metabolism. CRT improved the metabolomic profile. The succinate-glutamate ratio, an index of Krebs cycle activity, improved from 0.58 ± 0.13 to 2.84 ± 0.60 (P HF patients, indicating harmonization of myocardial energy substrate metabolism. CRT responders may have a favorable metabolomic profile as a potential biomarker for predicting CRT outcome. Published by Elsevier Inc.

  14. Energetics of geostrophic adjustment in rotating flow

    Science.gov (United States)

    Juan, Fang; Rongsheng, Wu

    2002-09-01

    Energetics of geostrophic adjustment in rotating flow is examined in detail with a linear shallow water model. The initial unbalanced flow considered first falls tinder two classes. The first is similar to that adopted by Gill and is here referred to as a mass imbalance model, for the flow is initially motionless but with a sea surface displacement. The other is the same as that considered by Rossby and is referred to as a momentum imbalance model since there is only a velocity perturbation in the initial field. The significant feature of the energetics of geostrophic adjustment for the above two extreme models is that although the energy conversion ratio has a large case-to-case variability for different initial conditions, its value is bounded below by 0 and above by 1 / 2. Based on the discussion of the above extreme models, the energetics of adjustment for an arbitrary initial condition is investigated. It is found that the characteristics of the energetics of geostrophic adjustment mentioned above are also applicable to adjustment of the general unbalanced flow under the condition that the energy conversion ratio is redefined as the conversion ratio between the change of kinetic energy and potential energy of the deviational fields.

  15. Migration on Wings Aerodynamics and Energetics

    CERN Document Server

    Kantha, Lakshmi

    2012-01-01

    This book is an effort to explore the technical aspects associated with bird flight and migration on wings. After a short introduction on the birds migration, the book reviews the aerodynamics and Energetics of Flight and presents the calculation of the Migration Range. In addition, the authors explains aerodynamics of the formation flight and finally introduces great flight diagrams.

  16. Error propagation in energetic carrying capacity models

    Science.gov (United States)

    Pearse, Aaron T.; Stafford, Joshua D.

    2014-01-01

    Conservation objectives derived from carrying capacity models have been used to inform management of landscapes for wildlife populations. Energetic carrying capacity models are particularly useful in conservation planning for wildlife; these models use estimates of food abundance and energetic requirements of wildlife to target conservation actions. We provide a general method for incorporating a foraging threshold (i.e., density of food at which foraging becomes unprofitable) when estimating food availability with energetic carrying capacity models. We use a hypothetical example to describe how past methods for adjustment of foraging thresholds biased results of energetic carrying capacity models in certain instances. Adjusting foraging thresholds at the patch level of the species of interest provides results consistent with ecological foraging theory. Presentation of two case studies suggest variation in bias which, in certain instances, created large errors in conservation objectives and may have led to inefficient allocation of limited resources. Our results also illustrate how small errors or biases in application of input parameters, when extrapolated to large spatial extents, propagate errors in conservation planning and can have negative implications for target populations.

  17. Energetic utilization of dietary fiber in pigs

    NARCIS (Netherlands)

    Rijnen, M.M.J.A.

    2003-01-01

    The energetic utilization of fermentable dietary fiber (fDF) of different fiber sources and its relation to physical activity and housing conditions was studied in three experiments. In all experiments the daily intake of digestible nutrients, nitrogen and energy balances, heat production, and

  18. Radiation hormesis: an ecological and energetic perspective.

    Science.gov (United States)

    Parsons, P A

    2001-09-01

    Organisms in natural habitats are exposed to an array of environmental stresses, which all have energetic costs. Under this ecological scenario, hormesis for ionizing radiation becomes an evolutionary expectation at exposures substantially exceeding background. This conclusion implies that some relaxation of radiation protection criteria is worthy of serious consideration. Copyright 2001 Harcourt Publishers Ltd.

  19. Estimating Instantaneous Energetic Cost During Gait Adaptation

    Science.gov (United States)

    2014-08-31

    energetic penalties imposed by various gait disabilities, and the 30   evaluation of the effectiveness of rehabilitation interventions at mitigating...Jarasch R. Energy expenditure and biomechanical characteristics of 412   lower limb amputee gait:: The influence of prosthetic alignment and

  20. Energetic utilisation of biomass in Hungary

    International Nuclear Information System (INIS)

    Barotfi, I.

    1994-01-01

    Energetic utilisation of biomass has been known since prehistoric times and was only pushed into the background by the technological developments of the last century. The energy crisis and, more recently, environmental problems have now brought it back to the fore, and efforts are being made worldwide to find modern technical applications for biomass and contribute to its advance. (orig.) [de

  1. Cryocycling of energetic materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, S.; Nilson, R.; Handrock, J.; Revelli, V.; Weingarten, L. [and others

    1997-08-01

    The Cryocycling of Energetic Materials Project was executed in the period FY`94-96 as a Life Cycle Engineering activity in the Memorandum of Understanding (MOU) on advanced conventional munitions. This MOU is an agreement between the Departments of Energy and Defense (Office of Munitions) that facilitates the development of technologies of mutual interest to the two Departments. The cryocycling process is a safe, environmentally friendly, and cost effective means of rubblizing bulk energetic materials so that they can be easily reused in a variety of new products. For this reason, cryocycling of excess solid energetic materials is one of the recycle/reuse strategies under study for demilitarized munitions in the Departments of Energy and Defense. These strategies seek to minimize the environmental damage associated with disposal of decommissioned energetic materials. In addition, they encourage technologies that can be used to derive economic benefit from reuse/reapplication of materials that would otherwise be treated as hazardous wastes. 45 refs., 38 figs., 7 tabs.

  2. Energetic Systems and Nanotechnology - A Look Ahead

    National Research Council Canada - National Science Library

    Kavetsky, Robert; Anand, Davinder; Goldwasser, Judah; Bruck, Hugh; Doherty, Ruth; Armstrong, Ron

    2005-01-01

    ... in insensitive munitions built around the idea of "Combat Safe" Insensitive Munitions (CSIM); and 2) the importance of developing the next generation of in-house experts in energetic systems who will carry on a tradition of transitioning breakthrough research into military systems.

  3. Energetic materials standards – Chemical compatibility

    NARCIS (Netherlands)

    Tuukkanen, I.M.; Bouma, R.H.B.

    2014-01-01

    Subgroup A Energetic Materials Team, SG/A (EMT), develops and maintains standards that are relevant to all life-cycle phases of ammunition/weapon systems. STANAG 4147 is the standard regarding chemical compatibility of explosives with munition components, and is a document of prime importance.

  4. Energetic constraints on species coexistence in birds

    NARCIS (Netherlands)

    Pigot, Alexander L.; Tobias, Joseph A.; Jetz, Walter

    2016-01-01

    The association between species richness and ecosystem energy availability is one of the major geographic trends in biodiversity. It is often explained in terms of energetic constraints, such that coexistence among competing species is limited in low productivity environments. However, it has proven

  5. Safety in cardiac surgery

    NARCIS (Netherlands)

    Siregar, S.

    2013-01-01

    The monitoring of safety in cardiac surgery is a complex process, which involves many clinical, practical, methodological and statistical issues. The objective of this thesis was to measure and to compare safety in cardiac surgery in The Netherlands using the Netherlands Association for

  6. [Advances in cardiac pacing].

    Science.gov (United States)

    de Carranza, María-José Sancho-Tello; Fidalgo-Andrés, María Luisa; Ferrer, José Martínez; Mateas, Francisco Ruiz

    2012-01-01

    This article contains a review of the current status of remote monitoring and follow-up involving cardiac pacing devices and of the latest developments in cardiac resynchronization therapy. In addition, the most important articles published in the last year are discussed. Copyright © 2012 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  7. Cardiac Catheterization (For Kids)

    Science.gov (United States)

    ... First Aid & Safety Doctors & Hospitals Videos Recipes for Kids Kids site Sitio para niños How the Body Works ... Educators Search English Español Cardiac Catheterization KidsHealth / For Kids / Cardiac Catheterization What's in this article? What Is ...

  8. Advances in magnetospheric physics, 1971--1974: energetic particles

    International Nuclear Information System (INIS)

    West, H.I. Jr.

    1974-12-01

    An account is given of energetic particle research in magnetospheric physics for the time period 1971--1974. Emphasis is on relating the various aspects of energetic particles to magnetospheric processes. 458 refs. (U.S.)

  9. Mathematical cardiac electrophysiology

    CERN Document Server

    Colli Franzone, Piero; Scacchi, Simone

    2014-01-01

    This book covers the main mathematical and numerical models in computational electrocardiology, ranging from microscopic membrane models of cardiac ionic channels to macroscopic bidomain, monodomain, eikonal models and cardiac source representations. These advanced multiscale and nonlinear models describe the cardiac bioelectrical activity from the cell level to the body surface and are employed in both the direct and inverse problems of electrocardiology. The book also covers advanced numerical techniques needed to efficiently carry out large-scale cardiac simulations, including time and space discretizations, decoupling and operator splitting techniques, parallel finite element solvers. These techniques are employed in 3D cardiac simulations illustrating the excitation mechanisms, the anisotropic effects on excitation and repolarization wavefronts, the morphology of electrograms in normal and pathological tissue and some reentry phenomena. The overall aim of the book is to present rigorously the mathematica...

  10. Biomaterials for cardiac regeneration

    CERN Document Server

    Ruel, Marc

    2015-01-01

    This book offers readers a comprehensive biomaterials-based approach to achieving clinically successful, functionally integrated vasculogenesis and myogenesis in the heart. Coverage is multidisciplinary, including the role of extracellular matrices in cardiac development, whole-heart tissue engineering, imaging the mechanisms and effects of biomaterial-based cardiac regeneration, and autologous bioengineered heart valves. Bringing current knowledge together into a single volume, this book provides a compendium to students and new researchers in the field and constitutes a platform to allow for future developments and collaborative approaches in biomaterials-based regenerative medicine, even beyond cardiac applications. This book also: Provides a valuable overview of the engineering of biomaterials for cardiac regeneration, including coverage of combined biomaterials and stem cells, as well as extracellular matrices Presents readers with multidisciplinary coverage of biomaterials for cardiac repair, including ...

  11. Sudden cardiac death

    Directory of Open Access Journals (Sweden)

    Neeraj Parakh

    2015-01-01

    Full Text Available Sudden cardiac death is one of the most common cause of mortality worldwide. Despite significant advances in the medical science, there is little improvement in the sudden cardiac death related mortality. Coronary artery disease is the most common etiology behind sudden cardiac death, in the above 40 years population. Even in the apparently healthy population, there is a small percentage of patients dying from sudden cardiac death. Given the large denominator, this small percentage contributes to the largest burden of sudden cardiac death. Identification of this at risk group among the apparently healthy individual is a great challenge for the medical fraternity. This article looks into the causes and methods of preventing SCD and at some of the Indian data. Details of Brugada syndrome, Long QT syndrome, Genetics of SCD are discussed. Recent guidelines on many of these causes are summarised.

  12. Assessment of accident energetics in LMFBR core-disruptive accidents

    International Nuclear Information System (INIS)

    Fauske, H.K.

    1977-01-01

    An assessment of accident energetics in LMFBR core-disruptive accidents is given with emphasis on the generic issues of energetic recriticality and energetic fuel-coolant interaction events. Application of a few general behavior principles to the oxide-fueled system suggests that such events are highly unlikely following a postulated core meltdown event

  13. Effects of Hypertension and Exercise on Cardiac Proteome Remodelling

    Directory of Open Access Journals (Sweden)

    Bernardo A. Petriz

    2014-01-01

    Full Text Available Left ventricle hypertrophy is a common outcome of pressure overload stimulus closely associated with hypertension. This process is triggered by adverse molecular signalling, gene expression, and proteome alteration. Proteomic research has revealed that several molecular targets are associated with pathologic cardiac hypertrophy, including angiotensin II, endothelin-1 and isoproterenol. Several metabolic, contractile, and stress-related proteins are shown to be altered in cardiac hypertrophy derived by hypertension. On the other hand, exercise is a nonpharmacologic agent used for hypertension treatment, where cardiac hypertrophy induced by exercise training is characterized by improvement in cardiac function and resistance against ischemic insult. Despite the scarcity of proteomic research performed with exercise, healthy and pathologic heart proteomes are shown to be modulated in a completely different way. Hence, the altered proteome induced by exercise is mostly associated with cardioprotective aspects such as contractile and metabolic improvement and physiologic cardiac hypertrophy. The present review, therefore, describes relevant studies involving the molecular characteristics and alterations from hypertensive-induced and exercise-induced hypertrophy, as well as the main proteomic research performed in this field. Furthermore, proteomic research into the effect of hypertension on other target-demerged organs is examined.

  14. Smectite alteration

    International Nuclear Information System (INIS)

    Anderson, D.M.

    1984-11-01

    This report contains the proceedings of a second workshop in Washington DC December 8-9, 1983 on the alteration of smectites intended for use as buffer materials in the long-term containment of nuclear wastes. It includes extended summaries of all presentations and a transcript of the detailed scientific discussion. The discussions centered on three main questions: What is the prerequisite for and what is the precise mechanism by which smectite clays may be altered to illite. What are likly sources of potassium with respect to the KBS project. Is it likely that the conversion of smectite to illite will be of importance in the 10 5 to the 10 6 year time frame. The workshop was convened to review considerations and conclusions in connection to these questions and also to broaden the discussion to consider the use of smectite clays as buffer materials for similar applications in different geographical and geological settings. SKBF/KBS technical report 83-03 contains the proceedings from the first workshop on these matters that was held at the State University of New York, Buffalo May 26-27, 1982. (Author)

  15. Energetic costs of performance in trained and untrained Anolis carolinensis lizards.

    Science.gov (United States)

    Lailvaux, Simon P; Wang, Andrew Z; Husak, Jerry F

    2018-03-12

    The energetic costs of performance constitute a non-trivial component of animals' daily energetic budgets. However, we currently lack an understanding of how those costs are partitioned among the various stages of performance development, maintenance, and production. We manipulated individual investment in performance by training Anolis carolinensis lizards for endurance or sprinting ability. We then measured energetic expenditure both at rest and immediately following exercise to test whether such training alters the maintenance and production costs of performance. Trained lizards had lower resting metabolic rates than controls, suggestive of a maintenance saving associated with enhanced performance as opposed to a cost. Production costs also differed, with sprint-trained lizards incurring the largest energetic performance cost and experiencing the longest recovery times compared to endurance trained and control animals. Although performance training modifies metabolism, production costs are probably the key drivers of trade-offs between performance and other life-history traits in this species. © 2018. Published by The Company of Biologists Ltd.

  16. Gene Therapy in Cardiac Arrhythmias

    Directory of Open Access Journals (Sweden)

    Praveen S.V

    2006-04-01

    Full Text Available Gene therapy has progressed from a dream to a bedside reality in quite a few human diseases. From its first application in adenosine deaminase deficiency, through the years, its application has evolved to vascular angiogenesis and cardiac arrhythmias. Gene based biological pacemakers using viral vectors or mesenchymal cells tested in animal models hold much promise. Induction of pacemaker activity within the left bundle branch can provide stable heart rates. Genetic modification of the AV node mimicking beta blockade can be therapeutic in the management of atrial fibrillation. G protein overexpression to modify the AV node also is experimental. Modification and expression of potassium channel genes altering the delayed rectifier potassium currents may permit better management of congenital long QT syndromes. Arrhythmias in a failing heart are due to abnormal calcium cycling. Potential targets for genetic modulation include the sarcoplasmic reticulum calcium pump, calsequestrin and sodium calcium exchanger.Lastly the ethical concerns need to be addressed.

  17. Imaging for cardiac electrophysiology

    Directory of Open Access Journals (Sweden)

    Benoit Desjardins

    2016-11-01

    Full Text Available Clinical cardiac electrophysiology is the study of the origin and treatment of arrhythmia. There has been considerable recent development in this field, where imaging has had a transformational impact. In this invited review, we offer a global overview of the most important developments in the use of imaging in cardiac electrophysiology. We first describe the radiological imaging modalities involved in cardiac electrophysiology, to assess cardiac anatomy, function and scar. We then introduce an imaging modality with which readers are probably unfamiliar (electroanatomical mapping [EAM], but which is routinely used by electrophysiologists to plan and guide cardiac mapping and cardiac ablation therapy by catheter, a therapy which can reduce or even cure arrhythmia. We identify the limitations of EAM and describe how radiological imaging modalities can complement this technique. We then describe and illustrate how imaging has helped the diagnosis of arrhythmogenic conditions, and how imaging is used to plan and guide clinical cardiac electrophysiologic procedures and assess their results and complications. We focus on the two most common arrhythmias for which imaging has the greatest impact: atrial fibrillation and ventricular tachycardia.

  18. Cardiac tumors: echo assessment

    Directory of Open Access Journals (Sweden)

    Rekha Mankad MD

    2016-12-01

    Full Text Available Cardiac tumors are exceedingly rare (0.001–0.03% in most autopsy series. They can be present anywhere within the heart and can be attached to any surface or be embedded in the myocardium or pericardial space. Signs and symptoms are nonspecific and highly variable related to the localization, size and composition of the cardiac mass. Echocardiography, typically performed for another indication, may be the first imaging modality alerting the clinician to the presence of a cardiac mass. Although echocardiography cannot give the histopathology, certain imaging features and adjunctive tools such as contrast imaging may aid in the differential diagnosis as do the adjunctive clinical data and the following principles: (1 thrombus or vegetations are the most likely etiology, (2 cardiac tumors are mostly secondary and (3 primary cardiac tumors are mostly benign. Although the finding of a cardiac mass on echocardiography may generate confusion, a stepwise approach may serve well practically. Herein, we will review such an approach and the role of echocardiography in the assessment of cardiac masses.

  19. Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins.

    Directory of Open Access Journals (Sweden)

    Chunxiang Yao

    Full Text Available Reactive protein cysteine thiolates are instrumental in redox regulation. Oxidants, such as hydrogen peroxide (H2O2, react with thiolates to form oxidative post-translational modifications, enabling physiological redox signaling. Cardiac disease and aging are associated with oxidative stress which can impair redox signaling by altering essential cysteine thiolates. We previously found that cardiac-specific overexpression of catalase (Cat, an enzyme that detoxifies excess H2O2, protected from oxidative stress and delayed cardiac aging in mice. Using redox proteomics and systems biology, we sought to identify the cysteines that could play a key role in cardiac disease and aging. With a 'Tandem Mass Tag' (TMT labeling strategy and mass spectrometry, we investigated differential reversible cysteine oxidation in the cardiac proteome of wild type and Cat transgenic (Tg mice. Reversible cysteine oxidation was measured as thiol occupancy, the ratio of total available versus reversibly oxidized cysteine thiols. Catalase overexpression globally decreased thiol occupancy by ≥1.3 fold in 82 proteins, including numerous mitochondrial and contractile proteins. Systems biology analysis assigned the majority of proteins with differentially modified thiols in Cat Tg mice to pathways of aging and cardiac disease, including cellular stress response, proteostasis, and apoptosis. In addition, Cat Tg mice exhibited diminished protein glutathione adducts and decreased H2O2 production from mitochondrial complex I and II, suggesting improved function of cardiac mitochondria. In conclusion, our data suggest that catalase may alleviate cardiac disease and aging by moderating global protein cysteine thiol oxidation.

  20. Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins.

    Science.gov (United States)

    Yao, Chunxiang; Behring, Jessica B; Shao, Di; Sverdlov, Aaron L; Whelan, Stephen A; Elezaby, Aly; Yin, Xiaoyan; Siwik, Deborah A; Seta, Francesca; Costello, Catherine E; Cohen, Richard A; Matsui, Reiko; Colucci, Wilson S; McComb, Mark E; Bachschmid, Markus M

    2015-01-01

    Reactive protein cysteine thiolates are instrumental in redox regulation. Oxidants, such as hydrogen peroxide (H2O2), react with thiolates to form oxidative post-translational modifications, enabling physiological redox signaling. Cardiac disease and aging are associated with oxidative stress which can impair redox signaling by altering essential cysteine thiolates. We previously found that cardiac-specific overexpression of catalase (Cat), an enzyme that detoxifies excess H2O2, protected from oxidative stress and delayed cardiac aging in mice. Using redox proteomics and systems biology, we sought to identify the cysteines that could play a key role in cardiac disease and aging. With a 'Tandem Mass Tag' (TMT) labeling strategy and mass spectrometry, we investigated differential reversible cysteine oxidation in the cardiac proteome of wild type and Cat transgenic (Tg) mice. Reversible cysteine oxidation was measured as thiol occupancy, the ratio of total available versus reversibly oxidized cysteine thiols. Catalase overexpression globally decreased thiol occupancy by ≥1.3 fold in 82 proteins, including numerous mitochondrial and contractile proteins. Systems biology analysis assigned the majority of proteins with differentially modified thiols in Cat Tg mice to pathways of aging and cardiac disease, including cellular stress response, proteostasis, and apoptosis. In addition, Cat Tg mice exhibited diminished protein glutathione adducts and decreased H2O2 production from mitochondrial complex I and II, suggesting improved function of cardiac mitochondria. In conclusion, our data suggest that catalase may alleviate cardiac disease and aging by moderating global protein cysteine thiol oxidation.

  1. Energetic costs of mange in wolves estimated from infrared thermography

    Science.gov (United States)

    Cross, Paul C.; Almberg, Emily S.; Haase, Catherine G; Hudson, Peter J.; Maloney, Shane K; Metz, Matthew C; Munn, Adam J; Nugent, Paul; Putzeys, Olivier; Stahler, Daniel R.; Stewart, Anya C; Smith, Doug W.

    2016-01-01

    Parasites, by definition, extract energy from their hosts and thus affect trophic and food web dynamics even when the parasite may have limited effects on host population size. We studied the energetic costs of mange (Sarcoptes scabiei) in wolves (Canis lupus) using thermal cameras to estimate heat losses associated with compromised insulation during the winter. We combined the field data of known, naturally infected wolves with data set on captive wolves with shaved patches of fur as a positive control to simulate mange-induced hair loss. We predict that during the winter in Montana, more severe mange infection increases heat loss by around 5.2 to 12 MJ per night (1240 to 2850 kcal, or a 65% to 78% increase) for small and large wolves, respectively accounting for wind effects. To maintain body temperature would require a significant proportion of a healthy wolf's total daily energy demands (18-22 MJ/day). We also predict how these thermal costs may increase in colder climates by comparing our predictions in Bozeman, Montana to those from a place with lower ambient temperatures (Fairbanks, Alaska). Contrary to our expectations, the 14°C differential between these regions was not as important as the potential differences in wind speed. These large increases in energetic demands can be mitigated by either increasing consumption rates or decreasing other energy demands. Data from GPS-collared wolves indicated that healthy wolves move, on average, 17 km per day, which was reduced by 1.5, 1.8 and 6.5 km for light, medium, and severe hair loss. In addition, the wolf with the most hair loss was less active at night and more active during the day, which is the converse of the movement patterns of healthy wolves. At the individual level mange infections create significant energy demands and altered behavioral patterns, this may have cascading effects on prey consumption rates, food web dynamics, predator-prey interactions, and scavenger communities.

  2. The composition of corotating energetic particle streams

    International Nuclear Information System (INIS)

    McGuire, R.E.; von Rosenvinge, T.T.; McDonald, F.B.

    1978-01-01

    The relative abundances of 1.5--23 MeV per nucleon ions in corotating nucleon streams are compared with ion abundances in particle events associated with solar flares and with solar and solar wind abundances. He/O and C/O ratios are found to be a factor of the order 2--3 greater in corotating streams than in flare-associated events. The distribution of H/He ratios in corotating streams is found to be much narrower and of lower average value than in flare-associated events. H/He in corotating energetic particle streams compares favorably in both lack of variability and numerical value with H/He in high-speed solar wind plasma streams. The lack of variability suggests that the source population for the corotating energetic particles is the solar wind, a suggestion consistent with acceleration of the corotating particles in interplanetary space

  3. Energetic Particle Estimates for Stellar Flares

    Science.gov (United States)

    Youngblood, Allison; Chamberlin, Phil; Woods, Tom

    2018-01-01

    In the heliosphere, energetic particles are accelerated away from the Sun during solar flares and/or coronal mass ejections where they frequently impact the Earth and other solar system bodies. Solar (or stellar) energetic particles (SEPs) not only affect technological assets, but also influence mass loss and chemistry in planetary atmospheres (e.g., depletion of ozone). SEPs are increasingly recognized as an important factor in assessing exoplanet habitability, but we do not yet have constraints on SEP emission from any stars other than the Sun. Until indirect measurements are available, we must assume solar-like particle production and apply correlations between solar flares and SEPs detected near Earth to stellar flares. We present improved scaling relations between solar far-UV flare flux and >10 MeV proton flux near Earth. We apply these solar scaling relations to far-UV flares from exoplanet host stars and discuss the implications for modeling chemistry and mass loss in exoplanet atmospheres.

  4. Energetics in robotic flight at small scales.

    Science.gov (United States)

    Karydis, Konstantinos; Kumar, Vijay

    2017-02-06

    Recent advances in design, sensing and control have led to aerial robots that offer great promise in a range of real-world applications. However, one critical open question centres on how to improve the energetic efficiency of aerial robots so that they can be useful in practical situations. This review paper provides a survey on small-scale aerial robots (i.e. less than 1 m 2 area foot print, and less than 3 kg weight) from the point of view of energetics. The paper discusses methods to improve the efficiency of aerial vehicles, and reports on recent findings by the authors and other groups on modelling the impact of aerodynamics for the purpose of building energy-aware motion planners and controllers.

  5. HAWC and Solar Energetic Transient Events

    Science.gov (United States)

    Lara, A.; Ryan, J. M.

    2013-12-01

    The High Altitude Water Cherenkov (HAWC) observatory is being constructed at the volcano Sierra Negra (4100 m a.s.l.) in Mexico. HAWC's primary purpose is the study of both galactic and extra-galactic sources of high energy gamma rays. The HAWC instrument will consist of 300 large water Cherenkov detectors whose counting rate will be sensitive to cosmic rays with energies above the geomagnetic cutoff of the site ( ˜ 8 GV). In particular, HAWC will detect solar energetic particles known as Ground Level Enhancements (GLEs), and the effect of Coronal Mass Ejections on the galactic cosmic rays, known as Forbush Decreases (FDs). The Milagro experiment, the HAWC predecessor, successfully observed GLEs and the HAWC engineering array "VAMOS" already observed a FD. HAWC will be sensitive to γ rays and neutrons produced during large solar flares. In this work, we present the instrument and discuss its capability to observe solar energetic events. i. e., flares and CMEs.

  6. Generic considerations of LMFBR hypothetical accident energetics

    Energy Technology Data Exchange (ETDEWEB)

    Fauske, H.K.; Cho, D.H.; Epstein, M.; Grolmes, M.A.; Henry, R.E.

    1978-01-01

    The paper provides a preliminary assessment of generic accident energetics issues associated with alternatives relative to the reference (U,Pu) oxide fuel in liquid metal fast breeder reactors. The alternatives considered include thorium- and uranium-based oxide, carbide and metal fuel types. This assessment is made within the context of low probability, but potentially large consequence accidents, e.g., core-disruptive accidents.

  7. Theoretical studies on energetic materials bearing pentaflurosulphyl ...

    Indian Academy of Sciences (India)

    Theoretical studies on the compounds with SF5 groups. 1167. Table 2. Calculated total energies (E0), zero-point energies (ZPE), densities and heats of formation (HOFs) for the title energetic materials. E0 and ZPE are in a.u., HOFs are in kJ/mol, densities are in g/cm3. Compound. E0. ZPE. Hf, gas. Hf, sub. Hf, solid. Density.

  8. Energetic Issues Concerning the Content of Money

    OpenAIRE

    Negoescu Gheorghe; Radu Riana Iren

    2012-01-01

    In full times of crisis, money has become increasingly more important. We put the issue to analyze whether money can be considered a form of energy. The article is taking into consideration the conservation of energy and for money is due to kinetic energy during the boom and to potential energy during the crisis. In the article is also made an illustration of the energetic content of money at a company’s level.

  9. Stochastic Energetics for Non-Gaussian Processes

    Science.gov (United States)

    Kanazawa, Kiyoshi; Sagawa, Takahiro; Hayakawa, Hisao

    2012-05-01

    By introducing a new stochastic integral, we investigate the energetics of classical stochastic systems driven by non-Gaussian white noises. In particular, we introduce a decomposition of the total energy difference into the work and the heat for each trajectory, and derive a formula to calculate the heat from experimental data on the dynamics. We apply our formulation and results to a Langevin system driven by a Poisson noise.

  10. Energetic cost of walking in fossil hominins.

    Science.gov (United States)

    Vidal-Cordasco, M; Mateos, A; Zorrilla-Revilla, G; Prado-Nóvoa, O; Rodríguez, J

    2017-11-01

    Many biomechanical studies consistently show that a broader pelvis increases the reaction forces and bending moments across the femoral shaft, increasing the energetic costs of unloaded locomotion. However, a biomechanical model does not provide the real amount of metabolic energy expended in walking. The aim of this study is to test the influence of pelvis breadth on locomotion cost and to evaluate the locomotion efficiency of extinct Pleistocene hominins. The current study measures in vivo the influence of pelvis width on the caloric cost of locomotion, integrating anthropometry, body composition and indirect calorimetry protocols in a sample of 46 subjects of both sexes. We show that a broader false pelvis is substantially more efficient for locomotion than a narrower one and that the influence of false pelvis width on the energetic cost is similar to the influence of leg length. Two models integrating body mass, femur length and bi-iliac breadth are used to estimate the net and gross energetic costs of locomotion in a number of extinct hominins. The results presented here show that the locomotion of Homo was not energetically more efficient than that of Australopithecus and that the locomotion of extinct Homo species was not less efficient than that of modern Homo sapiens. The changes in the anatomy of the pelvis and lower limb observed with the appearance of Homo ergaster probably did not fully offset the increased expenditure resulting from a larger body mass. Moreover, the narrow pelvis in modern humans does not contribute to greater efficiency of locomotion. © 2017 Wiley Periodicals, Inc.

  11. Stroke of a cardiac myxoma origin.

    Science.gov (United States)

    Yuan, Shi-Min; Humuruola, Gulimila

    2015-01-01

    The clinical features of cardiac myxoma stroke have not been sufficiently described. Debates remain concerning the options and timing of treatment and the clinical outcomes are unknown. This article aims to highlight the pertinent aspects of this rare condition. Data source of the present study came from a comprehensive literature collection of cardiac myxoma stroke in PubMed, Google search engine and Highwire Press for the year range 2000-2014. Young adults, female predominance, single cerebral vessel (mostly the middle cerebral artery), multiple territory involvements and solitary left atrial myxoma constituted the outstanding characteristics of this patient setting. The most common affected cerebral vessel (the middle cerebral artery) and areas (the basal ganglion, cerebellum and parietal and temporal regions) corresponded well to the common manifestations of this patient setting, such as conscious alteration, ataxia, hemiparesis and hemiplegia, aphasia and dysarthria. Initial computed tomography scan carried a higher false negative rate for the diagnosis of cerebral infarction than magnetic resonance imaging did. A delayed surgical resection of cardiac myxoma was associated with an increased risk of potential consequences in particular otherwise arterial embolism. The mortality rate of this patient population was 15.3%. Cardiac myxoma stroke is rare. Often does it affect young females. For an improved diagnostic accuracy, magnetic resonance imaging of the brain and echocardiography are imperative for young stroke patients in identifying the cerebral infarct and determining the stroke of a cardiac origin. Immediate thrombolytic therapy may completely resolve the cerebral stroke and improve the neurologic function of the patients. An early surgical resection of cardiac myxoma is recommended in patients with not large territory cerebral infarct.

  12. Stroke of a cardiac myxoma origin

    Directory of Open Access Journals (Sweden)

    Shi-Min Yuan

    2015-04-01

    Full Text Available AbstractObjective:The clinical features of cardiac myxoma stroke have not been sufficiently described. Debates remain concerning the options and timing of treatment and the clinical outcomes are unknown. This article aims to highlight the pertinent aspects of this rare condition.Methods:Data source of the present study came from a comprehensive literature collection of cardiac myxoma stroke in PubMed, Google search engine and Highwire Press for the year range 2000-2014.Results:Young adults, female predominance, single cerebral vessel (mostly the middle cerebral artery, multiple territory involvements and solitary left atrial myxoma constituted the outstanding characteristics of this patient setting. The most common affected cerebral vessel (the middle cerebral artery and areas (the basal ganglion, cerebellum and parietal and temporal regions corresponded well to the common manifestations of this patient setting, such as conscious alteration, ataxia, hemiparesis and hemiplegia, aphasia and dysarthria. Initial computed tomography scan carried a higher false negative rate for the diagnosis of cerebral infarction than magnetic resonance imaging did. A delayed surgical resection of cardiac myxoma was associated with an increased risk of potential consequences in particular otherwise arterial embolism. The mortality rate of this patient population was 15.3%.Conclusion:Cardiac myxoma stroke is rare. Often does it affect young females. For an improved diagnostic accuracy, magnetic resonance imaging of the brain and echocardiography are imperative for young stroke patients in identifying the cerebral infarct and determining the stroke of a cardiac origin. Immediate thrombolytic therapy may completely resolve the cerebral stroke and improve the neurologic function of the patients. An early surgical resection of cardiac myxoma is recommended in patients with not large territory cerebral infarct.

  13. Nuclear energy I, Non-energetic applications

    International Nuclear Information System (INIS)

    Lartigue G, J.; Navarrete T, M.; Cabrera M, L.; Arandia, P.A.; Arriola S, H.

    1986-01-01

    The nuclear energy is defined as the energy produced or absorbed in the nuclear reactions, therefore, these are divided in endothermic and exothermic. The exothermic nuclear reactions present more interest from the point of view of its applications and they can show in four main forms: radioactivity (from 0 to 4 MeV/reaction; light nucleus fusion ( ∼ 20 MeV/reaction), heavy nucleus fusion (∼ 200 MeV/reaction) and nucleons annihilation ( ∼ 2000 MeV/reaction). Nowadays only the fission has reached the stage of profitable energetic application, finding the other three forms in research and development. The non-energetic applications of the nuclear energy are characterized by they do not require of prior conversion to another form of energy and they are made through the use of radioisotopes as well as through the use of endothermic reaction caused in particle accelerators. In this work are presented some of the non-energetic applications with its theoretical and experimental basis as well as its benefits of each one. (Author)

  14. Nonadditive Compositional Curvature Energetics of Lipid Bilayers

    Science.gov (United States)

    Sodt, A. J.; Venable, R. M.; Lyman, E.; Pastor, R. W.

    2016-09-01

    The unique properties of the individual lipids that compose biological membranes together determine the energetics of the surface. The energetics of the surface, in turn, govern the formation of membrane structures and membrane reshaping processes, and thus they will underlie cellular-scale models of viral fusion, vesicle-dependent transport, and lateral organization relevant to signaling. The spontaneous curvature, to the best of our knowledge, is always assumed to be additive. We describe observations from simulations of unexpected nonadditive compositional curvature energetics of two lipids essential to the plasma membrane: sphingomyelin and cholesterol. A model is developed that connects molecular interactions to curvature stress, and which explains the role of local composition. Cholesterol is shown to lower the number of effective Kuhn segments of saturated acyl chains, reducing lateral pressure below the neutral surface of bending and favoring positive curvature. The effect is not observed for unsaturated (flexible) acyl chains. Likewise, hydrogen bonding between sphingomyelin lipids leads to positive curvature, but only at sufficient concentration, below which the lipid prefers negative curvature.

  15. Calculation of the energetics of chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, T.H. Jr.; Harding, L.B.; Shepard, R.L.; Harrison, R.J.

    1988-01-01

    To calculate the energetics of chemical reactions we must solve the electronic Schroedinger equation for the molecular conformations of importance for the reactive encounter. Substantial changes occur in the electronic structure of a molecular system as the reaction progresses from reactants through the transition state to products. To describe these changes, our approach includes the following three elements: the use of multiconfiguration self-consistent field wave functions to provide a consistent zero-order description of the electronic structure of the reactants, transition state, and products; the use of configuration interaction techniques to describe electron correlation effects needed to provide quantitative predictions of the reaction energetics; and the use of large, optimized basis sets to provide the flexibility needed to describe the variations in the electronic distributions. With this approach we are able to study reactions involving as many as 5--6 atoms with errors of just a few kcal/mol in the predicted reaction energetics. Predictions to chemical accuracy, i.e., to 1 kcal/mol or less, are not yet feasible, although continuing improvements in both the theoretical methodology and computer technology suggest that this will soon be possible, at least for reactions involving small polyatomic species. 4 figs.

  16. Energetic particle investigation using the ERNE instrument

    Directory of Open Access Journals (Sweden)

    J. Torsti

    1996-05-01

    Full Text Available During solar flares and coronal mass ejections, nuclei and electrons accelerated to high energies are injected into interplanetary space. These accelerated particles can be detected at the SOHO satellite by the ERNE instrument. From the data produced by the instrument, it is possible to identify the particles and to calculate their energy and direction of propagation. Depending on variable coronal/interplanetary conditions, different kinds of effects on the energetic particle transport can be predicted. The problems of interest include, for example, the effects of particle properties (mass, charge, energy, and propagation direction on the particle transport, the particle energy changes in the transport process, and the effects the energetic particles have on the solar-wind plasma. The evolution of the distribution function of the energetic particles can be measured with ERNE to a better accuracy than ever before. This gives us the opportunity to contribute significantly to the modeling of interplanetary transport and acceleration. Once the acceleration/transport bias has been removed, the acceleration-site abundance of elements and their isotopes can be studied in detail and compared with spectroscopic observations.

  17. Energetic Particles Dynamics in Mercury's Magnetosphere

    Science.gov (United States)

    Walsh, Brian M.; Ryou, A.S.; Sibeck, D. G.; Alexeev, I. I.

    2013-01-01

    We investigate the drift paths of energetic particles in Mercury's magnetosphere by tracing their motion through a model magnetic field. Test particle simulations solving the full Lorentz force show a quasi-trapped energetic particle population that gradient and curvature drift around the planet via "Shabansky" orbits, passing though high latitudes in the compressed dayside by equatorial latitudes on the nightside. Due to their large gyroradii, energetic H+ and Na+ ions will typically collide with the planet or the magnetopause and will not be able to complete a full drift orbit. These simulations provide direct comparison for recent spacecraft measurements from MESSENGER. Mercury's offset dipole results in an asymmetric loss cone and therefore an asymmetry in particle precipitation with more particles precipitating in the southern hemisphere. Since the planet lacks an atmosphere, precipitating particles will collide directly with the surface of the planet. The incident charged particles can kick up neutrals from the surface and have implications for the formation of the exosphere and weathering of the surface

  18. Study on penetration-induced initiation of energetic fragment

    Science.gov (United States)

    Qiao, Xiangxin; Xu, Heyang

    2017-09-01

    In order to investigate penetration-induced initiation of energetic fragment penetrating target, PTFE/Al (mass ratio 73.5/26.5) pressed and sintered into a Ф8mm × 8mm cylinder. To form energetic fragment, the cylinder was put into a closed container made by 35CrMnSiA. The container is 12mm long, 2mm thick. Energetic fragments were launched by a 14.5mm ballistic gun with a series of velocities and the penetrate process was simulated by AUTODYN-3D. The results show that the stress peak of energetic material exceed the initiation threshold, and energetic material will deflagrate, when energetic fragments impact velocity more than 800 m/s. The research results can provide reference for designs of energetic warhead.

  19. Socially differentiated cardiac rehabilitation

    DEFF Research Database (Denmark)

    Meillier, Lucette Kirsten; Nielsen, Kirsten Melgaard; Larsen, Finn Breinholt

    2012-01-01

    cardiac rehabilitation programme. Methods: From 1 September 2002 to 31 December 2005, 388 first-incidence MI patients ≤75 years were hospitalised. Register check for newly hospitalised MI patients, screening interview, and systematic referral were conducted by a project nurse. Patients were referred...... to a standard rehabilitation programme (SRP). If patients were identified as socially vulnerable, they were offered an extended version of the rehabilitation programme (ERP). Excluded patients were offered home visits by a cardiac nurse. Concordance principles were used in the individualised programme elements......Aim: The comprehensive cardiac rehabilitation (CR) programme after myocardial infarction (MI) improves quality of life and results in reduced cardiac mortality and recurrence of MI. Hospitals worldwide face problems with low participation rates in rehabilitation programmes. Inequality...

  20. Cardiac Procedures and Surgeries

    Science.gov (United States)

    ... the Procedure Does A stent is a wire mesh tube used to prop open an artery during ... a Heart Attack • Heart Attack Tools & Resources • Support Network Heart Attack Tools & Resources My Cardiac Coach What ...

  1. Defining the Cardiac Fibroblast

    Science.gov (United States)

    Ivey, Malina J.; Tallquist, Michelle D.

    2017-01-01

    Cardiac fibrosis remains an important health concern, but the study of fibroblast biology has been hindered by a lack of effective means for identifying and tracking fibroblasts. Recent advances in fibroblast-specific lineage tags and reporters have permitted a better understanding of these cells. After injury multiple cell types have been implicated as the source for extracellular matrix producing cells, but emerging studies suggest that resident cardiac fibroblasts contribute substantially to the remodeling process. In this review, we discuss recent findings regarding cardiac fibroblast origin and identity. Our understanding of cardiac fibroblast biology and fibrosis is still developing and will expand profoundly in the next few years, with many of the recent findings regarding fibroblast gene expression and behavior laying down the groundwork for interpreting the purpose and utility of these cells before and after injury. PMID:27746422

  2. Cardiac Catheterization (For Parents)

    Science.gov (United States)

    ... cases, the doctor might call for a cardiac magnetic resonance imaging (MRI) scan or a CAT scan . ... first couple of days. This means no heavy lifting (more than 10 pounds) and no sports. After ...

  3. Cardiac Catheterization (For Teens)

    Science.gov (United States)

    ... doctor may also call for a cardiac MRI (magnetic resonance imaging) scan or a CT (computerized tomography) ... first couple of days. This means no heavy lifting (nothing over 10 pounds) and no sports. After ...

  4. Cardiac biomarkers in Neonatology

    OpenAIRE

    Vijlbrief, D.C.

    2015-01-01

    In this thesis, the role for cardiac biomarkers in neonatology was investigated. Several clinically relevant results were reported. In term and preterm infants, hypoxia and subsequent adaptation play an important role in cardiac biomarker elevation. The elevated natriuretic peptides are indicative of abnormal function; elevated troponins are suggestive for cardiomyocyte damage. This methodology makes these biomarkers of additional value in the treatment of newborn infants, separate or as a co...

  5. Cardiac imaging in adults

    International Nuclear Information System (INIS)

    Jaffe, C.C.

    1987-01-01

    This book approaches adult cardiac disease from the correlative imaging perspective. It includes chest X-rays and angiographs, 2-dimensional echocardiograms with explanatory diagrams for clarity, plus details on digital radiology, nuclear medicine techniques, CT and MRI. It also covers the normal heart, valvular heart disease, myocardial disease, pericardial disease, bacterial endocarditis, aortic aneurysm, cardiac tumors, and congenital heart disease of the adult. It points out those aspects where one imaging technique has significant superiority

  6. Cardiac imaging in adults

    Energy Technology Data Exchange (ETDEWEB)

    Jaffe, C.C.

    1987-01-01

    This book approaches adult cardiac disease from the correlative imaging perspective. It includes chest X-rays and angiographs, 2-dimensional echocardiograms with explanatory diagrams for clarity, plus details on digital radiology, nuclear medicine techniques, CT and MRI. It also covers the normal heart, valvular heart disease, myocardial disease, pericardial disease, bacterial endocarditis, aortic aneurysm, cardiac tumors, and congenital heart disease of the adult. It points out those aspects where one imaging technique has significant superiority.

  7. Awareness in cardiac anesthesia.

    LENUS (Irish Health Repository)

    Serfontein, Leon

    2010-02-01

    Cardiac surgery represents a sub-group of patients at significantly increased risk of intraoperative awareness. Relatively few recent publications have targeted the topic of awareness in this group. The aim of this review is to identify areas of awareness research that may equally be extrapolated to cardiac anesthesia in the attempt to increase understanding of the nature and significance of this scenario and how to reduce it.

  8. Differentiation of sarcoplasmic reticulum during cardiac myogenesis

    International Nuclear Information System (INIS)

    Pegg, W.; Michalak, M.

    1987-01-01

    The composition and function of fetal and mature sheep cardiac sarcoplasmic reticulum membranes were investigated. Phospholamban, a major phosphoprotein in the mature sarcoplasmic reticulum membranes, was present in early stages of cardiac myogenesis. This fetal form of phospholamban was phosphorylated by cAMP-dependent protein kinase but not in the presence of Ca 2+ and calmodulin. 35 Ca 2+ uptake and Ca 2+ -dependent ATPase activity were low in fetal sarcoplasmic reticulum compared with the adult controls, although the apparent affinities for Ca 2+ were similar. Sarcoplasmic reticulum vesicles isolated at all developmental stages had very low levels of plasma membrane and mitochondrial contamination. Sarcoplasmic reticulum 45 Ca 2+ uptake and Ca 2+ -dependent. ATPase activities were not affected by micromolar concentrations of vanadate, and the accumulated 45 Ca 2+ could not be released by the addition of NaCl. The amount of both the 110- and 55-kDa protein bands, identified with pecific antibodies as Ca 2+ -ATPase and calsequestrin, respectively, was low in early stages of cardiac myogenesis. Age-related differences in the Ca 2+ transport properties of cardiac sarcoplasmic reticulum and in the amount of the Ca 2+ -ATPase and calsequestrin may explain alterations in the regulation of intracellular Ca 2+ concentrations in the fetal heart. This may contribute to the developmental changes in myocardial function

  9. Multiscale Characterization of Engineered Cardiac Tissue Architecture.

    Science.gov (United States)

    Drew, Nancy K; Johnsen, Nicholas E; Core, Jason Q; Grosberg, Anna

    2016-11-01

    In a properly contracting cardiac muscle, many different subcellular structures are organized into an intricate architecture. While it has been observed that this organization is altered in pathological conditions, the relationship between length-scales and architecture has not been properly explored. In this work, we utilize a variety of architecture metrics to quantify organization and consistency of single structures over multiple scales, from subcellular to tissue scale as well as correlation of organization of multiple structures. Specifically, as the best way to characterize cardiac tissues, we chose the orientational and co-orientational order parameters (COOPs). Similarly, neonatal rat ventricular myocytes were selected for their consistent architectural behavior. The engineered cells and tissues were stained for four architectural structures: actin, tubulin, sarcomeric z-lines, and nuclei. We applied the orientational metrics to cardiac cells of various shapes, isotropic cardiac tissues, and anisotropic globally aligned tissues. With these novel tools, we discovered: (1) the relationship between cellular shape and consistency of self-assembly; (2) the length-scales at which unguided tissues self-organize; and (3) the correlation or lack thereof between organization of actin fibrils, sarcomeric z-lines, tubulin fibrils, and nuclei. All of these together elucidate some of the current mysteries in the relationship between force production and architecture, while raising more questions about the effect of guidance cues on self-assembly function. These types of metrics are the future of quantitative tissue engineering in cardiovascular biomechanics.

  10. Cardiac syndrome X. Diagnosis, pathogenesis and management.

    Science.gov (United States)

    Kaski, Juan Carlos; Aldama, Guillermo; Cosín-Sales, Juan

    2004-01-01

    Patients with cardiac syndrome X (typical chest pain and normal coronary arteriograms) represent a heterogeneous syndrome, which encompasses different pathogenic mechanisms. Although symptoms in most patients with cardiac syndrome X are non-cardiac, a sizable proportion of them have angina pectoris due to transient myocardial ischemia. Thus radionuclide myocardial perfusion defects, coronary sinus oxygen saturation abnormalities and pH changes, myocardial lactate production and stress-induced alterations of cardiac high energy phosphate suggest an ischemic origin of symptoms in at least a proportion of patients with cardiac syndrome X. Microvascular abnormalities, caused by endothelial dysfunction, appear to be responsible for myocardial ischemia in patients with cardiac syndrome X. Endothelial dysfunction is likely to be multifactorial in these patients and it is conceivable that risk factors such as hypertension, hypercholesterolemia, diabetes mellitus and smoking can contribute to its development. Most patients with cardiac syndrome X are postmenopausal women and estrogen deficiency has been therefore proposed as a pathogenic factor in female patients. Additional factors such as abnormal pain perception may contribute to the pathogenesis of chest pain in patients with angina pectoris and normal coronary angiograms. Although prognosis is good regarding survival, patients with cardiac syndrome X have an impaired quality of life. Management of this syndrome represents a major challenge to the treating physician. Understanding the mechanism underlying the condition is of vital importance for patient management. Thus diagnostic tests should aim at identifying the cause of the symptoms in the individual patient, i.e. myocardial ischemia, increased pain perception, abnormalities of adrenergic tone, non-cardiac mechanisms, etc. Moreover, it is important to bear in mind that treatment of cardiac syndrome X should be mainly directed towards improving quality of life, as

  11. Anisotropic silk biomaterials containing cardiac extracellular matrix for cardiac tissue engineering.

    Science.gov (United States)

    Stoppel, Whitney L; Hu, Dongjian; Domian, Ibrahim J; Kaplan, David L; Black, Lauren D

    2015-03-31

    Cardiac malformations and disease are the leading causes of death in the United States in live-born infants and adults, respectively. In both of these cases, a decrease in the number of functional cardiomyocytes often results in improper growth of heart tissue, wound healing complications, and poor tissue repair. The field of cardiac tissue engineering seeks to address these concerns by developing cardiac patches created from a variety of biomaterial scaffolds to be used in surgical repair of the heart. These scaffolds should be fully degradable biomaterial systems with tunable properties such that the materials can be altered to meet the needs of both in vitro culture (e.g. disease modeling) and in vivo application (e.g. cardiac patch). Current platforms do not utilize both structural anisotropy and proper cell-matrix contacts to promote functional cardiac phenotypes and thus there is still a need for critically sized scaffolds that mimic both the structural and adhesive properties of native tissue. To address this need, we have developed a silk-based scaffold platform containing cardiac tissue-derived extracellular matrix (cECM). These silk-cECM composite scaffolds have tunable architectures, degradation rates, and mechanical properties. Subcutaneous implantation in rats demonstrated that addition of the cECM to aligned silk scaffold led to 99% endogenous cell infiltration and promoted vascularization of a critically sized scaffold (10 × 5 × 2.5 mm) after 4 weeks in vivo. In vitro, silk-cECM scaffolds maintained the HL-1 atrial cardiomyocytes and human embryonic stem cell-derived cardiomyocytes and promoted a more functional phenotype in both cell types. This class of hybrid silk-cECM anisotropic scaffolds offers new opportunities for developing more physiologically relevant tissues for cardiac repair and disease modeling.

  12. Mammalian energetics. Flexible energetics of cheetah hunting strategies provide resistance against kleptoparasitism.

    Science.gov (United States)

    Scantlebury, David M; Mills, Michael G L; Wilson, Rory P; Wilson, John W; Mills, Margaret E J; Durant, Sarah M; Bennett, Nigel C; Bradford, Peter; Marks, Nikki J; Speakman, John R

    2014-10-03

    Population viability is driven by individual survival, which in turn depends on individuals balancing energy budgets. As carnivores may function close to maximum sustained power outputs, decreased food availability or increased activity may render some populations energetically vulnerable. Prey theft may compromise energetic budgets of mesopredators, such as cheetahs and wild dogs, which are susceptible to competition from larger carnivores. We show that daily energy expenditure (DEE) of cheetahs was similar to size-based predictions and positively related to distance traveled. Theft at 25% only requires cheetahs to hunt for an extra 1.1 hour per day, increasing DEE by just 12%. Therefore, not all mesopredators are energetically constrained by direct competition. Other factors that increase DEE, such as those that increase travel, may be more important for population viability. Copyright © 2014, American Association for the Advancement of Science.

  13. Alterations in electrodermal activity and cardiac parasympathetic tone during hypnosis.

    Science.gov (United States)

    Kekecs, Zoltán; Szekely, Anna; Varga, Katalin

    2016-02-01

    Exploring autonomic nervous system (ANS) changes during hypnosis is critical for understanding the nature and extent of the hypnotic phenomenon and for identifying the mechanisms underlying the effects of hypnosis in different medical conditions. To assess ANS changes during hypnosis, electrodermal activity and pulse rate variability (PRV) were measured in 121 young adults. Participants either received hypnotic induction (hypnosis condition) or listened to music (control condition), and both groups were exposed to test suggestions. Blocks of silence and experimental sound stimuli were presented at baseline, after induction, and after de-induction. Skin conductance level (SCL) and high frequency (HF) power of PRV measured at each phase were compared between groups. Hypnosis decreased SCL compared to the control condition; however, there were no group differences in HF power. Furthermore, hypnotic suggestibility did not moderate ANS changes in the hypnosis group. These findings indicate that hypnosis reduces tonic sympathetic nervous system activity, which might explain why hypnosis is effective in the treatment of disorders with strong sympathetic nervous system involvement, such as rheumatoid arthritis, hot flashes, hypertension, and chronic pain. Further studies with different control conditions are required to examine the specificity of the sympathetic effects of hypnosis. © 2015 Society for Psychophysiological Research.

  14. Molecular Alterations in a Mouse Cardiac Model of Friedreich Ataxia

    DEFF Research Database (Denmark)

    Anzovino, Amy; Chiang, Shannon; Brown, Bronwyn E

    2017-01-01

    Nuclear factor-erythroid 2-related factor-2 (Nrf2) is a master regulator of the antioxidant response. However, studies in models of Friedreich ataxia, a neurodegenerative and cardiodegenerative disease associated with oxidative stress, reported decreased Nrf2 expression attributable to unknown me...

  15. Toxicity of ad lib. overfeeding: effects on cardiac tissue.

    Science.gov (United States)

    Faine, L A; Diniz, Y S; Almeida, J A; Novelli, E L B; Ribas, B O

    2002-05-01

    The aim of the present study was to determine the effects of ad lib. overfeeding and of dietary restriction (DR) on oxidative stress in cardiac tissue. Lipoperoxide concentrations were decreased and antioxidant enzymes were increased in moderate-DR-fed rats. Severe-DR induced increased lipoperoxide concentrations. Overfeeding increased lipoperoxide levels in cardiac tissue. Total superoxide dismutase (SOD) and Cu-Zn superoxide dismutase (Cu-Zn SOD) activities were decreased in cardiac tissue at 35 days of overfeeding. As no changes in glutathione peroxidase (GSH-Px) were observed in overfed rats, while SOD and Cu-Zn SOD activities were decreased in these animals, it is assumed that superoxide anion is an important intermediate in the toxicity of ad lib. overfeeding. Overfeeding induced alterations in markers of oxidative stress in cardiac tissue.

  16. Observation of enhanced radial transport of energetic ion due to energetic particle mode destabilized by helically-trapped energetic ion in the Large Helical Device

    Science.gov (United States)

    Ogawa, K.; Isobe, M.; Kawase, H.; Nishitani, T.; Seki, R.; Osakabe, M.; LHD Experiment Group

    2018-04-01

    A deuterium experiment was initiated to achieve higher-temperature and higher-density plasmas in March 2017 in the Large Helical Device (LHD). The central ion temperature notably increases compared with that in hydrogen experiments. However, an energetic particle mode called the helically-trapped energetic-ion-driven resistive interchange (EIC) mode is often excited by intensive perpendicular neutral beam injections on high ion-temperature discharges. The mode leads to significant decrease of the ion temperature or to limiting the sustainment of the high ion-temperature state. To understand the effect of EIC on the energetic ion confinement, the radial transport of energetic ions is studied by means of the neutron flux monitor and vertical neutron camera newly installed on the LHD. Decreases of the line-integrated neutron profile in core channels show that helically-trapped energetic ions are lost from the plasma.

  17. Solar Energetic Particle Studies with PAMELA

    Science.gov (United States)

    Bravar, U.; Christian, E. R.; deNolfo, Georgia; Ryan, J. M.; Stochaj, S.

    2011-01-01

    The origin of the high-energy solar energetic particles (SEPs) may conceivably be found in composition signatures that reflect the elemental abundances of the low corona and chromosphere vs. the high corona and solar wind. The presence of secondaries, such as neutrons and positrons, could indicate a low coronal origin of these particles. Velocity dispersion of different species and over a wide energy range can be used to determine energetic particle release times at the Sun. Together with multi-wavelength imaging, in- situ observations of a variety of species, and coverage over a wide energy range provide a critical tool in identifying the origin of SEPs, understanding the evolution of these events within the context of solar active regions, and constraining the acceleration mechanisms at play. The Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA)instrument, successfully launched in 2006 and expected to remain operational until at least the beginning of 2012, measures energetic particles in the same energy range as ground-based neutron monitors, and lower energies as well. It thus bridges the gap between low energy in-situ observations and ground-based Ground Level Enhancements (GLE) observations. It can measure the charge (up to Z=6) and atomic number of the detected particles, and it can identify and measure positrons and detect neutrons-an unprecedented array of data channels that we can bring to bear on the origin of high-energy SEPs. We present prelimiary results on the for the 2006 December 13 solar flare and GLE and the 2011 March 21 solar flare, both registering proton and helium enhancements in PAMELA. Together with multi- spacecraft contextual data and modeling, we discuss the PAMELA results in the context of the different acceleration mechanisms at play.

  18. The heart of the matter: Cardiac manifestations of endocrine disease

    Directory of Open Access Journals (Sweden)

    Aditya John Binu

    2017-01-01

    Full Text Available Endocrine disorders manifest as a disturbance in the milieu of multiple organ systems. The cardiovascular system may be directly affected or alter its function to maintain the state of homeostasis. In this article, we aim to review the pathophysiology, diagnosis, clinical features and management of cardiac manifestations of various endocrine disorders.

  19. Cardiac radiology: centenary review.

    Science.gov (United States)

    de Roos, Albert; Higgins, Charles B

    2014-11-01

    During the past century, cardiac imaging technologies have revolutionized the diagnosis and treatment of acquired and congenital heart disease. Many important contributions to the field of cardiac imaging were initially reported in Radiology. The field developed from the early stages of cardiac imaging, including the use of coronary x-ray angiography and roentgen kymography, to nowadays the widely used echocardiographic, nuclear medicine, cardiac computed tomographic (CT), and magnetic resonance (MR) applications. It is surprising how many of these techniques were not recognized for their potential during their early inception. Some techniques were described in the literature but required many years to enter the clinical arena and presently continue to expand in terms of clinical application. The application of various CT and MR contrast agents for the diagnosis of myocardial ischemia is a case in point, as the utility of contrast agents continues to expand the noninvasive characterization of myocardium. The history of cardiac imaging has included a continuous process of advances in our understanding of the anatomy and physiology of the cardiovascular system, along with advances in imaging technology that continue to the present day.

  20. Energetically demanding transport in a supramolecular assembly.

    Science.gov (United States)

    Cheng, Chuyang; McGonigal, Paul R; Liu, Wei-Guang; Li, Hao; Vermeulen, Nicolaas A; Ke, Chenfeng; Frasconi, Marco; Stern, Charlotte L; Goddard, William A; Stoddart, J Fraser

    2014-10-22

    A challenge in contemporary chemistry is the realization of artificial molecular machines that can perform work in solution on their environments. Here, we report on the design and production of a supramolecular flashing energy ratchet capable of processing chemical fuel generated by redox changes to drive a ring in one direction relative to a dumbbell toward an energetically uphill state. The kinetics of the reaction pathway juxtapose a low energy [2]pseudorotaxane that forms under equilibrium conditions with a high energy, metastable [2]pseudorotaxane which resides away from equilibrium.

  1. R&D of Energetic Ionic Liquids

    Science.gov (United States)

    2011-11-01

    92oC) is also an Energetic Ionic Liquid • ADN-based monopropellant (LMP-103S) from ECAPS , Swedish Space Corporation • High performance „green...6 Toxicity Assessment of AF-M315E Toxicity Testing Results PROPERTY AF-M315E HYDRAZINE LD50 (rat), mg /kg 550 60 Dermal Irritation (rabbit...to yield low vapor toxicity – Sweden/ ECAPS LMP-103S • Propellant uses ADN-based formulation New PEP materials are likely to employ advanced

  2. Reversibly formed bilayer vesicles: Energetics and polydispersity

    DEFF Research Database (Denmark)

    Bergstöm, M.

    1997-01-01

    orders of magnitude larger than where the local free energy minima of the equilibrium vesicle actually occur. Moreover, according to our analysis, the relative width of a vesicle size distribution, sigma(R)/R-max, is generally at full equilibrium equal to 0.283, independently of the energetic vesicle....... and a statistical-mechanical factor that accounts for the fluctuations in composition, chain packing density and shape. We demonstrate that the free energy required to form a spherical vesicle is made up of two main contributions: the (size-independent) work of bending the constituent monolayers and the work...

  3. The energetic potential of bioethanol in Hungary

    Directory of Open Access Journals (Sweden)

    Károly Lakatos

    2008-11-01

    Full Text Available The basis of the bioethanol production is the agriculture, mostly the corn and wheat growing. With the analysis of their domesticharvest results, the process of the starch formation and the chemical-thermodynamical processes of the alcohol’s fermantation,we calculate the annual amount of the producible bioethanol on average and it’s energy. We determine the specific values of the CO2cycle. We examine the energetic possibilities of total substitution of the 2 billion litres of domestic petrol consumption with bioethanol.

  4. Initial Efficacy of a Cardiac Rehabilitation Transition Program: Cardiac TRUST

    OpenAIRE

    Dolansky, Mary A.; Zullo, Melissa; Boxer, Rebecca; Moore, Shirley M.

    2011-01-01

    Patients recovering from cardiac events are increasingly using postacute care, such as home health care and skilled nursing facility services. The purpose of this pilot study was to test the initial efficacy, feasibility, and safety of a specially designed postacute care transitional rehabilitation intervention for cardiac patients. Cardiac Transitional Rehabilitation Using Self- Management Techniques (Cardiac TRUST) is a family-focused intervention that includes progressive low-intensity wal...

  5. Energetic Ion Loss Diagnostic for the Wendelstein 7-AS Stellarator

    International Nuclear Information System (INIS)

    Darrow, D. S.; Werner, A.; Weller, A.

    2000-01-01

    A diagnostic to measure the loss of energetic ions from the Wendelstein 7-AS (W7-AS) stellarator has been built. It is capable of measuring losses of both neutral beam ions and energetic ions arising from ion cyclotron resonant heating. The probe can measure losses of both clockwise and counterclockwise-going energetic ions simultaneously, and accepts a wide range of pitch angles in both directions. Initial measurements by the diagnostic are reported

  6. Pediatric cardiac postoperative care

    Directory of Open Access Journals (Sweden)

    Auler Jr. José Otávio Costa

    2002-01-01

    Full Text Available The Heart Institute of the University of São Paulo, Medical School is a referral center for the treatment of congenital heart diseases of neonates and infants. In the recent years, the excellent surgical results obtained in our institution may be in part due to modern anesthetic care and to postoperative care based on well-structured protocols. The purpose of this article is to review unique aspects of neonate cardiovascular physiology, the impact of extracorporeal circulation on postoperative evolution, and the prescription for pharmacological support of acute cardiac dysfunction based on our cardiac unit protocols. The main causes of low cardiac output after surgical correction of heart congenital disease are reviewed, and methods of treatment and support are proposed as derived from the relevant literature and our protocols.

  7. Comprehensive cardiac rehabilitation

    DEFF Research Database (Denmark)

    Kruse, Marie; Hochstrasser, Stefan; Zwisler, Ann-Dorthe O

    2006-01-01

    OBJECTIVES: The costs of comprehensive cardiac rehabilitation are established and compared to the corresponding costs of usual care. The effect on health-related quality of life is analyzed. METHODS: An unprecedented and very detailed cost assessment was carried out, as no guidelines existed...... for the situation at hand. Due to challenging circumstances, the cost assessment turned out to be ex-post and top-down. RESULTS: Cost per treatment sequence is estimated to be approximately euro 976, whereas the incremental cost (compared with usual care) is approximately euro 682. The cost estimate is uncertain...... and may be as high as euro 1.877. CONCLUSIONS: Comprehensive cardiac rehabilitation is more costly than usual care, and the higher costs are not outweighed by a quality of life gain. Comprehensive cardiac rehabilitation is, therefore, not cost-effective....

  8. Determinants of myocardial energetics and efficiency in symptomatic hypertrophic cardiomyopathy.

    Science.gov (United States)

    Timmer, Stefan A J; Germans, Tjeerd; Götte, Marco J W; Rüssel, Iris K; Dijkmans, Pieter A; Lubberink, Mark; ten Berg, Jurrien M; ten Cate, Folkert J; Lammertsma, Adriaan A; Knaapen, Paul; van Rossum, Albert C

    2010-04-01

    Next to hypertrophy, hypertrophic cardiomyopathy (HCM) is characterized by alterations in myocardial energetics. A small number of studies have shown that myocardial external efficiency (MEE), defined by external work (EW) in relation to myocardial oxidative metabolism (MVO(2)), is reduced. The present study was conducted to identify determinants of MEE in patients with HCM by use of dynamic positron emission tomography (PET) and cardiovascular magnetic resonance imaging (CMR). Twenty patients with HCM (12 men, mean age: 55.2 + or - 13.9 years) and 11 healthy controls (7 men, mean age: 48.1 + or - 10 years) were studied with [(11)C]acetate PET to assess MVO(2). CMR was performed to determine left ventricular (LV) volumes and mass (LVM). Univariate and multivariate analyses were employed to determine independent predictors of myocardial efficiency. Between study groups, MVO(2) (controls: 0.12 + or - 0.04 ml x min(-1) x g(-1), HCM: 0.13 + or - 0.05 ml x min(-1) x g(-1), p = 0.64) and EW (controls: 9,139 + or - 2,484 mmHg x ml, HCM: 9,368 + or - 2,907 mmHg x ml, p = 0.83) were comparable, whereas LVM was significantly higher (controls: 99 + or - 21 g, HCM: 200 + or - 76 g, p efficiency. Mechanical external efficiency could independently be predicted by SV and LVM.

  9. Cardiac optogenetics : using light to monitor cardiac physiology

    NARCIS (Netherlands)

    Koopman, Charlotte D.|info:eu-repo/dai/nl/41375491X; Zimmermann, Wolfram-Hubertus; Knöpfel, Thomas; de Boer, Teun P.|info:eu-repo/dai/nl/30481878X

    2017-01-01

    Our current understanding of cardiac excitation and its coupling to contraction is largely based on ex vivo studies utilising fluorescent organic dyes to assess cardiac action potentials and signal transduction. Recent advances in optogenetic sensors open exciting new possibilities for cardiac

  10. Segregation and redistribution of end-of-process energetic materials

    International Nuclear Information System (INIS)

    McCabe, R.A.; Cummins, B.; Gonzalez, M.A.

    1993-03-01

    A system recovering then recycling or reusing end-of-process energetic materials has been developed at the Lawrence Livermore National Laboratory (LLNL). The system promotes separating energetic materials with high potential for reuse or recycling from those that have no further value. A feature of the system is a computerized electronic bulletin board for advertising the availability of surplus and recovered energetic materials and process chemicals to LLNL researchers, and for posting energetic materials, ''want ads.'' The system was developed and implemented to promote waste minimization and pollution prevention at LLNL

  11. Ultrafast Vibrational Spectrometer for Engineered Nanometric Energetic Materials

    National Research Council Canada - National Science Library

    Dlott, Dana

    2002-01-01

    The proposer requested funding for laser equipment that would be used to study engineered nanometric energetic materials consisting of nanometer metal particles, passivation layers and oxidizing binders...

  12. Chemical Dynamics Studies of Reactions in Energetic Materials

    National Research Council Canada - National Science Library

    Thompson, Donald O

    1997-01-01

    A theoretical/computational research program to develop methods, simulate complex reactions, and investigate the fundamental chemical dynamics of reactions of nitramine energetic materials occurring...

  13. Preliminary Hazard Analysis of Supercritical Fluid Separation of Energetic Materials

    National Research Council Canada - National Science Library

    1997-01-01

    .... Army Research Laboratory (ARL) and elsewhere, particularly at the Phasex Corporation, Lawrence, MA, has demonstrated the feasibility of separating the energetic moieties by use of supercritical CO2...

  14. [Role of cardiac magnetic resonance in cardiac involvement of Fabry disease].

    Science.gov (United States)

    Serra, Viviana M; Barba, Miguel Angel; Torrá, Roser; Pérez De Isla, Leopoldo; López, Mónica; Calli, Andrea; Feltes, Gisela; Torras, Joan; Valverde, Victor; Zamorano, José L

    2010-09-04

    Fabry disease is a hereditary disorder. Clinical manifestations are multisystemic. The majority of the patients remain undiagnosed until late in life, when alterations could be irreversible. Early detection of cardiac symptoms is of major interest in Fabry's disease (FD) in order to gain access to enzyme replacement therapy. Echo-Doppler tissular imaging (TDI) has been used as a cardiologic early marker in FD. This study is intended to determine whether the cardiac magnetic resonance is as useful tool as TDI for the early detection of cardiac affectation in FD. Echocardiography, tissue Doppler and Cardio magnetic resonance was performed in 20 patients with confirmed Fabry Disease. Left ventricular hypertrophy was defined as septum and left ventricular posterior wall thickness ≥12 mm. An abnormal TDI velocity was defined as (Sa), (Ea) and/or (Aa) velocities gadolinium-enhanced images sequences were obtained using magnetic resonance. Twenty patients included in the study were divided into three groups: 1. Those without left ventricular hypertrophy nor tissue Doppler impairment 2. Those without left ventricular hypertrophy and tissue Doppler impairment 3. Those with left ventricular hypertrophy and Tissue Doppler impairment. Late gadolinium enhancement was found in only one patient, who has already altered DTI and LVH. Tissue Doppler imaging (TDI) is the only diagnostic tool able to provide early detection of cardiac affectation in patients with FD. Magnetic resonance provides information of the disease severity in patients with LVH, but can not be used as an early marker of cardiac disease in patients with FD. However MRI could be of great value for diagnostic stratification. Copyright © 2009 Elsevier España, S.L. All rights reserved.

  15. Modelling of energetic molecule-surface interactions

    International Nuclear Information System (INIS)

    Kerford, M.

    2000-09-01

    This thesis contains the results of molecular dynamics simulations of molecule-surface interactions, looking particularly at fullerene molecules and carbon surfaces. Energetic impacts of fullerene molecules on graphite create defect craters. The relationship between the parameters of the impacting molecule and the parameters of the crater axe examined and found to be a function of the energy and velocity of the impacting molecule. Less energetic fullerene molecules can be scattered from a graphite surface and the partitioning of energy after a scattering event is investigated. It is found that a large fraction of the kinetic energy retained after impact is translational energy, with a small fraction of rotational energy and a number of vibrational modes. At impact energies where the surface is not broken and at normal incidence, surface waves axe seen to occur. These waves axe used to develop a method of desorbing molecules from a graphite surface without damage to either the surface or the molecules being desorbed. A number of fullerene molecules are investigated and ways to increase the desorption yield are examined. It is found that this is a successful technique for desorbing large numbers of intact molecules from graphite. This technique could be used for desorbing intact molecules into a gas phase for mass spectrometric analysis. (author)

  16. Energetic particle mode dynamics in tokamaks

    International Nuclear Information System (INIS)

    Zonca, F.; Briguglio, S.; Fogaccia, G.; Vlad, G.; Chen, L.; Zheng, L.-J.

    2001-01-01

    Energetic Particle Modes (EPM) are strongly driven oscillations excited via wave-particle resonant interactions at the characteristic frequencies of the energetic ions, ω tE , ω BE and/or ω-bar dE , i.e., respectively the transit frequency for circulating particles and the bounce and precessional drift frequencies for trapped ions. A sharp transition in the plasma stability at the critical EPM excitation threshold has been observed by nonperturbative gyrokinetic codes in terms of changes in normalized growth rate (γ/ω A , with ω A =ν A /qR 0 ), real frequency (ω r /ω A ) and parallel wave vector (k parallel qR 0 ) both as α=-R 0 q 2 β' of the thermal plasma and that, α E of fast ions are varied. The present work further explores theoretical aspects of EPM excitations by spatially localized particle sources, possibly associated with frequency chirping, which can radially trap the EPM in the region where the free energy source is strongest. Results of a nonperturbative 3D Hybrid MHD Gyrokinetic code are also presented to emphasize that nonlinear behaviors of EPM's are different from those of Toroidal Alfven Eigenmodes (TAE) and Kinetic TAE (KTAE) and that particle losses and mode saturation are consistent with the mode-particle pumping model (particle radial convection). Results of theoretical analyses of nonlinear EPM dynamics are also presented and the possible overlap with more general nonlinear dynamics problems is discussed. (author)

  17. Energetic Constraints on Species Coexistence in Birds.

    Science.gov (United States)

    Pigot, Alexander L; Tobias, Joseph A; Jetz, Walter

    2016-03-01

    The association between species richness and ecosystem energy availability is one of the major geographic trends in biodiversity. It is often explained in terms of energetic constraints, such that coexistence among competing species is limited in low productivity environments. However, it has proven challenging to reject alternative views, including the null hypothesis that species richness has simply had more time to accumulate in productive regions, and thus the role of energetic constraints in limiting coexistence remains largely unknown. We use the phylogenetic relationships and geographic ranges of sister species (pairs of lineages who are each other's closest extant relatives) to examine the association between energy availability and coexistence across an entire vertebrate class (Aves). We show that the incidence of coexistence among sister species increases with overall species richness and is elevated in more productive ecosystems, even when accounting for differences in the evolutionary time available for coexistence to occur. Our results indicate that energy availability promotes species coexistence in closely related lineages, providing a key step toward a more mechanistic understanding of the productivity-richness relationship underlying global gradients in biodiversity.

  18. Photomask repair using low-energetic electrons

    Science.gov (United States)

    Edinger, K.; Wolff, K.; Spies, P.; Luchs, T.; Schneider, H.; Auth, N.; Hermanns, Ch. F.; Waiblinger, M.

    2015-10-01

    Mask repair is an essential step in the mask manufacturing process as the extension of 193nm technology and the insertion of EUV are drivers for mask complexity and cost. The ability to repair all types of defects on all mask blank materials is crucial for the economic success of a mask shop operation. In the future mask repair is facing several challenges. The mask minimum features sizes are shrinking and require a higher resolution repair tool. At the same time mask blanks with different new mask materials are introduced to optimize optical performance and long term durability. For EUV masks new classes of defects like multilayer and phase defects are entering the stage. In order to achieve a high yield, mask repair has to cover etch and deposition capabilities and must not damage the mask. We will demonstrate in this paper that low energetic electron-beam (e-beam)-based mask repair is a commercially viable solution. Therefore we developed a new repair platform called MeRiT® neXT to address the technical challenges of this new technology. We will analyze the limits of the existing as well as lower energetic electron induced repair technologies theoretically and experimentally and show performance data on photomask reticles. Based on this data, we will give an outlook to future mask repair technology.

  19. Cardiac output measurement

    Directory of Open Access Journals (Sweden)

    Andreja Möller Petrun

    2014-02-01

    Full Text Available In recent years, developments in the measuring of cardiac output and other haemodynamic variables are focused on the so-called minimally invasive methods. The aim of these methods is to simplify the management of high-risk and haemodynamically unstable patients. Due to the need of invasive approach and the possibility of serious complications the use of pulmonary artery catheter has decreased. This article describes the methods for measuring cardiac output, which are based on volume measurement (Fick method, indicator dilution method, pulse wave analysis, Doppler effect, and electrical bioimpedance.

  20. Quantitative cardiac computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Thelen, M.; Dueber, C.; Wolff, P.; Erbel, R.; Hoffmann, T.

    1985-06-01

    The scope and limitations of quantitative cardiac CT have been evaluated in a series of experimental and clinical studies. The left ventricular muscle mass was estimated by computed tomography in 19 dogs (using volumetric methods, measurements in two axes and planes and reference volume). There was good correlation with anatomical findings. The enddiastolic volume of the left ventricle was estimated in 22 patients with cardiomyopathies; using angiography as a reference, CT led to systematic under-estimation. It is also shown that ECG-triggered magnetic resonance tomography results in improved visualisation and may be expected to improve measurements of cardiac morphology.

  1. Mechanisms of Cardiac Regeneration

    Science.gov (United States)

    Uygur, Aysu; Lee, Richard T.

    2016-01-01

    Adult humans fail to regenerate their hearts following injury, and this failure to regenerate myocardium is a leading cause of heart failure and death worldwide. Although all adult mammals appear to lack significant cardiac regeneration potential, some vertebrates can regenerate myocardium throughout life. In addition, new studies indicate that mammals have cardiac regeneration potential during development and very soon after birth. The mechanisms of heart regeneration among model organisms, including neonatal mice, appear remarkably similar. Orchestrated waves of inflammation, matrix deposition and remodeling, and cardiomyocyte proliferation are commonly seen in heart regeneration models. Understanding why adult mammals develop extensive scarring instead of regeneration is a crucial goal for regenerative biology. PMID:26906733

  2. Metabolic alterations derived from absence of Two-Pore Channel 1 ...

    Indian Academy of Sciences (India)

    2016-11-23

    Nov 23, 2016 ... To explore the cardiac function of TPCN1, we developed proteomic approaches as 2-DE-MALDI-MS and LC-MALDI-MS in the cardiac left ventricle of TPCN1 KO and WT mice, and found alterations in several proteins implicated in glucose and fatty acid metabolism in TPCN1 KO vs. WT mice. The results.

  3. Restoration of cardiac tissue thyroid hormone status in experimental hypothyroidism: a dose-response study in female rats.

    Science.gov (United States)

    Weltman, Nathan Y; Ojamaa, Kaie; Savinova, Olga V; Chen, Yue-Feng; Schlenker, Evelyn H; Zucchi, Riccardo; Saba, Alessandro; Colligiani, Daria; Pol, Christine J; Gerdes, A Martin

    2013-07-01

    Thyroid hormones (THs) play a pivotal role in regulating cardiovascular homeostasis. To provide a better understanding of the coordinated processes that govern cardiac TH bioavailability, this study investigated the influence of serum and cardiac TH status on the expression of TH transporters and cytosolic binding proteins in the myocardium. In addition, we sought to determine whether the administration of T(3) (instead of T(4)) improves the relationship between THs in serum and cardiac tissue and cardiac function over a short-term treatment period. Adult female Sprague Dawley rats were made hypothyroid by 7 weeks treatment with the antithyroid drug 6-n-propyl-2-thiouracil (PTU). After establishing hypothyroidism, rats were assigned to 1 of 5 graded T(3) dosages plus PTU for a 2-week dose-response experiment. Untreated, age-matched rats served as euthyroid controls. PTU was associated with depressed serum and cardiac tissue T(3) and T(4) levels, arteriolar atrophy, altered TH transporter and cytosolic TH binding protein expression, fetal gene reexpression, and cardiac dysfunction. Short-term administration of T(3) led to a mismatch between serum and cardiac tissue TH levels. Normalization of serum T(3) levels was not associated with restoration of cardiac tissue T(3) levels or cardiac function. In fact, a 3-fold higher T(3) dosage was necessary to normalize cardiac tissue T(3) levels and cardiac function. Importantly, this study provides the first comprehensive data on the relationship between altered TH status (serum and cardiac tissue), cardiac function, and the coordinated in vivo changes in cardiac TH membrane transporters and cytosolic TH binding proteins in altered TH states.

  4. Effects of short-term continuous positive airway pressure on myocardial sympathetic nerve function and energetics in patients with heart failure and obstructive sleep apnea: a randomized study.

    Science.gov (United States)

    Hall, Allison B; Ziadi, Maria C; Leech, Judith A; Chen, Shin-Yee; Burwash, Ian G; Renaud, Jennifer; deKemp, Robert A; Haddad, Haissam; Mielniczuk, Lisa M; Yoshinaga, Keiichiro; Guo, Ann; Chen, Li; Walter, Olga; Garrard, Linda; DaSilva, Jean N; Floras, John S; Beanlands, Rob S B

    2014-09-09

    Heart failure with reduced ejection fraction and obstructive sleep apnea (OSA), 2 states of increased metabolic demand and sympathetic nervous system activation, often coexist. Continuous positive airway pressure (CPAP), which alleviates OSA, can improve ventricular function. It is unknown whether this is due to altered oxidative metabolism or presynaptic sympathetic nerve function. We hypothesized that short-term (6-8 weeks) CPAP in patients with OSA and heart failure with reduced ejection fraction would improve myocardial sympathetic nerve function and energetics. Forty-five patients with OSA and heart failure with reduced ejection fraction (left ventricular ejection fraction 35.8±9.7% [mean±SD]) were evaluated with the use of echocardiography and 11C-acetate and 11C-hydroxyephedrine positron emission tomography before and ≈6 to 8 weeks after randomization to receive short-term CPAP (n=22) or no CPAP (n=23). Work metabolic index, an estimate of myocardial efficiency, was calculated as follows: (stroke volume index×heart rate×systolic blood pressure÷Kmono), where Kmono is the monoexponential function fit to the myocardial 11C-acetate time-activity data, reflecting oxidative metabolism. Presynaptic sympathetic nerve function was measured with the use of the 11C-hydroxyephedrine retention index. CPAP significantly increased hydroxyephedrine retention versus no CPAP (Δretention: +0.012 [0.002, 0.021] versus -0.006 [-0.013, 0.005] min(-1); P=0.003). There was no significant change in work metabolic index between groups. However, in those with more severe OSA (apnea-hypopnea index>20 events per hour), CPAP significantly increased both work metabolic index and systolic blood pressure (Penergetics. In those with more severe OSA, CPAP may improve cardiac efficiency. Further outcome-based investigation of the consequences of CPAP is warranted. http://www.clinicaltrials.gov. Unique identifier: NCT00756366. © 2014 American Heart Association, Inc.

  5. Neonatal cardiac emergencies

    African Journals Online (AJOL)

    Neonatal cardiac emergencies. The neonatal period is one that fills many generalists with fear – this article will help to dispel these concerns. George A Comitis, MB ChB, DCH (SA), DA (SA), FCPaed (SA), Cert Cardiology (SA) Paed. Consultant, Paediatric Cardiology Service of the Western Cape, Red Cross War Memorial ...

  6. Nonexercise cardiac stress testing

    International Nuclear Information System (INIS)

    Vacek, J.L.; Baldwin, T.

    1989-01-01

    Many patients who require evaluation for coronary artery disease are unable to undergo exercise stress testing because of physiologic or psychological limitations. Drs Vacek and Baldwin describe three alternative methods for assessment of cardiac function in these patients, all of which have high levels of diagnostic sensitivity and specificity. 23 references

  7. Cardiac magnetic resonance imaging

    African Journals Online (AJOL)

    2011-03-06

    Mar 6, 2011 ... Bruce Spottiswoode has a BSc in Electrical Engineering from the University of the Witwatersrand and a PhD in Biomedical Engineering on cardiac MRI from the. University of Cape Town. He has worked on developing electronics for the CSIR, on MRI image reconstruction for Siemens, and on X-ray imaging ...

  8. Sudden cardiac death

    DEFF Research Database (Denmark)

    Hougen, H P; Valenzuela, Antonio Jesus Sanchez; Lachica, E

    1992-01-01

    The study deals with the comparison of morphological, histochemical and biochemical methods applied to the detection of myocardial infarction in 150 medico-legal autopsies performed at the Institute of Forensic Pathology in Copenhagen. The study also included an NBT (formazan) test of cardiac cross...

  9. Cardiac magnetic resonance imaging

    African Journals Online (AJOL)

    2011-03-06

    Mar 6, 2011 ... Cardiac magnetic resonance imaging. Cardiovascular magnetic resonance imaging is becoming a routine diagnostic technique. BRUCE s sPOTTiswOOdE, PhD. MRC/UCT Medical Imaging Research Unit, University of Cape Town, and Division of Radiology, Stellenbosch University. Bruce Spottiswoode ...

  10. Post cardiac injury syndrome

    DEFF Research Database (Denmark)

    Nielsen, S L; Nielsen, F E

    1991-01-01

    The post-pericardiotomy syndrome is a symptom complex which is similar in many respects to the post-myocardial infarction syndrome and these are summarized under the diagnosis of the Post Cardiac Injury Syndrome (PCIS). This condition, which is observed most frequently after open heart surgery...

  11. Usefulness of cardiac MRI in the prognosis and follow-up of ischemic heart disease.

    Science.gov (United States)

    Hidalgo, A; Pons-Lladó, G

    2015-01-01

    Cardiac magnetic resonance imaging (MRI) is an important tool that makes it possible to evaluate patients with cardiovascular disease; in addition to infarction and alterations in myocardial perfusion, cardiac MRI is useful for evaluating other phenomena such as microvascular obstruction and ischemia. The main prognostic factors in cardiac MRI are ventricular dysfunction, necrosis in late enhancement sequences, and ischemia in stress sequences. In acute myocardial infarction, cardiac MRI can evaluate the peri-infarct zone and quantify the size of the infarct. Furthermore, cardiac MRI's ability to detect and evaluate microvascular obstruction makes it a fundamental tool for establishing the prognosis of ischemic heart disease. In patients with chronic ischemic heart disease, cardiac MRI can detect ischemia induced by pharmacological stress and can diagnose infarcts that can be missed on other techniques. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  12. Cardiac Development and Transcription Factors: Insulin Signalling, Insulin Resistance, and Intrauterine Nutritional Programming of Cardiovascular Disease

    Science.gov (United States)

    Govindsamy, Annelene; Naidoo, Strinivasen

    2018-01-01

    Programming with an insult or stimulus during critical developmental life stages shapes metabolic disease through divergent mechanisms. Cardiovascular disease increasingly contributes to global morbidity and mortality, and the heart as an insulin-sensitive organ may become insulin resistant, which manifests as micro- and/or macrovascular complications due to diabetic complications. Cardiogenesis is a sequential process during which the heart develops into a mature organ and is regulated by several cardiac-specific transcription factors. Disrupted cardiac insulin signalling contributes to cardiac insulin resistance. Intrauterine under- or overnutrition alters offspring cardiac structure and function, notably cardiac hypertrophy, systolic and diastolic dysfunction, and hypertension that precede the onset of cardiovascular disease. Optimal intrauterine nutrition and oxygen saturation are required for normal cardiac development in offspring and the maintenance of their cardiovascular physiology. PMID:29484207

  13. Stages in the energetics of baroclinic systems

    Science.gov (United States)

    Orlanski, Isidoro; Sheldon, John P.

    1995-10-01

    The results from several idealized and case studies are drawn together to form a comprehensive picture of "downstream baroclinic evolution" using local energetics. This new viewpoint offers a complementary alternative to the more conventional descriptions of cyclone development. These additional insights are made possible largely because the local energetics approach permits one to define an energy flux vector which accurately describes the direction of energy dispersion and quantifies the role of neighboring systems in local development. In this view, the development of a system's energetics is divided into three stages. In Stage 1, a pre-existing disturbance well upstream of an incipient trough loses energy via ageostrophic geopotential fluxes directed downstream through the intervening ridge, generating a new energy center there. In Stage 2, this new energy center grows vigorously, at first due to the convergence of these fluxes, and later by baroclinic conversion as well. As the center matures, it begins to export energy via geopotential fluxes to the eastern side of the trough, initiating yet another energy center. In Stage 3, this new energy center continues to grow while that on the western side of the trough decays due to a dwinding supply of energy via fluxes from the older upstream system and also as a consequence of its own export of energy downstream. As the eastern energy center matures, it exports energy further downstream, and the sequence begins anew. The USA "Blizzard of'93" is used as a new case study to test the limits to which this conceptual sequence might apply, as well as to augment the current limited set of case studies. It is shown that, despite the extraordinary magnitude of the event, the evolution of the trough associated with the Blizzard fits the conceptual picture of downstream baroclinic evolution quite well, with geopotential fluxes playing a critical rôle in three respects. First, fluxes from an old, decaying system in the

  14. Azelnidipine protects myocardium in hyperglycemia-induced cardiac damage

    Directory of Open Access Journals (Sweden)

    Puranik Amrutesh S

    2010-12-01

    Full Text Available Abstract Background Azelnidipine (AZL, a long-acting dihydropyridine-based calcium antagonist, has been recently approved and used for treating ischemic heart disease and cardiac remodeling after myocardial infarction, however, its effect on hyperglycemia-induced cardiac damage has not been studied. Methods This study examined the effect of AZL on circulating markers of cardiac damage, altered lipid and cytokines profile and markers of oxidative stress including homocysteine in diabetic rats. Results STZ induced diabetes caused a significant increase in blood glucose levels. It also resulted in an increase in the levels of homocysteine and cardiac damage markers, like Troponin-1, CK-MB, CK-NAC, uric acid, LDH and alkaline phosphatase. Moreover, there was an increase in the levels of proinflammatory cytokines like TNF-α, IFN-γ, and TGF-β and decrease in the levels of IL-4 and IL-10. Additionally, there was increase in the levels of cholesterol, triglycerides, LDL, VLDL and a decrease in HDL in these animals. There was an altered antioxidant enzyme profile which resulted in a notable increase in the levels of oxidative stress markers like lipid peroxides, nitric oxide and carbonylated proteins. Compared with the untreated diabetic rats, AZL treatment significantly reduced the levels of troponin-1 (P Conclusion Our results indicate that AZL treatment can reduce the risk of hyperglycemia induced metabolic disorders and its role can be further extended to explore its therapeutic potential in diabetic patients with cardiac complications.

  15. Maternal cardiac metabolism in pregnancy

    Science.gov (United States)

    Liu, Laura X.; Arany, Zolt

    2014-01-01

    Pregnancy causes dramatic physiological changes in the expectant mother. The placenta, mostly foetal in origin, invades maternal uterine tissue early in pregnancy and unleashes a barrage of hormones and other factors. This foetal ‘invasion’ profoundly reprogrammes maternal physiology, affecting nearly every organ, including the heart and its metabolism. We briefly review here maternal systemic metabolic changes during pregnancy and cardiac metabolism in general. We then discuss changes in cardiac haemodynamic during pregnancy and review what is known about maternal cardiac metabolism during pregnancy. Lastly, we discuss cardiac diseases during pregnancy, including peripartum cardiomyopathy, and the potential contribution of aberrant cardiac metabolism to disease aetiology. PMID:24448314

  16. Energetic adaptations persist after bariatric surgery in severely obese adolescents

    Science.gov (United States)

    Energetic adaptations induced by bariatric surgery have not been studied in adolescents or for extended periods postsurgery. Energetic, metabolic, and neuroendocrine responses to Roux-en-Y gastric bypass (RYGB) surgery were investigated in extremely obese adolescents. At baseline and at 1.5, 6, and...

  17. Rocket measurements of energetic particles in the midlatitude precipitation zone

    Science.gov (United States)

    Voss, H. D.; Smith, L. G.; Braswell, F. M.

    1980-01-01

    Measurements of energetic ion and electron properties as a function of altitude in the midlatitude zone of nighttime energetic particle precipitation are reported. The measurements of particle fluxes, energy spectra and pitch angle distributions were obtained by a Langmuir probe, six energetic particle spectrometers and an electrostatic analyzer on board a Nike Apache rocket launched near the center of the midlatitude zone during disturbed conditions. It is found that the incident flux was primarily absorbed rather than backscattered, and consists of mainly energetic hydrogen together with some helium and a small energetic electron component. Observed differential energy spectra of protons having an exponential energy spectrum, and pitch angle distributions at various altitudes indicate that the energetic particle flux decreases rapidly for pitch angles less than 70 deg. An energetic particle energy flux of 0.002 ergs/sq cm per sec is calculated which indicates the significance of energetic particles as a primary nighttime ionization source for altitudes between 120 and 200 km in the midlatitude precipitation zone.

  18. Energetic materials: crystallization, characterization and insensitive plastic bonded explosives

    NARCIS (Netherlands)

    Heijden, A.E.D.M. van der; Creyghton, Y.L.M.; Marino, E.; Bouma, R.H.B.; Scholtes, G.J.H.G.; Duvalois, W.; Roelands, C.P.M.

    2008-01-01

    The product quality of energetic materials is predominantly determined by the crystallization process applied to produce these materials. It has been demonstrated in the past that the higher the product quality of the solid energetic ingredients, the less sensitive a plastic bonded explosive

  19. Computational studies on energetic properties of nitrogen-rich ...

    Indian Academy of Sciences (India)

    Computational studies on energetic properties of nitrogen-rich energetic materials with ditetrazoles. LI XIAO-HONGa,b,∗ and ZHANG RUI-ZHOUa. aCollege of Physics and Engineering, Henan University of Science and Technology, Luoyang 471 003, China. bLuoyang Key Laboratory of Photoelectric Functional Materials, ...

  20. Energetic particles in the jovian magnetotail.

    Science.gov (United States)

    McNutt, R L; Haggerty, D K; Hill, M E; Krimigis, S M; Livi, S; Ho, G C; Gurnee, R S; Mauk, B H; Mitchell, D G; Roelof, E C; McComas, D J; Bagenal, F; Elliott, H A; Brown, L E; Kusterer, M; Vandegriff, J; Stern, S A; Weaver, H A; Spencer, J R; Moore, J M

    2007-10-12

    When the solar wind hits Jupiter's magnetic field, it creates a long magnetotail trailing behind the planet that channels material out of the Jupiter system. The New Horizons spacecraft traversed the length of the jovian magnetotail to >2500 jovian radii (RJ; 1 RJ identical with 71,400 kilometers), observing a high-temperature, multispecies population of energetic particles. Velocity dispersions, anisotropies, and compositional variation seen in the deep-tail (greater, similar 500 RJ) with a approximately 3-day periodicity are similar to variations seen closer to Jupiter in Galileo data. The signatures suggest plasma streaming away from the planet and injection sites in the near-tail region (approximately 200 to 400 RJ) that could be related to magnetic reconnection events. The tail structure remains coherent at least until it reaches the magnetosheath at 1655 RJ.

  1. Energetics study of West African dust haze

    International Nuclear Information System (INIS)

    Omotosho, J.B.

    1988-10-01

    The causes of the large and often persistent negative anomalies of equivalent potential temperature observed in the 900-700 hpa layer and which occurs in association with dust haze outbreaks over Kano in winter is investigated. Energetics results indicate that the primary mechanism for such anomalies is the horizontal transport of drier and, to a lesser extent, colder air at the upper levels by eddy motions, with consequent destabilization of the atmospheric boundary layer over the station. This is suggested as the mobilization mechanism responsible for raising dust from the surface over the Bilma/Faya-Largeau source region much further poleward. Temperature inversions were also found to be more pronounced during dust spells than in clear periods. (author). 18 refs, 6 figs, 2 tabs

  2. Baseline composition of solar energetic particles

    International Nuclear Information System (INIS)

    Meyer, J.

    1985-01-01

    We analyze all existing spacecraft observations of the highly variable heavy element composition of solar energetic particles (SEP) during non- 3 He-rich events. All data show the imprint of an ever-present basic composition pattern (dubbed ''mass-unbiased baseline'' SEP composition) that differs from the photospheric composition by a simple bias related to first ionization potential (FIP). In each particular observation, this mass-unbiased baseline composition is being distorted by an additional bias, which is always a monotonic function of mass (or Z). This latter bias varies in amplitude and even sign from observation to observation. To first order, it seems related to differences in the A/Z* ratio between elements (Z* = mean effective charge)

  3. Flexible energetic materials and related methods

    Energy Technology Data Exchange (ETDEWEB)

    Heaps, Ronald J.

    2018-03-06

    Energetic compositions and methods of forming components from the compositions are provided. In one embodiment, a composition includes aluminum, molybdenum trioxide, potassium perchlorate, and a binder. In one embodiment, the binder may include a silicone material. The materials may be mixed with a solvent, such as xylene, de-aired, shaped and cured to provide a self-supporting structure. In one embodiment, one or more reinforcement members may be added to provide additional strength to the structure. For example, a weave or mat of carbon fiber material may be added to the mixture prior to curing. In one embodiment, blade casting techniques may be used to form a structure. In another embodiment, a structure may be formed using 3-dimensional printing techniques.

  4. Acceleration and Propagation of Solar Energetic Particles

    Science.gov (United States)

    Klein, Karl-Ludwig; Dalla, Silvia

    2017-11-01

    Solar Energetic Particles (SEPs) are an important component of Space Weather, including radiation hazard to humans and electronic equipment, and the ionisation of the Earth's atmosphere. We review the key observations of SEPs, our current understanding of their acceleration and transport, and discuss how this knowledge is incorporated within Space Weather forecasting tools. Mechanisms for acceleration during solar flares and at shocks driven by Coronal Mass Ejections (CMEs) are discussed, as well as the timing relationships between signatures of solar eruptive events and the detection of SEPs in interplanetary space. Evidence on how the parameters of SEP events are related to those of the parent solar activity is reviewed and transport effects influencing SEP propagation to near-Earth locations are examined. Finally, the approaches to forecasting Space Weather SEP effects are discussed. We conclude that both flare and CME shock acceleration contribute to Space Weather relevant SEP populations and need to be considered within forecasting tools.

  5. Energetics and population ecology of Siberian herders.

    Science.gov (United States)

    Leonard, William R; Katzmarzyk, Peter T; Crawford, Michael H

    1996-01-01

    Methodological advances now permit human biologists to more effectively monitor energy dynamics in traditional societies. This study examines the nutritional ecology and energetics of semisubsistence herders of Siberia (Evenki) during a single season of their annual cycle (late summer). Total energy expenditure (TEE) among adults, as measured by daily heart-rate monitoring, is greater in Evenki men (TEE = 11.9 ± 2.8 MJ/d in men and 8.8 ± 2.1 MJ/d in women; P fat distribution. Evenki males appear to be undergoing a secular trend in stature, while no such increases are evident in females. These gender differences may reflect the differential impact to the changes associated with collectivization. Reduced metabolic requirements (due to declining activity and fertility levels), along with greater food availability, are likely to be responsible for the higher rates of obesity among Evenki women. © 1996 Wiley-Liss, Inc. Copyright © 1996 Wiley-Liss, Inc.

  6. Utilization of FEP energetics. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Frederking, T.H.K.; Abbassi, P.; Afifi, F.; Khandhar, P.K.; Ono, D.Y.; Chen, W.E.W.

    1987-12-01

    The research and development work on Fountain Effect Pump Systems (FEP systems) has been of interest in the competition between mechanical pumps for He II and FEP units. The latter do not have moving parts. In the course of the work, the energetics have been addressed using one part of a simple four-changes-of-state cycle. One option is the FEP ideal change of state at constant chemical potential (mu). The other option is the two-state sequence mu-P with a d mu=0 state change followed by an isobar. Questions of pump behavior, of flow rate response to temperature difference at the hot end, and related questions of thermodynamic cycle completion and heat transfer have been addressed. Porous media data obtained elucidate differences between vapor-liquid phase separation (VLPS) and Zero Net Mass Transfer (ZNMF).

  7. Energetic Di- and Trinitromethylpyridines: Synthesis and Characterization

    Directory of Open Access Journals (Sweden)

    Yiying Zhang

    2017-12-01

    Full Text Available Pyridine derivatives based on the addition of trinitromethyl functional groups were synthesized by the reaction of N2O4 with the corresponding pyridinecarboxaldoximes, then they were converted into dinitromethylide hydrazinium salts. These energetic compounds were fully characterized by IR and NMR spectroscopy, elemental analysis, differential scanning calorimetry (DSC, and X-ray crystallography. These pyridine derivatives have good densities, positive enthalpies of formation, and acceptable sensitivity values. Theoretical calculations carried out using Gaussian 03 and EXPLO5 programs demonstrated good to excellent detonation velocities and pressures. Each of these compounds is superior in performance to TNT, while 2,6-bis(trinitromethylpyridine (D = 8700 m·s−1, P = 33.2 GPa shows comparable detonation performance to that of RDX, but its thermal stability is too low, making it inferior to RDX.

  8. Solar energetic particles and radio burst emission

    Directory of Open Access Journals (Sweden)

    Miteva Rositsa

    2017-01-01

    Full Text Available We present a statistical study on the observed solar radio burst emission associated with the origin of in situ detected solar energetic particles. Several proton event catalogs in the period 1996–2016 are used. At the time of appearance of the particle origin (flare and coronal mass ejection we identified radio burst signatures of types II, III and IV by inspecting dynamic radio spectral plots. The information from observatory reports is also accounted for during the analysis. The occurrence of solar radio burst signatures is evaluated within selected wavelength ranges during the solar cycle 23 and the ongoing 24. Finally, we present the burst occurrence trends with respect to the intensity of the proton events and the location of their solar origin.

  9. Solar energetic particles and radio burst emission

    Science.gov (United States)

    Miteva, Rositsa; Samwel, Susan W.; Krupar, Vratislav

    2017-12-01

    We present a statistical study on the observed solar radio burst emission associated with the origin of in situ detected solar energetic particles. Several proton event catalogs in the period 1996-2016 are used. At the time of appearance of the particle origin (flare and coronal mass ejection) we identified radio burst signatures of types II, III and IV by inspecting dynamic radio spectral plots. The information from observatory reports is also accounted for during the analysis. The occurrence of solar radio burst signatures is evaluated within selected wavelength ranges during the solar cycle 23 and the ongoing 24. Finally, we present the burst occurrence trends with respect to the intensity of the proton events and the location of their solar origin.

  10. Effective charge of energetic ions in metals

    International Nuclear Information System (INIS)

    Kitagawa, M.; Brandt, W.

    1983-01-01

    The effective charge of energetic ion, as derived from stopping power of metals, is calculated by use of a dielectronic-response function method. The electronic distribution in the ion is described through the variational principle in a statistical approximation. The dependences of effective charge on the ion velocity, atomic number and r/sub s/-value of metal are derived at the low-velocity region. The effective charge becomes larger than the real charge of ion due to the close collisions. We obtain the quasi-universal equation of the fractional effective electron number of ion as a function of the ratio between the ionic size and the minimum distance approach. The comparsion between theoretical and experimental results of the effective charge is performed for the cases of N ion into Au, C and Al. We also discuss the equipartition rule of partially ionized ion at the high-velocity region

  11. Forces and energetics of intermittent swimming

    Science.gov (United States)

    Floryan, Daniel; Van Buren, Tyler; Smits, Alexander J.

    2017-08-01

    Experiments are reported on intermittent swimming motions. Water tunnel experiments on a nominally two-dimensional pitching foil show that the mean thrust and power scale linearly with the duty cycle, from a value of 0.2 all the way up to continuous motions, indicating that individual bursts of activity in intermittent motions are independent of each other. This conclusion is corroborated by particle image velocimetry (PIV) flow visualizations, which show that the main vortical structures in the wake do not change with duty cycle. The experimental data also demonstrate that intermittent motions are generally energetically advantageous over continuous motions. When metabolic energy losses are taken into account, this conclusion is maintained for metabolic power fractions less than 1.

  12. Energetic condensation growth of Nb thin films

    Directory of Open Access Journals (Sweden)

    M. Krishnan

    2012-03-01

    Full Text Available This paper describes energetic condensation growth of Nb films using a cathodic arc plasma, whose 60–120 eV ions penetrate a few monolayers into the substrate and enable sufficient surface mobility to ensure that the lowest energy state (crystalline structure with minimal defects is accessible to the film. Heteroepitaxial films of Nb were grown on a-plane sapphire and MgO crystals with good superconducting properties and crystal size (10  mm×20  mm limited only by substrate size. The substrates were heated to temperatures of up to 700°C and coated at 125°C, 300°C, 500°C, and 700°C. Film thickness was varied from ∼0.25  μm to >3  μm. Residual resistivity ratio (⟨RRR⟩ values (up to a record ⟨RRR⟩=587 on MgO and ⟨RRR⟩=328 on a-sapphire depend strongly on substrate annealing and deposition temperatures. X-ray diffraction spectra and pole figures reveal that RRR increases as the crystal structure of the Nb film becomes more ordered, consistent with fewer defects and, hence, longer electron mean-free path. A transition from Nb(110 to Nb(100 orientation on the MgO(100 lattice occurs at higher temperatures. This transition is discussed in light of substrate heating and energetic condensation physics. Electron backscattered diffraction and scanning electron microscope images complement the XRD data.

  13. Energetic materials: crystallization, characterization and insensitive plastic bonded explosives

    Energy Technology Data Exchange (ETDEWEB)

    Heijden, Antoine E.D.M. van der; Creyghton, Yves L.M.; Marino, Emanuela; Bouma, Richard H.B.; Scholtes, Gert J.H.G.; Duvalois, Willem [TNO Defence, Security and Safety, P. O. Box 45, 2280 AA Rijswijk (Netherlands); Roelands, Marc C.P.M. [TNO Science and Industry, P. O. Box 342, 7300 AH Apeldoorn (Netherlands)

    2008-02-15

    The product quality of energetic materials is predominantly determined by the crystallization process applied to produce these materials. It has been demonstrated in the past that the higher the product quality of the solid energetic ingredients, the less sensitive a plastic bonded explosive containing these energetic materials becomes. The application of submicron or nanometric energetic materials is generally considered to further decrease the sensitiveness of explosives. In order to assess the product quality of energetic materials, a range of analytical techniques is available. Recent attempts within the Reduced-sensitivity RDX Round Robin (R4) have provided the EM community a better insight into these analytical techniques and in some cases a correlation between product quality and shock initiation of plastic bonded explosives containing (RS-)RDX was identified, which would provide a possibility to discriminate between conventional and reduced sensitivity grades. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  14. Pentoxifylline Attenuates Cardiac Remodeling Induced by Tobacco Smoke Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Minicucci, Marcos; Oliveira, Fernando; Santos, Priscila; Polegato, Bertha; Roscani, Meliza; Fernandes, Ana Angelica; Lustosa, Beatriz; Paiva, Sergio; Zornoff, Leonardo; Azevedo, Paula, E-mail: paulasa@fmb.unesp.br [Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, São Paulo, SP (Brazil)

    2016-05-15

    Tobacco smoke exposure is an important risk factor for cardiac remodeling. Under this condition, inflammation, oxidative stress, energy metabolism abnormalities, apoptosis, and hypertrophy are present. Pentoxifylline has anti‑inflammatory, anti-apoptotic, anti-thrombotic and anti-proliferative properties. The present study tested the hypothesis that pentoxifylline would attenuate cardiac remodeling induced by smoking. Wistar rats were distributed in four groups: Control (C), Pentoxifylline (PX), Tobacco Smoke (TS), and PX-TS. After two months, echocardiography, invasive blood pressure measurement, biochemical, and histological studies were performed. The groups were compared by two-way ANOVA with a significance level of 5%. TS increased left atrium diameter and area, which was attenuated by PX. In the isolated heart study, TS lowered the positive derivate (+dp/dt), and this was attenuated by PX. The antioxidants enzyme superoxide dismutase and glutathione peroxidase were decreased in the TS group; PX recovered these activities. TS increased lactate dehydrogenase (LDH) and decreased 3-hydroxyacyl Coenzyme A dehydrogenases (OH-DHA) and citrate synthase (CS). PX attenuated LDH, 3-OH-DHA and CS alterations in TS-PX group. TS increased IL-10, ICAM-1, and caspase-3. PX did not influence these variables. TS induced cardiac remodeling, associated with increased inflammation, oxidative stress, apoptosis, and changed energy metabolism. PX attenuated cardiac remodeling by reducing oxidative stress and improving cardiac bioenergetics, but did not act upon cardiac cytokines and apoptosis.

  15. Blood storage duration and morbidity and mortality in children undergoing cardiac surgery. A retrospective analysis

    NARCIS (Netherlands)

    Baltsavias, Iris; Faraoni, David; Willems, Ariane; Kenz, Hanane El; Melot, Christian; de Hert, Stefan; van der Linden, Philippe

    2014-01-01

    Blood transfusion is frequently required in children undergoing cardiac surgery and is associated with altered postoperative outcome. This may be due to alterations in red blood cell properties related to the storage process. To evaluate the effect of blood storage duration on postoperative

  16. Mammalian energetics. Instantaneous energetics of puma kills reveal advantage of felid sneak attacks.

    Science.gov (United States)

    Williams, Terrie M; Wolfe, Lisa; Davis, Tracy; Kendall, Traci; Richter, Beau; Wang, Yiwei; Bryce, Caleb; Elkaim, Gabriel Hugh; Wilmers, Christopher C

    2014-10-03

    Pumas (Puma concolor) live in diverse, often rugged, complex habitats. The energy they expend for hunting must account for this complexity but is difficult to measure for this and other large, cryptic carnivores. We developed and deployed a physiological SMART (species movement, acceleration, and radio tracking) collar that used accelerometry to continuously monitor energetics, movements, and behavior of free-ranging pumas. This felid species displayed marked individuality in predatory activities, ranging from low-cost sit-and-wait behaviors to constant movements with energetic costs averaging 2.3 times those predicted for running mammals. Pumas reduce these costs by remaining cryptic and precisely matching maximum pouncing force (overall dynamic body acceleration = 5.3 to 16.1g) to prey size. Such instantaneous energetics help to explain why most felids stalk and pounce, and their analysis represents a powerful approach for accurately forecasting resource demands required for survival by large, mobile predators. Copyright © 2014, American Association for the Advancement of Science.

  17. Cardiac fusion and complex congenital cardiac defects in thoracopagus twins: diagnostic value of cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Park, Jeong-Jun [University of Ulsan College of Medicine, Asan Medical Center, Department of Pediatric Cardiac Surgery, Seoul (Korea, Republic of); Kim, Ellen Ai-Rhan [University of Ulsan College of Medicine, Asan Medical Center, Division of Neonatology, Department of Pediatrics, Seoul (Korea, Republic of); Won, Hye-Sung [University of Ulsan College of Medicine, Asan Medical Center, Department of Obstetrics and Gynecology, Seoul (Korea, Republic of)

    2014-09-15

    Most thoracopagus twins present with cardiac fusion and associated congenital cardiac defects, and assessment of this anatomy is of critical importance in determining patient care and outcome. Cardiac CT with electrocardiographic triggering provides an accurate and quick morphological assessment of both intracardiac and extracardiac structures in newborns, making it the best imaging modality to assess thoracopagus twins during the neonatal period. In this case report, we highlight the diagnostic value of cardiac CT in thoracopagus twins with an interatrial channel and complex congenital cardiac defects. (orig.)

  18. Effects of sublethal exposure to lead on levels of energetic compounds in Procambarus clarkii (Girard, 1852)

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, M.; Torreblanca, A.; Del Ramo, J.; Diaz-Mayans, J. (Univ. of Valencia (Spain))

    1994-05-01

    Lead is neither essential nor beneficial to living organisms; all existing data show that its metabolic effects are adverse. Lead is toxic to all phyla of aquatic biota. Most of the lead discharged into surface water is rapidly incorporated into suspended and bottom sediments. The American red crayfish, Procambarus clarkii, lives in a wide range of environmental conditions that include highly polluted waters. Lead present in take sediments can be available to aquatic animals such as P. clarkii because it is a detritivor and burrow into the sediment. In fact, we found remarkable levels of lead in tissues of P. clarkii caught in Albufera Lake and kept 15 days in clean water (e. g. 223 [mu]g/g dry weight in gills). Furthermore, P. clarkii has a high capacity for lead accumulation from water, and gills were the most important tissue of lead accumulation. Among effects that contaminants have on the physiology of the organisms, energetic state variables are important, since they will alter both survival and reproduction. Hepatopancreas is a major site for the energetic reserve in crayfish and is a site of lead accumulation, although metal concentration in this organ is not as high as gills. The purpose of this study was to examine changes in energy reserves in hepatopancreas and gills of the crayfish P. clarkii, in response to sublethal exposure to lead. Gills are directly exposed to contaminants in the environment, and they are the first organ showing alterations by the action of the contaminants. Hepatopancreas was also chosen due to both, its relevance in the energetic metabolism and its role in heavy metal detoxification mechanisms.

  19. Fetal cardiac assessment

    International Nuclear Information System (INIS)

    Greene, K.R.

    1983-01-01

    The better understanding of fetal cardiovascular physiology coupled with improved technology for non-invasive study of the fetus now enable much more detailed assessment of fetal cardiac status than by heart rate alone. Even the latter, relatively simple, measurement contains much more information than was previously realized. It is also increasingly clear that no single measurement will provide the answer to all clinical dilemmas either on cardiac function or the welfare of the fetus as a whole. There are obvious clinical advantages in measuring several variables from one signal and the measurement of heart rate, heart rate variation and waveform from the ECG in labour is a potentially useful combination. Systolic time intervals or flow measurements could easily be added or used separately by combining real-time and Doppler ultrasound probes

  20. Cardiac nuclear medicine

    Energy Technology Data Exchange (ETDEWEB)

    Gerson, M.C.

    1987-01-01

    The book begins with a review of the radionuclide methods available for evaluating cardiac perfusion and function. The authors discuss planar and tomographic thallium myocardial imaging, first-pass and equilibrium radionuclide angiography, and imaging with infarct-avid tracers. Several common but more specialized procedures are then reviewed: nonogemetric measurement of left ventricular volume, phase (Fourier) analysis, stroke volume ratio, right ventricular function, and diastolic function. A separate chapter is devoted to drug interventions and in particular the use of radionuclide ventriculography to monitor doxorubicin toxicity and therapy of congestive heart failure. The subsequent chapters provide a comprehensive guide to test selection, accuracy, and results in acute myocardial infarction, in postmyocardial infarction, in chronic coronary artery disease, before and after medical or surgical revascularization, in valvular heart disease, in cardiomyopathies, and in cardiac trauma.

  1. Cardiac defects, nuchal edema and abnormal lymphatic development are not associated with morphological changes in the ductus venosus

    NARCIS (Netherlands)

    Burger, Nicole B.; Haak, Monique C.; Kok, Evelien; de Groot, Christianne J. M.; Shou, Weinian; Scambler, Peter J.; Lee, Youngsook; Cho, Eunjin; Christoffels, Vincent M.; Bekker, Mireille N.

    2016-01-01

    In human fetuses with cardiac defects and increased nuchal translucency, abnormal ductus venosus flow velocity waveforms are observed. It is unknown whether abnormal ductus venosus flow velocity waveforms in fetuses with increased nuchal translucency are a reflection of altered cardiac function or

  2. Cardiac defects, nuchal edema and abnormal lymphatic development are not associated with morphological changes in the ductus venosus

    NARCIS (Netherlands)

    Burger, Nicole B.; Haak, Monique C.; Kok, Evelien; de Groot, Christianne J M; Shou, Weinian; Scambler, Peter J.; Lee, Youngsook; Cho, Eunjin; Christoffels, Vincent M.; Bekker, Mireille N.

    2016-01-01

    Background In human fetuses with cardiac defects and increased nuchal translucency, abnormal ductus venosus flow velocity waveforms are observed. It is unknown whether abnormal ductus venosus flow velocity waveforms in fetuses with increased nuchal translucency are a reflection of altered cardiac

  3. THE ROLE OF DRAG IN THE ENERGETICS OF STRONGLY FORCED EXOPLANET ATMOSPHERES

    International Nuclear Information System (INIS)

    Rauscher, Emily; Menou, Kristen

    2012-01-01

    In contrast to the Earth, where frictional heating is typically negligible, we show that drag mechanisms could act as an important heat source in the strongly forced atmospheres of some exoplanets, with the potential to alter the circulation. We modify the standard formalism of the atmospheric energy cycle to explicitly track the loss of kinetic energy and the associated frictional (re)heating, for application to exoplanets such as the asymmetrically heated 'hot Jupiters' and gas giants on highly eccentric orbits. We establish that an understanding of the dominant drag mechanisms and their dependence on local atmospheric conditions is critical for accurate modeling, not just in their ability to limit wind speeds, but also because they could possibly change the energetics of the circulation enough to alter the nature of the flow. We discuss possible sources of drag and estimate the strength necessary to significantly influence the atmospheric energetics. As we show, the frictional heating depends on the magnitude of kinetic energy dissipation as well as its spatial variation, so that the more localized a drag mechanism is, the weaker it can be and still affect the circulation. We also use the derived formalism to estimate the rate of numerical loss of kinetic energy in a few previously published hot Jupiter models with and without magnetic drag and find it to be surprisingly large, at 5%-10% of the incident stellar irradiation.

  4. Thermodynamic analysis questions claims of improved cardiac efficiency by dietary fish oil

    Science.gov (United States)

    Goo, Eden; Chapman, Brian; Hickey, Anthony J.R.

    2016-01-01

    Studies in the literature describe the ability of dietary supplementation by omega-3 fish oil to increase the pumping efficiency of the left ventricle. Here we attempt to reconcile such studies with our own null results. We undertake a quantitative analysis of the improvement that could be expected theoretically, subject to physiological constraints, by posing the following question: By how much could efficiency be expected to increase if inefficiencies could be eliminated? Our approach utilizes thermodynamic analyses to investigate the contributions, both singly and collectively, of the major components of cardiac energetics to total cardiac efficiency. We conclude that it is unlikely that fish oils could achieve the required diminution of inefficiencies without greatly compromising cardiac performance. PMID:27574288

  5. Molecular nuclear cardiac imaging

    International Nuclear Information System (INIS)

    Lee, Dong Soo; Paeng, Jin Chul

    2004-01-01

    Molecular nuclear cardiac imaging has included Tc-99m Annexin imaging to visualize myocardial apoptosis, but is now usually associated with gene therapy and cell-based therapy. Cardiac gene therapy was not successful so far but cardiac reporter gene imaging was made possible using HSV-TK (herpes simplex virus thymidine kinase) and F-18 FHBG (fluoro-hydroxymethylbutyl guanine) or I-124 FIAU (fluoro-deoxyiodo-arabino-furanosyluracil). Gene delivery was performed by needle injection with or without catheter guidance. TK expression did not last longer than 2 weeks in myocardium. Cell-based therapy of ischemic heart or failing heart looks promising, but biodistribution and differentiation of transplanted cells are not known. Reporter genes can be transfected to the stem/progenitor cells and cells containing these genes can be transplanted to the recipients using catheter-based purging or injection. Repeated imaging should be available and if promoter are varied to let express reporter transgenes, cellular (trans)differentiation can be studied. NIS (sodium iodide symporter) or D2R receptor genes are promising in this aspect

  6. Altered combustion characteristics of metallized energetics due to stable secondary material inclusion

    Science.gov (United States)

    Terry, Brandon C.

    Though metals and metalloids have been widely considered as reactive fuels, the ability to tune their ignition and combustion characteristics remains challenging. One means to accomplish this may be through low-level inclusion of secondary materials into the metallized fuel. While there are several potential methods to stably introduce secondary inclusion materials, this work focuses on the use of mechanical activation (MA) and metal alloys. Recent work has shown that low-level inclusion of fluoropolymers into aluminum particles can have a substantial effect on their combustion characteristics. The reflected shock ignition of mechanically activated aluminum/polytetrafluoroethylene (MA Al/PTFE) is compared to a physical mixture (PM) of Al/PTFE, neat spherical aluminum, and flake aluminum. It was found that the powders with higher specific surface areas ignited faster than the spherical particles of the same size, and had ignition delay times comparable to agglomerates of aluminum particles that were two orders of magnitude smaller in size. Flake aluminum powder had the same ignition delay as MA Al/PTFE, indicating that any initial aluminum/fluoropolymer reactions did not yield an earlier onset of aluminum oxidation. However, MA Al/PTFE did have a shorter total burn time. The PM of Al/PTFE powder had a shorter ignition delay than neat spherical aluminum due to the rapid decomposition of PTFE into reactive fluorocarbon compounds, but the subsequent fluorocarbon reactions also created a secondary luminosity profile that significantly increased the total burn time of the system. The explosive shock ignition of aluminum and aluminum-silicon eutectic alloy compacts was evaluated with and without polymer inclusions. A statistical analysis was completed, investigating the effects of: detonation train orientation (into or not into a hard surface); the high explosive driver; whether the metal/polymer system is mechanically activated; particle size; particle morphology (spherical or flake); metal type (Al or Al-Si); and whether the inclusion material is interacting or non-interacting with the parent metal. It was found that mechanically activated particles with an interacting inclusion material (polytetrafluoroethylene) and smaller particle sizes yielded increased blast wave strength, and more complete metal combustion. It was also found that orientation of the detonation train has a substantial effect on the completeness of combustion. While aluminum alloys are generally employed for their structural and mechanical properties, the low-level inclusion of secondary metals and metalloids may make such materials advantageous in propellant formulations and have not been fully considered. The aluminum-silicon (Al-Si) eutectic alloy was evaluated as a potential solid composite propellant fuel. Equilibrium calculations showed that Al-Si based propellants had comparable theoretical performance to equivalent aluminum based propellants, though at a typical specific impulse (ISP) reduction of roughly 2.5 seconds for most mixture ratios of interest. Interacting (polytetrafluoroethylene, PTFE) and non-interacting inclusion materials were mechanically activated (MA) with Al-Si (70/30 wt.% Al-Si/PTFE and 90/10 wt.% Al-Si/LDPE), which were shown to increase the powder reactivity. Neat and MA Al-Si powders were used in 15/71/14 wt.% (fuel additive)/(ammonium perchlorate)/binder propellant formulations. Environmentally cleaner solid composite propellants have been widely investigated as a means to reduce hydrochloric acid (HCl) formation. Past efforts to scavenge the chlorine ion have focused on replacing a portion of the chorine-containing oxidant (i.e., ammonium perchlorate) with an alkali metal nitrate. The alkali metal (e.g., Li or Na) in the nitrate reacts with the chlorine ion to form an alkali metal chloride (i.e., salt). While this technique can potentially reduce HCl formation, it also results in reduced theoretical specific impulse. Thermochemical calculations show that using aluminum-lithium (Al-Li) binary alloy can reduce HCl formation to less than 5% and increase the theoretical ISP by roughly 7 seconds compared to neat aluminum. Two solid propellants were made using 80/20 Al-Li alloy and neat aluminum as fuel additives. It was observed that the propellant combustion with neat aluminum formed large molten droplets at the surface, which is a well-known problem with aluminized propellants. In contrast, the Al-Li propellant formed an Al-Li melt-layer on the propellant surface during combustion. Droplets that were ejected from the melt-layer would typically undergo dispersive boiling or a shattering microexplosion, due to the large disparity in volatility (i.e., boiling points) between the aluminum and the lithium in the molten alloy. The halide scavenging effect of Al-Li propellants was verified using wet bomb combustion experiments. Additionally, no HCl evolution was detected using differential scanning calorimetry coupled with thermogravimetric analysis, mass spectrometry, and Fourier transform infrared absorption. (Abstract shortened by UMI.).

  7. Evolution of Ventricular Energetics in the Different Stages of Palliation of Hypoplastic Left Heart Syndrome: A Retrospective Clinical Study.

    Science.gov (United States)

    Di Molfetta, A; Iacobelli, R; Guccione, P; Di Chiara, L; Rocchi, M; Cobianchi Belisari, F; Campanale, M; Gagliardi, M G; Filippelli, S; Ferrari, G; Amodeo, A

    2017-12-01

    Hyperplastic left heart syndrome (HLHS) patients are palliated by creating a Fontan-type circulation passing from different surgical stages. The aim of this work is to describe the evolution of ventricular energetics parameters in HLHS patients during the different stages of palliation including the hybrid, the Norwood, the bidirectional Glenn (BDG), and the Fontan procedures. We conducted a retrospective clinical study enrolling all HLHS patients surgically treated with hybrid procedure and/or Norwood and/or BDG and/or Fontan operation from 2011 to 2016 collecting echocardiographic and hemodynamic data. Measured data were used to calculate energetic variables such as ventricular elastances, external and internal work, ventriculo-arterial coupling and cardiac mechanical efficiency. From 2010 to 2016, a total of 29 HLHS patients undergoing cardiac catheterization after hybrid (n = 7) or Norwood (n = 6) or Glenn (n = 8) or Fontan (n = 8) procedure were retrospectively enrolled. Ventricular volumes were significantly higher in the Norwood circulation than in the hybrid circulation (p = 0.03) with a progressive decrement from the first stage to the Fontan completion. Ventricular elastances were lower in the Norwood circulation than in the hybrid circulation and progressively increased passing from the first stage to the Fontan completion. The arterial elastance and Rtot increased in the Fontan circulation. The ventricular work progressively increased. Finally, the ventricular efficiency improves passing from the first to the last stage of palliation. The use of ventricular energetic parameters could lead to a more complete evaluation of such complex patients to better understand their adaptation to different pathophysiological conditions.

  8. Dystrophin genotype-cardiac phenotype correlations in Duchenne and Becker muscular dystrophies using cardiac magnetic resonance imaging.

    Science.gov (United States)

    Tandon, Animesh; Jefferies, John L; Villa, Chet R; Hor, Kan N; Wong, Brenda L; Ware, Stephanie M; Gao, Zhiqian; Towbin, Jeffrey A; Mazur, Wojciech; Fleck, Robert J; Sticka, Joshua J; Benson, D Woodrow; Taylor, Michael D

    2015-04-01

    Duchenne and Becker muscular dystrophies are caused by mutations in dystrophin. Cardiac manifestations vary broadly, making prognosis difficult. Current dystrophin genotype-cardiac phenotype correlations are limited. For skeletal muscle, the reading-frame rule suggests in-frame mutations tend to yield milder phenotypes. We performed dystrophin genotype-cardiac phenotype correlations using a protein-effect model and cardiac magnetic resonance imaging. A translational model was applied to patient-specific deletion, indel, and nonsense mutations to predict exons and protein domains present within truncated dystrophin protein. Patients were dichotomized into predicted present and predicted absent groups for exons and protein domains of interest. Development of myocardial fibrosis (represented by late gadolinium enhancement [LGE]) and depressed left ventricular ejection fraction (LVEF) were compared. Patients (n = 274) with predicted present cysteine-rich domain (CRD), C-terminal domain (CTD), and both the N-terminal actin-binding and cysteine-rich domains (ABD1 + CRD) had a decreased risk of LGE and trended toward greater freedom from LGE. Patients with predicted present CTD (exactly the same as those with in-frame mutations) and ABD1 + CRD trended toward decreased risk of and greater freedom from depressed LVEF. In conclusion, genotypes previously implicated in altering the dystrophinopathic cardiac phenotype were not significantly related to LGE and depressed LVEF. Patients with predicted present CRD, CTD/in-frame mutations, and ABD1 + CRD trended toward milder cardiac phenotypes, suggesting that the reading-frame rule may be applicable to the cardiac phenotype. Genotype-phenotype correlations may help predict the cardiac phenotype for dystrophinopathic patients and guide future therapies. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Resveratrol improves survival, hemodynamics and energetics in a rat model of hypertension leading to heart failure.

    Directory of Open Access Journals (Sweden)

    Stéphanie Rimbaud

    Full Text Available Heart failure (HF is characterized by contractile dysfunction associated with altered energy metabolism. This study was aimed at determining whether resveratrol, a polyphenol known to activate energy metabolism, could be beneficial as a metabolic therapy of HF. Survival, ventricular and vascular function as well as cardiac and skeletal muscle energy metabolism were assessed in a hypertensive model of HF, the Dahl salt-sensitive rat fed with a high-salt diet (HS-NT. Resveratrol (18 mg/kg/day; HS-RSV was given for 8 weeks after hypertension and cardiac hypertrophy were established (which occurred 3 weeks after salt addition. Resveratrol treatment improved survival (64% in HS-RSV versus 15% in HS-NT, p<0.001, and prevented the 25% reduction in body weight in HS-NT (P<0.001. Moreover, RSV counteracted the development of cardiac dysfunction (fractional shortening -34% in HS-NT as evaluated by echocardiography, which occurred without regression of hypertension or hypertrophy. Moreover, aortic endothelial dysfunction present in HS-NT was prevented in resveratrol-treated rats. Resveratrol treatment tended to preserve mitochondrial mass and biogenesis and completely protected mitochondrial fatty acid oxidation and PPARα (peroxisome proliferator-activated receptor α expression. We conclude that resveratrol treatment exerts beneficial protective effects on survival, endothelium-dependent smooth muscle relaxation and cardiac contractile and mitochondrial function, suggesting that resveratrol or metabolic activators could be a relevant therapy in hypertension-induced HF.

  10. A Monte Carlo model of crustal field influences on solar energetic particle precipitation into the Martian atmosphere

    Science.gov (United States)

    Jolitz, R. D.; Dong, C. F.; Lee, C. O.; Lillis, R. J.; Brain, D. A.; Curry, S. M.; Bougher, S.; Parkinson, C. D.; Jakosky, B. M.

    2017-05-01

    Solar energetic particles (SEPs) can precipitate directly into the atmospheres of weakly magnetized planets, causing increased ionization, heating, and altered neutral chemistry. However, strong localized crustal magnetism at Mars can deflect energetic charged particles and reduce precipitation. In order to quantify these effects, we have developed a model of proton transport and energy deposition in spatially varying magnetic fields, called Atmospheric Scattering of Protons and Energetic Neutrals. We benchmark the model's particle tracing algorithm, collisional physics, and heating rates, comparing against previously published work in the latter two cases. We find that energetic nonrelativistic protons precipitating in proximity to a crustal field anomaly will primarily deposit energy at either their stopping altitude or magnetic reflection altitude. We compared atmospheric ionization in the presence and absence of crustal magnetic fields at 50°S and 182°E during the peak flux of the 29 October 2003 "Halloween storm" SEP event. The presence of crustal magnetic fields reduced total ionization by 30% but caused ionization to occur over a wider geographic area.

  11. Sarcolipin overexpression improves muscle energetics and reduces fatigue

    Science.gov (United States)

    Sopariwala, Danesh H.; Pant, Meghna; Shaikh, Sana A.; Goonasekera, Sanjeewa A.; Molkentin, Jeffery D.; Weisleder, Noah; Ma, Jianjie; Pan, Zui

    2015-01-01

    Sarcolipin (SLN) is a regulator of sarcoendoplasmic reticulum calcium ATPase in skeletal muscle. Recent studies using SLN-null mice have identified SLN as a key player in muscle thermogenesis and metabolism. In this study, we exploited a SLN overexpression (SlnOE) mouse model to determine whether increased SLN level affected muscle contractile properties, exercise capacity/fatigue, and metabolic rate in whole animals and isolated muscle. We found that SlnOE mice are more resistant to fatigue and can run significantly longer distances than wild-type (WT). Studies with isolated extensor digitorum longus (EDL) muscles showed that SlnOE EDL produced higher twitch force than WT. The force-frequency curves were not different between WT and SlnOE EDLs, but at lower frequencies the pyruvate-induced potentiation of force was significantly higher in SlnOE EDL. SLN overexpression did not alter the twitch and force-frequency curve in isolated soleus muscle. However, during a 10-min fatigue protocol, both EDL and soleus from SlnOE mice fatigued significantly less than WT muscles. Interestingly, SlnOE muscles showed higher carnitine palmitoyl transferase-1 protein expression, which could enhance fatty acid metabolism. In addition, lactate dehydrogenase expression was higher in SlnOE EDL, suggesting increased glycolytic capacity. We also found an increase in store-operated calcium entry (SOCE) in isolated flexor digitorum brevis fibers of SlnOE compared with WT mice. These data allow us to conclude that increased SLN expression improves skeletal muscle performance during prolonged muscle activity by increasing SOCE and muscle energetics. PMID:25701006

  12. Hibernation energetics of free-ranging little brown bats.

    Science.gov (United States)

    Jonasson, Kristin A; Willis, Craig K R

    2012-06-15

    Hibernation physiology and energy expenditure have been relatively well studied in large captive hibernators, especially rodents, but data from smaller, free-ranging hibernators are sparse. We examined variation in the hibernation patterns of free-ranging little brown bats (Myotis lucifugus) using temperature-sensitive radio-transmitters. First, we aimed to test the hypothesis that age, sex and body condition affect expression of torpor and energy expenditure during hibernation. Second, we examined skin temperature to assess whether qualitative differences in the thermal properties of the hibernacula of bats, compared with the burrows of hibernating rodents, might lead to different patterns of torpor and arousal for bats. We also evaluated the impact of carrying transmitters on body condition to help determine the potential impact of telemetry studies. We observed large variation in the duration of torpor bouts within and between individuals but detected no effect of age, sex or body condition on torpor expression or estimates of energy expenditure. We observed the use of shallow torpor in the midst of periodic arousals, which may represent a unique adaptation of bats for conservation of energy during the most costly phase of hibernation. There was no difference in the body condition of hibernating bats outfitted with transmitters compared with that of control bats captured from the same hibernaculum at the same time. This study provides new information on the energetics of hibernation in an under-represented taxon and baseline data important for understanding how white-nose syndrome, a new disease devastating populations of hibernating bats in North America, may alter the expression of hibernation in affected bats.

  13. Titanium dioxide nanoparticle-induced dysfunction of cardiac hemodynamics is involved in cardiac inflammation in mice.

    Science.gov (United States)

    Hong, Fashui; Wu, Nan; Zhao, Xiangyu; Tian, Yusheng; Zhou, Yingjun; Chen, Ting; Zhai, Yanyu; Ji, Li

    2016-12-01

    In the past two decades, titanium dioxide nanoparticles (TiO 2 NPs) have been extensively used in medicine, food industry and other daily life, while their possible interactions with the their influence and human body on human health remain not well understood. Thus, the study was designed to examine whether long-term exposure to TiO 2 NPs cause myocardial dysfunction which is involved in cardiac lesions and alter expression of genes and proteins involving inflammatory response in the mouse heart. The findings showed that intragastric feeding for nine consecutive months with TiO 2 NPs resulted in titanium accumulation, infiltration of inflammatory cells and apoptosis of heart, reductions in net increases of body weight, cardiac indices of function (LV systolic pressure, maximal rate of pressure increase over time, maximal rate of pressure decrease over time and coronary flow), and increases in heart indices, cardiac indices of function (LV end-diastolic pressure and heart rate) in mice. TiO 2 NPs also decreased ATP production in the hearts. Furthermore, TiO 2 NPs increased expression of nuclear factor-κB, interleukin-lβ and tumour necrosis factor-α, and reduced expression of anti-inflammatory cytokines including suppressor of cytokine signaling (SOCS) 1 and SOCS3 in the cardiac tissue. These results suggest that TiO 2 NPs may modulate the cardiac function and expression of inflammatory cytokines. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2917-2927, 2016. © 2016 Wiley Periodicals, Inc.

  14. Do right-ventricular trabeculae gain energetic advantage from having a greater velocity of shortening?

    Science.gov (United States)

    Pham, Toan; Han, June-Chiew; Taberner, Andrew; Loiselle, Denis

    2017-10-15

    We designed a study to test whether velocity of shortening in right-ventricular tissue preparations is greater than that of the left side under conditions mimicking those encountered by the heart in vivo. Our experiments allowed us to explore whether greater velocity of shortening results in any energetic advantage. We found that velocity of shortening was higher in the rat right-ventricular trabeculae. These results at the tissue level seem paradoxical to the velocity of ventricular ejection at the organ level, and are not always in accord with shortening of unloaded cells. Despite greater velocity of shortening in right-ventricular trabeculae, they neither gained nor lost advantage with respect to both mechanical efficiency and the heat generated during shortening. Our study aimed to ascertain whether the interventricular difference of shortening velocity, reported for isolated cardiac tissues in vitro, affects interventricular mechano-energetic performance when tested under physiological conditions using a shortening protocol designed to mimic those in vivo. We isolated trabeculae from both ventricles of the rat, mounted them in a calorimeter, and performed experiments at 37°C and 5 Hz stimulus frequency to emulate conditions of the rat heart in vivo. Each trabecula was subjected to two experimental protocols: (i) isotonic work-loop contractions at a variety of afterloads, and (ii) isometric contractions at a variety of preloads. Velocity of shortening was calculated from the former protocol during the isotonic shortening phase of the contraction. Simultaneous measurements of force-length work and heat output allowed calculation of mechanical efficiency. The shortening-dependent thermal component was quantified from the difference in heat output between the two protocols. Our results show that both extent of shortening and velocity of shortening were higher in trabeculae from the right ventricle. Despite these differences, trabeculae from both ventricles

  15. Voyager 1: energetic ions and electrons in the jovian magnetosphere.

    Science.gov (United States)

    Vogt, R E; Cook, W R; Cummings, A C; Garrard, T L; Gehrels, N; Stone, E C; Trainor, J H; Schardt, A W; Conlon, T; Lal, N; McDonald, F B

    1979-06-01

    The observations of the cosmic-ray subsystem have added significantly to our knowledge of Jupiter's magnetosphere. The most surprising result is the existence of energetic sulfur, sodium, and oxygen nuclei with energies above 7 megaelectron volts per nucleon which were found inside of Io's orbit. Also, significant fluxes of similarly energetic ions reflecting solar cosmic-ray composition were observed throughout the magnetosphere beyond 11 times the radius of Jupiter. It was also found that energetic protons are enhanced by 30 to 70 percent in the active hemisphere. Finally, the first observations were made of the magnetospheric tail in the dawn direction out to 160 Jupiter radii.

  16. Galactic substructure and energetic neutrinos from the sun and earth.

    Science.gov (United States)

    Koushiappas, Savvas M; Kamionkowski, Marc

    2009-09-18

    We consider the effects of Galactic substructure on energetic neutrinos from annihilation of weakly interacting massive particles that have been captured by the Sun and Earth. Substructure gives rise to a time-varying capture rate and thus to time variation in the annihilation rate and resulting energetic-neutrino flux. However, there may be a time lag between the capture and annihilation rates. The energetic-neutrino flux may then be determined by the density of dark matter in the Solar System's past trajectory, rather than the local density. The signature of such an effect may be sought in the ratio of the direct- to indirect-detection rates.

  17. The viability and performance characterization of nano scale energetic materials on a semiconductor bridge (SCB)

    Science.gov (United States)

    Strohm, Gianna Sophia

    The move from conventional energetic composites to nano scale energetic mixtures (nano energetics) has shown dramatic improvement in energy release rate and sensitivity to ignition. A possible application of nano energetics is on a semiconductor bridge (SCB). An SCB typically requires a tenth of the energy input as compared to a bridge wire design with the same no-fire and is capable of igniting in tens of microseconds. For very low energy applications, SCBs can be manufactured to extremely small sizes and it is necessary to find materials with particle sizes that are even smaller to function. Reactive particles of comparable size to the bridge can lead to problems with ignition reliability for small bridges. Nano-energetic composites and the use of SCBs have been significantly studied individually, however, the process of combining nano energetics with an SCB has not been investigated extensively and is the focus of this work. Goals of this study are to determine if nano energetics can be used with SCBs to further reduce the minimum energy required and improve reliability. The performance of nano-scale aluminum (nAl) and bismuth oxide (Bi2O3) with nitrocellulose (NC), Fluorel(TM) FC 2175 (chemically equivalent to VitonRTM) and Glycidyl Azide Polymer (GAP) as binders where quantified initially using the SenTest(TM) algorithm at three weight fractions (5, 7, and 9%) of binder. The threshold energy was calculated and compared to previous data using conventional materials such as zirconium potassium chlorate (ZPC), mercuric 5-Nitrotetrazol (DXN-1) and titanium sub-hydride potassium per-chlorate (TSPP). It was found that even though there where only slight differences in performance between the binders with nAl/Bi2O 3 at any of the three binder weight fractions, the results show that these nano energetic materials require about half of the threshold energy compared to conventional materials using an SCB with an 84x42 mum bridge. Binder limit testing was conducted to

  18. PoET: Polarimeters for Energetic Transients

    Science.gov (United States)

    McConnell, Mark; Barthelmy, Scott; Hill, Joanne

    2008-01-01

    This presentation focuses on PoET (Polarimeters for Energetic Transients): a Small Explorer mission concept proposed to NASA in January 2008. The principal scientific goal of POET is to measure GRB polarization between 2 and 500 keV. The payload consists of two wide FoV instruments: a Low Energy Polarimeter (LEP) capable of polarization measurements in the energy range from 2-15 keV and a high energy polarimeter (Gamma-Ray Polarimeter Experiment - GRAPE) that will measure polarization in the 60-500 keV energy range. Spectra will be measured from 2 keV up to 1 MeV. The PoET spacecraft provides a zenith-pointed platform for maximizing the exposure to deep space. Spacecraft rotation will provide a means of effectively dealing with systematics in the polarization response. PoET will provide sufficient sensitivity and sky coverage to measure statistically significant polarization for up to 100 GRBs in a two-year mission. Polarization data will also be obtained for solar flares, pulsars and other sources of astronomical interest.

  19. Energetics of Boron Doping of Carbon Pores

    Science.gov (United States)

    Wexler, Carlos; St. John, Alexander; Connolly, Matthew

    2014-03-01

    Carbon-based materials show promise, given their light weight, large surface areas and low cost for storage of hydrogen and other gases, e.g., for energy applications. Alas, the interaction of H2 and carbon, 4-5kJ/mol, is insufficient for room-temperature operation. Boron doping of carbon materials could raise the binding energy of H2 to 12-15kJ/mol. The nature of the incorporation of boron into a carbon structure has not been studied so far. In this talk we will address the energetics of boron incorporation into a carbon matrix via adsorption and decomposition of decaborane by first principles calculations. These demonstrate: (a) A strong adsorption of decaborane to carbon (70-80kJ/mol) resulting in easy incorporation of decaborane, sufficient for up to 10-20% B:C at low decaborane vapour pressures. (b) Identification that boron acts as an electron acceptor when incorporated substitutionally into a graphene-like material, as expected due to its valence. (c) The electrostatic field near the molecule is responsible for ca. 2/3 of the enhancement of the H2-adsorbent interaction in aromatic compounds such as pyrene, coronene and ovalene. Supported by DOE DE-FG36-08GO18142, ACS-PRF 52696-ND5, and NSF 1069091.

  20. Energetic and economical comparison for biomass fuel

    International Nuclear Information System (INIS)

    Galins, A.; Grundulis, A.; Zihmane, K.

    2003-01-01

    The common agricultural biomass, such as wheat straw, rape straw, wheat small corn, wheat forage, rape oil cakes and other, we can use as fuel for heat production. The biomass application for burning depends on economical situation on agriculture and fuel market. Energetic and economical parameters of agricultural biomass are estimated and compared to wooden grain. As parameters for comparison used the biomass heat value Q (MJ/kg), specific cost per 1 kWh heat production C 0 (Ls/kWh) and the fuel consumption per 1 kWh heat production M 0 (kg/kWh). The rape oil cakes have best heat value (20.82 MJ/kg), but cheapest heat energy we can get from rape straw (0.0046 Ls/kWh). Expenses of heat production for forge wheat corn (0.011 Ls/kWh) are alike to wooden chip (0.0103 Ls/kWh) and wooden grain (0.0122 Ls/kWh) (authors)

  1. SURFACE ENERGETIC CHARACTERISTICS OF ACRYLIC BIOMATERIALS

    Directory of Open Access Journals (Sweden)

    Mihaela-Papusa Vasiliu (Diaconu

    2011-09-01

    Full Text Available Introduction: Surface energetic characteristics of biomaterials influence their adherence to cells and bacteria, surface adsobtion of plasmatic proteins, as well as the capacity of such surfaces of immobilizing some biological species extremely important in medicine. Materials and method: Acrylic surfaces with an area of approximately 2 cm² were employed for the experiments: Duracryl® Plus (Spofa/Dental Product, Czechia, Duracryl® Plus covered with Palaseal (Heraeus Kulzer GmbH, Wehrheim, Germany; artificial saliva AFNOR S90-701 (pH 8.01 was used as a working solution. Results and discussion: Drops of distilled water and artificial saliva, deposited on the working materials: Duracryl and Duracryl covered with Palaseal, were photographed with an optical device, after which each drop was computer-processed, and the contact angle for each liquid surface on the surfaces of the biomaterials here under investigation was determined. On the basis of the determinations made for each material in part, the arihtmetic mean was established. Conclusions: The wettability of dental materials is wholly characterized by the values of the contact angle between the drop of biological liquid and the surface. Low values of the contact angles indicate a good wettability. The results obtained support the conclusion that the surface energy of the solid and rugosity are essential for controlling the adhesive properties of saliva unto dental materials.

  2. Detonation Performance Analyses for Recent Energetic Molecules

    Science.gov (United States)

    Stiel, Leonard; Samuels, Philip; Spangler, Kimberly; Iwaniuk, Daniel; Cornell, Rodger; Baker, Ernest

    2017-06-01

    Detonation performance analyses were conducted for a number of evolving and potential high explosive materials. The calculations were completed for theoretical maximum densities of the explosives using the Jaguar thermo-chemical equation of state computer programs for performance evaluations and JWL/JWLB equations of state parameterizations. A number of recently synthesized materials were investigated for performance characterizations and comparisons to existing explosives, including TNT, RDX, HMX, and Cl-20. The analytic cylinder model was utilized to establish cylinder and Gurney velocities as functions of the radial expansions of the cylinder for each explosive. The densities and heats of formulation utilized in the calculations are primarily experimental values from Picatinny Arsenal and other sources. Several of the new materials considered were predicted to have enhanced detonation characteristics compared to conventional explosives. In order to confirm the accuracy of the Jaguar and analytic cylinder model results, available experimental detonation and Gurney velocities for representative energetic molecules and their formulations were compared with the corresponding calculated values. Close agreement was obtained with most of the data. Presently at NATO.

  3. Nerolidol effects on mitochondrial and cellular energetics.

    Science.gov (United States)

    Ferreira, Fernanda M; Palmeira, Carlos M; Oliveira, Maria M; Santos, Dario; Simões, Anabela M; Rocha, Sílvia M; Coimbra, Manuel A; Peixoto, Francisco

    2012-03-01

    In the present work, we evaluated the potential toxic effects of nerolidol, a sesquiterpenoid common in plants essential oils, both on mitochondrial and cellular energetics. Samples of enriched natural extracts of nerolidol (a racemic mixture of cis and trans isomers) were tested on rat liver mitochondria and a decrease in phosphorylative system was observed but not in the mitochondrial respiratory chain activity, which reflects a direct effect on F1-ATPase. Hence, respiratory control ratio was also decreased. Cellular ATP/ADP levels were significantly decreased in a concentration-dependent manner, possibly due to the direct effect of nerolidol on F(0)F(1)-ATPsynthase. Nerolidol stimulates respiratory activity probably due to an unspecific effect, since it does not show any protonophoric effect. Furthermore, we observed that mitochondrial permeability transition was delayed in the presence of nerolidol, possibly due to its antioxidant activity and because this compound decreases mitochondrial transmembrane electric potential. Our results also show that, in human hepatocellular liver carcinoma cell line (HepG2), nerolidol both induces cell death and arrests cell growth, probably related with the observed lower bioenergetic efficiency. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. The energetic characterization of pineapple crown leaves.

    Science.gov (United States)

    Braga, R M; Queiroga, T S; Calixto, G Q; Almeida, H N; Melo, D M A; Melo, M A F; Freitas, J C O; Curbelo, F D S

    2015-12-01

    Energetic characterization of biomass allows for assessing its energy potential for application in different conversion processes into energy. The objective of this study is to physicochemically characterize pineapple crown leaves (PC) for their application in energy conversion processes. PC was characterized according to ASTM E871-82, E1755-01, and E873-82 for determination of moisture, ash, and volatile matter, respectively; the fixed carbon was calculated by difference. Higher heating value was determined by ASTM E711-87 and ash chemical composition was determined by XRF. The thermogravimetric and FTIR analyses were performed to evaluate the thermal decomposition and identify the main functional groups of biomass. PC has potential for application in thermochemical processes, showing high volatile matter (89.5%), bulk density (420.8 kg/m(3)), and higher heating value (18.9 MJ/kg). The results show its energy potential justifying application of this agricultural waste into energy conversion processes, implementing sustainability in the production, and reducing the environmental liabilities caused by its disposal.

  5. The energetic ion substorm injection boundary

    International Nuclear Information System (INIS)

    Lopez, R.E.; Sibeck, D.G.; McEntire, R.W.; Krimigis, S.M.

    1990-01-01

    The substorm injection boundary model has enjoyed considerable success in explaining plasma signatures in the near-geosynchronous region. However, the injection boundary has remained primarily a phenomenological model. In this paper the authors examine 167 dispersionless energetic ion injections which were observed by AMPTE CCE. The radial and local time distribution of the events as a function of Kp is qualitatively similar to that envisioned in the injection boundary model of Mauk and McIlwain (1974). They argue that particles observed during dispersionless injections are locally energized during the disruption of the cross-tail current sheet. Therefore they identify the injection boundary, as derived from the spatial distribution of dispersionless injections, with the earthward edge of the region of the magnetotail which undergoes current sheet disruption during the substorm expansion phase. The authors show that this qualitative model for the generation of the injection boundary can provide an explanation for the dispersionless nature, the double spiral shape, and the Kp dependence of the boundary

  6. ARCTIC VECTOR OF BRITISH ENERGETIC STRATEGY

    Directory of Open Access Journals (Sweden)

    Natalia Valerievna Eremina

    2017-03-01

    Full Text Available The aim of the article is to reveal the forms, methods, content of British strategy in Arctic. Arctic is becoming the area of international cooperation among, first of all, Arctic states. Britain has ambitions to get the status of so-called “subarctic state” to prove its international leadership and acquire guarantees of energetic security. Now Britain has been elaborating the two strategies: military and scientific ones. The main instrument to solve the tasks for Britain is to participate in international structures, connected with Arctic. The article pays attention to the aspects that were not previously analyzed, such as: reasons of British interests in Arctic, bilateral and multilateral relationships between Britain and its partners, first of all, cooperation between Russia and Britain; British institutions; positive and negative aspects of British Arctic strategy; factors that have impact on its evolution, mainly EU and Scottish factors. The research allowed to make the conclusion that Britain does not have enough instruments to have a strong disposition in Arctic, though it plans to accelerate its participation in Arctic organizations. The article is based upon system and structural analysis.

  7. Solar energetic particles: Acceleration and transport

    Science.gov (United States)

    Cliver, Edward W.

    2000-06-01

    This paper reviews highlights of the 26th ICRC in the area of acceleration and propagation of solar energetic particles (SEPs). New results on SEP charge state and composition, a lively topic during the Conference, are covered in an accompanying paper by Klecker. I begin with a brief historical review of the field to provide context for the key advances/developments on SEP acceleration/propagation presented in Salt Lake City. These include: (1) the use of gamma-ray emissions as diagnostics of the acceleration process(es) and probes of the interaction region; (2) the observation of ~10 GeV (or higher) protons for the 6 November 1997 ground level event by the Milagrito experiment; (3) observations of coronal Moreton waves as ``smoking pistols'' of shock acceleration/injection of SEPs; (4) an investigation of the role of proton event spectra in the current ``two-class'' picture of SEP events; (5) an analysis of the Gnevyshev Gap in SEP activity; (6) a Ulysses-based determination of the dependence of SEP mean free path on radial distance from the Sun and on heliographic latitude, and (7) an examination of the dissipation range in the power spectrum of interplanetary magnetic field fluctuations. I conclude with a discussion of new instrumentation (e.g., Milagro, HESSI) and a look to the expected level of SEP activity for the approaching maximum of solar cycle 23. .

  8. Large gradual solar energetic particle events

    Directory of Open Access Journals (Sweden)

    Mihir Desai

    2016-09-01

    Full Text Available Abstract Solar energetic particles, or SEPs, from suprathermal (few keV up to relativistic ( $$\\sim $$ ∼ few GeV energies are accelerated near the Sun in at least two ways: (1 by magnetic reconnection-driven processes during solar flares resulting in impulsive SEPs, and (2 at fast coronal-mass-ejection-driven shock waves that produce large gradual SEP events. Large gradual SEP events are of particular interest because the accompanying high-energy ( $${>}10$$ > 10 s MeV protons pose serious radiation threats to human explorers living and working beyond low-Earth orbit and to technological assets such as communications and scientific satellites in space. However, a complete understanding of these large SEP events has eluded us primarily because their properties, as observed in Earth orbit, are smeared due to mixing and contributions from many important physical effects. This paper provides a comprehensive review of the current state of knowledge of these important phenomena, and summarizes some of the key questions that will be addressed by two upcoming missions—NASA’s Solar Probe Plus and ESA’s Solar Orbiter. Both of these missions are designed to directly and repeatedly sample the near-Sun environments where interplanetary scattering and transport effects are significantly reduced, allowing us to discriminate between different acceleration sites and mechanisms and to isolate the contributions of numerous physical processes occurring during large SEP events.

  9. Solar Energetic Particle Events: Phenomenology and Prediction

    Science.gov (United States)

    Gabriel, S. B.; Patrick, G. J.

    2003-04-01

    Solar energetic particle events can cause major disruptions to the operation of spacecraft in earth orbit and outside the earth's magnetosphere and have to be considered for EVA and other manned activities. They may also have an effect on radiation doses received by the crew flying in high altitude aircraft over the polar regions. The occurrence of these events has been assumed to be random, but there would appear to be some solar cycle dependency with a higher annual fluence occuring during a 7 year period, 2 years before and 4 years after the year of solar maximum. Little has been done to try to predict these events in real-time with nearly all of the work concentrating on statistical modelling. Currently our understanding of the causes of these events is not good. But what are the prospects for prediction? Can artificial intelligence techniques be used to predict them in the absence of a more complete understanding of the physics involved? The paper examines the phenomenology of the events, briefly reviews the results of neural network prediction techniques and discusses the conjecture that the underlying physical processes might be related to self-organised criticality and turblent MHD flows.

  10. Atypical energetic particle events observed prior energetic particle enhancements associated with corotating interaction regions

    Science.gov (United States)

    Khabarova, Olga; Malandraki, Olga; Zank, Gary; Jackson, Bernard; Bisi, Mario; Desai, Mihir; Li, Gang; le Roux, Jakobus; Yu, Hsiu-Shan

    2017-04-01

    Recent studies of mechanisms of particle acceleration in the heliosphere have revealed the importance of the comprehensive analysis of stream-stream interactions as well as the heliospheric current sheet (HCS) - stream interactions that often occur in the solar wind, producing huge magnetic cavities bounded by strong current sheets. Such cavities are usually filled with small-scale magnetic islands that trap and re-accelerate energetic particles (Zank et al. ApJ, 2014, 2015; le Roux et al. ApJ, 2015, 2016; Khabarova et al. ApJ, 2015, 2016). Crossings of these regions are associated with unusual variations in the energetic particle flux up to several MeV/nuc near the Earth's orbit. These energetic particle flux enhancements called "atypical energetic particle events" (AEPEs) are not associated with standard mechanisms of particle acceleration. The analysis of multi-spacecraft measurements of energetic particle flux, plasma and the interplanetary magnetic field shows that AEPEs have a local origin as they are observed by different spacecraft with a time delay corresponding to the solar wind propagation from one spacecraft to another, which is a signature of local particle acceleration in the region embedded in expanding and rotating background solar wind. AEPEs are often observed before the arrival of corotating interaction regions (CIRs) or stream interaction regions (SIRs) to the Earth's orbit. When fast solar wind streams catch up with slow solar wind, SIRs of compressed heated plasma or more regular CIRs are created at the leading edge of the high-speed stream. Since coronal holes are often long-lived structures, the same CIR re-appears often for several consecutive solar rotations. At low heliographic latitudes, such CIRs are typically bounded by forward and reverse waves on their leading and trailing edges, respectively, that steepen into shocks at heliocentric distances beyond 1 AU. Energetic ion increases have been frequently observed in association with CIR

  11. Blunt and Penetrating Cardiac Trauma.

    Science.gov (United States)

    Bellister, Seth A; Dennis, Bradley M; Guillamondegui, Oscar D

    2017-10-01

    Patients with traumatic cardiac injuries can present with wide variability in their severity of illness. The most severe will present in cardiac arrest, whereas the most benign may be altogether asymptomatic; most will fall somewhere in between. Management of cardiac injuries largely depends on mechanism of injury and patient physiology. Understanding the spectrum of injuries and their associated manifestations can help providers react more quickly and initiate potentially life-saving therapies more efficiently when time is critical. This article discusses the workup and management of both blunt and penetrating cardiac injuries. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Potassium supplementation reduces cardiac and renal hypertrophy independent of blood pressure in DOCA/salt mice.

    Science.gov (United States)

    Wang, Qing; Domenighetti, Andrea A; Pedrazzini, Thierry; Burnier, Michel

    2005-09-01

    We have demonstrated previously that deoxycorticosterone acetate (DOCA)/salt induces cardiac hypertrophy and left ventricular dysfunction independent of blood pressure (BP) in 1-renin gene mice. Because these mice also develop hypokalemia and metabolic alkalosis caused by mineralocorticoid excess, we investigated whether correcting hypokalemia by dietary potassium supplementation would prevent the DOCA/salt-induced cardiac hypertrophy, cardiac dysfunction, and electrocardiographic changes in normotensive, 1-renin gene and hypertensive, 2-renin gene mice. All mice were studied after 5 weeks of DOCA and salt administration. Potassium was given by adding 0.4 or 0.6% KCl to the drinking water. Our results show that correction of hypokalemia and metabolic alkalosis prevents cardiac hypertrophy and normalizes cardiac function without affecting BP in normotensive, 1-renin gene mice. In hypertensive, 2-renin gene mice, potassium supplementation induces a significant decrease in BP. The decrease in BP and correction of kalemia are associated with a significant but partial correction of cardiac hypertrophy. In both group of mice, electrocardiographic alterations were measured after administration of DOCA/salt, which could be corrected by potassium supplementation. Thus, these results show that correction of hypokalemia and metabolic alkalosis does prevent the development of cardiac hypertrophy and normalizes cardiac function independent of BP in normotensive, 1-renin gene mice that receive excess mineralocorticoid and salt. In 2-renin gene, hypertensive mice, potassium supplementation also prevents the development of cardiac hypertrophy, but the effect cannot be separated from the decrease in BP.

  13. Antifibrinolytics in cardiac surgery

    Directory of Open Access Journals (Sweden)

    Achal Dhir

    2013-01-01

    Full Text Available Cardiac surgery exerts a significant strain on the blood bank services and is a model example in which a multi-modal blood-conservation strategy is recommended. Significant bleeding during cardiac surgery, enough to cause re-exploration and/or blood transfusion, increases morbidity and mortality. Hyper-fibrinolysis is one of the important contributors to increased bleeding. This knowledge has led to the use of anti-fibrinolytic agents especially in procedures performed under cardiopulmonary bypass. Nothing has been more controversial in recent times than the aprotinin controversy. Since the withdrawal of aprotinin from the world market, the choice of antifibrinolytic agents has been limited to lysine analogues either tranexamic acid (TA or epsilon amino caproic acid (EACA. While proponents of aprotinin still argue against its non-availability. Health Canada has approved its use, albeit under very strict regulations. Antifibrinolytic agents are not without side effects and act like double-edged swords, the stronger the anti-fibrinolytic activity, the more serious the side effects. Aprotinin is the strongest in reducing blood loss, blood transfusion, and possibly, return to the operating room after cardiac surgery. EACA is the least effective, while TA is somewhere in between. Additionally, aprotinin has been implicated in increased mortality and maximum side effects. TA has been shown to increase seizure activity, whereas, EACA seems to have the least side effects. Apparently, these agents do not differentiate between pathological and physiological fibrinolysis and prevent all forms of fibrinolysis leading to possible thrombotic side effects. It would seem prudent to select the right agent knowing its risk-benefit profile for a given patient, under the given circumstances.

  14. A further study of spectral energetics in the winter atmosphere

    Science.gov (United States)

    Chen, T.-C.

    1982-01-01

    The contributions of standing (time-mean) and transient (time-departure) waves to the atmospheric spectral energetics are analyzed using the NMC (National Meteorological Center) data of winter 1976-1977. It is found that the standing long waves are responsible for the major horizontal sensible heat transport and also for the significant horizontal momentum transport. Furthermore, the major contents of eddy available energy and eddy kinetic energy of standing waves are in the long-wave regime. However, the spectral energetics analysis indicates that the standing long waves are energetically less efficient than the transient long and short waves. It is suggested that the lower efficiency of the standing long waves in the atmospheric energetics may be one of the physical factors causing the underforecast of the standing long waves in the numerical weather prediction models.

  15. Are we need this? Nuclear energetics not only in superlatives

    International Nuclear Information System (INIS)

    Dakowski, M.

    1999-01-01

    It is a polemic article being in opposition for the 'nuclear lobby' presenting only the advantages of nuclear energy. Some arguments against the development of nuclear option in energetics are presented here. Especially economical and safety aspects are discussed

  16. Progress Towards a Benchtop Energetics Capability (BRIEFING CHARTS)

    National Research Council Canada - National Science Library

    Fajardo, Mario E; Lewis, William K

    2006-01-01

    The incorporation of nanometric (sub-micron size) metal fuel and oxidizer particles into energetic materials is a promising approach to increasing significantly the systems-level performance of munitions...

  17. Use of energetic ion beams in materials synthesis and processing

    International Nuclear Information System (INIS)

    Appleton, B.R.

    1992-01-01

    A brief review of the use energetic ion beams and related techniques for the synthesis, processing, and characterization of materials is presented. Selected opportunity areas are emphasized with examples, and references are provided for more extensive coverage. (author)

  18. An Interdisciplinary Approach to Dinosaur Fossils, Morphology, Ethology, and Energetics.

    Science.gov (United States)

    Zipko, Stephen J.

    1981-01-01

    Describes an interdisciplinary minicourse on dinosaur fossils, morphology, ethology, and energetics. Suggests and provides examples of hands-on activities for junior high school- through college-level students. (DS)

  19. A Microforce-Based Theory for Energetic Materials

    National Research Council Canada - National Science Library

    Ruderman, Gregory

    1999-01-01

    Employing advanced tools of continuum thermomechanics, we have developed a fully three-dimensional framework, which in its most general form is able to model all the mentioned behaviors of energetic materials...

  20. Jupiter energetic particle experiment ESAD proton sensor design

    International Nuclear Information System (INIS)

    Gruhn, C.R.; Higbie, P.R.

    1977-12-01

    A proton sensor design for the Jupiter Energetic Particle Experiment is described. The sensor design uses avalanche multiplication in order to lower the effective energy threshold. A complete signal-to-noise analysis is given for this design

  1. Aerial energetic residue data from JBER C4 testing

    Data.gov (United States)

    U.S. Environmental Protection Agency — Aerially-collected energetic residues from surface detonation of C4. This dataset is associated with the following publication: Walsh, M., B. Gullett, M. Walsh, M....

  2. Exercise-related cardiac arrest in cardiac rehabilitation - The ...

    African Journals Online (AJOL)

    Prescribed physical activity plays a major role in the rehabilitation of patients with coronary artery disease, and as with any other form of treatment its benefits must be weighed against its possible risks. This study attempted to establish the safety of cardiac rehabilitation as a medical intervention at the Johannesburg Cardiac ...

  3. Hypertension and cardiac arrhythmias

    DEFF Research Database (Denmark)

    Lip, Gregory Y H; Coca, Antonio; Kahan, Thomas

    2017-01-01

    Hypertension (HTN) is a common cardiovascular risk factor leading to heart failure (HF), coronary artery disease (CAD), stroke, peripheral artery disease and chronic renal failure. Hypertensive heart disease can manifest as many types of cardiac arrhythmias, most commonly being atrial fibrillation......) Council on Hypertension convened a Task Force, with representation from the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE), with the remit of comprehensively reviewing the available evidence...

  4. CSI cardiac prevent 2015

    Directory of Open Access Journals (Sweden)

    S Ramakrishnan

    2015-01-01

    Full Text Available The CSI Cardiac Prevent 2015 was held at Hotel Taj Palace, New Delhi, on September 25-27, 2015. The major challenge was to create interest among cardiologists and physicians on preventive cardiology, a neglected area. The theme of the conference was "Innovations in Heart Disease Prevention.′′ This conference included "CSI at WHF Roadmap Workshop, Inauguration Ceremony, scientific program, plenary sessions, Nursing/Dietician track, Industry Exhibition, Social Events," Great India blood pressure Survey, and CSI Smart Heart App. A total of 848 delegates/faculties attended this conference against a total of 1140 people registered for the meeting.

  5. Single ventricle cardiac defect

    International Nuclear Information System (INIS)

    Eren, B.; Turkmen, N.; Fedakar, R.; Cetin, V.

    2010-01-01

    Single ventricle heart is defined as a rare cardiac abnormality with a single ventricle chamber involving diverse functional and physiological defects. Our case is of a ten month-old baby boy who died shortly after admission to the hospital due to vomiting and diarrhoea. Autopsy findings revealed cyanosis of finger nails and ears. Internal examination revealed; large heart, weighing 60 grams, single ventricle, without a septum and upper membranous part. Single ventricle is a rare pathology, hence, this paper aims to discuss this case from a medico-legal point of view. (author)

  6. Cascaded Soliton Compression of Energetic Femtosecond Pulses at 1030 nm

    DEFF Research Database (Denmark)

    Bache, Morten; Zhou, Binbin

    2012-01-01

    We discuss soliton compression with cascaded second-harmonic generation of energetic femtosecond pulses at 1030 nm. We discuss problems encountered with soliton compression of long pulses and show that sub-10 fs compressed pulses can be achieved.......We discuss soliton compression with cascaded second-harmonic generation of energetic femtosecond pulses at 1030 nm. We discuss problems encountered with soliton compression of long pulses and show that sub-10 fs compressed pulses can be achieved....

  7. Radiational and energetic characteristics of diatomic molecules (data base)

    International Nuclear Information System (INIS)

    Kuznetsova, L.A.; Pazyuk, E.A.; Stolyarov, A.V.

    1993-01-01

    Data base on radiational and energetic characteristics of diatomic molecules was created. The base consists of two parts: reference system and recommended data system. The reference system contains the information about studies of radiational and energetic parameters of more than 1500 electronic states and 1700 electron transfers for ∼ 350 diatomic molecules and their ions. The base bibliography includes ∼ 3000 publications. 11 refs., 1 figs

  8. Dynamic disorder and the energetic costs of information transduction

    International Nuclear Information System (INIS)

    Thill, Peter

    2014-01-01

    We study a model of dynamic disorder relevant for signal transduction pathways in which enzymatic reaction rates fluctuate over several orders of magnitude. For the simple networks we consider, dynamic disorder drives the system far from equilibrium and imposes an energetic burden for high fidelity signaling capability. We study how the dynamics of the underlying stochastic behavior in the reaction rate process is related to the energetic cost of transmitting information through the network

  9. Carbon nanostructure formation driven by energetic particles

    International Nuclear Information System (INIS)

    Zhu Zhiyuan; Gong Jinlong; Zhu Dezhang

    2006-01-01

    Carbon nanostructures, especially carbon nanotubes (CNTs), have been envisaged to be the building blocks of a variety of nanoscale devices and materials. The inherent nanometer-size and ability of being either metallic or semiconductive of CNTs lead to their application in nanoelectronics. Excellent mechanical characteristics of CNTs suggest their use as structural reinforcements. However, to fully exploit the potential applications, effective means of tailoring CNT properties must be developed. Irradiation of materials with energetic particles beams (ions and electrons) is a standard and important tool for modifying material properties. Irradiation makes it possible to dope the samples, to create local amorphous region or vice versa, recrystallize the lattice and even drive a phase transition. In this paper, we report our results of (1) phase transfromation from carbon nanotubes to nanocrystalline diamond driven by hydrogen plasma, (2) onion-like nanostructure from carbon nanotubes driven by ion beams of several tens keV, and (3) amorphous carbon nanowire network formation by ion beam irradiation. Structural phase transformation from multiwalled carbon nanotubes to nanocrystalline diamond by hydrogen plasma post-treatment was carried out. Ultrahigh equivalent diamond nucleation density of more than 1011 nuclei/cm 2 was obtained. The diamond formation and growth mechanisms were proposed to be the consequence of the formation of sp3 bonded amorphous carbon clusters. The hydrogen chemisorption on curved graphite network and the energy deposited on CNTs by continuous impingement of activated molecular or atomic hydrogen are responsible for the formation of amorphous carbon matrix. Diamond nucleates and grows in the way similar to that of diamond chemical vapor deposition processes on amorphous carbon films. Furthermore, single crystalline diamond nanorods of 4-8 nm in diameter and up to 200 nm in length have been successfully synthesized by hydrogen plasma post

  10. African easterly wave energetics on intraseasonal timescales

    Science.gov (United States)

    Alaka, Ghassan J., Jr.

    African easterly waves (AEWs) are synoptic-scale eddies that dominate North African weather in boreal summer. AEWs propagate westward with a maximum amplitude near 700 hPa and a period of 2.5-6-days. AEWs and associated perturbation kinetic energy (PKE) exhibit significant intraseasonal variability in tropical North Africa during boreal summer, which directly impacts local agriculture and tropical cyclogenesis. This study performs a comprehensive analysis of the 30-90-day variability of AEWs and associated energetics using both reanalysis data and model output. Specifically, the PKE and perturbation available potential energy (PAPE) budgets are used to understand the factors that contribute to PKE maxima in West Africa and the extent to which these surges of AEW activity are modulated by the Madden-Julian oscillation (MJO). The role of the MJO in the intraseasonal variability of AEWs is assessed by comparing PKE sources as a function of an MJO index and a local 30-90-day West African PKE index. Since East Africa is an initiation zone for AEW activity and is modulated by the MJO, the relationship between this region and West Africa is a primary focus in this study. The intraseasonal variability of AEW energetics is first investigated in reanalysis products. While reanalysis data depicts a similar evolution of 30-90-day PKE anomalies in both the MJO and a local PKE index, the MJO index describes only a small (yet still significant) fraction of the local 30-90-day variance. In boreal summers with more significant MJO days, the correlation between the two indices is higher. Baroclinic energy conversions are important for the initiation of 30-90-day West African PKE events east of Lake Chad. In West Africa, both barotropic and baroclinic energy conversions maintain positive PKE anomalies before they propagate into the Atlantic. The primary role of diabatic heating is to destroy PAPE in a negative feedback to baroclinic energy conversions in West Africa. More frequent

  11. Cardiac Nonmyocyte Cell Functions and Crosstalks in Response to Cardiotoxic Drugs

    Directory of Open Access Journals (Sweden)

    Jessica Gambardella

    2017-01-01

    Full Text Available The discovery of the molecular mechanisms involved in the cardiac responses to anticancer drugs represents the current goal of cardio-oncology research. The oxidative stress has a pivotal role in cardiotoxic responses, affecting the function of all types of cardiac cells, and their functional crosstalks. Generally, cardiomyocytes are the main target of research studies on cardiotoxicity, but recently the contribution of the other nonmyocyte cardiac cells is becoming of growing interest. This review deals with the role of oxidative stress, induced by anticancer drugs, in cardiac nonmyocyte cells (fibroblasts, vascular cells, and immune cells. The alterations of functional interplays among these cardiac cells are discussed, as well. These interesting recent findings increase the knowledge about cardiotoxicity and suggest new molecular targets for both diagnosis and therapy.

  12. Inferring crossbridge properties from skeletal muscle energetics.

    Science.gov (United States)

    Barclay, C J; Woledge, R C; Curtin, N A

    2010-01-01

    Work is generated in muscle by myosin crossbridges during their interaction with the actin filament. The energy from which the work is produced is the free energy change of ATP hydrolysis and efficiency quantifies the fraction of the energy supplied that is converted into work. The purpose of this review is to compare the efficiency of frog skeletal muscle determined from measurements of work output and either heat production or chemical breakdown with the work produced per crossbridge cycle predicted on the basis of the mechanical responses of contracting muscle to rapid length perturbations. We review the literature to establish the likely maximum crossbridge efficiency for frog skeletal muscle (0.4) and, using this value, calculate the maximum work a crossbridge can perform in a single attachment to actin (33 x 10(-21) J). To see whether this amount of work is consistent with our understanding of crossbridge mechanics, we examine measurements of the force responses of frog muscle to fast length perturbations and, taking account of filament compliance, determine the crossbridge force-extension relationship and the velocity dependences of the fraction of crossbridges attached and average crossbridge strain. These data are used in combination with a Huxley-Simmons-type model of the thermodynamics of the attached crossbridge to determine whether this type of model can adequately account for the observed muscle efficiency. Although it is apparent that there are still deficiencies in our understanding of how to accurately model some aspects of ensemble crossbridge behaviour, this comparison shows that crossbridge energetics are consistent with known crossbridge properties.

  13. Detonation Shock Dynamics of Composite Energetic Materials.

    Science.gov (United States)

    Lee, Jaimin

    1990-01-01

    A reaction-rate equation for a composite energetic material was calibrated from two-dimensional steady-state experiment data by using the detonation shock dynamics theory. From experimental detonation velocities and shock -front shapes at different diameters for an ammonium nitrate -based emulsion explosive at 1.248 g/cm^3, the relationship between the detonation velocity normal to the shock-front and the shock-front curvature was obtained. By using this relationship and solving the quasi one-dimensional Euler equations of motion in a problem -conforming intrinsic-coordinate frame obtained from the detonation shock dynamics theory, the reaction rate was determined as a function of pressure and density: {dlambdaover dt} = 20.0 times 10^6 {rm exp}({-}14390/ sqrt{P/rho^{0.8418}})(1 - lambda)^{1.889}where lambda is the reaction extent, t is the time in s, P is the pressure in Pa, and rho is the density in kg/m^3 . The reaction-rate equation obtained for this emulsion explosive shows that the rate is very slow and weakly state dependent. These characteristics of the rate indicated that the nonideal behavior of most industrial-type explosives can be attributed to their slow and state-insensitive rates. By using the above rate equation, one-dimensional initiation experiments (wedge tests) were numerically modeled with a one-dimensional Lagrangian hydrodynamic code. The calculated shock trajectories agreed very well with experimental wedge test data. This agreement also suggested that the small shock-curvature asymptotics may be valid even for a relatively large value of the curvature. The calibration method developed in this study is independent of the form of the rate. Realistic rate equations for explosives can be obtained in a very systematic way from two-dimensional steady-state experiments.

  14. Energetic dialog EU and Russia slows

    International Nuclear Information System (INIS)

    Hirman, K.

    2004-01-01

    European Union maintains an individual dialog with Russia about cooperation in energy sphere since joint summit in Paris in October 2000. Both sides agreed there to create four export groups: for energy strategy, investments, infrastructure and technologies, efficiency and ecology. European Union expects that Russia will unequivocally take over the obligations by creation of suitable climate for investors. European Union considers as key preconditions the restructuring of the largest national monopoles. These conditions are also the important component of asking strategy of EU by the discussions about integration of Russia to WTO. One of the most important requests of Brussels is the restructuring of Gazprom concern, what means its division to mining and transport part. Russian part refuses all steps in this sphere. Author analyses the strategic interests of Russian government and of president Putin by planning and mining of oil and gas as like as by investments to the pipelines and gas lines. International Energetic Agency (IEA) assumes that the investments to oil and gas mining in Russia will be around 330 million USD till 2030. The similar situation is also in oil sector. More than half of huge oil deposits with the highest output are already mined. The oil mining in Russia reached 421 million tons in 2003. According to pessimistic estimations the gas mining will reach from 550 to 560 billion m 3 in the following decades, according to optimistic scenario it can reach up to 730 billion m 3 per year. In this case the netto export of oil from Russia could rise from present around 175 billion m 3 to 280 billion m 3 in 2030. IEA warns that these plans should be fulfilled only if massive foreign investments enter this sector. IEA also warns before concerns of investors about Russian legislation, property protection, cooperative regulation and transparentness of undertaking. Proposed pipelines among Russia, Near East, Africa and European Union are shown

  15. Cavitation Bubble Nucleation by Energetic Particles

    Energy Technology Data Exchange (ETDEWEB)

    West, C.D.

    1998-12-01

    In the early sixties, experimental measurements using a bubble chamber confirmed quantitatively the thermal spike theory of bubble nucleation by energetic particles: the energy of the slow, heavy alpha decay recoils used in those experiments matched the calculated bubble nucleation energy to within a few percent. It was a triumph, but was soon to be followed by a puzzle. Within a couple of years, experiments on similar liquids, but well below their normal boiling points, placed under tensile stress showed that the calculated bubble nucleation energy was an order of magnitude less than the recoil energy. Why should the theory work so well in the one case and so badly in the other? How did the liquid, or the recoil particle, "know" the difference between the two experiments? Another mathematical model of the same physical process, introduced in 1967, showed qualitatively why different analyses would be needed for liquids with high and low vapor pressures under positive or negative pressures. But, the quantitative agreement between the calculated nucleation energy and the recoil energy was still poor--the former being smaller by a factor of two to three. In this report, the 1967 analysis is extended and refined: the qualitative understanding of the difference between positive and negative pressure nucleation, "boiling" and "cavitation" respectively, is retained, and agreement between the negative pressure calculated to be needed for nucleation and the energy calculated to be available is much improved. A plot of the calculated negative pressure needed to induce bubble formation against the measured value now has a slope of 1.0, although there is still considerable scatter in the individual points.

  16. Regulation of cardiac microRNAs by serum response factor

    Directory of Open Access Journals (Sweden)

    Wei Jeanne Y

    2011-02-01

    Full Text Available Abstract Serum response factor (SRF regulates certain microRNAs that play a role in cardiac and skeletal muscle development. However, the role of SRF in the regulation of microRNA expression and microRNA biogenesis in cardiac hypertrophy has not been well established. In this report, we employed two distinct transgenic mouse models to study the impact of SRF on cardiac microRNA expression and microRNA biogenesis. Cardiac-specific overexpression of SRF (SRF-Tg led to altered expression of a number of microRNAs. Interestingly, downregulation of miR-1, miR-133a and upregulation of miR-21 occurred by 7 days of age in these mice, long before the onset of cardiac hypertrophy, suggesting that SRF overexpression impacted the expression of microRNAs which contribute to cardiac hypertrophy. Reducing cardiac SRF level using the antisense-SRF transgenic approach (Anti-SRF-Tg resulted in the expression of miR-1, miR-133a and miR-21 in the opposite direction. Furthermore, we observed that SRF regulates microRNA biogenesis, specifically the transcription of pri-microRNA, thereby affecting the mature microRNA level. The mir-21 promoter sequence is conserved among mouse, rat and human; one SRF binding site was found to be in the mir-21 proximal promoter region of all three species. The mir-21 gene is regulated by SRF and its cofactors, including myocardin and p49/Strap. Our study demonstrates that the downregulation of miR-1, miR-133a, and upregulation of miR-21 can be reversed by one single upstream regulator, SRF. These results may help to develop novel therapeutic interventions targeting microRNA biogenesis.

  17. Inflammation and cardiac dysfunction during sepsis, muscular dystrophy, and myocarditis

    Directory of Open Access Journals (Sweden)

    Ying Li

    2013-12-01

    Full Text Available Inflammation plays an important role in cardiac dysfunction under different situations. Acute systemic inflammation occurring in patients with severe burns, trauma, and inflammatory diseases causes cardiac dysfunction, which is one of the leading causes of mortality in these patients. Acute sepsis decreases cardiac contractility and impairs myocardial compliance. Chronic inflammation such as that occurring in Duchenne muscular dystropshy and myocarditis may cause adverse cardiac remodeling including myocyte hypertrophy and death, fibrosis, and altered myocyte function. However, the underlying cellular and molecular mechanisms for inflammatory cardiomyopathy are still controversial probably due to multiple factors involved. Potential mechanisms include the change in circulating blood volume; a direct inhibition of myocyte contractility by cytokines (tumor necrosis factor (TNF-a, interleukin (IL-1b; abnormal nitric oxide and reactive oxygen species (ROS signaling; mitochondrial dysfunction; abnormal excitation-contraction coupling; and reduced calcium sensitivity at the myofibrillar level and blunted b-adrenergic signaling. This review will summarize recent advances in diagnostic technology, mechanisms, and potential therapeutic strategies for inflammation-induced cardiac dysfunction.

  18. GRMD cardiac and skeletal muscle metabolism gene profiles are distinct.

    Science.gov (United States)

    Markham, Larry W; Brinkmeyer-Langford, Candice L; Soslow, Jonathan H; Gupte, Manisha; Sawyer, Douglas B; Kornegay, Joe N; Galindo, Cristi L

    2017-04-08

    Duchenne muscular dystrophy (DMD) is caused by mutations in the DMD gene, which codes for the dystrophin protein. While progress has been made in defining the molecular basis and pathogenesis of DMD, major gaps remain in understanding mechanisms that contribute to the marked delay in cardiac compared to skeletal muscle dysfunction. To address this question, we analyzed cardiac and skeletal muscle tissue microarrays from golden retriever muscular dystrophy (GRMD) dogs, a genetically and clinically homologous model for DMD. A total of 15 dogs, 3 each GRMD and controls at 6 and 12 months plus 3 older (47-93 months) GRMD dogs, were assessed. GRMD dogs exhibited tissue- and age-specific transcriptional profiles and enriched functions in skeletal but not cardiac muscle, consistent with a "metabolic crisis" seen with DMD microarray studies. Most notably, dozens of energy production-associated molecules, including all of the TCA cycle enzymes and multiple electron transport components, were down regulated. Glycolytic and glycolysis shunt pathway-associated enzymes, such as those of the anabolic pentose phosphate pathway, were also altered, in keeping with gene expression in other forms of muscle atrophy. On the other hand, GRMD cardiac muscle genes were enriched in nucleotide metabolism and pathways that are critical for neuromuscular junction maintenance, synaptic function and conduction. These findings suggest differential metabolic dysfunction may contribute to distinct pathological phenotypes in skeletal and cardiac muscle.

  19. METHOD OF PRODUCING ENERGETIC PLASMA FOR NEUTRON PRODUCTION

    Science.gov (United States)

    Bell, P.R.; Simon, A.; Mackin, R.J. Jr.

    1961-01-24

    A method is given for producing an energetic plasma for neutron production. An energetic plasma is produced in a small magnetically confined subvolume of the device by providing a selected current of energetic molecular ions at least greater than that required for producing a current of atomic ions sufficient to achieve "burnout" of neutral particles in the subvolume. The atomic ions are provided by dissociation of the molecular ions by an energetic arc discharge within the subvolume. After burnout, the arc discharge is terminated, the magnetic fields increased, and cold fuel feed is substituted for the molecular ions. After the subvolume is filled with an energetic plasma, the size of the magnetically confined subvolume is gradually increased until the entire device is filled with an energetic neutron producing plasma. The reactions which take place in the device to produce neutrons will generate a certain amount of heat energy which may be converted by the use of a conventional heat cycle to produce electrical energy.

  20. High-pressure and temperature investigations of energetic materials

    Science.gov (United States)

    Gump, J. C.

    2014-05-01

    Static high-pressure measurements are extremely useful for obtaining thermodynamic and phase stability information from a wide variety of materials. However, studying energetic materials can be challenging when extracting information from static high-pressure measurements. Energetic materials are traditionally C, H, N, O compounds with low crystalline symmetry, producing weak signal in commonly performed x-ray diffraction measurements. The small sample volume available in a static high-pressure cell exacerbates this issue. Additionally, typical hydrostatic compression media, such as methanol/ethanol, may react with many energetic materials. However, characterization of their thermodynamic parameters and phase stability is critical to understanding explosive performance and sensitivity. Crystalline properties, such as bulk modulus and thermal expansion, are necessary to accurately predict the behaviour of shocked solids using hydrodynamic codes. In order to obtain these values, equations of state of various energetic materials were investigated using synchrotron angle-dispersive x-ray diffraction experiments at static high-pressure and temperature. Intense synchrotron radiation overcomes the weak x-ray scattering of energetic materials in a pressure cell. The samples were hydrostatically compressed using a non-reactive hydrostatic medium and heated using a heated diamond anvil cell. Pressure - volume data for the materials were fit to the Birch-Murnaghan and Vinet formalisms to obtain bulk modulus and its first pressure derivative. Temperature - volume data at ambient pressure were fit to obtain the volume thermal expansion coefficient. Data from several energetic materials will be presented and compared.

  1. The Modeling of Pickup Ion or Energetic Particle Mediated Plasmas

    Science.gov (United States)

    Zank, G. P.; Mostafavi, P.; Hunana, P.

    2016-05-01

    Suprathermal energetic particles, such as solar energetic particles (SEPs) in the inner heliosphere and pickup ions (PUIs) in the outer heliosphere and the very local interstellar medium, often form a thermodynamically dominant component in their various environments. In the supersonic solar wind beyond > 10 AU, in the inner heliosheath (IHS), and in the very local interstellar medium (VLISM), PUIs do not equilibrate collisionally with the background plasma. Similarly, SEPs do not equilibrate collisionally with the background solar wind in the inner heliosphere. In the absence of equilibration between plasma components, a separate coupled plasma description for the energetic particles is necessary. Using a collisionless Chapman-Enskog expansion, we derive a closed system of multi-component equations for a plasma comprised of thermal protons and electrons, and suprathermal particles (SEPs, PUIs). The energetic particles contribute an isotropic scalar pressure to leading order, a collisionless heat flux at the next order, and a collisionless stress tensor at the second-order. The collisionless heat conduction and viscosity in the multi-fluid description results from a nonisotropic energetic particle distribution. A simpler single-fluid MHD-like system of equations with distinct equations of state for both the background plasma and the suprathermal particles is derived. We note briefly potential pitfalls that can emerge in the numerical modeling of collisionless plasma flows that contain a dynamically important energetic particle component.

  2. Delirium after Cardiac Surgery: A Pilot Study from a Single Tertiary Referral Center

    OpenAIRE

    Kumar, Ashok K; Jayant, Aveek; Arya, VK; Magoon, Rohan; Sharma, Ridhima

    2017-01-01

    Background: Advances in cardiac surgery has shifted paradigm of management to perioperative psychological illnesses. Delirium is a state of altered consciousness with easy distraction of thoughts. The pathophysiology of this complication is not clear, but identification of risk factors is important for positive postoperative outcomes. The goal of the present study was to prospectively identify the incidence, motoric subtypes, and risk factors associated with development of delirium in cardiac...

  3. Health Instruction Packages: Cardiac Anatomy.

    Science.gov (United States)

    Phillips, Gwen; And Others

    Text, illustrations, and exercises are utilized in these five learning modules to instruct nurses, students, and other health care professionals in cardiac anatomy and functions and in fundamental electrocardiographic techniques. The first module, "Cardiac Anatomy and Physiology: A Review" by Gwen Phillips, teaches the learner to draw…

  4. Pediatric Cardiac Surgery In Eritrea.

    African Journals Online (AJOL)

    The teams consisted of volunteer physicians from Germany, Italy and Switzerland including cardiac surgeons, pediatric cardiologists, cardiac anesthesiologists, pediatric intensivists, perfusionists, and other nursing staff. Each mission has routinely included at least 18 health professionals of different category to maximize the.

  5. Diagnostic value of cardiac cineangiography

    International Nuclear Information System (INIS)

    Han, Man Chung; Yeon, Kyung Mo; Im, Chung Gie; Yoo, Shi Joon

    1979-01-01

    Cineangiography is essential and excellent tool for evaluation of anatomy and pathophysiology of heart disease. 114 cases of cardiac cineangiography were analyzed. The following conditions are easily interpreted and diagnosed accurately by cineangiography. 1. Valvular insufficiency, especially small amount. 2. Valve motion, shape analysis. 3. Detection of shunt. 4. Ventricle wall movement. 5. Complexed congenita cardiac anomaly. 6. Coronary artery stenosis.

  6. The Danish Cardiac Rehabilitation Database

    DEFF Research Database (Denmark)

    Zwisler, Ann-Dorthe; Rossau, Henriette Knold; Nakano, Anne

    2016-01-01

    AIM OF DATABASE: The Danish Cardiac Rehabilitation Database (DHRD) aims to improve the quality of cardiac rehabilitation (CR) to the benefit of patients with coronary heart disease (CHD). STUDY POPULATION: Hospitalized patients with CHD with stenosis on coronary angiography treated with percutane...

  7. Neuromuscular diseases after cardiac transplantation

    NARCIS (Netherlands)

    Mateen, Farrah J.; van de Beek, Diederik; Kremers, Walter K.; Daly, Richard C.; Edwards, Brooks S.; McGregor, Christopher G. A.; Wijdicks, Eelco F. M.

    2009-01-01

    BACKGROUND: Cardiac transplantation is a therapeutic option in end-stage heart failure. Peripheral nervous system (PNS) disease is known to occur in cardiac transplant recipients but has not been fully characterized. METHODS: This retrospective cohort review reports the PNS-related concerns of 313

  8. Cardiac arrest – cardiopulmonary resuscitation

    Directory of Open Access Journals (Sweden)

    Basri Lenjani

    2014-01-01

    Conclusions: All survivors from cardiac arrest have received appropriate medical assistance within 10 min from attack, which implies that if cardiac arrest occurs near an institution health care (with an opportunity to provide the emergent health care the rate of survival is higher.

  9. Análise do consumo de oxigênio, freqüência cardíaca e dispêndio energético, durante as aulas do Jump Fit Análisis del consumo de oxígeno, frecuencia cardiaca y dispendio energético en las clases de Jump Fit Analysis of the oxygen intake, cardiac frequency and energetic expenditure during Jump Fit lessons

    Directory of Open Access Journals (Sweden)

    Elen Furtado

    2004-10-01

    identificar y evaluar el comportamiento de las variables funcionales, como: frecuencia cardiaca (FC, consumo de oxígeno (VO2, producción de dióxido de carbono (VCO2, cuociente respiratorio (QR, equivalente metabólico (MET y dispendio energético a través de la medición por espirometría de la rutina de una clase de Jump Fit. Las pruebas se realizaron en cuatro visitas por 10 mujeres que practican Jump Fit, con edad de 26,8 años (± 7,2, masa corporal de 57,6kg (± 6,8, altura de 162,2cm (± 3,9. La evaluación espirométrica de las diversas etapas de la clase reveló los siguientes resultados promedios: FC de 160,3bpm (± 8,9, VO2 de 1,59L.min-1 (± 0,45, QR 0,87 (± 0,10 y dispendio energético total 386,4kcal (± 13,8. El promedio de intensidad de la clase de Jump Fit correspondió al 75% (± 7,7 del VO2máximo. Para el análisis del comportamiento de las variables metabólicas en las distintas etapas de las clases se utilizó la ANOVA para medidas repetidas, con verificación de Bonferroni. Se empleó la prueba t para determinar se hubo diferencia entre las respuestas funcionales en las fases de reposo y del EPOC. Se adoptó el nivel de significancia de p Jump Fit lessons further the improvement of the general physical fitness through choreographies performed on an elastic surface with rhythm and movements variation with intervals and low impact. However, not much is known about the actual energetic expenditure and the behavior of the metabolic variables related to Jump Fit lessons. The objective of this study was to identify and to evaluate the behavior of the functional variables such as: heart rate (HR, oxygen intake (VO2, metabolic equivalent (MET and energetic expenditure through routine spirometry measurement of a Jump Fit lesson. The tests were performed in four visits by 10 women who practice Jump Fit with age of 26.8 (± 7.2, body mass of 57.6 kg (± 6.8 and height of 162.2 cm (± 3.9. The spirometric evaluation of the several stages of the lesson revealed

  10. Matrix Metalloproteinase 9 Secreted by Hypoxia Cardiac Fibroblasts Triggers Cardiac Stem Cell Migration In Vitro

    Directory of Open Access Journals (Sweden)

    Qing Gao

    2015-01-01

    Full Text Available Cessation of blood supply due to myocardial infarction (MI leads to complicated pathological alteration in the affected regions. Cardiac stem cells (CSCs migration plays a major role in promoting recovery of cardiac function and protecting cardiomyocytes in post-MI remodeling. Despite being the most abundant cell type in the mammalian heart, cardiac fibroblasts (CFs were underestimated in the mechanism of CSCs migration. Our objective in this study is therefore to investigate the migration related factors secreted by hypoxia CFs in vitro and the degree that they contribute to CSCs migration. We found that supernatant from hypoxia induced CFs could accelerate CSCs migration. Four migration-related cytokines were reported upregulated both in mRNA and protein levels. Upon adding antagonists of these cytokines, the number of migration cells significantly declined. When the cocktail antagonists of all above four cytokines were added, the migration cells number reduced to the minimum level. Besides, MMP-9 had an important effect on triggering CSCs migration. As shown in our results, MMP-9 induced CSCs migration and the underlying mechanism might involve TNF-α signaling which induced VEGF and MMP-9 expression.

  11. Moderate-Intensity Exercise Affects Gut Microbiome Composition and Influences Cardiac Function in Myocardial Infarction Mice

    Directory of Open Access Journals (Sweden)

    Zuheng Liu

    2017-09-01

    Full Text Available Physical exercise is commonly regarded as protective against cardiovascular disease (CVD. Recent studies have reported that exercise alters the gut microbiota and that modification of the gut microbiota can influence cardiac function. Here, we focused on the relationships among exercise, the gut microbiota and cardiac function after myocardial infarction (MI. Four-week-old C57BL/6J mice were exercised on a treadmill for 4 weeks before undergoing left coronary artery ligation. Cardiac function was assessed using echocardiography. Gut microbiomes were evaluated post-exercise and post-MI using 16S rRNA gene sequencing on an Illumina HiSeq platform. Exercise training inhibited declines in cardiac output and stroke volume in post-MI mice. In addition, physical exercise and MI led to alterations in gut microbial composition. Exercise training increased the relative abundance of Butyricimonas and Akkermansia. Additionally, key operational taxonomic units were identified, including 24 lineages (mainly from Bacteroidetes, Barnesiella, Helicobacter, Parabacteroides, Porphyromonadaceae, Ruminococcaceae, and Ureaplasma that were closely related to exercise and cardiac function. These results suggested that exercise training improved cardiac function to some extent in addition to altering the gut microbiota; therefore, they could provide new insights into the use of exercise training for the treatment of CVD.

  12. Cardiac changes in anorexia nervosa.

    Science.gov (United States)

    Spaulding-Barclay, Michael A; Stern, Jessica; Mehler, Philip S

    2016-04-01

    Introduction Anorexia nervosa is an eating disorder, which is associated with many different medical complications as a result of the weight loss and malnutrition that characterise this illness. It has the highest mortality rate of any psychiatric disorder. A large portion of deaths are attributable to the cardiac abnormalities that ensue as a result of the malnutrition associated with anorexia nervosa. In this review, the cardiac complications of anorexia nervosa will be discussed. A comprehensive literature review on cardiac changes in anorexia nervosa was carried out. There are structural, functional, and rhythm-type changes that occur in patients with anorexia nervosa. These become progressively significant as ongoing weight loss occurs. Cardiac changes are inherent to anorexia nervosa and they become more life-threatening and serious as the anorexia nervosa becomes increasingly severe. Weight restoration and attention to these cardiac changes are crucial for a successful treatment outcome.

  13. [Maternal cardiac arrhythmias in pregnancy].

    Science.gov (United States)

    Swiatkowska-Freund, Małgorzata; Ciach, Katarzyna; Kowalewska-Włas, Agnieszka; Preis, Krzysztof

    2005-12-01

    Perinatal care of women with cardiac arrhythmias is very important for every obstetrician. Maternal heart disease complicates 0.2 to 4% of pregnancies. The purpose of this study was to analyze the course of pregnancy, delivery and postpartum period pregnant women with cardiac arrhythmias We analyzed 14 pregnant women with cardiac arrhythmias. hospitalized in the Department of Obstetrics of Medical University of Gdańsk, 1998-2003. Time of delivery, weight and length of neonates in patients with cardiac arrhythmias was presented. Delivery and postpartum period were uncomplicated in all the patients and no stimulation was used. In two women with congenital complete atrio-ventricular block dicavital heart stimulator was applied. All patients and infants were discharged from hospital in good condition. We found no cardiological complications during pregnancy in patients with cardiac arrhythmias.

  14. Cardiac asystole in partial seizures.

    Science.gov (United States)

    Scott, C A; Fish, D R

    2000-06-01

    Literature review shows many anecdotal case reports of cardiac asystole in ictal recordings of partial seizures. We have reviewed our data from the last five years, of patients who are being assessed for epilepsy surgery and found 2 out of more than 1,500 complex partial seizures, recorded in 589 consecutive patients, showing a significant period of asystole (13 and 15 seconds). Our previous studies of cardiac and respiratory parameters during partial seizures showed that a central apnoea occurred in 39%. It is probable that sudden death during seizures is due to the interaction of both cardiac and respiratory irregularities. Although rare (occurrence cardiac asystole occurring in an epilepsy monitoring unit highlights the need for resuscitation equipment to be readily available and for trained nursing staff. Furthermore, it is important to recognize that the semiology of seizures may be affected by the consequences of secondary cardiac asystole.

  15. Cardiomyopathy induced by artificial cardiac pacing: myth or reality sustained by evidence?

    Science.gov (United States)

    Ferrari, Andrés Di Leoni; Borges, Anibal Pires; Albuquerque, Luciano Cabral; Sussenbach, Carolina Pelzer; da Rosa, Priscila Raupp; Piantá, Ricardo Medeiros; Wiehe, Mario; Goldani, Marco Antônio

    2014-01-01

    Implantable cardiac pacing systems are a safe and effective treatment for symptomatic irreversible bradycardia. Under the proper indications, cardiac pacing might bring significant clinical benefit. Evidences from literature state that the action of the artificial pacing system, mainly when the ventricular lead is located at the apex of the right ventricle, produces negative effects to cardiac structure (remodeling, dilatation) and function (dissinchrony). Patients with previously compromised left ventricular function would benefit the least with conventional right ventricle apical pacing, and are exposed to the risk of developing higher incidence of morbidity and mortality for heart failure. However, after almost 6 decades of cardiac pacing, just a reduced portion of patients in general would develop these alterations. In this context, there are not completely clear some issues related to cardiac pacing and the development of this cardiomyopathy. Causality relationships among QRS widening with a left bundle branch block morphology, contractility alterations within the left ventricle, and certain substrates or clinical (previous systolic dysfunction, structural heart disease, time from implant) or electrical conditions (QRS duration, percentage of ventricular stimulation) are still subjecte of debate. This review analyses contemporary data regarding this new entity, and discusses alternatives of how to use cardiac pacing in this context, emphasizing cardiac resynchronization therapy. PMID:25372916

  16. Imaging alterations of cardiomyocyte cAMP microdomains in disease

    Directory of Open Access Journals (Sweden)

    Alexander eFroese

    2015-08-01

    Full Text Available 3’,5’-cyclic adenosine monophosphate (cAMP is an important second messenger which regulates heart function by acting in distinct subcellular microdomains. Recent years have provided deeper mechanistic insights into compartmentalized cAMP signaling and its link to cardiac disease. In this mini review, we summarize newest developments in this field achieved by cutting-edge biochemical and biophysical techniques. We further compile the data from different studies into a bigger picture of so far uncovered alterations in cardiomyocyte cAMP microdomains which occur in compensated cardiac hypertrophy and chronic heart failure. Finally, future research directions and translational perspectives are briefly discussed.

  17. Germline energetics, aging and female infertility

    Science.gov (United States)

    Tilly, Jonathan L.; Sinclair, David A.

    2013-01-01

    SUMMARY The role of metabolism in ovarian aging is poorly described, despite the fact that ovaries fail earlier than most other organs. Growing interest in ovarian function is being driven by recent evidence that mammalian females routinely generate new oocytes during adult life through the activity of germline stem cells. In this perspective, we overview the female reproductive system as a powerful and clinically relevant model to understand links between aging and metabolism, and we discuss new concepts for how oocytes and their precursor cells might be altered metabolically to sustain or increase ovarian function and fertility in women. PMID:23747243

  18. Energetics in a model of prebiotic evolution

    Science.gov (United States)

    Intoy, B. F.; Halley, J. W.

    2017-12-01

    Previously we reported [A. Wynveen et al., Phys. Rev. E 89, 022725 (2014), 10.1103/PhysRevE.89.022725] that requiring that the systems regarded as lifelike be out of chemical equilibrium in a model of abstracted polymers undergoing ligation and scission first introduced by Kauffman [S. A. Kauffman, The Origins of Order (Oxford University Press, New York, 1993), Chap. 7] implied that lifelike systems were most probable when the reaction network was sparse. The model was entirely statistical and took no account of the bond energies or other energetic constraints. Here we report results of an extension of the model to include effects of a finite bonding energy in the model. We studied two conditions: (1) A food set is continuously replenished and the total polymer population is constrained but the system is otherwise isolated and (2) in addition to the constraints in (1) the system is in contact with a finite-temperature heat bath. In each case, detailed balance in the dynamics is guaranteed during the computations by continuous recomputation of a temperature [in case (1)] and of the chemical potential (in both cases) toward which the system is driven by the dynamics. In the isolated case, the probability of reaching a metastable nonequilibrium state in this model depends significantly on the composition of the food set, and the nonequilibrium states satisfying lifelike condition turn out to be at energies and particle numbers consistent with an equilibrium state at high negative temperature. As a function of the sparseness of the reaction network, the lifelike probability is nonmonotonic, as in our previous model, but the maximum probability occurs when the network is less sparse. In the case of contact with a thermal bath at a positive ambient temperature, we identify two types of metastable nonequilibrium states, termed locally and thermally alive, and locally dead and thermally alive, and evaluate their likelihood of appearance, finding maxima at an optimal

  19. Modelling rock fragmentation of Extremely Energetic Rockfalls

    Science.gov (United States)

    De Blasio, Fabio; Dattola, Giuseppe; Battista Crosta, Giovanni

    2017-04-01

    Extremely energetic rockfalls (EER) are phenomena for which the combination of a large volume (at least some thousands of m ) and a free fall height of hundreds of metres, results in a large released energy. We fix a threshold value of around 1/50 of kilotons to define such a type of events. Documented examples include several events with dif-ferent size in the Alps (Dru, 2005, 2011, 265,000, 59,200 m3; val Fiscalina - Cima Una, 2007, 40,000 m3; Thurwieser 2004, ca 2 Mm3; Cengalo, 2011, 1.5*105 m3 in 2016, in Switzerland; Civetta, 2013, ca 50,000 m3;), in the Apennines (Gran Sasso, 2006, 30,000 m3), Rocky Mountains (Yosemite, Happy Isles, 38,000 m3), and Himalaya. EERs may become more frequent on steep and sharp mountain peaks as a consequence of permafrost thawing at higher altitudes. In contrast to low energy rockfalls where block disintegration is limited, in EERs the impact after free fall causes an immediate and efficient release of energy much like an explosion. The severe disintegration of the rock and the corresponding air blast are capable of snapping trees many hundreds of metres ahead of the fall area. Pulverized rock at high speed can abrade tree logs, and the resulting suspension flow may travel much further the impact zone, blanketing vast surrounding areas. Using both published accounts of some of these events and collecting direct data for some of them, we present some basic models to describe the involved processes based on analogies with explosions and explosive fragmentation. Of the initial energy, one part is used up in the rock disintegration, and the rest is shared between the shock wave and air blast. The fragmentation energy is calculated based on the fitting of the dust size spectrum by using different proba-bilistic distribution laws and the definition of a surface energy and by considering the involved strain rate. We find the fragmentation is around one third of the initial boulder energy. Finally, we evaluate the velocity of the

  20. Silicon central pattern generators for cardiac diseases.

    Science.gov (United States)

    Nogaret, Alain; O'Callaghan, Erin L; Lataro, Renata M; Salgado, Helio C; Meliza, C Daniel; Duncan, Edward; Abarbanel, Henry D I; Paton, Julian F R

    2015-02-15

    Cardiac rhythm management devices provide therapies for both arrhythmias and resynchronisation but not heart failure, which affects millions of patients worldwide. This paper reviews recent advances in biophysics and mathematical engineering that provide a novel technological platform for addressing heart disease and enabling beat-to-beat adaptation of cardiac pacing in response to physiological feedback. The technology consists of silicon hardware central pattern generators (hCPGs) that may be trained to emulate accurately the dynamical response of biological central pattern generators (bCPGs). We discuss the limitations of present CPGs and appraise the advantages of analog over digital circuits for application in bioelectronic medicine. To test the system, we have focused on the cardio-respiratory oscillators in the medulla oblongata that modulate heart rate in phase with respiration to induce respiratory sinus arrhythmia (RSA). We describe here a novel, scalable hCPG comprising physiologically realistic (Hodgkin-Huxley type) neurones and synapses. Our hCPG comprises two neurones that antagonise each other to provide rhythmic motor drive to the vagus nerve to slow the heart. We show how recent advances in modelling allow the motor output to adapt to physiological feedback such as respiration. In rats, we report on the restoration of RSA using an hCPG that receives diaphragmatic electromyography input and use it to stimulate the vagus nerve at specific time points of the respiratory cycle to slow the heart rate. We have validated the adaptation of stimulation to alterations in respiratory rate. We demonstrate that the hCPG is tuneable in terms of the depth and timing of the RSA relative to respiratory phase. These pioneering studies will now permit an analysis of the physiological role of RSA as well as its any potential therapeutic use in cardiac disease. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

  1. Cardiac potassium channel subtypes

    DEFF Research Database (Denmark)

    Schmitt, Nicole; Grunnet, Morten; Olesen, Søren-Peter

    2014-01-01

    . The underlying posttranscriptional and posttranslational remodeling of the individual K(+) channels changes their activity and significance relative to each other, and they must be viewed together to understand their role in keeping a stable heart rhythm, also under menacing conditions like attacks of reentry......About 10 distinct potassium channels in the heart are involved in shaping the action potential. Some of the K(+) channels are primarily responsible for early repolarization, whereas others drive late repolarization and still others are open throughout the cardiac cycle. Three main K(+) channels...... that they could constitute targets for new pharmacological treatment of atrial fibrillation. The interplay between the different K(+) channel subtypes in both atria and ventricle is dynamic, and a significant up- and downregulation occurs in disease states such as atrial fibrillation or heart failure...

  2. Cardiac Rehabilitation Series: Canada

    Science.gov (United States)

    Grace, Sherry L.; Bennett, Stephanie; Ardern, Chris I.; Clark, Alexander

    2015-01-01

    Cardiovascular disease is among the leading causes of mortality and morbidity in Canada. Cardiac rehabilitation (CR) has a long robust history here, and there are established clinical practice guidelines. While the effectiveness of CR in the Canadian context is clear, only 34% of eligible patients participate, and strategies to increase access for under-represented groups (e.g., women, ethnic minority groups) are not yet universally applied. Identified CR barriers include lack of referral and physician recommendation, travel and distance, and low perceived need. Indeed there is now a national policy position recommending systematic inpatient referral to CR in Canada. Recent development of 30 CR Quality Indicators and the burgeoning national CR registry will enable further measurement and improvement of the quality of CR care in Canada. Finally, the Canadian Association of CR is one of the founding members of the International Council of Cardiovascular Prevention and Rehabilitation, to promote CR globally. PMID:24607018

  3. Hypertension and cardiac arrhythmias

    DEFF Research Database (Denmark)

    Lip, Gregory Y H; Coca, Antonio; Kahan, Thomas

    2017-01-01

    Hypertension is a common cardiovascular risk factor leading to heart failure (HF), coronary artery disease, stroke, peripheral artery disease and chronic renal insufficiency. Hypertensive heart disease can manifest as many cardiac arrhythmias, most commonly being atrial fibrillation (AF). Both...... supraventricular and ventricular arrhythmias may occur in hypertensive patients, especially in those with left ventricular hypertrophy (LVH) or HF. Also, some of the antihypertensive drugs commonly used to reduce blood pressure, such as thiazide diuretics, may result in electrolyte abnormalities (e.g. hypokalaemia......, hypomagnesemia), further contributing to arrhythmias, whereas effective control of blood pressure may prevent the development of the arrhythmias such as AF. In recognizing this close relationship between hypertension and arrhythmias, the European Heart Rhythm Association (EHRA) and the European Society...

  4. Mediastinitis after cardiac transplantation

    Directory of Open Access Journals (Sweden)

    Noedir A. G. Stolf

    2000-05-01

    Full Text Available OBJECTIVE: Assessment of incidence and behavior of mediastinitis after cardiac transplantation. METHODS: From 1985 to 1999, 214 cardiac transplantations were performed, 12 (5.6% of the transplanted patients developed confirmed mediastinitis. Patient's ages ranged from 42 to 66 years (mean of 52.3±10.0 years and 10 (83.3% patients were males. Seven (58.3% patients showed sternal stability on palpation, 4 (33.3% patients had pleural empyema, and 2 (16.7% patients did not show purulent secretion draining through the wound. RESULTS: Staphylococcus aureus was the infectious agent identified in the wound secretion or in the mediastinum, or both, in 8 (66.7% patients. Staphylococcus epidermidis was identified in 2 (16.7% patients, Enterococcus faecalis in 1 (8.3% patient, and the cause of mediastinitis could not be determined in 1 (8.3% patient. Surgical treatment was performed on an emergency basis, and the extension of the débridement varied with local conditions. In 2 (16.7% patients, we chose to leave the surgical wound open and performed daily dressings with granulated sugar. Total sternal resection was performed in only 1 (8.3% patient. Out of this series, 5 (41.7% patients died, and the causes of death were related to the infection. Autopsy revealed persistence of mediastinitis in 1 (8.3% patient. CONCLUSION: Promptness in diagnosing mediastinitis and precocious surgical drainage have changed the natural evolution of this disease. Nevertheless, observance of the basic precepts of prophylaxis of infection is still the best way to treat mediastinitis.

  5. Pitx2-mediated cardiac outflow tract remodeling.

    Science.gov (United States)

    Ma, Hsiao-Yen; Xu, Jun; Eng, Diana; Gross, Michael K; Kioussi, Chrissa

    2013-05-01

    Heart morphogenesis involves sequential anatomical changes from a linear tube of a single channel peristaltic pump to a four-chamber structure with two channels controlled by one-way valves. The developing heart undergoes continuous remodeling, including septation. Pitx2-null mice are characterized by cardiac septational defects of the atria, ventricles, and outflow tract. Pitx2-null mice also exhibited a short outflow tract, including unseptated conus and deformed endocardial cushions. Cushions were characterized with a jelly-like structure, rather than the distinct membrane-looking leaflets, indicating that endothelial mesenchymal transition was impaired in Pitx2(-/-) embryos. Mesoderm cells from the branchial arches and neural crest cells from the otic region contribute to the development of the endocardial cushions, and both were reduced in number. Members of the Fgf and Bmp families exhibited altered expression levels in the mutants. We suggest that Pitx2 is involved in the cardiac outflow tract septation by promoting and/or maintaining the number and the remodeling process of the mesoderm progenitor cells. Pitx2 influences the expression of transcription factors and signaling molecules involved in the differentiation of the cushion mesenchyme during heart development. Copyright © 2013 Wiley Periodicals, Inc.

  6. Glucose Transporters in Cardiac Metabolism and Hypertrophy

    Science.gov (United States)

    Shao, Dan; Tian, Rong

    2016-01-01

    The heart is adapted to utilize all classes of substrates to meet the high-energy demand, and it tightly regulates its substrate utilization in response to environmental changes. Although fatty acids are known as the predominant fuel for the adult heart at resting stage, the heart switches its substrate preference toward glucose during stress conditions such as ischemia and pathological hypertrophy. Notably, increasing evidence suggests that the loss of metabolic flexibility associated with increased reliance on glucose utilization contribute to the development of cardiac dysfunction. The changes in glucose metabolism in hypertrophied hearts include altered glucose transport and increased glycolysis. Despite the role of glucose as an energy source, changes in other nonenergy producing pathways related to glucose metabolism, such as hexosamine biosynthetic pathway and pentose phosphate pathway, are also observed in the diseased hearts. This article summarizes the current knowledge regarding the regulation of glucose transporter expression and translocation in the heart during physiological and pathological conditions. It also discusses the signaling mechanisms governing glucose uptake in cardiomyocytes, as well as the changes of cardiac glucose metabolism under disease conditions. PMID:26756635

  7. Cardiac autonomic dysfunction in West syndrome.

    Science.gov (United States)

    Jansen, Katrien; Vandeput, Steven; Van Huffel, Sabine; Lagae, Lieven

    2012-12-01

    West syndrome is an age-dependent epileptic encephalopathy. Autonomic changes are increasingly being recognized in patients with epilepsy: cardiac autonomic function is mediated by sympathetic and parasympathetic efferent activity to the heart and can provide information on the functional state of the autonomic nervous system. The goal of the study is to evaluate the effect of an early epileptic encephalopathy on the autonomic nervous system by measuring heart rate variability. Cardiac autonomic function was evaluated in 13 patients with West syndrome by measuring heart rate variability during 5 min epochs of ECG in wake, stage 2 and slow wave sleep. In 5 patients who developed subsequently another type of epilepsy, a second evaluation was performed after 3 years of follow-up. Results showed a lower heart rate in stage 2 sleep in patients with West syndrome. Spectral components did not show significant differences compared to age matched controls at the moment of presentation. After follow-up of 3 years we were able to demonstrate higher low frequency (LF), lower high frequency (HF) and a higher LF/HF ratio during slow wave sleep. This study shows a lower heart rate in patients presenting with West syndrome, already at the onset of the syndrome and before ACTH treatment. The epileptic encephalopathy is not sufficient to alter spectral components of heart rate at the moment of presentation. However, already after 3 years of epilepsy, chronic autonomic changes appear. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Sleep disturbances after non-cardiac surgery

    DEFF Research Database (Denmark)

    Rosenberg, Jacob

    2001-01-01

    After major non-cardiac surgery sleep pattern is usually disturbed with initial suppression of rapid eye movement sleep with a subsequent rebound during the first post-operative week. Deep sleep is also suppressed for several days after the operation and subjective sleep quality is impaired....... The sleep disturbances seem to be related to the magnitude of trauma and thereby to the surgical stress response and/or post-operative opioid administration. Post-operative sleep disturbances may contribute to the development of early post-operative fatigue, episodic hypoxaemia, haemodynamic instability...... and altered mental status, all with a potential negative effect on post-operative outcome. Minimizing surgical trauma and avoiding or minimizing use of opioids for pain relief may prevent or reduce post-operative sleep disturbances. Post-operative sleep pattern represents an important research field, since...

  9. Cardiac Arrhythmias In Congenital Heart Diseases

    Directory of Open Access Journals (Sweden)

    Paul Khairy

    2009-11-01

    Full Text Available Arrhythmias figure prominently among the complications encountered in the varied and diverse population of patients with congenital heart disease, and are the leading cause of morbidity and mortality. The incidence generally increases as the patient ages, with multifactorial predisposing features that may include congenitally malformed or displaced conduction systems, altered hemodynamics, mechanical or hypoxic stress, and residual or postoperative sequelae. The safe and effective management of arrhythmias in congenital heart disease requires a thorough appreciation for conduction system variants, arrhythmia mechanisms, underlying anatomy, and associated physiology. We, therefore, begin this review by presenting the scope of the problem, outlining therapeutic options, and summarizing congenital heart disease-related conduction system anomalies associated with disorders of the sinus node and AV conduction system. Arrhythmias encountered in common forms of congenital heart disease are subsequently discussed. In so doing, we touch upon issues related to risk stratification for sudden death, implantable cardiac devices, catheter ablation, and adjuvant surgical therapy.

  10. Cardiac syncope in pediatric patients.

    Science.gov (United States)

    Massin, Martial M; Malekzadeh-Milani, Sophie; Benatar, Avram

    2007-02-01

    To assess the epidemiology of cardiac syncope in children and evaluate the guidelines on its management. We analyzed the etiology to syncope and diagnostic workup in consecutive pediatric patients presenting with syncope in our emergency departments or cardiac outpatient clinics between 1997 and 2005, and who were subsequently diagnosed as having cardiac syncope. A primary cardiac cause was identified in 11 syncopal patients presenting to the emergency room and 14 patients to the cardiac clinic: supraventricular tachyarrhythmia in 9, ventricular tachyarrhythmia in 10, pacemaker dysfunction in 2, and isolated cases of sick sinus syndrome, hypoxic spell, hypertrophic cardiomyopathy, and primary pulmonary hypertension. Some elements suggested potential cardiac disease as a cause of syncope in all cases. The resting electrocardiogram and the echocardiogram were interpreted as positive and relevant to the diagnosis in 17 and 3 patients, respectively. Exercise electrocardiogram and Holter recording provided diagnostic information previously not seen on the resting electrocardiogram in six and three patients, respectively. Three children have died and one child has neurological sequelae following resuscitation. Our data support the premise that careful history taking with special focus on the events leading up to syncope, as well as a complete physical examination, can guide practitioners in discerning which syncopal children need further cardiac investigations. Copyright (c) 2007 Wiley Periodicals, Inc.

  11. Determinants of myocardial energetics and efficiency in symptomatic hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Timmer, Stefan A.J.; Germans, Tjeerd; Goette, Marco J.W.; Ruessel, Iris K.; Dijkmans, Pieter A.; Knaapen, Paul; Rossum, Albert C. van [VU University Medical Center, Department of Cardiology, 5F, Amsterdam (Netherlands); Lubberink, Mark; Lammertsma, Adriaan A. [VU University Medical Center, Department of Nuclear Medicine and PET Research, Amsterdam (Netherlands); Berg, Jurrien M. ten [St. Antonius Hospital, Department of Cardiology, Nieuwegein (Netherlands); Cate, Folkert J. ten [Thoraxcenter Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands)

    2010-04-15

    Next to hypertrophy, hypertrophic cardiomyopathy (HCM) is characterized by alterations in myocardial energetics. A small number of studies have shown that myocardial external efficiency (MEE), defined by external work (EW) in relation to myocardial oxidative metabolism (MVO{sub 2}), is reduced. The present study was conducted to identify determinants of MEE in patients with HCM by use of dynamic positron emission tomography (PET) and cardiovascular magnetic resonance imaging (CMR). Twenty patients with HCM (12 men, mean age: 55.2 {+-} 13.9 years) and 11 healthy controls (7 men, mean age: 48.1 {+-} 10 years) were studied with [{sup 11}C]acetate PET to assess MVO{sub 2}. CMR was performed to determine left ventricular (LV) volumes and mass (LVM). Univariate and multivariate analyses were employed to determine independent predictors of myocardial efficiency. Between study groups, MVO{sub 2} (controls: 0.12 {+-} 0.04 ml.min{sup -1}.g{sup -1}, HCM: 0.13 {+-} 0.05 ml.min{sup -1}.g{sup -1}, p = 0.64) and EW (controls: 9,139 {+-} 2,484 mmHg.ml, HCM: 9,368 {+-} 2,907 mmHg.ml, p = 0.83) were comparable, whereas LVM was significantly higher (controls: 99 {+-} 21 g, HCM: 200 {+-} 76 g, p < 0.001) and MEE was decreased in HCM patients (controls: 35 {+-} 8%, HCM: 21 {+-} 10%, p < 0.001). MEE was related to stroke volume (SV), LV outflow tract gradient, NH{sub 2}-terminal pro-brain natriuretic peptide (NT-proBNP) and serum free fatty acid levels (all p < 0.05). Multivariate analysis revealed that SV (ss = 0.74, p < 0.001) and LVM (ss = -0.43, p = 0.013) were independently related to MEE. HCM is characterized by unaltered MVO{sub 2}, impaired EW generation per gram of myocardial tissue and subsequent deteriorated myocardial efficiency. Mechanical external efficiency could independently be predicted by SV and LVM. (orig.)

  12. Characterization of endonuclease G and mitochondria-sarcoplasmic reticulum-related proteins during cardiac hypertrophy.

    Science.gov (United States)

    Liang, Xingguang; Ma, Kuifen; Rao, Yuefeng; Hong, Dongsheng; Huo, Zhaoxia; Ye, Ziqi; Huang, Mingzhu; Zhang, Xingguo; Zhao, Qingwei

    2015-09-01

    Endonuclease G (Endo G) is a novel determinant of cardiac hypertrophy. Here, we report the characterization of Endo G and mitochondria-sarcoplasmic reticulum-related proteins during cardiac hypertrophy, and hypothesize that Endo G regulate mitochondrial function partly through Mfn2 and Jp2 during cardiac hypertrophy. Our results show that Endo G levels gradually increased at the beginning of phenylephrine-induced cardiac hypertrophy, accompanied by an abnormal mitochondrial membrane potential. The up-regulation of Mfn2, Jp2, and Endo G appeared at an early stage of cardiac hypertrophy, whereas PGC1α was not up-regulated until a later stage. Abolishing Endo G with siRNA led to the uncoupling of the mitochondrial electron transport chain from ATP production and decreased PGC1α expression, likely by affecting the juxtaposition of the mitochondria and the sarcoplasmic reticulum via Mfn2 and Jp2. Furthermore, abolishing Jp2 altered the expression of Endo G expression and induced mitochondrial dysfunction, suggesting that mitochondrial abnormalities in cardiac hypertrophy are most likely caused by Endo G. Taken together, our study established a link between Endo G and mitochondrial function during cardiac hypertrophy, partly through the effects of Endo G on Mfn2 and Jp2, and revealed a role for Endo G in the crosstalk between the processes controlled by Mfn2 and Jp2 in maladaptive cardiac hypertrophy.

  13. Persistent phenotypic shift in cardiac fibroblasts: impact of transient renin angiotensin system inhibition.

    Science.gov (United States)

    Hale, Taben M

    2016-04-01

    Fibrotic cardiac remodeling ultimately leads to heart failure - a debilitating and costly condition. Select antihypertensive agents have been effective in reducing or slowing the development of cardiac fibrosis. Moreover, some experimental studies have shown that the reduction in fibrosis induced by these agents persists long after stopping treatment. What has not been as well investigated is whether this transient treatment results in a protection against future fibrotic cardiac remodeling. In the present review, previously published studies are re-examined to assess whether the relative percent increase in collagen deposition over an off-treatment period is attenuated, relative to control, following transient antihypertensive treatment in young or adult rats. Present findings suggest that transient inhibition of the renin angiotensin system (RAS) not only produces a sustained reduction in cardiac fibrosis, but also results in a degree of protection against future collagen deposition. In addition, prior transient RAS inhibition appears to alter the cardiac fibroblast phenotype such that these cells show a muted response to myocardial injury - namely reduced proliferation, chemokine release, and collagen deposition. This review puts forth several potential mechanisms underlying this long-term cardiac protection that is afforded by transient RAS inhibition. Specifically, fibroblast phenotypic change, cardiac fibroblast apoptosis, sustained suppression of the RAS, persistent reduction in left ventricular hypertrophy, and persistent reduction in arterial pressure are each discussed. Identifying the mechanisms ultimately responsible for this change in cardiac fibroblast response to injury, hypertension, and aging may reveal novel targets for therapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Metoclopramide-induced cardiac arrest

    Directory of Open Access Journals (Sweden)

    Martha M. Rumore

    2011-11-01

    Full Text Available The authors report a case of cardiac arrest in a patient receiving intravenous (IV metoclopramide and review the pertinent literature. A 62-year-old morbidly obese female admitted for a gastric sleeve procedure, developed cardiac arrest within one minute of receiving metoclopramide 10 mg via slow intravenous (IV injection. Bradycardia at 4 beats/min immediately appeared, progressing rapidly to asystole. Chest compressions restored vital function. Electrocardiogram (ECG revealed ST depression indicative of myocardial injury. Following intubation, the patient was transferred to the intensive care unit. Various cardiac dysrrhythmias including supraventricular tachycardia (SVT associated with hypertension and atrial fibrillation occurred. Following IV esmolol and metoprolol, the patient reverted to normal sinus rhythm. Repeat ECGs revealed ST depression resolution without pre-admission changes. Metoclopramide is a non-specific dopamine receptor antagonist. Seven cases of cardiac arrest and one of sinus arrest with metoclopramide were found in the literature. The metoclopramide prescribing information does not list precautions or adverse drug reactions (ADRs related to cardiac arrest. The reaction is not dose related but may relate to the IV administration route. Coronary artery disease was the sole risk factor identified. According to Naranjo, the association was possible. Other reports of cardiac arrest, severe bradycardia, and SVT were reviewed. In one case, five separate IV doses of 10 mg metoclopramide were immediately followed by asystole repeatedly. The mechanism(s underlying metoclopramide’s cardiac arrest-inducing effects is unknown. Structural similarities to procainamide may play a role. In view of eight previous cases of cardiac arrest from metoclopramide having been reported, further elucidation of this ADR and patient monitoring is needed. Our report should alert clinicians to monitor patients and remain diligent in surveillance and

  15. Fetal cardiac rhabdomyoma: case report

    Directory of Open Access Journals (Sweden)

    Seyed Mostafa Ghavami

    2016-07-01

    Full Text Available Background: The primary manifestation of cardiac tumors in embryonic period is a very rare condition. Cardiac rhabdomyomas most frequently arise in the ventricular myocardium, they may also occur in the atria and the epicardial surface. In spite of its benign nature, the critical location of the tumor inside the heart can lead to lethal arrhythmias and chamber obstruction. Multiple rhabdomyomas are strongly associated with tuberous sclerosis which is associated with mental retardation and epilepsy of variable severity. Ultrasonography as a part of routine prenatal screening, is the best method for the diagnosis of cardiac rhabdomyomas. In the review of articles published in Iran, fetal cardiac rhabdomyoma was not reported. Case presentation: We report a case of cardiac rhabdomyoma on a 24-year-old gravid 1, referred to Day Medical Imaging Center for routine evaluation of fetal abnormalities at 31 weeks of her gestational age. Ultrasonographic examination displayed a homogenous echogenic mass (13×9mm, originating from the left ventricle of the fetal heart. It was a normal pregnancy without any specific complications. Other organs of the fetus were found normal and no cardiac abnormalities were appeared. No Pericardial fluid effusion was found. The parents did not have consanguineous marriage. They did not also have any specific disease such as tuberous sclerosis. Conclusion: The clinical features of cardiac rhabdomyomas vary widely, depending on the location, size, and number of tumors in the heart. Although cardiac rhabdomyoma is a benign tumor in many affected fetuses, an early prenatal diagnosis of the tumor is of great significance in making efficient planning and providing adequate follow up visits of the patients and the complications such as, heart failure and outlet obstruction of cardiac chambers.

  16. Cardiac cone-beam CT

    International Nuclear Information System (INIS)

    Manzke, Robert

    2005-01-01

    This doctoral thesis addresses imaging of the heart with retrospectively gated helical cone-beam computed tomography (CT). A thorough review of the CT reconstruction literature is presented in combination with a historic overview of cardiac CT imaging and a brief introduction to other cardiac imaging modalities. The thesis includes a comprehensive chapter about the theory of CT reconstruction, familiarizing the reader with the problem of cone-beam reconstruction. The anatomic and dynamic properties of the heart are outlined and techniques to derive the gating information are reviewed. With the extended cardiac reconstruction (ECR) framework, a new approach is presented for the heart-rate-adaptive gated helical cardiac cone-beam CT reconstruction. Reconstruction assessment criteria such as the temporal resolution, the homogeneity in terms of the cardiac phase, and the smoothness at cycle-to-cycle transitions are developed. Several reconstruction optimization approaches are described: An approach for the heart-rate-adaptive optimization of the temporal resolution is presented. Streak artifacts at cycle-to-cycle transitions can be minimized by using an improved cardiac weighting scheme. The optimal quiescent cardiac phase for the reconstruction can be determined automatically with the motion map technique. Results for all optimization procedures applied to ECR are presented and discussed based on patient and phantom data. The ECR algorithm is analyzed for larger detector arrays of future cone-beam systems throughout an extensive simulation study based on a four-dimensional cardiac CT phantom. The results of the scientific work are summarized and an outlook proposing future directions is given. The presented thesis is available for public download at www.cardiac-ct.net

  17. Morphological effects on sensitivity of heterogeneous energetic materials

    Science.gov (United States)

    Roy, Sidhartha; Rai, Nirmal; Sen, Oishik; Udaykumar, H. S.

    2017-06-01

    The mesoscale physical response under shock loading in heterogeneous energetics is inherently linked to the microstructural characteristics. The current work demonstrates the connection between the microstructural features of porous energetic material and its sensitivity. A unified levelset based framework is developed to characterize the microstructures of a given sample. Several morphological metrics describing the mesoscale geometry of the materials are extracted using the current tool including anisotropy, tortuosity, surface to volume, nearest neighbors, size and curvature distributions. The relevant metrics among the ones extracted are identified and correlated to the mesoscale response of the energetic materials under shock loading. Two classes of problems are considered here: (a) field of idealized voids embedded in the HMX material and (b) real samples of pressed HMX. The effects of stochasticity associated with void arrangements on the sensitivity of the energetic material samples are shown. In summary, this work demonstrates the relationship between the mesoscale morphology and shock response of heterogeneous energetic materials using a levelset based framework.

  18. Energetic Particles: From Sun to Heliosphere - and vice versa

    Science.gov (United States)

    Wimmer-Schweingruber, R. F.; Rodriguez-Pacheco, J.; Boden, S.; Boettcher, S. I.; Cernuda, I.; Dresing, N.; Drews, C.; Droege, W.; Espinosa Lara, F.; Gomez-Herrero, R.; Heber, B.; Ho, G. C.; Klassen, A.; Kulkarni, S. R.; Mann, G. J.; Martin-Garcia, C.; Mason, G. M.; Panitzsch, L.; Prieto, M.; Sanchez, S.; Terasa, C.; Eldrum, S.

    2017-12-01

    Energetic particles in the heliosphere can be measured at their elevated energetic status after three processes: injection, acceleration, and transport. Suprathermal seed particles have speeds well above the fast magnetosonic speed in the solar wind frame of reference and can vary from location to location and within the solar activity cycle. Acceleration sites include reconnecting current sheets in solar flares or magnetspheric boundaries, shocks in the solar corona, heliosphere and a planetary obstacles, as well as planetary magnetospheres. Once accelerated, particles are transported from the acceleration site into and through the heliosphere. Thus, by investigating properties of energetic particles such as their composition, energy spectra, pitch-angle distribution, etc. one can attempt to distinguish their origin or injection and acceleration site. This in turn allows us to better understand transport effects whose underlying microphysics is also a key ingredient in the acceleration of particles. In this presentation we will present some clear examples which link energetic particles from their observing site to their source locations. These include Jupiter electrons, singly-charged He ions from CIRs, and 3He from solar flares. We will compare these examples with the measurement capabilities of the Energetic Particle Detector (EPD) on Solar Orbiter and consider implications for the key science goal of Solar Orbiter and Solar Proble Plus - How the Sun creates and controls the heliosphere.

  19. Acupuncture therapy related cardiac injury.

    Science.gov (United States)

    Li, Xue-feng; Wang, Xian

    2013-12-01

    Cardiac injury is the most serious adverse event in acupuncture therapy. The causes include needling chest points near the heart, the cardiac enlargement and pericardial effusion that will enlarge the projected area on the body surface and make the proper depth of needling shorter, and the incorrect needling method of the points. Therefore, acupuncture practitioners must be familiar with the points of the heart projected area on the chest and the correct needling methods in order to reduce the risk of acupuncture therapy related cardiac injury.

  20. Longstanding hyperthyroidism is associated with normal or enhanced intrinsic cardiomyocyte function despite decline in global cardiac function.

    Directory of Open Access Journals (Sweden)

    Nathan Y Weltman

    Full Text Available Thyroid hormones (THs play a pivotal role in cardiac homeostasis. TH imbalances alter cardiac performance and ultimately cause cardiac dysfunction. Although short-term hyperthyroidism typically leads to heightened left ventricular (LV contractility and improved hemodynamic parameters, chronic hyperthyroidism is associated with deleterious cardiac consequences including increased risk of arrhythmia, impaired cardiac reserve and exercise capacity, myocardial remodeling, and occasionally heart failure. To evaluate the long-term consequences of chronic hyperthyroidism on LV remodeling and function, we examined LV isolated myocyte function, chamber function, and whole tissue remodeling in a hamster model. Three-month-old F1b hamsters were randomized to control or 10 months TH treatment (0.1% grade I desiccated TH. LV chamber remodeling and function was assessed by echocardiography at 1, 2, 4, 6, 8, and 10 months of treatment. After 10 months, terminal cardiac function was assessed by echocardiography and LV hemodynamics. Hyperthyroid hamsters exhibited significant cardiac hypertrophy and deleterious cardiac remodeling characterized by myocyte lengthening, chamber dilatation, decreased relative wall thickness, increased wall stress, and increased LV interstitial fibrotic deposition. Importantly, hyperthyroid hamsters demonstrated significant LV systolic and diastolic dysfunction. Despite the aforementioned remodeling and global cardiac decline, individual isolated cardiac myocytes from chronically hyperthyroid hamsters had enhanced function when compared with myocytes from untreated age-matched controls. Thus, it appears that long-term hyperthyroidism may impair global LV function, at least in part by increasing interstitial ventricular fibrosis, in spite of normal or enhanced intrinsic cardiomyocyte function.

  1. NANOSTRUCTURE PATTERNING UNDER ENERGETIC PARTICLE BEAM IRRADIATION

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lumin [Regents of the University of Michigan; Lu, Wei [Regents of the University of Michigan

    2013-01-31

    Energetic ion bombardment can lead to the development of complex and diverse nanostructures on or beneath the material surface through induced self-organization processes. These self-organized structures have received particular interest recently as promising candidates as simple, inexpensive, and large area patterns, whose optical, electronic and magnetic properties are different from those in the bulk materials [1-5]. Compared to the low mass efficiency production rate of lithographic methods, these self-organized approaches display new routes for the fabrication of nanostructures over large areas in a short processing time at the nanoscale, beyond the limits of lithography [1,4]. Although it is believed that surface nanostructure formation is based on the morphological instability of the sputtered surface, driven by a kinetic balance between roughening and smoothing actions [6,7], the fundamental mechanisms and experimental conditions for the formation of these nanostructures has still not been well established, the formation of the 3-D naopatterns beneath the irradiated surface especially needs more exploration. During the last funding period, we have focused our efforts on irradiation-induced nanostructures in a broad range of materials. These structures have been studied primarily through in situ electron microscopy during electron or ion irradiation. In particular, we have performed studies on 3-D void/bubble lattices (in metals and CaF2), embedded sponge-like porous structure with uniform nanofibers in irradiated semiconductors (Ge, GaSb, and InSb), 2-D highly ordered pattern of nanodroplets (on the surface of GaAs), hexagonally ordered nanoholes (on the surface of Ge), and 1-D highly ordered ripple and periodic arrays (of Cu nanoparticles) [3,8-11]. The amazing common feature in those nanopatterns is the uniformity of the size of nanoelements (nanoripples, nanodots, nanovoids or nanofibers) and the distance separating them. Our research focuses on the

  2. Pluvials, Droughts, Energetics, and the Mongol Empire

    Science.gov (United States)

    Hessl, A. E.; Pederson, N.; Baatarbileg, N.

    2012-12-01

    The success of the Mongol Empire, the largest contiguous land empire the world has ever known, is a historical enigma. At its peak in the late 13th century, the empire influenced areas from the Hungary to southern Asia and Persia. Powered by domesticated herbivores, the Mongol Empire grew at the expense of agriculturalists in Eastern Europe, Persia, and China. What environmental factors contributed to the rise of the Mongols? What factors influenced the disintegration of the empire by 1300 CE? Until now, little high resolution environmental data have been available to address these questions. We use tree-ring records of past temperature and water to illuminate the role of energy and water in the evolution of the Mongol Empire. The study of energetics has long been applied to biological and ecological systems but has only recently become a theme in understanding modern coupled natural and human systems (CNH). Because water and energy are tightly linked in human and natural systems, studying their synergies and interactions make it possible to integrate knowledge across disciplines and human history, yielding important lessons for modern societies. We focus on the role of energy and water in the trajectory of an empire, including its rise, development, and demise. Our research is focused on the Orkhon Valley, seat of the Mongol Empire, where recent paleoenvironmental and archeological discoveries allow high resolution reconstructions of past human and environmental conditions for the first time. Our preliminary records indicate that the period 1210-1230 CE, the height of Chinggis Khan's reign is one of the longest and most consistent pluvials in our tree ring reconstruction of interannual drought. Reconstructed temperature derived from five millennium-long records from subalpine forests in Mongolia document warm temperatures beginning in the early 1200's and ending with a plunge into cold temperatures in 1260. Abrupt cooling in central Mongolia at this time is

  3. Inverse correlation between cardiac injury and cardiac anxiety: A potential role for communication

    NARCIS (Netherlands)

    van Beek, M.H.C.T.; Voshaar, R.C.O.; van Deelen, F.M.; van Balkom, A.J.L.M.; Pop, G.; Speckens, A.E.M.

    2014-01-01

    Objective: General anxiety in cardiac patients is associated with worsened cardiac course. An acute coronary syndrome (ACS) might evoke specific cardiac anxiety. We explored the characteristics associated with cardiac anxiety in ACS patients. Methods: We assessed cardiac anxiety in 237 patients

  4. Inverse Correlation Between Cardiac Injury and Cardiac Anxiety A Potential Role for Communication

    NARCIS (Netherlands)

    van Beek, Maria H. C. T.; Oude Voshaar, Richard; van Deelen, Femke M.; van Balkom, Anton J. L. M.; Pop, Gheorghe; Speckens, Anne E. M.

    2014-01-01

    Objective: General anxiety in cardiac patients is associated with worsened cardiac course. An acute coronary syndrome (ACS) might evoke specific cardiac anxiety. We explored the characteristics associated with cardiac anxiety in ACS patients. Methods: We assessed cardiac anxiety in 237 patients

  5. Inverse correlation between cardiac injury and cardiac anxiety: a potential role for communication

    NARCIS (Netherlands)

    Beek, M.H.C.T. van; Oude Voshaar, R.C.; Deelen, F.M. van; Balkom, A.J.L.M. van; Pop, G.A.; Speckens, A.E.M.

    2014-01-01

    OBJECTIVE: General anxiety in cardiac patients is associated with worsened cardiac course. An acute coronary syndrome (ACS) might evoke specific cardiac anxiety. We explored the characteristics associated with cardiac anxiety in ACS patients. METHODS: We assessed cardiac anxiety in 237 patients

  6. Chemical rocket propulsion a comprehensive survey of energetic materials

    CERN Document Server

    Shimada, Toru; Sinditskii, Valery; Calabro, Max

    2017-01-01

    Developed and expanded from the work presented at the New Energetic Materials and Propulsion Techniques for Space Exploration workshop in June 2014, this book contains new scientific results, up-to-date reviews, and inspiring perspectives in a number of areas related to the energetic aspects of chemical rocket propulsion. This collection covers the entire life of energetic materials from their conceptual formulation to practical manufacturing; it includes coverage of theoretical and experimental ballistics, performance properties, as well as laboratory-scale and full system-scale, handling, hazards, environment, ageing, and disposal. Chemical Rocket Propulsion is a unique work, where a selection of accomplished experts from the pioneering era of space propulsion and current technologists from the most advanced international laboratories discuss the future of chemical rocket propulsion for access to, and exploration of, space. It will be of interest to both postgraduate and final-year undergraduate students in...

  7. Energetic transition in the transport sector: Brazilian case

    International Nuclear Information System (INIS)

    Jannuzzi, Gilberto de Martino

    1999-01-01

    With the exception of the pipelines, the electrified railroad, the metro and some other urban systems, the transport depends totally on fossil fuels. The alternative fuels continue being a source of energy of smaller importance to global level, and Brazil it is the only country that maintains a program to great scale of derived liquid fuel of the biomass like substitute of the gasoline. Here we try to characterize the stage of energetic transition of the transport in Brazil, by means of the consolidation of the program of alcohol. The country has introduced a new fuel successfully that although it presents environmental benefits when not contributing to the net increase of gases that produce the greenhouse effect (GHG), it has turned out to be not very economic. Improvements in public transportation, the regional use of the alcohol, and bigger vehicular efficiency are some of the addresses that the energetic politics should take regarding a more sustainable energetic future for the national transport sector

  8. Kinetic Simulation and Energetic Neutral Atom Imaging of the Magnetosphere

    Science.gov (United States)

    Fok, Mei-Ching H.

    2011-01-01

    Advanced simulation tools and measurement techniques have been developed to study the dynamic magnetosphere and its response to drivers in the solar wind. The Comprehensive Ring Current Model (CRCM) is a kinetic code that solves the 3D distribution in space, energy and pitch-angle information of energetic ions and electrons. Energetic Neutral Atom (ENA) imagers have been carried in past and current satellite missions. Global morphology of energetic ions were revealed by the observed ENA images. We have combined simulation and ENA analysis techniques to study the development of ring current ions during magnetic storms and substorms. We identify the timing and location of particle injection and loss. We examine the evolution of ion energy and pitch-angle distribution during different phases of a storm. In this talk we will discuss the findings from our ring current studies and how our simulation and ENA analysis tools can be applied to the upcoming TRIO-CINAMA mission.

  9. Upper hybrid waves and energetic electrons in the radiation belt

    Science.gov (United States)

    Yoon, Peter H.; Kim, Sunjung; Hwang, Junga; Shin, Dae-Kyu

    2017-05-01

    Van Allen radiation belt is characterized by energetic electrons and ions trapped in the Earth's dipolar magnetic field lines and persisting for long periods. It is also permeated by high-frequency electrostatic fluctuations whose peak intensity occurs near the upper hybrid frequency. Such a phenomenon can be understood in terms of spontaneous emission of electrostatic multiple harmonic electron cyclotron waves by thermal plasmas. In the literature, the upper hybrid fluctuations are used as a proxy for determining the electron number density, but they also contain important information concerning the energetic electrons in the radiation belt and possibly the ring current electrons. The companion paper analyzes sample quiet time events and demonstrates that the upper hybrid fluctuations are predominantly emitted by tenuous population of energetic electrons. The present paper supplements detailed formalism of spontaneous thermal emission of multiple-harmonic cyclotron waves that include upper hybrid fluctuations.

  10. Cardiac atrophy after bed rest and spaceflight

    Science.gov (United States)

    Perhonen, M. A.; Franco, F.; Lane, L. D.; Buckey, J. C.; Blomqvist, C. G.; Zerwekh, J. E.; Peshock, R. M.; Weatherall, P. T.; Levine, B. D.

    2001-01-01

    Cardiac muscle adapts well to changes in loading conditions. For example, left ventricular (LV) hypertrophy may be induced physiologically (via exercise training) or pathologically (via hypertension or valvular heart disease). If hypertension is treated, LV hypertrophy regresses, suggesting a sensitivity to LV work. However, whether physical inactivity in nonathletic populations causes adaptive changes in LV mass or even frank atrophy is not clear. We exposed previously sedentary men to 6 (n = 5) and 12 (n = 3) wk of horizontal bed rest. LV and right ventricular (RV) mass and end-diastolic volume were measured using cine magnetic resonance imaging (MRI) at 2, 6, and 12 wk of bed rest; five healthy men were also studied before and after at least 6 wk of routine daily activities as controls. In addition, four astronauts were exposed to the complete elimination of hydrostatic gradients during a spaceflight of 10 days. During bed rest, LV mass decreased by 8.0 +/- 2.2% (P = 0.005) after 6 wk with an additional atrophy of 7.6 +/- 2.3% in the subjects who remained in bed for 12 wk; there was no change in LV mass for the control subjects (153.0 +/- 12.2 vs. 153.4 +/- 12.1 g, P = 0.81). Mean wall thickness decreased (4 +/- 2.5%, P = 0.01) after 6 wk of bed rest associated with the decrease in LV mass, suggesting a physiological remodeling with respect to altered load. LV end-diastolic volume decreased by 14 +/- 1.7% (P = 0.002) after 2 wk of bed rest and changed minimally thereafter. After 6 wk of bed rest, RV free wall mass decreased by 10 +/- 2.7% (P = 0.06) and RV end-diastolic volume by 16 +/- 7.9% (P = 0.06). After spaceflight, LV mass decreased by 12 +/- 6.9% (P = 0.07). In conclusion, cardiac atrophy occurs during prolonged (6 wk) horizontal bed rest and may also occur after short-term spaceflight. We suggest that cardiac atrophy is due to a physiological adaptation to reduced myocardial load and work in real or simulated microgravity and demonstrates the plasticity

  11. Hepatic mitochondrial energetics during catch-up fat with high-fat diets rich in lard or safflower oil

    OpenAIRE

    Crescenzo, R.; Bianco, F.; Falcone, I.; Tsalouhidou, S.; Yepuri, G.; Mougios, V.; Dulloo, A.; Liverini, G.; Iossa, S.

    2012-01-01

    We have investigated whether altered hepatic mitochondrial energetics could explain the differential effects of high-fat diets with low or high ω6 polyunsaturated fatty acid content (lard vs. safflower oil) on the efficiency of body fat recovery (catch-up fat) during refeeding after caloric restriction. After 2 weeks of caloric restriction, rats were isocalorically refed with a low-fat diet (LF) or high-fat diets made from either lard or safflower oil for 1 week, and energy balance and body c...

  12. Robotic Applications in Cardiac Surgery

    Directory of Open Access Journals (Sweden)

    Alan P. Kypson

    2008-11-01

    Full Text Available Traditionally, cardiac surgery has been performed through a median sternotomy, which allows the surgeon generous access to the heart and surrounding great vessels. As a paradigm shift in the size and location of incisions occurs in cardiac surgery, new methods have been developed to allow the surgeon the same amount of dexterity and accessibility to the heart in confined spaces and in a less invasive manner. Initially, long instruments without pivot points were used, however, more recent robotic telemanipulation systems have been applied that allow for improved dexterity, enabling the surgeon to perform cardiac surgery from a distance not previously possible. In this rapidly evolving field, we review the recent history and clinical results of using robotics in cardiac surgery.

  13. Understanding traumatic blunt cardiac injury.

    Science.gov (United States)

    El-Menyar, Ayman; Al Thani, Hassan; Zarour, Ahmad; Latifi, Rifat

    2012-01-01

    Cardiac injuries are classified as blunt and penetrating injuries. In both the injuries, the major issue is missing the diagnosis and high mortality. Blunt cardiac injuries (BCI) are much more common than penetrating injuries. Aiming at a better understanding of BCI, we searched the literature from January 1847 to January 2012 by using MEDLINE and EMBASE search engines. Using the key word "Blunt Cardiac Injury," we found 1814 articles; out of which 716 articles were relevant. Herein, we review the causes, diagnosis, and management of BCI. In conclusion, traumatic cardiac injury is a major challenge in critical trauma care, but the guidelines are lacking. A high index of suspicion, application of current diagnostic protocols, and prompt and appropriate management is mandatory.

  14. Understanding traumatic blunt cardiac injury

    Directory of Open Access Journals (Sweden)

    Ayman El-Menyar

    2012-01-01

    Full Text Available Cardiac injuries are classified as blunt and penetrating injuries. In both the injuries, the major issue is missing the diagnosis and high mortality. Blunt cardiac injuries (BCI are much more common than penetrating injuries. Aiming at a better understanding of BCI, we searched the literature from January 1847 to January 2012 by using MEDLINE and EMBASE search engines. Using the key word "Blunt Cardiac Injury," we found 1814 articles; out of which 716 articles were relevant. Herein, we review the causes, diagnosis, and management of BCI. In conclusion, traumatic cardiac injury is a major challenge in critical trauma care, but the guidelines are lacking. A high index of suspicion, application of current diagnostic protocols, and prompt and appropriate management is mandatory.

  15. Recent developments in cardiac pacing.

    Science.gov (United States)

    Rodak, D J

    1995-10-01

    Indications for cardiac pacing continue to expand. Pacing to improve functional capacity, which is now common, relies on careful patient selection and technical improvements, such as complex software algorithms and diagnostic capabilities.

  16. Shock Wave Structure in the Presence of Energetic Particles

    Science.gov (United States)

    Mostafavi, Parisa; Zank, Gary P.; Webb, Gary M.

    2017-09-01

    Energetic particles that are not equilibrated with the thermal plasma (such as pickup ions (PUIs), anomalous cosmic rays (ACRs) and solar energetic particles (SEPs)) can modify the structure of collisionless shock waves. This is relevant to the inner and outer heliosphere and the Very Local Interstellar Medium (VLISM) where observations of shock waves in the e.g., the inner heliosphere show that the energetic particle component pressure is greater than the both the magnetic field and thermal gas pressure (Lario et al., 2015). Voyager 2 observations revealed that the heliospheric termination shock (HTS) is very broad and mediated by energetic particles. PUIs and SEPs contribute both a collisionless heat flux and a higher-order viscosity. We show that the incorporation of both effects can completely determine the structure of collisionless shocks mediated by energetic ions. Since the reduced form of the PUI mediated plasma model is structurally identical to the classical cosmic ray two-fluid model (Axford et al., (1982)), we note that the presence of viscosity at least formally eliminates the need of a gas sub-shock in the classical two-fluid model, including in that regime where three are possible. By considering parameters upstream of the heliospheric termination shock (HTS), we show that the thermal gas remains relatively cold and the shock is mediated by PUIs. We determine the structure of the weak interstellar shock observed by Voyager 1. We consider the inclusion of the thermal heat flux and viscosity to address the most general form of an energetic particle-thermal plasma two-fluid model.

  17. Energetics and efficiency of a molecular motor model

    OpenAIRE

    Fogedby, Hans C.; Svane, Axel

    2013-01-01

    The energetics and efficiency of a linear molecular motor model proposed by Mogilner et al. (Phys. Lett. 237, 297 (1998)) is analyzed from an analytical point of view. The model which is based on protein friction with a track is described by coupled Langevin equations for the motion in combination with coupled master equations for the ATP hydrolysis. Here the energetics and efficiency of the motor is addressed using a many body scheme with focus on the efficiency at maximum power (EMP). It is...

  18. ENERGETIC EXTREMES IN REEF FISH OCCUPYING HARSH HABITATS

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2009-01-01

    Christopher Fulton1, John Steffensen2, Jacob Johansen3 Indo-Pacific Fish Conference, Fremantle, Western Australia, May 2009 - Talk Abstract: Fish living in harsh habitats often display phenotypic features that allow them to deal with extreme and/or highly variable environmental conditions. We......-swept environment (up to 1 m s-1) whilst incurring a relatively low energetic cost of transport. Paddle-finned sister taxa, which have slightly more rounded fins and occupy sheltered habitats, displayed similar levels of energetic efficiency, but at swimming speeds less than half that of their wing...

  19. Energetical and economical assessment of the waste heat problem

    International Nuclear Information System (INIS)

    Demicheli, U.; Voort, E. van der; Schneiders, A.; Zegers, P.

    1977-01-01

    Electrical power plants produce large quantities of low grade heat that remain unused. For ecological reasons this waste heat must be dispersed by means of expensive cooling devices. Waste heat could be used in acquacultural and agricultural complexes this replacing large amounts of primary energy. Energetical and economical aspects are discussed. The state of the art of these and other utilisations is outlined. A different approach to the problem is to reduce the production of waste heat. Various strategies to achieve this challenge are outlined and their actual state and possible future developments are discussed. Finally, the various most promising utilizations are examined from an energetical point of view

  20. ENERGETIC EXTREMES IN REEF FISH OCCUPYING HARSH HABITATS

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2009-01-01

    document how relatively small changes in fin morphology has afforded some coral reef fish taxa with exceptional locomotor performance and energetic efficiency, and how this key attribute may have played a key role in the evolution and ecology of several diverse Indo-Pacific reef fish families. Using......-finned counterparts. We discuss how such differences in locomotor efficiency are pivotal to the habitat-use of these fishes, and how eco-energetic models may be used to provide new insights into spatial variations in fish demography and ecology among coral reef habitat zones....

  1. Cardiac Regeneration and Stem Cells.

    Science.gov (United States)

    Zhang, Yiqiang; Mignone, John; MacLellan, W Robb

    2015-10-01

    After decades of believing the heart loses the ability to regenerate soon after birth, numerous studies are now reporting that the adult heart may indeed be capable of regeneration, although the magnitude of new cardiac myocyte formation varies greatly. While this debate has energized the field of cardiac regeneration and led to a dramatic increase in our understanding of cardiac growth and repair, it has left much confusion in the field as to the prospects of regenerating the heart. Studies applying modern techniques of genetic lineage tracing and carbon-14 dating have begun to establish limits on the amount of endogenous regeneration after cardiac injury, but the underlying cellular mechanisms of this regeneration remained unclear. These same studies have also revealed an astonishing capacity for cardiac repair early in life that is largely lost with adult differentiation and maturation. Regardless, this renewed focus on cardiac regeneration as a therapeutic goal holds great promise as a novel strategy to address the leading cause of death in the developed world. Copyright © 2015 the American Physiological Society.

  2. Cardiac misconceptions in healthcare workers.

    Science.gov (United States)

    Angus, Neil; Patience, Fiona; Maclean, Elizabeth; Corrigall, Helen; Bradbury, Ian; Thompson, David R; Atherton, Iain; Leslie, Stephen J

    2012-12-01

    Cardiac misconceptions are common and may have a detrimental effect on patients. Such misconceptions may be introduced or reinforced by vague and inconsistent advice from healthcare staff and can adversely affect health outcomes. To assess whether level of cardiac misconceptions significantly differs between groups of healthcare staff based on occupation. The 22-item York cardiac beliefs questionnaire (YCBQ) was administered to a convenience sample of healthcare staff (n = 263) in direct contact with cardiac patients. Data was also collected on the occupation of healthcare staff and years worked. Medical staff had the lowest mean score (17.5, CI 15.6-19.4), indicating fewest misconceptions, and unqualified healthcare workers had the highest mean score (32.1, CI 28.4-35.7). Analysis by ANOVA indicated differences between staff groups to be statistically significant (F = 17.66, p misconception score (Pearson's r = - 0.243, p misconceptions in different groups of healthcare staff. Education to correct cardiac misconceptions should be particularly targeted at unqualified healthcare staff. The importance of maintaining appropriate ratios of qualified to unqualified healthcare staff in the care of cardiac patients is supported by this study.

  3. FGF21 and cardiac physiopathology

    Directory of Open Access Journals (Sweden)

    Anna ePlanavila

    2015-08-01

    Full Text Available The heart is not traditionally considered either a target or a site of fibroblast growth factor-21 (FGF21 production. However, recent findings indicate that FGF21 can act as a cardiomyokine; that is, it is produced by cardiac cells at significant levels and acts in an autocrine manner on the heart itself. The heart is sensitive to the effects of FGF21, both systemic and locally generated, owing to the expression in cardiomyocytes of β-Klotho, the key co-receptor known to confer specific responsiveness to FGF21 action. FGF21 has been demonstrated to protect against cardiac hypertrophy, cardiac inflammation, and oxidative stress. FGF21 expression in the heart is induced in response to cardiac insults, such as experimental cardiac hypertrophy and myocardial infarction in rodents, as well as in failing human hearts. Intracellular mechanisms involving PPARα and Sirt1 mediate transcriptional regulation of the FGF21 gene in response to exogenous stimuli. In humans, circulating FGF21 levels are elevated in coronary heart disease and atherosclerosis, and are associated with a higher risk of cardiovascular events in patients with type 2 diabetes. These findings provide new insights into the role of FGF21 in the heart and may offer potential therapeutic strategies for cardiac disease.

  4. Cardiac involvement in myotonic dystrophy

    DEFF Research Database (Denmark)

    Lund, Marie; Diaz, Lars Jorge; Ranthe, Mattis Flyvholm

    2014-01-01

    genetic testing for DM1. Information on incident cardiac diseases was obtained from the NPR. We estimated standardized incidence ratios (SIRs) of cardiac disease compared with the background population, overall and according to selected diagnostic subgroups (cardiomyopathy, heart failure, conduction...... disorders, arrhythmias, and device implantation). In the DM cohort, SIR for any cardiac disease was 3.42 [95% confidence interval (CI) 3.01-3.86]; for a cardiac disease belonging to the selected subgroups 6.91 (95% CI: 5.93-8.01) and for other cardiac disease 2.59 (95% CI: 2.03-3.25). For a cardiac disease...... belonging to the selected subgroups, the risk was particularly high in the first year after DM diagnosis [SIR 15.4 (95% CI: 10.9-21.3)] but remained significantly elevated in subsequent years [SIR 6.07 (95% CI: 5.11-7.16]). The risk was higher in young cohort members [e.g. 20-39 years: SIR 18.1 (95% CI: 12...

  5. The Effect of Dexamethasone on Symptoms of Posttraumatic Stress Disorder and Depression After Cardiac Surgery and Intensive Care Admission : Longitudinal Follow-Up of a Randomized Controlled Trial

    NARCIS (Netherlands)

    Kok, Lotte; Hillegers, Manon H.; Veldhuijzen, Dieuwke S.; Cornelisse, Sandra; Nierich, Arno P.; Maaten, van der Joost M.; Rosseel, Peter M.; Hofland, Jan; Sep, Milou S.; Dieleman, Jan M.; Vinkers, Christiaan H.; Peelen, Linda M.; Joels, Marian; van Dijk, Diederik

    Objective: Cardiac surgery and postoperative admission to the ICU may lead to posttraumatic stress disorder and depression. Perioperatively administered corticosteroids potentially alter the risk of development of these psychiatric conditions, by affecting the hypothalamic-pituitary-adrenal axis.

  6. Sudden Cardiac Death

    DEFF Research Database (Denmark)

    Risgaard, Bjarke; Winkel, Bo Gregers; Jabbari, Reza

    2017-01-01

    Objectives This study sought to describe the use of pharmacotherapy in a nationwide cohort of young patients with sudden cardiac death (SCD). Background Several drugs have been associated with an increased risk of SCD and sudden arrhythmic death syndrome (SADS). It remains unclear how....... Autopsy was performed in 55%. Overall, 58% of SCD cases (n = 786) received at least 1 drug within 90 days before death. The most common drugs were analgesic drugs (n = 239; 18%), antihypertensive drugs (n = 234; 17%), and antibiotic drugs (n = 218; 16%). After multivariable adjustment, prescription...... of “brugadogenic” drugs or >1 QT-prolonging drug was associated with an increased risk of SADS compared with explained SCD (odds ratio: 2.16 [95% confidence interval: 1.12 to 4.17] and 2.91 [95% confidence interval: 1.46 to 5.81], respectively). Conclusions Pharmacotherapy was identified in 58% of the SCD cases...

  7. Cardiac output during exercise

    DEFF Research Database (Denmark)

    Siebenmann, C; Rasmussen, P.; Sørensen, H.

    2015-01-01

    Several techniques assessing cardiac output (Q) during exercise are available. The extent to which the measurements obtained from each respective technique compares to one another, however, is unclear. We quantified Q simultaneously using four methods: the Fick method with blood obtained from...... the right atrium (Q(Fick-M)), Innocor (inert gas rebreathing; Q(Inn)), Physioflow (impedance cardiography; Q(Phys)), and Nexfin (pulse contour analysis; Q(Pulse)) in 12 male subjects during incremental cycling exercise to exhaustion in normoxia and hypoxia (FiO2  = 12%). While all four methods reported...... a progressive increase in Q with exercise intensity, the slopes of the Q/oxygen uptake (VO2) relationship differed by up to 50% between methods in both normoxia [4.9 ± 0.3, 3.9 ± 0.2, 6.0 ± 0.4, 4.8 ± 0.2 L/min per L/min (mean ± SE) for Q(Fick-M), Q(Inn), QP hys and Q(Pulse), respectively; P = 0...

  8. Observations of Energetic Particle Escape at the Magnetopause: Early Results from the MMS Energetic Ion Spectrometer (EIS)

    Science.gov (United States)

    Cohen, I. J.; Mauk, B. H.; Anderson, B. J.; Westlake, J. H.; Sibeck, David Gary; Giles, Barbara L.; Pollock, C. J.; Turner, D. L.; Fennell, J. F.; Blake, J. B.; hide

    2016-01-01

    Energetic (greater than tens of keV) magnetospheric particle escape into the magnetosheath occurs commonly, irrespective of conditions that engender reconnection and boundary-normal magnetic fields. A signature observed by the Magnetospheric Multiscale (MMS) mission, simultaneous monohemispheric streaming of multiple species (electrons, H+, Hen+), is reported here as unexpectedly common in the dayside, dusk quadrant of the magnetosheath even though that region is thought to be drift-shadowed from energetic electrons. This signature is sometimes part of a pitch angle distribution evolving from symmetric in the magnetosphere, to asymmetric approaching the magnetopause, to monohemispheric streaming in the magnetosheath. While monohemispheric streaming in the magnetosheath may be possible without a boundary-normal magnetic field, the additional pitch angle depletion, particularly of electrons, on the magnetospheric side requires one. Observations of this signature in the dayside dusk sector imply that the static picture of magnetospheric drift-shadowing is inappropriate for energetic particle dynamics in the outer magnetosphere.

  9. Semiconductor nanostructures for plasma energetic systems

    Science.gov (United States)

    Mustafaev, Alexander; Smerdov, Rostislav; Klimenkov, Boris

    2017-10-01

    In this talk we discuss the research results of the three types of ultrasmall electrodes namely the nanoelectrode arrays based on composite nanostructured porous silicon (PS) layers, porous GaP and nanocrystals of ZnO. These semiconductor materials are of great interest to nano- and optoelectronic applications by virtue of their high specific surface area and extensive capability for surface functionalization. The use of semiconductor (GaN) cathodes in photon-enhanced thermionic emission systems has also proved to be effective although only a few (less than 1%) of the incident photons exceed the 3.3 eV GaN band gap. This significant drawback provided us with a solid foundation for our research in the field of nanostructured PS, and composite materials based on it exhibiting nearly optimal parameters in terms of the band gap (1.1 eV). The band gap modification for PS nanostructured layers is possible in the range of less than 1 eV and 3 eV due to the existence of quantum confinement effect and the remarkable possibilities of PS surface alteration thus providing us with a suitable material for both cathode and anode fabrication. The obtained results are applicable for solar concentration and thermionic energy conversion systems. Dr. Sci., Ph.D, Principal Scientist, Professor.

  10. Risk factors and the effect of cardiac resynchronization therapy on cardiac and non-cardiac mortality in MADIT-CRT

    DEFF Research Database (Denmark)

    Perkiomaki, Juha S; Ruwald, Anne-Christine; Kutyifa, Valentina

    2015-01-01

    AIMS: To understand modes of death and factors associated with the risk for cardiac and non-cardiac deaths in patients with cardiac resynchronization therapy with implantable cardioverter-defibrillator (CRT-D) vs. implantable cardioverter-defibrillator (ICD) therapy, which may help clarify...... the action and limitations of cardiac resynchronization therapy (CRT) in relieving myocardial dysfunction. METHODS AND RESULTS: In Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy (MADIT-CRT), during 4 years of follow-up, 169 (9.3%) of 1820 patients died of known...... causes, 108 (63.9%) deemed cardiac, and 61 (36.1%) non-cardiac. In multivariate analysis, increased baseline creatinine was significantly associated with both cardiac and non-cardiac deaths [hazard ratio (HR) 2.97, P

  11. Dietary Fatty Acids Alter Lipid Profiles and Induce Myocardial Dysfunction without Causing Metabolic Disorders in Mice.

    Science.gov (United States)

    Chen, Bainian; Huang, Yifan; Zheng, Dong; Ni, Rui; Bernards, Mark A

    2018-01-19

    Oversupply of bulk saturated fatty acids (SFA) induces metabolic disorders and myocardial dysfunction. We investigated whether, without causing metabolic disorders, the uptake of individual dietary SFA species alters lipid profiles and induces myocardial dysfunction. C57BL/6 mice were fed various customized long-chain SFA diets (40% caloric intake from SFA), including a beef tallow (HBD), cocoa butter (HCD), milk fat (HMD) and palm oil diet (HPD), for 6 months. An isocaloric fat diet, containing medium-chain triglycerides, served as a control (CHD). Long-term intake of dietary long-chain SFA differentially affected the fatty acid composition in cardiac phospholipids. All long-chain SFA diets increased the levels of arachidonic acid and total SFA in cardiac phospholipids. The preferential incorporation of individual SFA into the cardiac phospholipid fraction was dependent on the dietary SFA species. Cardiac ceramide content was elevated in all mice fed long-chain SFA diets, while cardiac hypertrophy was only presented in mice fed HMD or HPD. We have demonstrated that the intake of long-chain SFA species differentially alters cardiac lipid profiles and induces cardiac dysfunction, without causing remarkable metabolic disorders.

  12. Interventricular comparison of the energetics of contraction of trabeculae carneae isolated from the rat heart.

    Science.gov (United States)

    Han, June-Chiew; Taberner, Andrew J; Nielsen, Poul M F; Loiselle, Denis S

    2013-02-01

    We compare the energetics of right ventricular and left ventricular trabeculae carneae isolated from rat hearts. Using our work-loop calorimeter, we subjected trabeculae to stress-length work (W), designed to mimic the pressure-volume work of the heart. Simultaneous measurement of heat production (Q) allowed calculation of the accompanying change of enthalpy (H = W + Q). From the mechanical measurements (i.e. stress and change of length), we calculated work, shortening velocity and power. In combination with heat measurements, we calculated activation heat (Q(A)), crossbridge heat (Q(xb)) and two measures of cardiac efficiency: 'mechanical efficiency' ((mech) = W/H) and 'crossbridge efficiency' ((xb) = W/(H - Q(A))). With respect to their left ventricular counterparts, right venticular trabeculae have higher peak shortening velocity, and higher peak mechanical efficiency, but with no difference of stress development, twitch duration, work performance, shortening power or crossbridge efficiency. That is, the 35% greater maximum mechanical efficiency of right venticular than left ventricular trabeculae (13.6 vs. 10.2%) is offset by the greater metabolic cost of activation (Q(A)) in the latter. When corrected for this difference, crossbridge efficiency does not differ between the ventricles.

  13. Cardiac molecular-acclimation mechanisms in response to swimming-induced exercise in Atlantic salmon.

    Directory of Open Access Journals (Sweden)

    Vicente Castro

    Full Text Available Cardiac muscle is a principal target organ for exercise-induced acclimation mechanisms in fish and mammals, given that sustained aerobic exercise training improves cardiac output. Yet, the molecular mechanisms underlying such cardiac acclimation have been scarcely investigated in teleosts. Consequently, we studied mechanisms related to cardiac growth, contractility, vascularization, energy metabolism and myokine production in Atlantic salmon pre-smolts resulting from 10 weeks exercise-training at three different swimming intensities: 0.32 (control, 0.65 (medium intensity and 1.31 (high intensity body lengths s(-1. Cardiac responses were characterized using growth, immunofluorescence and qPCR analysis of a large number of target genes encoding proteins with significant and well-characterized function. The overall stimulatory effect of exercise on cardiac muscle was dependent on training intensity, with changes elicited by high intensity training being of greater magnitude than either medium intensity or control. Higher protein levels of PCNA were indicative of cardiac growth being driven by cardiomyocyte hyperplasia, while elevated cardiac mRNA levels of MEF2C, GATA4 and ACTA1 suggested cardiomyocyte hypertrophy. In addition, up-regulation of EC coupling-related genes suggested that exercised hearts may have improved contractile function, while higher mRNA levels of EPO and VEGF were suggestive of a more efficient oxygen supply network. Furthermore, higher mRNA levels of PPARα, PGC1α and CPT1 all suggested a higher capacity for lipid oxidation, which along with a significant enlargement of mitochondrial size in cardiac myocytes of the compact layer of fish exercised at high intensity, suggested an enhanced energetic support system. Training also elevated transcription of a set of myokines and other gene products related to the inflammatory process, such as TNFα, NFκB, COX2, IL1RA and TNF decoy receptor. This study provides the first

  14. Electron energetics in the expanding solar wind via Helios observations

    Czech Academy of Sciences Publication Activity Database

    Štverák, Štěpán; Trávníček, Pavel M.; Hellinger, Petr

    2015-01-01

    Roč. 120, č. 10 (2015), s. 8177-8193 ISSN 2169-9380 R&D Projects: GA ČR GAP209/12/2041; GA ČR GA15-17490S Institutional support: RVO:67985815 Keywords : solar wind * electrons energetics * transport processes Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.318, year: 2015

  15. The effect of stability treatmetn on the surface energetics of ...

    African Journals Online (AJOL)

    The effect of stability treatmetn on the surface energetics of inhalation grade lactose. IP Okoye. Abstract. No Abstract. Global Journal of Pure and Applied Physics Vol. 14 (1) 2008 pp.85-88. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  16. Energetics of lower tropospheric planetary waves over mid latitudes ...

    Indian Academy of Sciences (India)

    Energetics of lower tropospheric planetary waves over mid latitudes: Precursor for Indian summer monsoon. S M Bawiskar. ∗. , M D Chipade, P V Puranik and U V Bhide. Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pune 411 008, India. ∗ e-mail: bawiskar@hotmail.com. Based on NCEP/NCAR ...

  17. The Energetic Particle Environment of the Lunar Nearside: SEP Influence

    Science.gov (United States)

    Xu, Xiaojun; Angelopoulos, Vassilis; Wang, Yi; Zuo, Pingbing; Wong, Hon-Cheng; Cui, Jun

    2017-11-01

    The energetic particle environment of the lunar nearside is quite different from that of the lunar farside. Due to the shielding of the Earth’s magnetosphere and the Moon, the lunar nearside may receive much fewer energetic particles from the Sun. It is currently impossible to directly measure the received energetic particle flux of the whole lunar surface. By using the ARTEMIS and Wind observations, we qualitatively studied the shielding effect of the Earth’s magnetosphere and the lunar body from solar energetic particles (SEPs). We found that the Earth’s magnetosphere can effectively shield SEPs with energies up to 4 Mev during the SEP event. However, in the solar wind, the Moon can provide partial shielding from SEPs with energies ≤100 KeV. SEPs with energies above 150 KeV in the lunar shadow show no difference in flux from in the solar wind, which suggests that the nearside and farside are the same in receiving SEPs with energies above 150 KeV during the SEP event.

  18. The Prudent Parent : Energetic Adjustments in Avian Breeding

    NARCIS (Netherlands)

    Drent, R.H.; Daan, S.

    1980-01-01

    1. Energetics of reproduction in birds is reviewed with the question in mind how the parent adjusts its effort in relation to prevailing environmental conditions in order to maximize the output of young in its lifetime. Emphasis is on proximate controls, rather than ultimate factors measurable in

  19. Fast Reacting Nano Composite Energetic Materials: Synthesis and Combustion Characterization

    Science.gov (United States)

    2015-08-24

    understanding of fast reacting energetic nanocomposite systems (Kappagantula, Pantoya and Horn, Effect of surface coatings on aluminum fuel particles...J. Horn. "Effect of surface coatings on aluminum fuel particles toward nanocomposite combustion." Surface and Coatings Technology 237 (2013): 456...themal transport properties of aluminum‐ polytetrafluoroethylene nanocomposites with graphene and carbon nanotube additives 2012

  20. Computational studies on energetic properties of nitrogen-rich ...

    Indian Academy of Sciences (India)

    reac tan t. H0 f are sums of the HOFs for products and reactants in gas at 298.15 K, respectively. (P V ) equals nRT for reaction in gas phase and n = 0 for isodemic reactions. Detonation velocity (D) and pressure (P) are the most important targets of scaling the detonation char- acteristics of energetic materials. Kamlet-Jacobs ...

  1. Ultrashort-pulse laser generated nanoparticles of energetic materials

    Science.gov (United States)

    Welle, Eric J [Niceville, NM; Tappan, Alexander S [Albuquerque, NM; Palmer, Jeremy A [Albuquerque, NM

    2010-08-03

    A process for generating nanoscale particles of energetic materials, such as explosive materials, using ultrashort-pulse laser irradiation. The use of ultrashort laser pulses in embodiments of this invention enables one to generate particles by laser ablation that retain the chemical identity of the starting material while avoiding ignition, deflagration, and detonation of the explosive material.

  2. Impact of global warming on the energetics of lower tropospheric ...

    Indian Academy of Sciences (India)

    Impact of global warming on the energetics of lower tropospheric ultra-long waves and the Indian summer monsoon. M D Chipade∗. , J R Kulkarni and S M Bawiskar. Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pune 411 008, India. ∗. Corresponding author. e-mail: mukundchipade@yahoo.co.in.

  3. Regional and municipal energetic statistics - Sao Paulo State - 1986

    International Nuclear Information System (INIS)

    1988-10-01

    The main Brazilian energetic information for subsidizing planning studies in regional and municipal level are presented, including data for the year 1988 that represent the sale of the main petroleum by-product and hydrated alcohol and the electricity consumption. (C.G.C.)

  4. Study on the Energetic Parameters in a Photothermic Sensor with ...

    African Journals Online (AJOL)

    Study on the Energetic Parameters in a Photothermic Sensor with Black Polymeric Film. ... The evolution of incidental solar illumination on the horizontal plan of sensor and the temperature distribution are studied. Results showed that the ... Keywords: film, solar energy, greenhouse effect, design, radiation, illumination.

  5. Energetic lanthanide complexes: coordination chemistry and explosives applications

    International Nuclear Information System (INIS)

    Manner, V W; Barker, B J; Sanders, V E; Laintz, K E; Scott, B L; Preston, D N; Sandstrom, M; Reardon, B L

    2014-01-01

    Metals are generally added to organic molecular explosives in a heterogeneous composite to improve overall heat and energy release. In order to avoid creating a mixture that can vary in homogeneity, energetic organic molecules can be directly bonded to high molecular weight metals, forming a single metal complex with Angstrom-scale separation between the metal and the explosive. To probe the relationship between the structural properties of metal complexes and explosive performance, a new series of energetic lanthanide complexes has been prepared using energetic ligands such as NTO (5-nitro-2,4-dihydro-1,2,4-triazole-3-one). These are the first examples of lanthanide NTO complexes where no water is coordinated to the metal, demonstrating novel control of the coordination environment. The complexes have been characterized by X-ray crystallography, NMR and IR spectroscopies, photoluminescence, and sensitivity testing. The structural and energetic properties are discussed in the context of enhanced blast effects and detection. Cheetah calculations have been performed to fine-tune physical properties, creating a systematic method for producing explosives with 'tailor made' characteristics. These new complexes will be benchmarks for further study in the field of metalized high explosives.

  6. Energetic particle emission and nuclear dynamics around the Fermi energy

    International Nuclear Information System (INIS)

    Sapienza, P.; Coniglione, R.; Colonna, M.; Agodi, C.; Alba, R.; Bellia, G.; Del Zoppo, A.; Finocchiaro, P.; Greco, V.; Loukachine, K.; Maiolino, C.; Migneco, E.; Piatteli, P.; Santonocito, D.; Colonna, N.; Bruno, M.; D'Agostino, M.; Fiandri, M.L.; Vannini, G.; Gramegna, F.; Mastinu, P.F.; Fabbietti, L.; Iori, I.; Moroni, A.; Margagliotti, G.; Milazzo, P.M.; Rui, R.; Blumenfeld, Y.; Scarpaci, J.A.

    2004-01-01

    Energetic proton emission was investigated in the reaction 58 Ni+ 58 Ni at 30 AMeV and compared with the results of dynamical calculations with a momentum dependent mean field. Preliminary results on proton and intermediate mass fragment coincidences are also presented

  7. Energetic particle emission and nuclear dynamics around the Fermi energy

    Science.gov (United States)

    Sapienza, P.; Coniglione, R.; Colonna, M.; Agodi, C.; Alba, R.; Bellia, G.; Del Zoppo, A.; Finocchiaro, P.; Greco, V.; Loukachine, K.; Maiolino, C.; Migneco, E.; Piatteli, P.; Santonocito, D.; Colonna, N.; Bruno, M.; D'Agostino, M.; Fiandri, M. L.; Vannini, G.; Gramegna, F.; Mastinu, P. F.; Fabbietti, L.; Iori, I.; Moroni, A.; Margagliotti, G.; Milazzo, P. M.; Rui, R.; Blumenfeld, Y.; Scarpaci, J. A.

    2004-04-01

    Energetic proton emission was investigated in the reaction 58Ni+ 58Ni at 30 AMeV and compared with the results of dynamical calculations with a momentum dependent mean field. Preliminary results on proton and intermediate mass fragment coincidences are also presented.

  8. Energetic particle emission and nuclear dynamics around the Fermi energy

    Energy Technology Data Exchange (ETDEWEB)

    Sapienza, P.; Coniglione, R.; Colonna, M.; Agodi, C.; Alba, R.; Bellia, G.; Del Zoppo, A.; Finocchiaro, P.; Greco, V.; Loukachine, K.; Maiolino, C.; Migneco, E.; Piatteli, P.; Santonocito, D.; Colonna, N.; Bruno, M.; D' Agostino, M.; Fiandri, M.L.; Vannini, G.; Gramegna, F.; Mastinu, P.F.; Fabbietti, L.; Iori, I.; Moroni, A.; Margagliotti, G.; Milazzo, P.M.; Rui, R.; Blumenfeld, Y.; Scarpaci, J.A

    2004-04-05

    Energetic proton emission was investigated in the reaction {sup 58}Ni+{sup 58}Ni at 30 AMeV and compared with the results of dynamical calculations with a momentum dependent mean field. Preliminary results on proton and intermediate mass fragment coincidences are also presented.

  9. Structural, energetic and electronic properties of intercalated boron

    Indian Academy of Sciences (India)

    The effects of chirality and the intercalation of transitional metal atoms inside single walled BN nanotubes on structural, energetic and electronic properties have been considered in this paper. The thermodynamic stability of BN nanotubes can be improved by the intercalation of cobalt or nickel. BN nanotubes can behave ...

  10. The energetics of organic synthesis inside and outside the cell.

    Science.gov (United States)

    Amend, Jan P; LaRowe, Douglas E; McCollom, Thomas M; Shock, Everett L

    2013-07-19

    Thermodynamic modelling of organic synthesis has largely been focused on deep-sea hydrothermal systems. When seawater mixes with hydrothermal fluids, redox gradients are established that serve as potential energy sources for the formation of organic compounds and biomolecules from inorganic starting materials. This energetic drive, which varies substantially depending on the type of host rock, is present and available both for abiotic (outside the cell) and biotic (inside the cell) processes. Here, we review and interpret a library of theoretical studies that target organic synthesis energetics. The biogeochemical scenarios evaluated include those in present-day hydrothermal systems and in putative early Earth environments. It is consistently and repeatedly shown in these studies that the formation of relatively simple organic compounds and biomolecules can be energy-yielding (exergonic) at conditions that occur in hydrothermal systems. Expanding on our ability to calculate biomass synthesis energetics, we also present here a new approach for estimating the energetics of polymerization reactions, specifically those associated with polypeptide formation from the requisite amino acids.

  11. Structural, energetic and electronic properties of intercalated boron ...

    Indian Academy of Sciences (India)

    The effects of chirality and the intercalation of transitional metal atoms inside single walled BN nanotubes on structural, energetic and electronic properties have been considered in this paper. The thermodynamic stability of BN nanotubes can be improved by the intercalation of cobalt or nickel. BN nanotubes can behave ...

  12. Determining the energetics of vicinal perovskite oxide surfaces

    NARCIS (Netherlands)

    Wessels, W.A.; Bollmann, Tjeerd Rogier Johannes; Koster, Gertjan; Zandvliet, Henricus J.W.; Rijnders, Augustinus J.H.M.

    2017-01-01

    The energetics of vicinal SrTiO3(001) and DyScO3(110), prototypical perovskite vicinal surfaces, has been studied using topographic atomic force microscopy imaging. The kink formation and strain relaxation energies are extracted from a statistical analysis of the step meandering. Both perovskite

  13. MHD phenomena and transport of energetic ions in spherical tori

    International Nuclear Information System (INIS)

    Kolesnichenko, Ya.I.; Lutsenko, V.V.; Marchenko, V.S.; Yakovenko, Yu.V.; White, R.B.

    2003-01-01

    Mechanisms of the in the influence of MHD events on the beam ions in moderate-β plasmas relevant to current experiments on NSTX are studied. Change of the neutron yield caused by particle redistribution is evaluated. Destabilizing effect of the trapped energetic ions on ideal and non-ideal MHD modes in high-β plasmas is predicted. (author)

  14. Pulsations of Energetic Electron Pulsations In Association With Substorm Onset

    Science.gov (United States)

    Åsnes, A.; Stadsnes, J.; Bjordal, J.; Østgaard, N.; Haaland, S.; Rosenberg, T. J.; Detrick, D. L.

    The Polar Ionospheric X-ray Imaging Experiment (PIXIE) is giving detailed images of the energetic electron precipitation when the POLAR satellite is near perigee over the Antarctica. In this area the PIXIE images have a spatial resolution of the order of 100 km, and a temporal resolution of 10 s can be obtained. In this paper we present the results of a study focusing on the onset and expansion of a substorm occuring on July 24, 1998. In this event we observe strong modulations of the energetic electron precipitation with period around 1 minute following substorm onset. The pulsations were restricted to a narrow magnetic local time sector in the pre-midnight region, about 0.5 hours wide, and showed movement towards higher latitudes and earlier lo- cal times. The event will be discussed in context of measurements from ground sta- tions and satellites in geosynchronous orbit. Precipitation of energetic electrons will be compared with VLF/ELF ground measurements. Features in the energetic elec- tron precipitation will be mapped to the magnetospheric equatorial plane by field line tracing.

  15. Chemical physics of decomposition of energetic materials. Problems and prospects

    International Nuclear Information System (INIS)

    Smirnov, Lev P

    2004-01-01

    The review is concerned with analysis of the results obtained in the kinetic and mechanistic studies on decomposition of energetic materials (explosives, powders and solid propellants). It is shown that the state-of-the art in this field is inadequate to the potential of modern chemical kinetics and chemical physics. Unsolved problems are outlined and ways of their solution are proposed.

  16. Technological and energetic improvement of a propylene distillation column

    Directory of Open Access Journals (Sweden)

    Ostrovski Nikolaj

    2005-01-01

    Full Text Available A multicomponent distillation column for propylene purification was optimized in order to increase its energetic effectively. The ©-method coupled with the Soave-Redlich-Kwong equation of state for generating K-values and enthalpies was used. The optimal combination of pressure, temperature and reflux flow provided the decrease of steam consumption and loss of propylene with bottom flow.

  17. DNA-energetics-based analyses suggest additional genes in ...

    Indian Academy of Sciences (India)

    Permanent link: http://www.ias.ac.in/article/fulltext/jbsc/037/03/0433-0444 ... We present here a novel methodology for predicting new genes in prokaryotic genomes on the basis of inherent energetics of DNA. Regions of ... Quite surprisingly, the methodology identifies new genes even in well-annotated genomes. Also, the ...

  18. Foreshock waves as observed in energetic ion flux

    Czech Academy of Sciences Publication Activity Database

    Petrukovich, A. A.; Chugunova, O. M.; Inamori, T.; Kudela, Karel; Štetiarová, J.

    2017-01-01

    Roč. 122, č. 5 (2017), s. 4895-4904 ISSN 2169-9380 R&D Projects: GA MŠk EF15_003/0000481 Institutional support: RVO:61389005 Keywords : foreshock * waves * bow shock * energetic particles Subject RIV: DG - Athmosphere Sciences, Meteorology OBOR OECD: Meteorology and atmospheric sciences Impact factor: 2.733, year: 2016

  19. Energetic Requirements for Growth and Maintenance of the Cape ...

    African Journals Online (AJOL)

    Energetic requirements for growth and maintenance of the Cape gannet (Sula capensis) were studied by hand-rearing captive chicks and keeping juveniles in captivity at constant mass. Daily gain in mass was linear until 60 days of age; after 82 days the chicks lost mass prior to attaining fledging age (97 days).

  20. National energetic balance. Statistical compilation 1985-1991

    International Nuclear Information System (INIS)

    1992-01-01

    Compiles the statistical information supplied by governmental and private institutions which integrate the national energetic sector in Paraguay. The first part, refers to the whole effort of energy; second, energy transformation centres and the last part presents the energy flows, consolidated balances and other economic-power indicators

  1. DNA-energetics-based analyses suggest additional genes in ...

    Indian Academy of Sciences (India)

    2012-06-25

    Jun 25, 2012 ... [Khandelwal G, Gupta J and Jayaram B 2012 DNA-energetics-based analyses suggest additional genes in prokaryotes. J. Biosci. 37 433–444] DOI ..... illustration for detecting potential new genes in 12 different genomes with varied GC ..... maps and genetic map of DNA double strand. J. Phys. Soc. Jpn.

  2. Structural, energetic and electronic properties of intercalated boron ...

    Indian Academy of Sciences (India)

    Abstract. The effects of chirality and the intercalation of transitional metal atoms inside single walled BN nano- tubes on structural, energetic and electronic properties have been considered in this paper. The thermodynamic stability of BN nanotubes can be improved by the intercalation of cobalt or nickel. BN nanotubes can ...

  3. Regional and municipal energetic statistics - Sao Paulo State - 1987

    International Nuclear Information System (INIS)

    1989-01-01

    The main Brazilian energetic information for subsidizing planning studies in regional and municipal level are presented, including data for the year 1987 that represent the sale of the main petroleum by-product and hydrated alcohol and the electricity consumption. (C.G.C.)

  4. Energetic Mapping of Ni Catalysts by Detailed Kinetic Modeling

    DEFF Research Database (Denmark)

    Bjørgum, Erlend; Chen, De; Bakken, Mari G.

    2005-01-01

    precursor seems to result in more steplike sites, kinks, and defects for carbon monoxide dissociation. A detailed kinetic modeling of the TPO results based on elementary reaction steps has been conducted to give an energetic map of supported Ni catalysts. Experimental results from the ideal Ni surface fit...

  5. Proton thermal energetics in the solar wind: Helios reloaded

    Czech Academy of Sciences Publication Activity Database

    Hellinger, Petr; Trávníček, P.; Štverák, Štěpán; Matteini, L.; Velli, M.

    2013-01-01

    Roč. 118, č. 4 (2013), s. 1351-1365 ISSN 2169-9380 Institutional support: RVO:68378289 Keywords : solar wind * proton energetics * turbulent heating Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.440, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/jgra.50107/abstract

  6. Biomass consumption for energetic purpose in the household sector

    International Nuclear Information System (INIS)

    Gerardi, V.; Perrella, G.

    1999-01-01

    The report shows the results of a sampling survey performed to determine the biomass consumption for energetic purpose in the household sector. In particular, the methodology and sampling plan adopted to get a result with an error, at national level, of ±2.4%. are illustrated. Data are described and discusses [it

  7. Cardiac output monitoring

    Directory of Open Access Journals (Sweden)

    Mathews Lailu

    2008-01-01

    Full Text Available Minimally invasive and non-invasive methods of estimation of cardiac output (CO were developed to overcome the limitations of invasive nature of pulmonary artery catheterization (PAC and direct Fick method used for the measurement of stroke volume (SV. The important minimally invasive techniques available are: oesophageal Doppler monitoring (ODM, the derivative Fick method (using partial carbon dioxide (CO 2 breathing, transpulmonary thermodilution, lithium indicator dilution, pulse contour and pulse power analysis. Impedance cardiography is probably the only non-invasive technique in true sense. It provides information about haemodynamic status without the risk, cost and skill associated with the other invasive or minimally invasive techniques. It is important to understand what is really being measured and what assumptions and calculations have been incorporated with respect to a monitoring device. Understanding the basic principles of the above techniques as well as their advantages and limitations may be useful. In addition, the clinical validation of new techniques is necessary to convince that these new tools provide reliable measurements. In this review the physics behind the working of ODM, partial CO 2 breathing, transpulmonary thermodilution and lithium dilution techniques are dealt with. The physical and the physiological aspects underlying the pulse contour and pulse power analyses, various pulse contour techniques, their development, advantages and limitations are also covered. The principle of thoracic bioimpedance along with computation of CO from changes in thoracic impedance is explained. The purpose of the review is to help us minimize the dogmatic nature of practice favouring one technique or the other.

  8. Primary Cardiac Lymphoma

    Directory of Open Access Journals (Sweden)

    Shu-Ching Hsueh

    2006-04-01

    Full Text Available Primary cardiac lymphoma (PCL has rarely been reported in Chinese populations. PCL mostly occurs in the right atrium. The clinical manifestations may be variable and are attributed to its location, the presence of congestive heart failure, pericardial effusion, arrhythmia, and cardiomegaly. The prognosis is usually poor because it is usually found too late and therefore, clinicians should be aware of PCL. Imaging examinations are the best methods for initial diagnosis and include echocardiography, computed tomography (CT scan, magnetic resonance imaging (MRI, and radioisotope scan. However, the final diagnosis is made by pathology, such as cytologic examination of the effusive fluid and tissue biopsy. Because the tumors are difficult to resect, the main treatment for the disease is chemotherapy, which can be successful. Here, we report a 58-year-old man who had a tumor measuring 8 × 5 cm in the right atrium. By clinical staging, including chest X-ray, echocardiography, CT scan of the abdomen, MRI of the heart, whole body tumor Gallium scan, and gastrointestinal series, no metastatic lesion or involvement was found in other parts of the body. Pathologic findings including cytology of pericardial effusion and heart tumor biopsy revealed the case as a diffuse large B-cell lymphoma. After chemotherapy with COP (cyclophosphamide + vincristine + prednisone and CHOPBE (COP + doxorubicin + bleomycin + etoposide regimens, the intracardiac tumor had disappeared, but the patient survived for 12 months in total, despite additional radiotherapy over the pericardial lesions. It was presumed that because the tumor was very large and involved all 3 layers of the heart, it did not respond as well to the therapy as expected.

  9. Energetics, Biomechanics, and Performance in Masters' Swimmers: A Systematic Review.

    Science.gov (United States)

    Ferreira, Maria I; Barbosa, Tiago M; Costa, Mário J; Neiva, Henrique P; Marinho, Daniel A

    2016-07-01

    Ferreira, MI, Barbosa, TM, Costa, MJ, Neiva, HP, and Marinho, DA. Energetics, biomechanics, and performance in masters' swimmers: a systematic review. J Strength Cond Res 30(7): 2069-2081, 2016-This study aimed to summarize evidence on masters' swimmers energetics, biomechanics, and performance gathered in selected studies. An expanded search was conducted on 6 databases, conference proceedings, and department files. Fifteen studies were selected for further analysis. A qualitative evaluation of the studies based on the Quality Index (QI) was performed by 2 independent reviewers. The studies were thereafter classified into 3 domains according to the reported data: performance (10 studies), energetics (4 studies), and biomechanics (6 studies). The selected 15 articles included in this review presented low QI scores (mean score, 10.47 points). The biomechanics domain obtained higher QI (11.5 points), followed by energetics and performance (10.6 and 9.9 points, respectively). Stroke frequency (SF) and stroke length (SL) were both influenced by aging, although SF is more affected than SL. Propelling efficiency (ηp) decreased with age. Swimming performance declined with age. The performance declines with age having male swimmers deliver better performances than female counterparts, although this difference tends to be narrow in long-distance events. One single longitudinal study is found in the literature reporting the changes in performance over time. The remaining studies are cross-sectional designs focusing on the energetics and biomechanics. Overall, biomechanics parameters, such as SF, SL, and ηp, tend to decrease with age. This review shows the lack of a solid body of knowledge (reflected in the amount and quality of the articles published) on the changes in biomechanics, energetics, and performance of master swimmers over time. The training programs for this age-group should aim to preserve the energetics as much as possible and, concurrently, improve the

  10. Dual scattering foil design for poly-energetic electron beams.

    Science.gov (United States)

    Kainz, K K; Antolak, J A; Almond, P R; Bloch, C D; Hogstrom, K R

    2005-03-07

    The laser wakefield acceleration (LWFA) mechanism can accelerate electrons to energies within the 6-20 MeV range desired for therapy application. However, the energy spectrum of LWFA-generated electrons is broad, on the order of tens of MeV. Using existing laser technology, the therapeutic beam might require a significant energy spread to achieve clinically acceptable dose rates. The purpose of this work was to test the assumption that a scattering foil system designed for a mono-energetic beam would be suitable for a poly-energetic beam with a significant energy spread. Dual scattering foil systems were designed for mono-energetic beams using an existing analytical formalism based on Gaussian multiple-Coulomb scattering theory. The design criterion was to create a flat beam that would be suitable for fields up to 25 x 25 cm2 at 100 cm from the primary scattering foil. Radial planar fluence profiles for poly-energetic beams with energy spreads ranging from 0.5 MeV to 6.5 MeV were calculated using two methods: (a) analytically by summing beam profiles for a range of mono-energetic beams through the scattering foil system, and (b) by Monte Carlo using the EGS/BEAM code. The analytic calculations facilitated fine adjustments to the foil design, and the Monte Carlo calculations enabled us to verify the results of the analytic calculation and to determine the phase-space characteristics of the broadened beam. Results showed that the flatness of the scattered beam is fairly insensitive to the width of the input energy spectrum. Also, results showed that dose calculated by the analytical and Monte Carlo methods agreed very well in the central portion of the beam. Outside the useable field area, the differences between the analytical and Monte Carlo results were small but significant, possibly due to the small angle approximation. However, these did not affect the conclusion that a scattering foil system designed for a mono-energetic beam will be suitable for a poly-energetic

  11. Tom70 serves as a molecular switch to determine pathological cardiac hypertrophy

    Science.gov (United States)

    Li, Jun; Qi, Man; Li, Changming; Shi, Dan; Zhang, Dasheng; Xie, Duanyang; Yuan, Tianyou; Feng, Jing; Liu, Yi; Liang, Dandan; Xu, Xinran; Chen, Jinjin; Xu, Liang; Zhang, Hong; Ye, Jiangchuan; Lv, Fei; Huang, Jian; Peng, Luying; Chen, Yi-Han

    2014-01-01

    Pathological cardiac hypertrophy is an inevitable forerunner of heart failure. Regardless of the etiology of cardiac hypertrophy, cardiomyocyte mitochondrial alterations are always observed in this context. The translocases of mitochondrial outer membrane (Tom) complex governs the import of mitochondrial precursor proteins to maintain mitochondrial function under pathophysiological conditions; however, its role in the development of pathological cardiac hypertrophy remains unclear. Here, we showed that Tom70 was downregulated in pathological hypertrophic hearts from humans and experimental animals. The reduction in Tom70 expression produced distinct pathological cardiomyocyte hypertrophy both in vivo and in vitro. The defective mitochondrial import of Tom70-targeted optic atrophy-1 triggered intracellular oxidative stress, which led to a pathological cellular response. Importantly, increased Tom70 levels provided cardiomyocytes with full resistance to diverse pro-hypertrophic insults. Together, these results reveal that Tom70 acts as a molecular switch that orchestrates hypertrophic stresses and mitochondrial responses to determine pathological cardiac hypertrophy. PMID:25022898

  12. Energetic particle emission: preequilibrium emission and cooperative effects

    Energy Technology Data Exchange (ETDEWEB)

    Sapienza, P.; Coniglione, R.; Colonna, M.; Migneco, E.; Agodi, C.; Alba, R.; Bellia, G.; Zoppo, A. Del; Finocchiaro, P.; Greco, V.; Loukachine, K.; Maiolino, C.; Piattelli, P.; Santonocito, D. [INFN Lab. Nazionale del Sud, Via A. Doria 44, Catania (Italy); Colonna, N. [INFN, Bari (Italy); Bruno, M.; D Agostino, M.; Mastinu, P.F. [INFN and Dipartimento di Fisica, Bologna (Italy); Gramegna, F. [INFN Laboratorio Nazionale di Legnaro, Padova (Italy); Iori, I.; Fabbietti, L.; Moroni, A. [INFN and Dipartimento di Fisica, Milano (Italy); Margagliotti, G.V.; Milazzo, P.M.; Rui, R.; Vannini, G. [INFN and Dipartimento di Fisica, Trieste (Italy); Blumenfeld, Y.; Scarpaci, J.A. [Institut de Physique Nucleaire, IN2P3CNRS, F91406 Orsay (France)

    2001-09-01

    Full text: The {sup 58} Ni +{sup 58} Ni reaction at 30 A MeV was investigated at Laboratori Nazionale del Sud with the MEDEA and MULTICS apparatus. Energetic protons were detected in coincidence with photons, light charged particles (Z = 1, 2) (LCP) and intermediate and heavy fragments on an event by event basis. Protons with energy extending up to almost 20% of the total available energy, namely much larger than expected by coupling the relative motion with a sharp nucleon Fermi momentum distribution (kinematical limit), were measured in our experiment. We have also investigated the average proton multiplicity as a function of the number of participating nucleons A{sub part} (b) and a striking behavior with increasing energy is found. Indeed, the experimental proton multiplicity (full squares) displays the expected linear dependence on A{sub part} (b) for energy close to the kinematical limit (60 {<=} Ep {<=} 80 MeV), while the multiplicity of extremely energetic protons (130 {<=} Ep {<=} 150 MeV) exhibits an almost quadratic increase with A{sub part}. The comparison with BNV calculations which include the momentum dependence in the effective potential shows that the features of the energetic proton emission are well reproduced up to {approx_equal} 110 MeV while this approach fails to explain the almost quadratic dependence on the number of participant nucleons of the yield of very energetic protons (E{sub p}{sup NN} {>=} 130 MeV). So, the observed behavior calls for the introduction of mechanisms beyond the mean field and two body nucleon-nucleon collisions such as cooperative effects. In conclusions, these results shed some light on the emission of extremely energetic protons and can improve the understanding of the mechanism responsible for deep subthreshold particle production. Moreover, the detailed comparison with dynamical calculations allows to get a deeper insight on the first non equilibrated stage of the reaction where the highest temperatures and

  13. The Cardiac MR Images and Causes of Paradoxical Septal Motion

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Hun [Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Choi, Sang Il; Chun, Eun Ju [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Choi, Sung Hun [Ulsan University Hospital, Ulsan (Korea, Republic of); Park, Jae Hyung [Seoul National University Hospital, Seoul (Korea, Republic of)

    2010-10-15

    Real-time cine MRI studies using the steady-state free precession (SSFP) technique are very useful for evaluating cardiac and septal motion. During diastole, the septum acts as a compliant membrane between the two ventricles, and its position and geometry respond to even small alterations in the trans-septal pressure gradients. Abnormal septal motion can be caused by an overload of the right ventricle, delayed ventricular filling and abnormal conduction. In this study, we illustrate, based on our experiences, the causes of abnormal septal motion such as corrective surgery for tetralogy of Fallot, an atrial septal defect, pulmonary thromboembolism, mitral stenosis, constrictive pericarditis and left bundle branch block. In addition, we discuss the significance of paradoxical septal motion in the context of cardiac MR imaging.

  14. The Cardiac MR Images and Causes of Paradoxical Septal Motion

    International Nuclear Information System (INIS)

    Kim, Dong Hun; Choi, Sang Il; Chun, Eun Ju; Choi, Sung Hun; Park, Jae Hyung

    2010-01-01

    Real-time cine MRI studies using the steady-state free precession (SSFP) technique are very useful for evaluating cardiac and septal motion. During diastole, the septum acts as a compliant membrane between the two ventricles, and its position and geometry respond to even small alterations in the trans-septal pressure gradients. Abnormal septal motion can be caused by an overload of the right ventricle, delayed ventricular filling and abnormal conduction. In this study, we illustrate, based on our experiences, the causes of abnormal septal motion such as corrective surgery for tetralogy of Fallot, an atrial septal defect, pulmonary thromboembolism, mitral stenosis, constrictive pericarditis and left bundle branch block. In addition, we discuss the significance of paradoxical septal motion in the context of cardiac MR imaging

  15. Neurophysiology of space travel: energetic solar particles cause cell type-specific plasticity of neurotransmission.

    Science.gov (United States)

    Lee, Sang-Hun; Dudok, Barna; Parihar, Vipan K; Jung, Kwang-Mook; Zöldi, Miklós; Kang, Young-Jin; Maroso, Mattia; Alexander, Allyson L; Nelson, Gregory A; Piomelli, Daniele; Katona, István; Limoli, Charles L; Soltesz, Ivan

    2017-07-01

    In the not too distant future, humankind will embark on one of its greatest adventures, the travel to distant planets. However, deep space travel is associated with an inevitable exposure to radiation fields. Space-relevant doses of protons elicit persistent disruptions in cognition and neuronal structure. However, whether space-relevant irradiation alters neurotransmission is unknown. Within the hippocampus, a brain region crucial for cognition, perisomatic inhibitory control of pyramidal cells (PCs) is supplied by two distinct cell types, the cannabinoid type 1 receptor (CB 1 )-expressing basket cells (CB 1 BCs) and parvalbumin (PV)-expressing interneurons (PVINs). Mice subjected to low-dose proton irradiation were analyzed using electrophysiological, biochemical and imaging techniques months after exposure. In irradiated mice, GABA release from CB 1 BCs onto PCs was dramatically increased. This effect was abolished by CB 1 blockade, indicating that irradiation decreased CB 1 -dependent tonic inhibition of GABA release. These alterations in GABA release were accompanied by decreased levels of the major CB 1 ligand 2-arachidonoylglycerol. In contrast, GABA release from PVINs was unchanged, and the excitatory connectivity from PCs to the interneurons also underwent cell type-specific alterations. These results demonstrate that energetic charged particles at space-relevant low doses elicit surprisingly selective long-term plasticity of synaptic microcircuits in the hippocampus. The magnitude and persistent nature of these alterations in synaptic function are consistent with the observed perturbations in cognitive performance after irradiation, while the high specificity of these changes indicates that it may be possible to develop targeted therapeutic interventions to decrease the risk of adverse events during interplanetary travel.

  16. Influence of microorganisms on the alteration of glasses

    International Nuclear Information System (INIS)

    Besnainou, B.; Libert, M.F.

    1997-01-01

    Under specific conditions, microorganisms may enhance the alteration process of basaltic glass. However bacterial activity in the near field of a glass container would be possible only in environmental conditions provide nutrients and energetic substrates for bacterial growth. Depending of these conditions, microorganisms can: - modify the pH or the medium, - consume or produce soluble organic acids. To qualify the long term behaviour of glass, in presence of microorganisms, a qualitative and quantitative estimation of microbial activity potentialities and their consequences is needed. This must be achieved in studying the availability of the chemical species in the environment. (authors)

  17. Preservation of cardiac function by prolonged action potentials in mice deficient of KChIP2

    DEFF Research Database (Denmark)

    Grubb, Søren Jahn; Aistrup, Gary L; Koivumäki, Jussi T

    2015-01-01

    Inherited ion channelopathies and electrical remodeling in heart disease alter the cardiac action potential with important consequences for excitation-contraction coupling. Potassium channel-interacting protein 2 (KChIP2) is reduced in heart failure and interacts under physiological conditions...

  18. Cardiometabolic Risk Factors and Cardiac Health in Pre- and Postmenopausal Women

    DEFF Research Database (Denmark)

    Egelund, Jon

    Menopause changes the hormonal milieu drastically. To what extent these changes alter cardiometabolic risk factors and cardiac adaptations to aerobic training is still not entirely clear. In this thesis, these aspects were addressed in a large exercise training intervention study involving late pre...

  19. Prediction of tonic parasympathetic cardiac control using respiratory sinus arrhythmia: the need for respiratory control

    NARCIS (Netherlands)

    GROSSMAN, P.; Karemaker, J.; Wieling, W.

    1991-01-01

    Respiratory sinus arrhythmia (RSA) has received much attention in recent years due to the large body of evidence indicating that variations in this phenomenon represent alterations in parasympathetic cardiac control. Although it appears that respiratory sinus arrhythmia is mediated by vagal

  20. Tempol inhibits TGF-β and MMPs upregulation and prevents cardiac hypertensive changes.

    Science.gov (United States)

    Rizzi, Elen; Castro, Michele M; Ceron, Carla S; Neto-Neves, Evandro M; Prado, Cibele M; Rossi, Marcos A; Tanus-Santos, Jose E; Gerlach, Raquel F

    2013-04-30

    Increased oxidative stress upregulates matrix metalloproteinases (MMPs) and transforming grow factor (TGF-β), which are involved in hypertensive cardiac remodeling. We tested the hypothesis that tempol (an antioxidant) could prevent these alterations in two-kidney, one-clip (2K1C) hypertension. Sham-operated or hypertensive rats were treated with tempol (18 mg.kg(-1)day(-1) or vehicle) for 8 weeks. Systolic blood pressure was monitored weekly. At the end of the treatment, a catheter was inserted into the left carotid artery and into the left ventricle (LV) to assess arterial blood pressure and contractile function. Morphometry of the LV was carried out in hematoxylin/eosin sections and fibrosis was assessed in picrosirius red-stained sections. Cardiac TGF-β level was evaluated by immunofluorescence. Cardiac MMP-2 levels and activity were determined by gelatin zymography, in situ zymography, and immunofluorescence. Cardiac superoxide production was evaluated by dihydroethidium probe. Tempol treatment attenuated 2K1C-induced hypertension and reversed the contractile dysfunction in 2K1C rats. Cardiac hypertrophy was ameliorated by antioxidant treatment. Hypertensive rats showed increased cardiac MMP-2 levels, however tempol did not decrease MMP-2 levels. Increased TGF-β level, total gelatinolytic activity and oxidative stress were found in untreated 2K1C rats. Tempol treatment decreased oxidative stress, TGF-β levels, and gelatinolytic activity in 2K1C rats to control levels. Tempol blunted the increases in TGF-β, the proteolytic imbalance, and the morphological and functional alterations found in 2K1C-induced cardiac hypertrophy. These findings are consistent with the idea that antioxidants may help to prevent hypertension-induced cardiac hypertrophy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.